Statewide Scale Research Articles

Integrated modeling environment for statewide assessment of groundwater vulnerability from pesticide use in agriculture.

Atrazine, a herbicide widely used for corn production in the Midwest, has been detected in groundwater of several states, and has been identified as a possible human carcinogen. With the widespread use of pesticides in crop production, and the frequent detection of these chemicals in groundwater, large-scale risk assessments would help water resource managers to identify areas that are more susceptible to contamination and implement practices to ameliorate the problem. This paper presents an integrated, visual and interactive system for predicting potential environmental risks associated with pesticide contamination at spatial scales ranging from fields to landscapes and regions. The interactive system extends the predictive ability of the Pesticide Root Zone Model Release 2.0 (PRZM-2) to a landscape and statewide scale through integration with a geographic information system (GIS), graphical user interface and environmental databases. Predictions of statewide (Iowa) vulnerability of groundwater from atrazine leaching below the unsaturated zone were made to demonstrate the utility of the system, and the results were used in risk assessment. In the example application, atrazine fate and transport were evaluated using long-term climatic data (1980--1989) in combination with several environmental databases (eg STATSGO soils database) and exposure risks were expressed in terms of the probability of the predicted pesticide concentrations exceeding the maximum contaminant level (MCL) for drinking water. The results indicate that the predicted pesticide concentrations were significantly lower than the EPA-established MCL. In addition to providing an interactive environment for landscape-level assessment of potential risks from pesticide leaching, the system significantly reduces the time and resources needed to organize and manipulate data for use with PRZM-2, and provides an analytical framework for evaluating groundwater-leaching impacts of pesticide management practices.

CATASTROPHIC DECLINE OF A HIGH-DENSITY POPULATION OF HISPID COTTON RATS (SIGMODON HISPIDUS) IN CENTRAL OKLAHOMA

Along the northern periphery of their range, populations of the hispid cotton rat, Sigmodon hispidus, are vulnerable to major reductions in density and occasional local extinctions as a result of severe winter weather. Between our sampling periods on 3 December 2000 and 14 January 2001, 3 independent winter weather events, in conjunction with the coldest month in the state since 1983, affected central and eastern Oklahoma. We recorded a drastic decline in the population of hispid cotton rats at the Center for Subsurface and Ecological Assessment Research in central Oklahoma following these winter weather events. Densities dropped from 58.6 cotton rats/ha on 3 December 2000 to 1.2 cotton rats/ha on 14 January 2001. Although hispid cotton rat densities were declining before these winter weather events occurred, we attributed the dramatic decrease to severe winter weather and below-normal temperatures. As of 19 November 2001, the population of hispid cotton rats at the site had not recovered. Abundances between January and November 2001 ranged from 0.6 to 2.6 cotton rats/ha compared with a range of 30.1 to 112.5 during the same period in 2000. Additionally, we present evidence of populations of hispid cotton rats being affected at a statewide scale as a result of the weather in December 2000. We suspect that severe winters, such as the events described, might slow the northward advance of hispid cotton rats and serve to indirectly regulate populations along the intermediate and northern fringes of its range.

