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Sample records for largest boreal wetland

  1. Introducing a boreal wetland model within the Earth System model framework

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    Getzieh, R. J.; Brovkin, V.; Reick, C.; Kleinen, T.; Raddatz, T.; Raivonen, M.; Sevanto, S.

    2009-04-01

    Wetlands of the northern high latitudes with their low temperatures and waterlogged conditions are prerequisite for peat accumulation. They store at least 25% of the global soil organic carbon and constitute currently the largest natural source of methane. These boreal and subarctic peat carbon pools are sensitive to climate change since the ratio of carbon sequestration and emission is closely dependent on hydrology and temperature. Global biogeochemistry models used for simulations of CO2 dynamics in the past and future climates usually ignore changes in the peat storages. Our approach aims at the evaluation of the boreal wetland feedback to climate through the CO2 and CH4 fluxes on decadal to millennial time scales. A generic model of organic matter accumulation and decay in boreal wetlands is under development in the MPI for Meteorology in cooperation with the University of Helsinki. Our approach is to develop a wetland model which is consistent with the physical and biogeochemical components of the land surface module JSBACH as a part of the Earth System model framework ECHAM5-MPIOM-JSBACH. As prototypes, we use modelling approach by Frolking et al. (2001) for the peat dynamics and the wetland model by Wania (2007) for vegetation cover and plant productivity. An initial distribution of wetlands follows the GLWD-3 map by Lehner and Döll (2004). First results of the modelling approach will be presented. References: Frolking, S. E., N. T. Roulet, T. R. Moore, P. J. H. Richard, M. Lavoie and S. D. Muller (2001): Modeling Northern Peatland Decomposition and Peat Accumulation, Ecosystems, 4, 479-498. Lehner, B., Döll P. (2004): Development and validation of a global database of lakes, reservoirs and wetlands. Journal of Hydrology 296 (1-4), 1-22. Wania, R. (2007): Modelling northern peatland land surface processes, vegetation dynamics and methane emissions. PhD thesis, University of Bristol, 122 pp.

  2. Mosaic boreal landscapes with open and forested wetlands

    International Nuclear Information System (INIS)

    Sjoeberg, K.; Ericson, L.

    1997-01-01

    We review patterns and processes important for biodiversity in the Fennoscandian boreal forest, describe man's past and present impact and outline a strategy for conservation. The boreal landscape was earlier characterized by a mosaic of open and forested wetlands and forests. Drainage and felling operation have largely changed that pattern. Several organisms depend upon the landscape mosaic. Natural ecotones between mire and forest provide food resources predictable in space and time contrasting to unpredictable edges in the silvicultured landscape. The mosaic is also a prerequisite for organisms dependent on non-substitutable resources in the landscape. The importance of swamp forests has increased as they function as refugia for earlier more widespread old-growth species. Programmes for maintaining biodiversity in the boreal landscape should include the following points. First, the natural mosaic with open and forested wetlands must be maintained. Second, swamp forests must receive a general protection as they often constitute the only old-growth patches in the landscape. Third, we need to restore earlier disturbance regimes. Present strategy plans for conservation are insufficient, as they imply that a too large proportion of boreal organisms will not be able to survive outside protected areas. Instead, we need to focus more on how to preserve organisms in the man-influenced landscape. As a first step we need to understand how organisms are distributed in landscapes at various spatial scales. We need studies in landscapes where the original mosaic has faced various degrees of fragmentation. (au) 124 refs

  3. Wetlands in Canada's western boreal forest: Agents of change

    Energy Technology Data Exchange (ETDEWEB)

    Foote, L.; Krogman, N. [University of Alberta, Edmonton, AB (Canada). Dept. of Renewable Resources

    2006-11-15

    Wetlands of the western boreal forest are poorly studied. In the last decade (1990-2000) there were approximately 1810 northern hemisphere scientific papers published addressing boreal wetlands, tundra, taiga, or bogs. We explore the extent of understanding and impacts of six major agents of change affecting forested wetlands of the boreal zone: (1) commercial forestry, (2) petroleum extraction, (3) mining (bitumen, coal, peat, ore, and diamonds), (4) agriculture, (5) climate change, and (6) hydrologic alteration. Finally, we address the social context, costs, and recommendations for wetland maintenance.

  4. Long-term change in limnology and invertebrates in Alaskan boreal wetlands

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    Corcoran, R.M.; Lovvorn, J.R.; Heglund, P.J.

    2009-01-01

    Climate change is more pronounced at high northern latitudes, and may be affecting the physical, chemical, and biological attributes of the abundant wetlands in boreal forests. On the Yukon Flats, located in the boreal forest of northeast Alaska, wetlands originally sampled during 1985-1989 were re-sampled for water chemistry and macroinvertebrates in summer 2001-2003. Wetlands sampled lost on average 19% surface water area between these periods. Total nitrogen and most metal cations (Na, Mg, and Ca, but not K) increased between these periods, whereas total phosphorus and chlorophyll a (Chl a) declined. These changes were greater in wetlands that had experienced more drying (decreased surface area). Compared with 1985-1989, densities of cladocerans, copepods, and ostracods in both June and August were much higher in 2002-2003, whereas densities of amphipods, gastropods, and chironomid larvae were generally lower. In comparisons among wetlands in 2002-2003 only, amphipod biomass was lower in wetlands with lower Chl a, which might help explain the decline of amphipods since the late 1980s when Chl a was higher. The decline in Chl a corresponded to greatly increased zooplankton density in June, suggesting a shift in carbon flow from scrapers and deposit-feeders to water-column grazers. Declines in benthic and epibenthic deposit-feeding invertebrates suggest important food web effects of climate change in otherwise pristine wetlands of the boreal forest. ?? 2008 Springer Science+Business Media B.V.

  5. Modelling Holocene carbon accumulation and methane emissions of boreal wetlands – an Earth system model approach

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    R. J. Schuldt

    2013-03-01

    Full Text Available Since the Last Glacial Maximum, boreal wetlands have accumulated substantial amounts of peat, estimated at 180–621 Pg of carbon. Wetlands have significantly affected the atmospheric greenhouse gas composition in the past and will play a significant role in future changes of atmospheric CO2 and CH4 concentrations. In order to investigate those changes with an Earth system model, biogeochemical processes in boreal wetlands need to be accounted for. Thus, a model of peat accumulation and decay was developed and included in the land surface model JSBACH of the Max Planck Institute Earth System Model (MPI-ESM. Here we present the evaluation of model results from 6000 yr BP to the pre-industrial period. Over this period of time, 240 Pg of peat carbon accumulated in the model in the areas north of 40° N. Simulated peat accumulation rates agree well with those reported for boreal wetlands. The model simulates CH4 emissions of 49.3 Tg CH4 yr−1 for 6000 yr BP and 51.5 Tg CH4 yr−1 for pre-industrial times. This is within the range of estimates in the literature, which range from 32 to 112 Tg CH4 yr−1 for boreal wetlands. The modelled methane emission for the West Siberian Lowlands and Hudson Bay Lowlands agree well with observations. The rising trend of methane emissions over the last 6000 yr is in agreement with measurements of Antarctic and Greenland ice cores.

  6. Modelling carbon cycle in boreal wetlands with the Earth System Model ECHAM6/MPIOM

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    Getzieh, Robert J.; Brovkin, Victor; Kleinen, Thomas; Raivonen, Maarit; Sevanto, Sanna

    2010-05-01

    Wetlands of the northern high latitudes provide excellent conditions for peat accumulation and methanogenesis. High moisture and low O2 content in the soils lead to effective preservation of soil organic matter and methane emissions. Boreal Wetlands contain about 450 PgC and currently constitute a significant natural source of methane (CH4) even though they cover only 3% of the global land surface. While storing carbon and removing CO2 from the atmosphere, boreal wetlands have contributed to global cooling on millennial timescales. Undisturbed boreal wetlands are likely to continue functioning as a net carbon sink. On the other hand these carbon pools might be destabilised in future since they are sensitive to climate change. Given that processes of peat accumulation and decay are closely dependent on hydrology and temperature, this balance may be altered significantly in the future. As a result, northern wetlands could have a large impact on carbon cycle-climate feedback mechanisms and therefore play an important role in global carbon cycle dynamics. However global biogeochemistry models used for simulations of CO2 dynamics in past and future climates usually neglect carbon cycle in wetlands. We investigate the potential for positive or negative feedbacks to the climate system through fluxes of greenhouse gases (CO2 and CH4) with the general circulation model ECHAM6/MPIOM. A generic model of peat accumulation and decay has been developed and implemented into the land surface module JSBACH. We consider anaerobic biogeochemical processes which lead to formation of thick organic soils. Furthermore we consider specific wetland plant functional types (PFTs) in our model such as vascular plants (sedges) which impact methane transport and oxidation processes and non vascular plants (sphagnum mosses) which are promoting peat growth. As prototypes we use the modelling approaches by Frolking et al. (2001) as well as Walter & Heimann (2001) for the peat dynamics, and the

  7. Low methane flux from a constructed boreal wetland

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    Clark, M. G.; Humphreys, E.; Carey, S. K.

    2016-12-01

    The Sandhill Fen Watershed project in northern Alberta, Canada, is a pilot study in reconstructing a mixed upland and lowland boreal plain ecosystem. The physical construction of the 50 ha area was completed in 2012 and revegetation programs, through planting and seeding, began that same year and continued into 2013. Since then, the vegetation has developed a substantial cover over the reclaimed soil and peat substrates used to cap the engineered topography constructed from mine tailings. To monitor the dynamics of carbon cycling processes in this novel ecosystem, near weekly gas chamber measurements of methane fluxes were carried out over 3 growing seasons. Soil moisture, temperature and ion flux measurements, using Plant Root Simulator probes, were also collected alongside the gas flux plots. In the 3rd season, a transect was established in the lowlands along a moisture gradient to collect continuous reduction-oxidation potential measurements along with these other variables. Overall, methane effluxes remained low relative to what is expected for rewetted organic substrates. However, there is a trend over time towards increasing methane gas emissions that coincides with increasing fluxes of reduced metal ions and decreasing fluxes of sulphate in the fully saturated substrates. The suppressed levels of methane fluxes are possibly due to naturally occurring high levels of sulphate in the donor materials used to cap the ecosystem construction.

  8. C2-C10 hydrocarbon emissions from a boreal wetland and forest floor

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    H. Hellén

    2006-01-01

    Full Text Available Emissions of various C2-C10 hydrocarbons (VOCs and halogenated hydrocarbons (VHOCs from a boreal wetland and a Scots pine forest floor in south-western Finland were measured by the static chamber technique. Isoprene was the main non-methane hydrocarbon emitted by the wetland, but small emissions of ethene, propane, propene, 1-butene, 2-methylpropene, butane, pentane and hexane were also detected. The isoprene emission from the wetland was observed to follow the commonly-used isoprene emission algorithm. The mean emission potential of isoprene was 224 µg m-2 h-1 for the whole season. This is lower than the emission potentials published earlier; that is probably at least partly due to the cold and cloudy weather during the measurements. No emissions were detected of monoterpenes or halogenated hydrocarbons from the wetland. The highest hydrocarbon emissions from the Scots pine forest floor were measured in spring and autumn. However, only a few measurements were conducted during summer. The main compounds emitted were monoterpenes. Isoprene emissions were negligible. The total monoterpene emission rates varied from zero to 373 µg m-2 h-1. The results indicated that decaying plant litter may be the source for these emissions. Small emissions of chloroform (100-800 ng m-2 h-1, ethene, propane, propene, 2-methylpropene, cis-2-butene, pentane, hexane and heptane were detected. Comparison with Scots pine emissions showed that the forest floor may be an important monoterpene source, especially in spring.

  9. Determining Hydroperiod for Boreal and Prairie Pothole Wetlands using SAR, Optical and LiDAR Remote Sensing Data Fusion

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    Montgomery, J. S.; Hopkinson, C.; Brisco, B.; Patterson, S.; Chasmer, L.; Mahoney, C.

    2017-12-01

    Cultivation, irrigation networks, and infrastructure have all greatly impacted the ecology and hydrology of the Prairie Pothole and Boreal regions of western Canada. Due to sub-humid climate and high potential evaporation, many wetlands in these natural regions are seldom continuously occupied by water, and are often confined to local depressions. In the Boreal region, wetlands may be difficult to monitor due to their remote location, whereas prairie wetlands have highly varying degrees of surface water and soil saturation throughout the year. This study examines how high-resolution Lidar, Synthetic Aperture Radar (SAR), and optical data can be utilized in spatial-temporal studies to classify wetlands based on water extent, riparian vegetation, and topographic characteristics. An intensity (dB) threshold routine was used to extract open surface water extent to determine hydroperiod. Digital Elevation Models (DEM) are used with a topographic position index to infer local depressions, while Digital Surface Models (DSMs) are used to characterise vegetation structural characteristics within and proximal to wetlands. The proposed framework provides an index of wetland permanence and wetland class, where permanence varies seasonally and annually. Boreal wetland hydroperiod is less variable than that found in prairie pothole wetlands, most notably the semi-permanent class, varying by only 2%, compared to >50% in prairie pothole wetlands. For years studied, prairie pothole wetlands reached maximum water extent following major rainfall events. Seasonal and semi-permanent wetlands were found to have greater change in surface water between years than temporary wetlands (75.3% and 59.1% from average respectively). The lowest frequency of water pixel inundation for seasonal and semi-permanent wetlands was found to be in the year with the most precipitation during the growing season (2013, 384mm), compared to 2014 (289mm), and 2015 (310mm). A combination of statistical analyses

  10. Effects of Boreal Lake Wetlands on Atmospheric 13CH3D and 12CH2D2

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    Haghnegahdar, M. A.; Kohl, I. E.; Schauble, E. A.; Walter Anthony, K. M.; Young, E. D.

    2017-12-01

    Recently, we developed a theoretical model to investigate the potential use of 13CH3D and 12CH2D2 as tools for tracking atmospheric methane budget. We used electronic structure methods to estimate kinetic isotope fractionations associated with the major sink reactions of CH4 in air (reactions with •OH and Cl•), and literature data with reconnaissance measurements of the relative abundances of 13CH3D and 12CH2D2 to estimate the compositions of the largest atmospheric sources. Here we present new methane rare isotopologue data from boreal wetlands, comprising one of the most important sources, in order to evaluate the robustness of the model. Boreal wetlands (>55° N) account for more than half of the wetland area in the Northern hemisphere. We analyzed methane samples from high latitude lakes representing different geographical regions, geological and ecological contexts, methane fluxes, and isotopic signatures. Using clumped isotopes of CH4 we are able to determine the likely production mechanism for natural CH4 samples. So far, all of our analyzed samples except one plot in the microbial pure-culture methanogenesis field (Young et al. 2017) with ranges of -0.2‰ to +1.2‰ for Δ13CH3D, and -29.6‰ to -18.2‰ for Δ12CH2D2. These compositions are far from equilibrium. The one exception, from Lake Doughnut, Alaska, exhibits Δ13CH3D and Δ12CH2D2 values of +5.2‰ and +18.7‰, respectively, which fall near ambient thermodynamic equilibrium values. This may be an effect of methanotrophy. Mean Δ13CH3D and Δ12CH2D2 for all lake samples are +1.7‰ and -15.4‰ respectively, compared to our original estimate of +6.1‰ and +21.2‰ for the wetland methane source based on an assumption of equilibrium. If we assume that these samples are representative of the overall wetland source, Δ13CH3D decreases by 0.8‰ and Δ12CH2D2 decreases by 0.6‰ in our model of bulk atmospheric methane. Δ13CH3D and Δ12CH2D2 values of air (including •OH and Cl• sink

  11. Modelling wetland-groundwater interactions in the boreal Kälväsvaara esker, Northern Finland

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    Jaros, Anna; Rossi, Pekka; Ronkanen, Anna-Kaisa; Kløve, Bjørn

    2016-04-01

    Many types of boreal peatland ecosystems such as alkaline fens, aapa mires and Fennoscandia spring fens rely on the presence of groundwater. In these ecosystems groundwater creates unique conditions for flora and fauna by providing water, nutrients and constant water temperature enriching local biodiversity. The groundwater-peatland interactions and their dynamics are not, however, in many cases fully understood and their measurement and quantification is difficult due to highly heterogeneous structure of peatlands and large spatial extend of these ecosystems. Understanding of these interactions and their changes due to anthropogenic impact on groundwater resources would benefit the protection of the groundwater dependent peatlands. The groundwater-peatland interactions were investigated using the fully-integrated physically-based groundwater-surface water code HydroGeoSphere in a case study of the Kälväsvaara esker aquifer, Northern Finland. The Kälväsvaara is a geologically complex esker and it is surrounded by vast aapa mire system including alkaline and springs fens. In addition, numerous small springs occur in the discharge zone of the esker. In order to quantify groundwater-peatland interactions a simple steady-state model was built and results were evaluated using expected trends and field measurements. The employed model reproduced relatively well spatially distributed hydrological variables such as soil water content, water depths and groundwater-surface water exchange fluxes within the wetland and esker areas. The wetlands emerged in simulations as a result of geological and topographical conditions. They could be identified by high saturation levels at ground surface and by presence of shallow ponded water over some areas. The model outputs exhibited also strong surface water-groundwater interactions in some parts of the aapa system. These areas were noted to be regions of substantial diffusive groundwater discharge by the earlier studies. In

  12. The positive net radiative greenhouse gas forcing of increasing methane emissions from a thawing boreal forest-wetland landscape.

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    Helbig, Manuel; Chasmer, Laura E; Kljun, NatasCha; Quinton, William L; Treat, Claire C; Sonnentag, Oliver

    2017-06-01

    At the southern margin of permafrost in North America, climate change causes widespread permafrost thaw. In boreal lowlands, thawing forested permafrost peat plateaus ('forest') lead to expansion of permafrost-free wetlands ('wetland'). Expanding wetland area with saturated and warmer organic soils is expected to increase landscape methane (CH 4 ) emissions. Here, we quantify the thaw-induced increase in CH 4 emissions for a boreal forest-wetland landscape in the southern Taiga Plains, Canada, and evaluate its impact on net radiative forcing relative to potential long-term net carbon dioxide (CO 2 ) exchange. Using nested wetland and landscape eddy covariance net CH 4 flux measurements in combination with flux footprint modeling, we find that landscape CH 4 emissions increase with increasing wetland-to-forest ratio. Landscape CH 4 emissions are most sensitive to this ratio during peak emission periods, when wetland soils are up to 10 °C warmer than forest soils. The cumulative growing season (May-October) wetland CH 4 emission of ~13 g CH 4  m -2 is the dominating contribution to the landscape CH 4 emission of ~7 g CH 4  m -2 . In contrast, forest contributions to landscape CH 4 emissions appear to be negligible. The rapid wetland expansion of 0.26 ± 0.05% yr -1 in this region causes an estimated growing season increase of 0.034 ± 0.007 g CH 4  m -2  yr -1 in landscape CH 4 emissions. A long-term net CO 2 uptake of >200 g CO 2  m -2  yr -1 is required to offset the positive radiative forcing of increasing CH 4 emissions until the end of the 21st century as indicated by an atmospheric CH 4 and CO 2 concentration model. However, long-term apparent carbon accumulation rates in similar boreal forest-wetland landscapes and eddy covariance landscape net CO 2 flux measurements suggest a long-term net CO 2 uptake between 49 and 157 g CO 2  m -2  yr -1 . Thus, thaw-induced CH 4 emission increases likely exert a positive net radiative greenhouse gas

  13. Landscape control of uranium and thorium in boreal streams – spatiotemporal variability and the role of wetlands

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    F. Lidman

    2012-11-01

    Full Text Available The concentrations of uranium and thorium in ten partly nested streams in the boreal forest region were monitored over a two-year period. The investigated catchments ranged from small headwaters (0.1 km2 up to a fourth-order stream (67 km2. Considerable spatiotemporal variations were observed, with little or no correlation between streams. The fluxes of both uranium and thorium varied substantially between the subcatchments, ranging from 1.7 to 30 g km−2 a−1 for uranium and from 3.2 to 24 g km−2 a−1 for thorium. Airborne gamma spectrometry was used to measure the concentrations of uranium and thorium in surface soils throughout the catchment, suggesting that the concentrations of uranium and thorium in mineral soils are similar throughout the catchment. The fluxes of uranium and thorium were compared to a wide range of parameters characterising the investigated catchments and the chemistry of the stream water, e.g. soil concentrations of these elements, pH, TOC (total organic carbon, Al, Si and hydrogen carbonate, but it was concluded that the spatial variabilities in the fluxes of both uranium and thorium mainly were controlled by wetlands. The results indicate that there is a predictable and systematic accumulation of both uranium and thorium in boreal wetlands that is large enough to control the transport of these elements. On the landscape scale approximately 65–80% of uranium and 55–65% of thorium entering a wetland were estimated to be retained in the peat. Overall, accumulation in mires and other types of wetlands was estimated to decrease the fluxes of uranium and thorium from the boreal forest landscape by 30–40%, indicating that wetlands play an important role for the biogeochemical cycling of uranium and thorium in the boreal forest landscape. The atmospheric deposition of uranium and thorium was also quantified, and its contribution to boreal streams was

  14. Soil microbial community composition is correlated to soil carbon processing along a boreal wetland formation gradient

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    Chapman, Eric; Cadillo-Quiroz, Hinsby; Childers, Daniel L.; Turetsky, Merritt R.; Waldrop, Mark P.

    2017-01-01

    Climate change is modifying global biogeochemical cycles. Microbial communities play an integral role in soil biogeochemical cycles; knowledge about microbial composition helps provide a mechanistic understanding of these ecosystem-level phenomena. Next generation sequencing approaches were used to investigate changes in microbial functional groups during ecosystem development, in response to climate change, in northern boreal wetlands. A gradient of wetlands that developed following permafrost degradation was used to characterize changes in the soil microbial communities that mediate C cycling: a bog representing an “undisturbed” system with intact permafrost, and a younger bog and an older bog that formed following the disturbance of permafrost thaw. Reference 16S rRNA databases and several diversity indices were used to assess structural differences among these communities, to assess relationships between soil microbial community composition and various environmental variables including redox potential and pH. Rates of potential CO2 and CH4 gas production were quantified to correlate sequence data with gas flux. The abundance of organic C degraders was highest in the youngest bog, suggesting higher rates of microbial processes, including potential CH4 production. In addition, alpha diversity was also highest in the youngest bog, which seemed to be related to a more neutral pH and a lower redox potential. These results could potentially be driven by increased niche differentiation in anaerobic soils. These results suggest that ecosystem structure, which was largely driven by changes in edaphic and plant community characteristics between the “undisturbed” permafrost bog and the two bogs formed following permafrost thaw, strongly influenced microbial function.

  15. Direct and indirect climate change effects on carbon dioxide fluxes in a thawing boreal forest-wetland landscape.

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    Helbig, Manuel; Chasmer, Laura E; Desai, Ankur R; Kljun, Natascha; Quinton, William L; Sonnentag, Oliver

    2017-08-01

    In the sporadic permafrost zone of northwestern Canada, boreal forest carbon dioxide (CO 2 ) fluxes will be altered directly by climate change through changing meteorological forcing and indirectly through changes in landscape functioning associated with thaw-induced collapse-scar bog ('wetland') expansion. However, their combined effect on landscape-scale net ecosystem CO 2 exchange (NEE LAND ), resulting from changing gross primary productivity (GPP) and ecosystem respiration (ER), remains unknown. Here, we quantify indirect land cover change impacts on NEE LAND and direct climate change impacts on modeled temperature- and light-limited NEE LAND of a boreal forest-wetland landscape. Using nested eddy covariance flux towers, we find both GPP and ER to be larger at the landscape compared to the wetland level. However, annual NEE LAND (-20 g C m -2 ) and wetland NEE (-24 g C m -2 ) were similar, suggesting negligible wetland expansion effects on NEE LAND . In contrast, we find non-negligible direct climate change impacts when modeling NEE LAND using projected air temperature and incoming shortwave radiation. At the end of the 21st century, modeled GPP mainly increases in spring and fall due to reduced temperature limitation, but becomes more frequently light-limited in fall. In a warmer climate, ER increases year-round in the absence of moisture stress resulting in net CO 2 uptake increases in the shoulder seasons and decreases during the summer. Annually, landscape net CO 2 uptake is projected to decline by 25 ± 14 g C m -2 for a moderate and 103 ± 38 g C m -2 for a high warming scenario, potentially reversing recently observed positive net CO 2 uptake trends across the boreal biome. Thus, even without moisture stress, net CO 2 uptake of boreal forest-wetland landscapes may decline, and ultimately, these landscapes may turn into net CO 2 sources under continued anthropogenic CO 2 emissions. We conclude that NEE LAND changes are more likely to be

  16. Four decades of wetland changes of the largest freshwater lake in China in response to the Three Gorges Dam

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    Feng, L.

    2017-12-01

    Wetlands provide important ecosystem functions for water alteration and conservation of bio-diversity, yet they are vulnerable to both human activities and climate changes. Using four decades of Landsat, MODIS and HJ-1A/1B satellites observations, the long-term wetland changes in Poyang Lake, the largest freshwater lake of China, have been investigated in this study. A Support Vector Machines (SVM) method was firstly developed to obtain wetland classification maps of major cover types between 1973 and 2013 using Landsat and HJ-1A/1B images. A statistically significant increasing trend of the wetland vegetation (15.9 km2 year-1) was found, where the vegetation tended to spread into the lake center in the past four decades. While the transitions from mudflat to vegetation and vice versa were comparable before 2001, vegetation area increased by 620.8 km2 (16.6% of the lake area) between 2001 and 2013. Then, a phenology-based decision tree approach was developed to classify wetland vegetation at community level, with the help of the spatial and spectral information of frequent MODIS observations between 2000 and 2014. MODIS wetland maps confirmed the replacement of water and mudflat by expanded vegetated areas since the impoundment of the Three Gorges Dam (TGD), where both the total coverage of vegetation and the area of each community showed significantly increasing trends. More importantly, results indicated that the vegetation community transitions occurred mainly from hydrophilic cover types to those adapted to dryer conditions. Hydrological analysis revealed that 1) the relationships between the water levels and vegetation coverage showed two regimes for the pre-TGD period (before 2003) and post-TGD period (after 2003); and 2) despite the significant changes in wetland cover types, the most preferable water depth for each cover type remained stable before and after the TGD. The findings here unambiguously led to the conclusion that the landscape changes seen in

  17. An expert system model for mapping tropical wetlands and peatlands reveals South America as the largest contributor.

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    Gumbricht, Thomas; Roman-Cuesta, Rosa Maria; Verchot, Louis; Herold, Martin; Wittmann, Florian; Householder, Ethan; Herold, Nadine; Murdiyarso, Daniel

    2017-09-01

    Wetlands are important providers of ecosystem services and key regulators of climate change. They positively contribute to global warming through their greenhouse gas emissions, and negatively through the accumulation of organic material in histosols, particularly in peatlands. Our understanding of wetlands' services is currently constrained by limited knowledge on their distribution, extent, volume, interannual flood variability and disturbance levels. We present an expert system approach to estimate wetland and peatland areas, depths and volumes, which relies on three biophysical indices related to wetland and peat formation: (1) long-term water supply exceeding atmospheric water demand; (2) annually or seasonally water-logged soils; and (3) a geomorphological position where water is supplied and retained. Tropical and subtropical wetlands estimates reach 4.7 million km 2 (Mkm 2 ). In line with current understanding, the American continent is the major contributor (45%), and Brazil, with its Amazonian interfluvial region, contains the largest tropical wetland area (800,720 km 2 ). Our model suggests, however, unprecedented extents and volumes of peatland in the tropics (1.7 Mkm 2 and 7,268 (6,076-7,368) km 3 ), which more than threefold current estimates. Unlike current understanding, our estimates suggest that South America and not Asia contributes the most to tropical peatland area and volume (ca. 44% for both) partly related to some yet unaccounted extended deep deposits but mainly to extended but shallow peat in the Amazon Basin. Brazil leads the peatland area and volume contribution. Asia hosts 38% of both tropical peat area and volume with Indonesia as the main regional contributor and still the holder of the deepest and most extended peat areas in the tropics. Africa hosts more peat than previously reported but climatic and topographic contexts leave it as the least peat-forming continent. Our results suggest large biases in our current understanding of

  18. Hydrology is reflected in the functioning and community composition of methanotrophs in the littoral wetland of a boreal lake

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    Siljanen, H.M.P.; Saari, A.; Krause, S.; Lensu, A.; Abell, G.C.J.; Bodrossy, L.; Bodelier, P.L.E.; Martikainen, P.J.

    2011-01-01

    In lake ecosystems a major proportion of methane emissions originate from the littoral zone which can have a great spatial variability in hydrology, soil quality and vegetation. Hitherto, spatial heterogeneity and the effects it has on functioning and diversity of methanotrophs in littoral wetlands

  19. Effects of nitrogen load on the function and diversity of methanotrophs in the littoral wetland of a boreal lake

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    Henri MP Siljanen

    2012-02-01

    Full Text Available Methane is the second most abundant greenhouse gas in the atmosphere. A major part of the total methane emissions from lake ecosystems are emitted from littoral wetlands. Methane emissions are significantly reduced by methanotrophs as they use methane as the sole energy and carbon source. Function of methanotrophs can be either activated or suppressed by nitrogen. However, the effects of nitrogen on methanotrophs in littoral wetlands are unknown. Here we report how nitrogen loading in situ affected the function and diversity of methanotrophs in a littoral wetland. Methanotrophic community composition and functional diversity were analyzed with particulate methane monooxygenase (pmoA gene targeted microarray. Nitrogen load had no effects on methane oxidation potential and methane fluxes. Nitrogen load activated pmoA gene transcription of type I (Methylobacter, Methylomonas and LW21-freshwater phylotypes methanotrophs, but decreased the relative abundance of type II (Methylocystis, Methylosinus trichosporium and Methylosinus phylotypes methanotrophs. Hence, the overall activity of a methanotroph community in littoral wetlands is unlikely to be affected by nitrogen leached from the catchment area.

  20. Spatial variations in drainage efficiency in a boreal wetland environment as a function of lidar and radar-derived deviations from the regional hydraulic gradient

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    Hopkinson, C.; Brisco, B.; Chasmer, L.; Devito, K.; Montgomery, J. S.; Patterson, S.; Petrone, R. M.

    2017-12-01

    The dense forest cover of the Western Boreal Plains of northern Alberta is underlain by a mix of glacial moraines, sandy outwash sediments and clay plains possessing spatially variable hydraulic conductivities. The region is also characterised by a large number of post-glacial surface depression wetlands that have seasonally and topographically limited surface connectivity. Consequently, drainage along shallow regional hydraulic gradients may be dominated either by variations in surface geology or local variations in Et. Long-term government lake level monitoring is sparse in this region, but over a decade of hydrometeorological monitoring has taken place around the Utikuma Regional Study Area (URSA), a research site led by the University of Alberta. In situ lake and ground water level data are here combined with time series of airborne lidar and RadarSat II synthetic aperture radar (SAR) data to assess the spatial variability of water levels during late summer period characterised by flow recession. Long term Lidar data were collected or obtained by the authors in August of 2002, 2008, 2011 and 2016, while seasonal SAR data were captured approximately every 24 days during the summers of 2015, 2016 and 2017. Water levels for wetlands exceeding 100m2 in area across a north-trending 20km x 5km topographic gradient north of Utikuma Lake were extracted directly from the lidar and indirectly from the SAR. The recent seasonal variability in spatial water levels was extracted from SAR, while the lidar data illustrated more long term trends associated with land use and riparian vegetation succession. All water level data collected in August were combined and averaged at multiple scales using a raster focal statistics function to generate a long term spatial map of the regional hydraulic gradient and scale-dependent variations. Areas of indicated high and low drainage efficiency were overlain onto layers of landcover and surface geology to ascertain causal relationships

  1. Pipeline corridors through wetlands

    International Nuclear Information System (INIS)

    Zimmerman, R.E.; Wilkey, P.L.; Isaacson, H.R.

    1992-01-01

    This paper presents preliminary findings from six vegetational surveys of gas pipeline rights-of-way (ROW) through wetlands and quantifies the impacts of a 20-year-old pipeline ROW through a boreal forest wetland. Six sites of various ages were surveyed in ecosystems ranging from coastal marsh to forested wetland. At all sites except one, both the number and the percentage of wetland species on the Row approximated or exceeded those in the adjacent natural area. The boreal forest study showed that (1) adjacent natural wetland areas were not altered in type; (2) water sheet flow restriction had been reversed by nature; (3) no nonnative plant species invaded the natural area; (4) three-quarters of the ROW area was a wetland, and (5) the ROW increased diversity

  2. Spatial Distribution of Bacterial Communities Driven by Multiple Environmental Factors in a Beach Wetland of the Largest Freshwater Lake in China

    Directory of Open Access Journals (Sweden)

    Xia eDing

    2015-02-01

    Full Text Available The spatial distributions of bacterial communities may be driven by multiple environmental factors. Thus, understanding the relationships between bacterial distribution and environmental factors is critical for understanding wetland stability and the functioning of freshwater lakes. However, little research on the bacterial communities in deep sediment layers exists. In this study, thirty clone libraries of 16S rRNA were constructed from a beach wetland of the Poyang Lake along both horizontal (distance to the water-land junction and vertical (sediment depth gradients to assess the effects of sediment properties on bacterial community structure and diversity. Our results showed that bacterial diversity increased along the horizontal gradient and decreased along the vertical gradient. The heterogeneous sediment properties along gradients substantially affected the dominant bacterial groups at the phylum and species levels. For example, the NH4+ concentration decreased with increasing depth, which was positively correlated with the relative abundance of Alphaproteobacteria. The changes in bacterial diversity and dominant bacterial groups showed that the top layer had a different bacterial community structure than the deeper layers. Principal component analysis revealed that both gradients, not each gradient independently, contributed to the shift in the bacterial community structure. A multiple linear regression model explained the changes in bacterial diversity and richness along the depth and distance gradients. Overall, our results suggest that spatial gradients associated with sediment properties shaped the bacterial communities in the Poyang Lake beach wetland.

  3. Methane flux from boreal peatlands

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  4. Predicting Climate Change Impacts to the Canadian Boreal Forest

    Directory of Open Access Journals (Sweden)

    Trisalyn A. Nelson

    2014-03-01

    Full Text Available Climate change is expected to alter temperature, precipitation, and seasonality with potentially acute impacts on Canada’s boreal. In this research we predicted future spatial distributions of biodiversity in Canada’s boreal for 2020, 2050, and 2080 using indirect indicators derived from remote sensing and based on vegetation productivity. Vegetation productivity indices, representing annual amounts and variability of greenness, have been shown to relate to tree and wildlife richness in Canada’s boreal. Relationships between historical satellite-derived productivity and climate data were applied to modelled scenarios of future climate to predict and map potential future vegetation productivity for 592 regions across Canada. Results indicated that the pattern of vegetation productivity will become more homogenous, particularly west of Hudson Bay. We expect climate change to impact biodiversity along north/south gradients and by 2080 vegetation distributions will be dominated by processes of seasonality in the north and a combination of cumulative greenness and minimum cover in the south. The Hudson Plains, which host the world’s largest and most contiguous wetland, are predicted to experience less seasonality and more greenness. The spatial distribution of predicted trends in vegetation productivity was emphasized over absolute values, in order to support regional biodiversity assessments and conservation planning.

  5. Bioremediation of arsenic (As from mine effluent by a horizontal flow constructed wetland: A case study in largest borax reserve area in over the world, Kırka, Eskişehir

    Directory of Open Access Journals (Sweden)

    Onur Can Türker

    2016-12-01

    Full Text Available In this study, a horizontal flow constructed wetland (HFCW planted with Typha angustifolia, was tested to bioremediation potential for arsenic from mine effluent under the natural climatic conditions in largest boron mine reserve area over the world, Kırka (Eskişehir. Briefly, the objective of the present experiment was to investigate arsenic bioremediation capability of wetland system and asses the phytoremediation efficiency of T. angustifolia, selected as a donor plant in this study, with different initial arsenic concentrations. Our results indicated that HFCW has capability to decreased arsenic in mine effluent from 49 µg L-1 to 21.8 µg L-1 in a period of 84 days, suggesting that HFCW could be a reasonable bio-filter option to control arsenic pollution directly from mining effluent in largest borax reserve over the world. Furthermore, we found that arsenic concentration in outflow samples was stably below 10 µg L-1 (drinking water safety limit with an inflow range from 42.3 to 42.1 arsenic µg L-1 during the first 28 days. Our results also indicated that belowground parts of T.angustifolia accumulate more arsenic from mine effluent compared to aboveground parts during experiment period. Therefore, we suggested that belowground parts of the plants in HFCW play an important role for arsenic bioremediation from mine effluent which origin of Kırka Borax reserve area. In this respect, bioconcentration factor (BCF for the plants which grown in HFCW was found higher than those of control group. Moreover, results of the present experiment also showed that relatively high level of arsenic retained in the filtration media of HFCW during the experiment period, indicating that filtration media which was used in HFCW has potential to filter arsenic from mine effluent. Consequently, the scientific insight of the present study is to present an innovative, cost effective, and easy operating method for arsenic remediation from mine effluent.

  6. Treatment Wetlands

    OpenAIRE

    Dotro, Gabriela; Langergraber, Günter; Molle, Pascal; Nivala, Jaime; Puigagut, Jaume; Stein, Otto; Von Sperling, Marcos

    2017-01-01

    Overview of Treatment Wetlands; Fundamentals of Treatment Wetlands; Horizontal Flow Wetlands; Vertical Flow Wetlands; French Vertical Flow Wetlands; Intensified and Modified Wetlands; Free Water Surface Wetlands; Other Applications; Additional Aspects.

  7. Boreal forests

    International Nuclear Information System (INIS)

    Essen, P.A.; Ericson, L.; Ehnstroem, B.; Sjoeberg, K.

    1997-01-01

    We review patterns and processes important for biodiversity in the Fennoscandian boreal forest, describe man's past and present impact and outline a strategy for conservation. Natural disturbances, particularly forest fire and gap formation, create much of the structural and functional diversity in forest ecosystems. Several boreal plants and animals are adapted to fire regimes. In contrast, many organisms (epiphytic lichens, fungi, invertebrates) require stable conditions with long continuity in canopy cover. The highly mechanized and efficient Fennoscandian forest industry has developed during the last century. The result is that most natural forest has been lost and that several hundreds of species, mainly cryptograms and invertebrates, are threatened. The forestry is now in a transition from exploitation to sustainable production and has recently incorporated some measures to protect the environment. Programmes for maintaining biodiversity in the boreal forest should include at least three parts. First, the system of forest reserves must be significantly improved through protection of large representative ecosystems and key biotopes that host threatened species. Second, we must restore ecosystem properties that have been lost or altered. Natural disturbance regimes must be allowed to operate or be imitated, for example by artificial fire management. Stand-level management should particularly increase the amount of coarse woody debris, the number of old deciduous trees and large, old conifers, by using partial cutting. Third, natural variation should also be mimicked at the landscape level, for example, by reducing fragmentation and increasing links between landscape elements. Long-term experiments are required to evaluate the success of different management methods in maintaining biodiversity in the boreal forest. (au) 260 refs

  8. Emerging role of wetland methane emissions in driving 21st century climate change.

    Science.gov (United States)

    Zhang, Zhen; Zimmermann, Niklaus E; Stenke, Andrea; Li, Xin; Hodson, Elke L; Zhu, Gaofeng; Huang, Chunlin; Poulter, Benjamin

    2017-09-05

    Wetland methane (CH 4 ) emissions are the largest natural source in the global CH 4 budget, contributing to roughly one third of total natural and anthropogenic emissions. As the second most important anthropogenic greenhouse gas in the atmosphere after CO 2 , CH 4 is strongly associated with climate feedbacks. However, due to the paucity of data, wetland CH 4 feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change Fifth Assessment Report. The degree to which future expansion of wetlands and CH 4 emissions will evolve and consequently drive climate feedbacks is thus a question of major concern. Here we present an ensemble estimate of wetland CH 4 emissions driven by 38 general circulation models for the 21st century. We find that climate change-induced increases in boreal wetland extent and temperature-driven increases in tropical CH 4 emissions will dominate anthropogenic CH 4 emissions by 38 to 56% toward the end of the 21st century under the Representative Concentration Pathway (RCP2.6). Depending on scenarios, wetland CH 4 feedbacks translate to an increase in additional global mean radiative forcing of 0.04 W·m -2 to 0.19 W·m -2 by the end of the 21st century. Under the "worst-case" RCP8.5 scenario, with no climate mitigation, boreal CH 4 emissions are enhanced by 18.05 Tg to 41.69 Tg, due to thawing of inundated areas during the cold season (December to May) and rising temperature, while tropical CH 4 emissions accelerate with a total increment of 48.36 Tg to 87.37 Tg by 2099. Our results suggest that climate mitigation policies must consider mitigation of wetland CH 4 feedbacks to maintain average global warming below 2 °C.

  9. Russian boreal peatlands dominate the natural European methane budget

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  10. Carbon dynamics in wetland restoration

    Energy Technology Data Exchange (ETDEWEB)

    Kovalenko, K.; Ciborowski, J.; Gardner-Costa, J.; Slama, C. [Windsor Univ., ON (Canada); Daly, C.; Hornung, J. [Suncor Energy, Calgary, AB (Canada); Dixon, G.; Farwell, A. [Waterloo Univ., ON (Canada); Foote, L.; Frederick, K.; Roy, M. [Alberta Univ., Edmonton, AB (Canada); Liber, K. [Saskatchewan Univ., Saskatoon, SK (Canada); Smits, J. [Calgary Univ., AB (Canada); Wytrykush, C. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2010-07-01

    This study focused on the reclamation of wetland ecosystems impacted by oil sands development in the boreal wetlands. Although these wetlands play an important role in global carbon balance, their ecosystem function is compromised by direct and regional anthropogenic disturbance and climate change. Large oil sand mining areas that require reclamation generate substantial quantities of extraction process-affected materials. In order to determine if the reclaimed wetlands were restored to equivalent ecosystem function, this study evaluated carbon flows and food web structure in oil sands-affected wetlands. The purpose was to determine whether a prescribed reclamation strategy or topsoil amendment accelerates reclaimed wetland development to produce self-sustaining peatlands. In addition to determining carbon fluxes, this study measured compartment standing stocks for residual hydrocarbons, organic substrate, bacterioplankton, phytoplankton, biofilm, macrophytes, detritus, zoobenthos and aquatic-terrestrial exports. Most biotic 28 compartments differed between oil-sands-affected and reference wetlands, but the difference lessened with age. Macroinvertebrate trophic diversity was lower in oil sands-affected wetlands. Peat amendment seemed to speed convergence for some compartments but not others. These results were discussed in the context of restoration of ecosystem function and optimization of reclamation strategies.

  11. Constructed Wetlands

    Science.gov (United States)

    these systems can improve water quality, engineers and scientists construct systems that replicate the functions of natural wetlands. Constructed wetlands are treatment systems that use natural processes

  12. Carbon Cycling in Wetland Forest Soils

    Science.gov (United States)

    Carl C. Trettin; Martin F. Jurgensen

    2003-01-01

    Wetlands comprise a small proportion (i.e., 2 to 3%) of earth's terrestrial surface, yet they contain a significant proportion of the terrestrial carbon (C) pool. Soils comprise the largest terrestrial C pool (ca. 1550 Pg C in upper 100 cm; Eswaran et al., 1993; Batjes, 1996), and wetlands contain the single largest component, with estimates ranging between 18...

  13. Working group report on wetlands and wildlife

    International Nuclear Information System (INIS)

    Teels, B.

    1991-01-01

    The results and conclusions of a working group held to discuss the state of knowledge and knowledge gaps concerning climatic change impacts on wetlands and wildlife are presented. Prairie pothole wetlands are extremely productive and produce ca 50% of all ducks in North America. The most productive, and most vulnerable to climate change, are small potholes, often less than one acre in area. Changes in water regimes and land use will have more impact on wildlife than changes in temperature. There are gaps in knowledge relating to: boreal wetlands and their wildlife, and response to climate; wetland inventories that include the smallest wetlands; coordinated schemes for monitoring status and trends of wetlands and wildlife; and understanding of ecological relationships within wetlands and their wildlife communities. Recommendations include: coordinate and enhance existing databases to provide an integrated monitoring system; establish research programs to increase understanding of ecological relationships within wetland ecosystems; evaluate programs and policies that affect wetlands; and promote heightened public awareness of general values of wetlands

  14. Largest College Endowments, 2011

    Science.gov (United States)

    Chronicle of Higher Education, 2012

    2012-01-01

    Of all endowments valued at more than $250-million, the UCLA Foundation had the highest rate of growth over the previous year, at 49 percent. This article presents a table of the largest college endowments in 2011. The table covers the "rank," "institution," "market value as of June 30, 2011," and "1-year change" of institutions participating in…

  15. Boreal Inundation Mapping with SMAP Radiometer Data for Methane Studies

    Science.gov (United States)

    Kim, Seungbum; Brisco, Brian; Poncos, Valentin

    2017-04-01

    Inundation and consequent anoxic condition induce methane release, which is one of the most potent greenhouse gases. Boreal regions contain large amounts of organic carbon, which is a potentially major methane emission source under climatic warming conditions. Boreal wetlands in particular are one of the largest sources of uncertainties in global methane budget. Wetland spatial extent together with the gas release rate remains highly unknown. Characterization of the existing inundation database is poor, because of the inundation under clouds and dense vegetation. In this work, the inundation extent is derived using brightness temperature data acquired by the L-band Soil Moisture Active Passive (SMAP) satellite, which offers the L-band capabilities to penetrate clouds and vegetation at 3-day revisit. The fidelity of the SMAP watermask is assessed as a first step in this investigation by comparing with the following data sets: 3-m resolution maps derived using Radarsat synthetic aperture radar (SAR) data in northern Canada and multi-sensor climatology over Siberia. Because Radarsat coverages are limited despite its high spatial resolution, at the time and location where Radarsats are not available, we also compare with 3-km resolution SMAP SAR data that are concurrent with the SMAP radiometer data globally until July 2015. Inundation extents were derived with Radarsat, SMAP SAR, and SMAP radiometer over the 60 km x 60km area at Peace Athabasca Delta (PAD), Canada on 6 days in spring and summer 2015. The SMAP SAR results match the locations of Radarsat waterbodies. However, the SMAP SAR underestimates the water extent, mainly over mixed pixels that have subpixel land presence. The threshold value (-3 dB) applied to the SMAP SAR was determined previously over the global domain. The threshold is dependent on the type of local landcover within a mixed pixel. Further analysis is needed to locally optimize the threshold. The SMAP radiometer water fraction over Peace

  16. Riparian zone controls on base cation concentrations in boreal streams

    Science.gov (United States)

    Ledesma, J. L. J.; Grabs, T.; Futter, M. N.; Bishop, K. H.; Laudon, H.; Köhler, S. J.

    2013-01-01

    Forest riparian zones are a major in control of surface water quality. Base cation (BC) concentrations, fluxes, and cycling in the riparian zone merit attention because of increasing concern of negative consequences for re-acidification of surface waters from future climate and forest harvesting scenarios. We present a two-year study of BC and silica (Si) flow-weighted concentrations from 13 riparian zones and 14 streams in a boreal catchment in northern Sweden. The Riparian Flow-Concentration Integration Model (RIM) was used to estimate riparian zone flow-weighted concentrations and tested to predict the stream flow-weighted concentrations. Spatial variation in BC and Si concentrations as well as in flow-weighted concentrations was related to differences in Quaternary deposits, with the largest contribution from lower lying silty sediments and the lowest contribution from wetland areas higher up in the catchment. Temporal stability in the concentrations of most elements, a remarkably stable Mg / Ca ratio in the soil water and a homogeneous mineralogy suggest that the stable patterns found in the riparian zones are a result of distinct mineralogical upslope groundwater signals integrating the chemical signals of biological and chemical weathering. Stream water Mg / Ca ratio indicates that the signal is subsequently maintained in the streams. RIM gave good predictions of Ca, Mg, and Na flow-weighted concentrations in headwater streams. The difficulty in modelling K and Si suggests a stronger biogeochemical influence on these elements. The observed chemical dilution effect with flow in the streams was related to variation in groundwater levels and element concentration profiles in the riparian zones. This study provides a first step toward specific investigations of the vulnerability of riparian zones to changes induced by forest management or climate change, with focus on BC or other compounds.

  17. Preliminary Assessment of JERS-1 SAR to Discriminating Boreal Landscape Features for the Boreal Forest Mapping Project

    Science.gov (United States)

    McDonald, Kyle; Williams, Cynthia; Podest, Erika; Chapman, Bruce

    1999-01-01

    This paper presents an overview of the JERS-1 North American Boreal Forest Mapping Project and a preliminary assessment of JERS-1 SAR imagery for application to discriminating features applicable to boreal landscape processes. The present focus of the JERS-1 North American Boreal Forest Mapping Project is the production of continental scale wintertime and summertime SAR mosaics of the North American boreal forest for distribution to the science community. As part of this effort, JERS-1 imagery has been collected over much of Alaska and Canada during the 1997-98 winter and 1998 summer seasons. To complete the mosaics, these data will be augmented with data collected during previous years. These data will be made available to the scientific community via CD ROM containing these and similar data sets compiled from companion studies of Asia and Europe. Regional landscape classification with SAR is important for the baseline information it will provide about distribution of woodlands, positions of treeline, current forest biomass, distribution of wetlands, and extent of major rivercourses. As well as setting the stage for longer term change detection, comparisons across several years provides additional baseline information about short-term landscape change. Rapid changes, including those driven by fire, permafrost heat balance, flooding, and insect outbreaks can dominate boreal systems. We examine JERS-1 imagery covering selected sites in Alaska and Canada to assess quality and applicability to such relevant ecological and hydrological issues. The data are generally of high quality and illustrate many potential applications. A texture-based classification scheme is applied to selected regions to assess the applicability of these data for distinguishing distribution of such landcover types as wetland, tundra, woodland and forested landscapes.

  18. Browning boreal forests of western North America

    Science.gov (United States)

    Verbyla, David

    2011-12-01

    Forest Ecol. Manag. 227 219-32 Berg E E, Hillman K M, Dial R and DeRuwe A 2009 Recent woody invasion of wetlands on the Kenai Peninsula Lowlands, south-central Alaska: a major regime shift after 18 000 years of wet Sphagnum-sedge peat recruitment Canadian J. Forest Res. 39 2033-46 Brabets T P and Walvoord M A 2009 Trends in streamflow in the Yukon River Basin from 1944 to 2004 and the influence of the Pacific Decadal Oscillation J. Hydrol. 371 108-19 Bunn A G, Goetz S J, Kimball J S and Zhang K 2007 Northern high-latitude ecosystems respond to climate change EOS Trans. Am. Geophys. Union 88 333-40 D'Arrigo R, Kaufmann R K, Davi N, Jacoby G C, Laskowski C, Myneni R B and Cherubini P 2004 Thresholds for warming-induced growth decline at elevational tree line in the Yukon Territory, Canada Glob. Biogeochem. Cycles 18 GB3021 Goetz S J, Bunn A G, Fiske G J and Houghton R A 2005 Satellite-observed photosynthetic trends across boreal North America associated with climate and fire disturbance Proc. Natl Acad. Sci. USA 102 13521-5 Lloyd A H and Bunn A G 2007 Responses of the circumpolar boreal forest to the 20th century climate variability Environ. Res. Lett. 2 045013 Lloyd A H and Fastie C L 2002 Spatial and temporal variability in the growth and climate response of treeline trees in Alaska Clim. Change 52 481-509 Malmström C and Raffa K R 2000 Biotic disturbance agents in the boreal forest: considerations for vegetation change models Glob. Change Biol. 6 (Suppl. 1) 35-48 McGuire A D, Ruess R W, Lloyd A, Yarie J, Clein J S and Juday G P 2010 Vulnerability of white spruce tree growth in interior Alaska in response to climate variability: dendrochronological, demographic, and experimental perspectives Canadian J. Forest Res. 40 1197-209 Michealian M, Hogg E H, Hall R J and Arsenault E 2011 Massive mortality of aspen following severe drought along the southern edge of the Canadian boreal forest Glob. Change Biol. 17 2084-94 Parent M B and Verbyla D 2010 The browning of Alaska

  19. Book review: Southern Forested Wetlands: Ecology and Management

    Science.gov (United States)

    Carl C. Trettin

    2000-01-01

    The southern region has the largest proportion of wetlands in the conterminous US. The majority of that wetland resource is forested by diverse vegetation communities reflecting differences in soil, hydrology, geomorphology, climatic conditions and past management. Wetland resources in the southern US are very important to the economy providing both commodity and non-...

  20. Wetland Hydrology

    Science.gov (United States)

    This chapter discusses the state of the science in wetland hydrology by touching upon the major hydraulic and hydrologic processes in these complex ecosystems, their measurement/estimation techniques, and modeling methods. It starts with the definition of wetlands, their benefit...

  1. Newtonian boreal forest ecology

    OpenAIRE

    Hari, Pertti; Aakala, Tuomas; Aalto, Juho; Bäck, Jaana; Hollmén, Jaakko; Jõgiste, Kalev; Koupaei, Kourosh Kabiri; Kähkönen, Mika A.; Korpela, Mikko; Kulmala, Liisa; Nikinmaa, Eero; Pumpanen, Jukka; Salkinoja-Salonen, Mirja; Schiestl-Aalto, Pauliina; Simojoki, Asko

    2017-01-01

    Isaac Newton's approach to developing theories in his book Principia Mathematica proceeds in four steps. First, he defines various concepts, second, he formulates axioms utilising the concepts, third, he mathematically analyses the behaviour of the system defined by the concepts and axioms obtaining predictions and fourth, he tests the predictions with measurements. In this study, we formulated our theory of boreal forest ecosystems, called NewtonForest, following the four steps introduced by...

  2. Impacts of water development on aquatic macroinvertebrates, amphibians, and plants in wetlands of a semi-arid landscape

    Science.gov (United States)

    Euliss, Ned H.; Mushet, David M.

    2004-01-01

    We compared the macroinvertebrate and amphibian communities of 12 excavated and 12 natural wetlands in western North Dakota, USA, to assess the effects of artificially lengthened hydroperiods on the biotic communities of wetlands in this semi-arid region. Excavated wetlands were much deeper and captured greater volumes of water than natural wetlands. Most excavated wetlands maintained water throughout the study period (May to October 1999), whereas most of the natural wetlands were dry by June. Excavated wetlands were largely unvegetated or contained submergent and deep-marsh plant species. The natural wetlands had two well-defined vegetative zones populated by plant species typical of wet meadows and shallow marshes. Excavated wetlands had a richer aquatic macroinvertebrate community that included several predatory taxa not found in natural wetlands. Taxa adapted to the short hydroperiods of seasonal wetlands were largely absent from excavated wetlands. The amphibian community of natural and excavated wetlands included the boreal chorus frog (Pseudacris maculata), northern leopard frog (Rana pipiens), plains spadefoot (Scaphiopus bombifrons), Woodhouse's toad (Bufo woodhousii woodhousii), and tiger salamander (Ambystoma tigrinum). The plains spadefoot occurred only in natural wetlands while tiger salamanders occurred in all 12 excavated wetlands and only one natural wetland. Boreal chorus frogs and northern leopard frogs were present in both wetland types; however, they successfully reproduced only in wetlands lacking tiger salamanders. Artificially extending the hydroperiod of wetlands by excavation has greatly influenced the composition of native biotic communities adapted to the naturally short hydroperiods of wetlands in this semi-arid region. The compositional change of the biotic communities can be related to hydrological changes and biotic interactions, especially predation related to excavation.

  3. National Wetlands Inventory Lines

    Data.gov (United States)

    Minnesota Department of Natural Resources — Linear wetland features (including selected streams, ditches, and narrow wetland bodies) mapped as part of the National Wetlands Inventory (NWI). The National...

  4. Wetlands and Sustainability

    Directory of Open Access Journals (Sweden)

    Richard Smardon

    2014-11-01

    Full Text Available This editorial provides an overview of the special issue “Wetlands and Sustainability”. In particular, the special issue contains a review of Paul Keddy’s book “Wetland Ecology” with specific reference to wetland sustainability. It also includes papers addressing wetland data acquisition via radar and remote sensing to better understand wetland system dynamics, hydrologic processes linked to wetland stress and restoration, coastal wetlands land use conflict/management, and wetland utilization for water quality treatment.

  5. Fringe wetlands

    International Nuclear Information System (INIS)

    Lugo, A.E.

    1990-01-01

    Fringe wetlands are characterized by the dominance of few species, a clear species zonation, synchrony of ecological processes with episodic events, and simplicity in the structure of vegetation. The structure and ecosystem dynamics of fringe forested wetlands are presented with emphasis on saltwater wetlands because they have been studied more than freshwater ones. The study areas were Caribbean and Florida mangroves. Fringe wetlands are found on the water edge of oceans, inland estuaries, and lakes. Water motion in the fringe is bi-directional and perpendicular to the forest and due mostly to tidal energy in oceanic and estuarine fringes. in lakes, water moves in and out of the fringe under the influence of wind, waves, or seiches. some fringe forests are occasionally flushed by terrestrial runoff or aquifer discharge. In contrast, fringe forests located on small offshore islands or steep coastal shroes are isolated from terrestrial runoff or aquifer discharge, and their hydroperiod is controlled by tides and waves only. Literature reviews suggest that ecosystem parameters such as vegetation structure, tree growth, primary productivity, and organic matter in sediments respond proportionally to hydrologic energy. Human activity that impacts on fringe forested wetlands include harvesting of trees, oil pollution and eutrophication. 72 refs., 12 figs., 9 tabs

  6. The importance of water quality to wetland establishment

    International Nuclear Information System (INIS)

    Trites, M.; Bayley, S.

    2010-01-01

    Extracting oil from sands produces huge volumes of saline tailings. This presentation demonstrated that the ability to recreate boreal peatland communities after oil sands mining will be constrained by water quality. Typical boreal wetlands can be described along a bog to poor fen to rich fen gradient that correlates to increasing water pH and calcium concentration. There are major differences in vegetation communities along this gradient. Bogs and poor fens are characterized by slowly decomposing Sphagnum moss, while brown moss and productive herbaceous communities characterize rich fens. Post-mining wetlands generally have sodium concentrations above the tolerance limits of most freshwater peatland species. This study involved a survey of 25 boreal wetlands across a natural salinity gradient to determine a suite of potential native vegetation species to use for oils sand reclamation. Sixteen herbaceous vegetation communities that could be incorporated into oil sands wetlands were identified, but the diversity of communities decreased as salinity increased. Some of these wetlands had thick organic matter accumulations, despite having salinity equal to or higher than oil sands wetlands. Organic matter accumulation rates were also measured. If salinity is moderate and nutrient levels adequate, highly productive species like Carex aquatilis and Typha latifolia can accumulate organic matter quickly. Triglochin maritima can accumulate organic matter over the long term, even if salinity is high and nutrient levels are low. Although there is potential for peat to accumulate in future oil sands wetlands, the rates of peat accumulation will probably be slower than in undisturbed freshwater bogs and fens because of the elevated salinity. tabs., figs.

  7. The importance of water quality to wetland establishment

    Energy Technology Data Exchange (ETDEWEB)

    Trites, M.; Bayley, S. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences

    2010-07-01

    Extracting oil from sands produces huge volumes of saline tailings. This presentation demonstrated that the ability to recreate boreal peatland communities after oil sands mining will be constrained by water quality. Typical boreal wetlands can be described along a bog to poor fen to rich fen gradient that correlates to increasing water pH and calcium concentration. There are major differences in vegetation communities along this gradient. Bogs and poor fens are characterized by slowly decomposing Sphagnum moss, while brown moss and productive herbaceous communities characterize rich fens. Post-mining wetlands generally have sodium concentrations above the tolerance limits of most freshwater peatland species. This study involved a survey of 25 boreal wetlands across a natural salinity gradient to determine a suite of potential native vegetation species to use for oils sand reclamation. Sixteen herbaceous vegetation communities that could be incorporated into oil sands wetlands were identified, but the diversity of communities decreased as salinity increased. Some of these wetlands had thick organic matter accumulations, despite having salinity equal to or higher than oil sands wetlands. Organic matter accumulation rates were also measured. If salinity is moderate and nutrient levels adequate, highly productive species like Carex aquatilis and Typha latifolia can accumulate organic matter quickly. Triglochin maritima can accumulate organic matter over the long term, even if salinity is high and nutrient levels are low. Although there is potential for peat to accumulate in future oil sands wetlands, the rates of peat accumulation will probably be slower than in undisturbed freshwater bogs and fens because of the elevated salinity. tabs., figs.

  8. The Role of Driving Factors in Historical and Projected Carbon Dynamics in Wetland Ecosystems of Alaska

    Science.gov (United States)

    Lyu, Z.; Helene, G.; He, Y.; Zhuang, Q.; McGuire, A. D.; Bennett, A.; Breen, A. L.; Clein, J.; Euskirchen, E. S.; Johnson, K. D.; Kurkowski, T. A.; Pastick, N. J.; Rupp, S. T.; Wylie, B. K.; Zhu, Z.

    2017-12-01

    Wetlands are important terrestrial ecosystems in Alaska. It is important to understand and assess their role in the regional carbon dynamics in response to historical and projected environmental conditions. A coupled modeling framework that incorporates a fire disturbance model and two biogeochemical models was used to assess the relative influence of changing climate, atmospheric carbon dioxide (CO2) concentration, and fire regime on the historical and future carbon balance in wetland ecosystems of the four main Landscape Conservation Cooperatives (LCCs) of Alaska. Simulations were conducted for the historical period (1950-2009) and future projection period (2010-2099). These simulations estimate that the total carbon (C) storage in wetland ecosystems of Alaska is 5556 Tg C in 2009, with 89% of the C stored in soils. An estimated 175 Tg C was lost during the historical period, which is attributed to greater C lost from the Northwest Boreal LCC than C gained from the other three LCCs. The simulations for the projection period were conducted for six different scenarios driven by climate forcings from two different climate models for each of three CO2 emission scenarios. The mean total carbon storage increased 3.94 Tg C/yr by 2099, with variability among the simulations ranging from 2.02 Tg C/yr to 4.42 Tg C/yr. Across the four LCCs, the largest relative C storage increase occurred in the Arctic and North Pacific LCCs. These increases were primarily driven by increases in net primary production (NPP) that were greater than increases in heterotrophic respiration and fire emissions. Our analysis further indicates that NPP increase was primarily driven by CO2 fertilization ( 5% per 100 ppmv increase) as well as by increases in air temperature ( 1% per ° increase). Increases air temperature were estimated to be the primary cause for a projected 47.7% mean increase in wetlands biogenic CH4 emissions among the simulations ( 15% per ° increase). The combined effects of

  9. Thresholds for boreal biome transitions.

    Science.gov (United States)

    Scheffer, Marten; Hirota, Marina; Holmgren, Milena; Van Nes, Egbert H; Chapin, F Stuart

    2012-12-26

    Although the boreal region is warming twice as fast as the global average, the way in which the vast boreal forests and tundras may respond is poorly understood. Using satellite data, we reveal marked alternative modes in the frequency distributions of boreal tree cover. At the northern end and at the dry continental southern extremes, treeless tundra and steppe, respectively, are the only possible states. However, over a broad intermediate temperature range, these treeless states coexist with boreal forest (∼75% tree cover) and with two more open woodland states (∼20% and ∼45% tree cover). Intermediate tree covers (e.g., ∼10%, ∼30%, and ∼60% tree cover) between these distinct states are relatively rare, suggesting that they may represent unstable states where the system dwells only transiently. Mechanisms for such instabilities remain to be unraveled, but our results have important implications for the anticipated response of these ecosystems to climatic change. The data reveal that boreal forest shows no gradual decline in tree cover toward its limits. Instead, our analysis suggests that it becomes less resilient in the sense that it may more easily shift into a sparse woodland or treeless state. Similarly, the relative scarcity of the intermediate ∼10% tree cover suggests that tundra may shift relatively abruptly to a more abundant tree cover. If our inferences are correct, climate change may invoke massive nonlinear shifts in boreal biomes.

  10. Coupling of Water and Carbon Cycles in Boreal Ecosystems at Watershed and National Scales

    Science.gov (United States)

    Chen, J. M.; Ju, W.; Govind, A.; Sonnentag, O.

    2009-05-01

    The boreal landscapes is relatively flat giving the impression of spatial homogeneity. However, glacial activities have left distinct fingerprints on the vegetation distribution on moderately rolling terrains over the boreal landscape. Upland or lowland forests types or wetlands having various degrees of hydrological connectivitiy to the surrounding terrain are typical of the boreal landscape. The nature of the terrain creates unique hydrological conditions affecting the local-scale ecophysiological and biogeochemical processes. As part of the Canadian Carbon Program, we investigated the importance of lateral water redistribution through surface and subsurface flows in the spatial distribution of the vertical fluxes of water and carbon. A spatially explicit hydroecological model (BEPS-TerrainLab) has been developed and tested in forested and wetland watersheds . Remotely sensed vegetation parameters along with other spatial datasets are used to run this model, and tower flux data are used for partial validation. It is demonstrated in both forest and wetland watersheds that ignoring the lateral water redistribution over the landscape, commonly done in 1-dimensional bucket models, can cause considerable biases in the vertical carbon and water flux estimation, in addition to the distortion of the spatial patterns of these fluxes. The biases in the carbon flux are considerably larger than those in the water flux. The significance of these findings in national carbon budget estimation is demonstrated by separate modeling of 2015 watersheds over the Canadian landmass.

  11. National Wetlands Inventory Points

    Data.gov (United States)

    Minnesota Department of Natural Resources — Wetland point features (typically wetlands that are too small to be as area features at the data scale) mapped as part of the National Wetlands Inventory (NWI). The...

  12. National Wetlands Inventory Polygons

    Data.gov (United States)

    Minnesota Department of Natural Resources — Wetland area features mapped as part of the National Wetlands Inventory (NWI). The National Wetlands Inventory is a national program sponsored by the US Fish and...

  13. Modeling natural wetlands: A new global framework built on wetland observations

    Science.gov (United States)

    Matthews, E.; Romanski, J.; Olefeldt, D.

    2015-12-01

    Natural wetlands are the world's largest methane (CH4) source, and their distribution and CH4 fluxes are sensitive to interannual and longer-term climate variations. Wetland distributions used in wetland-CH4 models diverge widely, and these geographic differences contribute substantially to large variations in magnitude, seasonality and distribution of modeled methane fluxes. Modeling wetland type and distribution—closely tied to simulating CH4 emissions—is a high priority, particularly for studies of wetlands and CH4 dynamics under past and future climates. Methane-wetland models either prescribe or simulate methane-producing areas (aka wetlands) and both approaches result in predictable over- and under-estimates. 1) Monthly satellite-derived inundation data include flooded areas that are not wetlands (e.g., lakes, reservoirs, and rivers), and do not identify non-flooded wetlands. 2) Models simulating methane-producing areas overwhelmingly rely on modeled soil moisture, systematically over-estimating total global area, with regional over- and under-estimates, while schemes to model soil-moisture typically cannot account for positive water tables (i.e., flooding). Interestingly, while these distinct hydrological approaches to identify wetlands are complementary, merging them does not provide critical data needed to model wetlands for methane studies. We present a new integrated framework for modeling wetlands, and ultimately their methane emissions, that exploits the extensive body of data and information on wetlands. The foundation of the approach is an existing global gridded data set comprising all and only wetlands, including vegetation information. This data set is augmented with data inter alia on climate, inundation dynamics, soil type and soil carbon, permafrost, active-layer depth, growth form, and species composition. We investigate this enhanced wetland data set to identify which variables best explain occurrence and characteristics of observed

  14. Lake Alaotra wetlands: how long can Madagascar's most important ...

    African Journals Online (AJOL)

    The Alaotra wetlands represent the biggest lake and wetland complex in Madagascar and are home of several endemic species. The region constitutes the largest rice production area and inland fishery of Madagascar. Rice and fish are the main local sources of income. While the population has increased fivefold during ...

