Other Environmental Sciences Commons^™

Biodiversity Of Fungi In Red Imported Fire Ant (Hymenoptera: Formicidae) Mounds, Jennifer A. Zettler, Thomas M. Mcinnis Jr., Craig R. Allen, Timothy P. Spira

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The red imported fire ant, Solenopsis invicta Buren, became established in North America more than 70 yr ago, and it currently occupies most of the southeastern United States. Fire ants change the physical and chemical components of soil, which likely infuence soil fungi in ant mounds. To determine the effects of fire ants on soil fungi, we sampled soil from fire ant mounds and the surrounding nonmound soil. In addition, we sampled soil from the nests of the native ant Aphaenogaster texana carolinensis Wheeler. We found that both fire ant mounds and native ant nests had greater fungal abundance but …

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 …

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 …

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 …

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.

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 …

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 …

Effects Of Landsat 5 Thematic Mapper And Landsat 7 Enhanced Thematic Mapper Plus Radiometric And Geometric Calibrations And Corrections On Landscape Characterization, James E. Vogelmann, Dennis Helder, Ron Morfitt, Michael J. Choate, James W. Merchant, Henry Bulley

United States Geological Survey: Staff Publications

The Thematic Mapper (TM) instruments on board Landsats 4 and 5 provide high-quality imagery appropriate for many different applications, including land cover mapping, landscape ecology, and change detection. Precise calibration was considered to be critical to the success of the Landsat 7 mission and, thus, issues of calibration were given high priority during the development of the Enhanced Thematic Mapper Plus (ETM+). Data sets from the Landsat 5 TM are not routinely corrected for a number of radiometric and geometric artifacts, including memory effect, gain/bias, and interfocal plane misalignment. In the current investigation, the effects of correcting vs. not correcting …

Effects Of Fire Ants (Hymenoptera: Formicidae) On Hatching Turtles And Prevalence Of Fire Ants On Sea Turtle Nesting Beaches In Florida, Craig R. Allen, Elizabeth A. Forys, Kenneth G. Rice, Daniel P. Wojcik

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Red imported fire ants (Solenopsis invicta Buren) have increasingly been observed in loggerhead (Caretta caretta L.) and green (Chelonia mydas L.) sea turtle nests in Florida, and in the nests of freshwater turtles. They may be attracted to the disturbance, mucous and moisture associated with turtle nesting and establish foraging tunnels into turtle nests shortly after egg-laying, thus increasing the vulnerability of hatchlings to fire ant predation. We conducted experiments on a freshwater turtle (Pseudemys nelsoni Carr) to determine the potential impacts of S.invicta on turtle hatchlings. Over 70% of hatchlings were killed by S.invicta during …

The Non-Indigenous Ant, Solenopsis Invicta, Reduces Loggerhead Shrike And Native Insect Abundance, Craig R. Allen, R. Scott Lutz, Tim Lockley, Sherman A. Phillips Jr., Stephen Demarais

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The red imported fire ant (Solenopsis invicta Buren) is an aggressive, non-indigenous species that is a threat to native biota in the southeastern United States. We determined the effect of S. invicta on loggerhead shrike (Lanius ludovicianus L.) abundance and investigated a possible mechanism of impact, which is a reduction in insect prey availability. We used a fire ant bait (hydramethylnon) to reduce fire ant populations on one randomly chosen member of each of five pairs of 202-ha study areas in the Texas coastal Bend region, and also measured shrike relative abundance and a volumetric index of insect …

Potential Fire Ant (Hymenoptera: Formicidae) Impact On The Endangered Schaus Swallowtail (Lepidoptera: Papilionidae), Elizabeth A. Forys, Anna Quistorff, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The Schaus swallowtail, Papilio aristodemus ponceanus , historically occurred in tropical hardwood hammocks from South Miami to the upper Florida Keys and is currently listed as federally endangered. Much of the remaining hardwood hammock habitat is fragmented by roads and human development that may alter the microhabitat within the hammocks and increase the probability of invasion by non-native predators and competitors. One non-indigenous species that has recently invaded the Florida Keys, and that may impact the Schaus swallowtail is the red imported fire ant ( Solenopsis invicta Buren). We estimated abundance of red imported fire ants in Schaus swallowtail habitat …

Effects Of Fire Ants (Hymenoptera: Formicidae) On Hatching Turtles And Prevalence Of Fire Ants On Sea Turtle Nesting Beaches In Florida, Craig R. Allen, Elizabeth A. Forys, Kenneth G. Rice, Daniel P. Wojcik

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Red imported fire ants (Solenopsis invicta Buren) have increasingly been observed in loggerhead (Caretta caretta L.) and green (Chelonia mydas L.) sea turtle nests in Florida, and in the nests of freshwater turtles. They may be attracted to the disturbance, mucous and moisture associated with turtle nesting and establish foraging tunnels into turtle nests shortly after egg-laying, thus increasing the vulnerability of hatchlings to fire ant predation. We conducted experiments on a freshwater turtle (Pseudemys nelsoni Carr) to determine the potential impacts of S.invicta on turtle hatchlings. Over 70% of hatchlings were killed by S.invicta during …

The Likely Cause Of Extinction Of The Tree Snail Orthalicus Reses Reses (Say), E.A. Forys, A. Quistorff, Craig R. Allen, D.P. Wojcik

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The Stock Island tree snail, Orthalicus reses reses, went extinct in its native range in the Florida Keys in 1992. Fortunately, O. r. reses has been introduced elsewhere and further reintroductions are currently planned. Before these reintroductions are implemented, it is important to try and determine which factors were most likely to have caused the decline and extinction. While habitat destruction was probably the ultimate reason why there were so few tree snails, it is likely that an interaction of habitat fragmentation and the invasion of an exotic predator caused the final decline that lead to the extinction in …

Red Imported Fire Ants: Impact On Biodiversity, Daniel P. Wojcik, Craig R. Allen, Richard J. Brenner, Elizabeth A. Forys, Donald P. Jouvenaz, R. Scott Lutz

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

The red imported fire ant, Solenopsis invicta Buren (hereafter referred to as imported fire ant), long considered a regional problem, is receiving renewed attention nationwide, with infestations found in Arizona, Maryland, Nevada, New Mexico, and Virginia (Mitchell 1996). Recently, infestations discovered in several regions of California caused great public concern (Brennan 1999, Schrader 1999). Initially, infestations appeared to be isolated in almond groves in Kern County; presumably these infestations originated from bee hives transported interstate for the purpose of pollinating crops. Separately, ornamental plants arriving in Las Vegas, NV, were infested with fire ants, and records showed that the point …

Nonlethal Methods Of Examining Fish Stomach Contents, Jan F. Kamler, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Several nonlethal methods have been developed to determine the stomach contents of fish, including gastroscopes, tubes, stomach suction, stomach flushing, emetics, forceps, and chronic fistulas. By reviewing the literature on this subject, we found that the effectiveness (ability to remove all stomach contents) of the different methods depends on size, age, species of fish, and the size of the food items in the stomach. Overall, various methods of stomach flushing were the most effective method of recovering stomach items from a variety of fishes. Mechanized pressure appeared to be the most efficient method of stomach flushing for most large fishes. …