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Sample records for ombrotrophic peatland electronic

  1. Sequestration of arsenic in ombrotrophic peatlands

    Science.gov (United States)

    Rothwell, James; Hudson-Edwards, Karen; Taylor, Kevin; Polya, David; Evans, Martin; Allott, Tim

    2014-05-01

    Peatlands can be important stores of arsenic but we are lacking spectroscopic evidence of the sequestration pathways of this toxic metalloid in peatland environments. This study reports on the solid-phase speciation of anthropogenically-derived arsenic in atmospherically contaminated peat from the Peak District National Park (UK). Surface and sub-surface peat samples were analysed by synchrotron X-ray absorption spectroscopy on B18 beamline at Diamond Light Source (UK). The results suggest that there are contrasting arsenic sequestration mechanisms in the peat. The bulk arsenic speciation results, in combination with strong arsenic-iron correlations at the surface, suggest that iron (hydr)oxides are key phases for the immobilisation of arsenic at the peat surface. In contrast, the deeper peat samples are dominated by arsenic sulphides (arsenopyrite, realgar and orpiment). Given that these peats receive inputs solely from the atmosphere, the presence of these sulphide phases suggests an in-situ authigenic formation. Redox oscillations in the peat due to a fluctuating water table and an abundant store of legacy sulphur from historic acid rain inputs may favour the precipitation of arsenic sequestering sulphides in sub-surface horizons. Oxidation-induced loss of these arsenic sequestering sulphur species by water table drawdown has important implications for the mobility of arsenic and the quality of waters draining peatlands.

  2. The use of Sphagnum cellulose oxygen isotope ratios in ombrotrophic peatlands as a proxy for paleoclimate.

    Science.gov (United States)

    Taylor, M.; Pendall, E.; Jackson, S.; Booth, R. K.; Nichols, J. E.; Huang, Y.

    2006-12-01

    Developing proxies for discerning paleoclimate that are independent of the pollen record can provide insight into various aspects of climate variability and improve confidence in the interpretation of climate-vegetation interactions. To date, proxies including plant macrofossils, humification indices, testate amoebae, and ratios of n-alkane abundances have been used to infer past climate variability from temperate ombrotrophic peatlands in upper Midwestern North America. These proxies are used to infer past changes in surface-moisture conditions, which in ombrotrophic peatlands is primarily a function of precipitation and temperature. This study investigates the potential uses of stable oxygen isotopes to complement hydrologic proxies. δ18O of surface water and Sphagnum moss cellulose from bogs throughout North America indicates a correlation between average growing season temperatures and δ18O-values. The existence of a modern temperature signal in moss cellulose suggests that δ18O-derived records will not only complement paleohydrological records, but also help assess relative changes in precipitation and temperature. Humification and testate amoebae data from two cores taken from Minden and Irwin Smith Bogs in central and northeastern Michigan have recorded several extreme drought events during the Holocene, including one at 1000 YBP. Comparison of δ18O-values of picked Sphagnum remains to down-core humification and testate amoebae data suggest good temporal correspondence, with the δ18O-values around 1000 YBP indicating a warmer growing season.

  3. Novel Stable Isotope Methods for Assessing Changes in Seasonality of Precipitation from Sediments of Ombrotrophic Peatlands

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    Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Walcott, M.; Bradley, R.; Pilcher, J.; Huang, Y.

    2007-12-01

    The seasonality of precipitation is a key but often elusive climate parameter in paleoclimate reconstructions. Sediments from ombrotrophic peatlands are excellent archives of past changes in precipitation/evaporation balance. Here we show that these peatland sediments can also be used to assess changes in the seasonality of precipitation. We have recently determined that distributions of Sphagnum and vascular plant biomarkers sensitively record changes in hydrologic balance (Nichols et al., 2006, Org. Geochem. 37, 1505-1513), but biomarker distributions alone do not offer detailed information for the changes in seasonal precipitation. In this study, we combine biomarker and compound-specific H and C isotope ratios to create a more comprehensive picture of the changing climate affecting these sensitive ombrotrophic systems. We present here two sets of downcore data from sites in Arctic Europe as well as Eastern North America. Basic paleohydrology is established using a ratio of Sphagnum to vascular plant biomarkers (C23 and C29 n-alkanes, respectively. We further describe paleohydrology using novel stable isotope proxies based on δD and δ13C measurements of Sphagnum and vascular plant biomarkers. Because Sphagnum has no vascular system and loses water directly by evaporation, Sphagnum biomarkers enriched in deuterium indicate an evaporative growing season (summer). Vascular plants use their root systems to take up water stored within the peatland, so deuterium-depleted vascular plant biomarkers should indicate increased winter recharge of the peatland. A methanotrophic symbiont living inside the Sphagnum's hyaline (water-holding) cells is more active when the Sphagnum is wet and therefore provides more 13C depleted (methane- derived) carbon dioxide for biomass production when the growing season is less evaporative. Hence, 13C depleted Sphagnum biomarkers indicate increased methanotrophy and therefore a wetter summer. We corroborate our stable isotope proxies by

  4. Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

    Science.gov (United States)

    Elliott, David R; Caporn, Simon J M; Nwaishi, Felix; Nilsson, R Henrik; Sen, Robin

    2015-01-01

    The UK hosts 15-19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare peat

  5. Bacterial and fungal communities in a degraded ombrotrophic peatland undergoing natural and managed re-vegetation.

    Directory of Open Access Journals (Sweden)

    David R Elliott

    Full Text Available The UK hosts 15-19% of global upland ombrotrophic (rain fed peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6 and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals. Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in

  6. Bacterial and Fungal Communities in a Degraded Ombrotrophic Peatland Undergoing Natural and Managed Re-Vegetation

    Science.gov (United States)

    Elliott, David R.; Caporn, Simon J. M.; Nwaishi, Felix; Nilsson, R. Henrik; Sen, Robin

    2015-01-01

    The UK hosts 15–19% of global upland ombrotrophic (rain fed) peatlands that are estimated to store 3.2 billion tonnes of carbon and represent a critical upland habitat with regard to biodiversity and ecosystem services provision. Net production is dependent on an imbalance between growth of peat-forming Sphagnum mosses and microbial decomposition by microorganisms that are limited by cold, acidic, and anaerobic conditions. In the Southern Pennines, land-use change, drainage, and over 200 years of anthropogenic N and heavy metal deposition have contributed to severe peatland degradation manifested as a loss of vegetation leaving bare peat susceptible to erosion and deep gullying. A restoration programme designed to regain peat hydrology, stability and functionality has involved re-vegetation through nurse grass, dwarf shrub and Sphagnum re-introduction. Our aim was to characterise bacterial and fungal communities, via high-throughput rRNA gene sequencing, in the surface acrotelm/mesotelm of degraded bare peat, long-term stable vegetated peat, and natural and managed restorations. Compared to long-term vegetated areas the bare peat microbiome had significantly higher levels of oligotrophic marker phyla (Acidobacteria, Verrucomicrobia, TM6) and lower Bacteroidetes and Actinobacteria, together with much higher ligninolytic Basidiomycota. Fewer distinct microbial sequences and significantly fewer cultivable microbes were detected in bare peat compared to other areas. Microbial community structure was linked to restoration activity and correlated with soil edaphic variables (e.g. moisture and heavy metals). Although rapid community changes were evident following restoration activity, restored bare peat did not approach a similar microbial community structure to non-eroded areas even after 25 years, which may be related to the stabilisation of historic deposited heavy metals pollution in long-term stable areas. These primary findings are discussed in relation to bare

  7. Novel proxies for reconstructing paleohydrology from ombrotrophic peatlands: biomarker and compound-specific H and C stable isotope ratios

    Science.gov (United States)

    Wang, J.; Nichols, J. E.; Huang, Y.

    2008-12-01

    Ombrotrophic peatlands are excellent archives for paleohydrologic information because they are hydrologically isolated from their surroundings. However, quantitative proxies for deciphering peatland archives are lacking. Here, we present development and application of novel organic geochemical methods for quantitative reconstruction of paleohydrology from the ombrotrophic sediments, and comparison of organic geochemical data with conventional paleoecological proxies. Application of these methods to the sediments of several North American and European peatlands has revealed significant changes in the hydroclimate throughout the Holocene. The plant assemblage living at the surface of the peatland is tightly controlled by surface moisture. Under wet conditions, Sphagnum mosses, with no active mechanism for drawing water from below the surface of the peatland, are dominant. During dry conditions, vascular plants are more productive relative to Sphagnum. A ratio of the abundance of two biomarkers representing Sphagnum and vascular plants sensitively records changes in hydrologic balance (Nichols et al., 2006, Org. Geochem. 37, 1505-1513). We have further developed stable isotope models to compute climate parameters from compound-specific H and C isotope ratios of biomarkers to create a more comprehensive climate reconstruction. Vascular plant leaf waxes carry the D/H ratio signature of precipitation that is little affected by evaporation, whereas the Sphagnum biomarker records isotopic ratios of the water at the peatland surface, which is strongly enriched by evaporation. Evaporation amount can be calculated using the differences between D/H ratios of the two types of biomarkers. C isotope ratios of Sphagnum biomarkers can also be used to quantify surface wetness. Methanotrophic bacteria live symbiotically with Sphagnum, providing isotopically light carbon for photosynthesis. These bacteria are more active when the Sphagnum is wet, thus providing more 13C-depleted CO2

  8. Environmental and biogeochemical controls on N2 fixation in ombrotrophic peatlands

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    Zivkovic, T.; Moore, T. R.

    2017-12-01

    Northern peatlands have low atmospheric nitrogen (N) inputs and acquire N mostly via biological, microbially-driven N2-fixation. Little is known about rates and controls on N2-fixation in ombrotrophic bogs. We conducted two studies to test environmental and biogeochemical controls on N2-fixation. First, we used acetylene reduction assay (ARA) calibrated with 15N2 tracer to measure N2-fixation rates in three species of Sphagnum mosses along a hydrological gradient (beaver pond, hollow and hummock in bog margin and in bog) at Mer Bleue bog from June-October 2013 and May - November 2014. We tested the following controls: moisture availability, temperature, and PAR. The largest ARA rates throughout both seasons occurred in the pond in floating Sphagnum cuspidatum mats (50.3 ± 12.9 μmol m-2 d-1 Mean ± SE), which were up to 2.5 times larger than the rates found in the driest hummock site. There was a significant seasonal peak in both years in July and early August that coincided with the peak of the air temperature. In fact, 45% of the variance of N2 fixation rates over the two field seasons was explained by rain events, water table fluctuations and the surface peat temperature (multiple regression analysis, n = 539). Our results highlight the potential impact of climate change, namely negative effects due to potential droughts and positive effect of warming, on N2 fixation patterns in ombrotrophic peatlands. Secondly, we tested stoichiometric controls (Sphagnum tissue N and phosphorous (P) ratio) of N2-fixation. In a controlled environment, we selected eight study sites along a latitudinal gradient from temperate, boreal to subarctic zone in eastern Canada. We found that decreasing N:P ratio corresponded to increasing N2-fixation. N:P explained 65% of the variance in N2-fixation in hollows but only 20% in hummocks. Changes in neither N or P concentration alone explained the increase in N2-fixation better than N:P ratio. We interpret that the difference between

  9. Microbial metabolic potential for carbon degradation and nutrient (nitrogen and phosphorus) acquisition in an ombrotrophic peatland.

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    Lin, Xueju; Tfaily, Malak M; Green, Stefan J; Steinweg, J Megan; Chanton, Patrick; Imvittaya, Aopeau; Chanton, Jeffrey P; Cooper, William; Schadt, Christopher; Kostka, Joel E

    2014-06-01

    This study integrated metagenomic and nuclear magnetic resonance (NMR) spectroscopic approaches to investigate microbial metabolic potential for organic matter decomposition and nitrogen (N) and phosphorus (P) acquisition in soils of an ombrotrophic peatland in the Marcell Experimental Forest (MEF), Minnesota, USA. This analysis revealed vertical stratification in key enzymatic pathways and taxa containing these pathways. Metagenomic analyses revealed that genes encoding laccases and dioxygenases, involved in aromatic compound degradation, declined in relative abundance with depth, while the relative abundance of genes encoding metabolism of amino sugars and all four saccharide groups increased with depth in parallel with a 50% reduction in carbohydrate content. Most Cu-oxidases were closely related to genes from Proteobacteria and Acidobacteria, and type 4 laccase-like Cu-oxidase genes were >8 times more abundant than type 3 genes, suggesting an important and overlooked role for type 4 Cu-oxidase in phenolic compound degradation. Genes associated with sulfate reduction and methanogenesis were the most abundant anaerobic respiration genes in these systems, with low levels of detection observed for genes of denitrification and Fe(III) reduction. Fermentation genes increased in relative abundance with depth and were largely affiliated with Syntrophobacter. Methylocystaceae-like small-subunit (SSU) rRNA genes, pmoA, and mmoX genes were more abundant among methanotrophs. Genes encoding N2 fixation, P uptake, and P regulons were significantly enriched in the surface peat and in comparison to other ecosystems, indicating N and P limitation. Persistence of inorganic orthophosphate throughout the peat profile in this P-limiting environment indicates that P may be bound to recalcitrant organic compounds, thus limiting P bioavailability in the subsurface. Comparative metagenomic analysis revealed a high metabolic potential for P transport and starvation, N2 fixation, and

  10. Pet formation and mass balance in subarctic ombrotrophic peatlands around Abisko, northern Scandinavia

    International Nuclear Information System (INIS)

    Malmer, N.; Wallen, B.

    1996-01-01

    The apparent, short term litter formation rate in the dominating Sphagnum communities which characterise the extensive ombrotrophic parts of mires around Abisko, most of them with permafrost, has been estimated over a 14 yr period using a technique based on 14 C-labelling of the vegetation. The losses due to decay in the acrotelm have been estimated from the change in concentration of nitrogen above the upper limit of the catogelm. The litter formation rate in moss hummocks can be as high as 200 g m -2 yr -1 while the decay losses in the acrotelm are in the range of 40-50 g m -2 yr -1 . In hollows the decay rate is higher than in hummocks and the residence time of the organic matter is shorter (100 and 170 yr, respectively). The ombrotrophic peat is rather thin ( 14 C-datings indicate that the formation of ombrotrophic peat started over 800 yr ago. Until recent time the ombrotrophic peat accumulation rate has been 36-45 g m -2 yr -1 . However, on the mires larger than c. 10 ha the Sphagnum-dominated communities cover only a small part of the total mire surface, often less than one third, and the litter formation rate on the remaining parts of the surface is very low. Therefore, the present over all litter formation rate is only c.35 g m -2 yr -1 and does not even compensate for the decay losses in the acrotelm. Although the peat stratigraphy suggests and ongoing peat (and carbon) accumulation the carbon balance in the systems as a whole has changed from sink to source rather recently. (au)

  11. Using ‘snapshot’ measurements of CH4 fluxes from an ombrotrophic peatland to estimate annual budgets: interpolation versus modelling

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    S.M. Green

    2017-03-01

    Full Text Available Flux-chamber measurements of greenhouse gas exchanges between the soil and the atmosphere represent a snapshot of the conditions on a particular site and need to be combined or used in some way to provide integrated fluxes for the longer time periods that are often of interest. In contrast to carbon dioxide (CO2, most studies that have estimated the time-integrated flux of CH4 on ombrotrophic peatlands have not used models. Typically, linear interpolation is used to estimate CH4 fluxes during the time periods between flux-chamber measurements. CH4 fluxes generally show a rise followed by a fall through the growing season that may be captured reasonably well by interpolation, provided there are sufficiently frequent measurements. However, day-to-day and week-to-week variability is also often evident in CH4 flux data, and will not necessarily be properly represented by interpolation. Using flux chamber data from a UK blanket peatland, we compared annualised CH4 fluxes estimated by interpolation with those estimated using linear models and found that the former tended to be higher than the latter. We consider the implications of these results for the calculation of the radiative forcing effect of ombrotrophic peatlands.

  12. Water Table Depth Reconstruction in Ombrotrophic Peatlands Using Biomarker Abundance Ratios and Compound-Specific Hydrogen Isotope Composition

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    Nichols, J. E.; Jackson, S. T.; Booth, R. K.; Pendall, E. G.; Huang, Y.

    2005-12-01

    Sediment cores from ombrotrophic peat bogs provide sensitive records of changes in precipitation/evaporation (P/E) balance. Various proxies have been developed to reconstruct surface moisture conditions in peat bogs, including testate amoebae, plant macrofossils, and peat humification. Studying species composition of testate amoeba assemblages is time consuming and requires specialized training. Humification index can be influenced by environmental factors other than moisture balance. The plant macrofossil proxy is less quantitative and cannot be performed on highly decomposed samples. We demonstrate that the ratio of C23 alkane to C29 alkane abundance may provide a simple alternative or complementary means of tracking peatland water-table depth. Data for this proxy can be collected quickly using a small sample (100 mg dry). Water-table depth decreases during drought, and abundance of Sphagnum, the dominant peat-forming genus, decreases as vascular plants increase. Sphagnum moss produces mainly medium chain-length alkanes (C21-C25) while vascular plants (grasses and shrubs) produce primarily longer chain-length alkanes (C27-C31). Therefore, C23:C29 n-alkane ratios quantitatively track the water table depth fluctuations in peat bogs. We compared C23:C29 n-alkane ratios in a core from Minden Bog (southeastern Michigan) with water table depth reconstructions based on testate-amoeba assemblages and humification. The 184-cm core spans the past ~3kyr of continuous peat deposition in the bog. Our results indicate that the alkane ratios closely track the water table depth variations, with C29 most abundant during droughts. We also explored the use of D/H ratios in Sphagnum biomarkers as a water-table depth proxy. Compound-specific hydrogen isotope ratio analyses were performed on Sphagnum biomarkers: C23 and C25 alkane and C24 acid. Dry periods are represented in these records by an enrichment of deuterium in these Sphagnum-specific compounds. These events also correlate

  13. Recent 210Pb, 137Cs and 241Am accumulation in an ombrotrophic peatland from Amsterdam Island (Southern Indian Ocean).

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    Li, Chuxian; Le Roux, Gaël; Sonke, Jeroen; van Beek, Pieter; Souhaut, Marc; Van der Putten, Nathalie; De Vleeschouwer, François

    2017-09-01

    Over the past 50 years, 210 Pb, 137 Cs and 241 Am have been abundantly used in reconstructing recent sediment and peat chronologies. The study of global aerosol-climate interaction is also partially depending on our understanding of 222 Rn- 210 Pb cycling, as radionuclides are useful aerosol tracers. However, in comparison with the Northern Hemisphere, few data are available for these radionuclides in the Southern Hemisphere, especially in the South Indian Ocean. A peat core was collected in an ombrotrophic peatland from the remote Amsterdam Island (AMS) and was analyzed for 210 Pb, 137 Cs and 241 Am radionuclides using an underground ultra-low background gamma spectrometer. The 210 Pb Constant Rate of Supply (CRS) model of peat accumulations is validated by peaks of artificial radionuclides ( 137 Cs and 241 Am) that are related to nuclear weapon tests. We compared the AMS 210 Pb data with an updated 210 Pb deposition database. The 210 Pb flux of 98 ± 6 Bq·m -2 ·y -1 derived from the AMS core agrees with data from Madagascar and South Africa. The elevated flux observed at such a remote location may result from the enhanced 222 Rn activity and frequent rainfall in AMS. This enhanced 222 Rn activity itself may be explained by continental air masses passing over southern Africa and/or Madagascar. The 210 Pb flux at AMS is higher than those derived from cores collected in coastal areas in Argentina and Chile, which are areas dominated by marine westerly winds with low 222 Rn activities. We report a 137 Cs inventory at AMS of 144 ± 13 Bq·m -2 (corrected to 1969). Our data thus contribute to the under-represented data coverage in the mid-latitudes of the Southern Hemisphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. After ecological restoration of ombrotrophic peatlands: the microbiological viewpoint; Suivi de la restauration ecologique des tourbieres ombrotrophes: le point de vue microbiologique

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    Andersen, R. [University of Laval, Quebec, QC (Canada). Department of Phytology

    2006-01-01

    The goal is to assess peatland restoration at an 11-hectare peatland site at Bois-en-Bel that had been abandoned for 20 years. In 1999, an 8-hectare area was restored. Two hectares, separated by a buffer, were left untreated as a control. In 2003, samples were collected from the restored and control areas and from a nearby natural area. The dynamics of carbon and nitrogen, the effects of nutritive supplements, and production of carbon dioxide and methane were measured. The relationship between these variables and the microorganisms present are evaluated. 30 refs., 4 figs.

  15. Development of a multidisciplinary method for mapping spatial extent and C-content of tropical ombrotrophic peatlands

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    Illés, Gábor; Kristijono, Agus; Pfeifer, Norbert; Pásztor, László; Shandhyavitri, Ari; Szatmári, Gábor; Sutikno, Sigit; Molnár, Gábor; László, Péter; Árvai, Mátyás; Mészáros, János; Koós, Sándor; Bakacsi, Zsófia; Takács, Katalin; Király, Géza; Székely, Balázs

    2017-04-01

    , elements of gathered experience is integrated acquired in previous similar projects in Hungary, in the Pannonian Basin and in Indonesia, in southern Kalimantan and Indragiri Hilir, Sumatra. The pointwise and profilewise data acquisition of peat forms is converted to mapping methods augmented with a sophisticated sampling strategy. Besides the similarities - freshwater, ombrotrophic peatlands - we also have to focus on remarkable dissimilarities - e.g., herbaceous vs. woody peat material. In the case of the Pannonian Basin the peat occurrences have been developed as the filling up of the floodplains. In the Indonesian case, however, only the basin flanks are partly comparable to that generation mechanism, whereas see level changes play an important role in the development of the vast Indonesian peat occurrences. Geomorphometric approach helps in designing the sample strategy, remote sensing tools are responsible to deliver high-resolution topographic data as input. The varying thickness is assessed with geophysical measurements and shallow boreholes deployed at sampling points and profiles dictated by the sophisticated sampling strategy. During the measurement and sampling the experience gathered is fed back to the sampling strategy giving a dynamic plan for the continuation of the sampling. The advanced evaluation and visualization techniques applied result in a digital map system that also contains estimates on its quality and accuracy in the spatial context. This new approach brings us closer to the understanding of Indonesian peatland development that may also be used elsewhere in similar environmental contexts.

  16. Airborne Hyperspectral Evaluation of Maximum Gross Photosynthesis, Gravimetric Water Content, and CO2 Uptake Efficiency of the Mer Bleue Ombrotrophic Peatland

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    J. Pablo Arroyo-Mora

    2018-04-01

    Full Text Available Peatlands cover a large area in Canada and globally (12% and 3% of the landmass, respectively. These ecosystems play an important role in climate regulation through the sequestration of carbon dioxide from, and the release of methane to, the atmosphere. Monitoring approaches, required to understand the response of peatlands to climate change at large spatial scales, are challenged by their unique vegetation characteristics, intrinsic hydrological complexity, and rapid changes over short periods of time (e.g., seasonality. In this study, we demonstrate the use of multitemporal, high spatial resolution (1 m2 hyperspectral airborne imagery (Compact Airborne Spectrographic Imager (CASI and Shortwave Airborne Spectrographic Imager (SASI sensors for assessing maximum instantaneous gross photosynthesis (PGmax in hummocks, and gravimetric water content (GWC and carbon uptake efficiency in hollows, at the Mer Bleue ombrotrophic bog. We applied empirical models (i.e., in situ data and spectral indices and we derived spatial and temporal trends for the aforementioned variables. Our findings revealed the distribution of hummocks (51.2%, hollows (12.7%, and tree cover (33.6%, which is the first high spatial resolution map of this nature at Mer Bleue. For hummocks, we found growing season PGmax values between 8 μmol m−2 s−1 and 12 μmol m−2 s−1 were predominant (86.3% of the total area. For hollows, our results revealed, for the first time, the spatial heterogeneity and seasonal trends for gravimetric water content and carbon uptake efficiency for the whole bog.

  17. Spectro-spatial relationship between UAV derived high resolution DEM and SWIR hyperspectral data: application to an ombrotrophic peatland

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    Arroyo-Mora, J. Pablo; Kalacska, Margaret; Lucanus, Oliver; Soffer, Raymond; Leblanc, George

    2017-10-01

    Peatlands cover 3% of the globe and are key ecosystems for climate regulation. To better understand the potential effects of climate change in peatlands, a major challenge is to determine the complex relationship between hydrology, microtopography, vegetation patterns, and gas exchange. Here we study the spectral and spatial relationship of microtopographic features (e.g. hollows and hummocks) and near-surface water through narrow-band spectral indices derived from hyperspectral imagery. We used a very high resolution digital elevation model (2.5 cm horizontal, 2.2 cm vertical resolution) derived from an UAV based Structure from Motion photogrammetry to map hollows and hummocks in the peatland area. We also created a 2 cm spatial resolution orthophoto mosaic to enhance the visual identification of these hollows and hummocks. Furthermore, we collected SWIR airborne hyperspectral (880-2450 nm) imagery at 1 m pixel resolution over four time periods, from April to June 2016 (phenological gradient: vegetation greening). Our results revealed an increase in the water indices values (NDWI1640 and NDWI2130) and a decrease in the moisture stress index (MSI) between April and June. In addition, for the same period the NDWI2130 shows a bimodal distribution indicating potential to quantitatively assess moisture differences between mosses and vascular plants. Our results, using the digital surface model to extract NDWI2130 values, showed significant differences between hollows and hummocks for each time period, with higher moisture values for hollows (i.e. moss dominated). However, for June, the water index for hummocks approximated the values found in hollows. Our study shows the advantages of using fine spatial and spectral scales to detect temporal trends in near surface water in a peatland.

  18. Temperature sensitivity differences with depth and season between carbon, nitrogen, and phosphorus cycling enzyme activities in an ombrotrophic peatland system

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    Steinweg, J. M.; Kostka, J. E.; Hanson, P. J.; Schadt, C. W.

    2017-12-01

    Northern peatlands have large amounts of soil organic matter due to reduced decomposition. Breakdown of organic matter is initially mediated by extracellular enzymes, the activity of which may be controlled by temperature, moisture, and substrate availability, all of which vary seasonally throughout the year and with depth. In typical soils the majority of the microbial biomass and decomposition occurs within the top 30cm due to reduced organic matter inputs in the subsurface however peatlands by their very nature contain large amounts of organic matter throughout their depth profile. We hypothesized that potential enzyme activity would be greatest at the surface of the peat due to a larger microbial biomass compared to 40cm and 175cm below the surface and that temperature sensitivity would be greatest at the surface during winter but lowest during the summer due to high temperatures and enzyme efficiency. Peat samples were collected in February, July, and August 2012 from the DOE Spruce and Peatland Responses Under Climatic and Environmental Change project at Marcell Experimental Forest S1 bog. We measured potential activity of hydrolytic enzymes involved in three different nutrient cycles: beta-glucosidase (carbon), leucine amino peptidase (nitrogen), and phosphatase (phosphorus) at 15 temperature points ranging from 3°C to 65°C. Enzyme activity decreased with depth as expected but there was no concurrent change in activation energy (Ea). The reduction in enzyme activity with depth indicates a smaller pool which coincided with a decreased microbial biomass. Differences in enzyme activity with depth also mirrored the changes in peat composition from the acrotelm to the catotelm. Season did play a role in temperature sensitivity with Ea of β-glucosidase and phosphatase being the lowest in August as expected but leucine amino peptidase (a nitrogen acquiring enzyme) Ea was not influenced by season. As temperatures rise, especially in winter months, enzymatic

  19. Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota

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    Brian H. Hill; Terri M. Jicha; LaRae L.P. Lehto; Colleen M. Elonen; Stephen D. Sebestyen; Randy Kolka

    2016-01-01

    Wecompared nitrogen (N) storage and flux in soils froman ombrotrophic bogwith that of a minerotrophic fen to quantify the differences in N cycling between these two peatlands types in northernMinnesota (USA). Precipitation, atmospheric deposition, and bog and fen outflowswere analyzed for nitrogen species. Upland and peatland soil sampleswere analyzed for N content,...

  20. Contemporary Mobilization of Legacy Pb Stores by DOM in a Boreal Peatland

    Science.gov (United States)

    Jeff D. Jeremiason; Erin I. Baumann; Stephen D. Sebestyen; Alison M. Agather; Emily A. Seelen; Benjamin J. Carlson-Stehlin; Meghan M. Funke; James B. Cotner

    2018-01-01

    We examined how different landscape areas in a catchment containing a northern ombrotrophic peatland and upland mineral soils responded to dramatic decreases in atmospheric deposition of lead (Pb). Pb concentrations in the outflow stream from the peatland measured from 2009−2015 indicated continued mobilization and export of Pb derived from historic inputs to the bog....

  1. Decreased summer water table depth affects peatland vegetation

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Robroek, B.J.M.; Limpens, J.; Heijmans, M.M.P.D.; Schouten, M.G.C.; Berendse, F.

    2009-01-01

    Climate change can be expected to increase the frequency of summer droughts and associated low water tables in ombrotrophic peatlands. We studied the effects of periodic water table drawdown in a mesocosm experiment. Mesocosms were collected in Southern Sweden, and subsequently brought to an

  2. Temporal and Spatial Variation in Peatland Carbon Cycling and Implications for Interpreting Responses of an Ecosystem-Scale Warming Experiment

    Science.gov (United States)

    Natalie A. Griffiths; Paul J. Hanson; Daniel M. Ricciuto; Colleen M. Iversen; Anna M. Jensen; Avni Malhotra; Karis J. McFarlane; Richard J. Norby; Khachik Sargsyan; Stephen D. Sebestyen; Xiaoying Shi; Anthony P. Walker; Eric J. Ward; Jeffrey M. Warren; David J. Weston

    2017-01-01

    We are conducting a large-scale, long-term climate change response experiment in an ombrotrophic peat bog in Minnesota to evaluate the effects of warming and elevated CO2 on ecosystem processes using empirical and modeling approaches. To better frame future assessments of peatland responses to climate change, we characterized and compared spatial...

  3. Sulfate reduction in freshwater peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Oequist, M.

    1996-12-31

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO{sub 4}{sup 2-} concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 {mu}M. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 {mu}M h{sup -1} while in B and C they were 1 and 0.05 {mu}M h{sup -1}, respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 {mu}g d{sup -1} g{sup -1}) were found 10 cm below the water table, in B (ca. 1.0 {mu}g d{sup -1} g{sup -1}) in the vicinity of the water table, and in C (0.75 {mu}g d{sup -1} g{sup -1}) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m{sup -2} d{sup -1}, while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m{sup -2} d{sup -1}, respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination

  4. Sulfate reduction in freshwater peatlands

    International Nuclear Information System (INIS)

    Oequist, M.

    1996-01-01

    This text consist of two parts: Part A is a literature review on microbial sulfate reduction with emphasis on freshwater peatlands, and part B presents the results from a study of the relative importance of sulfate reduction and methane formation for the anaerobic decomposition in a boreal peatland. The relative importance of sulfate reduction and methane production for the anaerobic decomposition was studied in a small raised bog situated in the boreal zone of southern Sweden. Depth distribution of sulfate reduction- and methane production rates were measured in peat sampled from three sites (A, B, and C) forming an minerotrophic-ombrotrophic gradient. SO 4 2- concentrations in the three profiles were of equal magnitude and ranged from 50 to 150 μM. In contrast, rates of sulfate reduction were vastly different: Maximum rates in the three profiles were obtained at a depth of ca. 20 cm below the water table. In A it was 8 μM h -1 while in B and C they were 1 and 0.05 μM h -1 , respectively. Methane production rates, however, were more uniform across the three nutrient regimes. Maximum rates in A (ca. 1.5 μg d -1 g -1 ) were found 10 cm below the water table, in B (ca. 1.0 μg d -1 g -1 ) in the vicinity of the water table, and in C (0.75 μg d -1 g -1 ) 20 cm below the water table. In all profiles both sulfate reduction and methane production rates were negligible above the water table. The areal estimates of methane production for the profiles were 22.4, 9.0 and 6.4 mmol m -2 d -1 , while the estimates for sulfate reduction were 26.4, 2.5, and 0.1 mmol m -2 d -1 , respectively. The calculated turnover times at the sites were 1.2, 14.2, and 198.7 days, respectively. The study shows that sulfate reducing bacteria are important for the anaerobic degradation in the studied peatland, especially in the minerotrophic sites, while methanogenic bacteria dominate in ombrotrophic sites Examination paper. 67 refs, 6 figs, 3 tabs

  5. The Roles of Sphagnum and Cyperaceae in the Methane Cycle of an Ombrotrophic Bog Revealed by the Carbon Isotope Ratios of Leaf Waxes

    Science.gov (United States)

    Isles, P. D.; Nichols, J. E.; Peteet, D. M.; Kenna, T. C.

    2011-12-01

    Methane is a strong greenhouse gas, and the role of the terrestrial carbon cycle in the concentrations of atmospheric methane is poorly understood. What is clear, is that northern peatlands are a significant source of methane to the atmosphere. A recent discovery, and a topic of much scrutiny, has been the relationship between Sphagnum in peatlands and symbiotic methanotrophic bacteria. These bacteria oxidize methane produced at depth in peatlands before it is released to the atmosphere, contributing 13C-depleted CO2 to Sphagnum photosynthate. We seek to better understand the fate of methane produced in peatlands at depth, and the relationship between methane release from peatland surfaces and parameters such as temperature, moisture, and vegetation type. We compare carbon isotope ratios of leaf wax n-alkanes from sphagnum and vascular plants and major element chemistry at three different microhabitats, hummock, hollow, and sedge tussock, in Mer Bleue an ombrotrophic peatland near Ottowa, Ontario, Canada. We use these compound-specific carbon isotope measurements to constrain the amount of methane-derived CO2 incorporated by Sphagnum. We also compare our multiannually resolved down-core measurements to data from long-term monitoring of climate parameters and methane flux from the same microhabitats to ground-truth our sedimentary signature of methane with instrumental measurements.

  6. Do Peatlands Hibernate?

    Science.gov (United States)

    Dorrepaal, E.; Signarbieux, C.; Jassey, V.; Mills, R.; Buttler, A.; Robroek, B.

    2014-12-01

    Winter seasonality with extensive frost, snow cover and low incoming radiation characterise large areas at mid- and high latitudes, especially in mountain ranges and in the arctic. Given these adverse conditions, it is often assumed that ecosystem processes, such as plant photosynthesis, nutrient uptake and microbial activities, cease, or at best diminish to marginal rates compared to summer. However, snow is a good thermal insulator and a sufficiently thick snow cover might enable temperature-limited processes to continue in winter, especially belowground. Changes in winter precipitation may alter these conditions, yet, relative to the growing season, winter ecosystem processes remain poorly understood. We performed a snow-removal experiment on an ombrotrophic bog in the Swiss Jura mountains (1036 m.a.s.l.) to compare above- and belowground ecosystem processes with and without snow cover during mid- and late-winter (February and April) with the subsequent spring (June) and summer (July). The presence of 1m snow in mid-winter and 0.4m snow in late-winter strongly reduced the photosynthetic capacity (Amax) of Eriophorum vaginatum as well as the total microbial biomass compared to spring and summer values. Amax of Sphagnum magellanicum and uptake of 15N-labelled ammonium-nitrate by vascular plants were, however, almost as high or higher in mid- and late-winter as in summer. Snow removal increased the number of freeze-thaw cycles in mid-winter but also increased the minimum soil temperature in late-winter before ambient snow-melt. This strongly reduced all measured ecosystem processes in mid-winter compared to control and to spring and summer values. Plant 15N-uptake, Amax of Eriophorum and total microbial biomass returned to, or exceeded, control values soon before or after snowmelt. However, Sphagnum Amax and its length growth, as well as the structure of the microbial community showed clear carry-over effects of the reduced winter snow cover into next summer

  7. Ecoenzymatic stoichiometry and microbial processing of organic matter in northern bogs and fens reveals a common P-limitation between peatland types

    Science.gov (United States)

    Brian H. Hill; Colleen M. Elonen; Terri M. Jicha; Randall K. Kolka; LaRae L.P. Lehto; Stephen D. Sebestyen; Lindsey R. Seifert-Monson

    2014-01-01

    We compared carbon (C), nitrogen (N), and phosphorus (P) concentrations in atmospheric deposition, runoff, and soils with microbial respiration [dehydrogenase (DHA)] and ecoenzyme activity (EEA) in an ombrotrophic bog and a minerotrophic fen to investigate the environmental drivers of biogeochemical cycling in peatlands at the Marcell Experimental Forest in northern...

  8. Carbon and nitrogen dynamics in mesocosms of five different European peatlands

    Science.gov (United States)

    Blodau, Christian; Zajac, Katarzyna

    2015-04-01

    Elevated nitrogen (N) deposition, a key growth limiting nutrient in ombrotrophic peatlands, can cause various shifts in peatland N cycling. Quantification of N transformation rates and fluxes within peatlands that are induced by long-term N deposition is crucial for understanding the mechanisms and robustness of N retention. Using a 15N labeled tracer under steady state conditions at two water table levels, we investigated the fate of N in mesocosms from five European peatlands, which have a history of differing long-term N load. Peat contained the largest N pool, followed by Sphagnum (0 - 5 cm), shrubs, graminoids and the dissolved pool. We found a decline of N recovery from the peat and an increase of N recovery from shrubs and the dissolved pool across the N deposition gradient. Sphagnum mosses not only intercepted large amounts of 15N in the mesocosms (0.2 - 0.35 mg g-1) but they also retained the tracer most effectively relative to their biomass. Polluted sites (Lille Vildmose, Frölichshaier Sattelmoor) contained the largest dissolved nitrogen pools and the highest nitrate concentrations. At the same time the recoveries of their Sphagnum pools were in the range of the recovery recorded for the Sphagnum layer from the 'clean' site (Degerö Stormyr). Our experiment shows that a decline in N retention at levels above ca. 1.5 g m-2 yr-1, as expressed by elevated near-surface peat N content and increased dissolved N concentrations, might not be an evidence for Sphagnum saturation. As long as N is required for the synthesis of biomass Sphagnum species can thrive even at strongly elevated long-term N loads. A change in WT position from -28 to -8 cm influenced CO2 fluxes from mesocosms only to a small degree, which implies that small changes in water table position may be less important in controlling CO2 exchange with the atmosphere than often assumed. Although water table rise was a main driver for increase of methane emissions in all cores, short time lags (3

  9. Spatially explicit simulation of peatland hydrology and carbon dioxide exchange

    International Nuclear Information System (INIS)

    Sonnentag, O.

    2008-01-01

    A recent version of the Boreal Ecosystem Productivity Simulator (BEPS) was extended and modified to include northern peatlands. This thesis evaluated the BEPS-TerrainLab using observations made at the Mer Bleue bog located near Ottawa, Ontario, and the Sandhill fen located near Prince Albert, Saskatchewan. The code was revised to represent the multi-layer canopy and processes related to energy, water vapour and carbon dioxide fluxes through remotely-sensed leaf area index (LAI) maps. A quick and reliable method was also developed to determine shrub LAI with the LAI-2000 plant canopy analyzer. A large number of LAI data was collected at the Mer Bleue bog for the development of a new remote sensing-based methodology using multiple end member spectral unmixing to allow for separate tree and shrub LAI mapping in ombrotrophic peatlands. The methodology was also adapted for use in minerotrophic peatlands and their surrounding landscapes. These LAI maps within the BEPS-TerrainLab represented the tree and shrub layers of the Mer Bleue bog and the tree and shrub/sedge layers of the Sandhill fen. The study examined the influence of mesoscale topography (Mer Bleue bog) and macro- and mesoscale topography (Sandhill fen) on wetness, evapotranspiration, and gross primary productivity during the snow-free period of 2004. The results suggested that a peatland type-specific differentiation of macro- and mesoscale topographic effects on hydrology should be included in future peatland ecosystem modelling efforts in order to allow for a more realistic simulation of the soil water balance in peatlands and to reduce uncertainties in carbon dioxide and methane annual fluxes from wetlands

  10. Spatially explicit simulation of peatland hydrology and carbon dioxide exchange

    Energy Technology Data Exchange (ETDEWEB)

    Sonnentag, O.

    2008-08-01

    A recent version of the Boreal Ecosystem Productivity Simulator (BEPS) was extended and modified to include northern peatlands. This thesis evaluated the BEPS-TerrainLab using observations made at the Mer Bleue bog located near Ottawa, Ontario, and the Sandhill fen located near Prince Albert, Saskatchewan. The code was revised to represent the multi-layer canopy and processes related to energy, water vapour and carbon dioxide fluxes through remotely-sensed leaf area index (LAI) maps. A quick and reliable method was also developed to determine shrub LAI with the LAI-2000 plant canopy analyzer. A large number of LAI data was collected at the Mer Bleue bog for the development of a new remote sensing-based methodology using multiple end member spectral unmixing to allow for separate tree and shrub LAI mapping in ombrotrophic peatlands. The methodology was also adapted for use in minerotrophic peatlands and their surrounding landscapes. These LAI maps within the BEPS-TerrainLab represented the tree and shrub layers of the Mer Bleue bog and the tree and shrub/sedge layers of the Sandhill fen. The study examined the influence of mesoscale topography (Mer Bleue bog) and macro- and mesoscale topography (Sandhill fen) on wetness, evapotranspiration, and gross primary productivity during the snow-free period of 2004. The results suggested that a peatland type-specific differentiation of macro- and mesoscale topographic effects on hydrology should be included in future peatland ecosystem modelling efforts in order to allow for a more realistic simulation of the soil water balance in peatlands and to reduce uncertainties in carbon dioxide and methane annual fluxes from wetlands.

  11. Response of testate amoebae to a late Holocene ecosystem shift in an Amazonian peatland.

    Science.gov (United States)

    Swindles, Graeme T; Kelly, Thomas J; Roucoux, Katherine H; Lawson, Ian T

    2018-03-15

    To date there have only been two studies using testate amoebae as palaeoecological indicators in tropical peatlands. Here we present a new ∼500-year testate amoeba record from San Jorge, a domed peatland in Peruvian Amazonia, which has a well-constrained vegetation history based on pollen analysis. We observe a major shift from Hyalosphenia subflava to Cryptodifflugia oviformis-dominated communities at ∼50 cm depth (c. AD 1760), which suggests a change to drier conditions in the peatland. The application of a statistical transfer function also suggests a deepening of the water table at this time. The transition in the microbial assemblage occurs at a time when pollen and geochemical data indicate drier conditions (reduced influence of river flooding), leading to an ecosystem switch to more ombrotrophic-like conditions in the peatland. Our work illustrates the potential of testate amoebae as important tools in tropical peatland palaeoecology, and the power of multiproxy approaches for understanding the long-term development of tropical peatlands. Copyright © 2018 Elsevier GmbH. All rights reserved.

  12. DATING RECENT PEAT ACCUMULATION IN EUROPEAN OMBROTROPHIC BOGS

    NARCIS (Netherlands)

    van der Plicht, Johannes; Yeloff, Dan; van der Linden, Marjolein; van Geel, Bas; Brain, Sally; Chambers, Frank M.; Webb, Julia; Toms, Phillip; Hatté, C.; Jull, A.J.T.

    2013-01-01

    This study compares age estimates of recent peat deposits in 10 European ombrotrophic (precipitation-fed) bogs produced using the C-14 bomb peak, Pb-210, Cs-137, spheroidal carbonaceous particles (SCPs), and pollen. At 3 sites, the results of the different dating methods agree well. In 5 cores,

  13. Lateral expansion and carbon exchange of a boreal peatland in Finland resulting in 7000 years of positive radiative forcing

    Science.gov (United States)

    Mathijssen, Paul J. H.; Kähkölä, Noora; Tuovinen, Juha-Pekka; Lohila, Annalea; Minkkinen, Kari; Laurila, Tuomas; Väliranta, Minna

    2017-03-01

    Data on past peatland growth patterns, vegetation development, and carbon (C) dynamics during the various Holocene climate phases may help us to understand possible future climate-peatland feedback mechanisms. In this study, we analyzed and radiocarbon dated several peat cores from Kalevansuo, a drained bog in southern Finland. We investigated peatland succession and C dynamics throughout the Holocene. These data were used to reconstruct the long-term atmospheric radiative forcing, i.e., climate impact of the peatland since initiation. Kalevansuo peat records revealed a general development from fen to bog, typical for the southern boreal zone, but the timing of ombrotrophication varied in different parts of the peatland. Peat accumulation patterns and lateral expansion through paludification were influenced by fires and climate conditions. Long-term C accumulation rates were overall lower than the average values found from literature. We suggest the low accumulation rates are due to repeated burning of the peat surface. Drainage for forestry resulted in a nearly complete replacement of typical bog mosses by forest species within 40 years after drainage. The radiative forcing reconstruction suggested positive values (warming) for the first 7000 years following initiation. The change from positive to negative forcing was triggered by an expansion of bog vegetation cover and later by drainage. The strong relationship between peatland area and peat type with radiative forcing suggests a possible feedback for future changing climate, as high-latitude peatlands may experience prominent regime shifts, such as fen to bog transitions.

  14. Environmental controls of C, N and P biogeochemistry in peatland pools.

    Science.gov (United States)

    Arsenault, Julien; Talbot, Julie; Moore, Tim R

    2018-08-01

    Pools are common in northern peatlands but studies have seldom focused on their nutrient biogeochemistry, especially in relation to their morphological characteristics and through seasons. We determined the environmental characteristics controlling carbon (C), nitrogen (N) and phosphorus (P) biogeochemistry in pools and assessed their evolution over the course of the 2016 growing season in a subboreal ombrotrophic peatland of eastern Canada. We showed that water chemistry variations in 62 pools were significantly explained by depth (81.9%) and the surrounding vegetation type (14.8%), but not by pool area or shape. Shallow pools had larger dissolved organic carbon (DOC) and total nitrogen (TN) concentrations and lower pH than deep pools, while pools surrounded by coniferous trees had more recalcitrant DOC than pools where vegetation was dominated by mosses. The influence of depth on pool biogeochemistry was confirmed by the seasonal survey of pools of different sizes with 47.1% of the variation in pool water chemistry over time significantly explained. Of this, 67.3% was explained by the interaction between time and pool size and 32.7% by pool size alone. P concentrations were small in all pools all summer long and combined with high N:P ratios, are indicative of P-limitation. Our results show that pool biogeochemistry is influenced by internal processes and highlight the spatial and temporal heterogeneity of nutrient biogeochemistry in ombrotrophic peatlands. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. The stoichiometry of peatlands

    Science.gov (United States)

    Moore, Tim

    2017-04-01

    Stoichiometric principles have been developed and successfully applied to freshwater and marine ecosystems, which are characterized by short-lived, structurally simple organisms, simple food webs and an environment which allows rapid movement of water and elements. The application has been less successful in peatlands, and other terrestrial ecosystems: not surprising given their long-lived, structurally complex organisms, slow rates of organic matter decomposition, complex food webs and low hydraulic conductivities slowing water and element movement. I examine some aspects of what we know about stoichiometry in peatlands, especially involving nutrients such as C, N, P, K, Ca and Mg. I follow the cascade of stoichiometry from peatland plants through litter and into decomposing peat, drawing upon data from the Mer Bleue peatland and peatlands in Ontario. There are consistent patterns in stoichiometries, such as C:N, N:P and C:P across diverse peatlands, whereas patterns involving K, Ca and Mg show greater variability. Most of the changes in stoichiometry occur in the early stages of decomposition, from Von Post values 1 through 4. Peatlands are affected by disturbances, such as elevated atmospheric deposition of N and P, and I look at how these changes affect stoichiometric relationships. Finally, I present data on the changes in the stoichiometry of C, H and O, from plants through peat to coal beds. I conclude that while ecological stoichiometry in peatlands is not as 'simple' as in aquatic ecosystems, it offers contributions to our understanding of how peatlands function and respond to disturbance.

  16. CO2 and CH4 fluxes and carbon balance in the atmospheric interaction of boreal peatlands

    International Nuclear Information System (INIS)

    Alm, J.

    1997-01-01

    Release of CO 2 from peat was studied using IR analyzer in a range of boreal peatlands under varying nutrient status and moisture conditions. Root associated CO 2 efflux was separated from the total release by experiments both in the field and in a greenhouse. Emissions of CO 2 and CH 4 (the latter by gas chromatography) were measured during the snow-covered period and their contribution to the annual fluxes of these gases was inspected. Ecosystem exchange of CO 2 under varying irradiation, temperature and moisture conditions was measured at different microsites at two peatland sites with different nutrient ecology. One site represented minerotrophic conditions during a wet growing season and the other site ombrotrophic conditions during an exceptionally dry growing season. Annual carbon balances were compiled for the two sites, and the role of the microsites in the annual carbon balance and CH 4 release was studied. The Holocene history of CO 2 sequestration and CH 4 emission dynamics in a raised mire were simulated using lateral and vertical growth rates derived from radiocarbon ages of peat samples from mire bottom and vertical cores. The model was formulated for a geographic information system (GIS). Artificial or natural lowering of water table increased CO 2 release from peat. A drought lasting from late May to July caused a 90 g C m 2 net loss in the annual C balance of a natural ombrotrophic bog. In drained forested sites the increase in peat CO 2 release could be even 100 %, but the development of the tree layer at least partially compensated for these losses. Wet conditions induced a net accumulation of 67 g C m -2 a -1 in the minerotrophic fen site, while the long term average accumulation rate is estimated to be only 15 g C m -2 a -1 for Finnish fens. Carbon balance in boreal peatlands is thus extremely sensitive to year-to-year climatic variations. Root activity of vascular plants contributed to the total peat CO 2 efflux by 10-40 % as root respiration

  17. Nitrogen mineralization in forestry-drained peatland soils in the Stołowe Mountains National Park (Central Sudetes Mts

    Directory of Open Access Journals (Sweden)

    Glina Bartłomiej

    2016-06-01

    Full Text Available The aim of this work was to determine the intensity of nitrogen mineralization in forestry drained ombrotrophic peatland soils in the Stołowe Mountains National Park, SW Poland. Additionally discussion about the shallow organic soils classification according to Polish Soil Classification (2011 is presented. For the study three research transects were established on forestry drained ombrotrophic peatlands in the Stołowe Mountains. Each of the transect consisted of four (site A and B or five (site C sampling plots. Sampling was conducted in the year 2012. The soil samples for the basic soil properties analysis were sampled in April, whereas undisturbed soil samples were collected in stainless steel rings (100 cm3 every 10 cm in April (spring, July (summer and October (autumn to show the seasonal dynamics of nitrogen mineralization. Statistical analysis showed that the content of N-NH4 was mainly determined by actual soil moisture and precipitation rate, whereas the content of N-NO3 was positively correlated with air temperature. Among investigated peatlands the highest concentrations of mineral nitrogen forms was observed in the Długie Mokradło bog, situated on the Skalniak Plateau-summit. Additionally, the results obtained showed that implementation of new subtype: shallow fibric peat soils (in Polish: gleby torfowe fibrowe płytkie within the type of peat soils (in polish: gleby torfowe should be considered during developing of the next update of Polish Soil Classification.

  18. Peatland succession induces a shift in the community composition of Sphagnum-associated active methanotrophs.

    Science.gov (United States)

    Putkinen, Anuliina; Larmola, Tuula; Tuomivirta, Tero; Siljanen, Henri M P; Bodrossy, Levente; Tuittila, Eeva-Stiina; Fritze, Hannu

    2014-06-01

    Sphagnum-associated methanotrophs (SAM) are an important sink for the methane (CH4) formed in boreal peatlands. We aimed to reveal how peatland succession, which entails a directional change in several environmental variables, affects SAM and their activity. Based on the pmoA microarray results, SAM community structure changes when a peatland develops from a minerotrophic fen to an ombrotrophic bog. Methanotroph subtypes Ia, Ib, and II showed slightly contrasting patterns during succession, suggesting differences in their ecological niche adaptation. Although the direct DNA-based analysis revealed a high diversity of type Ib and II methanotrophs throughout the studied peatland chronosequence, stable isotope probing (SIP) of the pmoA gene indicated they were active mainly during the later stages of succession. In contrast, type Ia methanotrophs showed active CH4 consumption in all analyzed samples. SIP-derived (13)C-labeled 16S rRNA gene clone libraries revealed a high diversity of SAM in every succession stage including some putative Methylocella/Methyloferula methanotrophs that are not detectable with the pmoA-based approach. In addition, a high diversity of 16S rRNA gene sequences likely representing cross-labeled nonmethanotrophs was discovered, including a significant proportion of Verrucomicrobia-related sequences. These results help to predict the effects of changing environmental conditions on SAM communities and activity. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  19. Stable carbon and nitrogen isotopes in vertical peat profiles of natural and drained boreal peatlands

    Science.gov (United States)

    Nykänen, Hannu; Mpamah, Promise; Rissanen, Antti; Pitkänen, Aki; Turunen, Jukka; Simola, Heikki

    2015-04-01

    Peatlands form a significant carbon pool in the global carbon cycle. Change in peat hydrology, due to global warming is projected to change microbiological processes and peat carbon pool. We tested if bulk stable carbon and nitrogen isotopes serve as indicators of severe long term drying in peatlands drained for forestry. Depth profile analysis of peat, for their carbon and nitrogen content as well as their carbon and nitrogen stable isotopic signatures, were conducted for peatlands in southern and eastern Finland, having ombrotrophic and minerotrophic natural and corresponding drained pairs or separate drained sites. The selection of sites allowed us to compare changes due to different fertility and changes due to long term artificial drying. Drainage lasting over 40 years has led to changes in hydrology, vegetation, nutrient mineralization and respiration. Furthermore, increased nutrient uptake and possible recycling of peat nitrogen and carbon trough vegetation back to the peat surface, also possibly has an effect on the stable isotopic composition of peat carbon and nitrogen. We think that drainage induced changes somehow correspond to those caused by changed hydrology due to climate change. We will present data from these measurements and discuss their implications for carbon and nitrogen flows in peatlands.

  20. The Effect of Long-term Nutrient Addition on Peat Properties in an Ombrotrophic Bog

    Science.gov (United States)

    Moore, T. R.; Bubier, J. L.; Knorr, K. H.; Roy, C.

    2017-12-01

    Atmospheric inputs of nutrients, particularly N and P, to ecosystems have increased and may have a significant effect on nutrient-deficient peatlands such as bogs. At the Mer Bleue ombrotrophic bog near Ottawa, Canada, we have conducted an experiment over 10 to 20 years by adding 1.6 to 6.4 g N m-2 yr-1 (as NH4NO3), with/without 6 g P m-2 yr-1 (as K phosphate), to evaluate the effect of increased inputs on ecosystem functions. Increased N and P amendment has changed the vegetation from a mixed shrub-Sphagnum community into one dominated by shrubs with the disappearance of mosses, with changes in plant production and litter input. The largest N and P amendments have resulted in an increase in bulk density at 0-10 cm and a lowering of the peat surface by 10 to 20 cm, creating an effective rise in the water table and an increase in CH4 emission from 15 to 50 mg m-2 d-1. Peat cores to a depth of 40 cm were collected after 10 to 15 yr of amendment and showed little change in soil pH (range 4.1 to 4.5). There were substantial increases in the concentration of N and P in the peat (8 to 14 and 0.5 to 1.5 mg g-1, respectively) and general decreases in Ca and Mg concentration. The von Post humification index increased by about 1 unit in the heavily fertilized plots, with shrub leaves replacing Sphagnum as the primary litterfall. FTIR analysis of the 0-20 cm peat showed significant increases in abundance of phenolic+aliphatic, aromatic, and carboxylic relative to polysaccharide components, revealed by the following ratios of absorbance at the respective wavenumbers: 1420/1090 cm-1, 0.41 to 0.45; 1510/1090 cm-1, 0.23 to 0.30; 1630/1090 cm-1, 0.53 to 0.65; and 1720/1090 cm-1, 0.44 to 0.48, respectively. Laboratory incubations of peat samples showed that potential rates of aerobic CH4 consumption were unaffected by nutrient treatment, apart from position relative to the water table, whereas potential rates of anaerobic CH4 production near the water table increased under the P

  1. Late Holocene Drought Variability in Eastern North America: Evidence From the Peatland Archive

    Science.gov (United States)

    Booth, R. K.; Jackson, S. T.

    2006-12-01

    Tree-ring based drought chronologies from semi-arid regions of western North America have revealed substantial variability in water balance during the past 1000 years, including episodes of persistent drought more severe than any observed during historical times. Delimitation of regional and continental-scale footprints of these past drought events, including their spatial patterning in humid regions where moisture-sensitive paleoclimate records are scarce, is critical to understanding their dynamics and potential causes. Ombrotrophic peatlands are scattered throughout humid regions of North America at mid-latitudes and represent an underutilized source of multidecadal-scale information on past moisture variations. We are developing a spatial network of peatland-derived paleoclimate and paleoecological records in eastern North America, in an effort to 1) determine whether large, decadal to multidecadal droughts of the past several thousand years were spatially and temporally coherent, 2) assess whether the magnitude of past drought events was sufficient to force ecological change in terrestrial ecosystems, and 3) assess the underlying mechanisms and dynamics of widespread drought in North America. We have completed water-level reconstructions based on testate-amoeba assemblages from two ombrotrophic peatlands in mid-continental North America, Hole in the Bog (NC Minnesota) and Minden Bog (SE Michgian). We also have developed reconstructions from three Sphagnum-dominated kettle peatlands, South Rhody Peatland (NC Michigan), Hornet Peatland (NW Wisconsin), and Irwin Smith Peatland (NE Michigan). Although these kettle peatlands are not truly ombrotrophic, high-magnitude water-table fluctuations should still be attributable to climate variability, and we use these records to supplement our interpretation of regional climate history. Our results indicate that all high-magnitude fluctuations in water balance were spatially extensive, affecting bog-surface moisture

  2. Restoration of harvested peatlands

    International Nuclear Information System (INIS)

    Saarmets, Tiit

    1999-01-01

    A short analysis of the main topics of the IPS Symposium Peatland Restoration and Reclamation, Duluth, Minnesota, USA, 1998 is given. It has been single-mindedly recommended in Estonia so far that harvested peatland surfaces should be levelled and outflows shut. But following these recommendations will lead to an unfounded formation of marshy areas with a very low growth of plants. The reclamation of harvested peatlands for agricultural purposes is expensive and there is no commercial need for agricultural land in today's Estonia now. In the author's opinion the foreflows and intermediate ditches should be left open which would favour the growth of the brushwood to grow later into the forest of commercial value. (author)

  3. Tropical Peatland Geomorphology and Hydrology

    Science.gov (United States)

    Cobb, A.; Harvey, C. F.

    2017-12-01

    Tropical peatlands cover many low-lying areas in the tropics. In tropical peatlands, a feedback between hydrology, landscape morphology, and carbon storage causes waterlogged organic matter to accumulate into gently mounded land forms called peat domes over thousands of years. Peat domes have a stable morphology in which peat production is balanced by loss and net precipitation is balanced by lateral flow, creating a link between peatland morphology, rainfall patterns and drainage networks. We show how landscape morphology can be used to make inferences about hydrologic processes in tropical peatlands. In particular, we show that approaches using simple storage-discharge relationships for catchments are especially well suited to tropical peatlands, allowing river forecasting based on peatland morphology in catchments with tropical peatland subcatchments.

  4. Ecology of testate amoebae in an Amazonian peatland and development of a transfer function for palaeohydrological reconstruction.

    Science.gov (United States)

    Swindles, Graeme T; Reczuga, Monika; Lamentowicz, Mariusz; Raby, Cassandra L; Turner, T Edward; Charman, Dan J; Gallego-Sala, Angela; Valderrama, Elvis; Williams, Christopher; Draper, Frederick; Honorio Coronado, Euridice N; Roucoux, Katherine H; Baker, Tim; Mullan, Donal J

    2014-08-01

    Tropical peatlands represent globally important carbon sinks with a unique biodiversity and are currently threatened by climate change and human activities. It is now imperative that proxy methods are developed to understand the ecohydrological dynamics of these systems and for testing peatland development models. Testate amoebae have been used as environmental indicators in ecological and palaeoecological studies of peatlands, primarily in ombrotrophic Sphagnum-dominated peatlands in the mid- and high-latitudes. We present the first ecological analysis of testate amoebae in a tropical peatland, a nutrient-poor domed bog in western (Peruvian) Amazonia. Litter samples were collected from different hydrological microforms (hummock to pool) along a transect from the edge to the interior of the peatland. We recorded 47 taxa from 21 genera. The most common taxa are Cryptodifflugia oviformis, Euglypha rotunda type, Phryganella acropodia, Pseudodifflugia fulva type and Trinema lineare. One species found only in the southern hemisphere, Argynnia spicata, is present. Arcella spp., Centropyxis aculeata and Lesqueresia spiralis are indicators of pools containing standing water. Canonical correspondence analysis and non-metric multidimensional scaling illustrate that water table depth is a significant control on the distribution of testate amoebae, similar to the results from mid- and high-latitude peatlands. A transfer function model for water table based on weighted averaging partial least-squares (WAPLS) regression is presented and performs well under cross-validation (r(2)(apparent)= 0.76, RMSE = 4.29; r(2)(jack)= 0.68, RMSEP =5.18). The transfer function was applied to a 1-m peat core, and sample-specific reconstruction errors were generated using bootstrapping. The reconstruction generally suggests near-surface water tables over the last 3,000 years, with a shift to drier conditions at c. cal. 1218-1273 AD.

  5. Do oxygen stable isotopes track precipitation moisture source in vascular plant dominated peatlands?

    Science.gov (United States)

    Charman, D.; Amesbury, M. J.; Newnham, R.; Loader, N.; Goodrich, J. P.; Gallego-Sala, A. V.; Royles, J.; Keller, E. D.; Baisden, W. T.

    2014-12-01

    Variations in the isotopic composition of precipitation are determined by fractionation processes which occur during temperature and humidity dependent phase changes associated with evaporation and condensation. Oxygen stable isotope ratios have therefore been frequently used as a source of palaeoclimate data from a variety of proxy archives. Exploitation of this record from ombrotrophic peatlands, where the source water used in cellulose synthesis is derived solely from precipitation, has been mostly limited to Northern Hemisphere Sphagnum-dominated bogs, with limited application in the Southern Hemisphere (SH) or in peatlands dominated by vascular plants. Throughout New Zealand (NZ), the preserved root matrix of the restionaceous wire rush (Empodisma spp.) forms deep peat deposits. NZ provides an ideal location to undertake empirical research into oxygen isotope fractionation in vascular peatlands because sites are ideally suited to single taxon analysis, preserve potentially high resolution full Holocene palaeoclimate records and are situated in the climatically sensitive SH mid-latitudes. Crucially, large gradients exist in the mean isotopic composition of precipitation across NZ, caused primarily by the relative influence of different climate modes. We test the capacity for δ18O analysis of Empodisma alpha cellulose from ombrotrophic restiad peatlands in NZ to provide a methodology for developing palaeoclimate records. We took surface plant, water and precipitation samples over spatial (six sites spanning >10° latitude) and temporal (monthly measurements over one year) gradients. We found a strong link between the isotopic compositions of surface root water, the most likely source water for plant growth, and precipitation in both datasets. Back-trajectory modelling of precipitation moisture source for rain days prior to sampling showed clear seasonality in the temporal data that was reflected in surface root water. The link between source water and plant

  6. Small-scale variability in peatland pore-water biogeochemistry, Hudson Bay Lowland, Canada.

    Science.gov (United States)

    Ulanowski, T A; Branfireun, B A

    2013-06-01

    The Hudson Bay Lowland (HBL) of northern Ontario, Manitoba and Quebec, Canada is the second largest contiguous peatland complex in the world, currently containing more than half of Canada's soil carbon. Recent concerns about the ecohydrological impacts to these large northern peatlands resulting from climate change and resource extraction have catalyzed a resurgence in scientific research into this ecologically important region. However, the sheer size, heterogeneity and elaborate landscape arrangements of this ecosystem raise important questions concerning representative sampling of environmental media for chemical or physical characterization. To begin to quantify such variability, this study assessed the small-scale spatial (1m) and short temporal (21 day) variability of surface pore-water biogeochemistry (pH, dissolved organic carbon, and major ions) in a Sphagnum spp.-dominated, ombrotrophic raised bog, and a Carex spp.-dominated intermediate fen in the HBL. In general, pore-water pH and concentrations of dissolved solutes were similar to previously reported literature values from this region. However, systematic sampling revealed consistent statistically significant differences in pore-water chemistries between the bog and fen peatland types, and large within-site spatiotemporal variability. We found that microtopography in the bog was associated with consistent differences in most biogeochemical variables. Temporal changes in dissolved solute chemistry, particularly base cations (Na(+), Ca(2+) and Mg(2+)), were statistically significant in the intermediate fen, likely a result of a dynamic connection between surficial waters and mineral-rich deep groundwater. In both the bog and fen, concentrations of SO4(2-) showed considerable spatial variability, and a significant decrease in concentrations over the study period. The observed variability in peatland pore-water biogeochemistry over such small spatial and temporal scales suggests that under-sampling in

  7. Peatland Microbial Communities and Decomposition Processes in the James Bay Lowlands, Canada

    Science.gov (United States)

    Preston, Michael D.; Smemo, Kurt A.; McLaughlin, James W.; Basiliko, Nathan

    2012-01-01

    Northern peatlands are a large repository of atmospheric carbon due to an imbalance between primary production by plants and microbial decomposition. The James Bay Lowlands (JBL) of northern Ontario are a large peatland-complex but remain relatively unstudied. Climate change models predict the region will experience warmer and drier conditions, potentially altering plant community composition, and shifting the region from a long-term carbon sink to a source. We collected a peat core from two geographically separated (ca. 200 km) ombrotrophic peatlands (Victor and Kinoje Bogs) and one minerotrophic peatland (Victor Fen) located near Victor Bog within the JBL. We characterized (i) archaeal, bacterial, and fungal community structure with terminal restriction fragment length polymorphism of ribosomal DNA, (ii) estimated microbial activity using community level physiological profiling and extracellular enzymes activities, and (iii) the aeration and temperature dependence of carbon mineralization at three depths (0–10, 50–60, and 100–110 cm) from each site. Similar dominant microbial taxa were observed at all three peatlands despite differences in nutrient content and substrate quality. In contrast, we observed differences in basal respiration, enzyme activity, and the magnitude of substrate utilization, which were all generally higher at Victor Fen and similar between the two bogs. However, there was no preferential mineralization of carbon substrates between the bogs and fens. Microbial community composition did not correlate with measures of microbial activity but pH was a strong predictor of activity across all sites and depths. Increased peat temperature and aeration stimulated CO2 production but this did not correlate with a change in enzyme activities. Potential microbial activity in the JBL appears to be influenced by the quality of the peat substrate and the presence of microbial inhibitors, which suggests the existing peat substrate will have a large

  8. Peatland Open-water Pool Biogeochemistry: The Influence of Hydrology and Vegetation

    Science.gov (United States)

    Arsenault, J.; Talbot, J.; Moore, T. R.

    2017-12-01

    Peatland open-water pools are net sources of carbon to the atmosphere. However, their interaction with the surrounding peat remains poorly known. In a previous study, we showed that shallow pools are richer in nutrients than deep pools. While depth was the main driver of biogeochemistry variations across time and space, analyses also showed that pool's adjacent vegetation may have an influence on water chemistry. Our goal is to understand the relationship between the biogeochemistry of open-water pools and their surroundings in a subboreal ombrotrophic peatland of southern Quebec (Canada). To assess the influence of vegetation on pool water chemistry, we compare two areas covered with different types of vegetation: a forested zone dominated by spruce trees and an open area mostly covered by Sphagnum spp. To evaluate the direction of water (in or out of the pools), we installed capacitance water level probes in transects linking pools in the two zones. Wells were also installed next to each probe to collect peat pore water samples. Samples were taken every month during summer 2017 and analyzed for dissolved organic carbon, nitrogen and phosphorus, pH and specific UV absorbance. Preliminary results show differences in peat water chemistry depending on the dominant vegetation. In both zones, water levels fluctuations are disconnected between peat and the pools, suggesting poor horizontal water movement. Pool water chemistry may be mostly influenced by the immediate surrounding vegetation than by the local vegetation pattern. Climate and land-use change may affect the vegetation structure of peatlands, thus affecting pool biogeochemistry. Considering the impact of pools on the overall peatland capacity to accumulate carbon, our results show that more focus must be placed on pools to better understand peatland stability over time.

  9. The peatland map of Europe

    NARCIS (Netherlands)

    Tanneberger, Franziska; Tegetmeyer, C.; Busse, S.; Barthelmes, A.; Shumka, S.; Mariné, A.M.; Jenderedjian, K.; Steiner, G.M.; Essl, F.; Etzold, J.; Mendes, C.; Kozulin, A.; Frankard, P.; Milanović,; Ganeva, A.; Apostolova, I.; Alegro, A.; Delipetrou, P.; Navrátilová, J.; Risager, M.; Leivits, A.; Fosaa, A.M.; Tuominen, S.; Muller, F.; Bakuradze, T.; Sommer, M.; Christanis, K.; Szurdoki, E.; Oskarsson, H.; Brink, S.H.; Connolly, J.; Bragazza, L.; Martinelli, G.; Aleksāns, O.; Priede, A.; Sungaila, D.; Melovski, L.; Belous, T.; Saveljić, D.; Vries, De F.; Moen, A.; Dembek, W.; Mateus, J.; Hanganu, J.; Sirin, A.; Markina, A.; Napreenko, M.; Lazarević, P.; Stanová, V.Š.; Skoberne, P.; Pérez, P.H.; Pontevedra-Pombal, X.; Lonnstad, J.; Küchler, M.; Wüst-Galley, C.; Kirca, S.; Mykytiuk, O.; Lindsay, R.; Joosten, H.

    2017-01-01

    Based on the ‘European Mires Book’ of the International Mire Conservation Group (IMCG), this article provides a composite map of national datasets as the first comprehensive peatland map for the whole of Europe. We also present estimates of the extent of peatlands and mires in each European country

  10. Abstracts of the 15. annual workshop of the Peatland Ecology Research Group (PERG) : peatland event 2008

    International Nuclear Information System (INIS)

    2008-01-01

    The Peatland Ecology Research Group (PERG) deals with the integrated sustainable management of Canadian peatlands, with projects involving the development of ecological restoration of peatland ecosystems after peat mining; reclamation of abandoned peatlands; hydrology, geochemistry, microbiology of natural, harvested and restored peatlands; peatland conservation strategies; and Sphagnum moss ecology and productivity. The Group has established a method for the re-establishing vegetation on mined peatlands. Research by PERG has initiated the development of global peatland conservation strategies. This workshop featured 35 presentations, of which 9 have been catalogued separately for inclusion in this database

  11. Biological N2 fixation mainly controlled by Sphagnum tissue N:P ratio in ombrotrophic bogs

    Science.gov (United States)

    Zivkovic, Tatjana; Moore, Tim R.

    2017-04-01

    Most of the 18 Pg nitrogen (N) accumulated in northern nutrient-poor and Sphagnum-dominated peatlands (bogs and fens) can be attributed to N2-fixation by diazotrophs either associated with the live Sphagnum or non-symbiotically in the deeper peat such as through methane consumption close to the water table. Where atmospheric N deposition is low (Sphagnum, suggested by the increase in tissue N:P to >16. It is unclear how Sphagnum-hosted diazotrophic activity may be affected by N deposition and thus changes in N:P ratio. First, we investigated the effects of long-term addition of different sources of nitrogen (0, 1.6, 3.2 and 6.4 g N m-2 y-1as NH4Cl and NaNO3), and phosphorus (5 g P m-2 y-1as KH2PO4) on Sphagnum nutrient status (N, P and N:P ratio), net primary productivity (NPP) and Sphagnum-associated N2fixation at Mer Bleue, a temperate ombrotrophic bog. We show that N concentration in Sphagnum tissue increased with larger rates of N addition, with a stronger effect on Sphagnum from NH4 than NO3. The addition of P created a 3.5 fold increase in Sphagnum P content compared to controls. Sphagnum NPP decreased linearly with the rise in N:P ratio, while linear growth declined exponentially with increase in Sphagnum N content. Rates of N2-fixation determined in the laboratory significantly decreased in response to even the smallest addition of both N species. In contrast, the addition of P increased N2 fixation by up to 100 times compared to N treatments and up to 5-30 times compared to controls. The change in N2-fixation was best modeled by the N:P ratio, across all experimental treatments. Secondly, to test the role of N:P ratio on N2-fixation across a range of bogs, eight study sites along the latitudinal gradient from temperate, boreal to subarctic zone in eastern Canada were selected. From each bog, two predominant microptopographies, hummocks and hollows, were tested for both N2-fixation activity in the laboratory and Sphagnum tissue concentrations of N, P and N

  12. Can oxygen stable isotopes be used to track precipitation moisture source in vascular plant-dominated peatlands?

    Science.gov (United States)

    Amesbury, Matthew J.; Charman, Dan J.; Newnham, Rewi M.; Loader, Neil J.; Goodrich, Jordan; Royles, Jessica; Campbell, David I.; Keller, Elizabeth D.; Baisden, W. Troy; Roland, Thomas P.; Gallego-Sala, Angela V.

    2015-11-01

    Variations in the isotopic composition of precipitation are determined by fractionation processes which occur during temperature- and humidity-dependent phase changes associated with evaporation and condensation. Oxygen stable isotope ratios have therefore been frequently used as a source of palaeoclimate data from a variety of proxy archives, which integrate this signal over time. Applications from ombrotrophic peatlands, where the source water used in cellulose synthesis is derived solely from precipitation, have been mostly limited to Northern Hemisphere Sphagnum-dominated bogs, with few in the Southern Hemisphere or in peatlands dominated by vascular plants. New Zealand (NZ) provides an ideal location to undertake empirical research into oxygen isotope fractionation in vascular peatlands because single taxon analysis can be easily carried out, in particular using the preserved root matrix of the restionaceous wire rush (Empodisma spp.) that forms deep Holocene peat deposits throughout the country. Furthermore, large gradients are observed in the mean isotopic composition of precipitation across NZ, caused primarily by the relative influence of different climate modes. Here, we test whether δ18O of Empodisma α-cellulose from ombrotrophic restiad peatlands in NZ can provide a methodology for developing palaeoclimate records of past precipitation δ18O. Surface plant, water and precipitation samples were taken over spatial (six sites spanning >10° latitude) and temporal (monthly measurements over one year) gradients. A link between the isotopic composition of root-associated water, the most likely source water for plant growth, and precipitation in both datasets was found. Back-trajectory modelling of precipitation moisture source for rain days prior to sampling showed clear seasonality in the temporal data that was reflected in root-associated water. The link between source water and plant cellulose was less clear, although mechanistic modelling predicted mean

  13. The Effects of Peatland Plant Functional Types and Altered Hydrology on Porewater Chemistry in a Northern Bog

    Science.gov (United States)

    Daniels, A.; Kane, E. S.; Lilleskov, E. A.; Kolka, R. K.; Chimner, R. A.; Potvin, L. R.; Romanowicz, K. J.