  15. Methane emissions from global wetlands: An assessment of the uncertainty associated with various wetland extent data sets

    Science.gov (United States)

    Zhang, Bowen; Tian, Hanqin; Lu, Chaoqun; Chen, Guangsheng; Pan, Shufen; Anderson, Christopher; Poulter, Benjamin

    2017-09-01

    A wide range of estimates on global wetland methane (CH4) fluxes has been reported during the recent two decades. This gives rise to urgent needs to clarify and identify the uncertainty sources, and conclude a reconciled estimate for global CH4 fluxes from wetlands. Most estimates by using bottom-up approach rely on wetland data sets, but these data sets show largely inconsistent in terms of both wetland extent and spatiotemporal distribution. A quantitative assessment of uncertainties associated with these discrepancies among wetland data sets has not been well investigated yet. By comparing the five widely used global wetland data sets (GISS, GLWD, Kaplan, GIEMS and SWAMPS-GLWD), it this study, we found large differences in the wetland extent, ranging from 5.3 to 10.2 million km2, as well as their spatial and temporal distributions among the five data sets. These discrepancies in wetland data sets resulted in large bias in model-estimated global wetland CH4 emissions as simulated by using the Dynamic Land Ecosystem Model (DLEM). The model simulations indicated that the mean global wetland CH4 emissions during 2000-2007 were 177.2 ± 49.7 Tg CH4 yr-1, based on the five different data sets. The tropical regions contributed the largest portion of estimated CH4 emissions from global wetlands, but also had the largest discrepancy. Among six continents, the largest uncertainty was found in South America. Thus, the improved estimates of wetland extent and CH4 emissions in the tropical regions and South America would be a critical step toward an accurate estimate of global CH4 emissions. This uncertainty analysis also reveals an important need for our scientific community to generate a global scale wetland data set with higher spatial resolution and shorter time interval, by integrating multiple sources of field and satellite data with modeling approaches, for cross-scale extrapolation.

  16. Development of biogenic VOC emission inventories for the boreal forest

    Energy Technology Data Exchange (ETDEWEB)

    Tarvainen, V.

    2008-07-01

    The volatile organic compounds (VOCs) emitted by vegetation, especially forests, can affect local and regional atmospheric photochemistry through their reactions with atmospheric oxidants. Their reaction products may also participate in the formation and growth of new particles which affect the radiation balance of the atmosphere, and thus climate, by scattering and absorbing shortwave and longwave radiation and by modifying the radiative properties, amount and lifetime of clouds. Globally, anthropogenic VOC emissions are far surpassed by the biogenic ones, making biogenic emission inventories an integral element in the development of efficient air quality and climate strategies. The inventories are typically constructed based on landcover information, measured emissions of different plants or vegetation types, and empirical dependencies of the emissions on environmental variables such as temperature and light. This thesis is focused on the VOC emissions from the boreal forest, the largest terrestrial biome with characteristic vegetation patterns and strong seasonality. The isoprene, monoterpene and sesquiterpene emissions of the most prevalent boreal tree species in Finland, Scots pine, have been measured and their seasonal variation and dependence on temperature and light have been studied. The measured emission data and other available observations of the emissions of the principal boreal trees have been used in a biogenic emission model developed for the boreal forests in Finland. The model utilizes satellite landcover information, Finnish forest classification and hourly meteorological data to calculate isoprene, monoterpene, sesquiterpene and other VOC emissions over the growing season. The principal compounds emitted by Scots pine are DELTA3-carene and alpha-pinene in the south boreal zone and alpha- and beta-pinene in the north boreal zone. The monoterpene emissions are dependent on temperature and have a clear seasonal cycle with high emissions in spring

  17. Kansas Playa Wetlands

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the distribution, areal extent, and morphometry of playa wetlands throughout western Kansas. Playa wetlands were...

  18. Largest particle detector nearing completion

    CERN Multimedia

    2006-01-01

    "Construction of another part of the Large Hadron Collider (LHC), the worl's largest particle accelerator at CERN in Switzerland, is nearing completion. The Compact Muon Solenoid (CMS) is oner of the LHC project's four large particle detectors. (1/2 page)

  19. Climate change: Potential impacts and interactions in wetlands of the United States

    Science.gov (United States)

    Burkett, Virginia; Kusler, Jon

    2000-01-01

    Wetlands exist in a transition zone between aquatic and terrestrial environments which can be altered by subtle changes in hydrology. Twentieth century climate records show that the United States is generally experiencing a trend towards a wetter, warmer climate; some climate models suggest that his trend will continue and possibly intensify over the next 100 years. Wetlands that are most likely to be affected by these and other potential changes (e.g., sea-level rise) associated with atmospheric carbon enrichment include permafrost wetlands, coastal and estuarine wetlands, peatlands, alpine wetlands, and prairie pothote wetlands. Potential impacts range from changes in community structure to changes in ecological function, and from extirpation to enhancement. Wetlands (particularly boreal peatlands) play an important role in the global carbon cycle, generally sequestering carbon in the form of biomass, methane, dissolved organic material and organic sediment. Wetlands that are drained or partially dried can become a net source of methane and carbon dioxide to the atmosphere, serving as a positive biotic feedback to global warming. Policy options for minimizing the adverse impacts of climate change on wetland ecosystems include the reduction of current anthropogenic stresses, allowing for inland migration of coastal wetlands as sea-level rises, active management to preserve wetland hydrology, and a wide range of other management and restoration options.

  20. Recreating wetland ecosystems in an oil sands disturbed landscape : Suncor consolidated-tailings demonstration wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Daly, C. [Suncor Energy, Fort McMurray, AB (Canada). Aquatic Reclamation Research; Tedder, W.; Marlowe, P. [Golder Associates Ltd., Calgary, AB (Canada). Oil Sands Div.

    2009-10-01

    Open pit oil sands mining involves the disturbance of thin overburden covers of Boreal forest lands that must be returned to equivalent land capability after mining activities have ceased. Before mining starts, any wetlands are drained, timber is harvested, and peat, topsoils and subsoils are stockpiled for later use. This article discussed wetland reclamation activities conducted by Suncor Energy at its open pit mining operations. Research facilities were constructed in order to determine if wetlands constructed with consolidated tailings (CT) and pond effluent water (PEW) were able to support a sustainable vegetation community. Thirty-three cat-tail plots were established at the facility as well as unplanted plots in order to determine how quickly natural establishment occurred. Shoreline plug transplants and transplants from a natural saline lake were also introduced. Within 5 years, over 23 plant species had naturally colonized the CT wetlands. However, diversity was lower in CT and PEW-constructed wetlands. It was concluded that the application of a native peat-mineral mix soil may help to increase plant diversity. 20 refs., 5 figs.

  1. Observation of Wetland Dynamics with Global Navigation Satellite Signals Reflectometry

    Science.gov (United States)

    Zuffada, C.; Shah, R.; Nghiem, S. V.; Cardellach, E.; Chew, C. C.

    2015-12-01

    Wetland dynamics is crucial to changes in both atmospheric methane and terrestrial water storage. The Intergovernmental Panel on Climate Change's Fifth Assessment Report (IPCC AR5) highlights the role of wetlands as a key driver of methane (CH4) emission, which is more than one order of magnitude stronger than carbon dioxide as a greenhouse gas in the centennial time scale. Among the multitude of methane emission sources (hydrates, livestock, rice cultivation, freshwaters, landfills and waste, fossil fuels, biomass burning, termites, geological sources, and soil oxidation), wetlands constitute the largest contributor with the widest uncertainty range of 177-284 Tg(CH4) yr-1 according to the IPCC estimate. Wetlands are highly susceptible to climate change that might lead to wetland collapse. Such wetland destruction would decrease the terrestrial water storage capacity and thus contribute to sea level rise, consequently exacerbating coastal flooding problems. For both methane change and water storage change, wetland dynamics is a crucial factor with the largest uncertainty. Nevertheless, a complete and consistent map of global wetlands still needs to be obtained as the Ramsar Convention calls for a wetlands inventory and impact assessment. We develop a new method for observations of wetland change using Global Navigation Satellite Signals Reflectometry (GNSS-R) signatures for global wetland mapping in synergy with the existing capability, not only as a static inventory but also as a temporal dataset, to advance the capability for monitoring the dynamics of wetland extent relevant to addressing the science issues of CH4 emission change and terrestrial water storage change. We will demonstrate the capability of the new GNSS-R method over a rice field in the Ebro Delta wetland in Spain.

  2. Landscape heterogeneity, soil climate, and carbon exchange in a boreal black spruce forest.

    Science.gov (United States)

    Dunn, Allison L; Wofsy, Steven C; v H Bright, Alfram

    2009-03-01

    We measured soil climate and the turbulent fluxes of CO2, H2O, heat, and momentum on short towers (2 m) in a 160-yr-old boreal black spruce forest in Manitoba, Canada. Two distinct land cover types were studied: a Sphagnum-dominated wetland, and a feathermoss (Pleurozium and Hylocomium)-dominated upland, both lying within the footprint of a 30-m tower, which has measured whole-forest carbon exchange since 1994. Peak summertime uptake of CO2, was higher in the wetland than for the forest as a whole due to the influence of deciduous shrubs. Soil respiration rates in the wetland were approximately three times larger than in upland soils, and 30% greater than the mean of the whole forest, reflecting decomposition of soil organic matter. Soil respiration rates in the wetland were regulated by soil temperature, which was in turn influenced by water table depth through effects on soil heat capacity and conductivity. Warmer soil temperatures and deeper water tables favored increased heterotrophic respiration. Wetland drainage was limited by frost during the first half of the growing season, leading to high, perched water tables, cool soil temperatures, and much lower respiration rates than observed later in the growing season. Whole-forest evapotranspiration increased as water tables dropped, suggesting that photosynthesis in this forest was rarely subject to water stress. Our data indicate positive feedback between soil temperature, seasonal thawing, heterotrophic respiration, and evapotranspiration. As a result, climate warming could cause covariant changes in soil temperature and water table depths that may stimulate photosynthesis and strongly promote efflux of CO2 from peat soils in boreal wetlands.

  3. "Wetlands: Water Living Filters?",

    OpenAIRE

    Dordio, Ana; Palace, A. J.; Pinto, Ana Paula

    2008-01-01

    Human societies have indirectly used natural wetlands as wastewater discharge sites for many centuries. Observations of the wastewater depuration capacity of natural wetlands have led to a greater understanding of the potential of these ecosystems for pollutant assimilation and have stimulated the development of artificial wetlands systems for treatment of wastewaters from a variety of sources. Constructed wetlands, in contrast to natural wetlands, are human-made systems that are designed, bu...

  4. Ecological Sustainability of Birds in Boreal Forests

    Directory of Open Access Journals (Sweden)

    Gerald Niemi

    1998-12-01

    Full Text Available We review characteristics of birds in boreal forests in the context of their ecological sustainability under both natural and anthropogenic disturbances. We identify the underlying ecological factors associated with boreal bird populations and their variability, review the interactions between boreal bird populations and disturbance, and describe some tools on how boreal bird populations may be conserved in the future. The boreal system has historically been an area with extensive disturbance such as fire, insect outbreaks, and wind. In addition, the boreal system is vulnerable to global climate change as well as increasing pressure on forest and water resources. Current knowledge indicates that birds play an important role in boreal forests, and sustaining these populations affords many benefits to the health of boreal forests. Many issues must be approached with caution, including the lack of knowledge on our ability to mimic natural disturbance regimes with management, our lack of understanding on fragmentation due to logging activity, which is different from permanent conversion to other land uses such as agriculture or residential area, and our lack of knowledge on what controls variability in boreal bird populations or the linkage between bird population fluctuations and productivity. The essential role that birds can provide is to clarify important ecological concerns and variables that not only will help to sustain bird populations, but also will contribute to the long-term health of the boreal forest for all species, including humans.

  5. Ohio Uses Wetlands Program Development Grants to Protect Wetlands

    Science.gov (United States)

    The wetland water quality standards require the use of ORAM score to determine wetland quality. OEPA has also used these tools to evaluate wetland mitigation projects, develop performance standards for wetland mitigation banks and In Lieu Fee programs an.

  6. Photochemical Reactivity of Dissolved Organic Matter in Boreal Lakes

    Science.gov (United States)

    Gu, Y.; Vuorio, K.; Tiirola, M.; Perämäki, S.; Vahatalo, A.

    2016-12-01

    Boreal lakes are rich in dissolved organic matter (DOM) that terrestrially derived from forest soil and wetland, yet little is known about potential for photochemical transformation of aquatic DOM in boreal lakes. Transformation of chromophoric dissolved organic matter (CDOM) can decrease water color and enhance microbial mineralization, affecting primary production and respiration, which both affect the CO2 balance of the lakes. We used laboratory solar radiation exposure experiments with lake water samples collected from 54 lakes located in Finland and Sweden, representing different catchment composition and watershed location to assess photochemical reactivity of DOM. The pH of water samples ranged from 5.4 to 8.3, and the concentrations of dissolved iron (Fe) were between samples received simulated solar radiation corresponding to a daily dose of sunlight, and photomineralization of dissolved organic carbon (DOC) to dissolved inorganic carbon (DIC) was measured for determination of spectral apparent quantum yields (AQY). During irradiation, photobleaching decreased the absorption coefficients of CDOM at 330 nm between 4.9 and 79 m-1 by 0.5 to 11 m-1. Irradiation generated DIC from 2.8 to 79 μmol C L-1. The AQY at 330 nm ranged between 31 and 273 ×10-6 mol C mol photons-1 h-1, which was correlated positively with concentration of dissolved Fe, and negatively with pH. Further statistical analyze indicated that the interaction between pH and Fe may explain much of the photochemical reactivity of DOM in the examined lakes, and land cover concerns main catchment areas also can have impact on the photoreaction process. This study may suggest how environmental conditions regulate DOM photomineralization in boreal lakes.

  7. Wonderful Wetlands: An Environmental Education Curriculum Guide for Wetlands.

    Science.gov (United States)

    King County Parks Div., Redmond, WA.

    This curriculum guide was designed to give teachers, students, and society a better understanding of wetlands in the hope that they learn why wetlands should be valued and preserved. It explores what is meant by wetlands, functions and values of wetlands, wetland activities, and wetland offerings which benefit animal and plant life, recreation,…

  8. Magnitude and seasonality of wetland methane emissions from the Hudson Bay Lowlands (Canada

    Directory of Open Access Journals (Sweden)

    C. A. Pickett-Heaps

    2011-04-01

    Full Text Available The Hudson Bay Lowlands (HBL is the second largest boreal wetland ecosystem in the world and an important natural source of global atmospheric methane. We quantify the HBL methane emissions by using the GEOS-Chem chemical transport model to simulate aircraft measurements over the HBL from the ARCTAS and pre-HIPPO campaigns in May–July 2008, together with continuous 2004–2008 surface observations at Fraserdale (southern edge of HBL and Alert (Arctic background. The difference in methane concentrations between Fraserdale and Alert is shown to be a good indicator of HBL emissions, and implies a sharp seasonal onset of emissions in late May (consistent with the aircraft data, a peak in July–August, and a seasonal shut-off in September. The model, in which seasonal variation of emission is mainly driven by surface temperature, reproduces well the observations in summer but its seasonal shoulders are too broad. We suggest that this reflects the suppression of emissions by snow cover and greatly improve the model simulation by accounting for this effect. Our resulting best estimate for HBL methane emissions is 2.3 Tg a−1, several-fold higher than previous estimates (Roulet et al., 1994; Worthy et al., 2000.

  9. Magnitude and Seasonality of Wetland Methane Emissions from the Hudson Bay Lowlands (Canada)

    Science.gov (United States)

    Pickett-Heaps, C. A.; Jacob, D. J.; Wecht, K. J.; Kort, E. A.; Wofsy, S. C.; Diskin, G. S.; Worthy, D. E. J.; Kaplan, J. O.; Bey, I.; Drevet, J.

    2011-01-01

    The Hudson Bay Lowlands (HBL) is the second largest boreal wetland ecosystem in the world and an important natural source of global atmospheric methane. We quantify the HBL methane emissions by using the GEOS-Chem chemical transport model to simulate aircraft measurements over the HBL from the ARCTAS and pre-HIPPO campaigns in May-July 2008, together with continuous 2004-2008 surface observations at Fraserdale (southern edge of HBL) and Alert (Arctic background). The difference in methane concentrations between Fraserdale and Alert is shown to be a good indicator of HBL emissions, and implies a sharp seasonal onset of emissions in late May (consistent with the aircraft data), a peak in July-August, and a seasonal shut-off in September. The model, in which seasonal variation of emission is mainly driven by surface temperature, reproduces well the observations in summer but its seasonal shoulders are too broad. We suggest that this reflects the suppression of emissions by snow cover and greatly improve the model simulation by accounting for this effect. Our resulting best estimate for HBL methane emissions is 2.3 Tg/a, several-fold higher than previous estimates (Roulet et al., 1994; Worthy et al., 2000).

  10. Why are wetlands important?

    Science.gov (United States)

    Wetlands are among the most productive ecosystems in the world, comparable to rain forests and coral reefs. An immense variety of species of microbes, plants, insects, amphibians, reptiles, birds, fish, and mammals can be part of a wetland ecosystem.

  11. Percent Wetland Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  12. Percent Wetland Cover (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Wetlands act as filters, removing or diminishing the amount of pollutants that enter surface water. Higher values for percent of wetland cover (WETLNDSPCT) may be...

  13. VSWI Wetlands Advisory Layer

    Data.gov (United States)

    Vermont Center for Geographic Information — This dataset represents the DEC Wetlands Program's Advisory layer. This layer makes the most up-to-date, non-jurisdictional, wetlands mapping avaiable to the public...

  14. Temporal Data Fusion Approaches to Remote Sensing-Based Wetland Classification

    Science.gov (United States)

    Montgomery, Joshua S. M.

    This thesis investigates the ecology of wetlands and associated classification in prairie and boreal environments of Alberta, Canada, using remote sensing technology to enhance classification of wetlands in the province. Objectives of the thesis are divided into two case studies, 1) examining how satellite borne Synthetic Aperture Radar (SAR), optical (RapidEye & SPOT) can be used to evaluate surface water trends in a prairie pothole environment (Shepard Slough); and 2) investigating a data fusion methodology combining SAR, optical and Lidar data to characterize wetland vegetation and surface water attributes in a boreal environment (Utikuma Regional Study Area (URSA)). Surface water extent and hydroperiod products were derived from SAR data, and validated using optical imagery with high accuracies (76-97% overall) for both case studies. High resolution Lidar Digital Elevation Models (DEM), Digital Surface Models (DSM), and Canopy Height Model (CHM) products provided the means for data fusion to extract riparian vegetation communities and surface water; producing model accuracies of (R2 0.90) for URSA, and RMSE of 0.2m to 0.7m at Shepard Slough when compared to field and optical validation data. Integration of Alberta and Canadian wetland classifications systems used to classify and determine economic value of wetlands into the methodology produced thematic maps relevant for policy and decision makers for potential wetland monitoring and policy development.

  15. Silviculture's role in managing boreal forests

    Science.gov (United States)

    Russell T. Graham; Theresa B. Jain

    1998-01-01

    Boreal forests, which are often undeveloped, are a major source of raw materials for many countries. They are circumpolar in extent and occupy a belt to a width of 1000 km in certain regions. Various conifer and hardwood species ranging from true firs to poplars grow in boreal forests. These species exhibit a wide range of shade tolerance and growth characteristics,...

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

    Science.gov (United States)

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

    2011-12-01

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

  17. Capability of C-Band SAR for Operational Wetland Monitoring at High Latitudes

    Directory of Open Access Journals (Sweden)

    Julia Reschke

    2012-10-01

    Full Text Available Wetlands store large amounts of carbon, and depending on their status and type, they release specific amounts of methane gas to the atmosphere. The connection between wetland type and methane emission has been investigated in various studies and utilized in climate change monitoring and modelling. For improved estimation of methane emissions, land surface models require information such as the wetland fraction and its dynamics over large areas. Existing datasets of wetland dynamics present the total amount of wetland (fraction for each model grid cell, but do not discriminate the different wetland types like permanent lakes, periodically inundated areas or peatlands. Wetland types differently influence methane fluxes and thus their contribution to the total wetland fraction should be quantified. Especially wetlands of permafrost regions are expected to have a strong impact on future climate due to soil thawing. In this study ENIVSAT ASAR Wide Swath data was tested for operational monitoring of the distribution of areas with a long-term SW near 1 (hSW in northern Russia (SW = degree of saturation with water, 1 = saturated, which is a specific characteristic of peatlands. For the whole northern Russia, areas with hSW were delineated and discriminated from dynamic and open water bodies for the years 2007 and 2008. The area identified with this method amounts to approximately 300,000 km2 in northern Siberia in 2007. It overlaps with zones of high carbon storage. Comparison with a range of related datasets (static and dynamic showed that hSW represents not only peatlands but also temporary wetlands associated with post-forest fire conditions in permafrost regions. Annual long-term monitoring of change in boreal and tundra environments is possible with the presented approach. Sentinel-1, the successor of ENVISAT ASAR, will provide data that may allow continuous monitoring of these wetland dynamics in the future complementing global observations of

  18. A Passive Microwave L-Band Boreal Forest Freeze/Thaw and Vegetation Phenology Study

    Science.gov (United States)

    Roy, A.; Sonnentag, O.; Pappas, C.; Mavrovic, A.; Royer, A.; Berg, A. A.; Rowlandson, T. L.; Lemay, J.; Helgason, W.; Barr, A.; Black, T. A.; Derksen, C.; Toose, P.

    2016-12-01

    The boreal forest is the second largest land biome in the world and thus plays a major role in the global and regional climate systems. The extent, timing and duration of seasonal freeze/thaw (F/T) state influences vegetation developmental stages (phenology) and, consequently, constitute an important control on how boreal forest ecosystems exchange carbon, water and energy with the atmosphere. The effective retrieval of seasonal F/T state from L-Band radiometry was demonstrated using satellite mission. However, disentangling the seasonally differing contributions from forest overstory and understory vegetation, and the soil surface to the satellite signal remains challenging. Here we present initial results from a radiometer field campaign to improve our understanding of the L-Band derived boreal forest F/T signal and vegetation phenology. Two L-Band surface-based radiometers (SBR) are installed on a micrometeorological tower at the Southern Old Black Spruce site in central Saskatchewan over the 2016-2017 F/T season. One radiometer unit is installed on the flux tower so it views forest including all overstory and understory vegetation and the moss-covered ground surface. A second radiometer unit is installed within the boreal forest overstory, viewing the understory and the ground surface. The objectives of our study are (i) to disentangle the L-Band F/T signal contribution of boreal forest overstory from the understory and ground surface, (ii) to link the L-Band F/T signal to related boreal forest structural and functional characteristics, and (iii) to investigate the use of the L-Band signal to characterize boreal forest carbon, water and energy fluxes. The SBR observations above and within the forest canopy are used to retrieve the transmissivity (γ) and the scattering albedo (ω), two parameters that describe the emission of the forest canopy though the F/T season. These two forest parameters are compared with boreal forest structural and functional

  19. Detecting wetland changes in Shanghai, China using FORMOSAT and Landsat TM imagery

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Bo; Zhou, Yun-xuan; Thom, Ronald M.; Diefenderfer, Heida L.; Yuan, Qing

    2015-07-14

    Understanding the state of wetland ecosystems and their changes at the national and local levels is critical for wetland conservation, management, decision-making, and policy development practices. This study analyzed the wetlands in Shanghai, a province-level city, using remote sensing, image processing, and geographic information systems (GIS) techniques based on the Chinese national wetland inventory procedure and standards. FORMOSAT imagery acquired in 2012 and Navy nautical charts of the Yangtze estuarine area were used in conjunction with object-oriented segmentation, expert interpretation, and field validation to determine wetland status. Landsat imagery from 1985, 1995, 2000, 2003 and 2013 as well as social-economic data collected from 1985 to 2013 were used to further assess wetland changes. In 2013, Shanghai contained 376,970.6 ha of wetlands, and 78.8% of all wetlands were in marine or estuarine systems. Estuarine waters comprised the single largest wetland category. Between the first national wetland inventory in 2003 and the second national wetland inventory in 2013, Shanghai lost 50,519.13 ha of wetlands, amounting to a mean annual loss rate of 1.2% or an 11.8% loss over the decade. Declines were proportionately higher in marine and estuarine wetlands, with an annual loss of 1.8%, while there was a sharp increase of 1882.6% in constructed water storage areas for human uses. Diking, filling, impoundment and reclamation, which are all attributable to the economic development and urbanization associated with population increases, were the major factors that explained the gain and loss of wetlands. Additional factors affecting wetland losses and gains include sediment trapping by the hydropower system, which reduces supply to the estuary and erodes wetlands, and sediment trapping by the jetties, spur dikes, and diversion bulwark associated with a navigation channel deepening project, which has the converse effect, increasing saltmarsh wetland area at

  20. Freshwater Wetlands: A Citizen's Primer.

    Science.gov (United States)

    Catskill Center for Conservation and Development, Inc., Hobart, NY.

    The purpose of this "primer" for the general public is to describe the general characteristics of wetlands and how wetland alteration adversely affects the well-being of humans. Particular emphasis is placed on wetlands in New York State and the northeast. Topics discussed include wetland values, destruction of wetlands, the costs of…

  1. Estimating belowground carbon stocks in isolated wetlands of the Northern Everglades Watershed, central Florida, using ground penetrating radar (GPR) and aerial imagery

    Science.gov (United States)

    McClellan, Matthew; Comas, Xavier; Hinkle, Ross; Sumner, David M.

    2017-01-01

    Peat soils store a large fraction of the global soil carbon (C) pool and comprise 95% of wetland C stocks. While isolated freshwater wetlands in temperate and tropical biomes account for more than 20% of the global peatland C stock, most studies of wetland soil C have occurred in expansive peatlands in northern boreal and subarctic biomes. Furthermore, the contribution of small depressional wetlands in comparison to larger wetland systems in these environments is very uncertain. Given the fact that these wetlands are numerous and variable in terms of their internal geometry, innovative methods are needed for properly estimating belowground C stocks and their overall C contribution to the landscape. In this study, we use a combination of ground penetrating radar (GPR), aerial imagery, and direct measurements (coring) in conjunction with C core analysis to develop a relation between C stock and surface area, and estimate the contribution of subtropical depressional wetlands to the total C stock of pine flatwoods at the Disney Wilderness Preserve (DWP), Florida. Additionally, GPR surveys were able to image collapse structures underneath the peat basin of depressional wetlands, depicting lithological controls on the formation of depressional wetlands at the DWP. Results indicate the importance of depressional wetlands as critical contributors to the landscape C budget at the DWP and the potential of GPR-based approaches for (1) rapidly and noninvasively estimating the contribution of depressional wetlands to regional C stocks and (2) evaluating the formational processes of depressional wetlands.

  2. Estimating Belowground Carbon Stocks in Isolated Wetlands of the Northern Everglades Watershed, Central Florida, Using Ground Penetrating Radar and Aerial Imagery

    Science.gov (United States)

    McClellan, Matthew; Comas, Xavier; Benscoter, Brian; Hinkle, Ross; Sumner, David

    2017-11-01

    Peat soils store a large fraction of the global soil carbon (C) pool and comprise 95% of wetland C stocks. While isolated freshwater wetlands in temperate and tropical biomes account for more than 20% of the global peatland C stock, most studies of wetland soil C have occurred in expansive peatlands in northern boreal and subarctic biomes. Furthermore, the contribution of small depressional wetlands in comparison to larger wetland systems in these environments is very uncertain. Given the fact that these wetlands are numerous and variable in terms of their internal geometry, innovative methods are needed for properly estimating belowground C stocks and their overall C contribution to the landscape. In this study, we use a combination of ground penetrating radar (GPR), aerial imagery, and direct measurements (coring) in conjunction with C core analysis to develop a relation between C stock and surface area, and estimate the contribution of subtropical depressional wetlands to the total C stock of pine flatwoods at the Disney Wilderness Preserve (DWP), Florida. Additionally, GPR surveys were able to image collapse structures underneath the peat basin of depressional wetlands, depicting lithological controls on the formation of depressional wetlands at the DWP. Results indicate the importance of depressional wetlands as critical contributors to the landscape C budget at the DWP and the potential of GPR-based approaches for (1) rapidly and noninvasively estimating the contribution of depressional wetlands to regional C stocks and (2) evaluating the formational processes of depressional wetlands.

  3. Landscape control on the hydrogeochemistry of As, Co and Pb in a boreal stream network

    Science.gov (United States)

    Wällstedt, Teresia; Björkvald, Louise; Laudon, Hjalmar; Borg, Hans; Mörth, Carl-Magnus

    2017-08-01

    In a boreal stream network, stream water concentrations of As, Co and Pb (filtered, 30% wetland), which was suggested to be controlled by atmospheric deposition in combination with high DOC release from the wetlands. For Co, the highest concentrations were found in the forest dominated sites (>98% forest), which were attributed to the weathering of minerogenic sources. Contrasting response to runoff events could also be related to landscape type; during the spring flood, decreasing concentrations of As, Co and Pb were observed in the wetland dominated catchments due to dilution, while increasing concentrations during spring flood were observed in the mixed catchments (2-30% wetland) and to some degree in the forested catchments, probably due to flushing of the organic-rich riparian sources. Further, metal speciation was calculated using the geochemical equilibrium model Visual MINTEQ. This suggests that dissolved inorganic species of As and Co dominated in headwater streams with low pH while DOC had a major influencing role for Pb. In the larger mixed streams where pH was higher and precipitation of e.g. colloidal Fe and Mn (hydr)oxides was favoured, the major influencing factor was instead adsorption to colloidal Fe for As and Pb, while association to organic matter and colloids of e.g. Mn influenced the concentrations of Co. We thus conclude that landscape type and the magnitude of the runoff events are of great importance for the spatial and temporal variations of As, Co and Pb in this boreal stream network. Projected climate change, with increasing runoff, may therefore influence riverine concentrations and fluxes differently, depending on the prevailing landscape type.

  4. Competitive interactions among raptors in boreal forests.

    Science.gov (United States)

    Hakkarainen, Harri; Mykrä, Sakari; Kurki, Sami; Tornberg, Risto; Jungell, Sven

    2004-11-01

    We examined inter-specific interactions among goshawks ( Accipiter gentilis), common buzzards (Buteo buteo) and honey buzzards (Pernis apivorus) in western Finland in 1983-1996. Because goshawks are among the largest birds of prey species in boreal forests they may take over the nest of smaller and less-competitive forest-dwelling raptors when searching for suitable places for breeding. Accordingly, more than half of newly established goshawk territories were found on the territories previously occupied by the common buzzard and the honey buzzard. Otherwise, territory sharing between these species was rare. Fledgling production of honey buzzards was not associated with the presence of goshawks, probably owing to the almost 2 months later onset of breeding. This probably decreases competitive interactions between these two species. An intensive interference competition, instead, seemed to be evident between common buzzards and goshawks, because the fledgling production of common buzzards was decreased by 20% as a result of failures during incubation and nestling period in the vicinity (nests. Similarly, territory occupancy of common buzzards till the next breeding season was significantly reduced in the presence of goshawks. Relatively high proportions of occupied buzzard territories (17%) in the study area were shared by breeding goshawks on the same territory. This suggests that although their diets are dissimilar they inhabit similar habitats and might compete for the available prime nesting habitats within forest landscapes. In addition, goshawks benefit from taking over the complete nests of other raptors, imposing upon the original owners of the nest, because building a large stick nest is probably energetically costly. As a large raptor, the goshawk apparently has a competitive advantage over smaller ones, and may have an ever-increasing impact on smaller birds of prey, if there is a lack of sheltered forests inducing competition for the available nest sites.

  5. Comparative Hydrology, Water Quality, and Ecology of Selected Natural and Augmented Freshwater Wetlands in West-Central Florida

    Science.gov (United States)

    Lee, T.M.; Haag, K.H.; Metz, P.A.; Sacks, L.A.

    2009-01-01

    Comparing altered wetlands to natural wetlands in the same region improves the ability to interpret the gradual and cumulative effects of human development on freshwater wetlands. Hydrologic differences require explicit attention because they affect nearly all wetland functions and are an overriding influence on other comparisons involving wetland water quality and ecology. This study adopts several new approaches to quantify wetland hydrologic characteristics and then describes and compares the hydrology, water quality, and ecology of 10 isolated freshwater marsh and cypress wetlands in the mantled karst landscape of central Florida. Four of the wetlands are natural, and the other six have water levels indirectly lowered by ground-water withdrawals on municipally owned well fields. For several decades, the water levels in four of these altered wetlands have been raised by adding ground water in a mitigation process called augmentation. The two wetlands left unaugmented were impaired because their water levels were lowered. Multifaceted comparisons between the altered and natural wetlands are used to examine differences between marshes and cypress wetlands and to describe the effects of augmentation practices on the wetland ecosystems. In the karstic geologic setting, both natural and altered wetlands predominantly lost water to the surficial aquifer. Water leaking out of the wetlands created water-table mounds below the wetlands. The smallest mounds radiated only slightly beyond the vegetated area of the wetlands. The largest and steepest mounds occurred below two of the augmented wetlands. There, rapid leakage rates regenerated a largely absent surficial aquifer and mounds encompassed areas 7-8 times as large as the wetlands. Wetland leakage rates, estimated using a daily water-budget analysis applied over multiple years and normalized as inches per day, varied thirtyfold from the slowest leaking natural wetland to the fastest leaking augmented wetland. Leakage

  6. Tidal wetland vegetation and ecotone profiles: The Rush Ranch Open Space Preserve

    Science.gov (United States)

    The Rush Ranch Open Space Preserve (Rush Ranch) is a component site of the San Francisco Bay National Estuarine Research Reserve (SF Bay NERR) that includes one of the largest undiked tidal wetlands in the San Francisco Estuary. The brackish tidal wetlands grade into transitional vegetation and unde...

  7. Wetland Surface Water Processes

    National Research Council Canada - National Science Library

    1993-01-01

    .... Temporary storage includes channel, overbank, basin, and groundwater storage. Water is removed from the wetland through evaporation, plant transpiration, channel, overland and tidal flow, and groundwater recharge...

  8. Using Internet search behavior to assess public awareness of protected wetlands.

    Science.gov (United States)

    Do, Yuno; Kim, Ji Yoon; Lineman, Maurice; Kim, Dong-Kyun; Joo, Gea-Jae

    2015-02-01

    Improving public awareness of protected wetlands facilitates sustainable wetland management, which depends on public participation. One way of gauging public interest is by tracking Internet search behavior (ISB). We assessed public awareness of issues related to protected wetland areas (PWAs) in South Korea by examining the frequencies of specific queries (PWAs, Ramsar, Upo wetland, Sunchon Bay, etc.) using relative search volumes (RSVs) obtained from an Internet search engine. RSV shows how many times a search term is used relative to a second search term during a specific period. Public awareness of PWAs changed from 2007 to 2013. Initially the majority of Internet searches were related to the most well-known tidal and inland wetlands Sunchon Bay and Upo wetlands, which are the largest existing wetlands in Korea with the greatest historical exposure. Public awareness, as reflected in RSVs, of wetlands increased significantly following PWA designation for the wetlands in 2008, which followed the Ramsar 10th Conference of Contracting Parties to the Convention on Wetlands (COP10) meeting. Public interest was strongly correlated to the number of news articles in the popular media, as evidenced by the increase in Internet searches for specific wetlands and words associated with specific wetlands. Correspondingly, the number of visitors to specific wetlands increased. To increase public interest in wetlands, wetland aspects that enhance wetland conservation should be promoted by the government and enhanced via public education. Our approach can be used to gauge public awareness and participation in a wide range of conservation efforts. © 2014 Society for Conservation Biology.

  9. Loy Yang A - Australia's largest privatisation

    International Nuclear Information System (INIS)

    Yenckin, C.

    1997-01-01

    The recent A$4,746 million privatisation of the 2000MW Loy Yang A power station and the Loy Yang coal mine by the Victorian Government is Australia's largest privatisation and one of 1997's largest project financing deals. (author)

  10. Simulation of the water balance of boreal watersheds of northeastern British Columbia, Canada using MIKE SHE, an integrated hydrological model

    Science.gov (United States)

    Abadzadesahraei, S.; Déry, S.; Rex, J. F.

    2016-12-01

    Northeastern British Columbia (BC) is undergoing rapid development for oil and gas extraction, largely depending on subsurface hydraulic fracturing (fracking), which relies on available freshwater. Even though this industrial activity has made substantial contributions to regional and provincial economies, it is important to ensure that sufficient and sustainable water supplies are available for all those dependent on the resource, including ecological systems. Further, BC statistics predict that the northeastern region's population will increase by 30% over the next 25 years, thereby amplifying the demands of domestic and industrial water usage. Hence, given the increasing demands for surface water in the complex wetlands of northeastern BC, obtaining accurate long-term water balance information is of vital importance. Thus, this study aims to simulate the 1979-2014 water balance at two boreal watersheds using the MIKE SHE model. More specifically, this research intends to quantify the historical, and regional, water budgets and their associated hydrological processes at two boreal watersheds—the Coles Lake and Tsea Lake watersheds—in northeastern BC. The development of coupled groundwater and surface water model of these watersheds are discussed. The model setup, calibration process, and results are presented, focusing on the water balance of boreal watersheds. Hydrological components within these watersheds are quantified through a combination of intensive fieldwork, observational data, analysis and numerical modeling. The output from the model provides important information for decision makers to manage water resources in northeastern BC. Keywords: Northeastern BC; boreal watershed; water balance; MIKE SHE hydrological model.

  11. Forested wetland habitat

    Science.gov (United States)

    Duberstein, Jamie A.; Krauss, Ken W.; Kennish, Michael J.

    2015-01-01

    A forested wetland (swamp) is a forest where soils are saturated or flooded for at least a portion of the growing season, and vegetation, dominated by trees, is adapted to tolerate flooded conditions. A tidal freshwater forested wetland is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity of soil porewater less than 0.5 g/l. It is known locally as tidal várzea in the Amazon delta, Brazil. A tidal saltwater forested wetland (mangrove forest) is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity often exceeding 3 g/l and reaching levels that can exceed seawater. Mangrove ecosystems are composed of facultative halophytes that generally experience better growth at moderate salinity concentrations.

  12. The subcatchment- and catchment-scale hydrology of a boreal headwater peatland complex with sporadic permafrost.

    Science.gov (United States)

    Sonnentag, O.; Helbig, M.; Connon, R.; Hould Gosselin, G.; Ryu, Y.; Karoline, W.; Hanisch, J.; Moore, T. R.; Quinton, W. L.

    2017-12-01

    The permafrost region of the Northern Hemisphere has been experiencing twice the rate of climate warming compared to the rest of the Earth, resulting in the degradation of the cryosphere. A large portion of the high-latitude boreal forests of northwestern Canada grows on low-lying organic-rich lands with relative warm and thin isolated, sporadic and discontinuous permafrost. Along this southern limit of permafrost, increasingly warmer temperatures have caused widespread permafrost thaw leading to land cover changes at unprecedented rates. A prominent change includes wetland expansion at the expense of Picea mariana (black spruce)-dominated forest due to ground surface subsidence caused by the thawing of ice-rich permafrost leading to collapsing peat plateaus. Recent conceptual advances have provided important new insights into high-latitude boreal forest hydrology. However, refined quantitative understanding of the mechanisms behind water storage and movement at subcatchment and catchment scales is needed from a water resources management perspective. Here we combine multi-year daily runoff measurements with spatially explicit estimates of evapotranspiration, modelled with the Breathing Earth System Simulator, to characterize the monthly growing season catchment scale ( 150 km2) hydrological response of a boreal headwater peatland complex with sporadic permafrost in the southern Northwest Territories. The corresponding water budget components at subcatchment scale ( 0.1 km2) were obtained from concurrent cutthroat flume runoff and eddy covariance evapotranspiration measurements. The highly significant linear relationships for runoff (r2=0.64) and evapotranspiration (r2=0.75) between subcatchment and catchment scales suggest that the mineral upland-dominated downstream portion of the catchment acts hydrologically similar to the headwater portion dominated by boreal peatland complexes. Breakpoint analysis in combination with moving window statistics on multi

  13. Evaluating the significance of wetland restoration scenarios on phosphorus removal.

    Science.gov (United States)

    Daneshvar, Fariborz; Nejadhashemi, A Pouyan; Adhikari, Umesh; Elahi, Behin; Abouali, Mohammad; Herman, Matthew R; Martinez-Martinez, Edwin; Calappi, Timothy J; Rohn, Bridget G

    2017-05-01

    Freshwater resources are vital for human and natural systems. However, anthropogenic activities, such as agricultural practices, have led to the degradation of the quality of these limited resources through pollutant loading. Agricultural Best Management Practices (BMPs), such as wetlands, are recommended as a valuable solution for pollutant removal. However, evaluation of their long-term impacts is difficult and requires modeling since performing in-situ monitoring is expensive and not feasible at the watershed scale. In this study, the impact of natural wetland implementation on total phosphorus reduction was evaluated both at the subwatershed and watershed levels. The study area is the Saginaw River Watershed, which is largest watershed in Michigan. The phosphorus reduction performances of four different wetland sizes (2, 4, 6, and 8 ha) were evaluated within this study area by implementing one wetland at a time in areas identified to have the highest potential for wetland restoration. The subwatershed level phosphorus loads were obtained from a calibrated Soil and Water Assessment Tool (SWAT) model. These loads were then incorporated into a wetland model (System for Urban Stormwater Treatment and Analysis IntegratioN-SUSTAIN) to evaluate phosphorus reduction at the subwatershed level and then the SWAT model was again used to route phosphorus transport to the watershed outlet. Statistical analyses were performed to evaluate the spatial impact of wetland size and placement on phosphorus reduction. Overall, the performance of 2 ha wetlands in total phosphorus reduction was significantly lower than the larger sizes at both the subwatershed and watershed levels. Regarding wetland implementation sites, wetlands located in headwaters and downstream had significantly higher phosphorus reduction than the ones located in the middle of the watershed. More specifically, wetlands implemented at distances ranging from 200 to 250 km and 50-100 km from the outlet had the

  14. Carbon dynamics, food web structure and reclamation strategies in Athabasca oil sands wetlands (CFRAW)

    International Nuclear Information System (INIS)

    Ciborowski, J.J.; Dixon, G.; Foote, L.; Liber, K.; Smits, J.E.

    2007-01-01

    The remediation and ecology of oilsands constructed wetlands was discussed with reference to a project known as the Carbon dynamics, Food web structure and Reclamation strategies in Athabasca oil sands Wetlands (CFRAW). This joint project between 7 mining partners and 5 universities documents how tailings in constructed wetlands modify maturation leading to natural conditions in a reclaimed landscape. Since wetlands are expected to make up 20-50 per cent of the final reclamation landscape of areas surface mined for oil sands in northeastern Alberta, the project focuses on how quickly wetlands amended with reclamation materials approach the conditions seen in reference wetland systems. This study provided a conceptual model of carbon pathways and budgets to evaluate how the allocation of carbon among compartments changes as newly formed wetlands mature in the boreal system. It is likely that succession and community development will accelerate if constructed wetlands are supplemented with stockpiled peat or topsoil. The bitumens and naphthenic acids found in wetlands constructed with mine tailings materials are initially toxic, but may ultimately serve as an alternate source of carbon once they degrade or are metabolized by bacteria. This study evaluated the sources, biological uptake, pathways, and movement through the food web of materials used by the biota in constructed wetlands, with particular reference to how productivity of new wetlands is maintained. Net ecosystem productivity is being monitored along with rates of organic carbon accumulation from microbial, algal, and macrophyte production, and influx of outside materials. The rates of leaf litter breakdown and microbial respiration are also being monitored to determine how constituents speed or slow food web processes of young and older wetlands. Carbon and nitrogen stable isotope measurements indicate which sources are incorporated into the food web as wetlands age, and how this influences community

  15. broken magnet highlights largest collider's engineering challenges

    CERN Multimedia

    Inman, Mason

    2007-01-01

    "Even at the world's soon-to-be largest particle accelerator - a device that promises to push the boundaries of physics - scientists need to be mindful of one of the most fundamental laws in the universe: Murphy's Law. (2 pages)

  16. Permafrost thaw and fire history: implications of boreal tree cover changes on land surface properties and turbulent energy fluxes in the Taiga Plains, Canada

    Science.gov (United States)

    Sonnentag, Oliver; Helbig, Manuel; Payette, Fanny; Wischnewski, Karoline; Kljun, Natascha; Chasmer, Laura; Pappas, Christoforos; Detto, Matteo; Baltzer, Jennifer; Quinton, William; Marsh, Philip

    2016-04-01

    Given their large areal coverage, high carbon densities, and unique land surface properties and disturbance regimes (e.g., wildfires), the world's boreal forests are integral components of the global and regional climate systems. A large portion of boreal forests contain permafrost, i.e., perennially cryotic ground. In the Taiga Plains ecozone in northwestern Canada, the northernmost boreal forests grow on cold (100 m) continuous permafrost (>90 % in areal extent). More southerly boreal forests occur in areas with discontinuous (>50 - 90 % in areal extent), sporadic (>10 - 50 % in areal extent) and isolated permafrost (<10 % in areal extent). Using annual MODIS Percent Tree Cover (PTC) data from the MOD44B product in combination with spatial information on fire history, and permafrost and drainage characteristics, we show that in low-lying, poorly-drained areas along the southern fringe of permafrost, thawing induces widespread decreases in PTC and dominates over PTC increases due to post-fire regrowth. In contrast, PTC appears to be slightly increasing in the central and northern Taiga Plains with more stable discontinuous and continuous permafrost, respectively. While these increases are partly explained by post-fire regrowth, more favourable growing conditions may also contribute to increasing PTC. To better understand the implications of permafrost thaw on land surface properties (e.g., aerodynamic conductance for heat [ga] and surface conductance for water vapour [gs]), and the turbulent fluxes of latent (LE) and sensible heat (H) along the southern fringe of permafrost, we examined nested eddy covariance flux measurements made at two nearby locations at Scotty Creek (61°18' N; 121°18' W) starting May 2013. The low-lying, poorly-drained southern portion of this 152 km2-watershed contains rapidly thawing sporadic permafrost resulting in a highly dynamic mosaic dominated by decreasing forested permafrost peat plateaus, and increasing permafrost-free wetlands

  17. Carbon dynamics, food web structure and reclamation strategies in Athabasca oil sands wetlands (CFRAW) : overview and progress

    International Nuclear Information System (INIS)

    Ciborowski, J.; Dixon, D.G.; Foote, L.; Liber, K.; Smits, J.E.

    2009-01-01

    Seven oil sand mining partners and 5 university labs have joined forces to study the effects of mine tailings and process waters on development, health and function of wetland communities formed in post-mining landscapes. The collaborative effort, know as the carbon dynamics, food web structure and reclamation strategies in Athabasca oil sands wetlands (CRFAW), aims to identify the materials and strategies most effective and economical in producing a functioning reclamation landscape. This presentation reported on part of the study that tested predictions about how quickly wetlands amended with reclamation materials approach the conditions of reference wetland systems. It provided a conceptual model of carbon pathways and budgets to assess how the allocation of carbon among compartments changes as newly formed wetlands mature in the boreal system. It was assumed that stockpiling constructed wetlands with peat or topsoil would accelerate succession and community development. Although the bitumen and the naphthenic acids found in constructed wetlands are initially toxic, they may serve as an alternate source of carbon once they degrade. This study also assessed the sources, biological uptake, pathways, and movement through the food web of materials used by the biota in constructed wetlands. Additional studies are examining how the productivity of new wetlands is maintained. Net ecosystem productivity is being monitored along with rates of organic carbon accumulation from microbial, algal, and macrophyte production, and influx of outside materials. The rates of leaf litter breakdown and microbial respiration are being compared to determine how constituents speed or slow food web processes of young and older wetlands. Carbon and nitrogen isotope values in food web compartments indicate which sources are incorporated into the food web as wetlands age. The values are used to determine how this influences community development, food web structure and complexity, and the

  18. Nitrogen alters carbon dynamics during early succession in boreal forest

    Science.gov (United States)

    Steven D. Allison; Tracy B. Gartner; Michelle C. Mack; Krista McGuire; Kathleen. Treseder

    2010-01-01

    Boreal forests are an important source of wood products, and fertilizers could be used to improve forest yields, especially in nutrient poor regions of the boreal zone. With climate change, fire frequencies may increase, resulting in a larger fraction of the boreal landscape present in early successional stages. Since most fertilization studies have focused on mature...

  19. Boreal Forest Fire Cools Climate

    Science.gov (United States)

    Randerson, J. T.; Liu, H.; Flanner, M.; Chambers, S. D.; Harden, J. W.; Hess, P. G.; Jin, Y.; Mack, M. C.; Pfister, G.; Schuur, E. A.; Treseder, K. K.; Welp, L. R.; Zender, C. S.

    2005-12-01

    We report measurements, modeling, and analysis of carbon and energy fluxes from a boreal forest fire that occurred in interior Alaska during 1999. In the first year after the fire, ozone production, atmospheric aerosol loading, greenhouse gas emissions, soot deposition, and decreases in summer albedo contributed to a positive annual radiative forcing (RF). These effects were partly offset by an increase in fall, winter, and spring albedo from reduced canopy cover and increased exposure of snow-covered surfaces. The atmospheric lifetime of aerosols and ozone and are relatively short (days to months). The radiative effects of soot on snow are also attenuated rapidly from the deposition of fresh snow. As a result, a year after the fire, only two classes of RF mechanisms remained: greenhouse gas emissions and post-fire changes in surface albedo. Summer albedo increased rapidly in subsequent years and was substantially higher than unburned control areas (by more than 0.03) after 4 years as a result of grass and shrub establishment. Satellite measurements from MODIS of other interior Alaska burn scars provided evidence that elevated levels of spring and summer albedo (relative to unburned control areas) persisted for at least 4 decades after fire. In parallel, our chamber, eddy covariance, and biomass measurements indicated that the post-fire ecosystems switch from a source to a sink within the first decade. Taken together, the extended period of increased spring and summer albedo and carbon uptake of intermediate-aged stands appears to more than offset the initial warming pulse caused by fire emissions, when compared using the RF concept. This result suggests that management of forests in northern countries to suppress fire and preserve carbon sinks may have the opposite effect on climate as that intended.

  20. Mapping of Geographically Isolated Wetlands of Western Siberia Using High Resolution Space Images

    Science.gov (United States)

    Dyukarev, E.; Pologova, N.; Dyukarev, A.; Lane, C.; Autrey, B. C.

    2014-12-01

    Using the remote sensing data for integrated study of natural objects is actual for investigation of difficult to access areas of West Siberia. The research of this study focuses on determining the extent and spectral signatures of isolated wetlands within Ob-Tom Interfluve area using Landsat and Quickbird space images. High-resolution space images were carefully examined and wetlands were manually delineated. Wetlands have clear visible signs at the high resolution space images. 567 wetlands were recognized as isolated wetlands with the area about 10 000 ha (of 2.5% of the study area). Isolated wetlands with area less 2 ha are the most frequent. Half of the total amount of wetlands has area less than 6.4 ha. The largest isolated wetland occupies 797 ha, and only 5% have area more than 50 ha. The Landsat 7 ETM+ data were used for analysis of vegetation structure and spectral characteristics of wetlands. The masked isolated wetlands image was classified into 12 land cover classes using ISODATA unsupervised classification. The attribution of unsupervised classification results allowed us to clearly recognize 7 types of wetlands: tall, low and sparse ryams (Pine-Shrub-Sphagnum community), open wetlands with shrub, moss or sedge cover, and open water objects. Analysis of spectral profiles for all classes has shown that Landsat spectral bands 4 and 5 have higher variability. These bands allow to separate wetland classed definitely. Accuracy assessment of isolated wetland map shows a good agreement with expert field data. The work was supported by grants ISTC № 4079.

  1. Hydrologic response in karstic-ridge wetlands to rainfall and evapotranspiration, central Florida, 2001-2003

    Science.gov (United States)

    Knowles, Leel; Phelps, G.G.; Kinnaman, Sandra L.; German, Edward R.

    2005-01-01

    though rainfall was far above average during the study, wetland evaporation volumetrically exceeded rainfall. Ground-water inflow was effective in partially offsetting the negative residual between rainfall and evaporation, thus adding to wetland storage. Ground-water inflow was most common at both wetlands when rainfall continued for days or weeks, or during a week with more than about 2.5 inches of rainfall. Large decreases in wetland storage were associated with large negative fluxes of evaporation and ground-water exchange. The response of wetland water levels to rainfall showed a strong and similar relation at both study sites; however, the greater variability in the relation of wetland water-level change to rainfall at higher rainfall rates indicated that hydrologic processes other than rainfall became more important in the response of the wetland. Changes in wetland water levels seemed to be related more to vertical gradients than to lateral gradients. The largest wetland water-level rises were associated mostly with lower vertical gradients, when vertical head differences were below the 18-month average; however, at the Lyonia large wetland, extremely large lateral gradients toward the wetland during late June 2002 may have contributed to substantial gains in wetland water. During the remainder of the study, wetland water-level rises were associated mostly with decreasing vertical gradients and highly variable lateral gradients. Conversely, wetland water-level decreases were associated mostly with increasing vertical gradients and lateral gradients away from the wetland, particularly during the dry season. The potential for lateral ground-water exchange with the wetlands varied substantially more than that for vertical exchange. Potential for vertical losses of wetland water to ground water was highest during a dry period from December 2001 to June 2002, during the wet season of 2002, and for several months into the following dry season. Lateral he

  2. Wetlands and infectious diseases

    Directory of Open Access Journals (Sweden)

    Robert H. Zimmerman

    2001-01-01

    Full Text Available There is a historical association between wetlands and infectious disease that has led to the modification of wetlands to prevent disease. At the same time there has been the development of water resources projects that increase the risk of disease. The demand for more water development projects and the increased pressure to make natural wetlands economically beneficial creates the need for an ecological approach to wetland management and health assessment. The environmental and health interactions are many. There is a need to take into account the landscape, spatial boundaries, and cross-boundary interactions in water development projects as well as alternative methods to provide water for human needs. The research challenges that need to be addressed are discussed.

  3. Coastal Wetland Restoration Bibliography

    National Research Council Canada - National Science Library

    Yozzo, David

    1997-01-01

    This bibliography was compiled to provide biologists, engineers, and planners at Corps Districts and other agencies/ institutions with a guide to the diverse body of literature on coastal wetland restoration...

  4. Principles of Wetland Restoration

    Science.gov (United States)

    the return of a degraded ecosystem to a close approximation of its remaining natural potential - is experiencing a groundswell of support across the United States. The number of stream, river, lake, wetland and estuary restoration projects grows yearly

  5. Wetland Groundwater Processes

    National Research Council Canada - National Science Library

    Williams, Greg

    1993-01-01

    This technical note summarizes hydrologic and hydraulic (H AND H) processes and the related terminology that will likely be encountered during an evaluation of the effect of ground-water processes on wetland function...

  6. Carbon sequestration from boreal wildfires via Pyrogenic Carbon production

    Science.gov (United States)

    Santin, Cristina; Doerr, Stefan; Preston, Caroline

    2014-05-01

    allowed, for the first time, quantifying the whole range of PyC components found in-situ immediately after a typical boreal forest fire. The fire examined had a fireline intensity of ~8000 kw/m, which is typical of boreal fires in NW Canada and we found that more than 18% of the fuel consumed was converted to PyC. This rate by far exceeds previous estimates (1-3%) and suggests that PyC production has indeed been substantially underestimated. As boreal forests are the world's largest terrestrial biome and contain half of the forest ecosystem C with a third its net primary productivity being consumed by fire every year, our findings could imply that PyC production from wildfires is a potential carbon sequestration mechanism of sufficient magnitude that warrants inclusion in boreal and perhaps global C budget estimations.

  7. VEGETATION MAPPING IN WETLANDS

    Directory of Open Access Journals (Sweden)

    F. PEDROTTI

    2004-01-01

    Full Text Available The current work examines the main aspects of wetland vegetation mapping, which can be summarized as analysis of the ecological-vegetational (ecotone gradients; vegetation complexes; relationships between vegetation distribution and geomorphology; vegetation of the hydrographic basin lo which the wetland in question belongs; vegetation monitoring with help of four vegetation maps: phytosociological map of the real and potential vegetation, map of vegetation dynamical tendencies, map of vegetation series.

  8. [Changes of wetland landscape pattern in Dayang River Estuary based on high-resolution remote sensing image].

    Science.gov (United States)

    Wu, Tao; Zhao, Dong-zhi; Zhang, Feng-shou; Wei, Bao-quan

    2011-07-01

    Based on the comprehensive consideration of the high resolution characteristics of remote sensing data and the current situation of land cover and land use in Dayang River Estuary wetland, a classification system with different resolutions of wetland landscape in the Estuary was established. The landscape pattern indices and landscape transition matrix were calculated by using the high resolution remote sensing data, and the dynamic changes of the landscape pattern from 1984 to 2008 were analyzed. In the study period, the wetland landscape components changed drastically. Wetland landscape transferred from natural wetland into artificial wetland, and wetland core regional area decreased. Natural wetland's largest patch area index descended, and the fragmentation degree ascended; while artificial wetland area expanded, its patch number decreased, polymerization degree increased, and the maximum patch area index had an obvious increasing trend. Increasing human activities, embankment construction, and reclamation for aquaculture were the main causes for the decrease of wetland area and the degradation of the ecological functions of Dayang River Estuary. To constitute long-term scientific and reasonable development plan, establish wetland nature reserves, protect riverway, draft strict inspective regimes for aquaculture reclamation, and energetically develop resource-based tourism industry would be the main strategies for the protection of the estuarine wetland.

  9. [Research progress on wetland ecotourism].

    Science.gov (United States)

    Wang, Li-Long; Lu, Lin

    2009-06-01

    Wetland is rich in biodiversity and cultural diversity, possessing higher tourism value and environmental education and community participation functions. Wetland ecotourism reflects the sustainable development of tourism economy and wetland protection, having received great concern from governments and scholars at home and abroad. This paper summarized the related theories and practices, discussed the research advances in wetland ecotourism from the aspects of significance, progress, contents, methods and results, and pointed out the important research fields in the future, aimed to accelerate the development of wetland ecotourism research and to provide reference about the resources exploitation, environment protection, and scientific administration of wetland and related scenic areas.

  10. Soil Carbon in North American, Arctic, and Boreal Regions

    Science.gov (United States)

    Lajtha, K.; Bailey, V. L.; Schuur, E.; McGuire, D.; Romanovsky, V. E.

    2017-12-01

    Globally, soils contain more than 3 times as much as C as the atmosphere and >4 times more C than the world's biota, therefore even small changes in soil C stocks could lead to large changes in the atmospheric concentration of CO2. Since SOCCR-1, improvements have been made in quantifying stocks and uncertainties in stocks of soil C to a depth of 1 m across North America. Estimates for soil carbon stocks in the US (CONUS + Alaska) range from 151 - 162 Pg C, based on extensive sampling and analysis. Estimates for Canada average about 262 Pg C, but sampling is not as extensive. Soil C for Mexico is calculated as 18 Pg C, but there is a great deal of uncertainty surrounding this value. These soil carbon stocks are sensitive to agricultural management, land use and land cover change, and development and loss of C-rich soils such as wetlands. Climate change is a significant threat although may be partially mitigated by increased plant production. Carbon stored in permafrost zone circumpolar soils is equal to 1330-1580 Pg C, almost twice that contained in the atmosphere and about order of magnitude greater than carbon contained in plant biomass, woody debris, and litter in the boreal and tundra biomes combined. Surface air temperature change is amplified in high latitude regions such that Arctic temperature rise is about 2.5 times faster than for the globe as a whole, and thus 5 - 15% of this carbon is considered vulnerable to release to the atmosphere by the year 2100 following the current trajectory of global and Arctic warming. This amount is likely to be up to an order of magnitude larger loss than the increase in carbon stored in plant biomass under the same changing conditions. Models of soil organic matter dynamics have been greatly improved in the last decade by including greater process-level understanding of factors that affect soil C stabilization and destabilization, yet structural features of many models are still limited in representing Arctic and boreal

  11. Chapter 8. Current management situation: Boreal owls

    Science.gov (United States)

    Jon Verner

    1994-01-01

    The range of boreal owls (Aegolius funereus) in the United States includes Alaska, the mountains of the western United States, and the northern tier states from the Atlantic to Pacific (see Chapter 9). Based on the species' documented distribution (see National Geographic Society 1987, Hayward et al. 1987, Johnsgard 1988, and others) the owl may...

  12. Natural glyphosate tolerance in sweetvetch Hedysarum boreale

    Science.gov (United States)

    Sweetvetch (Hedysarum boreale Nutt.) a legume native to the western USA and Canada, is purported to have tolerance to glyphosate {N-(phosphonomethyl) glycine} herbide. Eight rates of glyphosate were tested for their effect on biomass yield (BMY) and survival of seedlings and mature plants. Treatme...

  13. Metro Multnomah Wetlands - Multnomah Channel Wetland Restoration Monitoring Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Multnomah Channel Wetland Restoration Monitoring Project characterizes wetlands use by juvenile salmonids and other fishes in the Multnomah Channel Marsh Natural...

  14. Wetlands & Deepwater Habitats - MO 2012 East West Gateway Wetlands (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Cowardin’s Classification of Wetlands and Deep Water Habitats of the United States (http://www.npwrc.usgs.gov/resource/wetlands/classwet/index.htm), together with...

  15. CERN tests largest superconducting solenoid magnet

    CERN Multimedia

    2006-01-01

    "CERN's Compacts Muon Solenoid (CMS) - the world's largest superconducting solenoid magnet - has reached full field in testing. The instrument is part of the proton-proton Large Hadron Collider (LHC) project, located in a giant subterranean chamber at Cessy on the Franco-Swiss border." (1 page)

  16. Wetlands Restoration Definitions and Distinctions

    Science.gov (United States)

    Ecological restoration is a valuable endeavor that has proven very difficult to define. The term indicates that degraded and destroyed natural wetland systems will be reestablished to sites where they once existed. But, what wetland ecosystems are we talki

  17. Wetland Program Development Grants (WPDGs)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Wetland Grant Database (WGD) houses grant data for Wetland Program Development Grants (created by EPA in 1990 under the Clean Water Act Section 104(b)(3)...

  18. Wetland Restoration and Sediment Removal

    Data.gov (United States)

    Department of the Interior — In 2008, Minnesota’s Private Lands Program and Wetland Management Districts began to compare different methods of restoring prairie pothole wetlands to see if there...

  19. Vegetative changes in boreal peatlands along salinity gradients resulting from produced water spills : implications for the environmental assessment and remediation of upstream oil and gas sites

    Energy Technology Data Exchange (ETDEWEB)

    Bright, D.; Harris, C.; Meier, M. [AECOM Canada Ltd., Ottawa, ON (Canada)

    2010-07-01

    In the province of Alberta, there are approximately 8,000 registered oil effluent and produced pipelines that have significant potential for ruptures and spills due to the highly corrosive nature of the emulsions and produced water they transport. Most releases occur in or adjacent to northern boreal wetlands. The first objective in spill response involves assessment and remediation for residuals, which involves handling and disposal of large volumes of salinized water. This presentation reported on a study that addressed the issues regarding the ecological features of semi-terrestrial and semi-aquatic components of boreal wetland environments as a basis for environmental protection at salt release sites. The fate of salt ions in such environments was examined along with the implications for secondary succession and ecological restoration. The study also examined the reasonable threshold concentration of salt ions in soils or water beyond which there is an inhibition to wetlands plants and bryophyte secondary succession; the reasonable threshold concentration of salt ions in water beyond which there may be adverse effects on invertebrates, vertebrates and other non-plant taxa; and species sensitivity distributions for floral and faunal assemblages found in boreal wetland habitats. The presentation summarized the 3 phases of a project that examined pipeline ruptures at 9 sites. Field methods and site sampling summaries were presented. It was difficult to locate study sites with residual salt contamination in surface media at concentrations above effects threshold for many species. It was concluded that the departures between surface and subsurface salinity indicates a smaller potential for effects on site vegetation. tabs., figs.

  20. Vegetative changes in boreal peatlands along salinity gradients resulting from produced water spills : implications for the environmental assessment and remediation of upstream oil and gas sites

    International Nuclear Information System (INIS)

    Bright, D.; Harris, C.; Meier, M.

    2010-01-01

    In the province of Alberta, there are approximately 8,000 registered oil effluent and produced pipelines that have significant potential for ruptures and spills due to the highly corrosive nature of the emulsions and produced water they transport. Most releases occur in or adjacent to northern boreal wetlands. The first objective in spill response involves assessment and remediation for residuals, which involves handling and disposal of large volumes of salinized water. This presentation reported on a study that addressed the issues regarding the ecological features of semi-terrestrial and semi-aquatic components of boreal wetland environments as a basis for environmental protection at salt release sites. The fate of salt ions in such environments was examined along with the implications for secondary succession and ecological restoration. The study also examined the reasonable threshold concentration of salt ions in soils or water beyond which there is an inhibition to wetlands plants and bryophyte secondary succession; the reasonable threshold concentration of salt ions in water beyond which there may be adverse effects on invertebrates, vertebrates and other non-plant taxa; and species sensitivity distributions for floral and faunal assemblages found in boreal wetland habitats. The presentation summarized the 3 phases of a project that examined pipeline ruptures at 9 sites. Field methods and site sampling summaries were presented. It was difficult to locate study sites with residual salt contamination in surface media at concentrations above effects threshold for many species. It was concluded that the departures between surface and subsurface salinity indicates a smaller potential for effects on site vegetation. tabs., figs.

  1. Wetlands: The changing regulatory landscape

    International Nuclear Information System (INIS)

    Glick, R.M.

    1993-01-01

    Protection of wetlands became a national issue in 1988 when President George Bush pledged no net loss of wetlands in the US under his open-quotes environmental presidency.close quotes As wetlands became a national issue, the job of protecting them became an obligation for many groups, including hydro-power developers. Now, when a site selected for development includes an area that may be classified as a wetland, the developer quickly discovers the importance of recognizing and protecting these natural habitats. Federal legislation severely limits development of wetland, and most states increase the restrictions with their own wetlands regulations. The difficulty of defining wetlands complicates federal and state enforcement. Land that appears to be dry may in fact be classified as a wetland. So, even if a site appears dry, potential hydro developers must confirm whether or not any jurisdictional wetlands are present. Regulated lands include much more than marshes and swamps. Further complicating the definition of wetlands, a recent court decision found that even artificially created wetlands, such as man-made ponds, may be subject to regulation. Hydro developers must be aware of current regulatory requirements before they consider development of any site that may contain wetlands. To be certain that a site is open-quotes buildableclose quotes from the standpoint of wetlands regulation, a developer must verify (with the help of state agencies) that the property does not contain any jurisdictional wetlands. If it does, the regulatory process before development becomes much more complicated. For the short term, uncertainty abounds and extreme caution is in order. Because the regulatory process has become so complex and an agreeable definition of wetlands so elusive, the trend among the Corps and collaborating agencies is to constrict nationwide permits in favor of narrowing the jurisdictional definition of wetlands

  2. Global warming and prairie wetlands

    International Nuclear Information System (INIS)

    Poiani, K.A.; Johnson, W.C.

