Description:    Nitrous oxide (N 2 O) emissions from grazed grasslands are estimated to be approximately 28% of global anthropogenic N 2 O emissions. Estimating the N 2 O flux from grassland soils is difficult because of its episodic nature. This study aimed to quantify the N 2 O emissions, the annual N 2 O flux and the emission factor (EF), and also to investigate the influence of environmental and soil variables controlling N 2 O emissions from grazed grassland. Nitrous oxide emissions were measured using static chambers at eight different grasslands in the South of Ireland from September 2007 to August 2009. The instantaneous N 2 O flux values ranged from -186 to 885.6 μg N 2 O-N m −2  h −1 and the annual sum ranged from 2 ± 3.51 to 12.55 ± 2.83 kg N 2 O-N ha −1  y −1 for managed sites. The emission factor ranged from 1.3 to 3.4%. The overall EF of 1.81% is about 69% higher than the Intergovernmental Panel on Climate Change (IPCC) default EF value of 1.25% which is currently used by the Irish Environmental Protection Agency (EPA) to estimate N 2 O emission in Ireland. At an N applied of approximately 300 kg ha −1  y −1 , the N 2 O emissions are approximately 5.0 kg N 2 O-N ha −1 y −1 , whereas the N 2 O emissions double to approximately 10 kg N ha −1 for an N applied of 400 kg N ha −1  y −1 . The sites with higher fluxes were associated with intensive N-input and frequent cattle grazing. The N 2 O flux at 17°C was five times greater than that at 5°C. Similarly, the N 2 O emissions increased with increasing water filled pore space (WFPS) with maximum N 2 O emissions occurring at 60–80% WFPS. We conclude that N application below 300 kg ha −1  y −1 and restricted grazing on seasonally wet soils will reduce N 2 O emissions. Content Type Journal Article Pages 1-20 DOI 10.1007/s10021-011-9434-x Authors Rashad Rafique, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Deirdre Hennessy, Department of Animals &, Grassland Science Research, Teagasc-Moorpark, Fermoy, Ireland Gerard Kiely, Department of Civil and Environmental Engineering, Centre for Hydrology, Micrometeorology and Climate Change, University College Cork, Cork, Ireland Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840

Description:    Wetland ecosystems are of global significance having productive, regulatory and informative function. These wetlands are crucial for the long-term protection of water sources, as well as the survival of its unique biodiversity. Most of the wetlands of Turkey are now facing serious threat from the anthropogenic sources and now near to the verge of extinction. This study has been carried out to monitor vegetation dynamics and ecological status of wetlands of Koyna basin at spatial and temporal scale. This study has involved MODerate-resolution Imaging Spectroradiometer (MODIS) images of the year 2000, 2004 and 2008 on daily basis with spatial resolution of 1 km. The MODIS 16 days composite NDVI time series products of 250-m spatial resolution from year 2000 to 2008 has been utilized to monitor the ecological status of the wetlands. The European Nature Information System habitat classification map, meteorological data (precipitation, temperature) coupled with field data has been utilized to validate NDVI values of nine habitats in the wetlands. The time series analyses of NDVI data values have been correlated with the groundwater level depth from 1996 to 2004. The overall analysis has shown a declining trend of NDVI over the year 2000 to 2008, indicated a degraded wetland condition in span of 9 years. Content Type Journal Article Pages 1-12 DOI 10.1007/s10113-011-0241-x Authors Jay Krishna Thakur, Department Hydrogeology and Environmental Geology, Institute of Geosciences, Martin Luther University, Von-Seckendorff-Platz 3, 06120 Halle (Saale), Germany P. K. Srivastava, Department of Civil Engineering, Water and Environment Management Research Center, University of Bristol, Bristol, BS8 1TR United Kingdom S. K. Singh, Centre of Atmospheric and Ocean Science, KBCAOS, IIDS, University of Allahabad, Allahabad, 211002 India Zoltán Vekerdy, Faculty of Geo-information Science and Earth Observation, Twente University, Hengelosestraat 99, 7514 AE Enschede, The Netherlands Journal Regional Environmental Change Online ISSN 1436-378X Print ISSN 1436-3798