    2012-12-01

    Northern wetlands, peatlands in particular, have been shown to store around 30% of the world's soil carbon and thus play a significant role in the carbon cycle of our planet. Carbon accumulation in peatlands is the result of retarded decomposition due to low oxygen availability in these water-logged environments. Changes in our planet's climate cycles are altering peatland hydrology and vegetation communities, resulting in changes in their ability to sequester carbon through increases in peat carbon oxidation and mineralization. To date, the consequences of altered hydrology and changes in vegetation communities, and their interactive effects on carbon storage, are not well understood. We have initiated a research plan that assesses the varying roles that water table variation and vegetation communities have on extracellular enzyme activity and labile carbon availability in porewater from an ombrotrophic bog. We assessed the effects of plant functional group (ericaceous shrubs, sedges, and bryophytes) and water table position on biogeochemical processes. Specifically, we measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), enzyme activity, organic acids, anions and cations, spectral indexes of aromaticity, and phenolic content in addressing our hypotheses of responses to climate change drivers. Research on these components will evaluate the relative importance of biology, water table, and their interactive affects on the porewater quality of peatlands. We hypothesized that oxygen availability will strongly influence decomposition in these systems but that this response will largely be mediated by changes in plant community and the enzymes associated with root exudates and mycorrhizae. To date, our data confirm vegetation and water table related patterns. Acetate and propionate concentrations in the sedge-dominated communities dropped significantly with depth and drainage, relative to the control and ericaceous treatments, which likely reflects

  14. Holocene Paleohydrological Changes in Northern Michigan: Interpretations of Biomarker Distributions and Compound Specific Stable Isotope Analysis from Peatlands

    Science.gov (United States)

    Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Huang, Y.

    2006-12-01

    Sediments of ombrotrophic peatlands are excellent archives for reconstructing past changes in precipitation/evaporation (P/E) balance. Multiproxy analysis of these sediments is critical for better understanding of climatic events experienced by these highly sensitive systems, as each proxy may respond to different climate parameters. In this study, we use distributions of n-alkanes and δD of Sphagnum biomarkers to interpret paleohydrology from sediments of Irwin Smith Bog, northern Michigan. We then integrate these data with pollen data and testate amoebae-inferred water table depth. Sphagnum moss is the dominant peat former in ombrotrophic bogs, but vascular plants become abundant when water tables are drawn down. Thus, the abundance of Sphagnum relative to vascular plants is indicative of peatland hydrology. The n-alkanes produced by Sphagnum differ from vascular plants in the relative abundance of the different homologues, with the former having excess amounts of shorter chain C23 n-alkane. We use several measures (compound ratios, PCA) to show changes in then-alkane distributions in the sediments, and thus changes in the peatland plant community. Our data provide high- resolution, quantitative paleohydrological records for the study region that are consistent with other records. We also show that the relative abundance of a newly identified Sphagnum biomarker, 2-heptacosanone, can be used to reconstruct changing plant communities. Because ombrotrophic systems lose water by evaporation, drier/warmer conditions cause hydrogen isotopic enrichment of bog water and Sphagnum biomarkers. We measured the δD of C23 n-alkane and 2-heptacosanone to provide additional paleoclimate information. Our multiproxy approach allows us to better understand the climate changes during key intervals of the Holocene. For example, a sharp decrease in the abundance of Tsuga canadensis (hemlock) pollen has been previously identified in records from many places throughout eastern North

  15. A Paleoevaporation Proxy Using Compound Specific Stable Isotope Measurements from Peatland Biomarkers

    Science.gov (United States)

    Wang, J.; Nichols, J. E.; Huang, Y.

    2009-12-01

    It is important to understand how evaporation from wetlands changes with climate. To do this, we have developed a paleoevaporation proxy for use in ombrotrophic peatland sediments. Using compound specific hydrogen isotopic ratios of vascular plant and Sphagnum biomarkers, we can quantitatively reconstruct past changes in evaporation. The contrast in H isotopic ratios of water available to living Sphagnum and water in the acrotelm can be used to estimate “f”—the fraction of water remaining after evaporation. Vascular plant leaf waxes record H isotopic ratios of precipitation which is little affected by evaporation, whereas the Sphagnum biomarker, C23 n-alkane, records H isotopic ratios of the water inside its cells and between its leaves, which is strongly affected by evaporation at the bog surface. Evaporation changes can then be calculated with the H-isotopic ratios of the two types of biomarkers. We calibrated the apparent fractionation of D/H ratios from source water to C23 n-alkane with lab-grown Sphagnum. We also present several reconstructions of paleoevaporation from peatlands throughout eastern North America. By comparison with overall hydrologic balance, we are able to understand the varying role of evaporation in the hydrologic system in both time and space.

  16. A decade of continuous NEE measurements at a Scottish peatland

    Science.gov (United States)

    Helfter, Carole; Campbell, Claire; Coyle, Mhairi; Anderson, Margaret; Drewer, Julia; Levy, Peter; Famulari, Daniela; Twigg, Marsailidh; Skiba, Ute; Billett, Michael; Dinsmore, Kerry; Nemitz, Eiko; Sutton, Mark

    2013-04-01

    Eddy-covariance measurements of carbon dioxide (CO2) fluxes have been running continuously at the Auchencorth Moss peatland site in Scotland (55o47'32N, 3o14'35W, 267 m a.s.l.) since the spring of 2002 which makes this study one of the longest ones to date on a peatland system. Auchencorth Moss is a low-lying, ombrotrophic peatland situated ca. 20 km south-west of Edinburgh. Peat depth ranges from 0.5 m and the site has a mean annual precipitation of 1155 mm. The open moorland site has an extensive uniform fetch of blanket bog to the south, west and north. The vegetation present within the flux measurement footprint comprises mixed grass species, heather and substantial areas of moss species (Sphagnum spp. and Polytrichum spp.). The eddy-covariance system consists of a Licor 7000 closed-path infrared gas analyser operating at 10 Hz for the simultaneous measurement of carbon dioxide and water vapour and of a Gill Windmaster Pro ultrasonic anemometer, operating at 20 Hz, and mounted atop a 3 m mast. The effective measurement height is 3.5 m with a vertical separation of 20 cm between the anemometer and the inlet of the sampling line. Air is sampled at 20 litres per minute through a 40 m long Dekabon line (internal diameter 4 mm). In addition to eddy-covariance measurements, the site is equipped with a weather station, soil temperature measurements, total solar radiation and photosynthetically active radiation (PAR) sensors, a tipping bucket for rainfall and, since April 2007, water table depth has been recorded at half-hourly interval. On an annual basis, the peatland at Auchencorth Moss has consistently been a net sink of CO2 in the study period 2002-2012 with a mean net ecosystem exchange (NEE) of - 69.1 ± 33.6 g C-CO2 m-2 yr-1. This value is at the high end of other recent studies as is the inter-annual range of NEE (-31.4 to -135.9 g C-CO2 m-2 yr-1). Inter-annual variations in NEE are significant and strongly correlated to the length of the growing seasons

  17. McGill wetland model: evaluation of a peatland carbon simulator developed for global assessments

    Directory of Open Access Journals (Sweden)

    F. St-Hilaire

    2010-11-01

    Full Text Available We developed the McGill Wetland Model (MWM based on the general structure of the Peatland Carbon Simulator (PCARS and the Canadian Terrestrial Ecosystem Model. Three major changes were made to PCARS: (1 the light use efficiency model of photosynthesis was replaced with a biogeochemical description of photosynthesis; (2 the description of autotrophic respiration was changed to be consistent with the formulation of photosynthesis; and (3 the cohort, multilayer soil respiration model was changed to a simple one box peat decomposition model divided into an oxic and anoxic zones by an effective water table, and a one-year residence time litter pool. MWM was then evaluated by comparing its output to the estimates of net ecosystem production (NEP, gross primary production (GPP and ecosystem respiration (ER from 8 years of continuous measurements at the Mer Bleue peatland, a raised ombrotrophic bog located in southern Ontario, Canada (index of agreement [dimensionless]: NEP = 0.80, GPP = 0.97, ER = 0.97; systematic RMSE [g C m−2 d−1]: NEP = 0.12, GPP = 0.07, ER = 0.14; unsystematic RMSE: NEP = 0.15, GPP = 0.27, ER = 0.23. Simulated moss NPP approximates what would be expected for a bog peatland, but shrub NPP appears to be underestimated. Sensitivity analysis revealed that the model output did not change greatly due to variations in water table because of offsetting responses in production and respiration, but that even a modest temperature increase could lead to converting the bog from a sink to a source of CO2. General weaknesses and further developments of MWM are discussed.

  18. The contribution of fine roots to peatland stability under changing environmental conditions

    Science.gov (United States)

    Malhotra, A.; Brice, D. J.; Childs, J.; Phillips, J.; Hanson, P. J.; Iversen, C. M.

    2017-12-01

    Fine-root production and traits are closely linked with ecosystem nutrient and water fluxes, and may regulate these fluxes in response to environmental change. Plant strategies can shift to favoring below- over aboveground biomass allocation when nutrients or moisture are limited. Fine-roots traits such as root tissue density (RTD) or specific root length (SRL) can also adapt to the environment, for example, by maximizing the area of soil exploited by decreasing RTD and increasing SRL during dry conditions. Fine-root trait plasticity could contribute to the stability of peatland carbon function in response to environmental change. However, the extent and mechanisms of peatland fine-root plasticity are unknown. We investigated fine-root growth and traits and their link to environmental factors and aboveground dynamics at SPRUCE (Spruce and Peatland Responses Under Changing Environments), a warming and elevated CO2 (eCO2) experiment in an ombrotrophic peatland. In the first growing season of whole ecosystem warming, fine-root production increased with warming and drying. Above- versus belowground allocation strategies varied by plant functional type (PFT). In shrubs, contrary to our expectation, aboveground- to fine-root production allocation ratio increased with dryer conditions, perhaps as a response to a concurrent increase in nutrients. Trait response hypotheses were largely supported, with RTD decreasing and SRL increasing with warming; however, response varied among PFTs. Once eCO2 was turned on in the second growing season, preliminary results suggest interactive effects of warming and eCO2 on total fine-root production: production decreased or increased with warming in ambient or elevated CO2 plots, respectively. Both trait and production responses to warming and eCO2 varied by microtopography and depth. Our results highlight plasticity of fine-root traits and biomass allocation strategies; the extent and mechanism of which varies by PFT. We will summarize

  19. Age, extent and carbon storage of the central Congo Basin peatland complex.

    Science.gov (United States)

    Dargie, Greta C; Lewis, Simon L; Lawson, Ian T; Mitchard, Edward T A; Page, Susan E; Bocko, Yannick E; Ifo, Suspense A

    2017-02-02

    Peatlands are carbon-rich ecosystems that cover just three per cent of Earth's land surface, but store one-third of soil carbon. Peat soils are formed by the build-up of partially decomposed organic matter under waterlogged anoxic conditions. Most peat is found in cool climatic regions where unimpeded decomposition is slower, but deposits are also found under some tropical swamp forests. Here we present field measurements from one of the world's most extensive regions of swamp forest, the Cuvette Centrale depression in the central Congo Basin. We find extensive peat deposits beneath the swamp forest vegetation (peat defined as material with an organic matter content of at least 65 per cent to a depth of at least 0.3 metres). Radiocarbon dates indicate that peat began accumulating from about 10,600 years ago, coincident with the onset of more humid conditions in central Africa at the beginning of the Holocene. The peatlands occupy large interfluvial basins, and seem to be largely rain-fed and ombrotrophic-like (of low nutrient status) systems. Although the peat layer is relatively shallow (with a maximum depth of 5.9 metres and a median depth of 2.0 metres), by combining in situ and remotely sensed data, we estimate the area of peat to be approximately 145,500 square kilometres (95 per cent confidence interval of 131,900-156,400 square kilometres), making the Cuvette Centrale the most extensive peatland complex in the tropics. This area is more than five times the maximum possible area reported for the Congo Basin in a recent synthesis of pantropical peat extent. We estimate that the peatlands store approximately 30.6 petagrams (30.6 × 10 15  grams) of carbon belowground (95 per cent confidence interval of 6.3-46.8 petagrams of carbon)-a quantity that is similar to the above-ground carbon stocks of the tropical forests of the entire Congo Basin. Our result for the Cuvette Centrale increases the best estimate of global tropical peatland carbon stocks by

  20. Distribution of 35 Elements in Peat Cores from Ombrotrophic Bogs Studied by Epithermal Neutron Activation Analysis

    CERN Document Server

    Frontasyeva, M V

    2004-01-01

    In ombrotrophic bogs the surface peat layer is supplied with chemical substances only from the atmosphere. Peat cores from these bogs therefore can be used to study temporal trends in atmospheric deposition of pollutants. In this work epithermal neutron activation analysis was applied for the first time to study the distribution of 35 elements in peat profiles from ombrotrophic bogs. The selected examples were from Finnmark county in northern Norway: one pristine site far from any local pollution source, and another strongly affected by long-term operation of Russian copper-nickel smelters located close to the border. The elements are classified with respect to their behavior in the uppermost 40 cm of the peat, and similarities and differences between the two profiles are discussed. As compared with other more commonly used analytical techniques based on acid decomposition of the sample ENAA has the advantage of providing the total concentrations of the elements.

  1. Rapid ecosystem shifts in peatlands: linking plant physiology and succession.

    Science.gov (United States)

    Granath, Gustaf; Strengbom, Joachim; Rydin, Håkan

    2010-10-01

    Stratigraphic records from peatlands suggest that the shift from a rich fen (calcareous fen) to an ombrotrophic bog can occur rapidly. This shift constitutes a switch from a species-rich ecosystem to a species-poor one with greater carbon storage. In this process, the invasion and expansion of acidifying bog species of Sphagnum (peat mosses) play a key role. To test under what conditions an acidifying bog species could invade a rich fen, we conducted three experiments, contrasting the bog species S. fucsum with the rich-fen species S. warnstorfii and S. teres. We first tested the effect of calcareous water by growing the three species at different constant height above the water table (HWT; 2, 7, and 14 cm) in a rich-fen pool and measured maximum photosynthetic rate and production and difference in length growth as an indicator of competition. In none of the species was the photosynthetic capacity negatively affected when placed at low HWT, but S. fuscum was a weaker competitor at low HWT. In our second experiment we transplanted the three species into microhabitats with different and naturally varying HWT in a rich fen. Here, S. fuscum nearly ceased to photosynthesize when transplanted to low HWT (brown moss carpet), while it performed similarly to the two rich-fen species at the intermediate level (S. warnstorfii hummock level). In contrast to S. fuscum, the rich-fen sphagna performed equally well in both habitats. The brown moss carpet was seasonally flooded, and in our third experiment we found that S. fuscum, but not S. teres, was severely damaged when submerged in rich-fen water. Our results suggest two thresholds in HWT affecting the ecosystem switch: one level that reduces the risk of submergence and a higher one that makes bog sphagna competitive against the rich-fen species.

  2. CO{sub 2} and CH{sub 4} fluxes and carbon balance in the atmospheric interaction of boreal peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Alm, J.

    1997-12-31

    Release of CO{sub 2} from peat was studied using IR analyzer in a range of boreal peatlands under varying nutrient status and moisture conditions. Root associated CO{sub 2} efflux was separated from the total release by experiments both in the field and in a greenhouse. Emissions of CO{sub 2} and CH{sub 4} (the latter by gas chromatography) were measured during the snow-covered period and their contribution to the annual fluxes of these gases was inspected. Ecosystem exchange of CO{sub 2} under varying irradiation, temperature and moisture conditions was measured at different microsites at two peatland sites with different nutrient ecology. One site represented minerotrophic conditions during a wet growing season and the other site ombrotrophic conditions during an exceptionally dry growing season. Annual carbon balances were compiled for the two sites, and the role of the microsites in the annual carbon balance and CH{sub 4} release was studied. The Holocene history of CO{sub 2} sequestration and CH{sub 4} emission dynamics in a raised mire were simulated using lateral and vertical growth rates derived from radiocarbon ages of peat samples from mire bottom and vertical cores. The model was formulated for a geographic information system (GIS). Artificial or natural lowering of water table increased CO{sub 2} release from peat. A drought lasting from late May to July caused a 90 g C m{sup 2} net loss in the annual C balance of a natural ombrotrophic bog. In drained forested sites the increase in peat CO{sub 2} release could be even 100 %, but the development of the tree layer at least partially compensated for these losses. Wet conditions induced a net accumulation of 67 g C m{sup -2}a{sup -1} in the minerotrophic fen site, while the long term average accumulation rate is estimated to be only 15 g C m{sup -2}a{sup -1} for Finnish fens. Carbon balance in boreal peatlands is thus extremely sensitive to year-to-year climatic variations. Root activity of vascular plants

  3. CO{sub 2} and CH{sub 4} fluxes and carbon balance in the atmospheric interaction of boreal peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Alm, J

    1998-12-31

    Release of CO{sub 2} from peat was studied using IR analyzer in a range of boreal peatlands under varying nutrient status and moisture conditions. Root associated CO{sub 2} efflux was separated from the total release by experiments both in the field and in a greenhouse. Emissions of CO{sub 2} and CH{sub 4} (the latter by gas chromatography) were measured during the snow-covered period and their contribution to the annual fluxes of these gases was inspected. Ecosystem exchange of CO{sub 2} under varying irradiation, temperature and moisture conditions was measured at different microsites at two peatland sites with different nutrient ecology. One site represented minerotrophic conditions during a wet growing season and the other site ombrotrophic conditions during an exceptionally dry growing season. Annual carbon balances were compiled for the two sites, and the role of the microsites in the annual carbon balance and CH{sub 4} release was studied. The Holocene history of CO{sub 2} sequestration and CH{sub 4} emission dynamics in a raised mire were simulated using lateral and vertical growth rates derived from radiocarbon ages of peat samples from mire bottom and vertical cores. The model was formulated for a geographic information system (GIS). Artificial or natural lowering of water table increased CO{sub 2} release from peat. A drought lasting from late May to July caused a 90 g C m{sup 2} net loss in the annual C balance of a natural ombrotrophic bog. In drained forested sites the increase in peat CO{sub 2} release could be even 100 %, but the development of the tree layer at least partially compensated for these losses. Wet conditions induced a net accumulation of 67 g C m{sup -2}a{sup -1} in the minerotrophic fen site, while the long term average accumulation rate is estimated to be only 15 g C m{sup -2}a{sup -1} for Finnish fens. Carbon balance in boreal peatlands is thus extremely sensitive to year-to-year climatic variations. Root activity of vascular plants

  4. Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from 210Pb and 137Cs dating

    International Nuclear Information System (INIS)

    Bao, K.; Xia, W.; Lu, X.; Wang, G.

    2010-01-01

    Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using 210 Pb and 137 Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported 210 Pb and 137 Cs decreased with the depth in both of the two sample cores. The 210 Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the 137 Cs time marker. Recent atmospheric 210 Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m -2 y -1 , which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m -2 y -1 with a range of Pb concentration of 14-262 μg g -1 . The Pb deposition patterns were consistent with increasing industrialization over the last 135-170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection.

  5. The peatland map of Europe

    Czech Academy of Sciences Publication Activity Database

    Tannenberger, F.; Tagetmeyer, C.; Busse, S.; Barthelmes, A.; Shumka, S.; Moles Mariné, A.; Jenderedjian, K.; Steiner, G. M.; Essl, F.; Etzold, J.; Mendes, C.; Kozulin, A.; Frankard, P.; Milanović, Ð.; Ganeva, A.; Apostolova, I.; Alegro, A.; Delipetrou, P.; Navrátilová, Jana; Risager, M.; Leivits, A.; Fosaa, A. M.; Tuominen, S.; Muller, F.; Bakuradze, T.; Sommer, M.; Christanis, K.; Szurdoki, E.; Oskarsson, H.; Brink, S. H.; Cannolly, J.; Bragazza, L.; Martinelli, G.; Aleksāns, O.; Priede, A.; Sungaila, D.; Melovski, L.; Belous, T.; Saveljić, D.; de Vries, F.; Moen, A.; Demberk, W.; Mateus, J.; Hanganu, J.; Sirin, A.; Markina, A.; Napreenko, M.; Lazarević, P.; Šefferová Stanová, V.; Skoberne, P.; Heras Peréz, P.; Pontevedra-Pombal, X.; Lonnstad, J.; Küchler, M.; Wüst-Galley, C.; Kirca, S.; Mykytiuk, O.; Lindsay, R.; Joosten, H.

    2017-01-01

    Roč. 19, nov 2017 (2017), č. článku 22. ISSN 1819-754X Institutional support: RVO:67985939 Keywords : peatland * distribution * map Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 1.129, year: 2016

  6. Evapotranspiration from two peatland watersheds

    Science.gov (United States)

    Roger R. Bay

    1968-01-01

    Measurements of precipitation, runoff, and bog water table levels have provided data for the calculation of evapotranspiration from two forested peatland watersheds near Grand Rapids, Minnesota (ca. 47? 32'N, 93? 28'W). Continuous hydrologie records were collected on one experimental bog for 6 years (1961-1966) and on the other for the past 2 years (1965-1966...

  7. Direct and indirect effects of ammonia, ammonium and nitrate on phosphatase activity and carbon fluxes from decomposing litter in peatland

    International Nuclear Information System (INIS)

    Johnson, David; Moore, Lucy; Green, Samuel; Leith, Ian D.; Sheppard, Lucy J.

    2010-01-01

    Here we investigate the response of soils and litter to 5 years of experimental additions of ammonium (NH 4 ), nitrate (NO 3 ), and ammonia (NH 3 ) to an ombrotrophic peatland. We test the importance of direct (via soil) and indirect (via litter) effects on phosphatase activity and efflux of CO 2 . We also determined how species representing different functional types responded to the nitrogen treatments. Our results demonstrate that additions of NO 3 , NH 4 and NH 3 all stimulated phosphatase activity but the effects were dependent on species of litter and mechanism (direct or indirect). Deposition of NH 3 had no effect on efflux of CO 2 from Calluna vulgaris litter, despite it showing signs of stress in the field, whereas both NO 3 and NH 4 reduced CO 2 fluxes. Our results show that the collective impacts on peatlands of the three principal forms of nitrogen in atmospheric deposition are a result of differential effects and mechanisms on individual components. - We found that nitrogen deposition affects microbial activity associated with litter through both indirect and direct mechanisms, but these effects were dependent on the chemical form of inorganic nitrogen compounds.

  8. Molybdenum-based diazotrophy in a Sphagnum peatland in northern Minnesota.

    Science.gov (United States)

    Warren, Melissa J; Lin, Xueju; Gaby, John C; Kretz, Cecilia B; Kolton, Max; Morton, Peter L; Pett-Ridge, Jennifer; Weston, David J; Schadt, Christopher W; Kostka, Joel E; Glass, Jennifer B

    2017-06-30

    Microbial N 2 fixation (diazotrophy) represents an important nitrogen source to oligotrophic peatland ecosystems, which are important sinks for atmospheric CO 2 and susceptible to changing climate. The objectives of this study were: (i) to determine the active microbial group and type of nitrogenase mediating diazotrophy in a ombrotrophic Sphagnum -dominated peat bog (the S1 peat bog, Marcell Experimental Forest, Minnesota, USA); and (ii) to determine the effect of environmental parameters (light, O 2 , CO 2 , CH 4 ) on potential rates of diazotrophy measured by acetylene (C 2 H 2 ) reduction and 15 N 2 incorporation. Molecular analysis of metabolically active microbial communities suggested that diazotrophy in surface peat was primarily mediated by Alphaproteobacteria ( Bradyrhizobiaceae and Beijerinckiaceae ). Despite higher dissolved vanadium (V; 11 nM) than molybdenum (Mo; 3 nM) in surface peat, a combination of metagenomic, amplicon sequencing and activity measurements indicated that Mo-containing nitrogenases dominate over the V-containing form. Acetylene reduction was only detected in surface peat exposed to light, with the highest rates observed in peat collected from hollows with the highest water content. Incorporation of 15 N 2 was suppressed 90% by O 2 and 55% by C 2 H 2 , and was unaffected by CH 4 and CO 2 amendments. These results suggest that peatland diazotrophy is mediated by a combination of C 2 H 2 -sensitive and C 2 H 2 -insensitive microbes that are more active at low O 2 and show similar activity at high and low CH 4 Importance Previous studies indicate that diazotrophy provides an important nitrogen source and is linked to methanotrophy in Sphagnum -dominated peatlands. However, the environmental controls and enzymatic pathways of peatland diazotrophy, as well as the metabolically active microbial populations that catalyze this process remain in question. Our findings indicate that oxygen levels and photosynthetic activity override low

  9. Methane flux from boreal peatlands

    International Nuclear Information System (INIS)

    Crill, P.; Bartlett, K.; Roulet, N.

    1992-01-01

    The peatlands in the boreal zone (roughly 45 deg - 60 degN) store a significant reservoir of carbon, much of which is potentially available for exchange with the atmosphere. The anaerobic conditions that cause these soils to accumulate carbon also makes wet, boreal peatlands significant sources of methane to the global troposphere. It is estimated that boreal wetlands contribute approximately 19.5 Tg methane per year. The data available on the magnitude of boreal methane emissions have rapidly accumulated in the past twenty years. This paper offers a short review of the flux measured (with range roughly 1 - 2000 mg methane/m2d), considers environmental controls of the flux and briefly discusses how climate change might affect future fluxes

  10. Peatland-GHG emissions in Europe

    Science.gov (United States)

    Droesler, Matthias

    2013-04-01

    Managed peatlands are hot spots for CO2, CH4 and N2O emissions. GHG which have been not fully integrated in past European climate projects. Peatlands contribute to European GHG emissions 10 times more per unit area than other terrestrial ecosystems. Peatland management and exploration by drainage, agricultural use and peat extraction turned pristine peatland GHG sinks into sources. Emissions can reach more than 40 t CO2equiv. ha-1 a-1 in intensively managed peatlands. On the other hand, the restoration of degraded peatlands does normally reduce these emissions significantly towards climate neutral levels, once the restoration work is done wisely. But in some cases the net climate effect do not decrease significantly depending on hydrological regimes, fertilization status of the peatlands, climate and vegetation type. In many European countries with significant peatland cover nationally funded projects were set up to investigate peatland GHG fluxes and their drivers. These scattered data and knowledge are currently being brought together under the coverage of the GHG-Europe project (Grant agreement no.: 244122) within a new synthesis to develop the relevant EF, identify the drivers and develop upscaling options for GHG-emissions. The talk will: (1) show a first cut of new Emission Factors for peatlands in Europe and compare these with IPCC-default values. (2) discuss the developed sensible response functions for GHG-fluxes against natural and anthropogenic drivers such as land use intensity, land management with drainage and climate variability. (3) show case studies from Germany show the applicability of response functions for upscaling of GHG-balances. (4) An outlook is given to the future European peatland GHG-Balance.

  11. Soils of peatlands: histosols and gelisols

    Science.gov (United States)

    Randy Kolka; Scott D. Bridgham; Chien-Lu. Ping

    2016-01-01

    Peatlands are a subset of wetlands that have accumulated significant amounts of soil organic matter. Soils of peatlands are colloquially known as peat, with mucks referring to peats that are decomposed to the point that the original plant remains are altered beyond recognition (Chapter 6, SSSA 2008). Generally, soils with a surface organic layer >40 cm thick...

  12. Towards sustainable management of Indonesian tropical peatlands

    NARCIS (Netherlands)

    Uda, Saritha Kittie; Hein, Lars; Sumarga, Elham

    2017-01-01

    Large areas of Indonesian peatlands have been converted for agricultural and plantation forest purposes. This requires draining with associated CO2 emissions and fire risks. In order to identify alternative management regimes for peatlands, it is important to understand the

  13. Record of Anthropocene pollution sources of lead in disturbed peatlands from Southern Poland

    Science.gov (United States)

    Fiałkiewicz-Kozieł, Barbara; De Vleeschouwer, François; Mattielli, Nadine; Fagel, Nathalie; Palowski, Bernard; Pazdur, Anna; Smieja-Król, Beata

    2018-04-01

    The importance of human impacts on Earth has led to the proposal of a new geologic epoch called the Anthropocene. However markers, recognizable in all records, are required to define this period. Here we combine elemental geochemistry with stable lead (Pb) isotopes and mineralogical analyses to decipher the sources of lead in two exploited ombrotrophic peat bogs (Puścizna Mała and Puścizna Krauszowska) from Southern Poland. The most disturbed parts of the cores, distinguished using bulk density and age-depth models (22-45 cm in PM and 22-46 cm in PK), were excluded from the interpretation. The two studied cores record ca. 2000 years of variations in lead accumulation rates and isotopic compositions. In the lowest part of the cores (2nd to 4th century AD for Puścizna Mała and 2nd century BC to 2nd century AD for Puścizna Krauszowska), the 206Pb/207Pb ratios (1.188) are consistent with natural supplies from the erosion of the nearby Tatra Mountains. From the 9th to the 19th century AD, 206Pb/207Pb ratios (1.176-1.179) are similar to the signatures obtained from Polish galena ores. The highest Pb accumulation rates are found around 1950 AD and reflect the primary influence of bituminous coal combustion together with the secondary influence of leaded gasoline. This result agrees with the occurrence and abundance of spheroidal aluminosilicates, an unambiguous marker of human industrial activity and coal burning as well as with the acceleration of Zn, Cd and Fe accumulation rate. Our results provide evidence that similar geochemical patterns exist in both analysed cores despite differences in the history of peatland exploitation. Therefore, given that extra care is taken to identify the disturbed peat layers, exploited peatlands can be used to record past changes in lead isotopic signature during the Anthropocene.

  14. Effects of experimental nitrogen deposition on peatland carbon pools and fluxes: a modeling analysis

    Science.gov (United States)

    Wu, Y.; Blodau, C.; Moore, T. R.; Bubier, J. L.; Juutinen, S.; Larmola, T.

    2014-07-01

    Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to analyze impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE) were evaluated against 8 years of observations and extrapolated for 80 years to identify potential effects of N fertilization and factors influencing model behavior. The model successfully simulated moss decline and raised GEP, ER and NEE on fertilized plots. GEP was systematically overestimated in the model compared to the field data due to high tolerance of Sphagnum to N deposition in the model. Model performance regarding the 8 year response of GEP and NEE to N was improved by introducing an N content threshold shifting the response of photosynthesis capacity to N content in shrubs and graminoids from positive to negative at high N contents. Such changes also eliminated the competitive advantages of vascular species and led to resilience of mosses in the long-term. Regardless of the large changes of C fluxes over the short-term, the simulated GEP, ER and NEE after 80 years depended on whether a graminoid- or shrub-dominated system evolved. When the peatland remained shrub-Sphagnum dominated, it shifted to a C source after only 10 years of fertilization at 6.4 g N m-2 yr-1, whereas this was not the case when it became graminoid-dominated. The modeling results thus highlight the importance of ecosystem adaptation and reaction of plant functional types to N deposition, when predicting the future C balance of N-polluted cool temperate bogs.

  15. Effects of experimental nitrogen deposition on peatland carbon pools and fluxes: a modelling analysis

    Science.gov (United States)

    Wu, Y.; Blodau, C.; Moore, T. R.; Bubier, J.; Juutinen, S.; Larmola, T.

    2015-01-01

    Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to explore impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE) were evaluated against 8 years of observations and extrapolated for 80 years to identify potential effects of N fertilization and factors influencing model behaviour. The model successfully simulated moss decline and raised GEP, ER and NEE on fertilized plots. GEP was systematically overestimated in the model compared to the field data due to factors that can be related to differences in vegetation distribution (e.g. shrubs vs. graminoid vegetation) and to high tolerance of vascular plants to N deposition in the model. Model performance regarding the 8-year response of GEP and NEE to N input was improved by introducing an N content threshold shifting the response of photosynthetic capacity (GEPmax) to N content in shrubs and graminoids from positive to negative at high N contents. Such changes also eliminated the competitive advantages of vascular species and led to resilience of mosses in the long-term. Regardless of the large changes of C fluxes over the short-term, the simulated GEP, ER and NEE after 80 years depended on whether a graminoid- or shrub-dominated system evolved. When the peatland remained shrub-Sphagnum-dominated, it shifted to a C source after only 10 years of fertilization at 6.4 g N m-2 yr-1, whereas this was not the case when it became graminoid-dominated. The modelling results thus highlight the importance of ecosystem adaptation and reaction of plant functional types to N deposition, when predicting the future C balance of N-polluted cool temperate bogs.

  16. Environmental controls of temporal and spatial variability in CO2 and CH4 fluxes in a neotropical peatland.

    Science.gov (United States)

    Wright, Emma L; Black, Colin R; Turner, Benjamin L; Sjögersten, Sofie

    2013-12-01

    Tropical peatlands play an important role in the global storage and cycling of carbon (C) but information on carbon dioxide (CO2) and methane (CH4) fluxes from these systems is sparse, particularly in the Neotropics. We quantified short and long-term temporal and small scale spatial variation in CO2 and CH4 fluxes from three contrasting vegetation communities in a domed ombrotrophic peatland in Panama. There was significant variation in CO2 fluxes among vegetation communities in the order Campnosperma panamensis > Raphia taedigera > Cyperus. There was no consistent variation among sites and no discernible seasonal pattern of CH4 flux despite the considerable range of values recorded (e.g. -1.0 to 12.6 mg m(-2) h(-1) in 2007). CO2 fluxes varied seasonally in 2007, being greatest in drier periods (300-400 mg m(-2) h(-1)) and lowest during the wet period (60-132 mg m(-2) h(-1)) while very high emissions were found during the 2009 wet period, suggesting that peak CO2 fluxes may occur following both low and high rainfall. In contrast, only weak relationships between CH4 flux and rainfall (positive at the C. panamensis site) and solar radiation (negative at the C. panamensis and Cyperus sites) was found. CO2 fluxes showed a diurnal pattern across sites and at the Cyperus sp. site CO2 and CH4 fluxes were positively correlated. The amount of dissolved carbon and nutrients were strong predictors of small scale within-site variability in gas release but the effect was site-specific. We conclude that (i) temporal variability in CO2 was greater than variation among vegetation communities; (ii) rainfall may be a good predictor of CO2 emissions from tropical peatlands but temporal variation in CH4 does not follow seasonal rainfall patterns; and (iii) diurnal variation in CO2 fluxes across different vegetation communities can be described by a Fourier model. © 2013 John Wiley & Sons Ltd.

  17. Redox processes in the rhizosphere of restored peatlands - The impact of vascular plant species on electrochemical properties of dissolved organic matter

    Science.gov (United States)

    Agethen, Svenja; Wolff, Franziska; Knorr, Klaus-Holger

    2016-04-01

    Restoration of cut over peatlands in Central Europe is challenging in a landscape overused for agriculture. Excess nutrient availability by excess fertilization triggers uncharacteristic vegetation that is one key driver for carbon cycling. Those nutrient rich systems are often dominated by graminoids, and were often found to emit substantial amounts of methane. Plants grown under nutrient rich conditions provide more labile carbon in rhizodeposition and litter that fuels methanogenesis. Such species often have aerenchyma that facilitates direct CH4 emissions to the atmosphere and therefore impair the climate cooling function of bogs. On the other hand, aerenchymatic tissue supplies oxygen to the rhizosphere, which may reduce methanogenesis or stimulate methane oxidation, as methanogenesis is a strictly anaerobic process. Which of the effects prevail is often unclear. Therefore, the aim of this study was to test the impact of different vegetation on rhizospheric redox conditions and methanogenesis, including aerenchymatic vascular plants that are dominant in restored cut over peatlands. As ombrotrophic peat is poor in inorganic electron acceptors (EAs) to suppress methanogenesis, we analyzed the electron acceptor (EACs) and electron donor capacities (EDCs) of dissolved organic matter (DOM) in the rhizosphere to understand the impact of vegetation on anaerobic organic matter degradation. We planted Juncus effusus, Eriophorum vaginatum, Eriophorum angustifolium, Sphagnum (mixture of S. magellanicum, S. papillosum, S. sec. acutifolia, 1/3 each) plus non-vegetated controls; six replicates per batch; in containers with untreated homogenized peat. The plants grow under constant conditions (20° C, 12h diurnal light cycles and 80% RH). Anoxic conditions were achieved by keeping the water table at +10 cm. For monitoring, the rhizosphere is equipped with suction and gas samplers. We measure dissolved CO2 and CH4 concentrations, inorganic EAs (NO3-, Fe(III), and SO42-) and

  18. Lead-210 and heavy metal contents in dated ombrotrophic peat hummocks from Finland

    International Nuclear Information System (INIS)

    El-Daoushy, F.; Tolonen, K.

    1984-01-01

    Two Sphagnum fuscum hummock cores, core 1, Kaerpaensuo bog and core F9, Kunonniemensuo bog. from Finland were used in this study. The peats are ombrotrophic and were dated using the moss-increment method. The mosses in both cores were carefully examined for their botanical composition, degree of humification, ash percentage and bulk density. The total accumulated dry peat-matter in the Kunonniemensuo core was almost double that in the Kaerpaensuo core. The total 210 Pb and the supported 210 Pb were measured by isotope dilution and the radon emanation technique. Materials in the same peat samples were analysed for their 210 Pb content at the Institute of Physics, Uppsala, Sweden and the Technical Research Centre of Finland, Espoo, Finland. The annual content of unsupported 210 Pb in the dated peat-layers shows that peat materials are effective traps which could yield information on atmospheric-fluxes both chronologically and regionally. Lead, copper, zinc, iron and manganese were also measured by flame atomic absorption spectrometry (AAS). The total accumulated amounts over the past 150 y of the heavy metals investigated are almost identical for both cores apart from manganese which is considerably higher in the Kunonniemensuo core. However, the metal profiles studied exhibit discontinuity zones more pronounced in the Kunonniemensuo core. The 210 Pb data indicate that growth rate and bulk density variations in ombrotrophic peat bogs affects the accumulation of 210 Pb and similar trace metals. (orig.)

  19. How can we conserve intact tropical peatlands?

    Science.gov (United States)

    Lawson, Ian; Roucoux, Katherine

    2017-04-01

    The scientific community has, for more than three decades, been expressing increasing alarm about the fate of peatlands in parts of Indonesia and Malaysia, where extensive land-use conversion and drainage for rice and oil palm have greatly compromised peatland hydrology, ecology, biological richness, and carbon storage. The discourse in the literature on these peatlands is now moving on from attempts to preserve the last remaining fragments of peat-swamp forest, towards discussion of how best to restore damaged ecosystems, and whether it is possible to manage plantations more 'sustainably'. It is becoming increasingly clear, however, that peatlands occur quite widely in other parts of the lowland tropics, including parts of Amazonia and the Congo Basin, and many of these peatlands can reasonably be described as 'intact': although few if any parts of the tropics are totally unaffected by human actions, the hydrology and functional ecology of these systems appear to be close to a 'natural' state. The question then arises as to what should be done with the knowledge of their existence. Here we analyse the arguments in favour of protecting intact peatlands, and the potential conflicts with other priorities such as economic development and social justice. We evaluate alternative mechanisms for protecting intact peatlands, focusing on the particular issues raised by peatlands as opposed to other kinds of tropical ecosystem. We identify ways in which natural science agendas can help to inform these arguments, using our own contributions in palaeoecology and carbon mapping as examples. Finally, we argue for a radical reconsideration of research agendas in tropical peatlands, highlighting the potential contribution of methodologies borrowed from the social sciences and humanities.

  20. Methanotrophy induces nitrogen fixation during peatland development

    Science.gov (United States)

    Larmola, Tuula; Leppänen, Sanna M.; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2014-01-01

    Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation. PMID:24379382

  1. Restoration techniques for Sphagnum-dominated peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Ferland, C.; Rochefort, L. [Laval University, Sainte-Foy, PQ (Canada). Department of Phytology

    1997-07-01

    After peat harvesting, peat mosses do not usually recolonize the abandoned site. The purpose of this study is to develop techniques for restoring peatlands. Sphagnum diaspores from natural peatlands were introduced to exploited peatlands. The influence of microrelief, of planting companion species with the Sphagnum, and of light phosphorus fertilization on establishment of a peat moss carpet are examined. The results show that Sphagnum diaspores can be reintroduced on bare peat surfaces. The restoration method is combined with techniques to improve substrata moisture conditions, such as creation of surface roughness and the use of companion plant species. 32 refs., 6 figs., 3 tabs.

  2. Effects of winter temperature and summer drought on net ecosystem exchange of CO2 in a temperate peatland

    Science.gov (United States)

    Helfter, Carole; Campbell, Claire; Dinsmore, Kerry; Drewer, Julia; Coyle, Mhairi; Anderson, Margaret; Skiba, Ute; Nemitz, Eiko; Billett, Michael; Sutton, Mark

    2014-05-01

    Northern peatlands are one of the most important global sinks of atmospheric carbon dioxide (CO2); their ability to sequester C is a natural feedback mechanism controlled by climatic variables such as precipitation, temperature, length of growing season and period of snow cover. In the UK it has been predicted that peatlands could become a net source of carbon in response to climate change with climate models predicting a rise in global temperature of ca. 3oC between 1961-1990 and 2100. Land-atmosphere exchange of CO2in peatlands exhibits marked seasonal and inter-annual variations, which have significant short- and long-term effects on carbon sink strength. Net ecosystem exchange (NEE) of CO2 has been measured continuously by eddy-covariance (EC) at Auchencorth Moss (55° 47'32 N, 3° 14'35 W, 267 m a.s.l.), a temperate peatland in central Scotland, since 2002. Auchencorth Moss is a low-lying, ombrotrophic peatland situated ca. 20 km south-west of Edinburgh. Peat depth ranges from 5 m and the site has a mean annual precipitation of 1155 mm. The vegetation present within the flux measurement footprint comprises mixed grass species, heather and substantial areas of moss species (Sphagnum spp. and Polytrichum spp.). The EC system consists of a LiCOR 7000 closed-path infrared gas analyser for the simultaneous measurement of CO2 and water vapour and of a Gill Windmaster Pro ultrasonic anemometer. Over the 10 year period, the site was a consistent yet variable sink of CO2 ranging from -34.1 to -135.9 g CO2-C m-2 yr-1 (mean of -69.1 ± 33.6 g CO2-C m-2 yr-1). Inter-annual variability in NEE was positively correlated to the length of the growing seasons and mean winter air temperature explained 93% of the variability in summertime sink strength, indicating a phenological memory-effect. Plant development and productivity were stunted by colder winters causing a net reduction in the annual carbon sink strength of this peatland where autotrophic processes are thought to be

  3. Mineral content in Sphagnum mosses from ombrotrophic bogs of southwestern Poland: pattern in species and elements

    Directory of Open Access Journals (Sweden)

    Bronisław Wojtuń

    2014-01-01

    Full Text Available Major elements (N, P, K, Ca, Mg, Na, Fe were analyzed in 11 Sphagnum species from ombrotrophic bogs in southwestern Poland. The material included species from wet to dry microsites. The highest levels of elements were recorded for S. lindbergii, whereas S. balticum and S. cuspidatum were poorest in elements. The microhabitat gradient from hummock to hollow species is clearly reflected by decreasing concentrations of Ca and Mg, and increasing concentration of Na. Phosphorus, K and N were much more enriched into moss tissues than the remaining elements. These three nutrients were also accumulated in the upper green parts of mosses, while the concentrations of Na and Fe were higher in the bottom brown parts. There were no differences in Ca and Mg between the green and brown segments.

  4. Effect of fire on phosphorus forms in Sphagnum moss and peat soils of ombrotrophic bogs.

    Science.gov (United States)

    Wang, Guoping; Yu, Xiaofei; Bao, Kunshan; Xing, Wei; Gao, Chuanyu; Lin, Qianxin; Lu, Xianguo

    2015-01-01

    The effect of burning Sphagnum moss and peat on phosphorus forms was studied with controlled combustion in the laboratory. Two fire treatments, a light fire (250 °C) and a severe fire (600 °C), were performed in a muffle furnace with 1-h residence time to simulate the effects of different forest fire conditions. The results showed that fire burning Sphagnum moss and peat soils resulted in losses of organic phosphorus (Po), while inorganic phosphorus (Pi) concentrations increased. Burning significantly changed detailed phosphorus composition and availability, with severe fires destroying over 90% of organic phosphorus and increasing the availability of inorganic P by more than twofold. Our study suggest that, while decomposition processes in ombrotrophic bogs occur very slowly, rapid changes in the form and availability of phosphorus in vegetation and litter may occur as the result of forest fires on peat soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Changing atmospheric fallout of magnetic particles recorded in recent ombrotrophic peat sections.

    Science.gov (United States)

    Oldfield, F; Thompson, R; Barber, K E

    1978-02-10

    Magnetic measurements of ombrotrophic peat allow a reconstruction of changes in the past fallout of magnetic particles through the atmosphere. In recent peat profiles from three sites in Britain and Northern Ireland, a marked increase in saturated isothermal remanent magnetization of the peat is recorded in levels which can be shown to postdate the onset of the Industrial Revolution. Furthermore the spatial variation in contemporary isothermal remanent magnetization values is consistent with a recent industrial and urban origin for the bulk of the magnetic minerals present. Pre-Industrial Revolution values are between two and three orders of magnitude lower, suggesting that the natural cosmic and terrestrial sources previously cited for such material have been dominated in recent times by the products of human activity. Magnetic measurements provide a simple, rapid, and nondestructive method of monitoring and differentiating various types of particulate atmospheric fallout for both recent and preindustrial times.

  6. Trace gas fluxes from northern peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Moore, T [McGill Univ., Montreal (Canada). Geography Dept.

    1997-12-31

    Peatlands cover large areas in northern environments: 1.1, 0.1 and 1.7 x 10{sup 4} km{sup 2} in Canada, Finland and the former Soviet Union, respectively. Interest has been generated into the role these extensive areas of peatlands play in controlling the chemistry of the atmosphere. In particular, it has become established that peatlands can be a source of methane (CH{sub 4}) and nitrous oxide (N{sub 2}O), and a sink of carbon dioxide (CO{sub 2}), the latter through the rates of plant production exceeding the rate of decomposition of plant material and peat. In this presentation the recent advances in trace gas flux measurements in northern peatlands are presented. (16 refs.)

  7. Trace gas fluxes from northern peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Moore, T. [McGill Univ., Montreal (Canada). Geography Dept.

    1996-12-31

    Peatlands cover large areas in northern environments: 1.1, 0.1 and 1.7 x 10{sup 4} km{sup 2} in Canada, Finland and the former Soviet Union, respectively. Interest has been generated into the role these extensive areas of peatlands play in controlling the chemistry of the atmosphere. In particular, it has become established that peatlands can be a source of methane (CH{sub 4}) and nitrous oxide (N{sub 2}O), and a sink of carbon dioxide (CO{sub 2}), the latter through the rates of plant production exceeding the rate of decomposition of plant material and peat. In this presentation the recent advances in trace gas flux measurements in northern peatlands are presented. (16 refs.)

  8. Northern peatlands in global climatic change

    Energy Technology Data Exchange (ETDEWEB)

    Laiho, R.; Laine, J.; Vasander, H. [eds.] [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    Northern peatlands are important in regulating the global climate. While sequestering carbon dioxide, these peatlands release ca. 24-39 Tg methane annually to the atmosphere. This is 5-20 % of the annual anthropogenic methane emissions to the atmosphere. The greenhouse gas balance of peatlands may change as a consequence of water level draw-down after land-use change, or if summers become warmer and drier, as has been predicted for high latitudes after climatic warming. Subsequent emissions of methane would decrease, whereas emissions of carbon dioxide and nitrous oxide would increase. Within the Finnish Research Programme on Climate Change (SILMU), the research project `Carbon Balance of Peatlands and Climate Change` (SUOSILMU) has been under progress since 1990. It is a co-operative research project, with research groups from the Universities of Helsinki and Joensuu, the Finnish Forest Research Institute, the National Public Health Institute and the Finnish Environment Agency. The research consortium of this project organised a workshop entitled `Northern Peatlands in Global Climatic Change - Hyytiaelae Revisited` October 8-12, 1995. The main objective of the workshop was to review the state of the art of the carbon cycling research in natural and managed peatlands. The role of peatlands in the greenhouse effect, their response and feedback to the predicted climate change, and the consequences of land-use changes were assessed, and the future research needs were evaluated. The latest information on the role of peatlands in the atmospheric change was given in 50 posters and 4 key lectures. Results of SUOSILMU projects were demonstrated during a 1-day field excursion to one of the intensive study sites, Lakkasuo near Hyytiaelae

  9. Simulating groundwater-peatland interactions in depression and slope peatlands in southern Quebec (Canada)

    Science.gov (United States)

    Larocque, M.; Quillet, A.; Paniconi, C.

    2013-12-01

    It is crucial to understand hydrogeological interactions between aquifers and peatlands in order to grasp the influence of aquifers in peatland water budgets, to understand the role of groundwater in the evolution or organic matter deposition, and to quantify how a peatland can sustain groundwater levels in a superficial aquifer. These questions have rarely been addressed in literature and there is currently no understanding of which process dominates aquifer-peatland exchanges in different geomorphological settings. The main purpose of the study was to use groundwater flow modeling to answer these questions in two contrasted geological contexts of southern Quebec (Canada). During a three-year study, six peatlands have been instrumented in the Becancour (Centre-du-Quebec) and Amos (Abitibi-Temiscamingue) regions of southern Quebec (Canada). At each site, either one or two transects of six piezometer nests (at 1.20 m depth in the organic deposits and in the mineral deposits below the peat) have been installed, for a total of twelve aquifer-peatland transects of approximately 500 m. The stratigraphy and geometry of the peatland-aquifer system, as well as the hydrodynamic properties of the organic and mineral deposits have been measured at all sites. Groundwater levels have been recorded from autumn 2010 to summer 2012. The Becancour peatlands have developed in depressions while the Amos peatlands have developed through the paludification of esker slopes. The maximum peat thickness measured in the Bécancour peatlands is 6.4 m while it is 4.5 m in the Amos region. In both regions, peatlands are fringed by sandy deposits that extend at least partly under the organic deposits. The thickness of these underlying deposits is not well defined, but available data suggests a metric scale thickness in areas close to the adjacent superficial aquifer. Field data is used to create 2D numerical models in Modflow to simulate flow between the shallow groundwater and the peatland on

  10. Gully hotspot contribution to landscape methane (CH4) and carbon dioxide (CO2) fluxes in a northern peatland

    International Nuclear Information System (INIS)

    McNamara, N.P.; Plant, T.; Oakley, S.; Ward, S.; Wood, C.; Ostle, N.

    2008-01-01

    Peatlands are long term carbon catchments that sink atmospheric carbon dioxide (CO 2 ) and source methane (CH 4 ). In the uplands of the United Kingdom ombrotrophic blanket peatlands commonly exist within Calluna vulgaris (L.) dominated moorland ecosystems. These landscapes contain a range of topographical features that influence local hydrology, climate and plant community composition. In this study we examined the variation in ecosystem CO 2 respiration and net CH 4 fluxes from typical plant-soil systems in dendritic drainage gullies and adjacent blanket peat during the growing season. Typically, Eriophorum spp., Sphagnum spp. and mixed grasses occupied gullies while C. vulgaris dominated in adjacent blanket peat. Gross CO 2 respiration was highest in the areas of Eriophorum spp. (650 ± 140 mg CO 2 m -2 h -1 ) compared to those with Sphagnum spp. (338 ± 49 mg CO 2 m -2 h -1 ), mixed grasses (342 ± 91 mg CO 2 m -2 h -1 ) and C. vulgaris (174 ± 63 mg CO 2 m -2 h -1 ). Measurements of the net CH 4 flux showed higher fluxes from the Eriophorum spp (2.2 ± 0.6 mg CH 4 m -2 h -1 ) locations compared to the Sphagnum spp. (0.6 ± 0.4 mg CH 4 m -2 h -1 ), mixed grasses (0.1 ±0.1 mg CH 4 m -2 h -1 ) and a negligible flux detected from C. vulgaris (0.0 ± 0.0 mg CH 4 m -2 h -1 ) locations. A GIS approach was applied to calculate the contribution of gullies to landscape scale greenhouse gas fluxes. Findings from the Moor House National Nature Reserve in the UK showed that although gullies occupied only 9.3% of the total land surface, gullies accounted for 95.8% and 21.6% of the peatland net CH 4 and CO 2 respiratory fluxes, respectively. The implication of these findings is that the relative contribution of characteristic gully systems need to be considered in estimates of landscape scale peatland greenhouse gas fluxes

  11. Mitigating wildfire carbon loss in managed northern peatlands through restoration

    Science.gov (United States)

    Granath, Gustaf; Moore, Paul A.; Lukenbach, Maxwell C.; Waddington, James M.

    2016-06-01

    Northern peatlands can emit large amounts of carbon and harmful smoke pollution during a wildfire. Of particular concern are drained and mined peatlands, where management practices destabilize an array of ecohydrological feedbacks, moss traits and peat properties that moderate water and carbon losses in natural peatlands. Our results demonstrate that drained and mined peatlands in Canada and northern Europe can experience catastrophic deep burns (>200 t C ha-1 emitted) under current weather conditions. Furthermore, climate change will cause greater water losses in these peatlands and subject even deeper peat layers to wildfire combustion. However, the rewetting of drained peatlands and the restoration of mined peatlands can effectively lower the risk of these deep burns, especially if a new peat moss layer successfully establishes and raises peat moisture content. We argue that restoration efforts are a necessary measure to mitigate the risk of carbon loss in managed peatlands under climate change.

  12. Energy potential of Finnish peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, K. (Geological Survey of Finland, Kuopio (Finland)); Valpola, S. (Geological Survey of Finland, Kokkola (Finland)), e-mail: kimmo.virtanen@gtk.fi, e-mail: samu.valpola@gtk.fi

    2011-07-01

    One-third of the Finnish land area is covered by mires and peat. GTK has investigated 2.0 million ha of the 9.3 million ha area covered by mires in Finland. According to the EU Commission, the broadly-based Finnish energy economy, with various energy sources, is the best in the EU. As a fuel, peat fulfils the goals of the EU energy policy in Finland well: it is local, its availability is good and the price is stable. The use of peat also enhances national security. At present, peat is used in around one hundred larger applications that co-generate electricity and heat. In Finland, the development of mires has led to several mire complex types and three main types: raised bogs in Southern Finland, aapa mires in Ostrobothnia and Lapland, and palsa mires in Northern Lapland. Peat layers are deepest in southern Finland and partly in the southern Finnish Lake area, the Region of North Karelia and in the area of central Lapland. The mean depth of geological mires is 1.41 m and the thickest drilled peat is 12.3 m. According to peat investigations, the national peat reserve totals 69.3 billion m3 in situ (peatlands larger than 20 hectares). The dry solids of peat are estimated at 6.3 billion tones. Sphagnum peat accounts for 54% and Carex peat for 45% of feasible peat reserves. Peatlands that are technically suitable for the peat industry cover a total area of 1.2 million ha and contain 29.6 billion m3 of peat in situ. Slightly humified peat suitable for horticultural and environmental use totals 5.9 billion m3 in situ. The energy peat reserve is 23.7 billion m3 in situ and its energy content is 12 800 TWh. (orig.)

  13. Distribution of peatlands in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Rieley, J. [Dept. of Life Science, Nottingham (United Kingdom); Page, S.E. [Leicester Univ. (United Kingdom). Dept. of Zoology; Setiadi, B. [Agency for the Assesment and Application of Technology, Jakarta (Indonesia)

    1996-12-31

    Indonesia contains between 160 and 270 000 km{sup 2} of peatland, mostly in the sub-coastal lowlands of Irian Jaya, Kalimantan and Sumatra; depth varies from 0.5 to more than 10 metres. Present day peat started to accumulate in response to very wet climatic conditions after the end of the last glacial period on waterlogged substrates of low nutrient status and oxygen deficiency. Coastal and basin peatlands were preceded by mangrove swamp; Yiigh peat (peat at a slightly higher elevation) was probably initiated in freshwater swamp. Dates of origin range from 800 to almost 5 000 years B.P. for the former and over 9 000 years B.P. for the latter. Lowland tropical peat is relatively homogeneous, consisting of trunks, branches and roots of trees; it is mainly fibric with low mineral content. Peat domes are ombrogenous with a water table close to or above the surface for most of the year. Lowland peat swamps support a zonation of forest types. The marginal, mixed swamp forest is dominated by high canopy trees whilst the interior `pole` forest consists of lower, smaller diameter trees. Indonesian peat swamp forests are an important reservoir of biodiversity; they contain several commercial tree species and provide a range of non-timber forest products. Almost 20 % of the peat swamp forests of Indonesia have been developed for agriculture and settlement. In their natural condition, however, they act as important water catchment and control systems, stabilize the landscape against erosion and maintain water quality for downstream riverine, estuarine and coastal fisheries. (orig.) (19 refs.)

  14. Andromeda polifolia and Oxycoccus microcarpus as pollution indicators for ombrotrophic bogs in the Western Sudety Mountains (SW Poland).

    Science.gov (United States)

    Wojtuń, Bronisław; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Klink, Agnieszka; Kempers, Alexander J

    2013-01-01

    Concentrations of the elements Cd, Cr, Cu, Fe, Li, Mn, N, Ni, Pb and Zn in Andromeda polifolia, Oxycoccus microcarpus and in the peat in which these plants grew were measured in the Western Sudety (Karkonosze and Izerskie Mts., SW Poland). Of both the investigated plant fruit, O. microcarpus harvested from wild populations are commonly used as medicines. Samples from ombrotrophic bogs were investigated within the area influenced by exhausts of the former Black Triangle, one of the most heavily industrialized and polluted areas in Europe. A. polifolia and O. microcarpus growing at the highest elevations contained the highest Cu, Li, Ni, Mn and Zn concentrations and in addition O. microcarpus also contained the highest Cr concentrations. Both the investigated species have wide circumpolar distribution in ombrotrophic mires of the Northern hemisphere. As this type of mires is nourished solely by atmospheric deposition, the increased metal concentrations in A. polifolia and O. microcarpus may be an indication that their habitats receive an atmospheric input of long-range transported pollution. Our investigation proves that both species are able to accumulate elevated metal levels and may be used in the bioindication of the metal status in ombrotrophic mires. Controlling the collection of O. microcarpus fruit for consumption and medicinal purposes is recommended as this species can accumulate increased metal levels. However, further more detailed studies are necessary to verify the inner translocation of metals into fruit.

  15. Environmental controls on δ13C variations of Sphagnum derived n-alkanes in the Dajiuhu peatland, central China

    Science.gov (United States)

    Huang, X.; Xue, J.; Wang, X.; WANG, H.; Meyers, P. A.; Qin, Y.; Gong, L.; Ding, W.

    2012-12-01

    derived lipids can be used as a proxy of surface wetness in peatlands. References Gorham, E., 1991. Northern peatlands: role in the carbon cycle and probable responses to climatic warming. Ecological Applications, 1, 182-195. Kip, N., van Winden, J.F., Pan, Y., et al., 2010. Global prevalence of methane oxidation by symbiotic bacteria in peat-moss ecosystems. Nature Geosciences 3, 617-621. Nichols, JE, Walcott, M, Bradley, R., et al., 2009. Quantitative assessment of precipitation seasonality and summer surface wetness using ombrotrophic sediments from an Arctic Norwegian peatland. Quaternary Research, 2009, 72: 443-451. Raghoebarsing, A.A., Smolders, A.J.P., Schmid, M.C., et al., 2005. Methanotrophic symbionts provide carbon for photosynthesis in peat bogs. Nature 436, 1153-1156.

  16. Direct human impacts on the peatland carbon sink

    Science.gov (United States)

    Jukka Laine; Kari Minkkinen; Carl Trettin

    2009-01-01

    Northern peatlands occupy over 3 million km2 globally and contain the largest carbon (C) pool (typically >100 kg C m-2) among terrestrial ecosystems. Agriculture, forestry, and peat harvesting are the principal human-induced activities that alter the peatland and hence the distribution and flux of carbon. As a prerequisite to those uses, the peatland is usually...

  17. Predicting the release of metals from ombrotrophic peat due to drought-induced acidification

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E.; Smith, E.J.; Lawlor, A.J.; Hughes, S.; Stevens, P.A

    2003-05-01

    Metals stored in peats can be remobilised by sulphuric acid, generated by the drought-induced oxidation of reduced sulphur. - Ombrotrophic peats in northern England and Scotland, close to industrial areas, have substantial contents of potentially toxic metals (Al, Ni, Cu, Zn, Cd and Pb) and of pollutant sulphur, all derived from atmospheric deposition. The peat sulphur, ordinarily in reduced form, may be converted to sulphuric acid under drought conditions, due to the entry of oxygen into the peats. The consequent lowering of soil solution pH is predicted to cause the release of metals held on ligand sites of the peat organic matter. The purpose of the present study was to explore, by simulation modelling, the extent of the metal response. Chemical variables (elemental composition, pH, metal contents) were measured for samples of ombrotrophic peats from three locations. Water extracts of the peats, and samples of local surface water, were also analysed, for pH, dissolved organic carbon (DOC) and metals. Metal release from peats due to acidification was demonstrated experimentally, and could be accounted for reasonably well using a speciation code (WHAM/Model VI). These data, together with information on metal and S deposition, and meteorology, were used to construct a simple description of peat hydrochemistry, based on WHAM/Model VI, that takes into account ion-binding by humic substances (assumed to be the 'active' constituents of the peat with respect to ion-binding). The model was used to simulate steady state situations that approximated the observed soil pH, metal pools and dissolved metal concentrations. Then, drought conditions were imposed, to generate increased concentrations of H{sub 2}SO{sub 4}, in line with those observed during the drought of 1995. The model calculations suggest that the pH will decrease from the initial steady state value of 4.3 to 3.3-3.6 during rewetting periods following droughts, depending upon assumptions about the

  18. Subsidence in tropical peatlands: Estimating CO2 fluxes from peatlands in Southeast Asia

    Science.gov (United States)

    Hoyt, A.; Harvey, C. F.; Seppalainen, S. S.; Chaussard, E.

    2017-12-01

    Tropical peatlands of Southeast Asia are an important global carbon stock. However, they are being rapidly deforested and drained. Peatland drainage facilitates peat decomposition, releases sequestered peat carbon to the atmosphere as CO2, and leads to subsidence of the peat surface. As a result, subsidence measurements can be used to monitor peatland carbon loss over time. Until now, subsidence measurements have been primarily limited to ground-based point measurements using subsidence poles. Here we demonstrate a powerful method to measure peatland subsidence rates across much larger areas than ever before. Using remotely sensed InSAR data, we map subsidence rates across thousands of square kilometers in Southeast Asia and validate our results against ground-based subsidence measurements. The method allows us to monitor subsidence in remote locations, providing unprecedented spatial information, and the first comprehensive survey of land uses such as degraded peatlands, burnt and open areas, shrub lands, and smallholder farmlands. Strong spatial patterns emerged, with the highest subsidence rates occurring at the centers of peat domes, where the peat is thickest and drainage depths are likely to be largest. Peatland subsidence rates were also strongly dependent on current and historical land use, with typical subsidence rates ranging from 2-4 cm/yr. Finally, we scaled up our results to calculate total annual emissions from peat decomposition in degraded peatlands.

  19. Investigations of freezing and cold storage for the analysis of peatland dissolved organic carbon (DOC) and absorbance properties.

    Science.gov (United States)

    Peacock, Mike; Freeman, Chris; Gauci, Vincent; Lebron, Inma; Evans, Chris D

    2015-07-01

    Although measured rates of biological degradation of DOC are typically low under dark conditions, it is assumed that water samples must be analysed soon after collection to provide an accurate measure of DOC concentration and UV-visible absorbance. To examine the impact of storage on DOC quality and quantity, we took water samples from an ombrotrophic peatland, and stored them in the dark at 4 °C for 138-1082 days. A median of 29% of DOC was lost during storage, but losses of absorbance at 254 nm were less. DOC loss followed a first-order exponential decay function, and was dependent on storage time. DOC half-life was calculated as 1253 days. Specific absorbance at 254 nm suggested that samples containing more aromatic DOC were more resistant to degradation, although time functioned as the primary control. Samples from two fens showed that loss of absorbance was greater at 400 nm rather than 254 nm, after 192 days storage, suggesting that non-aromatic DOC is preferentially degraded. These results suggest that samples can be stored for several months before losses of DOC become detectable, and that it is possible to back-calculate initial DOC concentrations in long-term stored samples based on known decay rates. Freeze/thaw experiments using samples from a range of peatlands suggested that DOC concentration was mostly unaffected by the process, but DOC increased 37% in one sample. Freezing had unpredictable and sometimes strong effects on absorbance, SUVA and E ratios, therefore freezing is not recommended as a method of preservation for these analyses.

  20. Behaviour of sulphur during diagenesis of a maritime ombrotrophic peat from Yell, Shetland Islands, UK

    International Nuclear Information System (INIS)

    Bartlett, Rebecca; Bottrell, Simon; Coulson, Jonathan

    2005-01-01

    Surface water, pore water, vegetation and peat cores were sampled from a waterlogged ombrotrophic peat bog on the Shetland Isles, UK and analysed for different S forms and their isotopic composition, in an attempt to elucidate the biogeochemical processes affecting S during peat diagenesis. Surface waters show that inputs of S to the peat have a maritime-dominated isotopic composition close to +20%% CDT . Uptake of S by vegetation introduces a -10%% shift in δ 34 S from these input values. Below the vegetation layer and down to 18cm depth, bacterial SO 4 2- reduction is the major control on S species distribution and isotopic composition within the solid peat and pore waters. In this part of the peat, preferential reduction of 32 SO 4 in pore water during metabolism produces isotopically light sulphide, which is incorporated into the solid phase in both inorganic and organic forms, while pore water SO 4 2- becomes enriched in 34 S. From 18 to 28cm, organic S content falls relative to C and residual organic S becomes 34 S-enriched, indicative of mineralization of organic S, a process which releases isotopically light S to the pore waters. Still deeper in the core (28 to ∼50cm), bacterial reduction of pore-water SO 4 2- , now enriched in 34 S, results in addition of isotopically heavy S to the solid phase. Limited pore water data suggest that below 50cm mineralization reactions again release S from the organic fraction of the peat

  1. Impact of the Little Ice Age cooling and 20th century climate change on peatland vegetation dynamics in central and northern Alberta using a multi-proxy approach and high-resolution peat chronologies

    Science.gov (United States)

    Magnan, Gabriel; van Bellen, Simon; Davies, Lauren; Froese, Duane; Garneau, Michelle; Mullan-Boudreau, Gillian; Zaccone, Claudio; Shotyk, William

    2018-04-01

    Northern boreal peatlands are major terrestrial sinks of organic carbon and these ecosystems, which are highly sensitive to human activities and climate change, act as sensitive archives of past environmental change at various timescales. This study aims at understanding how the climate changes of the last 1000 years have affected peatland vegetation dynamics in the boreal region of Alberta in western Canada. Peat cores were collected from five bogs in the Fort McMurray region (56-57° N), at the southern limit of sporadic permafrost, and two in central Alberta (53° N and 55° N) outside the present-day limit of permafrost peatlands. The past changes in vegetation communities were reconstructed using detailed plant macrofossil analyses combined with high-resolution peat chronologies (14C, atmospheric bomb-pulse 14C, 210Pb and cryptotephras). Peat humification proxies (C/N, H/C, bulk density) and records of pH and ash content were also used to improve the interpretation of climate-related vegetation changes. Our study shows important changes in peatland vegetation and physical and chemical peat properties during the Little Ice Age (LIA) cooling period mainly from around 1700 CE and the subsequent climate warming of the 20th century. In some bogs, the plant macrofossils have recorded periods of permafrost aggradation during the LIA with drier surface conditions, increased peat humification and high abundance of ericaceous shrubs and black spruce (Picea mariana). The subsequent permafrost thaw was characterized by a short-term shift towards wetter conditions (Sphagnum sect. Cuspidata) and a decline in Picea mariana. Finally, a shift to a dominance of Sphagnum sect. Acutifolia (mainly Sphagnum fuscum) occurred in all the bogs during the second half of the 20th century, indicating the establishment of dry ombrotrophic conditions under the recent warmer and drier climate conditions.

  2. The impact of climate change on Canadian peatlands

    International Nuclear Information System (INIS)

    Tarnocai, C.

    2009-01-01

    This paper discussed the sensitivity of Canadian peatlands to climate change, with particular emphasis on the carbon dynamics, water regime changes and the contribution of peatlands to atmospheric greenhouse gases. Peatlands cover 12 per cent of the Canadian landscape, with most occurring in the boreal and subarctic regions. In total, the peatlands contain nearly 147 Gt of soil organic carbon, or about 56 per cent of the organic carbon stored in all Canadian soils. A peatland sensitivity model that was used to determine the effect of climate warming on peatlands revealed that about 60 per cent of the boreal and subarctic regions and 56 per cent of the organic carbon mass in all Canadian peatlands will be severely to extremely severely affected by climate change, and at an accelerated rate than ever before. Climate change predictions suggest that the greatest effects of climate warming on Canadian peatlands will occur in areas with perennially frozen peat. The major concern in these areas is that the melting of the frozen peat will result in waterlogged conditions. In contrast, drying of non-permafrost peatlands will result in a higher frequency and extent of wildfires. As a result of these changes, large amounts of carbon in the forms of carbon dioxide (CO 2 ) and methane (CH 4 ) will be released into the atmosphere from these peatlands, which will further accelerate climate warming. 43 refs., 2 tabs., 7 figs.

  3. Managing peatland vegetation for drinking water treatment.

    Science.gov (United States)

    Ritson, Jonathan P; Bell, Michael; Brazier, Richard E; Grand-Clement, Emilie; Graham, Nigel J D; Freeman, Chris; Smith, David; Templeton, Michael R; Clark, Joanna M

    2016-11-18

    Peatland ecosystem services include drinking water provision, flood mitigation, habitat provision and carbon sequestration. Dissolved organic carbon (DOC) removal is a key treatment process for the supply of potable water downstream from peat-dominated catchments. A transition from peat-forming Sphagnum moss to vascular plants has been observed in peatlands degraded by (a) land management, (b) atmospheric deposition and (c) climate change. Here within we show that the presence of vascular plants with higher annual above-ground biomass production leads to a seasonal addition of labile plant material into the peatland ecosystem as litter recalcitrance is lower. The net effect will be a smaller litter carbon pool due to higher rates of decomposition, and a greater seasonal pattern of DOC flux. Conventional water treatment involving coagulation-flocculation-sedimentation may be impeded by vascular plant-derived DOC. It has been shown that vascular plant-derived DOC is more difficult to remove via these methods than DOC derived from Sphagnum, whilst also being less susceptible to microbial mineralisation before reaching the treatment works. These results provide evidence that practices aimed at re-establishing Sphagnum moss on degraded peatlands could reduce costs and improve efficacy at water treatment works, offering an alternative to 'end-of-pipe' solutions through management of ecosystem service provision.

  4. Stability of peatland carbon to rising temperatures

    Science.gov (United States)

    R. M. Wilson; A. M. Hopple; M. M. Tfaily; S. D. Sebestyen; C. W. Schadt; L. Pfeifer-Meister; C. Medvedeff; K. J. McFarlane; J. E. Kostka; M. Kolton; R.K. Kolka; L. A. Kluber; J. K. Keller; T. P. Guilderson; N. A. Griffiths; J. P. Chanton; S. D. Bridgham; P. J. Hanson

    2016-01-01

    Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have focused on surface warming. We show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH4 emissions. However,...

  5. Nitrogen dynamics in northern peatland ecosystems

    Science.gov (United States)

    Nitrogen pollution has become a global issue over the last century due to increased fertilizer use and burning of fossil fuels. Excess N has been responsible for algal blooms, hypoxic zones, climate change, and human health issues. Extent of peatlands in the Great Lakes basin is ...

  6. Spatial variation in below ground carbon cycling in a pristine peatland, driven by present and past vegetation

    Science.gov (United States)

    Mathijssen, Paul; Knorr, Klaus-Holger; Gałka, Mariusz; Borken, Werner

    2017-04-01

    Peat carbon cycling is controlled by both large scale factors, such as climate and hydrological setting, and small scale factors, such as microtopography, vegetation, litter quality, and rooting depth. These small scale factors commonly vary within peatlands, causing variation in the carbon balance at different locations within the same site. Understanding the relationship between small scale carbon cycling and vegetation helps us to assess the variation of carbon dynamics of peatlands, because vegetation composition acts as an integrator of factors such as microtopography, hydrology, and nutrient level. Variation in vegetation illustrates spatial variation of these underlying factors. Furthermore, the presence of certain plant species affects carbon cycling directly through litter quality or aeration through root tissues. In order to understand these within-site variations in terms of carbon cycling, we investigated carbon accumulation, decomposition, and biogeochemistry of pore waters along a transect of peat cores with changing vegetation and water levels in an ombrotrophic peatland in southern Patagonia. The transect ran from a Sphagnum magellanicum dominated spot with relatively high water table, to intermediately wet spots with mixed Sphagnum/shrubs vegetation, or dominated by Cyperaceae, eventually to a more elevated and drier spot dominated by cushion plants (mainly Astelia pumila). There were large differences in peat accumulation rates and peat densities, with faster peat growth and lower densities under Sphagnum, but overall carbon accumulation rates were quite similar in the various microenvironments. At most plots C/N ratios decreased with depth, concurrent with increasing humification index derived from FT-IR spectra. But under cushion plants this relation was opposite: more humification with depth, but also C/N ratios increases. This reflected the differing source material at depth under the cushion plants, and that the cushion plant peat layers were

  7. Potentially toxic metals in ombrotrophic peat along a 400 km English-Scottish transect

    Energy Technology Data Exchange (ETDEWEB)

    Smith, E.J. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom); Hughes, S. [Centre for Ecology and Hydrology (Bangor), Deiniol Road, Bangor, Gwynedd LL57 2UP (United Kingdom); Lawlor, A.J. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom); Lofts, S. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom); Simon, B.M. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom); Stevens, P.A. [Centre for Ecology and Hydrology (Bangor), Deiniol Road, Bangor, Gwynedd LL57 2UP (United Kingdom); Stidson, R.T. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom); Tipping, E. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom)]. E-mail: et@ceh.ac.uk; Vincent, C.D. [Centre for Ecology and Hydrology (Lancaster), Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP (United Kingdom)

    2005-07-15

    Four samples of ombrotrophic peat were collected from each of 10 upland locations in a transect from the southern Pennines to the Highland Boundary Fault, a total distance of ca. 400 km. Bulk compositions and other properties were determined. Total contents of Al and heavy metals (Ni, Cu, Zn, Cd, Pb) were determined following digestion with hydrofluoric acid, and concentrations of metals extractable with dilute nitric acid were also measured. Supernatants obtained from aqueous extractions of the peat samples were analysed for pH, major cations and anions, dissolved organic carbon and dissolved metals, and concentrations of free metal ions (Al{sup 3+}, Ni{sup 2+}, etc.) were estimated by applying a chemical speciation model. Both total and HNO{sub 3}-extractable metal concentrations varied along the transect, the highest values being found at locations close to industrial and former mining areas. The HNO{sub 3}-extractable soil metal contents of Ni, Cu and Cd were appreciably lower than lowest-observed-effect-concentrations (LOEC) for toxicity towards microorganisms in acid, organic rich soils. However, the contents of Zn at two locations, and of Pb at five locations exceeded LOECs, suggesting that they may be exerting toxic effects in the peats. Soil solution concentrations of free heavy metal ions (Cu{sup 2+}, Zn{sup 2+}, Cd{sup 2+}, Pb{sup 2+}) were substantially lower than LOECs for toxicity towards vascular plants, whereas concentrations of Al{sup 3+} were near to toxic levels at two locations. - P eat metal contents depend upon proximity to industrial and mining areas; the metals may be exerting toxic effects in some places.

