Other Environmental Sciences Commons^™

Cross-Scale Structure And Scale Breaks In Ecosystems And Other Complex Systems, Craig R. Allen, C. S. Holling

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The five articles in this special feature extend the discovery of regular patterns of deviation from scaling laws and from continuous distributions of attributes in ecosystems and other complex systems. These patterns suggest that these systems organize over discrete ranges of scale and that organization abruptly shifts with changes in scale. If this is so, scaling laws (for example, see West 1997, 1999; Zipf 1949) serve only as the baseline from which to measure those departures, and those departures indicate “scale breaks” (transitions) between scales of structure in complex systems. Patterns in the deviations from a scaling-law baseline may provide …

Variability Between Scales: Predictors Of Nomadism In Birds Of An Australian Mediterraneanclimate Ecosystem, Craig R. Allen, Denis A. Saunders

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Nomadism in animals is a response to resource distributions that are highly variable in time and space. Using the avian fauna of the Mediterranean-climate region of southcentral Australia, we tested a number of variables to determine if they predicted nomadism. These variables were species body mass, the distance in body mass terms to the edge of a body mass aggregation, and diet (for example, seeds, invertebrates, nectar, or plants). We utilized two different classifications of the avifauna that diverged in their definition of nomadic to build two different predictive models. Using both classifications, distance to the edge of a body …

Cross-Scale Morphology, Craig R. Allen, C.S. Holling

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The scaling of physical, biological, ecological and social phenomena has become a major focus of efforts to develop simple representations of complex systems. Much of the attention has been on discovering universal scaling laws that emerge from simple physical and geometric processes. But there are regular patterns of departures both from those scaling laws and from continuous distributions of attributes of systems; these departures often demonstrate the development of self-organized interactions between living systems and physical processes over narrower ranges of scale. Cross-scale morphology refers to morphological attributes of animals that are influenced by interaction with ecological structures and patterns …

Influence Of The Proximity And Amount Of Human Development And Roads On The Occurrence Of The Red Imported Fire Ant In The Lower Florida Keys, Elizabeth A. Forys, Craig R. Allen, Daniel P. Wojcik

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We examined the influence of both the proximity and extent of human developments and paved roads on the presence of the predatory, non-indigenous, red imported fire ant (Solenopsis invicta). This species was inadvertently introduced into the United States at the port of Mobile, Alabama, around 1930 and rapidly spread to many southeastern states, including Florida. More recently, S. invicta colonized the Florida Keys, an area with a high proportion of rare and endemic vertebrate and invertebrate species. We placed bait transects in transitional salt-marsh, pineland, and hardwood hammocks on 13 of the lower Florida Keys and compared habitat …

Implications Of Body Mass Patterns: Linking Ecological Structure And Process To Wildlife Conservation And Management, Jan P. Sendzimir, Craig R. Allen, Lance H. Gunderson, Craig A, Stow

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The unprecedented scale of problems affecting wildlife ecology today overwhelms many managers. Challenges are no longer local in origin, but rather a tangle of local, regional and even global externalities often interacting in unpredictable ways. Previously isolated ecosystems have become increasingly connected at global, hemispheric and regional levels, eroding their integrity. Endocrine-disrupting compounds applied in Mexico have changed avian sexual development in the Great Lakes (Colborn et al. 1996). Chamois (Rupicapra rupicapra) reproduction in the Carpathian mountains falters when the color of newborns is no longer cryptic because climate change prematurely melts snow cover (K. Perzanowski, Polish Academy …

Assessing State-Wide Biodiversity In The Florida Gap Analysis Project, L. G. Pearlstine, S. E. Smith, L. A. Brandt, C. R. Allen, W. M. Kitchens, J. Stenberg

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The Florida Gap (FI-Gap) project provides an assessment of the degree to which native animal species and natural communities are or are not represented in existing conservation lands. Those species and communities not adequately represented in areas being managed for native species constitute 'gaps' in the existing network of conservation lands. The United States Geological Survey Gap Analysis Program is a national effort and so, eventually, all 50 states will have completed it. The objective of FI-Gap was to provide broad geographic information on the status of terrestrial vertebrates, butterflies, skippers and ants and their respective habitats to address the …

