WorldWideScience

Sample records for wet meadow peatlands

  1. 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

  2. Vegetation Classification, Inventory, and Ecological Integrity Assessment of the Wet Meadow Habitats: Malheur National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this biotic inventory contribute greatly to the construction of a solid foundation for wet meadow management on the Refuge and the wildlife that it...

  3. Bird Nesting Effort in Wet Meadows at Baca National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In the summers of 2013, 2015, and 2016, U.S. Fish & Wildlife Service staff conducted research to determine nesting effort of avian species in the wet meadow...

  4. Wet Meadow Plant Associations, Malheur National Wildlife Refuge, Harney County, Oregon

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes vegetation data collected in July 2012 and July 2013 in wet meadow habitats on the Malheur National Wildlife Refuge. It incorporates portions...

  5. Soil CO2 efflux in three wet meadow ecosystems with different C and N status

    Czech Academy of Sciences Publication Activity Database

    Zemanová, K.; Čížková, Hana; Šantrůčková, H.

    Suppl.S, č. 9 (2008), s. 49-55 ISSN 1585-8553 Institutional research plan: CEZ:AV0Z60870520; CEZ:AV0Z60660521 Keywords : wet meadow * soil CO2 efflux * eutrophication Subject RIV: EH - Ecology, Behaviour Impact factor: 0.898, year: 2008

  6. Effects of grazing intensity on small mammal population ecology in wet meadows

    DEFF Research Database (Denmark)

    Schmidt, N.M.; Olsen, H.; Bildsøe, M.

    2005-01-01

    , grazing livestock had a negative effect on the peak biomass of small mammals, and the negative effect increased with grazing intensity, irrespective of whether pens were grazed by cattle or by sheep. More detailed analyses, however, revealed that an intermediate grazing intensity (approximately 400 kg......Livestock grazing is common management practice in wet grasslands. However, knowledge of its effects on small mammals is limited. We studied the influence of grazing intensity on small mammals in general and field voles Microtus agrestis in particular in two Danish wet meadows, 1998-2000. Generally...

  7. Effects of hydrological regime on development of Carex wet meadows in East Dongting Lake, a Ramsar Wetland for wintering waterbirds

    Science.gov (United States)

    Jing, Lei; Lu, Cai; Xia, Yan; Shi, Linlu; Zuo, Aojie; Lei, Jialing; Zhang, Hong; Lei, Guangchun; Wen, Li

    2017-02-01

    Wet meadows are one of the most important ecological components in floodplain, and are among the most dynamic ecosystems. Understanding the development of wet meadows and contributing environmental factors can provide better support for wetland management. Carex meadows in East Dongting Lake National Nature Reserve (EDLNNR) provide vital wintering ground for thousands of migratory waterbirds, and their ecological functions are under threated due to hydrological alternation. We measured wet meadow expansion in EDLNNR from 1989 to 2014, and explored its responses to hydrological and climatic factors within the generalised additive models (GAM) framework. We found an overall expansion of wet meadows over the study period. However, in contrast to many previous studies, our results showed that water level fluctuations at the hydrologic indicator site had only limited impacts on their development. Instead, sampling year, timing of water level recession, and local rainfall exerted significant effects. The effects of sampling year reflected the changes in sedimentation within Dongting Lake; and effects of timing of water withdrawal might be explained by the life history of the dominant sedge species. Our study suggested that the impacts of large scale hydrological alternation on vegetation may operate indirectly through its effects on sediment balance.

  8. Effects of hydrological regime on development of Carex wet meadows in East Dongting Lake, a Ramsar Wetland for wintering waterbirds.

    Science.gov (United States)

    Jing, Lei; Lu, Cai; Xia, Yan; Shi, Linlu; Zuo, Aojie; Lei, Jialing; Zhang, Hong; Lei, Guangchun; Wen, Li

    2017-02-06

    Wet meadows are one of the most important ecological components in floodplain, and are among the most dynamic ecosystems. Understanding the development of wet meadows and contributing environmental factors can provide better support for wetland management. Carex meadows in East Dongting Lake National Nature Reserve (EDLNNR) provide vital wintering ground for thousands of migratory waterbirds, and their ecological functions are under threated due to hydrological alternation. We measured wet meadow expansion in EDLNNR from 1989 to 2014, and explored its responses to hydrological and climatic factors within the generalised additive models (GAM) framework. We found an overall expansion of wet meadows over the study period. However, in contrast to many previous studies, our results showed that water level fluctuations at the hydrologic indicator site had only limited impacts on their development. Instead, sampling year, timing of water level recession, and local rainfall exerted significant effects. The effects of sampling year reflected the changes in sedimentation within Dongting Lake; and effects of timing of water withdrawal might be explained by the life history of the dominant sedge species. Our study suggested that the impacts of large scale hydrological alternation on vegetation may operate indirectly through its effects on sediment balance.

  9. Water Quality in a Wet Meadow, Platte River Valley, Central Nebraska

    Science.gov (United States)

    Emmons, Patrick J.

    1996-01-01

    The Platte River Valley in Nebraska, and in particular the reach from Kearney to Grand Island, is an extremely important natural habitat area. Over 300 migratory bird species, including several threatened and endangered species, have been observed along the Platte River. In the spring, nearly 500,000 sandhill cranes, along with millions of ducks and geese, use this reach as a staging and feeding area during their northerly migration. Wet meadows (grasslands which have waterlogged soils much of the year) are a critical part of this migratory-bird habitat. However, the area of wet meadows between Kearney and Grand Island has declined nearly 50 percent due to the activities of man. The condition of the remaining wet meadows is of vital importance. The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to describe the status and trends in the quality of the Nation's surface water and groundwater resources and to provide a sound understanding of the natural and human factors that affect the quality of these resources. A study of the groundwater beneath a selected wet meadow was undertaken as part of the Central Nebraska Basins NAWQA study unit. Observation wells were installed in the wet meadow at various distances along two transects downgradient from the edge of a corn field. One to five wells completed at depths of about 15 to 100 feet were located at each of the 5 sites. The wells were completed in the Platte River alluvium or the underlying Ogallala Formation. The depth to the water table ranges from 0 to 5 feet below land surface. The general direction of groundwater flow is parallel to flow in the Platte River. Selected wells were sampled in February, March, June, and December 1994 for major cations and anions, nutrients, and organonitrogen herbicides. Pesticides and fertilizers are used extensively in Nebraska to enhance the production of row crops. Some of these pesticides and fertilizers have migrated into the groundwater

  10. Wet meadow restoration in Western Europe : A quantitative assessment of the effectiveness of several techniques

    NARCIS (Netherlands)

    Klimkowska, Agata; Diggelen, Rudy Van; Bakker, Jan P.; Grootjans, Ab P.

    2007-01-01

    Techniques such as rewetting, topsoil removal, diaspore transfer or combinations of these are increasingly applied in fen meadow and flood meadow restoration in Western Europe. In this paper, we present a quantitative assessment of the effectiveness of the commonly used meadow restoration methods.

  11. Reciprocal Vegetation-Flow Feedbacks Driving Early-Stage Landscape Evolution in a Restored Wet Meadow

    Science.gov (United States)

    Larsen, L.; Merritts, D. J.; Walter, R. C.; Watts, D.

    2013-12-01

    Just as taxonomic classification has improved understanding in biology, ecogeomorphologists would benefit from a functional classification of biota based on the biophysical feedbacks that they engage in. Early stages of landscape development following disturbance provide a unique opportunity to delineate and understand these feedback processes, as the diversity in functional morphotypes (a.k.a. 'ecomorphs,' to expand on a concept from terrestrial ecology) is high and the potential for self-organization of landscape pattern strong. We used the opportunity of a stream restoration that reset its floodplain to 'initial conditions' to perform a suite of biophysical measurements designed to delineate the classes of feedback that influence landscape evolution in distinct ways. The Big Spring Run restoration (Lancaster, PA), completed in November 2011, involved removal of 15,000 t of legacy sediment from the valley bottom to expose a Holocene hydric layer and reestablish wet meadow hydrology and biota. By performing repeat biogeomorphic surveys within a study grid, we tested the hypothesis that distinct ecomorphs determine the persistence and location of channel and microtopographic features. The qualitatively distinct patch types surveyed included carpet-forming mat vegetation, tussock-forming vegetation, sparsely vegetated mudflats, benthic algal mats, mixed herbaceous communities, grasses, and clonal emergent vegetation. Within each sampling location, changes in vegetation community architecture, grain size distribution, critical shear stress for sediment entrainment, and topography were monitored over time, and flow resistance was measured. An overbank flow event that completely filled the floodplain provided an additional opportunity to measure vegetation-flow-sediment interactions. Once emergent vegetation was bent over by flow, vegetation had a negligible influence on flow velocity--in contrast to most other wetlands--but continued to shelter the bed from sediment

  12. Insect emergence in relation to floods in wet meadows and swamps in the River Dalälven floodplain.

    Science.gov (United States)

    Vinnersten, T Z Persson; Östman, Ö; Schäfer, M L; Lundström, J O

    2014-08-01

    Annual variation in flood frequency and hydroperiod during the vegetation season has ecological impacts on the floodplain biota. Although many insect groups may have a lower emergence during a flood event, it is poorly known how annual emergence of insects in temporary wetlands is related to the variation in hydrology. Between May and September, we studied the weekly emergence of 18 insect taxa over six consecutive years, 2002-2007, in six temporary flooded wetlands (four wet meadows and two forest swamps) in the River Dalälven floodplains, Central Sweden. We used emergence traps to collect emerging insects from terrestrial and aquatic parts of wet meadows and swamp forests. In all wetlands, the insect fauna was numerically dominated by the orders Diptera, Hymenoptera, Coleoptera and Homoptera. On a weekly basis, 9 out of the 18 insect taxa had lower emergence in weeks with flood than in weeks with no flood, whereas no taxon had a higher emergence in weeks with flood. Over the seasons, we related insect emergence to seasonal flood frequency and length of hydroperiod. The emergence of most studied taxa decreased with increasing hydroperiod, which suggests that emergence after floods do not compensate for the reduced emergence during floods. Only Culicidae and the aquatic Chironomidae sub-families Tanypodinae and Chironominae showed an increase in emergence with increasing hydroperiod, whereas Staphylinidae peaked at intermediate hydroperiod. We conclude that a hydroperiod covering up to 40% of the vegetation season has a significant negative effect on the emergence of most taxa and that only a few taxa occurring in the temporary wetlands are actually favoured by a flood regime with recurrent and unpredictable floods.

  13. Nutrient limitations in wet, drained and rewetted fen meadows : evaluation of methods and results

    NARCIS (Netherlands)

    Van Duren, IC; Pegtel, DM

    2000-01-01

    Restoration of wet grassland communities on peat soils involves management of nutrient supply and hydrology. The concept of nutrient limitation was discussed as well as its interaction with drainage and rewetting of severely drained peat soils. Different methods of assessing nutrient limitation were

  14. Keep wetlands wet: the myth of sustainable development of tropical peatlands - implications for policies and management.

    Science.gov (United States)

    Evers, Stephanie; Yule, Catherine M; Padfield, Rory; O'Reilly, Patrick; Varkkey, Helena

    2017-02-01

    Pristine tropical peat swamp forests (PSFs) represent a unique wetland ecosystem of distinctive hydrology which support unique biodiversity and globally significant stores of soil carbon. Yet in Indonesia and Malaysia, home to 56% of the world's tropical peatland, they are subject to considerable developmental pressures, including widespread drainage to support agricultural needs. In this article, we review the ecology behind the functioning and ecosystem services provided by PSFs, with a particular focus on hydrological processes as well as the role of the forest itself in maintaining those services. Drawing on this, we review the suitability of current policy frameworks and consider the efficacy of their implementation. We suggest that policies in Malaysia and Indonesia are often based around the narrative of oil palm and other major monocrops as drivers of prosperity and development. However, we also argue that this narrative is also being supported by a priori claims concerning the possibility of sustainability of peat swamp exploitation via drainage-based agriculture through the adherence to best management practices. We discuss how this limits their efficacy, uptake and the political will towards enforcement. Further, we consider how both narratives (prosperity and sustainability) clearly exclude important considerations concerning the ecosystem value of tropical PSFs which are dependent on their unimpacted hydrology. Current research clearly shows that the actual debate should be focused not on how to develop drainage-based plantations sustainably, but on whether the sustainable conversion to drainage-based systems is possible at all. © 2016 John Wiley & Sons Ltd.

  15. Have wet meadow restoration projects in the Southwestern U.S. been effective in restoring geomorphology, hydrology, soils, and plant species composition?

    Directory of Open Access Journals (Sweden)

    Ramstead Karissa M

    2012-09-01

    Full Text Available Abstract Background Wet meadows occur in numerous locations throughout the American Southwest, but in many cases have become heavily degraded. Among other things they have frequently been overgrazed and have had roads built through them, which have affected the hydrology of these wetland ecosystems. Because of the important hydrologic and ecological functions they are believed to perform, there is currently significant interest in wet meadow restoration. Several restoration projects have been completed recently or are underway in the region, sometimes at considerable expense and with minimal monitoring. The objective of this review was to evaluate the effects of wet meadow restoration projects in the southwestern United States on geomorphology, hydrology, soils and plant species composition. A secondary objective was to determine the effects of wet meadow restoration projects on wildlife. Methods Electronic databases, internet search engines, websites and personal contacts were used to find articles of relevance to this review. Articles were filtered by title, abstract and full text. Summary information for each of the articles remaining after the filtering process was compiled and used to assess the quality of the evidence presented using two different approaches. Results Our searches yielded 48 articles, of which 25 were published in peer-reviewed journals, 14 were monitoring or project reports, and 9 were published in conference proceedings or are unpublished theses or manuscripts. A total of 26 operational-scale restoration projects were identified. A wide range of restoration techniques were employed, ranging from small-scale manipulations of stream channels (e.g., riffle structures to large scale pond-and-plug projects. Other common restoration techniques included fencing to exclude livestock (and sometimes also native ungulates, other forms of grazing management, seeding, and transplanting seedlings. Most of the articles reported that

  16. Carbon accumulation in a permafrost polygon peatland: steady long-term rates in spite of shifts between dry and wet conditions.

    Science.gov (United States)

    Gao, Yang; Couwenberg, John

    2015-02-01

    Ice-wedge polygon peatlands contain a substantial part of the carbon stored in permafrost soils. However, little is known about their long-term carbon accumulation rates (CAR) in relation to shifts in vegetation and climate. We collected four peat profiles from one single polygon in NE Yakutia and cut them into contiguous 0.5 cm slices. Pollen density interpolation between AMS (14)C dated levels provided the time span contained in each of the sample slices, which--in combination with the volumetric carbon content--allowed for the reconstruction of CAR over decadal and centennial timescales. Vegetation representing dry palaeo-ridges and wet depressions was reconstructed with detailed micro- and macrofossil analysis. We found repeated shifts between wet and dry conditions during the past millennium. Dry ridges with associated permafrost growth originated during phases of (relatively) warm summer temperature and collapsed during relatively cold phases, illustrating the important role of vegetation and peat as intermediaries between ambient air temperature and the permafrost. The average long-term CAR across the four profiles was 10.6 ± 5.5 g C m(-2) yr(-1). Time-weighted mean CAR did not differ significantly between wet depression and dry ridge/hummock phases (10.6 ± 5.2 g C m(-2) yr(-1) and 10.3 ± 5.7 g C m(-2) yr(-1), respectively). Although we observed increased CAR in relation to warm shifts, we also found changes in the opposite direction and the highest CAR actually occurred during the Little Ice Age. In fact, CAR rather seems to be governed by strong internal feedback mechanisms and has roughly remained stable on centennial time scales. The absence of significant differences in CAR between dry ridge and wet depression phases suggests that recent warming and associated expansion of shrubs will not affect long-term rates of carbon burial in ice-wedge polygon peatlands. © 2014 John Wiley & Sons Ltd.

  17. Questioning ten common assumptions about peatlands

    Directory of Open Access Journals (Sweden)

    University of Leeds Peat Club:

    2017-07-01

    Full Text Available Peatlands have been widely studied in terms of their ecohydrology, carbon dynamics, ecosystem services and palaeoenvironmental archives. However, several assumptions are frequently made about peatlands in the academic literature, practitioner reports and the popular media which are either ambiguous or in some cases incorrect. Here we discuss the following ten common assumptions about peatlands: 1. the northern peatland carbon store will shrink under a warming climate; 2. peatlands are fragile ecosystems; 3. wet peatlands have greater rates of net carbon accumulation; 4. different rules apply to tropical peatlands; 5. peat is a single soil type; 6. peatlands behave like sponges; 7. Sphagnum is the main ‘ecosystem engineer’ in peatlands; 8. a single core provides a representative palaeo-archive from a peatland; 9. water-table reconstructions from peatlands provide direct records of past climate change; and 10. restoration of peatlands results in the re-establishment of their carbon sink function. In each case we consider the evidence supporting the assumption and, where appropriate, identify its shortcomings or ways in which it may be misleading.

  18. The role of Alnus glutinosa (l.) Gaertner in the secondary succession on wet meadows in the Piné High Plain (North Italy)

    OpenAIRE

    Gafta, Dan; Canullo, Roberto

    2017-01-01

    Four rnain successional stages in the abandoned rnowed meadows belonging to Junco Molinietum association are evidenced by means of a structural study of the colonizing tree species, and especially far the black alder. The graduai decrease in soil humidity and the forrnation of high tufts of Molinia make possible only the vegetative propagation of the black alder and the penetration of rnesophilous tree species. Under the alder wood, corresponding to the third stage of the succession, na...

  19. NC-Impacts of Peatland Ditching and Draining on Water Quality and Carbon Sequestration Benefits of Peatland Restoration

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Re-wetting peatlands through hydrology restoration on Pocosin Lakes National Wildlife Refuge will return previous drained wetlands to a more nature state and is...

  20. [Ash Meadows Purchase Proposal

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A proposal sent to the Richard King Mellon Foundation for a loan to fund the purchase of Ash Meadows by the Nature Conservancy. Ash Meadows, set outside of Las Vegas...

  1. Geomorphic processes affecting meadow ecosystems [chapter 3

    Science.gov (United States)

    Jerry R. Miller; Dru Germanoski; Mark L. Lord

    2011-01-01

    Three geomorphic processes are of primary concern with respect to the current and future state of wet meadow ecosystems: channel incision, avulsion (the abrupt movement of the channel to a new location on the valley floor), and gully formation. Gully formation often is accompanied by upvalley headcut migration and a phenomenon referred to as "groundwater sapping...

  2. Greenhouse gas flux from tropical peatlands: context and controls

    Science.gov (United States)

    Page, Susan; Jauhiainen, Jyrki; Hooijer, Aljosja

    2010-05-01

    . It discusses likely responses of tropical peatlands to a changing climate and considers the scope for mitigation to reduce greenhouse gas emissions, including hydrological rehabilitation and reforestation. This information is highly relevant to current tropical peatland carbon emission reduction programmes, which aim to re-wet the peat in order to reduce the CO2 flux from peat decomposition as well as from fire. There is an urgent requirement to develop simulation tools (models) capable of predicting the dynamic response of peatland ecosystem-atmosphere CO2exchange to environmental change and landuse (e.g. hydrological) management.

  3. 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.

  4. Holocene peatland initiation in the Greater Everglades

    Science.gov (United States)

    Dekker, Stefan; de Boer, Hugo; Dermody, Brian; Wagner-Cremer, Friederike; Wassen, Martin; Eppinga, Maarten

    2015-04-01

    The mechanisms involved in the initiation and development of the Greater Everglades peatland ecosystems in South Florida (USA) remain a topic of discussion. In this study, we present an overview of basal ages of peat deposits in South Florida, which shows two major episodes of peatland initiation between 7.0-4.5 kyr and 3.5-2.0 kyr. Our analysis of regional climate proxy datasets led to three alternative hypotheses that may explain the timing and duration of these two peatland initiation episodes: (1) decreased drainage due to relative sea level (RSL) rise during the Holocene (2) gradual increase in precipitation throughout the Holocene, and (3) a combination of increasing precipitation, rising RSL and oscillations in the climate system. We test whether these three hypotheses can explain the pattern of initiation and development of the Greater Everglades peatlands using models that simulate the non-linear processes involved in peat production and decomposition in combination with the local drainage conditions of Southern Florida. The model results suggest that RSL-rise alone cannot predict the onset of peat initiation in the Greater Everglades using our model setup. The model also implies that the climate was wet enough for peat development also during the early Holocene. The first two hypothesized mechanisms in combination with climate oscillations may explain the onset of peat accumulation at 8.2 kyr BP. The two-phased character of peat land initiation may be explained by the spatial distribution of local drainage conditions. As peatland development is highly non-linear, our model uncovers a mechanistic way how peats can suddenly shift from a dry high equilibrium to a wet low equilibrium resulting in lake formation as observed in paleo-ecological studies in the Greater Everglades.

  5. Plant biomass and species composition along an environmental gradient in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; E. N. Jack Brookshire; John E. Baham

    2004-01-01

    In riparian meadows, narrow zonation of the dominant vegetation frequently occurs along the elevational gradient from the stream edge to the floodplain terrace. We measured plant species composition and above- and belowground biomass in three riparian plant communities - a priori defined as wet, moist, and dry meadow - along short streamside topographic gradients in...

  6. Effects of traditional flood irrigation on invertebrates in lowland meadows.

    Science.gov (United States)

    Schirmel, Jens; Alt, Martin; Rudolph, Isabell; Entling, Martin H

    2014-01-01

    Lowland meadow irrigation used to be widespread in Central Europe, but has largely been abandoned during the 20th century. As a result of agri-environment schemes and nature conservation efforts, meadow irrigation is now being re-established in some European regions. In the absence of natural flood events, irrigation is expected to favour fauna typical of lowland wet meadows. We analysed the effects of traditional flood irrigation on diversity, densities and species composition of three invertebrate indicator taxa in lowland meadows in Germany. Unexpectedly, alpha diversity (species richness and Simpson diversity) and beta diversity (multivariate homogeneity of group dispersions) of orthopterans, carabids, and spiders were not significantly different between irrigated and non-irrigated meadows. However, spider densities were significantly higher in irrigated meadows. Furthermore, irrigation and elevated humidity affected species composition and shifted assemblages towards moisture-dependent species. The number of species of conservation concern, however, did not differ between irrigated and non-irrigated meadows. More variable and intensive (higher duration and/or frequency) flooding regimes might provide stronger conservation benefits, additional species and enhance habitat heterogeneity on a landscape scale.

  7. Effect of peat characteristics on P, N and DOC mobilization from re-wetted peat soils - a laboratory column study for the impacts of restoration on forestry-drained peatlands

    Science.gov (United States)

    Koskinen, Markku; Kaila, Annu; Asam, Zaki; Uusitalo, Risto; Smolander, Aino; Kiikkilä, Oili; Sarkkola, Sakari; Kitunen, Veikko; Fritze, Hannu; Nousiainen, Hannu; Tervahauta, Arja; Xiao, Liwen; Nieminen, Mika

    2016-04-01

    Peatlands are an integral part of the hydrological cycle in the boreal and temperate zones, providing ecosystem services such as water filtering. From the mid to late 1900's, over 15 ha of peatlands and wetlands were drained for forestry in the temperate and boreal zones, causing deterioration of biodiversity and loss of ecosystem services. They are now being restored in order to reverse this development. Restoration of pealands has been found to cause leaching of DOC and nutrients after water level rise and expansion of reducing conditions in the peat. A molar ratio between redox-sensitive Fe and P in the peat of Microbial biomass and mineralization potential of the peat were not found to be important for the export of DOC or P. High NO3 content in the peat predicted high export of NH4 under reducing conditions.

  8. Post-fire ecohydrological conditions at peatland margins in different hydrogeological settings of the Boreal Plain

    Science.gov (United States)

    Lukenbach, M. C.; Hokanson, K. J.; Devito, K. J.; Kettridge, N.; Petrone, R. M.; Mendoza, C. A.; Granath, G.; Waddington, J. M.

    2017-05-01

    In the Boreal Plain of Canada, the margins of peatland ecosystems that regulate solute and nutrient fluxes between peatlands and adjacent mineral uplands are prone to deep peat burning. Whether post-fire carbon accumulation is able to offset large carbon losses associated with the deep burning at peatland margins is unknown. For this reason, we examined how post-fire hydrological conditions (i.e. water table depth and periodicity, soil tension, and surface moisture content) and depth of burn were associated with moss recolonization at the peatland margins of three sites. We then interpreted these findings using a hydrogeological systems approach, given the importance of groundwater in determining conditions in the soil-plant-atmosphere continuum in peatlands. Peatland margins dominated by local groundwater flow from adjacent peatland middles were characterized by dynamic hydrological conditions that, when coupled with lowered peatland margin surface elevations due to deep burning, produced two common hydrological states: 1) flooding during wet periods and 2) rapid water table declines during dry periods. These dynamic hydrological states were unfavorable to peatland moss recolonization and bryophytes typical of post-fire recovery in mineral uplands became established. In contrast, at a peatland margin where post-fire hydrological conditions were moderated by larger-scale groundwater flow, flooding and rapid water table declines were infrequent and, subsequently, greater peatland-dwelling moss recolonization was observed. We argue that peatland margins poorly connected to larger-scale groundwater flow are not only prone to deep burning but also lags in post-fire moss recovery. Consequently, an associated reduction in post-fire peat accumulation may occur and negatively affect the net carbon sink status and ecohydrological and biogeochemical function of these peatlands.

  9. Characterizing the Source Water for Montane Meadows to Assess Resiliency under Changing Hydroclimatic Condition

    Science.gov (United States)

    Yarnell, S. M.; Peek, R.; Bell, A.; Weixelman, D.; Viers, J. H.

    2015-12-01

    Ecologically and hydrologically functioning montane meadows provide a variety of ecosystem services and create biological hotspots in high-elevation landscapes. They serve as wetlands that filter water, attenuate floods, sequester carbon, sustain downstream flows, and provide high productivity habitat in typically lower productivity mountain regions. Their importance to watershed quality and health is well recognized, and restoration of meadows is a high priority for resource management agencies and non-governmental organizations. Yet many meadow restoration projects have limited outcomes or fail to achieve the desired effects due to a lack of understanding the underlying hydrological and geomorphic processes inherent to meadows that contribute to their resiliency. Few studies exist on how meadows are sustained through time despite various land use impacts or how the origin of water supplying the meadow (snowmelt-dominated versus regional groundwater-dominated) may influence meadow conditions. Furthermore, as climate conditions continue to change, questions remain regarding which meadows will be most resistant to and resilient from climate warming and thus have the highest potential for successful and sustainable restoration of meadow processes. We discuss these concepts and present two methods for assessing the regional and local contributions of source water to meadows as an indicator of resiliency. On a broad scale, comparisons of satellite imagery using metrics such as normalized difference vegetation index (NDVI) for regions with meadows may be useful to detect inter-annual and seasonal variations in meadow wetness and thus indicate meadow sites with larger groundwater sources that are more resilient over time. Locally, use of a hydrogeomorphic typing key that relates water source, geomorphic position, groundwater table elevation, and plant species composition may be useful to detect local groundwater sources that provide greater consistency of conditions and

  10. COENOLOGICAL STATUS OF THE IRIS MEADOWS IN HUNGARY

    Directory of Open Access Journals (Sweden)

    E. SALAMON-ALBERT

    2010-04-01

    Full Text Available Species composition and vegetation structure by association and local diagnostic, constant and dominant species of Iridetum sibiricae was analysed from Hungary adjusting to the evaluation of European vegetation. Classification, ordination and statistical analyses was carried out to characterize and make distinction to some other wet meadow vegetation types. In the association habitat and management dependent subunits were formed.

  11. Meadow based Fraction Theory

    OpenAIRE

    Bergstra, Jan A.

    2015-01-01

    In the context of an involutive meadow a precise definition of fractions is formulated and on that basis formal definitions of various classes of fractions are given. The definitions follow the fractions as terms paradigm. That paradigm is compared with two competing paradigms for storytelling on fractions: fractions as values and fractions as pairs.

  12. A multi-scale evaluation of pack stock effects on subalpine meadow plant communities in the Sierra Nevada.

    Science.gov (United States)

    Lee, Steven R; Berlow, Eric L; Ostoja, Steven M; Brooks, Matthew L; Génin, Alexandre; Matchett, John R; Hart, Stephen C

    2017-01-01

    We evaluated the influence of pack stock (i.e., horse and mule) use on meadow plant communities in Sequoia and Yosemite National Parks in the Sierra Nevada of California. Meadows were sampled to account for inherent variability across multiple scales by: 1) controlling for among-meadow variability by using remotely sensed hydro-climatic and geospatial data to pair stock use meadows with similar non-stock (reference) sites, 2) accounting for within-meadow variation in the local hydrology using in-situ soil moisture readings, and 3) incorporating variation in stock use intensity by sampling across the entire available gradient of pack stock use. Increased cover of bare ground was detected only within "dry" meadow areas at the two most heavily used pack stock meadows (maximum animals per night per hectare). There was no difference in plant community composition for any level of soil moisture or pack stock use. Increased local-scale spatial variability in plant community composition (species dispersion) was detected in "wet" meadow areas at the two most heavily used meadows. These results suggest that at the meadow scale, plant communities are generally resistant to the contemporary levels of recreational pack stock use. However, finer-scale within-meadow responses such as increased bare ground or spatial variability in the plant community can be a function of local-scale hydrological conditions. Wilderness managers can improve monitoring of disturbance in Sierra Nevada meadows by adopting multiple plant community indices while simultaneously considering local moisture regimes.

  13. Flooding tolerance of four floodplain meadow species depends on age.

    Science.gov (United States)

    Gattringer, Johannes P; Donath, Tobias W; Eckstein, R Lutz; Ludewig, Kristin; Otte, Annette; Harvolk-Schöning, Sarah

    2017-01-01

    Numerous restoration campaigns focused on re-establishing species-rich floodplain meadows of Central Europe, whose species composition is essentially controlled by regular flooding. Climate change predictions expect strong alterations on the discharge regime of Europe's large rivers with little-known consequences on floodplain meadow plants. In this study, we aim to determine the effects of flooding on seedlings of different ages of four typical flood meadow species. To this end, we flooded seedlings of two familial pairs of flood meadow species of wetter and dryer microhabitats for 2 weeks each, starting 2, 4, 6, and 8 weeks after seedling germination, respectively. We show that a 2-week-flooding treatment had a negative effect on performance of seedlings younger than 6 weeks. Summer floods with high floodwater temperatures may have especially detrimental effects on seedlings, which is corroborated by previous findings. As expected, the plants from wet floodplain meadow microhabitats coped better with the flooding treatment than those from dryer microhabitats. In conclusion, our results suggest that restoration measures may perform more successfully if seedlings of restored species are older than the critical age of about 6 weeks before a spring flooding begins. Seasonal flow patterns may influence vegetation dynamics of floodplain meadows and should, therefore, be taken into account when timing future restoration campaigns.

  14. Flooding tolerance of four floodplain meadow species depends on age

    Science.gov (United States)

    Donath, Tobias W.; Eckstein, R. Lutz; Ludewig, Kristin; Otte, Annette; Harvolk-Schöning, Sarah

    2017-01-01

    Numerous restoration campaigns focused on re-establishing species-rich floodplain meadows of Central Europe, whose species composition is essentially controlled by regular flooding. Climate change predictions expect strong alterations on the discharge regime of Europe’s large rivers with little-known consequences on floodplain meadow plants. In this study, we aim to determine the effects of flooding on seedlings of different ages of four typical flood meadow species. To this end, we flooded seedlings of two familial pairs of flood meadow species of wetter and dryer microhabitats for 2 weeks each, starting 2, 4, 6, and 8 weeks after seedling germination, respectively. We show that a 2-week-flooding treatment had a negative effect on performance of seedlings younger than 6 weeks. Summer floods with high floodwater temperatures may have especially detrimental effects on seedlings, which is corroborated by previous findings. As expected, the plants from wet floodplain meadow microhabitats coped better with the flooding treatment than those from dryer microhabitats. In conclusion, our results suggest that restoration measures may perform more successfully if seedlings of restored species are older than the critical age of about 6 weeks before a spring flooding begins. Seasonal flow patterns may influence vegetation dynamics of floodplain meadows and should, therefore, be taken into account when timing future restoration campaigns. PMID:28467463

  15. Twenty Years of "Plug-and-Pond" Meadow Restoration: A Geomorphic Review

    Science.gov (United States)

    Natali, J.

    2015-12-01

    Channel incision has degraded the ecological function of wet meadows across montane regions of California. Conservation groups estimate that half of the Sierra Nevada's 333,000 acres of meadow are entrenched in a degraded state that is characterized by a shift from groundwater­fed, herbaceous vegetation to more sparse, drought­tolerant woody vegetation. My poster will present results of field research on a prominent restoration technique in California's montane meadows, the "Plug­and­Pond." Fundamentally, the technique re­channelizes the meadow by blocking flow into incised stream channels. Spoils dug from meadow sediments plug the incised channel, creating ponds as a by­product. One of three approaches to re­channelization ensues: (1) construct a new shallow and sinuous channel, (2) redirect flows into a remnant channel, (3) or allow the channel to define itself over the meadow floodplain. Re­ channelization aims to support overbank flows at 1.5 to 3 year recurrence intervals. Field surveys of ten of the oldest "plug-and-pond" meadow restoration projects in California reveal that channel bed degradation caused by meadow-scale changes to channel slope (i.e. culverts concentrating flows, channel straightening, meadow grazing) may be more conducive to intensive restoration approaches like Plug-and-Pond.

  16. 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.

  17. How hydrology and vegetation modify microclimate of a Sphagnum peatland?

    Science.gov (United States)

    Słowińska, Sandra; Słowiński, Michał; Marcisz, Katarzyna; Lamentowicz, Łukasz; Lamentowicz, Mariusz

    2014-05-01

    Climate and hydrology are key factors influencing peat accumulation and decomposition. This, in turn have strong influence on carbon sequestration what is nowadays the central aim of peatlands ecology. However, peatlands are not homogenous ecosystems. There are often a mosaic of vegetation patterns. Differences in depth of groundwater tables are also common at one object. We designed a long-term ecological study site in a Sphagnum peatland in the Northern Poland. We used five meteorological micro-stations and eleven piezometers located along two transects at 5,95 ha area. We have focused on microclimatic and hydrological changes during two growing seasons - 2012 and 2013. Significant differences in radiation, air temperature and humidity were recorded between plots, which were mainly a result of reduction of light availability by trees in two of five plots. That also influenced on surface wetness of Sphagnum mosses. Range of groundwater table changes varied between plots but trends were similar. Further research will focus on the synthesis of relationships between climate, hydrology and vegetation. A separate work will be concentrated on testate amoebae response to wetness, temperature and light availability. Our study is very important to better understand peatland functioning in transition climate in small spatial scale. Project supported by Polish National Science Centre grant No. NN306060940 and the grant PSPB-013/2010 from Switzerland through the Swiss Contribution to the enlarged European Union.

  18. Cattle grazing and conservation of a meadow-dependent amphibian species in the Sierra Nevada.

    Directory of Open Access Journals (Sweden)

    Leslie M Roche

    Full Text Available World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus. However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July-mid September grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this

  19. Cattle grazing and conservation of a meadow-dependent amphibian species in the Sierra Nevada.

    Science.gov (United States)

    Roche, Leslie M; Latimer, Andrew M; Eastburn, Danny J; Tate, Kenneth W

    2012-01-01

    World-wide population declines have sharpened concern for amphibian conservation on working landscapes. Across the Sierra Nevada's national forest lands, where almost half of native amphibian species are considered at risk, permitted livestock grazing is a notably controversial agricultural activity. Cattle (Bos taurus) grazing is thought to degrade the quality, and thus reduce occupancy, of meadow breeding habitat for amphibian species of concern such as the endemic Yosemite toad (Anaxyrus [ = Bufo] canorus). However, there is currently little quantitative information correlating cattle grazing intensity, meadow breeding habitat quality, and toad use of meadow habitat. We surveyed biotic and abiotic factors influencing cattle utilization and toad occupancy across 24 Sierra Nevada meadows to establish these correlations and inform conservation planning efforts. We utilized both traditional regression models and Bayesian structural equation modeling to investigate potential drivers of meadow habitat use by cattle and Yosemite toads. Cattle use was negatively related to meadow wetness, while toad occupancy was positively related. In mid and late season (mid July-mid September) grazing periods, cattle selected for higher forage quality diets associated with vegetation in relatively drier meadows, whereas toads were more prevalent in wetter meadows. Because cattle and toads largely occupied divergent zones along the moisture gradient, the potential for indirect or direct negative effects is likely minimized via a partitioning of the meadow habitat. During the early season, when habitat use overlap was highest, overall low grazing levels resulted in no detectable impacts on toad occupancy. Bayesian structural equation analyses supported the hypothesis that meadow hydrology influenced toad meadow occupancy, while cattle grazing intensity did not. These findings suggest cattle production and amphibian conservation can be compatible goals within this working landscape.

  20. 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.

  1. Drying-induced decomposition and associated changes in aggregation and carbon distribution in subalpine meadow soils: implication of drought

    Science.gov (United States)

    Berhe, A. A.; Arnold, C. L.; Ghezzehei, T. A.

    2016-12-01

    While peatlands are garnering much attention for their greenhouse gas feedback potential in a warming climate, the coupled biogeochemical and hydrological impact of structural and physical changes in these types of systems as a result of drought-induced drying and desiccation has not been studied in detail. The cyclic drawdown/recharge of the water table that exists in most peatland systems impose important controls on organic matter storage and decomposition as well as soil physical properties. In order to better understand how high elevation peatlands will respond to increasingly dry years, we incubated meadow soils collected along a hydrologic gradient at 5 different water potentials and measured the CO2 flux at intervals for over one year to determine how desiccation of meadow soils (from the Harvey Monroe Hall Research Natural Area at the crest of the Sierra Nevada) influences gaseous fluxes of C, as well as aggregation of the organic-rich soils and distribution of the soil C in different physical pools (macro- vs. micro-aggregate, and silt+ clay fractions). We found that the cumulative carbon mineralization was greatest at the highest (0.1 bar) and lowest (4 bar) water potential, across all regions of the meadow, indicating the presence of two separate pools of labile carbon that can be accessed only after a threshold of drying is reached in the soil. We also observe important changes associated with aggregate size distributions and fraction of total carbon distributed in three distinct pools.

  2. 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

  3. Current state of peatland soils as an effect of long-term drainage – preliminary results of peatland ecosystems investigation in the Grójecka Valley (central Poland

    Directory of Open Access Journals (Sweden)

    Glina Bartłomiej

    2016-03-01

    Full Text Available Understanding the effect of long-term drainage of peatland areas is helpful in future peatland management and regulations of water conditions. The aim of this work was to assess the current state of fen peatland soils in the Grójecka Valley (eastern part of the Wielkopolskie voivodeship, central Poland, affected by long-term agricultural use (pastures, meadows since the 1960s and potentially by lignite open pit mining industry (KWB Konin since 1980s. Field studies were carried out in 2015 in selected fen peatland areas. Soil material for laboratory analysis was collected from genetic horizons from four soil profiles. The surface horizons of studied organic and organo-mineral soils were built with well-developed moorsh material. They were classified as medium moorshiefied – MtII (profile 1, 3 and 4 and strongly moorshiefied – MtIII (profile 2. Obtained results of physical and physico-chemical analysis indicate that long-term peatland utilization connected with potential impact of the lignite mining, transformed mainly the upper horizons of studied organic and organo-mineral soils. However, despite obvious strong human impact on peatlands ecosystems, we cannot exclude the climate variables, what should be confirmed by long-term monitoring program. Furthermore, presented paper indicated that new subtype moorsh-muddy soils (in Polish: gleby murszowo-mułowe within the type of gleyic soils should be implemented in the next version of Polish Soil Classification.

  4. Sierra Meadows Project [ds4

    Data.gov (United States)

    California Department of Resources — Recognizing Montane Meadows and Quaking Aspen communities are a rare and valuable resource to plant and animal species in the Sierra Nevada, this project represents...

  5. AshMeadowsNaucorid_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Naucorid (Ambrysus amargosus) occur. "Nevada, Nye County. Point of Rocks Springs and...

  6. Biomass for energy from rewetted peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Wichtmann, W. [Institute for Sustainable Development of Landscape, Greifswald (Germany)

    2006-07-01

    In Germany the demand for biomass for energy purposes is increasing. The shortage of biomass can already be observed in hardening of prices. On arable lands conventional agriculture for comestibles competes with cultivation of industrial and energetical raw materials. Coevally the requirement for fen grasslands is declining. This implies a great chance for new concepts of land use on fen peatlands, that are no longer needed for grassland production. The utilisation of fens as grasslands is generally accompanied by heavy environmental impacts and the loss of species diversity. Here an alternative concept for fen-peatland use is proposed which involves the reestablishment of wet conditions. The naturally developing, high productive reed stands can be used as an energy source in direct combustion or for the production of liquid 'sun fuels'. The plantation of habitat-adapted plant species after rewetting could be a feasible alternative to spontaneous vegetation development. This practice helds economical promises. In Northern Germany alone, about 200,000 hectares of lowlands could be rewetted for biomass production. The harvest from these areas could feed 20 power plants of 20 MW capacity each. (orig.)

  7. Riparian Meadow Response to Modern Conservation Grazing Management

    Science.gov (United States)

    Oles, Kristin M.; Weixelman, Dave A.; Lile, David F.; Tate, Kenneth W.; Snell, Laura K.; Roche, Leslie M.

    2017-09-01

    Riparian meadows occupy a small proportion of the public lands in the western United States but they provide numerous ecosystem services, including the production of high-quality forage for livestock grazing. Modern conservation management strategies (e.g., reductions in livestock stocking rates and adoption of new riparian grazing standards) have been implemented to better balance riparian conservation and livestock production objectives on publicly managed lands. We examined potential relationships between long-term changes in plant community, livestock grazing pressure and environmental conditions at two spatial scales in meadows grazed under conservation management strategies. Changes in plant community were not associated with either livestock stocking rate or precipitation at the grazing allotment (i.e., administrative) scale. Alternatively, both grazing pressure and precipitation had significant, albeit modest, associations with changes in plant community at the meadow (i.e., ecological site) scale. These results suggest that reductions in stocking rate have improved the balance between riparian conservation and livestock production goals. However, associations between elevation, site wetness, precipitation, and changes in plant community suggest that changing climate conditions (e.g., reduced snowpack and changes in timing of snowmelt) could trigger shifts in plant communities, potentially impacting both conservation and agricultural services (e.g., livestock and forage production). Therefore, adaptive, site-specific management strategies are required to meet grazing pressure limits and safeguard ecosystem services within individual meadows, especially under more variable climate conditions.

  8. 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

    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...... 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...... vegetation and mosses. The microcosms represented wet hollows and dry hummocks of a boreal ombrotrophic bog. A water table drawdown treatment was applied to the hollows with naturally high water table. The mean (±SE) isoprene emission from hummocks with intact vegetation, 30 ± 6 µg m-2 h-1, was decreased...

  9. Hydrologic processes influencing meadow ecosystems [chapter 4

    Science.gov (United States)

    Mark L. Lord; David G. Jewett; Jerry R. Miller; Dru Germanoski; Jeanne C. Chambers

    2011-01-01

    The hydrologic regime exerts primary control on riparian meadow complexes and is strongly influenced by past and present geomorphic processes; biotic processes; and, in some cases, anthropogenic activities. Thus, it is essential to understand not only the hydrologic processes that operate within meadow complexes but also the interactions of meadow hydrology with other...

  10. Methanogenesis limitations in degraded peatlands after their hydrological restoration

    Science.gov (United States)

    Urbanová, Zuzana

    2017-04-01

    reflected a not fully restored vegetation structure with sufficient litter production. Thus, the re-establishment of peatland vegetation structure should lead to regeneration of methanogenic activity and microbial processes in restored peatlands. Moreover, the results showed that there is no risk of increased CH4 emissions in the case of nutrient poor bogs and SSF after re-wetting. For management, the methanogenic community composition, abundance and activity could be used as indicators of restoration success.

  11. Registration of Azov meadow fescue

    Science.gov (United States)

    'Azov' meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.; syn. Festuca pratensis Huds.; syn. Lolium pratense (Huds.) Darbysh.] is a synthetic population originating from 1000 parental genotypes. The parents of Azov were selected from ten Russian plant introductions, mostly originating from the...

  12. Meadow enriched ACP process algebras

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2009-01-01

    We introduce the notion of an ACP process algebra. The models of the axiom system ACP are the origin of this notion. ACP process algebras have to do with processes in which no data are involved. We also introduce the notion of a meadow enriched ACP process algebra, which is a simple generalization

  13. 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

  14. Peatland vulnerability to energy-related developments from climate change policy in Ireland: the case of wind farms

    Directory of Open Access Journals (Sweden)

    F. Renou-Wilson

    2009-05-01

    Full Text Available Ireland enjoys a wet and windy climate which is highly suitable for both peatlands and wind farms. There are currently 73 wind farms in Ireland, 39 of which are located on upland peatland - the oldest one on an industrially extracted blanket bog. The national and local (county level policy in relation to wind farms is to promote renewable energy in order to decrease dependence on imported fossil fuels and to mitigate climate change by reducing carbon emissions from non-renewable energy sources, whilst taking account of statutory obligations for planning and sustainable development. Lessons learned from past developments and ongoing monitoring have been applied in adapting guidelines for planning authorities and environmental impact assessment. However, although the vulnerability of peatland habitats is emphasised in the guideline documents, wind farm proposals for sensitive upland peatland sites continue to appear. Any development that involves drainage and fragmentation of peatlands has irreversible impacts on these ecosystems. Furthermore, the perceived ‘green profile’ of wind farms means that they tend to be viewed in a different light from other developments. It is proposed that any development on the nationally and internationally significant peatland resource of Ireland should undergo rigorous examination and impact assessment, and that degraded peatlands such as the industrial peat extraction areas in the Irish Midlands be selected as alternative locations for wind farm development.

  15. 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

  16. Climatic triggers for peatland initiation

    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.

    2017-04-01

    Peatlands are carbon-dense wetlands characterised by waterlogged, organic-rich soils. Modern-day peatlands have formed mainly since the Last Glacial Maximum (LGM), and despite covering only 3 % of the Earth's land surface are thought to store more than a third of all global soil carbon in the form of poorly decomposed plant detritus. Concern exists that this globally important carbon store may be vulnerable to near-future warming and changes in precipitation patterns, although the links between peatland development and climate are contested. The climatic and other environmental conditions that facilitate the initiation of peat are particularly poorly understood. We present the results of a novel, global study into the climate space of peat initiation since the LGM. We compiled a catalogue of radiocarbon dates of peat initiation from 942 sites that span a range of latitudes and biomes. We used the locations and ages of these peatlands to interrogate downscaled climate hindcasts at 500-yr intervals from a coupled atmosphere-ocean-vegetation general circulation model, HadCM3. This powerful combination of modelling and observational data provides a globally-consistent, temporally-extensive estimate of the climate spaces of peat initiation. In particular, it allows us to identify local and regional climatic changes that may have acted as triggers for peat formation. Peatlands in mid- and high-latitudes of both hemispheres, particularly in maritime locations, developed shortly after local increases in the time integral of growing season temperatures, and were seemingly not influenced by rainfall regime. Peat initiation at such sites appears to have been stimulated by temperature-driven increases in plant productivity in cold, postglacial landscapes, and was not water limited. The exception is the large peatland complex of the Western Siberian Lowlands, which was not glaciated during the last glacial period, and which appears to have been prompted instead by a strong

  17. Holocene climate change and peatland dynamics in the Altai Mountains in Northwest China

    Science.gov (United States)

    Zhao, Y.; Yu, Z.; Li, Q.; Zhao, W.

    2013-12-01

    Here we present preliminary results from a peat-core record to investigate responses of upland vegetation and peatlands to Holocene climate change in the Altai Mountains. Chronology of a 650-cm-long peat core from the Iron Arshad Khan (IAK) peatland in the western Altai Mountains was controlled by 20 AMS dates on identifiable terrestrial macrofossils, covering the entire Holocene. Lithology results indicate that the peat accumulation initiated at 11 ka (1 ka =1000 cal BP), with a sharp increase in organic matter content to >80%. Plant macrofossil data show a sequence of changes from the peatlands dominated by Cyperaceae before 8.1 ka, to Cyperaceae and brown moss-dominated at 8-4.5 ka, Sphagnum and Cyperaceae-dominated at 4.5-2 ka, and to Cyperaceae-dominated again after 2 ka. Carbon accumulation rates were highest at >40 gC/m2/yr at 8.5-7 ka, more than doubled the Holocene average at the site. Pollen analysis shows the highest tree pollen (mainly from Picea) of up to 59% occurred at 8-6.4 ka, suggesting a warm and wet mid-Holocene 'optimum' climate in the region. Organic matter bulk density shows an increasing trend after 6.4 ka, suggesting increasing cumulative decomposition of accumulated peat. Our multi-proxy data indicate clear responses of peatland species composition, moisture conditions and carbon accumulation to regional climate change. The cooling and drying trend since the mid-Holocene was likely in response to the decrease in summer insolation and in westerly-induced precipitation. Furthermore, our results from this temperate highland peatland may shed new lights on understanding peatland carbon dynamics in northern Eurasia, including the largest peatland basin in West Siberia, as well as Holocene climate changes in central Asia.

  18. Resilience in heterogeneous landscapes: The effect of topography on resilience of carbon uptake in northern peatlands

    Science.gov (United States)

    Nijp, Jelmer; Temme, Arnaud; van Voorn, George; Teuling, Ryan; Soons, Merel; Kooistra, Lammert

    2016-04-01

    Northern peatlands contain and store enormous amounts of carbon, and therefore represent an important component of the carbon cycle of the earth. In these wetland ecosystems, the quality of the soil added to the soil surface is determined by the type of peat-forming plants, and affects the carbon accumulated in the peat soil later formed and overall ecosystem functioning. Peatland vegetation is frequently organized in alternating dry hummocks with wet hollows. Such patterned vegetation is associated with different soil carbon accumulation rates, and may develop due to various self-regulating processes originating from ecohydrological feedbacks. Simulation models have shown that vegetation patterning may promote the resilience of peatlands to environmental change (climate, land use), hence maintaining their function as carbon sink. Critically, the results of these model studies rely on the fundamental assumption that environmental conditions are spatially homogeneous. Yet, in real landscape settings, catchment topography has a major impact on water flow and nutrient availability, and is expected to alter vegetation patterning. However, whether, where and how topography affects vegetation patterning in peatlands and associated resilience of ecosystem service provision remains unknown. By combining field observations, remote sensing, and dynamic simulation models (used both as 'sandbox' and 'resilience calculator' for given geomorphological settings), we determine how landscape topography affects ecohydrological processes, vegetation patterning, and associated resilience to environmental change in northern peatlands.

  19. Ectomycorrhizal root development in wet Alder carr forests in response to desiccation and eutrophication

    NARCIS (Netherlands)

    Baar, J.; Bastiaans, T.; Coevering van de, M.A.; Roelofs, J.G.M.

    2002-01-01

    Effects of desiccation and eutrophication on ectomycorrhizal (ECM) root development in wet Alder carr forests in The Netherlands were studied. In northwestern Europe, wet Alder carr forests are found mostly in peatlands and along streams, forming an important component of wetland ecosystems. The

  20. 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

  1. The effects of climate change on decomposition in Dutch peatlands : an exploration of peat origin and land use effects

    NARCIS (Netherlands)

    Brouns, K.

    2016-01-01

    Peat is formed in wet and acidic conditions, where net primary production exceeds the decomposition of organic matter. Peatlands cover a small part of the earth surface but hold vast amounts of carbon. Land use change and climate change can turn this large carbon sink into a carbon source, thereby

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

    Directory of Open Access Journals (Sweden)

    J. Connolly

    2017-03-01

    drains on a blanket bog in the west of Ireland. The results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from “wetlands drainage and rewetting”. The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

  3. Tracing peatland geomorphology: sediment and contaminant movements in eroding and restored systems

    Science.gov (United States)

    Shuttleworth, Emma; Evans, Martin; Hutchinson, Simon; Rothwell, James

    2015-04-01

    Peatlands are an important store of soil carbon, play a vital role in global carbon cycling, and can also act as sinks of atmospherically deposited heavy metals. However, large areas of blanket peat are significantly degraded and actively eroding as a direct result of anthropogenic pressures, which negatively impacts carbon and pollutant storage. The restoration of eroding UK peatlands is a major conservation concern, and over the last decade measures have been taken to control erosion and restore large areas of degraded peat. In severely eroded peatlands, topography is highly variable, and an appreciation of geomorphological form and process is key in understanding the controls on peatland function, and in mitigating the negative impacts of peatland erosion. The blanket peats of the Peak District, Southern Pennines, UK embody many problems and pressures faced by peatlands globally, and are amongst the most heavily eroded and contaminated in the world. The near-surface layer of the peat is contaminated by high concentrations of anthropogenically derived, atmospherically deposited heavy metals which are released into the fluvial system as a consequence of widespread erosion. Whilst not desirable, this legacy of lead pollution and its release offer a unique opportunity to trace peatland sediment movements and thus investigate the controls on sediment and contaminant mobility. A suite of established field, analytical and modelling techniques have been modified and adapted for use in peatland environments and these have been successfully employed in combination to address issues of sediment and contaminant release at a range of scales, including: (i) the development of field portable XRF to assess in situ lead concentrations in wet organic sediments; (ii) adaptation of time integrated mass flux samplers to explore spatial and temporal sediment dynamics in peatland streams; and (iii) the application of sediment source fingerprinting and numerical mixing models to

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

    Science.gov (United States)

    Connolly, J; Holden, N M

    2017-12-01

    results show that information on drain extent and location can be extracted from high resolution imagery and mapped with a high degree of accuracy. Under Article 3.4 of the Kyoto Protocol Annex 1 parties can account for greenhouse gas emission by sources and removals by sinks resulting from "wetlands drainage and rewetting". The ability to map the spatial extent, density and location of peatlands drains means that Annex 1 parties can develop strategies for drain blocking to aid reduction of CO 2 emissions, DOC runoff and water discoloration. This paper highlights some uncertainty around using one-size-fits-all emission factors for GHG in drained peatlands and re-wetting scenarios. However, the OBIA method is robust and accurate and could be used to assess the extent of drains in peatlands across the globe aiding the refinement of peatland carbon dynamics .