  8. Assessing sulfate and carbon controls on net methylmercury production in peatlands: An in situ mesocosm approach

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Carl P.J. [Department of Geography, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6 (Canada)], E-mail: mitchellc@si.edu; Branfireun, Brian A. [Department of Geography, University of Toronto at Mississauga, 3359 Mississauga Road North, Mississauga, Ontario L5L 1C6 (Canada); Kolka, Randall K. [Northern Research Station, US Department of Agriculture Forest Service, 1831 Highway 169 East, Grand Rapids, MN 55744 (United States)

    2008-03-15

    The transformation of atmospherically deposited inorganic Hg to the toxic, organic form methylmercury (MeHg) is of serious ecological concern because MeHg accumulates in aquatic biota, including fish. Research has shown that the Hg methylation reaction is dependent on the availability of SO{sub 4} (as an electron acceptor) because SO{sub 4}-reducing bacteria (SRB) mediate the biotic methylation of Hg. Much less research has investigated the possible organic C limitations to Hg methylation (i.e. from the perspective of the electron donor). Although peatlands are long-term stores of organic C, the C derived from peatland vegetation is of questionable microbial lability. This research investigated how both SO{sub 4} and organic C control net MeHg production using a controlled factorial addition design in 44 in situ peatland mesocosms. Two levels of SO{sub 4} addition and energetic-equivalent additions (i.e. same number of electrons) of a number of organic C sources were used including glucose, acetate, lactate, coniferous litter leachate, and deciduous litter leachate. This study supports previous research demonstrating the stimulation of MeHg production from SO{sub 4} input alone ({approx}200 pg/L/day). None of the additions of organic C alone resulted in significant MeHg production. The combined addition of SO{sub 4} and some organic C sources resulted in considerably more MeHg production ({approx}500 pg/L/day) than did the addition of SO{sub 4} alone, demonstrating that the highest levels of MeHg production can be expected only where fluxes of both SO{sub 4} and organic C are delivered concurrently. When compared to a number of pore water samples taken from two nearby peatlands, MeHg concentrations resulting from the combined addition of SO{sub 4} and organic C in this study were similar to MeHg 'hot spots' found near the upland-peatland interface. The formation of MeHg 'hot spots' at the upland-peatland interface may be dependent on concurrent

  9. Assessing sulfate and carbon controls on net methylmercury production in peatlands: An in situ mesocosm approach

    International Nuclear Information System (INIS)

    Mitchell, Carl P.J.; Branfireun, Brian A.; Kolka, Randall K.

    2008-01-01

    The transformation of atmospherically deposited inorganic Hg to the toxic, organic form methylmercury (MeHg) is of serious ecological concern because MeHg accumulates in aquatic biota, including fish. Research has shown that the Hg methylation reaction is dependent on the availability of SO 4 (as an electron acceptor) because SO 4 -reducing bacteria (SRB) mediate the biotic methylation of Hg. Much less research has investigated the possible organic C limitations to Hg methylation (i.e. from the perspective of the electron donor). Although peatlands are long-term stores of organic C, the C derived from peatland vegetation is of questionable microbial lability. This research investigated how both SO 4 and organic C control net MeHg production using a controlled factorial addition design in 44 in situ peatland mesocosms. Two levels of SO 4 addition and energetic-equivalent additions (i.e. same number of electrons) of a number of organic C sources were used including glucose, acetate, lactate, coniferous litter leachate, and deciduous litter leachate. This study supports previous research demonstrating the stimulation of MeHg production from SO 4 input alone (∼200 pg/L/day). None of the additions of organic C alone resulted in significant MeHg production. The combined addition of SO 4 and some organic C sources resulted in considerably more MeHg production (∼500 pg/L/day) than did the addition of SO 4 alone, demonstrating that the highest levels of MeHg production can be expected only where fluxes of both SO 4 and organic C are delivered concurrently. When compared to a number of pore water samples taken from two nearby peatlands, MeHg concentrations resulting from the combined addition of SO 4 and organic C in this study were similar to MeHg 'hot spots' found near the upland-peatland interface. The formation of MeHg 'hot spots' at the upland-peatland interface may be dependent on concurrent inputs of SO 4 and organic C in runoff from the adjacent upland hillslopes

  10. Emissions of methane and nitrogen oxides from peatland ecosystems

    International Nuclear Information System (INIS)

    Martikainen, P.J.; Nykaenen, H.; Laang, K.; Alm, J.; Silvola, J.

    1994-01-01

    Climatic change may cause drier, warmer summer in the high latitudes and cause remarkable changes in gas fluxes on peatlands. Drained peatlands can be used as models to predict the long-term effects of increased peat aeration on trace gas fluxes. Results are presented from studies about emissions of CH 4 , N 2 O and NO in both virgin and drained Finnish peatlands, and give some information about the factors regulating the production and consumption of these trace gases

  11. Meeting the challenge of mapping peatlands with remotely sensed data

    Directory of Open Access Journals (Sweden)

    O. N. Krankina

    2008-12-01

    Full Text Available Boreal peatlands play a major role in carbon and water cycling and other global environmental processes but understanding this role is constrained by inconsistent representation of peatlands on, or omission from, many global land cover maps. The comparison of several widely used global and continental-scale databases on peatland distribution with a detailed map for the St. Petersburg region of Russia showed significant under-reporting of peatland area, or even total omission. Analysis of the spatial agreement and disagreement with the detailed regional map indicated that the error of comission (overestimation was significantly lower than the error of omission (underestimation which means, that overall, peatlands were correctly classified as such in coarse resolution datasets but a large proportion (74–99% was overlooked. The coarse map resolution alone caused significant omission of peatlands in the study region. In comparison to categorical maps, continuous field mapping approach utilizing MODIS sensor data showed potential for a greatly improved representation of peatlands on coarse resolution maps. Analysis of spectral signatures of peatlands with different types of surface vegetation suggested that improved mapping of boreal peatlands on categorical maps is feasible. The lower reflectance of treeless peatlands in the near- and shortwave-infrared parts of the electromagnetic spectrum is consistent with the spectral signature of sphagnum mosses. However, when trees are present, the canopy architecture appears to be more important in defining the overall spectral reflectance of peatlands. A research focus on developing remote sensing methods for boreal peatlands is needed for adequate characterization of their global distribution.

  12. Wetland restoration: a survey of options for restoring peatlands

    International Nuclear Information System (INIS)

    Lode, Elve

    1999-01-01

    In spite of increased attention to wetland conservation following the Ramsar Convention on Wetlands of International Importance, the peat-harvesting industry in many countries is still interested in the further exploitation of peatlands. In some of the most industrialised countries, all natural peatlands have already been lost. In others, only small areas of native peatland remain. Among other possible uses for cut-over peatlands, peatland restoration is one: there is an urgent need for the development of measures for regenerating peat-accumulation processes. The redevelopment of a fen or bog peat landscape is a long-term process, which will probably take centuries. The restoration of any peatland may therefore be considered successful if the outcome is the development and growth of plant communities able to produce peat. The renewal of the hydrological regime of such areas is a major factor which determines the re-colonisation of cut-over peat fields by peat-forming plants. The aim of this paper is to give a brief survey of wetlands, and especially of peatland restoration options, for use in terminated peat-cuttings. It aims to show how peatland management may be made sustainable by means of existing and tried methods and principles, with the goal of returning cut-over peat fields to their former peat-accumulating state. A glossary of peat and peatland terminology is included 105 refs, 5 figs

  13. Carbon dynamics and ecosystem diversity of Amazonian peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laehteenoja, O.

    2011-07-01

    The overall aim was to initiate peatland research in Amazonia, which has been referred to as 'one of the large white spots on the global peatland map'. Specifically, the study was to clarify how common peat accumulation is on Amazonian floodplains, and how extensive and thick peat deposits can be encountered. Secondly, the intention was to study how rapidly Amazonian peatlands sequester carbon, and how much carbon they store and thirdly, to gain some understanding of the diversity of peatland ecosystem types and of the processes forming these ecosystems

  14. Effects of elevated atmospheric CO2 concentration and increased nitrogen deposition on growth and chemical composition of ombrotrophic Sphagnum balticum and oligo-mesotrophic Sphagnum papillosum

    NARCIS (Netherlands)

    Van der Heijden, E; Jauhiainen, J; Silvola, J; Vasander, H; Kuiper, PJC

    2000-01-01

    The ombrotrophic Sphagnum balticum (Russ.) C. Jens. and the oligo-mesotrophic Sphagnum papillosum Lindb. were grown at ambient (360 mu l l(-1)) and at elevated (720 mu l l(-1)) atmospheric CO2 concentrations and at different nitrogen deposition rates, varying between 0 and 30kg N ha(-1) yr(-1), The

  15. Peat decomposition records in three pristine ombrotrophic bogs in southern Patagonia

    Directory of Open Access Journals (Sweden)

    T. Broder

    2012-04-01

    Full Text Available Ombrotrophic bogs in southern Patagonia have been examined with regard to paleoclimatic and geochemical research questions but knowledge about organic matter decomposition in these bogs is limited. Therefore, we examined peat humification with depth by Fourier Transformed Infrared (FTIR measurements of solid peat, C/N ratio, and δ13C and δ15N isotope measurements in three bog sites. Peat decomposition generally increased with depth but distinct small scale variation occurred, reflecting fluctuations in factors controlling decomposition. C/N ratios varied mostly between 40 and 120 and were significantly correlated (R2 > 0.55, p < 0.01 with FTIR-derived humification indices. The degree of decomposition was lowest at a site presently dominated by Sphagnum mosses. The peat was most strongly decomposed at the driest site, where currently peat-forming vegetation produced less refractory organic material, possibly due to fertilizing effects of high sea spray deposition. Decomposition of peat was also advanced near ash layers, suggesting a stimulation of decomposition by ash deposition. Values of δ13C were 26.5 ± 2‰ in the peat and partly related to decomposition indices, while δ15N in the peat varied around zero and did not consistently relate to any decomposition index. Concentrations of DOM partly related to C/N ratios, partly to FTIR derived indices. They were not conclusively linked to the decomposition degree of the peat. DOM was enriched in 13C and in 15N relative to the solid phase probably due to multiple microbial modifications and recycling of N in these N-poor environments. In summary, the depth profiles of C/N ratios, δ13C values, and FTIR spectra seemed to reflect changes in environmental conditions affecting decomposition, such as bog wetness, but were dominated by site specific factors, and are further influenced by ash

  16. Historical accumulation rates of mercury in four Scottish ombrotrophic peat bogs over the past 2000 years

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, John G., E-mail: J.G.Farmer@ed.ac.uk [School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3JN, Scotland (United Kingdom); Anderson, Peter [Contaminated Land Assessment and Remediation Research Centre, University of Edinburgh, Edinburgh, EH9 3JL, Scotland (United Kingdom); Cloy, Joanna M.; Graham, Margaret C. [School of GeoSciences, University of Edinburgh, Edinburgh, EH9 3JN, Scotland (United Kingdom); MacKenzie, Angus B.; Cook, Gordon T. [Scottish Universities Environmental Research Centre, East Kilbride, G75 0QF, Scotland (United Kingdom)

    2009-10-15

    The historical accumulation rates of mercury resulting from atmospheric deposition to four Scottish ombrotrophic peat bogs, Turclossie Moss (northeast Scotland), Flanders Moss (west-central), Red Moss of Balerno (east-central) and Carsegowan Moss (southwest), were determined via analysis of {sup 210}Pb- and {sup 14}C-dated cores up to 2000 years old. Average pre-industrial rates of mercury accumulation of 4.5 and 3.7 {mu}g m{sup -2} y{sup -1} were obtained for Flanders Moss (A.D. 1-1800) and Red Moss of Balerno (A.D. 800-1800), respectively. Thereafter, mercury accumulation rates increased to typical maximum values of 51, 61, 77 and 85 {mu}g m{sup -2} y{sup -1}, recorded at different times possibly reflecting local/regional influences during the first 70 years of the 20th century, at the four sites (TM, FM, RM, CM), before declining to a mean value of 27 {+-} 15 {mu}g m{sup -2} y{sup -1} during the late 1990s/early 2000s. Comparison of such trends for mercury with those for lead and arsenic in the cores and also with direct data for the declining UK emissions of these three elements since 1970 suggested that a substantial proportion of the mercury deposited at these sites over the past few decades originated from outwith the UK, with contributions to wet and dry deposition arising from long-range transport of mercury released by sources such as combustion of coal. Confidence in the chronological reliability of these core-derived trends in absolute and relative accumulation of mercury, at least since the 19th century, was provided by the excellent agreement between the corresponding detailed and characteristic temporal trends in the {sup 206}Pb/{sup 207}Pb isotopic ratio of lead in the {sup 210}Pb-dated Turclossie Moss core and those in archival Scottish Sphagnum moss samples of known date of collection. The possibility of some longer-term loss of volatile mercury released from diagenetically altered older peat cannot, however, be excluded by the findings of this

  17. Historical accumulation rates of mercury in four Scottish ombrotrophic peat bogs over the past 2000 years

    International Nuclear Information System (INIS)

    Farmer, John G.; Anderson, Peter; Cloy, Joanna M.; Graham, Margaret C.; MacKenzie, Angus B.; Cook, Gordon T.

    2009-01-01

    The historical accumulation rates of mercury resulting from atmospheric deposition to four Scottish ombrotrophic peat bogs, Turclossie Moss (northeast Scotland), Flanders Moss (west-central), Red Moss of Balerno (east-central) and Carsegowan Moss (southwest), were determined via analysis of 210 Pb- and 14 C-dated cores up to 2000 years old. Average pre-industrial rates of mercury accumulation of 4.5 and 3.7 μg m -2 y -1 were obtained for Flanders Moss (A.D. 1-1800) and Red Moss of Balerno (A.D. 800-1800), respectively. Thereafter, mercury accumulation rates increased to typical maximum values of 51, 61, 77 and 85 μg m -2 y -1 , recorded at different times possibly reflecting local/regional influences during the first 70 years of the 20th century, at the four sites (TM, FM, RM, CM), before declining to a mean value of 27 ± 15 μg m -2 y -1 during the late 1990s/early 2000s. Comparison of such trends for mercury with those for lead and arsenic in the cores and also with direct data for the declining UK emissions of these three elements since 1970 suggested that a substantial proportion of the mercury deposited at these sites over the past few decades originated from outwith the UK, with contributions to wet and dry deposition arising from long-range transport of mercury released by sources such as combustion of coal. Confidence in the chronological reliability of these core-derived trends in absolute and relative accumulation of mercury, at least since the 19th century, was provided by the excellent agreement between the corresponding detailed and characteristic temporal trends in the 206 Pb/ 207 Pb isotopic ratio of lead in the 210 Pb-dated Turclossie Moss core and those in archival Scottish Sphagnum moss samples of known date of collection. The possibility of some longer-term loss of volatile mercury released from diagenetically altered older peat cannot, however, be excluded by the findings of this study.

  18. Fine root production at drained peatland sites

    Energy Technology Data Exchange (ETDEWEB)

    Finer, L [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Laine, J [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1997-12-31

    The preliminary results of the Finnish project `Carbon balance of peatlands and climate change` show that fine roots play an important role in carbon cycling on peat soils. After drainage the roots of mire species are gradually replaced by the roots of trees and other forest species. Pine fine root biomass reaches a maximum level by the time of crown closure, some 20 years after drainage on pine mire. The aim of this study is to compare the results of the sequential coring method and the ingrowth bag method used for estimating fine root production on three drained peatland sites of different fertility. The results are preliminary and continuation to the work done in the study Pine root production on drained peatlands, which is part of the Finnish project `Carbon cycling on peatlands and climate change`. In this study the fine root biomass was greater on the poor site than on the rich sites. Pine fine root production increased with the decrease in fertility. Root turnover and the production of field layer species were greater on the rich sites than on the poor site. The results suggested that the in growth bag method measured more root activity than the magnitude of production. More than two growing seasons would have been needed to balance the root dynamics in the in growth bags with the surrounding soil. That time would probably have been longer on the poor site than on the rich ones and longer for pine and field layer consisting of dwarf shrubs than for field layer consisting of sedge like species and birch. (11 refs.)

  19. Fine root production at drained peatland sites

    Energy Technology Data Exchange (ETDEWEB)

    Finer, L. [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Laine, J. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The preliminary results of the Finnish project `Carbon balance of peatlands and climate change` show that fine roots play an important role in carbon cycling on peat soils. After drainage the roots of mire species are gradually replaced by the roots of trees and other forest species. Pine fine root biomass reaches a maximum level by the time of crown closure, some 20 years after drainage on pine mire. The aim of this study is to compare the results of the sequential coring method and the ingrowth bag method used for estimating fine root production on three drained peatland sites of different fertility. The results are preliminary and continuation to the work done in the study Pine root production on drained peatlands, which is part of the Finnish project `Carbon cycling on peatlands and climate change`. In this study the fine root biomass was greater on the poor site than on the rich sites. Pine fine root production increased with the decrease in fertility. Root turnover and the production of field layer species were greater on the rich sites than on the poor site. The results suggested that the in growth bag method measured more root activity than the magnitude of production. More than two growing seasons would have been needed to balance the root dynamics in the in growth bags with the surrounding soil. That time would probably have been longer on the poor site than on the rich ones and longer for pine and field layer consisting of dwarf shrubs than for field layer consisting of sedge like species and birch. (11 refs.)

  20. Human influences on the health of northern peatlands

    International Nuclear Information System (INIS)

    Gorham, E.

    1991-01-01

    The present area of peat is estimated to be 342 million hectares, with an average depth of 2.3 m. Peatlands are of interest for their flora and fauna, as a habitat for wildlife, for their capacity to moderate stream flows, and for their sequestration of nitrogen and sulfur (elements important in stream and lake acidification). Of great biogeochemical significance is the role of northern peatlands in the global carbon cycle. Their total stock of carbon stored as peat is 455 Pg, or 64% of the amount present as atmospheric CO 2 , 55% of total plant biomass, and 30% of the global pool of soil carbon excluding peat. The rate of peatland sequestration of atmospheric carbon is very small compared to current emissions of 5.6 Pg from fossil fuel combustion. On the other hand, northern peatlands emit ca 0.046 gigatonnes of carbon in the form of methane, which is about 20 times as effective as a greenhouse gas than CO 2 . Human disturbances to peatlands come directly from forestry, agriculture, and fuel/horticultural peat extraction, and indirectly from destruction or utilization of surrounding upland ecosystems, deposition of pollutants, and global warming. Approaches to the study of human impacts on peatlands are outlined and suggestions are offered to guide peatland research. Peatland conservation and restoration are also briefly reviewed. 65 refs

  1. The institutional fit of peatland governance in Indonesia

    NARCIS (Netherlands)

    Uda, Saritha Kittie; Schouten, Greetje; Hein, Lars

    2018-01-01

    The Government of Indonesia has published a number of policies and regulations to better manage its vast amount of tropical peatland, yet the degradation and conversion of Indonesian peatlands still continues. This paper analyses the institutional fit between Indonesian regulations related to

  2. Peatlands: their nature and role in the biosphere

    International Nuclear Information System (INIS)

    Maltby, E.; Proctor, M.C.F.

    1996-01-01

    There are approximately 4 million km 2 of peatlands worldwide, covering some 3 % of the land surface. Their exact extent is uncertain within 150 000 km 2 or so. This is partly because of the difficulty of defining their boundaries precisely, and partly from simple lack of information, especially from parts of Canada and the former USSR, and within the tropical regions. Over 90 % of peatlands are in the temperate and cold belt in the Northern Hemisphere. It is estimated that almost 95 % of peatlands are found in just eight nations: CIS (former USSR) (38 %); Canada (28 %); USA (15 %); Indonesia (6 %); Finland (3 %); Sweden (2 %); China (1 %); Norway (1 %). European peatlands excluding the former USSR amount to just 7 % of the total area. African and South American peatlands each account for 1 % of the total. Central America holds less than 1 % of the global total. Tropical peatlands may account for as much as 10 % of the total area, and more than 7 % of the world total is in south-east Asia alone. The significance of the very large carbon store represented by the world's peatlands in relation to global carbon cycling, and the potential for global environmental change, is becoming increasingly apparent. In this chapter also the conditions for the formation of peat, limits of peat growth, element accumulation, nutrient cycling and budgets of peatlands are discussed. (29 refs.)

  3. Element cycling in upland/peatland watersheds Chapter 8.

    Science.gov (United States)

    Noel Urban; Elon S. Verry; Steven Eisenreich; David F. Grigal; Stephen D. Sebestyen

    2011-01-01

    Studies at the Marcell Experimental Forest (MEF) have measured the pools, cycling, and transport of a variety of elements in both the upland and peatland components of the landscape. Peatlands are important zones of element retention and biogeochemical reactions that greatly influence the chemistry of surface water. In this chapter, we summarize findings on nitrogen (N...

  4. Assessment of chemical properties of tropical peatland soil in ...

    African Journals Online (AJOL)

    The chemical assessment of the peatland in oil palm plantation in South Selangor Peatland Swamp in Malaysia were evaluated in this study. Soil samples were obtained from fifteen (15) different locations within the study area at three different depths of 0.5m, 1.5 m, and 2.5 m in three replicates at each depth, using peat ...

  5. Plant diversity associated with pools in natural and restored peatlands

    Directory of Open Access Journals (Sweden)

    N. Fontaine

    2007-06-01

    Full Text Available This study describes plant assemblages associated with the edges of peatland pools. We conducted inventories in six natural peatlands in the province of Québec (Canada in order to measure the contribution of pools to species diversity in climatic regions where peatlands are used for peat extraction. We also carried out vegetation surveys in a peatland that has been restored after peat extraction/harvesting to determine whether pool vegetation establishes along the edges of created pools when dry surface restoration techniques only are used. Pools enhanced plant species richness in natural peatlands. Around created pools, species associated with natural pools were still absent, and non-bog species were present, six years after restoration. On this basis, we emphasise the importance of preserving natural peatlands with pools. In order to restore fully the plant diversity associated with peatlands at harvested sites, it may be necessary to modify pool excavation techniques so that created pools resemble more closely those in natural peatlands. Active introduction of the plant species or communities associated with natural pools may also be needed; candidate species for North America include Andromeda glaucophylla, Cladopodiella fluitans, Carex limosa, Eriophorum virginicum, Rhynchospora alba and Sphagnum cuspidatum.

  6. Inventory and monitoring options of peatlands at regional scale

    DEFF Research Database (Denmark)

    Gardi, Ciro; Sommer, Stefan; Seep, Kalev

    2010-01-01

    Determination of the spatial extent of peatlands and monitoring their status is important for the evaluation of soil carbon stocks and greenhouse gas fluxes. At European Level there is a need to provide accurate and updated estimate of the distribution of peatlands. Comparison of national data wi...

  7. Restauration de la Tourbière de Landemarais, vingt années de suivi Landemarais peatland restoration : 20 years of monitoring

    Directory of Open Access Journals (Sweden)

    Bernard Clément, Jean-François Lebas, Emmanuelle Nogues et Ahmed Aidoud

    2011-05-01

    Full Text Available Procéder à la restauration de la dynamique naturelle d’un écosystème passe par un suivi scientifique efficace des opérations et de leurs effets écologiques. Après vingt ans de suivi de la réhabilitation de la tourbière de Landemarais en Bretagne, quels sont les résultats sur le maintien des espèces et des habitats ? Quelles sont les améliorations à envisager dans les pratiques de gestion ?Resulting from terrestrialization of a pond built in Xth century, the telmatic wetland of Landemarais is an acidic mire, locally differentiated by local ombrotrophic bogs. Linked to peat digging, particularly in 1968, the drainage has amplified the woodland dynamics. Integrated within the ENS ("Espaces naturels sensibles" network of the Conseil Général 35 in 1989, the objectives of peatland restoration were recovering open areas after woodland clearing and peat rewetting. These two actions had to be performed for re-initialisation of natural dynamic trajectories, already existing before disturbances. The targeted species populations and peat plant communities have recovered a steady states close to the previous ones. Nevertheless the managers have to face the woody species encroachment, such as Betula and Salix, by cutting and / or digging them every 2-4 years in order to maintain open habitats for conservation of the peatland target species and plant communities. Hypothesis of sod-cutting of the upper peat after woodland clearing is discussed.

  8. Impact of mine wastewaters on greenhouse gas emissions from northern peatlands used for mine water treatment

    Science.gov (United States)

    Palmer, Katharina; Ronkanen, Anna-Kaisa; Klöve, Björn; Hynynen, Jenna; Maljanen, Marja

    2015-04-01

    increasing distances from the ditch. NO3- concentrations were lower in pore water than in surface water, and the peak in NO3- concentration shifted further away from the distribution ditch with increasing depth. On the contrary, NH4+ concentrations were generally higher in pore water than in surface water, and peak concentrations increased with increasing depth. Highest NH4+ concentrations were detected in 30 to 60 cm depth near the outlet at the south end of TP 4. Fluxes of the greenhouse gases CH4 and N2O from 4 sampling points (2 from TP 4, 1 from TP 1, 1 from reference area) were measured on 7 different occasions 2013 and 2014. CH4 emissions were in the same range as measured in other northern pristine peatlands in the reference area, which is not influenced by mine wastewaters. Treatment peatlands showed only very minor CH4 emissions or even CH4 uptake. On the other hand, treatment peatlands showed high N2O emissions, which were in the same range as N2O emissions observed from northern peat soils used for agriculture. Highest emissions were generally observed near the wastewater distribution ditch of TP 4. N2O emissions from the reference area were negligible or even negative. NO3-, NH4+ and SO42- concentrations were determined from surface waters from each sampling point and sampling occasion. N2O emissions were positively correlated with NO3- concentrations, indicating denitrification-derived N2O production in treatment peatlands. On the other hand, CH4 emissions were negatively correlated with SO42- and NO3- concentrations, indicating that the presence of alternative electron acceptors in large amounts suppresses CH4 production in treatment peatlands. In conclusion, the study revealed that (i) treatment peatlands receive high loads of NO3-, NH4+ and SO42- which are not well retained in the peatlands, (ii) mine wastewaters positively and negatively affect N2O and CH4 emissions, respectively, (iii) N2O emissions are positively correlated with NO3- concentrations, and

  9. Peatlands and carbon flows. Outlook and importance for the Netherlands

    International Nuclear Information System (INIS)

    Verhagen, A.; Van den Akker, J.J.H.; Diemont, W.H.; Schrijver, R.A.M.; Wosten, H.M.; Blok, C.; Joosten, J.H.J.; Schouten, M.A.; Den Uyl, R.M.; Verweij, P.A.

    2010-02-01

    Peatlands are found on all continents, however, uncertainties regarding their size and exact locations are very high. Horticulture is the main user of peat in the Netherlands. Compared to other terrestrial ecosystems, peatlands are the most space-effective carbon stocks. Annual emissions of carbon dioxide from peat import for Dutch horticulture is between 0.2 and 0.3 Mt. Climate change will considerably increase most problems associated with peat soils in the Netherlands. It is difficult to establish a correlation between economic activities within the Netherlands and exploitation of tropical peatland. Of the products imported into the Netherlands palm oil perhaps is the most threatening to tropical peatlands. Given the increasing demand from, for example, India and China, the main challenge is to meet this demand without clearing forests, reclaiming peatland, or exploiting other carbon stocks.

  10. How important are peatlands globally in providing drinking water resources?

    Science.gov (United States)

    Xu, Jiren; Morris, Paul; Holden, Joseph

    2017-04-01

    The potential role of peatlands as water stores and sources of downstream water resources for human use is often cited in publications setting the context for the importance of peatlands, but is rarely backed up with substantive evidence. We sought to determine the global role of peatlands in water resource provision. We developed the Peat Population Index (PPI) that combines the coverage of peat and the local population density to show focused (hotspot) areas where there is a combination of both large areas of peat and large populations who would potentially use water sourced from those peatlands. We also developed a method for estimating the proportion of river water that interacted with contributing peatlands before draining into rivers and reservoirs used as a drinking water resource. The Peat Reservoir Index (PRI) estimates the contribution of peatlands to domestic water use to be 1.64 km3 per year which is 0.35 % of the global total. The results suggest that although peatlands are widespread, the spatial distribution of the high PPI and PRI river basins is concentrated in European middle latitudes particularly around major conurbations in The Netherlands, northern England, Scotland (Glasgow) and Ireland (Dublin), although there were also some important systems in Florida, the Niger Delta and Malaysia. More detailed research into water resource provision in high PPI areas showed that they were not always also high PRI areas as often water resources were delivered to urban centres from non-peat areas, despite a large area of peat within the catchment. However, particularly in the UK and Ireland, there are some high PRI systems where peatlands directly supply water to nearby urban centres. Thus both indices are useful and can be used at a global level while more local refinement enables enhanced use which supports global and local peatland protection measures. We now intend to study the impacts of peatland degradation and climate change on water resource

  11. Threats to intact tropical peatlands and opportunities for their conservation.

    Science.gov (United States)

    Roucoux, K H; Lawson, I T; Baker, T R; Del Castillo Torres, D; Draper, F C; Lähteenoja, O; Gilmore, M P; Honorio Coronado, E N; Kelly, T J; Mitchard, E T A; Vriesendorp, C F

    2017-12-01

    Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza-Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land-use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon-dense (domed pole forest) areas. New carbon-based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development. © 2017 The Authors. Conservation Biology published by Wiley Periodicals, Inc

  12. Organic matter evolution throughout a 100-cm ombrotrophic profile from an Italian floating mire

    Science.gov (United States)

    Zaccone, Claudio; D'Orazio, Valeria; Lobianco, Daniela; Miano, Teodoro M.

    2015-04-01

    The curious sight of an island floating and moving on a lake naturally, already described by Pliny the Elder in his Naturalis historia (AD 77-79), fascinated people from time immemorial. Floating mires are defined by the occurrence of emergent vegetation rooted in highly organic buoyant mats that rise and fall with changes in water level. Peat-forming floating mires could provide an exceptional tool for environmental studies, since much of their evolution, as well as the changes of the surrounding areas, is recorded in their peat deposits. A complete, 4-m deep peat core was collected in July 2012 from the floating island of Posta Fibreno, a relic mire in the Central Italy. This floating island has a diameter of ca. 30 m, a submerged thickness of about 3 m, and the vegetation is organized in concentric belts, from the Carex paniculata palisade to the Sphagnum centre. Here, some of the southernmost Italian populations of Sphagnum palustre occur. The 14C age dating of macrofossils removed from the sample at 360 cm of depth revealed that the island probably formed more than 500 yrs ago (435±20 yr BP). In the present work, we show preliminary results regarding the evolution of the organic matter along the first, ombrotrophic 100 cm of depth, hoping also to provide some insight into the possible mechanism of the evolution of this floating island. The 100 cm monolith was collected using a Wardenaar corer and cut frozen in 1-cm layers. It consists almost exclusively of Sphagnum mosses, often spaced out, in the top 20-30 cm, by leaves of Populus tremula that annually fell off. This section shows a very low bulk density, ranging from 0.017 and 0.059 g cm-3 (avg. value, 0.03±0.01 g cm-3), an average water content of 96.1±1.1%, and a gravimetric water content ranging between 14.3 and 41.5 gwater gdrypeat-1. The pH of porewaters was in the range 5-5.5. The C content along the profile ranged between 35 and 47% (avg., 41±1%), whereas the N between 0.3 and 0.9% (avg., 0.6±0

  13. Modelling and mapping trace element accumulation in Sphagnum peatlands at the European scale using a geomatic model of pollutant emissions dispersion.

    Science.gov (United States)

    Diaz-de-Quijano, Maria; Joly, Daniel; Gilbert, Daniel; Toussaint, Marie-Laure; Franchi, Marielle; Fallot, Jean-Michel; Bernard, Nadine

    2016-07-01

    Trace elements (TEs) transported by atmospheric fluxes can negatively impact isolated ecosystems. Modelling based on moss-borne TE accumulation makes tracking TE deposition in remote areas without monitoring stations possible. Using a single moss species from ombrotrophic hummock peatlands reinforces estimate quality. This study used a validated geomatic model of particulate matter dispersion to identify the origin of Cd, Zn, Pb and Cu accumulated in Sphagnum capillifolium and the distance transported from their emission sources. The residential and industrial sectors of particulate matter emissions showed the highest correlations with the TEs accumulated in S. capillifolium (0.28(Zn)-0.56(Cu)) and (0.27(Zn)-0.47(Cu), respectively). Distances of dispersion varied depending on the sector of emissions and the considered TE. The greatest transportation distances for mean emissions values were found in the industrial (10.6 km when correlating with all TEs) and roads sectors (13 km when correlating with Pb). The residential sector showed the shortest distances (3.6 km when correlating with Cu, Cd, and Zn). The model presented here is a new tool for evaluating the efficacy of air pollution abatement policies in non-monitored areas and provides high-resolution (200 × 200 m) maps of TE accumulation that make it possible to survey the potential impacts of TEs on isolated ecosystems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Peatland geoengineering: an alternative approach to terrestrial carbon sequestration.

    Science.gov (United States)

    Freeman, Christopher; Fenner, Nathalie; Shirsat, Anil H

    2012-09-13

    Terrestrial and oceanic ecosystems contribute almost equally to the sequestration of ca 50 per cent of anthropogenic CO(2) emissions, and already play a role in minimizing our impact on Earth's climate. On land, the majority of the sequestered carbon enters soil carbon stores. Almost one-third of that soil carbon can be found in peatlands, an area covering just 2-3% of the Earth's landmass. Peatlands are thus well established as powerful agents of carbon capture and storage; the preservation of archaeological artefacts, such as ancient bog bodies, further attest to their exceptional preservative properties. Peatlands have higher carbon storage densities per unit ecosystem area than either the oceans or dry terrestrial systems. However, despite attempts over a number of years at enhancing carbon capture in the oceans or in land-based afforestation schemes, no attempt has yet been made to optimize peatland carbon storage capacity or even to harness peatlands to store externally captured carbon. Recent studies suggest that peatland carbon sequestration is due to the inhibitory effects of phenolic compounds that create an 'enzymic latch' on decomposition. Here, we propose to harness that mechanism in a series of peatland geoengineering strategies whereby molecular, biogeochemical, agronomical and afforestation approaches increase carbon capture and long-term sequestration in peat-forming terrestrial ecosystems.

  15. Peatlands of the Peruvian Puna ecoregion: types, characteristics and disturbance

    Directory of Open Access Journals (Sweden)

    F. Salvador

    2014-05-01

    Full Text Available Peatlands represent one of the most important water resources in the Puna grassland ecoregion, but this fact is not yet widely recognised. Puna peatlands also provide key environmental services such as increasing the regional biodiversity of the Andean Altiplano plateau and contributing to the wellbeing of high-altitude human populations by providing grazing land and cooking fuel. We conducted a study in the Peruvian Puna ecoregion to describe the current condition of peatlands in terms of their vegetation, physical and chemical characteristics and disturbance status. Our results suggest that peat thickness, organic matter and degree of humification are good indicators for identifying peatlands in the Puna ecoregion. In general, the peatland sites that we sampled were dominated by mixtures of cushion and acaulescent rosette forming plants such as Distichia muscoides Nees & Meyen and Plantago tubulosa Decne. These Distichia and Plantago peatland sites were characterised by a mean surface water pH of 6.3, corrected electrical conductivity (K corr. in the range 300–1814 μS cm-1 and presented the following mean exchangeable cation values: Ca2+ 48 mg L-1, Mg2+ 9.6 mg L-1, Na+ 8.2 mg L-1 and K+ 2.1 mg L-1. The most common causes of disturbance we encountered were grazing, peat extraction and roads. Disturbance was most severe in mining sites, where peatlands are especially vulnerable because they are not under legal protection.

  16. Multi-method investigation of cushion peatlands (

    Science.gov (United States)

    Forbriger, M.; Schittek, K.; Höfle, B.; Siart, C.; Eitel, B.

    2012-04-01

    This study presents a multi-method and multi-proxy approach for palaeonvironmental investigations in the western andean cordillera of southern Peru (Lucanas province, 14° S) using cushion peatlands as terrestrial geoarchives. The region stretching between the Altiplano and the Peruvian desert in the lowland shares a long term settlement history, in which local cultures adapted to climate change in many different ways. Being one of the most outstanding human remains, the abri below Cerro Llamoca, 4.450 m a.s.l. in the uppermost ranges of the Llamoca peatland catchment area further reveals an occupation history of almost 10.000 years, as revealed by latest archaeological investigations. In remote and highly elevated regions such as the central Andes, cushion peatlands basically represent the only high resolution terrestrial archives suitable for geoarchaeological and palaeoenvironmental studies. Characterized by high accumulation rates, they ideally document environmental changes, particularly at small time intervals. Within the multidisciplinary project 'Andean Transect - Climate Sensitivity of pre-Columbian Man-Environment-Systems' several sediment cores with depths up to 11.5 m b.s. were recovered from the Llamoca peatland. Based on almost 100 AMS 14C-datings they provide a chronology of 8000 years and, thus, offer profound insights into climatic and environmental changes in the study area. While nearly homogeneous peat layers record stable environmental conditions, the heterogeneous granulometric composition of intercalated sediment layers documents several periods of intense geomorphodynamic activity. Due to high resolution geochemical analyses of peat layers (1 cm interval; humification degree, CNS measurements, XRF-scanning), the existence of slight and short-term trends of landscape development during these phases can be identified. Additional pollen, charred particles and plant macrofossil analyses confirm these findings and help reconstructing local

  17. Peatland Organic Matter Chemistry Trends Over a Global Latitudinal Gradient

    Science.gov (United States)

    Verbeke, B. A.; Hodgkins, S. B.; Carson, M. A.; Lamit, L. J.; Lilleskov, E.; Chanton, J.

    2017-12-01

    Peatlands contain a significant amount of the global soil carbon, and the climate feedback of carbon cycling within these peatland systems is still relatively unknown. Organic matter composition of peatlands plays a major role in determining carbon storage, and while high latitude peatlands seem to be the most sensitive to climate change, a global picture of peat organic matter chemistry is required to improve predictions and models of greenhouse gas emissions fueled by peatland decomposition. The objective of this research is to test the hypothesis that carbohydrate content of peatlands near the equator will be lower than high latitude peatlands, while aromatic content will be higher. As a part of the Global Peatland Microbiome Project (GPMP), around 2000 samples of peat from 10 to 70 cm across a latitudinal gradient of 79 N to 53 S were measured with Fourier transform infrared spectroscopy (FTIR) to examine the organic matter functional groups of peat. Carbohydrate and aromatic content, as determined by FTIR, are useful proxies of decomposition potential and recalcitrance, respectively. We found a highly significant relationship between carbohydrate and aromatic content, latitude, and depth. Carbohydrate content of high latitude sites were significantly greater than at sites near the equator, in contrast to aromatic content which showed the opposite trend. It is also clear that carbohydrate content decreases with depth while aromatic content increases with depth. Higher carbohydrate content at higher latitudes indicates a greater potential for lability and resultant mineralization to form the greenhouse gases, carbon dioxide and methane, whereas the composition of low latitude peatlands is consistent with their apparent stability. We speculate that the combination of low carbohydrates and high aromatics at warmer locations near the equator could foreshadow the organic matter composition of high latitude peat transitioning to a more recalcitrant form with a

  18. Vascular plants promote ancient peatland carbon loss with climate warming.

    Science.gov (United States)

    Walker, Tom N; Garnett, Mark H; Ward, Susan E; Oakley, Simon; Bardgett, Richard D; Ostle, Nicholas J

    2016-05-01

    Northern peatlands have accumulated one third of the Earth's soil carbon stock since the last Ice Age. Rapid warming across northern biomes threatens to accelerate rates of peatland ecosystem respiration. Despite compensatory increases in net primary production, greater ecosystem respiration could signal the release of ancient, century- to millennia-old carbon from the peatland organic matter stock. Warming has already been shown to promote ancient peatland carbon release, but, despite the key role of vegetation in carbon dynamics, little is known about how plants influence the source of peatland ecosystem respiration. Here, we address this issue using in situ (14)C measurements of ecosystem respiration on an established peatland warming and vegetation manipulation experiment. Results show that warming of approximately 1 °C promotes respiration of ancient peatland carbon (up to 2100 years old) when dwarf-shrubs or graminoids are present, an effect not observed when only bryophytes are present. We demonstrate that warming likely promotes ancient peatland carbon release via its control over organic inputs from vascular plants. Our findings suggest that dwarf-shrubs and graminoids prime microbial decomposition of previously 'locked-up' organic matter from potentially deep in the peat profile, facilitating liberation of ancient carbon as CO2. Furthermore, such plant-induced peat respiration could contribute up to 40% of ecosystem CO2 emissions. If consistent across other subarctic and arctic ecosystems, this represents a considerable fraction of ecosystem respiration that is currently not acknowledged by global carbon cycle models. Ultimately, greater contribution of ancient carbon to ecosystem respiration may signal the loss of a previously stable peatland carbon pool, creating potential feedbacks to future climate change. © 2016 John Wiley & Sons Ltd.

  19. Improved Hydrology over Peatlands in a Global Land Modeling System

    Science.gov (United States)

    Bechtold, M.; Delannoy, G.; Reichle, R.; Koster, R.; Mahanama, S.; Roose, Dirk

    2018-01-01

    Peatlands of the Northern Hemisphere represent an important carbon pool that mainly accumulated since the last ice age under permanently wet conditions in specific geological and climatic settings. The carbon balance of peatlands is closely coupled to water table dynamics. Consequently, the future carbon balance over peatlands is strongly dependent on how hydrology in peatlands will react to changing boundary conditions, e.g. due to climate change or regional water level drawdown of connected aquifers or streams. Global land surface modeling over organic-rich regions can provide valuable global-scale insights on where and how peatlands are in transition due to changing boundary conditions. However, the current global land surface models are not able to reproduce typical hydrological dynamics in peatlands well. We implemented specific structural and parametric changes to account for key hydrological characteristics of peatlands into NASA's GEOS-5 Catchment Land Surface Model (CLSM, Koster et al. 2000). The main modifications pertain to the modeling of partial inundation, and the definition of peatland-specific runoff and evapotranspiration schemes. We ran a set of simulations on a high performance cluster using different CLSM configurations and validated the results with a newly compiled global in-situ dataset of water table depths in peatlands. The results demonstrate that an update of soil hydraulic properties for peat soils alone does not improve the performance of CLSM over peatlands. However, structural model changes for peatlands are able to improve the skill metrics for water table depth. The validation results for the water table depth indicate a reduction of the bias from 2.5 to 0.2 m, and an improvement of the temporal correlation coefficient from 0.5 to 0.65, and from 0.4 to 0.55 for the anomalies. Our validation data set includes both bogs (rain-fed) and fens (ground and/or surface water influence) and reveals that the metrics improved less for fens. In

  20. Denitrification at two nitrogen-polluted, ombrotrophic Sphagnum bogs in Central Europe: Insights from porewater N2O-isotope profiles

    Czech Academy of Sciences Publication Activity Database

    Novák, M.; Gebauer, G.; Thoma, M.; Curik, J.; Štěpánová, M.; Jacková, I.; Buzek, F.; Bárta, J.; Santrucková, H.; Fottová, D.; Kuběna, Aleš Antonín

    2015-01-01

    Roč. 81, č. 1 (2015), s. 48-57 ISSN 0038-0717 Grant - others:GA ČR(CZ) GAP504/12/1782 Institutional support: RVO:67985556 Keywords : Denitrification * Nitrogen isotopes * Nitrous oxide * Ombrotrophic bog * Porewater * Sphagnum * Wetland * Engineering controlled terms * Meteorological problems Subject RIV: DD - Geochemistry Impact factor: 4.152, year: 2015 http://library.utia.cas.cz/separaty/2015/E/kubena-0439538.pdf

  1. Spontaneous revegetation of mined peatlands in eastern Canada

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, M.; Rochefort, L.; Quinty, F.; Lavoie, C [Laval University, Quebec, QC (Canada)

    2005-05-15

    Revegetation patterns of sphagnum recolonization at abandoned mined peatlands are assessed, based on a survey of 26 abandoned harvested peatlands, in the provinces of Quebec and New Brunswick. The impact of local and regional variables and the length of time since abandonment are examined. The vegetation structure of all 2571 trenches and 2595 blocks of abandoned block-cut areas and in all 395 vacuum fields of the mechanically mined areas was recorded. The species at 243 recolonized peat fields (selected by random sampling) were analyzed. The abandoned surfaces were found to be distinctly different depending on whether peat extraction was by hand block-cutting or vacuum mining methods. Block-cut peatlands recovered well; herb cover was similar to that in natural peatlands. Practically no sphagnum species recolonized the vacuum- mined peat fields. The species diversity in abandoned mined peat fields was observed to be high. 72 refs., 3 figs., 5 tabs., 1 app.

  2. Status of peatland degradation and development in Sumatra and Kalimantan.

    Science.gov (United States)

    Miettinen, Jukka; Liew, Soo Chin

    2010-01-01

    Peatlands cover around 13 Mha in Sumatra and Kalimantan, Indonesia. Human activities have rapidly increased in the peatland ecosystems during the last two decades, invariably degrading them and making them vulnerable to fires. This causes high carbon emissions that contribute to global climate change. For this article, we used 94 high resolution (10-20 m) satellite images to map the status of peatland degradation and development in Sumatra and Kalimantan using visual image interpretation. The results reveal that less than 4% of the peatland areas remain covered by pristine peatswamp forests (PSFs), while 37% are covered by PSFs with varying degree of degradation. Furthermore, over 20% is considered to be unmanaged degraded landscape, occupied by ferns, shrubs and secondary growth. This alarming extent of degradation makes peatlands vulnerable to accelerated peat decomposition and catastrophic fire episodes that will have global consequences. With on-going degradation and development the existence of the entire tropical peatland ecosystem in this region is in great danger.

  3. Fire Behavior in Pelalawan Peatland, Riau Province

    Directory of Open Access Journals (Sweden)

    BAMBANG HERO SAHARJO

    2006-01-01

    Full Text Available During dry season it is easily recognized that smoke will emerge at certain place both in Sumatra and Kalimantan that is in peatland. The worst situation occurred when fire burnt buried log in the logged over area where the fire fighter did not have any experience and knowledge on how to work with fire in peatland. Finally it had been found that one of the reasons why firefighter failed to fight fire in peatland is because they do not have any knowledge and experience on it. In order to know the fire behavior characteristics in different level of peat decomposition for fire management and sustainable management of the land for the community, research done in Pelalawan area, Riau Province, Indonesia, during dry season 2001. Three level of peat decomposition named Sapric, Hemic, and Fibric used. To conduct the research, two 400 m2 of plot each was established in every level of the peat decomposition. Burning done three weeks following slashing, cutting and drying at different time using circle method. During burning, flame length, rate of the spread of fire, flame temperature and following burning fuel left and the depth of peat destruction were measured. Results of research shown that in sapric site where sapric 2 has fuel load 9 ton ha-1 less than sapric 1, fire behavior was significantly different while peat destructed was deepest in sapric 2 with 31.87 cm. In hemic site where hemic 2 has fuel load 12.3 ton ha-1 more than hemic 1, fire behavior was significantly different and peat destructed deeper than hemic 1 that was 12.6 cm. In fibric site where fibric 1 has fuel load 3.5 ton ha-1 more than fibric 1, fire behavior was significantly different that has no burnt peat found. This results found that the different fuel characteristics (potency, moisture, bed depth, and type at the same level of peat decomposition will have significantly different fire behavior as it happened also on the depth of peat destruction except fibric. The same condition

  4. Nutrients and Hydrology Indicate the Driving Mechanisms of Peatland Surface Patterning

    NARCIS (Netherlands)

    Eppinga, M.B.; Ruiter, de P.C.; Wassen, M.J.; Rietkerk, M.

    2009-01-01

    Peatland surface patterning motivates studies that identify underlying structuring mechanisms. Theoretical studies so far suggest that different mechanisms may drive similar types of patterning. The long time span associated with peatland surface pattern formation, however, limits possibilities for

  5. AMS measurements of global fallout U-236 and Pu in an ombrotrophic peat profile: evidence for their post depositional migration

    Energy Technology Data Exchange (ETDEWEB)

    Quinto, Francesca; Hrnecek, Erich; Krachler, Michael [European Commission Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Shotyk, William [Department of Renewable Resources, University of Alberta, 839 General Services Building, Edmonton, AB (Canada); Steier, Peter; Winkler, Stephan; Golser, Robin [VERA Laboratory, Faculty of Physics, University of Vienna, Waehringer Strasse 17, A-1090 Vienna (Austria)

    2014-07-01

    U-236, Pu-239, Pu-240, Pu-241 and Pu-242 were analysed in an ombrotrophic peat core representing the last 80 years of atmospheric deposition. The determination of these isotopes at femtogram and attogram levels was possible by using ultra-clean laboratory procedures and accelerator mass spectrometry. Since the Pu isotopic composition characteristic for global fallout, as well as anthropogenic U-236, were identified in peat samples pre-dating the period of atmospheric atom bomb testing, migration of Pu and U within the peat profile is clearly indicated. The vertical profile of the U-236/U-238 isotopic ratio represents the first observation of the U-236 bomb peak in a terrestrial environment. Comparing the abundances of the global fallout derived U-236 and Pu-239 along the peat core, the post depositional migration of plutonium exceeds that of uranium. These results highlight, for the first time, the mobility of Pu and U in a peat bog with implications for their migration in other acidic, organic rich environments.

  6. Sphagnum mosses from 21 ombrotrophic bogs in the athabasca bituminous sands region show no significant atmospheric contamination of "heavy metals".

    Science.gov (United States)

    Shotyk, William; Belland, Rene; Duke, John; Kempter, Heike; Krachler, Michael; Noernberg, Tommy; Pelletier, Rick; Vile, Melanie A; Wieder, Kelman; Zaccone, Claudio; Zhang, Shuangquan

    2014-11-04

    Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the "cleanest", ancient peat samples ever tested from the northern hemisphere (ca. 6000-9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of "natural, background" values. The concentrations of "heavy metals" in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower.

  7. Decreasing concentrations of metals in Sphagnum mosses in ombrotrophic mires of the Sudety mountains (SW Poland) since late 1980s.

    Science.gov (United States)

    Wojtuń, Bronisław; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Kempers, Alexander J

    2013-06-01

    In this investigation we focus on the evaluation of changes in metal pollution between 1986 until 2011 by Sphagnum species as bioindicators in 100 km part of the Sudety mountains influenced by the former Black Triangle Region. Concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in various Sphagnum species all from ombrotrophic bogs in the Sudety mountains (SW Poland). The tested hypothesis was that overall improvements in pollution control in the former Black Triangle Region between 1986 until recent reduced the amount of metals deposited and accumulated by these plants. Concentrations of Cd, Cr, Cu, Fe, Pb and Zn in Sphagnum species were very high in 1986 indicating a heavy pollution of the examined bogs in this period, and significantly higher than in samples collected in 2011. The PCCA ordination showed the similar pattern in all bogs. In 2011 concentration of the Co was significantly higher in hollow species and concentration of Mn was significantly higher in those from hummocks. Differences between hollow/hummock sites were more important than species-specific abilities of Sphagnum mosses to accumulate metals. Species from hollows were better bioindicators of Co and those from hummocks were better bioindicators of Mn pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Peatland Carbon Dynamics in Alaska During Past Warm Climates

    Science.gov (United States)

    Yu, Z.; Cleary, K.; Massa, C.; Hunt, S. J.; Klein, E. S.; Loisel, J.

    2013-12-01

    Peatlands represent a large belowground carbon (C) pool in the biosphere. However, how peatland C sequestration capacity varies with changes in climate and climate-induced disturbance is still poorly understood and debated. Here we summarize results from Alaskan peatlands to document how peat C accumulation has responded to past warm climate intervals. We find that the greatest C accumulation rates at sites from the Kenai Peninsula to the North Slope occurred during the Holocene thermal maximum (HTM) in the early Holocene. This time period also corresponds with explosive formation and expansion of new peatlands on the landscape across Alaska. In addition, we note that many peatlands that existed during the earlier Holocene on the North Slope have disappeared and are presently covered by mineral soils under tundra or sandy deposits. During the Medieval Climate Anomaly (MCA) around 1000-500 years ago, several peatlands in Alaska show high rates of C accumulation when compared to the period before the MCA during the Neoglacial or the following Little Ice Age period. Altogether, our results indicate that the Alaskan landscape was very different during the last 10,000 years and that peatlands can rapidly accumulate C under warm climatic conditions. We speculate that warmth-stimulated increase in plant production surpasses increase in peat decomposition during the early Holocene, and potentially also during the MCA. Other factors that might have contributed to rapid peat accumulation during the early Holocene include increased summer sunlight, lowered sea levels, and decreased sea-ice cover/duration. Summer insolation was ca. 8% higher than today during the early Holocene due to orbital variations, which likely promoted plant productivity by increasing growing seasons sunlight. Furthermore, lower sea levels and exposed shallow continental shelves in the Beaufort Sea (Arctic Ocean) would have made the present-day Arctic Coastal Plain more continental, with warmer summers

  9. Nitrogen removal in Northern peatlands treating mine wastewaters

    Science.gov (United States)

    Palmer, Katharina; Karlsson, Teemu; Turunen, Kaisa; Liisa Räisänen, Marja; Backnäs, Soile

    2015-04-01

    Natural peatlands can be used as passive purification systems for mine wastewaters. These treatment peatlands are well-suited for passive water treatment as they delay the flow of water, and provide a large filtration network with many adsorptive surfaces on plant roots or soil particles. They have been shown to remove efficiently harmful metals and metalloids from mine waters due to variety of chemical, physical and biological processes such as adsorption, precipitation, sedimentation, oxidation and reduction reactions, as well as plant uptake. Many factors affect the removal efficiency such as inflow water quality, wetland hydrology, system pH, redox potential and temperature, the nature of the predominating purification processes, and the presence of other components such as salts. However, less attention has been paid to nitrogen (N) removal in peatlands. Thus, this study aimed to assess the efficiency of N removal and seasonal variation in the removal rate in two treatment peatlands treating mine dewatering waters and process effluent waters. Water sampling from treatment peatland inflow and outflow waters as well as pore waters in peatland were conducted multiple times during 2012-2014. Water samples were analysed for total N, nitrate-N and ammonium-N. Additionally, an YSI EXO2 device was used for continuous nitrate monitoring of waters discharged from treatment peatlands to the recipient river during summer 2014. The results showed that the oxic conditions in upper peat layer and microbial activity in treatment peatlands allowed the efficient oxidation of ammonium-N to nitrite-N and further to nitrate-N during summer time. However, the slow denitrification rate restricts the N removal as not all of the nitrate produced during nitrification is denitrified. In summer time, the removal rate of total N varied between 30-99 % being highest in late summer. N removal was clearly higher for treatment peatland treating process effluent waters than for peatland

  10. Restoration Ecology of Lowland tropical Peatlands in Southeast Asia: Current Knowledge and Future Research Directions

    NARCIS (Netherlands)

    Page, S.; Hoscilo, A.; Wösten, J.H.M.; Jauhiainen, J.; Silvius, M.J.; Rieley, J.; Ritzema, H.P.; Tansey, K.; Graham, L.; Vasander, H.; Limin, S.

    2009-01-01

    Studies of restoration ecology are well established for northern peatlands, but at an early stage for tropical peatlands. Extensive peatland areas in Southeast Asia have been degraded through deforestation, drainage and fire, leading to on- and off-site environmental and socio-economic impacts of

  11. Representing northern peatland microtopography and hydrology within the Community Land Model

    Science.gov (United States)

    X. Shi; P.E. Thornton; D.M. Ricciuto; P J. Hanson; J. Mao; Stephen Sebestyen; N.A. Griffiths; G. Bisht

    2015-01-01

    Predictive understanding of northern peatland hydrology is a necessary precursor to understanding the fate of massive carbon stores in these systems under the influence of present and future climate change. Current models have begun to address microtopographic controls on peatland hydrology, but none have included a prognostic calculation of peatland water table depth...

  12. Fire and Microtopography in Peatlands: Feedbacks and Carbon Dynamics

    Science.gov (United States)

    Benscoter, B.; Turetsky, M. R.

    2011-12-01

    Fire is the dominant natural disturbance in peatland ecosystems. Over the past decade, peat fires have emerged as an important issue for global climate change, human health, and economic loss, largely due to the extreme peat fire events in Indonesia and Russia that severely impacted metropolitan areas and social infrastructure. However, the impact and importance of fire in peatland ecosystems are more far-reaching. Combustion of vegetation and soil organic matter releases an average of 2.2 kg C m-2 to the atmosphere, primarily as CO2, as well as a number of potentially harmful emissions such as fine particulate matter and mercury. Additionally, while peatlands are generally considered to be net sinks of atmospheric carbon, the removal of living vegetation by combustion halts primary production following fire resulting in a net loss of ecosystem carbon to the atmosphere for several years. The recovery of carbon sink function is linked to plant community succession and development, which can vary based on combustion severity and the resulting post-fire microhabitat conditions. Microtopography has a strong influence on fire behavior and combustion severity during peatland wildfires. In boreal continental peatlands, combustion severity is typically greatest in low-lying hollows while raised hummocks are often lightly burned or unburned. The cross-scale influence of microtopography on landscape fire behavior is due to differences in plant community composition between microforms. The physiological and ecohydrological differences among plant communities result in spatial patterns in fuel availability and condition, influencing the spread, severity, and type of combustion over local to landscape scales. In addition to heterogeneous combustion loss of soil carbon, this differential fire behavior creates variability in post-fire microhabitat conditions, resulting in differences in post-fire vegetation succession and carbon exchange trajectories. These immediate and legacy

  13. New approaches to the restoration of shallow marginal peatlands.

    Science.gov (United States)

    Grand-Clement, E; Anderson, K; Smith, D; Angus, M; Luscombe, D J; Gatis, N; Bray, L S; Brazier, R E

    2015-09-15

    Globally, the historic and recent exploitation of peatlands through management practices such as agricultural reclamation, peat harvesting or forestry, have caused extensive damage to these ecosystems. Their value is now increasingly recognised, and restoration and rehabilitation programmes are underway to improve some of the ecosystem services provided by peatlands: blocking drainage ditches in deep peat has been shown to improve the storage of water, decrease carbon losses in the long-term, and improve biodiversity. However, whilst the restoration process has benefitted from experience and technical advice gained from restoration of deep peatlands, shallow peatlands have received less attention in the literature, despite being extensive in both uplands and lowlands. Using the experience gained from the restoration of the shallow peatlands of Exmoor National Park (UK), and two test catchments in particular, this paper provides technical guidance which can be applied to the restoration of other shallow peatlands worldwide. Experience showed that integrating knowledge of the historical environment at the planning stage of restoration was essential, as it enabled the effective mitigation of any threat to archaeological features and sites. The use of bales, commonly employed in other upland ecosystems, was found to be problematic. Instead, 'leaky dams' or wood and peat combination dams were used, which are both more efficient at reducing and diverting the flow, and longer lasting than bale dams. Finally, an average restoration cost (£306 ha(-1)) for Exmoor, below the median national value across the whole of the UK, demonstrates the cost-effectiveness of these techniques. However, local differences in peat depth and ditch characteristics (i.e. length, depth and width) between sites affect both the feasibility and the cost of restoration. Overall, the restoration of shallow peatlands is shown to be technically viable; this paper provides a template for such process

  14. Preferences of Local People for the Use of Peatlands: the Case of the Richest Peatland Region in Finland

    Directory of Open Access Journals (Sweden)

    Anne Tolvanen

    2013-06-01

    Full Text Available We analyze the potential for socioeconomically sustainable peatland use by investigating conflicting interests, revealing trade-offs that people are willing to accept, and studying whether opinions are dependent on socioeconomic and demographic factors. Opinions toward five forms of peatland use and seven peatland ecosystem services were surveyed in Northern Ostrobothnia in northern Finland in 2011. Choice experiment (CE was used to reveal trade-offs in land use preferences, and groups of respondents were identified using the latent class model (LCM. We identified three classes of respondents in which environmentalists showed a high preference toward the cessation of peat production and increase of peatland restoration, the production-oriented class preferred an increase in timber and peat production areas, and the current use supporters agreed on the present land use policy. However, all respondent classes agreed on the increase of nature protection and the present level of timber production and disagreed on the cessation of restoration. The CE revealed that environmentally minded people who are likely to consider the indirect use values and existence values important are less willing to make trade-offs between ecosystem services than those who emphasize direct use values. Because peatland restoration occurs in commercially unproductive peatlands, it improves both the direct use and existence values without reducing provisioning services of peatlands. Therefore, restoration is commonly accepted by the public, in contrast to management options that involve clear trade-offs between ecosystem services. We conclude that the understanding of preferences and trade-offs can enhance sustainable land use planning. It may be unrealistic, however, to expect a solution that all interest groups would completely accept.

  15. Towards a Global High Resolution Peatland Map in 2020

    Science.gov (United States)

    Barthelmes, Alexandra; Barthelmes, Karen-Doreen; Joosten, Hans; Dommain, Rene; Margalef, Olga

    2015-04-01

    Some 3% of land area on planet Earth (approx. 4 million km2) is covered by peatlands. About 10% (~ 0.3 % of the land area) are drained and responsible for a disproportional 5 % of the global anthropogenic CO2 emissions (Victoria et al., 2012). Additionally, peatland drainage and degradation lead to land subsidence, soil degradation, water pollution, and enhanced susceptibility to fire (Holden et al., 2004; Joosten et al., 2012). The global importance of peatlands for carbon storage and climate change mitigation has currently been recognized in international policy - since 2008 organic soils are subject of discussion in the UN Framework Convention on Climate Change (UNFCCC) (Joosten, 2011). In May 2013 the European Parliament decided that the global post 2020 climate agreement should include the obligation to report emissions and removals from peatland drainage and rewetting. Implementation of such program, however, necessitates the rapid availability of reliable, comprehensive, high resolution, spatially explicit data on the extent and status of peatlands. For many reporting countries this requires an innovation in peatland mapping, i.e. the better and integrative use of novel, but already available methods and technologies. We developed an approach that links various science networks, methodologies and data bases, including those of peatland/landscape ecology for understanding where and how peatlands may occur, those of remote sensing for identifying possible locations, and those of pedology (legacy soil maps) and (palaeo-)ecology for ground truthing. Such integration of old field data, specialized knowledge, and modern RS and GIS technologies enables acquiring a rapid, comprehensive, detailed and rather reliable overview, even on a continental scale. We illustrate this approach with a high resolution overview of peatland distribution, area, status and greenhouse gas fluxes e.g. for the East African countries Rwanda, Burundi, Uganda and Zambia. Furthermore, we

  16. Airborne Electromagnetic Mapping of Peatlands: a Case Study in Norway.

    Science.gov (United States)

    Silvestri, S.; Viezzoli, A.; Pfaffhuber, A. A.; Vettore, A.

    2017-12-01

    Peatlands are extraordinary reservoirs of organic carbon that can be found over a wide range of latitudes, in tropical, to temperate, to (sub)polar climates. According to some estimates, the carbon stored in peatlands almost match the atmospheric carbon pool. Peatlands degradation due to natural and anthropogenic factors releases every year large amount of CO2 and other green house gasses into the atmosphere. The conservation of peatlands is therefore a key measure to reduce emissions and to mitigate climate change. An effective plan to prevent peatlands degradation must move from a precise estimate of the volume of peat stored across vast territories around the world. One example are the several bogs that characterize large surfaces in Norway. Our research combines the use of high spatial resolution satellite optical data with Airborne Electromagnetic (AEM) and field measurements in order to map the extension and thickness of peat in Brøttum, Ringsaker province, Norway. The methodology allows us to quantify the volume of peat as well as the organic carbon stock. The variable thickness typical of Norwegian bogs allows us to test the limits of the AEM methodology in resolving near surface peat layers. This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 747809. Start date: 1 June 2017. Duration: 24 months

  17. In the line of fire: the peatlands of Southeast Asia.

    Science.gov (United States)

    Page, S E; Hooijer, A

    2016-06-05

    Peatlands are a significant component of the global carbon (C) cycle, yet despite their role as a long-term C sink throughout the Holocene, they are increasingly vulnerable to destabilization. Nowhere is this shift from sink to source happening more rapidly than in Southeast Asia, and nowhere else are the combined pressures of land-use change and fire on peatland ecosystem C dynamics more evident nor the consequences more apparent. This review focuses on the peatlands of this region, tracing the link between deforestation and drainage and accelerating C emissions arising from peat mineralization and fire. It focuses on the implications of the recent increase in fire occurrence for air quality, human health, ecosystem resilience and the global C cycle. The scale and controls on peat-driven C emissions are addressed, noting that although fires cause large, temporary peaks in C flux to the atmosphere, year-round emissions from peat mineralization are of a similar magnitude. The review concludes by advocating land management options to reduce future fire risk as part of wider peatland management strategies, while also proposing that this region's peat fire dynamic could become increasingly relevant to northern peatlands in a warming world.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Author(s).

  18. Built-up resilience to climate change in peatlands

    Science.gov (United States)

    Wang, H.; Tian, J.; Ho, M.; Flanagan, N. E.; Vilgalys, R.; Richardson, C. J.

    2017-12-01

    Peatlands have stored about 30% of global soil carbon over millennia. Most studies suggest that climate change effects, like drought and warming, may decrease C sequestration and increase C loss in peatlands, thus resulting in a positive feedback on climate change. However, the long-term feedback between plant-microbe mediated carbon processes and climate change still remains highly uncertain. Here, we conducted a series of field and lab experiments in southern shrub and northern Sphagnum peatlands to document how previously unrecognized mechanisms regulate the buildup of anti-microbial phenolics, which protects stored carbon directly by reducing phenol oxidase activity during short-term drought, and indirectly through a shift from low-phenolics Sphagnum/herbs to high-phenolics shrubs after long-term moderate drought. We further showed a symbiosis of slow-growing decomposers concomitant with a shift of high-phenolic plants, which increased peat resistance to disturbance. Our results indicate that shrub expansion induced by climate change in boreal peatlands may be a long-term self-adaptive mechanism not only increasing carbon sequestration, but also potentially protecting soil carbon. Therefore, peatlands are highly resilient ecosystems in which the symbiotic adaption of both plants and microbes, triggered by persistent climate change, likely can acclimate to the stressors and maintain their carbon sequestration function and processes.

  19. Delineation of peatland lagg boundaries from airborne LiDAR

    Science.gov (United States)

    Langlois, Melanie N.; Richardson, Murray C.; Price, Jonathan S.

    2017-09-01

    In Canada, peatlands are the most common type of wetland, but boundary delineation in peatland complexes has received little attention in the scientific literature. Typically, peatland boundaries are mapped as crisp, absolute features, and the transitional lagg zone—the ecotone found between a raised bog and the surrounding mineral land—is often overlooked. In this study, we aim (1) to advance existing approaches for detecting and locating laggs and lagg boundaries using airborne LiDAR surveys and (2) to describe the spatial distribution of laggs around raised bog peatlands. Two contrasting spatial analytical approaches for lagg detection were tested using five LiDAR-derived topographic and vegetation indices: topography, vegetation height, topographic wetness index, the standard deviation of the vegetation's height (as a proxy for the complexity of the vegetation's structure), and local indices of elevation variance. Using a dissimilarity approach (edge-detection, split-moving window analysis), no one variable accurately depicted both the lagg-mineral land and bog-lagg boundaries. Some indicators were better at predicting the bog-lagg boundary (i.e., vegetation height) and others at finding the lagg-mineral land boundary (i.e., topography). Dissimilarity analysis reinforces the usefulness of derived variables (e.g., wetness indices) in locating laggs, especially for those with weak topographic and vegetation gradients. When the lagg was confined between the bog and the adjacent upland, it took a linear form, parallel to the peatland's edge and was easier to predict. When the adjacent mineral land was flat or sloping away from the peatland, the lagg was discontinuous and intermittent and more difficult to predict.

  20. Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

    Directory of Open Access Journals (Sweden)

    D. K. Hare

    2017-11-01

    Full Text Available Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns

  1. Hydrogeological controls on spatial patterns of groundwater discharge in peatlands

    Science.gov (United States)

    Hare, Danielle K.; Boutt, David F.; Clement, William P.; Hatch, Christine E.; Davenport, Glorianna; Hackman, Alex

    2017-11-01

    Peatland environments provide important ecosystem services including water and carbon storage, nutrient processing and retention, and wildlife habitat. However, these systems and the services they provide have been degraded through historical anthropogenic agricultural conversion and dewatering practices. Effective wetland restoration requires incorporating site hydrology and understanding groundwater discharge spatial patterns. Groundwater discharge maintains wetland ecosystems by providing relatively stable hydrologic conditions, nutrient inputs, and thermal buffering important for ecological structure and function; however, a comprehensive site-specific evaluation is rarely feasible for such resource-constrained projects. An improved process-based understanding of groundwater discharge in peatlands may help guide ecological restoration design without the need for invasive methodologies and detailed site-specific investigation. Here we examine a kettle-hole peatland in southeast Massachusetts historically modified for commercial cranberry farming. During the time of our investigation, a large process-based ecological restoration project was in the assessment and design phases. To gain insight into the drivers of site hydrology, we evaluated the spatial patterning of groundwater discharge and the subsurface structure of the peatland complex using heat-tracing methods and ground-penetrating radar. Our results illustrate that two groundwater discharge processes contribute to the peatland hydrologic system: diffuse lower-flux marginal matrix seepage and discrete higher-flux preferential-flow-path seepage. Both types of groundwater discharge develop through interactions with subsurface peatland basin structure, often where the basin slope is at a high angle to the regional groundwater gradient. These field observations indicate strong correlation between subsurface structures and surficial groundwater discharge. Understanding these general patterns may allow resource

  2. Soil Carbon Chemistry and Greenhouse Gas Production in Global Peatlands

    Science.gov (United States)

    Normand, A. E.; Turner, B. L.; Lamit, L. J.; Smith, A. N.; Baiser, B.; Clark, M. W.; Hazlett, C.; Lilleskov, E.; Long, J.; Grover, S.; Reddy, K. R.

    2017-12-01

    Peatlands play a critical role in the global carbon cycle because they contain approximately 30% of the 1500 Pg of carbon stored in soils worldwide. However, the stability of these vast stores of carbon is under threat from climate and land-use change, with important consequences for global climate. Ecosystem models predict the impact of peatland perturbation on carbon fluxes based on total soil carbon pools, but responses could vary markedly depending on the chemical composition of soil organic matter. Here we combine experimental and observational studies to quantify the chemical nature and response to perturbation of soil organic matter in peatlands worldwide. We quantified carbon functional groups in a global sample of 125 freshwater peatlands using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy to determine the drivers of molecular composition of soil organic matter. We then incubated a representative subset of the soils under aerobic and anaerobic conditions to determine how organic matter composition influences carbon dioxide (CO2) and methane (CH4) emissions following drainage or flooding. The functional chemistry of peat varied markedly at large and small spatial scales, due to long-term land use change, mean annual temperature, nutrient status, and vegetation, but not pH. Despite this variation, we found predictable responses of greenhouse gas production following drainage based on soil carbon chemistry, defined by a novel Global Peat Stability Index, with greater CO2 and CH4 fluxes from soils enriched in oxygen-containing organic carbon (O-alkyl C) and depleted in aromatic and hydrophobic compounds. Incorporation of the Global Peat Stability Index of peatland organic matter into earth system models and management strategies, which will improve estimates of GHG fluxes from peatlands and ultimately advance management to reduce carbon loss from these sensitive ecosystems.

  3. Peatland Acidobacteria with a dissimilatory sulfur metabolism.

    Science.gov (United States)

    Hausmann, Bela; Pelikan, Claus; Herbold, Craig W; Köstlbacher, Stephan; Albertsen, Mads; Eichorst, Stephanie A; Glavina Del Rio, Tijana; Huemer, Martin; Nielsen, Per H; Rattei, Thomas; Stingl, Ulrich; Tringe, Susannah G; Trojan, Daniela; Wentrup, Cecilia; Woebken, Dagmar; Pester, Michael; Loy, Alexander

    2018-02-23

    Sulfur-cycling microorganisms impact organic matter decomposition in wetlands and consequently greenhouse gas emissions from these globally relevant environments. However, their identities and physiological properties are largely unknown. By applying a functional metagenomics approach to an acidic peatland, we recovered draft genomes of seven novel Acidobacteria species with the potential for dissimilatory sulfite (dsrAB, dsrC, dsrD, dsrN, dsrT, dsrMKJOP) or sulfate respiration (sat, aprBA, qmoABC plus dsr genes). Surprisingly, the genomes also encoded DsrL, which so far was only found in sulfur-oxidizing microorganisms. Metatranscriptome analysis demonstrated expression of acidobacterial sulfur-metabolism genes in native peat soil and their upregulation in diverse anoxic microcosms. This indicated an active sulfate respiration pathway, which, however, might also operate in reverse for dissimilatory sulfur oxidation or disproportionation as proposed for the sulfur-oxidizing Desulfurivibrio alkaliphilus. Acidobacteria that only harbored genes for sulfite reduction additionally encoded enzymes that liberate sulfite from organosulfonates, which suggested organic sulfur compounds as complementary energy sources. Further metabolic potentials included polysaccharide hydrolysis and sugar utilization, aerobic respiration, several fermentative capabilities, and hydrogen oxidation. Our findings extend both, the known physiological and genetic properties of Acidobacteria and the known taxonomic diversity of microorganisms with a DsrAB-based sulfur metabolism, and highlight new fundamental niches for facultative anaerobic Acidobacteria in wetlands based on exploitation of inorganic and organic sulfur molecules for energy conservation.