Initial Mortality Of Black Bass In B.A.S.S. Fishing Tournaments, Gene R. Wilde, Calub E. Shavlik, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We studied the initial mortality of black bass Micropterus spp. that were captured, weighed in, and released in fishing tournaments conducted by the Bass Anglers Sportsman Society between 1972 and 1998. Mean annual initial mortality (i.e., mortality before weigh-in and release) ranged from 1% to 30%. Initial mortality was greatest during the 1970s (15.2%) and decreased during the 1980s (5.7%) and 1990s (1.9%). Because initial mortality was uniformly low ( ≤5%) after 1982, we used results for 1983–1998 to assess relationships involving initial mortality. Initial mortality was correlated with bag size, mean fish weight per angler, and number of fish …

Functional Group Change Within And Across Scales Following Invasions And Extinctions In The Everglades Ecosystem, Elizabeth A. Forys, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Cross-scale resilience theory predicts that the combination of functional diversity within scales and functional redundancy across scales is an important attribute of ecosystems because it helps these systems resist minor ecological disruptions and regenerate after major disturbances such as hurricanes and fire. Using the vertebrate fauna of south Florida, we quantified how the loss of native species and invasion by nonnatives may alter functional group richness within and across scales. We found that despite large changes in species composition due to potential extinctions and successful invasions by nonnative species, functional group richness will not change significantly within scales, there will …

Organochlorine Chemical Residues In Fish From The Mississippi River Basin, 1995, C.J. Schmitt

United States Geological Survey: Staff Publications

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Fish were collected in late 1995 from 34 National Contaminant Biomonitoring Program (NCBP) stations and 13 National Water Quality Assessment Program (NAWQA) stations in the Mississippi River basin (MRB) and in late 1996 from a reference site in West Virginia. Four composite samples, each comprising (nominally) 10 adult common carp (Cyprinus carpio) or black bass (Micropterus spp.) of the same sex, were collected from each site and analyzed for organochlorine chemical residues by gas chromatography with electron capture detection. At the NCBP stations, which are located on relatively large rivers, concentrations of organochlorine chemical residues were generally lower than …

Evidence For The Timing And Duration Of The Last Interglacial Period From High-Precision Uranium-Series Ages Of Corals On Tectonically Stable Coastlines, Daniel R. Muhs

United States Geological Survey: Staff Publications

The last interglacial period has a timing and duration that can be estimated from U-series dating of emergent, coral-bearing deposits on tectonically stable coastlines. High-precision dating from Bermuda, the Bahamas, Hawaii, and Australia suggests that the last interglacial period had a sea level at least as high as present from ∼128,000 to 116,000 yr B.P. Sea level reached a near-present level more quickly after the close of the penultimate glacial period than at the close of the last glacial period and the duration of high sea level is longer than that implied by the deep-sea record.

Derivation Of A Tasselled Cap Transformation Based On Landsat 7 At-Satellite Reflectance, C. Huang, Wylie L. Yang, Collin Homer, G. Zylstra

United States Geological Survey: Staff Publications

A new tasselled cap transformation based on Landsat 7 at-satellite reflectance was developed. This transformation is most appropriate for regional applications where atmospheric correction is not feasible. The brightness, greenness and wetness of the derived transformation collectively explained over 97% of the spectral variance of the individual scenes used in this study.

Strontium Isotopic Signatures Of The Streams And Lakes Of Taylor Valley, Southern Victoria Land, Antarctica: Chemical Weathering In A Polar Climate, W. B. Lyons, Carmen A. Nezat, Larry V. Benson, Thomas D. Bullen, Elizabeth Y. Graham, Jesicca Kidd, Kathleen A. Welch, James M. Thomas

United States Geological Survey: Staff Publications

We have collected and analyzed a series of water samples from three closed-basin lakes (Lakes Bonney, Fryxell, and Hoare) in Taylor Valley, Antarctica, and the streams that flow into them. In all three lakes, the hypolimnetic waters have different ⁸⁷Sr/⁸⁶Sr ratios than the surface waters, with the deep water of Lakes Fryxell and Hoare being less radiogenic than the surface waters. The opposite occurs in Lake Bonney. The Lake Fryxell isotopic ratios are lower than modern-day ocean water and most of the whole-rock ratios of the surrounding geologic materials. A conceivable source of Sr to the system …

Inside Unlv, Diane Russell, Richard Jensen, Andy Grossman, Kevin Force

Inside UNLV

No abstract provided.

Effects Of Binary Combinations Of Herbicides On Freshwater Algae, Jill K. Taylor

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Inside Unlv, Betty Blodgett, Tom Flagg, Diane Russell

Inside UNLV

No abstract provided.