    1991-01-01

    In this article, the authors discuss current understanding and projections of global warming; review wetland vegetation dynamics to establish the strong relationship among climate, wetland hydrology, vegetation patterns and waterfowl habitat; discuss the potential effects of a greenhouse warming on these relationships; and illustrate the potential effects of climate change on wetland habitat by using a simulation model

  3. Wetland soils, hydrology and geomorphology

    Science.gov (United States)

    C. Rhett Jackson; James A. Thompson; Randall K. Kolka

    2014-01-01

    The hydrology, soils, and watershed processes of a wetland all interact with vegetation and animals over time to create the dynamic physical template upon which a wetland's ecosystem is based (Fig. 2.1). With respect to many ecosystem processes, the physical factors defining a wetland environment at any particular time are often treated as independent variables,...

  4. High-latitude cooling associated with landscape changes from North American boreal forest fires

    Directory of Open Access Journals (Sweden)

    B. M. Rogers

    2013-02-01

    Full Text Available Fires in the boreal forests of North America are generally stand-replacing, killing the majority of trees and initiating succession that may last over a century. Functional variation during succession can affect local surface energy budgets and, potentially, regional climate. Burn area across Alaska and Canada has increased in the last few decades and is projected to be substantially higher by the end of the 21st century because of a warmer climate with longer growing seasons. Here we simulated changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. When coupled to an Earth system model, younger vegetation from increased burning cooled the high-latitude atmosphere, primarily in the winter and spring, with noticeable feedbacks from the ocean and sea ice. Results from multiple scenarios suggest that a doubling of burn area would cool the surface by 0.23 ± 0.09 °C across boreal North America during winter and spring months (December through May. This could provide a negative feedback to winter warming on the order of 3–5% for a doubling, and 14–23% for a quadrupling, of burn area. Maximum cooling occurs in the areas of greatest burning, and between February and April when albedo changes are largest and solar insolation is moderate. Further work is needed to integrate all the climate drivers from boreal forest fires, including aerosols and greenhouse gasses.

  5. Hydro-climatic forcing of dissolved organic carbon in two boreal lakes of Canada.

    Science.gov (United States)

    Diodato, Nazzareno; Higgins, Scott; Bellocchi, Gianni; Fiorillo, Francesco; Romano, Nunzio; Guadagno, Francesco M

    2016-11-15

    The boreal forest of the northern hemisphere represents one of the world's largest ecozones and contains nearly one third of the world's intact forests and terrestrially stored carbon. Long-term variations in temperature and precipitation have been implied in altering carbon cycling in forest soils, including increased fluxes to receiving waters. In this study, we use a simple hydrologic model and a 40-year dataset (1971-2010) of dissolved organic carbon (DOC) from two pristine boreal lakes (ELA, Canada) to examine the interactions between precipitation and landscape-scale controls of DOC production and export from forest catchments to surface waters. Our results indicate that a simplified hydrologically-based conceptual model can enable the long-term temporal patterns of DOC fluxes to be captured within boreal landscapes. Reconstructed DOC exports from forested catchments in the period 1901-2012 follow largely a sinusoidal pattern, with a period of about 37years and are tightly linked to multi-decadal patterns of precipitation. By combining our model with long-term precipitation estimates, we found no evidence of increasing DOC transport or in-lake concentrations through the 20th century. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. A meta-analysis of coastal wetland ecosystem services in Liaoning Province, China

    Science.gov (United States)

    Sun, Baodi; Cui, Lijuan; Li, Wei; Kang, Xiaoming; Pan, Xu; Lei, Yinru

    2018-01-01

    Wetlands are impacted by economic and political initiatives, and their ecosystem services are attracting increasing public attention. It is crucial that management decisions for wetland ecosystem services quantify the economic value of the ecosystem services. In this paper, we aimed to estimate a monetary value for coastal wetland ecosystem services in Liaoning Province, China. We selected 433 observations from 85 previous coastal wetland economic evaluations (mostly in China) including detailed spatial and economic characteristics in each wetland, then used a meta-analysis scale transfer method to calculate the total value of coastal wetland ecosystem services in Liaoning Province. Our results demonstrated that, on average, the ecosystem services provided by seven different coastal wetland types were worth US40,648 per ha per year, and the total value was 28,990,439,041 in 2013. Shallow marine waters accounted for the largest proportion (83.97%). Variables with a significant positive effect on the ecosystem service values included GDP per capita, population density, distance from the wetland to the city center and the year of evaluation, while wetland size and latitude had negative relationships.

  7. Evaluation of methane emissions from West Siberian wetlands based on inverse modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H-S; Inoue, G [Research Institute for Humanity and Nature, 457-4 Motoyama, Kamigamo, Kita-ku, Kyoto 603-8047 (Japan); Maksyutov, S; Machida, T [National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Glagolev, M V [Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow 119991 (Russian Federation); Patra, P K [Research Institute for Global Change/JAMSTEC, 3173-25 Showa-cho, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Sudo, K, E-mail: heonsook.kim@gmail.com [Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)

    2011-07-15

    West Siberia contains the largest extent of wetlands in the world, including large peat deposits; the wetland area is equivalent to 27% of the total area of West Siberia. This study used inverse modeling to refine emissions estimates for West Siberia using atmospheric CH{sub 4} observations and two wetland CH{sub 4} emissions inventories: (1) the global wetland emissions dataset of the NASA Goddard Institute for Space Studies (the GISS inventory), which includes emission seasons and emission rates based on climatology of monthly surface air temperature and precipitation, and (2) the West Siberian wetland emissions data (the Bc7 inventory), based on in situ flux measurements and a detailed wetland classification. The two inversions using the GISS and Bc7 inventories estimated annual mean flux from West Siberian wetlands to be 2.9 {+-} 1.7 and 3.0 {+-} 1.4 Tg yr{sup -1}, respectively, which are lower than the 6.3 Tg yr{sup -1} predicted in the GISS inventory, but similar to those of the Bc7 inventory (3.2 Tg yr{sup -1}). The well-constrained monthly fluxes and a comparison between the predicted CH{sub 4} concentrations in the two inversions suggest that the Bc7 inventory predicts the seasonal cycle of West Siberian wetland CH{sub 4} emissions more reasonably, indicating that the GISS inventory predicts more emissions from wetlands in northern and middle taiga.

  8. Total and methyl mercury concentrations and fluxes from small boreal forest catchments in Finland

    International Nuclear Information System (INIS)

    Porvari, Petri; Verta, Matti

    2003-01-01

    Peatlands have higher methyl mercury output than uplands. - Total mercury (TotHg) and methyl mercury (MeHg) concentrations were studied in runoff from eight small (0.02-1.3 km 2 ) boreal forest catchments (mineral soil and peatland) during 1990-1995. Runoff waters were extremely humic (TOC 7-70 mg l -1 ). TotHg concentrations varied between 0.84 and 24 ng l -1 and MeHg between 0.03 and 3.8 ng l -1 . TotHg fluxes from catchments ranged from 0.92 to 1.8 g km -2 a -1 , and MeHg fluxes from 0.03 to 0.33 g km -2 a -1 . TotHg concentrations and output fluxes measured in runoff water from small forest catchments in Finland were comparable with those measured in other boreal regions. By contrast, MeHg concentrations were generally higher. Estimates for MeHg output fluxes in this study were comparable at sites with forests and wetlands in Sweden and North America, but clearly higher than those measured at upland or agricultural sites in other studies. Peatland catchments released more MeHg than pure mineral soil or mineral soil catchments with minor area of peatland

  9. 77 FR 63326 - Huron Wetland Management District, Madison Wetland Management District, and Sand Lake Wetland...

    Science.gov (United States)

    2012-10-16

    ..., consistent with sound principles of fish and wildlife management, conservation, legal mandates, and our... FXRS1265066CCP0] Huron Wetland Management District, Madison Wetland Management District, and Sand Lake Wetland Management District, SD; Final Comprehensive Conservation Plan and Finding of No Significant Impact for...

  10. Rain increases methane production and methane oxidation in a boreal thermokarst bog

    Science.gov (United States)

    Neumann, R. B.; Moorberg, C.; Turner, J.; Wong, A.; Waldrop, M. P.; Euskirchen, E. S.; Edgar, C.; Turetsky, M. R.

    2017-12-01

    thermokarst bogs to energy and oxygen inputs from rain, and have implications for how boreal wetland methane emissions may respond in the future to altered precipitation patterns. Advective delivery of energy and oxygen to wetland subsoils via rainwater is not currently a mechanism included in bottom-up wetland methane models.

  11. Soil surface CO2 flux in a boreal black spruce fire chronosequence

    Science.gov (United States)

    Wang, Chuankuan; Bond-Lamberty, Ben; Gower, Stith T.

    2003-02-01

    Understanding the effects of wildfire on the carbon (C) cycle of boreal forests is essential to quantifying the role of boreal forests in the global carbon cycle. Soil surface CO2 flux (Rs), the second largest C flux in boreal forests, is directly and indirectly affected by fire and is hypothesized to change during forest succession following fire. The overall objective of this study was to measure and model Rs for a black spruce (Picea mariana [Mill.] BSP) postfire chronosequence in northern Manitoba, Canada. The experiment design was a nested factorial that included two soil drainage classes (well and poorly drained) × seven postfire aged stands. Specific objectives were (1) to quantify the relationship between Rs and soil temperature for different aged boreal black spruce forests in well-drained and poorly drained soil conditions, (2) to examine Rs dynamics along postfire successional stands, and (3) to estimate annual soil surface CO2 flux for these ecosystems. Soil surface CO2 flux was significantly affected by soil drainage class (p = 0.014) and stand age (p = 0.006). Soil surface CO2 flux was positively correlated to soil temperature (R2 = 0.78, p aged stand combination. Soil surface CO2 flux was significantly greater at the well-drained than the poorly drained stands (p = 0.007) during growing season. Annual soil surface CO2 flux for the 1998, 1995, 1989, 1981, 1964, 1930, and 1870 burned stands averaged 226, 412, 357, 413, 350, 274, and 244 g C m-2 yr-1 in the well-drained stands and 146, 380, 300, 303, 256, 233, and 264 g C m-2 yr-1 in the poorly drained stands. Soil surface CO2 flux during the winter (from 1 November to 30 April) comprised from 5 to 19% of the total annual Rs. We speculate that the smaller soil surface CO2 flux in the recently burned than the older stands is mainly caused by decreased root respiration.

  12. Constructed wetlands : the Canadian context

    Energy Technology Data Exchange (ETDEWEB)

    Speer, S.; Champagne, P. [Queen' s Univ., Kingston, ON (Canada). Dept. of Civil Engineering

    2006-07-01

    Large volumes of wastewater from livestock and production facilities must be treated to minimize the contamination of waterways in agricultural areas. This paper investigated the use of constructed wetlands as a lower-cost and efficient method of treating agricultural wastewaters. The study found that while constructed wetlands required limited maintenance, temperature dependency of the constructed wetlands systems is a limiting factor in their widespread implementation. Lower operating temperatures are only overcome by constructing larger wetlands systems, which require a substantial amount of land. The Canadian climate poses significant challenges to the implementation of constructed wetlands, which become inoperative during winter months. Plants and bacteria normally become dormant or die during winter months, which can create a lag in wetland treatment during the initial months of operation in the Spring. Snowmelt and added rainfall in the Spring can also create a high flow within the wetland cells, as many constructed wetlands rely on runoff as a feed source. Washout of bacteria can occur. Wastewater storage systems or further engineering of the wetlands may be required. It was concluded that insulating wetland cells will maintain a warmer operating temperature, while the addition of an aeration system will increase the treatment efficiency of the wetland during winter months. 17 refs., 5 tabs., 2 figs.

  13. Crash testing the largest experiment on Earth

    OpenAIRE

    Cauchi, Marija

    2015-01-01

    Under Europe lies a 27 km tunnel that is both the coldest and hottest place on Earth. The Large Hadron Collider (LHC) has already found out what gives mass to all the matter in the Universe. It is now trying to go even deeper into what makes up everything we see around us. Dr Marija Cauchi writes about her research that helped protect this atom smasher from itself. Photography by Jean Claude Vancell. http://www.um.edu.mt/think/crash-testing-the-largest-experiment-on-earth/

  14. Microbiology of wetlands

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Dedysh, S.N.

    2013-01-01

    Watersaturated soil and sediment ecosystems (i.e. wetlands) are ecologically as well as economically important systems due to their high productivity, their nutrient (re)cycling capacities and their prominent contribution to global greenhouse gas emissions. Being on the transition between

  15. The world's largest LNG producer's next market

    International Nuclear Information System (INIS)

    Fuller, R.; Isworo Suharno; Simandjuntak, W.M.P.

    1996-01-01

    The development of the domestic gas market in Indonesia, the world's largest liquefied natural gas producing country, is described as part of the overall impact of the country's oil and gas production. The first large scale use of natural gas in Indonesia was established in 1968 when a fertiliser plant using gas as the feedstock was built. Ultimately, through increased yields, this has enabled Indonesia to be self-sufficient in rice and an exporter of fertiliser. Problems which stand in the way of further developments include: capital, though Pertamina and PGN are perceived as attractive for foreign investment; the lack of a regulatory framework for gas; geographical constraints, among them the fact that the gas deposits are remote from the largest population concentrations; lack of infrastructure. There are nevertheless plans for expansion and the provision of an integrated gas pipeline system. Pertamina, which has responsibility for all oil and gas developments, and PGN, whose primary role has been as a manufacturer and distributor of gas, are now working together in the coordination of all gas activities. (10 figures). (UK)

  16. The importance of local and landscape-scale processes to the occupancy of wetlands by pond-breeding amphibians

    Science.gov (United States)

    Scherer, Rick D.; Muths, Erin; Noon, Barry R.

    2012-01-01

    Variation in the distribution and abundance of species across landscapes has traditionally been attributed to processes operating at fine spatial scales (i.e., environmental conditions at the scale of the sampling unit), but processes that operate across larger spatial scales such as seasonal migration or dispersal are also important. To determine the relative importance of these processes, we evaluated hypothesized relationships between the probability of occupancy in wetlands by two amphibians [wood frogs (Lithobates sylvaticus) and boreal chorus frogs (Pseudacris maculata)] and attributes of the landscape measured at three spatial scales in Rocky Mountain National Park, Colorado. We used cost-based buffers and least-cost distances to derive estimates of landscape attributes that may affect occupancy patterns from the broader spatial scales. The most highly ranked models provide strong support for a positive relationship between occupancy by breeding wood frogs and the amount of streamside habitat adjacent to a wetland. The model selection results for boreal chorus frogs are highly uncertain, though several of the most highly ranked models indicate a positive association between occupancy and the number of neighboring, occupied wetlands. We found little evidence that occupancy of either species was correlated with local-scale attributes measured at the scale of individual wetlands, suggesting that processes operating at broader scales may be more important in influencing occupancy patterns in amphibian populations.

  17. Efficient gas exchange between a boreal river and the atmosphere

    Science.gov (United States)

    Huotari, Jussi; Haapanala, Sami; Pumpanen, Jukka; Vesala, Timo; Ojala, Anne

    2013-11-01

    largest uncertainties in accurately resolving the role of rivers and streams in carbon cycling stem from difficulties in determining gas exchange between water and the atmosphere. So far, estimates for river-atmosphere gas exchange have lacked direct ecosystem-scale flux measurements not disturbing gas exchange across the air-water interface. We conducted the first direct riverine gas exchange measurements with eddy covariance in tandem with continuous surface water CO2 measurements in a large boreal river for 30 days. Our measured gas transfer velocity was, on average, 20.8 cm h-1, which is clearly higher than the model estimates based on river channel morphology and water velocity, whereas our floating chambers gave comparable values at 17.3 cm h-1. These results demonstrate that present estimates for riverine CO2 emissions are very likely too low. This result is also relevant to any other gases emitted, as their diffusive exchange rates are similarly proportional to gas transfer velocity.

  18. Dissolved Oxygen Dynamics in Backwaters of North America's Largest River Swamp

    Science.gov (United States)

    Bueche, S. M.; Xu, Y. J.; Reiman, J. H.

    2017-12-01

    The Atchafalaya River (AR) is the largest distributary of the Mississippi River flowing through south-central Louisiana, creating North America's largest river swamp basin - the Atchafalaya River Basin (ARB). Prior to human settlement, the AR's main channel was highly connected to this large wetland ecosystem. However, due to constructed levee systems and other human modifications, much of the ARB is now hydrologically disconnected from the AR's main channel except during high flow events. This lack of regular inputs of fresh, oxygenated water to these wetlands, paired with high levels of organic matter decomposition in wetlands, has caused low oxygen-deprived hypoxic conditions in the ARB's back waters. In addition, due to the incredibly nutrient-rich and warm nature of the ARB, microbial decomposition in backwater areas with limited flow often results in potentially stressful, if not lethal, levels of DO for organisms during and after flood pulses. This study aims to investigate dynamics of dissolved oxygen in backwaters of the Atchafalaya River Basin, intending to answer a crucial question about hydrological and water quality connectivity between the river's mainstem and its floodplain. Specifically, the study will 1) conduct field water quality measurements, 2) collect composite water samples for chemical analysis of nutrients and carbon, 3) investigate DO dynamics over different seasons for one year, and 4) determine the major factors that affect DO dynamics in this unique swamp ecosystem. The study is currently underway; therefore, in this presentation we will share the major findings gained in the past several months and discuss backwater effects on river chemistry.

  19. Aboveground Biomass Monitoring over Siberian Boreal Forest Using Radar Remote Sensing Data

    Science.gov (United States)

    Stelmaszczuk-Gorska, M. A.; Thiel, C. J.; Schmullius, C.

    2014-12-01

    Aboveground biomass (AGB) plays an essential role in ecosystem research, global cycles, and is of vital importance in climate studies. AGB accumulated in the forests is of special monitoring interest as it contains the most of biomass comparing with other land biomes. The largest of the land biomes is boreal forest, which has a substantial carbon accumulation capability; carbon stock estimated to be 272 +/-23 Pg C (32%) [1]. Russian's forests are of particular concern, due to the largest source of uncertainty in global carbon stock calculations [1], and old inventory data that have not been updated in the last 25 years [2]. In this research new empirical models for AGB estimation are proposed. Using radar L-band data for AGB retrieval and optical data for an update of in situ data the processing scheme was developed. The approach was trained and validated in the Asian part of the boreal forest, in southern Russian Central Siberia; two Siberian Federal Districts: Krasnoyarsk Kray and Irkutsk Oblast. Together the training and testing forest territories cover an area of approximately 3,500 km2. ALOS PALSAR L-band single (HH - horizontal transmitted and received) and dual (HH and HV - horizontal transmitted, horizontal and vertical received) polarizations in Single Look Complex format (SLC) were used to calculate backscattering coefficient in gamma nought and coherence. In total more than 150 images acquired between 2006 and 2011 were available. The data were obtained through the ALOS Kyoto and Carbon Initiative Project (K&C). The data were used to calibrate a randomForest algorithm. Additionally, a simple linear and multiple-regression approach was used. The uncertainty of the AGB estimation at pixel and stand level were calculated approximately as 35% by validation against an independent dataset. The previous studies employing ALOS PALSAR data over boreal forests reported uncertainty of 39.4% using randomForest approach [2] or 42.8% using semi-empirical approach [3].

  20. Evaluation of Polarimetric SAR Decomposition for Classifying Wetland Vegetation Types

    Directory of Open Access Journals (Sweden)

    Sang-Hoon Hong

    2015-07-01

    Full Text Available The Florida Everglades is the largest subtropical wetland system in the United States and, as with subtropical and tropical wetlands elsewhere, has been threatened by severe environmental stresses. It is very important to monitor such wetlands to inform management on the status of these fragile ecosystems. This study aims to examine the applicability of TerraSAR-X quadruple polarimetric (quad-pol synthetic aperture radar (PolSAR data for classifying wetland vegetation in the Everglades. We processed quad-pol data using the Hong & Wdowinski four-component decomposition, which accounts for double bounce scattering in the cross-polarization signal. The calculated decomposition images consist of four scattering mechanisms (single, co- and cross-pol double, and volume scattering. We applied an object-oriented image analysis approach to classify vegetation types with the decomposition results. We also used a high-resolution multispectral optical RapidEye image to compare statistics and classification results with Synthetic Aperture Radar (SAR observations. The calculated classification accuracy was higher than 85%, suggesting that the TerraSAR-X quad-pol SAR signal had a high potential for distinguishing different vegetation types. Scattering components from SAR acquisition were particularly advantageous for classifying mangroves along tidal channels. We conclude that the typical scattering behaviors from model-based decomposition are useful for discriminating among different wetland vegetation types.

  1. Spatially Resolved Isotopic Source Signatures of Wetland Methane Emissions

    Science.gov (United States)

    Ganesan, A. L.; Stell, A. C.; Gedney, N.; Comyn-Platt, E.; Hayman, G.; Rigby, M.; Poulter, B.; Hornibrook, E. R. C.

    2018-04-01

    We present the first spatially resolved wetland δ13C(CH4) source signature map based on data characterizing wetland ecosystems and demonstrate good agreement with wetland signatures derived from atmospheric observations. The source signature map resolves a latitudinal difference of 10‰ between northern high-latitude (mean -67.8‰) and tropical (mean -56.7‰) wetlands and shows significant regional variations on top of the latitudinal gradient. We assess the errors in inverse modeling studies aiming to separate CH4 sources and sinks by comparing atmospheric δ13C(CH4) derived using our spatially resolved map against the common assumption of globally uniform wetland δ13C(CH4) signature. We find a larger interhemispheric gradient, a larger high-latitude seasonal cycle, and smaller trend over the period 2000-2012. The implication is that erroneous CH4 fluxes would be derived to compensate for the biases imposed by not utilizing spatially resolved signatures for the largest source of CH4 emissions. These biases are significant when compared to the size of observed signals.

  2. Fire, humans, and climate: modeling distribution dynamics of boreal forest waterbirds.

    Science.gov (United States)

    Börger, Luca; Nudds, Thomas D

    2014-01-01

    Understanding the effects of landscape change and environmental variability on ecological processes is important for evaluating resource management policies, such as the emulation of natural forest disturbances. We analyzed time series of detection/nondetection data using hierarchical models in a Bayesian multi-model inference framework to decompose the dynamics of species distributions into responses to environmental variability, spatial variation in habitat conditions, and population dynamics and interspecific interactions, while correcting for observation errors and variation in sampling regimes. We modeled distribution dynamics of 14 waterbird species (broadly defined, including wetland and riparian species) using data from two different breeding bird surveys collected in the Boreal Shield ecozone within Ontario, Canada. Temporal variation in species occupancy (2000-2006) was primarily driven by climatic variability. Only two species showed evidence of consistent temporal trends in distribution: Ring-necked Duck (Aythya collaris) decreased, and Red-winged Blackbird (Agelaius phoeniceus) increased. The models had good predictive ability on independent data over time (1997-1999). Spatial variation in species occupancy was strongly related to the distribution of specific land cover types and habitat disturbance: Fire and forest harvesting influenced occupancy more than did roads, settlements, or mines. Bioclimatic and habitat heterogeneity indices and geographic coordinates exerted negligible influence on most species distributions. Estimated habitat suitability indices had good predictive ability on spatially independent data (Hudson Bay Lowlands ecozone). Additionally, we detected effects of interspecific interactions. Species responses to fire and forest harvesting were similar for 13 of 14 species; thus, forest-harvesting practices in Ontario generally appeared to emulate the effects of fire for waterbirds over timescales of 10-20 years. Extrapolating to all

  3. Thermokarst rates intensify due to climate change and forest fragmentation in an Alaskan boreal forest lowland

    Science.gov (United States)

    Lara, M.; Genet, Helene; McGuire, A. David; Euskirchen, Eugénie S.; Zhang, Yujin; Brown, Dana R. N.; Jorgenson, M.T.; Romanovsky, V.; Breen, Amy L.; Bolton, W.R.

    2016-01-01

    Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse-scar bogs, low shrub/scrub, and forests growing on elevated ice-rich permafrost soils. Thermokarst has affected the lowlands of the Tanana Flats in central Alaska for centuries, as thawing permafrost collapses forests that transition to wetlands. Located within the discontinuous permafrost zone, this region has significantly warmed over the past half-century, and much of these carbon-rich permafrost soils are now within ~0.5 °C of thawing. Increased permafrost thaw in lowland boreal forests in response to warming may have consequences for the climate system. This study evaluates the trajectories and potential drivers of 60 years of forest change in a landscape subjected to permafrost thaw in unburned dominant forest types (paper birch and black spruce) associated with location on elevated permafrost plateau and across multiple time periods (1949, 1978, 1986, 1998, and 2009) using historical and contemporary aerial and satellite images for change detection. We developed (i) a deterministic statistical model to evaluate the potential climatic controls on forest change using gradient boosting and regression tree analysis, and (ii) a 30 × 30 m land cover map of the Tanana Flats to estimate the potential landscape-level losses of forest area due to thermokarst from 1949 to 2009. Over the 60-year period, we observed a nonlinear loss of birch forests and a relatively continuous gain of spruce forest associated with thermokarst and forest succession, while gradient boosting/regression tree models identify precipitation and forest fragmentation as the primary factors controlling birch and spruce forest change, respectively. Between 1950 and 2009, landscape-level analysis estimates a transition of ~15 km² or ~7% of birch forests to wetlands, where the greatest change followed warm periods. This work highlights that the vulnerability and resilience of

  4. Midcontinent Prairie-Pothole wetlands and climate change: An Introduction to the Supplemental Issue

    Science.gov (United States)

    Mushet, David M.

    2016-01-01

    The multitude of wetlands in the Prairie Pothole Region of North America forms one of Earth’s largest wetland complexes. The midcontinent location exposes this ecologically and economically important wetland system to a highly variable climate, markedly influencing ponded-water levels, hydroperiods, chemical characteristics, and biota of individual basins. Given their dominance on the landscape and recognized value, great interest in how projected future changes in climate will affect prairie-pothole wetlands has developed and spawned much scientific research. On June 2, 2015, a special symposium, “Midcontinent Prairie-Pothole Wetlands: Influence of a Changed Climate,” was held at the annual meeting of the Society of Wetland Scientists in Providence, Rhode Island, USA. The symposium’s twelve presenters covered a wide range of relevant topics delivered to a standing-room-only audience. Following the symposium, the presenters recognized the need to publish their presented papers as a combined product to facilitate widespread distribution. The need for additional papers to more fully cover the topic of prairie-pothole wetlands and climate change was also identified. This supplemental issue of Wetlands is the realization of that vision.

  5. Macroinvertebrate distribution and aquatic ecology in the Ruoergai (Zoige) Wetland, the Yellow River source region

    Science.gov (United States)

    Zhao, Na; Xu, Mengzhen; Li, Zhiwei; Wang, Zhaoyin; Zhou, Hanmi

    2017-09-01

    The Ruoergai (Zoige) Wetland, the largest plateau peatland in the world, is located in the Yellow River source region. The discharge of the Yellow River increases greatly after flowing through the Ruoergai Wetland. The aquatic ecosystem of the Ruoergai Wetland is crucial to the whole Yellow River basin. The Ruoergai wetland has three main kinds of water bodies: rivers, oxbow lakes, and marsh wetlands. In this study, macroinvertebrates were used as indicators to assess the aquatic ecological status because their assemblage structures indicate long-term changes in environments with high sensitivity. Field investigations were conducted in July, 2012 and in July, 2013. A total of 72 taxa of macroinvertebrates belonging to 35 families and 67 genera were sampled and identified. Insecta was the dominant group in the Ruoergai Basin. The alpha diversity of macroinvertebrates at any single sampling site was low, while the alpha diversity on a basin-wide scale was much higher. Macroinvertebrate assemblages in rivers, oxbow lakes, and marsh wetlands differ markedly. Hydrological connectivity was a primary factor causing the variance of the bio-community. The river channels had the highest alpha diversity of macroinvertebrates, followed by marsh wetlands and oxbow lakes. The density and biomass of Gastropoda, collector filterers, and scrapers increased from rivers to oxbow lakes and then to marsh wetlands. The river ecology was particular in the Ruoergai Wetland with the high beta diversity of macroinvertebrates, the low alpha diversity of macroinvertebrates, and the low taxa richness, density, and biomass of EPT (Ephemeroptera, Plecoptera, Trichoptera). To maintain high alpha diversity of macroinvertebrates macroinvertebrates in the Ruoergai Wetland, moderate connectivity of oxbow lakes and marsh wetlands with rivers and measures to control headwater erosion are both crucial.

  6. Evaluation of ALOS PALSAR Data for High-Resolution Mapping of Vegetated Wetlands in Alaska

    Directory of Open Access Journals (Sweden)

    Daniel Clewley

    2015-06-01

    Full Text Available As the largest natural source of methane, wetlands play an important role in the carbon cycle. High-resolution maps of wetland type and extent are required to quantify wetland responses to climate change. Mapping northern wetlands is particularly important because of a disproportionate increase in temperatures at higher latitudes. Synthetic aperture radar data from a spaceborne platform can be used to map wetland types and dynamics over large areas. Following from earlier work by Whitcomb et al. (2009 using Japanese Earth Resources Satellite (JERS-1 data, we applied the “random forests” classification algorithm to variables from L-band ALOS PALSAR data for 2007, topographic data (e.g., slope, elevation and locational information (latitude, longitude to derive a map of vegetated wetlands in Alaska, with a spatial resolution of 50 m. We used the National Wetlands Inventory and National Land Cover Database (for upland areas to select training and validation data and further validated classification results with an independent dataset that we created. A number of improvements were made to the method of Whitcomb et al. (2009: (1 more consistent training data in upland areas; (2 better distribution of training data across all classes by taking a stratified random sample of all available training pixels; and (3 a more efficient implementation, which allowed classification of the entire state as a single entity (rather than in separate tiles, which eliminated discontinuities at tile boundaries. The overall accuracy for discriminating wetland from upland was 95%, and the accuracy at the level of wetland classes was 85%. The total area of wetlands mapped was 0.59 million km2, or 36% of the total land area of the state of Alaska. The map will be made available to download from NASA’s wetland monitoring website.

  7. 40 CFR 258.12 - Wetlands.

    Science.gov (United States)

    2010-07-01

    ... degraded wetlands or creation of man-made wetlands); and (5) Sufficient information is available to make a... expansions shall not be located in wetlands, unless the owner or operator can make the following...

  8. Large carbon dioxide fluxes from headwater boreal and sub-boreal streams.

    Science.gov (United States)

    Venkiteswaran, Jason J; Schiff, Sherry L; Wallin, Marcus B

    2014-01-01

    Half of the world's forest is in boreal and sub-boreal ecozones, containing large carbon stores and fluxes. Carbon lost from headwater streams in these forests is underestimated. We apply a simple stable carbon isotope idea for quantifying the CO2 loss from these small streams; it is based only on in-stream samples and integrates over a significant distance upstream. We demonstrate that conventional methods of determining CO2 loss from streams necessarily underestimate the CO2 loss with results from two catchments. Dissolved carbon export from headwater catchments is similar to CO2 loss from stream surfaces. Most of the CO2 originating in high CO2 groundwaters has been lost before typical in-stream sampling occurs. In the Harp Lake catchment in Canada, headwater streams account for 10% of catchment net CO2 uptake. In the Krycklan catchment in Sweden, this more than doubles the CO2 loss from the catchment. Thus, even when corrected for aquatic CO2 loss measured by conventional methods, boreal and sub-boreal forest carbon budgets currently overestimate carbon sequestration on the landscape.

  9. Controls on moss evaporation in a boreal black spruce forest

    NARCIS (Netherlands)

    Heijmans, M.M.P.D.; Arp, W.J.; Chapin, F.S.

    2004-01-01

    [1] Mosses are an important component of the boreal forest, but little is known about their contribution to ecosystem carbon, water, and energy exchange. We studied the role of mosses in boreal forest evapotranspiration by conducting two experiments in a black spruce forest in Fairbanks, Alaska.

  10. Rock, Paper, Protest: The Fight for the Boreal Forest

    Science.gov (United States)

    Gunz, Sally; Whittaker, Linda

    2016-01-01

    Canada's boreal forests are second only to the Amazon in producing life-giving oxygen and providing a habitat for thousands of species, from the large woodland caribou to the smallest organisms. The boreal forests are the lifeblood of many Aboriginal communities and the thousands of workers, Aboriginal and non-Aboriginal, who harvest and process…

  11. Compromised development and survival in amphibians in reclaimed wetlands' water containing oil sands process-affected material

    International Nuclear Information System (INIS)

    Smits, J.; Schock, D.

    2010-01-01

    When closing a mine, operators must comply with government regulations to ensure that the sites are ecologically sustainable to support endemic flora and fauna. Creating wetlands in order to age and detoxify oil sands process-affected materials (OSPM) is a common reclamation strategy. In this study, amphibians indigenous to the boreal forest ecosystem were examined to determine if they can complete their lifecycle in water from reclaimed wetlands. Wood frog (Lithobates sylvaticus) eggs were collected from a natural pond 60 km south of an oil sand mining site. Tadpoles were raised in 1 of 6 water treatments refreshed every two days. The 2 reference water treatments included aged tap water and water from natural wetlands. The remaining 4 water treatments were from research wetlands on Syncrude and Suncor lease sites. Of the 120 tadpoles raised per water treatment, there was no significant difference in growth, development, or survival rates between the aged tap water and reference wetland water, but the fastest growth, development, and highest survival rates occurred in the two reference groups. There was a pronounced difference among the 4 treatment groups from Suncor and Syncrude reclamation sites. Survival was high in 3 of the water treatments from Syncrude and Suncor sites, but development rates were considerably reduced. Tadpoles that do not metamorphose before winter do not survive. It was therefore concluded that delayed development in tadpoles poses a serious risk to population stability in OSPM-containing wetlands.

  12. Restoration of ailing wetlands.

    Directory of Open Access Journals (Sweden)

    Oswald J Schmitz

    2012-01-01

    Full Text Available It is widely held that humankind's destructive tendencies when exploiting natural resources leads to irreparable harm to the environment. Yet, this thinking runs counter to evidence that many ecological systems damaged by severe natural environmental disturbances (e.g., hurricanes can restore themselves via processes of natural recovery. The emerging field of restoration ecology is capitalizing on the natural restorative tendencies of ecological systems to build a science of repairing the harm inflicted by humans on natural environment. Evidence for this, for example, comes from a new meta-analysis of 124 studies that synthesizes recovery of impacted wetlands worldwide. While it may take up to two human generations to see full recovery, there is promise, given human will, to restore many damaged wetlands worldwide.

  13. Wetlands - an underestimated economic resource?

    International Nuclear Information System (INIS)

    Gren, I.M.; Soederqvist, T.

    1996-01-01

    Wetlands are producing several valuable resources like fish, potential for recreation, water cleaning etc. These resources, and methods for assigning an economic value to them, are discussed in this article. Swedish and foreign empirical studies of the economic value of wetlands are reviewed. This review shows that socioeconomic estimates of the value of wetlands risk to be misleading if the direct and indirect values are not properly accounted for. 37 refs

  14. Modeling Lake Storage Dynamics to support Arctic Boreal Vulnerability Experiment (ABoVE)

    Science.gov (United States)

    Vimal, S.; Lettenmaier, D. P.; Smith, L. C.; Smith, S.; Bowling, L. C.; Pavelsky, T.

    2017-12-01

    The Arctic and Boreal Zone (ABZ) of Canada and Alaska includes vast areas of permafrost, lakes, and wetlands. Permafrost thawing in this area is expected to increase due to the projected rise of temperature caused by climate change. Over the long term, this may reduce overall surface water area, but in the near-term, the opposite is being observed, with rising paludification (lake/wetland expansion). One element of NASA's ABoVE field experiment is observations of lake and wetland extent and surface elevations using NASA's AirSWOT airborne interferometric radar, accompanied by a high-resolution camera. One use of the WSE retrievals will be to constrain model estimates of lake storage dynamics. Here, we compare predictions using the lake dynamics algorithm within the Variable Infiltration Capacity (VIC) land surface scheme. The VIC lake algorithm includes representation of sub-grid topography, where the depth and area of seasonally-flooded areas are modeled as a function of topographic wetness index, basin area, and slope. The topography data used is from a new global digital elevation model, MERIT-DEM. We initially set up VIC at sites with varying permafrost conditions (i.e., no permafrost, discontinuous, continuous) in Saskatoon and Yellowknife, Canada, and Toolik Lake, Alaska. We constrained the uncalibrated model with the WSE at the time of the first ABoVE flight, and quantified the model's ability to predict WSE and ΔWSE during the time of the second flight. Finally, we evaluated the sensitivity of the VIC-lakes model and compared the three permafrost conditions. Our results quantify the sensitivity of surface water to permafrost state across the target sites. Furthermore, our evaluation of the lake modeling framework contributes to the modeling and mapping framework for lake and reservoir storage change evaluation globally as part of the SWOT mission, planned for launch in 2021.

  15. Process-Based Modeling of Constructed Wetlands

    Science.gov (United States)

    Baechler, S.; Brovelli, A.; Rossi, L.; Barry, D. A.

    2007-12-01

    . The model has been successfully validated using published experimental data. Two measurement campaigns conducted on a CW facility from New South Wales, Australia have been used. The first set of data was used to calibrate the model, while the second trial, recorded two months later with a different loading rate, was used to identify possible changes in the wetland functioning. Further to this, a sensitivity analysis was performed to identify the main parameters controlling the system. As expected, the parameter with largest impact is oxygen mass-transfer rate.

  16. Tidal Wetlands and Coastal Ocean Carbon Dynamics

    Science.gov (United States)

    Hopkinson, C.; Wang, S. R.; Forbrich, I.; Giblin, A. E.; Cai, W. J.

    2017-12-01

    Recent overviews of coastal ocean C dynamics have tidal wetlands in a prominent position: a local sink for atmospheric CO2, a local store of OC, and a source of DIC and OC for the adjacent estuary and nearshore ocean. Over the past decade there have been great strides made in quantifying and understanding these flows and linkages. GPP and R of the wetlands are not nearly as imbalanced as thought 30 yrs ago. Heterotrophy of adjacent estuarine waters is not solely due to the respiration of OC exported from the marsh, rather we see the marsh directly respiring into the water during tidal inundation and accumulated marsh DIC draining into tidal creeks. Organic carbon burial on the marsh is still a relatively minor flux, but it is large relative to marsh NEE. Using literature and unpublished data on marsh DIC export, we used examples from Sapelo Island GA USA and Plum Island MA USA to constrain estimates of NEP and potential OC export. P. There remain large uncertainties in quantifying C dynamics of coupled wetland - estuary systems. Gas exchange from the water to atmosphere is one of the largest uncertainties. Work at Sapelo suggests that upwards of 40% of all daily exchange occurs from water flooding the marsh, which is but a few hours a day. This estimate is based on the intercept value for gas exchange vs wind velocity. Another major uncertainty comes from converting between O2 based estimates of metabolism to C. At Sapelo we find PQ and RQ values diverging greatly from Redfield. Finally, C dynamics of the coastal ocean, especially the role of tidal wetlands is likely to change substantially in the future. Studies at Plum Island show a reversal of the 4000 yr process of marsh progradation with marshes eroding away at their edges because of inadequate sediment supply and rising sea level. The fate of eroded OC is questionable. Landward transgression with SLR is the only likely counter to continued wetland loss - but that's a complex social issue requiring new

  17. Morphology of a Wetland Stream

    Science.gov (United States)

    Jurmu; Andrle

    1997-11-01

    / Little attention has been paid to wetland stream morphology in the geomorphological and environmental literature, and in the recently expanding wetland reconstruction field, stream design has been based primarily on stream morphologies typical of nonwetland alluvial environments. Field investigation of a wetland reach of Roaring Brook, Stafford, Connecticut, USA, revealed several significant differences between the morphology of this stream and the typical morphology of nonwetland alluvial streams. Six morphological features of the study reach were examined: bankfull flow, meanders, pools and riffles, thalweg location, straight reaches, and cross-sectional shape. It was found that bankfull flow definitions originating from streams in nonwetland environments did not apply. Unusual features observed in the wetland reach include tight bends and a large axial wavelength to width ratio. A lengthy straight reach exists that exceeds what is typically found in nonwetland alluvial streams. The lack of convex bank point bars in the bends, a greater channel width at riffle locations, an unusual thalweg location, and small form ratios (a deep and narrow channel) were also differences identified. Further study is needed on wetland streams of various regions to determine if differences in morphology between alluvial and wetland environments can be applied in order to improve future designs of wetland channels.KEY WORDS: Stream morphology; Wetland restoration; Wetland creation; Bankfull; Pools and riffles; Meanders; Thalweg

  18. Evolution of the Largest Mammalian Genome.

    Science.gov (United States)

    Evans, Ben J; Upham, Nathan S; Golding, Goeffrey B; Ojeda, Ricardo A; Ojeda, Agustina A

    2017-06-01

    The genome of the red vizcacha rat (Rodentia, Octodontidae, Tympanoctomys barrerae) is the largest of all mammals, and about double the size of their close relative, the mountain vizcacha rat Octomys mimax, even though the lineages that gave rise to these species diverged from each other only about 5 Ma. The mechanism for this rapid genome expansion is controversial, and hypothesized to be a consequence of whole genome duplication or accumulation of repetitive elements. To test these alternative but nonexclusive hypotheses, we gathered and evaluated evidence from whole transcriptome and whole genome sequences of T. barrerae and O. mimax. We recovered support for genome expansion due to accumulation of a diverse assemblage of repetitive elements, which represent about one half and one fifth of the genomes of T. barrerae and O. mimax, respectively, but we found no strong signal of whole genome duplication. In both species, repetitive sequences were rare in transcribed regions as compared with the rest of the genome, and mostly had no close match to annotated repetitive sequences from other rodents. These findings raise new questions about the genomic dynamics of these repetitive elements, their connection to widespread chromosomal fissions that occurred in the T. barrerae ancestor, and their fitness effects-including during the evolution of hypersaline dietary tolerance in T. barrerae. ©The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  19. Declining plant nitrogen supply and carbon accumulation in ageing primary boreal forest ecosystems

    Science.gov (United States)

    Högberg, Mona N.; Yarwood, Stephanie A.; Trumbore, Susan; Högberg, Peter

    2016-04-01

    Boreal forest soils are commonly characterized by a low plant nitrogen (N) supply. A high tree below-ground allocation of carbon (C) to roots and soil microorganisms in response to the shortage of N may lead to high microbial immobilisation of N, thus aggravating the N limitation. We studied the N supply at a Swedish boreal forest ecosystem chronosequence created by new land rising out of the sea due to iso-static rebound. The youngest soils develop with meadows by the coast, followed by a zone of dinitrogen fixing alder trees, and primary boreal conifer forest on ground up to 560 years old. With increasing ecosystem age, the proportion of microbial C out of the total soil C pool from the youngest to the oldest coniferous ecosystem was constant (c. 1-1.5%), whereas immobilised N (microbial N out of total soil N) increased and approached the levels commonly observed in similar boreal coniferous forests (c. 6-7 %), whereas gross N mineralization declined. Simultaneously, plant foliar N % decreased and the natural abundance of N-15 in the soil increased. More specifically, the difference in N-15 between plant foliage and soil increased, which is related to greater retention of N-15 relative to N-14 by ectomycorrhizal fungi as N is taken up from the soil and some N is transferred to the plant host. In the conifer forest, where these changes were greatest, we found increased fungal biomass in the F- and H-horizons of the mor-layer, in which ectomycorrhizal fungi are known to dominate (the uppermost horizon with litter and moss is dominated by saprotrophic fungi). Hence, we propose that the decreasing N supply to the plants and the subsequent decline in plant production in ageing boreal forests is linked to high tree belowground C allocation to C limited ectomycorrhizal fungi (and other soil microorganisms), a strong sink for available soil N. Data on organic matter C-14 suggested that the largest input of recently fixed plant C occurred in the younger coniferous forest

  20. Boreal Forests of Kamchatka: Structure and Composition

    OpenAIRE

    Eichhorn, Markus P.

    2010-01-01

    Central Kamchatka abounds in virgin old-growth boreal forest, formed primarily by Larix cajanderi and Betula platyphylla in varying proportions. A series of eight 0.25–0.30 ha plots captured the range of forests present in this region and their structure is described. Overall trends in both uplands and lowlands are for higher sites to be dominated by L. cajanderi with an increasing component of B. platyphylla with decreasing altitude. The tree line on wet sites is commonly formed by mono-domi...

  1. Canada's largest co-gen project

    International Nuclear Information System (INIS)

    Salaff, S.

    2000-01-01

    In November 2000, the TransAlta Energy Corp. began construction on its $400 million natural gas fuelled cogeneration project in Sarnia Ontario. The Sarnia Regional Cogeneration Project (SRCP) is designed to integrate a new 440 MW cogeneration facility to be built at the Sarnia Division of Dow Chemicals Canada Inc. with nearby existing generators totaling 210 MW at Dow and Bayer Inc. At 650 MW, the new facility will rank as Canada's largest cogeneration installation. Commercial operation is scheduled for October 2002. TransAlta owns three natural gas fuelled cogeneration facilities in Ontario (in Ottawa, Mississauga and Windsor) totaling 250 MW. The cost of electric power in Ontario is currently controlled by rising natural gas prices and the supply demand imbalance. This balance will be significantly affected by the possible return to service of 2000 MW of nuclear generating capacity. The SRCP project was announced just prior to the Ontario Energy Competition Act of October 1998 which committed the province to introduce competition to the electricity sector and which created major uncertainties in the electricity market. Some of the small, 25 MW projects which survived the market uncertainty included the Toronto-based Toromont Energy Ltd. project involving gas fuelled cogeneration and methane gas generation from landfill projects in Sudbury and Waterloo. It was emphasized that cogeneration and combined heat and power projects have significant environmental advantages over large combined cycle facilities. The Ontario Energy Board is currently considering an application from TransAlta to link the SRCP facility to Ontario's Hydro One Network Inc.'s transmission grid. 1 fig

  2. Boreal Forests of Kamchatka: Structure and Composition

    Directory of Open Access Journals (Sweden)

    Markus P. Eichhorn

    2010-09-01

    Full Text Available Central Kamchatka abounds in virgin old-growth boreal forest, formed primarily by Larix cajanderi and Betula platyphylla in varying proportions. A series of eight 0.25–0.30 ha plots captured the range of forests present in this region and their structure is described. Overall trends in both uplands and lowlands are for higher sites to be dominated by L. cajanderi with an increasing component of B. platyphylla with decreasing altitude. The tree line on wet sites is commonly formed by mono-dominant B. ermanii forests. Basal area ranged from 7.8–38.1 m2/ha and average tree height from 8.3–24.7 m, both being greater in lowland forests. Size distributions varied considerably among plots, though they were consistently more even for L. cajanderi than B. platyphylla. Upland sites also contained a dense subcanopy of Pinus pumila averaging 38% of ground area. Soil characteristics differed among plots, with upland soils being of lower pH and containing more carbon. Comparisons are drawn with boreal forests elsewhere and the main current threats assessed. These forests provide a potential baseline to contrast with more disturbed regions elsewhere in the world and therefore may be used as a target for restoration efforts or to assess the effects of climate change independent of human impacts.

  3. Roofvogels in de Nederlandse wetlands

    NARCIS (Netherlands)

    Dijkstra, Cornelis; Beemster, Nicolaas; Zijlstra, Menno; van Eerden, M; Daan, Serge

    1995-01-01

    Roofvogels in de Nederlandse wetlands (1995). C. Dijkstra, N. Beemster, M. Zijlstra, M. van Eerden, S. Daan RWS, RDIJ, Flevobericht nr. 381. ISBN 90-369-1147-8. Dit Flevobericht vormt de eindrapportage van het onderzoeksproject " De betekenis van grootschalige wetlands voor roofvogels". De verwerkte

  4. Carbon Storage in US Wetlands.

    Science.gov (United States)

    Background/Question/Methods Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in US wetlands or of the potential effects of human disturbance on these stocks. ...

  5. Spatial and temporal variations in shallow wetland groundwater quality

    Science.gov (United States)

    Schot, Paul P.; Pieber, Simone M.

    2012-02-01

    SummaryWetlands worldwide are threatened by environmental change. Differences in groundwater composition is one of the factors affecting wetland terrestrial floristic biodiversity. However, few studies discuss variations in wetland groundwater composition. This study presents an analysis of local-scale spatial and short-term temporal variations in 15 groundwater composition parameters of the 7 km2 Naardermeer wetland nature reserve in The Netherlands. Data is available from a network of 35 groundwater wells with 2-4 filters each, at depths between 50 and 800 cm, which were sampled about monthly over a 1-year period, totalling 1042 chemical analysis from 103 filter screens. Relative standard deviations indicate large differences in variation between parameters. Largest spatial and temporal variations were found for nutrients (NO3-, PO43-, NH4+) and redox sensitive parameters (Fe, Mn), and lowest variations for macroions and SiO2. A horizontal zonation in groundwater concentrations has been found related to soil type and soil wetness, with largest horizontal decrease in NO3- and SO42-, and largest increase in Fe and SiO2, going in the groundwater flow direction from dry sandy soils to wet peat/clay soils. No clear horizontal patterns have been found for the macroions. Spatial zonations in the north-south direction and with depth are absent for all parameters. Spatial and temporal variations were found to be related. 3D-maps indicate highest temporal fluctuations at filter screens with lowest median concentrations for NO3-, SO42- and Fe, but the reverse pattern for SiO2. High temporal variations of nutrients and redox sensitive parameters could not be traced back to a seasonal trend. The spatial and temporal variability of groundwater quality parameters as presented in this study, together with their reported effects on different vegetation types, may be used to design efficient monitoring schemes by nature managers having set specific vegetation development targets

  6. Genetic implications of phylogeographical patterns in the conservation of the boreal wetland butterfly Colias palaeno (Pieridae)

    Czech Academy of Sciences Publication Activity Database

    Krampl, K.; Čížek, O.; Madeira, P. M.; Ramos, A. A.; Konvička, Martin; Castilho, R.; Schmitt, T.

    2016-01-01

    Roč. 119, č. 4 (2016), s. 1068-1081 ISSN 0024-4066 R&D Projects: GA ČR(CZ) GA14-33733S Institutional support: RVO:60077344 Keywords : allozyme electrophoresis * cytochrome oxidase I * genetic structure Subject RIV: EH - Ecology, Behaviour Impact factor: 2.288, year: 2016 http://onlinelibrary.wiley.com/doi/10.1111/bij.12840/abstract

  7. First Polarimetric GNSS-R Measurements from a Stratospheric Flight over Boreal Forests

    Directory of Open Access Journals (Sweden)

    Hugo Carreno-Luengo

    2015-10-01

    Full Text Available The first-ever dual-frequency multi-constellation Global Navigation Satellite Systems Reflectometry (GNSS-R polarimetric measurements over boreal forests and lakes from the stratosphere are presented. Data were collected during the European Space Agency (ESA sponsored Balloon Experiments for University Students (BEXUS 19 stratospheric balloon experiment using the P(Y and C/A Reflect Ometer (PYCARO instrument operated in closed-loop mode. Maps of the polarimetric ratio for L1 and L2 Global Positioning System (GPS and GLObal Navigation Satellite System (GLONASS, and for E1 Galileo signals are derived from the float phase at 27,000 m height, and the specular points are geolocalized on the Earth’s surface. Polarimetric ratio ( maps over boreal forests are shown to be in the range 2–16 dB for the different GNSS codes. This result suggests that the scattering is taking place not only over the soil, but over the different forests elements as well. Additionally to the interpretation of the experimental results a theoretical investigation of the different contributions to the total reflectivity over boreal forests is performed using a bistatic scattering model. The simulated cross- (reflected Left Hand Circular Polarization LHCP and co-polar (reflected Right Hand Circular Polarization RHCP reflectivities are evaluated for the soil, the canopy, and the canopy–soil interactions for three different biomass densities: 725 trees/ha, 150 trees/ha and 72 trees/ha. For elevation angles larger than the Brewster angle, it is found that the cross-polar signal is dominant when just single reflections over the forests are evaluated, while in the case of multiple reflections the co-polar signal becomes the largest one. The first-ever dual-frequency multi-constellation Global Navigation Satellite Systems Reflectometry (GNSS-R polarimetric measurements over boreal forests and lakes from the stratosphere are presented. Data were collected during the European Space

  8. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Directory of Open Access Journals (Sweden)

    T. Wang

    2011-07-01

    Full Text Available Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m−2 d−1, when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m−2 d−1. Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m−2 d−1 of 0.70(±0.33, 0.60(±0.38, 0.62(±0.43, 0.49(±0.22 and 0.27(±0.08, respectively. Our cross site analysis showed that winter air (Tair and soil (Tsoil temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands. Besides temperature, the seasonal amplitude of the leaf area index (LAI, inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (

  9. Climate Change and Intertidal Wetlands

    Directory of Open Access Journals (Sweden)

    Pauline M. Ross

    2013-03-01

    Full Text Available Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause—the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the “squeeze” experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

  10. Climate change and intertidal wetlands.

    Science.gov (United States)

    Ross, Pauline M; Adam, Paul

    2013-03-19

    Intertidal wetlands are recognised for the provision of a range of valued ecosystem services. The two major categories of intertidal wetlands discussed in this contribution are saltmarshes and mangrove forests. Intertidal wetlands are under threat from a range of anthropogenic causes, some site-specific, others acting globally. Globally acting factors include climate change and its driving cause-the increasing atmospheric concentrations of greenhouse gases. One direct consequence of climate change will be global sea level rise due to thermal expansion of the oceans, and, in the longer term, the melting of ice caps and glaciers. The relative sea level rise experienced at any one locality will be affected by a range of factors, as will the response of intertidal wetlands to the change in sea level. If relative sea level is rising and sedimentation within intertidal wetlands does not keep pace, then there will be loss of intertidal wetlands from the seaward edge, with survival of the ecosystems only possible if they can retreat inland. When retreat is not possible, the wetland area will decline in response to the "squeeze" experienced. Any changes to intertidal wetland vegetation, as a consequence of climate change, will have flow on effects to biota, while changes to biota will affect intertidal vegetation. Wetland biota may respond to climate change by shifting in distribution and abundance landward, evolving or becoming extinct. In addition, impacts from ocean acidification and warming are predicted to affect the fertilisation, larval development, growth and survival of intertidal wetland biota including macroinvertebrates, such as molluscs and crabs, and vertebrates such as fish and potentially birds. The capacity of organisms to move and adapt will depend on their life history characteristics, phenotypic plasticity, genetic variability, inheritability of adaptive characteristics, and the predicted rates of environmental change.

  11. Challenges and Conundrums in Modeling Global Methane Emissions from Wetlands: An Empiricist's Viewpoint

    Science.gov (United States)

    Bridgham, S. D.

    2015-12-01

    Wetlands emit a third to half of the global CH4 flux and have the largest uncertainty of any emission source. Moreover, wetlands have provided an important radiative feedback to climate in the geologic and recent past. A number of largescale wetland CH4 models have been developed recently, but intermodel comparisons show wide discrepancies in their predictions. I present an empiricist's overview of the current limitations and challenges of more accurately modeling wetland CH4 emissions. One of the largest limitations is simply the poor knowledge of wetland area, with estimated global values varying by a more than a factor of three. The areas of seasonal and tropical wetlands are particularly poorly constrained. There are also few wetlands with complete, multi-year datasets for all of the input variables for many models, and this lack of data is particularly alarming in tropical wetlands given that they are arguably the single largest natural or anthropogenic global CH4 source. Almost all largescale CH4 models have little biogeochemical mechanistic detail and treat anaerobic carbon cycling in a highly simplified manner. The CH4:CO2 ratio in anaerobic carbon mineralization is a central parameter in many models, but is at most set at a few values with no mechanistic underpinning. However, empirical data show that this ratio varies by five orders of magnitude in different wetlands, and tropical wetlands appear to be particularly methanogenic, all for reasons that are very poorly understood. The predominance of the acetoclastic pathway of methanogenesis appears to be related to total CH4 production, but different methanogenesis pathways are generally not incorporated into models. Other important anaerobic processes such as humic substances acting as terminal electron acceptors, fermentation, homoacetogenesis, and anaerobic CH4 oxidation are also not included in most models despite evidence of their importance in empirical studies. Moreover, there has been an explosion

  12. Interaction of hydrological regime and vegetation in a seasonally flooded lake wetland (Poyang Lake) in China

    Science.gov (United States)

    Zhang, Qi

    2017-04-01

    Hydrological regime has been widely recognized as one of the major forces determining vegetation distribution in seasonally flooded wetlands. To explore the influences of hydrological conditions on the spatial distribution of wetland vegetation, an experimental transect in Poyang Lake wetland, the largest freshwater lake in China, was selected as a study area. In-situ high time frequency observations of climate, soil moisture, groundwater level and surface water level were simultaneously conducted. Vegetation was sampled periodically to obtain species composition, diversity and biomass. Results show that significant hydrological gradient exists along the experimental transect. Both groundwater level and soil moisture demonstrate high correlation with the distribution of different communities of vegetation. Above- and belowground biomass present Gaussian models along the gradient of groundwater depth in growing seasons. It was found that the optimal average groundwater depths for above- and belowground biomass are 0.8 m and 0.5 m, respectively. Numerical simulations using HYDRUS-1D further indicated that the groundwater depths had significant influences on the water usage by vegetation, which suggested the high dependence of wetland vegetation on groundwater, even in a wet climate zone such as Poyang Lake. The study revealed new knowledge on the interaction of hydrological regime and wetland vegetation, and provided scientific support for an integrated management of balancing wetland ecology and water resources development in Poyang Lake, and other lake floodplain wetlands, with strong human interferences.

  13. Wetlands Research Program. Wetland Evaluation Technique (WET). Volume 2. Methodology.

    Science.gov (United States)

    1987-10-01

    to waves taller than I ft? • " Guidelines: 1 "Sufficient" is defined as the height of vegetation or relief multiplied * by length of vegetation or...Sci., Interim Rep. No. 3, Gloucester Point, VA. 52 pp. 203 VI. 4 WET 2.0 Simmons, E. G. 1957. An ecological survey of the Upper Laguna Madre of Texas...A wetland class characterized by vegetation that is 6 m or taller . Fringe Wetland - Fringe wetlands along a channel (i.e.. river, stream, etc.)are

  14. Fire and drought experiments in northern wetlands: A climate change analogue

    Energy Technology Data Exchange (ETDEWEB)

    Hogenbirk, J.C.; Wen, R.W. (Alberta Univ., Edmonton, AB (Canada))

    1991-09-01

    Drought and fire, which may increase in frequency and severity because of global warming, were simulated in mid-boreal wetlands by transplanting soil block upslope to a lower water table and by prescribed burns. In the 2 years after treatments were applied to seasonally flooded vegetation zones in the Peace-Athabasca Delta, Alberta, the drought treatment did not significantly change stem density and height of the dominant hygrophytes Calamagrostics canadensis and Carex atherodes. Dicotyledonous species' density and richness increased 3- to 36-fold on soil blocks moved upslope to the driest vegetation zone relative to unmoved soil blocks. The percent cover of native dicotyledonous species was unaffected but that of xerophytic Eurasian species, Sonchus arvensis and Cirsium arvense, increased 5- to 13-fold after dought treatment. Fire, particularly the deepest burn, reduced graminoid density and height up to 90%. Dicotyledon density, but not richness, was generally higher after fire. Plant cover was unaffected by fire but Eurasian species' cover was still 3- to 15-fold greater than that of native species. Seasonally flooded vegetation zones will likely be shifted from flood-driven dynamics with cool and moist environmental conditions towards drought- and fire-driven dynamics with warmer and drier conditions. It is hypothesized that, under these climate change conditions, Eurasian species might dominate early successional communities in mid-boreal wetlands. 37 refs., 1 fig., 4 tabs.

  15. Remote sensing of wetlands applications and advances

    CERN Document Server

    Tiner, Ralph W; Klemas, Victor V

    2015-01-01

    Effectively Manage Wetland Resources Using the Best Available Remote Sensing Techniques Utilizing top scientists in the wetland classification and mapping field, Remote Sensing of Wetlands: Applications and Advances covers the rapidly changing landscape of wetlands and describes the latest advances in remote sensing that have taken place over the past 30 years for use in mapping wetlands. Factoring in the impact of climate change, as well as a growing demand on wetlands for agriculture, aquaculture, forestry, and development, this text considers the challenges that wetlands pose for remote sensing and provides a thorough introduction on the use of remotely sensed data for wetland detection. Taking advantage of the experiences of more than 50 contributing authors, the book describes a variety of techniques for mapping and classifying wetlands in a multitude of environments ranging from tropical to arctic wetlands including coral reefs and submerged aquatic vegetation. The authors discuss the advantages and di...

  16. Atrazine remediation in wetland microcosms.

    Science.gov (United States)

    Runes, H B; Bottomley, P J; Lerch, R N; Jenkins, J J

    2001-05-01

    Laboratory wetland microcosms were used to study treatment of atrazine in irrigation runoff by a field-scale-constructed wetland under controlled conditions. Three experiments, in which 1 ppm atrazine was added to the water column of three wetland, one soil control, and one water control microcosm, were conducted. Atrazine dissipation from the water column and degradate formation (deethylatrazine [DEA]; deisopropylatrazine [DIA]; and hydroxyatrazine [HA]) were monitored. Atrazine dissipation from the water column of wetland microcosms was biphasic. Less than 12% of the atrazine applied to wetland microcosms remained in the water column on day 56. Atrazine degradates were observed in water and sediment, with HA the predominant degradate. Analysis of day 56 sediment samples indicated that a significant portion of the initial application was detected as the parent compound and HA. Most probable number (MPN) assays demonstrated that atrazine degrader populations were small in wetland sediment. Wetland microcosms were able to reduce atrazine concentration in the water column via sorption and degradation. Based on results from this study, it is hypothesized that plant uptake contributed to atrazine dissipation from the water column.

  17. Potential Effects of Climate Change on the Water Level, Flora and Macro-fauna of a Large Neotropical Wetland

    OpenAIRE

    ?beda, B?rbara; Di Giacomo, Adrian S.; Neiff, Juan Jos?; Loiselle, Steven A.; Guadalupe Poi, Alicia S.; G?lvez, Jos? ?ngel; Casco, Silvina; C?zar, Andr?s

    2013-01-01

    Possible consequences of climate change in one of the world?s largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a l...

  18. Ditch network maintenance in peat-dominated boreal forests: Review and analysis of water quality management options.

    Science.gov (United States)

    Nieminen, Mika; Piirainen, Sirpa; Sikström, Ulf; Löfgren, Stefan; Marttila, Hannu; Sarkkola, Sakari; Laurén, Ari; Finér, Leena

    2018-03-27

    The objective of this study was to evaluate the potential of different water management options to mitigate sediment and nutrient exports from ditch network maintenance (DNM) areas in boreal peatland forests. Available literature was reviewed, past data reanalyzed, effects of drainage intensity modeled, and major research gaps identified. The results indicate that excess downstream loads may be difficult to prevent. Water protection structures constructed to capture eroded matter are either inefficient (sedimentation ponds) or difficult to apply (wetland buffers). It may be more efficient to decrease erosion, either by limiting peak water velocity (dam structures) or by adjusting ditch depth and spacing to enable satisfactory drainage without exposing the mineral soil below peat. Future research should be directed towards the effects of ditch breaks and adjusted ditch depth and spacing in managing water quality in DNM areas.

  19. The emergence of treatment wetlands

    International Nuclear Information System (INIS)

    Cole, S.

    1998-01-01

    Judging by the growing number of wetlands built for wastewater treatment around the world, this natural technology seems to have firmly established roots. After almost 30 years of use in wastewater treatment, constructed treatment wetlands now number over 500 in Europe and 600 in North America. Marsh-type surface flow systems are most common in North America, but subsurface flow wetlands, where wastewater flows beneath the surface of a gravel-rock bed, predominate in Europe. The inexpensive, low maintenance technology is in high demand in Central America, Eastern Europe, and Asia. New applications, from nitrate-contaminated ground water to effluent from high-intensity livestock operations, are also increasing. But in the United States, treatment-wetland technology has not yet gained national regulatory acceptance. Some states and EPA regions are eager to endorse them, but others are wary of this nontraditional method of treating wastewater. In part, this reluctance exists because the technology is not yet completely understood. Treatment wetlands also pose a potential threat to wildlife attracted to this new habitat -an ecosystem exposed to toxic compounds. New efforts are under way, however, to place the technology onto firmer scientific and regulatory ground. Long-term demonstration and monitoring field studies are currently probing the inner workings of wetlands and their water quality capabilities to provide better data on how to design more effective systems. A recent study of US policy and regulatory issues surrounding treatment wetlands has recommended that the federal government actively promote the technology and clear the regulatory roadblocks to enable wider use. Proponents argue that the net environmental benefits of constructed wetlands, such as restoring habitat and increasing wetlands inventory, should be considered. 8 refs., 6 photos

  20. Using Tradtional Ecological Knowledge to Protect Wetlands: the Swinomish Tribe's Wetland Cultural Assessment Project

    Science.gov (United States)

    Mitchell, T.

    2017-12-01

    "Traditional" wetland physical assessment modules do not adequately identify Tribal cultural values of wetlands and thus wetlands may not be adequately protected for cultural uses. This Swinomish Wetlands Cultural Assessment Project has developed a cultural resource scoring module that can be incorporated into wetland assessments to better inform wetland protections. Local native knowledge was gathered about the traditional uses of 99 native wetland plant species. A cultural scoring matrix was developed based on the presence of traditionally used plants in several use categories including: construction, ceremonial, subsistence, medicinal, common use, plant rarity, and place of value for each wetland. The combined score of the cultural and physcial modules provides an overall wetland score that relates to proscribed buffer protection widths. With this local native knowledge incorporated into wetland assessments, we are protecting and preserving Swinomish Reservation wetlands for both cultural uses and ecological functionality through the Tribe's wetland protection law.

  1. BOREAS TE-04 Gas Exchange Data from Boreal Tree Species

    Data.gov (United States)

    National Aeronautics and Space Administration — Contains TE-04 data on gas exchange studies of photosynthesis, respiration and stomatal conductance of boreal forest species using the MPH-1000 system.

  2. BOREAS TE-04 Branch Bag Data from Boreal Tree Species

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Contains 1996 TE-04 data of branch bag studies of photosynthesis, respiration and stomatal conductance of boreal forest species using the open MPH-1000...

  3. NPP Boreal Forest: Kuusamo, Finland, 1967-1971, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains three files (.txt format). One file provides stand characteristics, biomass, and production allocation data for an old-growth boreal...

  4. NPP Boreal Forest: Kuusamo, Finland, 1967-1972, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains three files (.txt format). One file provides stand characteristics, biomass, and production allocation data for an old-growth boreal forest...

  5. NPP Boreal Forest: Schefferville, Canada, 1974, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains two files (.txt format). One file provides above- and below-ground biomass, soil, and nutrient data for a mature boreal ecosystem (subarctic...

  6. NPP Boreal Forest: Schefferville, Canada, 1974, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains two files (.txt format). One file provides above- and below-ground biomass, soil, and nutrient data for a mature boreal ecosystem...

