Digital Commons Network^™

Swift Foxes And Ideal Free Distribution: Relative Influence Of Vegetation And Rodent Prey Base On Swift Fox Survival, Density, And Home Range Size, Craig M. Thompson, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

Swift foxes (Vulpes velox) are an endemic mesocarnivore of North America subject to resource and predation-based pressures. While swift fox demographics have been documented, there is little information on the importance of top-down versus bottom-up pressures or the effect of landscape heterogeneity. Using a consumable resource-based ideal free distribution model as a conceptual framework, we isolated the effects of resource-based habitat selection on fox population ecology. We hypothesized if swift fox ecology is predominantly resource dependent, distribution, survival, and space use would match predictions made under ideal free distribution theory. We monitored survival and home range use of …

U.S. Department Of Agriculture Wildlife Services: Providing Federal Leadership In Managing Conflicts With Wildlife, Mark E. Tobin

United States Department of Agriculture Wildlife Services: Staff Publications

The Wildlife Services Program (WS) of the U.S. Department of Agriculture, Animal and Plant Health Inspection Service, provides federal leadership in managing conflicts between wildlife and humans. The core vision of WS is to improve the coexistence of wildlife and people. The Animal Damage Control Act of 1931 and subsequent amendments provide broad authority for WS to conduct activities involving the control of nuisance mammals and birds and those mammal and bird species that are reservoirs for zoonotic diseases. Resources protected include agriculture and natural resources, human health and safety, property, and threatened and endangered species. WS strives to develop …

Rabies In North America: A Model Of The One Health Approach, Kurt C. Vercauteren, Christine Ellis, Richard Chipman, Thomas J. Deliberto, Stephanie A. Shwiff, Dennis Slate

United States Department of Agriculture Wildlife Services: Staff Publications

The One Health concept merges environmental, wildlife, domestic animal, and human health into a global, interconnected context. Though recently a popular catchphrase due to the emergence and reemergence of diseases such as foot-and-mouth disease (FMD), bluetongue, bovine spongiform encephalopathy (BSE), Q Fever, Rift Valley fever, Nipah virus, West Nile virus (WNV), severe acute respiratory syndrome (SARS), highly pathogenic H5N1 avian influenza, and plague, the One Health concept is not new. The One Health approach to managing infectious diseases aims to promote and implement meaningful collaboration and communication between multiple allied disciplines working locally, nationally, and internationally to attain optimal health …

On-Farmmitigation Of Transmission Of Tuberculosis Fromwhite-Tailed Deer To Cattle: Literature Review And Recommendations, W. David Walter, Charles W. Anderson, Rick Smith, Mike Vanderklok, James J. Averill, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

The Animal Industry Division of the Michigan Department of Agriculture and Rural Development (MDARD) has been challenged with assisting farmers with modifying farm practices to reduce potential for exposure to Mycobacterium bovis from wildlife to cattle. The MDARD recommendations for on-farm risk mitigation practices were developed from experiences in the US, UK and Ireland and a review of the scientific literature. The objectives of our study were to review the present state of knowledge on M. bovis excretion, transmission, and survival in the environment and the interactions of wildlife and cattle with the intention of determining if the current recommendations …

Historical And Current Status Of Laughing Gulls Breeding In New York State, Brian E. Washburn, Martin S. Lowney, Allen L. Gosser

United States Department of Agriculture Wildlife Services: Staff Publications

The Laughing Gull (Leucophaeus atricilla) was extirpated as a breeding bird from New York State by 1900. Recolonization of coastal New York by this colonial waterbird occurred in 1979 with discovery of 15 breeding pairs in Jamaica Bay (Queens County) New York, New York. We conducted a survey of Long Island salt marsh habitats in 2008 to document if other breeding colonies of Laughing Gulls existed. We identified 66 individual possible breeding areas and field surveys were conducted in each area during June 2008. Many areas appeared to provide suitable nesting habitat (i.e., large areas of salt marsh …

Invasive Rodents In The United States: Ecology, Impacts, And Management, Gary W. Witmer, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

