Now showing items 31-40 of 283
Effect of historical changes in land use and climate on the water budget of an urbanizing watershed
(American Geophysical Union, 2006-03-25)
We assessed the effects of historical (1931-1998) changes in both land-use and climate on the water budget of a rapidly urbanizing watershed, Ipswich River basin (IRB), in northeastern Massachusetts. Water diversions and ...
Correction to “Importance of carbon-nitrogen interactions and ozone on ecosystem hydrology during the 21st century”
(American Geophysical Union, 2009-08-22)
Decreased mass specific respiration under experimental warming is robust to the microbial biomass method employed
Hartley et al. question whether reduction in Rmass, under experimental warming, arises because of the biomass method. We show the method they treat as independent yields the same result. We describe why the substrate-depletion ...
Terrestrial C sequestration at elevated CO2 and temperature : the role of dissolved organic N loss
We used a simple model of carbon–nitrogen (C–N) interactions in terrestrial ecosystems to examine the responses to elevated CO2 and to elevated CO2 plus warming in ecosystems that had the same total nitrogen loss but that ...
Experimental assessment of the macroalgae Ascophyllum nodosum and Fucus vesiculosus for monitoring N sources at different time-scales using stable isotope composition
Stable isotope composition of brown macroalgae has been widely used to monitor N loading during the last decades but some of the required assumptions when using them to detect anthropogenic inputs remain untested. In this ...
Thermal adaptation of soil microbial respiration to elevated temperature
In the short-term heterotrophic soil respiration is strongly and positively related to temperature. In the long-term its response to temperature is uncertain. One reason for this is because in field experiments increases ...
Estimating uncertainty in ecosystem budget calculations
Ecosystem nutrient budgets often report values for pools and fluxes without any indication of uncertainty, which makes it difficult to evaluate the significance of findings or make comparisons across systems. We present ...
Seasonal use of a New England estuary by foraging contingents of migratory striped bass
(American Fisheries Society, 2009-12-10)
Using acoustic telemetry on migratory striped bass Morone saxatilis in Plum Island Estuary (PIE), Massachusetts, we found that striped bass (335–634 mm total length) tagged in the spring and summer of 2005 (n = 14) and ...
Objective indicators of pasture degradation from spectral mixture analysis of Landsat imagery
(American Geophysical Union, 2008-07-23)
Degradation of cattle pastures is a management concern that influences future land use in Amazonia. However, “degradation” is poorly defined and has different meanings for ranchers, ecologists, and policy makers. Here we ...
Nitrogen dynamics in a small arctic watershed: retention and downhill movement of 15N
We examined short- and long-term nitrogen (N) dynamics and availability along an arctic hillslope in Alaska, USA, using stable isotope of nitrogen (15N), as a tracer. Tracer levels of 15NH4+ were sprayed once onto the ...