Comparison of Detection Probability Associated with Burrowing Owl Survey Methods

Populations of western burrowing owls (Athene cunicularia hypugaea) appear to have declined in many portions of their range. A standardized survey and monitoring program is not available to quantify changes in abundance or distribution. Before a standardized survey method is selected for long-term, continent-wide burrowing owl monitoring, potential survey protocols should be rigorously tested. We evaluated 3 potential burrowing owl survey methods: line transect, roadside point-count, and driving surveys. We also examined the effectiveness of using call-broadcasts on point-count surveys to increase detection probability. We conducted 3 replicate borrowing owl surveys (either point-count or driving surveys) along 1,350 km of roads (114 survey routes) in eastern Wyoming, USA, between June and August 2000. Detection probability varied among observers for both point-count and driving surveys. Detection probability was higher on point-count, surveys (x = 64.3%) compared to driving surveys (x = 37.5%), and point-count surveys sampled a larger effective area away from the road. Walking line-transect surveys proved ineffective and inefficient for monitoring burrowing owls at large (statewide) scales. Nest-site detection probability was 47% during driving detection trials and 79% during point-count detection trials. We detected over twice as manly owls per unit distance on our point-count routes (0.038 owls/km) compared to our driving routes (0.016 owls/km), but detected more owls per unit time on our driving routes (0.339 owls/hr vs. 0.229 owls/hr on point-count routes). We detected 22% more owls using call-broadcast even though all of our detections on pointcount surveys were visual rather that aural. Estimates of breeding density were fairly similar based on our driving and point-count surveys (0.110 and 0.074 nest sites/km 2 , respectively). Standardized point-counts using call-broadcast along roadsides offer the best approach for monitoring population trends of burrowing owls at large (statewide) spatial scales. Based on our results, we developed a standardized survey protocol for monitoring burrowing owls at large spatial scales. Implementation of these monitoring protocols would provide more precise estimates of population trends of burrowing owls in North America.

Geological Controls on the Distribution and Origin of Selected Inorganic Ions in Ohio Groundwater

Contour maps showing the concentration of selected inorganic ions across the state of Ohio illustrate that high concentrations of some ions visually correlate with the location of major geologic features, whereas other ions are randomly distributed. Strontium and sulfate have high concentrations over the Cincinnati, Findlay, and Kankakee arches, where carbonate aquifers containing gypsum and celestite are located. The highest concentrations of potassium and beryllium are located along the Cambridge fault zone, a major structural feature in eastern Ohio. High concentrations of iron and nitrate are found adjacent to single wells. Nitrate highs may be related to anthropogenic contamination, whereas some iron anomalies are located where sulfate is high. The maps produced in this study indicate that statewide contour maps of ion concentrations are useful for correlating aquifer chemistry with the regional geology of an area and determining the background level of ions on a state-wide scale.

Estimating down deadwood from FIA forest inventory variables in Maine

Down deadwood (DDW) is a carbon component important in the function and structure of forest ecosystems, but estimating DDW is problematic because these data are not widely available in forest inventory databases. However, DDW data were collected on USDA Forest Service Forest Inventory and Analysis (FIA) plots during Maine's 1995 inventory. This study examines ways to predict DDW biomass from other FIA variables so that DDW could be estimated without tedious measurement. Our results include a regression model that predicts DDW as a function of stand size class, basal area of dead and cut trees, and dummy variables for forest type and forest industry ownership. We also found DDW similar to FIA's standing-tree mortality at a statewide scale.

The First Step for the Environmental Management of Australian Beaches: Establishing an Effective Policy Framework

Beach management and coastal management are interwoven and scale-dependent activities in Australia. Present coastal policies are broad and designed for large, national, and statewide scales. They specify ecologically sustainable development as the overarching goal for coastal management and provide the context for beach management. On smaller scales, an approach focusing on the reduction of geomorphic hazards as the basis of beach management was established by the Coastline Hazard Policy, with nonhazard aspects of beach management such as ecological, economic, and social concerns assuming secondary importance. Although beach management can occur effectively under these coastal management arrangements, better guidance is required to make this process as effective and efficient as possible. This guidance - the policy framework - could be better developed for beach management and better integrated with existing coastal management arrangements. While this policy development is not strictly necessary to achieve positive outcomes from beach management, it is necessary to effectively guide implementation of the existing broad coastal policies. Effective goals for beach management are yet to be thought out and clearly articulated in Australia. A good start would be to couple the present goals of ecologically sustainable development and hazards reduction into a coherent goal for beach management. A specific policy for beaches should be developed given the importance of beaches in Australia.