Many invasive rodents have become established in the United States and its territories. The species include several species of Rattus, house mice (Mus musculus), Gambian giant pouched rats (Cricetomys gambianus), ground squirrels (Spermophilus parryii), nutria (Myocastor coypus) and marmots (Marmota caligata). While most were introduced accidently, some were introduced for food or fur. Additionally, some native species of rodents have been placed on islands, at least on a temporary basis, to study rodent species interactions. These rodents have caused serious impacts to native flora and fauna, agriculture, and other …

Eradication Of Invasive Rodents On Islands Of The United States, Gary W. Witmer

United States Department of Agriculture Wildlife Services: Staff Publications

Many invasive rodents have become established in the United States and its territories. The list of invasive species includes several species of rats (Rattus spp.), house mice (Mus musculus), nutria (Myocastor coypus), Gambian giant pouched rats (Cricetomys gambianus), arctic ground squirrels (Spermophilus undulates), hoary marmots (Marmota caligata), voles (Microtus spp.), and deer mice (Peromyscus spp.). Some were introduced inadvertently (e.g., stowaways on ships or in cargo) while others were introduced purposefully (e.g., for the fur industry). Other less common reasons include rodents being put on islands as …

Vertebrate Species Introductions In The United States And Its Territories, Gary W. Witmer, Pam Fuller

United States Department of Agriculture Wildlife Services: Staff Publications

Thousands of species of plants and animals have been introduced to various parts of the world (Pimental 2011). Greatly increased levels of travel and international trade have been, in large part, responsible, but many pathways of introduction are involved and these vary by taxonomic group. Much concern, action, and funding has been directed towards invasive pathogens, insects, and plants because of the threat to agriculture and livestock production. However, a very large number of vertebrates have also been introduced with some causing substantial damage and losses to human and natural resources.

Estimates Of Energy And Prey Requirements Of Wolverines, Julie K. Young, Brian Hudgens, David K. Garcelon

United States Department of Agriculture Wildlife Services: Staff Publications

Wolverine (Gulo gulo) populations have decreased throughout much of their North American range and there is interest in establishing recovery programs in the Sierra Nevada of California and the Rocky Mountains of Colorado. Determining the sufficiency of prey resources is an important consideration for initiating wolverine recovery, yet there are limited data on resource availability and needs. Our goal is to estimate prey requirements based on wolverine caloric needs and the caloric content of prey likely to be available. We achieve this goal by modifying existing models to account for wolverine biology. Models show a male wolverine requires …

Cow Dogs: Use Of Livestock Protection Dogs For Reducing Predation And Transmission Of Pathogens From Wildlife To Cattle, Kurt C. Vercauteren, Michael J. Lavelle, Thomas M. Gehring, Jean-Marc Landry

United States Department of Agriculture Wildlife Services: Staff Publications

Dogs have been employed to protect an array of resources from various species of offending wildlife. Historically, livestock protection dogs (LPDs) protected domestic sheep and goats from predators based on development of a strong bond between protected and protector. Within reason, developing that bond between a LPD and other species of livestock should be achievable. We conducted several studies in which we raised and bonded LPDs with bovine calves and evaluated them for protecting cattle in a variety of settings. Though successful strategies in developing LPDs to protect cattle were similar to those established for sheep, we found differences that …

A Mutagenesis-Derived Broad-Spectrum Disease Resistance Locus In Wheat, Jackie Campbell, Hongtao Zhang, Michael J. Giroux, Leila Feiz, Yue Jin, Meinan Wang, Xianming Chen, Li Huang

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. Breeding durable disease resistance cultivars rely largely on continually introgressing new resistance genes, especially the genes with different defense mechanisms, into adapted varieties. Here, we describe a new resistance gene obtained by mutagenesis. The mutant, MNR220 (mutagenesis-derived new resistance), enhances resistance to three rusts and powdery mildew, with the characteristics of delayed disease …

The Relationship Between Variable Host Grouping And Functional Responses Among Parasitoids Of Antispila Nysaefoliella (Lepidoptera: Heliozelidae), Candace Low, Sonja J. Scheffer, Matthew L. Lewis, Michael W. Gates