Movement Of Rainbow And Brown Trout In Relation To Water Quality And Food Availability In Lake Ogallala, Nebraska, Corey M. Huxoll

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Effects Of Woody Cover In The Landscaping On Riparian Avifauna And A Preliminary Nesting Assessment, Micah W. Perkins

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Movements And Habitat Use By Hatchery-Reared Pallid Sturgeon In The Lower Platte River, Nebraska, Vaughn A. Snook

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.

Seasonal Patterns Of Photosynthesis In Douglas Fir Seedlings During The Third And Fourth Year Of Exposure To Elevated Co2 And Temperature, James D. Lewis, Melissa S. Lucash, David M. Olszyk, David T. Tingey

Environmental Science and Management Faculty Publications and Presentations

The interactive effects of elevated atmospheric CO₂ and temperature on seasonal patterns of photosynthesis in Douglas fir (Psuedotsuga menziesii (Mirb.) Franco) seedlings were examined. Seedlings were grown in sunlit chambers controlled to track either ambient (~400 p.p.m.) CO₂ or ambient +200 p.p.m. CO₂, and either ambient temperature or ambient +4 °C. Light-saturated net photosynthetic rates were measured approximately monthly over a 21 month period. Elevated CO₂ increased net photosynthetic rates by an average of 21% across temperature treatments during both the 1996 hydrologic year, the third year of exposure, and the 1997 hydrologic year. Elevated …

Fluxnet: A New Tool To Study The Temporal And Spatial Variability Of Ecosystem-Scale Carbon Dioxide, Water Vapor, And Energy Flux Densities, Dennis Baldocchi, Eva Falge, Lianhong Gu, Richard Olson, David Hollinger, Steve Running, Peter Anthoni, Ch. Bernhofer, Kenneth Davis, Robert Evans, Jose Fuente, Allen Goldstein, Gabriel Katul, Beverly Law, Xuhui Lee, Yadvinder Malhi, Tilden Meyers, William Munge, Walt Oechel, K.T. Paw U, Kim Pilegaard, H.P. Schmid, Riccardo Valentini, Shashi Verma, Timo Vesala, Kell Wilson, Steve Wofsy

School of Natural Resources: Faculty Publications

FLUXNET is a global network of micrometeorological flux measurement sites that measure the exchanges of carbon dioxide, water vapor, and energy between the biosphere and atmosphere. At present over 140 sites are operating on a long-term and continuous basis. Vegetation under study includes temperate conifer and broadleaved (deciduous and evergreen) forests, tropical and boreal forests, crops, grasslands, chaparral, wetlands, and tundra. Sites exist on five continents and their latitudinal distribution ranges from 70°N to 30°S.

FLUXNET has several primary functions. First, it provides infrastructure for compiling, archiving, and distributing carbon, water, and energy flux measurement, and meteorological, plant, and soil …

Test Of An Extended Mathematical Approach To Calculate Maize Leaf Area Index And Leaf Angle Distribution, Elizabeth A. Walter-Shea, Mark A. Mesarch

School of Natural Resources: Faculty Publications

No abstract provided.

Evaluation Of An Algorithm For Predicting Albedo In Heliotropic Crops, Elizabeth A. Walter-Shea, A. Weiss

School of Natural Resources: Faculty Publications

No abstract provided.

Value Of Incorporating Satellite-Derived Land Cover Data In Mm5/Place For Simulating Surface Temperatures, Todd M. Crawford, David J. Stensrud, Franz Mora, James W. Merchant, Peter J. Wetzel

School of Natural Resources: Faculty Publications

The Parameterization for Land–Atmosphere–Cloud Exchange (PLACE) module is used within the Fifth- Generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5) to determine the importance of individual land surface parameters in simulating surface temperatures. Sensitivity tests indicate that soil moisture and the coverage and thickness of green vegetation [as manifested by the values of fractional green vegetation coverage (fVEG) and leaf area index (LAI)] have a large effect on the magnitudes of surface sensible heat fluxes. The combined influence of LAI and fVEG is larger than the influence of soil moisture on the partitioning of the surface energy …

Some Perspectives On Recent In Situ Air Temperature Observations: Modeling The Microclimate Inside The Radiation Shields*, X. Lin, Kenneth Hubbard, Elizabeth A. Walter-Shea, James Brandle, G.E. Meyer