  7. Size-based hydroacoustic measures of within-season fish abundance in a boreal freshwater ecosystem.

    Directory of Open Access Journals (Sweden)

    Riley A Pollom

    Full Text Available Eleven sequential size-based hydroacoustic surveys conducted with a 200 kHz split-beam transducer during the summers of 2011 and 2012 were used to quantify seasonal declines in fish abundance in a boreal reservoir in Manitoba, Canada. Fish densities were sufficiently low to enable single target resolution and tracking. Target strengths converted to log2-based size-classes indicated that smaller fish were consistently more abundant than larger fish by a factor of approximately 3 for each halving of length. For all size classes, in both years, abundance (natural log declined linearly over the summer at rates that varied from -0.067 x day(-1 for the smallest fish to -0.016 x day(-1 for the largest (R2 = 0.24-0.97. Inter-annual comparisons of size-based abundance suggested that for larger fish (>16 cm, mean winter decline rates were an order of magnitude lower (-0.001 x day(-1 and overall survival higher (71% than in the main summer fishing season (mean loss rate -0.038 x day(-1; survival 33%. We conclude that size-based acoustic survey methods have the potential to assess within-season fish abundance dynamics, and may prove useful in long-term monitoring of productivity and hence management of boreal aquatic ecosystems.

  8. Size-based hydroacoustic measures of within-season fish abundance in a boreal freshwater ecosystem.

    Science.gov (United States)

    Pollom, Riley A; Rose, George A

    2015-01-01

    Eleven sequential size-based hydroacoustic surveys conducted with a 200 kHz split-beam transducer during the summers of 2011 and 2012 were used to quantify seasonal declines in fish abundance in a boreal reservoir in Manitoba, Canada. Fish densities were sufficiently low to enable single target resolution and tracking. Target strengths converted to log2-based size-classes indicated that smaller fish were consistently more abundant than larger fish by a factor of approximately 3 for each halving of length. For all size classes, in both years, abundance (natural log) declined linearly over the summer at rates that varied from -0.067 x day(-1) for the smallest fish to -0.016 x day(-1) for the largest (R2 = 0.24-0.97). Inter-annual comparisons of size-based abundance suggested that for larger fish (>16 cm), mean winter decline rates were an order of magnitude lower (-0.001 x day(-1)) and overall survival higher (71%) than in the main summer fishing season (mean loss rate -0.038 x day(-1); survival 33%). We conclude that size-based acoustic survey methods have the potential to assess within-season fish abundance dynamics, and may prove useful in long-term monitoring of productivity and hence management of boreal aquatic ecosystems.

  9. Boreal forest biomass classification with TanDEM-X

    OpenAIRE

    Torano Caicoya, Astor; Kugler, Florian; Papathanassiou, Kostas; Hajnsek, Irena

    2013-01-01

    High spatial resolution X-band interferometric SAR data from the TanDEM-X, in the operational DEM generation mode, are sensitive to forest structure and can therefore be used for thematic boreal forest classification of forest environments. The interferometric coherence in absence of temporal decorrelation depends strongly on forest height and structure. Due to the rather homogenous structure of boreal forest, forest biomass can be derived from forest height, on the basis of allometric equati...

  10. Size-mediated tree transpiration along soil drainage gradients in a boreal black spruce forest wildfire chronosequence.

    Science.gov (United States)

    Angstmann, J L; Ewers, B E; Kwon, H

    2012-05-01

    Boreal forests are crucial to climate change predictions because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through more frequent wildfires, warmer, longer growing seasons and potential drainage of forested wetlands. This study aims at quantifying controls over tree transpiration with drainage condition, stand age and species in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 2007 and data were collected through 2008 on 118 trees (69 Picea mariana (Mill.) Britton, Sterns & Poggenb. (black spruce), 25 Populus tremuloides Michx. (trembling aspen), 19 Pinus banksiana Lamb. (jack pine), 3 Larix laricina (Du Roi) K. Koch (tamarack) and 2 Salix spp. (willow)) at four stand ages (18, 43, 77 and 157 years old) each containing a well- and poorly-drained stand. Transpiration estimates from sap flux were expressed per unit xylem area, J(S), per unit ground area, E(C) and per unit leaf area, E(L), using sapwood (A(S)) and leaf (A(L)) area calculated from stand- and species-specific allometry. Soil drainage differences in transpiration were variable; only the 43- and 157-year-old poorly-drained stands had ∼ 50% higher total stand E(C) than well-drained locations. Total stand E(C) tended to decrease with stand age after an initial increase between the 18- and 43-year-old stands. Soil drainage differences in transpiration were controlled primarily by short-term physiological drivers such as vapor pressure deficit and soil moisture whereas stand age differences were controlled by successional species shifts and changes in tree size (i.e., A(S)). Future predictions of boreal climate change must include stand age, species and soil drainage heterogeneity to avoid biased estimates of forest water loss and latent energy exchanges.

  11. Global warming considerations in northern Boreal forest ecosystems

    International Nuclear Information System (INIS)

    Slaughter, C.W.

    1993-01-01

    The northern boreal forests of circumpolar lands are of special significance to questions of global climate change. Throughout its range, these forests are characterized by a relatively few tree species, although they may exhibit great spatial heterogeneity. Their ecosystems are simpler than temperate systems, and ecosystem processes are strongly affected by interactions between water, the landscape, and the biota. Northern boreal forest vegetation patterns are strongly influenced by forest fires, and distribution of forest generally coincides with occurrence of permafrost. Boreal forest landscapes are extremely sensitive to thermal disruption; global warming may result in lasting thermal and physical degradation of soils, altered rates and patterns of vegetation succession, and damage to engineered structures. A change in fire severity and frequency is also a significant concern. The total carbon pool of boreal forests and their associated peatlands is significant on a global scale; this carbon may amount to 10-20% of the global carbon pool. A change in latitudinal or elevational treeline has been suggested as a probable consequence of global warming. More subtle aspects of boreal forest ecosystems which may be affected by global warming include the depth of the active soil layer, the hydrologic cycle, and biological attributes of boreal stream systems. 48 refs., 2 figs

  12. Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle.

    Science.gov (United States)

    Gundale, Michael J; From, Fredrik; Bach, Lisbet H; Nordin, Annika

    2014-01-01

    It is proposed that increases in anthropogenic reactive nitrogen (Nr ) deposition may cause temperate and boreal forests to sequester a globally significant quantity of carbon (C); however, long-term data from boreal forests describing how C sequestration responds to realistic levels of chronic Nr deposition are scarce. Using a long-term (14-year) stand-scale (0.1 ha) N addition experiment (three levels: 0, 12.5, and 50 kg N ha(-1)  yr(-1) ) in the boreal zone of northern Sweden, we evaluated how chronic N additions altered N uptake and biomass of understory communities, and whether changes in understory communities explained N uptake and C sequestration by trees. We hypothesized that understory communities (i.e. mosses and shrubs) serve as important sinks for low-level N additions, with the strength of these sinks weakening as chronic N addition rates increase, due to shifts in species composition. We further hypothesized that trees would exhibit nonlinear increases in N acquisition, and subsequent C sequestration as N addition rates increased, due to a weakening understory N sink. Our data showed that understory biomass was reduced by 50% in response to the high N addition treatment, mainly due to reduced moss biomass. A (15) N labeling experiment showed that feather mosses acquired the largest fraction of applied label, with this fraction decreasing as the chronic N addition level increased. Contrary to our hypothesis, the proportion of label taken up by trees was equal (ca. 8%) across all three N addition treatments. The relationship between N addition and C sequestration in all vegetation pools combined was linear, and had a slope of 16 kg C kg(-1)  N. While canopy retention of Nr deposition may cause C sequestration rates to be slightly different than this estimate, our data suggest that a minor quantity of annual anthropogenic CO2 emissions are sequestered into boreal forests as a result of Nr deposition. © 2013 John Wiley & Sons Ltd.

  13. Decadal-scale ecosystem memory reveals interactive effects of drought and insect defoliation on boreal forest productivity

    Science.gov (United States)

    Itter, M.; D'Orangeville, L.; Dawson, A.; Kneeshaw, D.; Finley, A. O.

    2017-12-01

    Drought and insect defoliation have lasting impacts on the dynamics of the boreal forest. Impacts are expected to worsen under global climate change as hotter, drier conditions forecast for much of the boreal increase the frequency and severity of drought and defoliation events. Contemporary ecological theory predicts physiological feedbacks in tree responses to drought and defoliation amplify impacts potentially causing large-scale productivity losses and forest mortality. Quantifying the interactive impacts of drought and insect defoliation on regional forest health is difficult given delayed and persistent responses to disturbance events. We developed a Bayesian hierarchical model to estimate forest growth responses to interactions between drought and insect defoliation by species and size class. Delayed and persistent responses to past drought and defoliation were quantified using empirical memory functions allowing for improved detection of interactions. The model was applied to tree-ring data from stands in Western (Alberta) and Eastern (Québec) regions of the Canadian boreal forest with different species compositions, disturbance regimes, and regional climates. Western stands experience chronic water deficit and forest tent caterpillar (FTC) defoliation; Eastern stands experience irregular water deficit and spruce budworm (SBW) defoliation. Ecosystem memory to past water deficit peaked in the year previous to growth and decayed to zero within 5 (West) to 8 (East) years; memory to past defoliation ranged from 8 (West) to 12 (East) years. The drier regional climate and faster FTC defoliation dynamics (compared to SBW) likely contribute to shorter ecosystem memory in the West. Drought and defoliation had the largest negative impact on large-diameter, host tree growth. Surprisingly, a positive interaction was observed between drought and defoliation for large-diameter, non-host trees likely due to reduced stand-level competition for water. Results highlight the

  14. Tropical Wetlands as Carbon Sinks

    Science.gov (United States)

    Jones, M. B.; Saunders, M.

    2007-12-01

    This presentation focuses on the tropical wetlands of sub-Saharan Africa. These are an understudied ecosystem in which large emergent grasses and sedges normally dominate and which have the potential to sequester significant amounts of carbon. Measurements of Net Primary Production of these wetlands show that they are some of the highest values recorded for any ecosystem. We have used eddy covariance to measure Net Ecosystem Exchange of pristine and disturbed wetlands and show that pristine systems can have sink strengths as strong as tropical forests while disturbed systems that have been reclaimed for agricultural purposes have a very much reduced carbon sink activity and may be net carbon sources. The management issues surrounding the use of these wetlands illustrate a direct conflict between the production of food crops for the local population and the maintenance of carbon sequestration as an ecosystem service.

  15. Hydrocarbon removal with constructed wetlands

    OpenAIRE

    Eke, Paul Emeka

    2008-01-01

    Wetlands have long played a significant role as natural purification systems, and have been effectively used to treat domestic, agricultural and industrial wastewater. However, very little is known about the biochemical processes involved, and the use of constructed treatment wetlands in the removal of petroleum aromatic hydrocarbons from produced and/or processed water. Wastewaters from the oil industry contain aromatic hydrocarbons such as benzene, toluene, ethylbenzene and x...

  16. Land cover mapping, fire regeneration, and scaling studies in the Canadian boreal forest with 1 km AVHRR and Landsat TM data

    Science.gov (United States)

    Steyaert, L.T.; Hall, F.G.; Loveland, Thomas R.

    1997-01-01

    A multitemporal 1 km advanced very high resolution radiometer (AVHRR) land cover analysis approach was used as the basis for regional land cover mapping, fire disturbance-regeneration, and multiresolution land cover scaling studies in the boreal forest ecosystem of central Canada. The land cover classification was developed by using regional field observations from ground and low-level aircraft transits to analyze spectral-temporal clusters that were derived from an unsupervised cluster analysis of monthly normalized difference vegetation index (NDVI) image composites (April-September 1992). Quantitative areal proportions of the major boreal forest components were determined for a 821 km ?? 619 km region, ranging from the southern grasslands-boreal forest ecotone to the northern boreal transitional forest. The boreal wetlands (mostly lowland black spruce, tamarack, mosses, fens, and bogs) occupied approximately 33% of the region, while lakes accounted for another 13%. Upland mixed coniferous-deciduous forests represented 23% of the ecosystem. A SW-NE productivity gradient across the region is manifested by three levels of tree stand density for both the boreal wetland conifer and the mixed forest classes, which are generally aligned with isopleths of regional growing degree days. Approximately 30% of the region was directly affected by fire disturbance within the preceding 30-35 years, especially in the Canadian Shield Zone where large fire-regeneration patterns contribute to the heterogeneous boreal landscape. Intercomparisons with land cover classifications derived from 30-m Landsat Thematic Mapper (TM) data provided important insights into the relative accuracy of the 1 km AVHRR land cover classification. Primarily due to the multitemporal NDVI image compositing process, the 1 km AVHRR land cover classes have an effective spatial resolution in the 3-4 km range; therefore fens, bogs, small water bodies, and small patches of dry jack pine cannot be resolved within

  17. Quantifying spatial variability of depth of peat burn in wetlands in relation to antecedent characteristics using field data, multi-temporal and multi-spectral LiDAR

    Science.gov (United States)

    Chasmer, L.; Flade, L.; Virk, R.; Montgomery, J. S.; Hopkinson, C.; Thompson, D. K.; Petrone, R. M.; Devito, K.

    2017-12-01

    Landscape changes in the hydrological characteristics of wetlands in some parts of the Boreal region of Canada are occurring as a result of climate-induced feedbacks and anthropogenic disturbance. Wetlands are largely resilient to wildfire, however, natural, climatic and anthropogenic disturbances can change surface water regimes and predispose wetlands to greater depth of peat burn. Over broad areas, peat loss contributes to significant pollution emissions, which can affect community health. In this study, we a) quantify depth of peat burn and relationships to antecedent conditions (species type, topography, surficial geology) within three classified wetlands found in the Boreal Plains ecoregion of western Canada; and b) examine the impacts of wildfire on post-fire ground surface energy balance to determine how peat loss might affect local hydro-climatology and surface water feedbacks. High-resolution optical imagery, pre- and post-burn multi-spectral Light Detection And Ranging (LiDAR), airborne thermal infrared imagery, and field validation data products are integrated to identify multiple complex interactions within the study wetlands. LiDAR-derived depth of peat burn is within 1 cm (average) compared with measured (RMSE = 9 cm over the control surface), demonstrating the utility of LiDAR with high point return density. Depth of burn also correlates strongly with variations in Normalised Burn Ratio (NBR) determined for ground surfaces only. Antecedent conditions including topographic position, soil moisture, soil type and wetland species also have complex interactions with depth of peat loss within wetlands observed in other studies. However, while field measurements are important for validation and understanding eco-hydrological processes, results from remote sensing are spatially continuous. Temporal LiDAR data illustrate the full range of variability in depth of burn and wetland characteristics following fire. Finally, measurements of instantaneous surface

  18. Mine-associated wetlands as avian habitat

    International Nuclear Information System (INIS)

    Horstman, A.J.; Nawrot, J.R.; Woolf, A.

    1998-01-01

    Surveys for interior wetland birds at mine-associated emergent wetlands on coal surface mines in southern Illinois detected one state threatened and two state endangered species. Breeding by least bittern (Ixobrychus exilis) and common moorhen (Gallinula chloropus) was confirmed. Regional assessment of potential wetland bird habitat south of Illinois Interstate 64 identified a total of 8,109 ha of emergent stable water wetlands; 10% were associated with mining. Mine-associated wetlands with persistent hydrology and large expanses of emergent vegetation provide habitat that could potentially compensate for loss of natural wetlands in Illinois

  19. 78 FR 68719 - Floodplain Management and Protection of Wetlands

    Science.gov (United States)

    2013-11-15

    ... of wetlands in Sec. 55.2(b)(11) to cover manmade wetlands in order to ensure that wetlands built for...] RIN 2501-AD51 Floodplain Management and Protection of Wetlands AGENCY: Office of the Secretary, HUD... wetlands and floodplains. With respect to wetlands, the rule codifies existing procedures for Executive...

  20. Wetland Hydrology | Science Inventory | US EPA

    Science.gov (United States)

    This chapter discusses the state of the science in wetland hydrology by touching upon the major hydraulic and hydrologic processes in these complex ecosystems, their measurement/estimation techniques, and modeling methods. It starts with the definition of wetlands, their benefits and types, and explains the role and importance of hydrology on wetland functioning. The chapter continues with the description of wetland hydrologic terms and related estimation and modeling techniques. The chapter provides a quick but valuable information regarding hydraulics of surface and subsurface flow, groundwater seepage/discharge, and modeling groundwater/surface water interactions in wetlands. Because of the aggregated effects of the wetlands at larger scales and their ecosystem services, wetland hydrology at the watershed scale is also discussed in which we elaborate on the proficiencies of some of the well-known watershed models in modeling wetland hydrology. This chapter can serve as a useful reference for eco-hydrologists, wetland researchers and decision makers as well as watershed hydrology modelers. In this chapter, the importance of hydrology for wetlands and their functional role are discussed. Wetland hydrologic terms and the major components of water budget in wetlands and how they can be estimated/modeled are also presented. Although this chapter does not provide a comprehensive coverage of wetland hydrology, it provides a quick understanding of the basic co

  1. Carbon in boreal coniferous forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Westman, C.J.; Ilvesniemi, H.; Liski, J.; Mecke, M. [Helsinki Univ. (Finland). Dept. of Forest Ecology; Fritze, H.; Helmisaari, H.S.; Pietikaeinen, J.; Smolander, A. [Finnish Forest Research Inst., Vantaa (Finland)

    1996-12-31

    The working hypothesis of the research was that the soil of boreal forests is a large carbon store and the amount of C is still increasing in young soils, like in the forest soils of Finland, which makes these soils important sinks for atmospheric CO{sub 2}. Since the processes defining the soil C balance, primary production of plants and decomposition, are dependent on environmental factors and site properties, it was assumed that the organic carbon pool in the soil is also dependent on the same factors. The soil C store is therefore likely to change in response to climatic warming. The aim of this research was to estimate the C balance of forest soil in Finland and predict changes in the balance in response to changes in climatic conditions. To achieve the aim (1) intensive empirical experimentation on the density of C in different pools in the soil and on fluxes between the pools was done was done, (2) the effect of site fertility and climate on the amount and properties of organic C in forest soil was investigated and (3) dynamic modelling for investigating dynamics of the soil C storage was used

  2. Carbon in boreal coniferous forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Westman, C J; Ilvesniemi, H; Liski, J; Mecke, M [Helsinki Univ. (Finland). Dept. of Forest Ecology; Fritze, H; Helmisaari, H S; Pietikaeinen, J; Smolander, A [Finnish Forest Research Inst., Vantaa (Finland)

    1997-12-31

    The working hypothesis of the research was that the soil of boreal forests is a large carbon store and the amount of C is still increasing in young soils, like in the forest soils of Finland, which makes these soils important sinks for atmospheric CO{sub 2}. Since the processes defining the soil C balance, primary production of plants and decomposition, are dependent on environmental factors and site properties, it was assumed that the organic carbon pool in the soil is also dependent on the same factors. The soil C store is therefore likely to change in response to climatic warming. The aim of this research was to estimate the C balance of forest soil in Finland and predict changes in the balance in response to changes in climatic conditions. To achieve the aim (1) intensive empirical experimentation on the density of C in different pools in the soil and on fluxes between the pools was done was done, (2) the effect of site fertility and climate on the amount and properties of organic C in forest soil was investigated and (3) dynamic modelling for investigating dynamics of the soil C storage was used

  3. Annual cycle of methane emission from a boreal fen measured by the eddy covariance technique

    International Nuclear Information System (INIS)

    Rinne, Janne.; Pihlatie, Mari; Haapanala, Sami; Vesala, Timo; Riutta, Terhi; Tuittila, Eeva-Stiina; Aurela, Mika; Tuovinen, Juha-Pekka

    2007-01-01

    The northern wetlands are one of the major sources of methane into the atmosphere. We measured annual methane emission from a boreal minerotrophic fen, Siikaneva, by the eddy covariance method. The average wintertime emissions were below 1 mg/m 2 /h, and the summertime emissions about 3.5 mg/m 2 /h. The water table depth did have any clear effect on methane emissions. During most of the year the emission depended on the temperature of peat below the water table. However, during the high and late summer the emission was independent on peat temperature as well. No diurnal cycle of methane flux was found. The total annual emission from the Siikaneva site was 12.6 g/m 2 . The emissions of the snow free period contributed 91% to the annual emission. The emission pulse during the snow melting period was clearly detectable but of minor importance adding only less than 3% to the annual emission. Over 20% of the carbon assimilated during the year as carbon dioxide was emitted as methane. Thus methane emission is an important component of the carbon balance of the Siikaneva fen. This indicates need of taking methane into account when studying carbon balances of northern fen ecosystems

  4. Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia

    International Nuclear Information System (INIS)

    Peregon, A; Uchida, M; Yamagata, Y

    2009-01-01

    Although recent studies have recognized Northern Eurasian ecosystems as an important carbon reservoir, little is known about the forest-peatland interactions in a boreal environment induced by ongoing climatic changes. This study focuses on the evaluation of both the long-term and contemporary trends of land-cover changes and rates of lateral extension of peat-accumulating wetlands toward the adjacent forests, estimated at the southern climatic range of the Sphagnum-dominated mires in Western Siberia. We used the radiocarbon dates and stratigraphy of peat sediments from seven peat cores, analyzed at two types of forest-peatland ecotones, which are located close to each other but differ by topography and composition of their plant communities. The rate of lateral extension was found in a wide range varying from 2.3 to 791.7 cm yr -1 . It was observed to be rapid during the initial stage of mire development, but to have slowed down over the last 2000-3000 yr. Our results, therefore, strongly contradict the concept of progressive peat accumulation throughout the late Holocene and contribute to our knowledge about ongoing land-cover change in the natural ecosystems of the Northern hemisphere.

  5. Lateral extension in Sphagnum mires along the southern margin of the boreal region, Western Siberia

    Energy Technology Data Exchange (ETDEWEB)

    Peregon, A; Uchida, M; Yamagata, Y, E-mail: anna.peregon@nies.go.j [Center for Global Environmental Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2009-10-15

    Although recent studies have recognized Northern Eurasian ecosystems as an important carbon reservoir, little is known about the forest-peatland interactions in a boreal environment induced by ongoing climatic changes. This study focuses on the evaluation of both the long-term and contemporary trends of land-cover changes and rates of lateral extension of peat-accumulating wetlands toward the adjacent forests, estimated at the southern climatic range of the Sphagnum-dominated mires in Western Siberia. We used the radiocarbon dates and stratigraphy of peat sediments from seven peat cores, analyzed at two types of forest-peatland ecotones, which are located close to each other but differ by topography and composition of their plant communities. The rate of lateral extension was found in a wide range varying from 2.3 to 791.7 cm yr{sup -1}. It was observed to be rapid during the initial stage of mire development, but to have slowed down over the last 2000-3000 yr. Our results, therefore, strongly contradict the concept of progressive peat accumulation throughout the late Holocene and contribute to our knowledge about ongoing land-cover change in the natural ecosystems of the Northern hemisphere.

  6. CARVE Measurements of Atmospheric Methane Concentrations and Emissions in Arctic and Boreal Alaska

    Science.gov (United States)

    Miller, C. E.; Miller, J. B.; Chang, R. Y.; Sweeney, C.; Karion, A.; Wofsy, S. C.; Henderson, J.; Eluszkiewicz, J.; Mountain, M.; Oechel, W. C.

    2013-12-01

    The Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) is a NASA Earth Ventures (EV-1) investigation designed to quantify correlations between atmospheric and surface state variables for the Alaskan terrestrial ecosystems through intensive seasonal aircraft campaigns, ground-based observations, and analysis sustained over a 5-year mission. CARVE bridges critical gaps in our knowledge and understanding of Arctic ecosystems, linkages between the Arctic hydrologic and terrestrial carbon cycles, and the feedbacks from fires and thawing permafrost. We present CARVE airborne measurements of spatial and temporal patterns in atmospheric CH4 concentrations and estimated surface-atmosphere emissions for Arctic and Boreal Alaska. Continuous in situ CH4, CO2 and CO data are supplemented by periodic whole air flask samples from which 13CH4 and non-methane hydrocarbons are used to assess the relative contributions of wetlands, fossil fuel combustion, and oil and gas production to the observed CH4 signals. The CARVE project has also initiated monthly 14CH4 sampling at Barrow, AK (BRW) and the CARVE Tower in Fox, AK (CRV) to evaluate seasonal changes in the fraction of old carbon being mobilized via methanogenesis.

  7. Michigan Wetlands: Yours To Protect. A Citizen's Guide to Local Involvement in Wetland Protection. Second Edition.

    Science.gov (United States)

    Cwikiel, Wilfred

    This guidebook is designed to assist concerned Michigan citizens, local governments, conservation organizations, landowners, and others in their efforts to initiate wetlands protection activities. Chapter 1 focuses on wetland functions, values, losses, and the urgent need to protect wetland resources. Chapter 2 discusses wetland identification and…

  8. Designated Wetlands and Setback Distances in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This GIS layer depicts wetlands designated for protection in the state of Iowa. Designated wetland is defined in Iowa Code subsection 459.102(21) as follows: 21....

  9. Industry and forest wetlands: Cooperative research initiatives

    International Nuclear Information System (INIS)

    Shepard, J.P.; Lucier, A.A.; Haines, L.W.

    1993-01-01

    In 1989 the forest products industry responded to a challenge of the National Wetlands Policy Forum to initiate a cooperative research program on forest wetlands management organized through the National Council of the Paper Industry for Air and Stream Improvement (NCASI). The objective is to determine how forest landowners can manage wetlands for timber production while protecting other wetland functions such as flood storage, water purification, and food chain/wildlife habitat support. Studies supported by the NCASI in 9 states are summarized. Technical support on wetland regulatory issues to member companies is part of the research program. Since guidelines for recognizing wetlands for regulatory proposed have changed frequently, the NCASI has recommend an explicit link between wetland delineation and a classification system that considers difference among wetland types in vegetation, soils, hydrology, appearance, landscape position, and other factors. 16 refs

  10. 40 CFR 230.41 - Wetlands.

    Science.gov (United States)

    2010-07-01

    ... through secondary impacts. Discharging fill material in wetlands as part of municipal, industrial or recreational development may modify the capacity of wetlands to retain and store floodwaters and to serve as a...

  11. The changing effects of Alaska's boreal forest on the climate system

    Science.gov (United States)

    E.S. Euskirchen; A.D. McGuire; F.S. Chapin; T.S. Rupp

    2010-01-01

    In the boreal forests of Alaska, recent changes in climate have influenced the exchange of trace gases, water, and energy between these forests and the atmosphere. These changes in the structure and function of boreal forests can then feed back to impact regional and global climates. We examine the type and magnitude of the climate feedbacks from boreal forests in...

  12. Population structure and genetic diversity in North American Hedysarum boreale Nutt.

    Science.gov (United States)

    Bradley S. Bushman; Steven R. Larson; Michael D. Peel; Michael E. Pfrender

    2007-01-01

    Hedysarum boreale Nutt. is a perennial legume native to western North America, with robust foliage in the late spring season. Due to its wide native range, forage value, and N2 fixation, H. boreale is of interest for rangeland revegetation and production. Seed cost is a major obstacle for utilization of H. boreale, primarily due to seed shattering and unreliable seed...

  13. Dramatic decline of the bearded reedling, Panurus biarmicus, in Spanish Mediterranean wetlands

    Directory of Open Access Journals (Sweden)

    Belenguer Barrionuevo, R.

    2016-02-01

    Full Text Available The apparent stability of the bearded reedling in Spanish inland wetlands contrasts with its threatened status in Spanish coastal wetlands. The species has already disappeared from some coastal areas in Catalonia and its situation is critical in the region of Valencia. In 2013 we studied the breeding populations in three wetlands in Valencia using two methods: census by exhaustive search of individuals (territory mapping and distance sampling using line transects. We estimated the trend of these populations from data obtained in previous censuses (2005 and 2006, and assessed their viability in the medium and short term using count–based population viability analysis (PVA. Results were alarming in the three studied wetlands, especially in the Albufera de Valencia, where only one breeding pair was found. The percentage of decrease of estimated pairs was similar in all wetlands: ca. 90% between 2005 and 2013. Results from the PVAs predicted a 90% probability of reaching the quasi–extinction threshold before 2024 or 2028 for the largest population of bearded reedling in the Valencia region, El Hondo, while for the Santa Pola population this threshold would be reached before 2016 or 2017. The parallel trend and generalized decline in the Spanish coastal wetlands suggests that these Mediterranean wetlands probably share some specific factors that have adversely affected its populations. Given that all these natural spaces are surrounded by intensively irrigated crops that are subjected to the intense use of pesticides, we hypothesize that these products could have had a detrimental effect on the bearded reedling. This hypothesis is supported by the fact that the healthiest populations are situated in Iberian inland wetlands that are surrounded by dry crops, where the use of pesticides is less intense. We propose cataloguing the species as Endangered at regional level.

  14. How critical are wetlands for provisioning ecosystem services in East Africa?

    Science.gov (United States)

    Gettel, G. M.; van Dam, A. A.; Hes, E.; Irvine, K.

    2017-12-01

    East Africa is rapidly losing wetlands as the region intensifies agricultural development in rice, sugarcane, and aquaculture production. However, these wetlands are critically important to the livelihoods of region's most vulnerable smallholders, who depend on them for fisheries, water abstraction, and dry-season subsistence agriculture, including livestock grazing. At the same time, wetlands are used for their regulating services, including for water purification of waste-water in some of the region's largest capital cities (e.g. Kampala and Kigali). They also store an enormous, but poorly quantified amount of below-ground carbon and prevent excess nitrogen inputs to sensitive downstream ecosystems. Our research in papyrus wetlands in the Lake Victoria Basin aims to quantify trade-offs in provisioning and regulating services and link these services to socio-economic conditions of the smallholders. We present a framework for evaluating these trade-offs, which can ultimately be used for more informed management decisions for sustainable wetland management and for evaluating impacts on livelihoods. Specifically, we have found that papyrus wetlands can maintain many of their regulating functions, including high plant productivity and denitrification rates when native vegetation is allowed to grow back during wet-seasons, while during dry seasons they can be developed for economically important agricultural activities, including livestock grazing and crop production. This shows the possibility to include wetlands in management plans aimed to increase agricultural production without jeopardizing their ability to maintain other important regulating services. These patterns highlight the need to evaluate the regional importance of these wetlands for both food production and regulating services.

  15. Dramatic decline of the bearded reedling, Panurus biarmicus, in Spanish Mediterranean wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Belenguer Barrionuevo, R.; Lopez-Iborra, G. M.; Dies, J.I.; Castany i Alvaro, J.

    2016-07-01

    The apparent stability of the bearded reedling in Spanish inland wetlands contrasts with its threatened status in Spanish coastal wetlands. The species has already disappeared from some coastal areas in Catalonia and its situation is critical in the region of Valencia. In 2013 we studied the breeding populations in three wetlands in Valencia using two methods: census by exhaustive search of individuals (territory mapping) and distance sampling using line transects. We estimated the trend of these populations from data obtained in previous censuses (2005 and 2006), and assessed their viability in the medium and short term using count–based population viability analysis (PVA). Results were alarming in the three studied wetlands, especially in the Albufera de Valencia, where only one breeding pair was found. The percentage of decrease of estimated pairs was similar in all wetlands: ca. 90% between 2005 and 2013. Results from the PVAs predicted a 90% probability of reaching the quasi–extinction threshold before 2024 or 2028 for the largest population of bearded reedling in the Valencia region, El Hondo, while for the Santa Pola population this threshold would be reached before 2016 or 2017. The parallel trend and generalized decline in the Spanish coastal wetlands suggests that these Mediterranean wetlands probably share some specific factors that have adversely affected its populations. Given that all these natural spaces are surrounded by intensively irrigated crops that are subjected to the intense use of pesticides, we hypothesize that these products could have had a detrimental effect on the bearded reedling. This hypothesis is supported by the fact that the healthiest populations are situated in Iberian inland wetlands that are surrounded by dry crops, where the use of pesticides is less intense. We propose cataloguing the species as Endangered at regional level. (Author)

  16. Water, Energy and Carbon Balance Research: Recovery Trajectories For Oil Sands Reclamation and Disturbed Watersheds in the Western Boreal Forest

    Science.gov (United States)

    Petrone, R. M.; Carey, S. K.

    2014-12-01

    The Oil Sand Region (OSR) of North-Central Alberta exists within the sub-humid Boreal Plains (BP) ecozone, with a slight long-term moisture deficit regime. Despite this deficit, the BP is comprised of productive wetland and mixed wood (aspen and conifer dominated) forests. Reclamation activities are now underway at a large number of surface mining operations in the OSR, where target ecosystems are identified, soil prescriptions placed and commercial forest species planted. Some watersheds have been created that now contain wetlands. However, recent work in the BP suggests that over time wetlands supply moisture for the productivity of upland forests. Thus, water use of reclaimed forests is going to be critical in determining the sustainability of these systems and adjacent wetlands, and whether in time, either will achieve some form of equivalent capability that will allow for certification by regulators. A critical component in the success of any reclamation is that sufficient water is available to support target ecosystems through the course of natural climate cycles in the region. Water Use Efficiency (WUE), which links photosynthesis (GEP) with water use (Evapotranspiration (ET)), provides a useful metric to compare ecosystems and evaluate their utilization of resources. In this study, 41 site years of total growing season water and carbon flux data over 8 sites (4 reclamation, 4 regeneration) were evaluated using eddy covariance micrometeorological towers. WUE shows clear discrimination among ecosystem types as aspen stands assimilate more carbon per unit weight of water than conifers. WUEs also change with time as ecosystems become more effective at transpiring water through plant pathways compared with bare-soil evaporation, which allows an assessment of ability to limit water loss without carbon uptake. In addition, clonal rooting systems allow aspen forests to recover quicker after disturbance than reclamation sites in terms of their WUE. For reclamation

  17. 40 CFR 257.9 - Wetlands.

    Science.gov (United States)

    2010-07-01

    ... not locate such units in wetlands, unless the owner or operator can make the following demonstrations... actions (e.g., restoration of existing degraded wetlands or creation of man-made wetlands); and (5) Sufficient information is available to make a reasonable determination with respect to these demonstrations...

  18. North Dakota Wetlands Discovery Guide. Photocopy Booklet.

    Science.gov (United States)

    Dietz, Nancy J., Ed.; And Others

    This booklet contains games and activities that can be photocopied for classroom use. Activities include Wetland Terminology, Putting on the Map, Erosional Forces, Water in...Water out, Who Lives Here?, Wetlands in Disguise, Dichotomous Plant Game, Algae Survey, Conducting an Algal Survey, Water Quality Indicators Guide, Farming Wetlands, Wetlands…

  19. Description of the Wetlands Research Programme

    CSIR Research Space (South Africa)

    Walmsley, RD

    1988-01-01

    Full Text Available This report presents a rationale to the development of a multidisciplinary South African Wetland Research Programme. A definition of what is meant by the term wetland is given along with a general description of what types of wetland occur in South...

  20. Aerosol volatility in a boreal forest environment

    Science.gov (United States)

    Häkkinen, S. A. K.; ńijälä, M.; Lehtipalo, K.; Junninen, H.; Virkkula, A.; Worsnop, D. R.; Kulmala, M.; Petäjä, T.; Riipinen, I.

    2012-04-01

    Climate and health effects of atmospheric aerosols are determined by their properties such as their chemical composition. Aerosol chemical composition can be studied indirectly by measuring volatility of aerosol particles. The volatility of submicron aerosol particles (20-500 nm) was studied in a boreal forest site at SMEAR II (Station for Measuring Ecosystem-Atmosphere Relations II) station (Vesala et al., 1998) in Hyytiälä, Finland, during 01/2008-05/2010. The instrument used for the measurements was VDMPS (Volatility Differential Mobility Particle Sizer), which consists of two separate instruments: DMPS (Differential Mobility Particle Sizer, Aalto et al., 2001) and TD (Thermodenuder, Wehner et al., 2002). Aerosol evaporation was examined by heating the aerosol and comparing the total aerosol mass before and after heating. In the VDMPS system ambient aerosol sample was heated up to temperatures ranging from 80 °C to 280 °C. The higher the heating temperature was the more aerosol material was evaporated. There was a non-volatile residual present in aerosol particles when heated up to 280 °C. This residual explained (20±8)% of the total aerosol mass. Aerosol non-volatile mass fraction was highest during winter and smallest during summer months. The role of black carbon in the observed non-volatile residual was determined. Black carbon explained 40 to 90% of the non-volatile mass. Especially during colder seasons noticeable amount of non-volatile material, something else than black carbon, was observed. According to Kalberer et al. (2004) some atmospheric organic species can form polymers that have high evaporation temperatures. Also low-volatile organic salts may contribute to the non-volatile aerosol (Smith et al., 2010). Aerosol mass composition measured directly with AMS (Aerosol Mass Spectrometer, Jayne et al., 2000) was analyzed in order to examine the properties of the non-volatile material (other than black carbon). The AMS measurements were performed

  1. Use of ground-based radiometers for L-Band Freeze/Thaw retrieval in a boreal forest site

    Science.gov (United States)

    Roy, A.; Sonnentag, O.; Derksen, C.; Toose, P.; Pappas, C.; Mavrovic, A.; El Amine, M.; Royer, A.; Berg, A. A.; Rowlandson, T. L.; Barr, A.; Black, T. A.

    2017-12-01

    The boreal forest is the second largest land biome in the world and thus plays a major role in the global and regional climate systems. The extent, timing and duration of the seasonal freeze/thaw (F/T) state influences vegetation developmental stages (phenology) and, consequently, constitutes an important control on how boreal forest ecosystems exchange carbon, water and energy with the atmosphere. Recently, new L-Band satellite-derived F/T information has become available. However, disentangling the seasonally differing contributions from forest overstory and understory vegetation, and the ground surface to the satellite signal remains challenging. Here we present results from an ongoing campaign with two L-Band surface-based radiometers (SBR) installed on a micrometeorological tower at the Southern Old Black Spruce site (53.99°N / 105.12°W) in central Saskatchewan. One radiometer unit is installed on top of the tower viewing the multi-layer vegetation canopy from above. A second radiometer unit is installed within the multi-layer canopy, viewing the understory and the ground surface only. The objectives of our study are to (i) disentangle the L-Band F/T signal contribution of boreal forest overstory from the combined understory and ground surface contribution, and (ii) link the L-Band F/T signal to related boreal forest structural and functional characteristics. Analysis of these radiometer measurements made from September to November 2016 shows that when the ground surface is thawed, the main contributor to both radiometer signals is soil moisture. The Pearson correlation coefficient between brightness temperature (TB) at vertical polarization (V-pol) and soil permittivity is 0.79 for the radiometer above the canopy and 0.74 for the radiometer below the canopy. Under cold conditions when the soil was thawed (snow insulation) and the trees were frozen (below 0°C), TB at V-pol is negatively correlated with tree permittivity. The freezing tree contribution to

  2. RS- and GIS-based study on landscape pattern change in the Poyang Lake wetland area, China

    Science.gov (United States)

    Chen, Xiaoling; Li, Hui; Bao, Shuming; Wu, Zhongyi; Fu, Weijuan; Cai, Xiaobin; Zhao, Hongmei; Guo, Peng

    2006-10-01

    As wetland has been recognized as an important component of ecosystem, it is received ever-increasing attention worldwide. Poyang Lake wetlands, the international wetlands and the largest bird habitat in Asia, play an important role in biodiversity and ecologic protection. However, with the rapid economic growth and urbanization, landscape patterns in the wetlands have dramatically changed in the past three decades. To better understand the wetland landscape dynamics, remote sensing, geographic information system technologies, and the FRAGSTATS landscape analysis program were used to measure landscape patterns. Statistical approach was employed to illustrate the driving forces. In this study, Landsat images (TM and ETM+) from 1989 and 2000 were acquired for the wetland area. The landscapes in the wetland area were classified as agricultural land, urban, wetland, forest, grassland, unused land, and water body using a combination of supervised and unsupervised classification techniques integrated with Digital Elevation Model (DEM). Landscape indices, which are popular for the quantitative analysis of landscape pattern, were then employed to analyze the landscape pattern changes between the two dates in a GIS. From this analysis an understanding of the spatial-temporal patterns of landscape evolution was generated. The results show that wetland area was reduced while fragmentation was increased over the study period. Further investigation was made to examine the relationship between landscape metrics and some other parameters such as urbanization to address the driving forces for those changes. The urban was chosen as center to conduct buffer analysis in a GIS to study the impact of human-induced activities on landscape pattern dynamics. It was found that the selected parameters were significantly correlated with the landscape metrics, which may well indicate the impact of human-induced activities on the wetland landscape pattern dynamics and account for the driving

  3. The impact of boreal forest fire on climate warming

    Science.gov (United States)

    Randerson, J.T.; Liu, H.; Flanner, M.G.; Chambers, S.D.; Jin, Y.; Hess, P.G.; Pfister, G.; Mack, M.C.; Treseder, K.K.; Welp, L.R.; Chapin, F.S.; Harden, J.W.; Goulden, M.L.; Lyons, E.; Neff, J.C.; Schuur, E.A.G.; Zender, C.S.

    2006-01-01

    We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 ?? 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over an 80-year fire cycle (-2.3 ?? 2.2 Watts per square meter) because multidecadal increases in surface albedo had a larger impact than fire-emitted greenhouse gases. This result implies that future increases in boreal fire may not accelerate climate warming.

  4. Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem

    International Nuclear Information System (INIS)

    Mazurek, M.A.; Cofer, W.R. III; Levine, J.S.

    1991-01-01

    Smoke aerosol and background aerosol particles were collected from the controlled burning of boreal forest where vegetation species and relative mass distributions are known. Chemical mass balances were constructed for the total mass of carbonaceous aerosol particles emitted during the prescribed burn. In addition, a carbonaceous species inventory was developed for aerosol particles presnt under background, smoldering, and full-fire conditions; the production of organic carbon and elemental carbon particles is noted for these two fire regimes. Distributions of the solvent-soluble organic components of the sampled aerosols were generated to identify molecular properties that can be traced to unburned and pyrolyzed materials present in the boreal forest fuels

  5. The impact of boreal forest fire on climate warming.

    Science.gov (United States)

    Randerson, J T; Liu, H; Flanner, M G; Chambers, S D; Jin, Y; Hess, P G; Pfister, G; Mack, M C; Treseder, K K; Welp, L R; Chapin, F S; Harden, J W; Goulden, M L; Lyons, E; Neff, J C; Schuur, E A G; Zender, C S

    2006-11-17

    We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 +/- 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over an 80-year fire cycle (-2.3 +/- 2.2 Watts per square meter) because multidecadal increases in surface albedo had a larger impact than fire-emitted greenhouse gases. This result implies that future increases in boreal fire may not accelerate climate warming.

  6. Phytoremediation of arsenic in submerged soil by wetland plants.

    Science.gov (United States)

    Jomjun, Nateewattana; Siripen, Trichaiyaporn; Maliwan, Saeouy; Jintapat, Nateewattana; Prasak, Thavornyutikarn; Somporn, Choonluchanon; Petch, Pengchai

    2011-01-01

    Wetland aquatic plants including Canna glauca L., Colocasia esculenta L. Schott, Cyperus papyrus L. and Typha angustifolia L. were used in the phytoremediation of submerged soil polluted by arsenic (As). Cyperus papyrus L. was noticed as the largest biomass producer which has arsenic accumulation capacity of 130-172 mg As/kg plant. In terms of arsenic removal rate, however, Colocasia esculenta L. was recognized as the largest and fastest arsenic remover in this study. Its arsenic removal rate was 68 mg As/m2/day while those rates of Canna glauca L., Cyperus papyrus L. and Typha angustifolia L. were 61 mg As/m2/day, 56 mg As/m2/day, and 56 mg As/m2/day, respectively. Although the 4 aquatic plants were inferior in arsenic accumulation, their high arsenic removal rates were observed. Phytostabilization should be probable for the application of these plants.

  7. Examining the role of management practices and landscape context on methane dynamics from subtropical wetlands

    Science.gov (United States)

    DeLucia, Nicholas; Gomez-Casanovas, Nuria; Boughton, Elizabeth; Yang, Wendy; Bernacchi, Carl

    2017-04-01

    Globally, wetlands are the largest natural source of atmospheric CH4, an important GHG with a warming potential 25 times stronger than CO2 (IPCC 2008; Forster et al. 2013). In sub-tropical climates where precipitation and temperatures are high, land-use change and agricultural management practices often intersect with extensive wetland systems. The Everglades watershed in South Central Florida represents a large areal extent characterized by a high density of wetlands nested within agricultural fields dominated to a large extent by grazed rangelands. Soils are primarily Spodosols and Histosols and sustain a relatively high water table, even during the dry season. Here, rangelands dominated by native vegetation have been converted to agronomically 'improved pastures' suitable for large scale cattle ranching through high intensive agronomic practices including vegetation homogenization, fertilization and drainage. In this study we first tested the hypothesis that CH4 fluxes from small ephemeral wetlands are indirectly influenced by management practices associated with the agricultural fields in which they are nested. We found that wetlands embedded in agronomically 'Improved' pastures exhibit significantly higher CH4 fluxes compared to wetlands embedded in 'Native' pastures. Next, we sought to determine the mechanisms by which the surrounding landscapes affect methane production processes to better predict how expanding or intensifying agriculture will affect wetland methane fluxes. We focus on substrate supply in the form of substrate quality and quantity available to methanogens as it is a principle control over CH4 production and susceptible to ecosystem perturbations. This research was conducted at the McArthur Agro-Ecology Research Center on Buck Island Ranch, Lake Placid, Florida. Wetland CH4 fluxes were measured using static canopy chambers coupled with infrared gas analysis of CH4, CO2 and water vapor. Additionally, soil manipulation incubations were prepared

  8. Lake Superior Coastal Wetland Fish Assemblages and ...

    Science.gov (United States)

    The role of the coastal margin and the watershed context in defining the ecology of even very large lakes is increasingly being recognized and examined. Coastal wetlands are both important contributors to the biodiversity and productivity of large lakes and important mediators of the lake-basin connection. We explored wetland-watershed connections and their relationship to wetland function and condition using data collected from 37 Lake Superior wetlands spanning a substantial geographic and geomorphic gradient. While none of these wetlands are particularly disturbed, there were nevertheless clear relationships between watershed landuse and wetland habitat and biota, and these varied consistently across wetland type categories that reflected the strength of connection to the watershed. For example, water clarity and vegetation structure complexity declined with decreasing percent natural land cover, and these effects were strongest in riverine wetlands (having generally large watersheds and tributary-dominated hydrology) and weakest in lagoon wetlands (having generally small watersheds and lake-dominate hydrology). Fish abundance and species richness both increased with decreasing percent natural land cover while species diversity decreased, and again the effect was strongest in riverine wetlands. Lagoonal wetlands, which lack any substantial tributary, consistently harbored the fewest species of fish and a composition different from the more watershed-lin

  9. The nitrogen abatement cost in wetlands

    International Nuclear Information System (INIS)

    Bystroem, Olof

    1998-01-01

    The costs of abating agricultural nitrogen pollution in wetlands are estimated. By linking costs for construction of wetlands to the denitrification capacity of wetlands, an abatement cost function can be formed. A construction-cost function and a denitrification function for wetlands is estimated empirically. This paper establishes a link between abatement costs and the nitrogen load on wetlands. Since abatement costs fluctuate with nitrogen load, ignoring this link results in incorrect estimates of abatement costs. The results demonstrate that wetlands have the capacity to provide low cost abatement of nitrogen compounds in runoff. For the Kattegatt region in Sweden, marginal abatement costs for wetlands are shown to be lower than costs of land use changing measures, such as extended land under fallow or cultivation of fuel woods, but higher than the marginal costs of reducing nitrogen fertilizer

  10. Guaranteeing uptime at worl's largest particle physics lab

    CERN Multimedia

    Brodkin, Jon

    2007-01-01

    "As the European agency CERN was gearing up to build the world's largest particle accelerator, officials there knew they could not afford to have problems in their technical infrastructure cause any downtime." (1 page)

  11. Global carbon sequestration in tidal, saline wetland soils

    Science.gov (United States)

    Chmura, G.L.; Anisfeld, S.C.; Cahoon, D.R.; Lynch, J.C.

    2003-01-01

    Wetlands represent the largest component of the terrestrial biological carbon pool and thus play an important role in global carbon cycles. Most global carbon budgets, however, have focused on dry land ecosystems that extend over large areas and have not accounted for the many small, scattered carbon-storing ecosystems such as tidal saline wetlands. We compiled data for 154 sites in mangroves and salt marshes from the western and eastern Atlantic and Pacific coasts, as well as the Indian Ocean, Mediterranean Ocean, and Gulf of Mexico. The set of sites spans a latitudinal range from 22.4??S in the Indian Ocean to 55.5??N in the northeastern Atlantic. The average soil carbon density of mangrove swamps (0.055 ?? 0.004 g cm-3) is significantly higher than the salt marsh average (0.039 ?? 0.003 g cm-3). Soil carbon density in mangrove swamps and Spartina patens marshes declines with increasing average annual temperature, probably due to increased decay rates at higher temperatures. In contrast, carbon sequestration rates were not significantly different between mangrove swamps and salt marshes. Variability in sediment accumulation rates within marshes is a major control of carbon sequestration rates masking any relationship with climatic parameters. Globally, these combined wetlands store at least 44.6 Tg C yr-1 and probably more, as detailed areal inventories are not available for salt marshes in China and South America. Much attention has been given to the role of freshwater wetlands, particularly northern peatlands, as carbon sinks. In contrast to peatlands, salt marshes and mangroves release negligible amounts of greenhouse gases and store more carbon per unit area. Copyright 2003 by the American Geophysical Union.

  12. Biodiversity impacts from salinity increase in a coastal wetland.

    Science.gov (United States)

    Amores, Maria José; Verones, Francesca; Raptis, Catherine; Juraske, Ronnie; Pfister, Stephan; Stoessel, Franziska; Antón, Assumpció; Castells, Francesc; Hellweg, Stefanie

    2013-06-18

    A Life Cycle Impact Assessment method was developed to evaluate the environmental impact associated with salinity on biodiversity in a Spanish coastal wetland. The developed characterization factor consists of a fate and an effect factor and equals 3.16 × 10(-1) ± 1.84 × 10(-1) PAF · m(3) · yr · m(-3) (PAF: Potentially Affected Fraction of species) indicating a "potential loss of 0.32 m(3) ecosystem" for a water consumption rate of 1 m(3) · yr(-1). As a result of groundwater consumption with a rate of 1 m(3) · yr(-1), the PAF in the lost cubic meter of ecosystem equals 0.05, which has been proposed as the maximum tolerable effect to keep the ecosystem intact. The fate factor was calculated from seasonal water balances of the wetland Albufera de Adra. The effect factor was obtained from the fitted curve of the potentially affected fraction of native wetland species due to salinity and can be applied to other wetlands with similar species composition. In order to test the applicability of the characterization factor, an assessment of water consumption of greenhouse crops in the area was conducted as a case study. Results converted into ecosystem quality damage using the ReCiPe method were compared to other categories. While tomatoes are responsible for up to 30% of the impact of increased salinity due to water consumption on ecosystem quality in the studied area, melons have the largest impact per tonne produced.

  13. Effects of warming on the structure and function of a boreal black spruce forest

    Energy Technology Data Exchange (ETDEWEB)

    Stith T.Gower

    2010-03-03

    A strong argument can be made that there is a greater need to study the effect of warming on boreal forests more than on any other terrestrial biome. Boreal forests, the second largest forest biome, are predicted to experience the greatest warming of any forest biome in the world, but a process-based understanding of how warming will affect the structure and function of this economically and ecologically important forest biome is lacking. The effects of warming on species composition, canopy structure and biogeochemical cycles are likely to be complex; elucidating the underlying mechanisms will require long-term whole-ecosystem manipulation to capture all the complex feedbacks (Shaver et al. 2000, Rustad et al. 2001, Stromgren 2001). The DOE Program for Ecosystem Research funded a three year project (2002-2005) to use replicated heated chambers on soil warming plots in northern Manitoba to examine the direct effects of whole-ecosystem warming. We are nearing completion of our first growing season of measurements (fall 2004). In spite of the unforeseen difficulty of installing the heating cable, our heating and irrigation systems worked extremely well, maintaining environmental conditions within 5-10% of the specified design 99% of the time. Preliminary data from these systems, all designed and built by our laboratory at the University of Wisconsin, support our overall hypothesis that warming will increase the carbon sink strength of upland boreal black spruce forests. I request an additional three years of funding to continue addressing the original objectives: (1) Examine the effect of warming on phenology of overstory, understory and bryophyte strata. Sap flux systems and dendrometer bands, monitored by data loggers, will be used to quantify changes in phenology and water use. (2) Quantify the effects of warming on nitrogen and water use by overstory, understory and bryophytes. (3) Compare effects of warming on autotrophic respiration and above- and belowground

  14. Amine Measurements in Boreal Forest Air

    Science.gov (United States)

    Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

    2015-04-01

    Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

  15. Dissolved organic carbon and nitrogen release from boreal Holocene permafrost and seasonally frozen soils of Alaska

    Science.gov (United States)

    Wickland, Kimberly P.; Waldrop, Mark P.; Aiken, George R.; Koch, Joshua C.; Torre Jorgenson, M.; Striegl, Robert G.

    2018-06-01

    Permafrost (perennially frozen) soils store vast amounts of organic carbon (C) and nitrogen (N) that are vulnerable to mobilization as dissolved organic carbon (DOC) and dissolved organic and inorganic nitrogen (DON, DIN) upon thaw. Such releases will affect the biogeochemistry of permafrost regions, yet little is known about the chemical composition and source variability of active-layer (seasonally frozen) and permafrost soil DOC, DON and DIN. We quantified DOC, total dissolved N (TDN), DON, and DIN leachate yields from deep active-layer and near-surface boreal Holocene permafrost soils in interior Alaska varying in soil C and N content and radiocarbon age to determine potential release upon thaw. Soil cores were collected at three sites distributed across the Alaska boreal region in late winter, cut in 15 cm thick sections, and deep active-layer and shallow permafrost sections were thawed and leached. Leachates were analyzed for DOC, TDN, nitrate (NO3 ‑), and ammonium (NH4 +) concentrations, dissolved organic matter optical properties, and DOC biodegradability. Soils were analyzed for C, N, and radiocarbon (14C) content. Soil DOC, TDN, DON, and DIN yields increased linearly with soil C and N content, and decreased with increasing radiocarbon age. These relationships were significantly different for active-layer and permafrost soils such that for a given soil C or N content, or radiocarbon age, permafrost soils released more DOC and TDN (mostly as DON) per gram soil than active-layer soils. Permafrost soil DOC biodegradability was significantly correlated with soil Δ14C and DOM optical properties. Our results demonstrate that near-surface Holocene permafrost soils preserve greater relative potential DOC and TDN yields than overlying seasonally frozen soils that are exposed to annual leaching and decomposition. While many factors control the fate of DOC and TDN, the greater relative yields from newly thawed Holocene permafrost soils will have the largest

  16. The role of metabolism in modulating CO2 fluxes in boreal lakes

    Science.gov (United States)

    Bogard, Matthew J.; del Giorgio, Paul A.

    2016-10-01

    Lake CO2 emissions are increasingly recognized as an important component of the global CO2 cycle, yet the origin of these emissions is not clear, as specific contributions from metabolism and in-lake cycling, versus external inputs, are not well defined. To assess the coupling of lake metabolism with CO2 concentrations and fluxes, we estimated steady state ratios of gross primary production to respiration (GPP:R) and rates of net ecosystem production (NEP = GPP-R) from surface water O2 dynamics (concentration and stable isotopes) in 187 boreal lakes spanning long environmental gradients. Our findings suggest that internal metabolism plays a dominant role in regulating CO2 fluxes in most lakes, but this pattern only emerges when examined at a resolution that accounts for the vastly differing relationships between lake metabolism and CO2 fluxes. Fluxes of CO2 exceeded those from NEP in over half the lakes, but unexpectedly, these effects were most common and typically largest in a subset ( 30% of total) of net autotrophic lakes that nevertheless emitted CO2. Equally surprising, we found no environmental characteristics that distinguished this category from the more common net heterotrophic, CO2 outgassing lakes. Excess CO2 fluxes relative to NEP were best predicted by catchment structure and hydrologic properties, and we infer from a combination of methods that both catchment inputs and internal anaerobic processes may have contributed this excess CO2. Together, our findings show that the link between lake metabolism and CO2 fluxes is often strong but can vary widely across the boreal biome, having important implications for catchment-wide C budgets.

  17. Threshold Considerations and Wetland Reclamation in Alberta's Mineable Oil Sands

    Directory of Open Access Journals (Sweden)

    Lee Foote

    2012-03-01

    Full Text Available Oil sand extraction in Alberta, Canada is a multibillion dollar industry operating over 143 km² of open pit mining and 4600 km² of other bitumen strata in northern boreal forests. Oil production contributes to Canada-wide GDP, creates socio-cultural problems, provides energy exports and employment, and carries environmental risks regarding long-term reclamation uncertainties. Of particular concern are the implications for wetlands and water supply management. Mining of oil sands is very attractive because proven reserves of known quality occur in an accessible, politically stable environment with existing infrastructure and an estimated 5.5 billion extractable barrels to be mined over the next five decades. Extraction occurs under a set of limiting factors or thresholds including: limited social tolerance at local to international levels for externalities of oil sand production; water demands > availability; limited natural gas supplies for oil processing leading to proposals for hydroelectric dams and nuclear reactors to be constructed; difficulties in reclaiming sufficient habitat area to replace those lost. Replacement of the 85 km² of peat-forming wetlands forecast to be destroyed appears unlikely. Over 840 billion liters of toxic fluid byproducts are currently held in 170 km² of open reservoirs without any known process to purify this water in meaningful time frames even as some of it leaches into adjacent lands and rivers. Costs for wetland reclamation are high with estimates of $4 to $13 billion, or about 6% of the net profits generated from mining those sites. This raises a social equity question of how much reclamation is appropriate. Time frames for economic, political, and ecological actions are not well aligned. Local people on or near mine sites have had to change their area use for decades and have been affected by industrial development. Examining mining effects to estimate thresholds of biophysical realities, time scales

  18. In Situ Wetland Restoration Demonstration

    Science.gov (United States)

    2014-07-01

    wetland habitats where: habitat disruption should be minimized; desirable flora or fauna might be harmed by traditional remedial excavation methods...However, it is possible that short-term impacts to hydrophytic flora and fauna may occur. Other potential challenges include the long-term physical

  19. Magellanic Wetlands : More than Moor

    Czech Academy of Sciences Publication Activity Database

    Filipová, L.; Hédl, Radim; Dančák, M.

    2013-01-01

    Roč. 48, č. 2 (2013), s. 163-188 ISSN 1211-9520 R&D Projects: GA ČR GA206/08/0389 Institutional support: RVO:67985939 Keywords : wetland * vegetation * environment Subject RIV: EF - Botanics Impact factor: 1.612, year: 2013

  20. Nevada Test Site Wetlands Assessment

    Energy Technology Data Exchange (ETDEWEB)

    D. J. Hansen

    1997-05-01

    This report identifies 16 Nevada Test Site (NTS) natural water sources that may be classified by the U.S. Army Corps of Engineers (USACE) as jurisdictional wetlands and identifies eight water sources that may be classified as waters of the United States. These water sources are rare, localized habitats on the NTS that are important to regional wildlife and to isolated populations of water tolerant plants and aquatic organisms. No field investigations on the NTS have been conducted in the past to identify those natural water sources which would be protected as rare habitats and which may fall under regulatory authority of the Clean Water Act (CWA) of 1997. This report identifies and summarizes previous studies of NTS natural water sources, and identifies the current DOE management practices related to the protection of NTS wetlands. This report also presents management goals specific for NTS wetlands that incorporate the intent of existing wetlands legislation, the principles of ecosystem management, and the interests of regional land managers and other stakeholders.

  1. Rainfall spatiotemporal variability relation to wetlands hydroperiods

    Science.gov (United States)

    Serrano-Hidalgo, Carmen; Guardiola-Albert, Carolina; Fernandez-Naranjo, Nuria

    2017-04-01

    Doñana natural space (Southwestern Spain) is one of the largest protected wetlands in Europe. The wide marshes present in this natural space have such ecological value that this wetland has been declared a Ramsar reserve in 1982. Apart from the extensive marsh, there are also small lagoons and seasonally flooded areas which are likewise essential to maintain a wide variety of valuable habitats. Hydroperiod, the length of time each point remains flooded along an annual cycle, is a critical ecological parameter that shapes aquatic plants and animals distribution and determines available habitat for many of the living organisms in the marshes. Recently, there have been published two different works estimating the hydroperiod of Doñana lagoons with Landsat Time Series images (Cifuentes et al., 2015; Díaz-Delgado et al., 2016). In both works the flooding cycle hydroperiod in Doñana marshes reveals a flooding regime mainly driven by rainfall, evapotranspiration, topography and local hydrological management actions. The correlation found between rainfall and hydroperiod is studied differently in both works. While in one the rainfall is taken from one raingauge (Cifuentes et al., 2015), the one performed by Díaz-Delgado (2016) uses annual rainfall maps interpolated with the inverse of the distance method. The rainfall spatiotemporal variability in this area can be highly significant; however the amount of this importance has not been quantified at the moment. In the present work the geostatistical tool known as spatiotemporal variogram is used to study the rainfall spatiotemporal variability. The spacetime package implemented in R (Pebesma, 2012) facilities its computation from a high rainfall data base of more than 100 raingauges from 1950 to 2016. With the aid of these variograms the rainfall spatiotemporal variability is quantified. The principal aim of the present work is the study of the relation between the rainfall spatiotemporal variability and the

  2. Modelling atmospheric OH-reactivity in a boreal forest ecosystem

    DEFF Research Database (Denmark)

    Mogensen, D.; Smolander, S.; Sogachev, Andrey

    2011-01-01

    We have modelled the total atmospheric OH-reactivity in a boreal forest and investigated the individual contributions from gas phase inorganic species, isoprene, monoterpenes, and methane along with other important VOCs. Daily and seasonal variation in OH-reactivity for the year 2008 was examined...

  3. Global climate change adaptation: examples from Russian boreal forests

    International Nuclear Information System (INIS)

    Krankina, O.N.; Dixon, R.K.; Kirilenko, A.P.; Kobak, K.I.

    1997-01-01

    The Russian Federation contains approximately 20% of the world's timber resources and more than half of all boreal forests. These forests play a prominent role in environmental protection and economic development at global, national, and local levels, as well as, provide commodities for indigenous people and habitat for a variety of plant and animal species. The response and feedbacks of Russian boreal forests to projected global climate change are expected to be profound. Current understanding of the vulnerability of Russian forest resources to projected climate change is discussed and examples of possible adaptation measures for Russian forests are presented including: (1) artificial forestation techniques that can be applied with the advent of failed natural regeneration and to facilitate forest migration northward; (2) silvicultural measures that can influence the species mix to maintain productivity under future climates; (3) identifying forests at risk and developing special management adaption measures for them: (4) alternative processing and uses of wood and non-wood products from future forests; and (5) potential future infrastructure and transport systems that can be employed as boreal forests shift northward into melting permafrost zones. Current infrastructure and technology can be employed to help Russian boreal forests adapt to projected global environmental change, however many current forest management practices may have to be modified. Application of this technical knowledge can help policymakers identify priorities for climate change adaptation

  4. Regional coherency of boreal forest growth defines Arctic driftwood provenancing

    Czech Academy of Sciences Publication Activity Database

    Hellmann, L.; Agafonov, L.; Churakova (Sidorova), O.; Düthorn, E.; Eggertsson, O.; Esper, J.; Kirdyanov, A. V.; Knorre, A. A.; Moiseev, P.; Myglan, V. S.; Nikolaev, A. N.; Reinig, F.; Schweingruber, F.; Solomina, O.; Tegel, W.; Büntgen, Ulf

    2016-01-01

    Roč. 39, sep (2016), s. 3-9 ISSN 1125-7865 Institutional support: RVO:67179843 Keywords : mackenzie river driftwood * tree-ring data * central siberia * origin * archipelago * holocene * ocean * sea * ice * circulation * Driftwood * Arctic * Dendro-provenancing * Boreal Subject RIV: EF - Botanics Impact factor: 2.259, year: 2016

  5. Resilience of Alaska's Boreal Forest to Climatic Change

    Science.gov (United States)

    Chapin, F. S., III; McGuire, A. D.; Ruess, R. W.; Hollingsworth, T. N.; Mack, M. C.; Johnstone, J. F.; Kasischke, E. S.; Euskirchen, E. S.; Jones, J. B.; Jorgenson, M. T.; hide

    2010-01-01

    This paper assesses the resilience of Alaska s boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska s boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities.

  6. Modeling Alaska boreal forests with a controlled trend surface approach

    Science.gov (United States)

    Mo Zhou; Jingjing Liang

    2012-01-01

    An approach of Controlled Trend Surface was proposed to simultaneously take into consideration large-scale spatial trends and nonspatial effects. A geospatial model of the Alaska boreal forest was developed from 446 permanent sample plots, which addressed large-scale spatial trends in recruitment, diameter growth, and mortality. The model was tested on two sets of...

  7. Boreal forests and atmosphere - Biosphere exchange of carbon dioxide

    Science.gov (United States)

    D'Arrigo, Rosanne; Jacoby, Gordon C.; Fung, Inez Y.

    1987-01-01

    Two approaches to investigating the role of boreal forests in the global carbon cycle are presented. First, a tracer support model which incorporates the normalized-difference vegetation index obtained from advanced, very high resolution radiometer radiances was used to simulate the annual cycle of CO2 in the atmosphere. Results indicate that the seasonal growth of the combined boreal forests of North America and Eurasia accounts for about 50 percent of the mean seasonal CO2 amplitude recorded at Pt. Barrow, Alaska and about 30 percent of the more globally representative CO2 signal at Mauna Loa, Hawaii. Second, tree-ring width data from four boreal treeline sites in northern Canada were positively correlated with Pt. Barrow CO2 drawdown for the period 1971-1982. These results suggest that large-scale changes in the growth of boreal forests may be contributing to the observed increasing trend in CO2 amplitude. They further suggest that tree-ring data may be applicable as indices for CO2 uptake and remote sensing estimates of photosynthetic activity.

  8. Resilience of Alaska’s boreal forest to climatic change

    Science.gov (United States)

    Chapin, F.S.; McGuire, A. David; Ruess, Roger W.; Hollingsworth, Teresa N.; Mack, M.C.; Johnstone, J.F.; Kasischke, E.S.; Euskirchen, E.S.; Jones, J.B.; Jorgenson, M.T.; Kielland, K.; Kofinas, G.; Turetsky, M.R.; Yarie, J.; Lloyd, A.H.; Taylor, D.L.

    2010-01-01

    This paper assesses the resilience of Alaska’s boreal forest system to rapid climatic change. Recent warming is associated with reduced growth of dominant tree species, plant disease and insect outbreaks, warming and thawing of permafrost, drying of lakes, increased wildfire extent, increased postfire recruitment of deciduous trees, and reduced safety of hunters traveling on river ice. These changes have modified key structural features, feedbacks, and interactions in the boreal forest, including reduced effects of upland permafrost on regional hydrology, expansion of boreal forest into tundra, and amplification of climate warming because of reduced albedo (shorter winter season) and carbon release from wildfires. Other temperature-sensitive processes for which no trends have been detected include composition of plant and microbial communities, long-term landscape-scale change in carbon stocks, stream discharge, mammalian population dynamics, and river access and subsistence opportunities for rural indigenous communities. Projections of continued warming suggest that Alaska’s boreal forest will undergo significant functional and structural changes within the next few decades that are unprecedented in the last 6000 years. The impact of these social–ecological changes will depend in part on the extent of landscape reorganization between uplands and lowlands and on policies regulating subsistence opportunities for rural communities.