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Our study investigated the importance of variability in the parasitoid community as a source of selection on host group size using a field population of the tupelo leafminer, Antispila nysaefoliella Clemens, which specializes on tupelo, Nyssa sylvatica Marsh. Larvae were collected from leaves with variable numbers of larvae and screened for parasitism using polymerase chain reaction of mitochondrial cytochrome oxidase I using markers designed specifically for amplifying parasitoid DNA while excluding host DNA. This method of selective PCR was effective for detecting the presence and identifying species of immature stages of three hymenopteran superfamilies: Chalcidoidea, Ichneumonoidea and Platygastroidea, which represented …

Metabolic Engineering Of Novel Lignin In Biomass Crops, Ruben Vanholme, Kris Morreel, Chiarina Darrah, Paula Oyarce, John H. Grabber, John Ralph, Wout Boerjan

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Lignin, a phenolic polymer in the secondary wall, is the major cause of lignocellulosic biomass recalcitrance to efficient industrial processing. From an applications perspective, it is desirable that second-generation bioenergy crops have lignin that is readily degraded by chemical pretreatments but still fulfill its biological role in plants. Because plants can tolerate large variations in lignin composition, often without apparent adverse effects, substitution of some fraction of the traditional monolignols by alternative monomers through genetic engineering is a promising strategy to tailor lignin in bioenergy crops. However, successful engineering of lignin incorporating alternative monomers requires knowledge about phenolic metabolism in …

Genetic Population Substructure In Bison At Yellowstone National Park, Natalie D. Halbert, Peter J. P. Gogan, Philip W. Hedrick, Jacquelyn M. Wahl, James N. Derr

United States Geological Survey: Staff Publications

The Yellowstone National Park bison herd is 1 of only 2 populations known to have continually persisted on their current landscape since pre-Columbian times. Over the last century, the census size of this herd has fluctuated from around 100 individuals to over 3000 animals. Previous studies involving radiotelemetry, tooth wear, and parturition timing provide evidence of at least 2 distinct groups of bison within Yellowstone National Park. To better understand the biology of Yellowstone bison, we investigated the potential for limited gene flow across this population using multilocus Bayesian clustering analysis. Two genetically distinct and clearly defined subpopulations were identified …

Effects Of Biotic Disturbances On Forest Carbon Cycling In The United States And Canada, Jeffrey A. Hicke, Craig D. Allen, Ankur R. Desai, Michael C. Dietze, Ronald J. Hall, Edward (Ted) H. Hogg, Daniel M. Kashian, David Moore, Kenneth F. Raffa, Rona N. Sturrock, James Vogelmann

United States Geological Survey: Staff Publications

Forest insects and pathogens are major disturbance agents that have affected millions of hectares in North America in recent decades, implying significant impacts to the carbon (C) cycle. Here, we review and synthesize published studies of the effects of biotic disturbances on forest C cycling in the United States and Canada. Primary productivity in stands was reduced, sometimes considerably, immediately following insect or pathogen attack. After repeated growth reductions caused by some insects or pathogens or a single infestation by some bark beetle species, tree mortality occurred, altering productivity and decomposition. In the years following disturbance, primary productivity in some …

Landscape Controls On The Timing Of Spring, Autumn, And Growing Season Length In Mid-Atlantic Forests, Andrew J. Elmore, Steven M. Guinn, Burke J. Minsley, Andrew Richardson

United States Geological Survey: Staff Publications

The timing of spring leaf development, trajectories of summer leaf area, and the timing of autumn senescence have profound impacts to the water, carbon, and energy balance of ecosystems, and are likely influenced by global climate change. Limited field-based and remote-sensing observations have suggested complex spatial patterns related to geographic features that influence climate. However, much of this variability occurs at spatial scales that inhibit a detailed understanding of even the dominant drivers. Recognizing these limitations, we used nonlinear inverse modeling of medium-resolution remote sensing data, organized by day of year, to explore the influence of climate-related landscape factors on …