Description:    A 108-year (1901–2008) downscaling of the twentieth-century reanalysis (20CR) using the Regional Spectral Model (RSM) has been conducted for the southeastern United States (SEUS) at a horizontal grid resolution of 10 km. This 108-year product, named as the Florida Climate Institute-Florida State University Land–Atmosphere Reanalysis for the southeastern United States at 10-km resolution version 1.0 [FLAReS1.0], has primarily been developed for anticipated application studies in hydrology, crop management, ecology, and other interdisciplinary fields in the SEUS. The analysis of this downscaled product reveals that it ameliorates the issue of artificial discontinuity in the precipitation time series of the 20CR from the variations inherent to RSM. This centennial scale product allows us to begin examining decadal scale variations of the regional features of the SEUS. The fidelity of the low-frequency variations of the winter rainfall associated with the Atlantic Multi-decadal Oscillation (AMO) and the Pacific Decadal Oscillation is reasonably well captured in FLAReS1.0. In fact, the modulation of the El Niño-Southern Oscillation (ENSO) teleconnection with the SEUS rainfall by AMO in the downscaled product is also validated with observations. The ENSO-associated variations of accumulated rainfall from landfalling hurricanes in the SEUS are also well simulated in the downscaled climate simulation. It is to be noted that the success of this dynamical downscaling is also because the global reanalysis of 20CR showed comparable fidelity in these low-frequency variations of the SEUS climate. This method of dynamic downscaling global reanalysis with inclusion of spectral nudging at large wavelengths (in this case ≥500 km) toward the driving global reanalysis (20CR) is sometimes referred as a form of regional reanalysis. Content Type Journal Article Category Original Article Pages 1-9 DOI 10.1007/s10113-012-0372-8 Authors V. Misra, Department of Earth, Ocean and Atmospheric Science, Florida State University, P.O. Box 3064520, Tallahassee, FL 32306-4520, USA S. M. DiNapoli, Center for Ocean-Atmospheric Prediction Studies, Florida State University, 2035 E. Paul Dirac Dr., 200 RM Johnson Bldg, Tallahassee, FL 32306-2840, USA S. Bastola, Center for Ocean-Atmospheric Prediction Studies, Florida State University, 2035 E. Paul Dirac Dr., 200 RM Johnson Bldg, Tallahassee, FL 32306-2840, USA Journal Regional Environmental Change Online ISSN 1436-378X Print ISSN 1436-3798

Description:    Agricultural drainage is thought to alter greenhouse gas emissions from temperate peatlands, with CH 4 emissions reduced in favor of greater CO 2 losses. Attention has largely focussed on C trace gases, and less is known about the impacts of agricultural conversion on N 2 O or global warming potential. We report greenhouse gas fluxes (CH 4 , CO 2 , N 2 O) from a drained peatland in the Sacramento-San Joaquin River Delta, California, USA currently managed as a rangeland (that is, pasture). This ecosystem was a net source of CH 4 (25.8 ± 1.4 mg CH 4 -C m −2  d −1 ) and N 2 O (6.4 ± 0.4 mg N 2 O-N m −2  d −1 ). Methane fluxes were comparable to those of other managed temperate peatlands, whereas N 2 O fluxes were very high; equivalent to fluxes from heavily fertilized agroecosystems and tropical forests. Ecosystem scale CH 4 fluxes were driven by “hotspots” (drainage ditches) that accounted for less than 5% of the land area but more than 84% of emissions. Methane fluxes were unresponsive to seasonal fluctuations in climate and showed minimal temporal variability. Nitrous oxide fluxes were more homogeneously distributed throughout the landscape and responded to fluctuations in environmental variables, especially soil moisture. Elevated CH 4 and N 2 O fluxes contributed to a high overall ecosystem global warming potential (531 g CO 2 -C equivalents m −2  y −1 ), with non-CO 2 trace gas fluxes offsetting the atmospheric “cooling” effects of photoassimilation. These data suggest that managed Delta peatlands are potentially large regional sources of greenhouse gases, with spatial heterogeneity in soil moisture modulating the relative importance of each gas for ecosystem global warming potential. Content Type Journal Article Pages 1-15 DOI 10.1007/s10021-011-9411-4 Authors Yit Arn Teh, Environmental Change Research Group, School of Geography & Geosciences, University of St Andrews, St Andrews, KY16 9 AL Scotland, UK Whendee L. Silver, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Oliver Sonnentag, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Matteo Detto, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Maggi Kelly, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Dennis D. Baldocchi, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California 94702, USA Journal Ecosystems Online ISSN 1435-0629 Print ISSN 1432-9840