  9. Moss-nitrogen input to boreal forest soils

    DEFF Research Database (Denmark)

    Rousk, Kathrin; Jones, Davey; DeLuca, Thomas

    2014-01-01

    Cyanobacteria living epiphytically on mosses in pristine, unpolluted areas fix substantial amounts of atmospheric nitrogen (N) and therefore represent a primary source of N in N-limited boreal forests. However, the fate of this N is unclear, in particular, how the fixed N2 enters the soil and bec...... and that transfer of N to the soil is not facilitated by fungal hyphae....

  10. Factors limiting the recovery of boreal toads (Bufo b. boreas)

    Science.gov (United States)

    Carey, C.; Corn, P.S.; Jones, M.S.; Livo, L.J.; Muths, E.; Loeffler, C.W.; Lannoo, M.

    2005-01-01

    Boreal toads (Bufo b. boreas) are widely distributed over much of the mountainous western United States. Populations in the Southern Rocky Mountains suffered extensive declines in the late 1970s through early 1980s (Carey, 1993). At the time, these mass mortalities were thought to be associated with a bacterial infection (Carey, 1993). Although the few populations that survived the mass die-offs were not systematically monitored until at least 1993, no mass mortalities had been observed until 1996 when die-offs were observed. A mycotic skin infection associated with a chytrid fungus is now causing mortality of toads in at least two of the populations (M.S. Jones and D.E. Green, unpublished data; Muths et al., 2003). Boreal toads are now absent throughout large areas of their former distribution in Colorado and southern Wyoming and may be extinct in New Mexico (Corn et al., 1989; Carey, 1993; Stuart and Painter, 1994). These toads are classified as “endangered” by Colorado and New Mexico and are designated as a protected non-game species in Wyoming. The U.S. Fish and Wildlife Service has categorized the Southern Rocky Mountain populations for federal listing and is currently reviewing their designation as a “warranted but precluded” species for possible listing in the next few years. For the management of boreal toads and their habitats, a Boreal Toad Recovery Team was formed by the Colorado Division of Wildlife in 1995 as part of a collaborative effort with federal agencies within the United States’ departments of the Interior and Agriculture and with agencies in two adjoining states. To date, conservation agreements have been signed by eight state and federal agencies and by the Colorado Natural Heritage Program. Although boreal toads were considered common throughout their range in Colorado, no comprehensive surveys of the numbers and sizes of their populations were conducted prior to mass die-offs in the 1970s. Surveys completed in the late 1980s to

  11. China's natural wetlands: past problems, current status, and future challenges

    Science.gov (United States)

    Shuqing An; Harbin Li; Baohua Guan; Changfang Zhou; Zhongsheng Wang; Zifa Deng; Yingbiao Zhi; Yuhong Liu; Chi Xu; Shubo Fang; Jinhui Jiang; Hongli Li

    2007-01-01

    Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% coastal wetlands) because of the wetland reclamation during China's long history of civilization, and the...

  12. Macroinvertebrate abundance, water chemistry, and wetland characteristics affect use of wetlands by avian species in Maine

    Science.gov (United States)

    Longcore, J.R.; McAuley, D.G.; Pendelton, G.W.; Bennatti, C.R.; Mingo, T.M.; Stromborg, K.L.

    2006-01-01

    Our objective was to determine use by avian species (e.g., piscivores, marsh birds, waterfowl, selected passerines) of 29 wetlands in areas with low (chemistry, basin characteristics, and avian use of different wetland types. Shallow, beaver (Castor canadensis)-created wetlands with the highest phosphorus levels and abundant and varied macrophyte assemblages supported greater densities of macroinvertebrates and numbers of duck broods (88.3% of all broods) in contrast to deep, glacial type wetlands with sparse vegetation and lower invertebrate densities that supported fewer broods (11.7%). Low pH may have affected some acid-intolerant invertebrate taxa (i.e., Ephemeroptera), but high mean numbers of Insecta per wetland were recorded from wetlands with a pH of 5.51. Other Classes and Orders of invertebrates were more abundant on wetlands with pH > 5.51. All years combined use of wetlands by broods was greater on wetlands with pH ≤ 5.51 (77.4%) in contract to wetlands with pH > 5.51 that supported 21.8% of the broods. High mean brood density was associated with mean number of Insecta per wetland. For lentic wetlands created by beaver, those habitats contained vegetative structure and nutrients necessary to provide cover to support invertebrate populations that are prey of omnivore and insectivore species. The fishless status of a few wetlands may have affected use by some waterfowl species and obligate piscivores.

  13. Engineered wetlands : an innovative environmental solution

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, S.; Davis, B.M. [Jacques Whitford NAWE, White Bear Lake, MN (United States)

    2008-03-15

    Engineered wetlands are now considered as an emerging technology for the in situ remediation of hydrocarbon-contaminated soil and waters. Engineered wetlands incorporate a horizontal subsurface flow gravel bed reactor lined with impermeable liners, and are equipped with forced bed aeration systems in order to enhance oxygen delivery to the wetland's aerobic micro-organisms. The wetlands typically emphasize specific characteristics of wetland ecosystems to improve treatment capacities. This article discussed an engineered wetlands installed at a set of pipeline terminals as well as at a former British Petroleum (BP) refinery. The pipeline terminal generated contact wastewater containing BTEX and ammonia, and a subsurface engineered wetland was built in 1998. To date, the 16,000{sup 2} foot wetland has treated a flow-equalized input of approximately 1.5 m{sup 3} per day of contaminants. At the refinery, a wetland treatment system was designed to treat 6000 m{sup 3} of benzene, toluene, ethylbenzene and xylene (BTEX) and volatile organic compounds (VOCs). The treatment site consists of a golf course, river front trails, and a white water kayak course. A cascade aeration system was used for iron oxidation and air-stripping. A soil matrix biofilter was used for passive gas phase benzene removal, as well as for the removal of ferric hydroxide precipitates. It was concluded that engineered wetlands can offer long-term solutions to site remediation challenges. 1 fig.

  14. Engineered wetlands : an innovative environmental solution

    International Nuclear Information System (INIS)

    Wallace, S.; Davis, B.M.

    2008-01-01

    Engineered wetlands are now considered as an emerging technology for the in situ remediation of hydrocarbon-contaminated soil and waters. Engineered wetlands incorporate a horizontal subsurface flow gravel bed reactor lined with impermeable liners, and are equipped with forced bed aeration systems in order to enhance oxygen delivery to the wetland's aerobic micro-organisms. The wetlands typically emphasize specific characteristics of wetland ecosystems to improve treatment capacities. This article discussed an engineered wetlands installed at a set of pipeline terminals as well as at a former British Petroleum (BP) refinery. The pipeline terminal generated contact wastewater containing BTEX and ammonia, and a subsurface engineered wetland was built in 1998. To date, the 16,000 2 foot wetland has treated a flow-equalized input of approximately 1.5 m 3 per day of contaminants. At the refinery, a wetland treatment system was designed to treat 6000 m 3 of benzene, toluene, ethylbenzene and xylene (BTEX) and volatile organic compounds (VOCs). The treatment site consists of a golf course, river front trails, and a white water kayak course. A cascade aeration system was used for iron oxidation and air-stripping. A soil matrix biofilter was used for passive gas phase benzene removal, as well as for the removal of ferric hydroxide precipitates. It was concluded that engineered wetlands can offer long-term solutions to site remediation challenges. 1 fig

  15. Wetland restoration, flood pulsing, and disturbance dynamics

    Science.gov (United States)

    Middleton, Beth A.

    1999-01-01

    While it is generally accepted that flood pulsing and disturbance dynamics are critical to wetland viability, there is as yet no consensus among those responsible for wetland restoration about how best to plan for those phenomena or even whether it is really necessary to do so at all. In this groundbreaking book, Dr. Beth Middleton draws upon the latest research from around the world to build a strong case for making flood pulsing and disturbance dynamics integral to the wetland restoration planning process.While the initial chapters of the book are devoted to laying the conceptual foundations, most of the coverage is concerned with demonstrating the practical implications for wetland restoration and management of the latest ecological theory and research. It includes a fascinating case history section in which Dr. Middleton explores the restoration models used in five major North American, European, Australian, African, and Asian wetland projects, and analyzes their relative success from the perspective of flood pulsing and disturbance dynamics planning.Wetland Restoration also features a wealth of practical information useful to all those involved in wetland restoration and management, including: * A compendium of water level tolerances, seed germination, seedling recruitment, adult survival rates, and other key traits of wetland plant species * A bibliography of 1,200 articles and monographs covering all aspects of wetland restoration * A comprehensive directory of wetland restoration ftp sites worldwide * An extensive glossary of essential terms

  16. Influence of Vegetation on Long-term Phosphorus Sequestration in Subtropical Treatment Wetlands.

    Science.gov (United States)

    Bhomia, R K; Reddy, K R

    2018-03-01

    Sustainable operation of a treatment wetland depends on its continued treatment of influent water to achieve desired outflow water quality targets. Water treatment or nutrient reduction is attained by a combination of biotic and abiotic processes. We studied one of the world's largest treatment wetlands established to revive the Florida Everglades from impacts of excessive phosphorus (P) inputs. Phosphorus retained in the treatment wetlands is sequestered within the accumulated material via biotic and abiotic pathways that are influenced by the existing wetland vegetation. Recently accreted soils (RAS) provide a major sink for stored P, and long-term P removal efficiency of treatment wetlands is governed by the stability of accreted P because more stable P pools are less susceptible to mobilization and loss. We quantified reactive P (extracted with acid and alkali) and nonreactive P (not extracted with acid and alkali) pools in wetland soils by using an operationally defined P fractionation scheme and assessed the effect of emergent vs. submerged vegetation communities on stability of sequestered P. Reactive P comprised 63 to 79% of total P in wetland soils without a clear difference between two vegetation groups. The quantities of reactive P forms (inorganic vs. organic P) were significantly different between two vegetation types. A higher proportion of reactive P was stored as organic P in flocculent detrital organic matter (floc) and RAS under emergent vegetation (46-47% total P) in comparison with submerged vegetation (21-34% total P). The dominant P removal pathway in the submerged vegetation system was associated with calcium whereas plant uptake and peat burial appeared to be the main pathway in the emergent vegetation system. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  17. Anthropogenic protection alters the microbiome in intertidal mangrove wetlands in Hainan Island.

    Science.gov (United States)

    Yun, Juanli; Deng, Yongcui; Zhang, Hongxun

    2017-08-01

    Intertidal mangrove wetlands are of great economic and ecological importance. The regular influence of tides has led to the microbial communities in these wetlands differing significantly from those in other habitats. In this study, we investigated the microbiomes of the two largest mangrove wetlands in Hainan Island, China, which have different levels of anthropogenic protection. Soil samples were collected from the root zone of 13 mangrove species. The microbial composition, including key functional groups, was assessed using Illumina sequencing. Bioinformatics analysis showed that there was a significant difference in the microbiomes between the protected Bamen Bay and the unprotected Dongzhai Bay. The overall microbiome was assigned into 78 phyla and Proteobacteria was the most abundant phylum at both sites. In the protected wetland, there were fewer marine-related microbial communities, such as sulfate-reducing bacteria, and more terrestrial-related communities, such as Verrucomicrobia methanotrophs. We also observed distinct microbial compositions among the different mangrove species at the protected site. Our data suggest that the different microbiomes of the two mangrove wetlands are the result of a complex interaction of the different environmental variables at the two sites.

  18. A Wetland and a Lifeline: the Importance of Loktak Lake for Manipur, India

    Directory of Open Access Journals (Sweden)

    Konsam Nirmala Devi

    2017-02-01

    Full Text Available Wetlands are highly productive ecosystems which provide multiple-value ecosystem services. The Loktak Lake wetland is located in the Bishnupur district of the Indian state of Manipur, and is the largest freshwater wetland in Northeast India. The lake is used extensively by local people as a source of water for irrigation and domestic use and is an important wintering and staging area for water birds, particularly ducks. The Loktak Lake has a socioeconomic and cultural relationship with the people of Manipur. However, of late, the impacts of increase in population, urbanisation and the rapid pace of development have started being felt on Loktak Lake. The once over 266 sq. km large Loktak Lake is now showing signs of shrinking and reduction in wetland spread. The lake had a seasonal and pulsating characteristic which kept it clean and healthy. However, changes in its hydrology due to regulation of water flow for development purpose are now showing a detrimental effect on the health of this wetland. The following article is an attempt at putting greater focus on the lifeline of Manipur, the Loktak Lake and a floating island paradise where tourism is wanting.

  19. A SIMULATION STUDY ON THE SHRUNK WETLAND AROUND QINGHAI LAKE AND REGIONAL CLIMATE

    Institute of Scientific and Technical Information of China (English)

    WANG HanJie; JING Li; GAO YunXiao

    2005-01-01

    Because of the increasing concerns about global climate change, it has been known by more and more peoples that there is a close relationship between wetland and/or peatland resources and climate change. This paper presents a new methodology to study the local climate variation caused by wetland shrinking around Qinghai Lake, the largest in-land salty lake in China, by use of a regional climate model (RCM) that commonly used in climate change study. The objective focuses on the regional climate effect of the shrunk wetland coverage in recent years. The results of numerical experiment showed that if the wetland coverage around Qinhai Lake were recovered as if in early 50s of last century,the regional climate in this area could be better with more cloud covers, higher relative humidity and more precipitation. In the other word, the area of wetland reduced is one of the most important reasons that caused regional climate aridification,eco-environmental deterioration and even desertification around Qinhai Lake.

  20. Mapping anuran habitat suitability to estimate effects of grassland and wetland conservation programs

    Science.gov (United States)

    Mushet, David M.; Euliss, Ned H.; Stockwell, Craig A.

    2012-01-01

    The conversion of the Northern Great Plains of North America to a landscape favoring agricultural commodity production has negatively impacted wildlife habitats. To offset impacts, conservation programs have been implemented by the U.S. Department of Agriculture and other agencies to restore grassland and wetland habitat components. To evaluate effects of these efforts on anuran habitats, we used call survey data and environmental data in ecological niche factor analyses implemented through the program Biomapper to quantify habitat suitability for five anuran species within a 196 km2 study area. Our amphibian call surveys identified Northern Leopard Frogs (Lithobates pipiens), Wood Frogs (Lithobates sylvaticus), Boreal Chorus Frogs (Pseudacris maculata), Great Plains Toads (Anaxyrus cognatus), and Woodhouse’s Toads (Anaxyrus woodhousii) occurring within the study area. Habitat suitability maps developed for each species revealed differing patterns of suitable habitat among species. The most significant findings of our mapping effort were 1) the influence of deep-water overwintering wetlands on suitable habitat for all species encountered except the Boreal Chorus Frog; 2) the lack of overlap between areas of core habitat for both the Northern Leopard Frog and Wood Frog compared to the core habitat for both toad species; and 3) the importance of conservation programs in providing grassland components of Northern Leopard Frog and Wood Frog habitat. The differences in habitats suitable for the five species we studied in the Northern Great Plains, i.e., their ecological niches, highlight the importance of utilizing an ecosystem based approach that considers the varying needs of multiple species in the development of amphibian conservation and management plans.

  1. Moss and lichen cover mapping at local and regional scales in the boreal forest ecosystem of central Canada

    Science.gov (United States)

    Rapalee, G.; Steyaert, L.T.; Hall, F.G.

    2001-01-01

    Mosses and lichens are important components of boreal landscapes [Vitt et al., 1994; Bubier et al., 1997]. They affect plant productivity and belowground carbon sequestration and alter the surface runoff and energy balance. We report the use of multiresolution satellite data to map moss and lichens over the BOREAS region at a 10 m, 30 m, and 1 km scales. Our moss and lichen classification at the 10 m scale is based on ground observations of associations among soil drainage classes, overstory composition, and cover type among four broad classes of ground cover (feather, sphagnum, and brown mosses and lichens). For our 30 m map, we used field observations of ground cover-overstory associations to map mosses and lichens in the BOREAS southern study area (SSA). To scale up to a 1 km (AVHRR) moss map of the BOREAS region, we used the TM SSA mosaics plus regional field data to identify AVHRR overstory-ground cover associations. We found that: 1) ground cover, overstory composition and density are highly correlated, permitting inference of moss and lichen cover from satellite-based land cover classifications; 2) our 1 km moss map reveals that mosses dominate the boreal landscape of central Canada, thereby a significant factor for water, energy, and carbon modeling; 3) TM and AVHRR moss cover maps are comparable; 4) satellite data resolution is important; particularly in detecting the smaller wetland features, lakes, and upland jack pine sites; and 5) distinct regional patterns of moss and lichen cover correspond to latitudinal and elevational gradients. Copyright 2001 by the American Geophysical Union.

  2. Patterns in wetland microbial community composition and functional gene repertoire associated with methane emissions.

    Science.gov (United States)

    He, Shaomei; Malfatti, Stephanie A; McFarland, Jack W; Anderson, Frank E; Pati, Amrita; Huntemann, Marcel; Tremblay, Julien; Glavina del Rio, Tijana; Waldrop, Mark P; Windham-Myers, Lisamarie; Tringe, Susannah G

    2015-05-19

    Wetland restoration on peat islands previously drained for agriculture has potential to reverse land subsidence and sequester atmospheric carbon dioxide as peat accretes. However, the emission of methane could potentially offset the greenhouse gas benefits of captured carbon. As microbial communities play a key role in governing wetland greenhouse gas fluxes, we are interested in how microbial community composition and functions are associated with wetland hydrology, biogeochemistry, and methane emission, which is critical to modeling the microbial component in wetland methane fluxes and to managing restoration projects for maximal carbon sequestration. Here, we couple sequence-based methods with biogeochemical and greenhouse gas measurements to interrogate microbial communities from a pilot-scale restored wetland in the Sacramento-San Joaquin Delta of California, revealing considerable spatial heterogeneity even within this relatively small site. A number of microbial populations and functions showed strong correlations with electron acceptor availability and methane production; some also showed a preference for association with plant roots. Marker gene phylogenies revealed a diversity of major methane-producing and -consuming populations and suggested novel diversity within methanotrophs. Methanogenic archaea were observed in all samples, as were nitrate-, sulfate-, and metal-reducing bacteria, indicating that no single terminal electron acceptor was preferred despite differences in energetic favorability and suggesting spatial microheterogeneity and microniches. Notably, methanogens were negatively correlated with nitrate-, sulfate-, and metal-reducing bacteria and were most abundant at sampling sites with high peat accretion and low electron acceptor availability, where methane production was highest. Wetlands are the largest nonanthropogenic source of atmospheric methane but also a key global carbon reservoir. Characterizing belowground microbial communities

  3. National Wetland Mitigation Banking Study Wetland Migitation Banking.

    Science.gov (United States)

    1994-02-01

    habitat (i.e. number of snags, extent of exposed steep shoreline, etc.) rather than selecting species themselves as function indicators [ WWF 1992...etc.) that are converted to portray hydrologic, water quality, and habitat functions as well as wetland loss on watershed scales [ WWF 1992]. The...Natural Areas - include the Stewardship Program, a partnership program between the private and public sectors for conservation land acquisitions

  4. Introduction to the Wetland Book 1: Wetland structure and function, management, and nethods

    Science.gov (United States)

    Davidson, Nick C.; Middleton, Beth A.; McInnes, Robert J.; Everard, Mark; Irvine, Kenneth; Van Dam, Anne A.; Finlayson, C. Max; Finlayson, C. Max; Everard, Mark; Irvine, Kenneth; McInnes, Robert J.; Middleton, Beth A.; Van Dam, Anne A.; Davidson, Nick C.

    2016-01-01

    The Wetland Book 1 is designed as a ‘first port-of-call’ reference work for information on the structure and functions of wetlands, current approaches to wetland management, and methods for researching and understanding wetlands. Contributions by experts summarize key concepts, orient the reader to the major issues, and support further research on such issues by individuals and multidisciplinary teams. The Wetland Book 1 is organized in three parts - Wetland structure and function; Wetland management; and Wetland methods - each of which is divided into a number of thematic Sections. Each Section starts with one or more overview chapters, supported by chapters providing further information and case studies on different aspects of the theme.

  5. Joint Asymptotic Distributions of Smallest and Largest Insurance Claims

    Directory of Open Access Journals (Sweden)

    Hansjörg Albrecher

    2014-07-01

    Full Text Available Assume that claims in a portfolio of insurance contracts are described by independent and identically distributed random variables with regularly varying tails and occur according to a near mixed Poisson process. We provide a collection of results pertaining to the joint asymptotic Laplace transforms of the normalised sums of the smallest and largest claims, when the length of the considered time interval tends to infinity. The results crucially depend on the value of the tail index of the claim distribution, as well as on the number of largest claims under consideration.

  6. Challenges with the largest commercial hydrogen station in the world

    Energy Technology Data Exchange (ETDEWEB)

    Charbonneau, Thomas; Gauthier, Pierre [Air Liquide Canada (Canada)

    2010-07-01

    This abstract's objective is to share with the participants the story of the largest hydrogen fueling station made to this date and to kick-start the story, we will cover the challenges; first the technical ones; the operational ones; the distribution ones and; the financial ones. We will then move on to review the logistic (geographic) issues raised by the project and conclude our presentation by sharing the output values of the largest fueling station built so far in the world. (orig.)

  7. EnviroAtlas - Potential Wetland Areas - Contiguous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EnviroAtlas Potential Wetland Areas (PWA) dataset shows potential wetland areas at 30-meter resolution. Beginning two centuries ago, many wetlands were turned...

  8. Assessment of the Hydro-Ecological Impacts of the Three Gorges Dam on China’s Largest Freshwater Lake

    Directory of Open Access Journals (Sweden)

    Guiping Wu

    2017-10-01

    Full Text Available The Three Gorges Dam (TGD has received increasing attention with respect to its potential effects on downstream hydro-ecosystems. Poyang Lake is the largest freshwater lake downstream of the TGD, and it is not immune to these impacts. Here, we combine hydrological observations, remote sensing, a geographic information system (GIS, and landscape ecology technology to investigate the variability and spatial pattern of the hydro-ecological alterations to Poyang Lake induced by the operation of the TGD. It was found that the TGD caused significant hydro-ecological alterations across the Poyang Lake wetland. Specifically, the TGD operation altered the seasonal inundation pattern of Poyang Lake and significantly reduced the monthly inundation frequencies (IFs, which were especially notable (~30–40% from September to November. Spatially, the declining IFs led to an increase in the mudflat area that is suitable for the growth of vegetation. The vegetation area increased by 58.82 km2 and 463.73 km2 in the low- and high-water season, respectively, with the most significant changes occurring in the estuary delta of the Ganjiang and Raohe rivers. The results also indicated that the changes in the inundation pattern and floodplain vegetation have profoundly altered the structure and composition of the wetland, which has resulted in increased landscape diversity and a gradual increase in the complexity of the ecosystem composition under the influence of regulation of the TGD. Such results are of great importance for policymakers, as they may provide a reference for wetland water resource planning and landscape restoration in an operational dam environment.

  9. Airborne measurements of CO2, CH4 and HCN in boreal biomass burning plumes

    Science.gov (United States)

    O'Shea, Sebastian J.; Bauguitte, Stephane; Muller, Jennifer B. A.; Le Breton, Michael; Archibald, Alex; Gallagher, Martin W.; Allen, Grant; Percival, Carl J.

    2013-04-01

    Biomass burning plays an important role in the budgets of a variety of atmospheric trace gases and particles. For example, fires in boreal Russia have been linked with large growths in the global concentrations of trace gases such as CO2, CH4 and CO (Langenfelds et al., 2002; Simpson et al., 2006). High resolution airborne measurements of CO2, CH4 and HCN were made over Eastern Canada onboard the UK Atmospheric Research Aircraft FAAM BAe-146 from 12 July to 4 August 2011. These observations were made as part of the BORTAS project (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites). Flights were aimed at transecting and sampling the outflow from the commonly occurring North American boreal forest fires during the summer months and to investigate and identify the chemical composition and evolution of these plumes. CO2 and CH4 dry air mole fractions were determined using an adapted system based on a Fast Greenhouse Gas Analyser (FGGA, Model RMT-200) from Los Gatos Research Inc, which uses the cavity enhanced absorption spectroscopy technique. In-flight calibrations revealed a mean accuracy of 0.57 ppmv and 2.31 ppbv for 1 Hz observations of CO2 and CH4, respectively, during the BORTAS project. During these flights a number of fresh and photochemically-aged plumes were identified using simultaneous HCN measurements. HCN is a distinctive and useful marker for forest fire emissions and it was detected using chemical ionisation mass spectrometry (CIMS). In the freshest plumes, strong relationships were found between CH4, CO2 and other tracers for biomass burning. From this we were able to estimate that 8.5 ± 0.9 g of CH4 and 1512 ± 185 g of CO2 were released into the atmosphere per kg of dry matter burnt. These emission factors are in good agreement with estimates from previous studies and can be used to calculate budgets for the region. However for aged plumes the correlations between CH4 and other

  10. AirSWOT flights and field campaigns for the 2017 Arctic-Boreal Vulnerability Experiment (ABoVE)

    Science.gov (United States)

    Smith, L. C.; Pavelsky, T.; Lettenmaier, D. P.; Gleason, C. J.; Pietroniro, A.; Applejohn, A.; Arvesen, J. C.; Bjella, K.; Carter, T.; Chao, R.; Cooley, S. W.; Cooper, M. G.; Cretaux, J. F.; Douglass, T.; Faria, D.; Fayne, J.; Fiset, J. M.; Goodman, S.; Hanna, B.; Harlan, M.; Langhorst, T.; Marsh, P.; Moreira, D. M.; Minear, J. T.; Onclin, C.; Overstreet, B. T.; Peters, D.; Pettit, J.; Pitcher, L. H.; Russell, M.; Spence, C.; Topp, S.; Turner, K. W.; Vimal, S.; Wilcox, E.; Woodward, J.; Yang, D.; Zaino, A.

    2017-12-01

    Some 50% of Canada and 80% of Alaska is thought to be underlain by permafrost, influencing the hydrology, ecology and carbon cycles of Arctic-Boreal landscapes. This influence includes enhanced presence of millions of lakes and wetlands, which release trace gases while supporting critical ecosystems and traditional subsistence economies. Permafrost is challenging to infer from remote sensing and difficult to sample in the field. A series of 2017 AirSWOT flights flown for the NASA Arctic-Boreal Vulnerability Experiment (ABoVE) will study whether small variations in water surface elevations (WSEs) of Arctic-Boreal lakes are sensitive to presence and/or disturbance of permafrost. AirSWOT is an experimental NASA airborne radar designed to map WSE and a precursor to SWOT, a forthcoming NASA/CNES/CSA satellite mission to map WSE globally with launch in 2021. The ABoVE AirSWOT flight experiments adopted long flight lines of the broader ABoVE effort to traverse broad spatial gradients of permafrost, climate, ecology, and geology. AirSWOT acquisitions consisted of long (1000s of kilometers) strips of Ka-band interferometric radar imagery, and high resolution visible/NIR imagery and DEMs from a digital Cirrus CIR camera. Intensive AirSWOT mapping and ground-based GPS field surveys were conducted at 11 field sites for eight study areas of Canada and Alaska: 1) Saint-Denis, Redberry Lake, North Saskatchewan River (Saskatchewan); 2) Peace-Athabasca Delta (Alberta); 3) Slave River Delta (N.W.T.); 4) Canadian Shield (Yellowknife area, Daring Lake, N.W.T.); 5) Mackenzie River (Inuvik-Tuktoyaktuk corridor, N.W.T.); 6) Old Crow Flats (Yukon Territory); 7) Sagavanirktok River (Alaska); 8) Yukon Flats (Alaska). Extensive ground campaigns were conducted by U.S. and Canadian collaborators to collect high quality surveys of lake WSE, river WSE and discharge, and shoreline locations. Field experiments included traditional and novel GPS surveying methods, including custom-built GPS buoys

  11. Do geographically isolated wetlands influence landscape functions?

    OpenAIRE

    Cohen, Matthew J.; Creed, Irena F.; Alexander, Laurie; Basu, Nandita B.; Calhoun, Aram J. K.; Craft, Christopher; D’Amico, Ellen; DeKeyser, Edward; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lane, Charles R.; Lang, Megan

    2016-01-01

    Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bo...

  12. Treatment of wastewater with the constructed wetland

    International Nuclear Information System (INIS)

    Fernandez, R.; Olivares, S.

    2003-01-01

    Constructed wetland is an environmental sound, actual and economic solution for the treatment of wastewater. The use of these constructed wetlands increased in the last few years, principally in developed countries. However there is not much information about the performance of these biological systems in tropical and subtropical climates. In these review the state of art of these technology is given, and also the advantage of the use of the constructed wetland for the wastewater treatment in our country

  13. Diverse characteristics of wetlands restored under the Wetlands Reserve Program in the Southeastern United States

    Science.gov (United States)

    Diane De Steven; Joel M. Gramling

    2012-01-01

    The Wetlands Reserve Program (WRP) restores converted or degraded wetlands on private working lands; however, the nature and outcomes of such efforts are undocumented in the Southeastern U.S. Identification of wetland types is needed to assess the program's conservation benefits, because ecological functions differ with hydrogeomorphic (HGM) type. We reviewed...

  14. Characteristic community structure of Florida's subtropical wetlands: the Florida wetland condition index

    Science.gov (United States)

    Depending upon the classification scheme applied, there are between 10 and 45 different wetland types in Florida. Land use and land cover change has a marked effect on wetland condition, and different wetland types are affected differentially depending on many abiotic and biotic ...

  15. SLOSS or Not? Factoring Wetland Size Into Decisions for Wetland Conservation, Enhancement, Restoration, and Creation

    Science.gov (United States)

    Mitigation or replacement of several small impacted wetlands or sites with fewer large wetlands can occur deliberately through the application of functional assessment methods (e.g., Adamus 1997) or coincidentally as the result of market-based mechanisms for wetland mitigation ba...

  16. Artificial wetlands - yes or no?

    Czech Academy of Sciences Publication Activity Database

    Horák, Václav; Lusk, Stanislav; Halačka, Karel; Lusková, Věra

    2004-01-01

    Roč. 4, č. 2 (2004), s. 119-127 ISSN 1642-3593. [International Symposium on the Ecology of Fluvial Fishes /9./. Lodz, 23.06.2003-26.06.2003] R&D Projects: GA AV ČR IBS6093007; GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z6093917 Keywords : floodplain * artificial wetlands * fish communities Subject RIV: EH - Ecology, Behaviour

  17. Development of a spatial forest data base for the eastern boreal forest region of Ontario. Forest fragmentation and biodiversity project technical report No. 14

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    In 1991, a spatial forest database over large regions of Ontario was initiated as the basis for research into forest fragmentation and biodiversity using data generated from the digital analysis of LANDSAT thematic mapper satellite data integrated into a geographic information system (GIS). The project was later extended into the eastern segment of the Boreal forest system. This report describes preparation of the spatial forest data base over the eastern Boreal Forest Region that extends from the northern boundary of the Great Lakes-St. Lawrence Forest Region and the southern margin of the James Bay Lowland, between the Ontario-Quebec border and a point west of Michipicoten on Lake Superior. The report describes the methodology used to produce the data base and results, including mapping of water, dense and sparse conifer forest, mixed forest, dense and sparse deciduous forest, poorly vegetated areas, recent cutovers of less than 10 years, old cutovers and burns, recent burns of less than 10 years, wetlands, bedrock outcrops, agriculture, built-up areas, and mine tailings.

  18. Artificial wetland for wastewater treatment

    International Nuclear Information System (INIS)

    Arias I, Carlos A; Brix, Hans

    2003-01-01

    The development of constructed wetland technology for wastewater treatment has gone a long way and from an experimental and unknown empirical method, which was capable of handling wastewater a sound technology was developed. Thanks to research, and the work of many public and private companies that have gather valuable operation information, constructed wetland technology has evolved to be a relievable, versatile and effective way to treat wastewater, run off, handle sludge and even improve environmental quality and provide recreation sites, while maintaining low operation and maintenance costs, and at the same time, producing water of quality that can meet stringent regulations, while being and environmental friendly solution to treat waste-waters. Constructed wetlands can be established in many different ways and its characteristics can differ greatly, according to the user needs, the geographic site and even the climatic conditions of the area. The following article deals with the general characteristics of the technology and the physical and chemical phenomena that govern the pollution reduction with in the different available systems

  19. NAFTA: The World's Largest Trading Zone Turns 20

    Science.gov (United States)

    Ferrarini, Tawni Hunt; Day, Stephen

    2014-01-01

    Everyone under the age of 20 who has grown up in North America has lived in the common market created by NAFTA--the North American Free Trade Agreement. In a zone linking the United States, Canada, and Mexico, most goods and investments flow freely across borders to users, consumers, and investors. In 1994, NAFTA created the largest relatively…

  20. Synchrotron Emission on the Largest Scales: Radio Detection of the ...

    Indian Academy of Sciences (India)

    Abstract. Shocks and turbulence generated during large-scale structure formation are predicted to produce large-scale, low surface-brightness synchrotron emission. On the largest scales, this emission is globally correlated with the thermal baryon distribution, and constitutes the 'syn- chrotron cosmic-web'. I present the ...

  1. Building Earth's Largest Library: Driving into the Future.

    Science.gov (United States)

    Coffman, Steve

    1999-01-01

    Examines the Amazon.com online bookstore as a blueprint for designing the world's largest library. Topics include selection; accessibility and convenience; quality of Web sites and search tools; personalized service; library collection development, including interlibrary loan; library catalogs and catalog records; a circulation system; costs;…

  2. Analysis of Human Standing Balance by Largest Lyapunov Exponent

    Directory of Open Access Journals (Sweden)

    Kun Liu

    2015-01-01

    Full Text Available The purpose of this research is to analyse the relationship between nonlinear dynamic character and individuals’ standing balance by the largest Lyapunov exponent, which is regarded as a metric for assessing standing balance. According to previous study, the largest Lyapunov exponent from centre of pressure time series could not well quantify the human balance ability. In this research, two improvements were made. Firstly, an external stimulus was applied to feet in the form of continuous horizontal sinusoidal motion by a moving platform. Secondly, a multiaccelerometer subsystem was adopted. Twenty healthy volunteers participated in this experiment. A new metric, coordinated largest Lyapunov exponent was proposed, which reflected the relationship of body segments by integrating multidimensional largest Lyapunov exponent values. By using this metric in actual standing performance under sinusoidal stimulus, an obvious relationship between the new metric and the actual balance ability was found in the majority of the subjects. These results show that the sinusoidal stimulus can make human balance characteristics more obvious, which is beneficial to assess balance, and balance is determined by the ability of coordinating all body segments.

  3. Worlds largest particle physics laboratory selects Proxim Wireless Mesh

    CERN Multimedia

    2007-01-01

    "Proxim Wireless has announced that the European Organization for Nuclear Research (CERN), the world's largest particle physics laboratory and the birthplace of the World Wide Web, is using it's ORiNOCO AP-4000 mesh access points to extend the range of the laboratory's Wi-Fi network and to provide continuous monitoring of the lab's calorimeters" (1/2 page)

  4. PNNL supercomputer to become largest computing resource on the Grid

    CERN Multimedia

    2002-01-01

    Hewlett Packard announced that the US DOE Pacific Northwest National Laboratory will connect a 9.3-teraflop HP supercomputer to the DOE Science Grid. This will be the largest supercomputer attached to a computer grid anywhere in the world (1 page).

  5. Toward sustainable harvesting of Africa's largest medicinal plant ...

    African Journals Online (AJOL)

    Global demand for treating prostate disorders with Prunus africana bark extract has made P. africana Africa's largest medicinal plant export. Unsustainable harvesting practices can lead to local extirpations of this multipurpose tree. Survey research targeting P. africana harvesters in a Tanzania forest reserve revealed that ...

  6. Interactions Between Wetlands and Tidal Inlets

    National Research Council Canada - National Science Library

    Sanchez, Alejandro

    2008-01-01

    This Coastal and Hydraulics Engineering Technical Note (CHETN) presents numerical simulations investigating how the loss of wetlands in estuaries modifies tidal processes in inlet navigation channels...

  7. Forest fires may cause cooling in boreal Canada

    Science.gov (United States)

    Bhattacharya, Atreyee

    2012-08-01

    As climate in North America continues to become warmer and drier through the 21st century, a new study finds that fire may be playing an increasingly important role in shaping the climate of the boreal regions of Canada. Forest fires change the amount of shortwave radiation absorbed by Earth's surface by reducing vegetation cover and changing the composition of plant species, thereby changing the reflectivity of the surface (albedo). Fires also affect other ecosystem processes and increase aerosol (particularly soot) emission and deposition, all of which alter regional climate through a series of feedbacks mechanisms. Jin et al. used satellite observations of surface albedo from 2000 to 2011 and fire perimeter data since 1970 to study how forest fires affect surface albedo and associated shortwave radiation at the surface, across forests in boreal Canada.

  8. The role of fire in the boreal carbon budget

    Science.gov (United States)

    Harden, J.W.; Trumbore, S.E.; Stocks, B.J.; Hirsch, A.; Gower, S.T.; O'Neill, K. P.; Kasischke, E.S.

    2000-01-01

    To reconcile observations of decomposition rates, carbon inventories, and net primary production (NPP), we estimated long-term averages for C exchange in boreal forests near Thompson, Manitoba. Soil drainage as defined by water table, moss cover, and permafrost dynamics, is the dominant control on direct fire emissions. In upland forests, an average of about 10-30% of annual NPP was likely consumed by fire over the past 6500 years since these landforms and ecosystems were established. This long-term, average fire emission is much larger than has been accounted for in global C cycle models and may forecast an increase in fire activity for this region. While over decadal to century times these boreal forests may be acting as slight net sinks for C from the atmosphere to land, periods of drought and severe fire activity may result in net sources of C from these systems.

  9. Growth Decline Linked to Warming-Induced Water Limitation in Hemi-Boreal Forests

    OpenAIRE

    Wu, Xiuchen; Liu, Hongyan; Guo, Dali; Anenkhonov, Oleg A.; Badmaeva, Natalya K.; Sandanov, Denis V.

    2012-01-01

    Hemi-boreal forests, which make up the transition from temperate deciduous forests to boreal forests in southern Siberia, have experienced significant warming without any accompanying increase in precipitation during the last 80 years. This climatic change could have a profound impact on tree growth and on the stability of forest ecosystems in this region, but at present evidence for these impacts is lacking. In this study, we report a recent dramatic decline in the growth of hemi-boreal fore...

  10. Climate-Induced Boreal Forest Change: Predictions versus Current Observations

    Science.gov (United States)

    Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

    2007-01-01

    For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

  11. Recreation and tourism induced changes in northern boreal environments

    OpenAIRE

    Kangas, K. (Katja)

    2009-01-01

    Abstract The popularity of nature-based tourism has increased worldwide and peripheral areas with conservational value, like protected areas, are attractive destinations. The recreational use and construction of tourism facilities can cause environmental degradation and decrease the conservational and recreational value of areas if not well planned and managed. The aim of this thesis was to improve our knowledge of recreation and tourism induced changes in northern boreal environments. Dir...

  12. Partial coupling and differential regulation of biologically and photochemically labile dissolved organic carbon across boreal aquatic networks

    Science.gov (United States)

    Lapierre, J.-F.; del Giorgio, P. A.

    2014-10-01

    Despite the rapidly increasing volume of research on the biological and photochemical degradation of DOC (dissolved organic carbon) in aquatic environments, little is known of the large-scale patterns in biologically and photochemically degradable DOC (BDOC and PDOC, respectively) in continental watersheds, and on the links that exist between these two key properties that greatly influence the flow of carbon from continents to oceans. Here we explored the patterns in the concentrations and proportions of BDOC and PDOC across hundreds of boreal lakes, rivers and wetlands spanning a large range of system trophic status and terrestrial influence, and compared the drivers of these two reactive pools of DOC at the landscape level. Using standardized incubations of natural waters, we found that the concentrations of BDOC and PDOC covaried across all systems studied but were nevertheless related to different pools of dissolved organic matter (DOM; identified by fluorescence analyses) in ambient waters. Concentrations of nutrients and protein-like fluorescent DOM (FDOM) explained nearly half of the variation in BDOC, whereas PDOC was exclusively predicted by DOM optical properties, consistent with the photochemical degradability of specific FDOM pools that we experimentally determined. The concentrations of colored DOM (CDOM), which we use here as a proxy of terrestrial influence, almost entirely accounted for the observed relationship between FDOM and the concentrations of both BDOC and PDOC. The concentrations of CDOM and of the putative biolabile fluorescence component shifted from complete decoupling in clear-water environments to strong coupling in darker streams and wetlands. This suggests a baseline autochthonous BDOC pool fueled by internal production that is gradually overwhelmed by land-derived BDOC as terrestrial influence increases across landscape gradients. The importance of land as a major source of both biologically and photochemically degradable DOC for

  13. Partial coupling and differential regulation of biologically and photo-chemically labile dissolved organic carbon across boreal aquatic networks

    Science.gov (United States)

    Lapierre, J.-F.; del Giorgio, P. A.

    2014-05-01

    Despite the rapidly increasing volume of research on the biological and photochemical degradation of DOC in aquatic environments, little is known on the large-scale patterns in biologically and photo-chemically degradable DOC (Bd-DOC and Pd-DOC, respectively) in continental watersheds, and on the links that exist between these two key properties that greatly influence the flow of carbon from continents to oceans. Here we explore the patterns of Bd- and Pd-DOC across hundreds of boreal lakes, rivers and wetlands spanning a large range of system trophy and terrestrial influence, and compared the drivers of these two reactive pools of DOC at the landscape level. Using standardized incubations of natural waters, we found that the concentrations of Bd- and Pd-DOC co-varied across all systems studied but were nevertheless related to different pools of dissolved organic matter (DOM, identified by fluorescence analyses) in ambient waters. A combination of nutrients and protein-like DOM explained nearly half of the variation in Bd-DOC, whereas Pd-DOC was exclusively predicted by DOM optical properties, consistent with the photochemical degradability of specific fluorescent DOM (FDOM) pools that we experimentally determined. The concentrations of colored DOM (CDOM), a proxy of terrestrial influence, almost entirely accounted for the observed relationship between FDOM and the concentrations of both Bd- and Pd-DOC. The concentrations of CDOM and of the putative bio-labile fluorescence component shifted from complete decoupling in clear-water environments to strong coupling in browner streams and wetlands. This suggests a baseline autochthonous Bd-DOC pool fuelled by internal production that is gradually overwhelmed by land-derived Bd-DOC as terrestrial influence increases across landscape gradients. The importance of land as a major source of both biologically and photo-chemically degradable DOC for continental watersheds resulted in a partial coupling of those carbon pools in

  14. Wise use of wetlands: current state of protection and utilization of Chinese wetlands and recommendations for improvement.

    Science.gov (United States)

    Wang, Yanxia; Yao, Yong; Ju, Meiting

    2008-06-01

    Wetland protection and utilization sometimes appear to be in conflict, but promoting the wise use of wetlands can solve this problem. All countries face the challenge of sustainable development of wetlands to a greater or lesser extent, but the problem is especially urgent in developing countries, such as China, that want to accelerate their economic development without excessive environmental cost. Chinese wetlands contribute greatly to economic development, but improper use of these natural resources has endangered their existence. It is thus necessary to provide scientific guidance to managers and users of wetlands. In this paper, we analyze the present status of Chinese wetland protection and utilization, and discuss problems in six categories: a lack of public awareness of the need for wetland protection; insufficient funding for wetland protection and management; an imperfect legal system to protect wetlands; insufficient wetland research; lack of coordination among agencies and unclear responsibilities; and undeveloped technologies related to wetland use and protection. The wise use of Chinese wetlands will require improvements in four main areas: increased wetland utilization research, scientific management of wetland utilization, improved laws and regulations to protect wetlands, and wider dissemination of wetland knowledge. Based on these categories, we propose a framework for the optimization of wetland use by industry to provide guidance for China and other countries that cannot sacrifice economic benefits to protect their wetlands.

  15. North American Wetlands and Mosquito Control

    Science.gov (United States)

    Rey, Jorge R.; Walton, William E.; Wolfe, Roger J.; Connelly, Roxanne; O’Connell, Sheila M.; Berg, Joe; Sakolsky-Hoopes, Gabrielle E.; Laderman, Aimlee D.

    2012-01-01

    Wetlands are valuable habitats that provide important social, economic, and ecological services such as flood control, water quality improvement, carbon sequestration, pollutant removal, and primary/secondary production export to terrestrial and aquatic food chains. There is disagreement about the need for mosquito control in wetlands and about the techniques utilized for mosquito abatement and their impacts upon wetlands ecosystems. Mosquito control in wetlands is a complex issue influenced by numerous factors, including many hard to quantify elements such as human perceptions, cultural predispositions, and political climate. In spite of considerable progress during the last decades, habitat protection and environmentally sound habitat management still remain inextricably tied to politics and economics. Furthermore, the connections are often complex, and occur at several levels, ranging from local businesses and politicians, to national governments and multinational institutions. Education is the key to lasting wetlands conservation. Integrated mosquito abatement strategies incorporate many approaches and practicable options, as described herein, and need to be well-defined, effective, and ecologically and economically sound for the wetland type and for the mosquito species of concern. The approach will certainly differ in response to disease outbreaks caused by mosquito-vectored pathogens versus quality of life issues caused by nuisance-biting mosquitoes. In this contribution, we provide an overview of the ecological setting and context for mosquito control in wetlands, present pertinent information on wetlands mosquitoes, review the mosquito abatement options available for current wetlands managers and mosquito control professionals, and outline some necessary considerations when devising mosquito control strategies. Although the emphasis is on North American wetlands, most of the material is applicable to wetlands everywhere. PMID:23222252

  16. Ecosystem Responses to Partial Harvesting in Eastern Boreal Mixedwood Stands

    Directory of Open Access Journals (Sweden)

    Brian D. Harvey

    2013-05-01

    Full Text Available Partial harvesting has been proposed as a key aspect to implementing ecosystem management in the Canadian boreal forest. We report on a replicated experiment located in boreal mixedwoods of Northwestern Quebec. In the winter of 2000–2001, two partial harvesting treatments, one using a dispersed pattern, and a second, which created a (400 m2 gap pattern, were applied to a 90-year-old aspen-dominated mixed stand. The design also included a clear cut and a control. Over the course of the following eight years, live tree, coarse woody debris, regeneration and ground beetles were inventoried at variable intervals. Our results indicate that all harvesting treatments created conditions favorable to balsam fir (Abies balsamea sapling growth and trembling aspen (Populus tremuloides sapling recruitment. However, balsam fir and trembling aspen regeneration and ground beetles response to gap cuts were closer to patterns observed in clear cuts than in dispersed harvesting. The underlying reasons for these differing patterns can be linked to factors associated with the contrasting light regimes created by the two partial harvesting treatments. The study confirms that partially harvesting is an ecologically sound approach in boreal mixedwoods and could contribute to maintaining the distribution of stand ages at the landscape level.

  17. Slowing the rate of loss of mineral wetlands on human dominated landscapes - Diversification of farmers markets to include carbon (Invited)

    Science.gov (United States)

    Creed, I. F.; Badiou, P.; Lobb, D.

    2013-12-01

    Canada is the fourth-largest exporter of agriculture and agri-food products in the world (exports valued at 28B), but instability of agriculture markets can make it difficult for farmers to cope with variability, and new mechanisms are needed for farmers to achieve economic stability. Capitalizing on carbon markets will help farmers achieve environmentally sustainable economic performance. In order to have a viable carbon market, governments and industries need to know what the carbon capital is and what potential there is for growth, and farmers need financial incentives that will not only allow them to conserve existing wetlands but that will also enable them to restore wetlands while making a living. In southern Ontario, farmers' needs to maximize the return on investment on marginal lands have resulted in loss of 70-90% of wetlands, making this region one of the most threatened region in terms of wetland degradation and loss in Canada. Our project establishes the role that mineral wetlands have in the net carbon balance by contributing insight into the potential benefits to carbon management provided by wetland restoration efforts in these highly degraded landscapes. The goal was to establish the magnitude of carbon offsets that could be achieved through wetland conservation (securing existing carbon stocks) and restoration (creating new carbon stocks). The experimental design was to focus on (1) small (0.2-2.0 ha) and (2) isolated (no inflow or outflow) mineral wetlands with the greatest restoration potential that included (3) a range of restoration ages (drained (0 yr), 3 yr, 6 yr, 12 yr, 20 yr, 35 yr, intact marshes) to capture potential changes in rates of carbon sequestration with restoration age of wetland. From each wetland, wetland soil carbon pools samples were collected at four positions: centre of wetland (open-water); emergent vegetation zone; wet meadow zone where flooding often occurs (i.e., high water mark); and upland where flooding rarely

  18. Wetland succession in a permafrost collapse: interactions between fire and thermokarst

    Directory of Open Access Journals (Sweden)

    I. H. Myers-Smith

    2008-09-01

    Full Text Available To determine the influence of fire and thermokarst in a boreal landscape, we investigated peat cores within and adjacent to a permafrost collapse feature on the Tanana River Floodplain of Interior Alaska. Radioisotope dating, diatom assemblages, plant macrofossils, charcoal fragments, and carbon and nitrogen content of the peat profile indicate ~600 years of vegetation succession with a transition from a terrestrial forest to a sedge-dominated wetland over 100 years ago, and to a Sphagnum-dominated peatland in approximately 1970. The shift from sedge to Sphagnum, and a decrease in the detrended tree-ring width index of black spruce trees adjacent to the collapse coincided with an increase in the growing season temperature record from Fairbanks. This concurrent wetland succession and reduced growth of black spruce trees indicates a step-wise ecosystem-level response to a change in regional climate. In 2001, fire was observed coincident with permafrost collapse and resulted in lateral expansion of the peatland. These observations and the peat profile suggest that future warming and/or increased fire disturbance could promote permafrost degradation, peatland expansion, and increase carbon storage across this landscape; however, the development of drought conditions could reduce the success of both black spruce and Sphagnum, and potentially decrease the long-term ecosystem carbon storage.

  19. WETCHIMP-WSL: intercomparison of wetland methane emissions models over West Siberia

    Directory of Open Access Journals (Sweden)

    T. J. Bohn

    2015-06-01

    Full Text Available Wetlands are the world's largest natural source of methane, a powerful greenhouse gas. The strong sensitivity of methane emissions to environmental factors such as soil temperature and moisture has led to concerns about potential positive feedbacks to climate change. This risk is particularly relevant at high latitudes, which have experienced pronounced warming and where thawing permafrost could potentially liberate large amounts of labile carbon over the next 100 years. However, global models disagree as to the magnitude and spatial distribution of emissions, due to uncertainties in wetland area and emissions per unit area and a scarcity of in situ observations. Recent intensive field campaigns across the West Siberian Lowland (WSL make this an ideal region over which to assess the performance of large-scale process-based wetland models in a high-latitude environment. Here we present the results of a follow-up to the Wetland and Wetland CH4 Intercomparison of Models Project (WETCHIMP, focused on the West Siberian Lowland (WETCHIMP-WSL. We assessed 21 models and 5 inversions over this domain in terms of total CH4 emissions, simulated wetland areas, and CH4 fluxes per unit wetland area and compared these results to an intensive in situ CH4 flux data set, several wetland maps, and two satellite surface water products. We found that (a despite the large scatter of individual estimates, 12-year mean estimates of annual total emissions over the WSL from forward models (5.34 ± 0.54 Tg CH4 yr−1, inversions (6.06 ± 1.22 Tg CH4 yr−1, and in situ observations (3.91 ± 1.29 Tg CH4 yr−1 largely agreed; (b forward models using surface water products alone to estimate wetland areas suffered from severe biases in CH4 emissions; (c the interannual time series of models that lacked either soil thermal physics appropriate to the high latitudes or realistic emissions from unsaturated peatlands tended to be dominated by a single environmental driver

  20. East African wetland-catchment data base for sustainable wetland management

    Science.gov (United States)

    Leemhuis, Constanze; Amler, Esther; Diekkrüger, Bernd; Gabiri, Geofrey; Näschen, Kristian

    2016-10-01

    Wetlands cover an area of approx. 18 Mio ha in the East African countries of Kenya, Rwanda, Uganda and Tanzania, with still a relative small share being used for food production. Current upland agricultural use intensification in these countries due to demographic growth, climate change and globalization effects are leading to an over-exploitation of the resource base, followed by an intensification of agricultural wetland use. We aim on translating, transferring and upscaling knowledge on experimental test-site wetland properties, small-scale hydrological processes, and water related ecosystem services under different types of management from local to national scale. This information gained at the experimental wetland/catchment scale will be embedded as reference data within an East African wetland-catchment data base including catchment physical properties and a regional wetland inventory serving as a base for policy advice and the development of sustainable wetland management strategies.

  1. East African wetland-catchment data base for sustainable wetland management

    Directory of Open Access Journals (Sweden)

    C. Leemhuis

    2016-10-01

    Full Text Available Wetlands cover an area of approx. 18 Mio ha in the East African countries of Kenya, Rwanda, Uganda and Tanzania, with still a relative small share being used for food production. Current upland agricultural use intensification in these countries due to demographic growth, climate change and globalization effects are leading to an over-exploitation of the resource base, followed by an intensification of agricultural wetland use. We aim on translating, transferring and upscaling knowledge on experimental test-site wetland properties, small-scale hydrological processes, and water related ecosystem services under different types of management from local to national scale. This information gained at the experimental wetland/catchment scale will be embedded as reference data within an East African wetland-catchment data base including catchment physical properties and a regional wetland inventory serving as a base for policy advice and the development of sustainable wetland management strategies.

  2. Temporal properties of seismicity and largest earthquakes in SE Carpathians

    Directory of Open Access Journals (Sweden)

    S. Byrdina

    2006-01-01

    Full Text Available In order to estimate the hazard rate distribution of the largest seismic events in Vrancea, South-Eastern Carpathians, we study temporal properties of historical and instrumental catalogues of seismicity. First, on the basis of Generalized Extreme Value theory we estimate the average return period of the largest events. Then, following Bak et al. (2002 and Corral (2005a, we study scaling properties of recurrence times between earthquakes in appropriate spatial volumes. We come to the conclusion that the seismicity is temporally clustered, and that the distribution of recurrence times is significantly different from a Poisson process even for times largely exceeding corresponding periods of foreshock and aftershock activity. Modeling the recurrence times by a gamma distributed variable, we finally estimate hazard rates with respect to the time elapsed from the last large earthquake.

  3. Worlds Largest Wave Energy Project 2007 in Wales

    DEFF Research Database (Denmark)

    Christensen, Lars; Friis-Madsen, Erik; Kofoed, Jens Peter

    2006-01-01

    This paper introduces world largest wave energy project being developed in Wales and based on one of the leading wave energy technologies. The background for the development of wave energy, the total resource ands its distribution around the world is described. In contrast to wind energy turbines...... Dragon has to be scaled in accordance with the wave climate at the deployment site, which makes the Welch demonstrator device the worlds largest WEC so far with a total width of 300 meters. The project budget, the construction methods and the deployment site are also given....... a large number of fundamentally different technologies are utilised to harvest wave energy. The Wave Dragon belongs to the wave overtopping class of converters and the paper describes the fundamentals and the technical solutions used in this wave energy converter. An offshore floating WEC like the Wave...

  4. Upgrade and modernization of the six largest HPPs in Macedonia

    International Nuclear Information System (INIS)

    Hadzievska, M.

    2002-01-01

    In 1998, Electric Power Company of Macedonia and the International Bank for Development and Reconstruction, started the Power System Improvement Project a part of which is the Project for rehabilitation of the six largest Hydro Power Plants (HPPs) in the Republic of Macedonia. The six largest Hydro Power Plants (HPP Vrutok, HPP Raven, HPP Globocica, HPP Tikves and HPP Spilje and HPP Vrben) represent 91% of the country's hydropower capacity. The rehabilitation program is divided in five parts (contracts) and covers the refurbishment of: turbine runners, turbine and generator bearings, governors, inlet valves; butterfly valves, including accessories and control systems; generators, excitation system and voltage regulation; control system, protection and LV auxiliaries; switch gears and control gears in 220 kV, 110 kV and 35 kV substations. At the moment, only the implementation of switch gears has started, the first phase is already finished, and 50 % of the rehabilitation works for HPP Vrutok, the largest HPP, has been finished. With the realization of this project, greater hydropower production is expected. It also expected that HPPs will become a more vital part of the Macedonian power system

  5. Kabob report. Pt. 3. Chevron plant largest in Canada

    Energy Technology Data Exchange (ETDEWEB)

    1971-01-18

    Canada's largest fully integrated primary natural- gas processing and sulfur recovery plant is heading for physical completion by mid-summer of 1971. The Ralph M. Parsons Construction Co. of Canada Ltd., contractor for the S. Kaybob Beaverhill Lake Unit No. 3 gas-processing plant, to be operated by Chevron Standard Ltd., estimates completion by June 30. After that the $80 million complex will have tests and running in time. With any reasonable luck, it should be fully on stream by late summer. Preliminary construction on the 200-acre site started in Jan. 1969 with clearing and contouring of the main plant and sulfur storage sites. Initial rough grading started in the early summer, after spring breakup was over. Delivery of most of the big items was made by rail because the local secondary roads were inadequate for them. Concrete has been a large item. The contractor has its own batch plant on the site for the estimated 28,000 cu yd which will be needed for the whole job. Dominating the construction site from the start has been the high sulfur plant stack, first of the major items to be finished. It will serve to dispose of effluent from the largest sulfur recovery unit in Canada. It is 465 ft high, one of the largest in Alberta, and a significant contribution to pollution control and environmental protection.

  6. 398 ASSESSMENT OF WETLAND VALUATION PROCESSES FOR ...

    African Journals Online (AJOL)

    Osondu

    This study therefore examined the processes involved in the valuation of wetland resources for ... of the subsistence uses of wetland resources are also not ... hydrological cycle, playing a key role in the provision ..... Management Strategies at the River Basin Scale. A ... Using. GIS: A Thesis Submitted to the Graduate Faculty.

  7. Stochastic modeling of wetland-groundwater systems

    Science.gov (United States)

    Bertassello, Leonardo Enrico; Rao, P. Suresh C.; Park, Jeryang; Jawitz, James W.; Botter, Gianluca

    2018-02-01

    Modeling and data analyses were used in this study to examine the temporal hydrological variability in geographically isolated wetlands (GIWs), as influenced by hydrologic connectivity to shallow groundwater, wetland bathymetry, and subject to stochastic hydro-climatic forcing. We examined the general case of GIWs coupled to shallow groundwater through exfiltration or infiltration across wetland bottom. We also examined limiting case with the wetland stage as the local expression of the shallow groundwater. We derive analytical expressions for the steady-state probability density functions (pdfs) for wetland water storage and stage using few, scaled, physically-based parameters. In addition, we analyze the hydrologic crossing time properties of wetland stage, and the dependence of the mean hydroperiod on climatic and wetland morphologic attributes. Our analyses show that it is crucial to account for shallow groundwater connectivity to fully understand the hydrologic dynamics in wetlands. The application of the model to two different case studies in Florida, jointly with a detailed sensitivity analysis, allowed us to identify the main drivers of hydrologic dynamics in GIWs under different climate and morphologic conditions.

  8. Diversity patterns of temporary wetland macroinvertebrate ...

    African Journals Online (AJOL)

    Although macroinvertebrates are potentially useful for assessing the condition of temporary wetlands, little is yet known about them. Macroinvertebrate assemblages were assessed in 138 temporary wetlands in the south-western Cape, recording 126 taxa. However, predicted richness estimates were all higher than the ...

  9. Advancing the use of minirhizotrons in wetlands

    Science.gov (United States)

    C. M. Iversen; M. T. Murphy; M. F. Allen; J. Childs; D. M. Eissenstat; E.A. Lilleskov; T. M. Sarjala; V. L. Sloan; P. F. Sullivan

    2012-01-01

    Background. Wetlands store a substantial amount of carbon (C) in deep soil organic matter deposits, and play an important role in global fluxes of carbon dioxide and methane. Fine roots (i.e., ephemeral roots that are active in water and nutrient uptake) are recognized as important components of biogeochemical cycles in nutrient-limited wetland ecosystems. However,...

  10. Macroinvertebrate variation in endorheic depression wetlands in ...

    African Journals Online (AJOL)

    Aquatic macroinvertebrates are rarely used in wetland assessments due to their variation. However, in terms of biodiversity, these invertebrates form an important component of wetland fauna. Spatial and temporal variation of macroinvertebrate assemblages in endorheic depressions (locally referred to as 'pans') in ...

  11. The carbon balance of North American wetlands

    Science.gov (United States)

    Scott D. Bridgham; J. Patrick Megonigal; Jason K. Keller; Norman b. Bliss; Carl Trettin

    2006-01-01

    We examine the carbon balance of North American wetlands by reviewing and synthesizing the published literature and soil databases. North American wetlands contain about 220 Pg C, most of which is in peat. They are a small to moderate carbon sink of about 49 Tg C yr-l, although the uncertainty around this estimate is greater than 100%, with the...

  12. Pesticide mitigation capacities of constructed wetlands

    Science.gov (United States)

    Matthew T. Moore; Charles M. Cooper; Sammie Smith; John H. Rodgers

    2000-01-01

    This research focused on using constructed wetlands along field perimeters to buffer receiving water against potential effects of pesticides associated with storm runoff. The current study incorporated wetland mesocosm sampling following simulated runoff events using chlorpyrifos, atrazine, and metolachlor. Through this data collection and simple model analysis,...

  13. Fire impacts on European Boreal soils: A review

    Science.gov (United States)

    Pereira, Paulo; Oliva, Marc; Cerda, Artemi

    2016-04-01

    Fire is an important natural disturbance in boreal ecosystems, fundamental to understand plant distribution (Ryan, 2002; Wallenius et al., 2004; Granstrom, 2001). Nevertheless, nowadays the intense and successful, fire suppression measures are changing their ecological role (Pereira et al., 2013a,b). This is consequence of the lack of understanding of stakeholders and decision makers about the role of the fire in the ecosystems (Mierasukas and Pereira, 2013; Pereira et al., 2016). This fire suppression measures are increasing the amount of fuel accumulation and the risk of severe wildfires, which can increase of frequency and severity in a context of climate change. Fire is a good tool for landscape management and restoration of degraded ecosystems (Toivanen and Kotiaho, 2007). Fire is considered a soil forming factor (Certini, 2014) and in boreal environments it has been observed that low fire severities, do not change importantly soil properties, mean fire severities induce positive impacts on soil, since add an important amounts of nutrients into soil profile and high severity fires had negative impacts due to the high consumption of organic matter (Vanha-Majamaa et al., 2007; Pereira et al., 2014). References Certini, G., 2014. Fire as a soil-forming factor. Ambio, 43, 191-195 Granstrom A. 2001. Fire management for biodiversity in the European Boreal forest. Scandinavian Journal of Forest Research 3: 62-69. Mierauskas, P., Pereira, P. (2013) Stakeholders perception about prescribed fire use in Lithuania. First results, Flamma, 4(3), 157-161. Pereira, P., Cerdà, A., Jordán, A., Bolutiene, V., Úbeda, X., Pranskevicius, M., Mataix-Solera, J. (2013) Spatio-temporal vegetation recuperation after a grassland fire in Lithuania, Procedia Environmental Sciences, 19:856-864 Pereira, P., Mierauskas, P., Ubeda, X., Mataix-Solera, J.,Cerda, A. (2012) Fire in protected areas - the effect of the protection and importance of fire management, Environmental Research

  14. Different regional climatic drivers of Holocene large wildfires in boreal forests of northeastern America

    Science.gov (United States)

    Remy, Cécile C.; Hély, Christelle; Blarquez, Olivier; Magnan, Gabriel; Bergeron, Yves; Lavoie, Martin; Ali, Adam A.

    2017-03-01

    Global warming could increase climatic instability and large wildfire activity in circumboreal regions, potentially impairing both ecosystem functioning and human health. However, links between large wildfire events and climatic and/or meteorological conditions are still poorly understood, partly because few studies have covered a wide range of past climate-fire interactions. We compared palaeofire and simulated climatic data over the last 7000 years to assess causes of large wildfire events in three coniferous boreal forest regions in north-eastern Canada. These regions span an east-west cline, from a hilly region influenced by the Atlantic Ocean currently dominated by Picea mariana and Abies balsamea to a flatter continental region dominated by Picea mariana and Pinus banksiana. The largest wildfires occurred across the entire study zone between 3000 and 1000 cal. BP. In western and central continental regions these events were triggered by increases in both the fire-season length and summer/spring temperatures, while in the eastern region close to the ocean they were likely responses to hydrological (precipitation/evapotranspiration) variability. The impact of climatic drivers on fire size varied spatially across the study zone, confirming that regional climate dynamics could modulate effects of global climate change on wildfire regimes.

  15. TALL-HERB BOREAL FORESTS ON NORTH URAL

    Directory of Open Access Journals (Sweden)

    A. A. Aleinikov

    2016-09-01

    Full Text Available Background. One of the pressing aims of today’s natural resource management is its re-orientation to preserving and restoring ecological functions of ecosystems, among which the function of biodiversity maintenance plays an indicator role. The majority of today’s forests have not retained their natural appearance as the result of long-standing human impact. In this connection, refugia studies are becoming particularly interesting, as they give us an insight into the natural appearance of forests. Materials and methods. Studies were performed in dark conifer forests of the Pechora–Ilych reserve, in the lower reaches of the Bol’shaya Porozhnyaya River in 2013 yr. Vegetation data sampling was done at 50 temporary square plots of a fixed size (100 m2 randomly placed within a forest type. A list of plant species with species abundance was made for each forest layer. The overstorey (or tree canopy layer was denoted by the Latin letter A. The understorey layer (indicated by the letter B included tree undergrowth and tall shrubs. Ground vegetation was subdivided into the layers C and D. Layer C (field layer comprised the herbaceous species (herbs, grasses, sedges and dwarf shrubs together with low shrubs, tree and shrub seedlings. The height of the field layer was defined by the maximal height of the herbaceous species, ferns, and dwarf shrubs; the height varied from several cm to more than 200 cm in the ‘tall-herb’ forest types. Layer D (bottom layer included cryptogamic species (bryophytes and lichens. Species abundance in the each layer was usually assessed using the Braun-Blanquet cover scale (Braun-Blanquet 1928. The nomenclature used follows Cherepanov’s (1995 for vascular plants, and Ignatov & Afonina’s (1992. Results. The present article contains descriptions of unique tall-herb boreal forests of European Russia preserved in certain refugia which did not experience prolonged anthropogenic impact or any other catastrophes

  16. Are isolated wetlands groundwater recharge hotspots?

    Science.gov (United States)

    Webb, A.; Wicks, C. M.; Brantley, S. T.; Golladay, S. W.

    2017-12-01

    Geographically isolated wetlands (GIWs) are a common landscape feature in the mantled karst terrain of the Dougherty Plain physiographic district in Southwestern Georgia. These wetlands support a high diversity of obligate/facultative wetland flora and fauna, including several endangered species. While the ecological value of these wetlands is well documented, the hydrologic effects of GIWs on larger watershed processes, such as water storage and aquifer recharge, are less clear. Our project seeks to understand the spatial and temporal variation in recharge across GIWs on this mantled karst landscape. In particular, our first step is to understand the role of isolated wetlands (presumed sinkholes) in delivering water into the underlying aquifer. Our hypothesis is that many GIWs are actually water-filled sinkholes and are locations of focused recharge feeding either the underlying upper Floridan aquifer or the nearby creeks. If we are correct, then these sinkholes should exhibit "drains", i.e., conduits into the limestone bedrock. Thus, the purposes of our initial study are to image the soil-limestone contact (the buried epikarstic surface) and determine if possible subsurface drains exist. Our field work was conducted at the Joseph W Jones Ecological Research Center. During the dry season, we conducted ground penetrating radar (GPR) surveys as grids and lines across a large wetland and across a field with no surface expression of a wetland or sinkhole. We used GPR (200 MHz antenna) with 1-m spacing between antenna and a ping rate of 1 ping per 40 centimeters. Our results show that the epikarstic surface exhibits a drain underneath the wetland (sinkhole) and that no similar feature was seen under the field, even though the survey grid and spacing were similar. As our project progresses, we will survey additional wetlands occurring across varying soil types to determine the spatial distribution between surface wetlands and subsurface drains.