Long-Term Effects Of The ‘Exxon Valdez’ Oil Spill: Sea Otter Foraging In The Intertidal As A Pathway Of Exposure To Lingering Oil, James L. Bodkin, Brenda E. Ballachey, Heather A. Coletti, George G. Esslinger, Kimberly A. Kloecker, Stanley D. Rice, John A. Reed, Daniel H. Monson

United States Geological Survey: Staff Publications

The protracted recovery of some bird and mammal populations in western Prince William Sound (WPWS), Alaska, and the persistence of spilled ‘Exxon Valdez’ oil in intertidal sediments, suggests a pathway of exposure to consumers that occupy nearshore habitats. To evaluate the hypothesis that sea otter (Enhydra lutris) foraging allows access to lingering oil, we contrast spatial relations between foraging behavior and documented oil distribution. We recovered archival time-depth recorders implanted in 19 sea otters in WPWS, where lingering oil and de - layed ecosystem recovery are well documented. Sea otter foraging dives ranged from +2.7 to −92 m …

Gene Transcription In Sea Otters (Enhydra Lutris); Development Of A Diagnostic Tool For Sea Otter And Ecosystem Health, Lizabeth Bowen, A. Keith Miles, Michael Murray, Martin Haulena, Judy Tuttle, William Van Bonn, Lance Adams, James L. Bodkin, Brenda Ballachey, James A. Estes, M. Tim Tinker, Robin Keister, Jeffrey L. Stott

United States Geological Survey: Staff Publications

Gene transcription analysis for diagnosing or monitoring wildlife health requires the ability to distinguish pathophysiological change from natural variation. Herein, we describe methodology for the development of quantitative real-time polymerase chain reaction (qPCR) assays to measure differential transcript levels of multiple immune function genes in the sea otter (Enhydra lutris); sea otter-specific qPCR primer sequences for the genes of interest are defined. We establish a ‘reference’ range of transcripts for each gene in a group of clinically healthy captive and free-ranging sea otters. The 10 genes of interest represent multiple physiological systems that play a role in immuno-modulation, …

Preliminary Assessment Of The Hoghopper™ For Excluding Non-Target Wildlife, Tyler A. Campbell, Michael J. Bodenchuk, John D. Eisemann, Steven J. Lapidge, Linton Staples, Phil Morrow

United States Department of Agriculture Wildlife Services: Staff Publications

Feral swine populations are expanding throughout the U.S., where they are causing increasing amounts of damage to agriculture, natural resources, and property and threaten human health and safety. Methods to control feral swine damage in the U.S. consist of integrated fencing, trapping, snaring, and shooting (including hunting with dogs) efforts. New methods that are being developed to control feral swine damage include toxicants and fertility control agents. For these emerging technologies to be effective at the population level, they must function through oral routes of delivery. Concurrent to the development of orallydelivered actives, a cost-effective system that delivers biologics to …

Rats! Foiled Again: A History Of Rodent Control Methods Development At The National Wildlife Research Center, Kathleen A. Fagerstone, Michael W. Fall, Gary W. Witmer, William C. Pitt

United States Department of Agriculture Wildlife Services: Staff Publications

The National Wildlife Research Center (NWRC) and its predecessor laboratories have a long history of developing materials and methods for managing rodents and the damage they cause. The NWRC has been influential in exploring, developing, and maintaining legal uses of many traditional field rodenticides such as strychnine and zinc phosphide. Products have been developed for managing rodents in a variety of locales, and for managing a variety of species, from commensal rodents in urban areas, to pocket gophers and mountain beaver in forests, prairie dogs and ground squirrels on rangelands, and nutria and beaver in wetlands. Considerable research has also …

Grizzly Bear Population Vital Rates And Trend In The Northern Continental Divide Ecosystem, Montana, Richard D. Mace, Daniel W. Carney, Tonya Chilton-Radandt, Stacy A. Courville, Mark A. Haroldson, Richard B. Harris, James Jonkel, Bruce Mclellan, Michael Madel, Timothy Manley, Charles Schwartz, Christopher Servheen, Gordon Stenhouse, John S. Waller, Erik Wenum