  5. Division by zero in common meadows

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2014-01-01

    Common meadows are fields expanded with a total inverse function. Division by zero produces an additional value denoted with "a" that propagates through all operations of the meadow signature (this additional value can be interpreted as an error element). We provide a basis theorem for so-called

  6. Division by zero in common meadows

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.; De Nicola, R.; Hennicker, R.

    2015-01-01

    Common meadows are fields expanded with a total inverse function. Division by zero produces an additional value denoted with "a" that propagates through all operations of the meadow signature (this additional value can be interpreted as an error element). We provide a basis theorem for so-called

  7. Hydrological modelling of drained blanket peatland

    Science.gov (United States)

    Ballard, C. E.; McIntyre, N.; Wheater, H. S.; Holden, J.; Wallage, Z. E.

    2011-09-01

    SummaryOpen ditch drainage is a commonly implemented land management practice in upland blanket peatlands, particularly in the UK, where policy decisions between the 1940s and 1970s led to widespread drainage of the uplands. The change in the hydrological regime associated with the drainage of blanket peat is poorly understood, yet has perceived importance for flooding, low flows and water quality. We propose a new simplified physics-based model that allows the associated hydrological processes and flow responses to be explored. The model couples four one-dimensional models to represent a three-dimensional hillslope, allowing for the exploration of flow and water table response throughout the model domain for a range of drainage configurations and peat properties. The model is tested against a data set collected from Oughtershaw Beck, UK, with results showing good model performance for wet periods although less conformity with borehole observations during rewetting periods. A wider exploration of model behaviour indicates that the model is consistent with the hydrological response reported in the literature for a number of drained blanket peat sites, and therefore has potential to provide guidance to decision makers concerning the effects of management practices. Through a global sensitivity analysis, we conclude that further field investigations to assist in the surface and drain roughness parameterisation would help reduce the uncertainty in the model predictions.

  8. Confronting uncertainty in peatland ecohydrology

    Science.gov (United States)

    Morris, P. J.; Waddington, J. M.; Baird, A. J.; Belyea, L. R.

    2011-12-01

    Background and Rationale: Peatlands are heavily water-controlled systems; long-term peat accumulation relies on slow organic matter decay in cool, saturated soil conditions. This interdependence of ecological, hydrological and biogeochemical processes makes peatlands prime examples of ecohydrological systems. Peatland ecohydrology exhibits a number of facets of complexity in the form of multiple mutual interdependencies between physical and biological processes and structures. Uncertainty as to the underlying mechanisms that control complex systems arises from a wide variety of sources; in this paper we explore three types of uncertainty in reference to peatland ecohydrology. 1) Parameterization. Analysis of complex systems such as peatlands lends itself naturally to a simulation modelling approach. An obvious source of uncertainty under a modelling approach is that of parameterization. A central theme in modelling studies is often that of sensitivity analysis: parameters to which model behavior is sensitive must be understood with high fidelity; in less sensitive areas of a model a greater level of uncertainty may be tolerated. Using a simple peatland water-budget model we demonstrate the importance of separating uncertainty from sensitivity. Using a Monte Carlo approach to analyze the model's behavior we identify those parameters that are both uncertain and to which the model's behavior is sensitive, and which therefore exhibit the most pressing need for further research. 2) Model structure. A more subtle form of uncertainty surrounds the assumed algorithmic structure of a model. We analyze the behavior of a simple ecohydrological model of long-term peatland development. By sequentially switching different feedbacks on and off we demonstrate that the level of complexity represented in the model is of central importance to the model's behavior, distinct from parameterization. 3) Spatial heterogeneity. We examine the role of horizontal spatial heterogeneity by

  9. Determining the effects of cattle grazing treatments on Yosemite toads (Anaxyrus [=Bufo] canorus in montane meadows.

    Directory of Open Access Journals (Sweden)

    Susan K McIlroy

    Full Text Available Amphibians are experiencing a precipitous global decline, and population stability on public lands with multiple uses is a key concern for managers. In the Sierra Nevada Mountains (California, USA, managers have specifically identified livestock grazing as an activity that may negatively affect Yosemite toads due to the potential overlap of grazing with toad habitat. Grazing exclusion from Yosemite toad breeding and rearing areas and/or entire meadows have been proposed as possible management actions to alleviate the possible impact of cattle on this species. The primary objective of this study was to determine if different fencing treatments affect Yosemite toad populations. We specifically examined the effect of three fencing treatments on Yosemite toad breeding pool occupancy, tadpoles, and young of the year (YOY. Our hypothesis was that over the course of treatment implementation (2006 through 2010, Yosemite toad breeding pool occupancy and early life stage densities would increase within two fencing treatments relative to actively grazed meadows due to beneficial changes to habitat quality in the absence of grazing. Our results did not support our hypothesis, and showed no benefit to Yosemite toad presence or early life stages in fenced or partially fenced meadows compared to standard USDA Forest Service grazing levels. We found substantial Yosemite toad variation by both meadow and year. This variation was influenced by meadow wetness, with water table depth significant in both the tadpole and YOY models.

  10. 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...

  11. Plant species distribution in relation to water-table depth and soil redox potential in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; John E. Baham

    2006-01-01

    The distribution of riparian plant species is largely driven by hydrologic and soil variables, and riparian plant communities frequently occur in relatively distinct zones along streamside elevational and soil textural gradients. In two montane meadows in northeast Oregon, USA, we examined plant species distribution in three riparian plant communities¡ªdefined as wet,...

  12. Transformation of fractions into simple fractions in divisive meadows

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    Meadows are alternatives for fields with a purely equational axiomatization. At the basis of meadows lies the decision to make the multiplicative inverse operation total by imposing that the multiplicative inverse of zero is zero. Divisive meadows are meadows with the multiplicative inverse

  13. Climate, geography, and tree establishment in subalpine meadows of the Olympic Mountains, Washington, USA

    Science.gov (United States)

    Woodward, Andrea; Schreiner, Edward G.; Silsbee, D.G.

    1995-01-01

    Noticeable changes in vegetation distribution have occurred in the Pacific Northwest during the last century as trees have established in some subalpine meadows. To study the relationship of this process to climate, recently established trees were aged in six subalpine meadows in the Olympic Mountains, Washington. The sites represent three points along a steep precipitation gradient. Subalpine fir (Abies lasiocarpa) has been establishing at the dry end of the gradient, mountain hemlock (Tsuga mertensiana) at the wet end, and both species in the center. Establishment patterns were compared with deviations from the century-long average for these weather variables: winter precipitation, Palmer Drought Severity Index, and winter, October, and May temperatures. Results show that establishment occurred in dry areas when weather conditions were wetter than average, and in wet areas under drier than average conditions. Establishment at central sites did not show consistent relationships with climate. If future climatic conditions continue to warm, establishment of subalpine fir in subalpine meadows in dry areas may cease and mountain hemlock may resume in wet areas.

  14. Multi-decadal water-table manipulation alters peatland hydraulic structure and moisture retention.

    Science.gov (United States)

    Moore, Paul; Morris, Paul; Waddington, James

    2015-04-01

    Peatlands are a globally important store of freshwater and soil carbon. However, there is a concern that these water and carbon stores may be at risk due to climate change as vapour pressure deficits, evapotranspiration and summer moisture deficits are expected to increase, leading to greater water table (WT) drawdown in northern continental regions where peatlands are prevalent. We argue that in order to evaluate the hydrological response (i.e. changes in WT level, storage, surface moisture availability, and moss evaporation) of peatlands under future climate change scenarios, the hydrophysical properties of peat and disparities between microforms must be well understood. A peatland complex disturbed by berm construction in the 1950's was used to examine the long-term impact of WT manipulation on peatland hydraulic properties and moisture retention at three adjacent sites with increasing average depth to WT (WET, INTermediate reference, and DRY). All three sites exhibited a strong depth dependence for hydraulic conductivity, specific yield, and bulk density. Moreover, the effect of microform on near-surface peat properties tended to be greater than the site effect. Bulk density was found to explain a high amount of variance (r2 > 0.69) in moisture retention across a range of pore water pressures (-15 to -500 cm H2O), where bulk density tended to be higher in hollows. The estimated residual water content for surface Sphagnum samples, while on average lower in hummocks (0.082 m3 m-3) versus hollows (0.087 m3 m-3), increased from WET (0.058 m3 m-3) to INT (0.088 m3 m-3) to DRY (0.108 m3 m-3) which has important implications for moisture stress under conditions of persistent WT drawdown. While we did not observe significant differences between sites, we did observe a greater proportional coverage and greater relative height of hummocks at the drier sites. Given the potential importance of microtopographic succession for altering peatland hydraulic structure, our

  15. AshMeadowsSpeckledDace_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each of...

  16. AshMeadowsAmargosaPupfish_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) occur. "Nevada, Nye County: Each of...

  17. Evaluating mountain meadow groundwater response to Pinyon-Juniper and temperature in a great basin watershed

    Science.gov (United States)

    Carroll, Rosemary W.H.; Huntington, Justin L.; Snyder, Keirith A.; Niswonger, Richard G.; Morton, Charles; Stringham, Tamzen K.

    2017-01-01

    This research highlights development and application of an integrated hydrologic model (GSFLOW) to a semiarid, snow-dominated watershed in the Great Basin to evaluate Pinyon-Juniper (PJ) and temperature controls on mountain meadow shallow groundwater. The work used Google Earth Engine Landsat satellite and gridded climate archives for model evaluation. Model simulations across three decades indicated that the watershed operates on a threshold response to precipitation (P) >400 mm/y to produce a positive yield (P-ET; 9%) resulting in stream discharge and a rebound in meadow groundwater levels during these wetter years. Observed and simulated meadow groundwater response to large P correlates with above average predicted soil moisture and with a normalized difference vegetation index threshold value >0.3. A return to assumed pre-expansion PJ conditions or an increase in temperature to mid-21st century shifts yielded by only ±1% during the multi-decade simulation period; but changes of approximately ±4% occurred during wet years. Changes in annual yield were largely dampened by the spatial and temporal redistribution of evapotranspiration across the watershed: Yet the influence of this redistribution and vegetation structural controls on snowmelt altered recharge to control water table depth in the meadow. Even a small-scale removal of PJ (0.5 km2) proximal to the meadow will promote a stable, shallow groundwater system resilient to droughts, while modest increases in temperature will produce a meadow susceptible to declining water levels and a community structure likely to move toward dry and degraded conditions.

  18. 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.

  19. 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

    ditches. The findings were supported by the studies conducted from 2005 at drained peatland sites in Moscow region (European part of Russia) which are used for peat extraction or as hayfield (Chistotin et al., 2006). Unexpected transient methane fluxes were observed at the inter-ditch surfaces in two types of sites: milled peat extraction area and used as a hay field after partial peat extraction. Under warm and wet conditions methane was released even from peat stockpiles. Microbiological studies showed not lower and near to twice higher genomic diversity of methanogens in extracted sites and in a hayfield as compared to virgin mire. We suppose that well-developed plant roots at the grassland provide a source of fresh organic material used for CH4 production. To test this hypothesis, a pot experiment with mesocosms which model three succession stages (bare peat, grass sowing, and developed grassland) under permanently high or fluctuating wetness was conducted. Methane efflux from peat under developed grassland was higher as compared to the other treatments. Under permanently high water supply the methane emission was 1 to 2 orders of magnitude higher. The obtained results clearly showed that plant organic matter can be an additional source of methane after rewetting which is obviously needed for abandoned peatland sites not used for agriculture any more. To mitigate the emissions, such management options as removal of the surface peat layer before rewetting could be applied. This practice could have additional benefits achieved by bringing day surface closer to ground water table level and forming more favorable soil conditions for mire species.

  20. Feeling bogged down about climate change mitigation? Insights from a new high resolution peatland-bog model validated at two Dutch monitoring sites.

    Science.gov (United States)

    Lippmann, Tanya; van Huissteden, Ko; Hendriks, Dimmie

    2017-04-01

    Increasing the global carbon sink is one of two options to mitigate CO2 and CH4 increases in the atmosphere (the other is emissions reductions at the source). Peatlands release carbon to the atmosphere when disturbed by natural or human causes and absorb carbon when vegetation and soil organic matter accumulate after rewetting or natural revegetation. However, rewetting of drained peatlands is frequently not considered as a climate mitigation strategy due to the enhanced methane emissions that accompany newly formed anaerobic peatland environments. We hypothesise that at most sites, this trend will be temporal but long-term, lasting for tens of years post re-wetting before stabilisation takes place. This study investigates the ability of rewetted peatland sites to act as either a source or sink for atmospheric methane and carbon dioxide under climate change. The hydrology of a peatland is fundamental to its functioning. Therefore, the use of a full water balance table has the potential to simulate greenhouse gas fluxes to a greater degree of certainty. MODFLOW is the internationally most widely used ground and surface water model and is freely available to the scientific community. This is the first time that a gridded peatland process based model has been constructed at a spatial resolution as high as 25m x 25m. This new high-resolution model allows for investigation into the complex biophysical and hydrological factors that are necessary to reliably estimate atmospheric greenhouse gas fluxes in a peatland ecosystem. We assess the model's skill against observations collected at two monitoring sites of differing soil properties and vegetation in the Netherlands. These results discuss site-specific suitability of peatland regeneration, useful for climate change mitigation activities. Aside from the insight into transient atmosphere-peatland carbon fluxes, this work is a stepping stone towards more robust model coupling and greater spatial coverage.

  1. 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.

  2. Effects of Permafrost Thaw on Net Ecosystem Carbon Balance in a Subarctic Peatland

    Science.gov (United States)

    Wang, Z.; Roulet, N. T.; Moore, T. R.

    2014-12-01

    This research is to assess changes in net ecosystem carbon balance (NECB) with permafrost thaw in northern peatland: in particular how changes in C biogeochemistry influence NECB. Thawed transects associated with varying stages of permafrost thaw: from palsas with intact permafrost (P), through edge of palsa (EP), dry lawn (DL), wet lawn (WL), edge of thawed pond (ET), pond sedges (PS), to several thawed ponds (TP) in a subarctic peatland in northern Quebec were sampled in the snow free seasons of 2013 and 2014. The exchange of CO2 and CH4, vegetation, dissolved organic C (DOC) concentration and biodegradability, active layer depth, air and peat temperatures, water table depth (WT), pH, and conductivity were measured. Peat temperatures were quite similar among different locations, but the WT decreased significantly along the transect creating varied environmental conditions that supporting different plant communities. From dry to wet area, vegetation abundance and biomass showed reductions of shrubs and lichens, and increases of Sphagnum, grasses and sedges. Pore water pH increased from dry to wet area, and conductivity slightly decreased. Wet thaw area WL, ET and PS had relatively higher season gross ecosystem production (GEP) and higher season ecosystem respiration (ER), but relative similar net ecosystem CO2 exchange (NEE). Only TP had a significant higher positive season NEE. Palsa was the only CH4 sink, and quite high CH4 emissions were found after it thawed. CH4-C release significantly increased from dry to wet in thawed area, which even several times bigger than total C exchange in ET and PS. Generally, wet area had higher DOC concentration and higher DOC biodegradability indicated by lower SUVA254 (except PS which received great influence from pond). All components in the NECB (GEP, ER, CH4, DOC) increased significantly in magnitude from palsa to wet thawed area, and ecosystem C sink turned into source as palsa thawed into PS and TP. These results

  3. Combustibility of biomass from wet fens in Belarus and its potential as a substitute for peat in fuel briquettes

    Directory of Open Access Journals (Sweden)

    W. Wichtmann

    2014-01-01

    Full Text Available Peatland drainage has caused enormous environmental problems at global scale; in particular, ongoing greenhouse gas emissions and soil degradation. In Belarus, which is rich in peatlands and a hotspot of emissions from drained peatlands, several thousand hectares have already been re-wetted but are not used productively. Moreover, vast areas of wet (undrained peatland that are designated for nature conservation are in need of mowing and biomass removal. Plants such as common reed (Phragmites australis, reed canary grass (Phalaris arundinacea and sedges (Carex spp. which frequently dominate these areas could be harvested and used as fuel, potentially as a substitute for peat. In this study we analysed the yield and combustibility of late harvests in March/April 2009 and 2010. The yields of 3.7–11.7 t DM ha-1 were within the range reported from other studies on wetland plants. Concentrations of Cl, S, N, P, C, Ca, K, Mg and Na, as well as water and ash contents, indicated similar or better combustibility when compared to other straw-like (graminaceous plants such as Miscanthus. The full replacement of peat fuel by biomass from wet peatlands in Belarus would require an area of 680,000 ha, i.e. 'only' half of the peatland that has been drained for agriculture.

  4. 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.)

  5. Holocene development of Amazonia's oldest peatland

    Science.gov (United States)

    Swindles, Graeme T.; Morris, Paul J.; Whitney, Bronwen; Galka, Mariusz; Galloway, Jennifer M.; Gallego-Sala, Angela; Macumber, Andrew L.; Mullan, Donal; Smith, Mark W.; Amesbury, Matt; Roland, Thomas; Sanei, Hameed; Patterson, R. Timothy; Parry, Lauren; Charman, Dan J.; Lopez, Omar R.; Valderamma, Elvis; Watson, Elizabeth J.; Lähteenoja, Outi; Baird, Andy J.

    2017-04-01

    Peatlands represent some of the most carbon-dense ecosystems of Amazonia. However, little is known about the mechanisms of Amazonian peatland development and their ecohydrological dynamics over time. We present a comprehensive multiproxy dataset from Aucayacu peat dome, the oldest peatland yet discovered in Amazonia (peat initiation occurred between 8.9 and 5.8 ka cal. BP). Our dataset includes analyses of peat physical properties, carbon and nitrogen, humification, organic matter characteristics, macrofossils, pollen, charcoal and testate amoebae. Sedimentological techniques were applied to minerogenic deposits underneath the peatland to understand the nature of the floodplain environment before peat initiation. A transfer function was used to reconstruct past hydrological conditions from subfossil testate amoeba assemblages and carbon accumulation (CA) rates were determined from bulk density and percentage carbon data. A robust chronology was achieved using 210Pb and 14C (14 radiocarbon dates on a 3-m core) determinations, modelled using a Bayesian approach. We used the datasets to investigate the long-term ecohydrological development and controls on carbon accumulation in an Amazonian peat dome. The peatland developed in three distinct stages; (i) abandoned river channel with standing open water and aquatic plants; (ii) inundated forest swamp; and (iii) ombrotrophic bog ( 3.9 ka cal. BP). Local burning occurred twice during the peatland's development as evidenced by macroscopic charcoal but appears to have become more pronounced in the last 100 years. We present a conceptual model of the role of autogenic and allogenic (climate, floodplain) processes on the long-term development of the peatland and the marked variations in carbon accumulation rates over the Holocene. Amazonian peatlands are important carbon stores and ecosystems, and represent important archives of past climatic and ecological information. They should form key foci for conservation efforts.

  6. 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

  7. 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

  8. Vast Peatlands Found in the Congo Basin

    Science.gov (United States)

    Fatoyinbo, Lola

    2017-01-01

    Southeast Asias share of Earths tropical peatlands was previously put at 561, but the largest of the tropics peatland complexes might in fact lie elsewhere. On page 86, Dargie et al. combine satellite data with extensive field measurements of peat depth, carbon concentration and radiocarbon dating to produce a map of potential peat extent and carbon stocks in the Cuvette Centrale depression of the central Congo Basin. The authors propose that the Cuvette Centrale represents the worlds largest tropical peatland complex, covering 145,500 square kilometres and possibly storing about 30 petagrams of carbon (1 Pg is 1015 grams) the equivalent of 20 years of current US carbon emissions from fossil fuels. Tropical peatlands have garnered increasing attention in recent years owing to their crucial role as terrestrial organic carbon reserves and the implications of peatland loss for climate change. Thick peat soils (ranging from 30 cm to up to 30 m)3 form in areas where water-logged soils create anoxic conditions that prevent organic materials such as dead leaves and wood from fully decomposing. The largest areas of peat are in temperate regions, but large areas of forested peatlands are also found in the tropics.

  9. 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.)

  10. 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.

  11. Decision support system for peatland management in the humid tropics

    NARCIS (Netherlands)

    Ritzema, H.P.; Grobbe, T.; Chong, T.; Wösten, J.H.M.

    2003-01-01

    Large areas of globally important tropical peatland in Southeast Asia are threatened by land clearance, degradation and fire, jeopardising their natural functions as reservoirs of biodiversity, carbon stores and hydrological buffers. Many development projects on tropical peatlands have failed

  12. Multidisciplinary approach to identify aquifer-peatland connectivity

    Science.gov (United States)

    Larocque, Marie; Pellerin, Stéphanie; Cloutier, Vincent; Ferlatte, Miryane; Munger, Julie; Quillet, Anne; Paniconi, Claudio

    2015-04-01

    In southern Quebec (Canada), wetlands sustain increasing pressures from agriculture, urban development, and peat exploitation. To protect both groundwater and ecosystems, it is important to be able to identify how, where, and to what extent shallow aquifers and wetlands are connected. This study focuses on peatlands which are especially abundant in Quebec. The objective of this research was to better understand aquifer-peatland connectivity and to identify easily measured indicators of this connectivity. Geomorphology, hydrogeochemistry, and vegetation were selected as key indicators of connectivity. Twelve peatland transects were instrumented and monitored in the Abitibi (slope peatlands associated with eskers) and Centre-du-Quebec (depression peatlands) regions of Quebec (Canada). Geomorphology, geology, water levels, water chemistry, and vegetation species were identified/measured on all transects. Flow conditions were simulated numerically on two typical transects. Results show that a majority of peatland transects receives groundwater from a shallow aquifer. In slope peatlands, groundwater flows through the organic deposits towards the peatland center. In depression peatlands, groundwater flows only 100-200 m within the peatland before being redirected through surface routes towards the outlet. Flow modeling and sensitivity analysis have identified that the thickness and hydraulic conductivity of permeable deposits close to the peatland and beneath the organic deposits influence flow directions within the peatland. Geochemical data have confirmed the usefulness of total dissolved solids (TDS) exceeding 14 mg/L as an indicator of the presence of groundwater within the peatland. Vegetation surveys have allowed the identification of species and groups of species that occur mostly when groundwater is present, for instance Carex limosa and Sphagnum russowii. Geomorphological conditions (slope or depression peatland), TDS, and vegetation can be measured

  13. 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

  14. Seed dispersal in agricultural habitats and the restoration of species-rich meadows = Dispersie van zaden in cultuurlandschappen en het herstel van soortenrijke graslanden

    NARCIS (Netherlands)

    Dorp, van D.

    1996-01-01


    The restoration of species-rich meadows on former agricultural land in the Netherlands has a high priority, because these ecosystems have been disappearing rapidly due to eutrophication and acidification and falling water tables. In order to be able to restore such ecosystems on wet

  15. Meadow management and treatment options [chapter 8

    Science.gov (United States)

    Jeanne C. Chambers; Jerry R. Miller

    2011-01-01

    Restoration and management objectives and approaches are most effective when based on an understanding of ecosystem processes and the long- and short-term causes of disturbance (Wohl and others 2005). As detailed in previous chapters, several factors are critical in developing effective management strategies for streams and their associated meadow ecosystems in the...

  16. Edificio de viviendas. Lake Meadows Chicago

    Directory of Open Access Journals (Sweden)

    Skidmore - Owings y Merrill, Arquitectos

    1958-09-01

    Full Text Available "Lake Meadows" es una amplia parcela, de cuatrocientos mil metros cuadrados, situada en las afueras de Chicago, con vistas dominantes sobre el lago Michigan. En tan bello emplazamiento se ha construido uno de los más atractivos conjuntos residenciales norteamericanos.

  17. Genetic diversity and structure in two protected Posidonia oceanica meadows.

    Science.gov (United States)

    Micheli, Carla; D'Esposito, Daniela; Belmonte, Alessandro; Peirano, Andrea; Valiante, Luigi Maria; Procaccini, Gabriele

    2015-08-01

    Posidonia oceanica meadows growing along the west Mediterranean coastline are under continuous anthropogenic pressure. The way meadow health correlates with genetic and genotypic diversity in P. oceanica, is still under debate. Here we report a microsatellite analysis of two P. oceanica meadows living in protected areas of the Ligurian (Monterosso al Mare, MPA of "Cinque Terre") and central Tyrrhenian Sea (Santa Marinella, regional Site of Community Importance). Both meadows were recently classified as "disturbed", according to shoot density and other phenological parameters. Between the two meadows, Santa Marinella showed higher genetic diversity, while clear genetic substructure was present in both sites, reflecting high spatial heterogeneity. The present study suggests that genetic diversity does not match unequivocally with shoot density and leaf morphology and that small scale intra-meadow heterogeneity is an important factor to consider for establishing the relation between genetic/genotypic variability and health of natural seagrass meadows. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. 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.

  19. Vaginitis test - wet mount

    Science.gov (United States)

    Wet prep - vaginitis; Vaginosis - wet mount; Trichomoniasis - wet mount; Vaginal candida - wet mount ... a rash, painful intercourse, or odor after intercourse. Trichomoniasis , a sexually transmitted disease. Vaginal yeast infection .

  20. Yield and carrying capacity of meadows in Albania

    Directory of Open Access Journals (Sweden)

    Hajno Luan

    2011-01-01

    Full Text Available This study was carried out during 2003-2005 and included total meadow surface of 32,000 ha from seven regions throughout Albania (summer meadows of Shishtavec, Gramoz, Çajup, Lenie, Progonat, and winter meadows of Heremec-Delvine and Dukaj. The results of the study showed that average dry matter yield of the summer meadows is low (about 0.6±0.14 t ha-1 ranging from 0.33±0.07 t ha-1 to 0.53±0.10 t ha-1 at poor meadows (Progonat, Cajup Lenie and from 0.9±0.17 t ha-1 to 0.95±0.18 t ha-1 at rich meadows (Gramoz Shistavec. Dry matter yield of the winter meadows ranged from 0.45±0.17 t ha-1 (Dukaj to 0.57±0.13 t ha-1 (Heremec-Delvine. Regarding the rate of herbaceous biomass utilization in general, the plots closer to the villages were overstocked, which put high pressure on meadows resulting in their degradation. The coefficient of herbaceous phytomass utilization was about 94-95% at Lenia's meadows and a few other meadows close to villages. At a few plots of meadows (Lenia, Gramoz, Shishtavec situated away from villages and at high sea level, the coefficient of meadow utilization reached 50-60%. Energetic value expressed by starch unit (SU depends on the flora and environmental conditions. According to laboratory analyses, the meadows of Dukaj had the highest energetic values (about 1.16±0.22 SU kg-1 dry matter while Lenia' meadows had the lowest energetic values (about 0.84 ±0.16 SU kg-1 dry matter.

  1. Automated calculation of the evapotranspiration and crop coefficients for a large number of peatland sites using diurnal groundwater table fluctuations

    Science.gov (United States)

    Maurer, Eike; Bechtold, Michel; Dettmann, Ullrich; Tiemeyer, Bärbel

    2014-05-01

    Evapotranspiration is one of the main processes controlling peatland hydrology. Greenhouse gas (GHG) emissions from peatlands are in turn strongly controlled by the groundwater table. Through the increasing political and scientific interest to reduce GHG emissions, monitoring and modelling strategies to optimize re-wetting strategies and to quantify GHG emissions are needed. To achieve these aims, an accurate determination of the evapotranspiration as an essential part of the water balance is required. Many different approaches are known to determine the evapotranspiration. They are mostly either expensive or hard to parameterize. Plant specific crop coefficients (Kc-values) are an option to calculate plant-specific evapotranspiration but due to the lack of Kc-values for typical peatland vegetation types more data on evapotranspiration from peatlands in the temperate zone are required. Furthermore, simple methods to estimate evapotranspiration are needed especially for monitoring projects. Diurnal groundwater table fluctuations caused by root water uptake and groundwater inflow can be used to calculate daily evapotranspiration rates. This approach was first described by White (1932) who compared groundwater recovery rates at night to the decline during daytime. Besides the groundwater table data only the specific yield (Sy) is needed to calculate evapotranspiration. However, the method has some limitations because not all days can be evaluated which leads to data gaps during rainy and very dry or very wet periods. This study presents an automated method to calculate the specific yield, evapotranspiration and crop coefficients for a large number of sites covering all major peatland types and their typical land uses in Germany. As an input for our method, only groundwater level, precipitation and grass reference evapotranspiration (ET0) data is required. In a first step, the groundwater level data was smoothed by a LOESS function. In a second step, site-specific SY

  2. Land use of drained peatlands: Greenhouse gas fluxes, plant production, and economics.

    Science.gov (United States)

    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.

  3. Past Peatland Distribution as an Indicator of Hydroclimate and Temperature

    Science.gov (United States)

    Treat, C. C.; Jones, M.; Lacourse, T.; Payne, R.; Peteet, D. M.; Sannel, B.; Stelling, J.; Talbot, J.; Williams, C. J.; Kleinen, T.; Grosse, G.; Yu, Z.; Finkelstein, S. A.; Broothaerts, N.; Dommain, R.; Kuhry, P.; Lähteenoja, O.; Dalton, A.; Notebaert, B.; Swindles, G. T.; Tarnocai, C.; Verstraeten, G.; Xia, Z.; Brovkin, V.

    2016-12-01

    Peatlands, wetlands with > 30 cm of organic sediment, cover more than 3 x 106 km2 of the earth surface and have been accumulating carbon and sediments throughout the Holocene. The location of peatland formation and accumulation has been dynamic over time, as peat formation in areas like Alaska and the West Siberian Lowlands preceded peat formation in Fennoscandia and Eastern North America due to more favorable climate for peat formation. Using the geographic distribution of peatlands in the past can indicate general climatic conditions, including hydroclimate, given that the underlying geology is well understood. Peatlands form under a variety of climatic conditions and landscape positions but do not persist under arid conditions, instead requiring either humid conditions or cold temperatures. However, peatlands may have existed in the past in areas not currently suitable for peatland formation and persistence, but where peats can be found at depth within the sediment column. Here we map the locations of histic paleosols, relict peat, and buried peats since the Last Glacial Maximum using a compilation of sites from previous studies. We compare these records of past peatland distribution to present-day peatland distribution. We evaluate regional differences in timing of peatland development in these buried peatlands to the development of extant peatlands. Finally, we compare the timing of past peatland extent to the to modeled paleoclimate during the Quaternary. In addition to implications for paleoclimate, these past peatlands are not well accounted for in present-day soil carbon stocks but could be an important component of deep soil carbon pools.

  4. Greenhouse Gas Fluxes from Peatland Pools

    Science.gov (United States)

    Turner, E.; Baird, A. J.; Billett, M. F.; Chapman, P. J.; Dinsmore, K. J.; Holden, J.

    2015-12-01

    Peatlands contain around one third of the global soil carbon (C) stock. Understanding the processes in peatland C cycling, and in particular those involved in the release of the greenhouse gases (GHGs) CO2 and CH4 to the atmosphere, is a current research priority. Natural open-water pools are a common feature of many peatlands, and previous research suggests pools can be strong sources of atmospheric GHGs, particularly CH4, and thus have the potential to play an important role in global radiative forcing. The area of open-water in peatlands is rapidly expanding in a warming Arctic (e.g. Walter et al., 2007) while artificially created pools are becoming more commonplace in the recent drive to restore the hydrological functioning of drained peatlands by blocking ditches. We present the results of >2 years of comprehensive field monitoring from pool complexes in the Flow Country of northern Scotland, the largest expanse (c.4000 km2) of blanket bog in Europe. Concentrations and fluxes of CO2 and CH4 are presented from 12 intensively monitored pools and the adjacent terrestrial surface. We examined both natural (n = 6) and artificial (n = 6) pools, which allowed us to quantify how pools created during restoration compare to undisturbed sites. C and hydrology budgets were determined for the study pools and the adjacent terrestrial surface. Dissolved concentrations of GHGs ranged from 0.08-4.68 mg CO2-C L-1 and 0.01-731 µg CH4-C L-1 in natural pools, and 0.29-10.38 mg CO2-C L-1 and 0.04-239 µg CH4-C L-1 in artificial pools. GHG fluxes from natural pool surfaces ranged between -2.47-653 mg CH4 m-2 d-1 and -31.7-14.8 g CO2 m-2 d-1. Artificial pool GHG fluxes were -8.19-581 mg CH4 m-2 d-1 and -7.66-34.9 g CO2 m-2 d-1. We provide more accurate GHG budgets for peatlands with natural pool complexes by considering their relative importance at the landscape-scale, and outline the potential effect on GHG fluxes when creating artificial pools during peatland restoration

  5. Nebela jiuhuensis nov. sp. (Amoebozoa; Arcellinida; Hyalospheniidae): A New Member of the Nebela saccifera - equicalceus - ansata Group Described from Sphagnum Peatlands in South-Central China.

    Science.gov (United States)

    Qin, Yangmin; Man, Baiying; Kosakyan, Anush; Lara, Enrique; Gu, Yansheng; Wang, Hongmei; Mitchell, Edward A D

    2016-09-01

    Hyalospheniids are among the most common and conspicuous testate amoebae in high-latitude peatlands and forest humus. These testate amoebae were widely studied as bioindicators and are increasingly used as models in microbial biogeography. However, data on their diversity and ecology are still very unevenly distributed geographically: notably, data are lacking for low-latitude peatlands. We describe here a new species, Nebela jiuhuensis, from peatlands near the Middle Yangtze River reach of south-central China with characteristic morphology. The test (shell) has hollow horn-like lateral extensions also found in N. saccifera, N. equicalceus (=N. hippocrepis), and N. ansata, three large species restricted mostly to Sphagnum peatlands of Eastern North America. Mitochondrial cytochrome oxidase (COI) data confirm that N. jiuhuensis is closely related to the morphologically very similar North American species N. saccifera and more distantly to N. ansata within the N. penardiana group. These species are all found in wet mosses growing in poor fens. Earlier reports of morphologically similar specimens found in South Korea peatlands suggest that N. jiuhuensis may be distributed in comparable peatlands in Eastern Asia (China and Korea). The discovery of such a conspicuous new species in Chinese peatlands suggests that many new testate amoebae species are yet to be discovered, including potential regional endemics. Furthermore, human activities (e.g., drainage, agriculture, and pollution) have reduced the known habitat of N. jiuhuensis, which can thus be considered as locally endangered. We, therefore, suggest that this very conspicuous micro-organism with a probably limited geographical distribution and specific habitat requirement should be considered as a flagship species for microbial biogeography as well as local environmental conservation and management. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  6. L'Anse Aux Meadows, Newfoundland

    Science.gov (United States)

    2008-01-01

    L'Anse aux Meadows is a site on the northernmost tip of the island of Newfoundland, located in the Province of Newfoundland and Labrador, Canada, where the remains of a Viking village were discovered in 1960 by the Norwegians Helge and Anne Ingstad. The only authenticated Viking settlement in North America outside Greenland, it was the site of a multi-year archaeological dig that found dwellings, tools and implements that verified its time frame. The settlement, dating more than five hundred years before Christopher Columbus, contains the earliest European structures in North America. Named a World Heritage site by UNESCO, it is thought by many to be the semi-legendary 'Vinland' settlement of explorer Leif Ericson around AD 1000. The settlement at L'Anse aux Meadows consisted of at least eight buildings, including a forge and smelter, and a lumber yard that supported a shipyard. The largest house measured 28.8 by 15.6 m and consisted of several rooms. Sewing and knitting tools found at the site indicate women were present at L'Anse aux Meadows The image was acquired on September 14, 2007, covers an area of 14.2 x 14.6 km, and is located at 51.5 degrees north latitude, 55.6 degrees west longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  7. 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.

  8. Characterization of a Highly Biodiverse Floodplain Meadow Using Hyperspectral Remote Sensing within a Plant Functional Trait Framework

    Directory of Open Access Journals (Sweden)

    Suvarna Punalekar

    2016-02-01

    Full Text Available We assessed the potential for using optical functional types as effective markers to monitor changes in vegetation in floodplain meadows associated with changes in their local environment. Floodplain meadows are challenging ecosystems for monitoring and conservation because of their highly biodiverse nature. Our aim was to understand and explain spectral differences among key members of floodplain meadows and also characterize differences with respect to functional traits. The study was conducted on a typical floodplain meadow in UK (MG4-type, mesotrophic grassland type 4, according to British National Vegetation Classification. We compared two approaches to characterize floodplain communities using field spectroscopy. The first approach was sub-community based, in which we collected spectral signatures for species groupings indicating two distinct eco-hydrological conditions (dry and wet soil indicator species. The other approach was “species-specific”, in which we focused on the spectral reflectance of three key species found on the meadow. One herb species is a typical member of the MG4 floodplain meadow community, while the other two species, sedge and rush, represent wetland vegetation. We also monitored vegetation biophysical and functional properties as well as soil nutrients and ground water levels. We found that the vegetation classes representing meadow sub-communities could not be spectrally distinguished from each other, whereas the individual herb species was found to have a distinctly different spectral signature from the sedge and rush species. The spectral differences between these three species could be explained by their observed differences in plant biophysical parameters, as corroborated through radiative transfer model simulations. These parameters, such as leaf area index, leaf dry matter content, leaf water content, and specific leaf area, along with other functional parameters, such as maximum carboxylation capacity

  9. Last millennium multiproxy high-resolution palaeoenvironmental study based on a subalpine peatland

    Science.gov (United States)

    Lamentowicz, Mariusz; van der Knaap, Willem O.; van Leeuwen, Jacqueline F. N.; Hangartner, Sarah; Lamentowicz, Łukasz; Mitchell, Edward A. D.; Mauquoy, Dmitri; Kamenik, Christian; Goslar, Tomasz

    2010-05-01

    Subfossil testate amoebae (Protists) and stable oxygen isotopes supported by pollen were used to reconstruct the hydrological history of the last 1000 years from Mauntschas mire in the south-eastern Swiss Alps (Upper Engadin valley; 1818 m a.s.l.). This peatland, located at the bottom of an Alpine valley, recorded local hydrological changes that could be related to precipitation/temperature changes since AD 1000. Using a testate-amoeba training set, which was developed from samples collected in 2007 from peatlands in the same valley, we reconstructed depth to the water table (DWT) in Mauntschas mire. During the instrumental period (starting AD 1864), DWT were correlated with measured temperatures and winter precipitation. Over the last millennium the following changes were inferred: (i) since AD 1000 the presence of Archerella flavum indicated wet conditions; (ii) the habitat became moistest towards AD 1300; (iii) after AD 1300 testate amoebae indicated a gradual decrease of the water table; (iv) during AD 1580-1630 A. flavum indicated increased moisture - this wet period coincided with a cold anomaly recorded in the Alps; (v) between AD 1670 and 1715 the water table decreased again; (vi) another pronounced wet phase was recorded AD 1715-1850 with the maximum water table ca. AD 1780; (vii) during the instrumental period (1864-2003) the water table decreased gradually, following the trend of increasing temperatures. Among the pollen, the maximum wetness during the Little Ice Age (ca AD 1800) was reflected by pollen maxima of Cyperaceae and Selaginella. When climate became warmer and drier after AD 1850 (end of the Little Ice Age), Sphagnum spores were abundant. There was good agreement between DWT and the Pinus non-cembra pollen, suggesting temperature as the common driving factor. The stable oxygen isotopes (d18O) from Sphagnum stems showed similarities with DWT, with an anti-correlated phase at the end of the 19th century.

  10. Meadow contraction and extinction debt in meadow plants and moths in the Western Cascades

    Science.gov (United States)

    Meadows in the western Cascades have contracted and fragmented by approximately 50% in the past 60 years. These habitats occupy only about 5% of the landscape of the western Cascades but are important for the preservation of biodiversity and rare species. This habitat loss and ...

  11. 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.)

  12. Effects of tropospheric ozone on methane and carbon dioxide fluxes from peatland mesocosms

    Science.gov (United States)

    Toet, Sylvia; Oliver, Vikki; Helgason, Thorunn; Peacock, Simon; Barnes, Jeremy; Ineson, Phil; Ashmore, Mike

    2010-05-01

    Tropospheric ozone is currently the third most important greenhouse gas, and also the most important gaseous air pollutant globally in terms of effects on vegetation world-wide. At present levels it poses a significant threat to crop yield and forest productivity of sensitive species, while background ozone concentrations are expected to increase further during the next decades. The potential importance of ozone in reducing carbon assimilation, and consequently in increasing atmospheric carbon dioxide concentrations, has been recognised. However, regional modelling studies are based on the impact of ozone on photosynthetic rates and above-ground growth, and do not consider effects of ozone on belowground carbon fluxes. The limited experimental data on the long-term effects of ozone on belowground carbon processes, mainly from arable crop and forest systems, are a major constraint to understanding the impacts of ozone on global carbon fluxes. Very little attention has been paid to ozone effects on peatland carbon dynamics, though northern peatlands store a third of the global soil organic carbon pool and are an important source of atmospheric methane. The aims of this study were to assess the long-term effects of elevated ozone on carbon dioxide and methane fluxes in temperate peatland mesocosms and to identify underlying plant, soil and microbial processes. Mesocosms from a wet heath (Isle of Skye, UK) with vegetation dominated by the peat moss Sphagnum papillosum and the sedge Schoenus nigricans have been exposed to ambient (control) and three elevated levels of ozone in open-top chambers from May 2008. Methane emission, carbon dioxide fluxes and relevant plant and soil variables were measured every 6 weeks (growing season) or 8 weeks (winter). Methane emissions were significantly reduced by elevated ozone over the first 18 months of the experiment. Ecosystem respiration only showed a significant increase in response to ozone in the second growing season, while

  13. 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.

  14. Key biogeochemical factors affecting soil carbon storage in Posidonia meadows

    Science.gov (United States)

    Serrano, Oscar; Ricart, Aurora M.; Lavery, Paul S.; Mateo, Miguel Angel; Arias-Ortiz, Ariane; Masque, Pere; Rozaimi, Mohammad; Steven, Andy; Duarte, Carlos M.

    2016-08-01

    Biotic and abiotic factors influence the accumulation of organic carbon (Corg) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2-4 m depth) accumulated 3- to 4-fold higher Corg stocks (averaging 6.3 kg Corg m-2) at 3- to 4-fold higher rates (12.8 g Corg m-2 yr-1) compared to meadows closer to the deep limits of distribution (at 6-8 m depth; 1.8 kg Corg m-2 and 3.6 g Corg m-2 yr-1). In shallower meadows, Corg stocks were mostly derived from seagrass detritus (88 % in average) compared to meadows closer to the deep limit of distribution (45 % on average). In addition, soil accumulation rates and fine-grained sediment content (Posidonia meadows, respectively. The patterns found support the hypothesis that Corg storage in seagrass soils is influenced by interactions of biological (e.g., meadow productivity, cover and density), chemical (e.g., recalcitrance of Corg stocks) and physical (e.g., hydrodynamic energy and soil accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.

  15. Controls on meadow distribution and characteristics [chapter 2

    Science.gov (United States)

    Dru Germanoski; Jerry R. Miller; Mark L. Lord

    2011-01-01

    Meadow complexes are located in distinct geomorphic and hydrologic settings that allow groundwater to be at or near the ground surface during at least part of the year. Meadows are manifestations of the subsurface flow system, and their distribution is controlled by factors that cause localized zones of groundwater discharge. Knowledge of the factors that serve as...

  16. 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 ...

  17. Satellite-based peatland mapping: potential of the MODIS sensor.

    Science.gov (United States)

    D. Pflugmacher; O.N. Krankina; W.B. Cohen

    2006-01-01

    Peatlands play a major role in the global carbon cycle but are largely overlooked in current large-scale vegetation mapping efforts. In this study, we investigated the potential of the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to capture extent and distribution of peatlands in the St. Petersburg region of Russia.

  18. 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.

  19. Inventory and monitoring options of peatlands at regional scale

    DEFF Research Database (Denmark)

    Gardi, Ciro; Sommer, Stefan; Seep, Kalev

    2010-01-01

    on the enhanced integration of existing thematic maps through GIS analysis in combination with remote sensing, has been applied to Estonia, as study case. Existing national maps and field inventory of Estonian peatlands have been used for a GIS based evaluation of peatlands relevant information contained...

  20. 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...

  1. 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

  2. Historical Meadow Dynamics in Southwest British Columbia: a Multidisciplinary Analysis

    Directory of Open Access Journals (Sweden)

    Dana Lepofsky

    2003-12-01

    Full Text Available The recent encroachment of woody species threatening many western North American meadows has been attributed to diverse factors. We used a suite of methods in Chittenden Meadow, southwestern British Columbia, Canada, to identify the human, ecological, and physical factors responsible for its historical dynamics and current encroachment by woody vegetation. We evaluated three hypotheses about the origin and processes maintaining the meadow: the meadow is (1 of recent human origin; (2 of ancient human origin, maintained by aboriginal burning; and (3 of ancient non-human origin, not maintained by aboriginal burning. Our data supported the idea that the meadow had ancient non-human origins and its recent history and current status have resulted from complex interactions among landform, climate, and fire. Soil properties (both horizonation and charcoal content indicate that the meadow is of ancient, non-human origin. Tree ages in the meadow and surrounding forest indicate that encroachment is recent, not related to a variety of recent human activities, and is probably a result of increasing spring temperature and decreasing spring snow depth. Although ethnographic surveys and historical documents revealed indigenous use of the general area over millennia, including the use of fire as a management tool, we found little direct evidence of indigenous use of the meadow. However, there was no proxy record of fire frequency in the meadow that we could have used to determine the role of fire in maintaining the meadow in the past, or the role of humans in igniting those fires. Thus, the historical role of humans in the maintenance of the meadow by prescribed fire remains indeterminate. Based on these conclusions, we combined hypotheses (2 and (3 into an a posteriori hypothesis that reflects changing interactions among people, fire, and climate over time. Without management intervention, we expect that tree encroachment will continue. Several general lessons

  3. Modelling vegetation dynamics for Alpine meadows

    Science.gov (United States)

    Della Chiesa, Stefano; Bertoldi, Giacomo; Wohlfahrt, Georg; Rist, Armin; Niedrist, Georg; Albertson, John D.; Tappeiner, Ulrike

    2010-05-01

    Regional climate scenarios predict a temperature increase and a summer precipitation decrease for the European Alps. This is expected to lead to longer vegetation periods, but also to drought stress in Alpine meadows ecosystems. It is therefore uncertain if the predicted climatic changes will lead to an increase or decrease of biomass production in these grassland ecosystems. Understanding plant growth requires to consider the complex interactions between soil, atmosphere and climate via its physiological properties, in particular LAI, stomatal resistance, rooting depth, albedo, surface roughness and effects on soil moisture. Vegetation Dynamic Models (VDM) coupled with hydrological models take into account these interactions in order to study and estimate biomass production quantitatively. In this contribution, the VDM previously developed by Montaldo et al. (2005) for semi-arid environments is extended to Alpine meadows in the Stubai Valley (Eastern Austria) which are typically not subjected to water and nutrient stresses, but undergoing low temperature limitations. The aim is to assess the model robustness. Moreover, the effects of mowing practice during the season were taken into consideration. The VDM has then been implemented in the distributed hydrological model GEOtop (Rigon et al., 2006). The VDM performed well in the considered case study. The validation and calibration of the model is presented and then the effects of increased temperature and decreased precipitation are investigated numerically. In order to evaluate in the field the effects of climatic change on Alpine grassland biomass production, the inner Alpine continental Mazia Valley (South Tyrol, Italy) has been chosen in 2009 for Long-Term Ecological Research. These climatic changes will be simulated by manipulations along an altitudinal gradient comprising measuring stations at about 1000 m, 1500 m and 2000 m a.s.l.. Meadow monoliths will be transplanted downslope to simulate temperature

  4. Response of peatland ecosystem to climatic changes in Central-Eastern Europe: a long-term ecological approach

    Science.gov (United States)

    Slowinska, S.; Marcisz, K.; Slowinski, M. M.; Lamentowicz, M.; Lamentowicz, L.; Mitchell, E. A.

    2013-12-01

    Northern peatlands play a major role in the global carbon cycle, and they are valuable archives of the past environmental change. The functioning of these ecosystems depends on the feedback between biotic and abiotic factors that are still not fully understood. In our study we investigated relationships between hydrological (groundwater level fluctuations, hydrochemistry), meteorological conditions near the ground (air temperature and humidity, photosynthetically active radiation, leaf wetness, temperature and moisture of Sphagnum) and biological factors: vegetation patterns, Sphagnum mosses growth and testate amoebae (Protists) composition. We designed a long-term ecological study site in a Sphagnum mire in Northern Poland that consisted of five meteorological micro stations and eleven piezometers located in two transects at 5,95 ha area. During the growing season 2012 we observed significant differences between plots in terms of micrometeorological and hydrological conditions that resulted in different Sphagnum increments and seasonal dynamics of testate amoebae communities. Our study is very important to better understand how temperate peatlands react to the climatic change and recent warming. Obtained results revealed a high sensitivity of bog ecosystem to e.g. short-term heat waves. Further research will be conducted to model a potential response of Sphagnum peatland to the future climate change. Project supported by Polish National Science Centre grant No. NN306060940 and the grant PSPB-013/2010 from Switzerland through the Swiss Contribution to the enlarged European Union.

  5. Response of Peatland Carbon Accumulation to Postglacial Climate Changes on the Seward Peninsula, Western Alaska

    Science.gov (United States)

    Hunt, S. J.; Yu, Z.

    2011-12-01

    Understanding how carbon-rich peatland ecosystems have responded to past warm climates in terms of carbon (C) dynamics and community composition is crucial for projecting possible future changes. Warm climates in the recent past, such as the Bølling-Allerød interstadial (14.7-12.7 cal ka) and Holocene Thermal Maximum (HTM; 11-9 ka), provide unique opportunities to study peatland C dynamics and ecosystem change. Here we present preliminary data from a 272-cm peat core (core NL10-2) collected from the edge of Niukluk Lake on Seward Peninsula, Alaska (64° 49.645' N, 163° 27.235' W; elevation = 16 m asl). Niukluk Lake is a thermokarst lake located in the discontinuous permafrost zone near the forest-tundra ecotone and experiences a maritime climate, which is controlled by the Bering Sea and sea surface conditions (especially sea-ice extent). The chronology is based on 12 AMS dates from Sphagnum and other terrestrial plant macrofossils over the last 13.5 ka. Organic matter content (OM) shows a long-term increasing trend throughout the core since 13.5 ka, ranging from 90% at the top of the core. Peat began accumulating at this site by 13.5 ka and was initially characterized by a very high carbon accumulation rate (67 g C m-2 yr-1 from 13.5 to 12.8 ka), potentially due to early deglacial warming during the Bølling-Allerød period. Dominance of well-preserved brown moss, aquatic species and high C accumulation rates during the majority of the Bølling-Allerød indicate a wet peatland surface and possibly a wet and warm climate. Preliminary pollen analysis during the Bølling-Allerød indicates a Betula and Salix dominated upland with a regional presence of Picea and Larix, along with the presence of aquatic species. Also, abundant charcoals are present at this interval, suggesting that wildfires might play a major role in modulating regional flora and permafrost dynamics. This highly productive period was followed by a hiatus from 12.8 ka to 9 ka, perhaps due partly

  6. The Influence of Landscape Morphology on Peatland Dynamics and Carbon Accumulation Inferred from Ground Penetrating Radar (GPR) and Peat Core Analysis

    Science.gov (United States)

    Loisel, J.; Nolan, J. T.; Yu, Z.; Parkesian, A.; Slater, L. D.

    2010-12-01

    Northern peatlands have potential for strong feedbacks on the climate system through their impact on the global carbon (C) cycle. Since the Last Glacial Maximum, these ecosystems have sequestered about 550 Gt of organic C (Yu et al. 2010, GRL) and have been important sources of methane to the atmosphere. Over this period, peatlands have spread throughout the northern landscape to cover approximately 3% of today’s global land surface. As peatland dynamics are complex and often non-linear, however, patterns of regional peatland area expansion remain speculative, despite the critical role this spatio-temporal aspect plays in Holocene C stock and flux estimates. Using near-surface geophysics and peat core analysis, we show that slope gradient and basin topography exert deterministic controls on peatland lateral expansion and C accumulation. Our study was conducted in a 14,000 year-old sloping peatland complex (62°N, 150°W) whose growth was interrupted for about 1000 years when Mt. Hayes erupted between 4390 and 3430 cal. BP. Peat thickness and subsurface topography were obtained using GPR combined with high-resolution surface elevation data. The continuous, 15 cm-thick tephra layer was clearly visible in the GPR surveys and was used as a chronostratigraphic marker to delineate ‘post-tephra’ peatland dynamics. Radiocarbon dating was performed on post-tephra peat sediments. Results indicate rapid peat re-colonization (taking 10,000 years) under the initial geomorphic conditions (with a slope ≈ 2°). Under the reasonable assumption that post-tephra peatland dynamics were primarily affected by tephra-modified topography, and not by time or climate, we calculated peat C accumulation rates (PCAR) for the past 3000 years using bulk density and depth measurements from several cores with various slopes. We found a positive, exponential relationship between bulk density and slope, which is negatively correlated with peat thickness and PCAR. For example, one core with a

  7. 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

    dominant. The site is wet throughout most of the year (water table depth < 5 cm below the peat surface), but there are indications that drought enhanced heterotrophic respiration and depressed gross primary productivity (GPP); a sustained drought during the summer of 2010 (maximum water table depth 36 cm below surface) was accompanied by a two-fold increase in total respiration and a 30% decrease in GPP. The cold preceding winter could also have contributed to lowering GPP, and disentangling the confounding adverse effects of drought and winter climate on GPP is thus not straightforward. Whilst 2010 had the smallest NEE in the 2002-2012 period, the largest values were found for years with warm winters and relatively wet growing seasons. A simple parameterisation of the effects of PAR on GPP of and air temperature on ecosystem respiration, suggest that a rise in air temperature of 1° C between 2012 and 2065 could lead to a 73% increase in the carbon sink strength of the peatland, provided hydrological conditions remain unchanged. This demonstrates that climate change is not likely to change this peatland into a carbon source by 2100.

  8. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  9. Exploring spatial heterogeneity and resilience in northern peatlands

    Science.gov (United States)

    Malhotra, A.; Roulet, N. T.