  17. Is wetland mitigation successful in Southern California?

    Science.gov (United States)

    Cummings, D. L.; Rademacher, L. K.

    2004-12-01

    Wetlands perform many vital functions within their landscape position; they provide unique habitats for a variety of flora and fauna and they act as treatment systems for upstream natural and anthropogenic waste. California has lost an estimated 91% of its wetlands. Despite the 1989 "No Net Loss" policy and mitigation requirements by the regulatory agencies, the implemented mitigation may not be offsetting wetlands losses. The "No Net Loss" policy is likely failing for numerous reasons related to processes in the wetlands themselves and the policies governing their recovery. Of particular interest is whether these mitigation sites are performing essential wetlands functions. Specific questions include: 1) Are hydric soil conditions forming in mitigation sites; and, 2) are the water quality-related chemical transformations that occur in natural wetlands observed in mitigation sites. This study focuses on success (or lack of success) in wetlands mitigation sites in Southern California. Soil and water quality investigations were conducted in wetland mitigation sites deemed to be successful by vegetation standards. Observations of the Standard National Resource Conservation Service field indicators of reducing conditions were made to determine whether hydric soil conditions have developed in the five or more years since the implementation of mitigation plans. In addition, water quality measurements were performed at the inlet and outlet of these mitigation sites to determine whether these sites perform similar water quality transformations to natural wetlands within the same ecosystem. Water quality measurements included nutrient, trace metal, and carbon species measurements. A wetland location with minimal anthropogenic changes and similar hydrologic and vegetative features was used as a control site. All sites selected for study are within a similar ecosystem, in the interior San Diego and western Riverside Counties, in Southern California.

  18. 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.

  19. Transient peat properties in two pond-peatland complexes in the sub-humid Western Boreal Plain, Canada

    Directory of Open Access Journals (Sweden)

    R.M. Petrone

    2008-03-01

    Full Text Available In the Canadian Western Boreal Plain (WBP, wetlands (ponds and peatlands comprise up to 50% of the landscape and represent unique habitat where summer precipitation is often outpaced by evapotranspiration and hillslope groundwater position does not follow topography. In this sub-humid location, groundwater fluxes and stores in riparian peatlands influence pond water levels and root zone moisture sources for forested uplands. To accurately describe the transport and retention of water in peat, it is important to consider peat subsidence. This paper quantifies the amount and effect of seasonal subsidence in a riparian peatland in the Utikuma Lake region in north-central Alberta, Canada. Results demonstrate that the deep and poorly decomposed peat deposits are resistant to compression, and that thick (and persistent ground frost hinders pore collapse (shrinkage above the water table until late summer when the ground has thawed. Even then, subsidence is still limited to the top 50 cm and is not closely related to changes in peatland water table or pond water level. Thus the water balance of these ponds and riparian areas appears to be less sensitive to peat volume changes than it is to the persistence of a substantial frost layer well into the snow-free period.

  20. Characterization of breeding habitats for black and surf scoters in the eastern boreal forest and subarctic regions of Canada

    Science.gov (United States)

    Perry, M.C.; Kidwell, D.M.; Wells, A.M.; Lohnes, E.J.R.; Osenton, P.C.; Altmann, S.H.; Hanson, Alan; Kerekes, Joseph; Paquet, Julie

    2006-01-01

    We analyzed characteristics of wetland habitats used by breeding black scoters (Melanitta nigra) and surf scoters (M. perspicillata) in the eastern boreal forest and subarctic regions of Canada based on satellite telemetry data collected in the spring and summer. During 2002 and 2004, nine black scoters (four males, five females) were tracked to breeding areas in Quebec, Manitoba, and Northwest Territories. In addition, in 2001?04, seven surf scoters (three males, four females) were tracked to breeding areas in Labrador, Quebec, Northwest Territories, and Nunavut. Based on satellite telemetry data, locations of black and surf scoters in breeding areas were not significantly different in regard to latitude and longitude. Presumed breeding areas were manually plotted on topographic maps and percent cover type and water were estimated. Breeding habitat of black scoters was significantly different than that for surf scoters, with black scoters mainly using open (tundra) areas (44%) and surf scoters using mainly forest areas (66%). Surf scoters presumed breeding areas were at significantly higher elevations than areas used by black scoters. Some breeding areas were associated with islands, but the role of islands for breeding areas is equivocal. These results aid in the identification of potentially critical breeding areas and provide a baseline classification of breeding habitats used by these two species.

  1. Co-regulation of redox processes in freshwater wetlands as a function of organic matter availability?

    International Nuclear Information System (INIS)

    Alewell, C.; Paul, S.; Lischeid, G.; Storck, F.R.

    2008-01-01

    Wetlands have important filter functions in landscapes but are considered to be the biggest unknowns regarding their element dynamics under global climate change. Information on sink and source function of sulphur, nitrogen, organic matter and acidity in wetlands is crucial for freshwater regeneration. Recent results indicate that redox processes are not completely controlled by the sequential reduction chain (that is electron acceptor availability) but that electron donor availability may be an important regulator. Our hypothesis was that only sites which are limited in their electron donor availability (low concentrations of dissolved organic carbon (DOC)) follow the concept of the sequential reduction chain. We compared the results of two freshwater wetland systems: 1) three forested fens within a boreal spruce catchment in a low mountain range in southern Germany (high DOC regime) and 2) three floodplain soils within a groundwater enrichment area in the Rhein valley in northwest Switzerland (low DOC regime). Micro scale investigations (a few cm 3 ) with dialyse chambers as well as soil solution and groundwater concentrations at the forested fens (high DOC regime) indicated simultaneous consumption of nitrate and sulphate with release of iron, manganese and methane (CH 4 ) as well as an enrichment in stable sulphur isotopes indicating a co-existence of processes attributed to different redox gradients. Soil and aquifer gas measurements down to 4.6 m at the groundwater enrichment site (low DOC regime and carbon limitation) showed extreme high rates of metabolism with carbon dioxide (CO 2 ) , dinitrous oxide (N 2 O) and CH 4 concentrations reaching fifty, thirty and three times atmospheric concentrations, respectively. Simultaneously, groundwater oxygen (O 2 ) saturation was between 50 and 95%. We concluded that independent of DOC regime the sequential reduction chain was not a suitable concept in our systems. Instead of electron acceptor or donor availability

  2. 76 FR 79145 - Floodplain Management and Protection of Wetlands

    Science.gov (United States)

    2011-12-21

    ...] RIN 2501-AD51 Floodplain Management and Protection of Wetlands Correction In proposed rule document... Type of proposed action Type of proposed action (new Wetlands or 100- Non-wetlands area reviewable... construction in wetlands locations. \\2\\ Or those paragraphs of Sec. 55.20 that are applicable to an action...

  3. 7 CFR 1410.10 - Restoration of wetlands.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Restoration of wetlands. 1410.10 Section 1410.10... Restoration of wetlands. (a) An owner or operator who entered into a CRP contract on land that is suitable for restoration to wetlands or that was restored to wetlands while under such contract, may, if approved by CCC...

  4. 7 CFR 12.30 - NRCS responsibilities regarding wetlands.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false NRCS responsibilities regarding wetlands. 12.30 Section 12.30 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND CONSERVATION Wetland Conservation § 12.30 NRCS responsibilities regarding wetlands. (a) Technical and...

  5. 44 CFR 10.14 - Flood plains and wetlands.

    Science.gov (United States)

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Flood plains and wetlands. 10... Flood plains and wetlands. For any action taken by FEMA in a flood plain or wetland, the provisions of... Executive Order 11988, Flood Plain Management, and Executive Order 11990, Protection of Wetlands (44 CFR...

  6. On leadership and success in professional wetland science

    Science.gov (United States)

    The Society of Wetland Scientists and the wetland profession are fortunate to have an abundance of leaders. These leaders respond to the needs of the Society for guidance and direction. They also consistently advance wetland science and improve the quality of wetland management...

  7. Natural wetland in China | Pan | African Journal of Environmental ...

    African Journals Online (AJOL)

    As it is known to all, wetland is one of the most crucial ecosystems in the world, with large varieties in China. How to protect wetland in China has become a more serious problem and five typical wetlands were selected in the article to illustrate the condition. Through the comparison between the past and present of wetland, ...

  8. Determination of the health of Lunyangwa wetland using Wetland Classification and Risk Assessment Index

    Science.gov (United States)

    Wanda, Elijah M. M.; Mamba, Bhekie B.; Msagati, Titus A. M.; Msilimba, Golden

    2016-04-01

    Wetlands are major sources of various ecological goods and services including storage and distribution of water in space and time which help in ensuring the availability of surface and groundwater throughout the year. However, there still remains a poor understanding of the range of values of water quality parameters that occur in wetlands either in its impacted state or under natural conditions. It was thus imperative to determine the health of Lunyangwa wetland in Mzuzu City in Malawi in order to classify and determine its state. This study used the Escom's Wetland Classification and Risk Assessment Index Field Guide to determine the overall characteristics of Lunyangwa wetland and to calculate its combined Wetland Index Score. Data on site information, field measurements (i.e. EC, pH, temperature and DO) and physical characteristics of Lunyangwa wetland were collected from March, 2013 to February, 2014. Results indicate that Lunyangwa wetland is a largely open water zone which is dominated by free-floating plants on the water surface, beneath surface and emergent in substrate. Furthermore, the wetland can be classified as of a C ecological category (score = 60-80%), which has been moderately modified with moderate risks of the losses and changes occurring in the natural habitat and biota in the wetland. It was observed that the moderate modification and risk were largely because of industrial, agricultural, urban/social catchment stressors on the wetland. This study recommends an integrated and sustainable management approach coupled with continuous monitoring and evaluation of the health of the wetland for all stakeholders in Mzuzu City. This would help to maintain the health of Lunyangwa wetland which is currently at risk of being further modified due to the identified catchment stressors.

  9. BUFFER ZONE METHOD, LAND USE PLANNING AND CONSERVATION STRATEGIES ABOUT WETLANDS UNDER URBANIZATION PRESSURE IN TURKEY

    OpenAIRE

    Ergen, Baris

    2010-01-01

    Wetlands are special areas that they offer habitat for terrestrial and water life. Wetlands are nest sides also for amphibian, for this reason wetlands offer wide range diversity for species. Wetlands are also reproduction regions for birds. Wetlands have special importance for ecosystem because they obstruct erosion. Wetlands absorb contaminants from water therefore wetlands contribute to clean water and they offer more potable water. Wetlands obstruct waterflood. In that case wetlands must ...

  10. The Environmental Responsibility of the World’s Largest Banks

    Directory of Open Access Journals (Sweden)

    Ryszawska Bożena

    2018-03-01

    Full Text Available Sustainability transition is changing the role and function of banks, specially their products and services also in relation to stakeholders. Banks are one of the main actors supporting the transition to sustainable economy. The purpose of this study is to emphasise the role of world’s largest banks in that process. Banks are slowly responding to the new demand of sustainability and responsibility, and they try to align with it. The paper is based on an overview of the world’s five largest banks that employ corporate social responsibility (CSR reporting standards, together with detailed enumeration of pro-environmental activities included in the reports. The first section of this paper presents the most popular approaches to the problem at hand, as reported in professional literature. Section two presents the characteristics of the CSR actions in banks. The third section discusses the environmental actions of the biggest banks in Global Reporting Initiative (GRI reporting the most popular standard for reporting non-financial information. And the last part of the paper presents the conclusions resulting from the article. The research was conducted using a variety of sources, such as scientific articles, statistical data, CSR reports of the world’s largest banks, as well reporting principles and standard disclosures. The basic method used in the process of writing was a critical analysis of literature and reports concerning the CSR reporting standards, environmental responsibilities of different kinds of entities, as well as own observations based on special reports of banks. In the article, also the analysis of financial market data, induction method and comparison method have been used. The main conclusions of the analysis of the CSR reports disclosed by the world’s largest banks confirm all three of the theses presented in the article. The findings suggest that the banks under study can be regarded as environmentally responsible

  11. Longevity in Calumma parsonii, the World's largest chameleon.

    Science.gov (United States)

    Tessa, Giulia; Glaw, Frank; Andreone, Franco

    2017-03-01

    Large body size of ectothermic species can be correlated with high life expectancy. We assessed the longevity of the World's largest chameleon, the Parson's chameleon Calumma parsonii from Madagascar by using skeletochronology of phalanges taken from preserved specimens held in European natural history museums. Due to the high bone resorption we can provide only the minimum age of each specimen. The highest minimum age detected was nine years for a male and eight years for a female, confirming that this species is considerably long living among chameleons. Our data also show a strong correlation between snout-vent length and estimated age. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Environmental isotope signatures of the largest freshwater lake in Kerala

    International Nuclear Information System (INIS)

    Unnikrishnan Warrier, C.

    2007-01-01

    Sasthamkotta lake, the largest freshwater lake in Kerala, serves as a source for drinking water for more than half a million people. Environmental 137 Cs analysis done on undisturbed sediment core samples reveals that the recent rate of sedimentation is not uniform in the lake. The useful life of lake is estimated as about 800 years. The δD and δ 18 O values of the lake waters indicate that the lake is well mixed with a slight variation horizontally. The stable isotope studies on well waters from the catchment indicate hydraulic communication with the lake and lake groundwater system is flow-through type. Analytical model also supports this view. (author)

  13. Uranium Immobilization in Wetland Soils

    Science.gov (United States)

    Jaffe, Peter R.; Koster van Groos, Paul G.; Li, Dien; Chang, Hyun-Shik; Seaman, John C.; Kaplan, Daniel I.; Peacock, Aaron D.; Scheckel, Kirk

    2014-05-01

    In wetlands, which are a major feature at the groundwater-surface water interface, plants deliver oxygen to the subsurface to keep root tissue aerobic. Some of this oxygen leaches into the rhizosphere where it will oxidize iron that typically precipitates on or near roots. Furthermore, plans provide carbon via root exudates and turnover, which in the presence of the iron oxides drives the activity of heterotrophic iron reducers in wetland soils. Oxidized iron is an important electron acceptor for many microbially-driven transformations, which can affect the fate and transport of several pollutants. It has been shown that heterotrophic iron reducing organisms, such as Geobacter sp., can reduce water soluble U(VI) to insoluble U(IV). The goal of this study was to determine if and how iron cycling in the wetland rhizosphere affects uranium dynamics. For this purpose, we operated a series of small-scale wetland mesocosms in a greenhouse to simulate the discharge of uranium-contaminated groundwater to surface waters. The mesocosms were operated with two different Fe(II) loading rates, two plant types, and unplanted controls. The mesocosms contained zones of root exclusion to differentiate between the direct presence and absence of roots in the planted mesocosms. The mesocosms were operated for several month to get fully established, after which a U(VI) solution was fed for 80 days. The mesocosms were then sacrificed and analyzed for solid-associated chemical species, microbiological characterization, micro-X-ray florescence (µ-XRF) mapping of Fe and U on the root surface, and U speciation via X-ray Absorption Near Edge Structure (XANES). Results showed that bacterial numbers including Geobacter sp., Fe(III), as well as total uranium, were highest on roots, followed by sediments near roots, and lowest in zones without much root influence. Results from the µ-XRF mapping on root surfaces indicated a strong spatial correlation between Fe and U. This correlation was

  14. Spatiotemporal variability and modeling of the solar irradiance transmissivity through a boreal forest

    Science.gov (United States)

    Nadeau, D.; Isabelle, P. E.; Asselin, M. H.; Parent, A. C.; Jutras, S.; Anctil, F.

    2017-12-01

    Solar irradiance is the largest driver of land-surface exchanges of energy, water and trace gases. Its absorption by a forest canopy generates considerable sensible and latent heat fluxes as well as tree temperature changes. A fraction of the irradiance gets transmitted through the canopy and powers another layer of energy fluxes, which can reach substantial values. Transmitted radiation is also of particular relevance to understory vegetation photosynthesis, snowpack energetics and soil temperature dynamics. Boreal forest canopy transmissivity needs to be quantified to properly reproduce land-atmosphere interactions in the circumpolar boreal biome, but its high spatiotemporal variability makes it a challenging task. The objective of this study is to characterize the spatiotemporal variability in under-canopy radiation and to evaluate the performance of various models in representing plot-scale observations. The study site is located in Montmorency Forest (47°N, 71°W), in southern Quebec, Canada. The vegetation includes mostly juvenile balsam firs, up to 6 to 8 m tall. Since January 2016, a 15-m flux tower measures the four components of radiation, as well as other relevant fluxes and meteorological variables, on a ≈10° northeast-facing slope. In summer 2016, 20 portable weather stations were mounted in a 150 m x 200 m grid around the flux tower. These stations were equipped with silicon-cell pyranometers and provided measurements of downwelling irradiance at a height of 2 m. This setup allowed us to compute irradiance transmissivity and to assess its spatiotemporal variability at the site. First, we show that the average of daily incoming energy varies tremendously across the sites, from 1 MJ/m2 to nearly 9 MJ/m2, due to large variations in canopy structure over short distances. Using a regression tree analysis, we show that transmissivity mostly depends on sun elevation, diffuse fraction of radiation, sky and sun view fraction and wind speed above canopy. We

  15. Boreal mire carbon exchange: sensitivity to climate change and anthropogenic nitrogen and sulfur deposition

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Tobias

    2010-07-01

    Boreal peatlands are important long-term sinks of atmospheric carbon and in the same time the largest natural source of methane to the atmosphere. A changing climate as well as deposition of anthropogenically derived pollutants, such as nitrogen and sulfur, has the potential to affect the processes that control the carbon exchange in peatlands. Many of the biogeochemical responses to changed environmental conditions, such as changed plant community composition, are slow and therefore long-term studies are required. In this thesis I have investigated the long-term effects of nitrogen addition, sulfur addition and greenhouse enclosures on carbon exchange by using a field manipulation experiment in a boreal minerogenic, oligotrophic mire after 10-12 years of treatment. Treatment effects on CH{sub 4} emissions, gross primary production (GPP), ecosystem respiration (Reco) and net ecosystem exchange (NEE) were estimated from 1-2 seasons of chamber flux measurements. Treatment effects on potential CH{sub 4} production and oxidation were estimated in incubations of peat from different depth intervals. The effect of nitrogen deposition on carbon accumulation was evaluated in peat cores at different depth intervals. The long-term nitrogen additions have: shifted plant community composition from being dominated by Sphagnum to being dominated by sedges and dwarf shrubs; changed mire surface microtopography so that mean water table is closer to the surface in plots with high nitrogen; increased CH{sub 4} production and emission; increased Reco slightly but have not affected GPP or NEE; reduced the peat height increment, but increased both peat bulk density and carbon content, leading to an unchanged carbon accumulation. The long-term sulfur additions have not reduced CH{sub 4} emissions, only slightly reduced CH{sub 4} production and did not have any effect on the CO{sub 2} carbon exchange. The greenhouse treatment, manifested in increased air and soil temperatures, reduced

  16. Chapter 11. Conservation status of boreal owls in the United States

    Science.gov (United States)

    Gregory D. Hayward

    1994-01-01

    Previous chapters outlined the biology and ecology of boreal owls as well as the ecology of important vegetation communities based on literature from North America and Europe. That technical review provides the basis to assess the current conservation status of boreal owls in the United States. By conservation status, we mean the demographic condition of the species as...

  17. The effect of fire intensity on soil respiration in Siberia boreal forest

    Science.gov (United States)

    S. Baker; A. V. Bogorodskaya

    2010-01-01

    Russian boreal forests have an annual wildfire activity averaging 10 to 20 million ha, which has increased in recent years. This wildfire activity, in response to changing climate has the potential to significantly affect the carbon storage capacity of Siberian forests. A better understanding of the effect of fire on soil respiration rates in the boreal forest of...

  18. Pennsylvania boreal conifer forests and their bird communities: past, present, and potential

    Science.gov (United States)

    Douglas A. Gross

    2010-01-01

    Pennsylvania spruce (Picea spp.)- and eastern hemlock (Tsuga canadensis)-dominated forests, found primarily on glaciated parts of the Allegheny Plateau, are relicts of boreal forest that covered the region following glacial retreat. The timber era of the late 1800s and early 1900s (as late as 1942) destroyed most of the boreal...

  19. The pollination ecology of Hedysarum boreale Nutt. (Fabaceae) and evaluation of its pollinating bees for restoration seed production

    Science.gov (United States)

    Katharine A. Swoboda

    2007-01-01

    Federal land managers desire a consistent and cost-effective source of Hedysarum boreale Nutt. seed for rangeland restoration in the Great Basin and adjacent ecosystems. The breeding biology of H. boreale was assessed via hand pollination experiments at 2 sites in Cache County, Utah, USA in 2003. H. boreale was found to be self-compatible, but did not produce fruit and...

  20. Geographically isolated wetlands: Rethinking a misnomer

    Science.gov (United States)

    Mushet, David M.; Calhoun, Aram J.K.; Alexander, Laurie C.; Cohen, Matthew J.; DeKeyser, Edward S.; Fowler, Laurie G.; Lane, Charles R.; Lang, Megan W.; Rains, Mark C.; Walls, Susan

    2015-01-01

    We explore the category “geographically isolated wetlands” (GIWs; i.e., wetlands completely surrounded by uplands at the local scale) as used in the wetland sciences. As currently used, the GIW category (1) hampers scientific efforts by obscuring important hydrological and ecological differences among multiple wetland functional types, (2) aggregates wetlands in a manner not reflective of regulatory and management information needs, (3) implies wetlands so described are in some way “isolated,” an often incorrect implication, (4) is inconsistent with more broadly used and accepted concepts of “geographic isolation,” and (5) has injected unnecessary confusion into scientific investigations and discussions. Instead, we suggest other wetland classification systems offer more informative alternatives. For example, hydrogeomorphic (HGM) classes based on well-established scientific definitions account for wetland functional diversity thereby facilitating explorations into questions of connectivity without an a priori designation of “isolation.” Additionally, an HGM-type approach could be used in combination with terms reflective of current regulatory or policymaking needs. For those rare cases in which the condition of being surrounded by uplands is the relevant distinguishing characteristic, use of terminology that does not unnecessarily imply isolation (e.g., “upland embedded wetlands”) would help alleviate much confusion caused by the “geographically isolated wetlands” misnomer.

  1. Urban wetlands: restoration or designed rehabilitation?

    Directory of Open Access Journals (Sweden)

    Beth Ravit

    2017-05-01

    Full Text Available The continuing loss of urban wetlands due to an expanding human population and urban development pressures makes restoration or creation of urban wetlands a high priority. However, urban wetland restorations are particularly challenging due to altered hydrologic patterns, a high proportion of impervious surface and stormwater runoff, degraded urban soils, historic contamination, and competitive pressure from non-native species. Urban wetland projects must also consider human-desired socio-economic benefits. We argue that using current wetland restoration approaches and existing regulatory “success” criteria, such as meeting restoration targets for vegetation structure based on reference sites in non-urban locations, will result in “failed” urban restorations. Using three wetland Case Studies in highly urbanized locations, we describe geophysical tools, stormwater management methods, and design approaches useful in addressing urban challenges and in supporting “successful” urban rehabilitation outcomes. We suggest that in human-dominated landscapes, the current paradigm of “restoration” to a previous state must shift to a paradigm of “rehabilitation”, which prioritizes wetland functions and values rather than vegetation structure in order to provide increased ecological benefits and much needed urban open space amenities.

  2. Fishing down the largest coral reef fish species.

    Science.gov (United States)

    Fenner, Douglas

    2014-07-15

    Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Coastal vegetation invasion increases greenhouse gas emission from wetland soils but also increases soil carbon accumulation

    International Nuclear Information System (INIS)

    Chen, Yaping; Chen, Guangcheng; Ye, Yong

    2015-01-01

    Soil properties and soil–atmosphere fluxes of CO 2 , CH 4 and N 2 O from four coastal wetlands were studied throughout the year, namely, native Kandelia obovata mangrove forest vs. exotic Sonneratia apetala mangrove forest, and native Cyperus malaccensis salt marsh vs. exotic Spartina alterniflora salt marsh. Soils of the four wetlands were all net sources of greenhouse gases while Sonneratia forest contributed the most with a total soil–atmosphere CO 2 -equivalent flux of 137.27 mg CO 2 m −2 h −1 , which is 69.23%, 99.75% and 44.56% higher than that of Kandelia, Cyperus and Spartina, respectively. The high underground biomass and distinctive root structure of Sonneratia might be responsible for its high greenhouse gas emission from the soil. Soils in Spartina marsh emitted the second largest amount of total greenhouse gases but it ranked first in emitting trace greenhouse gases. Annual average CH 4 and N 2 O fluxes from Spartina soil were 13.77 and 1.14 μmol m −2 h −1 , respectively, which are 2.08 and 1.46 times that of Kandelia, 1.03 and 1.15 times of Sonneratia, and 1.74 and 1.02 times of Cyperus, respectively. Spartina has longer growing season and higher productivity than native marshes which might increase greenhouse gas emission in cold seasons. Exotic wetland soils had higher carbon stock as compared to their respective native counterparts but their carbon stocks were offset by a larger proportion because of their higher greenhouse gas emissions. Annual total soil–atmosphere fluxes of greenhouse gases reduced soil carbon burial benefits by 8.1%, 9.5%, 6.4% and 7.2% for Kandelia, Sonneratia, Cyperus and Spartina, respectively, which narrowed down the gaps in net soil carbon stock between native and exotic wetlands. The results indicated that the invasion of exotic wetland plants might convert local coastal soils into a considerable atmospheric source of greenhouse gases although they at the same time increase soil carbon accumulation

  4. Coastal vegetation invasion increases greenhouse gas emission from wetland soils but also increases soil carbon accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yaping [Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian (China); Chen, Guangcheng [Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, Fujian (China); Ye, Yong, E-mail: yeyong.xmu@gmail.com [Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Xiamen 361102, Fujian (China)

    2015-09-01

    Soil properties and soil–atmosphere fluxes of CO{sub 2}, CH{sub 4} and N{sub 2}O from four coastal wetlands were studied throughout the year, namely, native Kandelia obovata mangrove forest vs. exotic Sonneratia apetala mangrove forest, and native Cyperus malaccensis salt marsh vs. exotic Spartina alterniflora salt marsh. Soils of the four wetlands were all net sources of greenhouse gases while Sonneratia forest contributed the most with a total soil–atmosphere CO{sub 2}-equivalent flux of 137.27 mg CO{sub 2} m{sup −2} h{sup −1}, which is 69.23%, 99.75% and 44.56% higher than that of Kandelia, Cyperus and Spartina, respectively. The high underground biomass and distinctive root structure of Sonneratia might be responsible for its high greenhouse gas emission from the soil. Soils in Spartina marsh emitted the second largest amount of total greenhouse gases but it ranked first in emitting trace greenhouse gases. Annual average CH{sub 4} and N{sub 2}O fluxes from Spartina soil were 13.77 and 1.14 μmol m{sup −2} h{sup −1}, respectively, which are 2.08 and 1.46 times that of Kandelia, 1.03 and 1.15 times of Sonneratia, and 1.74 and 1.02 times of Cyperus, respectively. Spartina has longer growing season and higher productivity than native marshes which might increase greenhouse gas emission in cold seasons. Exotic wetland soils had higher carbon stock as compared to their respective native counterparts but their carbon stocks were offset by a larger proportion because of their higher greenhouse gas emissions. Annual total soil–atmosphere fluxes of greenhouse gases reduced soil carbon burial benefits by 8.1%, 9.5%, 6.4% and 7.2% for Kandelia, Sonneratia, Cyperus and Spartina, respectively, which narrowed down the gaps in net soil carbon stock between native and exotic wetlands. The results indicated that the invasion of exotic wetland plants might convert local coastal soils into a considerable atmospheric source of greenhouse gases although they at the

  5. Incorporating H2 Dynamics and Inhibition into a Microbially Based Methanogenesis Model for Restored Wetland Sediments

    Science.gov (United States)

    Pal, David; Jaffe, Peter

    2015-04-01

    Estimates of global CH4 emissions from wetlands indicate that wetlands are the largest natural source of CH4 to the atmosphere. In this paper, we propose that there is a missing component to these models that should be addressed. CH4 is produced in wetland sediments from the microbial degradation of organic carbon through multiple fermentation steps and methanogenesis pathways. There are multiple sources of carbon for methananogenesis; in vegetated wetland sediments, microbial communities consume root exudates as a major source of organic carbon. In many methane models propionate is used as a model carbon molecule. This simple sugar is fermented into acetate and H2, acetate is transformed to methane and CO2, while the H2 and CO2 are used to form an additional CH4 molecule. The hydrogenotrophic pathway involves the equilibrium of two dissolved gases, CH4 and H2. In an effort to limit CH4 emissions from wetlands, there has been growing interest in finding ways to limit plant transport of soil gases through root systems. Changing planted species, or genetically modifying new species of plants may control this transport of soil gases. While this may decrease the direct emissions of methane, there is little understanding about how H2 dynamics may feedback into overall methane production. The results of an incubation study were combined with a new model of propionate degradation for methanogenesis that also examines other natural parameters (i.e. gas transport through plants). This presentation examines how we would expect this model to behave in a natural field setting with changing sulfate and carbon loading schemes. These changes can be controlled through new plant species and other management practices. Next, we compare the behavior of two variations of this model, with or without the incorporation of H2 interactions, with changing sulfate, carbon loading and root volatilization. Results show that while the models behave similarly there may be a discrepancy of nearly

  6. Modelling nitrogen transformation and removal in mara river basin wetlands upstream of lake Victoria

    Science.gov (United States)

    Mayo, Aloyce W.; Muraza, Marwa; Norbert, Joel

    2018-06-01

    Lake Victoria, the largest lake in Africa, is a resource of social-economic potential in East Africa. This lake receives water from numerous tributaries including Mara River, which contributes about 4.8% of the total Lake water inflow. Unfortunately, Mara River basin faces environmental problems because of intensive settlement, agriculture, overgrazing in the basin and mining activities, which has lead to water pollution in the river, soil erosion and degradation, decreased soil fertility, loss of vegetation cover, decreased water infiltration capacity and increased sedimentation. One of the pollutants carried by the river includes nitrogen, which has contributed to ecological degradation of the Lake Victoria. Therefore this research work was intended to determine the effectiveness of Mara River wetland for removal of nitrogen and to establish nitrogen removal mechanisms in the wetland. To predict nitrogen removal in the wetland, the dynamics of nitrogen transformation was studied using a conceptual numerical model that takes into account of various processes in the system using STELLA II version 9.0®2006 software. Samples of model input from water, plants and sediments were taken for 45 days and were analyzed for pH, temperature, and DO in situ and chemical parameters such as NH3-N, Org-N, NO2-N, and NO3-N were analyzed in the laboratory in accordance with Standard methods. For plants, the density, dominance, biomass productivity and TN were determined and for sediments TN was analyzed. Inflow into the wetland was determined using stage-discharge relationship and was found to be 734,400 m3/day and the average wetland volume was 1,113,500 m3. Data collected by this study were used for model calibration of nitrogen transformation in this wetland while data from another wetland were used for model validation. It was found that about 37.8% of total nitrogen was removed by the wetland system largely through sedimentation (26.6%), plant uptake (6.6%) and

  7. Simulation of Forest Cover Dynamics for Eastern Eurasian Boreal Forests

    Science.gov (United States)

    Shugart, H. H.; Yan, X.; Zhang, N.; Isaev, A. S.; Shuman, J. K.

    2006-12-01

    We are developing and testing a boreal zone forest dynamics model capable of simulating the forest cover dynamics of the Eurasian boreal forest, a major biospheric ecosystem with potentially large roles in the planetary carbon cycle and in the feedback between terrestrial surface and the atmosphere. In appreciating the role of this region in the coupling between atmosphere and terrestrial surface, on must understand the interactions between CO2 source/sink relationships (associated with growing or clearing forests) and the albedo effects (from changes in terrestrial surface cover). There is some evidence that in the Eurasian Boreal zone, the Carbon budget effects from forest change may oppose the albedo changes. This creates complex feedbacks between surface and atmosphere and motivates the need for a forest dynamics model that simultaneous represents forest vegetation and carbon storage and release. A forest dynamics model applied to Eastern Eurasia, FAREAST, has been tested using three types of information: 1. Direct species composition comparisons between simulated and observed mature forests at the same locations; 2. Forest type comparisons between simulated and observed forests along altitudinal gradients of several different mountains; 3. Comparison with forest stands in different succession stages of simulated forests. Model comparisons with independent data indicate the FAREAST model is capable of representing many of the broad features of the forests of Northeastern China. After model validation in the Northeast China region, model applications were developed for the forests of the Russian Far East. Continental-scale forest cover can be simulated to a relatively realistic degree using a forest gap model with standard representations of individual-plant processes. It appears that such a model, validated relatively locally in this case, in Northeastern China, can then be applied over a much larger region and under conditions of climatic change.

  8. Anthropogenic nitrogen deposition enhances carbon sequestration in boreal soils.

    Science.gov (United States)

    Maaroufi, Nadia I; Nordin, Annika; Hasselquist, Niles J; Bach, Lisbet H; Palmqvist, Kristin; Gundale, Michael J

    2015-08-01

    It is proposed that carbon (C) sequestration in response to reactive nitrogen (Nr ) deposition in boreal forests accounts for a large portion of the terrestrial sink for anthropogenic CO2 emissions. While studies have helped clarify the magnitude by which Nr deposition enhances C sequestration by forest vegetation, there remains a paucity of long-term experimental studies evaluating how soil C pools respond. We conducted a long-term experiment, maintained since 1996, consisting of three N addition levels (0, 12.5, and 50 kg N ha(-1) yr(-1) ) in the boreal zone of northern Sweden to understand how atmospheric Nr deposition affects soil C accumulation, soil microbial communities, and soil respiration. We hypothesized that soil C sequestration will increase, and soil microbial biomass and soil respiration will decrease, with disproportionately large changes expected compared to low levels of N addition. Our data showed that the low N addition treatment caused a non-significant increase in the organic horizon C pool of ~15% and a significant increase of ~30% in response to the high N treatment relative to the control. The relationship between C sequestration and N addition in the organic horizon was linear, with a slope of 10 kg C kg(-1) N. We also found a concomitant decrease in total microbial and fungal biomasses and a ~11% reduction in soil respiration in response to the high N treatment. Our data complement previous data from the same study system describing aboveground C sequestration, indicating a total ecosystem sequestration rate of 26 kg C kg(-1) N. These estimates are far lower than suggested by some previous modeling studies, and thus will help improve and validate current modeling efforts aimed at separating the effect of multiple global change factors on the C balance of the boreal region. © 2015 John Wiley & Sons Ltd.

  9. Limnology of Jagatpur wetland, Bhagalpur (Bihar), India.

    Science.gov (United States)

    Kumar, Brajnandan

    2011-10-01

    The water quality in Jagatpur wetland was assessed in terms of physico - chemical characteristics for two years, between August 2003-July 2005. The variations in different physico-chemical parameters have been discussed in this paper in relation to fluctuating climatic condition. The wetland is experiencing racing eutrophication as evidenced by pH was acidic to alkaline, total hardness was considerably high, bicarbonate was in moderate amount, phosphate-phosphorus content was in a range of medium to high and higher values of COD. The present status of the quality of water of Jagatpur wetland is delineated in this paper.

  10. Reduction of neonicotinoid insecticide residues in Prairie wetlands by common wetland plants.

    Science.gov (United States)

    Main, Anson R; Fehr, Jessica; Liber, Karsten; Headley, John V; Peru, Kerry M; Morrissey, Christy A

    2017-02-01

    Neonicotinoid insecticides are frequently detected in wetlands during the early to mid-growing period of the Canadian Prairie cropping season. These detections also overlap with the growth of macrophytes that commonly surround agricultural wetlands which we hypothesized may reduce neonicotinoid transport and retention in wetlands. We sampled 20 agricultural wetlands and 11 macrophyte species in central Saskatchewan, Canada, over eight weeks to investigate whether macrophytes were capable of reducing movement of neonicotinoids from cultivated fields and/or reducing concentrations in surface water by accumulating insecticide residues into their tissues. Study wetlands were surrounded by clothianidin-treated canola and selected based on the presence (n=10) or absence (n=10) of a zonal plant community. Neonicotinoids were positively detected in 43% of wetland plants, and quantified in 8% of all plant tissues sampled. Three plant species showed high rates of detection: 78% Equisetum arvense (clothianidin, range: wetlands had higher detection frequency and water concentrations of clothianidin (β±S.E.: -0.77±0.26, P=0.003) and thiamethoxam (β±S.E.: -0.69±0.35, P=0.049) than vegetated wetlands. We assessed the importance of wetland characteristics (e.g. vegetative zone width, emergent plant height, water depth) on neonicotinoid concentrations in Prairie wetlands over time using linear mixed-effects models. Clothianidin concentrations were significantly lower in wetlands surrounded by taller plants (β±S.E.: -0.57±0.12, P≤0.001). The results of this study suggest that macrophytes can play an important role in mitigating water contamination by accumulating neonicotinoids and possibly slowing transport to wetlands during the growing season. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Diverse growth trends and climate responses across Eurasia's boreal forest

    Czech Academy of Sciences Publication Activity Database

    Hellmann, L.; Agafonov, L.; Ljungqvist, F. C.; Churakova (Sidorova), O.; Duethorn, E.; Esper, J.; Hulsmann, L.; Kirdyanov, A. V.; Moiseev, P.; Myglan, V. S.; Nikolaev, A. N.; Reinig, F.; Schweingruber, F. H.; Solomina, O.; Tegel, W.; Büntgen, Ulf

    2016-01-01

    Roč. 11, č. 7 (2016), č. článku 074021. ISSN 1748-9326 R&D Projects: GA MŠk(CZ) LO1415 Institutional support: RVO:67179843 Keywords : 20th-century summer warmth * tree-ring chronology * scots pine * 2 millennia * temperature variability * northern-hemisphere * central siberia * worlds forests * white spruce * carbon-cycle * boreal forest * climate variability * dendroecology * Eurasia * forest productivity * global warming * high northern latitudes Subject RIV: EH - Ecology, Behaviour Impact factor: 4.404, year: 2016

  12. Gamma-ray irradiation of a boreal forest ecosystem

    International Nuclear Information System (INIS)

    Guthrie, J.E.; Dugle, J.R.

    1983-01-01

    A long-term radiation ecology research project called Field Irradiator - Gamma (FIG) began at the Whiteshell Nuclear Research Establishment in 1968. The experimental area is in southeastern Manitoba and is located on the western edge of the Precambrian shield. The project studies the ecological effects continuous exposure to a gradient of gamma radiation has on a mixed boreal forest ecosystem. The gradient ranges from 1 to 460,000 times the natural background radiation level. This paper describes the forest, the gamma irradiator and its radiation field, and the research program

  13. Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem

    Science.gov (United States)

    Mazurek, Monica A.; Cofer, Wesley R., III; Levine, Joel S.

    1991-01-01

    During the boreal forest burn studied, the ambient concentrations for the particle carbon smoke aerosol are highest for the full-fire burn conditions and vary significantly throughout the burn. Collection strategies must accordingly define ranges in the smoke aerosol concentrations produced. While the highest elemental C concentrations are observed during full-fire conditions, the great majority of smoke aerosol particles are in the form of organic C particles irrespective of fire temperature. The formation of organic C light-scattering particles was a significant process in the burn studied.

  14. The Impact of Boreal Forest Fire on Climate Warming

    OpenAIRE

    Randerson, J. T.; Liu, H.; Flanner, M. G.; Chambers, S. D.; Jin, Y.; Hess, P. G.; Pfister, G.; Mack, M. C.; Treseder, K. K.; Welp, L. R.; Chapin, F. S.; Harden, J. W.; Goulden, M. L.; Lyons, E.; Neff, J. C.

    2006-01-01

    We report measurements and analysis of a boreal forest fire, integrating the effects of greenhouse gases, aerosols, black carbon deposition on snow and sea ice, and postfire changes in surface albedo. The net effect of all agents was to increase radiative forcing during the first year (34 ± 31 Watts per square meter of burned area), but to decrease radiative forcing when averaged over an 80-year fire cycle (–2.3 ± 2.2 Watts per square meter) because multidecadal increases in surface albedo ha...

  15. The Effect of Pollution on Newly-Formed Particle Composition in Boreal Forest

    Science.gov (United States)

    Vaattovaara, Petri

    2010-05-01

    Petri Vaattovaara (1), Tuukka Petäjä (2), Jorma Joutsensaari (1), Pasi Miettinen (1), Boris Zaprudin (1,6), Aki Kortelainen (1), Juha Heijari (3,7), Pasi Yli-Pirilä (3), Pasi Aalto (2), Doug R. Worsnop (4), and Ari Laaksonen(1,5) (1) University of Eastern Finland, Finland (2) University of Helsinki, Finland (3) University of Eastern Finland, Finland (4) Aerodyne Research Inc., USA (5) Finnish Meteorological Institute, Finland (6) Currently at University of Turku, Finland (7) Currently at Maritime Research Centre, Finland Email address of the Corresponding author: Petri.Vaattovaara@uef.fi The geographical extent of the tropical, temperate and boreal forests is about 30% of the Earth's land surface. Those forests are located around the world in different climate zones effecting widely on atmospheric composition via new particle formation. The Boreal forests solely cover one third of the forests extent and are one of the largest vegetation environments, forming a circumpolar band throughout the northern hemisphere continents, with a high potential to affect climate processes [1]. In order to more fully understand the possible climatic effects of the forests, the properties of secondary organic aerosols (SOA) in varying conditions (e.g. a change in meteorological parameters or in the concentrations of biogenic and antropogenic trace gases) need to be better known. In this study, we applied the UFO-TDMA (ultrafine organic tandem differential mobility analyzer [2]) and the UFH-TDMA (ultrafine hygroscopicity tandem differential mobility analyzer [3]) methods parallel to shed light on the evolution of the nucleation and Aitken mode particle compositions (via physic-chemical properties) at a virgin boreal forest site in varying conditions. The measurements were carried out at Hyytiälä forest station in Northern Europe (Finland) during 15 spring nucleation events. We also carried out a statistical analysis using linear correlations in order to explain the variability in

  16. Carbon and energy fluxes from China's largest freshwater lake

    Science.gov (United States)

    Gan, G.; LIU, Y.

    2017-12-01

    Carbon and energy fluxes between lakes and the atmosphere are important aspects of hydrology, limnology, and ecology studies. China's largest freshwater lake, the Poyang lake experiences tremendous water-land transitions periodically throughout the year, which provides natural experimental settings for the study of carbon and energy fluxes. In this study, we use the eddy covariance technique to explore the seasonal and diurnal variation patterns of sensible and latent heat fluxes of Poyang lake during its high-water and low-water periods, when the lake is covered by water and mudflat, respectively. We also determine the annual NEE of Poyang lake and the variations of NEE's components: Gross Primary Productivity (GPP) and Ecosystem Respiration (Re). Controlling factors of seasonal and diurnal variations of carbon and energy fluxes are analyzed, and land cover impacts on the variation patterns are also studied. Finally, the coupling between the carbon and energy fluxes are analyzed under different atmospheric, boundary stability and land cover conditions.

  17. SSC RIAR is the largest centre of research reactors

    International Nuclear Information System (INIS)

    Kalygin, V.V.

    1997-01-01

    The State Scientific Centre (SSC) ''Research Institute of Atomic Reactors'' (RIAR) is situated 100 km to the south-east from Moscow, in Dimitrovgrad, the Volga Region of the Russian Federation. SSC RIAR is the largest centre of research reactors in Russia. At present there are 5 types of reactor facilities in operation, including two NPP. One of the main tasks the Centre is the investigations on safety increase for power reactors. Broad international connections are available at the Institute. On the basis of the SSC RIAR during 3 years work has been done on the development of the branch training centre (TC) for the training of operation personnel of research and pilot reactors in Russia. (author). 3 tabs

  18. BALU: Largest autoclave research facility in the world

    Directory of Open Access Journals (Sweden)

    Hakan Ucan

    2016-03-01

    Full Text Available Among the large-scale facilities operated at the Center for Lightweight-Production-Technology of the German Aerospace Center in Stade BALU is the world's largest research autoclave. With a loading length of 20m and a loading diameter of 5.8 m the main objective of the facility is the optimization of the curing process operated by components made of carbon fiber on an industrial scale. For this reason, a novel dynamic autoclaving control has been developed that is characterized by peripheral devices to expend the performance of the facility for differential applications, by sensing systems to detect the component state throughout the curing process and by a feedback system, which is capable to intervene into the running autoclave process.

  19. Switzerland's largest wood-pellet factory in Balsthal

    International Nuclear Information System (INIS)

    Stohler, F.

    2004-01-01

    This article describes how a small Swiss electricity utility has broken out of its traditional role in power generation and the distribution of electricity and gone into the production of wood pellets. The pellets, which are made from waste wood (sawdust) available from wood processing companies, are produced on a large scale in one of Europe's largest pellets production facilities. The boom in the use of wood pellets for heating purposes is discussed. The article discusses this unusual approach for a Swiss power utility, which also operates a wood-fired power station and is even involved in an incineration plant for household wastes. The markets being aimed for in Switzerland and in Europe are described, including modern low-energy-consumption housing projects. A further project is described that is to use waste wood available from a large wood processing facility planned in the utility's own region

  20. Opportunities for biodiversity gains under the world's largest reforestation programme

    Science.gov (United States)

    Hua, Fangyuan; Wang, Xiaoyang; Zheng, Xinlei; Fisher, Brendan; Wang, Lin; Zhu, Jianguo; Tang, Ya; Yu, Douglas W.; Wilcove, David S.

    2016-01-01

    Reforestation is a critical means of addressing the environmental and social problems of deforestation. China's Grain-for-Green Program (GFGP) is the world's largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP's biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on birds and bees in Sichuan Province, we find that GFGP reforestation results in modest gains (via mixed forest) and losses (via monocultures) of bird diversity, along with major losses of bee diversity. Moreover, all current modes of GFGP reforestation fall short of restoring biodiversity to levels approximating native forests. However, even within existing modes of reforestation, GFGP can achieve greater biodiversity gains by promoting mixed forests over monocultures; doing so is unlikely to entail major opportunity costs or pose unforeseen economic risks to households. PMID:27598524

  1. SSC RIAR is the largest centre of research reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kalygin, V V [State Scientific Centre, Research Inst. of Atomic Reactors (Russian Federation)

    1997-10-01

    The State Scientific Centre (SSC) ``Research Institute of Atomic Reactors`` (RIAR) is situated 100 km to the south-east from Moscow, in Dimitrovgrad, the Volga Region of the Russian Federation. SSC RIAR is the largest centre of research reactors in Russia. At present there are 5 types of reactor facilities in operation, including two NPP. One of the main tasks the Centre is the investigations on safety increase for power reactors. Broad international connections are available at the Institute. On the basis of the SSC RIAR during 3 years work has been done on the development of the branch training centre (TC) for the training of operation personnel of research and pilot reactors in Russia. (author). 3 tabs.

  2. The largest Silurian vertebrate and its palaeoecological implications

    Science.gov (United States)

    Choo, Brian; Zhu, Min; Zhao, Wenjin; Jia, Liaotao; Zhu, You'an

    2014-01-01

    An apparent absence of Silurian fishes more than half-a-metre in length has been viewed as evidence that gnathostomes were restricted in size and diversity prior to the Devonian. Here we describe the largest pre-Devonian vertebrate (Megamastax amblyodus gen. et sp. nov.), a predatory marine osteichthyan from the Silurian Kuanti Formation (late Ludlow, ~423 million years ago) of Yunnan, China, with an estimated length of about 1 meter. The unusual dentition of the new form suggests a durophagous diet which, combined with its large size, indicates a considerable degree of trophic specialisation among early osteichthyans. The lack of large Silurian vertebrates has recently been used as constraint in palaeoatmospheric modelling, with purported lower oxygen levels imposing a physiological size limit. Regardless of the exact causal relationship between oxygen availability and evolutionary success, this finding refutes the assumption that pre-Emsian vertebrates were restricted to small body sizes. PMID:24921626

  3. Largest US oil and gas fields, August 1993

    International Nuclear Information System (INIS)

    1993-01-01

    The Largest US Oil and Gas Fields is a technical report and part of an Energy Information Administration (EIA) series presenting distributions of US crude oil and natural gas resources, developed using field-level data collected by EIA's annual survey of oil and gas proved reserves. The series' objective is to provide useful information beyond that routinely presented in the EIA annual report on crude oil and natural gas reserves. These special reports also will provide oil and gas resource analysts with a fuller understanding of the nature of US crude oil and natural gas occurrence, both at the macro level and with respect to the specific subjects addressed. The series' approach is to integrate EIA's crude oil and natural gas survey data with related data obtained from other authoritative sources, and then to present illustrations and analyses of interest to a broad spectrum of energy information users ranging from the general public to oil and gas industry personnel

  4. Drivers of variability in tree transpiration in a Boreal Black Spruce Forest Chronosequence

    Science.gov (United States)

    Angstmann, J. L.; Ewers, B. E.; Kwon, H.

    2009-12-01

    Boreal forests are of particular interest in climate change studies because of their large land area and ability to sequester and store carbon, which is controlled by water availability. Heterogeneity of these forests is predicted to increase with climate change through the impact of more frequent wildfires, warmer, longer growing seasons, and potential drainage of forested wetlands. This study aims to quantify the influence of stand age, drainage condition, and species on tree transpiration and its drivers in a central Canadian black spruce boreal forest. Heat dissipation sensors were installed in 113 trees (69 Picea mariana (black spruce), 25 Populus tremuloides (trembling aspen), and 19 Pinus banksiana (jack pine) at four stand ages, each containing a well- and poorly-drained site over three growing seasons (2006-2008). Sap flux per unit xylem area, JS, was expressed as transpiration per unit ground area, EC, and transpiration per unit leaf area, EL, using site- and species-specific allometry to obtain sapwood area (AS)and leaf area(AL)per unit ground area. Well-drained, younger Picea mariana daily JS was 47-64% greater than the older well-drained burn ages and younger poorly-drained stands were 64-68% greater than the two oldest poorly-drained stands. Daily EL in the well-drained Picea mariana stands was on average 12-33% higher in younger stand than in the two oldest stands whereas young, poorly-drained Picea mariana had 71% greater daily EL than the older stands. Well-drained Picea mariana trees had 52% higher daily EC than older trees and poorly-drained Picea mariana in the 1964 burn had 42-81% higher daily EC than the oldest stands. Populus tremuloides located in the two youngest stands had daily JS 38-58% greater rates than the 1930 burn, whereas daily EL and EC had no distint differences due to high interannual variability. Pinus banksiana experienced 21-33% greater daily JS in the 1989 burn than in the older 1964 burn for well- and poorly-drained sites

  5. The largest glitch observed in the Crab pulsar

    Science.gov (United States)

    Shaw, B.; Lyne, A. G.; Stappers, B. W.; Weltevrede, P.; Bassa, C. G.; Lien, A. Y.; Mickaliger, M. B.; Breton, R. P.; Jordan, C. A.; Keith, M. J.; Krimm, H. A.

    2018-05-01

    We have observed a large glitch in the Crab pulsar (PSR B0531+21). The glitch occurred around MJD 58064 (2017 November 8) when the pulsar underwent an increase in the rotation rate of Δν = 1.530 × 10-5 Hz, corresponding to a fractional increase of Δν/ν = 0.516 × 10-6 making this event the largest glitch ever observed in this source. Due to our high-cadence and long-dwell time observations of the Crab pulsar we are able to partially resolve a fraction of the total spin-up of the star. This delayed spin-up occurred over a timescale of ˜1.7 days and is similar to the behaviour seen in the 1989 and 1996 large Crab pulsar glitches. The spin-down rate also increased at the glitch epoch by Δ \\dot{ν } / \\dot{ν } = 7 × 10^{-3}. In addition to being the largest such event observed in the Crab, the glitch occurred after the longest period of glitch inactivity since at least 1984 and we discuss a possible relationship between glitch size and waiting time. No changes to the shape of the pulse profile were observed near the glitch epoch at 610 MHz or 1520 MHz, nor did we identify any changes in the X-ray flux from the pulsar. The long-term recovery from the glitch continues to progress as \\dot{ν } slowly rises towards pre-glitch values. In line with other large Crab glitches, we expect there to be a persistent change to \\dot{ν }. We continue to monitor the long-term recovery with frequent, high quality observations.

  6. Diurnal and Seasonal Variations of Eddy-Covariance Carbon Dioxide Fluxes Above an Urban Wetland, Partitioned by Vegetation Cover

    Science.gov (United States)

    Schafer, K. V.; Duman, T.

    2017-12-01

    The New Jersey Meadowlands are an urban brackish marsh with a long history of human activity causing disturbances and alterations. Carbon emissions were measured from two sites in the Meadowlands, a natural site and a restored site, using eddy-covariance (EC) from 2014 to 2016. At each site, the EC towers were placed at the interface of two vegetation covers, allowing capturing this aspect of the wetland's heterogeneity. Using footprint modeling and light response curves we were able to partition measured fluxes between vegetation cover types and compare CO2 fluxes from patches of invasive versus native wetland vegetation communities. We show that further separating the data into seasonal and diurnal fluxes reveals patterns in CO2 fluxes that allow determining the nature of each vegetation cover as a source or sink for CO2. Our results also show that CO2 emissions from the restored wetland are significantly higher than the natural wetland. Areas of invasive Phragmites australis at the natural site had the lowest CO2 release rates during winter. These were consistently lower in magnitude than summer daytime uptake, therefore making this part of the wetland a CO2 sink. Areas planted with native Spartina alterniflora at the restored site had the largest uptake during daytime, therefore seemingly justifying restoration activities. However, they also had the highest emission rates during summer nighttime, and therefore the daily summer net uptake was not the highest compared with other vegetation covers. Furthermore, emissions from the restored site during winter were larger compared to the natural site, indicating that restoration activities might have led to a significant increase of carbon release from the wetland. Thus, during the study period the restored wetland acted as a carbon source.

  7. Stakeholder Involvement in Tourism Destination Development: A Case of Dunga Beach and Wetland, Kisumu County, Kenya

    Directory of Open Access Journals (Sweden)

    Joshua Otieno Wanga

    2014-09-01

    In Kenya, Tourism is the second largest source of foreign exchange revenue following agriculture; it however, faces numerous challenges sustainability due the complex nature of tourism destinations. Tourism destinations are complex and dynamic systems that involve various stakeholders each with different understanding of same tourism system. These different perceptions can be tapped to develop a common tourism model that helps achieve the overall sustainable tourism development objective of a given destination. This paper describes participatory systems approach to develop a shared understanding amongst stakeholders of the tourism system in Dunga Beach and Wetland, in Kisumu County, Kenya. The process includes the development of a systems model that represents a holistic understanding of the interconnectedness and relationships between the various components that impact on sustainable development of tourism in Dunga. The model is intended for use as a framework for enhancing ecotourism experiences by stakeholders who are ecotourism experience providers in Dunga for the satisfaction of tourists in Dunga beach and wetland.

  8. Conceptual Models for Ecosystem Management through the Participation of Local Social Actors: the Río Cruces Wetland Conflict

    Directory of Open Access Journals (Sweden)

    Luisa E. Delgado

    2009-06-01

    Full Text Available In 2004, the emigration and death of black-necked swans (Cygnus melancoryphus from the Río Cruces wetland (Valdivia, Chile triggered one of the largest ecosocial conflicts in Chilean history. The main local social actors of this still unsolved conflict are the Chilean government, a pulp-mill company, and a local nongovernmental organization. The central issues of the conflict are disagreement over the reason for the swans' migration, the need to restore the black-necked swan population in the wetland, and the relationship between economic development and wetland conservation. We applied a physical, ecological, and social system approach to generate conceptual or qualitative ecosystem models representing the perceptions of all social actors. Our results showed that each actor group perceived the ecosystem in a different and, in some cases, divergent way. Furthermore, all of them carried only partial representations of the wetland and the conflict. We linked all the models to generate an integrated view of the Río Cruces wetland ecosystem. We propose that this approach can be replicated as a tool for generating synthetic, integrated conceptual models of ecosystems, even in the presence of strong divergence and a lack of consensus among social actors.

  9. Coastal wetlands: an integrated ecosystem approach

    Science.gov (United States)

    Perillo, G. M. E.; Wolanski, E.; Cahoon, D.R.; Brinson, M.M.

    2009-01-01

    Coastal wetlands are under a great deal of pressure from the dual forces of rising sea level and the intervention of human populations both along the estuary and in the river catchment. Direct impacts include the destruction or degradation of wetlands from land reclamation and infrastructures. Indirect impacts derive from the discharge of pollutants, changes in river flows and sediment supplies, land clearing, and dam operations. As sea level rises, coastal wetlands in most areas of the world migrate landward to occupy former uplands. The competition of these lands from human development is intensifying, making the landward migration impossible in many cases. This book provides an understanding of the functioning of coastal ecosystems and the ecological services that they provide, and suggestions for their management. In this book a CD is included containing color figures of wetlands and estuaries in different parts of the world.

  10. VT National Wetlands Inventory Map Data - polygons

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) VCGI downloaded NWI quads from the US FWS web site and reprojected to VCS NAD83. NWI digital data files are records of wetlands location and...

  11. Design and maintenance of subsurface gravel wetlands.

    Science.gov (United States)

    2015-02-01

    This report summarizes the University of New Hampshire Stormwater Center (UNHSC) evaluation of : a review of Subsurface Gravel Wetlands design and specifications used by the New Hampshire : Department of Transportation (NHDOT or Department). : Subsur...

  12. NOAA C-CAP National Wetland Potential

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The probability rating which covers landcover mapping provides a continuum of wetness from dry to water. The layer is not a wetland classification but provides the...

  13. VT National Wetlands Inventory Map Data - lines

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) VCGI downloaded NWI quads from the US FWS web site and reprojected to VCS NAD83. NWI digital data files are records of wetlands location and...

  14. 76 FR 777 - National Wetland Plant List

    Science.gov (United States)

    2011-01-06

    ... the Wetland Conservation Provisions of the Food Security Act. Other applications of the list include... recommended changes and additions to the NWPL. The process will be supported by an interactive Web site where...

  15. Importance of boreal rivers in providing iron to marine waters.

    Directory of Open Access Journals (Sweden)

    Emma S Kritzberg

    Full Text Available This study reports increasing iron concentrations in rivers draining into the Baltic Sea. Given the decisive role of iron to the structure and biogeochemical function of aquatic ecosystems, this trend is likely one with far reaching consequences to the receiving system. What those consequences may be depends on the fate of the iron in estuarine mixing. We here assess the stability of riverine iron by mixing water from seven boreal rivers with artificial sea salts. The results show a gradual loss of iron from suspension with increasing salinity. However, the capacity of the different river waters to maintain iron in suspension varied greatly, i.e. between 1 and 54% of iron was in suspension at a salinity of 30. The variability was best explained by iron:organic carbon ratios in the riverine waters--the lower the ratio the more iron remained in suspension. Water with an initially low iron:organic carbon ratio could keep even higher than ambient concentrations of Fe in suspension across the salinity gradient, as shown in experiments with iron amendments. Moreover, there was a positive relationship between the molecular size of the riverine organic matter and the amount of iron in suspension. In all, the results point towards a remarkably high transport capacity of iron from boreal rivers, suggesting that increasing concentrations of iron in river mouths may result in higher concentrations of potentially bioavailable iron in the marine system.

  16. Portrait of a small population of boreal toads (Anaxyrus boreas)

    Science.gov (United States)

    Muths, Erin; Scherer, Rick D.

    2011-01-01

    Much attention has been given to the conservation of small populations, those that are small because of decline, and those that are naturally small. Small populations are of particular interest because ecological theory suggests that they are vulnerable to the deleterious effects of environmental, demographic, and genetic stochasticity as well as natural and human-induced catastrophes. However, testing theory and developing applicable conservation measures for small populations is hampered by sparse data. This lack of information is frequently driven by computational issues with small data sets that can be confounded by the impacts of stressors. We present estimates of demographic parameters from a small population of Boreal Toads (Anaxyrus boreas) that has been surveyed since 2001 by using capture-recapture methods. Estimates of annual adult survival probability are high relative to other Boreal Toad populations, whereas estimates of recruitment rate are low. Despite using simple models, clear patterns emerged from the analyses, suggesting that population size is constrained by low recruitment of adults and is declining slowly. These patterns provide insights that are useful in developing management directions for this small population, and this study serves as an example of the potential for small populations to yield robust and useful information despite sample size constraints.

  17. Production and Transport of Ozone From Boreal Forest Fires

    Science.gov (United States)

    Tarasick, David; Liu, Jane; Osman, Mohammed; Sioris, Christopher; Liu, Xiong; Najafabadi, Omid; Parrington, Mark; Palmer, Paul; Strawbridge, Kevin; Duck, Thomas

    2013-04-01

    In the summer of 2010, the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites) mission was planned by several universities and government agencies in the United Kingdom, Canada, and USA. Nearly 100 ozone soundings were made at 13 stations through the BORTAS Intensive Sounding Network, although aircraft measurements were unfortunately cancelled due to the volcanic eruption in Iceland. 2010 was actually an exceptional year for Canadian boreal fires. MODIS (Moderate Resolution Imaging Spectroradiometer) fire count data shows large fire events in Saskatchewan on several days in July. High amounts of NO2 close to the large fires are observed from OMI satellite data, indicating that not all NO2 is converted to PAN. Also associated with the fires, large amounts of CO, another precursor of ozone, are observed in MOPITT (Measurements Of Pollution In The Troposphere), AIRS and TES (Tropospheric Emission Spectrometer) satellite data in the middle to upper troposphere. These chemical conditions combined with sunny weather all favour ozone production. Following days with large fire activity, layers of elevated ozone mixing ratio (over 100 ppbv) are observed downwind at several sites. Back-trajectories suggest the elevated ozone in the profile is traceable to the fires in Saskatchewan. Lidar profiles also detect layers of aerosol at the same heights. However, the layers of high ozone are also associated with low humidity, which is not expected from a combustion source, and suggests the possibility of entrainment of stratospheric air.

  18. Feasibility of using geothermal effluents for waterfowl wetlands

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-09-01

    This project was conducted to evaluate the feasibility of using geothermal effluents for developing and maintaining waterfowl wetlands. Information in the document pertains to a seven State area the West where geothermal resources have development potential. Information is included on physiochemical characteristics of geothermal effluents; known effects of constituents in the water on a wetland ecosystem and water quality criteria for maintaining a viable wetland; potential of sites for wetland development and disposal of effluent water from geothermal facilities; methods of disposal of effluents, including advantages of each method and associated costs; legal and institutional constraints which could affect geothermal wetland development; potential problems associated with depletion of geothermal resources and subsidence of wetland areas; potential interference (adverse and beneficial) of wetlands with ground water; special considerations for wetlands requirements including size, flows, and potential water usage; and final conclusions and recommendations for suitable sites for developing demonstration wetlands.

  19. Wetland Mitigation Monitoring at the Fernald Preserve - 13200

    Energy Technology Data Exchange (ETDEWEB)

    Powell, Jane [Fernald Preserve Site Manager, DOE Office of Legacy Management, Harrison, Ohio (United States); Bien, Stephanie; Decker, Ashlee; Homer, John [Environmental Scientist, S.M. Stoller Corporation, Harrison, Ohio (United States); Wulker, Brian [Intern, S.M. Stoller Corporation, Harrison, Ohio (United States)

    2013-07-01

    The U.S. Department of Energy is responsible for 7.2 hectares (17.8 acres) of mitigation wetland at the Fernald Preserve, Ohio. Remedial activities affected the wetlands, and mitigation plans were incorporated into site-wide ecological restoration planning. In 2008, the Fernald Natural Resource Trustees developed a comprehensive wetland mitigation monitoring approach to evaluate whether compensatory mitigation requirements have been met. The Fernald Preserve Wetland Mitigation Monitoring Plan provided a guideline for wetland evaluations. The Ohio Environmental Protection Agency (Ohio EPA) wetland mitigation monitoring protocols were adopted as the means for compensatory wetland evaluation. Design, hydrologic regime, vegetation, wildlife, and biogeochemistry were evaluated from 2009 to 2011. Evaluations showed mixed results when compared to the Ohio EPA performance standards. Results of vegetation monitoring varied, with the best results occurring in wetlands adjacent to forested areas. Amphibians, particularly ambystomatid salamanders, were observed in two areas adjacent to forested areas. Not all wetlands met vegetation performance standards and amphibian biodiversity metrics. However, Fernald mitigation wetlands showed substantially higher ratings compared to other mitigated wetlands in Ohio. Also, soil sampling results remain consistent with other Ohio mitigated wetlands. The performance standards are not intended to be 'pass/fail' criteria; rather, they are reference points for use in making decisions regarding future monitoring and maintenance. The Trustees approved the Fernald Preserve Wetland Mitigation Monitoring Report with the provision that long-term monitoring of the wetlands continues at the Fernald Preserve. (authors)

  20. Wetland Mitigation Monitoring at the Fernald Preserve - 13200

    International Nuclear Information System (INIS)

    Powell, Jane; Bien, Stephanie; Decker, Ashlee; Homer, John; Wulker, Brian

    2013-01-01

    The U.S. Department of Energy is responsible for 7.2 hectares (17.8 acres) of mitigation wetland at the Fernald Preserve, Ohio. Remedial activities affected the wetlands, and mitigation plans were incorporated into site-wide ecological restoration planning. In 2008, the Fernald Natural Resource Trustees developed a comprehensive wetland mitigation monitoring approach to evaluate whether compensatory mitigation requirements have been met. The Fernald Preserve Wetland Mitigation Monitoring Plan provided a guideline for wetland evaluations. The Ohio Environmental Protection Agency (Ohio EPA) wetland mitigation monitoring protocols were adopted as the means for compensatory wetland evaluation. Design, hydrologic regime, vegetation, wildlife, and biogeochemistry were evaluated from 2009 to 2011. Evaluations showed mixed results when compared to the Ohio EPA performance standards. Results of vegetation monitoring varied, with the best results occurring in wetlands adjacent to forested areas. Amphibians, particularly ambystomatid salamanders, were observed in two areas adjacent to forested areas. Not all wetlands met vegetation performance standards and amphibian biodiversity metrics. However, Fernald mitigation wetlands showed substantially higher ratings compared to other mitigated wetlands in Ohio. Also, soil sampling results remain consistent with other Ohio mitigated wetlands. The performance standards are not intended to be 'pass/fail' criteria; rather, they are reference points for use in making decisions regarding future monitoring and maintenance. The Trustees approved the Fernald Preserve Wetland Mitigation Monitoring Report with the provision that long-term monitoring of the wetlands continues at the Fernald Preserve. (authors)

  1. Flora characteristics of Chenier Wetland in Bohai Bay and biogeographic relations with adjacent wetlands

    Science.gov (United States)

    Zhao, Yanyun; Lu, Zhaohua; Liu, Jingtao; Hu, Shugang

    2017-12-01

    A key step towards the restoration of heavily disturbed fragile coastal wetland ecosystems is determining the composition and characteristics of the plant communities involved. This study determined and characterized the community of higher plants in the Chenier wetland of Bohai Bay using a combination of field surveys, quadrat approaches, and multivariate statistical analyses. This community was then compared to other adjacent wetlands (Tianjin, Qinhuangdao, Laizhouwan, Jiaozhouwan, and Yellow River Delta wetland) located near the Huanghai and Bohai Seas using principal coordinate analysis (PCoA). Results showed a total of 56 higher plant species belonging to 52 genera from 20 families in Chenier wetland, the majority of which were dicotyledons. Single-species families were predominant, while larger families, including Gramineae, Compositae, Leguminosae, and Chenopodiaceae contained a higher number of species (each⩾6 species). Cosmopolitan species were also dominant with apparent intrazonality. Abundance (number of species) of temperate species was twice that of tropical taxa. Species number of perennial herbs, such as Gramineae and Compositae, was generally higher. Plant diversity in the Chenier wetland, based on the Shannon-Wiener index, was observed to be between the Qinhuangdao and Laizhouwan indices, while no significant difference was found in other wetlands using the Simpson index. Despite these slight differences in diversity, PCoA based on species abundance and composition of the wetland flora suggest that the Bohai Chenier community was highly similar to the coastal wetlands in Tianjin and Laizhouwan, further suggesting that these two wetlands could be important breeding grounds and resources for the restoration of the plant ecosystem in the Chenier wetland.