  4. Northern peatland carbon stocks and dynamics: a review

    Directory of Open Access Journals (Sweden)

    Z. C. Yu

    2012-10-01

    Full Text Available Peatlands contain a large belowground carbon (C stock in the biosphere, and their dynamics have important implications for the global carbon cycle. However, there are still large uncertainties in C stock estimates and poor understanding of C dynamics across timescales. Here I review different approaches and associated uncertainties of C stock estimates in the literature, and on the basis of the literature review my best estimate of C stocks and uncertainty is 500 ± 100 (approximate range gigatons of C (Gt C in northern peatlands. The greatest source of uncertainty for all the approaches is the lack or insufficient representation of data, including depth, bulk density and carbon accumulation data, especially from the world's large peatlands. Several ways to improve estimates of peat carbon stocks are also discussed in this paper, including the estimates of C stocks by regions and further utilizations of widely available basal peat ages.

    Changes in peatland carbon stocks over time, estimated using Sphagnum (peat moss spore data and down-core peat accumulation records, show different patterns during the Holocene, and I argue that spore-based approach underestimates the abundance of peatlands in their early histories. Considering long-term peat decomposition using peat accumulation data allows estimates of net carbon sequestration rates by peatlands, or net (ecosystem carbon balance (NECB, which indicates more than half of peat carbon (> 270 Gt C was sequestrated before 7000 yr ago during the Holocene. Contemporary carbon flux studies at 5 peatland sites show much larger NECB during the last decade (32 ± 7.8 (S.E. g C m−2 yr–1 than during the last 7000 yr (∼ 11 g C m−2 yr–1, as modeled from peat records across northern peatlands. This discrepancy highlights the urgent need for carbon accumulation data and process understanding, especially at decadal and centennial timescales

  5. Ecophysiology at SPRUCE: Impacts of whole ecosystem warming and elevated CO2 on leaf-level photosynthesis and respiration of two ericaceous shrubs in a boreal peatland

    Science.gov (United States)

    Ward, E. J.; Dusenge, M. E.; Warren, J.; Murphy, B. K.; Way, D.; King, A. W.; McLennan, D.; Montgomery, R.; Stefanski, A.; Reich, P. B.; Cruz Aguilar, M.; Wullschleger, S.; Bermudez Villanueva, R.; Hanson, P. J.

    2017-12-01

    The Spruce and Peatland Responses Under Changing Environments (SPRUCE) project is a large-scale, long-term experiment investigating the effects of warming and elevated CO2 on an ombrotrophic bog in Minnesota, USA. SPRUCE uses 10 large (12.8-m diameter) enclosures to increase air and soil temperatures to a range of targets (+0 °C, +2.25 °C, +4.5 °C, +6.75 °C, +9 °C) under both ambient and elevated (+500 ppm) CO2 concentrations. Whole-ecosystem-warming treatments began in August 2015 and elevated CO2 treatments began in June 2016. This talk will address the photosynthetic and respiratory responses of vascular plants to the treatments as measured with a variety of in-situ and ex-situ measurements conducted throughout the 2016 and 2017 growing seasons. We will focus on the responses of two dominant ericaceous shrubs (Rhododendron groenlandicum and Chamaedaphne calyculata), which account for more 80% of the understory biomass of this open-canopy forest. Such physiological changes are not only leading indicators of changes in plant growth and community structure, but are crucial to understanding carbon cycling of raised bogs and representing boreal peatlands in global dynamic vegetation models. Pre-treatment data collected at this site indicate that the physiologically active season typically begins in late May and extends into the fall until freezing nighttime temperatures are consistently reached, typically in October. Post-treatment measurements made during seasonal transitions indicate a longer active physiological season in warmer treatments. Results from 2016 measurements show some degree of thermal acclimation of photosynthesis in R. groenlandicum and of respiration in both species in the early growing season, but not late season. Late season measurements show a down-regulation of photosynthesis in both shrub species grown under elevated CO2. Taken as a whole, these results indicate complex interactions between phenological changes and treatment effects on

  6. Peatland Microbial Communities as Indicators of the Extreme Atmospheric Dust Deposition.

    Science.gov (United States)

    Fiałkiewicz-Kozieł, B; Smieja-Król, B; Ostrovnaya, T M; Frontasyeva, M; Siemińska, A; Lamentowicz, M

    We investigated a peat profile from the Izery Mountains, located within the so-called Black Triangle, the border area of Poland, Czech Republic, and Germany. This peatland suffered from an extreme atmospheric pollution during the last 50 years, which created an exceptional natural experiment to examine the impact of pollution on peatland microbes. Testate amoebae (TA), Centropyxis aerophila and Phryganella acropodia , were distinguished as a proxy of atmospheric pollution caused by extensive brown coal combustion. We recorded a decline of mixotrophic TA and development of agglutinated taxa as a response for the extreme concentration of Al (30 g kg -1 ) and Cu (96 mg kg -1 ) as well as the extreme amount of fly ash particles determined by scanning electron microscopy (SEM) analysis, which were used by TA for shell construction. Titanium (5.9 %), aluminum (4.7 %), and chromium (4.2 %) significantly explained the highest percentage of the variance in TA data. Elements such as Al, Ti, Cr, Ni, and Cu were highly correlated ( r  > 0.7, p  < 0.01) with pseudostome position/body size ratio and pseudostome position. Changes in the community structure, functional diversity, and mechanisms of shell construction were recognized as the indicators of dust pollution. We strengthen the importance of the TA as the bioindicators of the recent atmospheric pollution.

  7. Retention of atmospheric Cu, Ni, Cd and Zn in an ombrotrophic peat profile near the Outokumpu Cu-Ni mine, SE-Finland

    Science.gov (United States)

    Rausch, N.; Nieminen, T. M.; Ukonmaanaho, L.; Cheburkin, A.; Krachler, M.; Shotyk, W.

    2003-05-01

    Peat cores taken from ombrotrophic bogs are widely used to reconstruct historical records of atmospheric lead and mercury déposition[1, 2]. In this study, the retention of copper, nickel, cadmium and zinc in peat bogs are studied by comparing high resolution, age dated concentration profiles with emissions from the main local source, the Outokumpu copper-nickel mine. An ombrotrophic peat core was taken from the vicinity of Outokumpu, E Finland. Copper and zinc concentrations of dry peat were measured by XRF, cadmium and nickel by GF-AAS, and sample ages by 210Pb. Only copper and nickel show enhanced concentrations in layers covering the mining period, indicating a retention of these elements. However, the more detailed comparison of ore production rates and concentrations in age-dated samples show clearly that only copper is likely to be permanently fixed, while nickel doesn't reflect the mining activity. Even though copper is retained in the upper part of the profile, a possible redeposition of this element by secondary processes (e.g., water table fluctuations) can not be excluded. This question will be resolved by further investigations, e.g. by pore water profiles.

  8. Fire Distribution in Peninsular Malaysia, Sumatra and Borneo in 2015 with Special Emphasis on Peatland Fires.

    Science.gov (United States)

    Miettinen, Jukka; Shi, Chenghua; Liew, Soo Chin

    2017-10-01

    In this paper, we analyze the spatio-temporal distribution of vegetation fires in Peninsular Malaysia, Sumatra, and Borneo in the severe El Niño year of 2015, concentrating on the distribution of fires between mineral soils and peatland areas, and between land cover types in peatland areas. The results reveal that 53% of all Moderate Resolution Imaging Spectroradiometer (MODIS) fire detections were recorded in peatlands that cover only 12% of the study area. However, fire occurrence in the peatland areas was highly dependent on land cover type. Pristine peat swamp forests (PSF) experienced only marginal fire activity (30 fire detections per 1000 km 2 ) compared to deforested undeveloped peatlands (831-915 fire detections per 1000 km 2 ). Our results also highlight the extreme fire vulnerability of the southern Sumatran and Bornean peatlands under strong El Niño conditions: 71% of all peatland hotspots were detected in the provinces of South Sumatra and Central Kalimantan, which contain 29% of peatlands in the study area. Degraded PSF and all deforested peatland land cover types, including managed areas, in the two provinces were severely affected, demonstrating how difficult it is to protect even managed drained agricultural areas from unwanted fires during dry periods. Our results thereby advocate rewetting and rehabilitation as the primary management option for highly fire prone degraded undeveloped peatland areas, whenever feasible, as a means to reduce fire risk during future dry episodes.

  9. Northern peatland initiation lagged abrupt increases in deglacial atmospheric CH4.

    Science.gov (United States)

    Reyes, Alberto V; Cooke, Colin A

    2011-03-22

    Peatlands are a key component of the global carbon cycle. Chronologies of peatland initiation are typically based on compiled basal peat radiocarbon (14C) dates and frequency histograms of binned calibrated age ranges. However, such compilations are problematic because poor quality 14C dates are commonly included and because frequency histograms of binned age ranges introduce chronological artefacts that bias the record of peatland initiation. Using a published compilation of 274 basal 14C dates from Alaska as a case study, we show that nearly half the 14C dates are inappropriate for reconstructing peatland initiation, and that the temporal structure of peatland initiation is sensitive to sampling biases and treatment of calibrated 14C dates. We present revised chronologies of peatland initiation for Alaska and the circumpolar Arctic based on summed probability distributions of calibrated 14C dates. These revised chronologies reveal that northern peatland initiation lagged abrupt increases in atmospheric CH4 concentration at the start of the Bølling-Allerød interstadial (Termination 1A) and the end of the Younger Dryas chronozone (Termination 1B), suggesting that northern peatlands were not the primary drivers of the rapid increases in atmospheric CH4. Our results demonstrate that subtle methodological changes in the synthesis of basal 14C ages lead to substantially different interpretations of temporal trends in peatland initiation, with direct implications for the role of peatlands in the global carbon cycle.

  10. Peatlands as a unique climatic hotspots

    Science.gov (United States)

    Slowinska, S.; Marcisz, K.; Slowinski, M. M.; Blazejczyk, K.; Lamentowicz, M.

    2017-12-01

    Peatlands are unique environments, often acting as microrefugia of various taxa. High groundwater table, organic soils, specific vegetation and topography are important determinants of their local climatic conditions. However, relations between those determinants are not stable. For example, seasonal changes in weather patterns, hydrological dynamics, and local vegetation may alter microclimate. Additionally, long-term changes are important factor, as for example overgrowing due to significant change of microclimate conditions, what in turn changes geochemical and biological processes in the peat layer. We have been investigating interactions between abiotic and biotic factors of a small Sphagnum mire (ca. 6.0 ha) for over ten years now. The mire is located in Poland in transitional temperate climate and is the only place in polish lowlands where glacial relict Betula nana occurs. Identification of local climate of the mire, its microclimatic differentiation and its influence on surroundings were objectives of the study. We recorded water level fluctuations, photosynthetically active radiation (PAR), air temperature and humidity, and peat temperature at five monitoring plots at the mire and observed significant differences between them. We also investigated Sphagnum mosses growth and testate amoeba diversity and community structure to understand biological response of those differences. We observed that local climate of the mire was significantly different from open area reference place, it was much colder especially during nights. The average minimal temperature at the height 30 cm for growing seasons 2010-2012 was 3.7oC lower there and ground frosts occurred even in the summer. The climate of the mire affected the forest directly adjacent to it, and depending on weather conditions the strength and the distance of this interaction was different. Our results show that micro-environmental changes affects on biological processes and should be taken into consideration

  11. Geomorphology and landscape organization of a northern peatland complex

    Science.gov (United States)

    Richardson, M. C.

    2012-12-01

    The geomorphic evolution of northern peatlands is governed by complex ecohydrological feedback mechanisms and associated hydro-climatic drivers. For example, prevailing models of bog development (i.e. Ingram's groundwater mounding hypothesis and variants) attempt to explicitly link bog dome characteristics to the regional climate based on analytical and numerical models of lateral groundwater flow and the first-order control of water table position on rates of peat accumulation. In this talk I will present new results from quantitative geomorphic analyses of a northern peatland complex at the De Beers Victor diamond mine site in the Hudson Bay Lowlands of northern Ontario. This work capitalizes on spatially-extensive, high-resolution topographic (LiDAR) data to rigorously test analytical and numerical models of bog dome development in this landscape. The analysis and discussion are then expanded beyond individual bog formations to more broadly consider ecohydrological drivers of landscape organization, with implications for understanding and modeling catchment-scale runoff response. Results show that in this landscape, drainage patterns exhibit relatively well-organized characteristics consistent with observed runoff responses in six gauged research catchments. Interpreted together, the results of these geomorphic and hydrologic analyses help refine our understanding of water balance partitioning among different landcover types within northern peatland complexes. These findings can be used to help guide the development of appropriate numerical model structures for hydrologic prediction in ungauged peatland basins of northern Canada.

  12. Resource contrast in patterned peatlands increases along a climatic gradient

    NARCIS (Netherlands)

    Eppinga, M.B.; Rietkerk, M.; Belyea, L.R.; Nilsson, M.B.; Ruiter, de P.C.; Wassen, M.J.

    2010-01-01

    Spatial patterning of ecosystems can be explained by several mechanisms. One approach to disentangling the influence of these mechanisms is to study a patterned ecosystem along a gradient of environmental conditions. This study focused on hummock–hollow patterning of peatlands. Previous models

  13. Climate-driven flushing of pore water in peatlands

    Science.gov (United States)

    Siegel, D. I.; Reeve, A. S.; Glaser, P. H.; Romanowicz, E. A.

    1995-04-01

    NORTHERN peatlands can act as either important sources or sinks for atmospheric carbon1,2. It is therefore important to understand how carbon cycling in these regions will respond to a changing climate. Existing carbon balance models for peatlands assume that fluid flow and advective mass transport are negligible at depth3,4, and that the effects of climate change should be essentially limited to the near-surface. Here we report the response of groundwater flow and porewater chemistry in the Glacial Lake Agassiz peat-lands of northern Minnesota to the regional drought cycle. Comparison of field observations and numerical simulations indicates that climate fluctuations of short duration may temporarily reverse the vertical direction of fluid flow through the peat, although this has little effect on water chemistry5. On the other hand, periods of drought persisting for at least 3-5 years produce striking changes in the chemistry of the pore water. These longer-term changes in hydrology influence the flux of nutrients and dissolved organic matter through the deeper peat, and therefore affect directly the rates of fermentation and methanogenesis, and the export of dissolved carbon compounds from the peatland.

  14. Establishing trees on cut-over peatlands in eastern Canada

    Directory of Open Access Journals (Sweden)

    J. Bussières

    2008-12-01

    Full Text Available Four major tree-planting trials on cut-over peatlands in eastern Canada were surveyed in 2002, in order to evaluate the potential use of trees in rehabilitation following horticultural peat extraction. At one of the sites, an experiment to determine the appropriate fertilisation rate for trees planted on cut-over peatlands was also conducted over several years. Tree performance was assessed by measuring survival, total height and annual growth of red maple (Acer rubrum L., tamarack (Larix laricina (Du Roi Koch., black spruce (Picea mariana (Mill. B.S.P., jack pine (Pinus banksiana Lamb. and hybrid poplar (Populus spp.. Establishment and growth of tamarack and black spruce in cut-over peatlands showed good potential when compared to performance in conventional forestry plantations. Red maple and jack pine gave poor productivity but promising survival, whilst hybrid poplar plantings failed. Adding nutrients was essential for growth but dosages above 122.5 g of 3.4N-8.3P-24.2K per tree gave no further improvement. Therefore, several different tree species can be planted to reclaim cut-over peatlands in eastern Canada, so long as the appropriate species are chosen and nutrients are provided.

  15. GHG mitigation of agricultural peatlands requires coherent policies

    DEFF Research Database (Denmark)

    Regina, Kristina; Budiman, Arif; Greve, Mogens Humlekrog

    2016-01-01

    As soon as peat soil is drained for agricultural production, the peat starts to degrade, which causes emissions to the atmosphere. In countries with large peatland areas, the GHG mitigation potential related to management of these soils is often estimated as the highest amongst the measures...

  16. Russian boreal peatlands dominate the natural European methane budget

    International Nuclear Information System (INIS)

    Schneider, Julia; Jungkunst, Hermann F; Wolf, Ulrike; Schreiber, Peter; Kutzbach, Lars; Gazovic, Michal; Miglovets, Mikhail; Mikhaylov, Oleg; Grunwald, Dennis; Erasmi, Stefan; Wilmking, Martin

    2016-01-01

    About 60% of the European wetlands are located in the European part of Russia. Nevertheless, data on methane emissions from wetlands of that area are absent. Here we present results of methane emission measurements for two climatically different years from a boreal peatland complex in European Russia. Winter fluxes were well within the range of what has been reported for the peatlands of other boreal regions before, but summer fluxes greatly exceeded the average range of 5–80 mg CH 4 m −2 d −1 for the circumpolar boreal zone. Half of the measured fluxes ranged between 150 and 450 mg CH 4 m −2 d −1 . Extrapolation of our data to the whole boreal zone of European Russia shows that theses emissions could amount to up to 2.7 ± 1.1 Tg CH 4 a −1 , corresponding to 69% of the annual emissions from European wetlands or 33% of the total annual natural European methane emission. In 2008, climatic conditions corresponded to the long term mean, whereas the summer of 2011 was warmer and noticeably drier. Counterintuitively, these conditions led to even higher CH 4 emissions, with peaks up to two times higher than the values measured in 2008. As Russian peatlands dominate the areal extend of wetlands in Europe and are characterized by very high methane fluxes to the atmosphere, it is evident, that sound European methane budgeting will only be achieved with more insight into Russian peatlands. (letter)

  17. IMPROVING WATER REGIME IN MLACA TĂTARILOR PEATLAND

    Directory of Open Access Journals (Sweden)

    Ionuţ Cristian Moale

    2017-07-01

    Full Text Available Following the project Restoration strategies of the deteriorated peatland ecosystems from Romania (PeatRo, it has been shown that Romania has 32 peatlands that need hydrological restoration taking into account the increasing of human activities and changes in land use. These peatlands are distributed in the Alpine region (30 and in the Continental region (2. In this paper, we started from the assumption that the evapotranspiration process can be reduced by decreasing the spread of colonizing species Betula pendula and Rhamnus frangula, in order to reduce the evapotranspiration rate. To establish the conditions for hydrology restoration, we used a conceptual model applied to the peatland functioning in order to quantify the water inflows (from runoff and rainfall and outflows (overbank outflows, by evaporation, by colonizing species transpiration. To estimate the rate of evapotranspiration for these species, we used in the model as input data: height and diameter of the individuals, the number of individuals, the leaf area of individual, wind speed, temperature, humidity, the number of sun hours / day, the surface of the water table. Model results show that evapotranspiration process can be reduced after implementation of specific restoration activities, demonstrating a real improvement on water regime.

  18. Carbon storage in forests and peatlands of Russia

    Science.gov (United States)

    V.A. Alexeyev; R.A. Birdsey; [Editors

    1998-01-01

    Contains information about carbon storage in the vegetation, soils, and peatlands of Russia. Estimates of carbon storage in forests are derived from statistical data from the 1988 national forest inventory of Russia and from other sources. Methods are presented for converting data on timber stock into phytomass of tree stands, and for estimating carbon storage in...

  19. Peatland Ecosystem Processes in the Maritime Antarctic During Warm Climates.

    Science.gov (United States)

    Loisel, Julie; Yu, Zicheng; Beilman, David W; Kaiser, Karl; Parnikoza, Ivan

    2017-09-27

    We discovered a 50-cm-thick peat deposit near Cape Rasmussen (65.2°S), in the maritime Antarctic. To our knowledge, while aerobic 'moss banks' have often been examined, waterlogged 'peatlands' have never been described in this region before. The waterlogged system is approximately 100 m 2 , with a shallow water table. Surface vegetation is dominated by Warnstorfia fontinaliopsis, a wet-adapted moss commonly found in the Antarctic Peninsula. Peat inception was dated at 2750 cal. BP and was followed by relatively rapid peat accumulation (~0.1 cm/year) until 2150 cal. BP. Our multi-proxy analysis then shows a 2000-year-long stratigraphic hiatus as well as the recent resurgence of peat accumulation, sometime after 1950 AD. The existence of a thriving peatland at 2700-2150 cal. BP implies regionally warm summer conditions extending beyond the mid-Holocene; this finding is corroborated by many regional records showing moss bank initiation and decreased sea ice extent during this time period. Recent peatland recovery at the study site (maritime Antarctic region may promote a more peatland-rich landscape in the future.

  20. Beaver Mediated Water Table Dynamics in Mountain Peatlands

    Science.gov (United States)

    Karran, D. J.; Westbrook, C.; Bedard-Haughn, A.

    2016-12-01

    Water table dynamics play an important role in the ecological and biogeochemical processes that regulate carbon and water storage in peatlands. Beaver are common in these habitats and the dams they build have been shown to raise water tables in other environments. However, the impact of beaver dams in peatlands, where water tables rest close to the surface, has yet to be determined. We monitored a network of 50 shallow wells in a Canadian Rocky Mountain peatland for 6 years. During this period, a beaver colony was maintaining a number of beaver ponds for four years until a flood event removed the colony from the area and breached some of the dams. Two more years of data were collected after the flood event to assess whether the dams enhanced groundwater storage. Beaver dams raised water tables just as they do in other environments. Furthermore, water tables within 100 meters of beaver dams were more stable than those further away and water table stability overall was greater before the flood event. Our results suggest the presence/absence of beaver in peatlands has implications for groundwater water storage and overall system function.

  1. Modelling Peatland Hydrology: Three cases from Northern Europe

    NARCIS (Netherlands)

    Querner, E.P.; Mioduszewski, W.; Povilaitis, A.; Slesicka, A.

    2010-01-01

    Many of the peatlands that used to extend over large parts of Northern Europe have been reclaimed for agriculture. Human influence continues to have a major impact on the hydrology of those that remain, affecting river flow and groundwater levels. In order to understand this hydrology it is

  2. Polygonal patterned peatlands of the White Sea islands

    Science.gov (United States)

    Kutenkov, S. A.; Kozhin, M. N.; Golovina, E. O.; Kopeina, E. I.; Stoikina, N. V.

    2018-03-01

    The summits and slopes of some islands along the northeastern and northern coasts of the White Sea are covered with dried out peatlands. The thickness of the peat deposit is 30–80 cm and it is separated by troughs into gently sloping polygonal peat blocks up to 20 m2 in size. On some northern islands the peat blocks have permafrost cores. The main components of the dried out peatlands vegetation are dwarf shrubs and lichens. The peat stratigraphy reveals two stages of peatland development. On the first stage, the islands were covered with wet cottongrass carpets, which repeated the convex relief shape. On the second stage, they were occupied by the xeromorphic vegetation. We suggest that these polygonal patterned peatlands are the remnants of blanket bogs, the formation of which assumes the conditions of a much more humid climate in the historical past. The time of their active development was calculated according to the White Sea level changes and radiocarbon dates from 1000–4000 BP.

  3. The role of fire in UK peatland and moorland management

    NARCIS (Netherlands)

    Davies, G.M.; Kettridge, Nicholas; Stoof, Cathelijne R.; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M.; Marrs, Rob; Allen, Katherine A.; Doerr, Stefan H.; Clay, Gareth D.; McMorrow, Julia; Vandvik, Vigdis

    2016-01-01

    Fire has been used for centuries to generate and manage some of the UK’s cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That

  4. Vegetation management with fire modifies peatland soil thermal regime.

    Science.gov (United States)

    Brown, Lee E; Palmer, Sheila M; Johnston, Kerrylyn; Holden, Joseph

    2015-05-01

    Vegetation removal with fire can alter the thermal regime of the land surface, leading to significant changes in biogeochemistry (e.g. carbon cycling) and soil hydrology. In the UK, large expanses of carbon-rich upland environments are managed to encourage increased abundance of red grouse (Lagopus lagopus scotica) by rotational burning of shrub vegetation. To date, though, there has not been any consideration of whether prescribed vegetation burning on peatlands modifies the thermal regime of the soil mass in the years after fire. In this study thermal regime was monitored across 12 burned peatland soil plots over an 18-month period, with the aim of (i) quantifying thermal dynamics between burned plots of different ages (from post burning), and (ii) developing statistical models to determine the magnitude of thermal change caused by vegetation management. Compared to plots burned 15 + years previously, plots recently burned (management effects. Temperatures measured in soil plots burned vegetation regrows. Our findings that prescribed peatland vegetation burning alters soil thermal regime should provide an impetus for further research to understand the consequences of thermal regime change for carbon processing and release, and hydrological processes, in these peatlands. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  5. Calculating carbon budgets of wind farms on Scottish peatlands

    Directory of Open Access Journals (Sweden)

    D.R. Nayak

    2010-04-01

    Full Text Available The reliability of calculation methods for the carbon emission savings to be achieved in Scotland by replacing power generated from fossil fuels (and other more conventional sources with that produced by large-scale wind farm developments is a cause for concern, largely in relation to wind farms sited on peatlands. Scottish Government policy is to deliver renewable energy without environmental harm, and to meet biodiversity objectives including the conservation of designated wildlife sites and important habitats such as peatlands. The implications for carbon emissions of developing a wind farm are, therefore, just one aspect of the suite of considerations that the planning system takes into account. This paper presents a simple methodology for prospectively calculating the potential carbon emission savings to be realised by developing wind farms on peatland, forestland or afforested peatland. The total carbon emission savings of an individual wind farm are estimated by accounting emissions from the power source that will be replaced by wind power against: loss of carbon due to production, transportation, erection, operation and dismantling of the wind farm components (the infrastructure overhead; loss of carbon due to backup power generation; loss of carbon stored in peat and forest; loss of carbon-fixing potential of peatland and forest; and carbon savings due to habitat improvement. Most of the carbon losses are determined by national infrastructure, but those from peat soil and plants are influenced by site selection and management practices. The extent of drainage around each constructed element of the wind farm is a major factor for greenhouse gas emissions. Consideration of an example site with a low extent of drainage, where management practices that minimise net carbon losses (e.g. undrained floating roads, habitat improvement and site restoration on decommissioning were used indicates that emissions from the soil and plants may cancel

  6. Methanogenesis limitations in degraded peatlands after their hydrological restoration

    Science.gov (United States)

    Urbanová, Zuzana

    2017-04-01

    Peatlands are ecosystems that can have a high degree of carbon sequestration due to CO2 fixation and low decomposition rates, but on the other hand, they are a source of CH4. Past drainage or mining can disturb these natural functions with rewetting being the main method used to bring back their original ecosystem properties. Methanogenic community composition and its activity seems to be very sensitive to environmental changes and therefore its limited activity after restoration can reflect the not fully restored functioning of the microbial community and its processes in the rewetted peatlands. To find the cause for this methanogenesis limitation we determined the abundance and composition of the methanogenic community and methane potential production in pristine, long-term drained and rewetted bogs and spruce swamp forests (SSF) in the Šumava Mountains (Czech Republic), using high-throughput barcoded sequencing, qPCR and anaerobic incubation of peat samples in relation to peat biochemical properties. Long-term drainage led to a strongly reduced diversity, abundance and activity of the methanogenic community in both peatland types. In restored sites, methanogenic abundance and community composition reached a pristine like state, however their activity measured as CH4 production remained as low as in drained sites. Substrate limitation was expected; therefore we further added different substrates during anaerobic incubation of the peat samples. In addition to glucose and ethanol, we added natural complex substrates from peatland plants (sedges, Sphagnum) to simulate the effect of the spreading of peatland species and their litter on methanogenic activity. The results unambiguously confirmed the limitation of methanogens by substrate availability due to the previous long-term drainage and strongly decomposed peat. The addition of natural substrates led to an increase in CH4 production, which was close to values in pristine sites. The limited CH4 production

  7. Greenhouse impact of Finnish peatlands 1900-2100

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J; Minkkinen, K [Helsinki Univ. (Finland). Dept. of Ecology; Tolonen, K; Turunen, J [Joensuu Univ. (Finland). Dept. of Biology; Martikainen, P; Nykaenen, H [National Public Health Inst. Kuopio (Finland). Dept. of Environmental Microbiology; Sinisalo, J; Savolainen, I [VTT Energy, Espoo (Finland)

    1997-12-31

    Northern peatlands are significant in regulating the global climate. While sequestering carbon dioxide (CO{sub 2}, ca. 100 Tg C a{sup -} {sup 1}), these peatlands release cat 24-39 Tg methane (CH{sub 4}) annually to the atmosphere. This is 5-15 % of the annual anthropogenic and 10-35 % of the annual natural CH4 emissions to the atmosphere. The greenhouse gas balance of peatlands may change as a consequence of water level drawdown after land use change, or if summers become warmer and drier, as has been predicted for high latitudes after climatic warming. Currently, some 15 million hectares of northern peatlands and other wetlands have been drained for forestry. More than 90 % of this area is found in Scandinavia and the former Soviet Union. The area drained annually has, however, been declining during the last two decades and, in Finland for instance the annual drained area of nearly 300 000 hectares in the late 1960`s has decreased to cat 35 000 hectares in the early 1990`s. Radiative forcing is the change in the radiative energy balance at the tropopause and it is the driving force behind the greenhouse effect. It is a common quantity for most greenhouse gases and takes into account the dynamics of the greenhouse impact. Radiative forcing model was used to compute the greenhouse impact of the drainage of the peatlands, combining the effects of CO{sub 2} and CH4 balances; N{sub 2}O was not included in the calculations because its contribution is minor. (14 refs.)

  8. Macroinvertebrate community assembly in pools created during peatland restoration.

    Science.gov (United States)

    Brown, Lee E; Ramchunder, Sorain J; Beadle, Jeannie M; Holden, Joseph

    2016-11-01

    Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

  9. Greenhouse impact of Finnish peatlands 1900-2100

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Minkkinen, K. [Helsinki Univ. (Finland). Dept. of Ecology; Tolonen, K.; Turunen, J. [Joensuu Univ. (Finland). Dept. of Biology; Martikainen, P.; Nykaenen, H. [National Public Health Inst. Kuopio (Finland). Dept. of Environmental Microbiology; Sinisalo, J.; Savolainen, I. [VTT Energy, Espoo (Finland)

    1996-12-31

    Northern peatlands are significant in regulating the global climate. While sequestering carbon dioxide (CO{sub 2}, ca. 100 Tg C a{sup -} {sup 1}), these peatlands release cat 24-39 Tg methane (CH{sub 4}) annually to the atmosphere. This is 5-15 % of the annual anthropogenic and 10-35 % of the annual natural CH4 emissions to the atmosphere. The greenhouse gas balance of peatlands may change as a consequence of water level drawdown after land use change, or if summers become warmer and drier, as has been predicted for high latitudes after climatic warming. Currently, some 15 million hectares of northern peatlands and other wetlands have been drained for forestry. More than 90 % of this area is found in Scandinavia and the former Soviet Union. The area drained annually has, however, been declining during the last two decades and, in Finland for instance the annual drained area of nearly 300 000 hectares in the late 1960`s has decreased to cat 35 000 hectares in the early 1990`s. Radiative forcing is the change in the radiative energy balance at the tropopause and it is the driving force behind the greenhouse effect. It is a common quantity for most greenhouse gases and takes into account the dynamics of the greenhouse impact. Radiative forcing model was used to compute the greenhouse impact of the drainage of the peatlands, combining the effects of CO{sub 2} and CH4 balances; N{sub 2}O was not included in the calculations because its contribution is minor. (14 refs.)

  10. Annual carbon balance of a peatland 10 yr following restoration

    Directory of Open Access Journals (Sweden)

    M. Strack

    2013-05-01

    Full Text Available Undisturbed peatlands represent long-term net sinks of carbon; however, peat extraction converts these systems into large and persistent sources of greenhouse gases. Although rewetting and restoration following peat extraction have taken place over the last several decades, very few studies have investigated the longer term impact of this restoration on peatland carbon balance. We determined the annual carbon balance of a former horticulturally-extracted peatland restored 10 yr prior to the study and compared these values to the carbon balance measured at neighboring unrestored and natural sites. Carbon dioxide (CO2 and methane (CH4 fluxes were measured using the chamber technique biweekly during the growing season from May to October 2010 and three times over the winter period. Dissolved organic carbon (DOC export was measured from remnant ditches in the unrestored and restored sites. During the growing season the restored site had greater uptake of CO2 than the natural site when photon flux density was greater than 1000 μmol m−2 s−1, while the unrestored site remained a source of CO2. Ecosystem respiration was similar between natural and restored sites, which were both significantly lower than the unrestored site. Methane flux remained low at the restored site except from open water pools, created as part of restoration, and remnant ditches. Export of DOC during the growing season was 5.0 and 28.8 g m−2 from the restored and unrestored sites, respectively. Due to dry conditions during the study year all sites acted as net carbon sources with annual balance of the natural, restored and unrestored sites of 250.7, 148.0 and 546.6 g C m−2, respectively. Although hydrological conditions and vegetation community at the restored site remained intermediate between natural and unrestored conditions, peatland restoration resulted in a large reduction in annual carbon loss from the system resulting in a carbon balance more similar to a natural

  11. Extent and status of mires, peatlands, and organic soils in Europe

    Science.gov (United States)

    Tanneberger, Franziska; Barthelmes, Alexandra; Tegetmeyer, Cosima; Busse, Stephan; Joosten, Hans

    2016-04-01

    Key words: peatland distribution, peatland drainage, GIS, Global Peatland Database, European Mires Book The relevance of drained peatlands to climate change due to emission of huge amounts of greenhouse gases has recently been recognised e.g. by IPCC, FAO, and the European Union. Oppositely, natural and restored peatlands provide ecosystem services like enhancing biodiversity, nutrient retention, groundwater storage, flood mitigation, and cooling. To evaluate the drainage status of peatlands and organic soils and to develop specific restoration strategies comprehensive and exact geospatial data are needed. The Global Peatland Database (GPD) is hosted at Greifswald Mire Centre (http://tiny.cc/globalpeat). Currently, it provides estimates on location, extent, and drainage status of peatlands and organic soils for 268 countries and regions of the world. Due to the large diversity of definitions and terms for peatlands and organic soils, this mapping follows the broad definition of organic soils from IPCC that gives a minimum soil organic carbon threshold of 12% and considers any depth of the organic layer larger than 10 cm. GIS datasets are continuously collected, specific terms and definitions analysed and the completeness and accuracy of the datasets evaluated. Currently, the GPD contains geospatial data on peatlands and organic soils for all European countries (except Moldova). Recent information on status, distribution, and conservation of mires and peatlands in Europe is summarised in the European Mires Book. It includes descriptions from 49 countries and other geographic entities in Europe. All country chapters follow a generic structure and include also extensive descriptions of national terminology (also in national languages and script) and typologies as well as up to date area statistics and maps. They are complemented by integrative chapters presenting mire classification, mire regionality, peatland use, and mire conservation in Europe. The European Mires

  12. Peatland Bryophytes in a Changing Environment : Ecophysiological Traits and Ecosystem Function

    OpenAIRE

    Granath, Gustaf

    2012-01-01

    Peatlands are peat forming ecosystems in which not fully decomposed plant material builds up the soil. The sequestration of carbon into peat is mainly associated with the bryophyte genus Sphagnum (peat mosses), which dominate and literally form most peatlands. The responses of Sphagnum to environmental change help us to understand peatland development and function and to predict future changes in a rapidly changing world. In this thesis, the overarching aim was to use ecophysiological traits ...

  13. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    OpenAIRE

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward; Carrivick, Jonathan L.; Woulds, Clare; Raby, Cassandra; Mullan, Donal; Roland, Thomas P.; Galloway, Jennifer M.; Parry, Lauren; Kokfelt, Ulla; Garneau, Michelle; Charman, Dan J.; Holden, Joseph

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (~ 200 km north of the Arctic Circle). Multivariate statistical analysis confirms that water-table depth and moisture content are the dominant controls on the distribution of testate amoebae, corroborating the results from studies in mid-latitude peatlands. We present a ne...

  14. The effect of peatland drainage and restoration on Odonata species richness and abundance

    OpenAIRE

    Elo, Merja; Penttinen, Jouni; Kotiaho, Janne Sakari

    2015-01-01

    Background Restoration aims at reversing the trend of habitat degradation, the major threat to biodiversity. In Finland, more than half of the original peatland area has been drained, and during recent years, restoration of some of the drained peatlands has been accomplished. Short-term effects of the restoration on peatland hydrology, chemistry and vegetation are promising but little is known about how other species groups apart from vascular plants and bryophytes respond to restoration effo...

  15. Microclimate of Developed Peatland of the Mega Rice Project in Central Kalimantan

    Directory of Open Access Journals (Sweden)

    Adi Jaya

    2010-01-01

    Full Text Available In Indonesia peatland covers an area of 16 to 27 Mha and this ecosystem is vitally linked toenvironmental and conservation issues, as well as its economic value for human survival. These peatlands are,however, the subject of various land use pressures, including forestry, agriculture, energy and horticulture. A fieldstudy was carried out 6 years after the end of failed peatland development project shows that inappropriate andunsustainable forms of peatland management have resulted in degradation of the natural forest vegetation, draw-downof the peat water table, increase of peat surface and air temperatures and recurrent surface and ground fires. Implicationsof microclimate for possible restoration options

  16. Macroinvertebrate community assembly in pools created during peatland restoration

    International Nuclear Information System (INIS)

    Brown, Lee E.; Ramchunder, Sorain J.; Beadle, Jeannie M.; Holden, Joseph

    2016-01-01

    Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

  17. Paludiculture on marginal lands - sustainable use of wet peatlands

    Science.gov (United States)

    Oehmke, Claudia; Dahms, Tobias; Wichmann, Sabine; Wichtmann, Wendelin

    2017-04-01

    Peatlands are marginal lands. If they are drained, they show a short initial productive period. Soil degradation due to peat oxidation leads to numerous problems which increasingly restrict agricultural use and cause significant environmental impacts such as greenhouse gas emissions and eutrophication and thereby produce high external costs. Worldwide greenhouse gas emissions from drained peatlands have a significant share ( 10%) in the emissions from agriculture, forestry and other land use (AFOLU) sectors (Smith et al. 2014). In Germany they contribute more than 35% to the total emissions from agriculture (agricultural sector and cropland and grassland management) (UBA 2016). Rewetting drained peatlands can significantly reduce environmental problems caused by peatland drainage. Continuation of agricultural use with adapted crops and machinery, so called paludiculture (Latin ‚palus' = swamp) stops further degradation, maintains the peat body, reduces climate change mitigation and produces renewable fuels and raw materials. Fen and bog soils are suitable for various different paludicultures. The biomass of Sphagnum (sphagnum farming) cultivated on cut-over bogs or degraded bog grasslands can be used as raw material for horticultural growing media. Flood-tolerant and productive plant species like Common Reed, Reed Canary Grass, Cattail, Black Alder and different Sedge species are suitable for paludiculture on fen soils. Biomass utilization ranges from traditional forms, like fodder production or the use of Common Reed as roof thatch, to new utilization options, that includes biomass use for heat generation, co-subtrates for biorefineries or construction and insulation products. The above-ground biomass of one hectare Common Reed (winter yield=8 t DM) equates to an energy content of 3,000 litre heating oil. A district heating plant (800 kW) in NE Germany demonstrates the feasibility of using biomass from wet fen meadows for local heat generation. Moreover, tests

  18. Peatland Microbial Carbon Use Under Warming using Isotopic Fractionation

    Science.gov (United States)

    Gutknecht, J.

    2016-12-01

    Peatlands are a critical natural resource, especially in their role as carbon sinks. Most of the world's peatlands are located in Northern ecosystems where the climate is changing at a rapid pace, and there is great interest and concern with how climate change will influence them. Although studies regarding the response of peatlands to climate change have emerged, the microbial mediation of C cycling in these systems is still less well understood. In this study, 13CPLFA analysis was used to characterize the microbial community and it's carbon use at the Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) Project. The SPRUCE project is an extensive study of the response of peatlands to climatic manipulation in the Marcell Experimental Forest in northern Minnesota. Heating rods were installed in peatland plots where peat is being warmed at several levels including ambient, +2.5, +4.5, +6.75, and +9 degrees Celsius, at a depth of 3 meters, beginning July of 2014. Samples were taken June 2014, September 2014, and June 2015, throughout the depth profile. We found very high microbial, and especially fungal growth at shallow depths, owing in part to the influence of fungal-like lipids present in Sphagnum stems, and in part to dense mycorrhizal colonization in shrub and tree species. Isotopic data shows that microbial biomass has an enriched δ13C lower in the peat profile, indicating as expected that microbes at depth utilize older carbon or carbon more enriched in 13C. The increase over depth in the δ13C signature may also reflect the increased dominance of pre-industrial carbon that is more enriched in 13C. In this early period of warming we did not see clear effects of warming, either due to the highly heterogeneous microbial growth across the bog, or to the short term deep warming only. We expect that with the initiation of aboveground warming in July 2016, warming will begin to show stronger effects on microbial C cycling.

  19. Macroinvertebrate community assembly in pools created during peatland restoration

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Lee E., E-mail: l.brown@leeds.ac.uk; Ramchunder, Sorain J.; Beadle, Jeannie M.; Holden, Joseph

    2016-11-01

    Many degraded ecosystems are subject to restoration attempts, providing new opportunities to unravel the processes of ecological community assembly. Restoration of previously drained northern peatlands, primarily to promote peat and carbon accumulation, has created hundreds of thousands of new open water pools. We assessed the potential benefits of this wetland restoration for aquatic biodiversity, and how communities reassemble, by comparing pool ecosystems in regions of the UK Pennines on intact (never drained) versus restored (blocked drainage-ditches) peatland. We also evaluated the conceptual idea that comparing reference ecosystems in terms of their compositional similarity to null assemblages (and thus the relative importance of stochastic versus deterministic assembly) can guide evaluations of restoration success better than analyses of community composition or diversity. Community composition data highlighted some differences in the macroinvertebrate composition of restored pools compared to undisturbed peatland pools, which could be used to suggest that alternative end-points to restoration were influenced by stochastic processes. However, widely used diversity metrics indicated no differences between undisturbed and restored pools. Novel evaluations of restoration using null models confirmed the similarity of deterministic assembly processes from the national species pool across all pools. Stochastic elements were important drivers of between-pool differences at the regional-scale but the scale of these effects was also similar across most of the pools studied. The amalgamation of assembly theory into ecosystem restoration monitoring allows us to conclude with more certainty that restoration has been successful from an ecological perspective in these systems. Evaluation of these UK findings compared to those from peatlands across Europe and North America further suggests that restoring peatland pools delivers significant benefits for aquatic fauna by

  20. Deciphering human-climate interactions in an ombrotrophic peat record: REE, Nd and Pb isotope signatures of dust supplies over the last 2500 years (Misten bog, Belgium)

    Science.gov (United States)

    Fagel, N.; Allan, M.; Le Roux, G.; Mattielli, N.; Piotrowska, N.; Sikorski, J.

    2014-06-01

    A high-resolution peat record from Eastern Belgium reveals the chronology of dust deposition for the last 2500 years. REE and lithogenic elements in addition to Nd and Pb isotopes were measured in a 173 cm age-dated peat profile and provide a continuous chronology of dust source and intensity. Calculated dust flux show pronounced increases c. 300 BC, 600 AD, 1000 AD, 1200 AD and from 1700 AD, corresponding to local and regional human activities combined with climate change. The Industrial Revolution samples (1700-1950 AD) are characterised by a significant enrichment in Sc-normalised REE abundance (sum REE/Sc > 25) due to intensive coal combustion. For the pre-Industrial Revolution samples, the Sc-normalised REE abundance (10 climate. Combining REE abundance, fractionation between Light REE and Heavy REE and Nd isotope data in ombrotrophic peat allows one to distinguish between dust flux changes related to human and climate forcings.

  1. Effects of peatland drainage management on peak flows

    OpenAIRE

    C. E. Ballard; N. McIntyre; H. S. Wheater

    2011-01-01

    Open ditch drainage has historically been a common land management practice in upland blanket peats, particularly in the UK. However, peatland drainage is now generally considered to have adverse effects on the upland environment, including increased peak flows. As a result, drain blocking has become a common management strategy in the UK over recent years, although there is only anecdotal evidence to suggest that this might decrease peak flows. The change in the hydrologica...

  2. Design of Spillway Structures of Peatland Rewetting systems

    Directory of Open Access Journals (Sweden)

    Sainov Mihail Petrovich

    2014-03-01

    Full Text Available In summer 2010 drought and heat weather cause numerous peat fires. During two months Moscow was shrouded in acid smoke. To prevent such situations government of Moscow region decided to rewet previously drained peatlands. Peatland rewetting systems can be divided into two types. The first type is watering system based on previously used drainage system. The main idea of this method is rising of groundwater levels with the help of special water retaining constructions installed in drainage canals. The design of water receivers allows keeping up water level in canals and draining excesses. There are two types of water receivers: dock-type water receiver and water receiver as a portal to the gate. The choice of one or another type of water receiver depends on the canal depth. If it is less than 1.5 m, we apply portal construction. At the depth of more than 1.5 m the mine water receiver is more suitable. The second way of watering previously drained peatlands is the creation of ponds, dams on streams and small rivers. Special discharge structures increase water level in the river upstream. In downstream water level rises due to the redistribution of the flow. As a result, the groundwater level rises and peat become watered. There are two types of spillway structures: with direct overflow wall and labyrinth overflow wall. Structure with direct overflow wall is applicable on small rivers. In narrow alignments with high consumptions it is better to use another type of weir. As output it is necessary to notice that all constructions used in peatlands watering were designed as simple and reliable as possible. It is so because unpredictable weather conditions can cause beyond the design flows so weirs must have necessary reserve of passing costs.

  3. Carbon storage and long-term rate of accumulation in high-altitude Andean peatlands of Bolivia

    Science.gov (United States)

    J.A. Hribljan; D.J. Cooper; J. Sueltenfuss; E.C. Wolf; K.A. Heckman; Erik Lilleskov; R.A. Chimner

    2015-01-01

    The high-altitude (4,500+ m) Andean mountain range of north-western Bolivia contains many peatlands. Despite heavy grazing pressure and potential damage from climate change, little is known about these peatlands. Our objective was to quantify carbon pools, basal ages and long-term peat accumulation rates in peatlands in two areas of the arid puna ecoregion of Bolivia:...

  4. Global peatland initiation driven by regionally asynchronous warming.

    Science.gov (United States)

    Morris, Paul J; Swindles, Graeme T; Valdes, Paul J; Ivanovic, Ruza F; Gregoire, Lauren J; Smith, Mark W; Tarasov, Lev; Haywood, Alan M; Bacon, Karen L

    2018-05-08

    Widespread establishment of peatlands since the Last Glacial Maximum represents the activation of a globally important carbon sink, but the drivers of peat initiation are unclear. The role of climate in peat initiation is particularly poorly understood. We used a general circulation model to simulate local changes in climate during the initiation of 1,097 peatlands around the world. We find that peat initiation in deglaciated landscapes in both hemispheres was driven primarily by warming growing seasons, likely through enhanced plant productivity, rather than by any increase in effective precipitation. In Western Siberia, which remained ice-free throughout the last glacial period, the initiation of the world's largest peatland complex was globally unique in that it was triggered by an increase in effective precipitation that inhibited soil respiration and allowed wetland plant communities to establish. Peat initiation in the tropics was only weakly related to climate change, and appears to have been driven primarily by nonclimatic mechanisms such as waterlogging due to tectonic subsidence. Our findings shed light on the genesis and Holocene climate space of one of the world's most carbon-dense ecosystem types, with implications for understanding trajectories of ecological change under changing future climates.

  5. Neotropical peatland methane emissions along a vegetation and biogeochemical gradient.

    Science.gov (United States)

    Winton, R Scott; Flanagan, Neal; Richardson, Curtis J

    2017-01-01

    Tropical wetlands are thought to be the most important source of interannual variability in atmospheric methane (CH4) concentrations, yet sparse data prevents them from being incorporated into Earth system models. This problem is particularly pronounced in the neotropics where bottom-up models based on water table depth are incongruent with top-down inversion models suggesting unaccounted sinks or sources of CH4. The newly documented vast areas of peatlands in the Amazon basin may account for an important unrecognized CH4 source, but the hydrologic and biogeochemical controls of CH4 dynamics from these systems remain poorly understood. We studied three zones of a peatland in Madre de Dios, Peru, to test whether CH4 emissions and pore water concentrations varied with vegetation community, soil chemistry and proximity to groundwater sources. We found that the open-canopy herbaceous zone emitted roughly one-third as much CH4 as the Mauritia flexuosa palm-dominated areas (4.7 ± 0.9 and 14.0 ± 2.4 mg CH4 m-2 h-1, respectively). Emissions decreased with distance from groundwater discharge across the three sampling sites, and tracked changes in soil carbon chemistry, especially increased soil phenolics. Based on all available data, we calculate that neotropical peatlands contribute emissions of 43 ± 11.9 Tg CH4 y-1, however this estimate is subject to geographic bias and will need revision once additional studies are published.

  6. Neotropical peatland methane emissions along a vegetation and biogeochemical gradient.

    Directory of Open Access Journals (Sweden)

    R Scott Winton

    Full Text Available Tropical wetlands are thought to be the most important source of interannual variability in atmospheric methane (CH4 concentrations, yet sparse data prevents them from being incorporated into Earth system models. This problem is particularly pronounced in the neotropics where bottom-up models based on water table depth are incongruent with top-down inversion models suggesting unaccounted sinks or sources of CH4. The newly documented vast areas of peatlands in the Amazon basin may account for an important unrecognized CH4 source, but the hydrologic and biogeochemical controls of CH4 dynamics from these systems remain poorly understood. We studied three zones of a peatland in Madre de Dios, Peru, to test whether CH4 emissions and pore water concentrations varied with vegetation community, soil chemistry and proximity to groundwater sources. We found that the open-canopy herbaceous zone emitted roughly one-third as much CH4 as the Mauritia flexuosa palm-dominated areas (4.7 ± 0.9 and 14.0 ± 2.4 mg CH4 m-2 h-1, respectively. Emissions decreased with distance from groundwater discharge across the three sampling sites, and tracked changes in soil carbon chemistry, especially increased soil phenolics. Based on all available data, we calculate that neotropical peatlands contribute emissions of 43 ± 11.9 Tg CH4 y-1, however this estimate is subject to geographic bias and will need revision once additional studies are published.

  7. The Role of Peat Layers on Iron Dynamics in Peatlands

    Directory of Open Access Journals (Sweden)

    Arifin Fahmi

    2010-09-01

    Full Text Available The research aimed to study the effect of peat thickness and humification stage of the peat material on Fe solubility at the peatlands with sulfidic material as substratum. The research was conducted at three conditionals of ombrogen peatlands ie ; deep, moderate and shallow peat. Soil samples were collected by using peat borer according to interlayer (the border layer of peat and mineral layer and conditional of soil horizons. The sample point depth were (cm G.s2 : 25, G.s1 : 50, Int.s : 70, M.s1 : 90 and M.s2 : 100 for shallow peat, G.m2 : 47, G.m1 : 100, Int.m : 120 and M.m1 : 135 for moderate peat and G.d3 : 50, G.d2 : 150, G.d1 : 200, Int.d : 220 and M.d1 : 235 for deep peat respectively. The results showed that most of Fe on the tested soils was found in organic forms. The peat layers above the sulfidic material decreased the Fe2+ solubility at peatlands. Fe2+ concentration in peat layer decreased with its increasing distance from sulfidic material. There was any other processes beside complexation and chelation of Fe2+ by humic material and its processes was reduction of Fe3+ and this conditions was reflected in redox potential values (Eh.

  8. Ammonium release from a blanket peatland into headwater stream systems

    International Nuclear Information System (INIS)

    Daniels, S.M.; Evans, M.G.; Agnew, C.T.; Allott, T.E.H.

    2012-01-01

    Hydrochemical sampling of South Pennine (UK) headwater streams draining eroded upland peatlands demonstrates these systems are nitrogen saturated, with significant leaching of dissolved inorganic nitrogen (DIN), particularly ammonium, during both stormflow and baseflow conditions. DIN leaching at sub-catchment scale is controlled by geomorphological context; in catchments with low gully densities ammonium leaching dominates whereas highly gullied catchments leach ammonium and nitrate since lower water tables and increased aeration encourages nitrification. Stormflow flux calculations indicate that: approximately equivalent amounts of nitrate are deposited and exported; ammonium export significantly exceeds atmospheric inputs. This suggests two ammonium sources: high atmospheric loadings; and mineralisation of organic nitrogen stored in peat. Downstream trends indicate rapid transformation of leached ammonium into nitrate. It is important that low-order headwater streams are adequately considered when assessing impacts of atmospheric loads on the hydrochemistry of stream networks, especially with respect to erosion, climate change and reduced precipitation. - Highlights: ► Headwaters draining eroded South Pennine (UK) peatlands are nitrogen saturated. ► Ammonium and nitrate leaching arises from aeration due to lower water tables. ► Nitrate deposition equals export during storms; ammonium export exceeds input. ► Ammonia input from high atmospheric loading and mineralisation of organic nitrogen. ► Downstream nitrogen trends indicate rapid transformation of ammonium into nitrate. - Inorganic nitrogen leaching from South Pennine peatlands is dominated by ammonium that is rapidly transformed within-streams to nitrate.

  9. Decadal vegetation changes in a northern peatland, greenhouse gas fluxes and net radiative forcing

    DEFF Research Database (Denmark)

    Johansson, Torbjörn; Malmer, Nils; Crill, Patrick M

    2006-01-01

    SUB-ARCTIC MIRE; CLIMATE-CHANGE; BOREAL PEATLANDS; METHANE EMISSIONS; VASCULAR PLANTS; CARBON-DIOXIDE; PERMAFROST THAW; CO2 EXCHANGE; WATER-TABLE......SUB-ARCTIC MIRE; CLIMATE-CHANGE; BOREAL PEATLANDS; METHANE EMISSIONS; VASCULAR PLANTS; CARBON-DIOXIDE; PERMAFROST THAW; CO2 EXCHANGE; WATER-TABLE...

  10. Interannual, seasonal, and retrospective analysis of the methane and carbon dioxide budgets of a temperate peatland

    Science.gov (United States)

    D.M. Olson; T.J. Griffis; A. Noormets; R. Kolka; J. Chen

    2013-01-01

    Three years (2009-2011) of near-continuous methane (CH4) and carbon dioxide (CO2) fluxes were measured with the eddy covariance (EC) technique at a temperate peatland located within the Marcell Experimental Forest, in northern Minnesota, USA. The peatland was a net source of CH4 and a net sink of CO...

  11. The effects of hydrologic fluctuation and sulfate regeneration on mercury cycling in an experimental peatland

    Science.gov (United States)

    J.K. Coleman Wasik; D.R. Engstrom; C.P.J. Mitchell; E.B. Swain; B.A. Monson; S.J. Balogh; J.D. Jeremiason; B.A. Branfireun; R.K. Kolka; J.E. Almendinger

    2015-01-01

    A series of severe droughts during the course of a long-term, atmospheric sulfate-deposition experiment in a boreal peatland in northern Minnesota created a unique opportunity to study how methylmercury (MeHg) production responds to drying and rewetting events in peatlands under variable levels of sulfate loading. Peat oxidation during extended dry periods mobilized...

  12. Peatland vascular plant functional types affect methane dynamics by altering microbial community structure

    NARCIS (Netherlands)

    Robroek, B.J.M.; Jassey, Vincent E.J.; Kox, Martine A.R.; Berendsen, Roeland L.; Mills, Robert T.E.; Cécillon, Lauric; Puissant, Jérémy; Meima-Franke, M.; Bakker, Peter A.H.M.; Bodelier, Paul

    2015-01-01

    Peatlands are natural sources of atmospheric methane (CH4), an important greenhouse gas. It is established that peatland methane dynamics are controlled by both biotic and abiotic conditions, yet the interactive effect of these drivers is less studied, and consequently poorly understood. Climate

  13. Spatio-temporal trends of nitrogen deposition and climate effects on Sphagnum productivity in European peatlands

    International Nuclear Information System (INIS)

    Granath, Gustaf; Limpens, Juul; Posch, Maximilian; Mücher, Sander; Vries, Wim de

    2014-01-01

    To quantify potential nitrogen (N) deposition impacts on peatland carbon (C) uptake, we explored temporal and spatial trends in N deposition and climate impacts on the production of the key peat forming functional group (Sphagnum mosses) across European peatlands for the period 1900–2050. Using a modelling approach we estimated that between 1900 and 1950 N deposition impacts remained limited irrespective of geographical position. Between 1950 and 2000 N deposition depressed production between 0 and 25% relative to 1900, particularly in temperate regions. Future scenarios indicate this trend will continue and become more pronounced with climate warming. At the European scale, the consequences for Sphagnum net C-uptake remained small relative to 1900 due to the low peatland cover in high-N areas. The predicted impacts of likely changes in N deposition on Sphagnum productivity appeared to be less than those of climate. Nevertheless, current critical loads for peatlands are likely to hold under a future climate. - Highlights: • We model the effect of N deposition combined with climate on production of Sphagnum between 1900 and 2050. • Spatially explicit projections are indicated on an updated European peatland distribution map. • Results stress the vulnerability of temperate Sphagnum peatlands to current and future N deposition. • Future impacts of N deposition on Sphagnum productivity likely depend more on climate change than on N deposition rate. - Temperate Sphagnum peatlands are vulnerable to current and future N deposition and current critical loads for peatlands are likely to hold under a future climate

  14. Evaluating the use of testate amoebae for palaeohydrological reconstruction in permafrost peatlands

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Amesbury, Matthew J.; Turner, T. Edward

    2015-01-01

    The melting of high-latitude permafrost peatlands is a major concern due to a potential positive feedback on global climate change. We examine the ecology of testate amoebae in permafrost peatlands, based on sites in Sweden (similar to 200 km north of the Arctic Circle). Multivariate statistical ...

  15. Influence of climate change factors on carbon dynamics in northern forested peatlands

    Science.gov (United States)

    C.C Trettin; R. Laiho; K. Minkkinen; J. Laine

    2005-01-01

    Peatlands are carbon-accumulating wetland ecosystems, developed through an imbalance among organic matter production and decomposition processes. Soil saturation is the principal cause of anoxic conditions that constrain organic matter decay. Accordingly, changes in the hydrologic regime will affect the carbon (C) dynamics in forested peatlands. Our objective is to...

  16. Initial response of the nitrogen cycle to soil warming in Northern Minnesota peatlands

    Science.gov (United States)

    Peatlands store 30% of global soil carbon. Many of these peatlands are located in boreal regions which are expected to have the highest temperature increases in response to climate change. As climate warms, peat decomposition may accelerate and release greenhouse gases. Spruce a...

  17. Community based ecological restoration of peatland in Central Mongolia for climate change mitigation and adaptation

    NARCIS (Netherlands)

    Minayeva, Tatiana; Chultem, Dugarjav; Grootjans, Ab; Yamkhin, Jambaljav; Sirin, Andrey; Suvorov, Gennady; Batdorj, Oyunbileg; Tsamba, Batdorj

    2017-01-01

    Peatlands cover almost 2 % of Mongolia. They play crucial role in regulation of key natural processes in ecosystems and provide unique resources to maintain traditional way of life and livelihoods of herders. During the last decades, Mongolian peatlands severely degraded both due to the climate

  18. Controls on Ecosystem and Root Respiration in an Alaskan Peatland

    Science.gov (United States)

    McConnell, N. A.; McGuire, A. D.; Harden, J. W.; Kane, E. S.; Turetsky, M. R.

    2010-12-01

    Boreal ecosystems cover 14% of the vegetated surface on earth and account for 25-30% of the world’s soil carbon (C), mainly due to large carbon stocks in deep peat and frozen soil layers. While peatlands have served as historical sinks of carbon, global climate change may trigger re-release of C to the atmosphere and may turn these ecosystems into net C sources. Rates of C release from a peatland are determined by regional climate and local biotic and abiotic factors such as vegetation cover, thaw depth, and peat thickness. Soil CO2 fluxes are driven by both autotrophic (plant) respiration and heterotrophic (microbial) respiration. Thus, changes in plant and microbial activity in the soil will impact CO2 emissions from peatlands. In this study, we explored environmental and vegetation controls on ecosystem respiration and root respiration in a variety of wetland sites. The study was conducted at the Alaskan Peatland Experiment (APEX; www.uoguelph.ca/APEX) sites in the Bonanza Creek Experimental Forest located 35 km southwest of Fairbanks Alaska. We measured ecosystem respiration, root respiration, and monitored a suite of environmental variables along a vegetation and soil moisture gradient including a black spruce stand with permafrost, a shrubby site with permafrost, a tussock grass site, and a herbaceous open rich fen. Within the rich fen, we have been conducting water table manipulations including a control, lowered, and raised water table treatment. In each of our sites, we measured total ecosystem respiration using static chambers and root respiration by harvesting roots from the uppermost 20 cm and placing them in a root cuvette to obtain a root flux. Ecosystem respiration (ER) on a μmol/m2/sec basis varied across sites. Water table was a significant predictor of ER at the lowered manipulation site and temperature was a strong predictor at the control site in the rich fen. Water table and temperature were both significant predictors of ER at the raised

  19. Seasonal changes in peatland surface elevation recorded at GPS stations in the Red Lake Peatlands, northern Minnesota, USA

    Science.gov (United States)

    Reeve, A.S.; Glaser, P.H.; Rosenberry, Donald O.

    2013-01-01

    Northern peatlands appear to hold large volumes of free-phase gas (e.g., CH4 and CO2), which has been detected by surface deformations, pore pressure profiles, and electromagnetic surveys. Determining the gas content and its impact in peat is challenging because gas storage depends on both the elastic properties of the peat matrix and the buoyant forces exerted by pore fluids. We therefore used a viscoelastic deformation model to estimate these variables by adjusting model runs to reproduce observed changes in peat surface elevation within a 1300 km2 peatland. A local GPS network documented significant changes in surface elevations throughout the year with the greatest vertical displacements associated with rapid changes in peat water content and unloadings due to melting of the winter snowpack. These changes were coherent with changes in water table elevation and also abnormal pore pressure changes measured by nests of instrumented piezometers. The deformation model reproduced these changes when the gas content was adjusted to 10% of peat volume, and Young's modulus was varied between 5 and 100 kPa as the peat profile shifted from tension to compression. In contrast, the model predicted little peat deformation when the gas content was 3% or lower. These model simulations are consistent with previous estimates of gas volume in northern peatlands and suggest an upper limit of gas storage controlled by the elastic moduli of the peat fabric.

  20. Ecological restoration of peatlands in steppe and forest-steppe areas

    Science.gov (United States)

    Minayeva, Tatiana; Sirin, Andrey; Dugarjav, Chultem

    2016-04-01

    Peatlands in the arid and semi-arid regions of steppe and forest steppe belt of Eurasia have some specific features. That demands the special approach to their management and restoration. The distribution of peatlands under conditions of dry climate is very limited and they are extremely vulnerable. Peatlands in those regions are found in the highlands where temperate conditions still present, in floodplains where they can get water from floods and springs, or in karst areas. Peatlands on watersheds present mainly remains from the more humid climate periods. Water and carbon storage as well as maintenance of the specific biodiversity are the key ecosystem natural functions of peatlands in the steppe and forest steppe. The performance of those functions has strong implications for people wellness and livelihood. Anyhow, peatlands are usually overlooked and poorly represented in the systems of natural protected areas. Land management plans, mitigation and restoration measures for ecosystems under use do not usually include special measures for peatlands. Peatlands'use depends on the traditional practices. Peat extraction is rather limited in subhumid regions but still act as one of the threats to peatlands. The most of peatlands are used as pastures and grasslands. In densely populated areas large part of peatlands are transformed to the arable lands. In many cases peatlands of piedmonts and highlands are affected by industrial developments: road construction, mining of subsoil resources (gold, etc.). Until now, the most of peatlands of steppe and forest steppe region are irreversibly lost, what also effects water regime, lands productivity, biodiversity status. To prevent further dramatic changes the ecological restoration approach should be introduced in the subhumid regions. The feasibility study to assess the potential for introducing ecological restoration techniques for peatlands in the arid and semi-arid conditions had been undertaken in steppe and forest

  1. Long-term carbon accumulation in Andes peatlands

    Science.gov (United States)

    Huaman, Yizet; Moreira-turq, Patricia; Willems, Bram; Espinoza, Raul; Turq, Bruno; Apaéstegui, James; Llanos, Romina

    2017-04-01

    High-altitude peatlands of the Andes still remain relatively unexplored since most of the studies on carbon capture in tropical soils have focused on peatlands in low altitude areas, leaving aside the importance of the study of high mountain wetlands, currently called "bofedales" located between 3000 and 5000 masl, covering most of the Andes mountains in South America. These peatlands in turn may also represent important paleoclimatic records. In this study, we investigated three peatland cores (APA-01, APA2-01, and APA2-02) at different altitudes (4210 m, 4420 m and 4432 m, respectively) in high Andean Peatlands of southern Peru. The peatland studied is located at the headwater basin Cachi River, in the town of Ayacucho, Peru. The aim of this study was to evaluate the role played by past climatic changes on the peatlands carbon accumulation. Each core was sectioned centimeter by centimeter and sub samples (n = 31) were collected for radiocarbon dating by AMS (acceleration mass spectrometer) and were used to create a sedimentological model based on the program Clam2.2R. The concentrations of carbon and nitrogen were determined from a C / H / N elemental analyzer and the stable carbon and nitrogen isotopes (δ13C and δ15N) were also analyzed. The bulk density was determined based on the volume occupied by the sediment (g /cm3). Finally, the carbon accumulation rate (gC m-2año-1) was determined. The three cores were characterized by two sedimentary units, the results present in the first sedimentary unit of APA01 an average long-term carbon accumulation rate of 59 gC m-2año-1, APA2-01 with 32 gC m-2año-1 and finally APA2-02 with 24 gC m-2año-1; for the second sedimentary unit we have: APA01 on average 17 gC m-2año-1, APA2-01 with 33 gC m-2año-1 and finally APA2-02 with 49 gC m-2año-1. In conclusion, we can say that the carbon accumulation rate for the first sedimentary unit of the three cores decreases as the altitude increases; on the other hand, we have the

  2. Moderate drop in water table increases peatland vulnerability to post-fire regime shift.

    Science.gov (United States)

    Kettridge, N; Turetsky, M R; Sherwood, J H; Thompson, D K; Miller, C A; Benscoter, B W; Flannigan, M D; Wotton, B M; Waddington, J M

    2015-01-27

    Northern and tropical peatlands represent a globally significant carbon reserve accumulated over thousands of years of waterlogged conditions. It is unclear whether moderate drying predicted for northern peatlands will stimulate burning and carbon losses as has occurred in their smaller tropical counterparts where the carbon legacy has been destabilized due to severe drainage and deep peat fires. Capitalizing on a unique long-term experiment, we quantify the post-wildfire recovery of a northern peatland subjected to decadal drainage. We show that the moderate drop in water table position predicted for most northern regions triggers a shift in vegetation composition previously observed within only severely disturbed tropical peatlands. The combined impact of moderate drainage followed by wildfire converted the low productivity, moss-dominated peatland to a non-carbon accumulating shrub-grass ecosystem. This new ecosystem is likely to experience a low intensity, high frequency wildfire regime, which will further deplete the legacy of stored peat carbon.

  3. Effects of different nitrogen forms, ammonia gas and wet deposited ammonium and nitrate, on methane and nitrous oxide emissions from an ombrotrophic bog, Whim Moss, in the Scottish Borders

    OpenAIRE

    Sheppard, L. J.; Leith, I. D.; Field, C.; van Dijk, N.; Rung, M.; Skiba, U.

    2008-01-01

    Enhanced reactive nitrogen deposition may compromise the sustainability and functioning of bogs, with respect to carbon sequestration and greenhouse gas production. Since 2002, three N forms have been applied to an ombrotrophic bog growing Calluna, Sphagnum capillifolium and Eriophorum vaginatum in order to test this. Significant changes in species cover and soil chemistry, especially in response to elevated ammonia concentrations, have been recorded. Ammonia deposition has also increased nit...

  4. Sources of Respired Carbon in a Northern Minnesota Ombrotrophic Spruce Bog: Preliminary 14C Results from the SPRUCE Site.

    Science.gov (United States)

    Guilderson, T. P.; McNicol, G.; Machin, A.; Hanson, P. J.; McFarlane, K. J.; Osuna, J. L.; Pett-Ridge, J.; Singleton, M. J.

    2014-12-01

    A significant uncertainty in future land-surface carbon budgets is the response of wetlands to climate change. A corollary and related question is the future net climate (radiative) forcing impact from wetlands. Active wetlands emit both CO2 and CH4 to the atmosphere. CH4 is, over a few decades, a much more potent greenhouse gas than CO2. CO2 has a longer atmospheric lifetime and a longer 'tail' to its radiative influence. Whether wetlands are a net source or sink of atmospheric carbon under future climate change will depend on ecosystem response to rising temperatures and elevated CO2. The largest uncertainty in future wetland C-budgets, and their climate forcing is the stability of the large below-ground carbon stocks, often in the form of peat, and the partitioning of CO2 and CH4 released via ecosystem respiration. In advance of a long-term experimental warming and elevated CO2 manipulation at the DOE Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) site in the Marcell Experimental Forest, we have characterized the source of respired carbon used for both the production of CO2 and CH4. Samples were collected in early June, late July, and will be collected in early September from three large (~1.1 m2, ~0.5m3) chambers from the control plot, and two of the experimental plots selected for heating (+9°C, +4.5°C). Early June fluxes from the three chambers were ~5500 mgC-m-2-d-1 and ~16 mgC-m-2-d-1 for CO2 and CH4 respectively. Radiocarbon analysis of CO2 and CH4 indicate that the source for the respired carbon is for the most part recent, with most 14C values between 30 and 40‰ - i.e., carbon that was photosynthetically fixed in the last few years. In concert with rising air and ground temperatures fluxes in late July increased to ~6500 mgC-m-2-d-1 and ~86 mgC-m-2-d-1. Although deep-heating was initiated in mid to late June we hypothesize that the July respiration signal is dominated by the regular seasonal cycle of natural warming

  5. Impact of peat mining, and restoration on methane turnover potentials and methane-cycling microorganisms in a northern bog

    NARCIS (Netherlands)

    Reumer, Max; Harnisz, M.; Lee, H.J.; Reim, A.; Grunert, O.; Putkinen, A.; Fritze, H.; Bodelier, P.L.E.; Ho, A.

    2018-01-01

    Ombrotrophic peatlands are a recognized global carbon reservoir. Without restoration and peat regrowth, harvested peatlands are dramatically altered, impairing its carbon sink function, with consequences for methane turnover. Previous studies determined the impact of commercial mining on the peat

  6. Responsible management of tropical peatlands: balancing competing demands on a fragile resource

    Science.gov (United States)

    Page, Susan; Evans, Christopher; Gauci, Vincent

    2017-04-01

    In 2010 the International Peatland Society published a strategy for responsible peatland management, with the following guiding principles: (i) ensure that high conservation value peatlands are identified and conserved, (ii) manage 'utilised' peatlands responsibly, and (iii) rehabilitate or restore drained, degraded or otherwise irreversibly changed peatlands to restore as many ecological and landscape functions as possible. At the time of its publication, the main focus of the strategy was on northern peatlands, although a few partner organisations in SE Asia were involved in the strategy consultation process. Given the rapid rate of peatland development in SE Asia in the last 7 years and the growing interest in tropical peatland rehabilitation and restoration, we believe that it is now timely to review what a strategy for responsible tropical peatland management might look like. SE Asia's peatlands cover 250,000 km2 of the region and store 69 Gt C but they are subject to continuing deforestation, biodiversity loss, land subsidence/flooding, increasing greenhouse gas (GHG) emissions, and health impacts due to air pollution from land-clearing fires, all of which pose huge regional and global challenges. Around 75% of the peatlands have been deforested in the last 20 years, with 35% of cleared land now under industrial plantation, 34% under smallholder cultivation, and 25% unutilised, largely as a result of uncontrolled land-clearing fires. The production intensity (GHG emissions per calorie produced) of crops grown on SE Asian organic soils is among the highest in the world (Carlson et al. 2016). There are clear tensions between reconciling peatland management for conservation goals (of biodiversity, carbon and natural resources) with economic and livelihood development goals. A balance needs to be struck between the absolute value and distribution of short term economic gains vs. peatland management strategies that deliver longer-term, sustainable and shared

  7. Environmental control of methane fluxes over a Danish peatland

    Science.gov (United States)

    Herbst, M.; Ringgaard, R.; Friborg, T.; Soegaard, H.

    2009-12-01

    Reducing the greenhouse gas (GHG) emissions from natural and anthropogenic environments has become a key issue over the last decades. In Denmark the management of the wetlands is playing a key role in these attempts. The wetland area of Skjern Meadows in the western part of Denmark is one of the best known examples of peatland restauration in northern Europe. The valley of the Skjern river was restored in 2002, after it had been drained for about 35 years. A micrometeorological instrument mast was erected in the centre of the 2200 ha large area in the summer of 2008, in order to facilitate continuous eddy covariance measurements of the exchange of carbon dioxide and methane between the peatland and the atmosphere. A sonic anemometer (R3, Gill) was used together with a closed-path CO2 analyzer (LI-7000, Li-Cor) and a closed-path CH4 analyzer (DLT-100, Los Gatos). A measurement height of 7 m above the surface ensures that the observed eddy fluxes represent an average signal from the entire peatland. The first year of data collection confirmed the expectation that the area functions as a moderate CO2 sink, whilst it releases methane into the atmosphere. During a 12-months period starting in September 2008, the wetland removed 119 g CO2-C per m2 from the atmosphere and emitted 6 g CH4-C per m2. If the amount of the emitted CH4 is converted into CO2 equivalents, it remained lower than the annual CO2 uptake (188 versus 437 g CO2). This means that the restored peatland functions as a weak greenhouse gas sink, despite its methane production. Whilst the annual CO2 uptake at Skjern Meadows was similar to that reported by Friborg et al. (2003) for a Siberian wetland, the CH4 emission was much lower. The average CO2 and CH4 flux rates were both lower than those estimated for a Dutch wetland by Hendriks et al. (2007). The CH4 emission showed no particular diurnal pattern, but daily rates varied considerably throughout the year. This variability can be correlated to variations

  8. Mercury evasion from a boreal peatland shortens the timeline for recovery from legacy pollution.

    Science.gov (United States)

    Osterwalder, Stefan; Bishop, Kevin; Alewell, Christine; Fritsche, Johannes; Laudon, Hjalmar; Åkerblom, Staffan; Nilsson, Mats B

    2017-11-22

    Peatlands are a major source of methylmercury that contaminates downstream aquatic food webs. The large store of mercury (Hg) in peatlands could be a source of Hg for over a century even if deposition is dramatically reduced. However, the reliability of Hg mass balances can be questioned due to missing long-term land-atmosphere flux measurements. We used a novel micrometeorological system for continuous measurement of Hg peatland-atmosphere exchange to derive the first annual Hg budget for a peatland. The evasion of Hg (9.4 µg m -2 yr -1 ) over the course of a year was seven times greater than stream Hg export, and over two times greater than wet bulk deposition to the boreal peatland. Measurements of dissolved gaseous Hg in the peat pore water also indicate Hg evasion. The net efflux may result from recent declines in atmospheric Hg concentrations that have turned the peatland from a net sink into a source of atmospheric Hg. This net Hg loss suggests that open boreal peatlands and downstream ecosystems can recover more rapidly from past atmospheric Hg deposition than previously assumed. This has important implications for future levels of methylmercury in boreal freshwater fish and the estimation of historical Hg accumulation rates from peat profiles.