School of Natural Resources: Faculty Publications

Air temperature measurement has inherent biases associated with the particular radiation shield and sensor deployed. The replacement of the Cotton Region Shelter (CRS) with the Maximum–Minimum Temperature System (MMTS) and the introduction of Automated Surface Observing System (ASOS) air temperature observing systems during the NWS modernization introduced bias shifts in federal networks that required quantification. In rapidly developing nonfederal networks, the Gill shield temperature systems are widely used. All of these systems house an air temperature sensor in a radiation shield to prevent radiation loading on the sensors; a side effect is that the air temperature entering a shield is …

Impacts Of Predation On Northern Bobwhite And Scaled Quail, Dale Rollins, John P. Carroll

School of Natural Resources: Faculty Publications

Northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) populations have declined throughout most of their distribution, and these declines have become more dramatic in recent years. In this review, we examine the role of predation in quail management. Predation is the major source of nest loss and of mortality for young and adult quail. Mean nest success across studies reviewed was 28%. Estimates of annual survival rates have varied from 5 to 26% for radiotelemetry studies and from 15 to 30% based on age-ratio studies. Breeding season survival estimates ranged from 13 to 51% in telemetry …

Bollgard Cotton: An Assessment Of Global Economic, Environmental, And Social Benefits, Julie M. Edge, John H. Benedict, John P. Carroll, H. Keith Reding

School of Natural Resources: Faculty Publications

Insect-protected crops like Bollgard (Monsanto Company, St. Louis) Bacillus thuringiensis (Bt) cotton are bringing cotton growers new alternatives to broad-spectrum insecticide use in integrated pest management. After five years (1996-2000) of commercial use, a number of benefits of Bt cotton technology to growers, the environment, and society at large have been reported; however, the benefits of the technology have not been examined to date from a holistic point of view. Accordingly, the objectives of this paper were to examine the potential economic, environmental, and social benefits of Bt cotton compared with broad-spectrum insecticide use, as reported in current literature, …

Estimating Abundance Of Galliformes: Tools And Application, Michael J. Conroy, John P. Carroll

School of Natural Resources: Faculty Publications

A large number of techniques are available for assessing populations of vertebrates. However, application of many of those techniques to Galliformes is hampered by a variety of constraints. These problems are often magnified by poor understanding of the biology of many species of concern, and an absence of valid estimates of abundance and demographic parameters. Researchers interested in developing estimates of Galliformes populations must address a number of key issues before collecting field data, to avoid biases in the resulting population estimates. General guidance exists for the identification of appropriate population estimation techniques, and a dichotomous key has been developed …

Ant–Seed Mutualisms: Can Red Imported Fire Ants Sour The Relationship?, Jennifer A. Zettler, Timothy P. Spira, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Invasion by the red imported fire ant, Solenopsis invicta, has had negative impacts on individual animal and plant species, but little is known about how S. invicta affects complex mutualistic relationships. In some eastern forests of North America, 30% of herbaceous species have ant-dispersed seeds. We conducted experiments to determine if fire ants are attracted to seeds of these plant species and assessed the amount of scarification or damage that results from handling by fire ants. Fire ants removed nearly 100% of seeds of the ant-dispersed plants Trillium undulatum, T. discolor, T. catesbaei, Viola rotundifolia, and Sanguinaria canadensis. …

The Spatial Distribution Of Diversity Between Disparate Taxa: Spatial Correspondence Between Mammals And Ants Across South Florida, Usa, Craig R. Allen, L. G. Pearlstine, D.P. Wojcik, W.M. Kitchens

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Gap Analysis takes a proactive landscape-level approach to conserving native species by identifying nodes of high biological diversity. It uses vertebrate species richness as an index of overall biological diversity. However, it remains unknownwhether or not the spatial distribution of vertebrate diversity correspondswith the diversity of other taxa. We tested whether landscape-level diversity patterns corresponded between a vertebrate and an invertebrate taxon, mammals and ants, across the southern half of the Florida peninsula, USA. Composite digital maps with a 30-m spatial resolution were produced for each taxon. Spatial correspondence between the taxa was determined by normalizing and then subtracting the …

Modeling Viable Mammal Populations In Gap Analyses, Craig R. Allen, L. G. Pearlstine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Gap analysis is an approach to conserving biological diversity that maps species richness and identifies sites that ought to be protected but are not in conservation networks. Gap analyses based on species richness may have high error rates when species models are based solely on species-habitat association, because patches too small to support populations are still considered to be potential habitat. We incorporated information on the home range and dispersal distances of the mammals of Florida to estimate minimum critical areas (MCA) to support minimum viable populations for each mammal species. Incorporating MCA decreases the area occupied by the highest …