  2. Do geographically isolated wetlands influence landscape functions?

    Science.gov (United States)

    Cohen, Matthew J.; Creed, Irena F.; Alexander, Laurie C.; Basu, Nandita; Calhoun, Aram J.K.; Craft, Christopher; D’Amico, Ellen; DeKeyser, Edward S.; Fowler, Laurie; Golden, Heather E.; Jawitz, James W.; Kalla, Peter; Kirkman, L. Katherine; Lane, Charles R.; Lang, Megan; Leibowitz, Scott G.; Lewis, David Bruce; Marton, John; McLaughlin, Daniel L.; Mushet, David M.; Raanan-Kiperwas, Hadas; Rains, Mark C.; Smith, Lora; Walls, Susan C.

    2015-01-01

    Geographically isolated wetlands (GIWs), those surrounded by uplands, exchange materials, energy, and organisms with other elements in hydrological and habitat networks, contributing to landscape functions, such as flow generation, nutrient and sediment retention, and biodiversity support. GIWs constitute most of the wetlands in many North American landscapes, provide a disproportionately large fraction of wetland edges where many functions are enhanced, and form complexes with other water bodies to create spatial and temporal heterogeneity in the timing, flow paths, and magnitude of network connectivity. These attributes signal a critical role for GIWs in sustaining a portfolio of landscape functions, but legal protections remain weak despite preferential loss from many landscapes. GIWs lack persistent surface water connections, but this condition does not imply the absence of hydrological, biogeochemical, and biological exchanges with nearby and downstream waters. Although hydrological and biogeochemical connectivity is often episodic or slow (e.g., via groundwater), hydrologic continuity and limited evaporative solute enrichment suggest both flow generation and solute and sediment retention. Similarly, whereas biological connectivity usually requires overland dispersal, numerous organisms, including many rare or threatened species, use both GIWs and downstream waters at different times or life stages, suggesting that GIWs are critical elements of landscape habitat mosaics. Indeed, weaker hydrologic connectivity with downstream waters and constrained biological connectivity with other landscape elements are precisely what enhances some GIW functions and enables others. Based on analysis of wetland geography and synthesis of wetland functions, we argue that sustaining landscape functions requires conserving the entire continuum of wetland connectivity, including GIWs.

  3. Interactive biotic and abiotic regulators of soil carbon cycling: evidence from controlled climate experiments on peatland and boreal soils.

    Science.gov (United States)

    Briones, María Jesús I; McNamara, Niall P; Poskitt, Jan; Crow, Susan E; Ostle, Nicholas J

    2014-09-01

    Partially decomposed plant and animal remains have been accumulating in organic soils (i.e. >40% C content) for millennia, making them the largest terrestrial carbon store. There is growing concern that, in a warming world, soil biotic processing will accelerate and release greenhouse gases that further exacerbate climate change. However, the magnitude of this response remains uncertain as the constraints are abiotic, biotic and interactive. Here, we examined the influence of resource quality and biological activity on the temperature sensitivity of soil respiration under different soil moisture regimes. Organic soils were sampled from 13 boreal and peatland ecosystems located in the United Kingdom, Ireland, Spain, Finland and Sweden, representing a natural resource quality range of C, N and P. They were incubated at four temperatures (4, 10, 15 and 20 °C) at either 60% or 100% water holding capacity (WHC). Our results showed that chemical and biological properties play an important role in determining soil respiration responses to temperature and moisture changes. High soil C : P and C : N ratios were symptomatic of slow C turnover and long-term C accumulation. In boreal soils, low bacterial to fungal ratios were related to greater temperature sensitivity of respiration, which was amplified in drier conditions. This contrasted with peatland soils which were dominated by bacterial communities and enchytraeid grazing, resulting in a more rapid C turnover under warmer and wetter conditions. The unexpected acceleration of C mineralization under high moisture contents was possibly linked to the primarily role of fermented organic matter, instead of oxygen, in mediating microbial decomposition. We conclude that to improve C model simulations of soil respiration, a better resolution of the interactions occurring between climate, resource quality and the decomposer community will be required. © 2014 John Wiley & Sons Ltd.

  4. The phytoremediation ability of a polyculture constructed wetland to treat boron from mine effluent

    International Nuclear Information System (INIS)

    Türker, Onur Can; Böcük, Harun; Yakar, Anıl

    2013-01-01

    Highlights: ► We assessed the phytoremediation ability of a polyculture constructed wetland (PCW) to treat boron (B) from mine effluent. ► B in mine effluent decreased from 187 mg l −1 to 123 mg l −1 (32% removal rate) through the PCW. ► Estimated methane production, energy yields and electrical energy yields of the PCW increased with biomass production. ► Cattails accumulated more than 250 mg kg −1 B and common reed accumulated 38 mg kg −1 B at the end of the experiment. -- Abstract: This study focuses on describing the ability of a small-scale, subsurface-flow-polyculture-constructed wetland (PCW) to treat boron (B) mine effluent from the world's largest borax mine (Kırka, Turkey) under field conditions. This application is among the first effluent treatment methods of this type in both Turkey and the world. This study represents an important resource on how subsurface-flow-constructed wetlands could be used to treat B mine effluents in the field conditions. To this end, an experimental wetland was vegetated with common reed (Phragmites australis) and cattails (Typha latifolia), and mine effluent was moved through the wetland. The results of the present study show that B concentrations of the mine effluent decreased from 187 to 123 mg l −1 (32% removal rate) on average. The T. latifolia individuals absorbed a total of 250 mg kg −1 whereas P. australis in the PCW absorbed a total of 38 mg kg −1 B during the research period

  5. Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands.

    Science.gov (United States)

    Dalcin Martins, Paula; Hoyt, David W; Bansal, Sheel; Mills, Christopher T; Tfaily, Malak; Tangen, Brian A; Finocchiaro, Raymond G; Johnston, Michael D; McAdams, Brandon C; Solensky, Matthew J; Smith, Garrett J; Chin, Yu-Ping; Wilkins, Michael J

    2017-08-01

    Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions. © 2017 John Wiley & Sons Ltd.

  6. Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Dalcin Martins, Paula [Microbiology Department, The Ohio State University, Columbus OH 43210 USA; Hoyt, David W. [Environmental Molecular Sciences Laboratory, Richland WA 99350 USA; Bansal, Sheel [United States Geological Survey - Northern Prairie Wildlife Research Center, Jamestown ND 58401 USA; Mills, Christopher T. [United States Geological Survey, Crustal Geophysics and Geochemistry Science Center, Building 20, Denver Federal Center Denver CO 80225 USA; Tfaily, Malak [Environmental Molecular Sciences Laboratory, Richland WA 99350 USA; Tangen, Brian A. [United States Geological Survey - Northern Prairie Wildlife Research Center, Jamestown ND 58401 USA; Finocchiaro, Raymond G. [United States Geological Survey - Northern Prairie Wildlife Research Center, Jamestown ND 58401 USA; Johnston, Michael D. [School of Earth Sciences, The Ohio State University, Columbus OH 43210 USA; McAdams, Brandon C. [School of Earth Sciences, The Ohio State University, Columbus OH 43210 USA; Solensky, Matthew J. [United States Geological Survey - Northern Prairie Wildlife Research Center, Jamestown ND 58401 USA; Smith, Garrett J. [Microbiology Department, The Ohio State University, Columbus OH 43210 USA; Chin, Yu-Ping [School of Earth Sciences, The Ohio State University, Columbus OH 43210 USA; Wilkins, Michael J. [Microbiology Department, The Ohio State University, Columbus OH 43210 USA; School of Earth Sciences, The Ohio State University, Columbus OH 43210 USA

    2017-02-23

    Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR, and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations, or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield non-competitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions.

  7. Environmental gradients across wetland vegetation groups in the arid slopes of Western Alborz Mountains, N. Iran

    Directory of Open Access Journals (Sweden)

    Asghar Kamrani

    2011-01-01

    Full Text Available Mountain wetlands are unique ecosystems in the arid southern slopes of Alborz range, the second largest range in Iran. The spatial distribution characteristics of wetland vegetation in the arid region of the Alborz and the main factors affecting their distributional patterns were studied. A classification of vegetation and ecological characteristics were carried out using data extracted from 430 relevés in 90 wetland sites. The data were analyzed using Two Way Indicator Species Analysis (TWINSPAN and detrended correspondence analysis (DCA. The wetland vegetation of Alborz Mountain was classified into four large groups. The first vegetation group was calcareous rich vegetation, mainly distributed in the river banks and characterized by helophytes such as Bolboschoenus affinis as indicator species. The second group was saline transitional vegetation, distributed in the ecotone areas and dominated by Phragmites australis. The third vegetation group is wet meadow vegetation which mainly consists of geophytes, endemic and Irano-Turanian species, distributed in the higher altitudes. This vegetation is mainly characterized by indicator species such as Carex orbicularis, high level concentration of Fe2+ and percentage of organic matter in the soil. The fourth vegetation group is aquatic vegetation, distributed in the lakeshores. The aquatic group species are mainly hydrophytic such as Batrachium trichophyllum. The TWINSPAN vegetation groups could be also recognized in the DCA graphs and ecologically differentiated by ANOVA of studied variables. Four vegetation groups can be differentiated on two first axes of indirect ordination. There is a gradient of pH, EC and organic matter associated with altitude on the DCA diagram. Correlation analysis between the axes of DCA and environmental factors shows that altitude, soil texture and other dependant environmental variables (e.g. pH are the main environmental factors affecting the distribution of wetland

  8. Effect of antecedent terrestrial land-use on C and N cycling in created wetlands

    Science.gov (United States)

    McCalley, C. K.; Al Graiti, T.; Williams, T.; Huang, S.; McGowan, M. B.; Eddingsaas, N. C.; Tyler, A. C.

    2017-12-01

    Land-use legacies and their interaction with both management actions and climate variability has a poorly characterized impact on the development of ecosystem functions and the trajectory of climate-carbon feedbacks. The complex structure-function relationships in wetlands foster delivery of valuable, climate sensitive, ecosystem services (carbon sequestration, nutrient removal, flood control, etc.) but also make them susceptible to colonization by invasive plants and lead to emission of key greenhouse gases. This project uses created wetland ecosystems as a model to understand how heterogeneity in antecedent conditions interacts with management options to create unique structure-function scenarios and a range of climate feedback outcomes. We utilized ongoing experiments in created wetlands that differ in antecedent conditions (crop agriculture, livestock grazing) and investigated how management options (invasive species removal, organic matter addition) interact with legacy impacts to promote key ecosystem functions, including greenhouse gas emissions, carbon sequestration, denitrification and plant biodiversity. The effects of antecedent land-use on soil chemistry, coupled with hydrologic patterns resulted in wetlands with divergent C and N dynamics despite their similar creation history. Additionally, the occurrence of extreme weather events (drought and excessive flooding) during the study period highlighted the overarching role that increased climate variability will play in determining key ecosystem processes in wetlands. Responses to management were linked to hydro-period: while organic matter addition successfully increased soil organic matter to more closely replicate natural systems at all sites, it had the largest impact on C and N cycling when soils were saturated. Overall, environmental conditions that promoted saturated soils, both those shaped by human activities or climate extremes, enhanced primary productivity, nutrient removal and greenhouse gas

  9. The phytoremediation ability of a polyculture constructed wetland to treat boron from mine effluent

    Energy Technology Data Exchange (ETDEWEB)

    Türker, Onur Can [Faculty of Science and Letters, Department of Biology, Aksaray University, Aksaray (Turkey); Böcük, Harun, E-mail: hbocuk@anadolu.edu.tr [Faculty of Science, Department of Biology, Anadolu University, Eskişehir (Turkey); Yakar, Anıl [Faculty of Science, Department of Biology, Anadolu University, Eskişehir (Turkey)

    2013-05-15

    Highlights: ► We assessed the phytoremediation ability of a polyculture constructed wetland (PCW) to treat boron (B) from mine effluent. ► B in mine effluent decreased from 187 mg l{sup −1} to 123 mg l{sup −1} (32% removal rate) through the PCW. ► Estimated methane production, energy yields and electrical energy yields of the PCW increased with biomass production. ► Cattails accumulated more than 250 mg kg{sup −1} B and common reed accumulated 38 mg kg{sup −1} B at the end of the experiment. -- Abstract: This study focuses on describing the ability of a small-scale, subsurface-flow-polyculture-constructed wetland (PCW) to treat boron (B) mine effluent from the world's largest borax mine (Kırka, Turkey) under field conditions. This application is among the first effluent treatment methods of this type in both Turkey and the world. This study represents an important resource on how subsurface-flow-constructed wetlands could be used to treat B mine effluents in the field conditions. To this end, an experimental wetland was vegetated with common reed (Phragmites australis) and cattails (Typha latifolia), and mine effluent was moved through the wetland. The results of the present study show that B concentrations of the mine effluent decreased from 187 to 123 mg l{sup −1} (32% removal rate) on average. The T. latifolia individuals absorbed a total of 250 mg kg{sup −1} whereas P. australis in the PCW absorbed a total of 38 mg kg{sup −1} B during the research period.

  10. Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands.

    Science.gov (United States)

    Lee, Se-Yeun; Ryan, Maureen E; Hamlet, Alan F; Palen, Wendy J; Lawler, Joshua J; Halabisky, Meghan

    2015-01-01

    Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916-2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce

  11. Projecting the Hydrologic Impacts of Climate Change on Montane Wetlands

    Science.gov (United States)

    Hamlet, Alan F.; Palen, Wendy J.; Lawler, Joshua J.; Halabisky, Meghan

    2015-01-01

    Wetlands are globally important ecosystems that provide critical services for natural communities and human society. Montane wetland ecosystems are expected to be among the most sensitive to changing climate, as their persistence depends on factors directly influenced by climate (e.g. precipitation, snowpack, evaporation). Despite their importance and climate sensitivity, wetlands tend to be understudied due to a lack of tools and data relative to what is available for other ecosystem types. Here, we develop and demonstrate a new method for projecting climate-induced hydrologic changes in montane wetlands. Using observed wetland water levels and soil moisture simulated by the physically based Variable Infiltration Capacity (VIC) hydrologic model, we developed site-specific regression models relating soil moisture to observed wetland water levels to simulate the hydrologic behavior of four types of montane wetlands (ephemeral, intermediate, perennial, permanent wetlands) in the U. S. Pacific Northwest. The hybrid models captured observed wetland dynamics in many cases, though were less robust in others. We then used these models to a) hindcast historical wetland behavior in response to observed climate variability (1916–2010 or later) and classify wetland types, and b) project the impacts of climate change on montane wetlands using global climate model scenarios for the 2040s and 2080s (A1B emissions scenario). These future projections show that climate-induced changes to key driving variables (reduced snowpack, higher evapotranspiration, extended summer drought) will result in earlier and faster drawdown in Pacific Northwest montane wetlands, leading to systematic reductions in water levels, shortened wetland hydroperiods, and increased probability of drying. Intermediate hydroperiod wetlands are projected to experience the greatest changes. For the 2080s scenario, widespread conversion of intermediate wetlands to fast-drying ephemeral wetlands will likely reduce

  12. Modeling the Impacts of Boreal Deforestation on the Near-Surface Temperature in European Russia

    Directory of Open Access Journals (Sweden)

    Zhihui Li

    2013-01-01

    Full Text Available Boreal deforestation plays an important role in affecting regional and global climate. In this study, the regional temperature variation induced by future boreal deforestation in European Russia boreal forest region was simulated based on future land cover change and the Weather Research and Forecasting (WRF model. This study firstly tested and validated the simulation results of the WRF model. Then the land cover datasets in different years (2000 as baseline year, 2010, and 2100 was used in the WRF model to explore the impacts of boreal deforestation on the near-surface temperature. The results indicated that the WRF model has good ability to simulate the temperature change in European Russia. The land cover change in European Russia boreal forest region, which will be characterized by the conversion from boreal forests to croplands (boreal deforestation in the future 100 years, will lead to significant change of the near-surface temperature. The regional annual temperature will decrease by 0.58°C in the future 100 years, resulting in cooling effects to some extent and making the near-surface temperature decrease in most seasons except the spring.

  13. National recovery strategy for woodland caribou (Rangifer tarandus caribou, boreal population, in Canada

    Directory of Open Access Journals (Sweden)

    Dave Hervieux

    2007-04-01

    Full Text Available Recovery planning for the boreal population of woodland caribou is a complex task, spanning eight Canadian provinces and territories. To accommodate unique situations across the country, recovery planning for this Species at Risk Act-listed threatened species is occurring at both provincial/ territorial and national levels. The national recovery strategy strives to identify nationally important issues and provide direction for provinces and territories as they plan and implement boreal caribou recovery within their jurisdictions. The national vision is to conserve and recover boreal caribou and their habitat across Canada. Specific goals are to: 1 Prevent extirpation of local boreal caribou populations from all existing caribou ranges; and 2 Maintain or enhance local boreal caribou populations at or to self-sustaining levels within all existing caribou ranges; and 3 Maintain or enhance boreal caribou habitat to support self-sustaining local populations. Nineteen broad national approaches are identified. These approaches include items relating to: habitat planning and management, caribou population monitoring and management, management of human-caused mortality, management of other wildlife species, consideration of government legislation and policy,promotion of stewardship and public outreach, and research. Specific outcomes are provided for each stated recovery approach. For more information on Canada's national recovery strategy for the boreal population of woodland caribou please see www.speciesatrisk.gc.ca/recovery/default_e.cfm

  14. The effects of boreal forest expansion on the summer Arctic frontal zone

    Energy Technology Data Exchange (ETDEWEB)

    Liess, Stefan; Snyder, Peter K.; Harding, Keith J. [University of Minnesota, Department of Soil, Water, and Climate, Saint Paul, MN (United States)

    2012-05-15

    Over the last 100 years, Arctic warming has resulted in a longer growing season in boreal and tundra ecosystems. This has contributed to a slow northward expansion of the boreal forest and a decrease in the surface albedo. Corresponding changes to the surface and atmospheric energy budgets have contributed to a broad region of warming over areas of boreal forest expansion. In addition, mesoscale and synoptic scale patterns have changed as a result of the excess energy at and near the surface. Previous studies have identified a relationship between the positioning of the boreal forest-tundra ecotone and the Arctic frontal zone in summer. This study examines the climate response to hypothetical boreal forest expansion and its influence on the summer Arctic frontal zone. Using the Weather Research and Forecasting model over the Northern Hemisphere, an experiment was performed to evaluate the atmospheric response to expansion of evergreen and deciduous boreal needleleaf forests into open shrubland along the northern boundary of the existing forest. Results show that the lower surface albedo with forest expansion leads to a local increase in net radiation and an average hemispheric warming of 0.6 C at and near the surface during June with some locations warming by 1-2 C. This warming contributes to changes in the meridional temperature gradient that enhances the Arctic frontal zone and strengthens the summertime jet. This experiment suggests that continued Northern Hemisphere high-latitude warming and boreal forest expansion might contribute to additional climate changes during the summer. (orig.)

  15. Host-pathogen metapopulation dynamics suggest high elevation refugia for boreal toads

    Science.gov (United States)

    Mosher, Brittany A.; Bailey, Larissa L.; Muths, Erin L.; Huyvaert, Kathryn P

    2018-01-01

    Emerging infectious diseases are an increasingly common threat to wildlife. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is an emerging infectious disease that has been linked to amphibian declines around the world. Few studies exist that explore amphibian-Bd dynamics at the landscape scale, limiting our ability to identify which factors are associated with variation in population susceptibility and to develop effective in situdisease management. Declines of boreal toads (Anaxyrus boreas boreas) in the Southern Rocky Mountains are largely attributed to chytridiomycosis but variation exists in local extinction of boreal toads across this metapopulation. Using a large-scale historic dataset, we explored several potential factors influencing disease dynamics in the boreal toad-Bd system: geographic isolation of populations, amphibian community richness, elevational differences, and habitat permanence. We found evidence that boreal toad extinction risk was lowest at high elevations where temperatures may be sub-optimal for Bd growth and where small boreal toad populations may be below the threshold needed for efficient pathogen transmission. In addition, boreal toads were more likely to recolonize high elevation sites after local extinction, again suggesting that high elevations may provide refuge from disease for boreal toads. We illustrate a modeling framework that will be useful to natural resource managers striving to make decisions in amphibian-Bdsystems. Our data suggest that in the southern Rocky Mountains high elevation sites should be prioritized for conservation initiatives like reintroductions.

  16. The microbial communities and potential greenhouse gas production in boreal acid sulphate, non-acid sulphate, and reedy sulphidic soils

    Energy Technology Data Exchange (ETDEWEB)

    Šimek, Miloslav, E-mail: misim@upb.cas.cz [Biology Centre AS CR, v. v. i., Institute of Soil Biology, 370 05 České Budějovice (Czech Republic); University of South Bohemia, Faculty of Science, 370 05 České Budějovice (Czech Republic); Virtanen, Seija; Simojoki, Asko [Department of Food and Environmental Sciences, University of Helsinki, FI-00014 Helsinki (Finland); Chroňáková, Alica; Elhottová, Dana; Krištůfek, Václav [Biology Centre AS CR, v. v. i., Institute of Soil Biology, 370 05 České Budějovice (Czech Republic); Yli-Halla, Markku [Department of Food and Environmental Sciences, University of Helsinki, FI-00014 Helsinki (Finland)

    2014-01-01

    Acid sulphate (AS) soils along the Baltic coasts contain significant amounts of organic carbon and nitrogen in their subsoils. The abundance, composition, and activity of microbial communities throughout the AS soil profile were analysed. The data from a drained AS soil were compared with those from a drained non-AS soil and a pristine wetland soil from the same region. Moreover, the potential production of methane, carbon dioxide, and nitrous oxide from the soils was determined under laboratory conditions. Direct microscopic counting, glucose-induced respiration (GIR), whole cell hybridisation, and extended phospholipid fatty acid (PLFA) analysis confirmed the presence of abundant microbial communities in the topsoil and also in the deepest Cg2 horizon of the AS soil. The patterns of microbial counts, biomass and activity in the profile of the AS soil and partly also in the non-AS soil therefore differed from the general tendency of gradual decreases in soil profiles. High respiration in the deepest Cg2 horizon of the AS soil (5.66 μg C g{sup − 1} h{sup − 1}, as compared to 2.71 μg C g{sup − 1} h{sup − 1} in a top Ap horizon) is unusual but reasonable given the large amount of organic carbon in this horizon. Nitrous oxide production peaked in the BCgc horizon of the AS and in the BC horizon of the non-AS soil, but the peak value was ten-fold higher in the AS soil than in the non-AS soil (82.3 vs. 8.6 ng N g{sup − 1}d{sup − 1}). The data suggest that boreal AS soils on the Baltic coast contain high microbial abundance and activity. This, together with the abundant carbon and total and mineral nitrogen in the deep layers of AS soils, may result in substantial gas production. Consequently, high GHG emissions could occur, for example, when the generally high water table is lowered because of arable farming. - Highlights: •Boreal acid sulphate soils contain large amounts of organic C and N in subsoils. •Microbial communities throughout the acid

  17. Identification and characterization of wetlands in the Bear Creek watershed

    International Nuclear Information System (INIS)

    Rosensteel, B.A.; Trettin, C.C.

    1993-10-01

    The primary objective of this study was to identify, characterize, and map the wetlands in the Bear Creek watershed. A preliminary wetland categorization system based on the Cowardin classification system (Cowardin et al. 1979) with additional site-specific topographic, vegetation, and disturbance characteristic modifiers was developed to characterize the type of wetlands that exist in the Bear Creek watershed. An additional objective was to detect possible relationships among site soils, hydrology, and the occurrence of wetlands in the watershed through a comparison of existing data with the field survey. Research needs are discussed in the context of wetland functions and values and regulatory requirements for wetland impact assessment and compensatory mitigation

  18. Design-a-wetland: a tool for generating and assessing constructed wetland designs for wastewater treatment

    International Nuclear Information System (INIS)

    Casaril, Carolina J.

    2007-01-01

    Full text: Full text: The hydrological cycle is a key cycle affected by current and predicted climate change. Wetlands are one of the key ecosystems within the hydrological cycle and could contribute significantly in facing the challenges of climate change, such as water shortage. The impact of wetlands on greenhouse gas emissions is much debated and, conversely, the impact of climate change on wetlands also raises many questions. There have been many attempts to harness and integrate the natural capacities of wetlands into constructed systems. These systems are especially designed for multiple purposes. They can be used for wastewater treatment and reuse, and have the potential to increase sustainability by changing land and water use practices. This project generates a 'Design-A-Wetland' prototype model, designed to facilitate decision-making in the creation of constructed wetlands. Constructed wetlands are specifically tailored to their end use; water treatment fish and fowl habitat, flood buffer zones, or sequestration of greenhouse gases. This project attempts to answer the following questions: Can a single integrated decision model be created for the design and assessment of artificial wetlands, provided either entry or exit standards are known and specified?; Can the elements of a system of interfacing the model with public consultation be specified?; The project identifies model schematics and lays the groundwork for modelling suited to the wide variety of inputs required for decision making

  19. Functional roles of wetlands: a case study of the coastal wetlands of ...

    African Journals Online (AJOL)

    The Coastal Wetland of the study area is used extensively for a large number of activities. It is also threatened because of their vulnerability and attractiveness for development. These therefore prompted a study of the Wetlands for a period of 18 months (July 1997 – December 1998) to identify the functional roles that ...

  20. National Wetland Condition Assessment 2011: A Collaborative Survey of the Nation's Wetlands

    Science.gov (United States)

    The National Wetland Condition Assessment 2011: A Collaborative Survey presents the results of an unprecedented assessment of the nation’s wetlands. This report is part of the National Aquatic Resource Surveys, a series of statistically based surveys designed to provide the publi...

  1. Inclusion of Riparian Wetland Module (RWM) into the SWAT model for assessment of wetland hydrological benefit

    Science.gov (United States)

    Wetlands are an integral part of many agricultural watersheds. They provide multiple ecosystem functions, such as improving water quality, mitigating flooding, and serving as natural habitats. Those functions are highly depended on wetland hydrological characteristics and their connectivity to the d...

  2. Oceans of Opportunity. Harnessing Europe's largest domestic energy resource

    International Nuclear Information System (INIS)

    Fichaux, N.; Wilkes, J.

    2009-09-01

    Europe's offshore wind potential is enormous and able to power Europe seven times over. Over 100 GW of offshore wind projects are already in various stages of planning. If realised, these projects would produce 10% of the EU's electricity whilst avoiding 200 million tonnes of CO2 emissions each year. EWEA has a target of 40 GW of offshore wind in the EU by 2020, implying an average annual market growth of 28% over the coming 12 years. The EU market for onshore wind grew by an average 32% per year in the 12-year period from 1992-2004 - what the wind energy industry has achieved on land can be repeated at sea. EWEA's proposed offshore grid builds on the 11 offshore grids currently operating and 21 offshore grids currently being considered by the grid operators in the Baltic and North Seas to give Europe a truly pan-European electricity super highway. Strong political support and action from Europe's policy-makers will allow a new, multi-billion euro industry to be built. This new industry will deliver thousands of green collar jobs and a new renewable energy economy and establish Europe as world leader in offshore wind power technology. A single European electricity market with large amounts of wind power will bring affordable electricity to consumers, reduce import dependence, cut CO2 emissions and allow Europe to access its largest domestic energy source.

  3. Characterization of the largest effector gene cluster of Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Thomas Brefort

    2014-07-01

    Full Text Available In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function.

  4. El Paso natural gas nearing completion of system's largest expansion

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    El Paso Natural Gas Co.'s largest expansion program in its 64-year history will be completed along its northern system this spring or early summer. According to the company, the three-tiered, $241.5 million expansion program will increase El Paso's gas-transport capacity by 835 MMcfd to 2.5 bcfd of conventional and coal-seam gas from the San Juan basin in northwestern New Mexico. That's enough natural gas, says the company, to supply the needs of a city of more than 800,000 residents. This paper reports that the expansion involves the San Juan Triangle system, the company's northern main line, and the Permian-San Juan crossover line. The company also filed with the Federal Energy Regulatory Commission (FERC) in October 1991 to construct a new $15.2 million compressor station, Rio Vista, south of Bloomfield, N.M. The station would be used to move additional gas to the main line

  5. Benchmark Testing of the Largest Titanium Aluminide Sheet Subelement Conducted

    Science.gov (United States)

    Bartolotta, Paul A.; Krause, David L.

    2000-01-01

    To evaluate wrought titanium aluminide (gamma TiAl) as a viable candidate material for the High-Speed Civil Transport (HSCT) exhaust nozzle, an international team led by the NASA Glenn Research Center at Lewis Field successfully fabricated and tested the largest gamma TiAl sheet structure ever manufactured. The gamma TiAl sheet structure, a 56-percent subscale divergent flap subelement, was fabricated for benchmark testing in three-point bending. Overall, the subelement was 84-cm (33-in.) long by 13-cm (5-in.) wide by 8-cm (3-in.) deep. Incorporated into the subelement were features that might be used in the fabrication of a full-scale divergent flap. These features include the use of: (1) gamma TiAl shear clips to join together sections of corrugations, (2) multiple gamma TiAl face sheets, (3) double hot-formed gamma TiAl corrugations, and (4) brazed joints. The structural integrity of the gamma TiAl sheet subelement was evaluated by conducting a room-temperature three-point static bend test.

  6. Largest US oil and gas fields, August 1993

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-06

    The Largest US Oil and Gas Fields is a technical report and part of an Energy Information Administration (EIA) series presenting distributions of US crude oil and natural gas resources, developed using field-level data collected by EIA`s annual survey of oil and gas proved reserves. The series` objective is to provide useful information beyond that routinely presented in the EIA annual report on crude oil and natural gas reserves. These special reports also will provide oil and gas resource analysts with a fuller understanding of the nature of US crude oil and natural gas occurrence, both at the macro level and with respect to the specific subjects addressed. The series` approach is to integrate EIA`s crude oil and natural gas survey data with related data obtained from other authoritative sources, and then to present illustrations and analyses of interest to a broad spectrum of energy information users ranging from the general public to oil and gas industry personnel.

  7. Phosphorus Loadings to the World's Largest Lakes: Sources and Trends

    Science.gov (United States)

    Fink, Gabriel; Alcamo, Joseph; Flörke, Martina; Reder, Klara

    2018-04-01

    Eutrophication is a major water quality issue in lakes worldwide and is principally caused by the loadings of phosphorus from catchment areas. It follows that to develop strategies to mitigate eutrophication, we must have a good understanding of the amount, sources, and trends of phosphorus pollution. This paper provides the first consistent and harmonious estimates of current phosphorus loadings to the world's largest 100 lakes, along with the sources of these loadings and their trends. These estimates provide a perspective on the extent of lake eutrophication worldwide, as well as potential input to the evaluation and management of eutrophication in these lakes. We take a modeling approach and apply the WorldQual model for these estimates. The advantage of this approach is that it allows us to fill in large gaps in observational data. From the analysis, we find that about 66 of the 100 lakes are located in developing countries and their catchments have a much larger average phosphorus yield than the lake catchments in developed countries (11.1 versus 0.7 kg TP km-2 year-1). Second, the main source of phosphorus to the examined lakes is inorganic fertilizer (47% of total). Third, between 2005-2010 and 1990-1994, phosphorus pollution increased at 50 out of 100 lakes. Sixty percent of lakes with increasing pollution are in developing countries. P pollution changed primarily due to changing P fertilizer use. In conclusion, we show that the risk of P-stimulated eutrophication is higher in developing countries.

  8. LHC : The World's Largest Vacuum Systems being commissioned at CERN

    CERN Document Server

    Jiménez, J M

    2008-01-01

    When it switches on in 2008, the 26.7 km Large Hadron Collider (LHC) at CERN, will have the world's largest vacuum system operating over a wide range of pressures and employing an impressive array of vacuum technologies. This system is composed by 54 km of UHV vacuum for the circulating beams and 50 km of insulation vacuum around the cryogenic magnets and the liquid helium transfer lines. Over the 54 km of UHV beam vacuum, 48 km of this are at cryogenic temperature (1.9 K). The remaining 6 km of beam vacuum containing the insertions for "cleaning" the proton beams, radiofrequency cavities for accelerating the protons as well as beam-monitoring equipment is at ambient temperature and uses non-evaporable getter (NEG) coatings - a vacuum technology that was born and industrialized at CERN. The pumping scheme is completed using 780 ion pumps to remove noble gases and to provide pressure interlocks to the 303 vacuum safety valves. Pressure readings are provided by 170 Bayard-Alpert gauges and 1084 gauges (Pirani a...

  9. When clusters collide: constraints on antimatter on the largest scales

    International Nuclear Information System (INIS)

    Steigman, Gary

    2008-01-01

    Observations have ruled out the presence of significant amounts of antimatter in the Universe on scales ranging from the solar system, to the Galaxy, to groups and clusters of galaxies, and even to distances comparable to the scale of the present horizon. Except for the model-dependent constraints on the largest scales, the most significant upper limits to diffuse antimatter in the Universe are those on the ∼Mpc scale of clusters of galaxies provided by the EGRET upper bounds to annihilation gamma rays from galaxy clusters whose intracluster gas is revealed through its x-ray emission. On the scale of individual clusters of galaxies the upper bounds to the fraction of mixed matter and antimatter for the 55 clusters from a flux-limited x-ray survey range from 5 × 10 −9 to −6 , strongly suggesting that individual clusters of galaxies are made entirely of matter or of antimatter. X-ray and gamma-ray observations of colliding clusters of galaxies, such as the Bullet Cluster, permit these constraints to be extended to even larger scales. If the observations of the Bullet Cluster, where the upper bound to the antimatter fraction is found to be −6 , can be generalized to other colliding clusters of galaxies, cosmologically significant amounts of antimatter will be excluded on scales of order ∼20 Mpc (M∼5×10 15 M sun )

  10. GlobWetland Africa: Implementing Sustainable Earth Observation Based Wetland Monitoring Capacity in Africa and Beyond

    DEFF Research Database (Denmark)

    Tottrup, Christian; Riffler, Michael; Wang, Tiejun

    and decision support, [iii] receive a freely available, open, flexible and modifiable framework for easy establishment of new wetland observatories, for easy integration in existing observatory infrastructures and for easy adaptation to new requirements, e.g. changes in management processes.......Lack of data, appropriate information and challenges in human and institutional capacity put a serious constraint on effective monitoring and management of wetlands in Africa. Conventional data are often lacking in time or space, of poor quality or available at locations that are not necessarily...... for the conservation, wiseuse and effective management of wetlands in Africa and to provide African stakeholders with the necessary EO methods and tools to better fulfil their commitments and obligations towards the Ramsar Convention on Wetlands. The main objective of GlobWetland Africa (GW-A) is to provide the major...

  11. Wetlands of the Gulf Coast

    Science.gov (United States)

    2001-01-01

    This set of images from the Multi-angle Imaging SpectroRadiometer highlights coastal areas of four states along the Gulf of Mexico: Louisiana, Mississippi, Alabama and part of the Florida panhandle. The images were acquired on October 15, 2001 (Terra orbit 9718)and represent an area of 345 kilometers x 315 kilometers.The two smaller images on the right are (top) a natural color view comprised of red, green, and blue band data from MISR's nadir(vertical-viewing) camera, and (bottom) a false-color view comprised of near-infrared, red, and blue band data from the same camera. The predominantly red color of the false-color image is due to the presence of vegetation, which is bright at near-infrared wavelengths. Cities appear as grey patches, with New Orleans visible at the southern edge of Lake Pontchartrain, along the left-hand side of the images. The Lake Pontchartrain Bridge runs approximately north-south across the middle of the lake. The distinctive shape of the Mississippi River Delta can be seen to the southeast of New Orleans. Other coastal cities are visible east of the Mississippi, including Biloxi, Mobile and Pensacola.The large image is similar to the true-color nadir view, except that red band data from the 60-degree backward-looking camera has been substituted into the red channel; the blue and green data from the nadir camera have been preserved. In this visualization, green hues appear somewhat subdued, and a number of areas with a reddish color are present, particularly near the mouths of the Mississippi, Pascagoula, Mobile-Tensaw, and Escambia Rivers. Here, the red color is highlighting differences in surface texture. This combination of angular and spectral information differentiates areas with aquatic vegetation associated with poorly drained bottom lands, marshes, and/or estuaries from the surrounding surface vegetation. These wetland regions are not as well differentiated in the conventional nadir views.Variations in ocean color are apparent in

  12. Development of an indicator to monitor mediterranean wetlands.

    Science.gov (United States)

    Sanchez, Antonio; Abdul Malak, Dania; Guelmami, Anis; Perennou, Christian

    2015-01-01

    Wetlands are sensitive ecosystems that are increasingly subjected to threats from anthropogenic factors. In the last decades, coastal Mediterranean wetlands have been suffering considerable pressures from land use change, intensification of urban growth, increasing tourism infrastructure and intensification of agricultural practices. Remote sensing (RS) and Geographic Information Systems (GIS) techniques are efficient tools that can support monitoring Mediterranean coastal wetlands on large scales and over long periods of time. The study aims at developing a wetland indicator to support monitoring Mediterranean coastal wetlands using these techniques. The indicator makes use of multi-temporal Landsat images, land use reference layers, a 50m numerical model of the territory (NMT) and Corine Land Cover (CLC) for the identification and mapping of wetlands. The approach combines supervised image classification techniques making use of vegetation indices and decision tree analysis to identify the surface covered by wetlands at a given date. A validation process is put in place to compare outcomes with existing local wetland inventories to check the results reliability. The indicator´s results demonstrate an improvement in the level of precision of change detection methods achieved by traditional tools providing reliability up to 95% in main wetland areas. The results confirm that the use of RS techniques improves the precision of wetland detection compared to the use of CLC for wetland monitoring and stress the strong relation between the level of wetland detection and the nature of the wetland areas and the monitoring scale considered.

  13. Abiotic and biotic determinants of leaf carbon exchange capacity from tropical to high boreal biomes

    Science.gov (United States)

    Smith, N. G.; Dukes, J. S.

    2016-12-01

    Photosynthesis and respiration on land represent the two largest fluxes of carbon dioxide between the atmosphere and the Earth's surface. As such, the Earth System Models that are used to project climate change are high sensitive to these processes. Studies have found that much of this uncertainty is due to the formulation and parameterization of plant photosynthetic and respiratory capacity. Here, we quantified the abiotic and biotic factors that determine photosynthetic and respiratory capacity at large spatial scales. Specifically, we measured the maximum rate of Rubisco carboxylation (Vcmax), the maximum rate of Ribulose-1,5-bisphosphate regeneration (Jmax), and leaf dark respiration (Rd) in >600 individuals of 98 plant species from the tropical to high boreal biomes of Northern and Central America. We also measured a bevy of covariates including plant functional type, leaf nitrogen content, short- and long-term climate, leaf water potential, plant size, and leaf mass per area. We found that plant functional type and leaf nitrogen content were the primary determinants of Vcmax, Jmax, and Rd. Mean annual temperature and mean annual precipitation were not significant predictors of these rates. However, short-term climatic variables, specifically soil moisture and air temperature over the previous 25 days, were significant predictors and indicated that heat and soil moisture deficits combine to reduce photosynthetic capacity and increase respiratory capacity. Finally, these data were used as a model benchmarking tool for the Community Land Model version 4.5 (CLM 4.5). The benchmarking analyses determined errors in the leaf nitrogen allocation scheme of CLM 4.5. Under high leaf nitrogen levels within a plant type the model overestimated Vcmax and Jmax. This result suggested that plants were altering their nitrogen allocation patterns when leaf nitrogen levels were high, an effect that was not being captured by the model. These data, taken with models in mind

  14. Mapping Above- and Below-Ground Carbon Pools in Boreal Forests: The Case for Airborne Lidar.

    Science.gov (United States)

    Kristensen, Terje; Næsset, Erik; Ohlson, Mikael; Bolstad, Paul V; Kolka, Randall

    2015-01-01

    A large and growing body of evidence has demonstrated that airborne scanning light detection and ranging (lidar) systems can be an effective tool in measuring and monitoring above-ground forest tree biomass. However, the potential of lidar as an all-round tool for assisting in assessment of carbon (C) stocks in soil and non-tree vegetation components of the forest ecosystem has been given much less attention. Here we combine the use airborne small footprint scanning lidar with fine-scale spatial C data relating to vegetation and the soil surface to describe and contrast the size and spatial distribution of C pools within and among multilayered Norway spruce (Picea abies) stands. Predictor variables from lidar derived metrics delivered precise models of above- and below-ground tree C, which comprised the largest C pool in our study stands. We also found evidence that lidar canopy data correlated well with the variation in field layer C stock, consisting mainly of ericaceous dwarf shrubs and herbaceous plants. However, lidar metrics derived directly from understory echoes did not yield significant models. Furthermore, our results indicate that the variation in both the mosses and soil organic layer C stock plots appears less influenced by differences in stand structure properties than topographical gradients. By using topographical models from lidar ground returns we were able to establish a strong correlation between lidar data and the organic layer C stock at a stand level. Increasing the topographical resolution from plot averages (~2000 m2) towards individual grid cells (1 m2) did not yield consistent models. Our study demonstrates a connection between the size and distribution of different forest C pools and models derived from airborne lidar data, providing a foundation for future research concerning the use of lidar for assessing and monitoring boreal forest C.

  15. Isoprene emission from wetland sedges

    Directory of Open Access Journals (Sweden)

    A. Ekberg

    2009-04-01

    Full Text Available High latitude wetlands play an important role for the surface-atmosphere exchange of carbon dioxide (CO2 and methane (CH4, but fluxes of biogenic volatile organic compounds (BVOC in these ecosystems have to date not been extensively studied. This is despite BVOC representing a measurable proportion of the total gaseous C fluxes at northern locations and in the face of the high temperature sensitivity of these systems that requires a much improved process understanding to interpret and project possible changes in response to climate warming. We measured emission of isoprene and photosynthetic gas exchange over two growing seasons (2005–2006 in a subarctic wetland in northern Sweden with the objective to identify the physiological and environmental controls of these fluxes on the leaf scale. The sedge species Eriophorum angustifolium and Carex rostrata were both emitters of isoprene. Springtime emissions were first detected after an accumulated diurnal mean temperature above 0°C of about 100 degree days. Maximum measured growing season standardized (basal emission rates (20°C, 1000 μmol m−2 s−1 were 1075 (2005 and 1118 (2006 μg C m−2 (leaf area h−1 in E. angustifolium, and 489 (2005 and 396 (2006 μg C m−2 h−1 in C. rostrata. Over the growing season, basal isoprene emission varied in response to the temperature history of the last 48 h. Seasonal basal isoprene emission rates decreased with leaf nitrogen (N, which may be explained by the typical growth and resource allocation pattern of clonal sedges as the leaves age. The observations were used to model emissions over the growing season, accounting for effects of temperature history, links to leaf assimilation rate and the light and temperature dependencies of the cold-adapted sedges.

  16. Reach and messages of the world's largest ivory burn.

    Science.gov (United States)

    Braczkowski, Alexander; Holden, Matthew H; O'Bryan, Christopher; Choi, Chi-Yeung; Gan, Xiaojing; Beesley, Nicholas; Gao, Yufang; Allan, James; Tyrrell, Peter; Stiles, Daniel; Brehony, Peadar; Meney, Revocatus; Brink, Henry; Takashina, Nao; Lin, Ming-Ching; Lin, Hsien-Yung; Rust, Niki; Salmo, Severino G; Watson, James Em; Kahumbu, Paula; Maron, Martine; Possingham, Hugh P; Biggs, Duan

    2018-03-01

    Recent increases in ivory poaching have depressed African elephant populations. Successful enforcement has led to ivory being stockpiled. Stockpile destruction is becoming increasingly popular, and most destruction has occurred in the last five years. Ivory destruction is intended to send a strong message against ivory consumption, both in promoting a taboo on ivory use and catalyzing policy change. However, there has been no effort to establish the distribution and extent of media reporting on ivory destruction events globally. We analyze media coverage across eleven important nation states of the largest ivory destruction event in history (Kenya, 30 April 2016). We used a well-accepted online media crawling tool and key language translations to search online and print newspapers. We found most online news on the ivory burn came from the US (81% of articles), while print news was dominated by Kenya (61% of articles). We subjected online articles from five key countries and territories to content analysis and found 86-97% of all online articles reported the burn as a positive conservation action, while between 4-50% discussed ivory burning as having a negative impact on elephant conservation. Most articles discussed law enforcement and trade bans as effective for elephant conservation. There was more relative search interest globally on the 2016 Kenyan ivory burn than any other in five years. Our study is the first attempt to track the spread of media around an ivory burn and is a case study in tracking the effects of a conservation-marketing event. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Genome size analyses of Pucciniales reveal the largest fungal genomes.

    Science.gov (United States)

    Tavares, Sílvia; Ramos, Ana Paula; Pires, Ana Sofia; Azinheira, Helena G; Caldeirinha, Patrícia; Link, Tobias; Abranches, Rita; Silva, Maria do Céu; Voegele, Ralf T; Loureiro, João; Talhinhas, Pedro

    2014-01-01

    Rust fungi (Basidiomycota, Pucciniales) are biotrophic plant pathogens which exhibit diverse complexities in their life cycles and host ranges. The completion of genome sequencing of a few rust fungi has revealed the occurrence of large genomes. Sequencing efforts for other rust fungi have been hampered by uncertainty concerning their genome sizes. Flow cytometry was recently applied to estimate the genome size of a few rust fungi, and confirmed the occurrence of large genomes in this order (averaging 225.3 Mbp, while the average for Basidiomycota was 49.9 Mbp and was 37.7 Mbp for all fungi). In this work, we have used an innovative and simple approach to simultaneously isolate nuclei from the rust and its host plant in order to estimate the genome size of 30 rust species by flow cytometry. Genome sizes varied over 10-fold, from 70 to 893 Mbp, with an average genome size value of 380.2 Mbp. Compared to the genome sizes of over 1800 fungi, Gymnosporangium confusum possesses the largest fungal genome ever reported (893.2 Mbp). Moreover, even the smallest rust genome determined in this study is larger than the vast majority of fungal genomes (94%). The average genome size of the Pucciniales is now of 305.5 Mbp, while the average Basidiomycota genome size has shifted to 70.4 Mbp and the average for all fungi reached 44.2 Mbp. Despite the fact that no correlation could be drawn between the genome sizes, the phylogenomics or the life cycle of rust fungi, it is interesting to note that rusts with Fabaceae hosts present genomes clearly larger than those with Poaceae hosts. Although this study comprises only a small fraction of the more than 7000 rust species described, it seems already evident that the Pucciniales represent a group where genome size expansion could be a common characteristic. This is in sharp contrast to sister taxa, placing this order in a relevant position in fungal genomics research.

  18. Recovery of black-necked swans, macrophytes and water quality in a Ramsar wetland of southern Chile: Assessing resilience following sudden anthropogenic disturbances.

    Science.gov (United States)

    Jaramillo, Eduardo; Lagos, Nelson A; Labra, Fabio A; Paredes, Enrique; Acuña, Emilio; Melnick, Daniel; Manzano, Mario; Velásquez, Carlos; Duarte, Cristian

    2018-07-01

    In 2004 migration and mortality for unknown reasons of the herbivorous Black necked swan (Cygnus melancorhyphus (Molina, 1782)) occurred within the Río Cruces wetland (southern Chile), a Ramsar Site and nature sanctuary. Before 2004, this wetland hosted the largest breeding population of this water bird in the Neotropic Realm. The concurrent decrease in the spatial occurrence of the aquatic plant Egeria densa Planch. 1849 - the main food source of swans - was proposed as a cause for swan migration and mortality. Additionally, post-mortem analyses carried out on swans during 2004 showed diminished body weight, high iron loads and histopathological abnormalities in their livers, suggesting iron storage disease. Various hypotheses were postulated to describe those changes; the most plausible related to variations in water quality after a pulp mill located upstream the wetland started to operate in February 2004. Those changes cascaded throughout the stands of E. densa whose remnants had high iron contents in their tissues. Here we present results of a long-term monitoring program of the wetland components, which show that swan population abundance, body weights and histological liver conditions recovered to pre-disturbance levels in 2012. The recovery of E. densa and iron content in plants throughout the wetland, also returned to pre-disturbance levels in the same 8-year time period. These results show the temporal scale over which resilience and natural restoring processes occur in wetland ecosystems of temperate regions such as southern Chile. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Monitoring Ecological and Environmental Changes in Coastal Wetlands in the Yellow River Delta from 1987 to 2010 Using Remote Sensing Techniques

    Science.gov (United States)

    Shang, Kun; Zhao, Dong; Gan, Fuping; Xiao, Chenchao

    2016-04-01

    Many wetlands in the world have degraded rapidly in recent years, especially in China. The Yellow River Delta (YRD) is one of the largest deltas in China. The YRD Nature Reserve is one of China's most complete, broadest, and youngest wetland ecological systems in the warm-temperate zone. Most previous studies have placed particular emphasis on ecological environment or landscape of the YRD based on the distribution of wetlands. In recent years, with the rapid development of the city of Dongying, located in the YRD, the impacts of human activities are increasingly significant, so that monitoring changes in the wetlands has become especially important. In this research, we applied an improved Support Vector Machine (SVM) approach to wetland classification based on feature band set construction and optimization using seven Landsat images. By extracting waterlines, classifying wetlands and deriving landscape parameters, we have achieved high-frequency comprehensive monitoring of the wetlands in the YRD over a relatively long period. It offers a better estimate of wetland change trends than certain previous studies. From 1987 to 2010, the natural waterline primarily experienced erosion due to precipitation abnormalities, as well as coastal exploitation, as the co-analyzed meteorological data suggest. Meanwhile, the artificial waterline barely changed. The wetland area decreased rapidly from approximately 4,607 km2 to 2,714 km2 between 1987 and 2000. Ecological resilience and landscape diversity also decreased significantly during this period. The major impact factors were most likely urbanization, population expansion and the exploitation of the wetlands. After 2000, ecological resilience exhibited a positive trend. However, because newly built aquatic farms and salt works caused serious damages and threatened the natural beach landscape, the landscape fragmentation of muddy and sandy beaches increased after 2000. According to the results, more effective policies and

  20. Mirror image hydrocarbons from Tropical and Boreal forests

    Directory of Open Access Journals (Sweden)

    J. Williams

    2007-01-01

    Full Text Available Monoterpenes, emitted in large quantities by trees to attract pollinators and repel herbivores, can exist in mirror image forms called enantiomers. In this study such enantiomeric pairs have been measured in ambient air over extensive forest ecosystems in South America and northern Europe. For the dominant monoterpene, α-pinene, the (−-form was measured in large excess over the (+-form over the Tropical rainforest, whereas the reverse was observed over the Boreal forest. Interestingly, over the Tropical forest (−-α-pinene did not correlate with its own enantiomer, but correlated well with isoprene. The results indicate a remarkable ecosystem scale enantiomeric fingerprint and a nexus between the biosphere and atmosphere.

  1. Improved Mapping of Riparian Wetlands Using Reach Topography (ECOSERV)

    Science.gov (United States)

    Riparian wetlands provide a suite of ecosystems services including floodwater retention, biogeochemical processing, and habitat provisioning. However in one mid-Atlantic watershed the National Wetlands Inventory was shown to underrepresent these systems by greater than 50%. These...

  2. Improved Mapping of Riparian Wetlands Using Reach Topography

    Science.gov (United States)

    Riparian wetlands provide a suite of ecosystems services including floodwater retention, biogeochemical processing, and habitat provisioning. However in one mid-Atlantic watershed the National Wetlands Inventory was shown to underrepresent these systems by greater than 50%. These...

  3. a comparison of wetland valuation purposes in lagos metropolis

    African Journals Online (AJOL)

    Osondu

    streams to maintain flow throughout the dry season, and ... consequently the wetland filtration process and the quality of the water in ... restoration versus degradation of wetlands. ... value to individual species based on economic functions and ...

  4. The study of Phosphorus distribution at Putrajaya Wetland

    Science.gov (United States)

    Mubin Zahari, Nazirul; Malek, Nur Farzana Fasiha Abdul; Fai, Chow Ming; Humaira Haron, Siti; Hafiz Zawawi, Mohd; Nazmi Ismail, Iszmir; Mohamad, Daud; Syamsir, Agusril; Sidek, Lariyah Mohd; Zakwan Ramli, Mohd; Ismail, Norfariza; Zubir Sapian, Ahmad; Noordin, Normaliza; Rahaman, Nurliyana Abdul; Muhamad, Yahzam; Mat Saman, Jarina

    2018-04-01

    This study is concerning phosphorus distribution in Putrajaya Wetland. Phosphorus is one of the important component in nutrients for living things be it aquatic or non – aquatic organisms. Total phosphorus (TP) results will give some information on the trophic status of surface water in water bodies. The focus of this study is to determine the total phosphorus concentration in Putrajaya Wetland which is in the inlet of the wetland then outlet of the wetland (Central Wetland Lake). The water sample is taken from Putrajaya Wetland and the test was conducted in the laboratory. The result from this study shows the results for total phosphorus according to month, sampling station and cells. Lowest total phosphate at the Central Wetland compare with all the wetland arms cells.

  5. New species of Eunotia from small isolated wetlands in Florida

    Science.gov (United States)

    Diatom species composition of small wetlands is diverse and unique due to a plethora of spatial and temporal variables. Diatoms from small wetlands can contribute greatly to better understanding microbial biodiversity, distribution, dispersal and populations.

  6. Wetland Polygons, California, 2016, California Aquatic Resources Inventory

    Data.gov (United States)

    U.S. Environmental Protection Agency — This feature class contains polgon features depicting wetlands that are standardized to a common wetland classification system (CARI) and provide additional source...

  7. Geothermal wetlands: an annotated bibliography of pertinent literature

    Energy Technology Data Exchange (ETDEWEB)

    Stanley, N.E.; Thurow, T.L.; Russell, B.F.; Sullivan, J.F.

    1980-05-01

    This annotated bibliography covers the following topics: algae, wetland ecosystems; institutional aspects; macrophytes - general, production rates, and mineral absorption; trace metal absorption; wetland soils; water quality; and other aspects of marsh ecosystems. (MHR)

  8. Kansas Protects and Restores Wetlands, Streams and Riparian Areas

    Science.gov (United States)

    Wetland Program Development Grant (WPDG) in 2007 when the Kansas State Conservation Commission began identifying team members interested in developing a framework for a comprehensive Kansas Wetland and Aquatic Resources Conservation Plan.

  9. Local institutions for sustaining wetland resources and community ...

    African Journals Online (AJOL)

    Administrator

    Data collection methods. Qualitative ..... Sondu-Miriu wetland some traditional fishing methods, for example, the ... ted processing, cooking and trading activities in the three wetlands. .... water access was making the water dirty after collection.

  10. Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem

    International Nuclear Information System (INIS)

    Mazurek, M.A.; Cofer, W.R. III; Levine, J.S.

    1990-10-01

    The identity and ambient mass concentrations of radiatively important carbonaceous aerosols were measured for a boreal forest prescribed burn conducted in northern Ontario, CAN in August 1989. Nonsize-segregated airborne particles were collected for smoldering-fire and full-fire conditions using a helicopter sampling platform. Total carbon (TC), organic carbon (OC) and elemental carbon (EC) were measured. Smoke plume mass concentrations of the OC and EC particles were greatest for full-fire conditions and had ranges of 1.560 to 2.160 mg/m -1 (OC) and 0.120 to 0.160 mg/m -3 (EC) with OC:EC ratios of 10 to 18, respectively. Smoldering fire conditions showed smoke plume OC and EC levels of 0.570--1.030 mg/m -3 (OC) and 0.006--0.050 mg/m -3 (EC) and much higher ratios of OC:EC (21 to 95). These aerosol data indicate the formation of EC particles is greatest during full-fire combustion of boreal forest material relative to smoldering combustion. However, EC particles comprise a minor fraction of the particulate carbon smoke aerosols for both full-fire and smoldering conditions; the major component of carbonaceous smoke aerosols emitted during the prescribed burn is OC. Overall, the OC and EC in-plume smoke aerosol data show nonuniform production of these particles during various stages of the prescribed burn, and major differences in the type of carbonaceous aerosol that is generated (OC versus EC)

  11. Northwest Boreal Landscape Conservation Cooperative strategic plan 2015 - 2025

    Science.gov (United States)

    Markon, Carl; Schroff, Eric

    2016-01-01

    The Northwest Boreal Landscape Conservation Cooperative (NWB LCC) is a voluntary, diverse, self-directed management-science partnership, informing and promoting integrated science, sustainable natural and cultural resource management, and conservation to address impacts of climate change and other stressors within and across ecosystems. The NWB LCC area includes parts of Alaska, Yukon, Northwest Territories, and British Columbia. Our partnership reflects both the broad geographic scope and an extensive array of active and engaged participants including resource management organizations, government representatives, policy makers, Tribes and First Nations, industry leaders, researchers, non-governmental organizations, and research/education institutions. Bringing together diverse partners will help assure the northwest boreal is a functioning, sustainable landscape. We live in an era of profound conservation challenges, including the loss and fragmentation of habitats, genetic isolation, invasive species, and unnatural wildfire. The effects of rapidly changing climate are already evident on the landscape. In these circumstances, it is imperative that natural resource management agencies, science providers, Tribes, First Nations, conservation organizations, and other stakeholders work together to understand the drivers and impacts of landscape change and to determine how best to address those challenges. Further, it is essential that the public and communities receive clear communication about the vision and activities of the NWB LCC. Open public access to NWB LCC activities and products will promote acceptance and support of the science that guides potential changes in management action and conservation strategy. This strategic plan provides a great opportunity for the NWB LCC to share our approach and intentions to the LCC members, collaborators, communities, and the public at large.

  12. Grasslands, wetlands, and agriculture: the fate of land expiring from the Conservation Reserve Program in the Midwestern United States

    Science.gov (United States)

    Morefield, Philip E.; LeDuc, Stephen D.; Clark, Christopher M.; Iovanna, Richard

    2016-09-01

    The Conservation Reserve Program (CRP) is the largest agricultural land-retirement program in the United States, providing many environmental benefits, including wildlife habitat and improved air, water, and soil quality. Since 2007, however, CRP area has declined by over 25% nationally with much of this land returning to agriculture. Despite this trend, it is unclear what types of CRP land are being converted, to what crops, and where. All of these specific factors greatly affect environmental impacts. To answer these questions, we quantified shifts in expiring CRP parcels to five major crop-types (corn, soy, winter and spring wheat, and sorghum) in a 12-state, Midwestern region of the United States using a US Department of Agriculture (USDA), field-level CRP database and USDA’s Cropland Data Layer. For the years 2010 through 2013, we estimate almost 30%, or more than 530 000 ha, of expiring CRP land returned to the production of these five crops in our study area, with soy and corn accounting for the vast majority of these shifts. Grasslands were the largest type of CRP land converted (360 000 ha), followed by specifically designated wildlife habitat (76 000 ha), and wetland areas (53 000 ha). These wetland areas were not just wetlands themselves, but also a mix of land covers enhancing or protecting wetland ecosystem services (e.g., wetland buffers). Areas in the Dakotas, Nebraska, and southern Iowa were hotspots of change, with the highest areas of CRP land moving back to agriculture. By contrast, we estimate only a small amount (˜3%) of the expiring land shifted into similar, non-CRP land-retirement or easement programs. Reconciling needs for food, feed, fuel, and healthy ecosystems is an immense challenge for farmers, conservationists, and state and federal agencies. Reduced enrollment and the turnover of CRP land from conservation to agriculture raises questions about sustaining ecosystem services in this region.

  13. Plant species and communities in Poyang Lake, the largest freshwater lake in China

    Directory of Open Access Journals (Sweden)

    Wang, H. F.

    2015-12-01

    Full Text Available Studying plant species richness and composition of a wetland is essential when estimating its ecological importance and ecosystem services, especially if a particular wetland is subjected to human disturbances. Poyang Lake, located in the middle reaches of Yangtze River (central China, constitutes the largest freshwater lake of the country. It harbours high biodiversity and provides important habitat for local wildlife. A dam that will maintain the water capacity in Poyang Lake is currently being planned. However, the local biodiversity and the likely effects of this dam on the biodiversity (especially on the endemic and rare plants have not been thoroughly examined. Therefore, in order to assess the richness of plant species and plant communities in Poyang Lake, we conducted a detailed field investigation combined with a literature review. A total of 124 families, 339 genera, and 512 species (including sub-species, varieties and forms as well as eight dominant plant communities were identified, confirming the lake’s wetland as a regional hotspot of plant diversity. It is imperative to carry out further research on the impact of damming on the vegetation, particularly research focusing on protecting local biodiversity, maintaining the lake’s ecosystem services, controlling the spread of invasive species, and restoring degraded ecosystems.El estudio de la riqueza y la composición de especies vegetales de un humedal es esencial a la hora de estimar su importancia ecológica y sus servicios ecosistémicos, especialmente cuando éste está sujeto a perturbaciones humanas. El lago Poyang, situado en el curso medio del río Yangtsé (China central constituye la mayor superfície de agua dulce del país. Alberga una elevada biodiversidad y proporciona hábitats importantes para la flora y fauna locales. En la actualidad existen planes de construir una presa que mantendrá el volumen de agua del lago estable. Sin embargo, y hasta la fecha, apenas

  14. Breeding biology and incremental benefits of outcrossing for the restoration wildflower, Hedysarum boreale (Fabaceae)

    Science.gov (United States)

    Northern sweetvetch, Hedysarum boreale, is an herbaceous perennial of the Rocky Mountains whose seed is desired for rehabilitating degraded plant communities. Through experimental manual pollinations, the necessity of pollinators was shown by the failures of autopollination and wind pollination, ev...

  15. Identifying forest patterns from space to explore dynamics across the circumpolar boreal

    Science.gov (United States)

    Montesano, P. M.; Neigh, C. S. R.; Feng, M.; Channan, S.; Sexton, J. O.; Wagner, W.; Wooten, M.; Poulter, B.; Wang, L.

    2017-12-01

    A variety of forest patterns are the result of interactions between broad-scale climate and local-scale site factors and history across the northernmost portion of the circumpolar boreal. Patterns of forest extent, height, and cover help describe forest structure transitions that influence future and reflect past dynamics. Coarse spaceborne observations lack structural detail at forest transitions, which inhibits understanding of these dynamics. We highlight: (1) the use of sub-meter spaceborne stereogrammetry for deriving structure estimates in boreal forests; (2) its potential to complement other spaceborne estimates of forest structure at critical scales; and (3) the potential of these sub-meter and other Landsat-derived structure estimates for improving understanding of broad-scale boreal dynamics such as carbon flux and albedo, capturing the spatial variability of the boreal-tundra biome boundary, and assessing its potential for change.

  16. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome.

    Science.gov (United States)

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Liang, Shunlin; Zhao, Shuqing; Chen, Jingming; Xu, Wenfang; Li, Xianglan; Barr, Alan; Andrew Black, T; Yan, Wende; Goulden, Mike L; Kulmala, Liisa; Lindroth, Anders; Margolis, Hank A; Matsuura, Yojiro; Moors, Eddy; van der Molen, Michiel; Ohta, Takeshi; Pilegaard, Kim; Varlagin, Andrej; Vesala, Timo

    2014-06-26

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascular plants can because of its much lower photosynthetic capacity. Here, based on eddy covariance measurements, we show that the difference in photosynthetic capacity between these two plant functional types has never been explicitly included when estimating regional GPP in the boreal region, resulting in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order to adequately assess the role of the boreal region in the global carbon cycle.

  17. Carbon dynamics in lakes of the boreal forest under a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    Benoy, G.; Wrona, F. [Environment Canada, Saskatoon, SK (Canada). National Water Research Inst.; Cash, K. [Environment Canada, Saskatoon, SK (Canada). Prairie and Northern Wildlife Research Centre; McCauley, E. [Calgary Univ., AB (Canada). Dept. of Biology

    2007-09-15

    This article reviewed factors influencing lake ecosystem carbon dynamics in boreal forest regions and identified research areas needed to accurately forecast the impacts of climate change on carbon pools and flux rates. The review suggested that carbon pools in profundal and littoral sediments across the boreal forest should be identified. Climate change experiments should be conducted to quantify ecosystem carbon dynamics as well as changes in aquatic food web structures. Whole system experiments are also needed to examine the hydrologic and bio-geochemical conditions in which allochthonous carbon is integrated into food webs in potentially drier climates. Results also indicated the need for a watershed-scale assessment of carbon budgets for lakes in transitional zones between boreal forests, prairies, parklands, forests, and tundra. It was concluded that studies are also needed to investigate the integration of lacustrine carbon pools and flux rates on carbon budgets at both the local watershed and boreal forest biome scale. 113 refs., 3 figs.

  18. Differentiating moss from higher plants is critical in studying the carbon cycle of the boreal biome

    Science.gov (United States)

    Yuan, Wenping; Liu, Shuguang; Dong, Wenjie; Liang, Shunlin; Zhao, Shuqing; Chen, Jingming; Xu, Wenfang; Li, Xianglan; Barr, Alan; Black, T. Andrew; Yan, Wende; Goulden, Michael; Kulmala, Liisa; Lindroth, Anders; Margolis, Hank A.; Matsuura, Yojiro; Moors, Eddy; van der Molen, Michiel; Ohta, Takeshi; Pilegaard, Kim; Varlagin, Andrej; Vesala, Timo

    2014-01-01

    The satellite-derived normalized difference vegetation index (NDVI), which is used for estimating gross primary production (GPP), often includes contributions from both mosses and vascular plants in boreal ecosystems. For the same NDVI, moss can generate only about one-third of the GPP that vascular plants can because of its much lower photosynthetic capacity. Here, based on eddy covariance measurements, we show that the difference in photosynthetic capacity between these two plant functional types has never been explicitly included when estimating regional GPP in the boreal region, resulting in a substantial overestimation. The magnitude of this overestimation could have important implications regarding a change from a current carbon sink to a carbon source in the boreal region. Moss abundance, associated with ecosystem disturbances, needs to be mapped and incorporated into GPP estimates in order to adequately assess the role of the boreal region in the global carbon cycle.