  9. Potential for using remote sensing to estimate carbon fluxes across northern peatlands - A review.

    Science.gov (United States)

    Lees, K J; Quaife, T; Artz, R R E; Khomik, M; Clark, J M

    2018-02-15

    Peatlands store large amounts of terrestrial carbon and any changes to their carbon balance could cause large changes in the greenhouse gas (GHG) balance of the Earth's atmosphere. There is still much uncertainty about how the GHG dynamics of peatlands are affected by climate and land use change. Current field-based methods of estimating annual carbon exchange between peatlands and the atmosphere include flux chambers and eddy covariance towers. However, remote sensing has several advantages over these traditional approaches in terms of cost, spatial coverage and accessibility to remote locations. In this paper, we outline the basic principles of using remote sensing to estimate ecosystem carbon fluxes and explain the range of satellite data available for such estimations, considering the indices and models developed to make use of the data. Past studies, which have used remote sensing data in comparison with ground-based calculations of carbon fluxes over Northern peatland landscapes, are discussed, as well as the challenges of working with remote sensing on peatlands. Finally, we suggest areas in need of future work on this topic. We conclude that the application of remote sensing to models of carbon fluxes is a viable research method over Northern peatlands but further work is needed to develop more comprehensive carbon cycle models and to improve the long-term reliability of models, particularly on peatland sites undergoing restoration. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  10. The distribution and amount of carbon in the largest peatland complex in Amazonia

    International Nuclear Information System (INIS)

    Draper, Frederick C; Baker, Timothy R; Roucoux, Katherine H; Lawson, Ian T; Mitchard, Edward T A; Honorio Coronado, Euridice N; Zaráte, Ricardo; Lähteenoja, Outi; Torres Montenegro, Luis; Valderrama Sandoval, Elvis

    2014-01-01

    Peatlands in Amazonian Peru are known to store large quantities of carbon, but there is high uncertainty in the spatial extent and total carbon stocks of these ecosystems. Here, we use a multi-sensor (Landsat, ALOS PALSAR and SRTM) remote sensing approach, together with field data including 24 forest census plots and 218 peat thickness measurements, to map the distribution of peatland vegetation types and calculate the combined above- and below-ground carbon stock of peatland ecosystems in the Pastaza-Marañon foreland basin in Peru. We find that peatlands cover 35 600 ± 2133 km 2 and contain 3.14 (0.44–8.15) Pg C. Variation in peat thickness and bulk density are the most important sources of uncertainty in these values. One particular ecosystem type, peatland pole forest, is found to be the most carbon-dense ecosystem yet identified in Amazonia (1391 ± 710 Mg C ha −1 ). The novel approach of combining optical and radar remote sensing with above- and below-ground carbon inventories is recommended for developing regional carbon estimates for tropical peatlands globally. Finally, we suggest that Amazonian peatlands should be a priority for research and conservation before the developing regional infrastructure causes an acceleration in the exploitation and degradation of these ecosystems. (letter)

  11. Greenhouse gas balances in low-productive drained boreal peatlands - is climate-friendly management possible?

    Science.gov (United States)

    Ojanen, Paavo; Minkkinen, Kari; Heikkinen, Tiina; Penttilä, Timo

    2016-04-01

    Five million hectares of peatland has been drained for forestry in Finland. About 20% of that, i.e. one million hectares, has been estimated to be so low-productive that the profitability of keeping them in forestry is questionable. At the same time, drainage has introduced changes in the ecosystem functions of these peatlands, including fluxes of greenhouse gases. Options to manage such peatlands include for example 1) no measures, i.e. leaving the drained peatlands as they are 2) increasing intensity by e.g. repetitive fertilisations and 3) restoration back to functional peatlands. Here we estimate the greenhouse gas impacts of these three management options. We collected GHG and organic carbon flux data from 50 low-productive peatlands under these management options over two years 2014-2015. Gas fluxes (CO2, CH4, N2O) were measured with closed chambers. Litter production rates of different plants above and below ground were estimated using litter traps (trees), biomass sampling (roots), through-grow nets (mosses), allometric biomass models (other vasculars) and published turnover rates (roots, other vasculars). Characteristics for estimating tree stand biomass increment were measured at each site from circular sample plots. In this presentation we will estimate the GHG impacts for the different management options, and aim to find the most climate-friendly options for the management of low-productive peatlands in the short and long term. This work was funded by Life+ LIFE12/ENV/FI/150.

  12. How temporal patterns in rainfall determine the geomorphology and carbon fluxes of tropical peatlands

    Science.gov (United States)

    Hoyt, Alison M.; Gandois, Laure; Eri, Jangarun; Dommain, René; Abu Salim, Kamariah; Kai, Fuu Ming; Haji Su’ut, Nur Salihah; Harvey, Charles F.

    2017-01-01

    Tropical peatlands now emit hundreds of megatons of carbon dioxide per year because of human disruption of the feedbacks that link peat accumulation and groundwater hydrology. However, no quantitative theory has existed for how patterns of carbon storage and release accompanying growth and subsidence of tropical peatlands are affected by climate and disturbance. Using comprehensive data from a pristine peatland in Brunei Darussalam, we show how rainfall and groundwater flow determine a shape parameter (the Laplacian of the peat surface elevation) that specifies, under a given rainfall regime, the ultimate, stable morphology, and hence carbon storage, of a tropical peatland within a network of rivers or canals. We find that peatlands reach their ultimate shape first at the edges of peat domes where they are bounded by rivers, so that the rate of carbon uptake accompanying their growth is proportional to the area of the still-growing dome interior. We use this model to study how tropical peatland carbon storage and fluxes are controlled by changes in climate, sea level, and drainage networks. We find that fluctuations in net precipitation on timescales from hours to years can reduce long-term peat accumulation. Our mathematical and numerical models can be used to predict long-term effects of changes in temporal rainfall patterns and drainage networks on tropical peatland geomorphology and carbon storage. PMID:28607068

  13. How temporal patterns in rainfall determine the geomorphology and carbon fluxes of tropical peatlands.

    Science.gov (United States)

    Cobb, Alexander R; Hoyt, Alison M; Gandois, Laure; Eri, Jangarun; Dommain, René; Abu Salim, Kamariah; Kai, Fuu Ming; Haji Su'ut, Nur Salihah; Harvey, Charles F

    2017-06-27

    Tropical peatlands now emit hundreds of megatons of carbon dioxide per year because of human disruption of the feedbacks that link peat accumulation and groundwater hydrology. However, no quantitative theory has existed for how patterns of carbon storage and release accompanying growth and subsidence of tropical peatlands are affected by climate and disturbance. Using comprehensive data from a pristine peatland in Brunei Darussalam, we show how rainfall and groundwater flow determine a shape parameter (the Laplacian of the peat surface elevation) that specifies, under a given rainfall regime, the ultimate, stable morphology, and hence carbon storage, of a tropical peatland within a network of rivers or canals. We find that peatlands reach their ultimate shape first at the edges of peat domes where they are bounded by rivers, so that the rate of carbon uptake accompanying their growth is proportional to the area of the still-growing dome interior. We use this model to study how tropical peatland carbon storage and fluxes are controlled by changes in climate, sea level, and drainage networks. We find that fluctuations in net precipitation on timescales from hours to years can reduce long-term peat accumulation. Our mathematical and numerical models can be used to predict long-term effects of changes in temporal rainfall patterns and drainage networks on tropical peatland geomorphology and carbon storage.

  14. Development in techniques for studying forest roads on peatlands

    International Nuclear Information System (INIS)

    Saarilahti, M.

    1988-01-01

    A light seismic method, a short-pulse radar and a microwave probe are tested in assessing the properties of a forest road constructed on peatland. The light seismic method gave reliable values for estimating the bearing capacity of the road. It was found that bearing capacity was mostly dependent on embankment thickness, but quality of labric might also have an influence. Embankment thickness and peat depth can be measured on the radargram, and some additional information on road bed and peat obtained. The microwave peat probe permits recording of the continuous moisture profile in situ, which improves accuracy of planning

  15. Use of ash in the fertilisation of peatland forests

    International Nuclear Information System (INIS)

    Moilanen, M.; Korpilahti, A.

    2000-01-01

    About 100,000 tonnes of bark and other wood-based ash are produced annually by the forest industries and heating plants in Finland. This amount would be sufficient for fertilising about 25,000 hectares of forest. When applied to peatland forests, this would produce extra forest growth of about 75,000 m 3 per a year. When considering the objectives of forestry, the practical benefits and economic profitability of ash fertilisation are at their peak on peatlands rich in nitrogen. Wood ash induces added tree growth (measured in terms of stemwood) in pine stands on herb- and sedge-rich parklands within 2-3 years of application. On nitrogen-deficient dwarf-shrub and Sphagnum-rich peatlands this growth reaction manifests itself only after 7-8 years have passed and even then at a considerably lower level. The application of mere ash does not result in notable increases in tree growth on upland forest sites. However, ash does change the growth conditions by reducing the acidity of the soil and by accelerating microbial decomposition. The phosphorus contained in ash has not been observed to have been leached into drainage waters on drained sites, at least not during the first two years after application, provided that care has been practised when spreading ash. However, the movement of readily-soluble nutrients has been observed and more so on nutrient-poor sites than on nutrient-rich sites. Although the suitability of ash as fertiliser in peatland forests has been recognised on the basis of long-term ash trials established at the Finnish Forest Research Institute, ash fertilisation has not been carried out made on a practical scale mainly because of the dust problem when spreading it. The purpose of pretreatment with ash is first and foremost to transform the ash into sufficiently dust-free form to enable it to be spread readily. An added advantage is that pelletised ash causes a lesser pH shock to plank than ash in dust form. (orig.)

  16. Development in techniques for studying forest roads on peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Saarilahti, M.

    1988-07-01

    A light seismic method, a short-pulse radar and a microwave probe are tested in assessing the properties of a forest road constructed on peatland. The light seismic method gave reliable values for estimating the bearing capacity of the road. It was found that bearing capacity was mostly dependent on embankment thickness, but quality of labric might also have an influence. Embankment thickness and peat depth can be measured on the radargram, and some additional information on road bed and peat obtained. The microwave peat probe permits recording of the continuous moisture profile in situ, which improves accuracy of planning.

  17. Carbon dynamics in peatland pool systems: the role of light

    Science.gov (United States)

    Pickard, Amy; Heal, Kate; McLeod, Andy; Dinsmore, Kerry

    2016-04-01

    Open-water pools are widespread in peatlands and are considered to represent biogeochemical hotspots within the peatland landscape. However the contribution of pool systems to wider peatland C cycling has not been quantified fully and there is a lack of knowledge of the role of photochemical processes in such environments. In this study, light exposure experiments were conducted in two contrasting pools to test the reactivity of aquatic C. The first study site was located at Cross Lochs (CL), Forsinard, in the Flow Country of Northern Scotland, in a 412 m2 pool characterised by low dissolved organic carbon (DOC) concentrations (˜15 mg C L-1). The second site was located at Red Moss of Balerno (RM), a raised bog in central Scotland, in a 48 m2 pool with high DOC concentrations (˜35 mg C L-1). Experiments took place over 9 days in situ at each pool in mid-summer 2015, with 500 mL water samples contained in bags transparent to sunlight and in opaque control bags. After field exposure, optical, chemical and stable C isotope analyses were conducted on the samples. Significant differences in biogeochemical cycling of DOC were detected between the two systems, with DOC losses as a percentage of the total C pool 15% higher at RM than at CL after light exposure. The mean DOC concentration of light exposed samples at RM declined steeply initially, with 83% observed DOC degradation occurring by day 3 of the experiment. Total losses of 7.9 mg DOC L-1were observed in light exposed samples at RM, along with decreasing E4:E6 ratios, suggesting that material remaining at the end of the experiment was humified. Depletion of DOC was positively correlated with production of CO2 at both sites, with concentrations of up to 4.3 mg CO2-C L-1 recorded at RM. Stable C isotope signatures at both sites were altered under light treatment, as demonstrated by the production of enriched δ13C-DOC (+0.46 ‰ relative to opaque bags) and depleted δ13C-DIC (-0.97 ‰ relative to opaque bags) at

  18. Dynamic vertical profiles of peat porewater chemistry in a northern peatland

    Science.gov (United States)

    Natalie A. Griffiths; Stephen D. Sebestyen

    2016-01-01

    We measured pH, cations, nutrients, and total organic carbon (TOC) over 3 years to examine weekly to monthly variability in porewater chemistry depth profiles (0–3.0 m) in an ombrotrophic bog in Minnesota, USA. We also compared temporal variation at one location to spatial variation in depth profiles at 16 locations across the bog. Most solutes exhibited large...

  19. The response of soil carbon storage and microbially mediated carbon turnover to simulated climatic disturbance in a northern peatland forest. Revisiting the concept of soil organic matter recalcitrance

    Energy Technology Data Exchange (ETDEWEB)

    Kostka, Joel [Georgia Inst. of Technology, Atlanta, GA (United States)

    2015-09-14

    The goal of this project was to investigate changes in the structure of dissolved and solid phase organic matter, the production of CO2 and CH4, and the composition of decomposer microbial communities in response to the climatic forcing of environmental processes that determine the balance between carbon gas production versus storage and sequestration in peatlands. Cutting-edge analytical chemistry and next generation sequencing of microbial genes were been applied to habitats at the Marcell Experimental Forest (MEF), where the US DOE’s Oak Ridge National Laboratory and the USDA Forest Service are constructing a large-scale ecosystem study entitled, “Spruce and Peatland Responses Under Climatic and Environmental Change”(SPRUCE). Our study represented a comprehensive characterization of the sources, transformation, and decomposition of organic matter in the S1 bog at MEF. Multiple lines of evidence point to distinct, vertical zones of organic matter transformation: 1) the acrotelm consisting of living mosses, root material, and newly formed litter (0-30 cm), 2) the mesotelm, a mid-depth transition zone (30-75 cm) characterized by labile organic C compounds and intense decomposition, and 3) the underlying catotelm (below 75cm) characterized by refractory organic compounds as well as relatively low decomposition rates. These zones are in part defined by physical changes in hydraulic conductivity and water table depth. O-alkyl-C, which represents the carbohydrate fraction in the peat, was shown to be an excellent proxy for soil decomposition rates. The carbon cycle in deep peat was shown to be fueled by modern carbon sources further indicating that hydrology and surface vegetation play a role in belowground carbon cycling. We provide the first metagenomic study of an ombrotrophic peat bog, with novel insights into microbial specialization and functions in this unique terrestrial ecosystem. Vertical structuring of microbial communities

  20. Long-term effects of ozone on CO2 exchange in peatland microcosms

    DEFF Research Database (Denmark)

    Haapala, JK; Mörsky, SK; Rinnan, Riikka

    2011-01-01

    Effects of elevated tropospheric ozone concentration on the CO2 exchange of peatland microcosms and the photosynthetic capacity of the dominating sedge, Eriophorum vaginatum, were studied in a four-year open-field experiment. The net ecosystem CO2 exchange and the dark respiration rate of the mic......Effects of elevated tropospheric ozone concentration on the CO2 exchange of peatland microcosms and the photosynthetic capacity of the dominating sedge, Eriophorum vaginatum, were studied in a four-year open-field experiment. The net ecosystem CO2 exchange and the dark respiration rate...... exchange of the peatland microcosms....

  1. Spatially Explicit Simulation of Mesotopographic Controls on Peatland Hydrology and Carbon Fluxes

    Science.gov (United States)

    Sonnentag, O.; Chen, J. M.; Roulet, N. T.

    2006-12-01

    A number of field carbon flux measurements, paleoecological records, and model simulations have acknowledged the importance of northern peatlands in terrestrial carbon cycling and methane emissions. An important parameter in peatlands that influences both net primary productivity, the net gain of carbon through photosynthesis, and decomposition under aerobic and anaerobic conditions, is the position of the water table. Biological and physical processes involved in peatland carbon dynamics and their hydrological controls operate at different spatial scales. The highly variable hydraulic characteristics of the peat profile and the overall shape of the peat body as defined by its surface topography at the mesoscale (104 m2) are of major importance for peatland water table dynamics. Common types of peatlands include bogs with a slightly domed centre. As a result of the convex profile, their water supply is restricted to atmospheric inputs, and water is mainly shed by shallow subsurface flow. From a modelling perspective the influence of mesotopographic controls on peatland hydrology and thus carbon balance requires that process-oriented models that examine the links between peatland hydrology, ecosystem functioning, and climate must incorporate some form of lateral subsurface flow consideration. Most hydrological and ecological modelling studies in complex terrain explicitly account for the topographic controls on lateral subsurface flow through digital elevation models. However, modelling studies in peatlands often employ simple empirical parameterizations of lateral subsurface flow, neglecting the influence of peatlands low relief mesoscale topography. Our objective is to explicitly simulate the mesotopographic controls on peatland hydrology and carbon fluxes using the Boreal Ecosystem Productivity Simulator (BEPS) adapted to northern peatlands. BEPS is a process-oriented ecosystem model in a remote sensing framework that takes into account peatlands multi

  2. Fractionation of 137Cs and Pu in natural peatland

    International Nuclear Information System (INIS)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-01-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. - Highlights: • Decrease of exchangeable 137 Cs and its increase in residual fraction with depth. • High 137 Cs transfer factor contrary to its low quantity in bioavailable fractions. • Fulvic/humic acids are a more effective carrier for Pu than for Cs

  3. Fractionation of (137)Cs and Pu in natural peatland.

    Science.gov (United States)

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-08-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Microtopography and methane flux in boreal peatlands, northern Ontario, Canada

    International Nuclear Information System (INIS)

    Bubier, J.; Costello, A.; Moore, T.R.; Roulet, N.T.; Savage, K.

    1993-01-01

    Peatlands act as a major sink of carbon dioxide and a source of methane. Fluxes of methane were measured by a static chamber technique at hummock, hollow, and lawn microtopographic locations in 12 peatland sites near Cochrane, northern Ontario, from May to October 1991. Average fluxes (mg/m 2 /d) were 2.3 at hummocks, 44.4 at hollows, and 15.6 at lawns. Methane flux was negatively correlated with average water table position based on the 36 locations, with hummocks having a smaller flux than hollows or lawns, where the water table depth was <25 cm. Peat samples from a bog hummock and hollow failed to produce methane during anaerobic incubations in the laboratory; samples from a poor fen hollow produced <1.4 μg/g/d. The production decreased with depth but was greater than the rates observed during incubation of samples from an adjacent hummock. Rates of methane consumption during aerobic incubations ranged from 1 to 55 μg/g/d and were greatest in the surface layers and decreased with depth. Differences in methane emissions between hummocks and hollows appear to be controlled primarily by greater methane production rates in hollows compared with hummocks. Of secondary importance are the capacity of the peat profiles to consume methane during its transport to the peat surface and warmer temperatures at the water table beneath hollows compared with hummocks. 29 refs., 4 figs., 2 tabs

  5. Palaeoecology of testate amoebae in a tropical peatland.

    Science.gov (United States)

    Swindles, Graeme T; Lamentowicz, Mariusz; Reczuga, Monika; Galloway, Jennifer M

    2016-09-01

    We present the first detailed analysis of subfossil testate amoebae from a tropical peatland. Testate amoebae were analysed in a 4-m peat core from western Amazonia (Peru) and a transfer function developed from the site was applied to reconstruct changes in water table over the past ca. 8,000 years. Testate amoebae were in very low abundance in the core, especially in the lower 125cm, due to a combination of poor preservation and obscuration by other organic matter. A modified preparation method enabled at least 50 testate amoebae to be counted in each core sample. The most abundant taxa preserved include Centropyxis aculeata, Hyalosphenia subflava, Phryganella acropodia and Trigonopyxis arcula. Centropyxis aculeata, an unambiguous wet indicator, is variably present and indicates several phases of near-surface water table. Our work shows that even degraded, low-abundance assemblages of testate amoebae can provide useful information regarding the long-term ecohydrological developmental history of tropical peatlands. Copyright © 2015 Elsevier GmbH. All rights reserved.

  6. Opportunities for reducing greenhouse gas emissions in tropical peatlands.

    Science.gov (United States)

    Murdiyarso, D; Hergoualc'h, K; Verchot, L V

    2010-11-16

    The upcoming global mechanism for reducing emissions from deforestation and forest degradation in developing countries should include and prioritize tropical peatlands. Forested tropical peatlands in Southeast Asia are rapidly being converted into production systems by introducing perennial crops for lucrative agribusiness, such as oil-palm and pulpwood plantations, causing large greenhouse gas (GHG) emissions. The Intergovernmental Panel on Climate Change Guidelines for GHG Inventory on Agriculture, Forestry, and Other Land Uses provide an adequate framework for emissions inventories in these ecosystems; however, specific emission factors are needed for more accurate and cost-effective monitoring. The emissions are governed by complex biophysical processes, such as peat decomposition and compaction, nutrient availability, soil water content, and water table level, all of which are affected by management practices. We estimate that total carbon loss from converting peat swamp forests into oil palm is 59.4 ± 10.2 Mg of CO(2) per hectare per year during the first 25 y after land-use cover change, of which 61.6% arise from the peat. Of the total amount (1,486 ± 183 Mg of CO(2) per hectare over 25 y), 25% are released immediately from land-clearing fire. In order to maintain high palm-oil production, nitrogen inputs through fertilizer are needed and the magnitude of the resulting increased N(2)O emissions compared to CO(2) losses remains unclear.

  7. River ecosystem response to prescribed vegetation burning on Blanket Peatland.

    Science.gov (United States)

    Brown, Lee E; Johnston, Kerrylyn; Palmer, Sheila M; Aspray, Katie L; Holden, Joseph

    2013-01-01

    Catchment-scale land-use change is recognised as a major threat to aquatic biodiversity and ecosystem functioning globally. In the UK uplands rotational vegetation burning is practised widely to boost production of recreational game birds, and while some recent studies have suggested burning can alter river water quality there has been minimal attention paid to effects on aquatic biota. We studied ten rivers across the north of England between March 2010 and October 2011, five of which drained burned catchments and five from unburned catchments. There were significant effects of burning, season and their interaction on river macroinvertebrate communities, with rivers draining burned catchments having significantly lower taxonomic richness and Simpson's diversity. ANOSIM revealed a significant effect of burning on macroinvertebrate community composition, with typically reduced Ephemeroptera abundance and diversity and greater abundance of Chironomidae and Nemouridae. Grazer and collector-gatherer feeding groups were also significantly less abundant in rivers draining burned catchments. These biotic changes were associated with lower pH and higher Si, Mn, Fe and Al in burned systems. Vegetation burning on peatland therefore has effects beyond the terrestrial part of the system where the management intervention is being practiced. Similar responses of river macroinvertebrate communities have been observed in peatlands disturbed by forestry activity across northern Europe. Finally we found river ecosystem changes similar to those observed in studies of wild and prescribed forest fires across North America and South Africa, illustrating some potentially generic effects of fire on aquatic ecosystems.

  8. Abrupt vegetation transitions characterise long-term Amazonian peatland development

    Science.gov (United States)

    Roucoux, K. H.; Baker, T. R.; Gosling, W. D.; Honorio Coronado, E.; Jones, T. D.; Lahteenoja, O.; Lawson, I. T.

    2012-04-01

    Recent investigations of wetlands in western Amazonia have revealed the presence of extensive peatlands with peat deposits of up to 8 m-thick developing under a variety of vegetation types (Lähteenoja et al. 2012). Estimated to cover 150,000 km2 (Schulman et al. 1999), these peatlands make a valuable contribution to landscape and biological diversity and represent globally important carbon stores. In order to understand the processes leading to peat formation, and the sensitivity of these environments to future climatic change, it is necessary to understand their long-term history. The extent to which peatland vegetation changes over time, the stability of particular communities, the controls on transitions between vegetation types and how these factors relate to the accumulation of organic matter are not yet known. We report the first attempt to establish the long-term (millennial scale) vegetation history of a recently-described peatland site: Quistococha, a palm swamp, or aguajal, close to Iquitos in northern Peru. The vegetation is dominated by Mauritia flexuosa and Mauritiella armata and occupies a basin which is thought to be an abandoned channel of the River Amazon. We obtained a 4 m-long peat sequence from the deepest part of the basin. AMS-radiocarbon dating yielded a maximum age of 2,212 cal yr BP for the base of the peat, giving an average accumulation rate of 18 cm per century. Below the peat are 2 m of uniform, largely inorganic pale grey clays of lacustrine origin, which are underlain by an unknown thickness of inorganic sandy-silty clay of fluvial origin. Pollen analysis, carried out at c. 88-year intervals, shows the last 2,212 years to be characterised by the development of at least four distinct vegetation communities, with peat accumulating throughout. The main phases were: (1) Formation of Cyperaceae (sedge) fen coincident with peat initiation; (2) A short-lived phase of local Mauritia/Mauritiella development; (3) Development of mixed wet

  9. The role of emergent vegetation in structuring aquatic insect communities in peatland drainage ditches

    NARCIS (Netherlands)

    Whatley, M.H.; van Loon, E.E.; Vonk, J.A.; van der Geest, H.G.; Admiraal, W.

    2014-01-01

    Availability of macrophyte habitat is recognized as an important driver of aquatic insect communities in peatland drainage ditches; however, eutrophication can lead to the decline of submerged vegetation. While emergent vegetation is able to persist in eutrophicated ditches, vegetation removal,

  10. The long-term fate of permafrost peatlands under rapid climate warming

    DEFF Research Database (Denmark)

    Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal

    2015-01-01

    Permafrost peatlands contain globally important amounts of soil organic carbon, owing to cold conditions which suppress anaerobic decomposition. However, climate warming and permafrost thaw threaten the stability of this carbon store. The ultimate fate of permafrost peatlands and their carbon...... stores is unclear because of complex feedbacks between peat accumulation, hydrology and vegetation. Field monitoring campaigns only span the last few decades and therefore provide an incomplete picture of permafrost peatland response to recent rapid warming. Here we use a high-resolution palaeoecological...... approach to understand the longer-term response of peatlands in contrasting states of permafrost degradation to recent rapid warming. At all sites we identify a drying trend until the late-twentieth century; however, two sites subsequently experienced a rapid shift to wetter conditions as permafrost thawed...

  11. Relationships between aquatic invertebrates, water quality and vegetation in an Andean peatland system

    Directory of Open Access Journals (Sweden)

    E. Oyague Passuni

    2015-12-01

    Full Text Available Peatlands (known as bofedales in the Peruvian Andes provide important social and environmental services in the Peruvian Puna ecoregion, especially as sources of water and forage for domestic livestock. In biological terms, these peatlands are key habitats with their own community structure, dynamics and interactions; and they serve as biodiversity hotspots within the High Andes. In this article we assess the relationships between: (i physical structure, (ii water quality, (iii plant communities and (iv the assemblages of aquatic invertebrates (benthic macroinvertebrates in three peatlands located in Cuzco Region, southern Peru. The results suggest that the benthic macroinvertebrate assemblage is a good indicator of the trophic status of the small pools that are typically present in bofedales. Trophic status is, in turn, primarily related to spatial and seasonal water availability and the types of plant communities present in each peatland.

  12. Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon

    Czech Academy of Sciences Publication Activity Database

    Evans, C. D.; Page, S. E.; Jones, T.; Moore, S.; Gauci, V.; Laiho, R.; Hruška, Jakub; Allott, T. E. H.; Billet, M. F.; Tipping, E.; Freeman, Ch.; Garnett, M. H.

    2014-01-01

    Roč. 28, č. 11 (2014), s. 1215-1234 ISSN 0886-6236 Institutional support: RVO:67179843 Keywords : peatland * drainage * dissolved organic carbon * radiocarbon Subject RIV: EH - Ecology, Behaviour Impact factor: 3.965, year: 2014

  13. Peatland restoration in Canada by the sphagnum moss layer transfer method

    Energy Technology Data Exchange (ETDEWEB)

    Rochefort, L.; Boismenu, C. [Laval Univ., Quebec City, PQ (Canada). Dept. de Phytologie, Peatland Ecology and Research Group; Quinty, F. [SNC-Lavalin, Montreal, PQ (Canada)

    2009-04-01

    This article described a peatland restoration approach that has received international recognition for restoring the ecological functions of cutover sphagnum dominated peatlands. The Peatland Ecology Research Group (PERG) conducted a long-term study at the Bois-des-Bel (BDB) peatland site in Quebec to restore plant composition to a peat accumulating ecosystem. The sphagnum moss layer transfer restoration method includes 5 obligatory steps and one optional. These include planning; surface preparation; plant collection and spreading; straw mulch spreading; blocking drainage ditches; and fertilization if needed. Variable moisture conditions throughout the restoration site contribute to the spatial variability in the development of the sphagnum layer. The site has been monitored each year since its restoration. sphagnum cover reached 60 per cent in the restored zone in 2005, a value close to the range of sphagnum cover found in natural sites. In addition, a new moss layer has developed with an average of 25 cm in thickness. 27 refs., 4 figs.

  14. Microbial enzyme activities of peatland soils in south central Alaska lowlands

    Science.gov (United States)

    Microbial enzyme activities related to carbon and nutrient acquisition were measured on Alaskan peatland soils as indicators of nutrient limitation and biochemical sustainability. Peat decomposition is mediated by microorganisms and enzymes that in turn are limited by various ph...

  15. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest

    Science.gov (United States)

    Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O.; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O.

    2016-01-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. PMID:26896139

  16. Carbon sequestration in Southeast Asian tropical peatlands over the Holocene period: large-scale hydrological controls

    Science.gov (United States)

    Dommain, R.; Couwenberg, J.; Cobb, A.; Gandois, L.; Kai, F.; Su'ut, N.; Abu Salim, K.; Harvey, C. F.; Glaser, P. H.; Joosten, H.

    2012-12-01

    Tropical peatlands are recognized as a significant sink of carbon dioxide and an important source of methane. Low latitude peatlands contain an estimated pool of 90 Pg C, of which ca. 70 Pg C is stored in Southeast Asian peatlands. However, the Holocene development of this carbon reservoir is poorly established. Here we provide a synthesis of carbon uptake rates by tropical peatlands in Southeast Asia across millennial timescales for the past 11,000 years. Our reconstruction of the carbon accumulation history for Borneo, Sumatra and Peninsular Malaysia is based on a synthesis of radiocarbon dated peat profiles, modeling of peatland extent, and a new carbon accumulation record from Brunei (NW-Borneo). During the early Holocene the first peatlands formed in southern Borneo under the influence of a strong monsoon and rapid rise in sea-level. The carbon accumulation rate (CAR) in these peatlands was on average 60 g C m-2 yr-1 at this time. Peatlands started to spread across the coastal lowlands of Borneo, Sumatra and Peninsular Malaysia after 8000 cal BP only when the rate of rising sea-level decreased. The major phase of coastal peatland initiation lasted from 7000 to 4000 cal BP. This period was marked by a Holocene precipitation maximum, suppressed El Niño activity, and the Holocene maximum in sea-level on the Sunda Shelf. The mean CAR of coastal peatlands at this time was 80 g C m-2 yr-1, with a Holocene peak of ~100 g C m-2 yr-1 from 4900 to 4500 cal BP. Significantly, atmospheric CO2 concentrations measured in the Taylor Dome Antarctic ice core indicate a plateau during this period of otherwise rising CO2 concentrations. During the Late Holocene CAR declined both in coastal peatlands (ca. 70 g C m-2 yr-1) and in southern Borneo (ca. 20 g C m-2 yr-1) in response to falling sea-levels and increased El Niño frequency and intensity. In fact, several peatlands in southern Borneo have stopped accumulating peat-carbon under higher El Niño activity. These results

  17. Water and peat chemistry comparisons of natural and peat-harvested peatlands across Canada and their relevance to peatland restoration

    International Nuclear Information System (INIS)

    Windmulder, H.L.; Rochefort, L.; Vitt, D.H.

    1996-01-01

    Water and peat chemistry comparisons of four post-harvested and neighbouring, undisturbed peatlands across Canada show that harvesting alters chemical conditions. Commercial harvesting removes the surface peat and exposes layers farther down the peat deposit. The newly exposed peat layers that were formed in earlier developmental stages of the peatland can be more minerotrophic and/or more variable in chemical composition than undisturbed bog peat. All the harvested sites were originally bogs. Only one site, which had minimal peat removed, presently has chemical conditions somewhat similar to the original surface, with low elemental levels typical of bogs. Two sites are now chemically similar to poor fens and one site is similar to a moderate-rich fen. Levels of sodium, potassium, calcium, magnesium, sulphate and chloride in three of the harvested sites are higher than normal values found in natural, unharvested bogs, and result from the exposure of fen peat. Higher levels of ammonium-nitrogen and nitrate-nitrogen in the peat and water of all the harvested sites are present, with higher ammonium associated with wetter sites and higher nitrate levels associated with drier sites

  18. Influence of forest management on the changes of organic soil properties in border part of Kragle Mokradlo Peatland (Stolowe Mountains National Park, Poland)

    Science.gov (United States)

    Bogacz, A.; Roszkowicz, M.

    2009-04-01

    . CONCLUSIONS Shallow organic soils occupy the ombrotrophic sites of a border part of Kragle Mokradlo Peatland. The variety of organic soil throphism in the object resulted from the placement on the base sandstone, partial mixing of soil horizons as well as from muddy and fluvial processes. Peat horizons present in the studied profiles were generally classified as hemic and sapric, sometimes as fibric. Soil horizons exhibited differed thickness and ash content. Forest management strongly changed the properties of organic soil. REFERENCES Bogacz, A. (2000). Physical properties of organic soil in Stolowe Mountains National Park (Poland). Suo 51,3; pp.105-113. Gee, G.W. and Bauder, J.W. (1986). Particle-size analysis. In: Klute, A.(ed.) Methods of Soil Analysis Part I. Agronomy series No. 9. Am. Soc. Agronomy Soil Sci. Am, Inc., Publ., Madison, WI.pp. 383-411. Horawski, M. (1987). Torfoznawstwo dla meliorantow. Pojecia podstawowe.[Peat science for melioration. Basic definitions.]. Wydawnictwo Akademii Rolniczej w Krakowie. pp.37-39.[In Polish]. Lubliner - Mianowska, K. (1951). Wskazowki do badania torfu. Metody geobotaniczne, polowe i laboratoryjne [Hints to peat research. In: Geobotanical, field and laboratory methods] Państwowe Wydawnictwo Techniczne, Katowice.pp.58-60. [In Polish]. Lynn, W.C., Mc Kinzie, W.E., Grossman, R.B. (1974). Field Laboratory Test for characterization of Histosols. In: Histosols, their characteristics, classification and use. pp. 11-20. Oznaczanie gatunku, rodzaju i typu torfu. (1977). [Peat and peat varies. Determination of classes, sort and types of peat]. Polish standard PN-76/G-02501, [Polish Normalization Commitee]. pp.1-11.[In Polish]. Word Reference Base for Soil Resources. 1998. Word Soil Resources Report, 84. FAO-ISRIC-ISSS, Rome, pp.1-88. Zawadzki, S. (1970). Relationship between the content of organic matter and physical properties of hydrogenic soils. Polish Journal of Soil Science Vol.III, 1; pp.3-9.

  19. Managing erosion, sediment transport and water quality in drained peatland catchments

    Energy Technology Data Exchange (ETDEWEB)

    Marttila, H.

    2010-07-01

    Peatland drainage changes catchment conditions and increases the transport of suspended solids (SS) and nutrients. New knowledge and management methods are needed to reduce SS loading from these areas. This thesis examines sediment delivery and erosion processes in a number of peatland drainage areas and catchments in order to determine the effects of drainage on sediment and erosion dynamics and mechanics. Results from studies performed in peat mining, peatland forestry and disturbed headwater catchments in Finland are presented and potential sediment load management methods are discussed for drainage areas and headwater brooks. Particular attention is devoted to erosion of organic peat, sediment transport and methods to reduce the impacts of peatland drainage in boreal headwaters. This thesis consists of six articles. The first and second papers focus on the erosion and sediment transport processes at peat harvesting and peatland forestry drainage networks. The results indicate that in-channel processes are important in drained peatland, since the drainage network often constitutes temporary inter-storm storage for eroding and transporting material. Sediment properties determine the bed sediment erosion sensitivity, as fluffy organic peat sediment consolidates over time. As flashiness and peak runoff control sediment entrainment and transport from drained peatland areas, water quality management should include peak runoff management. The third, fourth and fifth papers studies use and application of peak runoff control (PRC) method to the peat harvesting and peatland forestry conditions for water protection. Results indicate that effective water quality management in drained peatland areas can be achieved using this method. Installation of the PRC structures is a useful and cost-effective way of storing storm runoff waters temporarily in the ditch system and providing a retention time for eroded sediment to settle to the ditch bed and drainage network. The main

  20. Modelling hydrological processes and dissolved organic carbon dynamics in a rehabilitated Sphagnum-dominated peatland

    Science.gov (United States)

    Bernard-Jannin, Léonard; Binet, Stéphane; Gogo, Sébastien; Leroy, Fabien; Perdereau, Laurent; Laggoun-Défarge, Fatima

    2017-04-01

    Sphagnum-dominated peatlands represent a global major stock of carbon (C). Dissolved organic carbon (DOC) exports through runoff and leaching could reduce their potential C sink function and impact downstream water quality. DOC production in peatlands is strongly controlled by the hydrology, especially water table depth (WTD). Therefore, disturbances such as drainage can lead to increase DOC exports by lowering the WTD. Hydrological restoration (e.g. rewetting) can be undertaken to restore peatland functioning with an impact on DOC exports. The objective of this study is to assess the impact of drainage and rewetting on hydrological processes and their interactions with DOC dynamics in a Sphagnum dominated peatland. A hydrological model has been applied to a drained peatland (La Guette, France) which experienced a rewetting action on February 2014 and where WTD has been recorded in four piezometers at a 15 min time step since 2009. In addition, DOC concentrations in the peatland have been measured 6 times a year since 2014. The hydrological model is a WTD dependent reservoir model composed by two reservoirs representing the micro and macro porosity of the peatland (Binet et al., 2013). A DOC production module in both reservoirs was implemented based on temperature and WTD. The model was calibrated against WTD and DOC concentrations for each piezometer. The results show that the WTD in the study area is strongly affected by local meteorological conditions that could hide the effect of the rewetting action. The preliminary results evidenced that an additional source of water, identified as groundwater supply originating from the surrounding sandy layer aquifer, is necessary to maintain the water balance, especially during wet years (NS>0.8). Finally, the DOC module was able to describe DOC concentrations measured in the peatland and could be used to assess the impact of rewetting on DOC dynamics at different locations and to identify the factors of control of DOC

  1. Methylmercury dynamics at the upland-peatland interface: Topographic and hydrogeochemical controls

    Science.gov (United States)

    Carl P. J. Mitchell; Brian A. Branfireun; Randall K. Kolka

    2009-01-01

    Peatlands are important environments for the transformation of atmospherically deposited inorganic mercury into the bioaccumulative form, methylmercury (MeHg), which may accumulate in downstream aquatic biota, particularly in fish. In recent research, it was suggested that MeHg production and/or accumulation ‘‘hot spots’’ at the upland-peatland interface were the...

  2. Peatland carbon stocks and accumulation rates in the Ecuadorian páramo

    Science.gov (United States)

    John A. Hribljan; Esteban Suarez; Katherine A. Heckman; Erik Lilleskov; Rodney A. Chimner

    2016-01-01

    The páramo is a high altitude tropical Andean ecosystem that contains peatlands with thick horizons of carbon (C) dense soils. Soil C data are sparse for most of the pa´ramo, especially in peatlands, which limits our ability to provide accurate regional and country wide estimates of C storage. Therefore, the objective of our research was to quantify belowground C...

  3. Upscaling Our Approach to Peatland Carbon Sequestration: Remote Sensing as a Tool for Carbon Flux Estimation.

    Science.gov (United States)

    Lees, K.; Khomik, M.; Clark, J. M.; Quaife, T. L.; Artz, R.

    2017-12-01

    Peatlands are an important part of the Earth's carbon cycle, comprising approximately a third of the global terrestrial carbon store. However, peatlands are sensitive to climatic change and human mismanagement, and many are now degraded and acting as carbon sources. Restoration work is being undertaken at many sites around the world, but monitoring the success of these schemes can be difficult and costly using traditional methods. A landscape-scale alternative is to use satellite data in order to assess the condition of peatlands and estimate carbon fluxes. This work focuses on study sites in Northern Scotland, where parts of the largest blanket bog in Europe are being restored from forest plantations. A combination of laboratory and fieldwork has been used to assess the Net Ecosystem Exchange (NEE), Gross Primary Productivity (GPP) and respiration of peatland sites in different conditions, and the climatic vulnerability of key peat-forming Sphagnum species. The results from these studies have been compared with spectral data in order to evaluate the extent to which remote sensing can function as a source of information for peatland health and carbon flux models. This work considers particularly the effects of scale in calculating peatland carbon flux. Flux data includes chamber and eddy covariance measurements of carbon dioxide, and radiometric observations include both handheld spectroradiometer results and satellite images. Results suggest that despite the small-scale heterogeneity and unique ecosystem factors in blanket bogs, remote sensing can be a useful tool in monitoring peatland health and carbon sequestration. In particular, this study gives unique insights into the relationships between peatland vegetation, carbon flux and spectral reflectance.

  4. Changes in vegetation, peat properties and peat accumulation in Swedish peatlands as revealed by archive data.

    Science.gov (United States)

    Schoning, Kristian; Sohlenius, Gustav

    2016-04-01

    In this investigation we have studied patterns in peat accumulation and changes in mire status since the early 1900s for two areas in Sweden. In the early 1900s the Geological Survey of Sweden collected a vast amount of peat and peatland data, including information on vegetation and land-use. We have used this archive data to evaluate changes in mire vegetation, mire wetness and surface peat properties, rates of peat accumulation, succession in young wetlands and the effects of cultivation on peatlands. In total 156 mires in an uplift area of eastern middle Sweden were included in the data-set, including both pristine mires and peatlands used for agricultural purposes. In this area new peatlands have continuously been formed during the past 7 000 years making it possible to evaluate changes in peat accumulation over time. The other study area is situated in the south Swedish Uplands where we have revisited some larger bogs. The results from our investigation show that many of the peatlands have underwent major changes since the early 1900s. In most of the small peatlands we have found important changes in vegetation where mire vegetation has been replaced by nutrient demanding and/or dry species flora while the tree stand on large mires in south Sweden have increased. In some mires humification has increased in the uppermost peat-layers and the mire surface have become drier compared to the early 1900s. In eastern middle Sweden there are indications that the peat accumulation is lower 0,5 mm/year in older peatlands compared with younger ones 1,2 mm/year, although the mire vegetation in the older peatlands is dominated by sphagnum. The peat depth of the cultivated mires in this area shows a mean decrease of 40 cm since the early 1900s.

  5. Denial of long-term issues with agriculture on tropical peatlands will have devastating consequences

    OpenAIRE

    Wijedasa, Lahiru S.; Jauhiainen, Jyrki; Könönen, Mari; Lampela, Maija; Vasander, Harri; Leblanc, Marie-Claire; Evers, Stephanie; Smith, E. L. Thomas; Yule, Catherine M.; Varkkey, Helena; Lupascu, Massimo; Parish, Faizal; Singleton, Ian; Clements, Gopalasamy R.; Aziz, Sheema Abdul

    2017-01-01

    The first International Peat Congress (IPC) held in the tropics - in Kuching (Malaysia) - brought together over 1000 international peatland scientists and industrial partners from across the world (“International Peat Congress with over 1000 participants!,” 2016). The congress covered all aspects of peatland ecosystems and their management, with a strong focus on the environmental, societal and economic challenges associated with contemporary large-scale agricultural conversion of tropical pe...

  6. Groundwater dynamics in mountain peatlands with contrasting climate, vegetation, and hydrogeological setting

    Science.gov (United States)

    Millar, David J.; Cooper, David J.; Ronayne, Michael J.

    2018-06-01

    Hydrological dynamics act as a primary control on ecosystem function in mountain peatlands, serving as an important regulator of carbon fluxes. In western North America, mountain peatlands exist in different hydrogeological settings, across a range climatic conditions, and vary in floristic composition. The sustainability of these ecosystems, particularly those at the low end of their known elevation range, is susceptible to a changing climate via changes in the water cycle. We conducted a hydrological investigation of two mountain peatlands, with differing vegetation, hydrogeological setting (sloping vs basin), and climate (strong vs weak monsoon influence). Growing season saturated zone water budgets were modeled on a daily basis, and subsurface flow characterizations were performed during multiple field campaigns at each site. The sloping peatland expectedly showed a strong lateral groundwater potential gradient throughout the growing season. Alternatively, the basin peatland had low lateral gradients but more pronounced vertical gradients. A zero-flux plane was apparent at a depth of approximately 50 cm below the peat surface at the basin peatland; shallow groundwater above this depth moved upward towards the surface via evapotranspiration. The differences in groundwater flow dynamics between the two sites also influenced water budgets. Higher groundwater inflow at the sloping peatland offset higher rates of evapotranspiration losses from the saturated zone, which were apparently driven by differences in vegetative cover. This research revealed that although sloping peatlands cover relatively small portions of mountain watersheds, they provide unique settings where vegetation directly utilizes groundwater for transpiration, which were several-fold higher than typically reported for surrounding uplands.

  7. Fungal communities in ancient peatlands developed from different periods in the Sanjiang Plain, China.

    Science.gov (United States)

    Zhang, Zhenqing; Zhou, Xue; Tian, Lei; Ma, Lina; Luo, Shasha; Zhang, Jianfeng; Li, Xiujun; Tian, Chunjie

    2017-01-01

    Peatlands in the Sanjiang Plain could be more vulnerable to global warming because they are located at the southernmost boundary of northern peatlands. Unlike bacteria, fungi are often overlooked, even though they play important roles in substance circulation in the peatland ecosystems. Accordingly, it is imperative that we deepen our understanding of fungal community structure and diversity in the peatlands. In this study, high-throughput Illumina sequencing was used to study the fungal communities in three fens in the Sanjiang Plain, located at the southern edge of northern peatlands. Peat soil was collected from the three fens which developed during different periods. A total of 463,198 fungal ITS sequences were obtained, and these sequences were classified into at least six phyla, 21 classes, more than 60 orders and over 200 genera. The fungal community structures were distinct in the three sites and were dominated by Ascomycota and Basidiomycota. However, there were no significant differences between these three fens in any α-diversity index (p > 0.05). Soil age and the carbon (C) accumulation rate, as well as total carbon (TC), total nitrogen (TN), C/N ratio, and bulk density were found to be closely related to the abundance of several dominant fungal taxa. We captured a rich fungal community and confirmed that the dominant taxa were those which were frequently detected in other northern peatlands. Soil age and the C accumulation rate were found to play important roles in shaping the fungal community structure.

  8. Vulnerability of the peatland carbon sink to sea-level rise

    Science.gov (United States)

    Whittle, Alex; Gallego-Sala, Angela V.

    2016-06-01

    Freshwater peatlands are carbon accumulating ecosystems where primary production exceeds organic matter decomposition rates in the soil, and therefore perform an important sink function in global carbon cycling. Typical peatland plant and microbial communities are adapted to the waterlogged, often acidic and low nutrient conditions that characterise them. Peatlands in coastal locations receive inputs of oceanic base cations that shift conditions from the environmental optimum of these communities altering the carbon balance. Blanket bogs are one such type of peatlands occurring in hyperoceanic regions. Using a blanket bog to coastal marsh transect in Northwest Scotland we assess the impacts of salt intrusion on carbon accumulation rates. A threshold concentration of salt input, caused by inundation, exists corresponding to rapid acidophilic to halophilic plant community change and a carbon accumulation decline. For the first time, we map areas of blanket bog vulnerable to sea-level rise, estimating that this equates to ~7.4% of the total extent and a 0.22 Tg yr-1 carbon sink. Globally, tropical peatlands face the proportionally greatest risk with ~61,000 km2 (~16.6% of total) lying ≤5 m elevation. In total an estimated 20.2 ± 2.5 GtC is stored in peatlands ≤5 m above sea level, which are potentially vulnerable to inundation.

  9. Net ecosystem CO2 exchange of a cutover peatland rehabilitated with a transplanted acrotelm

    International Nuclear Information System (INIS)

    Cagampan, J.P.; Waddington, J.M.

    2008-01-01

    Peatlands are an important long-term sink for atmospheric carbon dioxide (CO 2 ). The storage function of peatland ecosystems is significantly impacted by drainage and extraction processes, which can result in the release of significant amounts of CO 2 . This paper investigated the net ecosystem CO 2 exchange of a newly developed extraction-restoration technique that preserved the acrotelm and replaced it directly on the cut surface of the peatlands. The technique used a modified block-cut method with a back-hoe to create a drainage ditch. Actrotelm and surface vegetation were removed and placed to one side, and the peat was mechanically removed. The acrotelm was then transplanted over the older and more decomposed catotelm peat to create a trench topography in which the natural peatland was higher than the extracted zone. Air temperatures, water table levels, and volumetric moisture content levels were measured throughout the experiment. Measurements of CO 2 exchange were taken for the duration of a Spring and summer growing season at 12 sampling locations. Results of the experiment showed that the technique was successful in maintaining moisture conditions similar to those observed in the natural peatlands. However, the peatlands where the technique was used were still net emitters of CO 2 . Recommendations for improving the technique included using more care when removing upper peat layers; limiting surface damage; and reducing spaces and gaps between the transplanted acrotelm. 34 refs., 8 figs

  10. A survey of ASEAN instruments relating to peatlands, mangroves and other wetlands: The REDD+ context

    Directory of Open Access Journals (Sweden)

    Kheng-Lian Koh

    2013-07-01

    Full Text Available Since the 13th Association of Southeast Asian Nations (ASEAN Summit in November 2007, held in Singapore, ASEAN has accelerated its response to climate change issues, including REDD+ as a mechanism for climate change mitigation and adaptation, and to enhance conservation and sustainable use of natural resources. There are many wetlands in ASEAN including more than 25 million ha of peatlands spread over Indonesia, Malaysia, Thailand, Brunei, Philippines, Vietnam and Lao PDR. The peatlands account for 60 per cent of global tropical peatland resources. They are of significance for sequestration of carbon. However, degraded wetlands, including peatlands, are also a major source of greenhouse gases contributing to global warming. Of the types of wetlands, ASEAN has focused attention predominantly on peatlands in relation to REDD+, mainly because of the ‘Indonesian Haze’. The Asia-Pacific Centre for Environmental Law (APCEL organised a Workshop titled, REDD+ and Legal Regimes of Mangroves, Peatland and Other Wetlands: ASEAN and the World, in Singapore from 15-16 November 2012. The articles contained in this special themed edition of the International Journal of Rural Law and Policy (IJRLP contains a selection of the papers presented. This editorial will provide a brief background to some aspects of REDD+. Included in this issue of IJRLP is a summary of the proceedings of the workshop as interpreted by the assigned rapporteur and editors of APCEL. These summaries were reviewed and approved by the presenters.

  11. Fungal communities in ancient peatlands developed from different periods in the Sanjiang Plain, China.

    Directory of Open Access Journals (Sweden)

    Zhenqing Zhang

    Full Text Available Peatlands in the Sanjiang Plain could be more vulnerable to global warming because they are located at the southernmost boundary of northern peatlands. Unlike bacteria, fungi are often overlooked, even though they play important roles in substance circulation in the peatland ecosystems. Accordingly, it is imperative that we deepen our understanding of fungal community structure and diversity in the peatlands. In this study, high-throughput Illumina sequencing was used to study the fungal communities in three fens in the Sanjiang Plain, located at the southern edge of northern peatlands. Peat soil was collected from the three fens which developed during different periods. A total of 463,198 fungal ITS sequences were obtained, and these sequences were classified into at least six phyla, 21 classes, more than 60 orders and over 200 genera. The fungal community structures were distinct in the three sites and were dominated by Ascomycota and Basidiomycota. However, there were no significant differences between these three fens in any α-diversity index (p > 0.05. Soil age and the carbon (C accumulation rate, as well as total carbon (TC, total nitrogen (TN, C/N ratio, and bulk density were found to be closely related to the abundance of several dominant fungal taxa. We captured a rich fungal community and confirmed that the dominant taxa were those which were frequently detected in other northern peatlands. Soil age and the C accumulation rate were found to play important roles in shaping the fungal community structure.

  12. Groundwater flow in a coastal peatland and its influence on submarine groundwater discharge

    Science.gov (United States)

    Ptak, T.; Ibenthal, M.; Janssen, M.; Massmann, G.; Lenartz, B.

    2017-12-01

    Coastal peatlands are characterized by intense interactions between land and sea, comprising both a submarine discharge of fresh groundwater and inundations of the peatland with seawater. Nutrients and salts can influence the biogeochemical processes both in the shallow marine sediments and in the peatland. The determination of flow direction and quantity of groundwater flow are therefore elementary. Submarine groundwater discharge (SGD) has been reported from several locations in the Baltic. The objective of this study is to quantify the exchange of fresh and brackish water across the shoreline in a coastal peatland in Northeastern Germany, and to assess the influence of a peat layer extending into the Baltic Sea. Below the peatland, a shallow fine sand aquifer differs in depth and is limited downwards by glacial till. Water level and electrical conductivity (EC) are permanently measured in different depths at eight locations in the peatland. First results indicate a general groundwater flow direction towards the sea. Electrical conductivity measurements suggest different permeabilities within the peat layer, depending on its thickness and degradation. Near the beach, EC fluctuates partially during storm events due to seawater intrusion and reverse discharge afterwards. The groundwater flow will be verified with a 3D model considering varying thicknesses of the aquifer. Permanent water level and electrical conductivity readings, meteorological data and hydraulic conductivity from slug tests and grain size analysis are the base for the calibration of the numerical model.

  13. Vulnerability of the peatland carbon sink to sea-level rise

    Science.gov (United States)

    Whittle, Alex; Gallego-Sala, Angela V.

    2016-01-01

    Freshwater peatlands are carbon accumulating ecosystems where primary production exceeds organic matter decomposition rates in the soil, and therefore perform an important sink function in global carbon cycling. Typical peatland plant and microbial communities are adapted to the waterlogged, often acidic and low nutrient conditions that characterise them. Peatlands in coastal locations receive inputs of oceanic base cations that shift conditions from the environmental optimum of these communities altering the carbon balance. Blanket bogs are one such type of peatlands occurring in hyperoceanic regions. Using a blanket bog to coastal marsh transect in Northwest Scotland we assess the impacts of salt intrusion on carbon accumulation rates. A threshold concentration of salt input, caused by inundation, exists corresponding to rapid acidophilic to halophilic plant community change and a carbon accumulation decline. For the first time, we map areas of blanket bog vulnerable to sea-level rise, estimating that this equates to ~7.4% of the total extent and a 0.22 Tg yr−1 carbon sink. Globally, tropical peatlands face the proportionally greatest risk with ~61,000 km2 (~16.6% of total) lying ≤5 m elevation. In total an estimated 20.2 ± 2.5 GtC is stored in peatlands ≤5 m above sea level, which are potentially vulnerable to inundation. PMID:27354088

  14. Short-term vegetation change on rehabilitated peatland on Rietvlei Nature Reserve

    Directory of Open Access Journals (Sweden)

    C.E. Venter

    2003-12-01

    Full Text Available Natural peatlands occur on the Rietvlei Nature Reserve. Before the Pretoria City Council acquired the land, these peatlands were mined by private land-owners. Ditches were constructed to drain the area for mining and the peatlands became desicrated. Later the area was proclaimed as a nature reserve and has since then been managed as such. Rehabilitation of the drained peatland on Rietvlei Nature Reserve first started in 2000 as a Working for Water project. The aim of the rehabilitation was to close the ditches and rewet the peatland, to enable possible revival of the peatland. A baseline vegetation survey was undertaken during the summer (March to April of 2001 to determine the nature of the pioneer communities that established on the rehabilitated area. This survey was repeated during the summer (March to April of 2002 to detect changes in the vegetation. The same sample plots were used on both occasions. The initial pioneer vegetation was mostly composed of weedy annuals.

  15. Contrasting vulnerability of drained tropical and high-latitude peatlands to fluvial loss of stored carbon

    Science.gov (United States)

    Evans, Chris D.; Page, Susan E.; Jones, Tim; Moore, Sam; Gauci, Vincent; Laiho, Raija; Hruška, Jakub; Allott, Tim E. H.; Billett, Michael F.; Tipping, Ed; Freeman, Chris; Garnett, Mark H.

    2014-11-01

    Carbon sequestration and storage in peatlands rely on consistently high water tables. Anthropogenic pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of pressures including drainage, burning, land conversion for agriculture, timber, and biofuel production, cause loss of peat-forming vegetation and exposure of previously anaerobic peat to aerobic decomposition. This can shift peatlands from net CO2 sinks to large CO2 sources, releasing carbon held for millennia. Peatlands also export significant quantities of carbon via fluvial pathways, mainly as dissolved organic carbon (DOC). We analyzed radiocarbon (14C) levels of DOC in drainage water from multiple peatlands in Europe and Southeast Asia, to infer differences in the age of carbon lost from intact and drained systems. In most cases, drainage led to increased release of older carbon from the peat profile but with marked differences related to peat type. Very low DOC-14C levels in runoff from drained tropical peatlands indicate loss of very old (centuries to millennia) stored peat carbon. High-latitude peatlands appear more resilient to drainage; 14C measurements from UK blanket bogs suggest that exported DOC remains young (use changes in the tropics. Data from the UK Peak District, an area where air pollution and intensive land management have triggered Sphagnum loss and peat erosion, suggest that additional anthropogenic pressures may trigger fluvial loss of much older (>500 year) carbon in high-latitude systems. Rewetting at least partially offsets drainage effects on DOC age.

  16. Fungal communities in ancient peatlands developed from different periods in the Sanjiang Plain, China

    Science.gov (United States)

    Tian, Lei; Ma, Lina; Luo, Shasha; Zhang, Jianfeng; Li, Xiujun

    2017-01-01

    Peatlands in the Sanjiang Plain could be more vulnerable to global warming because they are located at the southernmost boundary of northern peatlands. Unlike bacteria, fungi are often overlooked, even though they play important roles in substance circulation in the peatland ecosystems. Accordingly, it is imperative that we deepen our understanding of fungal community structure and diversity in the peatlands. In this study, high-throughput Illumina sequencing was used to study the fungal communities in three fens in the Sanjiang Plain, located at the southern edge of northern peatlands. Peat soil was collected from the three fens which developed during different periods. A total of 463,198 fungal ITS sequences were obtained, and these sequences were classified into at least six phyla, 21 classes, more than 60 orders and over 200 genera. The fungal community structures were distinct in the three sites and were dominated by Ascomycota and Basidiomycota. However, there were no significant differences between these three fens in any α-diversity index (p > 0.05). Soil age and the carbon (C) accumulation rate, as well as total carbon (TC), total nitrogen (TN), C/N ratio, and bulk density were found to be closely related to the abundance of several dominant fungal taxa. We captured a rich fungal community and confirmed that the dominant taxa were those which were frequently detected in other northern peatlands. Soil age and the C accumulation rate were found to play important roles in shaping the fungal community structure. PMID:29236715

  17. Subsidence and carbon loss in drained tropical peatlands

    Directory of Open Access Journals (Sweden)

    A. Hooijer

    2012-03-01

    Full Text Available Conversion of tropical peatlands to agriculture leads to a release of carbon from previously stable, long-term storage, resulting in land subsidence that can be a surrogate measure of CO2 emissions to the atmosphere. We present an analysis of recent large-scale subsidence monitoring studies in Acacia and oil palm plantations on peatland in SE Asia, and compare the findings with previous studies. Subsidence in the first 5 yr after drainage was found to be 142 cm, of which 75 cm occurred in the first year. After 5 yr, the subsidence rate in both plantation types, at average water table depths of 0.7 m, remained constant at around 5 cm yr−1. The results confirm that primary consolidation contributed substantially to total subsidence only in the first year after drainage, that secondary consolidation was negligible, and that the amount of compaction was also much reduced within 5 yr. Over 5 yr after drainage, 75 % of cumulative subsidence was caused by peat oxidation, and after 18 yr this was 92 %. The average rate of carbon loss over the first 5 yr was 178 t CO2eq ha−1 yr−1, which reduced to 73 t CO2eq ha−1 yr−1 over subsequent years, potentially resulting in an average loss of 100 t CO2eq ha−1 yr−1 over 25 yr. Part of the observed range in subsidence and carbon loss values is explained by differences in water table depth, but vegetation cover and other factors such as addition of fertilizers also influence peat oxidation. A relationship with groundwater table depth shows that subsidence and carbon loss are still considerable even at the highest water levels theoretically possible in plantations. This implies that improved plantation water management will reduce these impacts by 20 % at most, relative to current conditions, and that high rates of carbon loss and land subsidence are

  18. Using 13C isotopes to explore denitrification-dependent anaerobic methane oxidation in a paddy-peatland.

    Science.gov (United States)

    Shi, Yao; Wang, Zhongqiang; He, Chunguang; Zhang, Xinyu; Sheng, Lianxi; Ren, Xiaodong

    2017-01-18

    Peatlands are organic-matter-rich but nitrogen-limited natural systems, the carbon/nitrogen (C/N) status of which are subject to increasing exposure from long-term nitrate (NO 3 - ) fertilizer inputs and atmospheric nitrogen (N) deposits. To manage and protect these unique environments, an improved understanding of denitrification-dependent anaerobic oxidation of methane (DAMO) in peatlands is needed. In this study, we used stable isotope measurements and incubation with NO 3 - additions to facilitate an investigation and comparison of the potential DAMO rates in a paddy-peatland that has been influenced by N fertilizer over 40 years and an undisturbed peatland in northeast China. Monitoring of 13 CO 2 production confimed DAMO did occur in both the paddy-peatland and the undisturbed peatland, the rates of which increased with NO 3 - additions, but decreased logarithmically with time. When NO 3 - was added, there were no significant differences between the CH 4 oxidation in the paddy-peatland and peatland samples after 36 hours of incubation (97.08 vs. 143.69 nmol g -1 dry peat) and the potential DAMO rate after incubation for 1 hour (92.53 vs. 69.99 nmol g -1  h -1 ). These results indicate that the occurrence of DAMO in peatlands might be controlled by the amount of NO 3 - applied and the depth to which it penetrates into the anoxic layer.

  19. Quantifying climatic impacts on peatland in the Zoige basin, China

    Science.gov (United States)

    Gao, P.; Li, Z.; Hu, X.

    2017-12-01

    Actual evapotranspiration (ET) of the Zoige basin in the Yellow River source region of China is a critical parameter for understanding water balance of peatland in the Zoige basin and hence the cause of the changing land cover. Using daily meteorological data sets of Zoige, Hongyuan, and Maqu stations from 1967 to 2011, the well-known FAO56 Penman-Monteith (P-M) formula was selected to calculate the reference crop evapotranspiration (ET0) in combination with the crop coefficient method in which the crop coefficient Kc is modified in terms of local climatic conditions. By classifying land cover of the Zoige basin in to swamp, grassland, water surface, and desert, the actual ET cover time for each type was obtained. Since late 1990s, the ET0 increased along with the increased air temperature. Different from previous studies, the ET of the swamp was slightly lower than that of water surface, but was slightly larger than the difference between annual precipitation and runoff in the Zoige basin. The increase of ET in the past 45 years was small in comparison with the change of the annual precipitation. More specifically, the annual precipitation, which was about 560-860 mm, slightly decreased between 1967 and 1997, and increased 2.23% in the 1998-2011 period. These results allowed us to conclude that though the slightly increased ET might be a factor leading to the long-term swamp dewatering, it cannot be the primary cause of the degraded peatland swamp and grassland in the Zoige basin.

  20. Variable carbon losses from recurrent fires in drained tropical peatlands.

    Science.gov (United States)

    Konecny, Kristina; Ballhorn, Uwe; Navratil, Peter; Jubanski, Juilson; Page, Susan E; Tansey, Kevin; Hooijer, Aljosja; Vernimmen, Ronald; Siegert, Florian

    2016-04-01

    Tropical peatland fires play a significant role in the context of global warming through emissions of substantial amounts of greenhouse gases. However, the state of knowledge on carbon loss from these fires is still poorly developed with few studies reporting the associated mass of peat consumed. Furthermore, spatial and temporal variations in burn depth have not been previously quantified. This study presents the first spatially explicit investigation of fire-driven tropical peat loss and its variability. An extensive airborne Light Detection and Ranging data set was used to develop a prefire peat surface modelling methodology, enabling the spatially differentiated quantification of burned area depth over the entire burned area. We observe a strong interdependence between burned area depth, fire frequency and distance to drainage canals. For the first time, we show that relative burned area depth decreases over the first four fire events and is constant thereafter. Based on our results, we revise existing peat and carbon loss estimates for recurrent fires in drained tropical peatlands. We suggest values for the dry mass of peat fuel consumed that are 206 t ha(-1) for initial fires, reducing to 115 t ha(-1) for second, 69 t ha(-1) for third and 23 t ha(-1) for successive fires, which are 58-7% of the current IPCC Tier 1 default value for all fires. In our study area, this results in carbon losses of 114, 64, 38 and 13 t C ha(-1) for first to fourth fires, respectively. Furthermore, we show that with increasing proximity to drainage canals both burned area depth and the probability of recurrent fires increase and present equations explaining burned area depth as a function of distance to drainage canal. This improved knowledge enables a more accurate approach to emissions accounting and will support IPCC Tier 2 reporting of fire emissions. © 2015 John Wiley & Sons Ltd.

  1. PEAT-CO2. Assessment of CO2 emissions from drained peatlands in SE Asia

    International Nuclear Information System (INIS)

    Hooijer, A.; Silvius, M.; Woesten, H.; Page, S.

    2006-12-01

    Forested tropical peatlands in SE Asia store at least 42,000 Megatonnes of soil carbon. This carbon is increasingly released to the atmosphere due to drainage and fires associated with plantation development and logging. Peatlands make up 12% of the SE Asian land area but account for 25% of current deforestation. Out of 27 million hectares of peatland, 12 million hectares (45%) are currently deforested and mostly drained. One important crop in drained peatlands is palm oil, which is increasingly used as a biofuel in Europe. In the PEAT-CO2 project, present and future emissions from drained peatlands were quantified using the latest data on peat extent and depth, present and projected land use and water management practice, decomposition rates and fire emissions. It was found that current likely CO2 emissions caused by decomposition of drained peatlands amounts to 632 Mt/y (between 355 and 874 Mt/y). This emission will increase in coming decades unless land management practices and peatland development plans are changed, and will continue well beyond the 21st century. In addition, over 1997-2006 an estimated average of 1400 Mt/y in CO2 emissions was caused by peatland fires that are also associated with drainage and degradation. The current total peatland CO2 emission of 2000 Mt/y equals almost 8% of global emissions from fossil fuel burning. These emissions have been rapidly increasing since 1985 and will further increase unless action is taken. Over 90% of this emission originates from Indonesia, which puts the country in 3rd place (after the USA and China) in the global CO2 emission ranking. It is concluded that deforested and drained peatlands in SE Asia are a globally significant source of CO2 emissions and a major obstacle to meeting the aim of stabilizing greenhouse gas emissions, as expressed by the international community. It is therefore recommended that international action is taken to help SE Asian countries, especially Indonesia, to better conserve

  2. Land Use Change and Recommendation for Sustainable Development of Peatland for Agriculture: Case Study at Kubu Raya and Pontianak Districts, West Kalimantan

    OpenAIRE

    Wahyunto, Wahyunto; Supriatna, Wahyu; Agus, Fahmuddin

    2010-01-01

    Peatland is an increasingly important land resource for livelihood, economic development, and terrestrial carbon storage. Kubu Raya and Pontianak Districts of West Kalimantan rely their future agricultural development on this environmentally fragile peatland because of the dominance (58% and 16% area, respectively) of this land in the two districts. A study aimed to evaluate land use changes on peatland and to develop strategies for sustainable peatland use and management for agriculture. Tim...

  3. Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery.

    Science.gov (United States)

    Connolly, J; Holden, N M

    2017-12-01

    Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA) was performed on a very high resolution satellite image (Geoeye-1) to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ) were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA) of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95-97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO 2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of drains on a blanket bog in the west of Ireland. The

  4. Detecting peatland drains with Object Based Image Analysis and Geoeye-1 imagery

    Directory of Open Access Journals (Sweden)

    J. Connolly

    2017-03-01

    Full Text Available Abstract Background Peatlands play an important role in the global carbon cycle. They provide important ecosystem services including carbon sequestration and storage. Drainage disturbs peatland ecosystem services. Mapping drains is difficult and expensive and their spatial extent is, in many cases, unknown. An object based image analysis (OBIA was performed on a very high resolution satellite image (Geoeye-1 to extract information about drain location and extent on a blanket peatland in Ireland. Two accuracy assessment methods: Error matrix and the completeness, correctness and quality (CCQ were used to assess the extracted data across the peatland and at several sub sites. The cost of the OBIA method was compared with manual digitisation and field survey. The drain maps were also used to assess the costs relating to blocking drains vs. a business-as-usual scenario and estimating the impact of each on carbon fluxes at the study site. Results The OBIA method performed well at almost all sites. Almost 500 km of drains were detected within the peatland. In the error matrix method, overall accuracy (OA of detecting the drains was 94% and the kappa statistic was 0.66. The OA for all sub-areas, except one, was 95–97%. The CCQ was 85%, 85% and 71% respectively. The OBIA method was the most cost effective way to map peatland drains and was at least 55% cheaper than either field survey or manual digitisation, respectively. The extracted drain maps were used constrain the study area CO2 flux which was 19% smaller than the prescribed Peatland Code value for drained peatlands. Conclusions The OBIA method used in this study showed that it is possible to accurately extract maps of fine scale peatland drains over large areas in a cost effective manner. The development of methods to map the spatial extent of drains is important as they play a critical role in peatland carbon dynamics. The objective of this study was to extract data on the spatial extent of

  5. The Methane to Carbon Dioxide Ratio Produced during Peatland Decomposition and a Simple Approach for Distinguishing This Ratio

    Science.gov (United States)

    Chanton, J.; Hodgkins, S. B.; Cooper, W. T.; Glaser, P. H.; Corbett, J. E.; Crill, P. M.; Saleska, S. R.; Rich, V. I.; Holmes, B.; Hines, M. E.; Tfaily, M.; Kostka, J. E.

    2014-12-01

    Peatland organic matter is cellulose-like with an oxidation state of approximately zero. When this material decomposes by fermentation, stoichiometry dictates that CH4 and CO2 should be produced in a ratio approaching one. While this is generally the case in temperate zones, this production ratio is often departed from in boreal peatlands, where the ratio of belowground CH4/CO2 production varies between 0.1 and 1, indicating CO2 production by a mechanism in addition to fermentation. The in situ CO2/CH4 production ratio may be ascertained by analysis of the 13C isotopic composition of these products, because CO2 production unaccompanied by methane production produces CO2 with an isotopic composition similar to the parent organic matter while methanogenesis produces 13C depleted methane and 13C enriched CO2. The 13C enrichment in the subsurface CO2 pool is directly related to the amount of if formed from methane production and the isotopic composition of the methane itself. Excess CO2 production is associated with more acidic conditions, Sphagnum vegetation, high and low latitudes, methane production dominated by hydrogenotrophic methane production, 13C depleted methane, and generally, more nutrient depleted conditions. Three theories have been offered to explain these observations— 1) inhibition of acetate utilization, acetate build-up and diffusion to the surface and eventual aerobic oxidation, 2) the use of humic acids as electron acceptors, and the 3) utilization of organic oxygen to produce CO2. In support of #3, we find that 13C-NMR, Fourier transform infrared (FT IR) spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) clearly show the evolution of polysaccharides and cellulose towards more decomposed humified alkyl compounds stripped of organic oxygen utilized to form CO2. Such decomposition results in more negative carbon oxidation states varying from -1 to -2. Coincident with this reduction in oxidation state, is the

  6. The impact of long-term changes in water table height on carbon cycling in sub-boreal peatlands

    Science.gov (United States)

    Pypker, T. G.; Moore, P. A.; Waddington, J. M.; Hribljan, J. A.; Ballantyne, D.; Chimner, R. A.

    2011-12-01

    Peatlands are a critical component in the global carbon (C) cycle because they have been slowly sequestering atmospheric greenhouse gases as peat since the last glaciation. Today, soil C stocks in peatlands are estimated to represent 224 to 455 Pg, equal to 12-30% of the global soil C pool. At present, peatlands are estimated to sequester 76 Tg C yr-1. The flux of C to and from peatlands is likely to respond to climate change, thereby influencing atmospheric C concentrations. Peatland C budgets are tightly linked to their hydrology, hence, it is critical we understand how changes in hydrology will affect the C budgets of peatlands. The main objective of the project was to determine how long-term changes in water table height affect CO2 and CH4 fluxes from three adjacent peatlands. This study took place in the Seney National Wildlife Refuge (SNWR) in the Upper Peninsula of Michigan. SNWR is home to the largest wetland drainage project in Michigan. In 1912, ditches and dikes were created in an effort to convert approximately 20,000 ha of peatland to agriculture. The ditches and dikes were unsuccessful in creating agricultural land, but they are still in place. The manipulation of water table heights provides an opportunity to research how long-term peat drying or wetting alters C cycling in peatlands. From May to November in 2009, 2010 and 2011, we monitored CO2 fluxes using eddy covariance and chamber techniques in three adjacent peatlands with lowered, relatively unaltered ("control") and raised water table heights. In 2011, we installed CH4 analyzers to continuously monitor CH4 fluxes at the sites with high and relatively unaltered water table heights. The results are compared across sites to determine how changes in water table height might affect C fluxes sub-boreal peatlands.