    2011-12-01

    Northern peatlands cover only 3% of the worlds land area while storing approximately 30% of the world's soil carbon making them important players in the global and regional carbon (C) cycle (Gorham 1991). Current peatland research attempts to predict changes in peatland biogeochemistry given climate change scenarios. However, the focus is primarily on linear responses to changes rather than on self regulation properties that are present in complex systems. Studying peatlands as complex adaptive systems (CAS) is important to fully understand peatland resilience and therefore to better predict response to disturbances. Peatlands possess properties of CAS such as spatial heterogeneity (SH), localized flows, self-organizing structures and non-linearity (Belyea and Baird 2006). The broad hypothesis of our proposed research is that SH in peatlands is positively connected with ecosystem resilience. To address our broad hypothesis we propose to 1) characterize SH in peatlands (using two visible indices of microtopography [MT] and vegetation structure [VEG]), 2) quantify the auto-correlation between visible SH and biogeochemical parameters and 3) investigate short term resilience using the response of biogeochemical parameters to environmental changes. The selection of biogeochemical parameters is based on prevalent theories on the persistence of MT in peatlands and parameters are related to peat accumulation (function of decomposition and net primary production; NPP), hydrology and nutrients (Swanson and Grigal 1988, Belyea and Clymo 2001, Eppinga et al. 2009). Field measurements will be conducted in the Stordalen mire in Abisko, Sweden. This site provides a steep environmental gradient with the presence of 3 peatland types- palsa, bog and fen. Each of these peatland types have varying degrees of spatial heterogeneity, exogenous controls (related to hydrology and permafrost), and therefore hypothesized varying degrees of resilience. Measurements will include nutrients, NPP

  10. Crane Meadows National Wildlife Refuge: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Crane Meadows NWR for the next 15 years. This plan outlines the Refuge vision and...

  11. Great Meadows National Wildlife Refuge : Narrative Report : January - Decemeber 1972

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Great Meadows NWR and satellite refuges outlines refuge accomplishments during the 1972 calendar year. The report begins by...

  12. Comprehensive Conservation Plan: Cokeville Meadows National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) executive summary was written to guide management on Cokeville Meadows National Wildlife Refuge for the next 15 years....

  13. Ash Meadows National Wildlife Refuge : A plan for the future

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The management plan is to maintain Ash Meadows Refuge as a natural ecosystem. To accomplish this, the area will be restored as much as possible to conditions which...

  14. The Trail Inventory of Cokeville Meadows NWR [Cycle 2

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The purpose of this report is to create a baseline inventory of all non-motorized trails on Cokeville Meadows National Wildlife Refuge. Trails in this inventory are...

  15. Ash Meadows Pupfish Preserve: A proposal from The Nature Conservancy

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Ash Meadows region of southwest Nevada has evolved since the last period of glaciation into a unique alkali desert ecosystem. The remnant springs, pools and...

  16. Narrative Report : Calendar Year 1976 : Great Meadows National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This narrative report for Great Meadows National Wildlife Refuge outlines Refuge accomplishments during the 1976 calendar year. The report begins with an...

  17. Experimental infection of meadow voles (Microtus pennsylvanicus) with sheep scrapie

    Science.gov (United States)

    Carlson, CM; Schneider, Jay R.; Pedersen, Janice C.; Heisey, Dennis M.; Johnson, Christopher J.

    2015-01-01

    Meadow voles (Microtus pennsylvanicus) are permissive to chronic wasting disease (CWD) infection, but their susceptibility to other transmissible spongiform encephalopathies (TSEs) is poorly characterized. In this initial study, we intracerebrally challenged 6 meadow voles with 2 isolates of sheep scrapie. Three meadow voles acquired a TSE after the scrapie challenge and an extended incubation period. The glycoform profile of proteinase K-resistant prion protein (PrP(res)) in scrapie-sick voles remained similar to the sheep inocula, but differed from that of voles clinically affected by CWD. Vacuolization patterns and disease-associated prion protein (PrP(Sc)) deposition were generally similar in all scrapie-affected voles, except in the hippocampus, where PrP(Sc) staining varied markedly among the animals. Our results demonstrate that meadow voles can acquire a TSE after intracerebral scrapie challenge and that this species could therefore prove useful for characterizing scrapie isolates.

  18. Key biogeochemical factors affecting soil carbon storage in Posidonia meadows

    KAUST Repository

    Serrano, Oscar

    2016-08-15

    Biotic and abiotic factors influence the accumulation of organic carbon (C-org) in seagrass ecosystems. We surveyed Posidonia sinuosa meadows growing in different water depths to assess the variability in the sources, stocks and accumulation rates of Corg. We show that over the last 500 years, P. sinuosa meadows closer to the upper limit of distribution (at 2-4 m depth) accumulated 3- to 4-fold higher C-org stocks (averaging 6.3 kg C-org m(-2) at 3- to 4-fold higher rates (12.8 gC(org) m(-2) yr(-1) ) compared to meadows closer to the deep limits of distribution (at 6-8 m depth; 1.8 kg C-org m(-2) and 3.6 g C-org m(-2) yr(-1) . In shallower meadows, C-org stocks were mostly derived from seagrass detritus (88% in average) compared to meadows closer to the deep limit of distribution (45% on average). In addition, soil accumulation rates and fine-grained sediment content (< 0.125 mm) in shallower meadows (2.0 mm yr(-1) and 9 %, respectively) were approximately 2-fold higher than in deeper meadows (1.2 mm yr(-1) and 5 %, respectively). The C-org stocks and accumulation rates accumulated over the last 500 years in bare sediments (0.6 kg C-org m(-2) and 1.2 g C-org m(-2) yr(-1)were 3- to 11-fold lower than in P. sinuosa meadows, while fine-grained sediment content (1 %) and seagrass detritus contribution to the Corg pool (20 %) were 8- and 3-fold lower than in Posidonia meadows, respectively. The patterns found support the hypothesis that Corg storage in seagrass soils is influenced by interactions of biological (e.g., meadow productivity, cover and density), chemical (e.g., recalcitrance of Corg stocks) and physical (e.g., hydrodynamic energy and soil accumulation rates) factors within the meadow. We conclude that there is a need to improve global estimates of seagrass carbon storage accounting for biogeochemical factors driving variability within habitats.

  19. Long term peatland subsidence: Experimental study and modeling scenarios in the Venice coastland

    Science.gov (United States)

    Zanello, Francesca; Teatini, Pietro; Putti, Mario; Gambolati, Giuseppe

    2011-12-01

    Land subsidence in drained cultivated peatlands is responsible for a number of serious environmental concerns and economical problems at both the local and the global scale. In low-lying coastal areas it enhances the risk of flooding, the saltwater contamination of shallow aquifers, and the maintenance costs of the systems that help keep the farmland drained. Since the subsidence is a major consequence of the bio-oxidation of the soil organic fraction in the upper aerated zone, cropped peatlands in temperate and tropic regions are important sources of CO2 into the atmosphere. A 4-year long experimental study has been performed in a drained peatland located south of the Venice Lagoon, Italy, to help calibrate a land subsidence model developed to predict the expected behavior of the ground surface elevation. Continuous monitoring of the hydrological regime and land displacements shows that the vertical movement of the peat surface consists of the superimposition of daily/seasonal time-scale reversible deformations related to soil moisture, depth to the water table, and temperature fluctuations, and long term irreversible subsidence due to peat oxidation. A novel two-step modeling approach to separate the two contributions from the available observations is presented. First, the elastic component is computed by integrating the peat vertical deformations evaluated by a constitutive relationship describing the porosity variation with the moisture content and pore pressure changes implemented into a variably saturated flow equation-based numerical code. The observed trend is then filtered from the computed reversible displacement and is used to calibrate an empirical relationship relating land subsidence rate to drainage depth and soil temperature. The results show that in recent years the subsidence rate ranged from 3 to 15 mm a-1. The large variability is due to the different climate conditions underlying the monitoring period, in particular a wet 2002 and a very dry

  20. Beetle and spider fauna of meadows affected by traffic pollution

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, R.

    1974-01-01

    The comparative effects of heavy versus light motor traffic on the composition of two meadow fauna, beetles and spiders, were investigated. Three of the meadows were adjacent to a very busy road and two to a little-used road. The numbers of species and of individual specimens of Carabidae were significantly lower (Wilcoxon test < 0.05) at the edges of the meadows on the busy road than at the edges of those on the little-used road. There was a reduction in the number of species of the Araneae group (Wilcoxon test > 0.05). Comparison of the number of individuals of representative species in the differently situated meadows revealed a reduction in the number of specimens on the sites adjacent to the busy road. A few exhibited greater number of individual specimens on the sites adjacent to the busy road than on those near the rural road. The diversity index of Shannon and Weaver generally yielded a lower value for the border zone of the meadows on the busy road, while there was no change observed for the meadows bordering on the rural road. Individuals captured near the edge of the busy road showed a significantly higher level of body lead than those captured in the middle of the field. 70 references, 4 figures, 1 table.

  1. Using multi-temporal Sentinal-2 imagery for mapping Andean meadows and surface soil moisture in central Chile

    Science.gov (United States)

    Araya, Rocio; Fassnacht, Fabian E.; Lopatin, Javier; Hernández, H. Jaime

    2017-04-01

    0.62, while the root mean square errors were between 2.19 g/g and 4.8 g/g. We concluded that BSVM and SVMR are suitable for Andean meadow and surface soil moisture mapping, producing reliable results with few samples. Moreover, Sentinel-2 allows a good understanding of variability within the meadows, and gives a high spatial and temporal resolution to assess future changes and establish whether the site is effectively drained or still maintains the wetness require to preserve these ecosystems.

  2. Water management: the key for sustainable management of tropical peatlands

    NARCIS (Netherlands)

    Ritzema, H.P.

    2004-01-01

    Through a combination of research, education and advisory projects, Alterra-ILRI with a number of partner organisations in Europe, Indonesia and Malaysia is promoting the wise use of tropical peatlands.

  3. BOREAS Follow-On DSP-10 Regridded Peatland Maps

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: These images were produced by aggregating 1' gridded data layers derived from the polygon-based Peatlands of Canada Database (Tarnocai et al., 2000) to 10'...

  4. BOREAS Follow-On DSP-10 Regridded Peatland Maps

    Data.gov (United States)

    National Aeronautics and Space Administration — These images were produced by aggregating 1' gridded data layers derived from the polygon-based Peatlands of Canada Database (Tarnocai et al., 2000) to 10'...

  5. Early life history transitions and recruitment of Picea mariana in thawed boreal permafrost peatlands.

    Science.gov (United States)

    Camill, Philip; Chihara, Laura; Adams, Brad; Andreassi, Christian; Barry, Ann; Kalim, Sahir; Limmer, Jacob; Mandell, Mike; Rafert, Greg

    2010-02-01

    Black spruce (Picea mariana) is the most abundant tree species in the boreal biome, but little is known about how climate warming may change recruitment in peatlands, especially those affected by permafrost thaw. We used results from a seven-year study in northern Manitoba, Canada, to address the following questions: (1) What is the relative importance of early life history transitions on P. mariana recruitment? (2) How are these transitions mediated by biological and environmental factors, including competition, facilitation, disease, herbivory, water table depth, and soil nutrients? (3) Do interactions among these factors create additional recruitment limitations beyond those imposed by environmental factors changing with climate warming, such as hydrology? Seed rain was measured over six years on forested permafrost plateaus and in neighboring collapse scar bogs. Seed germination and seedling survival and growth were measured over 4-5 years in collapse scars and assessed across a three-level water table treatment. Survival and growth experiments examined additional combinations of above- and belowground vascular plant competition and fertilizer addition. Results showed that failure of germination and survival on growing moss surfaces and reduced survival of seedlings in wetter microsites were primary constraints. Seed influx was significantly lower in collapse scars but likely did not limit recruitment. Biological and environmental factors mediating these life history transitions also differed in relative importance, and interactions among them tended to amplify recruitment limitation. Seedling survival was most strongly controlled by fast-growing mosses in wet microsites but also was influenced by apparent drowning in wet plots, herbivory, and loss of foliage caused by a fungal pathogen. Seedling growth was strongly controlled by water table depth, nutrient and competition levels, and fungal pathogens. Multiple, interacting factors will affect P. mariana

  6. Does high reactive nitrogen input from the atmosphere decrease the carbon sink strength of a peatland?

    Science.gov (United States)

    Brümmer, Christian; Zöll, Undine; Hurkuck, Miriam; Schrader, Frederik; Kutsch, Werner

    2017-04-01

    Mid-latitude peatlands are often exposed to high atmospheric nitrogen deposition when located in close vicinity to agricultural land. As the impacts of altered deposition rates on nitrogen-limited ecosystems are poorly understood, we investigated the surface-atmosphere exchange of several nitrogen and carbon compounds using multiple high-resolution measurement techniques and modeling. Our study site was a protected semi-natural bog ecosystem. Local wind regime and land use in the adjacent area clearly regulated whether total reactive nitrogen (ΣNr) concentrations were ammonia (NH3) or NOx-dominated. Eddy-covariance measurements of NH3 and ΣNr revealed concentration, temperature and surface wetness-dependent deposition rates. Intermittent periods of NH3 and ΣNr emission likely attributed to surface water re-emission and soil efflux, respectively, were found, thereby indicating nitrogen oversaturation in this originally N-limited ecosystem. Annual dry plus wet deposition resulted in 20 to 25 kg N ha-1 depending on method and model used, which translated into a four- to fivefold exceedance of the ecosystem-specific critical load. As the bog site had likely been exposed to the observed atmospheric nitrogen burden over several decades, a shift in grass species' composition towards a higher number of nitrophilous plants was already visible. Three years of CO2 eddy flux measurements showed that the site was a small net sink in the range of 33 to 268 g CO2 m-2 yr-1. Methane emissions of 32 g CO2-eq were found to partly offset the sequestered carbon through CO2. Our study indicates that the sink strength of the peatland has likely been decreased through elevated N deposition over the past decades. It also demonstrates the applicability of novel micrometeorological measurement techniques in biogeochemical sciences and stresses the importance of monitoring long-term changes in vulnerable ecosystems under anthropogenic pressure and climate change.

  7. Photosynthetic activity buffers ocean acidification in seagrass meadows

    Science.gov (United States)

    Hendriks, I. E.; Olsen, Y. S.; Ramajo, L.; Basso, L.; Steckbauer, A.; Moore, T. S.; Howard, J.; Duarte, C. M.

    2013-07-01

    Macrophytes growing in shallow coastal zones characterized by intense metabolic activity have the capacity to modify pH within their canopy and beyond. We observed diel pH ranges is in shallow (5-12 m) seagrass (Posidonia oceanica) meadows from 0.06 pH units in September to 0.24 units in June. The carbonate system (pH, DIC, and aragonite saturation state (ΩAr) and O2 within the meadows displayed strong diel variability driven by primary productivity, and changes in chemistry were related to structural parameters of the meadow, in particular, the leaf surface area available for photosynthesis (LAI). LAI was positively correlated to mean and max pHNBS and max ΩAr. Oxygen production positively influenced the range and maximum pHNBS and the range of ΩAr. In June, vertical mixing (as Turbulent Kinetic Energy) influenced ΩAr, while in September there was no effect of hydrodynamics on the carbonate system within the canopy. ΩAr was positively correlated with the calcium carbonate load of the leaves, demonstrating a direct link between structural parameters, ΩAr and carbonate deposition. There was a direct relationship between ΩAr, influenced directly by meadow LAI, and CaCO3 content of the leaves. Therefore, calcifying organisms, e.g. epiphytes with carbonate skeletons, might benefit from the modification of the carbonate system by the meadow. The meadow might be capable of providing refugia for calcifiers by increasing pH and ΩAr through metabolic activity. There is, however, concern for the ability of seagrasses to provide this refugia function in the future. The predicted decline of seagrass meadows may alter the scope for alteration of pH within a seagrass meadow and in the water column above the meadow, particularly if shoot density and biomass decline, both strongly linked to LAI. Organisms associated with seagrass communities may therefore suffer from the loss of pH buffering capacity in degraded meadows.

  8. 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

  9. 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.

  10. Nitrogen fixation in Red Sea seagrass meadows

    KAUST Repository

    Abdallah, Malak

    2017-05-01

    Seagrasses are key coastal ecosystems, providing many ecosystem services. Seagrasses increase biodiversity as they provide habitat for a large set of organisms. In addition, their structure provides hiding places to avoid predation. Seagrasses can grow in shallow marine coastal areas, but several factors regulate their growth and distribution. Seagrasses can uptake different kinds of organic and inorganic nutrients through their leaves and roots. Nitrogen and phosphorous are the most important nutrients for seagrass growth. Biological nitrogen fixation is the conversion of atmospheric nitrogen into ammonia by diazotrophic bacteria. This process provides a significant source of nitrogen for seagrass growth. The nitrogen fixation is controlled by the nif genes which are found in diazotrophs. The main goal of the project is to measure nitrogen fixation rates on seagrass sediments, in order to compare among various seagrass species from the Red Sea. Moreover, we will compare the fixing rates of the Vegetated areas with the bare sediments. This project will help to ascertain the role of nitrogen fixing bacteria in the development of seagrass meadows.

  11. Do we miss the hot spots? – The use of very high resolution aerial photographs to quantify carbon fluxes in peatlands

    Directory of Open Access Journals (Sweden)

    T. Becker

    2008-10-01

    Full Text Available Accurate determination of carbon balances in heterogeneous ecosystems often requires the extrapolation of point based measurements. The ground resolution (pixel size of the extrapolation base, e.g. a land-cover map, might thus influence the calculated carbon balance, in particular if biogeochemical hot spots are small in size. In this paper, we test the effects of varying ground resolution on the calculated carbon balance of a boreal peatland consisting of hummocks (dry, lawns (intermediate and flarks (wet surfaces. The generalizations in lower resolution imagery led to biased area estimates for individual micro-site types. While areas of lawns and hummocks were stable below a threshold resolution of ~60 cm, the maximum of the flark area was located at resolutions below 25 cm and was then decreasing with coarsening resolution. Using a resolution of 100 cm instead of 6 cm led to an overestimation of total CO2 uptake of the studied peatland area (approximately 14 600 m2 of ~5% and an underestimation of total CH4 emission of ~6%. To accurately determine the surface area of scattered and small-sized micro-site types in heterogeneous ecosystems (e.g. flarks in peatlands, a minimum ground resolution appears necessary. In our case this leads to a recommended resolution of 25 cm, which can be derived by conventional airborne imagery. The usage of high resolution imagery from commercial satellites, e.g. Quickbird, however, is likely to underestimate the surface area of biogeochemical hot spots. It is important to note that the observed resolution effect on the carbon balance estimates can be much stronger for other ecosystems than for the investigated peatland. In the investigated peatland the relative hot spot area of the flarks is very small and their hot spot characteristics with respect to CH4 and CO2 fluxes is rather modest.

  12. Peatland Acidobacteria with a dissimilatory sulfur metabolism

    DEFF Research Database (Denmark)

    Hausmann, Bela; Pelikan, Claus; Herbold, Craig W

    2018-01-01

    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...

  13. Coral Community Structure and Recruitment in Seagrass Meadows

    Directory of Open Access Journals (Sweden)

    Kathryn E. Lohr

    2017-11-01

    Full Text Available Coral communities are increasingly found to populate non-reef habitats prone to high environmental variability. Such sites include seagrass meadows, which are generally not considered optimal habitats for corals as a result of limited suitable substrate for settlement and substantial diel and seasonal fluctuations in physicochemical conditions relative to neighboring reefs. Interest in understanding the ability of corals to persist in non-reef habitats has grown, however little baseline data exists on community structure and recruitment of scleractinian corals in seagrass meadows. To determine how corals populate seagrass meadows, we surveyed the established and recruited coral community over 25 months within seagrass meadows at Little Cayman, Cayman Islands. Simultaneous surveys of established and recruited coral communities at neighboring back-reef sites were conducted for comparison. To fully understand the amount of environmental variability to which corals in each habitat were exposed, we conducted complementary surveys of physicochemical conditions in both seagrass meadows and back-reefs. Despite overall higher variability in physicochemical conditions, particularly pH, compared to the back-reef, 14 coral taxa were capable of inhabiting seagrass meadows, and multiple coral families were also found to recruit to these sites. However, coral cover and species diversity, richness, and evenness were lower at sites within seagrass meadows compared to back-reef sites. Although questions remain regarding the processes governing recruitment, these results provide evidence that seagrass beds can serve as functional habitats for corals despite high levels of environmental variability and suboptimal conditions compared to neighboring reefs.

  14. Understanding carbon cycling in northern peatlands: Recent developments and future prospects

    Science.gov (United States)

    Baird, Andrew J.; Comas, Xavier; Slater, Lee D.; Belyea, Lisa R.; Reeve, A. S.

    Although one of the earliest recorded investigations of peatlands is attributed to King [1685] more than 3 centuries ago [Gorham, 1953], Weber's [1902] treatise on the Aukštumala Raised Bog in Lithuania is still considered the first comprehensive ecohydrological study of peatlands and the foundation for modern peatland science. Weber's monograph was pioneering for different reasons: (1) it integrated disciplines such as stratigraphy, hydrology, chemistry, and ecology to describe, classify, and model peatlands forms and their development (e.g., internal processes), and (2) it investigated potential interactions between peatland (mostly hydrology) and changes in climate and sea level (e.g., external forcing). Since then, most peatlands science has focused on the peatland archive (e.g., pollen and macrofossils) for environmental and climate reconstruction over the Holocene, whereas processes controlling the response of peatlands to climate change have tended to be overlooked.

  15. 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

  16. Carbon balance of rewetted peatland forests in low mountain range areas, Germany

    Science.gov (United States)

    Krüger, Jan Paul; Dotterweich, Markus; Kopf, Christoph; Schüler, Gebhard; Scherzer, Jörg

    2017-04-01

    Peatland soils store a great proportion of the global soil carbon pool and are an important component of the global carbon cycle. Drainage of peatlands, for agricultural or forestry usage, leads to a loss of carbon from the soil to the atmosphere and the former carbon sink becomes a carbon source. Peatland rewetting has become a well applicable management tool to reduce the greenhouse gas emissions from peatland soils. However, the impact of rewetting on the carbon balance of drained peatland forest in low mountain range is rare. The aim of this project is to quantify the carbon balance of rewetted peatlands in the Hunsrück-Hochwald National Park. Worth protecting peatland's with forest called "Brücher" are characteristic of nature in the Hunsrück. Since the 19th century these peatlands have been drained by ditches for spruce forests. The survey of surface area of the peatlands is the first important part of the project. Furthermore, a peatland land register for the national park and adjacent areas will be developed. Based on peatland area and carbon stocks the carbon pools of different degradation stages of these peatland can be investigated. Furthermore, terrestrial laser scan data and geoelectrical measurements will be applied for estimating the carbon pool of the vegetation and the soil. This approach enables us to quantify the whole ecosystem carbon pool. A space-for-time substitution allows for a first estimation of the carbon balance of the rewetted peatlands in the Hunsrück-Hochwald National Park. The main aim of a comprehensive carbon balancing will be achieved based upon the peatland characteristics and upscaling of carbon stocks from peatlands with different restoration/degradation scenarios. Moreover, the obtained data will be used for a long-term carbon balance monitoring of the rewetted peatlands in this region.

  17. Impact of mooring activities on carbon stocks in seagrass meadows

    KAUST Repository

    Serrano, O.

    2016-03-16

    Boating activities are one of the causes that threaten seagrass meadows and the ecosystem services they provide. Mechanical destruction of seagrass habitats may also trigger the erosion of sedimentary organic carbon (Corg) stocks, which may contribute to increasing atmospheric CO2. This study presents the first estimates of loss of Corg stocks in seagrass meadows due to mooring activities in Rottnest Island, Western Australia. Sediment cores were sampled from seagrass meadows and from bare but previously vegetated sediments underneath moorings. The Corg stores have been compromised by the mooring deployment from 1930s onwards, which involved both the erosion of existing sedimentary Corg stores and the lack of further accumulation of Corg. On average, undisturbed meadows had accumulated ~6.4 Kg Corg m−2 in the upper 50 cm-thick deposits at a rate of 34 g Corg m−2 yr−1. The comparison of Corg stores between meadows and mooring scars allows us to estimate a loss of 4.8 kg Corg m−2 in the 50 cm-thick deposits accumulated over ca. 200 yr as a result of mooring deployments. These results provide key data for the implementation of Corg storage credit offset policies to avoid the conversion of seagrass ecosystems and contribute to their preservation.

  18. Carbon accumulation of tropical peatlands over millennia: a modeling approach.

    Science.gov (United States)

    Kurnianto, Sofyan; Warren, Matthew; Talbot, Julie; Kauffman, Boone; Murdiyarso, Daniel; Frolking, Steve

    2015-01-01

    Tropical peatlands cover an estimated 440,000 km2 (~10% of global peatland area) and are significant in the global carbon cycle by storing about 40-90 Gt C in peat. Over the past several decades, tropical peatlands have experienced high rates of deforestation and conversion, which is often associated with lowering the water table and peat burning, releasing large amounts of carbon stored in peat to the atmosphere. We present the first model of long-term carbon accumulation in tropical peatlands by modifying the Holocene Peat Model (HPM), which has been successfully applied to northern temperate peatlands. Tropical HPM (HPMTrop) is a one-dimensional, nonlinear, dynamic model with a monthly time step that simulates peat mass remaining in annual peat cohorts over millennia as a balance between monthly vegetation inputs (litter) and monthly decomposition. Key model parameters were based on published data on vegetation characteristics, including net primary production partitioned into leaves, wood, and roots; and initial litter decomposition rates. HPMTrop outputs are generally consistent with field observations from Indonesia. Simulated long-term carbon accumulation rates for 11,000-year-old inland, and 5000-year-old coastal peatlands were about 0.3 and 0.59 Mg C ha(-1) yr(-1), and the resulting peat carbon stocks at the end of the 11,000-year and 5000-year simulations were 3300 and 2900 Mg C ha(-1), respectively. The simulated carbon loss caused by coastal peat swamp forest conversion into oil palm plantation with periodic burning was 1400 Mg C ha(-1) over 100 years, which is equivalent to ~2900 years of C accumulation in a hectare of coastal peatlands. © 2014 John Wiley & Sons Ltd.

  19. 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...

  20. Peatlands and the carbon cycle: from local processes to global implications - a synthesis

    NARCIS (Netherlands)

    Limpens, J.; Berendse, F.; Blodau, C.; Canadell, J.G.; Freeman, C.; Holden, J.; Roulet, N.; Rydin, H.; Schaepman-Strub, G.

    2008-01-01

    Peatlands cover only 3% of the Earth's land surface but boreal and subarctic peatlands store about 15-30% of the world's soil carbon ( C) as peat. Despite their potential for large positive feedbacks to the climate system through sequestration and emission of greenhouse gases, peatlands are not

  1. Peatlands on National Forests of the Northern Rocky Mountains: Ecology and conservation

    Science.gov (United States)

    Steve W. Chadde; J. Stephen Shelly; Robert J. Bursik; Robert K. Moseley; Angela G. Evenden; Maria Mantas; Fred Rabe; Bonnie Heidel

    1998-01-01

    This overview of peatland ecology and conservation on National Forests in the Northern Rocky Mountains describes physical components, vegetation, vascular and nonvascular flora, and invertebrate fauna on peatlands. Detailed site descriptions for 58 peatlands in Idaho, Montana, and northeastern Washington are included.

  2. 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

  3. Subalpine meadow plant communities in Yosemite and Sequoia and Kings Canyon National Parks, 2011-2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This publication presents data collected within meadows from samples used to assess meadow plant community responses to recreational pack stock as part of a USGS...

  4. Seagrasses under threat: Understanding the resilience of temperate seagrass meadows in a changing environment

    NARCIS (Netherlands)

    Soissons, L.M.

    2017-01-01

    Despite being highly valuable ecosystems, seagrass meadows are threatened worldwide, mostly by human activities. In order to preserve seagrass meadows from collapse, we need to better understand their resilience in a changing environment. By means of various

  5. The flux of organic matter through a peatland ecosystem - a molecular budget of C in peatlands

    Science.gov (United States)

    Worrall, Fred; Moody, Catherine; Clay, Gareth

    2017-04-01

    Carbon budgets of peatlands are now common and studies have considered nitrogen, oxygen and energy budgets, but no study has considered the whole composition of the organic matter as it transfers through a peatland. Organic matter samples were taken from each organic matter reservoir and fluvial transfer pathway and analysed the samples by 13C nuclear magnetic resonance (NMR) and thermogravimetric analysis. The samples analysed were: aboveground, belowground, heather, mosses and sedges, litter layer, a peat core, and monthly samples of particulate and dissolved organic matter. All organic matter samples were taken from a 100% peat catchment within Moor House National Nature Reserve in the North Pennines, UK, and collected samples were compared to standards of lignin, cellulose, humic acid and plant protein. Results showed that the thermogravimetric trace of the sampled organic matter were distinctive with the DOM traces being marked out by very low thermal stability relative other organic matter types. The peat profile shows a significant trend with depth from vegetation- to lignin-like composition. A principal component analysis (PCA) of the NMR data shows that the DOM was a mixture of plant and peat compositions reacting to form a highly evolved composition that perhaps represents autochthonous stream processes. When all traces are weighted according to the observed dry matter and carbon budgets for the catchment then it is possible to judge what has been lost in the transition through and into the ecosystem. By plotting this "lost" trace it possible to assess its composition which is either 97% cellulose and 3% humic acid or 92% and 8% lignin. The "lost" composition shows that peatland processes preferentially remove carbohydrates and retaining lignin compounds reflected. Similarly the NMR traces show that while O-alkyl functional groups were selectively lost in the transition while alkyl groups were selectively enriched.

  6. The potential peatland extent and carbon sink in Sweden, as related to the Peatland / Ice Age Hypothesis

    Directory of Open Access Journals (Sweden)

    F. Lindberg

    2012-09-01

    Full Text Available Peatlands cover approximately 65,600 km2 (16 % of the Swedish land area. The available areas suitable for peatland expansion are far from occupied after ca. 12,000 years of the present interglacial. We estimate the potential extent of peatland in Sweden, based on slope properties of possible areas excluding lakes and glaciofluvial deposits. We assume no human presence or anthropic effects, so the calculation is speculative. It may have been relevant for previous interglacials.We calculate the potential final area of peatlands in three scenarios where they cover all available land with different maximum slope angles (1−3 º using a Digital Elevation Model (DEM. The three scenarios yield potential peatland areas of 95,663 km2 (21 % of total available area, 168,287 km2 (38 % and 222,141 km2 (50 %. The relative increases from the present 65,600 km2 are 46, 157 and 239 % respectively.The slope scenarios give CO2 uptake rates of 8.9−10.8, 18.1−22.4 and 24.6−30.5 Mt yr−1. Under global warming conditions with isotherms moved northwards and to higher altitudes, following an increase of raised bog area, the CO2 uptake rates might increase to 12.2−13.8, 24.4−27.7 and 33.5−37.9 Mt yr−1; i.e. up to 4.3−4.9 vpb of atmospheric CO2. If we make the speculative extrapolation from Sweden to all high latitude peatlands, and assume that all suitable areas with slope angle ≤ 3 ° become occupied, the global peatland CO2 sink might approach 3.7 Gt yr−1 (about 2 vpm yr−1 and potentially cause a net radiative cooling approaching 5 W m−2.

  7. 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.

  8. Off-site embankments to protect fields from the growth of peatlands in the Valli Grandi Veronesi Meridionali (Italy during Middle and Recent Bronze Age

    Directory of Open Access Journals (Sweden)

    Claudio Balista

    2016-12-01

    ceramic material recovered from a intrasite excavation by F. Zorzi made around the mid of the last century and documented in a dissertation by Zanetti (1970-71. It allowed for the first time to present aspects of material culture (pottery facies, belonging to the first large RBA settlement of CdT, surrounded by the embanked. On these basis was initiated a revision of the stratigraphic position of the two samples for14C dating collected in the 90’s of the last century from the great embankment of CdT, both related to MBA/RBA. In the light of the analysis of the above mentioned ceramics, it was possible to discriminate a phase of MBA3 nucleated site without bounding embankment, but probably with a moat, from the later phase of RBA with massive embankment and surrounded by multiple ditches. Finally, the juxtaposition of the two systems separated from the earthen bank of the SAM, first meadows and pastures, latter fields delimited by long ditches (maybe opened fields and others small and closed, it has given rise to an important result directed to the definition of socio-political organisation which regulated this fundamental transect in the MBA-RBA for the economy and polity of VGVM near the sites of CDT and FP. The construction of the SAM embankment, erected to preserve the balanced distribution of lands allocated to support the two major sites, could therefore be reviewed as an expression of a huge collective work, continuously maintained, presumably demanded by the elite-polity of VGVM, to prevent the formation of peatlands. These, due to the rise of water table for paleoidrographic reasons, tended to invade the cultivated fields. This engineering earthwork had to play an important role for regulation and control for the drain and irrigation network made of main and secondary ditches extending to the nearby fields, before dissipating in the lower land of marginal pasture-wet meadows, next to fluvial woodland.

  9. 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).

  10. Export from Seagrass Meadows Contributes to Marine Carbon Sequestration

    KAUST Repository

    Duarte, Carlos M.

    2017-01-17

    Seagrasses export a substantial portion of their primary production, both in particulate and dissolved organic form, but the fate of this export production remains unaccounted for in terms of seagrass carbon sequestration. Here we review available evidence on the fate of seagrass carbon export to conclude that this represents a significant contribution to carbon sequestration, both in sediments outside seagrass meadows and in the deep sea. The evidence presented implies that the contribution of seagrass meadows to carbon sequestration has been underestimated by only including carbon burial within seagrass sediments.

  11. 75 FR 39037 - Crane Meadows National Wildlife Refuge, Morrison County, MN

    Science.gov (United States)

    2010-07-07

    ... Fish and Wildlife Service Crane Meadows National Wildlife Refuge, Morrison County, MN AGENCY: Fish and... assessment (EA) for Crane Meadows National Wildlife Refuge (NWR) for public review and comment. In this draft... the following methods. You may also drop off comments in person at Crane Meadows NWR. 1. Agency Web...

  12. Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

    Directory of Open Access Journals (Sweden)

    Y. A. Teh

    2017-08-01

    Full Text Available The Amazon plays a critical role in global atmospheric budgets of methane (CH4 and nitrous oxide (N2O. However, while we have a relatively good understanding of the continental-scale flux of these greenhouse gases (GHGs, one of the key gaps in knowledge is the specific contribution of peatland ecosystems to the regional budgets of these GHGs. Here we report CH4 and N2O fluxes from lowland tropical peatlands in the Pastaza–Marañón foreland basin (PMFB in Peru, one of the largest peatland complexes in the Amazon basin. The goal of this research was to quantify the range and magnitude of CH4 and N2O fluxes from this region, assess seasonal trends in trace gas exchange, and determine the role of different environmental variables in driving GHG flux. Trace gas fluxes were determined from the most numerically dominant peatland vegetation types in the region: forested vegetation, forested (short pole vegetation, Mauritia flexuosa-dominated palm swamp, and mixed palm swamp. Data were collected in both wet and dry seasons over the course of four field campaigns from 2012 to 2014. Diffusive CH4 emissions averaged 36.05 ± 3.09 mg CH4–C m−2 day−1 across the entire dataset, with diffusive CH4 flux varying significantly among vegetation types and between seasons. Net ebullition of CH4 averaged 973.3 ± 161.4 mg CH4–C m−2 day−1 and did not vary significantly among vegetation types or between seasons. Diffusive CH4 flux was greatest for mixed palm swamp (52.0 ± 16.0 mg CH4–C m−2 day−1, followed by M. flexuosa palm swamp (36.7 ± 3.9 mg CH4–C m−2 day−1, forested (short pole vegetation (31.6 ± 6.6 mg CH4–C m−2 day−1, and forested vegetation (29.8 ± 10.0 mg CH4–C m−2 day−1. Diffusive CH4 flux also showed marked seasonality, with divergent seasonal patterns among ecosystems. Forested vegetation and mixed palm swamp showed significantly higher

  13. Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

    Science.gov (United States)

    Arn Teh, Yit; Murphy, Wayne A.; Berrio, Juan-Carlos; Boom, Arnoud; Page, Susan E.

    2017-08-01

    The Amazon plays a critical role in global atmospheric budgets of methane (CH4) and nitrous oxide (N2O). However, while we have a relatively good understanding of the continental-scale flux of these greenhouse gases (GHGs), one of the key gaps in knowledge is the specific contribution of peatland ecosystems to the regional budgets of these GHGs. Here we report CH4 and N2O fluxes from lowland tropical peatlands in the Pastaza-Marañón foreland basin (PMFB) in Peru, one of the largest peatland complexes in the Amazon basin. The goal of this research was to quantify the range and magnitude of CH4 and N2O fluxes from this region, assess seasonal trends in trace gas exchange, and determine the role of different environmental variables in driving GHG flux. Trace gas fluxes were determined from the most numerically dominant peatland vegetation types in the region: forested vegetation, forested (short pole) vegetation, Mauritia flexuosa-dominated palm swamp, and mixed palm swamp. Data were collected in both wet and dry seasons over the course of four field campaigns from 2012 to 2014. Diffusive CH4 emissions averaged 36.05 ± 3.09 mg CH4-C m-2 day-1 across the entire dataset, with diffusive CH4 flux varying significantly among vegetation types and between seasons. Net ebullition of CH4 averaged 973.3 ± 161.4 mg CH4-C m-2 day-1 and did not vary significantly among vegetation types or between seasons. Diffusive CH4 flux was greatest for mixed palm swamp (52.0 ± 16.0 mg CH4-C m-2 day-1), followed by M. flexuosa palm swamp (36.7 ± 3.9 mg CH4-C m-2 day-1), forested (short pole) vegetation (31.6 ± 6.6 mg CH4-C m-2 day-1), and forested vegetation (29.8 ± 10.0 mg CH4-C m-2 day-1). Diffusive CH4 flux also showed marked seasonality, with divergent seasonal patterns among ecosystems. Forested vegetation and mixed palm swamp showed significantly higher dry season (47.2 ± 5.4 mg CH4-C m-2 day-1 and 85.5 ± 26.4 mg CH4-C m-2 day-1, respectively) compared to wet season emissions

  14. Oligo-Miocene peatland ecosystems of the Gippsland Basin and modern analogues

    Science.gov (United States)

    Korasidis, Vera A.; Wallace, Malcolm W.; Wagstaff, Barbara E.; Holdgate, Guy R.

    2017-02-01

    A detailed examination of the brown coal facies preserved in the Latrobe Valley Morwell 1B seam indicates that the type of peat-forming environment and the associated hydrological regime are the main factors influencing the development of lithotypes in brown coal deposits. New palynological data from the Morwell 1B seam suggests that each respective lithotype in the lightening-upwards lithotype cycles was deposited in a particular depositional environment that was characterised by a distinct floral community. The laminated dark lithotype represents a fire-prone emergent marsh that grew on the margins of a coastal lagoon and/or freshwater swamp. This facies grades into the dark lithotype, representing the transition from a meadow marsh to a periodically flooded ombrogenous forested bog. The medium and lighter lithotypes are interpreted as being deposited in an angiosperm-dominated ombrogenous forest bog that was intolerant of fire. These peat-forming environments are interpreted as being largely controlled by moisture and relative depth to water table. Each environment produces distinct lithotypes and lightening-upwards cycles are interpreted as terrestrialization cycles. As the peat grew upwards and above the water table, less moist conditions prevailed and lighter lithotypes were produced. The observed change in colour, from darker to lighter lithotypes, results from the environment evolving from anaerobic/inundated to less anaerobic/less moist settings via terrestrialization. The thin and laterally extensive light and pale lithotypes that top the cycles are interpreted to represent a residual layer of concentrated, oxidation resistant peat-forming elements that result from intense weathering and aerobic degradation of the peats. At a generic level, modern lowland bogs of South Westland in New Zealand have remarkably similar floral/ecological gradients to those of the Oligo-Miocene Morwell 1B brown coal cycles in Australia. This suggests that modern New Zealand

  15. Echo Meadows Project Winter Artificial Recharge.

    Energy Technology Data Exchange (ETDEWEB)

    Ziari, Fred

    2002-12-19

    This report discusses the findings of the Echo Meadows Project (BPA Project 2001-015-00). The main purpose of this project is to artificially recharge an alluvial aquifer, WITH water from Umatilla River during the winter high flow period. In turn, this recharged aquifer will discharge an increased flow of cool groundwater back to the river, thereby improving Umatilla River water quality and temperature. A considerable side benefit is that the Umatilla River should improve as a habitat for migration, spanning, and rearing of anadromous and resident fish. The scope of this project is to provide critical baseline information about the Echo Meadows and the associated reach of the Umatilla River. Key elements of information that has been gathered include: (1) Annual and seasonal groundwater levels in the aquifer with an emphasis on the irrigation season, (2) Groundwater hydraulic properties, particularly hydraulic conductivity and specific yield, and (3) Groundwater and Umatilla River water quality including temperature, nutrients and other indicator parameters. One of the major purposes of this data gathering was to develop input to a groundwater model of the area. The purpose of the model is to estimate our ability to recharge this aquifer using water that is only available outside of the irrigation season (December through the end of February) and to estimate the timing of groundwater return flow back to the river. We have found through the data collection and modeling efforts that this reach of the river had historically returned as much as 45 cubic feet per second (cfs) of water to the Umatilla River during the summer and early fall. However, this return flow was reduced to as low as 10 cfs primarily due to reduced quantities of irrigation application, gain in irrigation efficiencies and increased groundwater pumping. Our modeling indicated that it is possible to restore these critical return flows using applied water outside of the irrigation season. We further

  16. Biases in methane chamber measurements in peatlands

    Science.gov (United States)

    Juszczak, R.

    2013-03-01

    The paper presents results of CH4 emission measurements at peatland with the application of the dynamic chamber technique. The measurements were conducted in two types of chambers differing in shape, height, volume and technology used to assure their tightness. The study tested how the following factors: 1) forced chamber headspace mixing or its absence, 2) mistakes of the person conducting measurements, 3) improper application of linear technique for calculating CH4 fluxes, and 4) simulated air sampling typical for static chambers, influence the significance of errors and the underestimation rate of CH4 fluxes measured in situ. It was indicated that chamber headspace mixing allows estimating methane fluxes with a smaller error than in the case of measurements conducted without mixing, and CH4 fluxes in such conditions can be 47 to 58% higher (depending on the chamber type) than in a chamber without fans. Using dynamic chambers and a fast analyzer to measure methane fluxes allows shortening the methane measurement process to a few minutes. On the other hand, using static chambers for methane flux measurements may lead to 70% underestimation of the calculated flux.

  17. Potential environmental effects of pack stock on meadow ecosystems of the Sierra Nevada, USA

    Science.gov (United States)

    Ostoja, Steven M.; Brooks, Matthew L.; Moore, Peggy E.; Berlow, Eric L.; Robert Blank,; Roche, Jim; Chase, Jennifer T.; Sylvia Haultain,

    2014-01-01

    Pack and saddle stock, including, but not limited to domesticated horses, mules, and burros, are used to support commercial, private and administrative activities in the Sierra Nevada. The use of pack stock has become a contentious and litigious issue for land management agencies in the region inter alia due to concerns over effects on the environment. The potential environmental effects of pack stock on Sierra Nevada meadow ecosystems are reviewed and it is concluded that the use of pack stock has the potential to influence the following: (1) water nutrient dynamics, sedimentation, temperature, and microbial pathogen content; (2) soil chemistry, nutrient cycling, soil compaction and hydrology; (3) plant individuals, populations and community dynamics, non-native invasive species, and encroachment of woody species; and (4) wildlife individuals, populations and communities. It is considered from currently available information that management objectives of pack stock should include the following: minimise bare ground, maximise plant cover, maintain species composition of native plants, minimise trampling, especially on wet soils and stream banks, and minimise direct urination and defecation by pack stock into water. However, incomplete documentation of patterns of pack stock use and limited past research limits current understanding of the effects of pack stock, especially their effects on water, soils and wildlife. To improve management of pack stock in this region, research is needed on linking measurable monitoring variables (e.g. plant cover) with environmental relevancy (e.g. soil erosion processes, wildlife habitat use), and identifying specific environmental thresholds of degradation along gradients of pack stock use in Sierra Nevada meadows.

  18. Lateglacial and Holocene climate, disturbance and permafrost peatland dynamics on the Seward Peninsula, western Alaska

    Science.gov (United States)

    Hunt, Stephanie D.; Yu, Zicheng; Jones, Miriam C.

    2013-01-01

    Northern peatlands have accumulated large carbon (C) stocks, acting as a long-term atmospheric C sink since the last deglaciation. How these C-rich ecosystems will respond to future climate change, however, is still poorly understood. Furthermore, many northern peatlands exist in regions underlain by permafrost, adding to the challenge of projecting C balance under changing climate and permafrost dynamics. In this study, we used a paleoecological approach to examine the effect of past climates and local disturbances on vegetation and C accumulation at a peatland complex on the southern Seward Peninsula, Alaska over the past ∼15 ka (1 ka = 1000 cal yr BP). We analyzed two cores about 30 m apart, NL10-1 (from a permafrost peat plateau) and NL10-2 (from an adjacent thermokarst collapse-scar bog), for peat organic matter (OM), C accumulation rates, macrofossil, pollen and grain size analysis.A wet rich fen occurred during the initial stages of peatland development at the thermokarst site (NL10-2). The presence of tree pollen from Picea spp. and Larix laricinia at 13.5–12.1 ka indicates a warm regional climate, corresponding with the well-documented Bølling–Allerød warm period. A cold and dry climate interval at 12.1–11.1 ka is indicated by the disappearance of tree pollen and increase in Poaceae pollen and an increase in woody material, likely representing a local expression of the Younger Dryas (YD) event. Following the YD, the warm Holocene Thermal Maximum (HTM) is characterized by the presence of Populus pollen, while the presence of Sphagnum spp. and increased C accumulation rates suggest high peatland productivity under a warm climate. Toward the end of the HTM and throughout the mid-Holocene a wet climate-induced several major flooding disturbance events at 10 ka, 8.1 ka, 6 ka, 5.4 ka and 4.7 ka, as evidenced by decreases in OM, and increases in coarse sand abundance and aquatic fossils (algae Chara and water fleas Daphnia). The initial

  19. 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

  20. 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

  1. Water retention in a peatland with organic matter in different decomposition stages

    Directory of Open Access Journals (Sweden)

    José Ricardo da Rocha Campos

    2011-08-01

    Full Text Available Peatlands are ecosystems formed by successive pedogenetic processes, resulting in progressive accumulation of plant remains in the soil column under conditions that inhibit the activity of most microbial decomposers. In Diamantina, state of Minas Gerais, Brazil, a peatland is located at 1366 m asl, in a region with a quartz-rich lithology and characteristic wet grassland vegetation. For this study, the peat area was divided in 12 transects, from which a total of 90 soil samples were collected at a distance of 20 m from each other. The properties rubbed fiber content (RF, bulk density (Bd, mineral material (MM, organic matter (OM, moisture (Moi and maximum water holding capacity (MWHC were analyzed in all samples. From three selected profiles of this whole area, samples were collected every 27 cm from the soil surface down to a depth of 216 cm. In these samples, moisture was additionally determined at a pressure of 10 kPa (Moi10 or 1500 kPa (Moi1500, using Richards' extractor and soil organic matter was fractionated by standard procedures. The OM decomposition stage of this peat was found to increase with soil depth. Moi and MWHC were highest in layers with less advanced stages of OM decomposition. The humin levels were highest in layers in earlier stages of OM decomposition and with higher levels of water retention at MWHC and Moi10. Humic acid contents were higher in layers at an intermediate stage of decomposition of organic matter and with lowest levels of water retention at MWHC, Moi10 and Moi1500.

  2. 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

  3. Occurrence of entomopathogenic fungi in arable soil and meadow soil

    Directory of Open Access Journals (Sweden)

    Ryszard Miętkowski

    2014-08-01

    Full Text Available The samples of soil for experiment were taken from arable field and meadow. Larvae of Laspeyresia pomonella and Plodia interpuactella were used as an "insect bait" for isolation of entomopathogenic fungi from the soil. Beauveria bassiana, Metarhizium anisopliae, Paecilomyces farinosus and P. fumosoroseus were isolated from both kinds of soil.

  4. Prospects for fen meadow restoration on severely degraded fens

    NARCIS (Netherlands)

    Klimkowska, Agata; Diggelen, Rudy Van; Grootjans, Ab P.; Kotowski, Wiktor

    2010-01-01

    The majority of fens in Europe have been transformed for agricultural purposes and have disappeared or become degraded. Fen meadows that developed under low-intensity management of fens also have become degraded. In this paper, we consider the available restoration methods, biotic constraints for

  5. Seagrass meadows (Posidonia oceanica) distribution and trajectories of change

    Science.gov (United States)

    Telesca, Luca; Belluscio, Andrea; Criscoli, Alessandro; Ardizzone, Giandomenico; Apostolaki, Eugenia T.; Fraschetti, Simonetta; Gristina, Michele; Knittweis, Leyla; Martin, Corinne S.; Pergent, Gérard; Alagna, Adriana; Badalamenti, Fabio; Garofalo, Germana; Gerakaris, Vasilis; Louise Pace, Marie; Pergent-Martini, Christine; Salomidi, Maria

    2015-01-01

    Posidonia oceanica meadows are declining at alarming rates due to climate change and human activities. Although P. oceanica is considered the most important and well-studied seagrass species of the Mediterranean Sea, to date there has been a limited effort to combine all the spatial information available and provide a complete distribution of meadows across the basin. The aim of this work is to provide a fine-scale assessment of (i) the current and historical known distribution of P. oceanica, (ii) the total area of meadows and (iii) the magnitude of regressive phenomena in the last decades. The outcomes showed the current spatial distribution of P. oceanica, covering a known area of 1,224,707 ha, and highlighted the lack of relevant data in part of the basin (21,471 linear km of coastline). The estimated regression of meadows amounted to 34% in the last 50 years, showing that this generalised phenomenon had to be mainly ascribed to cumulative effects of multiple local stressors. Our results highlighted the importance of enforcing surveys to assess the status and prioritize areas where cost-effective schemes for threats reduction, capable of reversing present patterns of change and ensuring P. oceanica persistence at Mediterranean scale, could be implemented. PMID:26216526

  6. Blue carbon stocks in Baltic Sea eelgrass (Zostera marina) meadows

    DEFF Research Database (Denmark)

    Rohr, Maria Emilia; Bostrom, Christoffer; Canal-Vergés, Paula

    2016-01-01

    Although seagrasses cover only a minor fraction of the ocean seafloor, their carbon sink capacity accounts for nearly one-fifth of the total oceanic carbon burial and thus play a critical structural and functional role in many coastal ecosystems. We sampled 10 eelgrass (Zostera marina) meadows in...

  7. Cyanobacterial Occurrence and Diversity in Seagrass Meadows in ...

    African Journals Online (AJOL)

    Abstract: We report on the occurrence and diversity of cyanobacteria in intertidal seagrass meadows at Ocean Road and Mjimwema, Dar es Salaam, Tanzania. Nutrients, temperature and salinity were measured as comparative environmental factors. A total of 19 different cyanobacteria taxa were encountered, out of which ...

  8. The biodiversity and stability of alpine meadow plant communities in ...

    African Journals Online (AJOL)

    Kobresia pygmaea meadow community diversities in relation to altitude gradients (4200, 4300, 4400, 4450) on free grazing grassland was studied in the range of Chenduo county, Yushu prefecture, Qinghai province. Species richness and diversity index of vegetations in the four altitudes were comparatively analyzed.

  9. The biodiversity and stability of alpine meadow plant communities in ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-10-02

    Oct 2, 2012 ... The biodiversity and stability of alpine meadow plant communities in relation to altitude gradient in three ... grassland to global climate change. MATERIALS AND METHODS. Site description ..... ultramafic substrate and altitude in south western New Zealand [J]. Vegetation 86:15-20. Wills KJ, Whittaker RJ ...

  10. Plant community responses to prescribed burning in Wisconsin sedge meadows

    Science.gov (United States)

    Michael A. Kost; Diane De Steven

    2000-01-01

    In northern temperate regions, sedge meadows dominated by the tussock-sedge Carex stricta Lam. (Cyperaceae) were historically a fire-maintained community type. In two Wisconsin natural areas (Lulu Lake and Summerton), the authors assessed the effects of time since prescribed spring burning on plant composition and aboveground biomass in eight sedge...

  11. Growing season methane emissions from a permafrost peatland of northeast China: Observations using open-path eddy covariance method

    Science.gov (United States)

    Yu, Xueyang; Song, Changchun; Sun, Li; Wang, Xianwei; Shi, Fuxi; Cui, Qian; Tan, Wenwen

    2017-03-01

    The mid-high latitude permafrost peatlands in the Northern Hemisphere is a major natural source of methane (CH4) to the atmosphere. Ecosystem scale CH4 emissions from a typical permafrost peatland in the Great Hing'an Mountains were observed during the growing season of 2014 and 2015 using the open-path eddy covariance method. Relevant environmental factors such as temperature and precipitation were also collected. There was a clear diurnal variation in methane emissions in the second half of each growing season, with significantly higher emission rates in the wet sector of study area. The daily CH4 exchange ranged from 1.8 mg CH4 m-2 d-1 to 40.2 mg CH4 m-2 d-1 in 2014 and ranged from -3.9 to 15.0 mg CH4 m-2 d-1 in 2015. There were no peaks of CH4 fluxes during the spring thawing period. However, large peaks of CH4 emission were found in the second half of both growing seasons. The CH4 emission after Jul 25th accounted for 77.9% of total growing season emission in 2014 and 85.9% in 2015. The total CH4 emission during the growing season of 2014 and 2015 was approximately 1.52 g CH4 m-2 and 0.71 g CH4 m-2, respectively. CH4 fluxes during the growing seasons were significantly correlated with thawing depth (R2 = 0.71, P emissions in permafrost peatlands. Our multiyear observations indicate that the time-lagged volume of precipitation during the growing season is a key factor in interpreting locally inter-annual variations in CH4 emissions. Our results suggested that the low temperature in the deep soil layers effectively restricts methane production and emission rates; these conditions may create significant positive feedback under global climate change.

  12. Wetting, Prewetting and Superfluidity

    OpenAIRE

    Taborek, P.

    2009-01-01

    Experiments on adsorption and wetting of quantum fluids (4He and 3He) on weakly binding alkali metal substrates are reviewed. Helium on weak substrates can undergo a variety of phase transitions including wetting, prewetting, layering, and liquid-vapor transitions. Another characteristic feature of weak substrates is the absence of an immobile quasi solid layer which is present on all conventional strong substrates. Both the absence of the immobile layer and the interaction with surface phase...