  19. GIS learning tool for world's largest earthquakes and their causes

    Science.gov (United States)

    Chatterjee, Moumita

    The objective of this thesis is to increase awareness about earthquakes among people, especially young students by showing the five largest and two most predictable earthquake locations in the world and their plate tectonic settings. This is a geographic based interactive tool which could be used for learning about the cause of great earthquakes in the past and the safest places on the earth in order to avoid direct effect of earthquakes. This approach provides an effective way of learning for the students as it is very user friendly and more aligned to the interests of the younger generation. In this tool the user can click on the various points located on the world map which will open a picture and link to the webpage for that point, showing detailed information of the earthquake history of that place including magnitude of quake, year of past quakes and the plate tectonic settings that made this place earthquake prone. Apart from knowing the earthquake related information students will also be able to customize the tool to suit their needs or interests. Students will be able to add/remove layers, measure distance between any two points on the map, select any place on the map and know more information for that place, create a layer from this set to do a detail analysis, run a query, change display settings, etc. At the end of this tool the user has to go through the earthquake safely guidelines in order to be safe during an earthquake. This tool uses Java as programming language and uses Map Objects Java Edition (MOJO) provided by ESRI. This tool is developed for educational purpose and hence its interface has been kept simple and easy to use so that students can gain maximum knowledge through it instead of having a hard time to install it. There are lots of details to explore which can help more about what a GIS based tool is capable of. Only thing needed to run this tool is latest JAVA edition installed in their machine. This approach makes study more fun and

  20. Gas Research Institute wetland research program

    International Nuclear Information System (INIS)

    Wilkey, P.L.; Zimmerman, R.E.; Isaacson, H.R.

    1992-01-01

    As part of three ongoing research projects, the Gas Research Institute (GRI) is studying the natural gas industry's impacts on wetlands and how to manage operations so that impacts can be minimized or eliminated. The objective of the first project is to gain a better understanding of the causes and processes of wetland loss in the Louisiana deltaic plain and what role gas pipeline canals play in wetland loss. On the basis of information gathered from the first projects, management and mitigation implications for pipeline construction and maintenance will be evaluated. The objective of the second project is to assess the floral and faunal communities on existing rights-of-way (ROWs) that pass through numerous types of wetlands across the United States. The emphasis of the project is on pipelines that were installed within the past five years. The objective of the third project is to evaluate the administrative, jurisdictional, technical, and economic issues of wetland mitigation banking. This paper discusses these projects, their backgrounds, some of the results to date, and the deliverables

  1. Forms of organic phosphorus in wetland soils

    Science.gov (United States)

    Cheesman, A. W.; Turner, B. L.; Reddy, K. R.

    2014-12-01

    Phosphorus (P) cycling in freshwater wetlands is dominated by biological mechanisms, yet there has been no comprehensive examination of the forms of biogenic P (i.e., forms derived from biological activity) in wetland soils. We used solution 31P NMR spectroscopy to identify and quantify P forms in surface soils of 28 palustrine wetlands spanning a range of climatic, hydrogeomorphic, and vegetation types. Total P concentrations ranged between 51 and 3516 μg P g-1, of which an average of 58% was extracted in a single-step NaOH-EDTA procedure. The extracts contained a broad range of P forms, including phosphomonoesters (averaging 24% of the total soil P), phosphodiesters (averaging 10% of total P), phosphonates (up to 4% of total P), and both pyrophosphate and long-chain polyphosphates (together averaging 6% of total P). Soil P composition was found to be dependant upon two key biogeochemical properties: organic matter content and pH. For example, stereoisomers of inositol hexakisphosphate were detected exclusively in acidic soils with high mineral content, while phosphonates were detected in soils from a broad range of vegetation and hydrogeomorphic types but only under acidic conditions. Conversely inorganic polyphosphates occurred in a broad range of wetland soils, and their abundance appears to reflect more broadly that of a "substantial" and presumably active microbial community with a significant relationship between total inorganic polyphosphates and microbial biomass P. We conclude that soil P composition varies markedly among freshwater wetlands but can be predicted by fundamental soil properties.

  2. Greenhouse gas flux dynamics in wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Silvola, J.; Alm, J.; Saarnio, S. [Joensuu Univ. (Finland). Dept. of Biology; Martikainen, P.J. [National Public Health Inst., Kuopio (Finland). Dept. of Environmental Microbiology

    1996-12-31

    Two important greenhouse gases, CO{sub 2} and CH{sub 4}, are closely connected to the carbon cycling of wetlands. Although virgin wetlands are mostly carbon accumulating ecosystems, major proportion of the CO{sub 2} bound annually in photosynthesis is released back to the atmosphere. Main portion of the carbon cycling in wetlands is quite fast while a small proportion of carbon diffusing from soil is released from organic matter, which may be ten thousand years old. Methane is formed in the anaerobic layers of wetlands, from where it is released gradually to the atmosphere. The decomposition in anaerobic conditions is very slow, which means that usually only a few percent of the annual carbon cycling takes place as methane. Research on CO{sub 2} fluxes of different virgin and managed peatlands was the main topic of this project during the first phase of SILMU. The measurements were made during two seasons in varying conditions in c. 30 study sites. In the second phase of SILMU the research topics were the spatial and temporal variation of CO{sub 2} and CH{sub 4} fluxes, the relationships between vegetation and gas fluxes as well as carbon balance studies in wetlands at some intensive sites

  3. Broken connections of wetland cultural knowledge

    Science.gov (United States)

    Middleton, Beth A.

    2016-01-01

    As global agriculture intensifies, cultural knowledge of wetland utilization has eroded as natural resources become more stressed, and marginal farmers move away from the land. The excellent paper by Fawzi et al. (2016) documents a particularly poignant case of traditional knowledge loss among the Marsh Arab women of Iraq. Through interviews, the authors document the breakdown of skill transfer from the older to younger generation of women. The authors link the loss of their cultural knowledge with the loss of wetlands in the region. Women no longer can help provide for their families using wetland products, and along with that, their ancient knowledge of plant usage is lost. These ancient skills included medicinal uses, and reed harvesting for weaving and water buffalo fodder. As, the majority of the Mesopotamian Marshes have dried, this way of life is being forgotten (Fawzi et al. 2015). The global tragedy is that while the careful alliance of wetlands and people have sustained human cultures for millennia, degraded wetlands lose their ability to provide these services (Maltby 1980).

  4. Greenhouse gas flux dynamics in wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Silvola, J; Alm, J; Saarnio, S [Joensuu Univ. (Finland). Dept. of Biology; Martikainen, P J [National Public Health Inst., Kuopio (Finland). Dept. of Environmental Microbiology

    1997-12-31

    Two important greenhouse gases, CO{sub 2} and CH{sub 4}, are closely connected to the carbon cycling of wetlands. Although virgin wetlands are mostly carbon accumulating ecosystems, major proportion of the CO{sub 2} bound annually in photosynthesis is released back to the atmosphere. Main portion of the carbon cycling in wetlands is quite fast while a small proportion of carbon diffusing from soil is released from organic matter, which may be ten thousand years old. Methane is formed in the anaerobic layers of wetlands, from where it is released gradually to the atmosphere. The decomposition in anaerobic conditions is very slow, which means that usually only a few percent of the annual carbon cycling takes place as methane. Research on CO{sub 2} fluxes of different virgin and managed peatlands was the main topic of this project during the first phase of SILMU. The measurements were made during two seasons in varying conditions in c. 30 study sites. In the second phase of SILMU the research topics were the spatial and temporal variation of CO{sub 2} and CH{sub 4} fluxes, the relationships between vegetation and gas fluxes as well as carbon balance studies in wetlands at some intensive sites

  5. Responses of Isolated Wetland Herpetofauna to Upland Forest Management

    International Nuclear Information System (INIS)

    Russell, K.R.; Hanlin, H.G.; Wigley, T.B.; Guynn, D.C. Jr.

    2002-01-01

    Measurement of responses of herpetofauna at isolated wetlands in the Coastal Plain of South Carolina to disturbance of adjacent loblolly pine forest. Many species of isolated wetland herpetofauna in the Southeastern Coastal Plain may tolerate some disturbance in adjacent upland stands. Responses of isolated wetland herpetofauna to upland silviculture and the need for adjacent forested buffers likely depend on the specific landscape context in which the wetlands occur and composition of the resident herpetofaunal community

  6. Icelandic Inland Wetlands: Characteristics and Extent of Draining

    OpenAIRE

    Gudmundsson, Jon; Brink, Sigmundur H.; Arnalds, Olafur; Gisladottir, Fanney O.; Oskarsson, Hlynur

    2016-01-01

    Iceland has inland wetland areas with soils exhibiting both Andosol and Histosol properties which are uncommon elsewhere on Earth. They are generally fertile, with higher bird-nest densities than in similar wetlands in the neighboring countries, with nutrients released by rapid weathering of aeolian materials of basaltic nature. Icelandic inland wetlands cover about 9000 km2 constituting 19.4 % of the vegetated surfaces of the island. The wetland soils are often 1–3 m thick and store 33 to >1...

  7. Development of a "Hydrologic Equivalent Wetland" Concept for Modeling Cumulative Effects of Wetlands on Watershed Hydrology

    Science.gov (United States)

    Wang, X.; Liu, T.; Li, R.; Yang, X.; Duan, L.; Luo, Y.

    2012-12-01

    Wetlands are one of the most important watershed microtopographic features that affect, in combination rather than individually, hydrologic processes (e.g., routing) and the fate and transport of constituents (e.g., sediment and nutrients). Efforts to conserve existing wetlands and/or to restore lost wetlands require that watershed-level effects of wetlands on water quantity and water quality be quantified. Because monitoring approaches are usually cost or logistics prohibitive at watershed scale, distributed watershed models, such as the Soil and Water Assessment Tool (SWAT), can be a best resort if wetlands can be appropriately represented in the models. However, the exact method that should be used to incorporate wetlands into hydrologic models is the subject of much disagreement in the literature. In addition, there is a serious lack of information about how to model wetland conservation-restoration effects using such kind of integrated modeling approach. The objectives of this study were to: 1) develop a "hydrologic equivalent wetland" (HEW) concept; and 2) demonstrate how to use the HEW concept in SWAT to assess effects of wetland restoration within the Broughton's Creek watershed located in southwestern Manitoba of Canada, and of wetland conservation within the upper portion of the Otter Tail River watershed located in northwestern Minnesota of the United States. The HEWs were defined in terms of six calibrated parameters: the fraction of the subbasin area that drains into wetlands (WET_FR), the volume of water stored in the wetlands when filled to their normal water level (WET_NVOL), the volume of water stored in the wetlands when filled to their maximum water level (WET_MXVOL), the longest tributary channel length in the subbasin (CH_L1), Manning's n value for the tributary channels (CH_N1), and Manning's n value for the main channel (CH_N2). The results indicated that the HEW concept allows the nonlinear functional relations between watershed processes

  8. The changing effects of Alaska's boreal forests on the climate system

    Energy Technology Data Exchange (ETDEWEB)

    Euskirchen, E.S.; Chapin, F.S. III [Alaska Univ., Fairbanks, AK (United States). Dept. of Biology, Inst. of Arctic Biology; McGuire, A.D. [United Sates Geological Survey, Fairbanks, AK (United States). Alaska Cooperative Fish and Wildlife Research Unit; Alaska Univ., Fairbanks, AK (United States); Rupp, T.S. [Alaska Univ., Fairbanks, AK (United States). Dept. of Forest Sciences

    2010-07-15

    The boreal forest is the northernmost forested biome and is expected to be sensitive to global warming. Recent climate warming in the boreal forests of Alaska has influenced the exchange of trace gases, water, and energy between the forests and the atmosphere. In turn, these changes in the structure and function of boreal forests can influence regional and global climates. This study examined the type and magnitude of the climate feedbacks from boreal forests in Alaska. Biogeophysical and biogeochemical feedbacks were examined with particular reference to surface energy balance across boreal ecosystems and over the full annual cycle. The impact of ground heat exchange on permafrost was studied in terms of vegetation dynamics and disturbance regimes such as fires and insect outbreaks. In general, research has indicated that the net effect of a warming climate is a positive regional feedback to warming. The main positive climate feedbacks are currently related to decreases in surface albedo due to decreases in snow cover. Fewer negative feedbacks have been identified, and they may not be large enough to counterbalance the large positive feedbacks. These positive feedbacks are most dominant at the regional scale and reduce the resilience of the boreal vegetation by amplifying the rate of regional warming. This paper also described carbon and methane release from permafrost degradation, changes in lake area, changes in land use and snow season changes. The role of earth system models in representing climate feedbacks from Alaskan boreal forests was discussed. It was concluded that although the boreal forest provides climate regulation as an ecosystem service, the net effect of the climate feedbacks to climate warming are not fully understood. As such, there is a need to continue to evaluate feedback pathways, given the recent warming in Alaska and the large variety of associated mechanisms that can change terrestrial ecosystems and affect the climate system. 59 refs

  9. Indirect effects of rodents on arthropods in a Scandinavian boreal forest

    OpenAIRE

    Malá, Barbora

    2016-01-01

    Rodents in boreal forest are an important component of food webs. Their role as drivers of the boreal forest ecosystem is debated. As herbivores they affect plant communities and alter qualities of plants. Consequently availability of food resources for other herbivorous species is altered. In my thesis I studied whether rodents indirectly influence communities of arthropods via plant resources. It is assumed that phytophagous arthropods respond to changes in plant resources by different feed...

  10. Technical note: Comparison of methane ebullition modelling approaches used in terrestrial wetland models

    Science.gov (United States)

    Peltola, Olli; Raivonen, Maarit; Li, Xuefei; Vesala, Timo

    2018-02-01

    Emission via bubbling, i.e. ebullition, is one of the main methane (CH4) emission pathways from wetlands to the atmosphere. Direct measurement of gas bubble formation, growth and release in the peat-water matrix is challenging and in consequence these processes are relatively unknown and are coarsely represented in current wetland CH4 emission models. In this study we aimed to evaluate three ebullition modelling approaches and their effect on model performance. This was achieved by implementing the three approaches in one process-based CH4 emission model. All the approaches were based on some kind of threshold: either on CH4 pore water concentration (ECT), pressure (EPT) or free-phase gas volume (EBG) threshold. The model was run using 4 years of data from a boreal sedge fen and the results were compared with eddy covariance measurements of CH4 fluxes.Modelled annual CH4 emissions were largely unaffected by the different ebullition modelling approaches; however, temporal variability in CH4 emissions varied an order of magnitude between the approaches. Hence the ebullition modelling approach drives the temporal variability in modelled CH4 emissions and therefore significantly impacts, for instance, high-frequency (daily scale) model comparison and calibration against measurements. The modelling approach based on the most recent knowledge of the ebullition process (volume threshold, EBG) agreed the best with the measured fluxes (R2 = 0.63) and hence produced the most reasonable results, although there was a scale mismatch between the measurements (ecosystem scale with heterogeneous ebullition locations) and model results (single horizontally homogeneous peat column). The approach should be favoured over the two other more widely used ebullition modelling approaches and researchers are encouraged to implement it into their CH4 emission models.

  11. A Regional Guidebook for Applying the Hydrogeomorphic Approach to Assessing Wetland Functions of Flats Wetlands in the Everglades

    National Research Council Canada - National Science Library

    Noble, Chris

    2002-01-01

    .... However, a variety of other potential uses have been identified, including the determination of minimal effects under the Food Security Act, design of wetland restoration projects, and management of wetlands...

  12. The road to higher permanence and biodiversity in exurban wetlands.

    Science.gov (United States)

    Urban, Mark C; Roehm, Robert

    2018-01-01

    Exurban areas are expanding throughout the world, yet their effects on local biodiversity remain poorly understood. Wetlands, in particular, face ongoing and substantial threats from exurban development. We predicted that exurbanization would reduce the diversity of wetland amphibian and invertebrate communities and that more spatially aggregated residential development would leave more undisturbed natural land, thereby promoting greater local diversity. Using structural equation models, we tested a series of predictions about the direct and indirect pathways by which exurbanization extent, spatial pattern, and wetland characteristics might affect diversity patterns in 38 wetlands recorded during a growing season. We used redundancy, indicator species, and nested community analyses to evaluate how exurbanization affected species composition. In contrast to expectations, we found higher diversity in exurban wetlands. We also found that housing aggregation did not significantly affect diversity. Exurbanization affected biodiversity indirectly by increasing roads and development, which promoted permanent wetlands with less canopy cover and more aquatic vegetation. These pond characteristics supported greater diversity. However, exurbanization was associated with fewer temporary wetlands and fewer of the species that depend on these habitats. Moreover, the best indicator species for an exurban wetland was the ram's head snail, a common disease vector in disturbed ponds. Overall, results suggest that exurbanization is homogenizing wetlands into more permanent water bodies. These more permanent, exurban ponds support higher overall animal diversity, but exclude temporary wetland specialists. Conserving the full assemblage of wetland species in expanding exurban regions throughout the world will require protecting and creating temporary wetlands.

  13. Mitigating Losses of Wetland Ecosystems: A Context for Evaluation.

    Science.gov (United States)

    Mattingly, Rosanna L.

    1994-01-01

    Preservation of our wetlands has been an issue for many years. Today, despite current laws and those adopted 200 years ago, the wetlands remain insufficiently protected and developed. A holistic guide and suggestions for the classroom are provided to aid in efforts directed at wetland education, research and management. (ZWH)

  14. Changes in Landscape Pattern of Wetland around Hangzhou Bay

    Science.gov (United States)

    Lin, Wenpeng; Li, Yuan; Xu, Dan; Zeng, Ying

    2018-04-01

    Hangzhou Bay is an important estuarial coastal wetland, which offers a large number of land and ecological resources. It plays a significant role in the sustainable development of resources, environment and economy. In this paper, based on the remote sensing images in 1996, 2005 and 2013, we extracted the coastal wetland data and analyzed the wetland landscape pattern of the Hangzhou Bay in the past 20 years. The results show that: (1) the area of coastal wetland is heading downwards in the recent decades. Paddy field and the coastal wetland diminish greatly. (2) the single dynamic degree of wetland of the Hangzhou Bay displays that paddy fields and coastal wetlands are shrinking, but lakes, reservoirs and ponds are constantly expanding. (3) the wetland landscape pattern index shows that total patch area of the coastal wetland and paddy fields have gradually diminished. The Shannon diversity index, the Shannon evenness index as well as the landscape separation index of the coastal wetlands in the Hangzhou Bay increase steadily. The landscape pattern in the study area has shown a trend of high fragmentation, dominance decreases, but some dominant landscape still exist in this region. (4) Urbanization and natural factors lead to the reduction of wetland area. Besides the pressure of population is a major threat to the wetland. The study will provide scientific basis for long-term planning for this region.

  15. Balancing carbon sequestration and GHG emissions in a constructed wetland

    NARCIS (Netherlands)

    Klein, de J.J.M.; Werf, van der A.K.

    2014-01-01

    In many countries wetlands are constructed or restored for removing nutrients from surface water. At the same time vegetated wetlands can act as carbon sinks when CO2 is sequestered in biomass. However, it is well known that wetlands also produce substantial amounts of greenhouse gasses CH4 and N2O.

  16. HANDBOOK FOR CONSTRUCTED WETLANDS RECEIVING ACID MINE DRAINAGE

    Science.gov (United States)

    In the summer of 1987, a pilot constructed wetland was built at the Big Five Tunnel in Idaho Springs, Colorado. This report details the theory, design and construction of wetlands receiving acid mine drainages, based on the second and third year of operation of this wetland, whic...

  17. Geographically Isolated Wetlands: Why We Should Keep the Term

    Science.gov (United States)

    Use of the term "isolated wetlands" in the U.S. Supreme Court’s SWANCC decision created confusion, since it could imply functional isolation. In response, the term "geographically isolated wetlands" (GIWs) - wetlands surrounded by uplands - was introduced in 2003. A recent arti...

  18. 7 CFR 623.13 - Wetlands reserve plan of operations.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Wetlands reserve plan of operations. 623.13 Section... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.13 Wetlands reserve plan of operations. (a) After NRCS has accepted the applicant for enrollment in the...

  19. Socio-Economic Determinants of Wetland Cultivation in Kemise ...

    African Journals Online (AJOL)

    A study of wetland use in Kemise, central Illubabor, southwestern Ethiopia, shows food shortage as the main factor behind wetland cultivation in the locality. However, discriminant analysis results indicate that it is the wealthier farmers who tend to cultivate wetlands rather than the economically less fortunate ones.

  20. Biodiversity studies in three Coastal Wetlands in Ghana, West Africa ...

    African Journals Online (AJOL)

    Plant biodiversity studies of three coastal wetlands in Ghana were made. The wetlands are the Sakumo, Muni-Pomadze and Densu Delta Ramsar sites. Each wetland is made up of a flood plain which consists of salt marsh (about 20%), mangrove swamps (between 15 and 30%), fresh water swamp (about 40 - 45%), and in ...

  1. Managing Wetlands for Improved Food Security in Uganda | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Researchers will determine the food security status of households adjacent to wetlands and the part that wetlands resources contribute to it. They will analyze the tradeoffs in using wetlands for crop production. And, they will test, adapt and promote agricultural technologies that enhance productivity while minimizing ...

  2. 32 CFR 644.319 - Protection of wetlands.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Protection of wetlands. 644.319 Section 644.319... ESTATE HANDBOOK Disposal § 644.319 Protection of wetlands. The requirements of Executive Order 11990, Protection of Wetlands, 42 FR 26961, (24 May 1977) are applicable to the disposal of Federal lands and...

  3. 7 CFR 1410.11 - Farmable Wetlands Program.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Farmable Wetlands Program. 1410.11 Section 1410.11... Wetlands Program. (a) In addition to other allowable enrollments, land may be enrolled in this program through the Farmable Wetlands Program (FWP) within the overall Conservation Reserve Program provided for...

  4. Structural and functional loss in restored wetland ecosystems.

    Directory of Open Access Journals (Sweden)

    David Moreno-Mateos

    2012-01-01

    Full Text Available Wetlands are among the most productive and economically valuable ecosystems in the world. However, because of human activities, over half of the wetland ecosystems existing in North America, Europe, Australia, and China in the early 20th century have been lost. Ecological restoration to recover critical ecosystem services has been widely attempted, but the degree of actual recovery of ecosystem functioning and structure from these efforts remains uncertain. Our results from a meta-analysis of 621 wetland sites from throughout the world show that even a century after restoration efforts, biological structure (driven mostly by plant assemblages, and biogeochemical functioning (driven primarily by the storage of carbon in wetland soils, remained on average 26% and 23% lower, respectively, than in reference sites. Either recovery has been very slow, or postdisturbance systems have moved towards alternative states that differ from reference conditions. We also found significant effects of environmental settings on the rate and degree of recovery. Large wetland areas (>100 ha and wetlands restored in warm (temperate and tropical climates recovered more rapidly than smaller wetlands and wetlands restored in cold climates. Also, wetlands experiencing more (riverine and tidal hydrologic exchange recovered more rapidly than depressional wetlands. Restoration performance is limited: current restoration practice fails to recover original levels of wetland ecosystem functions, even after many decades. If restoration as currently practiced is used to justify further degradation, global loss of wetland ecosystem function and structure will spread.

  5. Development of soil properties and nitrogen cycling in created wetlands

    Science.gov (United States)

    Wolf, K.L.; Ahn, C.; Noe, G.B.

    2011-01-01

    Mitigation wetlands are expected to compensate for the loss of structure and function of natural wetlands within 5–10 years of creation; however, the age-based trajectory of development in wetlands is unclear. This study investigates the development of coupled structural (soil properties) and functional (nitrogen cycling) attributes of created non-tidal freshwater wetlands of varying ages and natural reference wetlands to determine if created wetlands attain the water quality ecosystem service of nitrogen (N) cycling over time. Soil condition component and its constituents, gravimetric soil moisture, total organic carbon, and total N, generally increased and bulk density decreased with age of the created wetland. Nitrogen flux rates demonstrated age-related patterns, with younger created wetlands having lower rates of ammonification, nitrification, nitrogen mineralization, and denitrification potential than older created wetlands and natural reference wetlands. Results show a clear age-related trajectory in coupled soil condition and N cycle development, which is essential for water quality improvement. These findings can be used to enhance N processing in created wetlands and inform the regulatory evaluation of mitigation wetlands by identifying structural indicators of N processing performance.

  6. Accumulation and bioaccessibility of trace elements in wetland ...

    African Journals Online (AJOL)

    Accumulation of trace metals in sediment can cause severe ecological impacts. In this study, determination of elemental concentrations in water and sediment was done. Shadegan wetland is one of the most important wetlands in southwest of Iran and is among the Ramsar-listed wetlands. Wastewaters from industries ...

  7. Quantifying greenhouse gas sources and sinks in managed wetland systems

    Science.gov (United States)

    Stephen M Ogle; Patrick Hunt; Carl Trettin

    2014-01-01

    This chapter provides methodologies and guidance for reporting greenhouse gas (GHG) emissions and sinks at the entity scale for managed wetland systems. More specifically, it focuses on methods for managed palustrine wetlands.1 Section 4.1 provides an overview of wetland systems and resulting GHG emissions, system boundaries and temporal scale, a summary of the...

  8. The upland flooding experiment : assessing the impact of reservoir creation on the biogeochemical cycling of mercury in boreal forest uplands

    Energy Technology Data Exchange (ETDEWEB)

    Rolfhus, K.R. [Wisconsin Univ., Madison, WI (United States). Water Chemistry Program; Bodaly, R.A.; Fudge, R.J.P.; Huebert, D.; Paterson, M.J. [Department of Fisheries and Oceans, Ottawa, ON (Canada) Fresh Water Inst.; Hall, B.D.; St Louis, V.L. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences; Krabbenhoft, D.P. [U.S. Geological Survey (United States); Hurley, J.P. [Wisconsin Univ., Madison, WI (United States). Water Resources Inst.; Peech, K. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Entomology

    2000-07-01

    One of the major environmental problems associated with boreal hydroelectric reservoirs such as those found in Canada and other northern countries is the elevated concentrations of mercury (Hg) in fish. A flooding experiment was conducted in northern Ontario to study methyl mercury (MeHg) production/bioaccumulation and greenhouse gas dynamics in impoundments with flooded upland forests of different soil carbon content, moisture and vegetation. The study, entitled Upland Flooding Experiment (FLUDEX) took place in June 1999 at the Experimental Lakes Area (ELA) where three impoundments of 0.7 ha were flooded to a depth of 1 m using oligotrophic lake water. The hydraulic residence time was 10-14 days. Responses to flooding were compared among treatment reservoirs and to previously flooded wetlands. The study included researchers from Canada and the United States who characterized mercury species fluxes from soils, the overall reservoir mass balance for total Hg and MeHg, inorganic Hg and MeHg concentration in zooplankton, benthic invertebrates, emerging insects and fish. Carbon decomposition was also examined. Preliminary results, one year after inundation, show significantly high levels of MeHg concentration compared to the feed water and that of surrounding natural lakes. Outflow samples from the dry forest areas showed the highest concentrations of Hg and MeHg, with lower concentrations from the moist forest. The lowest levels were observed from the outflow from the driest forest reservoir. A rapid pulse of inorganic Hg appears to have been released during the first 2 weeks of flooding. Soil leaching was found to be the main mechanism or inorganic Hg supply while MeHg appears to have been supplied by in situ microbial methylation. It was also shown that forage fish introduced into the reservoir had significantly elevated concentrations of MeHg compared to fish in natural lakes.

  9. The microbial communities and potential greenhouse gas production in boreal acid sulphate, non-acid sulphate, and reedy sulphidic soils.

    Science.gov (United States)

    Šimek, Miloslav; Virtanen, Seija; Simojoki, Asko; Chroňáková, Alica; Elhottová, Dana; Krištůfek, Václav; Yli-Halla, Markku

    2014-01-01

    Acid sulphate (AS) soils along the Baltic coasts contain significant amounts of organic carbon and nitrogen in their subsoils. The abundance, composition, and activity of microbial communities throughout the AS soil profile were analysed. The data from a drained AS soil were compared with those from a drained non-AS soil and a pristine wetland soil from the same region. Moreover, the potential production of methane, carbon dioxide, and nitrous oxide from the soils was determined under laboratory conditions. Direct microscopic counting, glucose-induced respiration (GIR), whole cell hybridisation, and extended phospholipid fatty acid (PLFA) analysis confirmed the presence of abundant microbial communities in the topsoil and also in the deepest Cg2 horizon of the AS soil. The patterns of microbial counts, biomass and activity in the profile of the AS soil and partly also in the non-AS soil therefore differed from the general tendency of gradual decreases in soil profiles. High respiration in the deepest Cg2 horizon of the AS soil (5.66 μg Cg(-1)h(-1), as compared to 2.71 μg Cg(-1)h(-1) in a top Ap horizon) is unusual but reasonable given the large amount of organic carbon in this horizon. Nitrous oxide production peaked in the BCgc horizon of the AS and in the BC horizon of the non-AS soil, but the peak value was ten-fold higher in the AS soil than in the non-AS soil (82.3 vs. 8.6 ng Ng(-1)d(-1)). The data suggest that boreal AS soils on the Baltic coast contain high microbial abundance and activity. This, together with the abundant carbon and total and mineral nitrogen in the deep layers of AS soils, may result in substantial gas production. Consequently, high GHG emissions could occur, for example, when the generally high water table is lowered because of arable farming. © 2013.

  10. Fluxes of methane and nitrogen oxides in various boreal mire ecosystems. Effects of land-use activities and environmental changes

    International Nuclear Information System (INIS)

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

    1996-01-01

    Atmospheric impact of peatlands is a sum of their gas fluxes. In contrast to carbon dioxide, peatlands are net sources for methane (CH 4 ). Methane is an end product in the anaerobic decomposition processes and it has greater capacity to absorb infrared radiation than carbon dioxide. Most of the data on the CH 4 release from northern peatlands is from North America. The total amount of methane released from wetlands is calculated to be 110 Tg yr -1 of which 34 percent (38 Tg yr -1 ) is estimated to be emitted from the northern peatlands. Peat with high content of nitrogen is a potential source for gaseous nitrogen oxides, i.e. nitrous oxide (N 2 O) and nitric oxide (NO). However, the importance of peatlands in producing these trace gases is poorly known. Nitrous oxide and nitric oxide are important components in the atmospheric chemistry and N 2 O also is an effective greenhouse gas. Land-use activities and environmental changes can affect the atmospheric impacts of peatlands by modifying their biogeochemistry. This article presents a short summary of the studies whose objectives were: (1) to measure fluxes of CH 4 and N 2 O on wide range of natural mires in Finland, (2) to study the short- and long-term changes in fluxes of CH 4 , N 2 O and NO on boreal peatlands after lowering their water table. Peatlands used for agriculture, forestry and peat mining were included in the studies. The results from mires drained for forestry may reflect the possible changes in the trace gas fluxes if water table will drop in the northern peatlands as a result of drier climate, (3) to study the effects of nitrogen load on the fluxes of CH 4 , N 2 O and NO, (4) to identify the microbiological processes important for the fluxes of N 2 O, NO and CH 4 , and to study the environmental factors regulating these microbial processes

  11. Potential effects of climate change on the water level, flora and macro-fauna of a large neotropical wetland.

    Directory of Open Access Journals (Sweden)

    Bárbara Úbeda

    Full Text Available Possible consequences of climate change in one of the world's largest wetlands (Ibera, Argentina were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds. On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication presents an important challenge to the conservation of neotropical wetlands in the coming decades.

  12. Potential effects of climate change on the water level, flora and macro-fauna of a large neotropical wetland.

    Science.gov (United States)

    Úbeda, Bárbara; Di Giacomo, Adrian S; Neiff, Juan José; Loiselle, Steven A; Poi, Alicia S Guadalupe; Gálvez, José Ángel; Casco, Silvina; Cózar, Andrés

    2013-01-01

    Possible consequences of climate change in one of the world's largest wetlands (Ibera, Argentina) were analysed using a multi-scale approach. Climate projections coupled to hydrological models were used to analyse variability in wetland water level throughout the current century. Two potential scenarios of greenhouse gas emissions were explored, both resulting in an increase in the inter-annual fluctuations of the water level. In the scenario with higher emissions, projections also showed a long-term negative trend in water-level. To explore the possible response of biota to such water-level changes, species-area relationships of flora and aerial censuses of macro-fauna were analysed during an extraordinary dry period. Plant species richness at the basin scale was found to be highly resistant to hydrological changes, as the large dimension of the wetland acts to buffer against the water-level variations. However, local diversity decreased significantly with low water levels, leading to the loss of ecosystem resilience to additional stressors. The analysis of macro-fauna populations suggested that wetland provides refuge, in low water periods, for the animals with high dispersal ability (aquatic and migratory birds). On the contrary, the abundance of animals with low dispersal ability (mainly herbivorous species) was negatively impacted in low water periods, probably because they are required to search for alternative resources beyond the wetland borders. This period of resource scarcity was also related to increased mortality of large mammals (e.g. marsh deer) around water bodies with high anthropogenic enrichment and cyanobacteria dominance. The synergy between recurrent climatic fluctuations and additional stressors (i.e. biological invasions, eutrophication) presents an important challenge to the conservation of neotropical wetlands in the coming decades.

  13. Flood pulsing in the Sudd wetland: analysis of seasonal variations in 2 inundation and evapotranspiration in Southern Sudan

    Science.gov (United States)

    Senay, Gabriel B.; Rebelo, L-M.; McCartney, M.P.

    2012-01-01

    Located on the Bahr el Jebel in South Sudan, the Sudd is one of the largest floodplain wetlands in the world. Seasonal inundation drives the hydrologic, geomorphological, and ecological processes, and the annual flood pulse is essential to the functioning of the Sudd. Despite the importance of the flood pulse, various hydrological interventions are planned upstream of the Sudd to increase economic benefits and food security. These will not be without consequences, in particular for wetlands where the biological productivity, biodiversity, and human livelihoods are dependent on the flood pulse and both the costs and benefits need to be carefully evaluated. Many African countries still lack regional baseline information on the temporal extent, distribution, and characteristics of wetlands, making it hard to assess the consequences of development interventions. Because of political instability in Sudan and the inaccessible nature of the Sudd, recent measurements of flooding and seasonal dynamics are inadequate. Analyses of multitemporal and multisensor remote sensing datasets are presented in this paper, in order to investigate and characterize flood pulsing within the Sudd wetland over a 12-month period. Wetland area has been mapped along with dominant components of open water and flooded vegetation at five time periods over a single year. The total area of flooding (both rain and river fed) over the 12 months was 41 334 km2, with 9176 km2 of this constituting the permanent wetland. Mean annual total evaporation is shown to be higher and with narrower distribution of values from areas of open water (1718 mm) than from flooded vegetation (1641 mm). Although the exact figures require validation against ground-based measurements, the results highlight the relative differences in inundation patterns and evaporation across the Sudd.

  14. Net exchanges of CO2, CH4 and N2O between the terrestrial ecosystems and the atmosphere in boreal and arctic region: Towards a full greenhouse gas budget

    Science.gov (United States)

    Zhang, B.; Tian, H.; Lu, C.; Yang, J.; Kamaljit, K.; Pan, S.

    2014-12-01

    Boreal and arctic terrestrial ecosystem is a unique ecological region due to large portion of wetland and permafrost distribution. Increasing disturbances, like permafrost-thaw, fire event, climate extreme, would greatly change the patterns and variations of greenhouse gas emission and further affect the feedback between terrestrial ecosystem and climate change. Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) accounted for more than 85% of the radioactive forcing (RF) due to long-lived greenhouse gases. However, few studies have considered the full budget of three gases together in this region. In this study, we used a process-based model (Dynamic Land Ecosystem Model), driven by multiple global change factors, to quantify the magnitude, spatial and temporal variation of CO2, CH4 and N2O across the boreal and arctic regions. Simulated results have been evaluated against field observations, inventory-based and atmospheric inversion estimates. By implementing a set of factorial simulations, we further quantify the relative contribution of climate, atmospheric composition, fire to the CO2, CH4 and N2O fluxes. Continued warming climate potentially could shift the inter-annual and intra-annual variation of greenhouse gases fluxes. The understanding of full budget in this region could provide insights for reasonable future projection, which is also crucial for developing effective mitigation strategies.

  15. BVOC ecosystem flux measurements at a high latitude wetland site

    Directory of Open Access Journals (Sweden)

    T. Holst

    2010-02-01

    Full Text Available In this study, we present summertime concentrations and fluxes of biogenic volatile organic compounds (BVOCs measured at a sub-arctic wetland in northern Sweden using a disjunct eddy-covariance (DEC technique based on a proton transfer reaction mass spectrometer (PTR-MS. The vegetation at the site was dominated by Sphagnum, Carex and extit{Eriophorum} spp. The measurements reported here cover a period of 50 days (1 August to 19 September 2006, approximately one half of the growing season at the site, and allowed to investigate the effect of day-to-day variation in weather as well as of vegetation senescence on daily BVOC fluxes, and on their temperature and light responses. The sensitivity drift of the DEC system was assessed by comparing H3O+-ion cluster formed with water molecules (H3O+(H2O at m37 with water vapour concentration measurements made using an adjacent humidity sensor, and the applicability of the DEC method was analysed by a comparison of sensible heat fluxes for high frequency and DEC data obtained from the sonic anemometer. These analyses showed no significant PTR-MS sensor drift over a period of several weeks and only a small flux-loss due to high-frequency spectrum omissions. This loss was within the range expected from other studies and the theoretical considerations.

    Standardised (20 °C and 1000 μmol m−2 s−1 PAR summer isoprene emission rates found in this study of 329 μg C m−2 (ground area h−1 were comparable with findings from more southern boreal forests, and fen-like ecosystems. On a diel scale, measured fluxes indicated a stronger temperature dependence than emissions from temperate or (subtropical ecosystems. For the first time, to our knowledge, we report ecosystem methanol fluxes from a sub-arctic ecosystem. Maximum daytime emission fluxes were around 270 μg m−2 h−1

  16. Multiple factors influence the vegetation composition of Southeast U.S. wetlands restored in the Wetlands Reserve Program

    Science.gov (United States)

    Diane De Steven; Joel M. Gramling

    2013-01-01

    Degradation of wetlands on agricultural lands contributes to the loss of local or regional vegetation diversity. The U.S. Department of Agriculture’s Wetlands Reserve Program (WRP) funds the restoration of degraded wetlands on private ‘working lands’, but these WRP projects have not been studied in the Southeast United States. Wetland hydrogeomorphic type influences...

  17. Wetland biogeochemical processes and simulation modeling

    Science.gov (United States)

    Bai, Junhong; Huang, Laibin; Gao, Haifeng; Jia, Jia; Wang, Xin

    2018-02-01

    As the important landscape with rich biodiversity and high productivity, wetlands can provide numerous ecological services including playing an important role in regulating global biogeochemical cycles, filteringpollutants from terrestrial runoff and atmospheric deposition, protecting and improving water quality, providing living habitats for plants and animals, controlling floodwaters, and retaining surface water flow during dry periods (Reddy and DeLaune, 2008; Qin and Mitsch, 2009; Zhao et al., 2016). However, more than 50% of the world's wetlands had been altered, degraded or lost through a wide range of human activities in the past 150 years, and only a small percentage of the original wetlands remained around the world after over two centuries of intensive development and urbanization (O'connell, 2003; Zhao et al., 2016).

  18. Watching the Creation of Southern California's Largest Reservoir

    Science.gov (United States)

    2001-01-01

    The new Diamond Valley Lake Reservoir near the city of Hemet in Riverside County is billed as the largest earthworks construction project in U.S.history. Construction began in 1995 and involved 31 million cubic meters of foundation excavation and 84 million cubic meters of embankment construction. This set of MISR images captures the most recent phase in the reservoir's activation. At the upper left is a natural-color view acquired by the instrument's vertical-viewing (nadir) camera on March 14, 2000 (Terra orbit 1273), shortly after the Metropolitan Water District began filling the reservoir with water from the Colorado River and Northern California. Water appears darker than the surrounding land. The image at the upper right was acquired nearly one year later on March 1, 2001 (Terra orbit 6399), and shows a clear increase in the reservoir's water content. When full, the lake will hold nearly a trillion liters of water.According to the Metropolitan Water District, the 7 kilometer x 3 kilometer reservoir nearly doubles Southern California's above-groundwater storage capacity. In addition to routine water management, Diamond Valley Lake is designed to provide protection against drought and a six-month emergency supply in the event of earthquake damage to a major aqueduct. In the face of electrical power shortages, it is also expected to reduce dependence on the pumping of water from northern mountains during the high-demand summer months. An unexpected result of site excavation was the uncovering of mastodon and mammoth skeletons along with bones from extinct species not previously thought to have been indigenous to the area, such as the giant long-horned bison and North American lion. A museum and interpretive center is being built to protect these finds.The lower MISR image, from May 20, 2001 (Terra orbit 7564), is a false-color view combining data from the instrument's 26-degree forward view (displayed as blue) with data from the 26-degree backward view

  19. Drilling the Bushveld Complex- the world's largest layered mafic intrusion

    Science.gov (United States)

    Ashwal, L. D.; Webb, S. J.; Trumbull, R. B.

    2013-12-01

    The fact that surprising new discoveries can be made in layered mafic intrusions (e.g., subtle 100-150 m cyclicity in apparently homogeneous cumulates over 1000s of m) means that we are still in the first-order characterization phase of understanding these objects. Accordingly, we have secured funding from ICDP for a planning workshop to be held in Johannesburg in early 2014, aimed at scientific drilling of the Bushveld Complex, the world's largest layered mafic intrusion. Science objectives include, but are not limited to: 1. Magma chamber processes & melt evolution. How many melts/magmas/mushes were involved, what were their compositions and how did they interact? What, if anything, is missing from the Complex, and where did it go? Did Bushveld magmatism have an effect upon Earth's atmosphere at 2 Ga? 2. Crust-mantle interactions & origin of Bushveld granitoids. Are Bushveld granites & rhyolites crustal melts, differentiates from the mafic magmas or products of immiscibility? How can the evolved isotopic signatures in the mafic rocks (e.g., epsilon Nd to -8) be understood? 3. Origin of ore deposits. What were the relative roles of gravity settling, magma mixing, immiscibility and hydrothermal fluid transport in producing the PGE, Cr and V deposits? We have identified 3 potential drilling targets representing a total of ~12 km of drill core. Exact locations of drill sites are to be discussed at the workshop. Target A- East-Central Bushveld Complex. We propose 3 overlapping 3 km boreholes that will provide the first roof-to-floor continuous coverage of the Rustenburg Layered Suite. These boreholes will represent a curated, internationally available reference collection of Bushveld material for present and future research. Target B- Southeastern Bushveld Complex. We propose a single borehole of ~2 km depth, collared in Rooiberg felsite, and positioned to intersect the Roof Zone, Upper Zone, Main Zone and floor of the Complex. Amongst other things, this site will

  20. Final Status Survey for the Largest Decommissioning Project on Earth

    International Nuclear Information System (INIS)

    Dubiel, R.W.; Miller, J.; Quayle, D.

    2006-01-01

    To assist the United States Department of Energy's (US DOE's) re-industrialization efforts at its gaseous diffusion site in Oak Ridge, Tennessee, known as the East Tennessee Technology Park (ETTP), the US DOE awarded a 6-year Decontamination and Decommissioning (D and D) contract to BNG America (formerly BNFL Inc.) in 1997. The ETTP 3-Building D and D Project included the removal and disposition of the materials and equipment from the K-33, K-31, and K-29 Gaseous Diffusion Plant buildings. The three buildings comprise more than 4.8 million square feet (446,000 square meters) of floor surface area and more than 350 million pounds (148 million kilograms) of hazardous and radioactively contaminated material, making it the largest nuclear D and D project in progress anywhere in the world. The logistical hurdles involved in a project of this scope and magnitude required an extensive amount of Engineering and Health Physics professionals. In order to accomplish the Final Status Survey (FSS) for a project of this scope, the speed and efficiency of automated survey equipment was essential. Surveys of floors, structural steel and ceilings up to 60 feet (18 meters) were required. The FSS had to be expanded to include additional remediation and surveys due to characterization surveys and assumptions regarding the nature and extent of contamination provided by the US DOE. Survey design and technical bases had to consider highly variable constituents; including uranium from depleted to low enrichment, variable levels of Technetium-99 and transuranic nuclides, which were introduced into the cascade during the 1960's when recycled uranium (RU) from Savannah River was re-enriched at the facility. The RU was transported to unexpected locations from leaks in the cascade by complex building ventilation patterns. The primary survey tool used for the post remediation and FSS was the Surface Contamination Monitor (SCM) and the associated Survey Information Management System (SIMS

  1. Soil Redox Dynamics Vary with Landscape Position and Hydroperiod in the Pantanal Wetland Ecosystem

    Science.gov (United States)

    Couto, E. G.; Johnson, M. S.; Pinto-jr, O.; Leite, N. K.

    2012-12-01

    The Pantanal wetland ecosystem of central South America is the largest tropical wetland complex in the world. Nevertheless, biogeochemistry in the Pantanal is quite limited. A unimodal precipitation regime averages approximately 1200 mm y-1 during the six-month rainy season, leading to seasonal flooding on much, but not all, of the landscape. We investigated the impact of landscape position and hydroperiod on soil redox potential (Eh) in four research locations in the Northern Pantanal near Poconé, Mato Grosso: two locations subject to flooding (a flooded forest and a flooded scrub forest) and two locations with infrequent surface flooding (tree islands known as cordilheiras). Redox sensors were installed at 10 cm and 30 cm depths at each of the four locations with half-hourly data recorded over all hydro-periods (dry season, rising water, flood and falling water). Here we summarize results to date in this ongoing study. Reducing conditions were observed in response to both precipitation events saturating soil from the surface downward, as well as in response to regional flooding dynamics that saturate soil from below. These are helping to guide design of a study on methane dynamics in the Pantanal wetland complex.

  2. Hydrological disturbance diminishes predator control in wetlands.

    Science.gov (United States)

    Dorn, Nathan J; Cook, Mark I

    2015-11-01

    Effects of predators on prey populations can be especially strong in aquatic ecosystems, but disturbances may mediate the strength of predator limitation and even allow outbreaks of some prey populations. In a two-year study we investigated the numerical responses of crayfish (Procambarus fallax) and small fishes (Poeciliidae and Fundulidae) to a brief hydrological disturbance in replicated freshwater wetlands with an experimental drying and large predatory fish reduction. The experiment and an in situ predation assay tested the component of the consumer stress model positing that disturbances release prey from predator limitation. In the disturbed wetlands, abundances of large predatory fish were seasonally reduced, similar to dynamics in the Everglades (southern Florida). Densities of small fish were unaffected by the disturbance, but crayfish densities, which were similar across all wetlands before drying, increased almost threefold in the year after the disturbance. Upon re-flooding, juvenile crayfish survival was inversely related to the abundance of large fish across wetlands, but we found no evidence for enhanced algal food quality. At a larger landscape scale (500 km2 of the Everglades), crayfish densities over eight years were positively correlated with the severity of local dry disturbances (up to 99 days dry) during the preceding dry season. In contrast, densities of small-bodied fishes in the same wetlands were seasonally depressed by dry disturbances. The results from our experimental wetland drought and the observations of crayfish densities in the Everglades represent a large-scale example of prey population release following a hydrological disturbance in a freshwater ecosystem. The conditions producing crayfish pulses in the Everglades appear consistent with the mechanics of the consumer stress model, and we suggest crayfish pulses may influence the number of nesting wading birds in the Everglades.

  3. Biotic development comparisons of a wetland constructed to treat mine water drainage with a natural wetland system

    International Nuclear Information System (INIS)

    Webster, H.J.; Hummer, J.W.; Lacki, M.J.

    1994-01-01

    Using 5-yr of baseline data from a constructed wetland, the authors compared the biotic changes in this wetland to conditions in a natural wetland to determine if biotic development patterns were similar. The constructed wetland was built in 1985 to treat a coal mine discharge and was planted with broadleaf cattail (Typha latifolia) within the three-cell, 0.26 ha wetland. Species richness in permanent quadrants of the constructed wetland declined over the study period, while cattail coverage increased. Plant species composition diversified at the edges, with several species becoming established. The constructed wetland deepened and expanded slightly in area coverage during the study period. The constructed wetland supported herptofaunal communities that appeared more stable through time than those of the natural wetland and sustained a rudimentary food chain dependent upon autotrophic algal populations. Despite fundamental differences in substrate base, morphology, and water flow patterns, biotic trends for the constructed wetland coincided with succession-like patterns at the natural wetland. They suggest that further shifts in the biotic composition of the constructed wetland are likely, but the system should continue to persist if primary production meets or exceeds the microbial metabolic requirements necessary to treat mine drainage

  4. Investigating public decisions about protecting wetlands.

    Science.gov (United States)

    Getzner, Michael

    2002-03-01

    Quantitative analyses of species protection decisions taken by public authorities regularly show that ecological factors, such as the probability of extinction, often play a minor role in the decision-making process. The taxonomy of the species or its potential conflict with economic development is a more powerful factor. This paper presents quantitative empirical research on the protection of wetlands in Austria. Econometrically estimated models show that geographical and ecological factors (such as the size of the area, elevation and importance for biodiversity) play a significant role in the protection of wetlands. Additional influences include conflict variables encoding the negative effects of the primary economic sector (agriculture) or tourism.

  5. Methane emissions in Danish riparian wetlands

    DEFF Research Database (Denmark)

    Audet, Joachim; Johansen, Jan Ravn; Andersen, Peter Mejlhede

    2013-01-01

    The present study was conducted to (i) investigate parameters influencing the fluxes of the greenhouse gas methane (CH4) in Danish riparian wetlands with contrasting vegetation characteristics and (ii) develop models relating CH4 emissions to soil and/or vegetation parameters integrating the spat......The present study was conducted to (i) investigate parameters influencing the fluxes of the greenhouse gas methane (CH4) in Danish riparian wetlands with contrasting vegetation characteristics and (ii) develop models relating CH4 emissions to soil and/or vegetation parameters integrating...

  6. Groundwater in the Boreal Plains: How Climate and Geology Interact to Control Water Table Configurations in a Sub-Humid, Low-Relief Region

    Science.gov (United States)

    Hokanson, K. J.; Devito, K.; Mendoza, C. A.

    2017-12-01

    The Boreal Plain (BP) region of Canada, a landscape characterized by low-relief, a sub-humid climate and heterogeneous glacial landforms, is experiencing unprecedented anthropogenic and natural disturbance, including climate change and oil & gas operations. Understanding the controls on and the natural variability of water table position, and subsequently predicting changes in water table position under varying physical and climatic scenarios will become important as water security becomes increasingly threatened. The BP is composed of a mosaic of forestland, wetland, and aquatic land covers that contrast in dominant vegetation cover, evapotranspiration, and soil storage that, in turn, influence water table configurations. Additionally, these land-covers overlie heterogeneous glacial landforms with large contrasts in storage and hydraulic properties which, when coupled with wet-dry climate cycles, result in complex water table distributions in time and space. Several forestland-wetland-pond complexes were selected at the Utikuma Research Study Area (URSA) over three distinct surficial geologic materials (glacial fluvial outwash, stagnant ice moraine, lacustrine clay plain) to explore the roles of climate (cumulative departure from the long term yearly mean precipitation), geology, topographic position, and land cover on water table configurations over 15 years (2002 - 2016). In the absence of large groundwater flow systems, local relief and shallow low conductivity substrates promote the formation of near-surface water tables that are less susceptible to climate variation, regardless of topography. Furthermore, in areas of increased storage, wet and dry climate conditions can result in appreciably different water table configurations over time, ranging from mounds to hydraulic depressions, depending on the arrangement of land-covers, dominant surficial geology, and substrate layering.

  7. Mapping long-term wetland response to climate

    Science.gov (United States)

    Zhou, Q.; Gallant, A.; Rover, J.

    2016-12-01

    Wetlands provide unique feeding and breeding habitat for numerous waterfowl species. The distribution of wetlands has been considerably changed due to agricultural land conversion and hydrologic modification. Climate change may further impact wetlands through altered moisture regimes. This study characterized long-term variation in wetland conditions by using dense time series from all available Landsat data from 1985 to 2014. We extracted harmonic frequencies from 30 years to two years to delineate the long-term variation in all seven Landsat bands. A cluster analysis and unsupervised classification then enabled us to map different classes of wetland response. We demonstrated the method in the Prairie Pothole Region in North Dakota.

  8. Observations On Some Upper Amazonian Wetlands of Southeastern Peru

    Science.gov (United States)

    Householder, J. E.; Muttiah, R.; Khanal, S.

    2007-05-01

    Upper Amazonian wetlands represent little studied, poorly understood, and grossly under protected systems. Scientific investigation of Amazonian wetlands is in its infancy; nor is there much known about their ecological services. Regionally, wetlands form a ubiquitous and significant component of floodplain habitat fed by perennial springs as well as overland runoff. Locally, wetland vegetation forms bewilderingly complex vegetation mosaics that seem to be governed by local topography and hydrology. Drawing upon intensive field campaigns and remotely sensed imagery, we summarize the results and experiences gathered in wetlands of southeastern Peru.

  9. Conservation of Mexican wetlands: role of the North American Wetlands Conservation Act

    Science.gov (United States)

    Wilson, M.H.; Ryan, D.A.

    1997-01-01

    Mexico's wetlands support a tremendous biological diversity and provide significant natural resource benefits to local communities. Because they are also critical stopover and wintering grounds for much of North America's waterfowl and other migratory birds, Mexico has become an important participant in continental efforts to conserve these resources through the North American Wetlands Conservation Act. Funding from the Act has supported partnerships in a number of Mexico's priority wetlands to conduct data analyses and dissemination, mapping, environmental education, wetland restoration, development of sustainable economic alternatives for local people, and reserve planning and management. These partnerships, with the close involvement of Mexico's Federal Government authority, the Instituto Nacional de Ecologia, have advanced conservation in a uniquely Mexican model that differs from that employed in the United States and Canada.

  10. Connecting the Dots: Hydrologic Connectivity Between Wetlands and Other Wetlands and Waterbodies

    Science.gov (United States)

    Wetlands perform numerous ecosystem functions that in turn provide abundant ecosystem services beneficial to humankind. These may include, but are not limited to, flood water storage and release, nutrient transformations, carbon sequestration, and the provision of habitat or ref...

  11. Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Mississippi: WETLANDS (Wetland Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains vector polygons representing coastal wetlands classified according to the Environmental Sensitivity Index (ESI) classification system for...

  12. Final Report for Wetlands as a Source of Atmospheric Methane: A Multiscale and Multidisciplinary Approach

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, Karis J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-28

    Boreal peatlands contain large amounts of old carbon, protected by anaerobic and cold conditions. Climate change could result in favorable conditions for the microbial decomposition and release of this old peat carbon as CO2 or CH4 back into the atmosphere. Our goal was to test the potential for this positive biological feedback to climate change at SPRUCE (Spruce and Peatland Response Under Climatic and Environmental Change), a manipulation experiment funded by DOE and occurring in a forested bog in Minnesota. Taking advantage of LLNL’s capabilities and expertise in chemical and isotopic signatures we found that carbon emissions from peat were dominated by recently fixed photosynthates, even after short-term experimental warming. We also found that subsurface hydrologic transport was surprisingly rapid at SPRUCE, supplying microbes with young dissolved organic carbon (DOC). We also identified which microbes oxidize CH4 to CO2 at SPRUCE and found that the most active of these also fix N2 (which means they can utilize atmospheric N, making it accessible for other microbes and plants). These results reflect important interactions between hydrology, carbon cycling, and nitrogen cycling present at the bog and relevant to interpreting experimental results and modeling the wetland response to experimental treatments. LLNL involvement at SPRUCE continues through collaborations and a small contract with ORNL, the lead lab for the SPRUCE experiment.

  13. Use of Stable Isotopes and Incubation Studies to Characterize Methane Production Mechanism in Northern Wetlands

    Science.gov (United States)

    Chanton, J. P.; Fields, D.; Hines, M. E.; Rooney-Varga, J.

    2003-12-01

    Arctic and boreal ecosystems are important since they occupy greater than 1/5 of the Earth's terrestrial surface, they are sensitive to subtle climate changes, and they have significant effects on the atmosphere. Methanogenesis is dominated by two major pathways, acetotrophic (i.e., acetoclastic) methanogenesis in which acetate is the immediate precursor of CH4 (and CO2), and H2/CO2 methanogenesis in which CH4 is a product of H2 oxidation coupled with CO2 reduction. Recent studies suggest that acetotrophic methanogenesis does not occur widely in the northern wetlands and acetate can accumulate to high levels (Duddleston et al., 2002; Hines et al., 2001a). Methanogenesis at these sites is dominated by the H2/CO2 pathway and the importance of acetate as a precursor of CH4 seems to decrease with decreasing temperature and increasing oligotrophy. We surveyed a transect across Alaska from Deadhorse to Anchorage and used stable isotope distributions of DIC, CH4 and H2O to discern the relative importance of differing methane production mechanisms. These results compared favorably to incubation studies. Vegetation type was found to be a strong indicator of methane production mechanism, with Carex indicating acetotrophic methaneogenesis and sphagnum being an indicator of a lack of acetate methaneogenesis. The effects of production pathway variation on the dD of methane will also be presented.

  14. Development of the reed bed in Matsalu wetland, Estonia: responses to neotectonic land uplift, sea level changes and human influences

    Directory of Open Access Journals (Sweden)

    Mats Meriste

    2015-05-01

    Full Text Available We studied reed bed development in Matsalu wetland and the Kasari River delta, Estonia, since the late 18th century using historical schemes, topographical maps and aerial photographs. Our aim was to understand the mechanisms controlling reed distribution in Matsalu wetland, the largest coastal wetland of the eastern Baltic Sea occupying an area of about 25 km2. Natural development of the reed bed in Matsalu Bay and the Kasari delta is mainly controlled by shoreline displacement due to post-glacial neotectonic land uplift. The dredging of the Kasari delta in the 1920s–1930s caused a rapid seaward migration of reed bed communities due to the dispersal of fragmented rhizomes on the shallow sea bottom and along the canal banks reaching Matsalu Bay, while the landward parts of the former wetland were occupied by meadow communities. The expansion of the reed bed started in between the 1951s and 1970s and a maximum extent of 27 km2 was gained by the late 1970s at the peak of eutrophication. In the last decades the reed bed development has been influenced by sea level rise and increased intensity of cyclonic activity in the Baltic Sea, which has caused the deterioration of the reed bed that was weakened by eutrophication due to nutrient inflow from agricultural landscapes mainly in the 1960s–1980s.

  15. Object-Based Image Analysis in Wetland Research: A Review

    Directory of Open Access Journals (Sweden)

    Iryna Dronova

    2015-05-01

    Full Text Available The applications of object-based image analysis (OBIA in remote sensing studies of wetlands have been growing over recent decades, addressing tasks from detection and delineation of wetland bodies to comprehensive analyses of within-wetland cover types and their change. Compared to pixel-based approaches, OBIA offers several important benefits to wetland analyses related to smoothing of the local noise, incorporating meaningful non-spectral features for class separation and accounting for landscape hierarchy of wetland ecosystem organization and structure. However, there has been little discussion on whether unique challenges of wetland environments can be uniformly addressed by OBIA across different types of data, spatial scales and research objectives, and to what extent technical and conceptual aspects of this framework may themselves present challenges in a complex wetland setting. This review presents a synthesis of 73 studies that applied OBIA to different types of remote sensing data, spatial scale and research objectives. It summarizes the progress and scope of OBIA uses in wetlands, key benefits of this approach, factors related to accuracy and uncertainty in its applications and the main research needs and directions to expand the OBIA capacity in the future wetland studies. Growing demands for higher-accuracy wetland characterization at both regional and local scales together with advances in very high resolution remote sensing and novel tasks in wetland restoration monitoring will likely continue active exploration of the OBIA potential in these diverse and complex environments.

  16. Evaluation of a market in wetland credits: entrepreneurial wetland banking in Chicago.

    Science.gov (United States)

    Robertson, Morgan; Hayden, Nicholas

    2008-06-01

    With the rise of market-led approaches to environmental policy, compensation for permitted discharge of dredge or fill material into wetlands under Section 404 of the U.S. Clean Water Act has been purchased increasingly from entrepreneurial third-party providers. The growth of this practice (i.e., entrepreneurial wetland banking) has resolved many challenges associated with wetland compensation. But it has also produced (1) quantifiable temporal loss of wetland ecological functions, (2) spatial redistribution of wetland area, and (3) a degree of regulatory instability that may pose a threat to entrepreneurial compensation as a sustainable component of wetland-compensation policy. We used achieved compensation ratios, lapse between bank credit sale and the attainment of performance standards, distance between impact and bank site, and changes in bank market area to examine these 3 factors. We analyzed data from a census of all such transactions in the Chicago District of the U.S. Army Corps of Engineers, compiled from site visits, Corps databases, and contacts with consultants and Section 404 permittees. Entrepreneurial banking provided compensation at a lower overall ratio than nonbank forms of compensation. Approximately 60% of bank credits were sold after site-protection standards were met but before ecological performance standards were met at the bank site. The average distance between bank and impact site was approximately 26 km. The area of markets within which established banks can sell wetland credits has fluctuated considerably over the study period. Comparing these data with similar data for other compensation mechanisms will assist in evaluating banking as an element of conservation policy. Data characterizing the performance of entrepreneurial wetland banks in actual regulatory environments are scarce, even though it is the most established of similar markets that have become instrumental to federal policy in administering several major environmental

  17. Hydrological science and wetland restoration: some case studies from Europe

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Throughout the world, wetlands are increasingly being recognised as important elements of the landscape because of their high biodiversity and goods and services they provide to mankind. After many decades of wetland destruction and conversion, large areas of wetlands are now protected under the International Convention on Wetlands (Ramsar and regional or national legislation such as the European Union Habitats Directive. In many cases, there is a need to restore the ecological character of the wetland through appropriate water management. This paper provides examples of scientific knowledge of wetland hydrology that can guide such restoration. It focuses on the need for sound hydrological science on a range of issues including water level control, topography, flood storage, wetland connections with rivers and sustainability of water supply under climate change.

  18. Interhemispheric temperature difference as a predictor of boreal winter ENSO

    Science.gov (United States)

    Piskozub, Jacek; Gutowska, Dorota

    2013-04-01

    We use statistical analysis to show statistically significant relationship between the boreal winter MEI index of ENSO and HadCRUT3 temperature difference between Northern and Southern hemispheres (NH - SH) during the preceding summer. Correlation values increase (in absolute terms) if the correlated time periods are increased from month to seasonal length. For example December and January (DJ) MEI values anticorrelate stronger with the preceding MJJA period than with any of the four months taken separately. We believe this is further evidence that the correlation is caused by a real physical process as increase of the averaging period tends to reduce statistical noise. The motivation for looking for such a relationship comes from review of literature on paleoclimatic ENSO behavior. We have noticed that in many cases relatively cold NH coincided with "strong ENSO" (frequent El Niños), for example the Ice Age periods and Little Ice Age. On the other hand periods of relatively warm NH (the Holocene climate optimum or Medieval Climate Anomaly) are coincident with frequent or even "permanent" La Niñas. This relationship suggest the influence of the position of Intertropical Convergence Zone (ITCZ) on the frequency of El Niños. The simplest physical mechanism of the relationship is that the positive (negative) NH-SH temperature difference causes a north (south) shift of ITCZ with a parallel shift of trade wind zones. The North-South orographic difference between the Panama Isthmus and the South America may cause stronger (weaker) trade winds in Eastern Tropical Pacific increasing (decreasing) the thermochemical tilt which, in turn, causes a more negative (positive) ENSO values. Of course this may be only a first approximation of the real mechanism of this "teleconnection". The correlations we have found are not strong even if statistically significant. For example, the MJJA NH-SH temperature vs. DJ MEI correlation has r = -0.28 implying it explains only 8% of boreal

  19. Tropical influence on boreal summer mid-latitude stationary waves

    Energy Technology Data Exchange (ETDEWEB)

    Douville, Herve [Meteo-France/CNRM-GAME, Toulouse (France); CNRM/GMGEC/VDR, Toulouse (France); Bielli, S.; Deque, M.; Tyteca, S.; Voldoire, A. [Meteo-France/CNRM-GAME, Toulouse (France); Cassou, C. [CNRS-Cerfacs, Toulouse (France); Hall, N.M.J. [CNES/LEGOS, Toulouse (France)

    2011-11-15

    While organized tropical convection is a well-known source of extratropical planetary waves, state-of-the-art climate models still show serious deficiencies in simulating accurately the atmospheric response to tropical sea surface temperature (SST) anomalies and the associated teleconnections. In the present study, the remote influence of the tropical atmospheric circulation is evaluated in ensembles of global boreal summer simulations in which the Arpege-Climat atmospheric General Circulation Model (GCM) is nudged towards 6-h reanalyses. The nudging is applied either in the whole tropical band or in a regional summer monsoon domain. Sensitivity tests to the experimental design are first conducted using prescribed climatological SST. They show that the tropical relaxation does not improve the zonal mean extratropical climatology but does lead to a significantly improved representation of the mid-latitude stationary waves in both hemispheres. Low-pass filtering of the relaxation fields has no major effect on the model response, suggesting that high-frequency tropical variability is not responsible for extratropical biases. Dividing the nudging strength by a factor 10 only decreases the magnitude of the response. Model errors in each monsoon domain contribute to deficiencies in the model's mid-latitude climatology, although an exaggerated large-scale subsidence in the central equatorial Pacific appears as the main source of errors for the representation of stationary waves in the Arpege-Climat model. Case studies are then conducted using either climatological or observed SST. The focus is first on summer 2003 characterized by a strong and persistent anticyclonic anomaly over western Europe. This pattern is more realistic in nudging experiments than in simulations only driven by observed SST, especially when the nudging domain is centred over Central America. Other case studies also show a significant tropical forcing of the summer mid-latitude stationary waves

  20. Nitrogen balance along a northern boreal forest fire chronosequence.

    Science.gov (United States)

    Palviainen, Marjo; Pumpanen, Jukka; Berninger, Frank; Ritala, Kaisa; Duan, Baoli; Heinonsalo, Jussi; Sun, Hui; Köster, Egle; Köster, Kajar

    2017-01-01

    Fire is a major natural disturbance factor in boreal forests, and the frequency of forest fires is predicted to increase due to climate change. Nitrogen (N) is a key determinant of carbon sequestration in boreal forests because the shortage of N limits tree growth. We studied changes in N pools and fluxes, and the overall N balance across a 155-year non stand-replacing fire chronosequence in sub-arctic Pinus sylvestris forests in Finland. Two years after the fire, total ecosystem N pool was 622 kg ha-1 of which 16% was in the vegetation, 8% in the dead biomass and 76% in the soil. 155 years after the fire, total N pool was 960 kg ha-1, with 27% in the vegetation, 3% in the dead biomass and 69% in the soil. This implies an annual accumulation rate of 2.28 kg ha-1 which was distributed equally between soil and biomass. The observed changes in N pools were consistent with the computed N balance +2.11 kg ha-1 yr-1 over the 155-year post-fire period. Nitrogen deposition was an important component of the N balance. The biological N fixation increased with succession and constituted 9% of the total N input during the 155 post-fire years. N2O fluxes were negligible (≤ 0.01 kg ha-1 yr-1) and did not differ among post-fire age classes. The number and intensity of microbial genes involved in N cycling were lower at the site 60 years after fire compared to the youngest and the oldest sites indicating potential differences in soil N cycling processes. The results suggest that in sub-arctic pine forests, the non-stand-replacing, intermediate-severity fires decrease considerably N pools in biomass but changes in soil and total ecosystem N pools are slight. Current fire-return interval does not seem to pose a great threat to ecosystem productivity and N status in these sub-arctic forests.