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Full-Text Articles in Life Sciences

Evidence For 20th Century Climate Warming And Wetland Drying In The North American Prairie Pothole Region, Brett A. Werner, W. Carter Johnson, Glenn R. Guntenspergen Sep 2013

Evidence For 20th Century Climate Warming And Wetland Drying In The North American Prairie Pothole Region, Brett A. Werner, W. Carter Johnson, Glenn R. Guntenspergen

Natural Resource Management Faculty Publications

The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate …


A Survey Of Aquatic Invertebrate Communities In Nebraska Sandhill Lakes Reveals Potential Alternative Ecosystem States, J.C. Jolley, E.S. Albin, M.A. Kaemingk, D.W. Willis Jun 2013

A Survey Of Aquatic Invertebrate Communities In Nebraska Sandhill Lakes Reveals Potential Alternative Ecosystem States, J.C. Jolley, E.S. Albin, M.A. Kaemingk, D.W. Willis

Natural Resource Management Faculty Publications

Aquatic invertebrate communities are important to shallow lake ecosystem form and function, providing vital components to the food web and thereby important to achieving lake management goals. We characterized lake invertebrate communities and physicochemical variables in six Nebraska Sandhill lakes and examined these characteristics within an alternative stable state framework. Surveys were conducted during 2005 within each of these lakes by sampling aquatic macroinvertebrate abundance, zooplankton abundance and biomass, phytoplankton biomass, and physicochemical variables. When placed within an alternative stable state framework, the response variables exhibited a gradient of different ecosystem states. Two lakes appeared congruent with the clear water …


Migrating Mule Deer: Effects Of Anthropogenically Altered Landscapes, Patrick E. Lendrum, Charles R. Anderson Jr., Kevin L. Monteith, Jonathan A. Jenks, R. Terry Bowyer May 2013

Migrating Mule Deer: Effects Of Anthropogenically Altered Landscapes, Patrick E. Lendrum, Charles R. Anderson Jr., Kevin L. Monteith, Jonathan A. Jenks, R. Terry Bowyer

Natural Resource Management Faculty Publications

Background: Migration is an adaptive strategy that enables animals to enhance resource availability and reduce risk of predation at a broad geographic scale. Ungulate migrations generally occur along traditional routes, many of which have been disrupted by anthropogenic disturbances. Spring migration in ungulates is of particular importance for conservation planning, because it is closely coupled with timing of parturition. The degree to which oil and gas development affects migratory patterns, and whether ungulate migration is sufficiently plastic to compensate for such changes, warrants additional study to better understand this critical conservation issue.
Methodology/Principal Findings: We studied timing and synchrony of …


Effects Of Plant Phenology And Vertical Height On Accuracy Of Radio-Telemetry Locations, Troy Grovenburg, Christopher N. Jacques, Robert W. Klaver, Christopher S. Deperno, Chad P. Lehman, Todd J. Brinkman, Kevin A. Robling, Susan P. Rupp, Jonathan A. Jenks Mar 2013

Effects Of Plant Phenology And Vertical Height On Accuracy Of Radio-Telemetry Locations, Troy Grovenburg, Christopher N. Jacques, Robert W. Klaver, Christopher S. Deperno, Chad P. Lehman, Todd J. Brinkman, Kevin A. Robling, Susan P. Rupp, Jonathan A. Jenks

Natural Resource Management Faculty Publications

The use of very high frequency (VHF) radio-telemetry remains wide-spread in studies of wildlife ecology andmanagement. However, few studies have evaluated the influence of vegetative obstruction on accuracy in differing habitats with varying transmitter types and heights. Using adult and fawn collars at varying heights above the ground (0, 33, 66 and 100 cm) to simulate activities (bedded, feeding and standing) and ages (neonate, juvenile and adult) of deer Odocoileus spp., we collected 5,767 bearings and estimated 1,424 locations (28-30 for each of 48 subsamples) in three habitat types (pasture, grassland and forest), during two stages of vegetative growth (spring …


Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown Feb 2013

Continuous, Pulsed And Disrupted Nutrient Subsidy Effects On Ecosystem Productivity, Stability, And Energy Flow, Michael J. Weber, Michael L. Brown

Natural Resource Management Faculty Publications

Resource pulses and subsidies can supply ecosystems with an important source of nutrients that supports additional productivity at multiple trophic levels. Common carp Cyprinus carpio provide ecosystems with a continuous nutrient subsidy through bioturbation and excretion but may also initiate a nutrient pulse through carcass decomposition. We examined how continuous (common carp foraging and excretion), pulsed (carcass decomposition) and disrupted (carp introduced and then removed) nutrient subsidies differed in their ability to alter nutrient availability, ecosystem productivity and stability and energy flow. Nitrogen and phosphorus availability and primary production were highest in pulsed, intermediate in continuous and lowest for disrupted …