  13. A Water Budget Approach to Study the Hydrologic Response of Mountain Meadow Restoration Following Conifer Removal

    Science.gov (United States)

    Van Oosbree, G. F.; Surfleet, C. G.; Jasbinsek, J. J.

    2014-12-01

    Mountain meadows are important ecological habitats that have degraded in quality and distribution due to fire suppression and poor land use practices in the Sierra Nevada Mountains. Conifer encroachment in mountain meadows has accelerated and is one of the reasons for the decline of meadow habitat. To date there are few studies which quantify the hydrologic response of meadow restoration due to vegetation or conifer removal. This study is using a before after control intervention (BACI) study design to determine the hydrologic response of restoration to a historic meadow encroached by conifers (study meadow). A water budget approach has been developed to quantify the hydrology of the control and study meadow before and after restoration. Measurements of groundwater depth and soil moisture are currently being taken on the control and study meadows. A total of 14 Odyssey water level capacitance instruments were installed to a 1.5 meter depth and 14 soil moisture instruments were installed to a 30 cm depth using a spatially balanced random sampling approach. Electrical resistivity imaging (ERI) was used to determine soil moisture and depth to groundwater across forest-meadow ecotones present on the meadows. Additionally, ERI was used to extrapolate point measurements of groundwater depth and soil moisture across the study and control areas. The weekly water budget indicates differences between the control meadow and study meadow in the first year prior to conifer removal. The ERI indicated differences in sub surface geology, soil moisture, and groundwater depth both between the control and study meadows and along the forest-meadow ecotones. ERI was demonstrated to improve the spatial extrapolation of soil moisture and groundwater point measurements.

  14. 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 km2) compared to deforested undeveloped peatlands (831-915 fire detections per 1000 km2). 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.

  15. 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.

  16. 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.

  17. N cycling in SPRUCE (Spruce Peatlands Response Under ...

    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 the nitrogen cycle can have consequences on NO3, NH4 availability or pollution, and potentially increase nitrous oxide (N2O) emissions, a persistent greenhouse gas (GHG). These consequences can cascade to altering whole ecosystem functions and effecting human health.We are investigating nitrogen cycling response to elevated temperature and CO2 in a boreal peatland. Spruce and Peatland Responses Under Climate and Environmental Change (SPRUCE) project initiated soil warming in 2014 in ten peatland mesocosms (five temperature treatments from ambient (+0°C) to +9°C) and elevated CO2 in half of the mesocosms in 2016. Peat cores at three depths (acrotelm, catotelm, deep peat) were analyzed in the laboratory for denitrification, nitrification, and ammonification. We expect denitrification, nitrification, and ammonification rates to increase, and denitrification efficiency to decrease with rising temperatures- potentially contaminating water resources with NO3, NH4 and increase N2O concentrations in our atmosphere. This research will enhance the scientific understanding of how nitrogen cycling, an important functional eco-service, responds under environmental conditions including elevated CO2

  18. 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

  19. Trajectories of ecosystem service change in restored peatlands

    Science.gov (United States)

    Evans, Martin; Shuttleworth, Emma; Pilkington, Mike; Allott, Tim; Walker, Jonathan; Spencer, Tom

    2017-04-01

    Peatlands provide a wide range of ecosystem services but across the world degradation of these systems through a range of human impacts has had a negative effect on the provision of these services. A wide variety of peatland restoration approaches have been developed with the aim of mitigating these impacts. Understanding of trajectories of change in ecosystem structure and function is central to evaluating the efficacy of these restoration methods. This paper considers data on post-restoration trajectories of water table change, vegetation recovery, runoff production and water quality based on extensive data from peatland restoration work in the southern Pennines of the U.K. Data have been compiled from multiple restoration initiatives undertaken across the region, spanning up to 12 years post restoration. The data show variations in the time scale of ecosystem change which are indicative of the process basis of the ecosystem trajectories. Rapid changes in runoff are controlled by physical changes to the peatland surface. These are contrasted with longer term evolution of vegetation and water table behaviour which suggest ongoing recovery as the ecosystem adjusts to the restoration process. In order to assess restoration of ecosystem function, and so of ecosystem services, it is important that the process links between ecosystem structure and function are well understood. Establishing typical restoration trajectories can be of practical use in determining restoration project milestones, and can also provide insight into the nature of these process links.

  20. 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

  1. Assessing Biogenic Methane Content in Various Peatland Landforms Using GPR

    Science.gov (United States)

    Parsekian, A.; Comas, X.; Nolan, J.; Glaser, P.; Chanton, J.; Slater, L.

    2008-12-01

    Northern peatlands are known to be a source of biogenic methane, although efforts to accurately quantify their impact on the global carbon budget are ongoing. An important step towards a better understanding of the dynamics of methane releases to the atmosphere is to identify peatland landforms (i.e. raised bog, fen water track, open pools) where gas is accumulating in the subsurface compared to places where there is little subsurface methane. Additionally, it is important to identify areas of the vertical peat profile where high volumes of free-phase methane are present. In this study, we use ground penetrating radar (GPR) to acquire data on where free-phase gas (FPG) methane may be accumulating within the peat strata, and then make comparisons between various peatland landforms. 1-dimensional GPR common mid-point velocity analysis has been coupled with innovative subsurface gas sampling to identify the areas within northern peatlands that have significant gas trapped below confining layers in the subsurface. Gas samples are evaluated for total recovered volume and total methane concentration in order to support the GPR findings. Traditional 2-dimensional radar profiles were used to identify and estimate the depth at which laterally continuous woody confining layers are present, and therefore zones where gas can be expected to be found. By using 1-D, 2-D and direct sampling methods, it is now possible to identify potential areas of gas accumulation with a higher level of confidence.

  2. 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.

  3. Wet gas sampling

    Energy Technology Data Exchange (ETDEWEB)

    Welker, T.F.

    1997-07-01

    The quality of gas has changed drastically in the past few years. Most gas is wet with hydrocarbons, water, and heavier contaminants that tend to condense if not handled properly. If a gas stream is contaminated with condensables, the sampling of that stream must be done in a manner that will ensure all of the components in the stream are introduced into the sample container as the composite. The sampling and handling of wet gas is extremely difficult under ideal conditions. There are no ideal conditions in the real world. The problems related to offshore operations and other wet gas systems, as well as the transportation of the sample, are additional problems that must be overcome if the analysis is to mean anything to the producer and gatherer. The sampling of wet gas systems is decidedly more difficult than sampling conventional dry gas systems. Wet gas systems were generally going to result in the measurement of one heating value at the inlet of the pipe and a drastic reduction in the heating value of the gas at the outlet end of the system. This is caused by the fallout or accumulation of the heavier products that, at the inlet, may be in the vapor state in the pipeline; hence, the high gravity and high BTU. But, in fact, because of pressure and temperature variances, these liquids condense and form a liquid that is actually running down the pipe as a stream or is accumulated in drips to be blown from the system. (author)

  4. 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

  5. Wet oxidation of quinoline

    DEFF Research Database (Denmark)

    Thomsen, A.B.; Kilen, H.H.

    1998-01-01

    The influence of oxygen pressure (0.4 and 2 MPa). reaction time (30 and 60 min) and temperature (260 and 280 degrees C) on the wet oxidation of quinoline has been studied. The dominant parameters for the decomposition of quinoline were oxygen pressure and reaction temperature. whereas the reaction...... if low oxygen pressure or long reaction times were used. The reaction products derived from the experiment in which quinoline was mostly decomposed were studied with respect to biological degradation. The results showed that these products were highly digestible under activated sludge treatment....... The combined wet oxidation and biological treatment of reaction products resulted in 91% oxidation of the parent compound to CO2 and water. Following combined wet oxidation and biological treatment the sample showed low toxicity towards Nitrosomonas and no toxicity towards Nitrobacter. (C) 1998 Elsevier...

  6. 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

  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)

    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.)

  8. Wetting of Water on Graphene

    OpenAIRE

    Bera, Bijoyendra; Shahidzadeh, Noushine; Mishra, Himanshu; Bonn, Daniel

    2016-01-01

    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measurin...

  9. Blue carbon stocks in Baltic Sea eelgrass (Zostera marina) meadows

    DEFF Research Database (Denmark)

    Rohr, Maria Emilia; Bostrom, Christoffer; Canal-Vergés, Paula

    2016-01-01

    storage and carbon sink capacity of eelgrass meadows in Finland and Denmark, were 281 and 1809 EUR ha(-1), respectively. For a more comprehensive picture of seagrass carbon storage capacity, we conclude that future blue carbon studies should, in a more integrative way, investigate the interactions between......Although seagrasses cover only a minor fraction of the ocean seafloor, their carbon sink capacity accounts for nearly one-fifth of the total oceanic carbon burial and thus play a critical structural and functional role in many coastal ecosystems. We sampled 10 eelgrass (Zostera marina) meadows...... in Finland and 10 in Denmark to explore seagrass carbon stocks (C-org stock) and carbon accumulation rates (C-org accumulation) in the Baltic Sea area. The study sites represent a gradient from sheltered to exposed locations in both regions to reflect expected minimum and maximum stocks and accumulation...

  10. [Relationships between horqin meadow NDVI and meteorological factors].

    Science.gov (United States)

    Qu, Cui-ping; Guan, De-xin; Wang, An-zhi; Jin, Chang-jie; Wu, Jia-bing; Wang, Ji-jun; Ni, Pan; Yuan, Feng-hui

    2009-01-01

    Based on the 2000-2006 MODIS 8-day composite NDVI and day-by-day meteorological data, the seasonal and inter-annual variations of Horqin meadow NDVI as well as the relationships between the NDVI and relevant meteorological factors were studied. The results showed that as for the seasonal variation, Horqin meadow NDVI was more related to water vapor pressure than to precipitation. Cumulated temperature and cumulated precipitation together affected the inter-annual turning-green period significantly, and the precipitation in growth season (June and July), compared with that in whole year, had more obvious effects on the annual maximal NDVI. The analysis of time lag effect indicated that water vapor pressure had a persistent (about 12 days) prominent effect on the NDVI. The time lag effect of mean air temperature was 11-15 days, and the cumulated dual effect of the temperature and precipitation was 36-52 days.

  11. Low Evapotranspiration Enhances the Resilience of Peatland Carbon Stocks to Fire

    Science.gov (United States)

    Kettridge, N.; Lukenbach, M. C.; Hokanson, K. J.; Hopkinson, C.; Devito, K. J.; Petrone, R. M.; Mendoza, C. A.; Waddington, J. M.

    2017-09-01

    Boreal peatlands may be vulnerable to projected changes in the wildfire regime under future climates. Extreme drying during the sensitive postfire period may exceed peatland ecohydrological resilience, triggering long-term degradation of these globally significant carbon stocks. Despite these concerns, we show low peatland evapotranspiration at both the plot- and landscape-scale postfire, in water-limited peatlands dominated by feather moss that are ubiquitous across continental western Canada. Low postfire evapotranspiration enhances the resilience of carbon stocks in such peatlands to wildfire disturbance and reinforces their function as a regional source of water. Near-surface water repellency may provide an important, previously unexplored, regulator of peatland evapotranspiration that can induce low evapotranspiration in the initial postfire years by restricting the supply of water to the peat surface.

  12. Biotic interactions and vegetation management on coastal meadows

    OpenAIRE

    Niemelä, M.

    2009-01-01

    Abstract Conservation of rare habitats and species are central elements in the management of semi-natural grasslands of high biodiversity. Understanding the impacts of various abiotic and biotic interactions and management methods on threatened species is fundamental to their conservation. In the present study, effects of competition, plant parasitism, grazing and mowing were studied at the community level in Bothnian Bay coastal meadows and in greenhouse. This was the first time when the ...

  13. Selected indicators of effective fertilization of meadow grasslands

    Directory of Open Access Journals (Sweden)

    Ivan Holúbek

    2015-03-01

    Full Text Available The issues of nutrition and fertilization of meadow phytocenosis with the emphasis on the production effectiveness and economic effectiveness were observed at the low, medium and high intensity of fertilization using artificial fertilizers. The obtained results are based on the research of valley meadows (series A, mountainous meadows (series B and semi-natural and additionally sown and ploughed mountainous meadows (series C. In series A, in the observed period, the production effectiveness reached 14.93–23.76 kg of hay and the economic effectiveness reached 1.07–1.43 €. The higher production effectiveness and economic effectiveness are produced by doses of nutrients in the ratio N : P : K – 1 : 0.35 : 0.5. The highest production effectiveness and economic effectiveness were determined in variants fertilized by lower doses of artificial fertilizers (variants 7 and 12. The influence of PK and NPK nutrients on the production effectiveness and economic effectiveness of fertilization of different grasslands in different altitudes was observed in series B: the higher the altitude (from 350 to 850 meters above the sea level, the lower the indicators of production and economic effectiveness of artificial fertilizers. In series C, the loss of phosphoric and potassic nutrition is represented by higher inputs than outputs. Semi-natural grasslands and ploughed grasslands fertilized by medium and high intensity of NPK fertilizers (var.3–90 N kg*ha-1 + PK a var.4–180 N kg*ha-1 + PK are economically effective.

  14. Effects of disturbance regime on carbohydrate reserves in meadow plants

    Czech Academy of Sciences Publication Activity Database

    Janeček, Štěpán; Bartušková, Alena; Bartoš, Michael; Altman, Jan; de Bello, Francesco; Doležal, Jiří; Latzel, Vít; Lanta, V.; Lepš, J.; Klimešová, Jitka

    2015-01-01

    Roč. 7, plv123 (2015), s. 1-16 ISSN 2041-2851 R&D Projects: GA ČR GA526/09/0963; GA ČR GAP505/12/1296; GA ČR GB14-36079G Institutional support: RVO:67985939 Keywords : Carbohydrates * management * meadow Subject RIV: EH - Ecology, Behaviour Impact factor: 2.079, year: 2015

  15. 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

  16. Wetting of real surfaces

    CERN Document Server

    Bormashenko, Edward Yu

    2013-01-01

    The problem of wetting and drop dynamics on various surfaces is very interesting from both the scientificas well as thepractical viewpoint, and subject of intense research.The results are scattered across papers in journals, sothis workwill meet the need for a unifying, comprehensive work.

  17. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Hugo S. Caram; Natalie Foster

    1999-03-30

    The elastic modulus E of wet granular material was found to be of the order of 0.25 MPa, this value does not compare well with the value predicted for a cubic array of spheres under Hertzian contact were the predicted values were in the order of 250 MPa . The strain-stress behavior of a wet granular media was measured using a split Parfitt tensile tester. In all cases the stress increases linearly with distance until the maximum uniaxial tensile stress is reached. The stress then decreases exponentially with distance after this maximum is reached. The linear region indicates that wet solids behave elastically for stresses below the tensile stresses and can store significant elastic energy. The elastic deformation cannot be explained by analyzing the behavior of individual capillary bridges and requires accounting for the deformation of the solids particles. The elastic modulus of the wet granular material remains unexplained. New information was found to support the experimental finding and a first theory to explain the very small elastic modulus is presented. A new model based on the used of the finite element method is being developed.

  18. The Wet Chaparral

    OpenAIRE

    Hope, Audrey Marie

    2017-01-01

    The Wet Chaparral: Poetry at Home (Out There) is an MFA thesis exhibition of new sculptures by Audrey Hope. The thesis paper describes the exhibition, discusses the artist’s personal and artistic motivations, and analyzes writings relevant to the work.

  19. Predation risk of artificial ground nests in managed floodplain meadows

    Science.gov (United States)

    Arbeiter, Susanne; Franke, Elisabeth

    2018-01-01

    Nest predation highly determines the reproductive success in birds. In agricultural grasslands, vegetation characteristics and management practices influences the predation risk of ground breeders. Little is known so far on the predation pressure on non-passerine nests in tall swards. Investigations on the interaction of land use with nesting site conditions and the habitat selection of nest predators are crucial to develop effective conservation measures for grassland birds. In this study, we used artificial nests baited with quail and plasticine eggs to identify potential predators of ground nests in floodplain meadows and related predation risk to vegetation structure and grassland management. Mean daily predation rate was 0.01 (±0.012) after an exposure duration of 21 days. 70% of all observed nest predations were caused by mammals (Red Fox and mustelids) and 17.5% by avian predators (corvids). Nest sites close to the meadow edge and those providing low forb cover were faced with a higher daily predation risk. Predation risk also increased later in the season. Land use in the preceding year had a significant effect on predation risk, showing higher predation rates on unmanaged sites than on mown sites. Unused meadows probably attract mammalian predators, because they provide a high abundance of small rodents and a more favourable vegetation structure for foraging, increasing also the risk of incidental nest predations. Although mowing operation is a major threat to ground-nesting birds, our results suggest that an annual removal of vegetation may reduce predation risk in the subsequent year.

  20. Dissolved organic carbon fluxes by seagrass meadows and macroalgal beds

    Directory of Open Access Journals (Sweden)

    Cristina eBarron

    2014-10-01

    Full Text Available Estimates of dissolved organic carbon (DOC release by marine macrophyte communities (seagrass meadows and macroalgal beds based on in situ benthic chambers from published and unpublished are compiled in this study. The effect of temperature and light availability on DOC release by macrophyte communities was examined. Almost 85 % of the seagrass communities and all of macroalgal communities examined acted as net sources of DOC. Net DOC fluxes in seagrass communities increase positively with water temperature. In macroalgal communities net DOC fluxes under light exceeded those under dark condition, however, this trend was weaker in seagrass communities. Shading of a mixed seagrass meadow in The Philippines led to a significant reduction on the net DOC release when shading was maintained for 6 days compared to only 2 days of shading. Net DOC fluxes increased with increasing community respiration, but were independent of primary production or net community production. The estimated global net DOC flux, and hence export, from marine macrophytes is about 0.158 ± 0.055 Pg C yr-1 or 0.175 ± 0.056 Pg C yr-1 depending on the global extent of seagrass meadows considered.

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

    OpenAIRE

    Marttila, H. (Hannu)

    2011-01-01

    Abstract 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 distu...

  2. Variation in winter snowpack depth and duration influences summer soil respiration in a subalpine meadow

    Science.gov (United States)

    Arnold, C. L.; Ghezzehei, T. A.; Berhe, A. A.

    2012-12-01

    Subalpine meadows in the Sierra Nevada rely on the depth and duration of the winter snowpack to supply ample water to restore the water table in the meadow during the spring snowmelt. This study examines the role that interannual variability in the winter snowpack plays in the overall rate of summer soil respiration along a hydrologic gradient in a subalpine meadow. Carbon dioxide efflux from the meadow was measured from June through September in 2011 and 2012 using soil collars and a LICOR 8100A infrared gas analyzer. Preliminary results show that soil respiration rates are influenced by the hydrologic gradient across the meadow, with drier regions peaking earlier in the summer as compared to wetter regions. We also show that high snowpack years can suppress soil respiration in the meadow until late in the summer season as compared to low snowpack years, where soil respiration peaks early in the summer.

  3. Stream characteristics and their implications for the protection of riparian fens and meadows

    DEFF Research Database (Denmark)

    Baattrup-Pedersen, A.; Larsen, S.E.; Andersen, Peter Mejlhede

    2011-01-01

    ) concentration exceeded 40–50 μg P L−1, whereas meadow vegetation responded less strongly to TP. 5. Our findings highlight the importance of restoring hydrology of riparian areas to improve conditions for fen and meadow vegetation, but also that the water chemistry should be considered when measures......-based classification model was used to translate species lists into a standardised interpretation of habitat types protected by the HD in Denmark. 3. No size dependency was found regarding the distribution of fen and meadow vegetation. Instead, the distribution of fen and meadow vegetation was strongly affected...... by the morphology of the streams. Alkaline fens, periodically inundated meadows and meadows occurred six, five and four times, respectively, less frequently along channelised compared with natural stream reaches. Our results indicate that stream channelisation strongly interfered with the natural hydrology...

  4. 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

  5. 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

  6. Meadows with dandelions of the section Palustria in Pogórze Dynowskie, S Poland

    Directory of Open Access Journals (Sweden)

    Krzysztof Oklejewicz

    2017-06-01

    Full Text Available The paper presents ecological characteristics of meadows with Taraxacum sect. Palustria in Pogórze Dynowskie. Field studies were carried out using the patrol method. Floristic description was made, methods of meadow use were evaluated and habitat conditions were determined based on Ellenberg’s bioindication method on every meadow with marsh dandelions. Analyses were performed in eight sites with T. mendax, T. paucilobum, T. polonicum, T. portentosum, and T. vindobonense.

  7. Estimating above-ground biomass on mountain meadows and pastures through remote sensing

    Science.gov (United States)

    Barrachina, M.; Cristóbal, J.; Tulla, A. F.

    2015-06-01

    Extensive stock-breeding systems developed in mountain areas like the Pyrenees are crucial for local farming economies and depend largely on above-ground biomass (AGB) in the form of grass produced on meadows and pastureland. In this study, a multiple linear regression analysis technique based on in-situ biomass collection and vegetation and wetness indices derived from Landsat-5 TM data is successfully applied in a mountainous Pyrenees area to model AGB. Temporal thoroughness of the data is ensured by using a large series of images. Results of on-site AGB collection show the importance for AGB models to capture the high interannual and intraseasonal variability that results from both meteorological conditions and farming practices. AGB models yield best results at midsummer and end of summer before mowing operations by farmers, with a mean R2, RMSE and PE for 2008 and 2009 midsummer of 0.76, 95 g m-2 and 27%, respectively; and with a mean R2, RMSE and PE for 2008 and 2009 end of summer of 0.74, 128 g m-2 and 36%, respectively. Although vegetation indices are a priori more related with biomass production, wetness indices play an important role in modeling AGB, being statistically selected more frequently (more than 50%) than other traditional vegetation indexes (around 27%) such as NDVI. This suggests that middle infrared bands are crucial descriptors of AGB. The methodology applied in this work compares favorably with other works in the literature, yielding better results than those works in mountain areas, owing to the ability of the proposed methodology to capture natural and anthropogenic variations in AGB which are the key to increasing AGB modeling accuracy.

  8. Seagrass meadows as a globally significant carbonate reservoir

    KAUST Repository

    Mazarrasa, I.

    2015-08-24

    There has been growing interest in quantifying the capacity of seagrass ecosystems to act as carbon sinks as a natural way of offsetting anthropogenic carbon emissions to the atmosphere. However, most of the efforts have focused on the particulate organic carbon (POC) stocks and accumulation rates and ignored the particulate inorganic carbon (PIC) fraction, despite important carbonate pools associated with calcifying organisms inhabiting the meadows, such as epiphytes and benthic invertebrates, and despite the relevance that carbonate precipitation and dissolution processes have in the global carbon cycle. This study offers the first assessment of the global PIC stocks in seagrass sediments using a synthesis of published and unpublished data on sediment carbonate concentration from 403 vegetated and 34 adjacent un-vegetated sites. PIC stocks in the top 1 m of sediment ranged between 3 and 1660 Mg PIC ha−1, with an average of 654 ± 24 Mg PIC ha−1, exceeding those of POC reported in previous studies by about a factor of 5. Sedimentary carbonate stocks varied across seagrass communities, with meadows dominated by Halodule, Thalassia or Cymodocea supporting the highest PIC stocks, and tended to decrease polewards at a rate of −8 ± 2 Mg PIC ha−1 per degree of latitude (general linear model, GLM; p < 0.0003). Using PIC concentrations and estimates of sediment accretion in seagrass meadows, the mean PIC accumulation rate in seagrass sediments is found to be 126.3 ± 31.05 g PIC m−2 yr−1. Based on the global extent of seagrass meadows (177 000 to 600 000 km2), these ecosystems globally store between 11 and 39 Pg of PIC in the top metre of sediment and accumulate between 22 and 75 Tg PIC yr−1, representing a significant contribution to the carbonate dynamics of coastal areas. Despite the fact that these high rates of carbonate accumulation imply CO2

  9. The energy and entropy budgets of UK peatlands - are some peatlands near equilibrium?

    Science.gov (United States)

    Worrall, Fred; Morrison, Ross; Kettridge, Nick; Page, Sue; Kaduk, Jorg; Evans, Chris; Rayment, Mark; Cumming, Alex

    2017-04-01

    The energy budget of an ecosystem must obey the 2nd law of thermodynamics even if it is an open system. Several studies have sought to use a consideration of entropy budgets to understand ecosystem energy budgets and more specifically evapotranspiration. It has been assumed that ecosystems are far-from-equilibrium systems and as such would always seek to maximise their entropy production. Although the approach has been used to consider the behaviour of environments there are no studies that have tested the approach or its implications: maximum entropy production (MEP) is a prediction of the far-from-equilibrium assumption that could be tested. The simplest way for an ecosystem to maximise entropy production is to maximise water loss through evapotranspiration. To test whether a system is acting to maximise entropy production this study chose to consider how the energy budget of a peatland system responded to changes in incoming energy, specifically how a change in net radiation was transferred to changes in latent heat flux - an ecosystem maximising its entropy production would transfer the majority of change in net radiation to change in latent heat flux. This study considered nine sites across the UK where an energy budget had been measured. All sites were on peat but included: upland and lowland sites; sites under intensive and extensive agriculture; and sites with differing nutrient status. The changes in the energy fluxes were assessed on a daily time step and the comparison made between the change in net radiation and the change in latent flux. Statistically significant positive linear relationships were found for all sites; however, the average proportion of a change in net radiation that was transferred to change in latent heat flux varied from 24 to 57%, i.e. for some sites the majority of change in input was transferred to latent heat while at another site, the majority was transferred to sensible heat flux. The most intact site (Moor House, North

  10. Invasion of subalpine meadows by lodgepole pine in Yellowstone National Park, Wyoming, USA

    Energy Technology Data Exchange (ETDEWEB)

    Jakubos, B.; Romme, W.H. (Fort Lewis College, Durango, CO (United States))

    1993-11-01

    Many of the dry and mesic subalpine meadows in Yellowstone National Park are bordered by bands of small lodgepole pine trees. The authors asked whether these stands of small trees represent a directional process of meadow invasion, or alternatively, (1) small patches of postfire succession or; (2) more-or-less stable populations of trees having small stature because of adverse site conditions. Transect studies revealed that the bands of small trees were consistently younger than adjacent forest stands of obvious fire origin, that they lacked any evidence of fire, and that the trees were progressively younger as they approached the meadow. Soils under the young trees generally were more similar to meadow soils than to coniferous forest soils. The authors concluded, therefore, that meadow invasion has been occurring as a directional process since at least the mid- to late 1800s. Frequency of tree establishment in two dry meadows was positively correlated with mean June temperature and total summer precipitation (R[sup 2] = 0.49, P<0.0001, multiple stepwise regression). Thus, the major cause of tree invasion into dry meadows appears to be a regional climatic trend towards warmer and wetter growing seasons since the end of the Little Ice Age. Tree establishment in two mesic meadows was more weakly and inconsistently correlated with weather variables. Thus, the mechanism of invasion of mesic meadows may involve interactions of episodic seed crops and microhabitat changes at the forest border, as well as regional climatic variability. 30 refs., 7 figs., 1 tab.

  11. WET SOLIDS FLOW ENHANCEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-03-25

    The yield locus, tensile strength and fracture mechanisms of wet granular materials were studied. The yield locus of a wet material was shifted to the left of that of the dry specimen by a constant value equal to the compressive isostatic stress due to pendular bridges. for materials with straight yield loci, the shift was computed from the uniaxial tensile strength, either measured in a tensile strength tester or calculated from the correlation, and the angle of internal friction of the material. The predicted shift in the yield loci due to different moisture contents compare well with the measured shift in the yield loci of glass beads, crushed limestone, super D catalyst and Leslie coal. Measurement of the void fraction during the shear testing was critical to obtain the correct tensile strength theoretically or experimentally.

  12. Wetting in Color

    OpenAIRE

    Burgess, Ian Bruce

    2012-01-01

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly...

  13. Production and Energetic Utilization of Biomass from Rewetted Peatlands

    OpenAIRE

    Ahlhaus, M; Barz, M.; Timmermann, T; W. Wichtmann

    2008-01-01

    Among other biomass fuels, common reed (Phragmites australis) is considered as a promising source for Bioenergy. Within the project “ENIM” partners from science, industry and agriculture develops an integrated process to use common reed from rewetted peatlands for the combined heat and power generation in a biomass CHP plant. Ecologically compatible solutions of the reed production and harvesting will be investigated, the necessary logistic will be developed and finally the proces...

  14. Could managed burning of peatlands lead to carbon storage?

    Science.gov (United States)

    Clay, G.; Worrall, F.

    2007-12-01

    Peatlands are the UK's largest single terrestrial carbon store with carbon stored in UK peatlands than in forests of Britain and France combined. Unlike most northern peatlands in the peat soils of the UK are heavily managed for recreation and agriculture and due to their proximity to major centres of population are under more anthropogenic pressure than most peatlands. A typical management strategy on UK upland peats is the use of managed fire to restrict vegetation. Fires are used upon a 10-25 year rotation and are described as "cool" as they remove the crown of the vegetation without scorching the litter layer or the underlying soil. In this case the fire destroys primary productivity and limits litter production but produces char. Char is a low volume, highly refractory, high carbon content product while litter is a high volume, decomposable, lower carbon content product. Therefore, the question is if there are fire conditions underwhich the production of char causes more carbon to be stored in the peat than would have been stored if no fire management had been employed. This study uses detailed vegetation studies from a long term monitoring site in order to assess litter and biomass production; in laboratory experimental burns were undertaken in order to assess the amount and controls upon char production and the carbon content of that char. Results of field and laboratory observations are used to model carbon accumulation under s aseries of fire management scenarios and the modelling shows that cools burns at long rotations could lead to higher carbon storage than if no fire had occurred, further than in several cases more carbon accumulation occurred even if less depth of peat was generated.

  15. How intensive agriculture affects surface-atmosphere exchange of nitrogen and carbon compounds over peatland

    Science.gov (United States)

    Bruemmer, C.; Richter, U.; Schrader, F.; Hurkuck, M.; Kutsch, W. L.

    2016-12-01

    Mid-latitude peatlands are often exposed to high atmospheric nitrogen deposition when located in close vicinity to agricultural land. As the impacts of altered deposition rates on nitrogen-limited ecosystems are poorly understood, we investigated the surface-atmosphere exchange of several nitrogen and carbon compounds using multiple high-resolution measurement techniques and modeling. Our study site was a protected semi-natural bog ecosystem. Local wind regime and land use in the adjacent area clearly regulated whether total reactive nitrogen (∑Nr) concentrations were ammonia (NH3) or NOx-dominated. Eddy-covariance measurements of NH3 and ∑Nr revealed concentration, temperature and surface wetness-dependent deposition rates. Intermittent periods of NH3 and ∑Nr emission likely attributed to surface water re-emission and soil efflux, respectively, were found, thereby indicating nitrogen oversaturation in this originally N-limited ecosystem. Annual dry plus wet deposition resulted in 20 to 25 kg N ha-1 depending on method and model used, which translated into a four- to fivefold exceedance of the ecosystem-specific critical load. As the bog site had likely been exposed to the observed atmospheric nitrogen burden over several decades, a shift in grass species' composition towards a higher number of nitrophilous plants was already visible. Three years of CO2 eddy flux measurements showed that the site was a small net sink in the range of 33 to 268 g CO2 m-2 yr-1. Methane emissions of 32 g CO2-eq were found to partly offset the sequestered carbon through CO2. Our study demonstrates the applicability of novel micrometeorological measurement techniques in biogeochemical sciences and stresses the importance of monitoring long-term changes in vulnerable ecosystems under anthropogenic pressure and climate change.

  16. Climate Change Driven Implications on Spatial Distribution of High Andean Peatlands in the Central Andes

    Science.gov (United States)

    Otto, Marco; Gibbons, Richard E.

    2013-04-01

    High Andean peatlands are among the most unique habitats in the tropical Andes and certainly among the least studied. High Andean peatlands occur patchily in montane grassland and scrub below snow line and above tree line. These high-elevation peatlands are sustained by glacial runoff and seasonal precipitation. We used remote sensing data to estimate that peatland habitat is approximately 2.5 % of our study region in the Puna, an ecoregion located in the high Andes above 4000 m a.s.l. Individual sizes of our estimated peatland polygons ranged from 0.72 ha to 1079 ha with a mean size of 4.9 ha. Climate change driven implications on spatial distribution of high Andean peatlands were assessed in two ways. First, we estimated the effect of predicted regional temperature increase by using the standard lapse rate of 2° C per 300 m for assessing peatland habitat patches that would remain above a critical thermocline. Nearly 80% of peatland habitat patches were predicted to occur below the thermocline if the prediction of 4° C temperature increase is realized. The second assessment relied on the quantified assumption that permanent snow or glacier cover, topographic characteristics (e.g. slope) and precipitation of a basin are essential variables in the occurrence of high Andean peatlands. All 17 basins were predicted to have a decrease in peatland habitat due to snow line uplift, decrease in precipitation and consequent insufficient wetland inflows. Total habitat loss was predicted for two basins in the semi-arid part of the study area with a snow line uplift to 5600 m and a projected decrease in precipitation of 1 mm per year over the next 40 years. A combined result of both assessments provides important information on climate change driven implications on the hydrology of high Andean peatlands and potential consequences for their spatial distribution within the Central Andes.

  17. Litter evenness influences short-term peatland decomposition processes.

    Science.gov (United States)

    Ward, Susan E; Ostle, Nick J; McNamara, Niall P; Bardgett, Richard D

    2010-10-01

    There is concern that changes in climate and land use could increase rates of decomposition in peatlands, leading to release of stored C to the atmosphere. Rates of decomposition are driven by abiotic factors such as temperature and moisture, but also by biotic factors such as changes in litter quality resulting from vegetation change. While effects of litter species identity and diversity on decomposition processes are well studied, the impact of changes in relative abundance (evenness) of species has received less attention. In this study we investigated effects of changes in short-term peatland plant species evenness on decomposition in mixed litter assemblages, measured as litter weight loss, respired CO(2) and leachate C and N. We found that over the 307-day incubation period, higher levels of species evenness increased rates of decomposition in mixed litters, measured as weight loss and leachate dissolved organic N. We also found that the identity of the dominant species influenced rates of decomposition, measured as weight loss, CO(2) flux and leachate N. Greatest rates of decomposition were when the dwarf shrub Calluna vulgaris dominated litter mixtures, and lowest rates when the bryophyte Pleurozium schreberi dominated. Interactions between evenness and dominant species identity were also detected for litter weight loss and leachate N. In addition, positive non-additive effects of mixing litter were observed for litter weight loss. Our findings highlight the importance of changes in the evenness of plant community composition for short-term decomposition processes in UK peatlands.

  18. Silicon in peatland biogeochemistry: the one to rule them all?

    Science.gov (United States)

    Schaller, Jörg; Reithmaier, Gloria; Knorr, Klaus-Holger; Planer-Friedrich, Britta

    2017-04-01

    Peatlands perform important ecosystem services, such as carbon storage, nutrient and trace element retention, and water quality regulation, all of which are influenced by peat decomposition. Since decomposition of organic material was recently shown to be accelerated by silicon (Si), the aim of this study was to examine how Si influences the decomposability of organic matter and the production of CH4 and CO2 in peatlands. Consequently, a Si fertilization experiment was conducted at a German fen site, increasing natural concentrations 4-fold. Under enhanced Si availability dissolved organic carbon, carbon dioxide and methane concentrations increased significantly in the porewater, indicating that Si negatively affects carbon storage. Dissolved nitrogen, phosphorus, iron, manganese, cobalt, zinc, and arsenic concentrations were also significantly higher under Si enriched conditions. This enhanced mobilization of major and trace elements may result from Si competing for binding sites and stronger reducing conditions, caused by accelerated decomposition. The stronger reducing conditions also increased reduction of arsenate to arsenite. In summary, increased Si concentrations negatively affected nutrient retention and induced mobilization of toxic elements. In a survey of 18 nearby fens, Si concentrations were found to cover a range from 1 to 9 mg/L, suggesting peatland processes and related ecosystem services to be strongly affected by Si availability.

  19. Variations in dissolved organic carbon concentrations across peatland hillslopes

    Science.gov (United States)

    Boothroyd, I. M.; Worrall, F.; Allott, T. E. H.

    2015-11-01

    Peatlands are important terrestrial carbon stores and dissolved organic carbon (DOC) is one of the most important contributors to carbon budgets in peatland systems. Many studies have investigated factors affecting DOC concentration in peatland systems, yet hillslope position has been thus far overlooked as a variable that could influence DOC cycling. This study investigates the importance of hillslope position with regard to DOC cycling. Two upland peat hillslopes were studied in the Peak District, UK, to determine what impact, if any, hillslope position had upon DOC concentration. Hillslope position was found to be a significant factor affecting variation in soil pore water DOC concentration, with bottom-slope positions having significantly lower DOC concentrations than up-slope because of dilution of DOC as water moves down-slope and is flushed out of the system via lateral throughflow. Water table drawdown on steeper mid-slopes increased DOC concentrations through increased DOC production and extended residence times allowing a build-up of humic-rich DOC compounds. Hillslope position did not significantly affect DOC concentrations in surface runoff water because of the dilution of near-surface soil pore water by precipitation inputs, while stream water had similar water chemistry properties to soil pore water under low-flow conditions.

  20. Nevada Department of Wildlife Native Fish and Amphibians Field Trip Report: To estimate the population sizes of Ash Meadows Amargosa pupfish and Ash Meadows speckled dace and also to monitor exotic species removal efforts

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Fish population monitoring has been ongoing since the 1980s at Ash Meadows National Wildlife Refuge. This year we conducted surveys on the Ash Meadows Amargosa...

  1. 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:...

  2. Net primary productivity of subalpine meadows in Yosemite National Park in relation to climate variability

    Science.gov (United States)

    Moore, Peggy E.; Van Wagtendonk, Jan W.; Yee, Julie L.; McClaran, Mitchel P.; Cole, David N.; McDougald, Neil K.; Brooks, Matthew L.

    2013-01-01

    Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate. Our objective was to describe patterns and variability in aboveground live vascular plant biomass in relation to climatic factors. We harvested aboveground biomass at peak growth from four 64-m2 plots each in xeric, mesic, and hydric meadows annually from 1994 to 2000. Data from nearby weather stations provided independent variables of spring snow water content, snow-free date, and thawing degree days for a cumulative index of available energy. We assembled these climatic variables into a set of mixed effects analysis of covariance models to evaluate their relationships with annual aboveground net primary productivity (ANPP), and we used an information theoretic approach to compare the quality of fit among candidate models. ANPP in the xeric meadow was negatively related to snow water content and thawing degree days and in the mesic meadow was negatively related to snow water content. Relationships between ANPP and these 2 covariates in the hydric meadow were not significant. Increasing snow water content may limit ANPP in these meadows if anaerobic conditions delay microbial activity and nutrient availability. Increased thawing degree days may limit ANPP in xeric meadows by prematurely depleting soil moisture. Large within-year variation of ANPP in the hydric meadow limited sensitivity to the climatic variables. These relationships suggest that, under projected warmer and drier conditions, ANPP will increase in mesic meadows but remain unchanged in xeric meadows because declines associated with increased temperatures would offset the increases from decreased snow water content.

  3. 75 FR 26747 - Meadow Lake Wind Farm III LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2010-05-12

    ...-1176-000] Meadow Lake Wind Farm III LLC; Supplemental Notice That Initial Market-Based Rate Filing... above-referenced proceeding of Meadow Lake Wind Farm III LLC's application for market-based rate...

  4. 75 FR 26747 - Meadow Lake Wind Farm IV LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2010-05-12

    ...] Meadow Lake Wind Farm IV LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request...-referenced proceeding of Meadow Lake Wind Farm IV LLC's application for market-based rate authority, with an...

  5. Turbulent mixing and fluid transport within Florida Bay seagrass meadows

    Science.gov (United States)

    Hansen, Jennifer C. R.; Reidenbach, Matthew A.

    2017-10-01

    Seagrasses serve an important function in the ecology of Florida Bay, providing critical nursery habitat and a food source for a variety of organisms. They also create significant benthic structure that induces drag, altering local hydrodynamics that can influence mixing and nutrient dynamics. Thalassia testudinum seagrass meadows were investigated to determine how shoot density and morphometrics alter local wave conditions, the generation of turbulence, and fluid exchange above and within the canopy. Sparsely vegetated and densely vegetated meadows were monitored, with shoot densities of 259 ± 26 and 484 ± 78 shoots m-2, respectively. The temporal and spatial structure of velocity and turbulence were measured using acoustic Doppler velocimeters and an in situ particle image velocimetry (PIV) system positioned both above and within the seagrass canopy. The retention of fluid within the canopy was determined by examining e-folding times calculated from the concentration curves of dye plumes released within the seagrass canopy. Results show that a shear layer with an inflection point develops at the top of the seagrass canopy, which generates instabilities that impart turbulence into the seagrass meadow. Compared to the overlying water column, turbulence was enhanced within the sparse canopy due to flow interaction with the seagrass blades, but reduced within the dense canopy. Wave generated oscillatory motion penetrated deeper into the canopy than unidirectional currents, enhancing fluid exchange. Both shoot density and the relative magnitude of wave- versus current-driven flow conditions were found to be important controls on turbulent exchange of water masses across the canopy-water interface.

  6. 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.

  7. 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, D. O.

    2013-12-01

    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.

  8. 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...

  9. 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...

  10. 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 ...

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

    NARCIS (Netherlands)

    Robroek, B.J.M.|info:eu-repo/dai/nl/314119116; Jassey, Vincent E.J.; Kox, Martine A.R.; Berendsen, R.L.|info:eu-repo/dai/nl/304824151; Mills, RobertT. E.; Meima-Franke, Marion; Puissant, Jérémy; Cécillon, Lauric; Bakker, P.A.H.M.|info:eu-repo/dai/nl/074744623; Bodelier, Paul L.E.

    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

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

    DEFF Research Database (Denmark)

    Johansson, T.; Malmer, N.; Crill, P. 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...

  14. Gaseous mercury fluxes in peatlands and the potential influence of climate change

    Science.gov (United States)

    Kristine M. Haynes; Evan S. Kane; Lynette Potvin; Erik A. Lilleskov; Randall K. Kolka; Carl P.J. Mitchell

    2017-01-01

    Climate change has the potential to significantly impact the stability of large stocks of mercury (Hg) stored in peatland systems due to increasing temperatures, altered water table regimes and subsequent shifts in vascular plant communities. However, the Hg exchange dynamics between the atmosphere and peatlands are not well understood. At the PEATcosm Mesocosm...

  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. 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

  17. Seed germination ecology of meadow knapweed (Centaurea x moncktonii) populations in New York State

    Science.gov (United States)

    The introduced meadow knapweed (Centaurea x moncktonii), a hybrid of black (C. nigra) and brown (C. jacea) knapweeds, appears to be common and expanding in New York agricultural lands, including pastures, meadows and waste areas. The biology and ecology of the hybrid is mostly unstudied, such as its...

  18. Foraging site choice and diet selection of Meadow Pipits Anthus pratensis breeding on grazed salt marshes

    NARCIS (Netherlands)

    van Klink, Roel; Mandema, Freek S.; Bakker, Jan P.; Tinbergen, Joost M.

    2014-01-01

    Capsule Breeding Meadow Pipits foraged for caterpillars and large spiders in vegetation that was less heterogeneous than vegetation at random locations.Aims To gain a better understanding of the foraging ecology of breeding Meadow Pipits on grazed coastal salt marshes, we tested three hypotheses:

  19. The Economic Benefits of Elk Viewing at the Jewell Meadows Wildlife Area in Oregon

    Science.gov (United States)

    Geoffrey Donovan; Patricia Champ

    2009-01-01

    In this study, a travel cost model is used to estimate the value of elk viewing at the Jewell Meadows Wildlife Area in Oregon. Jewell Meadows was originally established to provide winter browse and supplemental feeding for elk to reduce damage to nearby agricultural and forest land. However, because visitors are virtually guaranteed the opportunity to see large numbers...

  20. Net primary productivity of subalpine meadows in Yosemite National Park in relation to climate variability

    Science.gov (United States)

    Peggy E. Moore; Jan W. van Wagtendonk; Julie L. Yee; Mitchel P. McClaran; David N. Cole; Neil K. McDougald; Matthew L. Brooks

    2013-01-01

    Subalpine meadows are some of the most ecologically important components of mountain landscapes, and primary productivity is important to the maintenance of meadow functions. Understanding how changes in primary productivity are associated with variability in moisture and temperature will become increasingly important with current and anticipated changes in climate....

  1. Ten Years of Change in Sierran Stringer Meadows: An Evaluation of Range Condition Models

    Science.gov (United States)

    Barbara H. Allen

    1989-01-01

    Grazed Sierra Nevada stringer meadow systems were sampled on Blodgett Forest Research Station in northern California between 1977 and 1987 to determine cattle use, and to examine changes in production and species composition over time. Utilization of meadow species averaged 61 percent over the 10 years, but use increased to more than 80 percent utilization after 1985....

  2. Reconnaissance Study of Coso Volcanic Field, California, and Pickel Meadow, California

    Science.gov (United States)

    1988-09-01

    arsenic (As), gold (Au), cadmium (Cd), antimony (Sb), and zinc (Zn) in stream sediments, for Au, Cd, and Zn in heavy-mineral concentrates, and for...were collected along California State I lighway 108 between Sardine and Leavitt Meadow. The Pickel Meadow samples were collected in a square grid

  3. 75 FR 63505 - Crane Meadows National Wildlife Refuge, Morrison County, MN

    Science.gov (United States)

    2010-10-15

    ... Fish and Wildlife Service Crane Meadows National Wildlife Refuge, Morrison County, MN AGENCY: U.S. Fish... (CCP) and Finding of No Significant Impact (FONSI) for the Environmental Assessment (EA) for Crane... at the Crane Meadows National Wildlife Refuge Office or at public libraries near the refuge. You may...

  4. Hydrological landscape settings of base-rich fen mires and fen meadows : an overview

    NARCIS (Netherlands)

    Grootjans, A.P.; Adema, E.B.; Bleuten, W.; Joosten, H.; Madaras, M.; Janáková, M.; Middleton, B.

    2006-01-01

    Question: Why do similar fen meadow communities occur in different landscapes? How does the hydrological system sustain base-rich fen mires and fen meadows? Location: Interdunal wetlands and heathland pools in The Netherlands, percolation mires in Germany, Poland, and Siberia, and calcareous spring

  5. Seasonal distribution of meadow birds in relation to in-field heterogeneity and management

    NARCIS (Netherlands)

    Verhulst, J.; Kleijn, D.; Loonen, W.; Berendse, F.; Smit, C.

    2011-01-01

    Effectiveness of European initiatives to restore populations of meadow breeding waders is heavily debated. We studied field preference of meadow birds throughout the breeding season in four areas of over 100 ha each and related observed patterns of individual birds to in-field heterogeneity, sward

  6. Seasonal distribution of meadow birds in relation to in-field heterogeneity and management

    NARCIS (Netherlands)

    Verhulst, Jort; Kleijn, David; Loonen, Willem; Berendse, Frank; Smit, Christian

    Effectiveness of European initiatives to restore populations of meadow breeding waders is heavily debated. We studied field preference of meadow birds throughout the breeding season in four areas of over 100 ha each and related observed patterns of individual birds to in-field heterogeneity, sward

  7. SYNSYSTEMATIQUE DES PRAIRIES DE FRANCE (SYNSYSTEMATIC OF THE MEADOWS OF FRANCE

    Directory of Open Access Journals (Sweden)

    J.M. GEHU

    1999-01-01

    Full Text Available The synsystematic diagram of the meadows of France proposed in this work enumerates the main associations and the prairial superior unities of France giving them their great synecological features. The majority of these communities of meadows are usable in cutting or in pasture. They are grouped in the three following classes: Arrhenatheretea elatioris, Molinio-Juncetea and Agrostietea stoloniferae.

  8. Wetting in Color

    Science.gov (United States)

    Burgess, Ian Bruce

    Colorimetric litmus tests such as pH paper have enjoyed wide commercial success due to their inexpensive production and exceptional ease of use. However, expansion of colorimetry to new sensing paradigms is challenging because macroscopic color changes are seldom coupled to arbitrary differences in the physical/chemical properties of a system. In this thesis I present in detail the development of Wetting in Color Technology, focusing primarily on its application as an inexpensive and highly selective colorimetric indicator for organic liquids. The technology exploits chemically-encoded inverse-opal photonic crystals to control the infiltration of fluids to liquid-specific spatial patterns, projecting minute differences in liquids' wettability to macroscopically distinct, easy-to-visualize structural color patterns. It is shown experimentally and corroborated with theoretical modeling using percolation theory that the high selectivity of wetting, upon-which the sensitivity of the indicator relies, is caused by the highly symmetric structure of our large-area, defect-free SiO2 inverse-opals. The regular structure also produces a bright iridescent color, which disappears when infiltrated with liquid - naturally coupling the optical and fluidic responses. Surface modification protocols are developed, requiring only silanization and selective oxidation, to facilitate the deterministic design of an indicator that differentiates a broad range of liquids. The resulting tunable, built-in horizontal and vertical chemistry gradients allow the wettability threshold to be tailored to specific liquids across a continuous range, and make the readout rely only on countable color differences. As wetting is a generic fluidic phenomenon, Wetting in Color technology could be suitable for applications in authentication or identification of unknown liquids across a broad range of industries. However, the generic nature of the response also ensures chemical non-specificity. It is shown

  9. Carbon storage and release in Indonesian peatlands since the last deglaciation

    Science.gov (United States)

    Dommain, René; Couwenberg, John; Glaser, Paul H.; Joosten, Hans; Suryadiputra, I. Nyoman N.

    2014-08-01

    Peatlands have been recognised as globally important carbon sinks over long timescales that produced a global, net-climatic cooling effect over the Holocene. However, little is known about the role of tropical peatlands in the global carbon cycle. We therefore determine the past rates of carbon storage and release in the Indonesian peatlands of Kalimantan and Sumatra - the largest global concentration of tropical peatlands - since 20 ka (kiloannum before present). Using a novel GIS (geographic information system) approach we provide a spatially-explicit reconstruction of peatland expansion in a series of paleogeographic maps. Sea-level change is identified as the principal driver for peatland formation and expansion in western Indonesia as it controls both atmospheric moisture supply and the hydrological gradient on the islands. Initiation of inland peatlands in Kalimantan was coupled to periods of rapid deglacial sea-level rise with rates of over 10 mm yr-1 whereas coastal peatlands could only form after 7 ka when the rate of sea-level rise had slowed to 2.4 mm yr-1. Falling sea levels after 5 ka led to rapid peatland expansion in coastal lowlands and a doubling of the total peatland area in western Indonesia to 131,500 km2 between 2.3 ka and 0 ka. As a result of slow peatland expansion from 15 to 6 ka and rapid expansion afterwards the rate of annual carbon storage of all western Indonesian peatlands remained levels together with increased El Niño activity induced an annual carbon release of 0.15 Tg C yr-1 from aerobic peat decay since 2 ka. Cumulative carbon losses from anaerobic decomposition do not seem to limit peat bog growth in the tropical peatlands of Indonesia. Carbon losses from Holocene peat fires are only known from the Kutai basin since 4.4 ka with an associated release of 0.1-3.6 Tg C per fire event, which never surpassed the contemporaneous annual C storage. The peatlands of western Indonesia were thus a persistent carbon sink since 15 ka but this

  10. Comparative Study Of Alluvial Cnidion-Type Meadows In The Lower Danube River Basin

    Directory of Open Access Journals (Sweden)

    Schneider-Binder Erika

    2014-10-01

    Full Text Available Alluvial Cnidion-type meadows (Habitat type 6440 of the Habitats Directive, mostly characteristic for the lower courses of large rivers in continental climate conditions of Europe are presented from the Lower Danube upstream the municipality of Giurgiu (river-km 510-524. The ecological requirements of the characteristic species, as well as their sensitivity to human-induced changes that derive from regular flooding, drainage, intensification of use and/or abandonment, are highlighted; these changes frequently lead to a decrease of biodiversity of the Cnidion-type meadows or to their total loss The studied meadows are compared with similar alluvial meadows from other sites of the lower Danube River basin. Finally, the strong interlocking of Cnidion type meadows with those of the Agropyro-Rumicion, Molinion and Deschampsion caespitosae alliances are discussed.

  11. Continuous 1985–2012 Landsat Monitoring to Assess Fire Effects on Meadows in Yosemite National Park, California

    Directory of Open Access Journals (Sweden)

    Christopher E. Soulard

    2016-04-01

    Full Text Available To assess how montane meadow vegetation recovered after a wildfire that occurred in Yosemite National Park, CA in 1996, Google Earth Engine image processing was applied to leverage the entire Landsat Thematic Mapper archive from 1985 to 2012. Vegetation greenness (normalized difference vegetation index (NDVI was summarized every 16 days across the 28-year Landsat time series for 26 meadows. Disturbance event detection was hindered by the subtle influence of low-severity fire on meadow vegetation. A hard break (August 1996 was identified corresponding to the Ackerson Fire, and monthly composites were used to compare NDVI values and NDVI trends within burned and unburned meadows before, immediately after, and continuously for more than a decade following the fire date. Results indicate that NDVI values were significantly lower at 95% confidence level for burned meadows following the fire date, yet not significantly lower at 95% confidence level in the unburned meadows. Burned meadows continued to exhibit lower monthly NDVI in the dormant season through 2012. Over the entire monitoring period, the negative-trending, dormant season NDVI slopes in the burned meadows were also significantly lower than unburned meadows at 90% confidence level. Lower than average NDVI values and slopes in the dormant season compared to unburned meadows, coupled with photographic evidence, strongly suggest that evergreen vegetation was removed from the periphery of some meadows after the fire. These analyses provide insight into how satellite imagery can be used to monitor low-severity fire effects on meadow vegetation.

  12. A multi-scale evaluation of pack stack effects on subalpine meadow plant communities in the Sierra Nevada

    Science.gov (United States)

    We evaluated the influence of pack stock (i.e., horse and mule) use on meadow plant communities in Sequoia and Yosemite National Parks in the Sierra Nevada mountains of California. Meadows were sampled to account for inherent variability across multiple scales by: 1) controlling for among-meadow var...