  7. Methane and carbon dioxide exchange in a post-extraction, unrestored peatland in Eastern Quebec, Canada

    Science.gov (United States)

    Rankin, Tracy; Strachan, Ian; Strack, Maria

    2017-04-01

    Peatlands, in their pristine state, are important long-term sinks of carbon. The extraction of peat for agricultural purposes or for biofuel leads to a shift in the carbon dynamics. Changes in environmental conditions post extraction may also allow for invasive species to establish and spread across the peatland. Many studies have shown the benefits and advantages of various restoration management practices, but few studies have explored the carbon exchange from unrestored peatlands. Our study reports the methane (CH4) and carbon dioxide (CO2) fluxes from a post-extraction, unrestored peatland in Eastern Québec at both the plant community scale using static chambers, and at the ecosystem scale using an eddy covariance flux tower, over two complete years. Extraction of the Saint-Alexandre-de-Kamouraska peatland (SAK) started in the early 1970's and was halted in 1999. No restoration efforts have been implemented and the remnant ditches remain unblocked. The site consists of sparse patches of Eriophorum and a vast area of bare peat. Consequently, SAK is an overall source of carbon to the atmosphere, releasing an annual total of 153 g C m-2 and 241 g C m-2 in CO2 emissions for 2014 and 2015, respectively, and an average annual total of 1 g C m-2yr-1 in CH4 emissions. Phragmites and Typha, both invasive species, have established themselves in the ditches and are sources of methane; partly explaining the increased emissions in carbon fluxes to the atmosphere post extraction. Results from this study will help managers assess the importance of post-extraction peatland restoration, by comparing the differences in CO2 and CH4 exchange between restored and unrestored peatlands.

  8. Summer carbon dioxide and water vapor fluxes across a range of northern peatlands

    Science.gov (United States)

    Humphreys, Elyn R.; Lafleur, Peter M.; Flanagan, Lawrence B.; Hedstrom, Newell; Syed, Kamran H.; Glenn, Aaron J.; Granger, Raoul

    2006-12-01

    Northern peatlands are a diverse group of ecosystems varying along a continuum of hydrological, chemical, and vegetation gradients. These ecosystems contain about one third of the global soil carbon pool, but it is uncertain how carbon and water cycling processes and response to climate change differ among peatland types. This study examines midsummer CO2 and H2O fluxes measured using the eddy covariance technique above seven northern peatlands including a low-shrub bog, two open poor fens, two wooded moderately rich fens, and two open extreme-rich fens. Gross ecosystem production and ecosystem respiration correlated positively with vegetation indices and with each other. Consequently, 24-hour net ecosystem CO2 exchange was similar among most of the sites (an average net carbon sink of 1.5 ± 0.2 g C m-2 d-1) despite large differences in water table depth, water chemistry, and plant communities. Evapotranspiration was primarily radiatively driven at all sites but a decline in surface conductance with increasing water vapor deficit indicated physiological restrictions to transpiration, particularly at the peatlands with woody vegetation and less at the peatlands with 100% Sphagnum cover. Despite these differences, midday evapotranspiration ranged only from 0.21 to 0.34 mm h-1 owing to compensation among the factors controlling evapotranspiration. Water use efficiency varied among sites primarily as a result of differences in productivity and plant functional type. Although peatland classification includes a great variety of ecosystem characteristics, peatland type may not be an effective way to predict the magnitude and characteristics of midsummer CO2 and water vapor exchanges.

  9. Electronics

    Science.gov (United States)

    2001-01-01

    International Acer Incorporated, Hsin Chu, Taiwan Aerospace Industrial Development Corporation, Taichung, Taiwan American Institute of Taiwan, Taipei, Taiwan...Singapore and Malaysia .5 - 4 - The largest market for semiconductor products is the high technology consumer electronics industry that consumes up...Singapore, and Malaysia . A new semiconductor facility costs around $3 billion to build and takes about two years to become operational

  10. Carbon pools and productivity in a 1-km2 heterogeneous forest and peatland mosaic in Minnesota, USA

    Science.gov (United States)

    Peter Weishampel; Randall Kolka; Jennifer Y. King

    2009-01-01

    Determining the magnitude of carbon (C) storage in forests and peatlands is an important step towards predicting how regional carbon balance will respond to climate change. However, spatial heterogeneity of dominant forest and peatland cover types can inhibit accurate C storage estimates. We evaluated ecosystem C pools and productivity in the Marcell Experimental...

  11. Minor effects of long-term ozone exposure on boreal peatland species Eriophorum vaginatum and Sphagnum papillosum

    DEFF Research Database (Denmark)

    Mörsky, SK; Haapala, JK; Rinnan, Riikka

    2011-01-01

    The effects of long-term ozone fumigation on two common peatland plant species, a sedge Eriophorum vaginatum L. and a moss Sphagnum papillosum Lindb., were studied applying peatland microcosms. The peat cores with intact vegetation were cored from an oligotrophic pine fen and partially embedded...

  12. Initial Response of the Nitrogen Cycle to Soil Warming and Elevated CO2 in Northern Minnesota Peatlands

    Science.gov (United States)

    Peatlands store 30% of global soil carbon. Many of these peatlands are located in boreal regions which are expected to have the highest temperature increases in response to climate change. As climate warms, peat decomposition may accelerate and release greenhouse gases. Spruce an...

  13. Experimentally increased nutrient availability at the permafrost thaw front selectively enhances biomass production of deep-rooting subarctic peatland species

    NARCIS (Netherlands)

    Keuper, Frida; Dorrepaal, Ellen; van Bodegom, Peter M.; van Logtestijn, Richard; Venhuizen, Gemma; van Hal, Jurgen; Aerts, Rien

    2017-01-01

    Climate warming increases nitrogen (N) mineralization in superficial soil layers (the dominant rooting zone) of subarctic peatlands. Thawing and subsequent mineralization of permafrost increases plant-available N around the thaw-front. Because plant production in these peatlands is N-limited, such

  14. Environmental dynamics and carbon accumulation rate of a tropical peatland in Central Sumatra, Indonesia

    Science.gov (United States)

    Hapsari, Kartika Anggi; Biagioni, Siria; Jennerjahn, Tim C.; Reimer, Peter Meyer; Saad, Asmadi; Achnopha, Yudhi; Sabiham, Supiandi; Behling, Hermann

    2017-08-01

    Tropical peatlands are important for the global carbon cycle as they store 18% of the total global peat carbon. As they are vulnerable to changes in temperature and precipitation, a rapidly changing environment endangers peatlands and their carbon storage potential. Understanding the mechanisms of peatland carbon accumulation from studying past developments may, therefore, help to assess the future role of tropical peatlands. Using a multi-proxy palaeoecological approach, a peat core taken from the Sungai Buluh peatland in Central Sumatra has been analyzed for its pollen and spore, macro charcoal and biogeochemical composition. The result suggests that peat and C accumulation rates were driven mainly by sea level change, river water level, climatic variability and anthropogenic activities. It is also suggested that peat C accumulation in Sungai Buluh is correlated to the abundance of Freycinetia, Myrtaceae, Calophyllum, Stemonuraceae, Ficus and Euphorbiaceae. Sungai Buluh has reasonable potential for being a future global tropical peat C sinks. However, considering the impact of rapid global climate change in addition to land-use change following rapid economic growth in Indonesia, such potential may be lost. Taking advantage of available palaeoecological records and advances made in Quaternary studies, some considerations for management practice such as identification of priority taxa and conservation sites are suggested.

  15. Possible responses of northern peatlands to climate change in the zone of discontinuous permafrost, Manitoba, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Bubier, J L [New Hampshire Univ., Durham, NH (United States). Inst. for the Study of Earth, Oceans, and Space; Moore, T R [McGill Univ., Montreal (Canada). Geography Dept.

    1997-12-31

    More than half of the world`s peatlands occur in the boreal zone (45 - 60 deg C N. lat), a region which global climate models predict will experience large changes in temperature and precipitation with increasing atmospheric CO{sub 2} concentrations. The northern part of the boreal zone is characterised by discontinuous permafrost, an area that is particularly sensitive to climate change with the possible degradation and thawing of frozen peat. Peatlands are large sources of atmospheric methane (CH{sub 4}), an important greenhouse gas. Yet few measurements of methane have been conducted in discontinuous permafrost environments. As part of the Boreal Ecosystem-Atmosphere Study (BOREAS), CH{sub 4} flux was measured in a diverse peatland complex (bogs, fens, peat plateaus, and collapse scars), representing the complete range of temperature, moisture, and plant community gradients found in northern peatlands. The measurement period May to September 1994 was one of the warmest and driest seasons on record, which provided an opportunity to observe the short-term responses of different parts of the peatland ecosystem to a warmer and drier climate as an analog to predicted climate change in the region. (5 refs.)

  16. The long-term fate of permafrost peatlands under rapid climate warming

    Science.gov (United States)

    Swindles, Graeme T.; Morris, Paul J.; Mullan, Donal; Watson, Elizabeth J.; Turner, T. Edward; Roland, Thomas P.; Amesbury, Matthew J.; Kokfelt, Ulla; Schoning, Kristian; Pratte, Steve; Gallego-Sala, Angela; Charman, Dan J.; Sanderson, Nicole; Garneau, Michelle; Carrivick, Jonathan L.; Woulds, Clare; Holden, Joseph; Parry, Lauren; Galloway, Jennifer M.

    2015-01-01

    Permafrost peatlands contain globally important amounts of soil organic carbon, owing to cold conditions which suppress anaerobic decomposition. However, climate warming and permafrost thaw threaten the stability of this carbon store. The ultimate fate of permafrost peatlands and their carbon stores is unclear because of complex feedbacks between peat accumulation, hydrology and vegetation. Field monitoring campaigns only span the last few decades and therefore provide an incomplete picture of permafrost peatland response to recent rapid warming. Here we use a high-resolution palaeoecological approach to understand the longer-term response of peatlands in contrasting states of permafrost degradation to recent rapid warming. At all sites we identify a drying trend until the late-twentieth century; however, two sites subsequently experienced a rapid shift to wetter conditions as permafrost thawed in response to climatic warming, culminating in collapse of the peat domes. Commonalities between study sites lead us to propose a five-phase model for permafrost peatland response to climatic warming. This model suggests a shared ecohydrological trajectory towards a common end point: inundated Arctic fen. Although carbon accumulation is rapid in such sites, saturated soil conditions are likely to cause elevated methane emissions that have implications for climate-feedback mechanisms. PMID:26647837

  17. Contrasting controls on arsenic and lead budgets for a degraded peatland catchment in Northern England

    International Nuclear Information System (INIS)

    Rothwell, James J.; Taylor, Kevin G.; Evans, Martin G.; Allott, Timothy E.H.

    2011-01-01

    Atmospheric deposition of trace metals and metalloids from anthropogenic sources has led to the contamination of many European peatlands. To assess the fate and behaviour of previously deposited arsenic and lead, we constructed catchment-scale mass budgets for a degraded peatland in Northern England. Our results show a large net export of both lead and arsenic via runoff (282 ± 21.3 gPb ha -1 y -1 and 60.4 ± 10.5 gAs ha -1 y -1 ), but contrasting controls on this release. Suspended particulates account for the majority of lead export, whereas the aqueous phase dominates arsenic export. Lead release is driven by geomorphological processes and is a primary effect of erosion. Arsenic release is driven by the formation of a redox-dynamic zone in the peat associated with water table drawdown, a secondary effect of gully erosion. Degradation of peatland environments by natural and anthropogenic processes has the potential to release the accumulated pool of legacy contaminants to surface waters. - Highlights: → The fluvial outputs of arsenic and lead in the degraded peatland are an order-of-magnitude greater than atmospheric inputs. → The particulate phase dominates fluvial lead export, whereas the aqueous phase dominates fluvial arsenic export. → Lead export is a primary effect of peat erosion, whereas arsenic export is a secondary effect of peat erosion. - Degraded peatlands can be significant sources of previously deposited arsenic and lead

  18. Representing Northern Peatland Hydrology and Biogeochemistry with ALM Land Surface Model

    Science.gov (United States)

    Shi, X.; Ricciuto, D. M.; Thornton, P. E.; Hanson, P. J.; Xu, X.; Mao, J.; Warren, J.; Yuan, F.; Norby, R. J.; Sebestyen, S.; Griffiths, N.; Weston, D. J.; Walker, A.

    2017-12-01

    Northern peatlands are likely to be important in future carbon cycle-climate feedbacks due to their large carbon pool and vulnerability to hydrological change. Predictive understanding of northern peatland hydrology is a necessary precursor to understanding the fate of massive carbon stores in these systems under the influence of present and future climate change. Current models have begun to address microtopographic controls on peatland hydrology, but none have included a prognostic calculation of peatland water table depth for a vegetated wetland, independent of prescribed regional water tables. Firstly, we introduce a new configuration of the land model (ALM) of Accelerated Climate model for Energy (ACME), which includes a fully prognostic water table calculation for a vegetated peatland. Secondly, we couple our new hydrology treatment with vertically structured soil organic matter pool, and the addition of components from methane biogeochemistry. Thirdly, we introduce a new PFT for mosses and implement the water content dynamics and physiology of mosses. We inform and test our model based on SPRUCE experiment to get the reasonable results for the seasonal dynamics water table depths, water content dynamics and physiology of mosses, and correct soil carbon profiles. Then, we use our new model structure to test the how the water table depth and CH4 emission will respond to elevated CO2 and different warming scenarios.

  19. Differences in microbial community structure and nitrogen cycling in natural and drained tropical peatland soils.

    Science.gov (United States)

    Espenberg, Mikk; Truu, Marika; Mander, Ülo; Kasak, Kuno; Nõlvak, Hiie; Ligi, Teele; Oopkaup, Kristjan; Maddison, Martin; Truu, Jaak

    2018-03-16

    Tropical peatlands, which play a crucial role in the maintenance of different ecosystem services, are increasingly drained for agriculture, forestry, peat extraction and human settlement purposes. The present study investigated the differences between natural and drained sites of a tropical peatland in the community structure of soil bacteria and archaea and their potential to perform nitrogen transformation processes. The results indicate significant dissimilarities in the structure of soil bacterial and archaeal communities as well as nirK, nirS, nosZ, nifH and archaeal amoA gene-possessing microbial communities. The reduced denitrification and N 2 -fixing potential was detected in the drained tropical peatland soil. In undisturbed peatland soil, the N 2 O emission was primarily related to nirS-type denitrifiers and dissimilatory nitrate reduction to ammonium, while the conversion of N 2 O to N 2 was controlled by microbes possessing nosZ clade I genes. The denitrifying microbial community of the drained site differed significantly from the natural site community. The main reducers of N 2 O were microbes harbouring nosZ clade II genes in the drained site. Additionally, the importance of DNRA process as one of the controlling mechanisms of N 2 O fluxes in the natural peatlands of the tropics revealed from the results of the study.

  20. Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK

    International Nuclear Information System (INIS)

    Rothwell, James J.; Evans, Martin G.; Lindsay, John B.; Allott, Timothy E.H.

    2007-01-01

    Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably. - Multiple peat cores are required for accurate peatland Pb inventories

  1. Manure derived biochar can successfully replace phosphate rock amendment in peatland restoration.

    Science.gov (United States)

    Pouliot, Rémy; Hugron, Sandrine; Rochefort, Line; Godbout, Stéphane; Palacios, Joahnn H; Groeneveld, Elisabeth; Jarry, Isabelle

    2015-07-01

    Phosphate rock fertilization is commonly used in peatland restoration to promote the growth of Polytrichum strictum, a nurse plant which aids the establishment of Sphagnum mosses. The present study tested whether 1) phosphorus fertilization facilitates the germination of P. strictum spores and 2) biochar derived from local pig manure can replace imported phosphate rock currently used in peatland restoration. Various doses of biochar were compared to phosphate rock to test its effect directly on P. strictum stem regeneration (in Petri dishes in a growth chamber) and in a simulation of peatland restoration with the moss layer transfer technique (in mesocoms in a greenhouse). Phosphorus fertilization promoted the germination of P. strictum spores as well as vegetative stem development. Biochar can effectively replace phosphate rock in peatland restoration giving a new waste management option for rural regions with phosphorus surpluses. As more available phosphorus was present in biochar, an addition of only 3-9 g m(-2) of pig manure biochar is recommended during the peatland restoration process, which is less than the standard dose of phosphate rock (15 g m(-2)). Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Sphagnum peatland development at their southern climatic range in West Siberia: trends and peat accumulation patterns

    International Nuclear Information System (INIS)

    Peregon, Anna; Uchida, Masao; Shibata, Yasuyuki

    2007-01-01

    A region of western Siberia is vulnerable to the predicted climatic change which may induce an important modification to the carbon balance in wetland ecosystems. This study focuses on the evaluation of both the long-term and contemporary trends of peat (carbon) accumulation and its patterns at the southern climatic range of Sphagnum peatlands in western Siberia. Visible and physical features of peat and detailed reconstructions of successional change (or sediment stratigraphies) were analysed at two types of forest-peatland ecotones, which are situated close to each other but differ by topography and composition of their plant communities. Our results suggest that Siberian peatlands exhibit a general trend towards being a carbon sink rather than a source even at or near the southern limit of their distribution. Furthermore, two types of peat accumulation were detected in the study area, namely persistent and intermittent. As opposed to persistent peat accumulation, the intermittent one is characterized by the recurrent degradation of the upper peat layers at the marginal parts of raised bogs. Persistent peat accumulation is the case for the majority of Sphagnum peatlands under current climatic conditions. It might be assumed that more peat will accumulate under the 'increased precipitation' scenarios of global warming, although intermittent peat accumulation could result in the eventual drying that may change peatlands from carbon sinks to carbon sources

  3. Peatland water repellency: Importance of soil water content, moss species, and burn severity

    Science.gov (United States)

    Moore, P. A.; Lukenbach, M. C.; Kettridge, N.; Petrone, R. M.; Devito, K. J.; Waddington, J. M.

    2017-11-01

    Wildfire is the largest disturbance affecting peatlands, with northern peat reserves expected to become more vulnerable to wildfire as climate change enhances the length and severity of the fire season. Recent research suggests that high water table positions after wildfire are critical to limit atmospheric carbon losses and enable the re-establishment of keystone peatland mosses (i.e. Sphagnum). Post-fire recovery of the moss surface in Sphagnum-feathermoss peatlands, however, has been shown to be limited where moss type and burn severity interact to result in a water repellent surface. While in situ measurements of moss water repellency in peatlands have been shown to be greater for feathermoss in both a burned and unburned state in comparison to Sphagnum moss, it is difficult to separate the effect of water content from species. Consequently, we carried out a laboratory based drying experiment where we compared the water repellency of two dominant peatland moss species, Sphagnum and feathermoss, for several burn severity classes including unburned samples. The results suggest that water repellency in moss is primarily controlled by water content, where a sharp threshold exists at gravimetric water contents (GWC) lower than ∼1.4 g g-1. While GWC is shown to be a strong predictor of water repellency, the effect is enhanced by burning. Based on soil water retention curves, we suggest that it is highly unlikely that Sphagnum will exhibit strong hydrophobic conditions under field conditions.

  4. Towards large-scale paludiculture: addressing the challenges of biomass harvesting in wet and rewetted peatlands

    Directory of Open Access Journals (Sweden)

    C. Schröder

    2015-12-01

    Full Text Available Peatland drainage causes peat degradation, which results in high greenhouse gas emissions and ongoing subsidence of the ground surface. To avoid further land degradation, the rewetting of peatlands is essential. The new land use concept of paludiculture - the use of wet and rewetted peatlands for agriculture and forestry - now offers possibilities for landowners and land managers to continue using these sites under wet conditions. But new challenges arise due to the limited bearing capacity of wet soils, which restricts accessibility for machinery. Whilst many site-specific technical solutions for harvesting on wet peatland are available, it remains unclear whether current machinery is suitable for use in the large-scale implementation of paludiculture. Repeated crossings of the same ground can easily disturb the upper peat layer and cause serious problems for the removal of biomass. In this article we present available machinery and approaches to biomass harvesting; and explore how the number of transport runs required for biomass removal varies with productivity of the site, cargo capacity and working width of the harvesting machinery. The results are used in a discussion of logistics and infrastructure requirements to facilitate the implementation of paludiculture. Whilst there is still considerable scope for improvement of harvesting technologies, our results show that a peat-conserving harvest from wet and rewetted peatlands is possible with adjustments to harvesting technique, logistics and site infrastructure.

  5. Moss and peat hydraulic properties are optimized to maximise peatland water use efficiency

    Science.gov (United States)

    Kettridge, Nicholas; Tilak, Amey; Devito, Kevin; Petrone, Rich; Mendoza, Carl; Waddington, Mike

    2016-04-01

    Peatland ecosystems are globally important carbon and terrestrial surface water stores that have formed over millennia. These ecosystems have likely optimised their ecohydrological function over the long-term development of their soil hydraulic properties. Through a theoretical ecosystem approach, applying hydrological modelling integrated with known ecological thresholds and concepts, the optimisation of peat hydraulic properties is examined to determine which of the following conditions peatland ecosystems target during this development: i) maximise carbon accumulation, ii) maximise water storage, or iii) balance carbon profit across hydrological disturbances. Saturated hydraulic conductivity (Ks) and empirical van Genuchten water retention parameter α are shown to provide a first order control on simulated water tensions. Across parameter space, peat profiles with hypothetical combinations of Ks and α show a strong binary tendency towards targeting either water or carbon storage. Actual hydraulic properties from five northern peatlands fall at the interface between these goals, balancing the competing demands of carbon accumulation and water storage. We argue that peat hydraulic properties are thus optimized to maximise water use efficiency and that this optimisation occurs over a centennial to millennial timescale as the peatland develops. This provides a new conceptual framework to characterise peat hydraulic properties across climate zones and between a range of different disturbances, and which can be used to provide benchmarks for peatland design and reclamation.

  6. Possible responses of northern peatlands to climate change in the zone of discontinuous permafrost, Manitoba, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Bubier, J.L. [New Hampshire Univ., Durham, NH (United States). Inst. for the Study of Earth, Oceans, and Space; Moore, T.R. [McGill Univ., Montreal (Canada). Geography Dept.

    1996-12-31

    More than half of the world`s peatlands occur in the boreal zone (45 - 60 deg C N. lat), a region which global climate models predict will experience large changes in temperature and precipitation with increasing atmospheric CO{sub 2} concentrations. The northern part of the boreal zone is characterised by discontinuous permafrost, an area that is particularly sensitive to climate change with the possible degradation and thawing of frozen peat. Peatlands are large sources of atmospheric methane (CH{sub 4}), an important greenhouse gas. Yet few measurements of methane have been conducted in discontinuous permafrost environments. As part of the Boreal Ecosystem-Atmosphere Study (BOREAS), CH{sub 4} flux was measured in a diverse peatland complex (bogs, fens, peat plateaus, and collapse scars), representing the complete range of temperature, moisture, and plant community gradients found in northern peatlands. The measurement period May to September 1994 was one of the warmest and driest seasons on record, which provided an opportunity to observe the short-term responses of different parts of the peatland ecosystem to a warmer and drier climate as an analog to predicted climate change in the region. (5 refs.)

  7. Paludiculture as a chance for peatland and climate: the greenhouse gas balance of biomass production on two rewetted peatlands does not differ from the natural state

    Science.gov (United States)

    Günther, Anke; Huth, Vytas; Jurasinski, Gerald; Albrecht, Kerstin; Glatzel, Stephan

    2015-04-01

    In Europe, rising prices for farm land make it increasingly difficult for government administrations to compete with external investors during the acquisition of land for wetland conservation. Thus, adding economic value to these, otherwise "lost", areas by combining extensive land use with nature conservation efforts could increase the amount of ground available for wetland restoration. Against this background, the concept of paludiculture aims to provide biomass for multiple purposes from peatlands with water tables high enough to conserve the peat body. However, as plants have been shown to contribute to greenhouse gas exchange in peatlands, manipulating the vegetation (by harvesting, sowing etc.) might alter the effect of the restored peatlands on climate. Here, we present greenhouse gas data from two experimental paludiculture systems on formerly drained intensive grasslands in northern Germany. In a fen that has been rewetted more than 15 years ago three species of reed plants were harvested to simulate biomass production for bioenergy and as construction material. And in a peat bog that has been converted from drained grassland to a field with a controlled water table around ground surface Sphagnum mosses were cultivated to provide an alternative growing substrate for horticulture. In both systems, we determined carbon dioxide, methane, and nitrous oxide exchange using closed chambers over two years. Additionally, water and peat chemistry and environmental parameters as recorded by a weather station were analyzed. Both restored peatlands show greenhouse gas balances comparable to those of natural ecosystems. Nitrous oxide was not emitted in either system. Fluctuations of the emissions reflect changes in weather conditions across the study years. In the fen, relative emission patterns between plant species were not constant over time. We did not find a negative short-term effect of biomass harvest or Sphagnum cultivation on net greenhouse gas balances

  8. Geoecological controls on net mercury retention in northern peatlands

    Science.gov (United States)

    Bindler, R.; Rydberg, J.

    2010-12-01

    Peatlands, which receive much or all of their element inputs (e.g. nutrients or trace metals) via the atmosphere, are considered an ideal archive for studying past changes in mercury (Hg) deposition. These archives potentially contain information not only on important anthropogenic contributions to the environment over the past few centuries, but also on the natural antecedent conditions over the past several millennia. However, the assumption that Hg accumulation rates in peat represent an absolute record of past atmospheric deposition has proved problematic. In on-going studies of Hg retention in northern peatlands (bogs and oligotrophic fens) we find that net Hg accumulation is influenced by a range of geoecological factors in addition to actual changes in atmospheric deposition. Factors that influence the interception and net retention of Hg include differences in vegetation and microtopography - both of which may enhance dry deposition, and properties and processes within the peat such as decomposition that might influence long-term retention. Wetness, too, may play an important role in net retention in the surface peat through increased evasive losses of Hg. Differences between Hg concentrations in vascular plants and mosses are well established (at our site: 5-15 ng/g for leaves/needles of cottongrass, heather, Labrador tea and pine; 15-45 ng/g for mosses Sphagnum centrale and S. rubellum), but we also measured significant differences between different mosses within the same plots (S. rubellum, 24±3 ng/g; S. centrale, 18±2 ng/g). Further differences in Hg concentrations occur for single moss species in different settings; for example, Hg concentrations in S. centrale in open Sphagnum-only plots relative to plots including a mixture of vascular plants that form a field-layer canopy are 18±2 and 32±6 ng/g, respectively. As a result, sampling sites consisting of both Sphagnum and vascular plants have long-term cumulative inventories of mercury in the peat

  9. Multiyear greenhouse gas balances at a rewetted temperate peatland.

    Science.gov (United States)

    Wilson, David; Farrell, Catherine A; Fallon, David; Moser, Gerald; Müller, Christoph; Renou-Wilson, Florence

    2016-12-01

    Drained peat soils are a significant source of greenhouse gas (GHG) emissions to the atmosphere. Rewetting these soils is considered an important climate change mitigation tool to reduce emissions and create suitable conditions for carbon sequestration. Long-term monitoring is essential to capture interannual variations in GHG emissions and associated environmental variables and to reduce the uncertainty linked with GHG emission factor calculations. In this study, we present GHG balances: carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) calculated for a 5-year period at a rewetted industrial cutaway peatland in Ireland (rewetted 7 years prior to the start of the study); and compare the results with an adjacent drained area (2-year data set), and with ten long-term data sets from intact (i.e. undrained) peatlands in temperate and boreal regions. In the rewetted site, CO 2 exchange (or net ecosystem exchange (NEE)) was strongly influenced by ecosystem respiration (R eco ) rather than gross primary production (GPP). CH 4 emissions were related to soil temperature and either water table level or plant biomass. N 2 O emissions were not detected in either drained or rewetted sites. Rewetting reduced CO 2 emissions in unvegetated areas by approximately 50%. When upscaled to the ecosystem level, the emission factors (calculated as 5-year mean of annual balances) for the rewetted site were (±SD) -104 ± 80 g CO 2 -C m -2  yr -1 (i.e. CO 2 sink) and 9 ± 2 g CH 4 -C m -2  yr -1 (i.e. CH 4 source). Nearly a decade after rewetting, the GHG balance (100-year global warming potential) had reduced noticeably (i.e. less warming) in comparison with the drained site but was still higher than comparative intact sites. Our results indicate that rewetted sites may be more sensitive to interannual changes in weather conditions than their more resilient intact counterparts and may switch from an annual CO 2 sink to a source if triggered by slightly drier

  10. Permafrost Thaw increases Emissions of Nitrous Oxide from Subarctic Peatlands

    Science.gov (United States)

    Voigt, C.; Marushchak, M. E.; Lamprecht, R. E.; Jackowicz-Korczynski, M.; Lindgren, A.; Mastepanov, M.; Christensen, T. R.; Granlund, L.; Tahvanainen, T.; Martikainen, P. J.; Biasi, C.

    2017-12-01

    Permafrost soils in the Arctic are thawing, exposing not only carbon but also large nitrogen stocks. The decomposition of this vast pool of long-term immobile C and N stocks results in the release of greenhouse gases to the atmosphere. Among these, carbon dioxide (CO2) and methane (CH4) are being studied extensively, and gaseous C release from thawing permafrost is known to be substantial. Most recent studies, however, show that Arctic soils may further be a relevant source of the strong greenhouse gas nitrous oxide (N2O). As N2O is almost 300 times more powerful in warming the climate than CO2 based on a 100-yr time horizon, the release of N2O from thawing permafrost could create a significant non-carbon permafrost-climate feedback. To study the effect of permafrost thaw on N2O fluxes, we collected peat mesocosms from a Subarctic permafrost peatland, and subjected these intact soil-plant systems to sequential thawing from the top of the active layer down to the upper permafrost layer. Measurements of N2O fluxes were coupled with detailed soil analyses and process studies. Since N2O fluxes are highly dependent on moisture conditions and vegetation cover, we applied two distinct moisture treatments (dry vs. wet) and simulated permafrost thaw in vegetated as well as in naturally bare mesocosms. Under dry conditions, permafrost thaw clearly increased N2O emissions. We observed the largest post-thaw emissions from bare peat surfaces, a typical landform in subarctic peatlands previously identified as hot spots for Arctic N2O emissions. There, permafrost thaw caused a five-fold increase in emissions (0.56 vs. 2.81 mg N2O m-2 d-1). While water-logged conditions suppressed N2O emissions, the presence of vegetation lowered, but did not prevent post-thaw N2O release. Based on these findings, we show that one fourth of the Arctic land area could be vulnerable for N2O emissions when permafrost thaws. Our results demonstrate that Arctic N2O emissions may be larger than

  11. Land cover distribution in the peatlands of Peninsular Malaysia, Sumatra and Borneo in 2015 with changes since 1990

    Directory of Open Access Journals (Sweden)

    Jukka Miettinen

    2016-04-01

    Full Text Available Insular Southeast Asian peatlands have experienced rapid land cover changes over the past decades inducing a variety of environmental effects ranging from regional consequences on peatland ecology, biodiversity and hydrology to globally significant carbon emissions. In this paper we present the land cover and industrial plantation distribution in the peatlands of Peninsular Malaysia, Sumatra and Borneo in 2015 and analyse their changes since 1990. We create the 2015 maps by visual interpretation of 30 m resolution Landsat data and combine them with fully comparable and completed land cover maps of 1990 and 2007 (Miettinen and Liew, 2010. Our results reveal continued peatland deforestation and conversion into managed land cover types. In 2015, 29% (4.6 Mha of the peatlands in the study area remain covered by peat swamp forest (vs. 41% or 6.4 Mha in 2007 and 76% or 11.9 Mha in 1990. Managed land cover types (industrial plantations and small-holder dominated areas cover 50% (7.8 Mha of all peatlands (vs. 33% 5.2 Mha in 2007 and 11% 1.7 Mha in 1990. Industrial plantations have nearly doubled their extent since 2007 (2.3 Mha; 15% and cover 4.3 Mha (27% of peatlands in 2015. The majority of these are oil palm plantations (73%; 3.1 Mha while nearly all of the rest (26%; 1.1 Mha are pulp wood plantations. We hope that the maps presented in this paper will enable improved evaluation of the magnitude of various regional to global level environmental effects of peatland conversion and that they will help decision makers to define sustainable peatland management policies for insular Southeast Asian peatlands.

  12. Contribution of vegetation and water table on isoprene emission from boreal peatland microcosms

    DEFF Research Database (Denmark)

    Tiiva, Päivi; Faubert, Patrick; Räty, Sanna

    2009-01-01

    emission in these naturally wet ecosystems, although water table is predicted to decline due to climate warming. We studied the relative contribution of mosses vs. vascular plants to isoprene emission in boreal peatland microcosms in growth chambers by removing either vascular vegetation or both vascular...... hollows with intact vegetation, 45 ± 6 µg m-2 h-1, was decreased by 25% under water table drawdown. However, water table drawdown reduced net ecosystem carbon dioxide (CO2) exchange more dramatically than isoprene emission. Isoprene emission strongly correlated with both CO2 exchange and methane emission......Boreal peatlands are substantial sources of isoprene, a reactive hydrocarbon. However, it is not known how much mosses, vascular plants and peat each contribute to isoprene emission from peatlands. Furthermore, there is no information on the effects of declining water table depth on isoprene...

  13. [Nitrogen input altered testate amoebae community in peatland of Sanjiang Plain, Northeast China].

    Science.gov (United States)

    Song, Li-hong; Yan, Xiu-min; Wang, Ke-hong; Zhu, Xiao-yan; Wu, Dong-hu

    2015-02-01

    In the present study, an in situ control experiment was carried out to explore the response of testate amoebae to exogenous nitrogen addition in peatland of Sanjiang Plain. The results showed that nitrogen addition increased the biomass of testate amoebae at lower levels (6 g N · m(-2)), while decreased it at higher levels (> 12 g N · m(-2)). At genus level, nitrogen addition significantly increased the biomass of Arcella and Phryganella, decreased the biomass of Euglypha. Only lower nitrogen addition significantly increased the biomass of Centropyxis. At species level, nitrogen addition significantly decreased the biomass of Euglypha rotunda, while the biomass of either Centropyxis cassis or Phryganella acropodia was increased by a lower nitrogen addition treatment. This study suggested that the response of peatland testate amoebae to nitrogen addition was species specific, which could potentially be used as an indicator for the environment of peatlands.

  14. Climatic sensitivity of hydrology and carbon exchanges in boreal peatland ecosystems, with implications on sustainable management of reed canary grass (Phalaris arundinacea, L.) on cutaway peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Gong Jinnan

    2013-11-01

    The aim of the study was to investigate the effects of climate change on soil hydrology and carbon (C) fluxes in boreal peatland ecosystems, with implications for the feasibility of cultivating reed canary grass (Phalaris arundinacea, L; RCG) as a way to restore the C sink in cutaway peatlands under Finnish conditions. First, hydrological models were developed for pristine peatland ecosystems and the cutaway peatlands under RCG cultivation. Concurrently, the hydrological responses to varying climatic forcing and mire types were investigated for these ecosystems. Thereafter, process-based models for estimating the seasonal and annual C exchanges were developed for the pristine mires and cutaway peatlands. The C models incorporated the hydrological models for corresponding ecosystems. Model simulations based on the climate scenarios (ACCLIM, developed by the Finnish Meteorological Institute, FMI) were further carried out to study the impacts of climate change on the C exchanges in the peatland ecosystems during the 21st century. The simulation showed that the water table (WT) in the pristine Finnish mires would draw down slightly during the 21st century. Such a chance in WT would be related to a decrease in the CO{sub 2} sink but an increase in the CH{sub 4} source at the country scale, as driven mainly by the rising temperature (Ta) and increasing precipitation (P). These changes in CO{sub 2}/ CH{sub 4} fluxes would decrease the total C-greenhouse gas (GHG) sink (CO{sub 2} equilibrium) by 68% at the country scale, and the changes would be more pronounced toward the end of the century. The majority of pristine fens in southern and western Finland and the pristine bogs near the coastal areas would become centurial CO{sub 2} sources under the changing climate. On the other hand, the major distribution of fens in northern Finland would act to increase the CH{sub 4} source at the country scale, whereas the CH{sub 4} emission would tend to decrease with WT in the southern

  15. An impact of deforestation by extreme weather events on Sphagnum peatland ecosystem

    Science.gov (United States)

    Slowinski, M. M.; Łuców, D.; Kołaczek, P.; Tjallingii, R.; Lane, C. S.; Slowinska, S.; Tyszkowski, S.; Łokas, E.; Theuerkauf, M.; Brauer, A.; Lamentowicz, M.

    2017-12-01

    An increase in extreme weather phenomena has been observed over the last decades as a result of global climate warming. Terrestrial ecosystems are influenced by different types of disturbances such as e.g. deforestation, land-use, fragmentation, fire, floods or storms. Disturbance triggers may be natural or anthropogenic, but usually we observe negative feedback loops and interconnected causal factors. Here we investigate the effects of a tornado event on the peatland ecosystem of the Tuchola Pinewoods, Northern Poland. Deforestation by tornado events can cause severe perturbations of the hydrology and erosion that, in turn, affects adjacent lakes and peatlands. Martwe peatland provide an exceptional opportunity to study the impact of such extreme events, as it was struck by a tornado in 2012. Our research is focused on lake-peatland ecosystems that were directly affected by this tornado, and we consider the general transformation of the vegetation (mainly forests) over the last 150 years. Extensive clearing of the forest occurred in the nineteenth century due to human activity, and we compare this with the impact of the 2012 tornado. Accurate reconstructions will rely on a broad range of palaeoecological techniques such as pollen, macro-remains and testate amoebae, but also on geochemistry, i.e. μXRF scanning. The chronology of the records is based on 210Pb and radiocarbon dating and will incorporate correlations using (crypto)tephra markers of the Eyjafjöll (2010) and Askja (1875) eruptions. We expect to observe that disturbance (tornado-induced deforestation) affects the short-term changes in peatland productivity and biodiversity, through a cascading "top-down" effect. This research addresses the emerging issue of the impact of extreme phenomena and more general climate changes on peatland ecosystems, which will potentially help to inform adaptations to the environmental consequences of extreme events in the future. This project is funded by the Polish

  16. Decoding the Secrets of Carbon Preservation and GHG Flux in Lower-Latitude Peatlands

    Science.gov (United States)

    Richardson, C. J.; Flanagan, N. E.; Wang, H.; Ho, M.; Hodgkins, S. B.; Cooper, W. T.; Chanton, J.; Winton, S.

    2017-12-01

    The mechanisms regulating peat decomposition and C carbon storage in peatlands are poorly understood, particularly with regard to the importance of the biochemical compounds produced by different plant species and in turn peat quality controls on C storage and GHG flux. To examine the role of carbon quality in C accretion in northern compared to tropical peatlands we completed field and lab studies on bog peats collected in Minnesota, North Carolina, Florida and Peru to answer three fundamental questions; 1) is tropical peat more recalcitrant than northern peat 2) does the addition of aromatic and phenolic C compounds increase towards the tropics 3) do differences in the chemical structure of organic matter explain variances in carbon storage and GHG flux in tropical versus northern peatlands? Our main hypothesize is that high concentrations of phenolics and aromatic C compounds produced in shrub and tree plant communities in peatlands coupled with the fire production of biochar aromatics in peatlands may provide a dual biogeochemical latch mechanism controlling microbial decomposition of peat even under higher temperatures and seasonal drought. By comparing the peat bog soil cores collected from the MN peat bogs, NC Pocosins, FL Everglades and Peru palm swamps we find that the soils in the shrub-dominant Pocosin contain the highest phenolics, which microbial studies indicate have the strongest resistance to microbial decomposition. A chemical comparison of plant driven peat carbon quality along a north to south latitudinal gradient indicates that tropical peatlands have higher aromatic compounds, and enhanced phenolics, especially after light fires, which enhances C storage and affect GHG flux across the latitudinal gradient.

  17. Ecohydrological dynamics of peatlands and adjacent upland forests in the Rocky Mountains

    Science.gov (United States)

    Millar, D.; Parsekian, A.; Mercer, J.; Ewers, B. E.; Mackay, D. S.; Williams, D. G.; Cooper, D. J.; Ronayne, M. J.

    2017-12-01

    Mountain peatlands are susceptible to a changing climate via changes in the water cycle. Understanding the impacts of such changes requires knowledge of the hydrological processes within these peatlands and in the upland forests that supply them with water. We investigated hydrological processes in peatland catchments in the Rocky Mountains by developing empirical models of groundwater dynamics, and are working to improve subsurface water dynamics in a ecohydrological process model, the Terrestrial Regional Ecosystem Exchange Simulator (TREES). Results from empirical models showed major differences in water budget components between two peatlands with differing climate, vegetation, and hydrogeological settings. Several-fold higher rates of evapotranspiration from the saturated zone, and groundwater inflow were observed for a sloping fen in southern Wyoming than that of a basin fen in southwestern Colorado, where rainfall was two-fold higher due to stronger influence of the North American monsoon. We also present ongoing work coupling stable water isotope and borehole nuclear magnetic resonance analyses to test which soil water pools (bound or mobile) are used by dominant upland and peatland vegetation in two catchments in southern Wyoming. These data are being used to test whether the root hydraulic mechanisms in TREES can simulate water uptake from these two soil water pools, and sap flux measurements are being used to evaluate simulated transpiration. Preliminary results from this work suggest that upland vegetation utilize tightly-bound soil water pools, as these pools comprise the largest amount of subsurface water (> 80%) in the vadose zone long after snow melt. Conversely, it appears that herbaceous peatland hydrophytes may preferentially utilize mobile soil water pools, since their roots extend below the water table. The results of this work are expected to increase predictive understanding of hydrological processes in these important ecosystems.

  18. Permafrost conditions in peatlands regulate magnitude, timing, and chemical composition of catchment dissolved organic carbon export.

    Science.gov (United States)

    Olefeldt, David; Roulet, Nigel T

    2014-10-01

    Permafrost thaw in peatlands has the potential to alter catchment export of dissolved organic carbon (DOC) and thus influence downstream aquatic C cycling. Subarctic peatlands are often mosaics of different peatland types, where permafrost conditions regulate the hydrological setting of each type. We show that hydrological setting is key to observed differences in magnitude, timing, and chemical composition of DOC export between permafrost and nonpermafrost peatland types, and that these differences influence the export of DOC of larger catchments even when peatlands are minor catchment components. In many aspects, DOC export from a studied peatland permafrost plateau was similar to that of a forested upland catchment. Similarities included low annual export (2-3 g C m(-2) ) dominated by the snow melt period (~70%), and how substantial DOC export following storms required wet antecedent conditions. Conversely, nonpermafrost fens had higher DOC export (7 g C m(-2) ), resulting from sustained hydrological connectivity during summer. Chemical composition of catchment DOC export arose from the mixing of highly aromatic DOC from organic soils from permafrost plateau soil water and upland forest surface horizons with nonaromatic DOC from mineral soil groundwater, but was further modulated by fens. Increasing aromaticity from fen inflow to outlet was substantial and depended on both water residence time and water temperature. The role of fens as catchment biogeochemical hotspots was further emphasized by their capacity for sulfate retention. As a result of fen characteristics, a 4% fen cover in a mixed catchment was responsible for 34% higher DOC export, 50% higher DOC concentrations and ~10% higher DOC aromaticity at the catchment outlet during summer compared to a nonpeatland upland catchment. Expansion of fens due to thaw thus has potential to influence landscape C cycling by increasing fen capacity to act as biogeochemical hotspots, amplifying aquatic C cycling, and

  19. Effects of peatland drainage management on peak flows

    Directory of Open Access Journals (Sweden)

    C. E. Ballard

    2012-07-01

    Full Text Available Open ditch drainage has historically been a common land management practice in upland blanket peats, particularly in the UK. However, peatland drainage is now generally considered to have adverse effects on the upland environment, including increased peak flows. As a result, drain blocking has become a common management strategy in the UK over recent years, although there is only anecdotal evidence to suggest that this might decrease peak flows. The change in the hydrological regime associated with the drainage of blanket peat and the subsequent blocking of drains is poorly understood, therefore a new physics-based model has been developed that allows the exploration of the associated hydrological processes. A series of simulations is used to explore the response of intact, drained and blocked drain sites at field scales. While drainage is generally found to increase peak flows, the effect of drain blocking appears to be dependent on local conditions, sometimes decreasing and sometimes increasing peak flows. Based on insights from these simulations we identify steep smooth drains as those that would experience the greatest reduction in field-scale peak flows if blocked and recommend that future targeted field studies should be focused on examining surface runoff characteristics.

  20. Reservoirs as hotspots of fluvial carbon cycling in peatland catchments.

    Science.gov (United States)

    Stimson, A G; Allott, T E H; Boult, S; Evans, M G

    2017-02-15

    Inland water bodies are recognised as dynamic sites of carbon processing, and lakes and reservoirs draining peatland soils are particularly important, due to the potential for high carbon inputs combined with long water residence times. A carbon budget is presented here for a water supply reservoir (catchment area~9km 2 ) draining an area of heavily eroded upland peat in the South Pennines, UK. It encompasses a two year dataset and quantifies reservoir dissolved organic carbon (DOC), particulate organic carbon (POC) and aqueous carbon dioxide (CO 2 (aq)) inputs and outputs. The budget shows the reservoir to be a hotspot of fluvial carbon cycling, as with high levels of POC influx it acts as a net sink of fluvial carbon and has the potential for significant gaseous carbon export. The reservoir alternates between acting as a producer and consumer of DOC (a pattern linked to rainfall and temperature) which provides evidence for transformations between different carbon species. In particular, the budget data accompanied by 14 C (radiocarbon) analyses provide evidence that POC-DOC transformations are a key process, occurring at rates which could represent at least ~10% of the fluvial carbon sink. To enable informed catchment management further research is needed to produce carbon cycle models more applicable to these environments, and on the implications of high POC levels for DOC composition. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Atmospheric fallout radionuclides in peatland from Southern Poland.

    Science.gov (United States)

    Mróz, Tomasz; Łokas, Edyta; Kocurek, Justyna; Gąsiorek, Michał

    2017-09-01

    Two peat profiles were collected in a peat bog located in Southern Poland and their geochronology were determined using 210 Pb, 238,239+240 Pu and 137 Cs radiometric techniques. The 210 Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the Pu isotopes and 137 Cs time markers. Maximum activities of Pu isotopes were found at a depth corresponding to the early 1960s, which is the period characterized by the maximum nuclear weapon tests. The results showed that the 210 Pb method is the most accurate technique for the determination age and accumulation rate of a peat. The next part of this study calculated linear accumulation rates by analyzing 238,239+240 Pu and 137 Cs vertical distributions in the profiles. Activities of fallout isotopes were also measured in plants covering the peatland. The highest activities of 137 Cs and 210 Pb were found in Calluna vulgaris samples, and 239+240 Pu were found only in two samples (C. vulgaris and leaves of Oxycoccus quadripelatus). Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Peatlands and green frogs: A relationship regulated by acidity?

    Science.gov (United States)

    Mazerolle, M.J.

    2005-01-01

    The effects of site acidification on amphibian populations have been thoroughly addressed in the last decades. However, amphibians in naturally acidic environments, such as peatlands facing pressure from the peat mining industry, have received little attention. Through two field studies and an experiment, I assessed the use of bog habitats by the green frog (Rana clamitans melanota), a species sensitive to various forestry and peat mining disturbances. First, I compared the occurrence and breeding patterns of frogs in bog and upland ponds. I then evaluated frog movements between forest and bog habitats to determine whether they corresponded to breeding or postbreeding movements. Finally, I investigated, through a field experiment, the value of bogs as rehydrating areas for amphibians by offering living Sphagnum moss and two media associated with uplands (i.e., water with pH ca 6.5 and water-saturated soil) to acutely dehydrated frogs. Green frog reproduction at bog ponds was a rare event, and no net movements occurred between forest and bog habitats. However, acutely dehydrated frogs did not avoid Sphagnum. Results show that although green frogs rarely breed in bogs and do not move en masse between forest and bog habitats, they do not avoid bog substrates for rehydrating, despite their acidity. Thus, bogs offer viable summering habitat to amphibians, which highlights the value of these threatened environments in terrestrial amphibian ecology.

  3. Peatland fertilization. Short-term chemical effects on runoff water

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    In peatland forestry, fertilization is often needed to reach a good yield. Phosphorus and potassium are mainly used, but on nutrient poor fens and bogs, nitrogen also has be added. These fertilizers affect the environment and thereby influence the runoff waters. This essay concerns the first three months after fertilization, of which the first two weeks have been paid particular attention. As the mires of the sub-basins were sedge fens, with a pine stand in some areas but mostly treeless, the fertilizers used were ammonium nitrate , rock phosphate and potassium chloride . The fertilization was performed from the air. During the very first hours after fertilization, drastic changes in water chemistry were found. In one area pH dropped 0,3 units while at the other no immidiate change was seen. For the whole three months of the investigation period, the decreases in pH were in the range 0,1-0,5 units. Nitrogen concentration reached a peak of 260 mg/l, phosphorus 5 mg/l and potassium about 60 mg/l. These high values were of short duration but the concentrations were considerable increased during one week. Later, partly due to decreasing discharge, the water chemistry became almost similar to that measured under unfertilized conditions. The main loss of fertilizer occurred during the first two weeks and amounted to 22% of the applied nitrogen, about 1% of the phosphorus and 5-9% of K.

  4. Heterotrophic soil respiration in forestry-drained peatlands

    International Nuclear Information System (INIS)

    Minkkinen, K.; Shurpali, N. J.; Alm, J.; Penttilae, T.

    2007-01-01

    Heterotrophic soil respiration (CO 2 efflux from the decomposition of peat and root litter) in three forestry-drained peatlands with different site types and with a large climatic gradient from the hemi-boreal (central Estonia) to south (southern Finland) and north boreal (northern Finland) conditions was studied. Instantaneous fluxes varied between 0 and 1.3 g CO 2 -C m -2 h -1 , and annual fluxes between 248 and 515 g CO 2 -C m -2 a -1 . Variation in the annual fluxes among site types was studied only in the south-boreal site where we found a clear increase from nutrient-poor to nutrient-rich site types. More than half of the within-site variation was temporal and explained by soil surface (-5 cm) temperature (T5). The response of soil respiration to T5 varied between the sites; the most northerly site had the highest response to T5 and the most southerly the lowest. This trend further resulted in increased annual fluxes towards north. This unexpected result is hypothesised to be related to differences in site factors like substrate quality, nutrient status and hydrology but also to temperature acclimation, i.e., adaptation of decomposer populations to different climates. (orig.)

  5. Peatlands in Finland accumulate carbon more than the peat production and utilization liberates it

    International Nuclear Information System (INIS)

    Maentymaa, E.

    1997-01-01

    The peatlands in Finland bind more carbon dioxide then it is liberated into the air in peat combustion and production. Because the carbon accumulation into peatlands is higher than that of liberation, the peat deposits increase all the time in spite of peat economy. The emissions of methane, which is tens of times worse greenhouse gas then CO 2 , have decreased by 40 % due to forest drainage. Very small amounts of methane is released into the atmosphere from peat production sites. This is proven by the national SILMU research programme investigating the atmospheric changes

  6. Carbon isotopic composition of deep carbon gases in an ombrogenous peatland, northwestern Ontario, Canada

    International Nuclear Information System (INIS)

    Aravena, R.; Dinel, H.

    1993-01-01

    Radiocarbon dating and carbon isotope analyses of deep peat and gases in a small ombrogenous peatland in northwestern Ontario reveals the presence of old gases at depth that are 1000-2000 yr younger than the enclosing peat. The authors suggest that the most likely explanation to account for this age discrepancy is the downward movement by advection of younger dissolved organic carbon for use by fermentation and methanogens bacteria. This study identifies a potentially large supply of old carbon gases in peatlands that should be considered in global carbon models of the terrestrial biosphere

  7. Headwater peatland channels in south-eastern Australia; the attainment of equilibrium

    Science.gov (United States)

    Nanson, R. A.; Cohen, T. J.

    2014-05-01

    Many small headwater catchments (bank strengths have resulted in low width to depth ratios which accommodate rapid changes in flow velocity and depth with changes in discharge. In small peatland channels, planform adjustments have been sufficient to counter the energy provided by these hydraulically efficient cross-sections and have enabled the achievement of regime energy-slopes. In larger and higher energy peatland channels, large, armoured, stable, bedforms have developed. These bedforms integrate with planform adjustments to maintain a condition of minimum variance in energy losses as represented by the slope profiles and, therefore, a uniform increase in downstream entropy.

  8. A New Appraisal of Northern Peatlands and Global Atmospheric Methane Over the Holocene

    Science.gov (United States)

    MacDonald, G. M.; Holmquist, J. R.; Kremenetski, K.; Loisel, J.

    2015-12-01

    Use of large databases of peat cores to examine linkages between northern peatlands and atmospheric CH4 over the Holocene has been prone to uncertainties regarding 1. comparability of radiocarbon techniques and material dated, 2. appropriate summed probability distributions, 3. spatial representativeness of the sites, particularly in capturing sites south of the subarctic, 4. potential impacts of local lateral peatland expansion versus continental-scale peatland initiation, particularly in the late Holocene, and 5. impacts of changes in the proportion of high methane-producing fens vs Sphagnum bogs. We present a comparison of radiocarbon measurements from conventional counts, atomic mass spectrometry and differing peat materials to demonstrate a general compatibility of the various types of dates. We compare and apply several summed probability distribution methods to minimize any statistical bias in our analysis. We then present our analysis of a new data set of 7571 peatland cores from 4420 sites that extend into the temperate zone. Of these, 3732 cores inform on lateral expansion and 329 dates constrain the timing of fen-bog transition. Based on these data in original and gridded form we show that widespread peat initiation commenced at 16 kcal yr BP and reached a maximum rate at 11-8 kcal yr BP. Most sites began as fens, and peak transition to bogs occurred between 5 and 3 kcal yr BP, with a 1000 year lag between Eurasia and North America. There is no global late Holocene increase in lateral expansion. Based on modeled northern peatland area and ratio of fen/bog sites, CH4 production from northern peatlands increased rapidly from 11 to 9 cal yr BP, followed by slower increase until reaching a maximum at 5 kcal yr BP at 25 Tg per yr. From 4 kcal yr BP to Present, bogs become a dominant feature in the northern peatland landscape and CH4 production decreased to reach modern-day levels at about 20 Tg per yr. Northern peatlands have been a key infleunce on global

  9. Aquatic carbon export from peatland catchments recently undergone wind farm development

    Science.gov (United States)

    Smith, Ben; Waldron, Susan; Henderson, Andrew; Flowers, Hugh; Gilvear, David

    2013-04-01

    Scotland's peat landscapes are desirable locations for wind-based renewables due to high wind resources and low land use pressures in these areas. The environmental impact of sitting wind-based renewables on peats however, is unknown. Globally, peatlands are important terrestrial carbon stores. Given the topical nature of carbon-related issues, e.g. global warming and carbon footprints, it is imperative we help mitigate their degradation and maintain carbon sequestration. To do so, we need to better understand how peatland systems function with regards to their carbon balance (export versus sequestration) so we can assess their resilience and adaptation to hosting land-based renewable energy projects. Predicting carbon lost as a result of construction of wind farms built on peatland has not been fully characterised and this research will provide data that can supplement current 'carbon payback calculator' models for wind farms that aim to reinforce their 'green' credentials. Transfer of carbon from the terrestrial peatland systems to the aquatic freshwater and oceanic systems is most predominant during periods of high rainfall. It has been estimated that 50% of carbon is exported during only 10% of highest river flows, (Hinton et al., 1998). Furthermore, carbon export from peatlands is known to have a seasonal aspect with highest concentrations of dissolved organic carbon (DOC) found mostly in late summer months of August and September and lowest in December and January, (Dawson et al., 2004). Event sampling, where high intensity sample collection is carried out during high river flow periods, offers a better insight, understanding and estimation of carbon aquatic fluxes from peatland landscapes. The Gordonbush estate, near Brora, has an extensive peatland area where a wind farm development has recently been completed (April 2012). Investigations of aquatic carbon fluxes from this peatland system were started in July 2010, in conjunction with the start of

  10. Carbon emissions from Southeast Asian peatlands will increase despite emission-reduction schemes.

    Science.gov (United States)

    Wijedasa, Lahiru S; Sloan, Sean; Page, Susan E; Clements, Gopalasamy R; Lupascu, Massimo; Evans, Theodore A

    2018-06-01

    Carbon emissions from drained peatlands converted to agriculture in Southeast Asia (i.e. Peninsular Malaysia, Sumatra and Borneo) are globally significant and increasing. Here, we map the growth of Southeast Asian peatland agriculture and estimate CO 2 emissions due to peat drainage in relation to official land-use plans with a focus on the Reducing Emissions from Deforestation and Degradation (REDD+) related Indonesian moratorium on granting new concession licenses for industrial agriculture and logging. We find that, prior to 2010, 35% of Southeast Asian peatlands had been converted to agriculture, principally by smallholder farmers (15% of original peat extent) and industrial oil palm plantations (14%). These conversions resulted in 1.46-6.43 GtCO 2 of emissions between 1990 and 2010. This legacy of historical clearances on deep peat areas will contribute 51% (4.43-11.45 GtCO 2 ) of projected peatland CO 2 emissions over the period 2010-2130. In Indonesia, which hosts most of the region's peatland and where concession maps are publicly available, 70% of peatland conversion to agriculture occurred outside of known concessions for industrial plantation development, with smallholders accounting for 60% and industrial oil palm accounting for 34%. Of the remaining Indonesian peatswamp forest (PSF), 45% is not protected, and its conversion would amount to CO 2 emissions equivalent to 0.7-2.3% (5.14-14.93 Gt) of global fossil fuel and cement emissions released between 1990-2010. Of the peatland extent included in the moratorium, 48% was no longer forested, and of the PSF included 40-48% is likely to be affected by drainage impacts from agricultural areas and will emit CO 2 over time. We suggest that recent legislation and policy in Indonesia could provide a means of meaningful emission reductions if focused on revised land-use planning, PSF conservation both inside and outside agricultural concessions, and the development of agricultural practices based on

  11. Organic Matter Quality and its Influence on Carbon Turnover and Stabilization in Northern Peatlands

    Science.gov (United States)

    Turetsky, M. R.; Wieder, R. K.

    2002-12-01

    Peatlands cover 3-5 % of the world's ice-free land area, but store about 33 % of global terrestrial soil carbon. Peat accumulation in northern regions generally is controlled by slow decomposition, which may be limited by cold temperatures and water-logging. Poor organic matter quality also may limit decay, and microbial activity in peatlands likely is regulated by the availability of labile carbon and/or nutrients. Conversely, carbon in recalcitrant soil structures may be chemically protected from microbial decay, particularly in peatlands where carbon can be buried in anaerobic soils. Soil organic matter quality is controlled by plant litter chemical composition and the susceptibility of organic compounds to decomposition through time. There are a number of techniques available for characterizing organic quality, ranging from chemical proximate or elemental analysis to more qualitative methods such as nuclear magenetic resonance, pyrolysis/mass spectroscopy, and Fourier transform infrared spectroscopy. We generally have relied on proximate analysis for quantitative determination of several organic fractions (i.e., water-soluble carbohydrates, soluble nonpolars, water-soluble phenolics, holocellulose, and acid insoluble material). Our approaches to studying organic matter quality in relation to C turnover in peatlands include 1) 14C labelling of peatland vegetation along a latitudinal gradient in North America, allowing us to follow the fate of 14C tracer in belowground organic fractions under varying climates, 2) litter bag studies focusing on the role of individual moss species in litter quality and organic matter decomposition, and 3) laboratory incubations of peat to explore relationships between organic matter quality and decay. These studies suggest that proximate organic fractions vary in lability, but that turnover of organic matter is influenced both by plant species and climate. Across boreal peatlands, measures of soil recalcitrance such as acid

  12. Remote Sensing of Light Use Efficiency in a Boreal Forest and Peatland in James Bay, Quebec

    Science.gov (United States)

    Rogers, Cheryl

    The photochemical reflectance index (PRI) is a remotely sensed vegetation index that detects a decrease in spectral reflectance at 531nm associated with xanthophyll cycle activity. PRI has been shown to track light use efficiency (LUE) in a number of plant species. PRI shows great promise in improving our ability to sense photosynthetic fluxes of CO2 remotely. However, it has not been tested in all environments, and its applicability is particularly uncertain for peatland environments dominated by mosses. This research investigates the ability of PRI to track LUE in a boreal forest and peatland, and examines the spectral signal associated with xanthophyll cycle activity in heterogeneous peatland plots. This research also investigates the relationship between PRI and leaf area index (LAI) over space and time in a peatland. We found most plots examined in the peatland site did not exhibit a spectral signal associated with xanthophyll cycle activity when exposed to a transition from dark conditions to full sunlight. This transition should lead to a de-epoxidation of xanthophylls in leaf tissues and a decrease in reflectance at 531nm. Plots that did show the decrease in reflectance at 531nm after this change in light conditions also displayed a decrease in PRI. This indicates that PRI effectively detects the 531nm signal as well as xanthophyll cycle activity and light stress in these plots. However, the variability in the strength of the spectral response to changing light conditions may confound the PRI signal in practice, and make it difficult to interpret results of airborne or satellite data. We also found PRI at the peatland site to be sensitive to and directly correlated with spatial variability in LAI, and negatively correlated with temporal variability in LAI. These characteristics may result in further difficulties applying PRI in peatlands. PRI and LUE were correlated at both the forest and peatland site, however at both sites the PRI signal saturated around

  13. Carbon storage and long-term rate of accumulation in high-altitude Andean peatlands of Bolivia

    Directory of Open Access Journals (Sweden)

    J.A. Hribljan

    2015-11-01

    Full Text Available (1 The high-altitude (4,500+ m Andean mountain range of north-western Bolivia contains many peatlands. Despite heavy grazing pressure and potential damage from climate change, little is known about these peatlands. Our objective was to quantify carbon pools, basal ages and long-term peat accumulation rates in peatlands in two areas of the arid puna ecoregion of Bolivia: near the village of Manasaya in the Sajama National Park (Cordillera Occidentale, and in the Tuni Condoriri National Park (Cordillera Real. (2 We cored to 5 m depth in the Manasaya peatland, whose age at 5 m was ca. 3,675 yr. BP with a LARCA of 47 g m-2 yr-1. However, probing indicated that the maximum depth was 7–10 m with a total estimated (by extrapolation carbon stock of 1,040 Mg ha-1. The Tuni peat body was 5.5 m thick and initiated ca. 2,560 cal. yr. BP. The peatland carbon stock was 572 Mg ha-1 with a long-term rate of carbon accumulation (LARCA of 37 g m-2 yr-1. (3 Despite the dry environment of the Bolivian puna, the region contains numerous peatlands with high carbon stocks and rapid carbon accumulation rates. These peatlands are heavily used for llama and alpaca grazing.

  14. Permafrost distribution in peatlands of west-central Canada during the Holocene warm period 6000 years BP

    Energy Technology Data Exchange (ETDEWEB)

    Zoltai, S.C. [Canadian Forest Service, Edmonton, AB (Canada)

    1995-12-31

    The extent and timing of permafrost development in peatlands of west-central Canada are examined. The floristic composition of the permafrost peatlands was determined from macrofossil samples of cores drilled at 161 locations. Radiocarbon dating of substantial changes in the peat sequences and of basal peat deposition was used to provide chronological control. The reconstructed paleoenvironments show the presence or absence of permafrost at the time of peat formation. Permafrost distribution in peatlands is estimated during the warm period 6000 years BP. It is estimated that the mean annual temperature was approximately 5{degree}C warmer than at present. 42 refs., 3 figs., 4 tabs.

  15. Anthropogenic and geomorphic controls on peatland dynamics in contrasting floodplain environments during the Holocene and its impact on carbon storage

    Science.gov (United States)

    Verstraeten, Gert; Broothaerts, Nils; Notebaert, Bastiaan

    2016-04-01

    Peatlands are an important store of carbon in terrestrial environments, and scientific interest in peatlands has increased strongly in the light of the recent global climatic changes. Much attention has been paid to peatland dynamics in extensive arctic and boreal wetlands or to blanket peat in temperate regions. Nevertheless, long-term dynamics of peat in alluvial wetlands in temperate regions remains largely underresearched. In this study, data from three contrasting environments were used to provide more insights in the anthropogenic and geomorphic controls on peatland dynamics. The results show a high variability in alluvial peatland dynamics between the different study sites. In the central Belgian Loess Belt, alluvial peatlands developed during the early Holocene but gradually disappeared from the Mid-Holocene onwards due to the gradual intensification of agricultural activities in the catchment and consequent higher sedimentation rates in the floodplain system. The end of peat growth is shown to be diachronous at catchment scale, ranging between 6500 and 500 cal a BP. The disappearance of the alluvial peatlands has important implications since it potentially reduces the storage of locally produced C. Nevertheless, it was shown that this reduced production of local C but was outbalanced by the burial of hillslope derived C. Also within the sandy catchments of the Belgian Campine region alluvial peatlands initiated in the early Holocene but, here, they abruptly disappeared in the Mid-Holocene before the onset of intense agricultural activities in the catchment. This suggests that for the sandy regions, anthropogenic impact on peatland dynamics is less important compared to natural factors. For these regions, the disappearance of alluvial peatland formation resulted in a sharp decline in alluvial carbon storage as there is no compensation through hillslope derived C input. For the upper Dee catchment in NE Scotland, Holocene carbon floodplain storage varies

  16. Can frequent precipitation moderate drought impact on peatmoss carbon uptake in northern peatlands?

    NARCIS (Netherlands)

    Nijp, J.J.; Limpens, J.; Metselaar, K.; Zee, van der S.E.A.T.M.; Berendse, F.; Robroek, B.J.M.

    2015-01-01

    Northern peatlands represent a large global carbon store that potentially can be destabilised by summer water table drawdown. Precipitation can moderate negative impacts of water table drawdown by rewetting peatmoss (Sphagnum spp.), the ecosystems’ key species. Yet, the frequency for such rewetting

  17. Can frequent precipitation moderate the impact of drought on peatmoss carbon uptake in northern peatlands?

    NARCIS (Netherlands)

    Nijp, J.J.; Limpens, J.; Metselaar, K.; Zee, van der S.E.A.T.M.; Berendse, F.; Robroek, B.J.M.

    2014-01-01

    Northern peatlands represent a large global carbon store that can potentially be destabilized by summer water table drawdown. Precipitation can moderate the negative impacts of water table drawdown by rewetting peatmoss (Sphagnum spp.), the ecosystem's key species. Yet, the frequency of such

  18. Sphagnum re-introduction in degraded peatlands: the effects of aggregation, species and water table

    NARCIS (Netherlands)

    Robroek, B.J.M.; Ruijven, van J.; Schouten, M.G.C.; Breeuwer, A.J.G.; Crushell, P.H.; Berendse, F.; Limpens, J.

    2009-01-01

    In European peatlands which have been drained and cut-over in the past, re-vegetation often stagnates after the return of a species-poor Sphagnum community. Re-introduction of currently absent species may be a useful tool to restore a typical, and more diverse, Sphagnum vegetation and may ultimately

  19. Macrophyte loss drives decadal change in benthic invertebrates in peatland drainage ditches

    NARCIS (Netherlands)

    Whatley, M.H.; van Loon, E.; van Dam, H.; Vonk, J.A.; van der Geest, H.G.; Admiraal, W.

    2014-01-01

    1. Agricultural peatlands and their associated drainage systems are often highly managed and exposed to anthropogenic pressures, such as eutrophication and stable water tables, maintained via drainage during periods of high rainfall and inlet of, alkaline-rich, waters during dry periods. These

  20. The role of fire in UK peatland and moorland management: the need for informed, unbiased debate.

    Science.gov (United States)

    Davies, G Matt; Kettridge, Nicholas; Stoof, Cathelijne R; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M; Marrs, Rob; Allen, Katherine A; Doerr, Stefan H; Clay, Gareth D; McMorrow, Julia; Vandvik, Vigdis

    2016-06-05

    Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions.This article is part of the themed issue 'The interaction of fire and mankind'. © 2016 The Authors.

  1. Factors affecting re-vegetation dynamics of experimentally restored extracted peatland in Estonia.

    Science.gov (United States)

    Karofeld, Edgar; Müür, Mari; Vellak, Kai

    2016-07-01

    Increasing human activity continues to threaten peatlands, and as the area of natural mires declines, our obligation is to restore their ecosystem functions. Several restoration strategies have been developed for restoration of extracted peatlands, including "The moss layer transfer method", which was initiated on the Tässi extracted peatland in central Estonia in May 2012. Three-year study shows that despite the fluctuating water table, rainfall events can compensate for the insufficient moisture for mosses. Total plant cover on the restoration area attained 70 %, of which ~60 % is comprised of target species-Sphagnum mosses. From restoration treatments, spreading of plant fragments had a significant positive effect on the cover of bryophyte and vascular plants. Higher water table combined with higher plant fragments spreading density and stripping of oxidised peat layer affected positively the cover of targeted Sphagnum species. The species composition in the restoration area became similar to that in the donor site in a natural bog. Based on results, it was concluded that the method approved for restoration in North America gives good results also in the restoration of extracted peatland towards re-establishment of bog vegetation under northern European conditions.

  2. Wind farms on undegraded peatlands are unlikely to reduce future carbon emissions

    International Nuclear Information System (INIS)

    Smith, Jo; Nayak, Dali Rani; Smith, Pete

    2014-01-01

    Onshore wind energy is a key component of the renewable energies used by governments to reduce carbon emissions from electricity production, but will carbon emissions be reduced when wind farms are located on carbon-rich peatands? Wind farms are often located in uplands because most are of low agricultural value, are distant from residential areas, and are windy. Many UK uplands are peatlands, with layers of accumulated peat that represent a large stock of soil carbon. When peatlands are drained for construction there is a higher risk of net carbon loss than for mineral soils. Previous work suggests that wind farms sited on peatlands can reduce net carbon emissions if strictly managed for maximum retention of carbon. Here we show that, whereas in 2010, most sites had potential to provide net carbon savings, by 2040 most sites will not reduce carbon emissions even with careful management. This is due to projected changes in the proportion of fossil fuels used to generate electricity. The results suggest future policy should avoid constructing wind farms on undegraded peatlands unless drainage of peat is minimal and the volume excavated in foundations can be significantly reduced compared to energy output. - Highlights: • Future wind farms located on undegraded peats will not reduce carbon emissions. • This is due to projected changes in fossil fuels used to generate electricity. • Future policy should avoid constructing wind farms on undegraded peats

  3. Tropical/Subtropical Peatland Development and Global CH4 during the Last Glaciation.

    Science.gov (United States)

    Xu, Hai; Lan, Jianghu; Sheng, Enguo; Liu, Yong; Liu, Bin; Yu, Keke; Ye, Yuanda; Cheng, Peng; Qiang, Xiaoke; Lu, Fengyan; Wang, Xulong

    2016-07-28

    Knowledge of peatland development over the tropical/subtropical zone during the last glaciation is critical for understanding the glacial global methane cycle. Here we present a well-dated 'peat deposit-lake sediment' alternate sequence at Tengchong, southwestern China, and discuss the peatland development and its linkage to the global glacial methane cycle. Peat layers were formed during the cold Marine Isotope Stage (MIS)-2 and -4, whereas lake sediments coincided with the relatively warm MIS-3, which is possibly related to the orbital/suborbital variations in both temperature and Asian summer monsoon intensity. The Tengchong peatland formation pattern is broadly synchronous with those over subtropical southern China and other tropical/subtropical areas, but it is clearly in contrast to those over the mid-high Northern Hemisphere. The results of this work suggest that the shifts of peatland development between the tropical/subtropical zone and mid-high Northern Hemisphere may have played important roles in the glacial/interglacial global atmospheric CH4 cycles.

  4. Differences in carbon accumulation of two cut-over peatlands in Finland

    International Nuclear Information System (INIS)

    Roderfeld, H.; Vasander, H.; Tolonen, K.

    1994-01-01

    This study focused on the ecology of abandoned peatlands in Finland. The aim is to produce information about conditions favourable for recolonisation and regeneration of mires. This could serve as a basis for the management of milled peat cut-over sites which are designed for rewetting

  5. Characteristics of dissolved organic matter following 20 years of peatland restoration

    NARCIS (Netherlands)

    Höll, B.S.; Fiedler, S.; Jungkunst, H.F.; Kalbitz, K.; Freibauer, A.; Drösler, M.; Stahr, K.

    2009-01-01

    The changes in the amounts and composition of dissolved organic matter (DOM) following long-term peat restoration are unknown, although this fraction of soil organic matter affects many processes in such ecosystems. We addressed this lack of knowledge by investigating a peatland in south-west

  6. The effect of peatland drainage and restoration on Odonata species richness and abundance.

    Science.gov (United States)

    Elo, Merja; Penttinen, Jouni; Kotiaho, Janne S

    2015-04-09

    Restoration aims at reversing the trend of habitat degradation, the major threat to biodiversity. In Finland, more than half of the original peatland area has been drained, and during recent years, restoration of some of the drained peatlands has been accomplished. Short-term effects of the restoration on peatland hydrology, chemistry and vegetation are promising but little is known about how other species groups apart from vascular plants and bryophytes respond to restoration efforts. Here, we studied how abundance and species richness of Odonata (dragonflies and damselflies) respond to restoration. We sampled larvae in three sites (restored, drained, pristine) on each of 12 different study areas. We sampled Odonata larvae before restoration (n = 12), during the first (n = 10) and the third (n = 7) year after restoration and used generalized linear mixed models to analyze the effect of restoration. Drained sites had lower abundance and species richness than pristine sites. During the third year after restoration both abundance and species richness had risen in restored sites. Our results show that Odonata suffer from drainage, but seem to benefit from peatland restoration and are able to colonize newly formed water pools already within three years after restoration.

  7. Peat–water interrelationships in a tropical peatland ecosystem in Southeast Asia

    NARCIS (Netherlands)

    Wösten, J.H.M.; Clymans, E.; Page, S.E.; Rieley, J.O.; Limin, S.H.