United States Geological Survey: Staff Publications

We estimated grizzly bear (Ursus arctos) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio-collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892– 0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters …

Reconciling Estimates Of The Contemporary North American Carbon Balance Among Terrestrial Biosphere Models, Atmospheric Inversions, And A New Approach For Estimating Net Ecosystem Exchange From Inventory-Based Data, Daniel J. Hayes, David P. Turner, Graham Stinson, A. David Mcguire, Yaxing Wei, Tristram O. West, Linda S. Heath, Bernardus Dejong, Brian G. Mcconkey, Richard A. Birdsey, Werner A. Kurz, Andrew R. Jacobson, Deborah N. Huntzinger, Yude Pan, W. Mac Post, Robert B. Cook

United States Geological Survey: Staff Publications

We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000–2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks of CO₂, while accounting for lateral transfers of forest and crop products as well as their eventual emissions. The total NEE estimate of a -327 ± 252 TgC yr ^-1 sink for NA was driven primarily by CO₂ uptake in the Forest Lands sector (-248 TgC yr …

Long-Term Impacts Of Invasive Species On A Native Top Predator In A Large Lake System, Scott A. Rush, Gordon Paterson, Tim B. Johnson, Ken G. Drouillard, Gordon D. Haffner, Craig E. Hebert, Michael T. Arts, Daryl J. Mcgoldric, Sean M. Backus, Brian F. Lantry, Jana R. Lantry, Ted Schaner, Aaron T. Fisk

United States Geological Survey: Staff Publications

1. Declining abundances of forage fish and the introduction and establishment of non-indigenous species have the potential to substantially alter resource and habitat exploitation by top predators in large lakes.

2. We measured stable isotopes of carbon (δ¹³C) and nitrogen (δ¹⁵N) in field-collected and archived samples of Lake Ontario lake trout (Salvelinus namaycush) and five species of prey fish and compared current trophic relationships of this top predator with historical samples.

3. Relationships between δ¹⁵N and lake trout age were temporally consistent throughout Lake Ontario and confirmed the role of lake trout …

Lake Sturgeon Population Attributes And Reproductive Structure In The Namakan Reservoir, Minnesota And Ontario, S. L. Shaw, S. R. Chipps, Steve K. Windels, M. A. H. Webb, Darryl T. Mcleod, D. W. Willis

United States Geological Survey: Staff Publications

Quantified were the age, growth, mortality and reproductive structure of lake sturgeon (Acipenser fulvescens) collected in the US and Canadian waters of the Namakan Reservoir. The hypotheses were tested that (i) age and growth of lake sturgeon in the Namakan Reservoir would differ by sex and reproductive stage of maturity, and (ii) that the relative strength of year classes of lake sturgeon in the reservoir would be affected by environmental variables. To quantify age, growth and mortality of the population, existing data was used from a multiagency database containing information on all lake sturgeon sampled in the reservoir …

Hybridization Among Arctic White-Headed Gulls (Larus Spp.) Obscures The Genetic Legacy Of The Pleistocene, Sarah A. Sonsthagen, R. Terry Chesser, Douglas A. Bell, Carla J. Dove

United States Geological Survey: Staff Publications

We studied the influence of glacial oscillations on the genetic structure of seven species of white-headed gull that breed at high latitudes (Larus argentatus, L. canus, L. glaucescens, L. glaucoides, L. hyperboreus, L. schistisagus, and L. thayeri). We evaluated localities hypothesized as ice-free areas or glacial refugia in other Arctic vertebrates using molecular data from 11 microsatellite loci, mitochondrial DNA (mtDNA) control region, and six nuclear introns for 32 populations across the Holarctic. Moderate levels of genetic structure were observed for microsatellites (F_ST = 0.129), introns (Φ_ST = 0.185), and mtDNA control region (Φ …