  13. Multiscale variability of amphipod assemblages in Posidonia oceanica meadows

    Science.gov (United States)

    Sturaro, Nicolas; Lepoint, Gilles; Vermeulen, Simon; Gobert, Sylvie

    2015-01-01

    The study of spatial patterns is important in understanding the causes of the distribution and abundance of organisms, and it also provides a valuable basis for management and conservation. Amphipod crustaceans are key organisms in seagrass ecosystems. However, little attention has been paid to the spatial scales at which amphipod assemblages may vary. We examined variability patterns of amphipod populations inhabiting Posidonia oceanica meadows, over spatial scales spanning four orders of magnitude (1 to 1000 meters) and for two consecutive years. This study reports the scales that contributed most to spatial variation of amphipod assemblages and explores the potential processes driving the observed patterns, with particular emphasis on habitat features. The number of species, the diversity, and the density of some species varied substantially across years. For most species the highest spatial variation in density and biomass occurred at small scales (1 and 10 meters). Based on density data, the structure of amphipod assemblages did not differ at any scales investigated. The patchiness that occurred at small scales may have been related to habitat features, but only weakly. Instead, we postulate that amphipod behavioral processes likely represent good explanatory factors. Although, small-scale spatial variability can be an important feature of amphipod assemblages in P. oceanica meadows, some patterns may have gone undetected because they occur at scales smaller than those investigated.

  14. Food supply depends on seagrass meadows in the coral triangle

    Science.gov (United States)

    Unsworth, Richard K. F.; Hinder, Stephanie L.; Bodger, Owen G.; Cullen-Unsworth, Leanne C.

    2014-09-01

    The tropical seascape provides food and livelihoods to hundreds of millions of people, but the support of key habitats to this supply remains ill appreciated. For fisheries and conservation management actions to help promote resilient ecosystems, sustainable livelihoods, and food supply, knowledge is required about the habitats that help support fisheries productivity and the consequences of this for food security. This paper provides an interdisciplinary case study from the coral triangle of how seagrass meadows provide support for fisheries and local food security. We apply a triangulated approach that utilizes ecological, fisheries and market data combined with over 250 household interviews. Our research demonstrates that seagrass associated fauna in a coral triangle marine protected area support local food supply contributing at least 50% of the fish based food. This formed between 54% and 99% of daily protein intake in the area. Fishery catch was found to significantly vary with respect to village (p management mean the security of this food supply has the potential to be undermined in the long-term. Findings of this study have implications for the management and assessment of fisheries throughout the tropical seascape. Our study provides an exemplar for why natural resource management should move beyond biodiversity and consider how conservation and local food security are interlinked processes that are not mutually exclusive. Seagrass meadows are under sustained threat worldwide, this study provides evidence of the need to conserve these not just to protect biodiversity but to protect food security.

  15. Compositional and functional stability of aerobic methane consuming communities in drained and rewetted peat meadows

    NARCIS (Netherlands)

    Krause, Sascha; Niklaus, Pascal A.; Morcillo, Sara Badwan; Meima-Franke, M.; Lüke, Claudia; Reim, Andreas; Bodelier, Paul L.E.

    2015-01-01

    The restoration of peatlands is an important strategy to counteract subsidence and loss of biodiversity. However, responses of important microbial soil processes are poorly understood. We assessed functioning, diversity, and spatial organization of methanotrophic communities in drained and rewetted

  16. PREFACE: Wetting: introductory note

    Science.gov (United States)

    Herminghaus, S.

    2005-03-01

    The discovery of wetting as a topic of physical science dates back two hundred years, to one of the many achievements of the eminent British scholar Thomas Young. He suggested a simple equation relating the contact angle between a liquid surface and a solid substrate to the interfacial tensions involved [1], γlg cos θ = γsg - γsl (1) In modern terms, γ denotes the excess free energy per unit area of the interface indicated by its indices, with l, g and s corresponding to the liquid, gas and solid, respectively [2]. After that, wetting seems to have been largely ignored by physicists for a long time. The discovery by Gabriel Lippmann that θ may be tuned over a wide range by electrochemical means [3], and some important papers about modifications of equation~(1) due to substrate inhomogeneities [4,5] are among the rare exceptions. This changed completely during the seventies, when condensed matter physics had become enthusiastic about critical phenomena, and was vividly inspired by the development of the renormalization group by Kenneth Wilson [6]. This had solved the long standing problem of how to treat fluctuations, and to understand the universal values of bulk critical exponents. By inspection of the critical exponents of the quantities involved in equation~(1), John W Cahn discovered what he called critical point wetting: for any liquid, there should be a well-defined transition to complete wetting (i.e., θ = 0) as the critical point of the liquid is approached along the coexistence curve [7]. His paper inspired an enormous amount of further work, and may be legitimately viewed as the entrance of wetting into the realm of modern physics. Most of the publications directly following Cahn's work were theoretical papers which elaborated on wetting in relation to critical phenomena. A vast amount of interesting, and in part quite unexpected, ramifications were discovered, such as the breakdown of universality in thin film systems [8]. Simultaneously, a number

  17. Wet steam wetness measurement in a 10 MW steam turbine

    Directory of Open Access Journals (Sweden)

    Kolovratník Michal

    2014-03-01

    Full Text Available The aim of this paper is to introduce a new design of the extinction probes developed for wet steam wetness measurement in steam turbines. This new generation of small sized extinction probes was developed at CTU in Prague. A data processing technique is presented together with yielded examples of the wetness distribution along the last blade of a 10MW steam turbine. The experimental measurement was done in cooperation with Doosan Škoda Power s.r.o.

  18. Artificial Warming of Arctic Meadow under Pollution Stress: Experimental design

    Science.gov (United States)

    Moni, Christophe; Silvennoinen, Hanna; Fjelldal, Erling; Brenden, Marius; Kimball, Bruce; Rasse, Daniel

    2014-05-01

    Boreal and arctic terrestrial ecosystems are central to the climate change debate, notably because future warming is expected to be disproportionate as compared to world averages. Likewise, greenhouse gas (GHG) release from terrestrial ecosystems exposed to climate warming is expected to be the largest in the arctic. Artic agriculture, in the form of cultivated grasslands, is a unique and economically relevant feature of Northern Norway (e.g. Finnmark Province). In Eastern Finnmark, these agro-ecosystems are under the additional stressor of heavy metal and sulfur pollution generated by metal smelters of NW Russia. Warming and its interaction with heavy metal dynamics will influence meadow productivity, species composition and GHG emissions, as mediated by responses of soil microbial communities. Adaptation and mitigation measurements will be needed. Biochar application, which immobilizes heavy metal, is a promising adaptation method to promote positive growth response in arctic meadows exposed to a warming climate. In the MeadoWarm project we conduct an ecosystem warming experiment combined to biochar adaptation treatments in the heavy-metal polluted meadows of Eastern Finnmark. In summary, the general objective of this study is twofold: 1) to determine the response of arctic agricultural ecosystems under environmental stress to increased temperatures, both in terms of plant growth, soil organisms and GHG emissions, and 2) to determine if biochar application can serve as a positive adaptation (plant growth) and mitigation (GHG emission) strategy for these ecosystems under warming conditions. Here, we present the experimental site and the designed open-field warming facility. The selected site is an arctic meadow located at the Svanhovd Research station less than 10km west from the Russian mining city of Nikel. A splitplot design with 5 replicates for each treatment is used to test the effect of biochar amendment and a 3oC warming on the Arctic meadow. Ten circular

  19. 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

  20. Plant diversity affects GHG fluxes in an ecological engineering experiment in a disturbed Sphagnum peatland (La Guette, France)

    Science.gov (United States)

    Gogo, Sébastien; Laggoun-Défarge, Fatima; Leroy, Fabien; Guimbaud, Christophe; Bernard-Jannin, Léonard

    2017-04-01

    Many Sphagnum peatlands are experiencing vegetation change caused mainly by hydrological disturbances. In the context of these direct and indirect modifications, greenhouse gases (GHG) fluxes are affected by peat oxygenation, changes in litter composition (and thus decomposition) and rhizospheric processes (such as root exudates). This could lead a C sink system to switch to a source. To restore peatland functioning, ecological engineering works can be undertaken. Our study site, La Guette peatland (central France) is invaded by Molinia caerulea because a drain at the output decreased the water table depth. It was shown that it functioned as a source of C. In 2014, hydrological works were undertaken: 8 dams were installed, ditches were dug perpendicular to the water flow and back-filled with a mixture of shales and bentonite. In addition, a biodiversity experiment with 2 identical experimental stations was implemented: "downstream", close to the hydraulic works (relatively wet), "upstream", (relatively dry), with types of 3 vegetation plot (2m x 2m, n=4): 1) "control": intact vegetation (Molinia caerulea, Erica tetralix), 2) "bare" peat: vegetation and 5cm of peat were removed, 3) "Sphagnum": bare peat+Sphagnum. Our study aims to assess the effect of the vegetation treatment on the GHG fluxes. CO2 (ecosystem respiration or ER, Gross Primary Production or GPP, and Net Ecosystem Exchange) and CH4 fluxes (manual accumulation chamber), air and soil temperature, water table level, soil moisture were measured. After 18 months, half of the surface of "bare" and "Sphagnum" plots were covered by vegetation (Eriophorum angustifolium, Rynchospora alba, Trichophorum cespitosum). With time, as succession unfolds in these 2 types of station, ER and GPP increased. The sensitivity of ER to temperature increased sharply in "bare" and "Sphagnum" plots with years and became higher than the sensitivity in "control" plots. GPP increased with the total vegetation percentage cover

  1. Modelling effects of seasonal variation in water table depth on net ecosystem CO2 exchange of a tropical peatland

    Science.gov (United States)

    Mezbahuddin, M.; Grant, R. F.; Hirano, T.

    2014-02-01

    Seasonal variation in water table depth (WTD) determines the balance between aggradation and degradation of tropical peatlands. Longer dry seasons together with human interventions (e.g. drainage) can cause WTD drawdowns making tropical peatland C storage highly vulnerable. Better predictive capacity for effects of WTD on net CO2 exchange is thus essential to guide conservation of tropical peat deposits. Mathematical modelling of basic eco-hydrological processes under site-specific conditions can provide such predictive capacity. We hereby deploy a process-based mathematical model ecosys to study effects of seasonal variation in WTD on net ecosystem productivity (NEP) of a drainage affected tropical peat swamp forest at Palangkaraya, Indonesia. Simulated NEP suggested that the peatland was a C source (NEP ~ -2 g C m-2 d-1, where a negative sign represents a C source and a positive sign a C sink) during rainy seasons with shallow WTD, C neutral or a small sink (NEP ~ +1 g C m-2 d-1) during early dry seasons with intermediate WTD and a substantial C source (NEP ~ -4 g C m-2 d-1) during late dry seasons with deep WTD from 2002 to 2005. These values were corroborated by regressions (P 0.8, intercepts approaching 0 and slopes approaching 1. We also simulated a gradual increase in annual NEP from 2002 (-609 g C m-2) to 2005 (-373 g C m-2) with decreasing WTD which was attributed to declines in duration and intensity of dry seasons following the El Niño event of 2002. This increase in modelled NEP was corroborated by EC-gap filled annual NEP estimates. Our modelling hypotheses suggested that (1) poor aeration in wet soils during shallow WTD caused slow nutrient (predominantly phosphorus) mineralization and consequent slow plant nutrient uptake that suppressed gross primary productivity (GPP) and hence NEP (2) better soil aeration during intermediate WTD enhanced nutrient mineralization and hence plant nutrient uptake, GPP and NEP and (3) deep WTD suppressed NEP through a

  2. 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

  3. 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.

  4. 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.

  5. Climate-related changes in peatland carbon accumulation during the last millennium

    Directory of Open Access Journals (Sweden)

    D. J. Charman

    2013-02-01

    Full Text Available Peatlands are a major terrestrial carbon store and a persistent natural carbon sink during the Holocene, but there is considerable uncertainty over the fate of peatland carbon in a changing climate. It is generally assumed that higher temperatures will increase peat decay, causing a positive feedback to climate warming and contributing to the global positive carbon cycle feedback. Here we use a new extensive database of peat profiles across northern high latitudes to examine spatial and temporal patterns of carbon accumulation over the past millennium. Opposite to expectations, our results indicate a small negative carbon cycle feedback from past changes in the long-term accumulation rates of northern peatlands. Total carbon accumulated over the last 1000 yr is linearly related to contemporary growing season length and photosynthetically active radiation, suggesting that variability in net primary productivity is more important than decomposition in determining long-term carbon accumulation. Furthermore, northern peatland carbon sequestration rate declined over the climate transition from the Medieval Climate Anomaly (MCA to the Little Ice Age (LIA, probably because of lower LIA temperatures combined with increased cloudiness suppressing net primary productivity. Other factors including changing moisture status, peatland distribution, fire, nitrogen deposition, permafrost thaw and methane emissions will also influence future peatland carbon cycle feedbacks, but our data suggest that the carbon sequestration rate could increase over many areas of northern peatlands in a warmer future.

  6. Does peatland restoration make a difference to the millennial scale carbon balance?

    Science.gov (United States)

    Quillet, Anne; Roulet, Nigel; Wu, Jianghua

    2017-04-01

    Millennial peatland carbon balance is of crucial importance to assess the past and future forcing of peatlands carbon sequestration on climate. However drainage and exploitation of peatlands over the last and current centuries greatly affect the carbon balance of 25% of the global peatlands (Parish et al. 2008). Moreover, the impact of drainage is likely to remain for unforeseeable time, modifying the hydrology and the ecology of peatlands. The aim of this study is to assess the influence on the long-term carbon balance of restoration practices over abandonment on vacuum-extracted peatlands. We modified the Holocene Peat Model (Frolking et al. 2010) to simulate peat extraction as well as different post-extraction management strategies: abandonment, drainage blocking and restoration. Simulation results enable the comparison of the response of the system to different management strategies. The carbon balance is estimated for the millennia following extraction for different management strategies and different climate conditions. The difference between restoration practices and abandonment allows the assessment of the net carbon gain associated with restoration. Although it is expected that successful restoration practices are beneficial to the carbon budget of the ecosystem, it will take millennia to restore what has been extracted. In cases where the site is left abandoned, it is estimated that peat would degrade within centuries. The management strategies and the duration of the period of latency between extraction and restoration are key factors controlling the magnitude of the future carbon loss or gain of a peatland.

  7. Recovery of Donor Meadows of Posidonia sinuosa and Posidonia australis Contributes to Sustainable Seagrass Transplantation

    Directory of Open Access Journals (Sweden)

    Jennifer J. Verduin

    2012-01-01

    Full Text Available Donor meadow recovery is important in deciding whether removal of material from natural seagrass meadows is a sustainable activity. Thus an investigation into meadow regrowth was undertaken as part of a large-scale seagrass rehabilitation effort in Cockburn Sound, Western Australia. Several plug extraction configurations were examined in Posidonia sinuosa and Posidonia australis meadows to monitor shoot growth into plug scars. No significant differences in shoot growth between extraction configurations were observed, and both species increased their shoot numbers over two years, with P. sinuosa showing a significantly better recovery rate than P. australis. P. sinuosa shoot recovery into extracted areas was 2.2±0.1 shoots over 24 months, similar to shoot changes in controls (2.3 shoots over the same period. P. australis shoot recovery for each configuration was 0.8 ± 0.3 shoots in 24 months compared with 1.5 shoots in the controls. Based on the number of regrowing shoots, the predicted recovery time of a meadow is estimated at 4 years for P. sinuosa and three years for P. australis. Different plug extraction configurations do not appear to affect meadow recovery, and it can be concluded that established meadows of both species are sustainable providers of planting units for rehabilitation measures.

  8. Montane meadows in the Sierra Nevada: comparing terrestrial and aquatic assessment methods.

    Science.gov (United States)

    Purdy, Sarah E; Moyle, Peter B; Tate, Kenneth W

    2012-11-01

    We surveyed montane meadows in the northern Sierra Nevada and southern Cascades for two field seasons to compare commonly used aquatic and terrestrial-based assessments of meadow condition. We surveyed (1) fish, (2) reptiles, (3) amphibians, (4) aquatic macroinvertebrates, (5) stream geomorphology, (6) physical habitat, and (7) terrestrial vegetation in 79 meadows between the elevations of 1,000 and 3,000 m. From the results of those surveys, we calculated five multi-metric indices based on methods commonly used by researchers and land management agencies. The five indices consisted of (1) fish only, (2) native fish and amphibians, (3) macroinvertebrates, (4) physical habitat, and (5) vegetation. We compared the results of the five indices and found that there were significant differences in the outcomes of the five indices. We found positive correlations between the vegetation index and the physical habitat index, the invertebrate index and the physical habitat index, and the two fish-based indices, but there were significant differences between indices in both range and means. We concluded that the five indices provided very different interpretations of the condition in a given meadow. While our assessment of meadow condition changed based on which index was used, each provided an assessment of different components important to the overall condition of a meadow system. Utilizing a multimetric approach that accounts for both terrestrial and aquatic habitats provides the best means to accurately assess meadow condition, particularly given the disproportionate importance of these systems in the Sierra Nevada landscape.

  9. Current and future CO2 emissions from drained peatlands in Southeast Asia

    Directory of Open Access Journals (Sweden)

    H. Wösten

    2010-05-01

    Full Text Available 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 paper we estimate the carbon dioxide (CO2 emissions resulting from drainage of lowland tropical peatland for agricultural and forestry development which dominates the perturbation of the carbon balance in the region. Present and future emissions from drained peatlands are quantified using data on peatland extent and peat thickness, present and projected land use, water management practices and decomposition rates. Of the 27.1 Million hectares (Mha of peatland in Southeast Asia, 12.9 Mha had been deforested and mostly drained by 2006. This latter area is increasing rapidly because of increasing land development pressures. Carbon dioxide (CO2 emission caused by decomposition of drained peatlands was between 355 Mt y−1 and 855 Mt y−1 in 2006 of which 82% came from Indonesia, largely Sumatra and Kalimantan. At a global scale, CO2 emission from peatland drainage in Southeast Asia is contributing the equivalent of 1.3% to 3.1% of current global CO2 emissions from the combustion of fossil fuel. If current peatland development and management practices continue, these emissions are predicted to continue for decades. This warrants inclusion of tropical peatland CO2 emissions in global greenhouse gas emission calculations and climate mitigation policies. Uncertainties in emission calculations are discussed and research needs for improved estimates are identified.

  10. The energy balance of utilising meadow grass in Danish biogas production

    DEFF Research Database (Denmark)

    Meyer, Ane Katharina Paarup; Raju, Chitra Sangaraju; Kucheryavskiy, Sergey V.

    2015-01-01

    of meadow areas, different relevant geo-datasets, spatial analyses, and various statistical analyses. The results show that values for the energy return on energy invested (EROEI) ranging from 1.7 to 3.3 can be obtained when utilising meadow grasses in local biogas production. The total national net energy......This paper presents a study of the energy balance of utilising nature conservation biomass from meadow habitats in Danish biogas production. Utilisation of nature conservation grass in biogas production in Denmark represents an interesting perspective for enhancing nature conservation of the open...

  11. Cascading effects of predator-detritivore interactions depend on environmental context in a Tibetan alpine meadow.

    Science.gov (United States)

    Wu, Xinwei; Griffin, John N; Sun, Shucun

    2014-05-01

    Studies of grazing food webs show that species traits can interact with environmental factors to determine the strength of trophic cascades, but analogous context dependencies in detrital food webs remain poorly understood. In predator-detritivore-plant interaction chains, predators are expected to indirectly suppress plant biomass by reducing the density of plant-facilitating detritivores. However, this outcome can be reversed where above-ground predators drive burrowing detritivores to lower soil levels, strengthening their plant-facilitating effects. Here, we show that these trait-mediated indirect interactions further depend on environmental context in a Tibetan alpine meadow. In our study system, undulating topography generates higher (dry soil) patches interspersed with lower (wet soil) patches. Because the ability of detritivores to form deep burrows is likely to be limited by oxygen availability in low patches (wet soil), we hypothesized that (i) burrowing detritivores would undergo a vertical habitat shift, allowing them to more effectively avoid predation, in high - but not low - patches, and (ii) this shift would transmit positive effects of predators to plants in high patches by improving conditions in the lower soil layer. We tested these hypotheses using complementary field and glasshouse experiments examining whether the cascading effects of above-ground predatory beetles (presence/absence) on the density and behaviour of tunnel-forming detritivorous beetles, soil properties, and plant growth varied with patch type (low/high). Results revealed that predatory beetles did not reduce the density of detritivores in either patch type but had context-dependent trait-mediated effects, increasing the tunnelling depth of detritivores, improving soil conditions and ultimately increasing plant biomass in the high but not low patches. This study adds to an emerging predictive framework linking predators to plants in detritus food webs, demonstrating that these

  12. Greenhouse gas dynamics in degraded and restored tropical peatlands

    Directory of Open Access Journals (Sweden)

    J. Jauhiainen

    2016-06-01

    Full Text Available Agricultural and other land uses on ombrotrophic lowland tropical peat swamps typically lead to reduced vegetation biomass and water table drawdown. We review what is known about greenhouse gas (GHG dynamics in natural and degraded tropical peat systems in south-east Asia, and on this basis consider what can be expected in terms of GHG dynamics under restored conditions. Only limited in situ data are available on the effects of restoration and the consequences for peat carbon (C dynamics. Hydrological restoration seeks to bring the water table closer to the peat surface and thus re-create near-natural water table conditions, in order to reduce wildfire risk and associated fire impacts on the peat C store, as well as to reduce aerobic peat decomposition rates. However, zero emissions are unlikely to be achieved due to the notable potential for carbon dioxide (CO2 production from anaerobic peat decomposition processes. Increased vegetation cover (ideally woody plants resulting from restoration will increase shading and reduce peat surface temperatures, and this may in turn reduce aerobic decomposition rates. An increase in litter deposition rate will compensate for C losses by peat decomposition but also increase the supply of labile C, which may prime decomposition, especially in peat enriched with recalcitrant substrates. The response of tropical peatland GHG emissions to peatland restoration will also vary according to previous land use and land use intensity.

  13. Bryophyte spore germinability is inhibited by peatland substrates

    Science.gov (United States)

    Bu, Zhao-Jun; Li, Zhi; Liu, Li-Jie; Sundberg, Sebastian; Feng, Ya-Min; Yang, Yun-He; Liu, Shuang; Song, Xue; Zhang, Xing-Lin

    2017-01-01

    Bryophyte substrates and species may affect spore germination through allelopathy. Polytrichum strictum is currently expanding in peatlands in north-eastern China - is this an effect of its superior spore germinability or do its gametophytes have a stronger allelopathic effect than do Sphagnum? We conducted a spore burial experiment to test the effect of species identity, substrate and water table depth (WTD) on spore germinability and bryophyte allelopathic effect with P. strictum and two Sphagnum species (S. palustre and S. magellanicum). After 5 months of burial during a growing season, the spores were tested for germinability. Allelopathic effect of bryophyte substrates was assessed by the difference between spore germinability after being stored inside or outside the substrates. After burial, more than 90% of the spores lost their germinability across all three species due to ageing and allelopathy. Spore germinability differed among species, where the spores in S. palustre had a higher germination frequency than those in P. strictum. The three bryophytes maintained a higher germinability in Sphagnum than in Polytrichum hummocks, probably due to a stronger allelopathic effect of P. strictum. Water table drawdown by 10 cm increased germinability by more than 60% across the three species. The study indicates that P. strictum does not possess an advantage regarding spore germination but rather its gametophytes have a stronger allelopathic effect. Due to the weaker inhibitive effect of Sphagnum gametophytes, P. strictum may have a potential establishment superiority over Sphagnum in peatlands, in addition to a better drought tolerance, which may explain its current expansion.

  14. Methane emission by plant communities in an alpine meadow on the Qinghai-Tibetan Plateau: a new experimental study of alpine meadows and oat pasture

    Science.gov (United States)

    Wang, Shiping; Yang, Xiaoxia; Lin, Xingwu; Hu, Yigang; Luo, Caiyun; Xu, Guangping; Zhang, Zhenhua; Su, Ailing; Chang, Xiaofen; Chao, Zengguo; Duan, Jichuang

    2009-01-01

    Recently, plant-derived methane (CH4) emission has been questioned because limited evidence of the chemical mechanism has been identified to account for the process. We conducted an experiment with four treatments (i.e. winter-grazed, natural alpine meadow; naturally restored alpine meadow eight years after cultivation; oat pasture and bare soil without roots) during the growing seasons of 2007 and 2008 to examine the question of CH4 emission by plant communities in the alpine meadow. Each treatment consumed CH4 in closed, opaque chambers in the field, but two types of alpine meadow vegetation reduced CH4 consumption compared with bare soil, whereas oat pasture increased consumption. This result could imply that meadow vegetation produces CH4. However, measurements of soil temperature and water content showed significant differences between vegetated and bare soil and appeared to explain differences in CH4 production between treatments. Our study strongly suggests that the apparent CH4 production by vegetation, when compared with bare soil in some previous studies, might represent differences in soil temperature and water-filled pore space and not the true vegetation sources of CH4. PMID:19411273

  15. 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

  16. Responses of Regional Vegetation and Peatland Ecosystems to Climate Change Over the Last Millennium in the Western Lowlands of Kamchatka, Russia

    Science.gov (United States)

    Cleary, K.; Hunt, S. J.; Yu, Z.; Beilman, D.; Dirksen, V.; Bochicchio, C. J.; Loisel, J.

    2013-12-01

    Climate in high-latitude regions has warmed rapidly over the recent decades, causing widespread changes in sea-ice cover and terrestrial ecosystem dynamics such as greening of the Arctic. However, regional patterns of ecosystem response to warming are still poorly understood in several regions of the Arctic due to data gaps. In particular, we still lack detailed records in the Far East of Russia in terms of regional vegetation and peatland responses to recent warming. Kamchatka, located between the Sea of Okhotsk and the Pacific Ocean, is an ideal region for studying climate and ecosystem change due to minimum human impacts. Here we present multi-proxy data from a peat core (core KAM12-B1; 53.9146° N, 155.9361° E; approximately 1 km from the Sea of Okhotsk at an elevation of 15 m) in the western lowlands of Kamchatka to investigate regional vegetation and peatland responses to climate change during the last millennium. Chronology of the 1-m-long peat core was controlled by 7 AMS 14C dates, covering the last 900 years. Pollen analysis shows a ca. 10% decrease in tree pollen (mostly tree birches) at 1600-1900 AD, while macrofossil results show an increase in brown mosses (Drepanocladus sp.) during the same period. These ecological changes suggest a cool and possibly wet climate in a period corresponding to the widely documented Little Ice Age (LIA). The peatland also shows a slight decrease in carbon accumulation during the LIA. The most pronounced changes in the record have occurred since 50 years ago (post-LIA) and include (1) an increase in the abundance of pollen from warm-adapted tree species, including Betula ermanii (stone birch) and Betula platyphylla (white birch); (2) the dominance of peat mosses (Sphagnum) in macrofossil assemblages suggesting a drying trend due to climate or successional change; and (3) higher carbon accumulation rates. Taken together, these results from the pollen-based regional vegetation reconstruction and the macrofossil-based local

  17. Response of sphagnum peatland testate amoebae to a 1-year transplantation experiment along an artificial hydrological gradient.

    Science.gov (United States)

    Marcisz, Katarzyna; Fournier, Bertrand; Gilbert, Daniel; Lamentowicz, Mariusz; Mitchell, Edward A D

    2014-05-01

    Peatland testate amoebae (TA) are well-established bioindicators for depth to water table (DWT), but effects of hydrological changes on TA communities have never been tested experimentally. We tested this in a field experiment by placing Sphagnum carpets (15 cm diameter) collected in hummock, lawn and pool microsites (origin) at three local conditions (dry, moist and wet) using trenches dug in a peatland. One series of samples was seeded with microorganism extract from all microsites. TA community were analysed at T0: 8-2008, T1: 5-2009 and T2: 8-2009. We analysed the data using conditional inference trees, principal response curves (PRC) and DWT inferred from TA communities using a transfer function used for paleoecological reconstruction. Density declined from T0 to T1 and then increased sharply by T2. Species richness, Simpson diversity and Simpson evenness were lower at T2 than at T0 and T1. Seeded communities had higher species richness in pool samples at T0. Pool samples tended to have higher density, lower species richness, Simpson diversity and Simpson Evenness than hummock and/or lawn samples until T1. In the PRC, the effect of origin was significant at T0 and T1, but the effect faded away by T2. Seeding effect was strongest at T1 and lowest vanished by T2. Local condition effect was strong but not in line with the wetness gradient at T1 but started to reflect it by T2. Likewise, TA-inferred DWT started to match the experimental conditions by T2, but more so in hummock and lawn samples than in pool samples. This study confirmed that TA responds to hydrological changes over a 1-year period. However, sensitivity of TA to hydrological fluctuations, and thus the accuracy of inferred DWT changes, was habitat specific, pool TA communities being least responsive to environmental changes. Lawns and hummocks may be thus better suited than pools for paleoecological reconstructions. This, however, contrasts with the higher prediction error and species' tolerance for

  18. Quantitative assessment of the effects of agricultural practices designed to reduce {sup 137}Cs and {sup 90}Sr soil-plant transfer in meadows

    Energy Technology Data Exchange (ETDEWEB)

    Camps, M.; Rigol, A.; Hillier, S.; Vidal, M.; Rauret, G

    2004-10-01

    Agricultural practices (ploughing and reseeding, addition of lime and fertiliser) were tested as a feasible remediation strategy to reduce {sup 137}Cs (RCs) and {sup 90}Sr (RSr) soil-plant transfer in natural meadows in areas affected by the Chernobyl fallout. Field experiments were carried out for 2 years at six sites, covering dry and wet meadows. Observed results at field scale showed that ploughing plus reseeding provoked the main reduction in RSr transfer, with no further reduction after liming, while ploughing+reseeding+K fertiliser led to the maximum decrease in RCs transfer at most sites. The direct effects of agricultural practices on the exchange complex and soil solution composition were quantified by subsequent soil analyses. At the doses applied, lime did not affect the Ca+Mg concentrations in the exchange complex and soil solution of the ploughed soils, thus suggesting that the decrease in RSr transfer on treated plots was mainly due to the changes in the plant species after reseeding. With respect to RCs, changes in the K+NH{sub 4}{sup +} concentrations in the exchange complex and soil solution were consistent with changes in soil-plant transfer. Finally, RSr and RCs soil-plant transfer in ploughed plots was well predicted from soil properties, such as the solid-liquid distribution coefficient, the ionic composition of the soil solution and the exchangeable cations, with Pearson correlation coefficients of 0.98 and 0.86, respectively, between calculated and experimental log transfer factors.

  19. Species status assessment report New Mexico meadow jumping mouse (Zapus hudsonius luteus)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The New Mexico meadow jumping mouse (Zapus hudsonius luteus) (jumping mouse) lives in dense riparian herbaceous vegetation along streams from southern Colorado to...

  20. Outreach Plan : Crane Meadows National Wildlife Refuge : Special Deer & Turkey Hunting Opportunities

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a plan for special deer and turkey hunting opportunities at Crane Meadows NWR. Goals, strategies, messages, and key dates relevant to this plan are outlined.

  1. Draft comprehensive conservation plan and environmental assessment: Cokeville Meadows National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This draft Comprehensive Conservation Plan (CCP) was written to guide management on Cokeville Meadows NWR for the next 15 years. This plan outlines the Refuge vision...

  2. Sunkhaze Meadows National Wildlife Refuge and Carlton Pond Waterfowl Production Area: Comprehensive Conservation Plan

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Sunkhaze Meadows National Wildlife Refuge and Carlton Pond Waterfowl Production Area...

  3. Sunkhaze Meadows National Wildlife Refuge: Annual narrative report: Calendar year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sunkhaze Meadows NWR, Carlton Pond Waterfowl Production Area, Benton Unit, and Unity Unit outlines Refuge accomplishments during the...

  4. Sunkhaze Meadows National Wildlife Refuge, Carlton Pond National Wildlife Refuge: Annual narrative report: Fiscal year 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sunhaze Meadows NWR and Carlton Pond WPA outlines activities and accomplishments during the 2001 fiscal year. The report begins with...

  5. Sunkhaze Meadows National Wildlife Refuge, Carlton Pond National Wildlife Refuge: Annual narrative report: Fiscal year 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Sunhaze Meadows NWR and Carlton Pond WPA outlines activities and accomplishments during the 2000 fiscal year. The report begins with...

  6. Assessment of Cokeville Meadows National Wildlife Refuge, Wyoming for creosote contamination of wetlands

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Semi-permeable devices (SPMDs) were deployed in wetlands along a railroad right-of-way at the Cokeville Meadows National Wildlife Refuge, Lincoln County, Wyoming to...

  7. Soil acidity, temperature, and water relationships of four clovers in Sierra Nevada meadows

    Science.gov (United States)

    Raymond D. Ratliff; Ethelynda E. Harding

    1993-01-01

    Sites in meadows of the Sierra Nevada near Fresno, California, were studied to learn whether Bolander's (Trifolium holanderi Gray.), longstalked (T. longipes Nutt.), carpet (T. monanthum Gray.), and mountain (T. wormskioldii Lehm.) clovers occurred under the same soil acidity, temperature...

  8. Annual narrative report: Calendar year 2001: Supawna Meadows National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Supawna Meadows NWR outlines Refuge accomplishments during the 2001 calendar year. The report begins with a summary of the year's...

  9. Supawna Meadows National Wildlife Refuge: Annual narrative report: Calendar year 1998

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Supawna Meadows NWR outlines Refuge accomplishments during the 1998 calendar year. The report begins with a summary of the year's...

  10. Great Meadows National Wildlife Refuge : Annual Narrrative Report : Calendar Year 1983

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Great Meadows National Wildlife Refuge outlines Refuge accomplishments during the 1983 calendar year. The report begins with a...

  11. Great Meadows National Wildlife Refuge : Annual Narrrative Report : Calendar Year 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Great Meadows National Wildlife Refuge outlines Refuge accomplishments during the 1982 calendar year. The report begins with a...

  12. Bacterial biomass and DNA diversity in an alluvial meadow soil upon long-term fertilization

    NARCIS (Netherlands)

    Naumova, N.B.; Kuikman, P.J.

    2001-01-01

    The denaturing gradient gel-electrophoresis of bacterial DNA fragments and the assessment of bacterial biomass revealed changes in the diversity of the bacterial community in a meadow alluvial soil upon long-term fertilization.

  13. Great Meadows National Wildlife Refuge : Annual Narrrative Report : Calendar Year 1986

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Great Meadows National Wildlife Refuge outlines Refuge accomplishments during the 1986 calendar year. The report begins with a...

  14. Great Meadows National Wildlife Refuge : Annual Narrrative Report : Calendar Year 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Great Meadows National Wildlife Refuge outlines Refuge accomplishments during the 1981 calendar year. The report begins with a...

  15. Sediment toxicity of Long Meadow Lake Minnesota Valley National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Long Meadow Lake on the Minnesota Valley National Wildlife Refuge - an important waterfowl production area - serves as a major urban stormwater receptor in the...

  16. Supawna Meadows National Wildlife Refuge: Annual narrative report: Calendar year 1991

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Supawna Meadows NWR outlines Refuge accomplishments during the 1991 calendar year. The report begins with a summary of the year's...

  17. Supawna Meadows National Wildlife Refuge: Annual narrative report: Calendar year 1992

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This annual narrative report for Supawna Meadows NWR outlines Refuge accomplishments during the 1992 calendar year. The report begins with a summary of the year's...

  18. Contaminant survey of Sunkhaze Stream and Baker Brook: Sunkhaze Meadows National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — In 1993 a screening-level contaminant survey of the Sunkhaze Meadows National Wildlife Refuge was conducted by the Maine Field Office of the U.S. Fish and Wildlife...

  19. Burrowing shrimps and seagrass dynamics in shallow-water meadows off Bolinao (Nw Philippines)

    NARCIS (Netherlands)

    Nacorda, H.M.

    2008-01-01

    Keywords: sediment gaps, Alpheus macellarius, Thalassinidea, burrows, seagrass canopies, sediment characteristics, Philippines Small-scale disturbance of seagrass meadows by burrowing shrimps was assessed by mapping and quantifying apparent disturbance marks (burrow openings, sand patches, sand

  20. Anthropogenic Disturbance of Montane Meadows May Cause Substantial Loss of Soil Carbon to the Atmosphere

    Science.gov (United States)

    Reed, C. C.; Sullivan, B. W.; Hart, S. C.; Drew, M.; Merrill, A.

    2016-12-01

    High-elevation meadows are biological hotspots that contain high densities of soil carbon (C). The capacity of these ecosystems to sequester C depends on a combination of high primary productivity, seasonally low temperatures, and anaerobic soil conditions associated with water tables at or near the soil surface. However, anthropogenic disturbances in many montane meadows in California's Sierra Nevada have lowered water tables, decreased primary productivity, and created aerobic soil conditions - changes that may alter the balance of greenhouse gas (GHG) emissions and reverse meadows from a net C sink to a net source. Recently, C policy in California has spurred interest in the potential of hydrologic restoration to increase C sequestration in meadows. However, soil C pools and fluxes in degraded meadows must be quantified before the impacts of restoration can accurately be assessed. In this study, we measured soil C stocks in surface soil (1 m) and annual soil GHG fluxes (carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)) in three degraded, northern Sierra Nevada meadows. In a parallel laboratory incubation, we manipulated meadow soil water content to determine target goals for restoration of anaerobic conditions. Our results suggest that degraded meadows contain large reservoirs of existing C, but that this C may be vulnerable to decomposition under current conditions. Soil CO2 fluxes ranged from 26.7-33.1 Mg of CO2 ha-1 y-1, roughly equivalent to the amount of C sequestered annually by 70 acres of U.S. forests. These high rates of soil respiration, combined with low primary productivity, resulted in substantial losses of soil C with implications for climate change, ecosystem function, and restoration. Soils from these meadows were a net source of N2O and a net sink of CH4, but these fluxes were 4 orders of magnitude smaller than CO2. Also, we found substantial GHG emissions persist in these organic soils at peak soil moisture, suggesting that

  1. NACP Peatland Landcover Type and Wildfire Burn Severity Maps, Alberta, Canada

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides landcover maps of (1) peatland type (bog, fen, marsh, swamp) with levels of biomass (open, forested) and (2) Burn Severity Index (BSI)...

  2. NACP Peatland Land Cover Map of Upper Peninsula, Michigan, 2007-2011

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides a land cover map focused on peatland ecosystems in the upper peninsula of Michigan. The map was produced at 12.5-m resolution using a...

  3. 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...

  4. Global Peatland Carbon Balance and Land Use Change CO2 Emissions Through the Holocene

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set provides a time series of global peatland carbon balance and carbon dioxide emissions from land use change throughout the Holocene (the past 11,000...

  5. 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.

  6. Management of Peatland Shrub- and Forest-Dominated Communities for Threatened and Endangered Species

    National Research Council Canada - National Science Library

    Robertson, Kevin

    1998-01-01

    .... Peatland plant communities in the southeastern United States are important to landscape and regional biodiversity because they are often the only natural areas that have not been converted to urban...

  7. 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

  8. 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

  9. Remote influence of off-shore fish farm waste on Mediterranean seagrass (Posidonia oceanica) meadows.

    Science.gov (United States)

    Ruiz, J M; Marco-Méndez, C; Sánchez-Lizaso, J L

    2010-04-01

    The aim of this study was estimating the remote influence of waste dispersed from a large off-shore fish farm complex (6197 ton year(-1)) on the near-shore Posidonia oceanica meadow (26-27 m deep) located at a distance of 3 km. Measurements of isotopic nitrogen content in epiphytes and seagrass leaf tissues, epiphyte biomass, shoot size, herbivory pressure, shoot density and seagrass meadow cover, performed in this meadow (FA area) were compared with those obtained in an undisturbed control meadow (CA area) to evaluate: (1) the remote influence of waste and (2) the impact of such influence on seagrass condition. In addition, delta(15)N measurements in particulate organic matter of natural and anthropogenic origin were used in a single-isotope mixing model to elucidate the relative contributions of these sources to the isotopic N signal measured in epiphytes and leaf tissues. Total tissue N content was similar between meadow areas, but delta(15)N signatures were significantly higher in the FA area than in the CA area both in epiphytes and seagrass leaf tissues. Results from the mixing model, together with available information on local currents and previous studies, support the conclusion that the dispersion of farm wastes over large areas (spanning kilometres) are responsible for the elevated delta(15)N signatures found in the FA meadow area. Despite this, no changes in meadow structure were detected and only some changes at the level of seagrass community (epiphytes abundances and herbivores activity) could be interpreted at the light of nutrient-induced effects in the FA area. Results from this study indicate that concentrating aquaculture facilities in off-shore areas is a strategy not totally exempt of environmental risk on near-shore sensitive habitats such as seagrass meadows. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Modelling reference conditions for the upper limit of Posidonia oceanica meadows: a morphodynamic approach

    Science.gov (United States)

    Vacchi, Matteo; Misson, Gloria; Montefalcone, Monica; Archetti, Renata; Nike Bianchi, Carlo; Ferrari, Marco

    2014-05-01

    The upper portion of the meadows of the protected Mediterranean seagrass Posidonia oceanica occurs in the region of the seafloor mostly affected by surf-related effects. Evaluation of its status is part of monitoring programs, but proper conclusions are difficult to draw due to the lack of definite reference conditions. Comparing the position of the meadow upper limit with the beach morphodynamics (i.e. the distinctive type of beach produced by topography and wave climate) provided evidence that the natural landwards extension of meadows can be predicted. Here we present an innovative predictive cartographic approach able to identify the seafloor portion where the meadow upper limit should naturally lies (i.e. its reference conditions). The conceptual framework of this model is based on 3 essential components: i) Definition of the breaking depth geometry: the breaking limit represents the major constrain for the landward meadow development. We modelled the breaking limit (1 year return time) using the software Mike 21 sw. ii) Definition of the morphodynamic domain of the beach using the surf scaling index ɛ; iii) Definition of the P. oceanica upper limit geometry. We coupled detailed aerial photo with thematic bionomic cartography. In GIS environment, we modelled the seafloor extent where the meadow should naturally lies according to the breaking limit position and the morphodynamic domain of the beach. Then, we added the GIS layer with the meadow upper limit geometry. Therefore, the final output shows, on the same map, both the reference condition and the actual location of the upper limit. It make possible to assess the status of the landward extent of a given P. oceanica meadow and quantify any suspected or observed regression caused by anthropic factors. The model was elaborated and validated along the Ligurian coastline (NW Mediteraanean) and was positively tested in other Mediterranean areas.

  11. [The beetle and spider fauna of meadows affected by traffic pollution].

    Science.gov (United States)

    Maurer, R

    1974-12-01

    1. The comparative effects of heavy versus light motor traffic on the composition of two fauna, beetles and spiders, were investigated. All meadows chosen for the study were morphologically and topographically similar. Three of the meadows were adjacent to a very busy road and two to a little-used road. The fauna were examined at the edge and in the interior of each meadow and the meadows on the busy road were then compared with these on the other road. 2. The numbers of species and of individual specimens of Carabidae were significantly lower (Wilcoxon test 0.05). 3. Comparison of the number of individuals of representative species in the differently situated meadows revealed a reduction in the number of specimens of Clivina fossor, Bembidion lampros, Amara communis, Ocypus olens, Lycosa pullata, Lycosa tarsalis on the sites adjacent to the busy road. Whereas some species showed no demonstrable change, a few (Pterostichus cupreus, Philonthus varius, Pachygnatha degeeri) exhibited greater number of individual specimens on the sites adjacent to the busy road than on those near the rural road. 4. The diversity index of Shannon and Weaver generally yielded a lower value for the border zone of the meadows on the busy road, while there was no change observed for the meadows bordering on the rural toad. 5. The presence or absence of lead within an animal carcass was taken as an indicator of motor vehicle pollution. Quantitative estimation of body content of lead was performed in three representative beetle species by flame spectrometry. Individuals of Carabus auratus and Pterostichus cupreus captured near the edge of the busy road showed a significantly higher level of body lead than those captured in the middle of the field. No significant differences in lead deposits were observed between specimens of Ocypus olens captured on the roadside and those captured at other locations in the meadow, perhaps due to the greater range of mobility of this species.

  12. Forced wetting and hydrodynamic assist

    Science.gov (United States)

    Blake, Terence D.; Fernandez-Toledano, Juan-Carlos; Doyen, Guillaume; De Coninck, Joël

    2015-11-01

    Wetting is a prerequisite for coating a uniform layer of liquid onto a solid. Wetting failure and air entrainment set the ultimate limit to coating speed. It is well known in the coating art that this limit can be postponed by manipulating the coating flow to generate what has been termed "hydrodynamic assist," but the underlying mechanism is unclear. Experiments have shown that the conditions that postpone air entrainment also reduce the apparent dynamic contact angle, suggesting a direct link, but how the flow might affect the contact angle remains to be established. Here, we use molecular dynamics to compare the outcome of steady forced wetting with previous results for the spontaneous spreading of liquid drops and apply the molecular-kinetic theory of dynamic wetting to rationalize our findings and place them on a quantitative footing. The forced wetting simulations reveal significant slip at the solid-liquid interface and details of the flow immediately adjacent to the moving contact line. Our results confirm that the local, microscopic contact angle is dependent not simply only on the velocity of wetting but also on the nature of the flow that drives it. In particular, they support an earlier suggestion that during forced wetting, an intense shear stress in the vicinity of the contact line can assist surface tension forces in promoting dynamic wetting, thus reducing the velocity-dependence of the contact angle. Hydrodynamic assist then appears as a natural consequence of wetting that emerges when the contact line is driven by a strong and highly confined flow. Our theoretical approach also provides a self-consistent model of molecular slip at the solid-liquid interface that enables its magnitude to be estimated from dynamic contact angle measurements. In addition, the model predicts how hydrodynamic assist and slip may be influenced by liquid viscosity and solid-liquid interactions.

  13. Tropical peatland carbon dynamics simulated for scenarios of disturbance and restoration and climate change

    Science.gov (United States)

    Frolking, S. E.; Warren, M.; Dai, Z.; Kurnianto, S.; Hagen, S. C.

    2015-12-01

    Tropical peatlands contain a globally significant carbon pool. Southeast Asian peatlands are being deforested, drained and burned at very high rates, mostly for conversion to industrial oil palm or pulp and paper plantations. The climate mitigation potential of tropical peatlands has gained increasing attention in recent years as persistent greenhouse gas emissions can be avoided or decreased if peatlands remain intact or are rehabilitated. In addition, peatland conservation or rehabilitation for climate mitigation also includes multiple co-benefits such as maintenance of ecosystem services, biodiversity, and air quality from reduced fire occurrence. Inventory guidelines and methodologies have only recently become available, and are based on few data from a limited number of sites. Few heuristic tools are available to evaluate the impact of management practices on carbon dynamics in tropical peatlands, and the potential climate mitigation benefits of peatland restoration. We used a process based dynamic tropical peatland model to explore the C dynamics of several peatland management trajectories represented by hypothetical scenarios, within the context of simulated 21st century climate change. All scenarios with land use, including those with optimal restoration, simulate C loss over the 21st century, with C losses ranging from 10% to essentially 100% of pre-disturbance values. Fire, either prescribed as part of a crop rotation cycle, or stochastic occurrences in sub-optimally managed degraded land can be the dominant C-loss pathway, particularly in the drier climate scenario we tested. A single 25-year oil palm rotation, with a prescribed initial burn, lost 40-50 kg C/m2, equivalent to accumulation during the previous 500 years, 10-30% of which was restored in 75 years of optimal restoration. Our results indicate that even under the most optimistic scenario of hydrological and forest restoration and the wettest climate regime, only about one-third of the carbon

  14. CO2 and CH4 fluxes of an Alpine peatland during extraordinary summer drought

    Science.gov (United States)

    Drollinger, Simon; Glatzel, Stephan

    2016-04-01

    In peatland ecosystems, plant production exceeds decomposition due to their typical characteristic of waterlogged soils leading to peatland growth and an accumulation of thick organic soil layers. As a result, peatlands constitute a major global storage of carbon (C) by storing about 612 PgC in their peat, thus representing the most space-effective C stocks of all terrestrial ecosystems, similar in magnitude as the increasing atmospheric C pool (~ 850 PgC). However, little is known about the effects of climate change on peatlands and the contribution of Alpine peatlands as a source of greenhouse gases in the course of a changing climate. It is debatable how land-use changes and ongoing degradation of Alpine peatlands affect the peatland-atmosphere C exchange. On the one hand, more C may sequester due to increased plant growth in a warmer climate, on the other hand large amounts of respired C may release as a consequence of higher temperatures and lowered peatland water table depths due to increasing evaporation rates and extending drought periods. To examine the potential effects of climate change on the peatland carbon exchange with the atmosphere, we calculated CO2 and CH4 fluxes using the eddy covariance method. The investigated ombrotrophic peatland is located on the bottom of the Styrian Enns valley at an altitude of 632 m above sea level. It is a slightly degraded pine peat bog (62 ha) with a closed peat moss cover featuring the three plant associations Pino mugo-Sphagnetum magellanici, Sphagnetum magellanici, and Caricetum limosae, according to the prevailing hydrological site conditions. During summer drought in 2015, the water level decreased from an annual average water level of -10.44 cm to -28.50 cm below surface at the centre of the peat bog. Here, we present diurnal pattern of CO2 and CH4 fluxes during an extraordinary dry summer and compare them to calculated fluxes during periods characterised by precipitation and higher peat water levels of the

  15. Peatland Carbon Dynamics on the North Slope of Alaska During the Holocene: The Role of Climate, Sea Ice, and Buried Peat

    Science.gov (United States)

    Yu, Zicheng; Massa, Charly; Cleary, Kathleen; Jones, Benjamin; Grosse, Guido

    2014-05-01

    thick peat sequence was formed in an ice wedge polygonal trough at ~8 ka, suggesting localized but potentially widespread prolonged peat accumulation in these landscape elements that were vulnerable to degradation, thaw subsidence, and wetting since the HTM, and then peat growth was accelerated in the late Holocene. We hypothesize that the multitude ecological changes in the late Holocene were in response to regional climate warming caused by the reduction in sea-ice cover in the Chukchi Sea (de Vernal et al. 2013, QSR 79: 111-121), just off the coast of northern Alaska. If our observations from northern Alaska are also applicable to other high-latitude regions, our findings have important implications for understanding the role of peatlands in the global C cycle in the past (buried peat) and future (feedback from sea-ice reduction).

  16. 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...

  17. Palaeoecological evidence for anthropogenic acidification of a kettle-hole peatland in northern Poland

    OpenAIRE

    Lamentowicz, Mariucz; Tobolski, Kazimierz; Mitchell, Edward A.D.

    2010-01-01

    The Holocene developmental history of a small kettle-hole peatland in northern Poland was studied using radiocarbon dating and analyses of pollen, plant macrofossils and testate amoebae with the aim of sorting out the influences of climate change, autogenic succession and human impact. The mire followed the classical succession from lake to a Sphagnum-dominated peatland, but peat accumulation only started about 3000 cal. BP. A rapid shift to wetter conditions, lower pH and higher peat accumul...

  18. The impact of dredge-fill on Posidonia oceanica seagrass meadows: regression and patterns of recovery.

    Science.gov (United States)

    Badalamenti, Fabio; Alagna, Adriana; D'Anna, Giovanni; Terlizzi, Antonio; Di Carlo, Giuseppe

    2011-03-01

    Posidonia oceanica meadows can be severely damaged by dredge-fill operations. We report on the construction of gas pipelines that occurred between 1981 and 1993 in SW Sicily, Italy. A large portion of the meadow was mechanically removed, and the excavated trench was filled with a mosaic of substrates, ranging from sand to consolidated rock debris. Meadow loss and recovery were quantified over 7 years after the end of operations. We recorded an overall loss of 81.20 ha of meadow. Substrate strongly affected recovery as the percent cover by P. oceanica consistently increased on calcareous rubble, reaching values of 44.37 ± 3.05% in shallow sites after 7 years, whereas no significant increase occurred on other substrates. As in the Mediterranean Sea exploitation of coastal areas continues to grow with consequent impacts on P. oceanica meadows, this case study illustrates how artificial rubble-like materials could be employed to support the restoration of damaged meadows. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Frozen peatlands: carbon store and the climate change

    Science.gov (United States)

    Ogneva, Olga; Matyshak, George; Tarkhov, Matvey

    2017-04-01

    Peatlands soils in the northern permafrost region store approximately 40% of total Earth's soils carbon. These soils develop under the influence of cryogenic processes especially such as freeze-thaw and cryoturbations. Climate change predictions suggest that the frequency of soil freeze-thaw cycles (FTCs) will increase in cool temperate and other high-latitude regions. This trend may cause a response in organic matter decomposition rate - that will result in significant changes of greenhouse gases emission (CO2, CH4). For further predictions improvement of soils response to global climate changes it is necessary to estimate the impact of FTCs in permafrost soils on organic matter decomposition. We investigated the effects of FTCs on microbial biomass, basal respiration, metabolic quotient and dissolved organic matter (DOM) content (carbon - DOC and nitrogen - DON) in frozen peatlands soils by laboratory modelling experiment. Frozen peatlands from the north of Western Siberia in Nadym area (N65°19', E72°53'), in a zone of discontinuous permafrost were studied. The soil cover of these formations is represented by a complex of Typic Histoturbels (Turbic Cryosol) and Typic Historthels (Cryic Histosols). Peat profiles of both soil types were divided into horizons due to decomposition degree (from 15 to 55-60%), age (from 1000 to 5700 yrs) and botanic composition (oligotrophic, mesotrophic, eutrophic). During the experiment, first group of samples of peat horizons (field moisture content) were subjected for 10 times to 3-day FTCs at the temperature of -10 and +4 ° C. In the second group of peat samples were incubated at +4 ° C (with no freeze-thaw). It was established that all studied microbial properties were inversely proportional with decomposition degree of peat, except metabolic quotient. Our results illustrate that microbial activity, estimated by BR, shows resistance to FTCs and doesn't significantly differ after FTCs an average. Microbial biomass (carbon and

  20. Holocene Peatland Carbon Dynamics in Kamchatka, Far East Russia

    Science.gov (United States)

    Loisel, J.; Dirksen, V.; Beilman, D.; Dirksen, O.; Yu, Z.; Bochicchio, C. J.