CHARACTERIZING FISH COMMUNITY DIVERSITY ACROSS VIRGINIA LANDSCAPES: PREREQUISITE FOR CONSERVATION

The number of community types occurring within landscapes is an important, but often unprotected, component of biological diversity. Generally applicable protocols for characterizing community diversity need to be developed to facilitate conservation. We used several multivariate techniques to analyze geographic variation in the composition of fish communities in Virginia streams. We examined relationships between community composition and six landscape variables: drainage basin, physiography, stream order, elevation, channel slope, and map coordinates. We compared patterns at two scales (statewide and subdrainage-specific) to assess sensitivity of community classification to spatial scale. We also compared patterns based on characterizing communities by species composition vs. ecological composition. All landscape variables explained significant proportions of the variance in community composition. Statewide, they explained 32% of the variance in species composition and 48% of the variance in ecological composition. Typical communities in each drainage or physiography were statistically distinctive. Communities in different combinations of drainage, physiography, and stream size were even more distinctive, but composition was strongly spatially autocorrelated. Ecological similarity and species similarity of community pairs were strongly related, but replacement by ecologically similar species was common among drainage–physiography combinations. Landscape variables explained significant proportions of variance in community composition within selected subdrainages, but proportions were less than at the statewide scale, and the explanatory power of individual variables varied considerably among subdrainages. Community variation within subdrainages appeared to be much more closely related to environmental variation than to replacement among ecologically similar species. Our results suggest that taxonomic and ecological characterizations of community composition are complementary; both are useful in a conservation context. Landscape features such as drainage, physiography, and water body size generally may provide a basis for assessing aquatic community diversity, especially in regions where the biota is poorly known. Systematic conservation of community types would be a major advance relative to most current conservation programs, which typically focus narrowly on populations of imperiled species. More effective conservation of aquatic biodiversity will require new approaches that recognize the value of both species and assemblages, and that emphasize protection of key landscape-scale processes.

Plant-pest interactions in time and space: A Douglas-fir bark beetle outbreak as a case study

A conceptual model of Douglas-fir bark beetle (Dendroctonus pseudotsugae) dynamics and associated host tree mortality across multiple spatial and temporal scales was developed, then used to guide a study of the association between the occurrence of beetle- killed trees and factors that might render trees more susceptible to attack. Long-term records of beetle kill showed that beetle epidemics were associated with windstorms and drought at statewide and local spatial scales. At the landscape scale, beetle kill was associated with (i) portions of the landscape that were potentially drier (southern aspects, lower elevations) and (ii) portions of the landscape that had more mature and old-growth conifer vegetation. The patches of beetle-killed trees were aggregated with respect to other patches at scales of approximately 1 and 4 km. At the scale of the individual tree, there was not a strong relationship between beetle kill and resistance to attack measured by tree growth rate prior to attack. Our results show that landscape-scale phenomena and temporal patterns were more strongly correlated with beetle-kill events than was recent growth history at the scale of individual trees. We suggest that the multi-scale approach we employed is useful for elucidating the relative roles of fine- versus coarse-scale constraints on ecological processes.

The provision of services for rural youth with serious emotional and behavioral problems: Virginia's Comprehensive Services Act.

The problems of the delivery of mental health and social services to rural children and adolescents encapsulate many of the problems in the larger health care system. Consequently, many of the principles underlying the President's Health Security Plan are applicable to the reformation of this more specialized service system. The experience of the Commonwealth of Virginia in implementing the Comprehensive Services Act (CSA) highlights the scope of vision needed to transform an existing service delivery system into a coordinated system of care on a state-wide scale.

A SIMPLE SOIL MOISTURE INDEX TO FORECAST CROP YIELDS

Neutron probe soil moisture measurements obtained biweekly during the growing season between 1982 and 1991 from multiple depths under grass-covered plots at 17 Illinois Climate Network sites are used to forecast crop yields. A Soil Moisture Index (SMIX) that combines the effect of intensity, duration, and timing of drought or excessively wet conditions was computed by integrating the quantity of available soil moisture throughout the rooting zone over the growing season. Relationships between the SMIX values and crop yields are evaluated at county, regional, and statewide scales. Coefficients of determination (r 2) for relationships between the SMIX values and maize, soybeans, and hay yields at the statewide level are 0.88, 0.74, and 0.81, respectively, when the period of integration is terminated at the end of the growing season. This new soil index can be employed to forecast yields as early as 12 weeks before harvest for the state of Illinois. However, predictions with RMSE ≤ 10% of the mean yield can ...

