Now showing items 1-10 of 320
Processing arctic eddy-flux data using a simple carbon-exchange model embedded in the ensemble Kalman filter
(Ecological Society of America, 2010-07)
Continuous time-series estimates of net ecosystem carbon exchange (NEE) are routinely made using eddy covariance techniques. Identifying and compensating for errors in the NEE time series can be automated using a signal ...
Burn severity influences postfire CO2 exchange in Arctic tundra
(Ecological Society of America, 2011-03)
Burned landscapes present several challenges to quantifying landscape carbon balance. Fire scars are composed of a mosaic of patches that differ in burn severity, which may influence postfire carbon budgets through damage ...
Correction to “Importance of carbon-nitrogen interactions and ozone on ecosystem hydrology during the 21st century”
(American Geophysical Union, 2009-08-22)
Ecosystem feedbacks and cascade processes : understanding their role in the responses of Arctic and alpine ecosystems to environmental change
Global environmental change, related to climate change and the deposition of airborne N-containing contaminants, has already resulted in shifts in plant community composition among plant functional types in arctic and ...
Species compositional differences on different-aged glacial landscapes drive contrasting responses of tundra to nutrient addition
In the northern foothills of the Brooks Range, Alaska, moist non-acidic tundra dominates more recently deglaciated upland landscapes, whereas moist acidic tundra dominates older upland landscapes. In previous studies, ...
Effects of ozone on net primary production and carbon sequestration in the conterminous United States using a biogeochemistry model
The effects of air pollution on vegetation may provide an important control on the carbon cycle that has not yet been widely considered. Prolonged exposure to high levels of ozone, in particular, has been observed to ...
Soil hydraulic response to land-use change associated with the recent soybean expansion at the Amazon agricultural frontier
Clearing for large-scale soy production and the displacement of cattle-breeding by soybeans are major features of land-use change in the lowland Amazon that can alter hydrologic properties of soils and the runoff generation ...
Eutrophication in Portuguese estuaries evidenced by δ15N of macrophytes
Terrestrial inputs of nitrogen in estuaries are increasing and altering salt marsh primary production, plant communities and associated biota. We used N isotope ratios and %N in Spartina maritima, Halimione portulacoides, ...
N budgets and aquatic uptake in the Ipswich River basin, northeastern Massachusetts
(American Geophysical Union, 2004-11-05)
We calculated N budgets and conducted nutrient uptake experiments to evaluate the fate of N in the aquatic environment of the Ipswich River basin, northeastern Massachusetts. A mass balance indicates that the basin retains ...
Intentional versus unintentional nitrogen use in the United States : trends, efficiency and implications
Human actions have both intentionally and unintentionally altered the global economy of nitrogen (N), with both positive and negative consequences for human health and welfare, the environment and climate change. Here we ...