    2013-12-01

    The Russian Far East remains one of the last frontiers in terms of exploring high-latitude ecosystem - carbon - climate interactions. This region is characterized by a unique climate envelope as well as by large areas of peatlands, making Far East Russia a potentially important and undocumented carbon hotspot. However, very few field studies have documented the extent, depth, density, and C content of these organic soils, making it challenging to adequately estimate regional soil-C stocks for Far East Russia. Here we present soil-C stocks and Holocene C accumulation rates for two peatlands located on the Kamchatka Peninsula. Our study sites are located in two distinct physiographic regions of Kamchatka: the bog site KAM12-C1 (55 N, 156.5 E) is located on the western lowlands along the Sea of Okhotsk, and the rich fen site KAM12-C10 (55.5 N, 160 E) is found in the Central Kamchatka Depression (interior). Deep peat deposits characterize these two sites, with the bog site (450 cm) being shallower than the fen site (800 cm). Though radiocarbon ages are pending, preliminary chronologies constrained by tephra layers of known ages indicate that both sites started accumulating peaty deposits at least 9000 years ago. Bulk density measurements at 1-cm intervals along all both cores show very little variations, with a mean value of 0.1 g cm-3. Notable exceptions are the high density values (up to 0.2 g cm-3) recorded towards the top of the bog cores between 100 and 50 cm (around 1500 to 500 cal. BP). Organic matter content remains high (> 95%) throughout this period, indicating that the bulk density increase is not related to exogenous inorganic material deposits such as tephra or dust. Plant macrofossil analysis revealed that highly decomposed peat characterizes this time period, suggesting drier surface moisture conditions that resulted in intensified decomposition. The fen site similarly records increasing bulk density values from 200 to 100 cm. Our current chronologies do

  1. Estimating belowground carbon stocks in peatlands of the Ecuadorian páramo using ground-penetrating radar (GPR)

    Science.gov (United States)

    Xavier Comas; Neil Terry; John A. Hribljan; Erik A. Lilleskov; Esteban Suarez; Rodney A. Chimner; Randy K. Kolka

    2017-01-01

    The páramo ecoregion of Ecuador contains extensive peatlands that are known to contain carbon (C) dense soils capable of long-term C storage. Although high-altitude mountain peatlands are typically small when compared to low-altitude peatlands, they are abundant across the Andean landscape and are likely a key component in regional C cycling. Since efforts to quantify...

  2. 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.

  3. 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.

  4. The exposure of British peatlands to nitrogen deposition, 1900–2030

    Directory of Open Access Journals (Sweden)

    R.J. Payne

    2014-07-01

    Full Text Available Nitrogen (N pollution from industry and intensive agriculture is one of the greatest threats to ecosystems globally. Peatland ecosystems are particularly sensitive to atmospheric pollution and Great Britain has both extensive peatlands and high levels of nitrogen deposition. This study combines data from national pollutant deposition models, hind-casting factors and projections of future deposition with survey-based mire vegetation data to quantify the nitrogen deposition exposure of different vegetation communities and how this has changed over time. By sub-dividing a wide range of diverse peatland habitats the results give a more nuanced picture of N deposition to peatlands than has previously been possible. Grid cells containing mire vegetation receive an average of 14.1 kg N ha-1 yr-1 (decade to 2010 and have received an average cumulative deposition of 1312 kg N ha-1 since 1900. The lower limit of the critical load range is exceeded for 69.6 % of cells, but deposition levels and potential for consequent harm vary widely across Britain and between vegetation types. Nitrogen deposition to peatlands is currently falling and is projected to continue to fall until 2020 but with relatively little further change by 2030. N is likely to continue to accumulate in British peats for at least the first three decades of the 21st Century. It is clear that N deposition is currently a serious threat to British peatlands and is likely to remain so for some time to come.

  5. The compost bomb: thermal instability in peatland soils

    Science.gov (United States)

    Luke, C. M.; Cox, P. M.

    2009-04-01

    A simple model is constructed to investigate the effect of thermal energy generated by microbial respiration on soil temperature and soil carbon stocks, specifically in peat soils. Stability analysis shows a potential tipping point in the system beyond which a sudden large increase in soil temperature and decrease in soil carbon is predicted. Stability of the system depends on a dimensionless number, itself dependent on the effective soil thermal conductivity and the temperature sensitivity of microbial respiration. The influence of soil moisture on the effective thermal conductivity, and therefore the stability of the system, is also investigated. These results suggest that peatland soils insulated by a moss or lichen layer are potentially destabilised under certain conditions of warming and drying.

  6. Elemental distribution and pyrite occurrence in a freshwater peatland, Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Chaguegoff, C.; Goodarzi, F.; Fyfe, W.S. [University of Western Ontario, London, ON (Canada). Dept. of Earth Sciences

    1996-11-01

    A continental minerotrophic peatland in Alberta was studied for its botanical, petrographical, mineralogical and geochemical characteristics. Changes in peat stratigraphy and mineralogy are related, and development toward oligotrophic conditions is recorded. Elemental concentration and distribution vary in the peat profile, reflecting the influence of natural and anthropogenic factors on peat geochemistry. Many elements (Al, As, Ba, Co, Cr, Fe, Mn, Th, V) accumulate in the zone of water table fluctuation as a result of changes in redox chemistry. The relative elemental concentration at the surface and near-surface (e.g. As, Cr, Sb, Th, Ti, V) may also be attributed to atmospheric deposition related to anthropogenic activity. Chemical analysis (Al, Fe, Mg, Na, Si, Ti) also reveals the presence of a non-visible volcanic-ash rich layer near the base of the peat profile, possibly Mazama tephra. This study provides evidence of pyrite formation in a freshwater peat-forming environment, associated with high-sulphur peats.

  7. 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...... available in agriculture. Although the facts are well known, the policies leading to diminished emissions are often difficult to implement. We have analysed the reasons why the mitigation potential is not fully utilized and what could be done better in national implementation of climate policies. Four cases...... are used to illustrate the necessary steps to reach mitigation targets: determining the amount and properties of peat soils, estimating the potential, costs and feasibility of the mitigation measures, and selecting and implementing the best measures. A common feature for all of the cases was that national...

  8. A multi-scale evaluation of pack stock effects on subalpine meadow plant communities in the Sierra Nevada

    Science.gov (United States)

    Lee, Steven R.; Berlow, Eric L.; Ostoja, Steven M.; Brooks, Matthew L.; Génin, Alexandre; Matchett, John R.; Hart, Stephen C.

    2017-01-01

    We evaluated the influence of pack stock (i.e., horse and mule) use on meadow plant communities in Sequoia and Yosemite National Parks in the Sierra Nevada of California. Meadows were sampled to account for inherent variability across multiple scales by: 1) controlling for among-meadow variability by using remotely sensed hydro-climatic and geospatial data to pair stock use meadows with similar non-stock (reference) sites, 2) accounting for within-meadow variation in the local hydrology using in-situ soil moisture readings, and 3) incorporating variation in stock use intensity by sampling across the entire available gradient of pack stock use. Increased cover of bare ground was detected only within “dry” meadow areas at the two most heavily used pack stock meadows (maximum animals per night per hectare). There was no difference in plant community composition for any level of soil moisture or pack stock use. Increased local-scale spatial variability in plant community composition (species dispersion) was detected in “wet” meadow areas at the two most heavily used meadows. These results suggest that at the meadow scale, plant communities are generally resistant to the contemporary levels of recreational pack stock use. However, finer-scale within-meadow responses such as increased bare ground or spatial variability in the plant community can be a function of local-scale hydrological conditions. Wilderness managers can improve monitoring of disturbance in Sierra Nevada meadows by adopting multiple plant community indices while simultaneously considering local moisture regimes.

  9. Biophysical effects on the interannual variation in carbon dioxide exchange of an alpine meadow on the Tibetan Plateau

    Science.gov (United States)

    Wang, Lei; Liu, Huizhi; Sun, Jihua; Shao, Yaping

    2017-04-01

    Eddy covariance measurements from 2012 to 2015 were used to investigate the interannual variation in carbon dioxide exchange and its control over an alpine meadow on the south-east margin of the Tibetan Plateau. The annual net ecosystem exchange (NEE) in the 4 years from 2012 to 2015 was -114.2, -158.5, -159.9 and -212.6 g C m-2 yr-1, and generally decreased with the mean annual air temperature (MAT). An exception occurred in 2014, which had the highest MAT. This was attributed to higher ecosystem respiration (RE) and similar gross primary production (GPP) in 2014 because the GPP increased with the MAT, but became saturated due to the limit in photosynthetic capacity. In the spring (March to May) of 2012, low air temperature (Ta) and drought events delayed grass germination and reduced GPP. In the late wet season (September to October) of 2012 and 2013, the low Ta in September and its negative effects on vegetation growth caused earlier grass senescence and significantly lower GPP. This indicates that the seasonal pattern of Ta has a substantial effect on the annual total GPP, which is consistent with results obtained using the homogeneity-of-slopes (HOS) model. The model results showed that the climatic seasonal variation explained 48.6 % of the GPP variability, while the percentages explained by climatic interannual variation and the ecosystem functional change were 9.7 and 10.6 %, respectively.

  10. Carbon storage in the seagrass meadows of Gazi Bay, Kenya.

    Directory of Open Access Journals (Sweden)

    Michael N Githaiga

    Full Text Available Vegetated marine habitats are globally important carbon sinks, making a significant contribution towards mitigating climate change, and they provide a wide range of other ecosystem services. However, large gaps in knowledge remain, particularly for seagrass meadows in Africa. The present study estimated biomass and sediment organic carbon (Corg stocks of four dominant seagrass species in Gazi Bay, Kenya. It compared sediment Corg between seagrass areas in vegetated and un-vegetated 'controls', using the naturally patchy occurence of seagrass at this site to test the impacts of seagrass growth on sediment Corg. It also explored relationships between the sediment and above-ground Corg, as well as between the total biomass and above-ground parameters. Sediment Corg was significantly different between species, range: 160.7-233.8 Mg C ha-1 (compared to the global range of 115.3 to 829.2 Mg C ha-1. Vegetated areas in all species had significantly higher sediment Corg compared with un-vegetated controls; the presence of seagrass increased Corg by 4-6 times. Biomass carbon differed significantly between species with means ranging between 4.8-7.1 Mg C ha-1 compared to the global range of 2.5-7.3 Mg C ha-1. To our knowledge, these are among the first results on seagrass sediment Corg to be reported from African seagrass beds; and contribute towards our understanding of the role of seagrass in global carbon dynamics.

  11. Patterns and drivers of scattered tree loss in agricultural landscapes: orchard meadows in Germany (1968-2009.

    Directory of Open Access Journals (Sweden)

    Tobias Plieninger

    Full Text Available Scattered trees support high levels of farmland biodiversity and ecosystem services in agricultural landscapes, but they are threatened by agricultural intensification, urbanization, and land abandonment. This study aimed to map and quantify the decline of orchard meadows (scattered fruit trees of high nature conservation value for a region in Southwestern Germany for the 1968 2009 period and to identify the driving forces of this decline. We derived orchard meadow loss from 1968 and 2009 aerial images and used a boosted regression trees modelling framework to assess the relative importance of 18 environmental, demographic, and socio-economic variables to test five alternative hypothesis explaining orchard meadow loss. We found that orchard meadow loss occurred in flatter areas, in areas where smaller plot sizes and fragmented orchard meadows prevailed, and in areas near settlements and infrastructure. The analysis did not confirm that orchard meadow loss was higher in areas where agricultural intensification was stronger and in areas of lower implementation levels of conservation policies. Our results demonstrated that the influential drivers of orchard meadow loss were those that reduce economic profitability and increase opportunity costs for orchards, providing incentives for converting orchard meadows to other, more profitable land uses. These insights could be taken up by local- and regional-level conservation policies to identify the sites of persistent orchard meadows in agricultural landscapes that would be prioritized in conservation efforts.

  12. Patterns and Drivers of Scattered Tree Loss in Agricultural Landscapes: Orchard Meadows in Germany (1968-2009)

    Science.gov (United States)

    Plieninger, Tobias; Levers, Christian; Mantel, Martin; Costa, Augusta; Schaich, Harald; Kuemmerle, Tobias

    2015-01-01

    Scattered trees support high levels of farmland biodiversity and ecosystem services in agricultural landscapes, but they are threatened by agricultural intensification, urbanization, and land abandonment. This study aimed to map and quantify the decline of orchard meadows (scattered fruit trees of high nature conservation value) for a region in Southwestern Germany for the 1968 2009 period and to identify the driving forces of this decline. We derived orchard meadow loss from 1968 and 2009 aerial images and used a boosted regression trees modelling framework to assess the relative importance of 18 environmental, demographic, and socio-economic variables to test five alternative hypothesis explaining orchard meadow loss. We found that orchard meadow loss occurred in flatter areas, in areas where smaller plot sizes and fragmented orchard meadows prevailed, and in areas near settlements and infrastructure. The analysis did not confirm that orchard meadow loss was higher in areas where agricultural intensification was stronger and in areas of lower implementation levels of conservation policies. Our results demonstrated that the influential drivers of orchard meadow loss were those that reduce economic profitability and increase opportunity costs for orchards, providing incentives for converting orchard meadows to other, more profitable land uses. These insights could be taken up by local- and regional-level conservation policies to identify the sites of persistent orchard meadows in agricultural landscapes that would be prioritized in conservation efforts. PMID:25932914

  13. THE FERTILIZATION EFFECT OF PERMANENT MEADOWS WITH SPENT MUSHROM SUBSTRATE ON THE UPTAKING OF MANGANESE, COPPER AND ZINC BY THE MEADOW SWARD

    Directory of Open Access Journals (Sweden)

    Beata Wiśniewska-Kadżajan

    2013-04-01

    Full Text Available The study was conducted in the years 1999–2001 in a meadow with the following fertilizer combinations: control object (without fertilizer, NPK mineral fertilization, fertilizing with manure, manure with NPK fertilization, fertilizing with spent mushroom substrate; spent mushroom substrate with NPK fertilization. The aim of the study was to determine the effect of permanent grassland fertilization both with spent mushroom substrate and the one supplemented with NPK on the uptaking of manganese, copper and zinc by the meadow sward. After the cultivation of mushrooms, in comparison to the standard manure, the substrate used in the experiment was characterized by more than twice higher amount of manganese and zinc. However, the amount of copper in the organic materials was similar. In spite of having supplied lager amount of manganese, zinc and similar amount of copper to the mushrooms substrate, it caused the reduction of the uptake of the elements in the meadow sward. In spite of supplying larger amounts of manganese, zinc and copper the reduction of their uptaking by meadow sward was observed in comparison to manure mushroom substrate. This may be connected with a slightly alkaline reaction of the soil environment, thus limiting the uptake of the studied micronutrients.

  14. Towards better understanding of the response of Sphagnum peatland to increased temperature and reduced precipitation in Central Europe

    Science.gov (United States)

    Juszczak, Radoslaw; Basińska, Anna; Chojnicki, Bogdan; Gąbka, Maciej; Hoffmann, Mathias; Józefczyk, Damian; Lamentowicz, Mariusz; Leśny, Jacek; Łuców, Dominika; Moni, Christophe; Reczuga, Monika; Samson, Mateusz; Silvennoinen, Hanna; Stróżecki, Marcin; Urbaniak, Marek; Zielińska, Małgorzata; Olejnik, Janusz

    2017-04-01

    With respect to climate change peatlands are highly vulnerable ecosystems. Especially a potential drying in future might result in a major carbon source and release to the atmosphere. We carried out a field climate manipulation experiment at Rzecin peatland in western Poland to assess how increased temperature and reduced precipitation may impact carbon balance, vegetation, microbes and water chemistry of the Sphagnum peatland. Here, we present results of measurements conducted in two contrasting years (417 mm and 678 mm of precipitation in very dry 2015 and wet 2016, respectively). The experimental design consists of four treatments, each one replicated three times (control, CO; simulated warming, W; prolonged drought, D and warming & drought, W+D). Increased temperatures (T) during the year were achieved by infrared heaters (400W × 4 per site, approx. 60 Wṡm-2 addition of LW radiation). Precipitation was reduced using an automatic curtain, covering the site during nighttime hours of the growth seasons. The manipulation experiment was successful during both years, increasing the air (30 cm height) and soil temperature (5 cm depth, sites W and D) by up to 0.2 oC and 1.0 oC, respectively. Precipitation was reduced to 37 % during both years. At W+D site the peat temperature was nearly two times higher than on W site indicating the impact of drought on T increase. To study the C exchange we developed an automatic mobile platform for measuring CO2/CH4/H2O fluxes (LGR) as well as 13CO2 and 13CH4 fluxes (PICARRO CRDS G2201-i). Measurements were performed, using dynamic ecosystem chambers (for NEE and Reco) and combined with simultaneous measurements of surface spectral properties. Flux calculation and gap filling was done according to Hoffmann et al. 2015. Methane emissions were significantly higher on manipulated plots than on CO (25 gCṡm-2yr-1) during both years, but only in the very dry 2015, CH4 fluxes were the highest on W+D site (33 gC gCṡm-2yr-1). Besides

  15. Peatlands and the carbon cycle: from local processes to global implications – a synthesis

    Directory of Open Access Journals (Sweden)

    J. Limpens

    2008-10-01

    Full Text Available Peatlands cover only 3% of the Earth's land surface but boreal and subarctic peatlands store about 15–30% of the world's soil carbon (C as peat. Despite their potential for large positive feedbacks to the climate system through sequestration and emission of greenhouse gases, peatlands are not explicitly included in global climate models and therefore in predictions of future climate change. In April 2007 a symposium was held in Wageningen, the Netherlands, to advance our understanding of peatland C cycling. This paper synthesizes the main findings of the symposium, focusing on (i small-scale processes, (ii C fluxes at the landscape scale, and (iii peatlands in the context of climate change.

    The main drivers controlling C fluxes are largely scale dependent and most are related to some aspects of hydrology. Despite high spatial and annual variability in Net Ecosystem Exchange (NEE, the differences in cumulative annual NEE are more a function of broad scale geographic location and physical setting than internal factors, suggesting the existence of strong feedbacks. In contrast, trace gas emissions seem mainly controlled by local factors.

    Key uncertainties remain concerning the existence of perturbation thresholds, the relative strengths of the CO2 and CH4 feedback, the links among peatland surface climate, hydrology, ecosystem structure and function, and trace gas biogeochemistry as well as the similarity of process rates across peatland types and climatic zones. Progress on these research areas can only be realized by stronger co-operation between disciplines that address different spatial and temporal scales.

  16. Blanket peatland restoration leads to reduced storm runoff from headwater systems

    Science.gov (United States)

    Shuttleworth, Emma; Allott, Tim; Evans, Martin; Pilkington, Mike

    2016-04-01

    This paper presents data on the impact of largescale peatland restoration on catchment runoff from peatlands in northern England. The blanket peatlands of the Pennine hills are important sources of water supply and form the headwaters of major river systems. These peatlands are severely eroded with extensive gullying and bare peat resulting from the impacts of industrial pollution, overgrazing, wildfire and climatic change over the last millennium. In the last decade there has been a major programme of peatland restoration through re-vegetation and blocking of drainage lines in these systems. The Making Space for Water project has collected hydrological data from five micro-catchments(two restoration treatments, a bare peat control, a vegetated control and a previously restored site) over a four year period. This has allowed for both Before-After-Control-Intervention and Space for Time analysis of the impact of restoration on downstream runoff. Catchments became wetter following re-vegetation, water tables rose by 35 mm and overland flow production increased by 18%. Storm-flow lag times in restored catchments increased by up to 267 %, while peak storm discharge decreased by up to 37%. There were no statistically significant changes in percentage runoff, indicating limited changes to within-storm catchment storage. Natural flood management solutions are typically focussed around one of two main mechanisms, either enhanced storage of water in catchments or measures which slow transmission of water to channels and within channels. Upland peatlands are often mischaracterised as sponges and assumed to mitigate downstream runoff through additional storage. The results of this study suggest that whilst restoration of upland peatlands can lead to significant reductions in peak discharge, and has potential to contribute to natural flood risk management, the mechanism is an increase in catchment roughness and an associated decrease in flow velocities.

  17. Hydrological controls on dissolved organic carbon exports from a - French Pyrenean - mountainous peatland

    Science.gov (United States)

    Rosset, Thomas; Gandois, Laure; Antoine, Jean-Marc; Teisserenc, Roman; Binet, Stéphane

    2017-04-01

    At the catchment scale, peatlands disproportionally contribute to dissolved organic carbon (DOC) exports to surface waters. Rare attempts have been made to quantify and characterize these exports from mountainous peatlands where topography induce intense climatic events. The specific DOC contribution from the peatland has been tracked using fDOM (fluorescence of dissolved organic matter) sensors deployed both upstream and downstream of a mountainous (1340m) peatland in the Pyrenees. These high frequency (30 min) measurements have been coupled with water level, discharge and meteorological survey in order to identify controlling factors on DOC concentrations and fluxes. This study highlights strong hydrological controls on DOC concentrations and fluxes at the outlet of the peatland, especially during short and intense events of flood. Mass flux ranges are highly variable, averaged at 52g.h-1 for low flows periods and reaching 3.5kg.h-1 during extreme hydrological events. From September 2014 to March 2015, 75% of the DOC mass flux transited during 39 different flood events which represent 40% of the timescale. Water table levels fluctuates in the [0, - 45] cm range. During the high flow events, the highest DOC concentrations are associated with a narrow range of water table levels [-9, -15] cm. The relations between runoff and concentration during flood events showed two hysteretic behaviours: counter clockwise for floods with a maximum runoff inferior to 30 L.s-1 clockwise for events with a superior runoff, (DOC maximum concentration seems to be diluted by overflow from the upstream watershed). When considering the topographical watershed, a specific flux of 0.76 g C .m-2.yr-1 can be estimated. When reported to the peatland area, it reaches 32.3 g C .m-2.yr-1. During hot moments of short and intense floods, peatlands constitute hot spots of DOC exports to the surface waters in this mountainous watershed.

  18. Wetting of Water on Graphene

    KAUST Repository

    Bera, Bijoyendra

    2016-11-28

    The wetting properties of graphene have proven controversial and difficult to assess. The presence of a graphene layer on top of a substrate does not significantly change the wetting properties of the solid substrate, suggesting that a single graphene layer does not affect the adhesion between the wetting phase and the substrate. However, wetting experiments of water on graphene show contact angles that imply a large amount of adhesion. Here, we investigate the wetting of graphene by measuring the mass of water vapor adsorbing to graphene flakes of different thickness at different relative humidities. Our experiments unambiguously show that the thinnest of graphene flakes do not adsorb water, from which it follows that the contact angle of water on these flakes is ~180o. Thicker flakes of graphene nanopowder, on the other hand, do adsorb water. A calculation of the van der Waals (vdW) interactions that dominate the adsorption in this system confirms that the adhesive interactions between a single atomic layer of graphene and water are so weak that graphene is superhydrophobic. The observations are confirmed in an independent experiment on graphene-coated water droplets that shows that it is impossible to make liquid \\'marbles\\' with molecularly thin graphene.

  19. Surface structure determines dynamic wetting

    Science.gov (United States)

    Shiomi, Junichiro; Wang, Jiayu; Do-Quang, Minh; Cannon, James; Yue, Feng; Suzuki, Yuji; Amberg, Gustav

    2014-11-01

    Dynamic wetting, the spontaneous spreading process after droplet contacts a solid surface, is important in various engineering processes, such as in printing, coating, and lubrication. In the recent years, experiments and numerical simulations have greatly progressed the understanding in the dynamic wetting particularly on ``flat'' substrates. To gain further insight into the governing physics of the dynamic wetting, we perform droplet-wetting experiments on microstructured surfaces, just a few micrometers in size, with complementary numerical simulations, and investigate the dependence of the spreading rate on the microstructure geometries and fluid properties. We reveal that the influence of microstructures can be quantified in terms of a line friction coefficient for the energy dissipation rate at the contact line, and that this can be described in a simple formula in terms of the geometrical parameters of the roughness and the line-friction coefficient of the planar surface. The systematic study is also of practical importance since structures and roughness are omnipresent and their influence on spreading rate would give us additional degrees of freedom to control the dynamic wetting. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W., J.C., and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A.).

  20. Modeling Alpine Meadow Restoration Techniques and their Effects on Stream Stage Regimes

    Science.gov (United States)

    Moore, C. E.; Lundquist, J. D.; Loheide, S. P.

    2010-12-01

    Meadow ecosystems in the Sierra Nevada of California often suffer from negative anthropogenic impacts, resulting in stream incision and meadow aridification. Groundwater dependent ecosystems, such as meadows, are especially vulnerable to channel degradation because alteration of stream stage propagates through the groundwater system to affect riparian vegetation. Restoration aimed at raising water table elevation of degraded meadow systems is becoming a salient and viable option as managers recognize the importance of intact headwaters. Stream stage controls groundwater levels and thus, vegetation communities, more dramatically than stream discharge in groundwater dependent ecosystems. Here we use a one dimensional hydraulic model, Hydraulic Engineering Center - River Analysis System (HEC-RAS) to model stream stage along the Tuolumne River, given a time series of stream discharge. Extensive hydroclimatic monitoring since 2001, and groundwater monitoring since 2006, make Tuolumne Meadows, in Yosemite National Park, California a prime location for a validated case study, applicable to other snow dominated basins. In order to determine the most plausible, efficient and effective strategy of restoring impacted meadows, different management scenarios are modeled. HEC-RAS modeling provides critical stream stage boundary conditions for groundwater modeling. Scenarios are chosen that are most effective at increasing stream stage and therefore water table levels. The effectiveness is quantified by modeling how each scenario changes the rating curve for a particular channel. Additionally, surface stage modeling allows decision makers to see under what flow conditions and what time period of the hydrograph is affected by restoration. Quantification of stream stage alterations is key for understanding restoration impacts during the short growing season in alpine meadows. Results of HEC-RAS modeling at Tuolumne Meadows are presented in the following formats to highlight the

  1. The estimation of some wild flowers seed material from the natural-valuable meadow habitats

    Directory of Open Access Journals (Sweden)

    Janicka Maria

    2016-12-01

    Full Text Available The restoration of the species composition of the meadow habitats is often linked to the introduction of the typical species’ seeds. The effectiveness of that treatment requires getting the acquired detailed knowledge of the germination biology of peculiar species. Eight typical plant species of four non-forest habitats of the river valleys, representing the following types: Cnidion dubii (6440, Molinion (6410, Arrhenatherion (6510 and Festuco-Brometea (6210 were investigated. The diasporas were collected in the years 2014–2015 on the meadows of PLH 140016 protection area near Mniszew (Kozienice county, Mazovian voivodeship. The ability of seeds’ germination in the laboratory conditions was studied. It was stated that Cnidion and Molinion meadows’ species require pre-chilling to break the seeds’ dormancy, while the Arrhenatherion meadows and xerotermophilous swards do not require such treatment. The Allium angulosum, Plantago lanceolata, Achillea millefolium and Eryngium planum were characterized by high vigour and germination capability as well as the low share of dead seeds. The extremely drought in 2015 caused the decreasing in germination capability and increasing in the dead seeds’ share. The preliminary studies, presented in this paper, show that Cnidion and Molinion meadows may be most difficult to restore because of the necessity of breaking the seeds’ dormancy and higher sensitiveness for the unfavourable weather conditions during the seed ripening stage. The studies have practical significance for the works connected with the floristic diversity’ increasing of threatened communities and the restoration of the destroyed meadow habitats.

  2. Dynamic of Posidonia oceanica seagrass meadows in the northwestern Mediterranean: Could climate change be to blame?

    Science.gov (United States)

    Pergent, Gérard; Pergent-Martini, Christine; Bein, Aymeric; Dedeken, Marine; Oberti, Pascal; Orsini, Antoine; Santucci, Jean-François; Short, Frederic

    2015-07-01

    The distribution and the vitality of the P. oceanica meadow were monitored in the western Mediterranean at 15 sites along the coasts of Corsica (1000 km of coastline) using two monitoring systems, the Posidonia Monitoring Network and SeagrassNet, between 2004 and 2013. While the vitality of the meadow is satisfactory overall, due to the low impact of human pressure along these coasts, patterns of change over time show a slight degradation of the main descriptors of the meadow. The meadow's vitality index had declined on average by 8.6%, the BiPo index by 9.8%, and there was a regression of the lower limit at six sites. While this pattern of change may reflect local alterations in the environment (increase or decline in human pressure), the regressive dynamic of the meadow observed at the lower limit at several reference sites (e.g., Marine Protected Areas, sites distant from sources of human impact) is more worrying. Two hypotheses might explain the regression observed: (i) the rise in mean sea level during the study period, which may have resulted in a significant regression in sectors where the slope is relatively slight, and (ii) the North Atlantic Oscillation (NAO), which declined from 2002 to reach very low values in 2010. Copyright © 2015 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  3. Nematodes as indicators of environmental quality in seagrass (Posidonia oceanica meadows of the NW Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Valentina Losi

    2012-01-01

    Full Text Available Meiofauna in sediments colonized by Posidonia oceanica in the Ligurian Sea (NW Mediterranean was investigated to evaluate its use as an early warning indicator of environmental disturbance. Descriptors commonly used in seagrass health assessment are mainly related to the plant (e.g., phenological parameters and/or to the meadow (e.g., structural parameters and are subjected to long-term response times. Conversely, meiofauna is considered a good bioindicator with a rapid response to environmental variations, due to its main features (e.g., short life cycle, scarce mobility, presence/absence of tolerant/sensitive species. Meiofaunal community, sediment characteristics and organic matter descriptors in three meadows located in urbanized coastal areas were contrasted with those observed in three meadows located within Marine Protected Areas. Samplings were carried out in two distinct periods, at the beginning and at the end of the summer season, in order to individuate early changes in the meiofaunal assemblages. The meiofauna and, particularly, the nematode assemblage composition and diversity, highlighted differences among meadows at the end of the summer not detectable by organic matter descriptors and structural parameters of the meadow (e.g. shoot density. Nematodes are, thus, proposed as appropriate biological quality elements (BQEs able to show early responses to environmental disturbance.

  4. Stability and resilience of seagrass meadows to seasonal and interannual dynamics and environmental stress

    Science.gov (United States)

    Carr, Joel A.; D'Odorico, Paolo; McGlathery, Karen J.; Wiberg, Patricia L.

    2012-03-01

    Shallow coastal bays provide habitat for diverse fish and invertebrate populations and are an important source of sediment for surrounding marshes. The sediment dynamics of these bays are strongly affected by seagrass meadows, which limit sediment resuspension, thereby providing a more favorable light environment for their own survival and growth. Due to this positive feedback between seagrass and light conditions, it has been suggested that bare sediment and seagrass meadows are potential alternate stable states of the benthos in shallow coastal bays. To investigate the stability and resilience of seagrass meadows subjected to variation in environmental conditions (e.g., light, temperature), a coupled model of vegetation-sediment-water flow interactions and vegetation growth was developed. The model was used to examine the effect of dynamically varying seasonal and interannual seagrass density on sediment resuspension, water column turbidity, and the subsequent light environment on hourly time steps and then run over decadal time scales. A daily growth model was designed to capture both belowground biomass and the growth and senescence of aboveground biomass structural components (e.g., leaves and stems). This allowed us to investigate how the annual and seasonal variability in shoot and leaf density within a meadow affects the strength of positive feedbacks between seagrass and their light environment. The model demonstrates both the emergence of bistable behavior from 1.6 to 1.8 m mean sea level due to the strength of the positive feedback, as well as the limited resilience of seagrass meadows within this bistable range.

  5. Carbon monoxide exchange and partitioning of a managed mountain meadow

    Science.gov (United States)

    Hammerle, Albin; Kitz, Florian; Spielmann, Felix; Gerdel, Katharina; Wohlfahrt, Georg

    2016-04-01

    With an average mole fraction of 100 ppb carbon monoxide (CO) plays a critical role in atmospheric chemistry and thus has an indirect global warming potential. While sources/sinks of CO on land at least partially cancel out each other, the magnitude of CO sources and sinks is highly uncertain. Even if direct CO fluxes from/to land ecosystems are very much likely clearly lower in magnitude compared to anthropogenic emissions, biomass burning, emissions from chemical precursors and the OH sink, it may be premature to neglect any direct contributions of land ecosystems to the CO budget. In addition, changes in global climate and resulting changes in global productivity may require re-evaluating older data and assumptions. One major reason for the large uncertainty is a general scarcity of empirical data. An additional factor contributing to the uncertainty is the lack of ecosystem-scale CO exchange measurements, i.e. CO flux data that encompass all sources and sinks within an ecosystem. Here we present data on continuous eddy covariance measurements of CO-fluxes above a managed mountain grassland in combination with soil chamber flux measurements, within- and above-canopy concentration profiles and an inverse Lagrangian analysis to disentangle sinks and sources of CO. Results show the grassland ecosystem to be a net source for CO during daytime, with increasing flux rates at higher solar radiation. At night, if at all, the meadow is a slight sink for CO. The same holds true regarding the soil flux measurements. Additionally, a two-month rainout experiment revealed hardly any differences in CO soil fluxes between rainout- and control-plots unless extremely dry conditions were reached.

  6. Source and age of carbon in peatland surface waters: new insights from 14C analysis

    Science.gov (United States)

    Billett, Michael; Garnett, Mark; Dinsmore, Kerry; Leith, Fraser

    2013-04-01

    Peatlands are a significant source of carbon to the aquatic environment which is increasingly being recognised as an important flux pathway (both lateral and vertical) in total landscape carbon budgets. Determining the source and age of the carbon (in its various forms) is a key step to understanding the stability of peatland systems as well as the connectivity between the soil carbon pool and the freshwater environment. Novel analytical and sampling methods using molecular sieves have been developed for (1) within-stream, in situ sampling of CO2 in the field and (2) for the removal/separation of CO2 in the laboratory prior to 14C analysis of CH4. Here we present dual isotope (δ13C and 14C) data from freshwater systems in UK and Finnish peatlands to show that significant differences exist in the source and age of CO2, DOC (dissolved organic carbon) and POC (particulate organic carbon). Individual peatlands clearly differ in terms of their isotopic freshwater signature, suggesting that carbon cycling may be "tighter" in some systems compared to others. We have also measured the isotopic signature of different C species in peatland pipes, which appear to be able to tap carbon from different peat depths. This suggests that carbon cycling and transport within "piped-peatlands" may be more complex than previously thought. Some of our most recent work has focussed on the development of a method to measure the 14C component of CH4 in freshwaters. Initial results suggest that CH4 in peatland streams is significantly older than CO2 and derived from a much deeper source. We have also shown that the age (but not the source) of dissolved CO2 changes over the hydrological year in response to seasonal changes in discharge and temperature. Radiocarbon measurements in the peat-riparian-stream system suggest that a significant degree of connectivity exists in terms of C transport and cycling, although the degree of connectivity differs for individual C species. In summary, 14C

  7. Carbon Sequestration and Peat Accretion Processes in Peatland Systems: A North-South Comparison

    Science.gov (United States)

    Richardson, C. J.; Wang, H.; Bridgham, S. D.

    2012-12-01

    Millions of hectares of peatlands exist in the U.S. and Canada but few comparisons have been made on the process controlling peat accretion, carbon sequestration and GHG losses across latitudinal gradients. Historic threats to carbon sequestration for these areas have been drainage and conversion to agriculture and forestry, which promotes the decomposition of the organic matter in the soil, leading to accelerated soil subsidence, severe carbon losses, and accelerated transport of C and nutrients to adjoining ecosystems. A more recent and insidious threat to the survival of peatlands worldwide is the increased temperature and drought conditions projected for many areas of global peatlands (IPCC 2007). A comparison of carbon sequestration rates and controlling processes for southeastern shrub bogs, the Florida Everglades and selected peatlands of the northern US and Canada under current climatic conditions reveals several major differences in controlling factors and rates of sequestration and carbon flux. Numerous studies have shown that drought or drainage can unlock historically stored carbon, thus releasing more CO2 ¬ and dissolved organic carbon (Blodau et al. 2004; Furukawa et al. 2005; Von Arnold et al. 2005; Hirano et al. 2007), and such effects might last for decades (Fenner & Freeman 2011). The main driver of this process is the O2 introduced by drought or drainage, which will increase the activity of phenol oxidase, then accelerate the decomposition of phenol compounds, which is generally considered the "enzymatic latch" for carbon storage in peatlands (Freeman et al. 2001). However, our recent studies in southeastern peatlands along the coast of North Carolina have found that drought or drainage does not affect CO2 emission in some southern peatlands where the initial water level is below the ground surface (unsaturated peats), as polyphenol increases rather than decreases. Our results suggest that additional controlling factors, rather than anoxia exist

  8. Hot spots of mercury methylation in northern peatlands : spatial and seasonal variability

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.P.J.; Branfireun, B.A. [Toronto Univ., ON (Canada). Dept. of Geography; Heyes, A. [Maryland Univ., Solomons, MD (United States). Center for Environmental Science, Chesapeake Biological Lab; Kolka, R.K. [USDA Forest Service, North Central Research Station, Grand Rapids, MN (United States)

    2006-07-01

    Studies have shown that peatlands are an important sources of methylmercury (MeHg) to downstream aquatic ecosystems at the watershed scale. Hot spots of overly high MeHg concentration have been found to occur periodically in zones of groundwater upwelling. However, the spatiotemporal distribution, size, and importance of these MeHg hot spots to peatland MeHg export are not currently understood. For that reason, peat pore waters were sampled extensively throughout 4 small, northern peatlands in order to assess the spatial patterns of total mercury (HgT) and MeHg. The transferability of findings among peatlands was also assessed. Sampling took place during the spring, mid-summer and fall of 2005 at 2 peatlands in north central Minnesota and 2 in northwestern Ontario. In addition to this spatial survey, 4 high-resolution sampling grids were also established at the Minnesota sites in order to investigate the size of hot spots and the effects of upland runoff. In all cases, spatial variability in pore water MeHg concentration was much higher than the variability in HgT concentration, with standard deviations typically exceeding mean values. The spatial pattern of pore water MeHg concentration was characterized into the following 2 distinct zones: (1) the upland-peatland interface, where MeHg concentrations higher than 2 ng/L occur consistently, (2) the peatland interior, where concentrations rarely exceed 0.5 ng/L. In addition, extremely high concentrations of up to 12 ng/L were only found at the upland-peatland interface. These values corresponded to MeHg:HgT ratios greater than 65 per cent, while these ratios rarely exceeded 5 to 10 per cent elsewhere. It was concluded that these hot spots can be attributed to the limited reactants in zones where the in-situ biogeochemical milieu is conducive to mercury methylation. The uniform patterns noted across the peatlands indicate that spatial patterns of HgT and MeHg are important for mechanistic modelling and landscape

  9. 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...

  10. 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

  11. An appraisal of Indonesia's immense peat carbon stock using national peatland maps: uncertainties and potential losses from conversion

    Science.gov (United States)

    Matthew Warren; Kristell Hergoualc' h; J. Boone Kauffman; Daniel Murdiyarso; Randall Kolka

    2017-01-01

    Background: 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...

  12. Natural zinc enrichment in peatlands: Biogeochemistry of ZnS formation

    Science.gov (United States)

    Yoon, Soh-joung; Yáñez, Carolina; Bruns, Mary Ann; Martínez-Villegas, Nadia; Martínez, Carmen Enid

    2012-05-01

    Peatlands effectively retain heavy metals and prevent stream and watershed contamination. Sulfate reduction is considered the most significant process of metal immobilization in natural wetlands and microbial sulfate reduction is the presumed mechanism that results in the precipitation of metal sulfides. In this study, we examined the biogeochemical mechanisms involved in zinc retention and accumulation in a metalliferous peatland of western New York. In the reducing conditions of these peatlands zinc sulfides occurred as framboidal aggregates of sphalerite and polytypic wurtzite (2nH, n ⩾ 2) nanocrystallites associated with bacterial cells and organic matter. Bacterial cells were co-located with ZnS inside peat particles where the microenvironment remained anoxic. The peat zinc sulfide was depleted in 34S isotopes relative to the sulfate supplied to the peatland by 18-34 per mill, implicating its biological formation. Extraction of microbial community DNA from peat samples yielded diverse PCR amplicons from dissimilatory sulfite reductase (dsrAB) genes, indicating varied bacterial taxa capable of reducing forms of oxidized sulfur. Nanocrystals with distinct structural features were observed in samples containing contrasting dsrAB sequences. The results of this investigation provide clear evidence that microorganisms can influence the chemical forms of heavy metals in peatland environments. Our findings also provide insight into the conditions necessary to promote the immobilization of chalcophile elements in engineered systems for the treatment of acid mine drainage and wastewater effluents.

  13. Representing Northern Peatland Hydrology and Biogeochemistry within the Community Land Model

    Science.gov (United States)

    Shi, X.; Ricciuto, D. M.; Xu, X.; Thornton, P. E.; Hanson, P. J.; Mao, J.; Sebestyen, S.; Griffiths, N.

    2015-12-01

    Northern peatlands are projected to become very important in future carbon-climate feedback due to their large carbon storage and vulnerability to changes in hydrology and climate impacts. Understanding the hydrology and biogeochemistry is a fundamental task for projecting the fate of massive carbon stores in these systems under future climate change. Models have started to address microtopographic controls on peatland hydrology, but none have considered a prognostic calculation of water table dynamics in vegetated peatlands rather than prescribed regional water tables. We introduced here a new configuration of the Community Land Model (CLM), which includes a fully prognostic water table calculation between hummock and hollow microtopography in a vegetated peatland. We further integrated the hydrology treatment with vertically structured soil organic matter pools, and a newly developed microbial functional group-based methane module. The model was further used to test against observational data obtained within Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) project. Results for water table dynamic, carbon profile, and land surface fluxes of carbon dioxide and methane were reasonable. Model simulations showed that warming and elevated CO2 had significant impacts on land surface fluxes of methane and carbon dioxide. The warming-induced hydrological changes are another factors influencing biogeochemistry along soil profiles and land surface gas fluxes. These preliminary results provide some insights for field experiments as well as data-model comparison in next phase of the SPRUCE project.

  14. 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.

  15. Tracking Holocene Methane Release from Alaskan Peatlands using H and C isotope ratios of Biomarkers

    Science.gov (United States)

    Nichols, J. E.; Pavia, F. J.; Peteet, D. M.

    2012-12-01

    We track the carbon and hydrological cycles through the Holocene at each of six locations spanning nearly 12 degrees of latitude in the Alaskan Arctic and Subarctic. Both hydroclimate and vegetation assemblage have a strong influence on the amount of carbon stored in peatlands as well as the amount of methane released. To reconstruct the hydrologic balance of peatlands, we use hydrogen isotope ratios of leaf wax biomarkers extracted from peat. To estimate methane release from peatlands, we use our newly developed method which combines measurements of hydrogen and carbon isotope ratios of leaf wax n-alkanes from Sphangum and vascular plant species. We reconstruct plant assemblages using a combination of macrofossil counts and biomarker distributions. Times of increased evaporative water loss from peatlands, correspond with a takeover of the peatlands by sedges, a decrease in carbon sequestration and incease in methane release. Throughout the Holocene, we find concurrent shifts in the paleohydrology, paleoecology and paleocarbon cycles, indicating that these shifts may be driven by changing climate rather than autogenic processes.

  16. 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.

  17. 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.)

  18. Geophysical Evidence for Abiotic Controls on Peatland Patterning at Multiple Scales

    Science.gov (United States)

    Nolan, J.; Slater, L.; Glaser, P.; Comas, X.; O'Brien, M.

    2007-12-01

    The autogenic and allogenic controls on the formation of distinctive and dramatic vegetation patterning found in northern peatlands remain unclear. Groundwater model studies and investigations using point measurements lack intensive data over multiple scales, primarily due to the intensive time required and difficult logistics required to work in these remote ecosystems. We provide geophysical evidence that lithological controls on vegetation patterning exist at multiple scales in ombrotrophic peatlands of northern Minnesota and Maine. Surveys using electrical imaging methods (including resistivity, induced polarization, and ground penetrating radar) at sites in the Red Lake Peatland Complex (160 km2), as well as Kanokolus Bog (1.65 km2) and the Caribou Bog Peatland Complex (22 km2) in Maine reveal sharp vegetation gradients coinciding with changes in the mineral soil lithology. In contrast, large-scale, continuous, patterned zones found in the Red lake Complex coincide with strikingly uniform mineral soil lithology as inferred from the geophysical images. Small-scale (0.3 km2) vegetation patterns observed in Caribou Bog also coincide with small scale lithologic changes in both the mineral and organic deposits. These results provide evidence that the subsurface hydrogeologic framework regulates vegetation patterning in peatlands across multiple scales, presumably by regulating (1) the supply of mineral solutes to the surface vegetation water, and (2) water levels within the organic soil.

  19. 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.

  20. Spatial patterns of denitrification and its functional genes in peatlands

    Science.gov (United States)

    Mander, Ülo; Ligi, Teele; Truu, Marika; Truu, Jaak; Pärn, Jaan; Egorov, Sergey; Järveoja, Järvi; Vohla, Christina; Maddison, Martin; Soosaar, Kaido; Oopkaup, Kristjan; Teemusk, Alar; Preem, Jens-Konrad; Uuemaa, Evelyn

    2014-05-01

    This study is aimed to analyse relationships between the environmental factors and the spatial distribution of the main functional genes nirS, nirK, and nosZ regulating the denitrification process. Variations in hydrological regime, soil temperature and peat quality have been taken into the consideration at both local and global scale. Measurements of greenhouse gas (GHG) emissions using static chambers, groundwater analysis, gas and peat sampling for further laboratory analysis has been conducted in various peatlands in Iceland (two study areas, 2011), Transylvania/Romania (2012), Santa Catarina/Brazil (2012), Quebec/Canada (2012), Bashkortostan/Russian Federation (two study areas, 2012), Sichuan/China (2012), Estonia (two study areas, 2012), Florida/USA (2013, Sologne/France (2013), Jugra in West Siberia/Russia (2013), Uganda (2013), French Guyana (two study areas, 2013), Tasmania (two study areas, 2014) and New Zealand (two study areas, 2014). In each study area at least 2 transects along the groundwater depth gradient, one preferably in undisturbed, another one in drained area, and at least 3 rows of sampling sites (3-5 replicate chambers and 1 piezometer and soil sampling plot in each) in both has been established for studies. In each transect GHG emission was measured during 2-3 days in at least 5 sessions. In addition, organic sediments from the artificial riverine wetlands in Ohio/USA in 2009 and relevant gas emission studies have been used in the analyses. In the laboratories of Estonian University of Life Sciences and the University of Tartu, the peat chemical quality (pH, N, P, C, NH4, NO3) and N2O, CO2, and CH4 concentration in gas samples (50mL glass bottles and exetainers) were analysed. The peat samples for further pyrosequencing and qPCR analyses are stored in fridge by -22oC. This presentation will consider the variation of GHG emissions and hydrological conditions in the study sites. In addition, several selected biophysical factors will be taken

  1. Microbial responses to experimental warming in a peatland forest ecosystem

    Science.gov (United States)

    Kluber, L. A.; Hanson, P. J.; Schadt, C. W.

    2016-12-01

    The Spruce and Peatland Responses Under Climatic and Environmental Change (SPRUCE) experiment is a ten-year ecosystem manipulation experiment examining how peatland forests respond to increased temperature and CO2 levels. This experiment is expected to lead to various changes in ecosystem processes, including microbially mediated biogeochemical cycles that may ultimately alter the overall C balance of these ecosystems. The initial phase of this experiment began over the summer of 2014 by heating deep subsurface peat to +2.25, +4.5, +6.75 and +9.0 °C above ambient plots with a target heating zone of 1.5-2 meters depth. Whole ecosystem warming began the summer of 2015 with the addition of aboveground heating to the same target temperatures. The response of microbial communities to in-situ warming is assessed with qPCR and rRNA amplicon sequencing at eleven discrete depths across the peat profile to a depth of 200 cm. Additionally, metagenomic sequencing is used to characterize microbial metabolic and functional potential on four depths per profile. After one year of deep peat warming, microbial community structure and abundance of bacterial, archaeal, fungal, and methanogenic populations showed strong vertical stratification across the peat depth profile yet no clear response to the temperature treatments. In an effort to identify factors that may be limiting decomposition and microbial community change in deep peat, we conducted a microcosm incubation of deep peat (150-200 cm depth) at 6 and 15 °C to mimic ambient and +9 °C SPRUCE conditions. Additional treatments included elevated pH and the addition of N and P. Microcosms were monitored for CO2 and CH4 production, and microbial community dynamics were assessed using qPCR and amplicon sequencing. Increasing temperature elevated both CO2 and CH4 production while elevated pH only resulted in greater CH4 production. The effects of elevating temperature and pH in combination with N, P, or N+P additions were more

  2. Meadow development of the seagrass Posidonia oceanica on the rocky seabed: a preliminary study in the Ligurian Sea.

    Science.gov (United States)

    Montefalcone, Monica; Vacchi, Matteo; Schiaffino, Chiara Francesca; Morri, Carla; Cristina, Carbone; Cabella, Roberto; Elter, Franco Marco; Nike Bianchi, Carlo; Ferrari, Marco

    2014-05-01

    Seagrass meadows are key ecosystems in coastal waters, influencing coastal zone features in terms of wave attenuation and shoreline stabilization. Landscape patterns observed in seagrass habitats are often associated with natural effects by waves or currents, as well as by human induced disturbances. Posidonia oceanica, the most important and abundant seagrass in the Mediterranean Sea, forms large meadows from the sea surface down to 40 m depth, colonizing a wide range of substratum typologies. Several studies have correlated the occurrence of P. oceanica meadows with sedimentological features, but few have investigated the role of substratum typology in shaping the geometry of a meadow. Meadows often develop on sand, but may also colonize rock. The present study relates geological parameters (structural, geotechnical, and mineralogical) of the rocky substrata with the development and characteristics of two shallow P. oceanica meadows in the Ligurian Sea (NW Mediterranean). Preliminary results show that the seagrass, in situations of high hydrodynamics, may colonize only specific lithotypes of the rocky substratum such as the clastic sedimentary rocks (mainly sandstone) that are characterized by low porosity and high values of strength. Under these conditions, the plant is capable to settle in areas with high hydrodynamics, where its development is usually prevented by lack of strong rhizome anchoring. When the upper portion of the meadow is installed on sub-verticalized layered rock, on which differential erosion acts, the arrangement of the more tenacious layers becomes the main element characterizing meadow geometry.

  3. Effects of Spring Drought on Carbon Sequestration, Evapotranspiration and Water Use Efficiency in the Songnen Meadow Steppe in Northeast China.

    Science.gov (United States)

    Gang Dong; Jixun Guo; Jiquan Chen; Ge Sun; Song Gao; et al

    2011-01-01

    Global climate change projections suggest an increasing frequency of droughts and extreme rain events in the steppes of the Eurasian region. Using the eddy covariance method, we measured carbon and water balances of a meadow steppe ecosystem in Northeast China during 2 years which had contrasting precipitation patterns in spring seasons in 2007 and 2008. The meadow...

  4. Many prospects in after-use of cut-away peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Reinikainen, O.; Klemetti, V. (Vapo Oy, Jyvaeskylae (Finland)), Email: olli.reinikainen@vapo.fi, Email: veijo.klemetti@vapo.fi

    2009-07-01

    In Finland 1000-2000 hectares of cut-away peatlands are released from peat harvesting annually. So far these areas amount totally some 25000 hectares, but the released areas are supposed to increase considerably in coming years. These areas open up numerous alternatives for wise after-use. The most important mean for further land-use are forestry, arable farming, restoration and Sphagnum farming as well as wetland or bird sanctuary. Beside economical reasons several geological-hydrological and biological factors determine the applicable after-use alternative. Hydrology of the area is a fundamental factor for further land-use. By means of appropriate treatments former, barren peat harvesting sites can be converted into diverse biotopes, which have added value from environment as well as landscape and economics point of view. Likewise it will open up for the coming generations alternatives for new land-use when peat harvesting has been concluded. The drainage of the peat harvesting fields is mainly carried out by the gravimetric methods, but in part of the areas the mire bottom is lower than the water table in the receiving watershed. There drainage water is pumped to the wanted level. Pumping is used also for environmental reasons and in order to avoid too heavy excavation works. Vapo has more than 100 pumping stations operating in different parts of Finland. The area, which will be submerged below the water table, is about 7000 hectares, when the pumping is stopped after peat harvesting. The submerged areas will be bird sanctuaries with water table of zero to a couple of meters thick. Their beaches are fairly wet and suitable for the restoration to peat forming ecosystems or for the Sphagnum-farming. Majority of the cut-away area is more or less dry land with nutrient poor, especially phosphorus and potassium, peat surface preventing the establishment of the permanent vegetation. These areas can be treated so that the more even and boulder less parts will be turned

  5. RESEARCH REGARDING THE MELLIFEROUS CHARACTHERISTICS OF LABIATES FROM XEROPHILE MEADOWS FROM DANUBE VALLEY

    Directory of Open Access Journals (Sweden)

    NICOLETA ION

    2008-05-01

    Full Text Available The xerophile meadows in the Danube Valley are dry meadows, located at a great distance from the Danube and with underground waters at greater depth. Their floral composition is characterized by a small number of species pertaining to both mezoxerophiles and to xerophiles, yet the highest percentage is covered by xerophile species, which are characterized by their small foliage surface, the very narrow and tough limb, and acute porosity etc.In the floral composition of these species, the graminaceae species are best represented, followed by leguminous and lamiaceae, known in beekeeping as good honey plants. Thus, the researches carried out have shown that Lamiaceae species have a good participation, with variation limits raging from 15% to 50-60%. Leguminous species are represented less on xerophile meadows than in hidrophile meadows. Among these we mention: Lotus corniculatus L., Trifolium repens L. si Medicago lupulina L., all these species being known in beekeeping as good honey plants. Among gramineae species the most representatives are: Lolium perene L. and Poa pratensis L., yet with no melliferous value. Likewise, the group of „various” plants varied a lot as participation in the structure of the vegetal cover of xerophile meadows, depending on the place of research, all these species having no melliferous value. The current paper describes the results o biometric and melliferous researches carried out over the period 2003- 2005 on 5 plant species pertaining to the Lamiaceae family, namely: Salvia nemerosa L. – sage; Salvia pratensis L. – meadow sage; Marrubium vulgare L. – horehound;Lamium purpureum L. – purple deatnettle;Lamium amplexicaule L. – henbit deadnettle.