Temperature And Functional Traits Influence Differences In Nitrogen Uptake Capacity Between Native And Invasive Grasses, A. Joshua Leffler, Jeremy J. James, Thomas A. Monaco Jan 2013

Temperature And Functional Traits Influence Differences In Nitrogen Uptake Capacity Between Native And Invasive Grasses, A. Joshua Leffler, Jeremy J. James, Thomas A. Monaco

Natural Resource Management Faculty Publications

Performance differences between native and exotic invasive plants are often considered static, but invasive grasses may achieve growth advantages in western North America shrublands and steppe under only optimal growing conditions. We examine differences in N uptake and several morphological variables that influence uptake at temperatures between 5 and 25 C. We contrast two native perennial grasses in western North America: Elymus elymoides and Pseudoroegneria spicata; two invasive annual grasses: Bromus tectorum and Taeniatherum caputmedusae; and one highly selected non-native perennial grass: Agropyron cristatum. The influence of temperature on N uptake is poorly characterized, yet these invasive annual grasses are …


Topographic Home Range Of Large Mammals: Is Planimetric Home Range Still A Viable Method?, W. David Walter, Justin W. Fischer, Teresa J. Fink, Scott E. Hygnstrom, Jonathan A. Jenks, Kurt C. Vercauteren Jan 2013

Topographic Home Range Of Large Mammals: Is Planimetric Home Range Still A Viable Method?, W. David Walter, Justin W. Fischer, Teresa J. Fink, Scott E. Hygnstrom, Jonathan A. Jenks, Kurt C. Vercauteren

Natural Resource Management Faculty Publications

Topography influences movement trajectories, quality of forages used, and behavioral response of large herbivores to anthropogenic disturbances, but research is lacking on the influence of terrain complexity on size of home range. Size of home range usually is based on planimetric area and therefore rarely accounts for the true surface area traversed by an animal. We conducted radiotelemetry on bighorn sheep (Ovis canadensis), Rocky Mountain elk (Cervus elaphus), mule deer (Odocoileus hemionus), and white-tailed deer (O. virginianus) equipped with VHF collars at three sites from 2002 to 2006 to document size of home range in areas that ranged from 400 …


Sagebrush Ecosystem Characterization, Monitoring, And Forecasting With Remote Sensing: Quantifying Future Climate And Wildlife Habitat Change, Collin G. Homer Jan 2013

Sagebrush Ecosystem Characterization, Monitoring, And Forecasting With Remote Sensing: Quantifying Future Climate And Wildlife Habitat Change, Collin G. Homer

Electronic Theses and Dissertations

Sagebrush (Artemisia spp.) ecosystems constitute the largest single North American shrub ecosystem and provide vital ecological, hydrological, biological, agricultural, and recreational ecosystem services. Disturbances continue to alter this ecosystem, with climate change possibly representing the greatest future disturbance risk. Improved ways to characterize and monitor gradual change in this ecosystem are vital to its future management. A new remote sensing sagebrush characterization approach was developed in Wyoming which integrates three scales of remote sensing to derive four primary continuous field components (bare ground, herbaceousness, litter, and shrub), and four secondary components (sagebrush, big sagebrush, Wyoming sagebrush, and shrub …


Spring Clipping, Fire, And Simulated Increased Atmospheric Nitrogen Deposition Effects On Tallgrass Prairie Vegetation, Alexander J. Smart, Tabitha K. Scott, Sharon A. Clay, David E. Clay, Michelle K. Ohrtman, Eric M. Mousel Jan 2013

Spring Clipping, Fire, And Simulated Increased Atmospheric Nitrogen Deposition Effects On Tallgrass Prairie Vegetation, Alexander J. Smart, Tabitha K. Scott, Sharon A. Clay, David E. Clay, Michelle K. Ohrtman, Eric M. Mousel

Agronomy, Horticulture and Plant Science Faculty Publications

Defoliation aimed at introduced cool-season grasses, which uses similar resources of native grasses, could substantially reduce their competitiveness and improve the quality of the northern tallgrass prairie. The objective was to evaluate the use of early season clipping and fire in conjunction with simulated increased levels of atmospheric nitrogen deposition on foliar canopy cover of tallgrass prairie vegetation. This study was conducted from 2009 to 2012 at two locations in eastern South Dakota. Small plots arranged in a split-plot treatment design were randomized in four complete blocks on a warm-season grass interseeded and a native prairie site in east-central South …