    2008-01-01

    Interrelationships between peat and water were studied using a hydropedological modelling approach for adjacent relatively intact and degraded peatland in Central Kalimantan, Indonesia. The easy to observe degree of peat humification provided good guidance for the assignment of more difficult to

  8. Methylmercury declines in a boreal peatland when experimental sulfate deposition decreases

    Science.gov (United States)

    Jill K. Coleman Wasik; Carl P.J. Mitchell; Daniel R. Engstrom; Edward B. Swain; Bruce A. Monson; Steven J. Balogh; Jeffrey D. Jeremiason; Brian A. Branfireun; Susan L. Eggert; Randall K. Kolka; James E. Almendinger

    2012-01-01

    Between 2001 and 2008 we experimentally manipulated atmospheric sulfate-loading to a small boreal peatland and monitored the resulting short and long-term changes in methylmercury (MeHg) production. MeHg concentrations and %MeHg (fraction of total-Hg (HgT) present as MeHg) in the porewaters of the experimental treatment reached peak values within...

  9. An unexpected role for mixotrophs in the response of peatland carbon cycling to climate warming.

    Science.gov (United States)

    Jassey, Vincent E J; Signarbieux, Constant; Hättenschwiler, Stephan; Bragazza, Luca; Buttler, Alexandre; Delarue, Frédéric; Fournier, Bertrand; Gilbert, Daniel; Laggoun-Défarge, Fatima; Lara, Enrique; Mills, Robert T E; Mitchell, Edward A D; Payne, Richard J; Robroek, Bjorn J M

    2015-11-25

    Mixotrophic protists are increasingly recognized for their significant contribution to carbon (C) cycling. As phototrophs they contribute to photosynthetic C fixation, whilst as predators of decomposers, they indirectly influence organic matter decomposition. Despite these direct and indirect effects on the C cycle, little is known about the responses of peatland mixotrophs to climate change and the potential consequences for the peatland C cycle. With a combination of field and microcosm experiments, we show that mixotrophs in the Sphagnum bryosphere play an important role in modulating peatland C cycle responses to experimental warming. We found that five years of consecutive summer warming with peaks of +2 to +8°C led to a 50% reduction in the biomass of the dominant mixotrophs, the mixotrophic testate amoebae (MTA). The biomass of other microbial groups (including decomposers) did not change, suggesting MTA to be particularly sensitive to temperature. In a microcosm experiment under controlled conditions, we then manipulated the abundance of MTA, and showed that the reported 50% reduction of MTA biomass in the field was linked to a significant reduction of net C uptake (-13%) of the entire Sphagnum bryosphere. Our findings suggest that reduced abundance of MTA with climate warming could lead to reduced peatland C fixation.

  10. Current and future CO2 emissions from drained peatlands in Southeast Asia

    NARCIS (Netherlands)

    Hooijer, A.; Page, S.; Canadell, J.G.; Silvius, M.; Kwadijk, J.; Wösten, H.; Jauhiainen, J.

    2010-01-01

    Forested tropical peatlands in Southeast Asia store at least 42 000 Million metric tonnes (Mt) of soil carbon. Human activity and climate change threatens the stability of this large pool, which has been decreasing rapidly over the last few decades owing to deforestation, drainage and fire. In this

  11. Spatio-temporal trends of nitrogen deposition and climate effects on Sphagnum productivity in European peatlands.

    Science.gov (United States)

    Granath, Gustaf; Limpens, Juul; Posch, Maximilian; Mücher, Sander; de Vries, Wim

    2014-04-01

    To quantify potential nitrogen (N) deposition impacts on peatland carbon (C) uptake, we explored temporal and spatial trends in N deposition and climate impacts on the production of the key peat forming functional group (Sphagnum mosses) across European peatlands for the period 1900-2050. Using a modelling approach we estimated that between 1900 and 1950 N deposition impacts remained limited irrespective of geographical position. Between 1950 and 2000 N deposition depressed production between 0 and 25% relative to 1900, particularly in temperate regions. Future scenarios indicate this trend will continue and become more pronounced with climate warming. At the European scale, the consequences for Sphagnum net C-uptake remained small relative to 1900 due to the low peatland cover in high-N areas. The predicted impacts of likely changes in N deposition on Sphagnum productivity appeared to be less than those of climate. Nevertheless, current critical loads for peatlands are likely to hold under a future climate. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Carbon accumulation in peatlands of West Siberia over the last 2000 years

    Science.gov (United States)

    Beilman, David W.; MacDonald, Glen M.; Smith, Laurence C.; Reimer, Paula J.

    2009-03-01

    We use a network of cores from 77 peatland sites to determine controls on peat C content and peat C accumulation over the last 2000 years (since 2 ka) across Russia's West Siberian Lowland (WSL), the world's largest wetland region. Our results show a significant influence of fossil plant composition on peat C content, with peats dominated by Sphagnum having a lower C content. Radiocarbon-derived C accumulation since 2 ka at 23 sites is highly variable from site to site, but displays a significant N-S trend of decreasing accumulation at higher latitudes. Northern WSL peatlands show relatively small C accumulation of 7 to 35 kg C m-2 since 2 ka. In contrast, peatlands south of 60°N show larger accumulation of 42 to 88 kg C m-2. Carbon accumulation since 2 ka varies significantly with modern mean annual air temperature, with maximum C accumulation found between -1 and 0°C. Rates of apparent C accumulation since 2 ka show no significant relationship to long-term Holocene averages based on total C accumulation. A GIS-based extrapolation of our site data suggests that a substantial amount (˜40%) of total WSL peat C has accumulated since 2 ka, with much of this accumulation south of 60°N. The large peatlands in the southern WSL may be an important component of the Eurasian terrestrial C sink, and future warming could result in a shift northward in long-term WSL C sequestration.

  13. Ecohydrology of a Sphagnum peatland in transitional climate - an interdysciplinary study

    Science.gov (United States)

    Słowińska, S.; Słowiński, M.; Lamentowicz, M.; Skrzypek, G.

    2012-04-01

    Sphagnum peatlands of the Central Europe are regarded as the valuable and endangered habitats. Their existence depends on the complex climatic, hydrological, topographical and botanical conditions. Good understanding of peatlands' ecohydrology is crucial for the appropriate environmental management. Our long-term ecological study is focused on a poor fen located in Northern Poland - a unique floristic nature reserve and Nature 2000 area. Main aims of the research were to: a) understand an influence of the temperature and precipitation on the ground water, b) explain an impact of the local climate and the groundwater table level on testate amoebae communities, Sphagnum mosses growth and stable carbon, nitrogen and oxygen isotope compositions, c) use the neo- ecological data for the quantitative palaeoecological reconstructions. We have been conducting the monitoring of the growth of Sphagnum mosses in five plots. Vegetation was sampled three times during the growing season for the stable isotope and testate amoebae analyses (July, September and December 2009). Temperature of the air and acrotelm, air humidity, precipitation and groundwater table were recorded using automatic data loggers. Our research confirmed that even small fluctuation of temperature, precipitation and annual distribution of precipitation have a very strong impact on the hydrology of the peatland. Testate amoeba communities and stable isotopes from Sphagnum clearly indicated the hydrological response of the mire in the different parts of the peatland. The next step is a detailed seasonal study supported by the manipulative warming experiment.

  14. Mercury and Organic Carbon Relationships in Streams Draining Forested Upland/Peatland Watersheds

    Science.gov (United States)

    R. K. Kolka; D. F. Grigal; E. S. Verry; E. A. Nater

    1999-01-01

    We determined the fluxes of total mecury (HgT), total organic carbon (TOC), and dissolved organic carbon (DOC) from five upland/peatland watersheds at the watershed outlet. The difference between TOC and DOC was defined as particulate OC (POC). Concentrations of HgT showed moderate to strong relationships with POC (R2 = 0.77) when all watersheds...

  15. Scale-dependent spatial variability in peatland lead pollution in the southern Pennines, UK.

    Science.gov (United States)

    Rothwell, James J; Evans, Martin G; Lindsay, John B; Allott, Timothy E H

    2007-01-01

    Increasingly, within-site and regional comparisons of peatland lead pollution have been undertaken using the inventory approach. The peatlands of the Peak District, southern Pennines, UK, have received significant atmospheric inputs of lead over the last few hundred years. A multi-core study at three peatland sites in the Peak District demonstrates significant within-site spatial variability in industrial lead pollution. Stochastic simulations reveal that 15 peat cores are required to calculate reliable lead inventories at the within-site and within-region scale for this highly polluted area of the southern Pennines. Within-site variability in lead pollution is dominant at the within-region scale. The study demonstrates that significant errors may be associated with peatland lead inventories at sites where only a single peat core has been used to calculate an inventory. Meaningful comparisons of lead inventories at the regional or global scale can only be made if the within-site variability of lead pollution has been quantified reliably.

  16. Loss of the soil carbon storage function of drained forested peatlands

    Directory of Open Access Journals (Sweden)

    C. Wüst-Galley

    2016-04-01

    Full Text Available Peatlands form a large but unstable C store. Drainage of peatlands converts them into C sources, which is undesirable if increases in atmospheric CO2 levels are to be minimised. Therefore, quantification of C stocks and an understanding of which ecosystems or management regimes are capturing or emitting C is needed. Such information is scarce for temperate European forests. We studied the soil properties of sixteen peatlands in Switzerland, representing three forest types, to test whether peatlands that are more strongly affected by drainage (according to vegetation have lost their function as C sinks or stores. Bulk density and ash enrichment, as well as H/C, O/C and C/N quotients, indicated that the soils of the two forest types that appeared to be more strongly affected by drainage were more degraded and had lost their functions as C stores. Long-term net rates of C loss estimated using the ash residue method were similar across all three forest types, for sites where this could be estimated.

  17. Subsidence and carbon dioxide emissions in a smallholder peatland mosaic in Sumatra, Indonesia

    NARCIS (Netherlands)

    Khasanah, Nimatul; Noordwijk, van Meine

    2018-01-01

    Most attention in quantifying carbon dioxide (CO2) emissions from tropical peatlands has been on large-scale plantations (industrial timber, oil palm (Elaeis guinensis)), differing in drainage and land-use practices from those of smallholder farms. We measured subsidence and changes in bulk density

  18. Vegetation and carbon gas dynamics under a changed hydrological regime in central European peatlands

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Z.; Picek, T.; Hájek, Tomáš; Bufková, I.; Tuittila, E. S.

    2012-01-01

    Roč. 5, č. 1 (2012), 89-103 ISSN 1755-0874 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : peatland * carbon balance * restoration Subject RIV: EF - Botanics Impact factor: 0.924, year: 2012

  19. Plant functional types define magnitude of drought response in peatland CO2 exchange

    NARCIS (Netherlands)

    Kuiper, J.J.; Mooij, W.M.; Bragazza, L.; Robroek, B.J.M.

    2014-01-01

    Peatlands are important sinks for atmospheric carbon (C), yet the role of plant functional types (PFTs) for C sequestration under climatic perturbations is still unclear. A plant removal experiment was used to study the importance of vascular PFTs for the net ecosystem CO2 exchange (NEE) during

  20. Plant functional types define magnitude of drought response in peatland CO2 exchange

    NARCIS (Netherlands)

    Kuiper, J.J.; Mooij, W.M.; Bragazza, L.; Robroek, B.J.M.

    2014-01-01

    Peatlands are important sinks for atmospheric carbon (C), yet the role of plant functional types (PFTs) for C sequestration under climatic perturbations is still unclear. A plant-removal experiment was used to study the importance of vascular PFTs for the net ecosystem CO2 exchange (NEE) during

  1. N cycling in SPRUCE (Spruce Peatlands Response Under Climatic and Environmental Changes)

    Science.gov (United States)

    Peatlands located in boreal regions make up a third of global wetland area and are expected to have the highest temperature increases in response to climate change. As climate warms, we expect peat decomposition may accelerate, altering the cycling of nitrogen. Alterations in th...

  2. Synthesizing greenhouse gas fluxes across nine European peatlands and shrublands - responses to climatic and environmental changes

    NARCIS (Netherlands)

    Carter, M.S.; Larsen, K.S.; Emmett, B.; Estiarte, M.; Field, C.; Leith, I.D.; Lund, M.; Meijide, A.; Mills, R.T.E.; Niinemets, Ü.; Peñuelas, J.; Portillo-Estrada, M.; Schmidt, I.K.; Selsted, M.B.; Sheppard, L.J.; Sowerby, A.; Tietema, A.; Beier, B.

    2012-01-01

    In this study, we compare annual fluxes of methane (CH4), nitrous oxide (N2O) and soil respiratory carbon dioxide (CO2) measured at nine European peatlands (n = 4) and shrublands (n = 5). The sites range from northern Sweden to Spain, covering a span in mean annual air temperature from 0 to 16C, and

  3. The Acid-Base Balance Between Organic Acids and Circumneutral Ground Waters in Large Peatlands

    Science.gov (United States)

    Siegel, D. I.; Glaser, P. H.; So, J.

    2006-05-01

    Organic acids supply most of the acidity in the surface waters of bogs in peatlands. Yet, the fundamental geochemical properties of peatland organic acids are still poorly known. To assess the geochemical properties of typical organic acid assemblages in peatlands, we used a triprotic analog model for peat pore waters and surface waters in the Glacial Lake Agassiz Peatlands, optimizing on charge balance and calibrated to estimates of mole site density in DOC and triprotic acid dissociation constants. Before the calibration process, all bog waters and 76% of fen waters had more than +20% charge imbalance. After calibration, most electrochemically balanced within 20%. In the best calibration, the mole site denisty of bog DOC was estimated as ~0.05 mmol/mmol C., approximately 6 times smaller than that for fen DOC or the DOC in the fen deeper fen peats that underlie bogs. The three modeled de-protonation constants were; pKa1 = ~3.0, pKa2 = ~4.5 and pKa3 = ~7.0 for the bog DOC, and; pKa1 = ~5.2, pKa2 =~ 6.5 and pKa3 = ~7.0 for the fen DOC. Bog DOC, behaves as a strong acid despite its small mole site density. The DOC in bog runoff can therefore theoretically acidify the surface waters in adjacent fens wherever these waters do not receive sufficient buffering alkalinity from active groundwater seepage.

  4. Responsible management of peatlands in Canada, from peat industry to oil sands

    Science.gov (United States)

    Rochefort, Line

    2013-04-01

    Canada harbors one third of the peat resources of the world. Peat is an accumulated organic matter composed of dead and partly decomposed plant material, forming huge deposit through time in wetlands like peatlands and boreal coniferous swamps. Peat is a valuable resource as a growing media and soil amendments, an eco-friendly absorbent, also used as biofilters, for body care and for wastewater treatment. Peatlands also offer valuable ecological services : for example, they are the most efficient terrestrial ecosystem to store carbon on a long-term basis. Their ability to "cool off" the planet warrants a good look at their management. The horticultural peat industry of Canada has invested 22 years in R&D in habitat restoration and is now a strong leader in managing industrial peatlands in a sustainable way. The oil sand industry, which is strongly impacting the wetland landscapes of northern Canada, does realize that it has to reduce its ecological footprint, which is heavily criticized around the world. Decommissioned open mines near Fort McMurray have already begun recreating peatland ecosystems, and some restoration attempts of former oil pads are underway in the Peace River region. But the restoration of the largely disturbed wetland landscape of the oil sands is commanding innovative solutions.

  5. Strengthening community participation in reducing GHG emission from forest and peatland fire

    Science.gov (United States)

    Thoha, A. S.; Saharjo, B. H.; Boer, R.; Ardiansyah, M.

    2018-02-01

    Strengthening community participation is needed to find solutions to encourage community more participate in reducing Green House Gas (GHG) from forest and peatland fire. This research aimed to identify stakeholders that have the role in forest and peatland fire control and to formulate strengthening model of community participation through community-based early warning fire. Stakeholder mapping and action research were used to determine stakeholders that had potential influence and interest and to formulate strengthening model of community participation in reducing GHG from forest and peatland fire. There was found that position of key players in the mapping of stakeholders came from the government institution. The existence of community-based fire control group can strengthen government institution through collaborating with stakeholders having strong interest and influence. Moreover, it was found several local knowledge in Kapuas District about how communities predict drought that have potential value for developing the community-based early warning fire system. Formulated institutional model in this research also can be further developed as a model institution in the preservation of natural resources based on local knowledge. In conclusion, local knowledge and community-based fire groups can be integrated within strengthening model of community participation in reducing GHG from forest and peatland fire.

  6. Molecular Characterization of Methanogenic Communities in Core Sediments of the Dajiuhu Peatland, Central China

    Science.gov (United States)

    Wang, R.; Wang, H.

    2017-12-01

    Methane (CH4) is an important greenhouse gas with a global warming potential 22 times greater than carbon dioxide. Large amounts of CH4 can be produced and released by methanogenesis in peatland ecosystems, which make peatland ecosystems play an important role in mediating global climate change. Here we report the abundance and distribution of methanogenic communities and their correlation with physicochemical parameters along two sediment cores in the Dajiuhu Peatland via quantitative PCR, clone library construction of functional genes and statistical analysis. Uncultured Group and Fen Cluster were found to be the dominant methanogens at the upper part of the cores, and Rice and Related Rice Cluster became dominant in the bottom of the cores. Quantitative PCR showed that abundances of methanogenic communities ranged from 104 to 106 copies/ng DNA throughout the cores. Canonical Correlation Analysis (CCA) indicated that dissolved oxygen (DO) (P=0.046, F=1.4) was the main factor significantly controlling methanogenic communities. Our results enhance the understanding of the compositions and variations of methanogenic communities vertically and greatly help us to further investigate process of microbial methanogenesis in Dajiuhu Peatland.

  7. The role of fire in UK peatland and moorland management: the need for informed, unbiased debate

    Science.gov (United States)

    Davies, G. Matt; Kettridge, Nicholas; Stoof, Cathelijne R.; Gray, Alan; Ascoli, Davide; Fernandes, Paulo M.; Marrs, Rob; Clay, Gareth D.; McMorrow, Julia; Vandvik, Vigdis

    2016-01-01

    Fire has been used for centuries to generate and manage some of the UK's cultural landscapes. Despite its complex role in the ecology of UK peatlands and moorlands, there has been a trend of simplifying the narrative around burning to present it as an only ecologically damaging practice. That fire modifies peatland characteristics at a range of scales is clearly understood. Whether these changes are perceived as positive or negative depends upon how trade-offs are made between ecosystem services and the spatial and temporal scales of concern. Here we explore the complex interactions and trade-offs in peatland fire management, evaluating the benefits and costs of managed fire as they are currently understood. We highlight the need for (i) distinguishing between the impacts of fires occurring with differing severity and frequency, and (ii) improved characterization of ecosystem health that incorporates the response and recovery of peatlands to fire. We also explore how recent research has been contextualized within both scientific publications and the wider media and how this can influence non-specialist perceptions. We emphasize the need for an informed, unbiased debate on fire as an ecological management tool that is separated from other aspects of moorland management and from political and economic opinions. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216512

  8. Genetic diversity of Dyera polyphylla (Miq.) Steenis populations used in tropical peatland restoration in Indonesia

    NARCIS (Netherlands)

    Tata, Hesti Lestari; Muchugi, A.; Kariba, R.; Noordwijk, van M.

    2018-01-01

    Dyera polyphylla is a native tree species of peat swamp forests in Southeast Asia. Where it has been used in peatland restoration, the trees are of uncertain genetic origin. We analysed the genetic diversity of seven populations of D. polyphylla (9–20 individual trees per population) from both

  9. Canal blocking strategies for hydrological restoration of degraded tropical peatlands in Central Kalimantan, Indonesia

    NARCIS (Netherlands)

    Ritzema, H.P.; Limin, S.; Kusin, K.; Jauhiainen, J.; Wösten, H.

    2014-01-01

    In the 1990s the Government of Indonesia derided to develop one million hectares of peatlands for agriculture in Central Kalimantan on the Island of Borneo. The construction of thousands of kilometres of canals resulted in over-drainage and targets for agricultural production failed. Abandoned, the

  10. Source Areas of Water and Nitrate in a Peatland Catchment, Minnesota, USA

    Science.gov (United States)

    Sebestyen, S. D.

    2017-12-01

    In nitrogen polluted forests, stream nitrate concentrations increase and some unprocessed atmospheric nitrate may be transported to streams during stormflow events. This understanding has emerged from forests with upland mineral soils. In contrast, catchments with northern peatlands may have both upland soils and lowlands with deep organic soils, each with unique effects on nitrate transport and processing. While annual budgets show nitrate yields to be relatively lower from peatland than upland-dominated catchments, little is known about particular runoff events when stream nitrate concentrations have been higher (despite long periods with little or no nitrate in outlet streams) or the reasons why. I used site knowledge and expansive/extensive monitoring at the Marcell Experimental Forest in Minnesota, along with a targeted 2-year study to determine landscape areas, water sources, and nitrate sources that affected stream nitrate variation in a peatland catchment. I combined streamflow, upland runoff, snow amount, and frost depth data from long-term monitoring with nitrate concentration, yield, and isotopic data to show that up to 65% of stream nitrate during snowmelt of 2009 and 2010 was unprocessed atmospheric nitrate. Up to 46% of subsurface runoff from upland soils during 2009 was unprocessed atmospheric nitrate, which shows the uplands to be a stream nitrate source during 2009, but not during 2010 when upland runoff concentrations were below the detection limit. Differences are attributable to variations in water and nitrate sources. Little snow (a nitrate source), less upland runoff relative to peatland runoff, and deeper soil frost in the peatland caused a relatively larger input of nitrate from the uplands to the stream during 2009 and the peatland to the stream during 2010. Despite the near-absence of stream nitrate during much of rest of the year, these findings show an important time when nitrate transport affected downstream aquatic ecosystems, reasons

  11. Identification of the Criteria for Decision Making of Cut-Away Peatland Reuse.

    Science.gov (United States)

    Padur, Kadi; Ilomets, Mati; Põder, Tõnis

    2017-03-01

    The total area of abandoned milled peatlands which need to be rehabilitated for sustainable land-use is nearly 10,000 ha in Estonia. According to the agreement between Estonia and the European Union, Estonia has to create suitable conditions for restoration of 2000 ha of abandoned cut-away peatlands by 2023. The decisions on rehabilitation of abandoned milled peatlands have so far relied on a limited knowledgebase with unestablished methodologies, thus the decision making process needs a significant improvement. This study aims to improve the methodology by identifying the criteria for optimal decision making to ensure sustainable land use planning after peat extraction. Therefore relevant environmental, social and economic restrictive and weighted comparison criteria, which assess reuse alternatives suitability for achieving the goal, is developed in cooperation with stakeholders. Restrictive criteria are arranged into a decision tree to help to determine the implementable reuse alternatives in various situations. Weighted comparison criteria are developed in cooperation with stakeholders to rank the reuse alternatives. The comparison criteria are organised hierarchically into a value tree. In the situation, where the selection of a suitable rehabilitation alternative for a specific milled peatland is going to be made, the weighted comparison criteria values need to be identified and the presented approach supports the optimal and transparent decision making. In addition to Estonian context the general results of the study could also be applied to a cut-away peatlands in other regions with need-based site-dependent modifications of criteria values and weights.

  12. Rain events decrease boreal peatland net CO2 uptake through reduced light availability.

    Science.gov (United States)

    Nijp, Jelmer J; Limpens, Juul; Metselaar, Klaas; Peichl, Matthias; Nilsson, Mats B; van der Zee, Sjoerd E A T M; Berendse, Frank

    2015-06-01

    Boreal peatlands store large amounts of carbon, reflecting their important role in the global carbon cycle. The short-term exchange and the long-term storage of atmospheric carbon dioxide (CO2 ) in these ecosystems are closely associated with the permanently wet surface conditions and are susceptible to drought. Especially, the single most important peat forming plant genus, Sphagnum, depends heavily on surface wetness for its primary production. Changes in rainfall patterns are expected to affect surface wetness, but how this transient rewetting affects net ecosystem exchange of CO2 (NEE) remains unknown. This study explores how the timing and characteristics of rain events during photosynthetic active periods, that is daytime, affect peatland NEE and whether rain event associated changes in environmental conditions modify this response (e.g. water table, radiation, vapour pressure deficit, temperature). We analysed an 11-year time series of half-hourly eddy covariance and meteorological measurements from Degerö Stormyr, a boreal peatland in northern Sweden. Our results show that daytime rain events systematically decreased the sink strength of peatlands for atmospheric CO2 . The decrease was best explained by rain associated reduction in light, rather than by rain characteristics or drought length. An average daytime growing season rain event reduced net ecosystem CO2 uptake by 0.23-0.54 gC m(-2) . On an annual basis, this reduction of net CO2 uptake corresponds to 24% of the annual net CO2 uptake (NEE) of the study site, equivalent to a 4.4% reduction of gross primary production (GPP) during the growing season. We conclude that reduced light availability associated with rain events is more important in explaining the NEE response to rain events than rain characteristics and changes in water availability. This suggests that peatland CO2 uptake is highly sensitive to changes in cloud cover formation and to altered rainfall regimes, a process hitherto largely

  13. Above- and belowground linkages in Sphagnum peatland: climate warming affects plant-microbial interactions.

    Science.gov (United States)

    Jassey, Vincent E J; Chiapusio, Geneviève; Binet, Philippe; Buttler, Alexandre; Laggoun-Défarge, Fatima; Delarue, Frédéric; Bernard, Nadine; Mitchell, Edward A D; Toussaint, Marie-Laure; Francez, André-Jean; Gilbert, Daniel

    2013-03-01

    Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above- and belowground linkages that regulate soil organic carbon dynamics and C-balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top-predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum-polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above- and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands. © 2012 Blackwell Publishing Ltd.

  14. Understanding the structure of Exmoor's peatland ecosystems using laser-scanning technologies

    Science.gov (United States)

    Luscombe, D. J.; Anderson, K.; Wetherelt, A.; Grand-Clement, E.; Le-Feuvre, N.; Smith, D.; Brazier, R. E.

    2012-04-01

    Upland blanket peatlands in the UK are of high conservation value and in an intact state, provide important landscape services, such as carbon sequestration and flood attenuation. The drainage of many such wetlands for agricultural reclamation has resulted in changes to upland blanket mire topography, ecology, hydrological processes and carbon fluxes. There is a need for spatially explicit monitoring approaches at peatland sites in the UK as although there has been a national effort to restore drained peat uplands, baseline and post restoration monitoring of changes to ecosystem structure and function is largely absent. Climate change policy and the emerging carbon markets also necessitate the need for enhanced system understanding to inform carbon targets and understand the impacts of restoration. Exmoor is the focus of this research because many areas of upland peat have, in the past, been extensively drained through government "moorland reclamation" programs. A large restoration project funded by South West Water is currently underway in association with Exmoor National Park, The Environment Agency and Natural England. Exmoor also provides an analogue for other westerly peatlands in the British Isles in terms of its climate, ecology and drainage characteristics. Our approach employed airborne LiDAR data gathered by the Environment Agency Geomatics Group coupled with Terrestrial Laser Scanning (TLS) surveys. LiDAR data were processed to produce digital surface models (DSM) of the peatland surface at a 0.5m resolution. These data were further interrogated to separate vegetation structures and geomorphic features such as man-made drainage channels which have damaged the peatland. Over small extents the LiDAR derived DSM surface was then compared to a TLS derived DSM to examine the ability of these models to describe fine scale vegetation and geomorphic structure, which could then be extrapolated to larger spatial extents. Exploration of the data has shown that

  15. Nutrient Controls on Methane Emissions in a Permafrost Thaw Subarctic Peatland

    Science.gov (United States)

    Kashi, N. N.; Perryman, C. R.; Malhotra, A.; Marek, E. A.; Giesler, R.; Varner, R. K.

    2015-12-01

    Permafrost peatlands in northern latitudes are large reservoirs of sequestered carbon that are vulnerable to climate change. While peatlands account for a small fraction of total global land surfaces, their potential to release sequestered carbon in response to higher temperatures is of concern. Of particular relevance is the conversion of these carbon stores into methane (CH4), a strong greenhouse gas with a global warming potential 20 times greater than that of CO2 over a 100-year time frame. Here, we explore how key nutrients impact the consumption of CH4 at the Stordalen Mire in Abisko, Sweden, a discontinuous permafrost peatland with expanding thaw over the last century. Peatland CH4 emissions are highly spatially variable due to multiple emission pathways and strong dependence on several environmental factors. Among controls on CH4 emissions, such as temperature and water table depth, primary production of wetland vegetation is also a strong factor in the variability of CH4 emissions. Plant community shifts among permafrost thaw stages subsequently change nutrient cycling and availability, which in turn impacts primary production. Early stages of permafrost thaw are mosaicked with a variety of vascular plants and mosses. We analyzed potential enzymatic activities of chitinase, glucosidase, and phosphatase as proxies for organic nitrogen, carbon, and phosphorus cycling, respectively, in tandem with potential CH4 oxidation rates. In addition, stoichiometric ratios of carbon, nitrogen, and phosphorus concentrations are used to illustrate nutrient limitation controls on CH4 oxidation rates. While CH4 emissions are low throughout initial thaw stages, highest rates of potential CH4 oxidation. These permafrost thaw-induced CH4 oxidation rates are 5 and 11 times higher, in the surface and depth of the peat profile respectively, than subsequent aerobic permafrost thaw stages. As CH4 emissions are low in intact permafrost peatlands, these high rates of potential CH4

  16. On the use of mulching to mitigate permafrost thaw due to linear disturbances in sub-arctic peatlands

    Science.gov (United States)

    The presence or absence of permafrost significantly influences the hydrology and ecology of northern watersheds. Resource exploration activities are currently having noticeable effects on hydrological and ecological processes in sub-arctic peatlands. Disturbances such as seismic cutlines can result ...

  17. Peatland development and paleoclimate records from the Holocene peat archive in the foothills of the Eastern Sayan Mountains

    Science.gov (United States)

    Rodionova, A. B.; Grenaderova, A. V.

    2018-03-01

    Plant macrofossils data were used to identify the successive peatland communities during the last 3500 years in the floodplain of the Mana River (foothills of the Eastern Sayan Mountains). The reconstruction of the peatland development indicated that the peatland in the Mana River basin formed about 3500 years ago. The peatland formed as a result of overgrowing floodplain and water logging of terrace lows. The authors observed three successive changes: birch forest with sedge and hypnum mosses in the second half of the Subboreal period, wood-marsh plant association at the start of the Middle Subatlantic period (1600 years BP), the herb-wort phytocoenosis with inclusions of mezoeutrophycal plant species have been growing since the Late Subboreal period (950 years BP).

  18. Production of biomass in wet peatlands (paludiculture). The EU-AID project 'Wetland energy' in Belarus. Solutions for the substitution of fossil fuels (peat briquettes) by biomass from wet peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Wichtmann, Wendelin [Michael Succow Stiftung fuer den Schutz der Natur, Greifswald (Germany); Haberl, Andreas; Tanneberger, Franziska

    2012-07-01

    In Belarus, a pilot project demonstrating site adapted management of wet peatlands for biomass production have started recently. In cooperation with local stakeholders, the currently environmentally unfriendly peat extraction for energy will be converted into a sustainable land use system. By replacing the peat briquettes with locally produced briquettes using biomass from rewetted peatlands the income situation of remote and rural areas will be improved. In various combustion trials of peatland biomass in Germany and Belarus the suitability of the material for energy production has been demonstrated. The EU-Aid funded project in Belarus is realized by the Michael Succow Foundation in cooperation with the International Sacharov Environmental University (ISEU) and the Institute for Nature Management of the National Academy of Sciences (IfNM). Applied, site-specific management concepts, employing site adapted machinery for reed and sedge vegetation on wet peatlands will not only result in avoidance of environmentally harmful peat extraction, but also in benefits for distinctive biodiversity. This site adapted peatlands management (paludiculture) comprises the reduction of greenhousegas (GHG) emissions by rewetting of drained peatlands and by the replacement of fossil fuels by biomass from these sites. Under favourable conditions additionally CO{sub 2} sequestration by new peat formation reestablished. The biomass will be harvested with site adapted machinery and processed to fuel briquettes. (orig.)

  19. A Soil Service Index: Peatland soils as a case study for quantifying the value, vulnerability, and status of soils

    Science.gov (United States)

    Loisel, J.; Harden, J. W.; Hugelius, G.

    2017-12-01

    What are the most important soil services valued by land stewards and planners? Which soil-data metrics can be used to quantify each soil service? What are the steps required to quantitatively index the baseline value of soil services and their vulnerability under different land-use and climate change scenarios? How do we simulate future soil service pathways (or trajectories) under changing management regimes using process-based ecosystem models? What is the potential cost (economic, social, and other) of soil degradation under these scenarios? How sensitive or resilient are soil services to prescribed management practices, and how does sensitivity vary over space and time? We are bringing together a group of scientists and conservation organizations to answer these questions by launching Soil Banker, an open and flexible tool to quantify soil services that can be used at any scale, and by any stakeholder. Our overarching goals are to develop metrics and indices to quantify peatland soil ecosystem services, monitor change of these services, and guide management. This paper describes our methodology applied to peatlands and presents two case studies (Indonesia and Patagonia) demonstrating how Peatland Soil Banker can be deployed as an accounting tool of peatland stocks, a quantitative measure of peatland health, and as a projection of peatland degradation or enhancement under different land-use cases. Why peatlands? They store about 600 billion tons of carbon that account for ⅓ of the world's soil carbon. Peatlands have dynamic GHG exchanges of CO2, CH4, and NOx with the atmosphere, which plays a role in regulating global climate; studies indicate that peatland degradation releases about 2-3 billion tons of CO2 to the atmosphere annually. These ecosystems also provide local and regional ecosystem services: they constitute important components of the N and P cycles, store about 10% of the world's freshwater and buffer large fluxes of freshwater on an annual basis

  20. Peatlands and potatoes; organic wetland soils in Uganda

    Science.gov (United States)

    Farmer, Jenny; Langan, Charlie; Gimona, Alessandro; Poggio, Laura; Smith, Jo

    2017-04-01

    Land use change in Uganda's wetlands has received very little research attention. Peat soils dominate the papyrus wetlands of the south west of the country, but the areas they are found in have been increasingly converted to potato cultivation. Our research in Uganda set out to (a) document both the annual use of and changes to these soils under potato cultivation, and (b) the extent and condition of these soils across wetland systems. During our research we found it was necessary to develop locally appropriate protocols for sampling and analysis of soil characteristics, based on field conditions and locally available resources. Over the period of one year we studied the use of the peat soil for potato cultivation by smallholder farmers in Ruhuma wetland and measured changes to surface peat properties and soil nutrients in fields over that time. Farmer's use of the fields changed over the year, with cultivation, harvesting and fallow periods, which impacted on soil micro-topography. Measured soil properties changed over the course of the year as a result of the land use, with bulk density, nitrogen content, potassium and magnesium all reducing. Comparison of changes in soil carbon stocks over the study period were difficult to make as it was not possible to reach the bottom of the peat layer. However, a layer of fallow weeds discarded onto the soil prior to preparation of the raised potato beds provided a time marker which gave insight into carbon losses over the year. To determine the peatland extent, a spatial survey was conducted in the Kanyabaha-Rushebeya wetland system, capturing peat depths and key soil properties (bulk density, organic matter and carbon contents). Generalised additive models were used to map peat depth and soil characteristics across the system, and maps were developed for these as well as drainage and land use classes. Comparison of peat cores between the two study areas indicates spatial variability in peat depths and the influence of

  1. Proceedings of a symposium on the reclamation and restoration of boreal peatland and forest ecosystems : towards a sustainable future

    Energy Technology Data Exchange (ETDEWEB)

    Bhatti, J. [Natural Resources Canada, Ottawa, ON (Canada); Foote, L.; Moran, S. [Alberta Univ., Edmonton, AB (Canada); Nadeau, L. [Northern Alberta Inst. of Technology, Edmonton, AB (Canada); Rochefort, L. [Laval Univ., Quebec City, PQ (Canada); Short, P. [Canadian Sphagnum Peat Moss Association, St. Albert, AB (Canada); Vitt, D.H. [Southern Illinois Univ., Carbondale, IL (United States); Wieder, K. [Villanova Univ., Villanova, PA (United States)] (comps.)

    2010-07-01

    Disturbances in Canada's boreal forest occur in both upland forests and in peatlands. These disturbances originate from both anthropogenic and natural causes, particularly fire. Techniques for the restoration, as well as the reclamation of peatlands and forests impacted by agriculture, urban development, or oil and gas activities, have made significant advancement over the last decade and these techniques need to be incorporated into the regulation and management of peatland and forest ecosystems. This symposium addressed the issue of how this research is affected by climate change. The sessions were entitled: (1) reclaiming forest and forest soils impacted by oil and gas production, (2) influence of oil sands development on forest communities, (3) understanding the importance of peatland and forest carbon in the twenty-first century, (4) reclaiming wetlands on mined oil sands tailing, (5) disturbance in peatlands and its relevance to minimizing disturbance footprints and informing reclamation efforts, and (6) restoration and management of harvested peatlands. The symposium featured 37 presentations, of which 6 have been catalogued separately for inclusion in this database. refs., tabs., figs.

  2. Ecosystem-atmosphere exchange of CO2 in a temperate herbaceous peatland in the Sanjiang Plain of northeast China

    Science.gov (United States)

    Zhu, Xiaoyan; Song, Changchun; Swarzenski, Christopher M.; Guo, Yuedong; Zhang, Xinhow; Wang, Jiaoyue

    2015-01-01

    Northern peatlands contain a considerable share of the terrestrial carbon pool, which will be affected by future climatic variability. Using the static chamber technique, we investigated ecosystem respiration and soil respiration over two growing seasons (2012 and 2013) in a Carex lasiocarpa-dominated peatland in the Sanjiang Plain in China. We synchronously monitored the environmental factors controlling CO2 fluxes. Ecosystem respiration during these two growing seasons ranged from 33.3 to 506.7 mg CO2–C m−2 h−1. Through step-wise regression, variations in soil temperature at 10 cm depth alone explained 73.7% of the observed variance in log10(ER). The mean Q10 values ranged from 2.1 to 2.9 depending on the choice of depth where soil temperature was measured. The Q10 value at the 10 cm depth (2.9) appears to be a good representation for herbaceous peatland in the Sanjiang Plain when applying field-estimation based Q10values to current terrestrial ecosystem models due to the most optimized regression coefficient (63.2%). Soil respiration amounted to 57% of ecosystem respiration and played a major role in peatland carbon balance in our study. Emphasis on ecosystem respiration from temperate peatlands in the Sanjiang Plain will improve our basic understanding of carbon exchange between peatland ecosystem and the atmosphere.

  3. Subsurface structures and properties of a medium-scale peatland area by means of hydrogeophysical methods

    Science.gov (United States)

    Altdorff, Daniel; van der Kruk, Jan; Bechtold, Michel; Tiemeyer, Bärbel; Huismann, Sander

    2013-04-01

    Intact peatlands are natural sinks of climate-relevant atmospheric CO2 and they are able to store high amounts of organic carbon (C). In addition, intact peatlands are increasingly important given positive effects on biodiversity, hydrological processes and corresponding management issues. Nevertheless, large parts of peatlands in populated areas were modified by human activity during the last centuries. In Germany, more than 90% of the peatlands are drained, mainly for agricultural use. Due to the recent recognition of the positive effects of intact peatlands, there are presently several initiatives for re-wetting parts of these peatlands. However, a restoration to nearly natural conditions needs an evaluation of the current situation as well as an assessment of the restoration potential. Therefore, soil properties like peat layer thickness, bulk density and moisture content need to be known. Non-invasive hydrogeophysical methods offer the possibility for a time and cost-effective characterization of peatlands. In this study, we investigated a medium-scale peatland area (approximately 35 ha) of the 3000 ha large 'Großes Moor' peatland. We present apparent conductivity (ECa) values obtained from Electromagnetic Induction (EMI) measurements representative for three investigation depths (approximately 0.25, 0.5, and 1m). We selected zones with dissimilar ECa to identify areas where strong changes in the subsoil properties with depth are expected (i.e. shallow peat soil on top of sand). Within these areas, additional measurements were made using Ground Penetration Radar (GPR) and soil sampling was performed. In total, six 30 m long GPR profiles and corresponding common midpoint (CMP) measurements were recorded. Additionally, 15 soil cores were taken down to a depth of 0.9 m in order to obtain peat thickness, water content, pore water EC, bulk density (BD), as well as C and N content. Each core was divided into several 5 to 20 cm thick layers to obtain information on

  4. Ecoenzymatic stoichiometry and microbial processing of organic matter in northern bogs and fens reveals a common P limitation among peatland types

    Science.gov (United States)

    We compared C, N, and P concentrations in atmospheric deposition, runoff, and soil standing stocks with microbial respiration (DHA) and ecoenzyme activity (EEA) in an ombrotrophic bog (S2) and a minerotrophic fen (S3) to investigate the environmental drivers of biogeochemical cyc...

  5. Regulation of nitrogen removal and retention in sphagnum bogs and other peatlands

    International Nuclear Information System (INIS)

    Damman, A.W.H.

    1988-01-01

    Nitrogen concentrations range from 0.3-l.3% in ombrotrophic peat of raised bogs. Within ombrogenous bogs, the N concentration of the peat increases in oceanic regions, with the highest concentrations found in blanket bogs on Southern Hemisphere islands. In minerotrophic peat, N concentrations increase with age (depth) as in upland humus. In this paper, I propose that N immobilization is truncated at low levels in ombrotrophic peat because 1) microbial activity is reduced well below that determined by environmental conditions, and 2) N is not limiting decay, in spite of low N concentrations. Consequently, net mineralization of N occurs at C:N quotients 80 to over 100 in inland raised bogs. Nutrient deficiency, probably P deficiency, appears to limit microbial activity and N immobilization. The increased N immobilization in oceanic bogs is attributed to higher Mg inputs that stimulate the biochemical release of P by enzymatic catalysis, and hence increase microbial activity. In ombrotrophi bogs, peat formed during periods of slow accumulation and long residence in the acrotelm has the highest N concentrations but, paradoxically, has also lost more of its original N content than peat that accumulated rapidly. Irregular changes in the anaerobic peat reflect conditions of decay when the peat was in the acrotelm. In a dated profile, N losses were largest during the last 2000 yr. This indicates a change in environmental conditions in the surface peat. Presumably, during this period the bog reached its maximum elevation with respect to the water mound that can be maintained in the peat under the present climatic conditions, and N losses increased as peat accumulation decreased. (author)

  6. Assessment of the water and energy budget in a peatland catchment of the Alps using the process based GEOtop hydrological model

    DEFF Research Database (Denmark)

    Pullens, Johannes Wilhelmus Maria; Sottocornola, M.; Kiely, G.

    2018-01-01

    close interdependence of the carbon and water cycles in peatland ecosystems signal the importance of understanding the water cycle to the functioning of peatlands. With this aim, the water and energy cycle of an alpine catchment in Italy, which includes a peatland, was studied using the process......-based hydrological model GEOtop and a set of in situ measurements over 4 years (2012-2015). This is a challenging modelling exercise that has not been tried before with GEOtop. The catchment is heterogenous with land covers of peatland, grassland, scree and bare rock in a mountainous area. The GEOtop model was able...

  7. Changes to the Carbon and Energy fluxes in a Northern Peatland with Thawing Permafrost

    Science.gov (United States)

    Harder, S. R.; Roulet, N. T.; Crill, P. M.; Strachan, I. B.

    2017-12-01

    The maintenance of thaw of high carbon density landscapes in the permafrost region ultimately depends of how the energy balance is partitioned as temperatures and precipitation change, yet there are comparatively few energy balance studies, especially in peatlands that contain permafrost. While permafrost peatlands are currently net sinks of carbon, as Arctic temperatures rise and permafrost thaws, the future of these ecosystems and their capacity for carbon uptake is in question. Since 2012 we have been measuring the spatially integrated CO2, energy and water vapour fluxes from the Stordalen peatland (68°22'N, 19°03'E) using eddy covariance (EC). The Stordalen peatland is a heterogeneous peatland in the discontinuous permafrost zone where permafrost thaw is actively occurring, resulting in large changes to the landscape from year to year. Areas where permafrost is present are elevated by up to 1.5 m compared to the areas where permafrost has thawed causing differences in water table depth, peat temperatures, snow distribution, vegetation community and therefore in the carbon and energy fluxes. Our EC tower is located on the edge of a permafrost peat plateau (or palsa) where one fetch measures fluxes from an area underlain by permafrost and the other fetch sees the portion of the peatland where the permafrost has thawed. Within each sector, we have an array of soil temperature and water content sensors to determine the physical characteristics of each fetch. Extensive vegetation surveys (based on plant functional types or PFTs) have also been conducted to run a footprint analysis on the flux data to complete a comparative analysis of the magnitude and variability of the carbon and energy exchanges from PFT. The footprint analysis allows us to explain the difference in energy and carbon fluxes by examining the ecological, biogeochemical and physical characteristics within each footprint. We see distinctly different energy partitioning between the fetches

  8. Contrasting impact of forestry-drainage on CO2 balance at two adjacent peatlands in Finland

    Science.gov (United States)

    Lohila, Annalea; Minkkinen, Kari; Penttilä, Timo; Launiainen, Samuli; Koskinen, Markku; Ojanen, Paavo; Laurila, Tuomas

    2014-05-01

    Fate of carbon in peatlands after drainage has been a subject of many studies, particularly at agriculturally managed sites, but also at sites prepared for forestry. In general, the drainage of peatlands has been considered to trigger the decomposition rate of peat and to cause carbon dioxide (CO2) emissions from the peat into the atmosphere. However, there is not yet full consensus on what are the main regulating factors of the carbon balances in forested peatlands, and do all the forested peatland even act as a source of carbon into the atmosphere. In this study we compare the CO2 exchange rates at two adjacent peatland sites in southern Finland, drained for forestry about 40 years earlier. The pair of sites with similar climatic conditions offer an excellent case for studying the mechanisms controlling the carbon balances of forestry-drained peatlands. The sites differ from each other only by fertility, which has an impact on, e.g., tree growth rate. At both sites, CO2 and energy fluxes have been measured with the eddy covariance method over the course of 4 years, but not simultaneously. We have also built at both sites an automatic system consisting of six transparent closed chambers which collect data on the CO2 exchange of the forest floor vegetation (including tree roots) and soil around the year. This enables us to quantify the carbon uptake potential of the ground layer and the peat decomposition rates and helps us to understand the differences between the sites. The results show that the pine and dwarf-shrub-dominated site (nutrient-poor) is a large CO2 sink. The site with a mixture of spruce, birch and pine and lesser ground vegetation (nutrient-rich), on the contrary, has a close-to-neutral CO2 balance, despite the much higher tree growth rate there. In this presentation we will compare the general dynamics and climatic responses of CO2 exchange at the sites, compare the magnitude and factors causing interannual variation, and discuss potential reasons

  9. North Sea coastal peatlands - is a climate-smart revival possible?

    Science.gov (United States)

    van Huissteden, Ko; Lippmann, Tanya; Hendriks, Dimmie; Heijmans, Monique

    2017-04-01

    Coastal peatlands around the southern North Sea basin have been very widespread in the past, but centuries-long drainage and exploitation for agriculture and fuel has decreased the peatland area strongly. It has resulted in severe soil subsidence with adverse effects on flood safety and water quality, and large scale emission of CO2. However, the remedy of rewetting of drained peatlands that is often proposed, has uncertain outcomes as it may reduce CO2 emission, but enhance CH4 emission, in some cases dramatically. We present greenhouse gas balance examples from two peatland restoration experiments in the Netherlands. These are experiments with nature conservation as primary goal. These experiments show that the type of management of vegetation may have a very strong influence on the CH4 emission. A nutrient-rich wetland dominated by Typha sp. showed sustained, high emission of CH4 over many years. By contrast, a site where nutrient-rich topsoil was removed and a mesotrophic fen-like vegetation was established, showed very minor CH4 emission. The high emissions at the Typha site appears to result from a recently deposited peat layer of very labile organic matter. A third control site with lower water table and agricultural grassland showed considerably higher CO2 emission than the two nature conservation sites. The data from this site also shows the potential effects of climate extremes: an exceptionally warm and dry period in September 2016 showed an almost doubling of CO2 emission with respect to normal summer conditions. The future of coastal peatlands is attracting more attention from policy and spatial planning. Besides a return to (semi)natural peatland vegetation, there is a growing interest in agricultural products that allow a high water table (paludiculture). However, the effects of land use change on the peat greenhouse gas balance are very poorly known. This calls for more extensive quantification of the greenhouse gas balance under various management

  10. Drainage in Shallow Peatlands of Marginal Upland Landscapes: DOC Losses from High Flow Events

    Science.gov (United States)

    Grand-Clement, E.; Anderson, K.; Luscombe, D.; Gatis, N.; Benaud, P.; Brazier, R.

    2013-12-01

    Peatlands are widely represented in northern Europe, especially in the UK. In the South West of England (i.e. Exmoor, Dartmoor and Bodmin moors), climate change puts their existence under threat: according to recent modelling work, marginal peatlands are highly vulnerable to future temperature and precipitation change and are likely to be the first to disappear from as early as 2050. Additionally, peat cutting and intensive drainage for agricultural reclamation in the 19th and 20th century, have modified the hydrological behaviour of these shallow peatlands and dried out the upper layers, causing oxidation, erosion and vegetation change. Such anthropogenic interventions directly impact on the storage of carbon, but also the provision of other ecosystem services, such as the supply of drinking water, and the support of specific and rare habitats. Large restoration programs involving the blocking of drainage ditches are currently under way throughout the UK but, to date, little is known about the consequences of such management approaches on overall Carbon stocks, and whether the restoration can revert ecosystems back to a state similar to that of undisturbed peatlands. In this context, Exmoor is particularly vulnerable due to its location at the southernmost margin of the UK peatlands' geographical extent, and its dense network of drainage ditches putting pressure on already very shallow peat resources. We hypothesise that monitoring of these peatlands may provide an ';early warning system' for climatic impacts that could affect more northerly sites in years to come, as climates change more significantly. The aim of this study is to look at the current impact of peatland degradation on water quality on Exmoor during rainfall-runoff events. Our experimental approach employs detailed, high resolution monitoring of selected ditches that are representative of damaged conditions on Exmoor, from small- (30 x 30cm ditches) through medium- (50x50cm), large- (1-2m ditches

  11. In Situ Denitrification and Biological Nitrogen Fixation Under Enhanced Atmospheric Reactive Nitrogen Deposition in UK Peatlands

    Science.gov (United States)

    Ullah, Sami; Saiz Val, Ernesto; Sgouridis, Fotis; Peichl, Matthias; Nilsson, Mats

    2017-04-01

    Dinitrogen (N2) and nitrous oxide (N2O) losses due to denitrification and biological N2 fixation (BNF) are the most uncertain components of the nitrogen (N) cycle in peatlands under enhanced atmospheric reactive nitrogen (Nr) deposition. This uncertainty hampers our ability to assess the contribution of denitrification to the removal of biologically fixed and/or atmospherically deposited Nr in peatlands. This uncertainty emanates from the difficulty in measuring in situ soil N2 and N2O production and consumption in peatlands. In situ denitrification and its contribution to total N2O flux was measured monthly between April 2013 and October 2014 in peatlands in two UK catchments. An adapted 15N-Gas Flux method1 with low level addition of 15N tracer (0.03 ± 0.005 kg 15N ha-1) was used to measure denitrification and its contribution to net N2O production (DN2O/TN2O). BNF was measured in situ through incubation of selected sphagnum species under 15N2 gas tracer. Denitrification2 varied temporally and averaged 8 kg N-N2 ha-1 y-1. The contribution of denitrification was about 48% to total N2O flux3 of 0.05 kg N ha-1 y-1. Soil moisture, temperature, ecosystem respiration, pH and mineral N content mainly regulated the flux of N2 and N2O. Preliminary results showed suppression of BNF, which was 1.8 to 7 times lower in peatland mosses exposed to ˜15 to 20 kg N ha-1 y-1 Nr deposition in the UK than in peatland mosses in northern Sweden with background Nr deposition. Overall, the contribution of denitrification to Nr removal in the selected peatlands was ˜50% of the annual Nr deposition rates, making these ecosystems vulnerable to chronic N saturation. These results point to a need for a more comprehensive annual BNF measurement to more accurately account for total Nr input into peatlands and its atmospheric loss due to denitrification. References Sgouridis F, Stott A & Ullah S, 2016. Application of the 15N-Gas Flux method for measuring in situ N2 and N2O fluxes due to

  12. Community based ecological restoration of peatland in Central Mongolia for climate change mitigation and adaptation

    Science.gov (United States)

    Minayeva, Tatiana; Chultem, Dugarjav; Grootjans, Ab; Yamkhin, Jambaljav; Sirin, Andrey; Suvorov, Gennady; Batdorj, Oyunbileg; Tsamba, Batdorj

    2017-04-01

    Peatlands cover almost 2 % of Mongolia. They play crucial role in regulation of key natural processes in ecosystems and provide unique resources to maintain traditional way of life and livelihoods of herders. During the last decades, Mongolian peatlands severely degraded both due to the climate related events and due to overgrazing. The peat degradation causes significant losses of carbon store, GHG emissions and is followed by changes in water balance and water composition. The issue arises if such a type of ecosystems as peatlands could be a subject for ecosystem restoration in this arid and subhumid climate. Could it be considered as measure for climate change mitigation and adaptation? With funding opportunities from the Asian Development Bank a pilot project for peatland restoration had been launched in 2016 in Khashaat soum, Arkhangai aimag in Central Mongolia. The pilot aimed to merge local interests of herders with global targets of climate change mitigation. The following questions are addressed: what are the losses of natural functions and ecosystem services of peatland; what are expectations and demands of local communities and incentives for their involvement; how should and could look the target ecosystem; what are the technical solutions in order to achieve the target ecosystem characteristics; and what are the parameters for monitoring to assess the success of the project? The comprehensive baseline study addressed both natural and social aspects. The conclusions are: most of peat in the study area had been mineralised and has turned to organic rich soil with carbon content between 20 to 40 %, the key sources of water - small springs - are partly destroyed by cattle; the permafrost disappeared in this area and could not be the subject for restoration; local herders understand the value of peatland as water source and had carried out some voluntary activities for water storage and regulation such as dam construction; nevertheless there is no

  13. Drained peatlands used for extraction and agriculture: biogeochemical status with special attention to greenhouse gas fluxes and rewetting

    Science.gov (United States)

    Sirin, Andrey; Chistotin, Maxim; Suvorov, Gennady; Glagolev, Mikhail; Kravchenko, Irina; Minaeva, Tatiana

    2010-05-01

    Many peatlands previously drained for peat extraction or utilized for agriculture (directly or after partial cutoff) are left abandoned during last decades in Europe, and especially in its eastern part. In the European part of Russia alone, several million hectares of peatlands have been modified for peat extraction and agriculture by direct water level draw-down and nowadays are not under use by economic reasons. This makes up one of the most serious and urgent problems of wise use and management of peatlands in these regions with serious feedback to people, environment and economy (Quick Scan of Peatlands in Central and Eastern Europe, 2009). Drainage for agriculture leads to peat oxidation resulting in substantial emissions of greenhouse gases (carbon dioxide and sometimes nitrous oxide) to the atmosphere. Together with peat fires this is the most significant negative input of peatland degradation to climate change (Assessment on Peatlands Biodiversity and Climate Change, 2008; Peatlands and Climate Change, 2008). Besides that, dehydrated peatlands often release methane. Starting from 2003, the effect of drainage and subsequent utilization of peatlands on the emissions of carbon dioxide and methane was studied in Tomsk region (West Siberia) during the summer-fall periods (Glagolev et al. 2008). The measurements were conducted by chamber method at peatlands drained for use as croplands (now partly being fallows) and peat cutting (currently abandoned or reclaimed for forest planting, haying, or pasturing), as well as at a wide range of undrained oligotrophic, mesotrophic, and eutrophic mires and burnt mire areas of different regeneration stages. The statistical analysis of data from a large number of study sites indicated a higher release of carbon dioxide from disturbed peatlands compared to undrained ones. At the same time some drained peatlands had considerable methane emission rates, additionally enhanced by the intensive efflux from the surface of drainage

  14. Dominant Tree Species and Soil Type Affect the Fungal Community Structure in a Boreal Peatland Forest.

    Science.gov (United States)

    Sun, Hui; Terhonen, Eeva; Kovalchuk, Andriy; Tuovila, Hanna; Chen, Hongxin; Oghenekaro, Abbot O; Heinonsalo, Jussi; Kohler, Annegret; Kasanen, Risto; Vasander, Harri; Asiegbu, Fred O

    2016-05-01

    Boreal peatlands play a crucial role in global carbon cycling, acting as an important carbon reservoir. However, little information is available on how peatland microbial communities are influenced by natural variability or human-induced disturbances. In this study, we have investigated the fungal diversity and community structure of both the organic soil layer and buried wood in boreal forest soils using high-throughput sequencing of the internal transcribed spacer (ITS) region. We have also compared the fungal communities during the primary colonization of wood with those of the surrounding soils. A permutational multivariate analysis of variance (PERMANOVA) confirmed that the community composition significantly differed between soil types (P< 0.001) and tree species (P< 0.001). The distance-based linear models analysis showed that environmental variables were significantly correlated with community structure (P< 0.04). The availability of soil nutrients (Ca [P= 0.002], Fe [P= 0.003], and P [P= 0.003]) within the site was an important factor in the fungal community composition. The species richness in wood was significantly lower than in the corresponding soil (P< 0.004). The results of the molecular identification were supplemented by fruiting body surveys. Seven of the genera of Agaricomycotina identified in our surveys were among the top 20 genera observed in pyrosequencing data. Our study is the first, to our knowledge, fungal high-throughput next-generation sequencing study performed on peatlands; it further provides a baseline for the investigation of the dynamics of the fungal community in the boreal peatlands. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. Monitoring the effect of restoration measures in Indonesian peatlands by radar satellite imagery.

    Science.gov (United States)

    Jaenicke, J; Englhart, S; Siegert, F

    2011-03-01

    In the context of the ongoing climate change discussions the importance of peatlands as carbon stores is increasingly recognised in the public. Drainage, deforestation and peat fires are the main reasons for the release of huge amounts of carbon from peatlands. Successful restoration of degraded tropical peatlands is of high interest due to their huge carbon store and sequestration potential. The blocking of drainage canals by dam building has become one of the most important measures to restore the hydrology and the ecological function of the peat domes. This study investigates the capability of using multitemporal radar remote sensing imagery for monitoring the hydrological effects of these measures. The study area is the former Mega Rice Project area in Central Kalimantan, Indonesia, where peat drainage and forest degradation is especially intense. Restoration measures started in July 2004 by building 30 large dams until June 2008. We applied change detection analysis with more than 80 ENVISAT ASAR and ALOS PALSAR images, acquired between 2004 and 2009. Radar signal increases of up to 1.36 dB show that high frequency multitemporal radar satellite imagery can be used to detect an increase in peat soil moisture after dam construction, especially in deforested areas with a high density of dams. Furthermore, a strong correlation between cross-polarised radar backscatter coefficients and groundwater levels above -50 cm was found. Monitoring peatland rewetting and quantifying groundwater level variations is important information for vegetation re-establishment, fire hazard warning and making carbon emission mitigation tradable under the voluntary carbon market or REDD (Reducing Emissions from Deforestation and Degradation) mechanism. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Impact of an abrupt cooling event on interglacial methane emissions in northern peatlands

    Directory of Open Access Journals (Sweden)

    S. Zürcher

    2013-03-01

    Full Text Available Rapid changes in atmospheric methane (CH4, temperature and precipitation are documented by Greenland ice core data both for glacial times (the so called Dansgaard-Oeschger (D-O events as well as for a cooling event in the early Holocene (the 8.2 kyr event. The onsets of D-O warm events are paralleled by abrupt increases in CH4 by up to 250 ppb in a few decades. Vice versa, the 8.2 kyr event is accompanied by an intermittent decrease in CH4 of about 80 ppb over 150 yr. The abrupt CH4 changes are thought to mainly originate from source emission variations in tropical and boreal wet ecosystems, but complex process oriented bottom-up model estimates of the changes in these ecosystems during rapid climate changes are still missing. Here we present simulations of CH4 emissions from northern peatlands with the LPJ-Bern dynamic global vegetation model. The model represents CH4 production and oxidation in soils and transport by ebullition, through plant aerenchyma, and by diffusion. Parameters are tuned to represent site emission data as well as inversion-based estimates of northern wetland emissions. The model is forced with climate input data from freshwater hosing experiments using the NCAR CSM1.4 climate model to simulate an abrupt cooling event. A concentration reduction of ~10 ppb is simulated per degree K change of mean northern hemispheric surface temperature in peatlands. Peatland emissions are equally sensitive to both changes in temperature and in precipitation. If simulated changes are taken as an analogy to the 8.2 kyr event, boreal peatland emissions alone could only explain 23% of the 80 ppb decline in atmospheric methane concentration. This points to a significant contribution to source changes from low latitude and tropical wetlands to this event.

  17. Peatland use and transport of particulate organic matter in boreal headwater catchments

    Science.gov (United States)

    Marttila, Hannu; Karjalainen, Satu-Maaria; Nieminen, Mika; Kløve, Bjørn

    2014-05-01

    Peatland use can cause increased transport of particulate organic matter (POM) causing deteriorated water quality and especially siltation of stream beds. Even though topic has gained major attention among stakeholders it has received only minor efforts to solve the main sources and properties of transported particles. The development of effective management practices and evaluation of purification efficiency demands understanding of the sources of particulate matter in peat dominated catchments with various land uses and hydrological conditions. The objectives of this study were: (1) to determinate physical properties of POM in headwater brooks affected by different peatland uses, and; (2) to identity the sources of transported material by using sediment fingerprinting methods. For this purpose, two headwater catchments under peat extraction and peatland forestry land uses with 8 sampling points were monitored for 2 years using time integrated suspended sediment samplers. Data was completed by gap samples from 50 other headwater locations with different upstream land uses: pristine, peatland forestry and peat extraction. For the sources analysis, disturbed topsoil, stream bed sediment, banks of ditches and brooks, algae and various vegetation types were identified as the potential sediment sources. Stable isotopes (δ13C, δ15N) and C/N ratio were analyzed to discriminate between the possible sources. Results are further scaled against different land uses, landscape elements and seasonal hydrological conditions in headwaters. This paper presents the preliminary results from a two year study aiming to show various patterns in transport of POM in boreal headwater catchments. Due to strong land-water relationship in headwaters, further information on the properties of particles is needed to assess the downstream impacts of land use.

  18. Regional variation in the biogeochemical and physical characteristics of natural peatland pools.

    Science.gov (United States)

    Turner, T Edward; Billett, Michael F; Baird, Andy J; Chapman, Pippa J; Dinsmore, Kerry J; Holden, Joseph

    2016-03-01

    Natural open-water pools are a common feature of northern peatlands and are known to be an important source of atmospheric methane (CH4). Pool environmental variables, particularly water chemistry, vegetation community and physical characteristics, have the potential to exert strong controls on carbon cycling in pools. A total of 66 peatland pools were studied across three regions of the UK (northern Scotland, south-west Scotland, and Northern Ireland). We found that within-region variability of pool water chemistry was low; however, for many pool variables measured there were significant differences between regions. PCA analysis showed that pools in SW Scotland were strongly associated with greater vegetative cover and shallower water depth which is likely to increase dissolved organic carbon (DOC) mineralisation rates, whereas pools in N Scotland were more open and deeper. Pool water DOC, particulate organic carbon and dissolved CH4 concentrations were significantly different between regions. Pools in Northern Ireland had the highest concentrations of DOC (mean=14.5 mg L(-1)) and CH4 (mean=20.6 μg C L(-1)). Chloride and sulphate concentrations were significantly higher in the pools in N Scotland (mean values 26.3 and 2.40 mg L(-1), respectively) than elsewhere, due to a stronger marine influence. The ratio of UV absorbance at 465 nm to absorbance at 665 nm for pools in Northern Ireland indicated that DOC was sourced from poorly humified peat, potentially increasing the bioavailability and mineralisation of organic carbon in pools compared to the pools elsewhere. This study, which specifically aims to address a lack of basic biogeochemical knowledge about pool water chemistry, clearly shows that peatland pools are highly regionally variable. This is likely to be a reflection of significant regional-scale differences in peatland C cycling. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Soil greenhouse gas emissions from afforested organic soil croplands and cutaway peatlands

    International Nuclear Information System (INIS)

    Maekiranta, P.; Hytoenen, J.; Aro, L.

    2007-01-01

    The effects of land-use and land-use change on soil greenhouse gas (GHG) fluxes are of concern due to Kyoto Protocol requirements. To quantify the soil GHG-fluxes of afforested organic soils in Finland, chamber measurements of soil CO 2 , CH 4 and N 2 O fluxes were made during the years 2002 to 2005 on twelve organic soil cropland and six cutaway peatland sites afforested 9 to 35 years ago. The annual soil CO 2 effluxes were statistically modelled using soil temperature as the driving variable and the annual CH 4 and N 2 O fluxes were estimated using the average fluxes during the measurement period. Soil CO 2 effluxes on afforested organic soil croplands varied from 207 to 539 g CO 2 -C m -2 a -1 and on cutaway peatlands from 276 to 479 g CO 2 -C m -2 a -1 . Both the afforested organic soil cropland and cutaway peatland sites acted mainly as small sinks for CH 4 ; the annual flux ranged from -0.32 to 0.61 g CH 4 -C m -2 . Afforested organic croplands emitted more N 2 O (from 0.1 to over 3.0 g N 2 O-N m -2 a -1 ) than cutaway peatland sites (from 0.01 to 0.48 g N 2 O-N m -2 a -1 ). Due to the decrease in soil CO 2 efflux, and no change in CH 4 and N 2 O fluxes, afforestation of organic croplands appears to decrease the greenhouse impact of these lands. (orig.)

  20. Large interannual variability in net ecosystem carbon dioxide exchange of a disturbed temperate peatland.

    Science.gov (United States)

    Aslan-Sungur, Guler; Lee, Xuhui; Evrendilek, Fatih; Karakaya, Nusret

    2016-06-01

    Peatland ecosystems play an important role in the global carbon (C) cycle as significant C sinks. However, human-induced disturbances can turn these sinks into sources of atmospheric CO2. Long-term measurements are needed to understand seasonal and interannual variability of net ecosystem CO2 exchange (NEE) and effects of hydrological conditions and their disturbances on C fluxes. Continuous eddy-covariance measurements of NEE were conducted between August 2010 and April 2014 at Yenicaga temperate peatland (Turkey), which was drained for agricultural usage and for peat mining until 2009. Annual NEE during the three full years of measurement indicated that the peatland acted as a CO2 source with large interannual variability, at rates of 246, 244 and 663 g Cm(-2)yr(-1) for 2011, 2012, and 2013 respectively, except for June 2011, and May to July 2012. The emission strengths were comparable to those found for severely disturbed tropical peatlands. The peak CO2 emissions occurred in the dry summer of 2013 when water table level (WTL) was below a threshold value of -60 cm and soil water content (SCW) below a threshold value of 70% by volume. Water availability index was found to have a stronger explanatory power for variations in monthly ecosystem respiration (ER) than the traditional water status indicators (SCW and WTL). Air temperature, evapotranspiration and vapor pressure deficient were the most significant variables strongly correlated with NEE and its component fluxes of gross primary production and ER. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Temporal Changes in Photochemically Labile DOM and Implications for Carbon Budgets in Peatland Aquatic Systems

    Science.gov (United States)

    Pickard, A.

    2015-12-01

    Aquatic systems in peatland catchments are subject to high loading of dissolved organic matter (DOM) from surrounding terrestrial environments. However the significance of photochemical transformation of DOM in peatland carbon budgets remains poorly constrained. In this study UV irradiation experiments were conducted on water samples collected over one year from two contrasting systems in Scotland: a stream draining a peatland with high levels of DOM and a reservoir draining a peat catchment with low levels of DOM. Further samples were collected from the high DOM system during two storm events. After experimental exposure, optical and chemical analyses were employed to determine photochemical lability of the DOM pool. At both sites irradiation-induced decreases in dissolved organic carbon (DOC) as a percentage of the total carbon pool were greatest in winter, suggesting that DOM was depleted in photo-reactive molecules in summer. Seasonal variability in DOC was high at the stream site and was positively correlated with CO₂ and CO photoproduction (r2 = 0.81 and 0.83, respectively; pLignin phenol analyses indicate considerable contribution of peat to the DOM pool at the stream site, particularly during summer. Whilst DOC concentrations did not vary greatly during storm events, UV-Vis absorbance indicators did, signifying changing DOM source material from activation of different hydrological pathways. The most photo-reactive DOM occurred 5-10 hours after peak discharge, suggesting that storms replenish photochemically labile DOM in headwater streams. Conservative estimates using data from this study suggest that up to 7% of the DOM pool of peatland streams can be lost (primarily as CO₂ and CO) upon exposure to 8 hours of environmentally representative UV irradiation. Further investigation in field campaigns under natural UV exposure are underway to assess the importance of photodegradation of DOM as a loss pathway of carbon based gases from aquatic systems.

  2. Impacts of peatland and permafrost changes on the terrestrial carbon storage over the last 21 ka

    Science.gov (United States)

    Spahni, Renato; Stocker, Benjamin D.; Joos, Fortunat

    2014-05-01

    Paleoclimate records and global climate-carbon cycle models suggest a net increase in land carbon (C) storage between 300 and 700 Pg C (1 Pg C = 1015 g C) during the transition from the last glacial maximum (LGM), the Holocene up to the preindustrial period. Peat accumulation rate records imply an increase in peatland C of ~600 Pg C over the course of the Holocene. In high northern latitudes mineral and organic soils are subject to permafrost formation, which is believed to have been more extensive during glacial compared to interglacial periods. Soil C in permafrost regions represents the largest inert C pool on land at present. The spatio-temporal evolution, however, of C stocks in soils and vegetation remains poorly quantified and is uncertain. Here, the Land surface Processes and eXchanges (LPX-Bern) Dynamic Global Vegetation Model is applied in transient simulations to explore the evolution of permafrost, peatland and vegetation C over the last 21'000 years. The model is forced with temperature and precipitation output from the Trace-21ka climate simulation, and dynamically simulates the formation and disappearance of peatlands and permafrost soils, vegetation distribution and C stocks. Results indicate that peatlands and permfrost areas existed further south in the LGM, in agreement with available proxy information, and that their associated C was lost during the transition into the Holocene. The simulated loss of inert C is over-compensated by vegetation regrowth. The timing of the C relocation on land is compared to observational evidence from paleoclimate archives and estimates from ocean C inventory changes.

  3. Vegetation exerts a greater control on litter decomposition than climate warming in peatlands.

    Science.gov (United States)

    Ward, Susan E; Orwin, Kate H; Ostle, Nicholas J; Briones, J I; Thomson, Bruce C; Griffiths, Robert I; Oakley, Simon; Quirk, Helen; Bardget, Richard D

    2015-01-01

    Historically, slow decomposition rates have resulted in the accumulation of large amounts of carbon in northern peatlands. Both climate warming and vegetation change can alter rates of decomposition, and hence affect rates of atmospheric CO2 exchange, with consequences for climate change feedbacks. Although warming and vegetation change are happening concurrently, little is known about their relative and interactive effects on decomposition processes. To test the effects of warming and vegetation change on decomposition rates, we placed litter of three dominant species (Calluna vulgaris, Eriophorum vaginatum, Hypnum jutlandicum) into a peatland field experiment that combined warming.with plant functional group removals, and measured mass loss over two years. To identify potential mechanisms behind effects, we also measured nutrient cycling and soil biota. We found that plant functional group removals exerted a stronger control over short-term litter decomposition than did approximately 1 degrees C warming, and that the plant removal effect depended on litter species identity. Specifically, rates of litter decomposition were faster when shrubs were removed from the plant community, and these effects were strongest for graminoid and bryophyte litter. Plant functional group removals also had strong effects on soil biota and nutrient cycling associated with decomposition, whereby shrub removal had cascading effects on soil fungal community composition, increased enchytraeid abundance, and increased rates of N mineralization. Our findings demonstrate that, in addition to litter quality, changes in vegetation composition play a significant role in regulating short-term litter decomposition and belowground communities in peatland, and that these impacts can be greater than moderate warming effects. Our findings, albeit from a relatively short-term study, highlight the need to consider both vegetation change and its impacts below ground alongside climatic effects when

  4. The role of climate change in regulating Arctic permafrost peatland hydrological and vegetation change over the last millennium

    Science.gov (United States)

    Zhang, Hui; Piilo, Sanna R.; Amesbury, Matthew J.; Charman, Dan J.; Gallego-Sala, Angela V.; Väliranta, Minna M.

    2018-02-01

    Climate warming has inevitable impacts on the vegetation and hydrological dynamics of high-latitude permafrost peatlands. These impacts in turn determine the role of these peatlands in the global biogeochemical cycle. Here, we used six active layer peat cores from four permafrost peatlands in Northeast European Russia and Finnish Lapland to investigate permafrost peatland dynamics over the last millennium. Testate amoeba and plant macrofossils were used as proxies for hydrological and vegetation changes. Our results show that during the Medieval Climate Anomaly (MCA), Russian sites experienced short-term permafrost thawing and this induced alternating dry-wet habitat changes eventually followed by desiccation. During the Little Ice Age (LIA) both sites generally supported dry-hummock habitats, at least partly driven by permafrost aggradation. However, proxy data suggest that occasionally, MCA habitat conditions were drier than during the LIA, implying that evapotranspiration may create important additional eco-hydrological feedback mechanisms under warm conditions. All sites showed a tendency towards dry conditions as inferred from both proxies starting either from ca. 100 years ago or in the past few decades after slight permafrost thawing, suggesting that recent warming has stimulated surface desiccation rather than deeper permafrost thawing. This study shows links between two important controls over hydrology and vegetation changes in high-latitude peatlands: direct temperature-induced surface layer response and deeper permafrost layer-related dynamics. These data provide important backgrounds for predictions of Arctic permafrost peatlands and related feedback mechanisms. Our results highlight the importance of increased evapotranspiration and thus provide an additional perspective to understanding of peatland-climate feedback mechanisms.

  5. Variations in diatom communities at genus and species levels in peatlands (central China) linked to microhabitats and environmental factors.