  6. Fluxes of mercury and methylmercury during snowmelt in two peatland-dominated catchments, Minnesota, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.P.J.; Branfireun, B.A. [Toronto Univ., ON (Canada). Dept. of Geography; Kolka, R.K. [USDA Forest Service, North Central Research Station, Grand Rapids, MN (United States)

    2006-07-01

    The issue of methylmercury (MeHg) accumulation in aquatic biota was discussed. Methylmercury is the organic form of naturally transformed atmospherically-deposited mercury. Peatlands are significant sources of MeHg to downstream aquatic ecosystems. Although snowmelt is an important input in the water budget of northern peatlands, there is not much literature on the importance of peatlands to MeHg export during snowmelt. Therefore, this study examined the significance of the snowmelt period to total mercury (HgT) and MeHg output from 2 headwater peatland-dominated catchments. The purpose was to determine the source or sources of HgT and MeHg in runoff during snowmelt. The study took place in 2 forested upland-peatland catchments at the Marcell Experimental Forest in central Minnesota. Several hydrological compartments were sampled for Hg and coupled to hydrological measurements during the spring snowmelt from late March to mid-April 2005. Concentrations of HgT did not change appreciably over the snowmelt hydrograph. Maximum MeHg concentrations occurred at, or shortly following peak discharge. Maximum MeHg concentrations also coincided with maximum hydrological inputs from the peatland in each catchment. HgT and MeHg concentrations in the melting snowpack were very low and spatially uniform in contrast to concentrations in peatland pore waters which were high and showed high spatial variability. According to mass balance calculations from the 2 catchments, melting snow was responsible for 20 to 50 per cent of MeHg export and 7 to 15 per cent of HgT export. Most of the MeHg export came from within the peatland. Upland interflow was most significant for HgT export. It was concluded that processes within peatlands play a considerable role in mercury biogeochemistry and methylmercury flux from peatland-dominated catchments, even under cold snowmelt conditions.

  7. Long-term peat accumulation in temperate forested peatlands (Thuja occidentalis swamps in the Great Lakes region of North America

    Directory of Open Access Journals (Sweden)

    C.A. Ott

    2016-02-01

    Full Text Available Peatlands are being mapped globally because they are one of the largest pools of terrestrial carbon (C. Most inventories of C have been conducted in northern Sphagnum dominated peatlands or tropical peatlands. Northern white-cedar (cedar, Thuja occidentalis L. peatlands are amongst the most common peatland types in the Great Lakes Region of North America, yet there is no information on their C pool sizes or rates of C accumulation. Therefore, the main objectives of this study were to determine: 1 the ages of cedar peatlands; 2 the amount of C stored in the peat profile; and 3 the apparent long-term rate of C accumulation. We sampled 14 cedar peatland sites across northern Minnesota and the Upper Peninsula of Michigan, USA. Cedar peat was found to be derived mostly from wood and to have an average thickness of 1.12 m (range 0.3–3.25 m. Basal dates indicated that cedar peatlands were initiated between 1,970 and 8,590 years ago, and they appear to have been continuously occupied by cedar. Long-term apparent rates of C accumulation (LARCA ranged from a low of 6.4 g C m-2 yr-1 to a high of 39.7 g C m-2 yr-1, averaging 17.5 g C m-2 yr-1. Cedar peatlands tend to be shallower than Sphagnum peatlands in the region but, due to their higher bulk density (average 0.16 g cm-3, they contain high amounts of C with our sites averaging ~80 kg C m-2. Thus, they represent a regionally important pool of C.

  8. Inshore capture-based tuna aquaculture impact on Posidonia oceanica meadows in the eastern part of the Adriatic Sea.

    Science.gov (United States)

    Kružić, Petar; Vojvodić, Vjeročka; Bura-Nakić, Elvira

    2014-09-15

    Mapping and monitoring of the seagrass Posidonia oceanica in the eastern (Croatian) part of the Adriatic Sea since 2004 indicates a significant decline in meadow density in an area impacted by inshore capture-based tuna aquaculture. The density and overall condition of P. oceanica meadows impacted by tuna farms near Fulija Islet was compared to two reference sites (Iž Island and Mrtovnjak Islet). The factors with the most significant influence on P. oceanica meadows were found to be the input of organic matter originating from the cages, as well as high epiphyte biomass caused by nutrient enrichment. Significant differences in nutrient concentrations were found between the sites impacted by tuna farms (Fulija Islet) and the control stations. Shoot density of the P. oceanica meadows decreased at the stations in close vicinity to the tuna farm, which suggests that the tuna farm activity strongly affected the surrounding meadows. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Human impact on a small barrier reef meadow of Posidonia oceanica (L.) Delile on the north Tyrrhenian coast (Italy).

    Science.gov (United States)

    Mauro, Lenzi; Paola, Gennaro; Margherita, Volterrani; Rugiada, Roffilli; Francesca, Birardi; Primo, Micarelli; Duccio, Solari; Enrica, Franchi

    2013-12-15

    The health status of an emerging Posidonia oceanica meadow, subject to high human impact, was studied. Biometric variables, heavy metals, PAHs and C, N, P contents were determined in sediment and seagrass samples. The meadow was found to grow under oligotrophic conditions and an increase in nutrient content was only recorded in autumn. In sediment, Hg exceeded its ERL (effects range low) and sometimes also its ERM (effects range medium), and Cu was close to its ERL. In leaves, Hg and Cu were relatively high but below their respective ERLs. Sediments close to the meadow were heavily contaminated with pyrolytic PAHs, some of which exceeded their ERLs. P. oceanica did not show major accumulation of PAHs, lighter molecules predominating. Despite 40 years of intense human activity, meadow growth dynamics and contaminant accumulation did not suggest that the meadow was regressing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Summer moisture changes in the Lake Qinghai area on the northeastern Tibetan Plateau recorded from a meadow section over the past 8400 yrs

    Science.gov (United States)

    Li, Xiangzhong; Liu, Xiangjun; He, Yuxin; Liu, Weiguo; Zhou, Xin; Wang, Zheng

    2018-02-01

    Holocene climatic and environmental changes on the northeastern Tibetan Plateau (TP) have been widely discussed based on the climatic records from sedimentary cores. However, differences in the reconstructed climatic history from various studies in this region still exist, probably due to influence of climatic proxies from multiple factors and the chronological uncertainties in lacustrine sediments. Here we present records of terrestrial plant δ13C, soil color and total organic carbon content over the past 8400 years from a well-dated meadow section on the northeastern TP. The terrestrial plant δ13C value serves as a good summer precipitation/moisture indicator in the studied region. Soil color property and TOC content are also able to disentangle the moisture evolution history. All the data show much wet climates at 8400-7400 cal yr BP, dry climates at 7400-6000 cal yr BP and then wet conditions with fluctuation at 6000-3200 cal yr BP. Late Holocene moisture appears to be comparable with moist conditions from 6000 to 3200 cal yr BP. By further comparing the climatic variations in the Lake Qinghai area with records of the reconstructed summer temperature and the Asian Monsoon precipitation, we believe that the pattern of moisture/precipitation evolution in the Lake Qinghai area was not completely consistent with regions around Lake Qinghai, probably due to complicated interaction between the East Asian Summer Monsoon and the Indian Summer Monsoon.

  11. 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

  12. Mediating Water Temperature Increases Due to Livestock and Global Change in High Elevation Meadow Streams of the Golden Trout Wilderness.

    Science.gov (United States)

    Nusslé, Sébastien; Matthews, Kathleen R; Carlson, Stephanie M

    2015-01-01

    Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two "resting" meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita). In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey), leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ramshaw), which have been in a "resting" state since that time. Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure. In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow. Finally, we found that predicted temperatures under different global warming scenarios were likely to be higher in presence of livestock grazing. Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

  13. Mediating Water Temperature Increases Due to Livestock and Global Change in High Elevation Meadow Streams of the Golden Trout Wilderness.

    Directory of Open Access Journals (Sweden)

    Sébastien Nusslé

    Full Text Available Rising temperatures due to climate change are pushing the thermal limits of many species, but how climate warming interacts with other anthropogenic disturbances such as land use remains poorly understood. To understand the interactive effects of climate warming and livestock grazing on water temperature in three high elevation meadow streams in the Golden Trout Wilderness, California, we measured riparian vegetation and monitored water temperature in three meadow streams between 2008 and 2013, including two "resting" meadows and one meadow that is partially grazed. All three meadows have been subject to grazing by cattle and sheep since the 1800s and their streams are home to the imperiled California golden trout (Oncorhynchus mykiss aguabonita. In 1991, a livestock exclosure was constructed in one of the meadows (Mulkey, leaving a portion of stream ungrazed to minimize the negative effects of cattle. In 2001, cattle were removed completely from two other meadows (Big Whitney and Ramshaw, which have been in a "resting" state since that time. Inside the livestock exclosure in Mulkey, we found that riverbank vegetation was both larger and denser than outside the exclosure where cattle were present, resulting in more shaded waters and cooler maximal temperatures inside the exclosure. In addition, between meadows comparisons showed that water temperatures were cooler in the ungrazed meadows compared to the grazed area in the partially grazed meadow. Finally, we found that predicted temperatures under different global warming scenarios were likely to be higher in presence of livestock grazing. Our results highlight that land use can interact with climate change to worsen the local thermal conditions for taxa on the edge and that protecting riparian vegetation is likely to increase the resiliency of these ecosystems to climate change.

  14. Geochemistry of Mine Waste and Mill Tailings, Meadow Deposits, Streambed Sediment, and General Hydrology and Water Quality for the Frohner Meadows Area, Upper Lump Gulch, Jefferson County, Montana

    Science.gov (United States)

    Klein, Terry L.; Cannon, Michael R.; Fey, David L.

    2004-01-01

    Frohner Meadows, an area of low-topographic gradient subalpine ponds and wetlands in glaciated terrane near the headwaters of Lump Gulch (a tributary of Prickly Pear Creek), is located about 15 miles west of the town of Clancy, Montana, in the Helena National Forest. Mining and ore treatment of lead-zinc-silver veins in granitic rocks of the Boulder batholith over the last 120 years from two sites (Frohner mine and the Nellie Grant mine) has resulted in accumulations of mine waste and mill tailings that have been distributed downslope and downstream by anthropogenic and natural processes. This report presents the results of an investigation of the geochemistry of the wetlands, streams, and unconsolidated-sediment deposits and the hydrology, hydrogeology, and water quality of the area affected by these sources of ore-related metals. Ground water sampled from most shallow wells in the meadow system contained high concentrations of arsenic, exceeding the Montana numeric water-quality standard for human health. Transport of cadmium and zinc in ground water is indicated at one site near Nellie Grant Creek based on water-quality data from one well near the creek. Mill tailings deposited in upper Frohner Meadow contribute large arsenic loads to Frohner Meadows Creek; Nellie Grant Creek contributes large arsenic, cadmium, and zinc loads to upper Frohner Meadows. Concentrations of total-recoverable cadmium, copper, lead, and zinc in most surface-water sites downstream from the Nellie Grant mine area exceeded Montana aquatic-life standards. Nearly all samples of surface water and ground water had neutral to slightly alkaline pH values. Concentrations of arsenic, cadmium, lead, and zinc in streambed sediment in the entire meadow below the mine waste and mill tailings accumulations are highly enriched relative to regional watershed-background concentrations and exceed consensus-based, probable-effects concentrations for streambed sediment at most sites. Cadmium, copper, and

  15. Combining LiDAR and IKONOS data for eco-hydrological classification of an ombrotrophic peatland.

    Science.gov (United States)

    Anderson, K; Bennie, J J; Milton, E J; Hughes, P D M; Lindsay, R; Meade, R

    2010-01-01

    Remote sensing techniques have potential for peatland monitoring, but most previous work has focused on spectral approaches that often result in poor discrimination of cover types and neglect structural information. Peatlands contain structural "microtopes" (e.g., hummocks and hollows) which are linked to hydrology, biodiversity and carbon sequestration, and information on surface structure is thus a useful proxy for peatland condition. The objective of this work was to develop and test a new eco-hydrological mapping technique for ombrotrophic (rain-fed) peatlands using a combined spectral-structural remote sensing approach. The study site was Wedholme Flow, Cumbria, UK. Airborne light dectection and ranging (LiDAR) data were used with IKONOS data in a combined multispectral-structural approach for mapping peatland condition classes. LiDAR data were preprocessed so that spatial estimates of minimum and maximum land surface height, variance and semi-variance (from semi-variogram analysis) were extracted. These were assimilated alongside IKONOS data into a maximum likelihood classification procedure, and thematic outputs were compared. Ecological survey data were used to validate the results. Considerable improvements in thematic separation of peatland classes were achieved when spatially-distributed measurements of LiDAR variance or semi-variance were included. Specifically, the classification accuracy improved from 71.8% (IKONOS data only) to 88.0% when a LiDAR semi-variance product was used. Of note was the improved delineation of management classes (including Eriophorum bog, active raised bog and degraded raised bog). The application of a combined textural-optical approach can improve land cover mapping in areas where reliance on purely spectral discrimination approaches would otherwise result in considerable thematic uncertainty.

  16. Peatland carbon stores and fluxes in the Snowy Mountains, New South Wales, Australia

    Directory of Open Access Journals (Sweden)

    G.S. Hope

    2015-09-01

    Full Text Available Peatlands in the Snowy Mountains cover nearly 8000 ha and preserve 49 million m3 of peat, of which 27.1 million m3 is stored in Sphagnum shrublands and restiad moorlands and 21.9 million m3 is stored in sedge fen. The total carbon store is estimated to be about 3.55 Tg. Peat accumulation over the past 60 years indicates that the historical carbon accumulation rate is only 4950 Mg yr-1 for the entire peat estate. This equates to net carbon storage rates of 0.8–1.6 Mg ha-1 yr-1 which is similar to the rates of 0.2 to 2.3 Mg ha-1 yr-1 found in other temperate peatlands. Peat sections covering the last 3000 to 4000 years, however, retain a millennial-scale net long-term storage of 0.09 to 0.21 Mg ha-1 yr-1 totalling 2340 Mg yr-1. The lower storage value of the older peats is partly due to continuing slow peat decay but may also represent accelerated decay due to disturbance by a 100-year phase of stock grazing and intentional burning in the mountains. Some peatlands are recovering strongly since grazing was stopped but they are still vulnerable to hydrological changes caused by trampling by large mammals. Rates of carbon sequestration will be sensitive to climate change, as the peatlands are already stressed by these former land management practices and many are at their climatic limits. The active management of peatland hydrology and surface stabilisation is essential to peatland recovery and the conservation of these significant carbon stores.

  17. Biogeophysical impacts of peatland forestation on regional climate changes in Finland

    Directory of Open Access Journals (Sweden)

    Y. Gao

    2014-12-01

    Full Text Available Land cover changes can impact the climate by influencing the surface energy and water balance. Naturally treeless or sparsely treed peatlands were extensively drained to stimulate forest growth in Finland over the second half of 20th century. The aim of this study is to investigate the biogeophysical effects of peatland forestation on regional climate in Finland. Two sets of 18-year climate simulations were done with the regional climate model REMO by using land cover data based on pre-drainage (1920s and post-drainage (2000s Finnish national forest inventories. In the most intensive peatland forestation area, located in the middle west of Finland, the results show a warming in April of up to 0.43 K in monthly-averaged daily mean 2 m air temperature, whereas a slight cooling from May to October of less than 0.1 K in general is found. Consequently, snow clearance days over that area are advanced up to 5 days in the mean of 15 years. No clear signal is found for precipitation. Through analysing the simulated temperature and energy balance terms, as well as snow depth over five selected subregions, a positive feedback induced by peatland forestation is found between decreased surface albedo and increased surface air temperature in the snow-melting period. Our modelled results show good qualitative agreements with the observational data. In general, decreased surface albedo in the snow-melting period and increased evapotranspiration in the growing period are the most important biogeophysical aspects induced by peatland forestation that cause changes in climate. The results from this study can be further integrally analysed with biogeochemical effects of peatland forestation to provide background information for adapting future forest management to mitigate climate warming effects. Moreover, they provide insights about the impacts of projected forestation of tundra at high latitudes due to climate change.

  18. Rapid carbon loss and slow recovery following permafrost thaw in boreal peatlands.

    Science.gov (United States)

    Jones, Miriam C; Harden, Jennifer; O'Donnell, Jonathan; Manies, Kristen; Jorgenson, Torre; Treat, Claire; Ewing, Stephanie

    2017-03-01

    Permafrost peatlands store one-third of the total carbon (C) in the atmosphere and are increasingly vulnerable to thaw as high-latitude temperatures warm. Large uncertainties remain about C dynamics following permafrost thaw in boreal peatlands. We used a chronosequence approach to measure C stocks in forested permafrost plateaus (forest) and thawed permafrost bogs, ranging in thaw age from young (100 years) from two interior Alaska chronosequences. Permafrost originally aggraded simultaneously with peat accumulation (syngenetic permafrost) at both sites. We found that upon thaw, C loss of the forest peat C is equivalent to ~30% of the initial forest C stock and is directly proportional to the prethaw C stocks. Our model results indicate that permafrost thaw turned these peatlands into net C sources to the atmosphere for a decade following thaw, after which post-thaw bog peat accumulation returned sites to net C sinks. It can take multiple centuries to millennia for a site to recover its prethaw C stocks; the amount of time needed for them to regain their prethaw C stocks is governed by the amount of C that accumulated prior to thaw. Consequently, these findings show that older peatlands will take longer to recover prethaw C stocks, whereas younger peatlands will exceed prethaw stocks in a matter of centuries. We conclude that the loss of sporadic and discontinuous permafrost by 2100 could result in a loss of up to 24 Pg of deep C from permafrost peatlands. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  19. A high-resolution record of carbon accumulation rates during boreal peatland initiation

    Directory of Open Access Journals (Sweden)

    I. F. Pendea

    2012-07-01

    Full Text Available Boreal peatlands are a major global C sink, thus having important feedbacks to climate. A decreased concentration in atmospheric CO2 7000–10 000 yr ago has been linked to variations in peatland C accumulation rates attributed to a warm climate and increased productivity. Yet, this period also corresponds to early stages of peatland development (as peatland was expanding following retreat of ice sheets and increases in C storage could be associated with wetland evolution via lake filling or following marine shoreline emergence. Unravelling past links amongst peatland dynamics, C storage, and climate will help us assess potential feedbacks from future changes in these systems, but most studies are hampered by low temporal resolution. Here we provide a decadal scale C accumulation record for a fen that has begun transformation from salt marsh within the last 70 yr on the isostatically rebounding coast of James Bay, Québec. We determined time frames for wetland stages using palynological analyses to reconstruct ecological change and 210Pb and 137Cs to date the deposit. The average short-term C accumulation rates during the low and high tidal marsh and incipient fen stage (42, 87 and 182 g C m−2 yr−1, respectively were as much as six times higher than the global long-term (millennial average for northern peatlands. We suggest that the atmospheric CO2 flux during the early Holocene could be attributed, in part, to wetland evolution associated with isostatic rebound, which makes land for new wetland formation. Future climate warming will increase eustatic sea level, decrease rates of land emergence and formation of new coastal wetlands, ultimately decreasing rates of C storage of wetlands on rebounding coastlines.

  20. Differences in DOM of rewetted and natural peatlands - Results from high-field FT-ICR-MS and bulk optical parameters.

    Science.gov (United States)

    Herzsprung, Peter; Osterloh, Katja; von Tümpling, Wolf; Harir, Mourad; Hertkorn, Norbert; Schmitt-Kopplin, Philippe; Meissner, Ralph; Bernsdorf, Sabine; Friese, Kurt

    2017-05-15

    Peatlands can be a potential source of dissolved organic matter (DOM) in fresh water catchment areas. The quantity and quality of DOM can differ between pristine, degraded and rewetted peatlands. Due to the large scale and continuing losses of peatlands, their conservation and restoration has been increasingly emphasized. Mostly rewetting measures are required to improve the hydrology of damaged peatlands, which is a precondition for the resettlement of peat-forming plant species. Thus, in term of DOM, there is a special need to understand how rewetting measures affect DOM characteristics and concentrations. To estimate the potential leaching of humic substances from rewetted areas two natural sites were compared with four artificially rewetted sites in a peatland area of the Harz Mountains National Park, Germany. This was done with regards to DOM quality by combining the results from Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS, measured at one time in Spring) and excitation-emission-matrix fluorescence spectroscopy (EEMF, measured monthly for the period of one year). The DOM quality was significantly less variable in the pristine peatland soil water compared to the rewetted peatland soil waters, from both a spatial and a seasonal perspective. The soil water from the rewetted peatland sites showed a higher degree of humification compared to pristine peatland. DOC concentration was mostly consistent in the pristine peatland over the year. The rewetted peatlands showed higher DOC levels in Summer months and lower DOC in Winter months compared to the pristine peatland. It can be concluded that the rewetting of peatlands is coupled with high concentrations of DOC in soil water and its quality is highly aromatic (as reflected by the observed values from the humification index) during times with elevated temperature. The results may have a significant input for dynamic catchment area studies with regards to rewetting peatland sites. Copyright

  1. Modelling Holocene peatland and permafrost dynamics with the LPJ-GUESS dynamic vegetation model

    Science.gov (United States)

    Chaudhary, Nitin; Miller, Paul A.; Smith, Benjamin

    2016-04-01

    Dynamic global vegetation models (DGVMs) are an important platform to study past, present and future vegetation patterns together with associated biogeochemical cycles and climate feedbacks (e.g. Sitch et al. 2008, Smith et al. 2001). However, very few attempts have been made to simulate peatlands using DGVMs (Kleinen et al. 2012, Tang et al. 2015, Wania et al. 2009a). In the present study, we have improved the peatland dynamics in the state-of-the-art dynamic vegetation model (LPJ-GUESS) in order to understand the long-term evolution of northern peatland ecosystems and to assess the effect of changing climate on peatland carbon balance. We combined a dynamic multi-layer approach (Frolking et al. 2010, Hilbert et al. 2000) with soil freezing-thawing functionality (Ekici et al. 2015, Wania et al. 2009a) in LPJ-GUESS. The new model is named LPJ-GUESS Peatland (LPJ-GUESS-P) (Chaudhary et al. in prep). The model was calibrated and tested at the sub-arctic mire in Stordalen, Sweden, and the model was able to capture the reported long-term vegetation dynamics and peat accumulation patterns in the mire (Kokfelt et al. 2010). For evaluation, the model was run at 13 grid points across a north to south transect in Europe. The modelled peat accumulation values were found to be consistent with the published data for each grid point (Loisel et al. 2014). Finally, a series of additional experiments were carried out to investigate the vulnerability of high-latitude peatlands to climate change. We find that the Stordalen mire will sequester more carbon in the future due to milder and wetter climate conditions, longer growing seasons, and the carbon fertilization effect. References: - Chaudhary et al. (in prep.). Modelling Holocene peatland and permafrost dynamics with the LPJ-GUESS dynamic vegetation model - Ekici A, et al. 2015. Site-level model intercomparison of high latitude and high altitude soil thermal dynamics in tundra and barren landscapes. The Cryosphere 9: 1343

  2. Wet water glass production plant

    Directory of Open Access Journals (Sweden)

    Stanković Mirjana S.

    2003-01-01

    Full Text Available The IGPC Engineering Department designed basic projects for a wet hydrate dissolution plant, using technology developed in the IGPC laboratories. Several projects were completed: technological, machine, electrical, automation. On the basis of these projects, a production plant of a capacity of 75,000 t/y was manufactured, at "Zeolite Mira", Mira (VE, Italy, in 1997. and 1998, increasing detergent zeolite production, from 50,000 to 100,000 t/y. Several goals were realized by designing a wet hydrate dissolution plant. The main goal was increasing the detergent zeolite production. The technological cycle of NaOH was closed, and no effluents emitted, and there is no pollution (except for the filter cake. The wet water glass production process is fully automatized, and the product has uniform quality. The production process can be controlled manually, which is necessary during start - up, and repairs. By installing additional process equipment (centrifugal pumps and heat exchangers technological bottlenecks were overcome, and by adjusting the operation of autoclaves, and water glass filters and also by optimizing the capacities of process equipment.

  3. Different regimes of dynamic wetting

    Science.gov (United States)

    Gustav, Amberg; Wang, Jiayu; Do-Quang, Minh; Shiomi, Junichiro; Physiochemical fluid mechanics Team; Maruyama-Chiashi Laboratory Team

    2014-11-01

    Dynamic wetting, as observed when a droplet contacts a dry solid surface, is important in various engineering processes, such as printing, coating, and lubrication. Our overall aim is to investigate if and how the detailed properties of the solid surface influence the dynamics of wetting. Here we discuss how surface roughness influences the initial dynamic spreading of a partially wetting droplet by studying the spreading on a solid substrate patterned with microstructures just a few micrometers in size. This is complemented by matching numerical simulations. We present a parameter map, based on the properties of the liquid and the solid surface, which identifies qualitatively different spreading regimes, where the spreading speed is limited by either the liquid viscosity, the surface properties, or the liquid inertia. The peculiarities of the different spreading regimes are studied by detailed numerical simulations, in conjuction with experiments. This work was financially supported in part by, the Japan Society for the Promotion of Science (J.W. and J.S) and Swedish Governmental Agency for Innovation Systems (M.D.-Q. and G.A).

  4. 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.

  5. 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.

  6. Genotype by environment interaction effects of propagation and defoliation on meadow bromegrass

    Science.gov (United States)

    Sixty-three meadow bromegrass (Bromus riparius Rehm.) half-sib families were evaluated over two years at Millville, UT location for biomass production and nutritive value. Families were evaluated under either space-plant or sward conditions combined with either grazed or cut management. The objectiv...

  7. New Tools to Identify the Location of Seagrass Meadows: Marine Grazers as Habitat Indicators

    KAUST Repository

    Hays, Graeme C.

    2018-02-21

    Seagrasses are hugely valuable to human life, but the global extent of seagrass meadows remains unclear. As evidence of their value, a United Nations program exists (http://data.unep-wcmc.org/datasets/7) to try and assess their distribution and there has been a call from 122 scientists across 28 countries for more work to manage, protect and monitor seagrass meadows (http://www.bbc.com/news/science-environment-37606827). Emerging from the 12th International Seagrass Biology Workshop, held in October 2016, has been the view that grazing marine megafauna may play a useful role in helping to identify previously unknown seagrass habitats. Here we describe this concept, showing how detailed information on the distribution of both dugongs (Dugong dugon) and green sea turtles (Chelonia mydas) obtained, for example, by aerial surveys and satellite tracking, can reveal new information on the location of seagrass meadows. We show examples of how marine megaherbivores have been effective habitat indicators, revealing major, new, deep-water seagrass meadows and offering the potential for more informed estimates of seagrass extent in tropical and sub-tropical regions where current information is often lacking.

  8. Meadow vole-induced mortality of oak seedlings in a former agricultural field planting

    Science.gov (United States)

    Andrew B. Self; Andrew W. Ezell; Dennis Rowe; Emily B. Schultz; John D. Hodges

    2015-01-01

    Seedling mortality due to meadow vole herbivory is an often acknowledged but relatively unstudied aspect of hardwood afforestation. Vole-induced mortality is not typically a major item of concern in afforestation attempts. However, damage has been extreme in some plantings. A total of 4,320 bare-root Nuttall oak (Quercus texana Buckley), Shumard oak (Quercus shumardii...

  9. Invertebrates of Meadow Creek, Union County, Oregon, and their use as food by trout.

    Science.gov (United States)

    Carl E. McLemore; William R. Meehan

    1988-01-01

    From 1976 to 1980, invertebrates were collected three times each year from several reaches of Meadow Creek in eastern Oregon. Five sampling methods were used: benthos, drift, sticky traps, water traps, and fish stomachs. A total of 372 taxa were identified, of which 239 were used as food by rainbow trout (steelhead; Salmo gairdneri Richardson). Of...

  10. Carbon and nutrient deposition in a Mediterranean seagrass (Posidonia oceanica) meadow

    NARCIS (Netherlands)

    Gacia, E.; Duarte, C.M.; Middelburg, J.J.

    2002-01-01

    The annual depositional flux of carbon (C), nitrogen (N), and phosphorous (P) to the sediments under a northeast Spain Posidonia oceanica meadow was evaluated, and the sources and fate of the material deposited elucidated. The annual deposition of carbon represented 198 g C m-2 yr-1, 72% of which

  11. The large penumbra: long-distance effects of artificial beach nourishment on Posidonia oceanica meadows.

    Science.gov (United States)

    Manzanera, Marta; Alcoverro, Teresa; Jiménez, José A; Romero, Javier

    2014-09-15

    We used modelling and field approaches to assess the influence of beach nourishment on a relatively distant Posidonia oceanica seagrass meadow in the NW Mediterranean. Both sediment transport models and in situ observations showed that, two years after the nourishment and under wave climates prevalent during the study period, sediment movement was restricted to shallow waters (<7 m), above meadow shallow limit. The only significant impact on seagrass meadows during this period was an increase in fine sediments, associated with vertical rhizome growth rates 1.5-1.7 times higher than normal. However, running the model with data of wave climate over several decades indicates that strong storms able to transfer these sediments much deeper, potentially burying meadows, occur with a return period of about 25 years. Taken together, our results suggest that beach nourishment could result in significant sub-lethal and lethal consequences for seagrasses that may go unnoticed with short-term evaluations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. At home on foreign meadows: the reintroduction of two Maculineae butterfly species

    NARCIS (Netherlands)

    Wynhoff, I.

    2001-01-01

    Maculinea butterflies live as obligate parasites of specific Myrmica host ants in meadow and heathland habitat maintained by low intensity landuse. Changes in agriculture caused the decline and extinction of many populations. In The Netherlands,

  13. Pyrenean meadows in Natura 2000 network: grass production and plant biodiversity conservation

    Energy Technology Data Exchange (ETDEWEB)

    Reine, R.; Barrantes, O.; Chocarro, C.; Juarez, A.; Broca, A.; Maestro, M.; Ferrer, C.

    2014-06-01

    In semi-natural mountain meadows, yield and forage quality must be reconciled with plant biodiversity conservation. This study was performed to analyze the relationships between these three parameters. To quantify plant biodiversity and pastoral value (PV), phyto sociological inventories were performed in 104 semi-natural meadows in the Central Spanish Pyrenees included in the Natura 2000 network. Forage yields were calculated and forage samples were analyzed for relative feed value (RFV). We identified two main types of meadows: (i) those that had more intensive management, relatively close to farm buildings, with little or no slope, dominated by grasses, with low plant biodiversity, high PV and yield, but low forage quality and (ii) those that had less intensive management, distant from farm buildings, on slopes, richer in other forbs, with high plant biodiversity and forage quality, but low PV and yield. Conservation policies should emphasize less intensive management practices to maintain plant diversity in the semi-natural meadows in the Pyrenees. The widespread view that other forbs have low nutritional value should be revised in future research. These species often are undervalued by the PV method, because their nutritional quality, digestibility and intake are poorly understood. (Author)

  14. Carbon stores from a tropical seagrass meadow in the midst of anthropogenic disturbance.

    Science.gov (United States)

    Rozaimi, Mohammad; Fairoz, Mohammad; Hakimi, Tuan Mohamad; Hamdan, Nur Hidayah; Omar, Ramlan; Ali, Masni Mohd; Tahirin, Siti Aishah

    2017-06-30

    Seagrass meadows provide important carbon sequestration services but anthropogenic activities modify the natural ecosystem and inevitably lower carbon storage capacity. The tropical mixed-species meadows in the Sungai Pulai Estuary (Johor, Malaysia) are impacted by such activities. In this study, we provide baseline estimates for carbon stores analysed from sediment cores. In sediment depths up to 100cm, organic (OC) and inorganic carbon (IC) stores were 43-101MgCha-1 and 46-83MgCha-1, respectively, and are in the lower end of global average values. The bulk of OC (53-98%) originated from seston suggesting that the meadows had low capacity to retain seagrass-derived organic matter. The species factor resulted in some variability in OC stores but did not appear to influence IC values. The low carbon stores in the meadow may be a direct result of sediment disturbances but natural biogeochemical processes are not discounted as possible causal factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. The effects of matrix structure on movement decisions of meadow voles (Microtus pennsylvanicus)

    Science.gov (United States)

    Robin E. Russell; Robert K. Swihart; Bruce A. Craig

    2007-01-01

    The composition of the landscape between patches (the matrix) can have important effects on movement rates that potentially outweigh the effects of patch size and isolation. We conducted a small-scale experiment with radiocollared meadow voles (Microtus pennsylvanicus) to quantify the effects of matrix habitat on movement behavior of voles. Habitat...

  16. Diversity of lowland hay meadows and pastures in Western and Central Europe

    NARCIS (Netherlands)

    Rodríguez-Rojo, Maria Pilar; Jiménez-Alfaro, Borja; Jandt, Ute; Bruelheide, Helge; Rodwell, John S.; Schaminée, Joop H.J.; Perrin, Philip M.; Kacki, Zygmunt; Willner, Wolfgang; Fernández-González, Federico; Chytrý, Milan

    2017-01-01

    Questions: Which are the main vegetation types of lowland hay meadows and pastures in Western and Central Europe? What are the main environmental gradients that drive patterns of species composition? Is it possible to classify these grasslands to phytosociological alliances that reflect management

  17. Pyrenean meadows in Natura 2000 network: grass production and plant biodiversity conservation

    Directory of Open Access Journals (Sweden)

    Ramón Reiné

    2014-02-01

    Full Text Available In semi-natural mountain meadows, yield and forage quality must be reconciled with plant biodiversity conservation. This study was performed to analyze the relationships between these three parameters. To quantify plant biodiversity and pastoral value (PV, phytosociological inventories were performed in 104 semi-natural meadows in the Central Spanish Pyrenees included in the Natura 2000 network. Forage yields were calculated and forage samples were analyzed for relative feed value (RFV. We identified two main types of meadows: (i those that had “more intensive management,” relatively close to farm buildings, with little or no slope, dominated by grasses, with low plant biodiversity, high PV and yield, but low forage quality and (ii those that had “less intensive management,” distant from farm buildings, on slopes, richer in “other forbs”, with high plant biodiversity and forage quality, but low PV and yield. Conservation policies should emphasize less intensive management practices to maintain plant diversity in the semi-natural meadows in the Pyrenees. The widespread view that “other forbs” have low nutritional value should be revised in future research. These species often are undervalued by the PV method, because their nutritional quality, digestibility and intake are poorly understood.

  18. Multi-technique assessment of spatial and temporal variability of methane fluxes in a peat meadow

    NARCIS (Netherlands)

    Hendriks, D.M.D.; van Huissteden, J.; Dolman, A.J.

    2010-01-01

    Methane fluxes measured in a eutrophic peat meadow in The Netherlands dominated by vascular plants showed high spatial and temporal variability. To elucidate this variability as well as the underlying processes, various measurement techniques were used: soil gradients of methane concentrations, the

  19. Charcterization of meadow ecosystems based on watershed and valley segment/reach scale characteristics [chapter 7

    Science.gov (United States)

    Wendy Trowbridge; Jeanne C. Chambers; Dru Germanoski; Mark L. Lord; Jerry R. Miller; David G. Jewett

    2011-01-01

    Great Basin riparian meadows are highly sensitive to both natural and anthropogenic disturbance. As detailed in earlier chapters, streams in the central Great Basin have a natural tendency to incise due to their geomorphic history (Miller and others 2001, 2004). Anthropogenic disturbances, including overgrazing by livestock, mining activities, and roads in the valley...

  20. Geomorphology, hydrology, and ecology of Great Basin meadow complexes - implications for management and restoration

    Science.gov (United States)

    Jeanne C. Chambers; Jerry R. Miller

    2011-01-01

    This report contains the results of a 6-year project conducted by the U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station and U.S. Environmental Protection Agency, Office of Research and Development on stream incision and meadow ecosystem degradation in the central Great Basin. The project included a coarse-scale assessment of 56 different...

  1. Extent and reasons for meadows in South Bohemia becoming unsuitable for orchids

    Czech Academy of Sciences Publication Activity Database

    Štípková, Z.; Kindlmann, Pavel

    2015-01-01

    Roč. 5, č. 2 (2015), s. 142-147 ISSN 1805-0174 R&D Projects: GA ČR GB14-36098G Institutional support: RVO:67179843 Keywords : extinction * meadows * terrestrial orchids * South Bohemia Subject RIV: EF - Botanics

  2. Effect of abandonment and plant classification on carbohydrate reserves of meadow plants

    Czech Academy of Sciences Publication Activity Database

    Janeček, Štěpán; Lanta, Vojtěch; Klimešová, Jitka; Doležal, Jiří

    2010-01-01

    Roč. 13, č. 2 (2010), s. 243-251 ISSN 1435-8603 R&D Projects: GA ČR GA526/09/0963; GA ČR(CZ) GA526/06/0723 Institutional research plan: CEZ:AV0Z60050516 Keywords : carbohydrates * meadow * abandonment Subject RIV: EF - Botanics Impact factor: 2.409, year: 2010

  3. Vegetation Re-development After Fen Meadow Restoration by Topsoil Removal and Hay Transfer

    NARCIS (Netherlands)

    Klimkowska, A.; Kotowski, W.; Diggelen, R.; Grootjans, A.P.; Dzierza, P.; Brzezinska, K.

    2010-01-01

    We investigated the effects of different restoration treatments on the development of fen meadow communities: (1) depth of topsoil removal, with shallow (circa 20 cm) and deep (circa 40 cm) soil removal applied, (2) transfer of seed-containing hay, and (3) access of large animals. We carried out a

  4. The effects of drainage on groundwater quality and plant species distribution in stream valley meadows

    NARCIS (Netherlands)

    Grootjans, A.P.; Diggelen, R. van; Wassen, M.J.; Wiersinga, W.A.

    1988-01-01

    Conditions in fen meadows in Dutch stream valleys are influenced by both deep (Ca2+-rich) and shallow (Ca2+-poor) groundwater flows. The distribution patterns of phreatophytic (groundwater-influenced) plant species showed distinct relationships with the distribution of different groundwater types.

  5. Soil nematodes in alpine meadows of the Tatra National Park (Slovak Republic)

    Czech Academy of Sciences Publication Activity Database

    Háněl, Ladislav

    2017-01-01

    Roč. 54, č. 1 (2017), s. 48-67 ISSN 0440-6605 R&D Projects: GA ČR(CZ) GA14-09231S Institutional support: RVO:60077344 Keywords : soil nematodes * diversity * maturity * soil food web * alpine meadow Subject RIV: EH - Ecology, Behaviour OBOR OECD: Ecology Impact factor: 0.472, year: 2016

  6. Genetic relationships of meadow vole (Microtus pennsylvanicus) populations in central Appalachian wetlands

    Science.gov (United States)

    K. E. Francl; T. C. Glenn; S. B. Castleberry; W. M. Ford

    2008-01-01

    We sequenced and compared variation within a 375-base-pair segment of the mitochondrial DNA control region of 323 meadow voles (Microtus pennsylvanicus (Ord. 1815)) among 14 populations to determine the influence of past and present landscape connectivity among isolated wetlands in the central Appalachian Mountains. To best explain observed...

  7. Processes affecting the spatial distribution of seagrass meadow sedimentary material on Yao Yai Island, Thailand

    Science.gov (United States)

    Quak, Michelle S. Y.; Ziegler, Alan D.; Benner, Shawn G.; Evans, Sam; Todd, Peter A.; Gillis, Lucy G.; Vongtanaboon, Sukanya; Jachowski, Nick; Bouma, Tjeerd J.

    2016-12-01

    Many islands throughout SE Asia are experiencing rapid development and land-cover conversion that potentially threaten sensitive coastal ecosystems, such as seagrasses, through increased loading of sediment and nutrients originating from disturbed catchments draining to the sea. To evaluate this threat for one such island in Southern Thailand (Yao Yai), we perform sediment source tracing via end-member mixing analysis using stable isotopes δ13C and δ15N in organic matter to explore sediment loading in a seagrass meadow. The analysis indicates that sedimentary material in the meadow originates mostly from ocean-associated sources (∼62% from seagrass detritus, seston, and ocean sediments). Terrestrial material comprises ∼19% of the organic material found in the seagrass meadow, with another 20% originating from an adjacent mangrove forest. Approximately one-fourth of the seagrass meadow material (24%) is detritus that has been (re)deposited internally. The high contribution of terrestrial-derived organic matter deposited near the river mouth demonstrates that substantial quantities of sediment are being transferred from upslope erosion sources into the seagrass meadow. However, only a small amount of this material is deposited throughout the entire bay because much of the terrestrial- and mangrove-derived sediment is transferred to the open ocean via channels that are periodically dredged to allow boat access to two small inland harbours. This positive affect of dredging has not received very much attention in existing literature. River water flowing to the channels during falling tide delivers sediment to these efficient pathways, where much of it bypasses the seagrass meadow at periods of time when sediment deposition would normally be the greatest. There is growing concern that ongoing land-cover changes and planned urbanization related to tourism and agriculture on the island may boost sediment/nutrients above a critical threshold, beyond that revealed in

  8. Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows.

    Directory of Open Access Journals (Sweden)

    Damien M Hicks

    Full Text Available Planted meadows are increasingly used to improve the biodiversity and aesthetic amenity value of urban areas. Although many 'pollinator-friendly' seed mixes are available, the floral resources these provide to flower-visiting insects, and how these change through time, are largely unknown. Such data are necessary to compare the resources provided by alternative meadow seed mixes to each other and to other flowering habitats. We used quantitative surveys of over 2 million flowers to estimate the nectar and pollen resources offered by two exemplar commercial seed mixes (one annual, one perennial and associated weeds grown as 300m2 meadows across four UK cities, sampled at six time points between May and September 2013. Nectar sugar and pollen rewards per flower varied widely across 65 species surveyed, with native British weed species (including dandelion, Taraxacum agg. contributing the top five nectar producers and two of the top ten pollen producers. Seed mix species yielding the highest rewards per flower included Leontodon hispidus, Centaurea cyanus and C. nigra for nectar, and Papaver rhoeas, Eschscholzia californica and Malva moschata for pollen. Perennial meadows produced up to 20x more nectar and up to 6x more pollen than annual meadows, which in turn produced far more than amenity grassland controls. Perennial meadows produced resources earlier in the year than annual meadows, but both seed mixes delivered very low resource levels early in the year and these were provided almost entirely by native weeds. Pollen volume per flower is well predicted statistically by floral morphology, and nectar sugar mass and pollen volume per unit area are correlated with flower counts, raising the possibility that resource levels can be estimated for species or habitats where they cannot be measured directly. Our approach does not incorporate resource quality information (for example, pollen protein or essential amino acid content, but can easily do so

  9. Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows

    Science.gov (United States)

    Hicks, Damien M.; Ouvrard, Pierre; Baldock, Katherine C. R.; Baude, Mathilde; Goddard, Mark A.; Kunin, William E.; Mitschunas, Nadine; Memmott, Jane; Morse, Helen; Nikolitsi, Maria; Osgathorpe, Lynne M.; Potts, Simon G.; Robertson, Kirsty M.; Scott, Anna V.; Sinclair, Frazer; Westbury, Duncan B.; Stone, Graham N.

    2016-01-01

    Planted meadows are increasingly used to improve the biodiversity and aesthetic amenity value of urban areas. Although many ‘pollinator-friendly’ seed mixes are available, the floral resources these provide to flower-visiting insects, and how these change through time, are largely unknown. Such data are necessary to compare the resources provided by alternative meadow seed mixes to each other and to other flowering habitats. We used quantitative surveys of over 2 million flowers to estimate the nectar and pollen resources offered by two exemplar commercial seed mixes (one annual, one perennial) and associated weeds grown as 300m2 meadows across four UK cities, sampled at six time points between May and September 2013. Nectar sugar and pollen rewards per flower varied widely across 65 species surveyed, with native British weed species (including dandelion, Taraxacum agg.) contributing the top five nectar producers and two of the top ten pollen producers. Seed mix species yielding the highest rewards per flower included Leontodon hispidus, Centaurea cyanus and C. nigra for nectar, and Papaver rhoeas, Eschscholzia californica and Malva moschata for pollen. Perennial meadows produced up to 20x more nectar and up to 6x more pollen than annual meadows, which in turn produced far more than amenity grassland controls. Perennial meadows produced resources earlier in the year than annual meadows, but both seed mixes delivered very low resource levels early in the year and these were provided almost entirely by native weeds. Pollen volume per flower is well predicted statistically by floral morphology, and nectar sugar mass and pollen volume per unit area are correlated with flower counts, raising the possibility that resource levels can be estimated for species or habitats where they cannot be measured directly. Our approach does not incorporate resource quality information (for example, pollen protein or essential amino acid content), but can easily do so when suitable

  10. Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows.

    Science.gov (United States)

    Hicks, Damien M; Ouvrard, Pierre; Baldock, Katherine C R; Baude, Mathilde; Goddard, Mark A; Kunin, William E; Mitschunas, Nadine; Memmott, Jane; Morse, Helen; Nikolitsi, Maria; Osgathorpe, Lynne M; Potts, Simon G; Robertson, Kirsty M; Scott, Anna V; Sinclair, Frazer; Westbury, Duncan B; Stone, Graham N

    2016-01-01

    Planted meadows are increasingly used to improve the biodiversity and aesthetic amenity value of urban areas. Although many 'pollinator-friendly' seed mixes are available, the floral resources these provide to flower-visiting insects, and how these change through time, are largely unknown. Such data are necessary to compare the resources provided by alternative meadow seed mixes to each other and to other flowering habitats. We used quantitative surveys of over 2 million flowers to estimate the nectar and pollen resources offered by two exemplar commercial seed mixes (one annual, one perennial) and associated weeds grown as 300m2 meadows across four UK cities, sampled at six time points between May and September 2013. Nectar sugar and pollen rewards per flower varied widely across 65 species surveyed, with native British weed species (including dandelion, Taraxacum agg.) contributing the top five nectar producers and two of the top ten pollen producers. Seed mix species yielding the highest rewards per flower included Leontodon hispidus, Centaurea cyanus and C. nigra for nectar, and Papaver rhoeas, Eschscholzia californica and Malva moschata for pollen. Perennial meadows produced up to 20x more nectar and up to 6x more pollen than annual meadows, which in turn produced far more than amenity grassland controls. Perennial meadows produced resources earlier in the year than annual meadows, but both seed mixes delivered very low resource levels early in the year and these were provided almost entirely by native weeds. Pollen volume per flower is well predicted statistically by floral morphology, and nectar sugar mass and pollen volume per unit area are correlated with flower counts, raising the possibility that resource levels can be estimated for species or habitats where they cannot be measured directly. Our approach does not incorporate resource quality information (for example, pollen protein or essential amino acid content), but can easily do so when suitable data

  11. English Water Meadows: historic relics or focus for environmental management and inter-disciplinary research?

    Science.gov (United States)

    Cook, Hadrian

    2015-04-01

    Irrigated water meadows are found across Europe, from southern Scandinavia to Spain and in the Alpine regions and Italy. While the practice of engineering 'floated' meadow land for deliberate irrigation on hillsides and floodplains is widespread and ancient, since about 1600 AD the practice was widely adopted on floodplains in southern England where they improved the timing and productivity of grazing land and produced hay crops. They also became a part of English consciousness through art and literature. To some, water meadows are a relic of an agrarian past, to others they are the object of a range of foci for conservation, education, sustainable grass production, community engagement and recent research suggests water returned from meadow irrigation is beneficial to river water quality. Historically floodplain 'bedwork' water meadows grew from, and were integral in, the farming system of 'Wessex' involving sheep which produced dung for arable land and later supporting dairy and beef production, as well as hay. Where systems remain, this is largely due to the whim of individuals, the outcome of agri-environmental schemes. Water meadows may be managed by public, voluntary or private sector bodies. What is needed is a fresh look at how land owners, or communities, might micro-target them for heritage, habitat and grassland management. There are therefore interesting questions concerning their future: Who might invest in their restoration and maintenance? How might they be integrated into commercial farming? Are they of sufficient interest to restore en masse to become (once more) a major feature of the English chalk stream valleys? Do they provide a way into academic and public perception, combining environmental science, history, cultural heritage and environmental management? How might restoration and management become vehicles for public engagement? While each of these questions represents a major topic for discussion, this paper is an attempt to consolidate

  12. European wet deposition maps based on measurements

    NARCIS (Netherlands)

    Leeuwen EP van; Erisman JW; Draaijers GPJ; Potma CJM; Pul WAJ van; LLO

    1995-01-01

    To date, wet deposition maps on a European scale have been based on long-range transport model results. For most components wet deposition maps based on measurements are only available on national scales. Wet deposition maps of acidifying components and base cations based on measurements are needed

  13. Effects of tourism and topography on vegetation diversity in the subalpine meadows of the Dongling Mountains of Beijing, China.

    Science.gov (United States)

    Zhang, Jin-Tun; Xiang, ChunLing; Li, Min

    2012-02-01

    Subalpine meadows in the Dongling Mountains (located at E115º26'-115º40', N40º00'-40º05') of Beijing, China are important for tourism and the provision of ecosystem services. However, because of poor management serious degradation has occurred on these subalpine meadows. The aim of this paper is to present a quantitative analysis of effects of tourism disturbance and topography on the status and diversity of montane meadow communities and to provide direction for improved management. Sixty quadrats of 2 × 2 m(2) along 10 transects were set up to collect data on site characteristics and vegetation status. The relationships between community composition and structure, species diversity, and tourism disturbance and topographic variables were analyzed by multivariate methods (TWINSPAN and CCA). The results showed that eight meadow communities were identified by TWINSPAN. Most of them were seriously degraded. The first CCA axis identified an elevation and tourism disturbance intensity gradient, which illustrated that tourism disturbance and elevation were most important factors influencing meadow types, composition and structure. Some resistant species and response species to tourism disturbance were identified and can be used as indicator species of tourism disturbance. Species richness, heterogeneity and evenness were closely related to tourism disturbance and elevation. It is concluded that tourism disturbance must be controlled to enable grassland rehabilitation to occur in the meadows. Measures of effective management of the meadows were discussed.

  14. Effects of Tourism and Topography on Vegetation Diversity in the Subalpine Meadows of the Dongling Mountains of Beijing, China

    Science.gov (United States)

    Zhang, Jin-Tun; Xiang, Chunling; Li, Min

    2012-02-01

    Subalpine meadows in the Dongling Mountains (located at E115º26'-115º40', N40º00'-40º05') of Beijing, China are important for tourism and the provision of ecosystem services. However, because of poor management serious degradation has occurred on these subalpine meadows. The aim of this paper is to present a quantitative analysis of effects of tourism disturbance and topography on the status and diversity of montane meadow communities and to provide direction for improved management. Sixty quadrats of 2 × 2 m2 along 10 transects were set up to collect data on site characteristics and vegetation status. The relationships between community composition and structure, species diversity, and tourism disturbance and topographic variables were analyzed by multivariate methods (TWINSPAN and CCA). The results showed that eight meadow communities were identified by TWINSPAN. Most of them were seriously degraded. The first CCA axis identified an elevation and tourism disturbance intensity gradient, which illustrated that tourism disturbance and elevation were most important factors influencing meadow types, composition and structure. Some resistant species and response species to tourism disturbance were identified and can be used as indicator species of tourism disturbance. Species richness, heterogeneity and evenness were closely related to tourism disturbance and elevation. It is concluded that tourism disturbance must be controlled to enable grassland rehabilitation to occur in the meadows. Measures of effective management of the meadows were discussed.

  15. Soil organic carbon storage and soil CO2 flux in the alpine meadow ecosystem

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    High-resolution sampling,measurements of organic carbon contents and 14C signatures of selected four soil profiles in the Haibei Station situated on the northeast Tibetan Plateau,and application of 14C tracing technology were conducted in an attempt to investigate the turnover times of soil organic car-bon and the soil-CO2 flux in the alpine meadow ecosystem. The results show that the organic carbon stored in the soils varies from 22.12×104 kg C hm-2 to 30.75×104 kg C hm-2 in the alpine meadow eco-systems,with an average of 26.86×104 kg C hm-2. Turnover times of organic carbon pools increase with depth from 45 a to 73 a in the surface soil horizon to hundreds of years or millennia or even longer at the deep soil horizons in the alpine meadow ecosystems. The soil-CO2 flux ranges from 103.24 g C m-2 a-1 to 254.93 gC m-2 a-1,with an average of 191.23 g C m-2 a-1. The CO2 efflux produced from microbial decomposition of organic matter varies from 73.3 g C m-2 a-1 to 181 g C m-2 a-1. More than 30% of total soil organic carbon resides in the active carbon pool and 72.8%―81.23% of total CO2 emitted from or-ganic matter decomposition results from the topsoil horizon (from 0 cm to 10 cm) for the Kobresia meadow. Responding to global warming,the storage,volume of flow and fate of the soil organic carbon in the alpine meadow ecosystem of the Tibetan Plateau will be changed,which needs further research.

  16. A comparison between energy transfer and atmospheric turbulent exchanges over alpine meadow and banana plantation

    Science.gov (United States)

    Ding, Zhangwei; Ma, Yaoming; Wen, Zhiping; Ma, Weiqiang; Chen, Shiji

    2017-07-01

    Banana plantation and alpine meadow ecosystems in southern China and the Tibetan Plateau (TP) are unique in the underlying surfaces they exhibit. In this study, we used eddy covariance and a micrometeorological tower to examine the characteristics of land surface energy exchanges over a banana plantation in southern China and an alpine meadow in the Tibetan Plateau from May 2010 to August 2012. The results showed that the diurnal and seasonal variations in upward shortwave radiation flux and surface soil heat flux were larger over the alpine meadow than over the banana plantation surface. Dominant energy partitioning varied with season. Latent heat flux was the main consumer of net radiation flux in the growing season, whereas sensible heat flux was the main consumer during other periods. The Monin-Obukhov similarity theory was employed for comparative purposes, using sonic anemometer observations of flow over the surfaces of banana plantations in the humid southern China monsoon region and the semi-arid areas of the TP, and was found to be applicable. Over banana plantation and alpine meadow areas, the average surface albedo and surface aerodynamic roughness lengths under neutral atmospheric conditions were ˜0.128 and 0.47 m, and ˜0.223 and 0.01 m, respectively. During the measuring period, the mean annual bulk transfer coefficients for momentum and sensible heat were 1.47 × 10-2 and 7.13 × 10-3, and 2.91 × 10-3 and 1.96 × 10-3, for banana plantation and alpine meadow areas, respectively.

