Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily—and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have… More

in    0

Measurements of net ecosystem CO2 exchange (NEE) and energy balance were made using chamber-, tower-, and aircraft-based measurement techniques in Alaskan arctic tundra ecosystems during the 1994–1995 growing seasons (June-August). One of our objectives was to quantify the interrelationships between the NEE and the energy balance measurements made from different sampling techniques. Qualitative and quantitative… More

in    0

The spatial and temporal patterns in CO2 flux for the Kuparuk River Basin, a 9200-km2 watershed located in NE Alaska were estimated using the Regional Arctic CO2 Exchange Simulator (RACES) for the 1994–1995 growing seasons. RACES uses non-linear models and a Geographical Information System database (GIS) consisting of the normalized difference vegetation index (NDVI) and… More

in    0

Energy budgets were measured at Arctic tundra ecosystems in Alaska, USA. Measurements were carried out over coastal tundra at Prudhoe Bay in 1994, and at wet sedge, moist and dry tussock tundra around Happy Valley in 1995. Sensible heat flux, H, and latent heat flux, lE, were determined by an eddy correlation technique. Over the… More

in    0

Eddy covariance was used to measure the net CO2 exchange and energy balance of a moist-tussock tundra ecosystem at Happy Valley, Alaska (69°08.54′ N, 148°50.47′ W), during the 1994–1995 growing seasons (June–August). The system operated for 75–95% of the time, and energy balance closure was within 5%, indicating good system performance. Daily rates of evapotranspiration… More

in    0

Recent evidence indicates that significant amounts of C may be lost as CO2 to the atmosphere from tundra ecosystems during the fall, winter and spring months. Because high latitude ecosystems are particularly vulnerable to climate change, and contain large soil C stocks, the annual C budget is of particular interest. Significant amounts of CO2 loss… More

in    0