Identifying Grasslands Suitable For Cellulosic Feedstock Crops In The Greater Platte River Basin: Dynamic Modeling Of Ecosystem Performance With 250 M Emodis, Yingxin Gu, Stephen P. Boyte, Bruce K. Wylie, Larry L. Tieszen

United States Geological Survey: Staff Publications

This study dynamically monitors ecosystem performance (EP) to identify grasslands potentially suitable for cellulosic feedstock crops (e.g., switchgrass) within the Greater Platte River Basin (GPRB). We computed grassland site potential and EP anomalies using 9-year (2000–2008) time series of 250 m expedited moderate resolution imaging spectro-radiometer Normalized Difference Vegetation Index data, geophysical and biophysical data, weather and climate data, and EP models. We hypothesize that areas with fairly consistent high grassland productivity (i.e., high grassland site potential) in fair to good range condition (i.e., persistent ecosystem over performance or normal performance, indicating a lack of severe ecological disturbance) are potentially …

Simulated Effects Of Host Fish Distribution On Juvenile Unionid Mussel Dispersal In A Large River, J. A. Daraio, L. J. Weber, Steven J. Zigler, Teresa J. Newton, John M. Nestler

United States Geological Survey: Staff Publications

Larval mussels (Family Unionidae) are obligate parasites on fish, and after excystment from their host, as juveniles, they are transported with flow. We know relatively little about the mechanisms that affect dispersal and subsequent settlement of juvenile mussels in large rivers. We used a three-dimensional hydrodynamic model of a reach of the Upper Mississippi River with stochastic Lagrangian particle tracking to simulate juvenile dispersal. Sensitivity analyses were used to determine the importance of excystment location in two-dimensional space (lateral and longitudinal) and to assess the effects of vertical location (depth in the water column) on dispersal distances and juvenile settling …

Genetic Measures Confirm Familial Relationships And Strengthen Study Design, Stacie J. Robinson, Ryan D. Walrath, Timonthy R. Vandeelen, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Social structure and behavioral interactions between individuals shape basic biological processes, such as breeding; foraging and predator avoidance; movement and dispersal; and disease transmission. We used a targeted trapping strategy to capture kin groups of white-tailed deer (Odocoileus virginianus) during 2007 and 2008 in Sandhill Wildlife Research Area, Wisconsin, USA, in order to observe social behaviors. Because inferring family relationships from observation of behavior is subjective, we usedmeasures of genetic relatedness and parentage assignment tests to determine that our capture strategy was efficient for capturing related pairs (78% of groups contained 1 dyad of related animals). The results of …

Nwrc Chemical Effects Database – What’S Old Is New Again, Jeannette R. O'Hare, John D. Eisemann, Walter A. Bowles Jr., Edward W. Schafer Jr., Kathleen A. Fagerstone

United States Department of Agriculture Wildlife Services: Staff Publications

The United States Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services (USDA APHIS WS), National Wildlife Research Center (NWRC) “Chemical Effects Database” is an internet-accessible and searchable database that contains bioassay data records for chemicals evaluated for repellency, toxicity, reproductive inhibition, and immobilization of higher vertebrates, and phytotoxicity. These data are of value for environmental risk assessment, conduct of toxicology studies, and the development of safe, effective, and responsible tools to manage vertebrate pest species that cause damage. Chemical screening studies were conducted from 1943 to 1987 by predecessors of the NWRC, and by the U.S. Geological …

Identifying Potential Areas For Biofuel Production And Evaluating The Environmental Effects: A Case Study Of The James River Basin In The Midwestern United States, Yiping Wu, Shuguang Liu, Zhengpeng Li

United States Geological Survey: Staff Publications

Biofuels are now an important resource in the United States because of the Energy Independence and Security Act of 2007. Both increased corn growth for ethanol production and perennial dedicated energy crop growth for cellulosic feedstocks are potential sources to meet the rising demand for biofuels. However, these measures may cause adverse environmental consequences that are not yet fully understood. This study 1) evaluates the long-term impacts of increased frequency of corn in the crop rotation system on water quantity and quality as well as soil fertility in the James River Basin and 2) identifies potential grasslands for cultivating bioenergy …