  17. 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

  18. Seasonal variations in carbon dioxide exchange in an alpine wetland meadow on the Qinghai-Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    L. Zhao

    2010-04-01

    Full Text Available Alpine wetland meadow could functions as a carbon sink due to it high soil organic content and low decomposition. However, the magnitude and dynamics of carbon stock in alpine wetland ecosystems are not well quantified. Therefore, understanding how environmental variables affect the processes that regulate carbon fluxes in alpine wetland meadow on the Qinghai-Tibetan Plateau is critical. To address this issue, Gross Primary Production (GPP, Ecosystem Respiration (Reco, and Net Ecosystem Exchange (NEE were examined in an alpine wetland meadow using the eddy covariance method from October 2003 to December 2006 at the Haibei Research Station of the Chinese Academy of Sciences. Seasonal patterns of GPP and Reco were closely associated with leaf area index (LAI. The Reco showed a positive exponential to soil temperature and relatively low Reco occurred during the non-growing season after a rain event. This result is inconsistent with the result observed in alpine shrubland meadow. In total, annual GPP were estimated at 575.7, 682.9, and 630.97 g C m−2 in 2004, 2005, and 2006, respectively. Meanwhile, the Reco were equal to 676.8, 726.4, 808.2 g C m−2, and thus the NEE were 101.1, 44.0 and 173.2 g C m−2. These results indicated that the alpine wetland meadow was a moderately source of carbon dioxide (CO2. The observed carbon dioxide fluxes in the alpine wetland meadow were higher than other alpine meadow such as Kobresia humilis meadow and shrubland meadow.

  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. 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 (Pstructure (Psoil 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.

  1. Agricultural peatlands: towards a greenhouse gas sink - a synthesis of a Dutch landscape study

    NARCIS (Netherlands)

    Schrier-Uijl, A.P.; Kroon, P.S.; Hendriks, D.M.D.; Hensen, A.; Huissteden, van J.; Leffelaar, P.A.; Berendse, F.; Veenendaal, E.M.

    2014-01-01

    It is generally known that managed, drained peatlands act as carbon (C) sources. In this study we examined how mitigation through the reduction of the intensity of land management and through rewetting may affect the greenhouse gas (GHG) emission and the C balance of intensively managed, drained,

  2. 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.

  3. 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...

  4. Suppression of peatland methane emission by cumulative sulfate deposition in simulated acid rain

    Science.gov (United States)

    Nancy B. Dise; Elon S. Verry

    2001-01-01

    This field manipulation study tested the effect of weekly pulses of solutions of NH4NO3 and (NH4)2SO4 salts on the evolution of CH4 and N2O from peatland soils. Methane and nitrous oxide emission from a...

  5. The diversity of microfungi in peatlands originated from the White Sea

    NARCIS (Netherlands)

    Grum-Grzhimaylo, Olga A.; Debets, Fons; Bilanenko, Elena N.

    2016-01-01

    The diversity of culturable filamentous microfungi in peat and sediments of four peatlands at the coastal zone of Kandalaksha Bay of the White Sea (Murmansk region, Russia) was studied by culture methods on standard and selective media. Annually 100 samples were collected from the bogs 2007-2010.

  6. The diversity of microfungi in peatlands originated from the White Sea.

    Science.gov (United States)

    Grum-Grzhimaylo, Olga A; Debets, Alfons J M; Bilanenko, Elena N

    2016-01-01

    The diversity of culturable filamentous microfungi in peat and sediments of four peatlands at the coastal zone of Kandalaksha Bay of the White Sea (Murmansk region, Russia) was studied by culture methods on standard and selective media. Annually 100 samples were collected from the bogs 2007-2010. Based on morphological, molecular markers and cultural features, 211 taxa were identified. Fungal communities observed at the peatlands were influenced mostly by their sea origin. We discovered a large difference between fungal communities from the peat and the sediments of the peatlands. In contrast to the sediments, the fungal community of the peat was found to be consistent throughout sampling sites. Fungi with specific ecophysiology, such as Sphagnum-decomposing species (Oidiodendron griseum, O. tenuissimum. Penicillium spinulosum, P. thomii, Talaromyces funiculosus), psychrotolerant and associated with insects species (Pseudogymnoascus pannorum, Tolypocladium spp.), typical marine species (Acremonium spp.) were found. In addition, different types of sterile mycelia were characteristic for the researched peatlands. © 2016 by The Mycological Society of America.

  7. 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.

  8. 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.

  9. The effects of permafrost thaw on soil hydrologic, thermal, and carbon dynamics in an Alaskan peatland

    Science.gov (United States)

    Jonathan A. O' Donnell; M.Torre Jorgenson; Jennifer W. Harden; A.David McGuire; Mikhail Z. Kanevskiy; Kimberly P. Wickland

    2012-01-01

    Recent warming at high-latitudes has accelerated permafrost thaw in northern peatlands, and thaw can have profound effects on local hydrology and ecosystem carbon balance. To assess the impact of permafrost thaw on soil organic carbon (OC) dynamics, we measured soil hydrologic and thermal dynamics and soil OC stocks across a collapse-scar bog chronosequence in interior...

  10. 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...

  11. 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.

  12. 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.

  13. 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; plabile 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.

  14. 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.

  15. 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.

  16. 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 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 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. PMID:26896139

  17. Tropical Peatland water management modelling of the Air Hitam Laut catchment in Indonesia

    NARCIS (Netherlands)

    Wösten, H.; Hooijer, A.; Siderius, C.; Dira Satriadi Rais,; Aswandi Idris,; Rieley, J.

    2006-01-01

    Human induced land use change and associated fire alter profoundly the hydrology of tropical peatlands and thus affect the functioning of entire river catchments. The hydrological model SIMGRO was used to calculate the effects of drainage on peat water levels, peat surface morphology and river flows

  18. A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation

    NARCIS (Netherlands)

    Loisel, J.; Yu, Z.; Beilman, D.W.; Camill, P.; Alm, J.; Amesbury, M.J.; Anderson, D.; Andersson, S.; Bochicchio, C.; Barber, K.; Belyea, L.R.; Bunbury, J.; Chambers, F.M.; Charman, D.J.; De Vleeschouwer, F.; Fiałkiewicz-Kozieł, B.; Finkelstein, S.A.; Gałka, M.; Garneau, M.; Hammarlund, D; Hinchcliffe, W.; Holmquist, J.; Hughes, P.; Jones, M.C.; Klein, E.S.; Kokfelt, U.; Korhola, A.; Kuhry, P.; Lamarre, A.; Lamentowicz, M.; Large, D.; Lavoie, M.; Macdonald, G.; Magnan, G.; Mäkilä, M.; Mallon, G.; Mathijssen, P.; Mauquoy, D.; McCarroll, J.; Moore, T.R.; Nichols, J.; O'Reilly, B.; Oksanen, P.; Packalen, M.; Peteet, D.; Richard, P.J.H.; Robinson, S.; Ronkainen, T.; Rundgren, M.; Sannel, A.B.K.; Tarnocai, C.; Thom, T.; Tuittila, E.S.; Turetsky, M.; Väliranta, M.; van der Linden, M.; van Geel, B.; van Bellen, S.; Vitt, D.; Zhao, Y.; Zhou, W.

    2014-01-01

    Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45°N. It encompasses regions within which peat

  19. Peatland subsidence: are the biggest problems to be expected in the tropics?

    Science.gov (United States)

    Hooijer, A.; Erkens, G.; Vernimmen, R.; Page, S.; Triadi, B.; Applegate, G.

    2012-12-01

    Subsidence in drained peatlands is mainly caused by oxidation, which is highly temperature dependent. Subsidence rates, and the associated carbon emissions, are therefore far higher in tropical regions than in the temperate areas where most research has been done to date. In SE Asia alone, up to 25 Mha of lowland peatland is now being drained in ways that are unlikely to be sustainable beyond the short term, as surface lowering by about 4 metres within 50 years is expected to cause large-scale inundation and loss of agricultural production. Problems of similar scale may become apparent in other tropical regions, as agriculture expands into ever less suitable areas including peatlands. Applying recent findings on peat thickness, surface elevation and subsidence rate, we can now demonstrate the scale and timing of such problems for case study areas in Indonesia. To allow reduction of such impacts, which may be mitigated but often not prevented, it is important that local conditions are not seen in isolation, but rather investigated from a global perspective that integrates findings from different climate regions. Data from the Everglades and Sacramento Delta, peatlands in warm climates that were drained 100 years ago, provide the best analogue to what can be expected at a far larger scale in tropical regions.

  20. Planning hydrological restoration of peatlands in Indonesia to mitigate carbon dioxide emissions

    NARCIS (Netherlands)

    Jaenicke, J.; Wösten, H.; Budiman, A.; Siegert, F.

    2010-01-01

    Extensive degradation of Indonesian peatlands by deforestation, drainage and recurrent fires causes release of huge amounts of peat soil carbon to the atmosphere. Construction of drainage canals is associated with conversion to other land uses, especially plantations of oil palm and pulpwood trees,

  1. Mud, muddle and models in the knowledge value-chain to action on tropical peatland conservation

    NARCIS (Netherlands)

    Noordwijk, van M.; Matthews, R.B.; Agus, F.; Farmer, J.; Verchot, L.; Hergoualc’h, K.; Persch, S.; Tata, H.L.; Lusiana, B.; Widayati, A.; Dewi, S.

    2014-01-01

    Tropical peatlands are known not only for their high, area-based, carbon emissions in response to land-use change but also as hot spots of debate about associated data uncertainties. Perspectives are still evolving on factors underlying the variability and uncertainty. Debate includes the ways of

  2. 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

    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...

  3. 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...

  4. 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

  5. Shallow peatland ecohydrology - the control of peat depth on moss productivity

    Science.gov (United States)

    Dixon, Simon; Kettridge, Nicholas; Moore, Paul; Devito, Kevin; Tilak, Amey; Petrone, Rich; Mendoza, Carl; Waddington, Mike

    2017-04-01

    Northern peatlands represent an important sink in the global carbon cycle. Shallow peatlands and marginal connective wetlands can be essential components of many northern peatland landscape mosaics, playing a vital role in landscape connectivity and wider landscape hydrology. However the ecohydrological function of these shallow, marginal systems has been largely overlooked, with peatland hydrology research focused on relatively deep bog systems. In order to predict landscape scale wetland function and its vulnerability to climate change we need to understand how these shallow connective systems function. The balance between moss productivity and water loss provide a key component of these systems, as water use efficiency controls the rate of moss growth and thus controls the amount of atmospheric carbon sequestered in peat. Understanding how productivity of shallow peatland systems responds to changes in evaporative stress will aid predictions of peatland landscape hydrological function in a changing climate. To determine the factors influencing peat productivity, water balance simulations using Hydrus 1-D were conducted over annual growing seasons for different soil profile depths, compositions and antecedent moisture conditions. Our results demonstrate a bimodal distribution of peatland responses; either primarily conserving water by limiting evapotranspiration or, maximizing productivity. For sustained periods of evaporative stress, shallow marginal systems are least able to buffer periods of evaporative stress due to limited labile water storage, and will limit evaporation, conserve water and be less productive. Conversely, where present, both deep water storage and a shallow initial water table prolong the onset of high vegetative stress, thus maximizing moss productivity. However, a total depth of 0.8 m is identified as the threshold above which increasing peat depth has no further effect on changing vegetative stress response and thus landscape function

  6. Environmental indifference? A critique of environmentally deterministic theories of peatland archaeological site construction in Ireland

    Science.gov (United States)

    Plunkett, G.; McDermott, C.; Swindles, G. T.; Brown, D. M.

    2013-02-01

    Climate change, whether gradual or sudden, has frequently been invoked as a causal factor to explain many aspects of cultural change during the prehistoric and early historic periods. Critiquing such theories has often proven difficult, not least because of the imprecise dating of many aspects of the palaeoclimate or archaeological records and the difficulties of merging the two strands of research. Here we consider one example of the archaeological record - peatland site construction in Ireland - which has previously been interpreted in terms of social response to climate change and examine whether close scrutiny of the archaeological and palaeoenvironmental records upholds the climatically deterministic hypotheses. We evaluate evidence for phasing in the temporal distribution of trackways and related sites in Irish peatlands, of which more than 3500 examples have been recorded, through the examination of ˜350 dendrochronological and 14C dates from these structures. The role of climate change in influencing when such sites were constructed is assessed by comparing visually and statistically the frequency of sites over the last 4500 years with well-dated, multiproxy climate reconstructions from Irish peatlands. We demonstrate that national patterns of “peatland activity” exist that indicate that the construction of sites in bogs was neither a constant nor random phenomenon. Phases of activity (i.e. periods in which the number of structures increased), as well as the ‘lulls’ that separate them, show no consistent correlation with periods of wetter or drier conditions on the bogs, suggesting that the impetus for the start or cessation of such activity was not climatically-determined. We propose that trigger(s) for peatland site construction in Ireland must instead also be sought within the wider, contemporary social background. Perhaps not surprisingly, a comparison with archaeological and palynological evidence shows that peatland activity tends to occur at

  7. Mold management of wetted carpet.

    Science.gov (United States)

    Ong, Kee-Hean; Dixit, Anupma; Lewis, Roger D; MacDonald Perkins, Maureen; Backer, Denis; Condoor, Sridhar; Emo, Brett; Yang, Mingan

    2014-01-01

    This study evaluated the growth and removal of fungi on wetted carpet using newly designed technologies that rely on physical principles of steam, heat, and fluid flow. Sixty samples of carpet were embedded with heat-treated house dust, followed by embedding, wearing with a hexapod, and wetting. Samples were inoculated using a liquid suspension of Cladosporium sphaerospermum prior to placement over a water-saturated foam pad. Incubation times were 24 hr, 7 days, and 30 days. Cleaning was performed using three methods; high-flow hot water extraction, hot water and detergent, and steam. Fungal loading increased from approximately 1500 colony forming units per area (CFU/cm(2)) in 24 hr to a maximum of approximately 10,200 CFU/cm(2) after 7 days with a slight decline to 9700 CFU/cm(2) after 30 days incubation. Statistically significant differences were found among all three methods for removal of fungi for all three time periods (p mold spore decline from wetted carpet after 24 hr and 30 days, and over 92% efficiency after 7 days. The alternative methods exhibited lower efficiencies with a decline over time, from a maximum of 82% and 81% at 24 hr down to 60% and 43% at 30 days for detergent-hot water and high-flow, hot water extraction, respectively. The net effect of the mold management study demonstrates that while steam has a consistent fungal removal rate, the detergent and high-flow, hot water methods decline in efficiency with increasing incubation time.

  8. Coal combustion by wet oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

    1980-11-15

    The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

  9. Wet/Dry Vacuum Cleaner

    Science.gov (United States)

    Reimers, Harold; Andampour, Jay; Kunitser, Craig; Thomas, Ike

    1995-01-01

    Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

  10. The Red Lake Peatland Observatory (RLPO): A multi-sensor instrument array for monitoring carbon-water dynamics in a large northern peatland

    Science.gov (United States)

    Glaser, P. H.; Rosenberry, D. O.; Reeve, A. S.; Siegel, D. I.; Chanton, J. P.; Slater, L. D.; Comas, X.; Rhoades, J. M.; Allen, L.; Corbett, J.; D'Andrilli, J.; Tfilany, M. I.; Parsekian, A.; Nolan, J.; Sarkar, M.; Gracz, M.; Morin, P. J.

    2009-12-01

    The 1200 sq km Red Lake peatland in northern Minnesota has been the focus of an ongoing study of carbon-groundwater interactions for over 30 years. This large continuous expanse of peatland contains several major bog complexes, each of which covers over 100 sq. km. Each bog complex has 1) a forested bog crest that grades downslope into 2) gently sloping Sphagnum lawns and 3) fen water tracks that divide the lower flanks of the bog into ovoid-shaped "islands." Building upon past work we installed 20 new instrument stations in the RLII watershed to monitor fluxes of carbon, water, and heat continuously within the 4m-thick peat profile and also the atmospheric boundary layer on scales of meters to kilometers. This integrated array of stations comprise the Red Lake Peatland Observatory (RLPO), which now collects data from a) 14 dual-frequency GPS units arranged in a nested triangular network measuring vertical and lateral deformations of the peat mass caused by changes in water and gas storage, b) 2 eddy covariance units that monitor fluxes in heat, momentum, carbon dioxide, and water vapor across the atmospheric boundary layer, and c) 4 stations equipped with instrumented piezometers and meteorological sensors for measuring changes in water and gas storage within the entire peat profile. All remote stations communicate by radio to a base station and through the internet to a centralized database at the University of Minnesota that automatically downloads and stores sensor data on a daily basis. Large degassing events were previously detected by monitoring sharp depressuring cycles from a zone of overpressure at 2 m below the bog crest site that occurred synchronously with vertical oscillations of the peat surface in excess of 10 cm in hours. These types of measurements have now been extended to much finer sampling intervals across a much broader portion of the peatland. Free--phase gas appears to accumulate throughout the peat profile in winter after the surface

  11. Including hydrological self-regulating processes in peatland models: Effects on peatmoss drought projections.

    Science.gov (United States)

    Nijp, Jelmer J; Metselaar, Klaas; Limpens, Juul; Teutschbein, Claudia; Peichl, Matthias; Nilsson, Mats B; Berendse, Frank; van der Zee, Sjoerd E A T M

    2017-02-15

    The water content of the topsoil is one of the key factors controlling biogeochemical processes, greenhouse gas emissions and biosphere - atmosphere interactions in many ecosystems, particularly in northern peatlands. In these wetland ecosystems, the water content of the photosynthetic active peatmoss layer is crucial for ecosystem functioning and carbon sequestration, and is sensitive to future shifts in rainfall and drought characteristics. Current peatland models differ in the degree in which hydrological feedbacks are included, but how this affects peatmoss drought projections is unknown. The aim of this paper was to systematically test whether the level of hydrological detail in models could bias projections of water content and drought stress for peatmoss in northern peatlands using downscaled projections for rainfall and potential evapotranspiration in the current (1991-2020) and future climate (2061-2090). We considered four model variants that either include or exclude moss (rain)water storage and peat volume change, as these are two central processes in the hydrological self-regulation of peatmoss carpets. Model performance was validated using field data of a peatland in northern Sweden. Including moss water storage as well as peat volume change resulted in a significant improvement of model performance, despite the extra parameters added. The best performance was achieved if both processes were included. Including moss water storage and peat volume change consistently reduced projected peatmoss drought frequency with >50%, relative to the model excluding both processes. Projected peatmoss drought frequency in the growing season was 17% smaller under future climate than current climate, but was unaffected by including the hydrological self-regulating processes. Our results suggest that ignoring these two fine-scale processes important in hydrological self-regulation of northern peatlands will have large consequences for projected climate change impact on

  12. Testing peatland water-table depth transfer functions using high-resolution hydrological monitoring data

    Science.gov (United States)

    Swindles, Graeme T.; Holden, Joseph; Raby, Cassandra L.; Turner, T. Edward; Blundell, Antony; Charman, Dan J.; Menberu, Meseret Walle; Kløve, Bjørn

    2015-07-01

    Transfer functions are now commonly used to reconstruct past environmental variability from palaeoecological data. However, such approaches need to be critically appraised. Testate amoeba-based transfer functions are an established method for the quantitative reconstruction of past water-table variations in peatlands, and have been applied to research questions in palaeoclimatology, peatland ecohydrology and archaeology. We analysed automatically-logged peatland water-table data from dipwells located in England, Wales and Finland and a suite of three year, one year and summer water-table statistics were calculated from each location. Surface moss samples were extracted from beside each dipwell and the testate amoebae community composition was determined. Two published transfer functions were applied to the testate-amoeba data for prediction of water-table depth (England and Europe). Our results show that estimated water-table depths based on the testate amoeba community reflect directional changes, but that they are poor representations of the real mean or median water-table magnitudes for the study sites. We suggest that although testate amoeba-based reconstructions can be used to identify past shifts in peat hydrology, they cannot currently be used to establish precise hydrological baselines such as those needed to inform management and restoration of peatlands. One approach to avoid confusion with contemporary water-table determinations is to use residuals or standardised values for peatland water-table reconstructions. We contend that our test of transfer functions against independent instrumental data sets may be more powerful than relying on statistical testing alone.

  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. Rewetting Decreases Carbon Emissions from the Zoige Alpine Peatland on the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Lijuan Cui

    2017-06-01

    Full Text Available Peatlands play an important role in the global carbon cycle and potentially have a significant impact on regional climate change. Restoring and rewetting the degraded peatlands is an urgent task. However, effects of rewetting on the carbon emissions of peatlands remain poorly understood. In this study, the process of rewetting a piece of the degraded Zoige alpine peatland was experimentally simulated and the derived results were compared with those of natural rewetting by monitoring CO2 and CH4 fluxes and other environmental factors before and after rewetting. The natural rewetting results showed that rewetting decreased ecosystem respiration (ER by about 60%. Furthermore, rewetting increased CH4 emissions by 127%, decreased total carbon emissions (TCE from 270 to 157 mg CO2 m−2 h−1, and decreased TCE from the entire ecosystem by 42%. The results of the controlled experiment showed that ER decreased gradually as the degree of rewetting was increased, and CH4 fluxes and changes in water level were significantly and positively correlated: CH4 fluxes increased from 0.3 (water level −20 cm to 2.17 mg CH4 m−2 h−1 (water level 20 cm. After rewetting, the TCE of the whole ecosystem were significantly decreased. Regional observations showed that CO2 fluxes were significantly and negatively correlated to the water level; and the corresponding CO2 equivalent was significantly and positively correlated to the water level, while TCE were significantly and negatively correlated to the water level. Our findings indicate that rewetting can decrease carbon emissions and thus contribute in mitigating the adverse effects of climate change in alpine peatland.

  15. Methanotrophy potential versus methane supply by pore water diffusion in peatlands

    Science.gov (United States)

    Hornibrook, E. R. C.; Bowes, H. L.; Culbert, A.; Gallego-Sala, A. V.

    2009-08-01

    Low affinity methanotrophic bacteria consume a significant quantity of methane in wetland soils in the vicinity of plant roots and at the oxic-anoxic interface. Estimates of the efficiency of methanotrophy in peat soils vary widely in part because of differences in approaches employed to quantify methane cycling. High resolution profiles of dissolved methane abundance measured during the summer of 2003 were used to quantity rates of upward methane flux in four peatlands situated in Wales, UK. Aerobic incubations of peat from a minerotrophic and an ombrotrophic mire were used to determine depth distributions of kinetic parameters associated with methane oxidation. The capacity for methanotrophy in a 3 cm thick zone immediately beneath the depth of nil methane abundance in pore water was significantly greater than the rate of upward diffusion of methane in all four peatlands. Rates of methane diffusion in pore water at the minerotrophic peatlands were small (rates. Methanotrophy appears to consume entirely methane transported by pore water diffusion in the four peatlands with the exception of 4 of the 33 gas profiles sampled. Flux rates to the atmosphere regardless are high because of gas transport through vascular plants, in particular, at the minerotrophic sites. Cumulative rainfall amount 3-days prior to sampling correlated well with the distance between the water table level and the depth of 0 μmol l-1 methane, indicating that precipitation events can impact methane distributions in pore water. Further work is needed to characterise the kinetics of methane oxidation spatially and temporally in different wetland types in order to determine generalized relationships for methanotrophy in peatlands that can be incorporated into process-based models of methane cycling in peat soils.

  16. Organic matter loss from temperate ombrotrophic peatlands: An evaluation of the ash residue method

    Science.gov (United States)

    Leifeld, Jens; Gubler, Lena; Grünig, Andreas

    2010-05-01

    Acting as "carbon sinks" that store more carbon per unit area than any other ecosystem, peatlands play a major role in regulating global climate. This is slowly but increasingly recognized, hence there is an urgent need to estimate the carbon budgets of peatlands more precisely. Due to increased aeration and successive oxidation, pristine peatlands usually release much carbon upon drainage. However, there is a lack of both data and appropriate methods for a generalized large-scale prediction of these emissions. Intact ombrothrophic peatlands are characterized by low ash contents. But there is a significant increase of the ash content after water level drawdown following drainage accelerating the decomposition of organic matter. To infer carbon losses from drainage we compared ash contents of deeper catotelm peat layers and near-surface peat layers and we relied on the results of soil carbon inventories as well. Four sites each of different drainage status and land use history in Central Europe have been selected for analysis. The method proved to yield reasonable results, at least for two drained sites where the mean loss rates varied between 0.14 and 0.49 kg C m-2 a-1. However, also a pristine bog showed relative ash accumulation. Therefore ash accumulation seems not exclusively being confined to drained sites. Previous land management seems to play a quite important role, too. Rehabilitation of a previously impaired site dissipated the original ash peak profile. In conclusion, the method is suitable to predict carbon losses from ombrothrophic bogs, at least in some cases. However, in countries with a long lasting tradition of anthropogenic interference, like in Europe, it is difficult to attribute drainage as the only factor of ash accumulation in ombrotrophic peatlands.

  17. Modelling past, present and future peatland carbon accumulation across the pan-Arctic region

    Directory of Open Access Journals (Sweden)

    N. Chaudhary

    2017-09-01

    Full Text Available Most northern peatlands developed during the Holocene, sequestering large amounts of carbon in terrestrial ecosystems. However, recent syntheses have highlighted the gaps in our understanding of peatland carbon accumulation. Assessments of the long-term carbon accumulation rate and possible warming-driven changes in these accumulation rates can therefore benefit from process-based modelling studies. We employed an individual-based dynamic global ecosystem model with dynamic peatland and permafrost functionalities and patch-based vegetation dynamics to quantify long-term carbon accumulation rates and to assess the effects of historical and projected climate change on peatland carbon balances across the pan-Arctic region. Our results are broadly consistent with published regional and global carbon accumulation estimates. A majority of modelled peatland sites in Scandinavia, Europe, Russia and central and eastern Canada change from carbon sinks through the Holocene to potential carbon sources in the coming century. In contrast, the carbon sink capacity of modelled sites in Siberia, far eastern Russia, Alaska and western and northern Canada was predicted to increase in the coming century. The greatest changes were evident in eastern Siberia, north-western Canada and in Alaska, where peat production hampered by permafrost and low productivity due the cold climate in these regions in the past was simulated to increase greatly due to warming, a wetter climate and higher CO2 levels by the year 2100. In contrast, our model predicts that sites that are expected to experience reduced precipitation rates and are currently permafrost free will lose more carbon in the future.

  18. Modelling past, present and future peatland carbon accumulation across the pan-Arctic region

    Science.gov (United States)

    Chaudhary, Nitin; Miller, Paul A.; Smith, Benjamin

    2017-09-01

    Most northern peatlands developed during the Holocene, sequestering large amounts of carbon in terrestrial ecosystems. However, recent syntheses have highlighted the gaps in our understanding of peatland carbon accumulation. Assessments of the long-term carbon accumulation rate and possible warming-driven changes in these accumulation rates can therefore benefit from process-based modelling studies. We employed an individual-based dynamic global ecosystem model with dynamic peatland and permafrost functionalities and patch-based vegetation dynamics to quantify long-term carbon accumulation rates and to assess the effects of historical and projected climate change on peatland carbon balances across the pan-Arctic region. Our results are broadly consistent with published regional and global carbon accumulation estimates. A majority of modelled peatland sites in Scandinavia, Europe, Russia and central and eastern Canada change from carbon sinks through the Holocene to potential carbon sources in the coming century. In contrast, the carbon sink capacity of modelled sites in Siberia, far eastern Russia, Alaska and western and northern Canada was predicted to increase in the coming century. The greatest changes were evident in eastern Siberia, north-western Canada and in Alaska, where peat production hampered by permafrost and low productivity due the cold climate in these regions in the past was simulated to increase greatly due to warming, a wetter climate and higher CO2 levels by the year 2100. In contrast, our model predicts that sites that are expected to experience reduced precipitation rates and are currently permafrost free will lose more carbon in the future.

  19. The Paradox of Excess Nitrogen in Boreal Peatlands: Biogeochemical Gaps in Nitrogen Cycling Revealed

    Science.gov (United States)

    Vile, M. A.; Prsa, T.; Wieder, R.; Lamers, L. P.

    2011-12-01

    Globally, peatlands cover 3-4 % of the Earth's land surface (over 4 million km 2, yet they store 25-30 % of the world's soil carbon (C) and 9-16% of the world's soil nitrogen (N, 8-15 Pg) in peat. As in other terrestrial ecosystems, the cycling of C and N is closely linked, especially for ombrotrophic bogs. Bogs receive nutrient and water exclusively from the atmosphere, which ensures an N-limited, nutrient-poor habitat. In Alberta, NW Canada, peatlands have received exceptionally low atmospheric inputs of N (industrial expansion of Alberta's Oil Sands Mining (OSM) potentially threaten the pristine nature of peatlands through regionally elevated deposition of N-compounds (NOx). Prior to OSM, N inputs to bogs were limited exclusively to (1) biological N fixation, and (2) bulk background deposition. We examined the response of peatlands located in the OSM area to enhanced N deposition. Despite the large accumulation rates of N in peat, mean N:P ratios in Sphagnum moss capitula (11.0 ± 3.4; mean ± stdev) suggest that peat of boreal western Canada is still severely N limited and not limited by phosphorus. Collectively, these data underscore the severity of N-limitation in pristine bogs and their potential sensitivity to increased N inputs from oils sands mining. Additionally, because the majority of the data generated for N stress in peatlands is from eastern Canada and western Europe, we stress the need to encompass the response of bogs to N deposition within the bounds of the low N deposition gradient. We postulate the loss of symbiosis between Sphagnum and N-fixing microorganisms (cyanobacteria, bacteria) in nitrogen-polluted areas, and indicate its consequences at the species level (trade-off) and ecosystem level (including C sequestration).

  20. Changes in vascular plant functional types drive carbon cycling in peatlands

    Science.gov (United States)

    Zeh, Lilli; Bragazza, Luca; Erhagen, Björn; Limpens, Juul; Kalbitz, Karsten

    2016-04-01

    Northern peatlands store a large organic carbon (C) pool that is highly exposed to future environmental changes with consequent risk of releasing enormous amounts of C. Biotic changes in plant community structure and species abundance might have an even stronger impact on soil organic C dynamics in peatlands than the direct effects of abiotic changes. Therefore, a sound understanding of the impact of vegetation dynamics on C cycling will help to better predict the response of peatlands to environmental changes. Here, we aimed to assess the role of plant functional types (PFTs) in affecting peat decomposition in relation to climate warming. To this aim, we selected two peatlands at different altitude (i.e. 1300 and 1700 m asl) on the south-eastern Alps of Italy. The two sites represent a contrast in temperature, overall vascular plant biomass and relative ericoids abundance, with the highest biomass and ericoids occurrence at the low latitude. Within the sites we selected 20 plots of similar microtopographical position and general vegetation type (hummocks). All plots contained both graminoids and ericoids and had a 100% cover of Sphagnum mosses. The plots were subjected to four treatments (control, and three clipping treatments) in which we selectively removed aboveground biomass of ericoids, graminoids or both to explore the contribution of the different PFTs for soil respiration (n=5) and peat chemistry. Peat chemical composition was determined by the analysis of C and N and their stable isotopes in association with pyrolysis GC/MS. Soil respiration was measured after clipping with a Licor system. Preliminary findings suggest that peat decomposition pathway and rate depend on plant species composition and particularly on differences in root activity between PFTs. Finally, this study underlines the importance of biotic drivers to predict the effects of future environmental changes on peatland C cycling.

  1. Interaction between Posidonia oceanica meadows upper limit and hydrodynamics of four Mediterranean beaches

    Science.gov (United States)

    De Muro, Sandro; Ruju, Andrea; Buosi, Carla; Porta, Marco; Passarella, Marinella; Ibba, Angelo

    2017-04-01

    Posidonia oceanica meadow is considered to play an important role in the coastal geomorphology of Mediterranean beach systems. In particular, the importance of the meadow in protecting the coastline from erosion is well-recognized. Waves are attenuated by greater friction across seagrass meadows, which have the capacity to reduce water flow and therefore increase sediment deposition and accumulation as well as beach stability. The P. oceanica meadow upper limit usually occurs within the most dynamic zone of the beach system. Considering the great attention paid in the literature to the connection between the growth of P. oceanica and coastal hydrodynamics (Infantes et al., 2009; Vacchi et al., 2014; De Muro et al., 2016, 2017), this study aims at extending the previous work by investigating the combined influence of hydrodynamic parameters (e.g., wave-induced main currents and wave orbital velocity at the bottom) and different types of sea bottom (e.g., soft sediment, rocky substrates) on the position of the upper limit of the P. oceanica meadow. We applied this approach to 4 Mediterranean beach systems located on the Sardinian coastline (3 on the South and 1 on the North) and characterized by a wide range of orientations and incoming wave conditions. On these beaches, the extension of the P. oceanica meadows and the bathymetry have been obtained through detailed surveying campaigns and aerial photo analysis. In addition, high spatial resolution wave hydrodynamics have been reconstructed by running numerical simulations with Delft 3D. Offshore wave climate has been reconstructed by using measured datasets for those beaches that have a nearby buoy whose dataset is representative of the incoming wave conditions for that particular stretch of coast. Whereas, for those beaches with no availability of a representative measured dataset, wave climate has been analyzed from the NOAA hindcast dataset. From the whole range of incoming wave directions in deep waters, we

  2. Elucidating the mysteries of wetting.

    Energy Technology Data Exchange (ETDEWEB)

    Webb, Edmund Blackburn, III (,; ); Bourdon, Christopher Jay; Grillet, Anne Mary; Sackinger, Philip A.; Grest, Gary Stephen; Emerson, John Allen; Ash, Benjamin Jesse; Heine, David R.; Brooks, Carlton, F.; Gorby, Allen D.

    2005-11-01

    Nearly every manufacturing and many technologies central to Sandia's business involve physical processes controlled by interfacial wetting. Interfacial forces, e.g. conjoining/disjoining pressure, electrostatics, and capillary condensation, are ubiquitous and can surpass and even dominate bulk inertial or viscous effects on a continuum level. Moreover, the statics and dynamics of three-phase contact lines exhibit a wide range of complex behavior, such as contact angle hysteresis due to surface roughness, surface reaction, or compositional heterogeneities. These thermodynamically and kinetically driven interactions are essential to the development of new materials and processes. A detailed understanding was developed for the factors controlling wettability in multicomponent systems from computational modeling tools, and experimental diagnostics for systems, and processes dominated by interfacial effects. Wettability probed by dynamic advancing and receding contact angle measurements, ellipsometry, and direct determination of the capillary and disjoining forces. Molecular scale experiments determined the relationships between the fundamental interactions between molecular species and with the substrate. Atomistic simulations studied the equilibrium concentration profiles near the solid and vapor interfaces and tested the basic assumptions used in the continuum approaches. These simulations provide guidance in developing constitutive equations, which more accurately take into account the effects of surface induced phase separation and concentration gradients near the three-phase contact line. The development of these accurate models for dynamic multicomponent wetting allows improvement in science based engineering of manufacturing processes previously developed through costly trial and error by varying material formulation and geometry modification.

  3. Impact of groundwater table and plateau zokors (Myospalax baileyi) on ecosystem respiration in the Zoige Peatlands of China

    National Research Council Canada - National Science Library

    Zhou, Yan; Li, Nana; Grace, John; Yang, Meng; Lu, Cai; Geng, Xuemeng; Lei, Guangchun; Zhu, Wei; Deng, Yongfeng

    2014-01-01

    .... Mostly because of human impact, the peatlands at Zoige Wetlands face severe degradation, and the groundwater table is now lower than before, which has increased the population of the plateau zokor, a burrowing rodent...

  4. 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

  5. Towards a predictive model to assess the natural position of the Posidonia oceanica seagrass meadows upper limit.

    Science.gov (United States)

    Vacchi, Matteo; Montefalcone, Monica; Schiaffino, Chiara F; Parravicini, Valeriano; Bianchi, Carlo Nike; Morri, Carla; Ferrari, Marco

    2014-06-30

    The upper portion of the meadows of the protected Mediterranean seagrass Posidonia oceanica occurs in the region of the seafloor mostly affected by surf-related effects. Evaluation of its status is part of monitoring programs, but proper conclusions are difficult to draw due to the lack of definite reference conditions. Comparing the position of the meadow upper limit with the beach morphodynamics (i.e. the distinctive type of beach produced by topography and wave climate) provided evidence that the natural landwards extension of meadows can be predicted. An innovative model was therefore developed in order to locate the region of the seafloor where the meadow upper limit should lie in natural conditions (i.e. those governed only by hydrodynamics, in absence of significant anthropogenic impact). This predictive model was validated in additional sites, which showed perfect agreement between predictions and observations. This makes the model a valuable tool for coastal management. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Floristic diversity of extensively used fresh meadows (6510 in the Wielki Łęg Obrzański complex

    Directory of Open Access Journals (Sweden)

    Agnieszka Anna Klarzyńska

    2015-07-01

    Full Text Available One of the habitat types protected within the framework of the NATURA 2000 network due to the presence of species of European importance are fresh meadows from the Arrhenatherion alliance. The maintenance of their characteristic floristic composition depends on habitat conditions and extensive use, while any changes in this respect trigger succession transformations potentially threatening their nature value.  The aim of the study was to conduct nature and habitat valuation of one of the largest meadow complexes in the Wielkopolska region, i.e. Wielki Łęg Obrzański, which will make it possible to describe the preservation status of fresh meadows and their habitats.  Based on multifaceted analyses of 535 relevés made using the Braun-Blanquet method in the years 2006–2012 and representing the Arrhenatherion alliance, the phytosociological and botanical structure as well as constancy of species in individual variants (floristic types were determined. Moreover, their habitat conditions were defined, i.e. soil moisture and nitrogen content using the index method according to Ellenberg, while laboratory methods were used to determine the content of organic matter, soil moisture as well as the contents of potassium, magnesium and phosphorus in soil.  Floristic composition of fresh meadows from the Arrhenatherion alliance differs due to high heterogeneity of habitat. The presence of fresh meadow phytocenoses both on dried organic soils (the driest forms of flood meadows and on mineral soils (oak-hornbeam forests contributes to differences in the floristic composition both in ryegrass meadows and grass–fescue meadows, mainly due to soil moisture and fertility as well as sward use type. This constituted the basis for the identification of lower syntaxonomic units in the internal structure of the plant associations. Five variants were distinguished in Arrhenatheretum elatioris, while the community of Poa pratensis–Festuca rubra was developed

  7. Retention of contaminants in northern natural peatlands treating mine waste waters

    Science.gov (United States)

    Palmer, Katharina; Ronkanen, Anna-Kaisa; Klöve, Björn

    2014-05-01

    The mining industry in Finland is growing, leading to an increasing number of working and proposed mine sites. As a consequence, the amount of mine waste waters created is likewise increasing. This poses a great challenge for water management and purification, as these mine waste waters can lead to severe environmental and health consequences when released to receiving water bodies untreated. In the past years, the use of natural peatlands for cost-effective passive waste water treatment has been increasing. In this study, the fate of mine water contaminants in a treatment peatland receiving process waters from the Kittilä gold mine was investigated. Special attention was paid to the fate of potentially harmful substances such as arsenic, antimony or nickel. During the 4 years of operation, the peatland removed contaminants from process waters at varying efficiencies. While arsenic, antimony and nickel were retained at high efficiencies (>80% retention), other contaminants such as zinc, sulfate or iron were not retained or even leaching from the peatland. Soil samples taken in 2013 showed a linear increase of arsenic, antimony and nickel concentration in the peatland as compared to earlier sampling times, in agreement with the good retention efficiencies for those contaminants. Measured concentrations exceeded guideline values for contaminated soils, indicating that the prolonged use of treatment peatlands leads to high soil contamination and restrict further uses of the peatlands without remediation measures. Soil and pore water samples were taken along a transect with varying distance from the process water distribution ditch and analyzed for total and more easily mobile concentrations of contaminants (peat soil) as well as total and dissolved contaminants (water samples). Concentrations of contaminants such as arsenic, manganese or antimony in peat and pore water samples were highest near the distribution ditch and decreased with increasing distance from the

  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

    The amount of wastewaters generated during mining operations is increasing along with the increasing number of operation mines, which poses great challenges for mine water management and purification. Mine wastewaters contain high concentrations of nitrogen compounds such as nitrate (NO3-) and ammonium (NH4+) originating from remnant explosives as well as sulfate (SO42-) originating from the oxidation of sulfidic ores. At a mine site in Finnish Lapland, two natural peatlands have been used for cost-effective passive wastewater treatment. One peatland have been used for the treatment of drainage waters (TP 1), while the other has been used for the treatment of process-based wastewaters (TP 4). In this study, the impact of mine water derived nitrogen compounds as well as SO42- on the emission of the potent greenhouse gases methane (CH4) and nitrous oxide (N2O) from those treatment peatlands was investigated. Contaminant concentrations in the input and output waters of the treatment peatlands were monitored which allowed for the calculation of contaminant-specific retention efficiencies. Treatment peatlands showed generally good retention efficiencies for metals and metalloids (e.g. nickel, arsenic, antimony, up to 98% reduction in concentration) with rather low input-concentrations (i.e., in the μg/l-range). On the other hand, retention of contaminants with high input-concentrations (i.e., in mg/l-range) such as NO3-, NH4+ and SO42- was much lower (4-41%, 30-60% and -42-30%, respectively), indicating the limited capability of the treatment peatlands to cope with such high input concentrations. NO3- and NH4+ concentrations were determined in surface and pore water from TP 4 in July 2013 as well as in surface water from TP 1 and TP 4 in October 2013. Up to 720 μM NO3- and up to 600 μM NH4+ were detected in surface water of TP 4 in July 2013. NO3- and NH4+ concentrations in surface waters were highest near the mine wastewater distribution ditch and decreased with

  9. 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.

  10. Polarimetric synthetic aperture radar application for tropical peatlands classification: a case study in Siak River Transect, Riau Province, Indonesia

    Science.gov (United States)

    Novresiandi, Dandy Aditya; Nagasawa, Ryota

    2017-01-01

    Mapping spatial distributions of tropical peatlands is important for properly estimating carbon emissions and for providing information that aids in the sustainable management of tropical peatlands, particularly in Indonesia. This study evaluated the performance of phased array type L-band synthetic aperture radar (SAR) (PALSAR) dual-polarization and fully polarimetric data for tropical peatlands classification. The study area was in Siak River Transect, Riau Province, Indonesia, a rapidly developing region, where the peatland has been intensively converted mostly into oil palm plantations over the last two decades. Thus, polarimetric features derived after polarimetric decompositions, backscatter coefficients measurements, and the radar vegetation index were evaluated to classify tropical peatlands using the decision tree classifier. Overall, polarimetric features generated by the combination of dual-polarization and fully polarimetric data yielded an overall accuracy (OA) of 69% and a kappa coefficient (K) of 0.57. The integration of an additional feature, "distance to river," to the algorithm increased the OA to 76% and K to 0.66. These results indicated that the methodology in this study might serve as an efficient tool in tropical peatlands classification, especially when involving the use of L-band SAR dual-polarization and fully polarimetric data.

  11. Fluorescence spectroscopy of fulvic acids from fen peatlands

    Science.gov (United States)

    Maryganova, Victoria; Wojciech Szajdak, Lech

    2010-05-01

    Intensive cultivation and agricultural use of peatlands lead to the degradation and mineralization of peat. Fulvic acids (FA) as the most mobile part of peat organic matter can be considered as an early indicator of its changes. One of the most sensitive and simple methods for studying the structural chemistry of humic substances is fluorescence spectroscopy. The objective of this study was to analyze comparatively the fluorescence properties of FA from low-moor peats of different genesis and decomposition degree with respect to the peculiarities of their chemical structure. FA were isolated from 4 peat samples collected from different fen peatlands of Belarus. Fluorescence spectra were obtained on water solutions of FA at a concentration of 50 mg/L after adjustment to pH=2, 6 and 13 on a MSL-4800 spectrofluorimeter (Perkin Elmer, USA.) at 20 ± 2 oC. Emission spectra were obtained using an excitation wavelength of 365 nm. Excitation spectra were recorded by varying the excitation wavelength from 260 to 520 nm and measuring the fluorescence emission at a fixed wavelength of 520 nm. Elemental composition of FA and optical density at 465 nm (D465) of FA solutions in 0.1 N NaOH were determined. Emission spectra of FA are characterized by a broad featureless band of the maximum wavelengths at λ=460-475 nm. Excitation spectra of FA have three peaks localized in different wavelength regions. The maximum wavelengths and intensities of the excitation peaks depend on the pH values. The highest intensities are observed at pH=6. FA exhibit a main excitation peak at λ=355-370 nm, a minor peak at λ=395-400 nm, and a weak band at λ=430-440 nm. At pH=2, all the peaks decrease in intensity. With increasing the pH to 13, the excitation maximum at λ=355-370 nm shifts from 10 to 20 nm towards longer wavelengths compared to acidic solutions. A general decrease in fluorescence intensity is observed, the intensity decline of the peak at λ=355-370 nm being more marked than of the

  12. Real-Time Classification of Seagrass Meadows on Flat Bottom with Bathymetric Data Measured by a Narrow Multibeam Sonar System

    Directory of Open Access Journals (Sweden)

    Masahiro Hamana

    2016-01-01

    Full Text Available Seagrass meadows, one of the most important habitats for many marine species, provide essential ecological services. Thus, society must conserve seagrass beds as part of their sustainable development efforts. Conserving these ecosystems requires information on seagrass distribution and relative abundance, and an efficient, accurate monitoring system. Although narrow multibeam sonar systems (NMBSs are highly effective in resolving seagrass beds, post-processing methods are required to extract key data. The purpose of this study was to develop a simple method capable of detecting seagrass meadows and estimating their relative abundance in real time using an NMBS. Because most seagrass meadows grow on sandy seafloors, we proposed a way of discriminating seagrass meadows from the sand bed. We classify meadows into three categories of relative seagrass abundance using the 95% confidence level of beam depths and the depth range of the beam depth. These are respectively two times the standard deviation of beam depths, and the difference between the shallowest and the deepest depths in a 0.5 × 0.5 m grid cell sampled with several narrow beams. We examined Zostera caulescens Miki, but this simple NMBS method of seagrass classification can potentially be used to map seagrass meadows with longer shoots of other species, such as Posidonia, as both have gas filled cavities.

  13. Organic farming favours insect-pollinated over non-insect pollinated forbs in meadows and wheat fields.

    Directory of Open Access Journals (Sweden)

    Péter Batáry

    Full Text Available The aim of this study was to determine the relative effects of landscape-scale management intensity, local management intensity and edge effect on diversity patterns of insect-pollinated vs. non-insect pollinated forbs in meadows and wheat fields. Nine landscapes were selected differing in percent intensively used agricultural area (IAA, each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional meadows. Within fields, forbs were surveyed at the edge and in the interior. Both diversity and cover of forbs were positively affected by organic management in meadows and wheat fields. This effect, however, differed significantly between pollination types for species richness in both agroecosystem types (i.e. wheat fields and meadows and for cover in meadows. Thus, we show for the first time in a comprehensive analysis that insect-pollinated plants benefit more from organic management than non-insect pollinated plants regardless of agroecosystem type and landscape complexity. These benefits were more pronounced in meadows than wheat fields. Finally, the community composition of insect-pollinated and non-insect-pollinated forbs differed considerably between management types. In summary, our findings in both agroecosystem types indicate that organic management generally supports a higher species richness and cover of insect-pollinated plants, which is likely to be favourable for the density and diversity of bees and other pollinators.

  14. Organic farming favours insect-pollinated over non-insect pollinated forbs in meadows and wheat fields.

    Science.gov (United States)

    Batáry, Péter; Sutcliffe, Laura; Dormann, Carsten F; Tscharntke, Teja

    2013-01-01

    The aim of this study was to determine the relative effects of landscape-scale management intensity, local management intensity and edge effect on diversity patterns of insect-pollinated vs. non-insect pollinated forbs in meadows and wheat fields. Nine landscapes were selected differing in percent intensively used agricultural area (IAA), each with a pair of organic and conventional winter wheat fields and a pair of organic and conventional meadows. Within fields, forbs were surveyed at the edge and in the interior. Both diversity and cover of forbs were positively affected by organic management in meadows and wheat fields. This effect, however, differed significantly between pollination types for species richness in both agroecosystem types (i.e. wheat fields and meadows) and for cover in meadows. Thus, we show for the first time in a comprehensive analysis that insect-pollinated plants benefit more from organic management than non-insect pollinated plants regardless of agroecosystem type and landscape complexity. These benefits were more pronounced in meadows than wheat fields. Finally, the community composition of insect-pollinated and non-insect-pollinated forbs differed considerably between management types. In summary, our findings in both agroecosystem types indicate that organic management generally supports a higher species richness and cover of insect-pollinated plants, which is likely to be favourable for the density and diversity of bees and other pollinators.

  15. The chemical control of Sorghum halepense species in sunflower culture, in the Danube meadow.

    Science.gov (United States)

    Poienaru, S; Sarpe, N; Sarpe, I

    2005-01-01

    In the latest years, sunflower was cultivated in Romania on an area of 800-900 thousand hectares. On 100 or 150 thousand hectares we find it cultivated also in agricultural farms in the Danube Meadow, because sunflower has favorable conditions on these soils, productions exceeding sometimes over 4000 kg/ha, of course, in irrigation conditions. In the Danube Meadow, the first experiments on Sorghum halepense (Johnson grass) species were performed by Fane Popa and colleagues (1986), at the agricultural station of Braila, using the herbicide Fusilade. In our experiments, the herbicide fusillade was compared with different more recently synthesized herbicides: Super, Pantera, Agil, Select, with the specific purpose of identifying the most favorable dose.

  16. FACTORS AFFECTING GROUND WATER POLLUTION IN THE MEADOW OF BORCEA ARM

    Directory of Open Access Journals (Sweden)

    Cecilia NEAGU

    2014-04-01

    Full Text Available This paper aims to study the factors leading to water pollution by nitrates in the Meadow of Borcea arm, mainly derived from agricultural sources. mIn oder to model the amount of nitrate nitrogen in the soil, which can be partially used by plants or leached into the ground water, research was made on alluvial soil in the Meadow of Borcea arm. I tried to study in the laboratory the influence of three factors of nitrate nitrogen pollution of ground water: soil type, environmental conditions (temperature and humidity and the amount of mineral fertilizers incorporated. The resulting amount of nitrate nitrogen resulted with nitrogen fertilizer dose, and the temperature and it was affected by humidity especially 40-80% of field capacity.

  17. Simulations of dredged sediment spreading on a Posidonia oceanica meadow off the Ligurian coast, Northwestern Mediterranean.

    Science.gov (United States)

    Capello, M; Cutroneo, L; Ferranti, M P; Budillon, G; Bertolotto, R M; Ciappa, A; Cotroneo, Y; Castellano, M; Povero, P; Tucci, S

    2014-02-15

    The sandy deposits from dredging can have negative effects on the environment such as increase in suspended solids in the water column and their consequent transport. An experimental study was conducted to characterize water masses, dynamics, and sedimentation rates on the Ligurian continental shelf (Italy), where both a sand deposit, that could be used for beach nourishment, and a nearby Posidonia oceanica meadow coexist. The environmental plan provides a mathematical simulation of the sediment-dispersion to evaluate the possible impact on the meadow. It has been calculated that the dredging could double the concentration of suspended particles, but its scheduling will preclude a sediment accumulation. All the information obtained from this work will be used to study the environmental feasibility of the sand deposit exploitation and as starting point for drawing up the monitoring plan in case of dredging. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. 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

  19. Restoration of shallow peatlands on Exmoor (UK): initial effects on water quality

    Science.gov (United States)

    Grand-Clement, Emilie; Luscombe, David; Anderson, Karen; Gatis, Naomi; Ashe, Josie; Brazier, Richard

    2014-05-01

    Historical and recent anthropogenic pressure has had dramatic effects on peatlands throughout the UK. In the South West, drainage for agricultural reclamation and peat cutting since the 19th century has progressively altered the hydrological behaviour of the peatlands of Exmoor and Dartmoor National Parks. Lower water table levels have caused increased oxidation, erosion and vegetation change, further affecting the storage of carbon and the provision of other ecosystem services (i.e. supply of drinking water, biodiversity). Moreover, the location of these peatlands at the southernmost margin of the UK peatlands' geographical extent makes them extremely vulnerable to the predicted effects of climate change, i.e. increased temperature and change in rainfall pattern. An extensive programme of peatland restoration is currently underway on Exmoor. Drainage ditches were blocked to reinstate the hydrological behaviour, reduce the outflow of dissolved organic carbon and, in doing so, improve other ecosystem services delivered by peatlands. This paper will report on the water quality monitoring results from a small headwater catchment in Exmoor. We will show results comparing changes in Dissolved Organic Carbon (DOC) losses and colour pre- and post-restoration. Our experimental approach uses event-based water quality monitoring across three drainage ditches that are representative of the different scales of damage in the area. Samples were taken back to the laboratory and analysed for DOC and colour, using UV spectrophotometry and UV-vis spectrometry respectively. DOC loads were calculated using discharge for each drain. Overall, DOC concentrations ranged between 3 and 30mg/L. Both pre and post- restoration datasets presented high seasonal variability, with higher concentrations measured from June to September. No significant change in DOC concentrations was observed in the 6 months after restoration. It is hypothesised that the effects of restoration could be hidden by

  20. Under the Weather? A Critique of Environmental Deterministic Theories of Peatland Activity in Ireland

    Science.gov (United States)

    Plunkett, G.; McDermott, C.; Swindles, G. T.; Brown, D. M.

    2011-12-01

    Climate change, whether gradual or sudden, has frequently been invoked as a causal factor to explain many aspects of cultural change during the Irish prehistoric and early historic periods. More often than not, the link is based on an apparent temporal coincidence of a climate "event" and the subsequent initiation of a new cultural phase, recognised in the material culture, site architecture or site distribution patterns, rather than a demonstrated observance of societal response to an environmental change. Critiquing such theories has generally proven difficult, not least because of the imprecise dating of many aspects of the palaeoclimate or archaeological records and the difficulties of juxtaposing the two strands of research. This paper considers evidence for phasing in the temporal distribution of trackways and related sites in Irish peatlands, of which more than 3,500 examples have been recorded, through the examination of ~350 dendrochronological and 14C dates from these structures. The role of climate change in influencing when such sites were constructed is assessed by comparing visually and statistically the frequency of sites over the last 4,500 years with well-dated, multi-proxy climate reconstructions from Irish peatlands. We demonstrate that national patterns of "peatland activity" exist that indicate that the construction of sites in bogs was neither a constant nor random phenomenon. Phases of activity (i.e. periods in which the number of structures seems to have increased), as well as the lulls that separate them, show no consistent correlation with periods of wetter or drier conditions on the bogs, suggesting that the impetus for the start or cessation of such activity was not climatically-determined. We propose that trigger(s) for peatland site construction in Ireland must instead be sought within the wider, contemporary social background. Perhaps not surprisingly, a comparison with archaeological and palynological evidence shows that peatland