Now showing items 21-30 of 48
Sources of reactive nitrogen affecting ecosystems in Latin America and the Caribbean: current trends and future perspectives
(Kluwer Academic Publishers; Springer Science+Business Media, Inc., 2006-04-06)
While the amount of reactive nitrogen circulating at the global level has increased markedly in the last century, the effects of this increase are largely seen at the regional level due to interacting ecological and ...
Anthropogenic N deposition and the fate of 15 NO 3 − in a northern hardwood ecosystem
(Kluwer Academic Publishers; Springer Science+Business Media, 2004-06)
Human activity has substantially increased atmospheric NO 3 − deposition in many regions of the Earth, which could lead to the N saturation of terrestrial ecosystems. Sugar maple ( Acer saccharum Marsh.) dominated northern ...
Populus tremuloides photosynthesis and crown architecture in response to elevated CO 2 and soil N availability
(Springer-Verlag; Springer-Verlag Berlin Heidelberg, 1997-04)
We tested the hypothesis that elevated CO 2 would stimulate proportionally higher photosynthesis in the lower crown of Populus trees due to less N retranslocation, compared to tree crowns in ambient CO 2 . Such a response ...
Nutritional indices in the gypsy moth ( Lymantria dispar (L.)) under field conditions and host switching situations
(Springer-Verlag, 1994-03)
A large proportion of gypsy moths ( Lymantria dispar (L.)) are likely to experience multiple species diets in the field due to natural wandering and host switching which occurs with these insects. Nutritional indices in ...
Effects of Management Intensity and Season on Arboreal Ant Diversity and Abundance in Coffee Agroecosystems
(Kluwer Academic Publishers; Springer, 2006-01)
Agricultural intensification decreases arthropod predator diversity, abundance and population stability, and may affect interactions between top predators and their arthropod prey – ultimately affecting ecosystem services. ...
Physical-Biological Coupling in Southern Lake Michigan: Influence of Episodic Sediment Resuspension on Phytoplankton
(Kluwer Academic Publishers; Springer Science+Business Media, 2003-10)
The influence of episodic, sediment resuspension on phytoplankton abundance/volume and composition, the photosynthetic maximum rate (P B max ) and efficiency (α B ), and chlorophyll-specific growth (μ Chl ) was evaluated ...
Fine root chemistry and decomposition in model communities of north-temperate tree species show little response to elevated atmospheric CO 2 and varying soil resource availability
(Springer-Verlag, 2005-12)
Rising atmospheric [CO 2 ] has the potential to alter soil carbon (C) cycling by increasing the content of recalcitrant constituents in plant litter, thereby decreasing rates of decomposition. Because fine root turnover ...
Comparison of sleds versus plankton nets for sampling fish larvae and eggs
(Kluwer Academic Publishers; Springer Science+Business Media, 1985-05)
Fish larvae and fish eggs were sampled from the inshore waters of eastern Lake Michigan from 1978 through 1980, using a benthic sled and a plankton net towed within 0.5 m of the lake bottom. Differences between estimates ...
Microbial community composition and function beneath temperate trees exposed to elevated atmospheric carbon dioxide and ozone
(Springer-Verlag, 2002-04)
We hypothesized that changes in plant growth resulting from atmospheric CO 2 and O 3 enrichment would alter the flow of C through soil food webs and that this effect would vary with tree species. To test this idea, we ...
Microbial Community Structure and Oxidative Enzyme Activity in Nitrogen-amended North Temperate Forest Soils
(Springer-Verlag; Spreinger-Verlag, 2004-10)
Large regions of temperate forest are subject to elevated atmospheric nitrogen (N) deposition which can affect soil organic matter dynamics by altering mass loss rates, soil respiration, and dissolved organic matter ...