    Science.gov (United States)

    Chen, Xu; Bu, Zhaojun; Stevenson, Mark A; Cao, Yanmin; Zeng, Linghan; Qin, Bo

    2016-10-15

    Peatlands are a specialized type of organic wetlands, fulfilling essential roles as global carbon sinks, headwaters of rivers and biodiversity hotspots. Despite their importance, peatlands are being lost at an alarming rate due to human disturbance and climatic variability. Both the scientific and regulatory communities have focused considerable attention on developing tools for assessing environmental changes in peatlands. Diatoms are widely used in biomonitoring studies of lakes, rivers and streams as they have high abundance, specific ecological preferences and can respond rapidly to environmental change. However, diatom-based assessment studies in peatlands remain limited. The aims of this study were to identify indicator species and genus for three types of habitats (hummocks, hollows and ditch edges) in peatlands (central China), to examine the effects of physiochemical factors on diatom composition at genus and species levels, and to compare the efficiency of species- and genus-level identification in environmental assessment. Our results revealed that hummocks were characterized by drought-tolerant diatoms, while hollows were dominated by species and genus preferring wet conditions. Ditch edges were characterized by diatoms with different life strategies. Depth to water table, redox potential, conductivity and calcium were significant predictors of both genus- and species-level composition. According to ordination analyses, pH was not correlated with species composition while it was a significant factor associated with genus-level composition. Genus-level composition outperformed species composition in describing the response of diatoms to environmental variables. Our results indicate that diatoms can be useful environmental indicators of peatlands, and show that genus-level taxonomic analysis can be a potential tool for assessing environmental change in peatlands. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. The Effectiveness of Ameliorant to Increase Carbon Stock of Oilpalm and Rubber Plantation on Peatland

    Directory of Open Access Journals (Sweden)

    Ai Dariah

    2015-05-01

    Full Text Available Application of peatland amelioration can improve soil quality, reduce GHG emissions, and increase carbon sequestration. The research aimed to study the effect of peatland amelioration on oil palm and rubber carbon stock improvement. Research was conducted from August 2013 until June 2014. The researches on oil palm were done in Arang-arang Village, Kumpeh Subdistrict, Muaro Jambi District, and in Lubuk Ogong Village, Bandar Seikijang Sub-district, Pelalawan District. Both sites are in Jambi and Riau Province. The research on rubber was done in Jabiren Village, Jabiren Raya Subdistrict, Pulang Pisau District, Central Kalimantan Province. The study used a Randomized Completely Block Design (RCBD, in four treatments and four replications. The treatments were pugam (peat fertilizer enriched by polyvalent cation, manure; empty fruit bunch compost, and control (no application. The measurement of C stock was performed 10 months after application using nondestructive methods. The results showed that peatland amelioration treatments had no significant effect to improve C stock on oil palm in 6 years old and 7 years old of rubber. After 10 months of amelioration application, the treatments increased C - stock of oil palm and rubber were 2.1-2.4 Mg ha-1 and 5-11 Mg ha-1, respectively. Longer time observation may be needed to study the effect of ameliorant on C-stock of annual crops.

  7. Financial assessment of oil palm cultivation on peatland in Selangor, Malaysia

    Directory of Open Access Journals (Sweden)

    M.N. Noormahayu

    2009-02-01

    Full Text Available Oil palm plantations on peat soils are generally believed to have greater environmental impacts than those on other soil types. Nonetheless, Malaysia operates substantial incentives to maximise palm oil production, which in practice encourage the establishment of plantations on peatland. This paper explores the social and economic basis of oil palm cultivation on one peatland estate at Sungai Panjang in the state of Selangor, peninsular Malaysia. Data were obtained by conducting a questionnaire survey of 200 farmers who cultivate oil palm on peat soil. Some of the data were cross-tabulated against farmers’ ages in order to identify any age-related trends in education level, the area of land farmed, annual income and knowledge about oil palm cultivation. The Cobb-Douglas production function was used to model the financial output from oil palm in terms of the costs of chemical inputs and labour. The results indicated that cultivation of this crop gives decreasing returns to scale on peatland in Sungai Panjang, and that chemical inputs are more important than labour cost in determining the level of financial output. Finally, the financial viability of oil palm cultivation for farmers was assessed by calculating three financial indicators (NPV, BCR and IRR. This can be a profitable investment so long as growth conditions, costs, selling price and interest rate do not fluctuate substantially. Greater annual returns can be achieved over 20–25 years than over shorter periods, especially of less than 10 years.

  8. Characterizing Early Succession Following Wildfires at Different Severities in Boreal Bog and Fen Peatlands

    Science.gov (United States)

    Ernst, E. J.; Bourgeau-Chavez, L. L.; Kane, E. S.; Wagenbrenner, J. W.; Endres, S.

    2016-12-01

    The Arctic-boreal region is experiencing changes in climate, trending toward warmer summers, resulting in a greater occurrence of wildfires with longer burning periods and higher intensities. Drought-like conditions have dried surface fuels, leading to a higher probability of ignition, even in lowland peatlands. Previous work has been done to characterize post-fire succession rates in Arctic-boreal upland sites, but much less is known of fire effects and early successional dynamics in lowlands. Wildland fires are the number one disturbance in Canada's Northwest Territories (NWT), which characteristically burn at high intensities with large flame fronts, and result in some of the biggest wildfires in the world. Areas surrounding the Great Slave Lake, NWT—including parts of the Taiga Plains, Taiga Shield, and Boreal Plains ecozones—experienced exceptional wildfire activity in 2014 and 2015. We characterized burn severity of the bog and fen peat surface and canopy layers at several burned sites. To determine if the severe ground or crown wildfires were stand-replacing events, we characterized post-fire vegetation in peatlands in 2015 and 2016 based on seedling regeneration. We stratified sites according to estimated water residence times across the three ecozones and made comparisons between data collected at the same sites across years. This work adds much needed context for post-fire succession in boreal peatland ecosystems, as the susceptibility of these systems to burning will continue to increase with a warming climate.

  9. Predicting Vascular Plant Diversity in Anthropogenic Peatlands: Comparison of Modeling Methods with Free Satellite Data

    Directory of Open Access Journals (Sweden)

    Ivan Castillo-Riffart

    2017-07-01

    Full Text Available Peatlands are ecosystems of great relevance, because they have an important number of ecological functions that provide many services to mankind. However, studies focusing on plant diversity, addressed from the remote sensing perspective, are still scarce in these environments. In the present study, predictions of vascular plant richness and diversity were performed in three anthropogenic peatlands on Chiloé Island, Chile, using free satellite data from the sensors OLI, ASTER, and MSI. Also, we compared the suitability of these sensors using two modeling methods: random forest (RF and the generalized linear model (GLM. As predictors for the empirical models, we used the spectral bands, vegetation indices and textural metrics. Variable importance was estimated using recursive feature elimination (RFE. Fourteen out of the 17 predictors chosen by RFE were textural metrics, demonstrating the importance of the spatial context to predict species richness and diversity. Non-significant differences were found between the algorithms; however, the GLM models often showed slightly better results than the RF. Predictions obtained by the different satellite sensors did not show significant differences; nevertheless, the best models were obtained with ASTER (richness: R2 = 0.62 and %RMSE = 17.2, diversity: R2 = 0.71 and %RMSE = 20.2, obtained with RF and GLM respectively, followed by OLI and MSI. Diversity obtained higher accuracies than richness; nonetheless, accurate predictions were achieved for both, demonstrating the potential of free satellite data for the prediction of relevant community characteristics in anthropogenic peatland ecosystems.

  10. Ozone effects on Sphagnum mosses, carbon dioxide exchange and methane emission in boreal peatland microcosms

    International Nuclear Information System (INIS)

    Niemi, Riikka; Holopainen, Toini; Martikainen, Pertti J.; Silvola, Jouko

    2002-01-01

    Microcosms of a boreal peatland originating from an oligotrophic fen in Eastern Finland were fumigated under four ozone concentrations (0, 50, 100 and 150 ppb O 3 ) in laboratory growth chambers during two separate experiments (autumn and summer) for 4 and 6 weeks, respectively. Ozone effects on Sphagnum mosses and the fluxes of carbon dioxide and methane were evaluated. In both experiments, the three Sphagnum species studied showed only a few significant responses to ozone. In the autumn experiment, membrane permeability of S. angustifolium, measured as conductivity and magnesium leakage, was significantly higher under ozone fumigation (P=0.005 and 2 exchange during the 6-week-long summer experiment, but dark ecosystem respiration was transiently increased by ozone concentration of 100 ppb after 14 days of exposure (P<0.05). Fumigation with 100 ppb of ozone, however, more than doubled (P<0.05) methane emission from the peatland monoliths. Our results suggest that increasing tropospheric ozone concentration may cause substantial changes in the carbon gas cycling of boreal peatlands, even though these changes are not closely associated with the changes in Sphagnum vegetation

  11. Contrasting growth responses of dominant peatland plants to warming and vegetation composition.

    Science.gov (United States)

    Walker, Tom N; Ward, Susan E; Ostle, Nicholas J; Bardgett, Richard D

    2015-05-01

    There is growing recognition that changes in vegetation composition can strongly influence peatland carbon cycling, with potential feedbacks to future climate. Nevertheless, despite accelerated climate and vegetation change in this ecosystem, the growth responses of peatland plant species to combined warming and vegetation change are unknown. Here, we used a field warming and vegetation removal experiment to test the hypothesis that dominant species from the three plant functional types present (dwarf-shrubs: Calluna vulgaris; graminoids: Eriophorum vaginatum; bryophytes: Sphagnum capillifolium) contrast in their growth responses to warming and the presence or absence of other plant functional types. Warming was accomplished using open top chambers, which raised air temperature by approximately 0.35 °C, and we measured air and soil microclimate as potential mechanisms through which both experimental factors could influence growth. We found that only Calluna growth increased with experimental warming (by 20%), whereas the presence of dwarf-shrubs and bryophytes increased growth of Sphagnum (46%) and Eriophorum (20%), respectively. Sphagnum growth was also negatively related to soil temperature, which was lower when dwarf-shrubs were present. Dwarf-shrubs may therefore promote Sphagnum growth by cooling the peat surface. Conversely, the effect of bryophyte presence on Eriophorum growth was not related to any change in microclimate, suggesting other factors play a role. In conclusion, our findings reveal contrasting abiotic and biotic controls over dominant peatland plant growth, suggesting that community composition and carbon cycling could be modified by simultaneous climate and vegetation change.

  12. Seasonal changes in Sphagnum peatland testate amoeba communities along a hydrological gradient.

    Science.gov (United States)

    Marcisz, Katarzyna; Lamentowicz, Lukasz; Słowińska, Sandra; Słowiński, Michał; Muszak, Witold; Lamentowicz, Mariusz

    2014-10-01

    Testate amoebae are an abundant and functionally important group of protists in peatlands, but little is known about the seasonal patterns of their communities. We investigated the relationships between testate amoeba diversity and community structure and water table depth and light conditions (shading vs. insolation) in a Sphagnum peatland in Northern Poland (Linje mire) in spring and summer 2010. We monitored the water table at five sites across the peatland and collected Sphagnum samples in lawn and hummock micro-sites around each piezometer, in spring (3 May) and mid-summer (6 August) 2010. Water table differed significantly between micro-sites and seasons (Kruskal-Wallis test, p=0.001). The community structure of testate amoebae differed significantly between spring and summer in both hummock and lawn micro-sites. We recorded a small, but significant drop in Shannon diversity, between spring and summer (1.76 vs. 1.72). Strongest correlations were found between testate amoeba communities and water table lowering and light conditions. The relative abundance of mixotrophic species Hyalosphenia papilio, Archerella flavum and of Euglypha ciliata was higher in the summer. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. Effect of forest drainage on the carbon balance and greenhouse impact of Finnish peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Minkkinen, K.; Laiho, R. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The aim of this project is to produce an estimate of the change in the biomass and peat carbon stores arising from the drainage of peatlands for forestry, and of the change of greenhouse impact of these ecosystems. The study shows that the subsidence of mire surfaces due to drainage has been relatively small, on average about 20 cm. The observed increase in bulk density after drainage is caused by the physical compression of peat and the post-drainage input of organic material in the form of litter production from the above and below ground parts of the tree layer. Oxidative decay of organic matter may have further increased the compaction of peat, especially in fertile sites. When the changes in peat and vegetation carbon stores are summed up, it seems that, within the site types studied, the total impact of drainage to the ecosystem carbon store is close to zero on the nutrient rich sites and clearly positive on the poorer types. Water level drawdown in peatlands after drainage for forestry appears to decrease the greenhouse impact at least for a few hundred years. The estimated changes in all three emission components (CH{sub 4} emissions, CO{sub 2} sink from peatland and CO{sub 2} sequestered in trees) reduce the radiative forcing by approximately similar amounts

  14. Limited contribution of permafrost carbon to methane release from thawing peatlands

    Science.gov (United States)

    Cooper, Mark D. A.; Estop-Aragonés, Cristian; Fisher, James P.; Thierry, Aaron; Garnett, Mark H.; Charman, Dan J.; Murton, Julian B.; Phoenix, Gareth K.; Treharne, Rachael; Kokelj, Steve V.; Wolfe, Stephen A.; Lewkowicz, Antoni G.; Williams, Mathew; Hartley, Iain P.

    2017-07-01

    Models predict that thaw of permafrost soils at northern high latitudes will release tens of billions of tonnes of carbon (C) to the atmosphere by 2100 (refs ,,). The effect on the Earth’s climate depends strongly on the proportion of this C that is released as the more powerful greenhouse gas methane (CH4), rather than carbon dioxide (CO2) (refs ,); even if CH4 emissions represent just 2% of the C release, they would contribute approximately one-quarter of the climate forcing. In northern peatlands, thaw of ice-rich permafrost causes surface subsidence (thermokarst) and water-logging, exposing substantial stores (tens of kilograms of C per square meter, ref. ) of previously frozen organic matter to anaerobic conditions, and generating ideal conditions for permafrost-derived CH4 release. Here we show that, contrary to expectations, although substantial CH4 fluxes (>20 g CH4 m-2 yr-1) were recorded from thawing peatlands in northern Canada, only a small amount was derived from previously frozen C (effect of permafrost thaw on CH4 emissions from northern peatlands.

  15. Effect of forest drainage on the carbon balance and greenhouse impact of Finnish peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J; Minkkinen, K; Laiho, R [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1997-12-31

    The aim of this project is to produce an estimate of the change in the biomass and peat carbon stores arising from the drainage of peatlands for forestry, and of the change of greenhouse impact of these ecosystems. The study shows that the subsidence of mire surfaces due to drainage has been relatively small, on average about 20 cm. The observed increase in bulk density after drainage is caused by the physical compression of peat and the post-drainage input of organic material in the form of litter production from the above and below ground parts of the tree layer. Oxidative decay of organic matter may have further increased the compaction of peat, especially in fertile sites. When the changes in peat and vegetation carbon stores are summed up, it seems that, within the site types studied, the total impact of drainage to the ecosystem carbon store is close to zero on the nutrient rich sites and clearly positive on the poorer types. Water level drawdown in peatlands after drainage for forestry appears to decrease the greenhouse impact at least for a few hundred years. The estimated changes in all three emission components (CH{sub 4} emissions, CO{sub 2} sink from peatland and CO{sub 2} sequestered in trees) reduce the radiative forcing by approximately similar amounts

  16. The effect of increased temperature and nitrogen deposition on decomposition in bogs

    NARCIS (Netherlands)

    Breeuwer, A.J.G.; Heijmans, M.M.P.D.; Robroek, B.J.M.; Limpens, J.; Berendse, F.

    2008-01-01

    Despite their low primary production, ombrotrophic peatlands have a considerable potential to store atmospheric carbon as a result of their extremely low litter decomposition rates. Projected changes in temperature and nitrogen (N) deposition may increase decomposition rates by their positive

  17. Analyzing peatland discharge to streams in an Alaskan Watershed: An integration of end-member mixing analysis and a water balance approach

    Science.gov (United States)

    Some authors report that peatlands do not contribute substantially to flow during the dry season (Boelter & Verry 1977, Ingram 1983, Holden et al. 2004), while others report that watersheds with a higher cover of peatlands produce more flow during droughts (Ackroyd 1967, News...

  18. Bioavailability and radiocarbon age of fluvial dissolved organic matter (DOM) from a northern peatland-dominated catchment: effect of land-use change

    DEFF Research Database (Denmark)

    Hulatt, C.J.; Kaartokallio, H.; Asmala, E.

    2014-01-01

    . Bacterial growth efficiency ranged from 0.11 to 0.26 between areas of different land use, and these relatively low values reflect the humic-rich DOM released from boreal peatland. Despite the range of land-use types studied, including intensive peatland excavation areas, there was no detectable relationship...

  19. Intermediate-scale community-level flux of CO2 and CH4 in a Minnesota peatland: putting the SPRUCE project in a global context

    Science.gov (United States)

    P. J. Hanson; A. L. Gill; X. Xu; J. R. Phillips; D. J. Weston; Randy Kolka; J. S. Riggs; L. A. Hook

    2016-01-01

    Peatland measurements of CO2 and CH4 flux were obtained at scales appropriate to the in situ biological community below the tree layer to demonstrate representativeness of the spruce and peatland responses under climatic and environmental change (SPRUCE) experiment. Surface flux measurements were made using dual open-path...

  20. Multi-year net ecosystem carbon balance at a horticulture-extracted restored peatland

    Science.gov (United States)

    Nugent, Kelly; Strachan, Ian; Strack, Maria

    2017-04-01

    Restoration of previously extracted peatlands is essential to minimize the impact of drainage and peat removal. Best practices restoration methods have been developed that include ditch blocking, site leveling and reintroducing bog vegetation using the moss layer transfer technique. A long term goal of restoration is the return to a peat accumulating ecosystem. Bois-des-Bel is a cool-temperate bog, located in eastern Quebec, Canada, that was vacuum harvested until 1980 and restored in 1999. While several studies have used discrete (chamber) methods to determine the net carbon exchange from rewetted or restored peatlands, ours appears to be the first to have multiple complete years of net ecosystem carbon exchange from a restored northern peatland. An eddy covariance flux tower instrumented with a sonic anemometer and open-path CO2/H2O and CH4 analyzers was operated continuously over three years to produce a robust estimate of net carbon sequestration. Our initial results indicate that this restored peatland was a consistent moderate annual net sink for CO2, a moderate source of CH4 and had low losses of dissolved organic carbon compared to undisturbed northern latitude peatlands. Closed chambers combined with a fast response CO2/H2O/CH4 analyzer were used to investigate ecohydrological controls on net ecosystem exchange of CO2 (NEE) and CH4 flux from the restored fields and remnant ditches at the site. CH4 release was found to be an order of magnitude higher in the ditches compared to the fields, with non-vegetated ditch showing a greater range in flux compared to areas invaded by Typha latifolia. Bubble magnitude and count were highest in the non-vegetated ditch, followed by Typha plots and were undetectable in the restored fields. The latter may be partially attributed to the high cover of Eriophorum vaginatum in the restored fields, plants that have aerenchymous tissue, as well as a much deeper water table level. While the non-vegetated ditch areas were a steady

  1. Greenhouse gas flux measurements in a forestry-drained peatland indicate a large carbon sink

    Directory of Open Access Journals (Sweden)

    A. Lohila

    2011-11-01

    Full Text Available Drainage for forestry purposes increases the depth of the oxic peat layer and leads to increased growth of shrubs and trees. Concurrently, the production and uptake of the greenhouse gases carbon dioxide (CO2, methane (CH4 and nitrous oxide (N2O change: due to the accelerated decomposition of peat in the presence of oxygen, drained peatlands are generally considered to lose peat carbon (C. We measured CO2 exchange with the eddy covariance (EC method above a drained nutrient-poor peatland forest in southern Finland for 16 months in 2004–2005. The site, classified as a dwarf-shrub pine bog, had been ditched about 35 years earlier. CH4 and N2O fluxes were measured at 2–5-week intervals with the chamber technique. Drainage had resulted in a relatively little change in the water table level, being on average 40 cm below the ground in 2005. The annual net ecosystem exchange was −870 ± 100 g CO2 m−2 yr−1 in the calendar year 2005, indicating net CO2 uptake from the atmosphere. The site was a small sink of CH4 (−0.12 g CH4 m−2 yr−1 and a small source of N2O (0.10 g N2O m−2 yr−1. Photosynthesis was detected throughout the year when the air temperature exceeded −3 °C. As the annual accumulation of C in the above and below ground tree biomass (175 ± 35 g C m−2 was significantly lower than the accumulation observed by the flux measurement (240 ± 30 g C m−2, about 65 g C m−2 yr−1 was likely to have accumulated as organic matter into the peat soil. This is a higher average accumulation rate than previously reported for natural northern peatlands, and the first time C accumulation has been shown by EC measurements to occur in a forestry-drained peatland. Our results suggest that forestry

  2. How does whole ecosystem warming of a peatland affect methane production and consumption?

    Science.gov (United States)

    Hopple, A.; Brunik, K.; Keller, J.; Pfeifer-Meister, L.; Woerndle, G.; Zalman, C.; Hanson, P.; Bridgham, S. D.

    2017-12-01

    Peatlands are among Earth's most important terrestrial ecosystems due to their massive soil carbon (C) stores and significant release of methane (CH4) into the atmosphere. Methane has a sustained-flux global warming potential 45-times greater than carbon dioxide (CO2), and the accuracy of Earth system model projections relies on our mechanistic understanding of peatland CH4 cycling in the context of environmental change. The objective of this study was to determine, under in situ conditions, how heating of the peat profile affects ecosystem-level anaerobic C cycling. We assessed the response of CO2 and CH4 production, as well as the anaerobic oxidation of CH4 (AOM), in a boreal peatland following 13 months of deep peat heating (DPH) and 16 months of subsequent whole-ecosystem warming (surface and deep heating; WEW) as part of the Spruce and Peatland Responses Under Changing Environments (SPRUCE) project in northern Minnesota, USA. The study uses a regression-based experimental design including 5 temperature treatments that warmed the entire 2 m peat profile from 0 to +9 °C above ambient temperature. Soil cores were collected at multiple depths (25-200 cm) from each experimental chamber at the SPRUCE site and anaerobically incubated at in situ temperatures for 1-2 weeks. Methane and CO2 production in surface peat were positively correlated with elevated temperature, but no consistent temperature response was found at depth (75-200 cm) following DPH. However, during WEW, we observed significant increases in both surface and deep peat methanogenesis with increasing temperature. Surface peat had greater CH4 production rates than deeper peat, implying that the increased CH4 emissions observed in the field were largely driven by surface peat warming. The CO2:CH4 ratio was inversely correlated with temperature across all depths following 16 months of WEW, indicating that the entire peat profile is becoming more methanogenic with warming. We also observed AOM throughout

  3. Land use of drained peatlands: Greenhouse gas fluxes, plant production, and economics.

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    Kasimir, Åsa; He, Hongxing; Coria, Jessica; Nordén, Anna

    2017-10-10

    Drained peatlands are hotspots for greenhouse gas (GHG) emissions, which could be mitigated by rewetting and land use change. We performed an ecological/economic analysis of rewetting drained fertile peatlands in a hemiboreal climate using different land use strategies over 80 years. Vegetation, soil processes, and total GHG emissions were modeled using the CoupModel for four scenarios: (1) business as usual-Norway spruce with average soil water table of -40 cm; (2) willow with groundwater at -20 cm; (3) reed canary grass with groundwater at -10 cm; and (4) a fully rewetted peatland. The predictions were based on previous model calibrations with several high-resolution datasets consisting of water, heat, carbon, and nitrogen cycling. Spruce growth was calibrated by tree-ring data that extended the time period covered. The GHG balance of four scenarios, including vegetation and soil, were 4.7, 7.1, 9.1, and 6.2 Mg CO 2 eq ha -1  year -1 , respectively. The total soil emissions (including litter and peat respiration CO 2 + N 2 O + CH 4 ) were 33.1, 19.3, 15.3, and 11.0 Mg CO 2 eq ha -1  year -1 , respectively, of which the peat loss contributed 35%, 24%, and 7% of the soil emissions for the three drained scenarios, respectively. No peat was lost for the wet peatland. It was also found that draining increases vegetation growth, but not as drastically as peat respiration does. The cost-benefit analysis (CBA) is sensitive to time frame, discount rate, and carbon price. Our results indicate that the net benefit was greater with a somewhat higher soil water table and when the peatland was vegetated with willow and reed canary grass (Scenarios 2 and 3). We conclude that saving peat and avoiding methane release using fairly wet conditions can significantly reduce GHG emissions, and that this strategy should be considered for land use planning and policy-making. © 2017 John Wiley & Sons Ltd.

  4. Aerobic carbon-cycle related microbial communities in boreal peatlands: responses to water-level drawdown

    Energy Technology Data Exchange (ETDEWEB)

    Peltoniemi, K

    2010-07-01

    Boreal peatlands represent a considerable portion of the global carbon (C) pool. Water-level drawdown (WLD) causes peatland drying and induces a vegetation change, which affects the decomposition of soil organic matter and the release of greenhouse gases (CO{sub 2} and CH{sub 4}). The objective of this thesis was to study the microbial communities related to the C cycle and their response to WLD in two boreal peatlands. Both sampling depth and site type had a strong impact on all microbial communities. In general, bacteria dominated the deeper layers of the nutrient-rich fen and the wettest surfaces of the nutrient-poor bog sites, whereas fungi seemed more abundant in the drier surfaces of the bog. WLD clearly affected the microbial communities but the effect was dependent on site type. The fungal and methane-oxidizing bacteria (MOB) community composition changed at all sites but the actinobacterial community response was apparent only in the fen after WLD. Microbial communities became more similar among sites after long-term WLD. Litter quality had a large impact on community composition, whereas the effects of site type and WLD were relatively minor. The decomposition rate of fresh organic matter was influenced slightly by actinobacteria, but not at all by fungi. Field respiration measurements in the northern fen indicated that WLD accelerates the decomposition of soil organic matter. In addition, a correlation between activity and certain fungal sequences indicated that community composition affects the decomposition of older organic matter in deeper peat layers. WLD had a negative impact on CH{sub 4} oxidation, especially in the oligotrophic fen. Fungal sequences were matched to taxa capable of utilizing a broad range of substrates. Most of the actinobacterial sequences could not be matched to characterized taxa in reference databases. This thesis represents the first investigation of microbial communities and their response to WLD among a variety of boreal

  5. The influence of slope and peatland vegetation type on riverine dissolved organic carbon and water colour at different scales.

    Science.gov (United States)

    Parry, L E; Chapman, P J; Palmer, S M; Wallage, Z E; Wynne, H; Holden, J

    2015-09-15

    Peatlands are important sources of fluvial carbon. Previous research has shown that riverine dissolved organic carbon (DOC) concentrations are largely controlled by soil type. However, there has been little work to establish the controls of riverine DOC within blanket peatlands that have not undergone major disturbance from drainage or burning. A total of 119 peatland catchments were sampled for riverine DOC and water colour across three drainage basins during six repeated sampling campaigns. The topographic characteristics of each catchment were determined from digital elevation models. The dominant vegetation cover was mapped using 0.5m resolution colour infrared aerial images, with ground-truthed validation revealing 82% accuracy. Forward and backward stepwise regression modelling showed that mean slope was a strong (and negative) determinant of DOC and water colour in blanket peatland river waters. There was a weak role for plant functional type in determining DOC and water colour. At the basin scale, there were major differences between the models depending on the basin. The dominance of topographic predictors of DOC found in our study, combined with a weaker role of vegetation type, paves the way for developing improved planning tools for water companies operating in peatland catchments. Using topographic data and aerial imagery it will be possible to predict which tributaries will typically yield lower DOC concentrations and which are therefore more suitable and cost-effective as raw water intakes. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. The dynamics of fire regimes in tropical peatlands in Central Kalimantan, Borneo

    Science.gov (United States)

    Hoscilo, Agata; Page, Susan; Tansey, Kevin

    2010-05-01

    As a carbon-rich ecosystem, tropical peatland contributes significantly to terrestrial carbon storage and stability of the global carbon cycle. Vast areas of tropical peatland in SE Asia are degraded by the increasingly intensive scale of human activities, illustrated by high rates of deforestation, poor land-use management, selective illegal logging, and frequently repeated fires. Analysis of time-series satellite images performed in this study confirmed that fire regimes have dramatically changed in tropical peatlands over the last three decades (1973-2005). The study was conducted in the southern part of Central Kalimantan (Indonesian Borneo). We found that there was an evident increase in fire frequency and a decline in the fire return interval after implementation of the Mega Rice Project (1997-2005). Up until 1997, fires had affected a relatively small area, in total 23% of the study area, and were largely related to land clearance. This situation changed significantly during the last decade (1997-2005), when the widespread, intensive fires of 1997 affected a much larger area. Five years later, in 2002, extensive fires returned, affecting again 22% of the study area. Then, in 2004 and 2005, a further large area of peatland was on fire. Fire frequency analysis showed that during the period 1997-2005, around 45% of the study area was subject to multiple fires, with 37% burnt twice and 8% burnt three or more times. Near-annual occurrence of fire events reduces the rate and nature of vegetation regrowth. Hence, we observed a shift in the fire fuel type and amount over the period of investigation. After 1997, the fire fuel shifted from mainly peat swamp forest biomass towards non-woody biomass, dominated by regenerating vegetation, mainly ferns and a few trees. This secondary vegetation has been shown to be fire prone, although fire propagation is slower than in forest and restricted by both low fuel quality and load. Furthermore, we investigated the interaction

  7. Impact of peatland restoration on nutrient and carbon leaching from contrasting sites in southern Finland

    Science.gov (United States)

    Vasander, Harri; Sallantaus, Tapani; Koskinen, Markku

    2010-05-01

    Impacts of peatland restoration on nutrient and carbon leaching from contrasting sites in southern Finland Tapani Sallantaus1, Markku Koskinen2, Harri Vasander2 1)Finnish Environment Institute, Biodiversity unit, Box 140, FIN-00251 Helsinki, Finland, tapani.sallantaus@ymparisto.fi 2)Department of Forest Sciences, University of Helsinki, Box 27, FIN-00014 University of Helsinki, Finland, markku.koskinen@helsinki.fi, harri.vasander@helsinki.fi Less than 20 % of the original mire area of southern Finland is still in natural state. Even many peatlands in today's nature conservation areas had been partly or totally drained before conservation. Until now, about 15000 ha of peatlands have been restored in conservation areas. Here we present data concerning changes in leaching due to restoration in two contrasting areas in southern Finland. The peatlands in Seitseminen have originally been fairly open, growing stunted pine, and unfertile, either bogs or poor fens. The responses of tree stand to drainage in the 1960s were moderate, and the tree stand before restoration was about 50 m3/ha, on average. The trees were partly harvested before filling in the ditches mainly in the years 1997-1999 . The peatlands of Nuuksio are much more fertile than those in Seitseminen, and had greatly responded to drainage, which took place already in the 1930s and 1950s. The tree stand consisted mainly of spruce and exceeded 300 m3/ha in large part of the area. The ditches were dammed in the autumn 2001 and the tree stand was left standing. Runoff water quality was monitored in three basins in both areas. To obtain the leaching rates, we used simulated runoff data obtained from the Finnish Environment Institute, Hydrological Services Division. The responses in leaching were in the same direction in both cases. However, especially when calculated per restored hectare (Table 1), the responses were much stronger in the more fertile areas of Nuuksio for organic carbon and nitrogen, but not so much

  8. Increased losses of organic carbon and destabilising of tropical peatlands following deforestation, drainage and burning. (Invited)

    Science.gov (United States)

    Moore, S.; Gauci, V.; Evans, C.; Page, S. E.

    2013-12-01

    Tropical peatlands contain one of the largest pools of terrestrial organic carbon, amounting to about 89,000 teragrams. Approximately 65% of this carbon store is in Indonesia, where extensive anthropogenic degradation in the form of deforestation, drainage and associated fire is converting it into a globally significant source of atmospheric carbon dioxide. Unlike boreal and temperate forests and higher-latitude wetlands, however, the loss of fluvial organic carbon from tropical peats has yet to be fully quantified. Here, we present the first data from intact and degraded peat swamp forest (PSF) catchments in Central Kalimantan, Borneo, that indicate a doubling of fluvial organic carbon losses from tropical peatlands following deforestation and drainage. Through carbon-14 dating of dissolved organic carbon (DO14C), we find that leaching of DOC from intact PSF is derived mainly from recent primary production. In contrast, DOC from disturbed PSF consists mostly of much older carbon from deep within the peat column. When we include this fluvial carbon loss, which is often ignored in peatland carbon budgets, we find that it increases the estimate of total carbon lost from the disturbed peatlands in our study by 22%. We further estimate that since 1990, peatland disturbance has resulted in a 32% increase in fluvial organic carbon flux from Southeast Asia - an increase that equates to more than half of the entire annual fluvial organic carbon flux from all European peatlands. Finally, we monitored fluvial organic carbon fluxes following large-scale peatland fires in 2009/10 within the study sub-catchments and found fluvial carbon fluxes to be 30-70% larger in the fire-affected catchments when compared to fluxes during the same interval in the previous year (pre-fire). This is in marked contrast to the intact catchment (control/no fire) where there were no differences observed in fluxes 'pre to post fire years'. Our sub-catchment findings were also found to be

  9. Temporal variability in methane fluxes from tropical peatlands within the Peruvian Amazon

    Science.gov (United States)

    Murphy, Wayne; Berrio, Juan Carlos; Boom, Arnoud; Page, Sue; Arn Teh, Yit

    2016-04-01

    Tropical peatlands are one of the largest soil carbon (C) reservoirs globally and play a significant role in modulating fluxes of C between the tropical biosphere and atmosphere. These C fluxes are of global importance because tropical wetlands are the single largest natural source of atmospheric methane (CH4); while land-use change and biomass burning also contribute to the growing global atmospheric carbon dioxide (CO2) burden. Amazonian peatlands play a potentially important role in regional and global atmospheric budgets of C because of their large extent. These ecosystems cover an estimated 150,000km2, which is roughly three-quarters the size of Indonesian peatlands; the world's most extensive and well-studied tropical peatlands. Here we report CH4 fluxes from a lowland tropical peatland in the Pastaza-Maranon foreland basin in Peru, one of the largest peatland complexes in the lowland Amazon Basin. Strong prolonged seasonal rainfall events and the annual Amazon River flood-pulse may lead to pronounced temporal variability in biogeochemical cycling and trace gas fluxes, and this study explored how CH4 fluxes varied among wet and dry season periods in a number of key vegetation types in this region. Sampling was concentrated in 3 of the most numerically-dominant vegetation types: Forested Swamp, Mixed Palm Swamp and Mauritia flexuosa-dominated Palm Swamp, with data collection occurring in both wet and dry seasons over a 2 year period from 2012-2014 (4 field campaigns in total). Overall mean CH4 fluxes from the Forested Swamp, Mixed Palm Swamp and Mauritia flexuosa-dominated Palm Swamp for the entire sampling period were 31.06 ± 3.42 mg CH4 - C m-2 d-1, 52.03 ± 16.05 mg CH4 - C m-2 d-1 and 36.68 ± 4.32 mg CH4 - C m-2 d-1. CH4 emissions, when averaged across the entire dataset, did not differ significantly among habitats. However, when CH4 emissions were aggregated by season, the Mixed Palm Swamp showed a significantly different emissions from all other

  10. Tropical Peatland Burn Depth and Combustion Heterogeneity Assessed Using UAV Photogrammetry and Airborne LiDAR

    Directory of Open Access Journals (Sweden)

    Jake E. Simpson

    2016-12-01

    Full Text Available We provide the first assessment of tropical peatland depth of burn (DoB using structure from motion (SfM photogrammetry, applied to imagery collected using a low-cost, low-altitude unmanned aerial vehicle (UAV system operated over a 5.2 ha tropical peatland in Jambi Province on Sumatra, Indonesia. Tropical peat soils are the result of thousands of years of dead biomass accumulation, and when burned are globally significant net sources of carbon emissions. The El Niño year of 2015 saw huge areas of Indonesia affected by tropical peatland fires, more so than any year since 1997. However, the Depth of Burn (DoB of these 2015 fires has not been assessed, and indeed has only previously been assessed in few tropical peatland burns in Kalimantan. Therefore, DoB remains arguably the largest uncertainty when undertaking fire emissions calculations in these tropical peatland environments. We apply a SfM photogrammetric methodology to map this DoB metric, and also investigate combustion heterogeneity using orthomosaic photography collected using the UAV system. We supplement this information with pre-burn airborne light detection and ranging (LiDAR data, reducing uncertainty by estimating pre-burn soil height more accurately than from interpolation of adjacent unburned areas alone. Our pre-and post-fire Digital Terrain Models (DTMs show accuracies of 0.04 and 0.05 m (root-mean-square error, RMSE respectively, compared to ground-based global navigation satellite system (GNSS surveys. Our final DoB map of a 5.2 ha degraded peat swamp forest area neighboring Berbak National Park (Sumatra, Indonesia shows burn depths extending from close to zero to over 1 m, with a mean (±1σ DoB of 0.23 ± 0.19 m. This lies well within the range found by the few other studies available (on Kalimantan; none are available on Sumatra. Our combustion heterogeneity analysis suggests the deepest burns, which extend to ~1.3 m, occur around tree roots. We use these DoB data within

  11. Seasonal Trace Gas Dynamics on Minerotrophic Fen Peatlands in NE-Germany

    Science.gov (United States)

    Giebels, Michael; Beyer, Madlen; Augustin, Jürgen; Minke, Merten; Juszczak, Radoszlav; Serba, Tomasz

    2010-05-01

    In Germany more than 99 % of fens have lost their carbon and nutrient sink function due to heavy drainage and agricultural land use especially during the last decades and thus resulted in compression and heavy peat loss (CHARMAN 2002; JOOSTEN & CLARKE 2002; SUCCOW & JOOSTEN 2001; AUGUSTIN et al. 1996; KUNTZE 1993). Therefore fen peatlands play an important part (4-5 %) in the national anthropogenic trace gas budget. But only a small part of drained and agricultural used fens in NE Germany can be restored. Knowledge of the influence of land use to trace gas exchange is important for mitigation of the climate impact of the anthropogenic peatland use. We study carbon exchanges of several fen peatland use areas between soil and atmosphere at different sites in NE-Germany. Our research covers peatlands of supposed strongly climate forcing land use (cornfield and intensive pasture) and of probably less forcing, alternative types (meadow and extensive pasture) as well as rewetted (formerly drained) areas and near-natural sites like a low-degraded fen and a wetted alder woodland. We measured trace gas fluxes with manual and automatic chambers in periodic routines since spring 2007. The used chamber technique bases on DROESLER (2005). In total we now do research at 22 sites situated in 5 different locations covering agricultural, varying states of rewetted and near-natural treatments. We present results of at least 2 years of measurements and show significant differences in their annual trace gas balances depending on the genesis of the observed sites and the seasonal dynamics. Crosswise comparison of different site treatments combined with the seasonal environmental observations give good hints for the identification of main flux driving parameters. That is that a reduced intensity in land use as a supposed mitigating treatment did not show the expected effect, though a normal meadow treatment surprisingly resulted in the lowest balances in both years. For implementing a

  12. Seasonal Carbon Dynamics on Selected Fen Peatland Sites in NE-Germany

    Science.gov (United States)

    Giebels, Michael; Beyer, Madlen; Augustin, Jürgen; Minke, Merten; Juszczak, Radoszlav; Serba, Tomasz

    2010-05-01

    In Germany more than 99 % of fens have lost their carbon and nutrient sink function due to heavy drainage and agricultural land use especially during the last decades and thus resulted in compression and heavy peat loss (CHARMAN 2002; JOOSTEN & CLARKE 2002; SUCCOW & JOOSTEN 2001; AUGUSTIN et al. 1996; KUNTZE 1993). Therefore fen peatlands play an important part (4-5 %) in the national anthropogenic trace gas budget. But only a small part of drained and agricultural used fens in NE Germany can be restored. Knowledge of the influence of land use to trace gas exchange is important for mitigation of the climate impact of the anthropogenic peatland use. We study carbon exchanges of several fen peatland use areas between soil and atmosphere at different sites in NE-Germany. Our research covers peatlands of supposed strongly climate forcing land use (cornfield and intensive pasture) and of probably less forcing, alternative types (meadow and extensive pasture) as well as rewetted (formerly drained) areas and near-natural sites like a low-degraded fen and a wetted alder woodland. We measured trace gas fluxes with manual and automatic chambers in periodic routines since spring 2007. The used chamber technique bases on DROESLER (2005). In total we now do research at 22 sites situated in 5 different locations covering agricultural, varying states of rewetted and near-natural treatments. We present results of at least 2 years of measurements and show significant differences in their annual carbon balances depending on the genesis of the observed sites and the seasonal dynamics. Crosswise comparison of different site treatments combined with the seasonal environmental observations give good hints for the identification of main flux driving parameters. That is that a reduced intensity in land use as a supposed mitigating treatment did not show the expected effect, though a normal meadow treatment surprisingly resulted in the lowest CO2 balances in both years. For implementing a

  13. Mapping, organic matter mass and water volume of a peatland in Serra do Espinhaço Meridional

    Directory of Open Access Journals (Sweden)

    José Ricardo da Rocha Campos

    2012-06-01

    Full Text Available Peatlands form in areas where net primary of organic matter production exceeds losses due to the decomposition, leaching or disturbance. Due to their chemical and physical characteristics, bogs can influence water dynamics because they can store large volumes of water in the rainy season and gradually release this water during the other months of the year. In Diamantina, Minas Gerais, Brazil, a peatland in the environmental protection area of Pau-de-Fruta ensures the water supply of 40,000 inhabitants. The hypothesis of this study is that the peat bogs in Pau-de-Fruta act as an environment for carbon storage and a regulator of water flow in the Córrego das Pedras basin. The objective of this study was to estimate the water volume and organic matter mass in this peatland and to study the influence of this environment on the water flow in the Córrego das Pedras basin. The peatland was mapped using 57 transects, at intervals of 100 m. Along all transects, the depth of the peat bog, the Universal Transverse Mercator (UTM coordinates and altitude were recorded every 20 m and used to calculate the area and volume of the peatland. The water volume was estimated, using a method developed in this study, and the mass of organic matter based on samples from 106 profiles. The peatland covered 81.7 hectares (ha, and stored 497,767 m³ of water, representing 83.7 % of the total volume of the peat bog. The total amount of organic matter (OM was 45,148 t, corresponding to 552 t ha-1 of OM. The peat bog occupies 11.9 % of the area covered by the Córrego das Pedras basin and stores 77.6 % of the annual water surplus, thus controlling the water flow in the basin and consequently regulating the water course.

  14. The potential influence of short-term environmental variability on the composition of testate amoeba communities in Sphagnum peatlands.

    Science.gov (United States)

    Sullivan, Maura E; Booth, Robert K

    2011-07-01

    Testate amoebae are a group of moisture-sensitive, shell-producing protozoa that have been widely used as indicators of changes in mean water-table depth within oligotrophic peatlands. However, short-term environmental variability (i.e., sub-annual) also probably influences community composition. The objective of this study was to assess the potential influence of short-term environmental variability on the composition of testate amoeba communities in Sphagnum-dominated peatlands. Testate amoebae and environmental conditions, including hourly measurements of relative humidity within the upper centimeter of the peatland surface, were examined throughout the 2008 growing season at 72 microsites within 11 peatlands of Pennsylvania and Wisconsin, USA. Relationships among testate amoeba communities, vegetation, depth to water table, pH, and an index of short-term environmental variability (EVI), were examined using nonmetric multidimensional scaling and correlation analysis. Results suggest that EVI influences testate amoeba communities, with some taxa more abundant under highly variable conditions (e.g., Arcella discoides, Difflugia pulex, and Hyalosphenia subflava) and others more abundant when environmental conditions at the peatland surface were relatively stable (e.g., Archerella flavum and Bullinularia indica). The magnitude of environmental variability experienced at the peatland surface appears to be primarily controlled by vegetation composition and density. In particular, sites with dense Sphagnum cover had lower EVI values than sites with loose-growing Sphagnum or vegetation dominated by vascular plants and/or non-Sphagnum bryophytes. Our results suggest that more environmental information may be inferred from testate amoebae than previously recognized. Knowledge of relationships between testate amoebae and short-term environmental variability should lead to more detailed and refined environmental inferences.

  15. Towards spatial assessment of carbon sequestration in peatlands: spectroscopy based estimation of fractional cover of three plant functional types

    Directory of Open Access Journals (Sweden)

    G. Schaepman-Strub

    2009-02-01

    Full Text Available Peatlands accumulated large carbon (C stocks as peat in historical times. Currently however, many peatlands are on the verge of becoming sources with their C sequestration function becoming sensitive to environmental changes such as increases in temperature, decreasing water table and enhanced nitrogen deposition. Long term changes in vegetation composition are both, a consequence and indicator of future changes in C sequestration. Spatial continuous accurate assessment of the vegetation composition is a current challenge in keeping a close watch on peatland vegetation changes. In this study we quantified the fractional cover of three major plant functional types (PFTs; Sphagnum mosses, graminoids, and ericoid shrubs in peatlands, using field spectroscopy reflectance measurements (400–2400 nm on 25 plots differing in PFT cover. The data was validated using point intercept methodology on the same plots. Our results showed that the detection of open Sphagnum versus Sphagnumcovered by vascular plants (shrubs and graminoids is feasible with an R2 of 0.81. On the other hand, the partitioning of the vascular plant fraction into shrubs and graminoids revealed lower correlations of R2 of 0.54 and 0.57, respectively. This study was based on a dataset where the reflectance of all main PFTs and their pure components within the peatland was measured at local spatial scales. Spectrally measured species or plant community abundances can further be used to bridge scaling gaps up to canopy scale, ultimately allowing upscaling of the C balance of peatlands to the ecosystem level.

  16. Peatland pines as a proxy for water table fluctuations: disentangling tree growth, hydrology and possible human influence.

    Science.gov (United States)

    Smiljanić, Marko; Seo, Jeong-Wook; Läänelaid, Alar; van der Maaten-Theunissen, Marieke; Stajić, Branko; Wilmking, Martin

    2014-12-01

    Dendrochronological investigations of Scots pine (Pinus sylvestris L.) growing on Männikjärve peatland in central Estonia showed that annual tree growth of peatland pines can be used as a proxy for past variations of water table levels. Reconstruction of past water table levels can help us to better understand the dynamics of various ecological processes in peatlands, e.g. the formation of vegetation patterns or carbon and nitrogen cycling. Männikjärve bog has one of the longest water table records in the boreal zone, continuously monitored since 1956. Common uncertainties encountered while working with peatland trees (e.g. narrow, missing and wedging rings) were in our case exacerbated with difficulties related to the instability of the relationship between tree growth and peatland environment. We hypothesized that the instable relationship was mainly due to a significant change of the limiting factor, i.e. the rise of the water table level due to human activity. To test our hypothesis we had to use several novel methods of tree-ring chronology analysis as well as to test explicitly whether undetected missing rings biased our results. Since the hypothesis that the instable relationship between tree growth and environment was caused by a change in limiting factor could not be rejected, we proceeded to find possible significant changes of past water table levels using structural analysis of the tree-ring chronologies. Our main conclusions were that peatland pines can be proxies to water table levels and that there were several shifting periods of high and low water table levels in the past 200 years. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. An appraisal of Indonesia's immense peat carbon stock using national peatland maps: uncertainties and potential losses from conversion.

    Science.gov (United States)

    Warren, Matthew; Hergoualc'h, Kristell; Kauffman, J Boone; Murdiyarso, Daniel; Kolka, Randall

    2017-12-01

    A large proportion of the world's tropical peatlands occur in Indonesia where rapid conversion and associated losses of carbon, biodiversity and ecosystem services have brought peatland management to the forefront of Indonesia's climate mitigation efforts. We evaluated peat volume from two commonly referenced maps of peat distribution and depth published by Wetlands International (WI) and the Indonesian Ministry of Agriculture (MoA), and used regionally specific values of carbon density to calculate carbon stocks. Peatland extent and volume published in the MoA maps are lower than those in the WI maps, resulting in lower estimates of carbon storage. We estimate Indonesia's total peat carbon store to be within 13.6 GtC (the low MoA map estimate) and 40.5 GtC (the high WI map estimate) with a best estimate of 28.1 GtC: the midpoint of medium carbon stock estimates derived from WI (30.8 GtC) and MoA (25.3 GtC) maps. This estimate is about half of previous assessments which used an assumed average value of peat thickness for all Indonesian peatlands, and revises the current global tropical peat carbon pool to 75 GtC. Yet, these results do not diminish the significance of Indonesia's peatlands, which store an estimated 30% more carbon than the biomass of all Indonesian forests. The largest discrepancy between maps is for the Papua province, which accounts for 62-71% of the overall differences in peat area, volume and carbon storage. According to the MoA map, 80% of Indonesian peatlands are peatlands is conservatively estimated to be 10.6 GtC, equivalent to 42% of Indonesia's total peat carbon and about 12 years of global emissions from land use change at current rates. Considering the high uncertainties in peatland extent, volume and carbon storage revealed in this assessment of current maps, a systematic revision of Indonesia's peat maps to produce a single geospatial reference that is universally accepted would improve national peat carbon storage estimates and

  18. Brown carbon aerosols from burning of boreal peatlands: microphysical properties, emission factors, and implications for direct radiative forcing

    Directory of Open Access Journals (Sweden)

    R. K. Chakrabarty

    2016-03-01

    Full Text Available The surface air warming over the Arctic has been almost twice as much as the global average in recent decades. In this region, unprecedented amounts of smoldering peat fires have been identified as a major emission source of climate-warming agents. While much is known about greenhouse gas emissions from these fires, there is a knowledge gap on the nature of particulate emissions and their potential role in atmospheric warming. Here, we show that aerosols emitted from burning of Alaskan and Siberian peatlands are predominantly brown carbon (BrC – a class of visible light-absorbing organic carbon (OC – with a negligible amount of black carbon content. The mean fuel-based emission factors for OC aerosols ranged from 3.8 to 16.6 g kg−1. Their mass absorption efficiencies were in the range of 0.2–0.8 m2 g−1 at 405 nm (violet and dropped sharply to 0.03–0.07 m2 g−1 at 532 nm (green, characterized by a mean Ångström exponent of  ≈  9. Electron microscopy images of the particles revealed their morphologies to be either single sphere or agglomerated “tar balls”. The shortwave top-of-atmosphere aerosol radiative forcing per unit optical depth under clear-sky conditions was estimated as a function of surface albedo. Only over bright surfaces with albedo greater than 0.6, such as snow cover and low-level clouds, the emitted aerosols could result in a net warming (positive forcing of the atmosphere.

  19. Microbial production of nitrous oxide and nitric oxide in boreal peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Regina, K.

    1998-12-31

    Soils are an important source of nitrous oxide (N{sub 2}O) and nitric oxide (NO). N{sub 2}O is a greenhouse gas participating in both warming of the climate and the destruction of ozone, and NO is active in tropospheric chemistry. The fluxes and formation mechanisms of these gases in boreal Finnish peatlands were studied by both laboratory and field techniques. Special attention was paid to factors regulating their production, e.g. height of the water table, pH, temperature, nutrient level and nitrification activity. Both N{sub 2}O and NO fluxes were detected in the peatlands, some of which were sources of these trace gases and some sinks. The flux rates of N{sub 2}O ranged from negative values to several milligrammes per square metre per day. Natural peatlands were the lowest sources of N{sub 2}O, often showing negative fluxes, whereas sites drained for forestry some decades ago had markedly higher fluxes. A site drained for agriculture (grassland) was the highest source found. NO fluxes were observed on the two drained sites studied, a forested fen and the same field of grass, but not on a natural fen with a high water table. NO fluxes amounted to 16-30 % of the N{sub 2}O flux rates. The importance of the water table in regulating N{sub 2}0 fluxes was demonstrated in field and laboratory studies. It was shown in the laboratory that even a short lowering of the water table, for 14 weeks at 20 deg C, induced N{sub 2}0 fluxes from the fens that normally acted as sinks or only low sources. Raising the water table in peat monoliths from drained sites reduced the flux of N{sub 2}O. Nutrient-rich peatlands had much higher capacities for N{sub 2}O and NO production than poorer ones. The addition of KNO{sub 3}, NH{sub 4}Cl or urea to minerotrophic peat further increased the fluxes of N{sub 2}O and NO, and also nitrogen mineralisation. There was a clear connection between the fluxes of N{sub 2}0 and NO and nitrification activity measured as the numbers of nitrite

  20. Microbial production of nitrous oxide and nitric oxide in boreal peatlands

    International Nuclear Information System (INIS)

    Regina, K.

    1998-01-01

    Soils are an important source of nitrous oxide (N 2 O) and nitric oxide (NO). N 2 O is a greenhouse gas participating in both warming of the climate and the destruction of ozone, and NO is active in tropospheric chemistry. The fluxes and formation mechanisms of these gases in boreal Finnish peatlands were studied by both laboratory and field techniques. Special attention was paid to factors regulating their production, e.g. height of the water table, pH, temperature, nutrient level and nitrification activity. Both N 2 O and NO fluxes were detected in the peatlands, some of which were sources of these trace gases and some sinks. The flux rates of N 2 O ranged from negative values to several milligrammes per square metre per day. Natural peatlands were the lowest sources of N 2 O, often showing negative fluxes, whereas sites drained for forestry some decades ago had markedly higher fluxes. A site drained for agriculture (grassland) was the highest source found. NO fluxes were observed on the two drained sites studied, a forested fen and the same field of grass, but not on a natural fen with a high water table. NO fluxes amounted to 16-30 % of the N 2 O flux rates. The importance of the water table in regulating N 2 0 fluxes was demonstrated in field and laboratory studies. It was shown in the laboratory that even a short lowering of the water table, for 14 weeks at 20 deg C, induced N 2 0 fluxes from the fens that normally acted as sinks or only low sources. Raising the water table in peat monoliths from drained sites reduced the flux of N 2 O. Nutrient-rich peatlands had much higher capacities for N 2 O and NO production than poorer ones. The addition of KNO 3 , NH 4 Cl or urea to minerotrophic peat further increased the fluxes of N 2 O and NO, and also nitrogen mineralisation. There was a clear connection between the fluxes of N 2 0 and NO and nitrification activity measured as the numbers of nitrite-oxidising bacteria, nitrification potential or in situ net

  1. Microbial production of nitrous oxide and nitric oxide in boreal peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Regina, K

    1999-12-31

    Soils are an important source of nitrous oxide (N{sub 2}O) and nitric oxide (NO). N{sub 2}O is a greenhouse gas participating in both warming of the climate and the destruction of ozone, and NO is active in tropospheric chemistry. The fluxes and formation mechanisms of these gases in boreal Finnish peatlands were studied by both laboratory and field techniques. Special attention was paid to factors regulating their production, e.g. height of the water table, pH, temperature, nutrient level and nitrification activity. Both N{sub 2}O and NO fluxes were detected in the peatlands, some of which were sources of these trace gases and some sinks. The flux rates of N{sub 2}O ranged from negative values to several milligrammes per square metre per day. Natural peatlands were the lowest sources of N{sub 2}O, often showing negative fluxes, whereas sites drained for forestry some decades ago had markedly higher fluxes. A site drained for agriculture (grassland) was the highest source found. NO fluxes were observed on the two drained sites studied, a forested fen and the same field of grass, but not on a natural fen with a high water table. NO fluxes amounted to 16-30 % of the N{sub 2}O flux rates. The importance of the water table in regulating N{sub 2}0 fluxes was demonstrated in field and laboratory studies. It was shown in the laboratory that even a short lowering of the water table, for 14 weeks at 20 deg C, induced N{sub 2}0 fluxes from the fens that normally acted as sinks or only low sources. Raising the water table in peat monoliths from drained sites reduced the flux of N{sub 2}O. Nutrient-rich peatlands had much higher capacities for N{sub 2}O and NO production than poorer ones. The addition of KNO{sub 3}, NH{sub 4}Cl or urea to minerotrophic peat further increased the fluxes of N{sub 2}O and NO, and also nitrogen mineralisation. There was a clear connection between the fluxes of N{sub 2}0 and NO and nitrification activity measured as the numbers of nitrite

  2. Effect of microtopography on isotopic composition of methane in porewater and efflux at a boreal peatland

    Energy Technology Data Exchange (ETDEWEB)

    Dorodnikov, M.; Wilmking, M. [Greifswald Univ. (Georgia). Inst. of Botany and Landscape Ecology; Marushchak, M.; Biasi, C. [Univ. of Eastern Finland, Kuopio (Finland). Dept. of Environmental Science, Bioteknia 2], E-mail: maxim.dorodnikov@uef.fi

    2013-09-01

    The application of stable isotopes is an approach to identify pathways of methanogenesis, methane (CH{sub 4}) oxidation and transport in peatlands. We measured the stable C isotopic characteristics ({delta}C-13) of CH{sub 4} in peat profiles below hummocks, lawns and hollows of a Finnish mire to study the patterns of CH{sub 4} turnover. Porewater CH{sub 4} concentrations ([CH{sub 4}]; at 0.5-2 m) increased with depth below all microforms. Emissions of CH{sub 4} from hummocks were the lowest, and increased with the increasing water-saturated zone, being {approx}10 times higher from hollows. Thus, the microtopography of the peatland did not affect the porewater [CH{sub 4}] in the water-saturated part of the peat profile, but the CH{sub 4} emissions were affected due to differences in the oxidative potential of the microforms. There was a decrease in {delta}C-13-CH{sub 4} with depth below all microforms indicating dominance of CO{sub 2}-reduction over acetate cleavage pathway of methanogenesis at deep peat layers. However, estimated potential portions of transported CH{sub 4} comprised 50%-70% of the {delta}C-13-CH{sub 4} enrichment on microforms at the 0.5-m depth, hereby masking the acetate cleavage pathway of methanogenesis. Stable C composition ({delta}C-13) of CH{sub 4} proved to be a suitable (but not sufficient) tool to differentiate between types of methanogenesis in continuously water-saturated layers below microforms of a peatland. Combined flux-based and multi-isotopic approaches are needed to better understand the CH{sub 4} turnover process. (orig.)

  3. Antecedent conditions control carbon loss and downstream water quality from shallow, damaged peatlands.

    Science.gov (United States)

    Grand-Clement, E; Luscombe, D J; Anderson, K; Gatis, N; Benaud, P; Brazier, R E

    2014-09-15

    Losses of dissolved organic carbon (DOC) from drained peatlands are of concern, due to the effects this has on the delivery of ecosystem services, and especially on the long-term store of carbon and the provision of drinking water. Most studies have looked at the effect of drainage in deep peat; comparatively, little is known about the behaviour of shallow, climatically marginal peatlands. This study examines water quality (DOC, Abs(400), pH, E4/E6 and C/C) during rainfall events from such environments in the south west UK, in order to both quantify DOC losses, and understand their potential for restoration. Water samples were taken over a 19 month period from a range of drains within two different experimental catchments in Exmoor National Park; data were analysed on an event basis. DOC concentrations ranging between 4 and 21 mg L(-1) are substantially lower than measurements in deep peat, but remain problematic for the water treatment process. Dryness plays a critical role in controlling DOC concentrations and water quality, as observed through spatial and seasonal differences. Long-term changes in depth to water table (30 days before the event) are likely to impact on DOC production, whereas discharge becomes the main control over DOC transport at the time scale of the rainfall/runoff event. The role of temperature during events is attributed to an increase in the diffusion of DOC, and therefore its transport. Humification ratios (E4/E6) consistently below 5 indicate a predominance of complex humic acids, but increased decomposition during warmer summer months leads to a comparatively higher losses of fulvic acids. This work represents a significant contribution to the scientific understanding of the behaviour and functioning of shallow damaged peatlands in climatically marginal locations. The findings also provide a sound baseline knowledge to support research into the effects of landscape restoration in the future. Crown Copyright © 2014. Published by

  4. A ‘rare biosphere’ microorganism contributes to sulfate reduction in a peatland

    Science.gov (United States)

    Pester, Michael; Bittner, Norbert; Deevong, Pinsurang; Wagner, Michael; Loy, Alexander

    2015-01-01

    Methane emission from peatlands contributes substantially to global warming but is significantly reduced by sulfate reduction, which is fuelled by globally increasing aerial sulfur pollution. However, the biology behind sulfate reduction in terrestrial ecosystems is not well understood and the key players for this process as well as their abundance remained unidentified. Comparative 16S rRNA gene stable isotope probing in the presence and absence of sulfate indicated that a Desulfosporosinus species, which constitutes only 0.006% of the total microbial community 16S rRNA genes, is an important sulfate reducer in a long-term experimental peatland field site. Parallel stable isotope probing using dsrAB [encoding subunit A and B of the dissimilatory (bi)sulfite reductase] identified no additional sulfate reducers under the conditions tested. For the identified Desulfosporosinus species a high cell-specific sulfate reduction rate of up to 341 fmol SO42− cell−1 day−1 was estimated. Thus, the small Desulfosporosinus population has the potential to reduce sulfate in situ at a rate of 4.0–36.8 nmol (g soil w. wt.)−1 day−1, sufficient to account for a considerable part of sulfate reduction in the peat soil. Modeling of sulfate diffusion to such highly active cells identified no limitation in sulfate supply even at bulk concentrations as low as 10 μM. Collectively, these data show that the identified Desulfosporosinus species, despite being a member of the ‘rare biosphere’, contributes to an important biogeochemical process that diverts the carbon flow in peatlands from methane to CO2 and, thus, alters their contribution to global warming. PMID:20535221

  5. Can frequent precipitation moderate drought impact on peatmoss carbon uptake in northern peatlands?

    Science.gov (United States)

    Nijp, Jelmer; Limpens, Juul; Metselaar, Klaas; van der Zee, Sjoerd; Berendse, Frank; Robroek, Bjorn

    2014-05-01

    Northern peatlands represent one of the largest global carbon stores that can potentially be released by water table drawdown during extreme summer droughts. Small precipitation events may moderate negative impacts of deep water levels on carbon uptake by sustaining photosynthesis of peatmoss (Sphagnum spp.), the key species in these ecosystems. We experimentally assessed the importance of the temporal distribution of precipitation for Sphagnum water supply and carbon uptake during a stepwise decrease in water levels in a growth chamber. CO2 exchange and the water balance were measured for intact cores of three peatmoss species representative of three contrasting habitats in northern peatlands (Sphagnum fuscum, S. balticum and S. majus). For shallow water levels, capillary rise was the most important source of water for peatmoss photosynthesis and precipitation did not promote carbon uptake irrespective of peatmoss species. For deep water levels, however, precipitation dominated over capillary rise and moderated adverse effects of drought on carbon uptake by peat mosses. The ability to use the transient water supply by precipitation was species-specific: carbon uptake of S. fuscum increased linearly with precipitation frequency for deep water levels, whereas S. balticum and S. majus showed depressed carbon uptake at intermediate precipitation frequencies. Our results highlight the importance of precipitation for carbon uptake by peatmosses. The potential of precipitation to moderate drought impact, however, is species specific and depends on the temporal distribution of precipitation and water level. These results also suggest that modelling approaches in which water level depth is used as the only state variable determining water availability in the living moss layer and (in)directly linked to Sphagnum carbon uptake may have serious drawbacks. The predictive power of peatland ecosystem models may be reduced when deep water levels prevail, as precipitation

  6. Spatially explicit simulation of peatland hydrology and carbon dioxide exchange: Influence of mesoscale topography

    Science.gov (United States)

    Sonnentag, O.; Chen, J. M.; Roulet, N. T.; Ju, W.; Govind, A.

    2008-06-01

    Carbon dynamics in peatlands are controlled, in large part, by their wetness as defined by water table depth and volumetric liquid soil moisture content. A common type of peatland is raised bogs that typically have a multiple-layer canopy of vascular plants over a Sphagnum moss ground cover. Their convex form restricts water supply to precipitation and water is shed toward the margins, usually by lateral subsurface flow. The hydraulic gradient for lateral subsurface flow is governed by the peat surface topography at the mesoscale (˜200 m to 5 km). To investigate the influence of mesoscale topography on wetness, evapotranspiration (ET), and gross primary productivity (GPP) in a bog during the snow-free period, we compare the outputs of a further developed version of the daily Boreal Ecosystem Productivity Simulator (BEPS) with observations made at the Mer Bleue peatland, located near Ottawa, Canada. Explicitly considering mesoscale topography, simulated total ET and GPP correlate well with measured ET (r = 0.91) and derived gross ecosystem productivity (GEP; r = 0.92). Both measured ET and derived GEP are simulated similarly well when mesoscale topography is neglected, but daily simulated values are systematically underestimated by about 10% and 12% on average, respectively, due to greater wetness resulting from the lack of lateral subsurface flow. Owing to the differences in moss surface conductances of water vapor and carbon dioxide with increasing moss water content, the differences in the spatial patterns of simulated total ET and GPP are controlled by the mesotopographic position of the moss ground cover.

  7. Elemental, stable isotopic and biochemical characterization of soil organic matter alteration across a natural peatland gradient

    Science.gov (United States)

    Cowie, G.; Mowbray, S.; Belyea, L.; Laing, C.; Allton, K.; Abbott, G.; Muhammad, A.

    2010-12-01

    Northern peatlands store around one third of global soil C and thus represent a key reservoir. To elucidate how these systems might respond to climate change, field- and laboratory-based experimental incubation studies are being conducted at sites across a natural peatland gradient in the boreonemoral zone of central Sweden (Ryggmossen). The site comprises four successional stages, from edge to centre; Swamp Forest (SF), Lagg Fen (LF), Bog Margin (BM) and Bog Plateau (BP). The well-preserved succession shows strong decreases in mineral cations and pH, and distinct changes in vegetation and water-table depth. As an underpinning to these experiments, comprehensive characterization of natural soil organic matter (SOM) alteration has been carried out through detailed analyses of vegetation and downcore profiles at contrasting topographic sites (hummock vs hollow) in each of the four locations. As illustrated in Figure 1, while some similarities occur in downcore trends, contrasts are observed in C and N elemental and stable isotopic compositions, between stages and, in some cases, between microtopographic settings. Downcore trends and intersite differences are also observed in biochemical yields and molecular composition (carbohydrates, amino acids, phenols, lipids and D/L amino acid ratios). These reflect SOM decay and alteration combined with the effects of contrasting hydrologic, redox and nutrient regimes and differing vegetation and microbial inputs at each of the study sites. Multivariate analysis is used to to elucidate compositional patterns that characterize and delineate progressive SOM decay, specific vegetation types, and the effects of contrasting environmental conditions at the different sites. Figure 1. A. Organic carbon content (wt %), B. Atomic ratio of organic C to total N, C. Stable C isotopic composition of organic C (d13Corg), and D. Stable N isotopic composition of total nitrogen (d15N), all for core profiles from contrasting settings (hummock and

  8. Climate change drives a shift in peatland ecosystem plant community: implications for ecosystem function and stability.

    Science.gov (United States)

    Dieleman, Catherine M; Branfireun, Brian A; McLaughlin, James W; Lindo, Zoë

    2015-01-01

    The composition of a peatland plant community has considerable effect on a range of ecosystem functions. Peatland plant community structure is predicted to change under future climate change, making the quantification of the direction and magnitude of this change a research priority. We subjected intact, replicated vegetated poor fen peat monoliths to elevated temperatures, increased atmospheric carbon dioxide (CO2 ), and two water table levels in a factorial design to determine the individual and synergistic effects of climate change factors on the poor fen plant community composition. We identify three indicators of a regime shift occurring in our experimental poor fen system under climate change: nonlinear decline of Sphagnum at temperatures 8 °C above ambient conditions, concomitant increases in Carex spp. at temperatures 4 °C above ambient conditions suggesting a weakening of Sphagnum feedbacks on peat accumulation, and increased variance of the plant community composition and pore water pH through time. A temperature increase of +4 °C appeared to be a threshold for increased vascular plant abundance; however the magnitude of change was species dependent. Elevated temperature combined with elevated CO2 had a synergistic effect on large graminoid species abundance, with a 15 times increase as compared to control conditions. Community analyses suggested that the balance between dominant plant species was tipped from Sphagnum to a graminoid-dominated system by the combination of climate change factors. Our findings indicate that changes in peatland plant community composition are likely under future climate change conditions, with a demonstrated shift toward a dominance of graminoid species in poor fens. © 2014 John Wiley & Sons Ltd.

  9. Large-scale regionalization of water table depth in peatlands optimized for greenhouse gas emission upscaling

    Science.gov (United States)

    Bechtold, M.; Tiemeyer, B.; Laggner, A.; Leppelt, T.; Frahm, E.; Belting, S.

    2014-09-01

    Fluxes of the three main greenhouse gases (GHG) CO2, CH4 and N2O from peat and other soils with high organic carbon contents are strongly controlled by water table depth. Information about the spatial distribution of water level is thus a crucial input parameter when upscaling GHG emissions to large scales. Here, we investigate the potential of statistical modeling for the regionalization of water levels in organic soils when data covers only a small fraction of the peatlands of the final map. Our study area is Germany. Phreatic water level data from 53 peatlands in Germany were compiled in a new data set comprising 1094 dip wells and 7155 years of data. For each dip well, numerous possible predictor variables were determined using nationally available data sources, which included information about land cover, ditch network, protected areas, topography, peatland characteristics and climatic boundary conditions. We applied boosted regression trees to identify dependencies between predictor variables and dip-well-specific long-term annual mean water level (WL) as well as a transformed form (WLt). The latter was obtained by assuming a hypothetical GHG transfer function and is linearly related to GHG emissions. Our results demonstrate that model calibration on WLt is superior. It increases the explained variance of the water level in the sensitive range for GHG emissions and avoids model bias in subsequent GHG upscaling. The final model explained 45% of WLt variance and was built on nine predictor variables that are based on information about land cover, peatland characteristics, drainage network, topography and climatic boundary conditions. Their individual effects on WLt and the observed parameter interactions provide insight into natural and anthropogenic boundary conditions that control water levels in organic soils. Our study also demonstrates that a large fraction of the observed WLt variance cannot be explained by nationally available predictor variables and

  10. The response of vegetation structure to active warming and precipitation reduction of the Sphagnum peatland

    Science.gov (United States)

    Łuców, Dominika; Basińska, Anna; Chojnicki, Bogdan; Gąbka, Maciej; Józefczyk, Damian; Juszczak, Radosław; Leśny, Jacek; Olejnik, Janusz; Reczuga, Monika; Samson, Mateusz; Silvennoinen, Hanna; Stróżecki, Marcin; Urbaniak, Marek; Zielińska, Małgorzata; Lamentowicz, Mariusz

    2017-04-01

    The recent climate change (e.g. increased temperature and decreased precipitation) is expected to affect biodiversity and vegetation structure of the European peatlands, as well as carbon fluxes. Our experimental study carried out in Western Poland, tests the hypothesis that the increased temperature, in particular in combination with rainfall reduction affects vegetation structure of the Sphagnum peatland, through changes in moss and vascular plants abundance. The innovative climate manipulation system was installed on the Rzecin peatland in 2014. The field site consists of four blocks: "drought" "warming and drought" "warming" and "control". The air and peat temperatures were increased in 2015 and 2016 by about 0.2 oC and 1.0 oC, respectively, using infrared radiators. Precipitation was reduced by automatic curtain operated only during the nights by about 37 % in both years. Data resulting from the analyses of digital pictures as well as Point Intercept method were used to identify changes in vegetation structure as a response to warming and drought. We observed increase in abundance of vascular plant and decrease in abundance of mosses during the very dry 2015 vegetation season. It appeared that Carex spp. (C. limosa and C. rostrata) abundance responded positively to warming, while Sphagnum spp. (S. angustifolium and S. teres) responded negatively. The "warming" block was characterized by an increase in abundance of Carex spp. by 8.3 % to 16.7 % and decreased abundance of Sphagnum spp. from 25 % to 19.4 %, whereas in the block of "warming and drought" 11.4 % to by 18.3 and 38 % to 26.9 %, respectively in the August 2015. However, we observed decrease in Sphagnum spp. abundance in the treatment with rainfall reduction in wetter 2016, and their increase in the control. Our results show how considerable changes in vegetation structure can be expected under the stress of warming and modified rainfall conditions, even after a short-term manipulation. However, it is

  11. Reintroduction of Sphagnum into harvested peatlands: evaluation of various methods for protection against dessication

    Energy Technology Data Exchange (ETDEWEB)

    Rochefort, L.; Bastien, D.F. [Laval University, Sainte-Foy, PQ (Canada). Dept. of Phytology

    1998-09-01

    In order to restore peatlands after peat harvesting operations, Sphagnum diaspores were introduced in combination with 1) physical protection devices or 2) an irrigating system. The response of five Sphagnum species was investigated in relation to two types of peat substrates for two growing seasons. The physical protections consisting of plastic shade cloth (40% and 60% shade) improved the development of a greater number of capitula compared with control surfaces without protection or surfaces covered with a perforated polyethylene sheet. This stimulating effect could be caused by higher humidity created by a shale screen. Irrigation also enhanced the establishment success of Sphagnum but the effect was less successful than expected.

  12. Transient simulations of the carbon and nitrogen dynamics in northern peatlands: from the Last Glacial Maximum to the 21st century

    Directory of Open Access Journals (Sweden)

    R. Spahni

    2013-06-01

    Full Text Available The development of northern high-latitude peatlands played an important role in the carbon (C balance of the land biosphere since the Last Glacial Maximum (LGM. At present, carbon storage in northern peatlands is substantial and estimated to be 500 ± 100 Pg C (1 Pg C = 1015 g C. Here, we develop and apply a peatland module embedded in a dynamic global vegetation and land surface process model (LPX-Bern 1.0. The peatland module features a dynamic nitrogen cycle, a dynamic C transfer between peatland acrotelm (upper oxic layer and catotelm (deep anoxic layer, hydrology- and temperature-dependent respiration rates, and peatland specific plant functional types. Nitrogen limitation down-regulates average modern net primary productivity over peatlands by about half. Decadal acrotelm-to-catotelm C fluxes vary between −20 and +50 g C m−2 yr−1 over the Holocene. Key model parameters are calibrated with reconstructed peat accumulation rates from peat-core data. The model reproduces the major features of the peat core data and of the observation-based modern circumpolar soil carbon distribution. Results from a set of simulations for possible evolutions of northern peat development and areal extent show that soil C stocks in modern peatlands increased by 365–550 Pg C since the LGM, of which 175–272 Pg C accumulated between 11 and 5 kyr BP. Furthermore, our simulations suggest a persistent C sequestration rate of 35–50 Pg C per 1000 yr in present-day peatlands under current climate conditions, and that this C sink could either sustain or turn towards a source by 2100 AD depending on climate trajectories as projected for different representative greenhouse gas concentration pathways.

  13. Non-methane biogenic volatile organic compound emissions from boreal peatland microcosms under warming and water table drawdown

    DEFF Research Database (Denmark)

    Faubert, P; Tiiva, P; Nakam, TA

    2011-01-01

    assessed the combined effect of warming and water table drawdown on the BVOC emissions from boreal peatland microcosms. We also assessed the treatment effects on the BVOC emissions from the peat soil after the 7-week long experiment. Emissions of isoprene, monoterpenes, sesquiterpenes, other reactive VOCs...

  14. Crocodiles count on it: Regulation of discharge to Lake St Lucia Estuary by a South African peatland

    NARCIS (Netherlands)

    Price, J. S.; Grundling, P.; Grootjans, A.