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Full-Text Articles in Life Sciences

The Flood Pulse In A Semi-Arid Riparian Forest:Metabolic And Biogeochemical Responses To Inter-Flood Interval, H. M. Valett, Michelle A. Baker, J. A. Morrice, C. S. Crawford, M. C. Molles, C. N. Dahm, D. L. Moyer, J. R. Thibault Jan 2005

The Flood Pulse In A Semi-Arid Riparian Forest:Metabolic And Biogeochemical Responses To Inter-Flood Interval, H. M. Valett, Michelle A. Baker, J. A. Morrice, C. S. Crawford, M. C. Molles, C. N. Dahm, D. L. Moyer, J. R. Thibault

Biology Faculty Publications

Flood pulse inundation of riparian forests alters rates of nutrient retention and organic matter processing in the aquatic ecosystems formed in the forest interior. Along the Middle Rio Grande (New Mexico, USA), impoundment and levee construction have created riparian forests that differ in their inter-flood intervals (IFIs) because some floodplains are still regularly inundated by the flood pulse (i.e., connected), while other floodplains remain isolated from flooding (i.e., disconnected). This research investigates how ecosystem responses to the flood pulse relate to forest IFI by quantifying nutrient and organic matter dynamics in the Rio Grande floodplain during three years of experimental …


North American Watersnakes: A Natural History, Alan H. Savitzky Jan 2005

North American Watersnakes: A Natural History, Alan H. Savitzky

Biology Faculty Publications

No abstract provided.


Controls On Nitrogen Cycling In Terrestrial Ecosystems: A Synthetic Analysis Of Literature Data, M. S. Booth, E. Rastetter, John M. Stark Jan 2005

Controls On Nitrogen Cycling In Terrestrial Ecosystems: A Synthetic Analysis Of Literature Data, M. S. Booth, E. Rastetter, John M. Stark

Biology Faculty Publications

Isotope pool dilution studies are increasingly reported in the soils and ecology literature as a means of measuring gross rates of nitrogen (N) mineralization, nitrification, and inorganic N assimilation in soils. We assembled data on soil characteristics and gross rates from 100 studies conducted in forest, shrubland, grassland, and agricultural systems to answer the following questions: What factors appear to be the major drivers for production and consumption of inorganic N as measured by isotope dilution studies? Do rates or the relationships between drivers and rates differ among ecosystem types? Across a wide range of ecosystems, gross N mineralization is …


Evidence For A General Species Time Arearelationship, P. B. Adler, Ethan P. White, W. K. Lauenroth, D. M. Kaufman, A. Rassweiler, J. A. Rusak Jan 2005

Evidence For A General Species Time Arearelationship, P. B. Adler, Ethan P. White, W. K. Lauenroth, D. M. Kaufman, A. Rassweiler, J. A. Rusak

Biology Faculty Publications

The species-area relationship (SAR) plays a central role in biodiversity research, and recent work has increased awareness of its temporal analog, the species-time relationship (STR). Here we provide evidence for a general species-time-area-relationship (STAR), in which species number is a function of the area and time span of sampling, as well as their interaction. For eight assemblages ranging from lake zooplankton to desert rodents, this model outperformed a sampling-based model and two simpler models in which area and time had independent effects. In every case the interaction term was negative, meaning that rates of species accumulation in space decreased with …


Body Size, Energy Use, And Community Structure Of Small Mammals, S.K. Morgan Ernest Jan 2005

Body Size, Energy Use, And Community Structure Of Small Mammals, S.K. Morgan Ernest

Biology Faculty Publications

Body size has long been hypothesized to play a major role in community structure and dynamics. Two general hypotheses exist for how resources are distributed among body sizes: (1) resources are equally available and uniformly utilized across body sizes and (2) resources are differentially available to organisms of different body sizes, resulting in a nonuniform or modal distribution. It has also been predicted that the distri-bution of body sizes of species in a community should reflect the underlying availability of resources, with the emergence of aggregations of species around specific body sizes. I examined the relationship between energy utilization, body …


Intra-Guild Compensation Regulatesspecies Richness In Desert Rodents, J. Goheen, Ethan P. White, S.K. Morgan Ernest, J. H. Brown Jan 2005

Intra-Guild Compensation Regulatesspecies Richness In Desert Rodents, J. Goheen, Ethan P. White, S.K. Morgan Ernest, J. H. Brown

Biology Faculty Publications

Evidence from numerous studies suggests that species richness is an emergent property of local communities. The maintenance of species richness, despite changes in species composition and environmental conditions, requires compensatory colonization and extinction events with species coming from a regional pool. Using long-term data from a rodent community in the Chihuahuan Desert, we use randomization methods to test the null hypothesis that changes in species richness occur randomly. We find that the dynamics of species richness differ significantly from a random process, and that these nonrandom dynamics occur largely within the most speciose guild. Finally, we propose a general framework …