Distribution and Abundance of American Eels in Virginia Streams: Tests of Null Models across Spatial Scales

Abstract We examined distribution and abundance of small, medium, and large American eels Anguilla rostrata in Virginia streams by comparing observed with expected null-model patterns. At large spatial scales (across drainages or physiographies), densities of small and medium American eels decreased with distance from the ocean, and densities were not strongly or consistently related to local habitat features (e.g., habitat type, abundance of cover, water temperature, density of predators). A mathematical function, analogous to diffusion of particles from a concentrated source, accounted for up to 85% of the variance in densities of small- or medium-sized eels at statewide, physiographic, or river-drainage scales. At smaller spatial scales (e.g., within a drainage in a particular physiography), we found few relations between American eel density and habitat features. Exceptions to this pattern occurred at Coastal Plain sites of the James River drainage, where American eel densities were exceptionally high...

Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. 3. Techniques for assessment and surveillance

Severe morbidity due to schistosomiasis mansoni is now quite rare in Brazil; thus it is proposed that surveillance plus selective and multidisciplinary intervention limited to areas at high risk be the next step. Such a policy has to be carried out periodically and on a state-wide scale, and therefore will have to rely upon cheap and time-saving sampling procedures. Clinical features cannot at present be used as indicators, with the exception of grossly enlarged livers, which are more frequent in areas at high risk. Overall prevalence rates for a county or even city may also be misleading, even if broken down into units of smaller size. Thus, egg counts in the young age groups remain the best indicators for the detection of areas at high risk (i.e., the main foci of transmission). Egg counts performed on pooled specimens adequately reflect the risk rating of a particular neighbourhood, and have a favourable cost-benefit ratio. In addition, it is suggested that field personnel be trained in the empirical recognition of potential foci; such ‘screening by suspicion’ has been tested and found to be reliable.

Seasonal Habitat Use by River Otters and Everglades Mink in Florida

Seasonal habitat use by river otters (Lutra canadensis) and Everglades mink (Mustela vison evergladensis) was documented in the Big Cypress Swamp, Florida, using line transects of chalk-dusted trackboards and anal scent attractant. Response to scent was species-specific in late wet season, indicating that mating occurs in autumn, when water levels are high in marshes and swamps. Mustelids retreated from marshland as it dried, and most had moved to permanent ponds in the late dry season. This period of concentrated aquatic food coincides with lactation in mink. Use of line transects with olfactory attractants may enable monitoring of otter and mink population levels and trends on a regional or statewide scale, but rigorous testing of the technique is needed. J. WILDL. MANAGE. 46(2):375-381 The river otter is included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (U.S. Fish and Wildlife Service 1977). Treaty obligations require determination that otter harvest for export is not detrimental to the species before export permits are issued (Endangered Species Sci. Auth. 1978). The Everglades mink is listed as threatened by the Florida Game and Fresh Water Fish Commission (1980). Protected status has increased interest in these mustelids, but little is known of their biology in Florida. Information from reports by otter trappers was presented by McDaniel (1963). The scattered information available on Everglades mink has been reported by Layne (1974) and Brown (1978), and new data were presented by Smith (1980). Both species occur in the Big Cypress Swamp in southwestern Florida. The objective of our study was to use a measure of relative abundance, adapted from the scent station technique reported by Linhart and Knowlton (1975) and Linhart et al. (1977), to document seasonal habitat use by otters and mink within a large wetland in South Florida. Our research was funded by an NIH Biomedical Grant through the University of Florida Division of Sponsored Research. Work in the Fakahatchee Strand State Preserve was encouraged by J. A. Stevenson and K. C. Alvarez and supported in the field by R. Goble and R. Baker, all of the Florida Department of Natural Resources. We thank D. B. Barbour, J. Jones, B. Tatje, and J. Thompson for assistance in the field.

A Public Health Rh Program on a State-wide Scale

A Public Health Rh Program on a State-wide Scale

THE AFTER-CARE OF POLIOMYELITIS IN VERMONT

The history of the after-care of poliomyelitis in Vermont is of interest as it was the first state-wide work in this field undertaken anywhere in the country, and is today the most fully developed scheme for the aftercare of the disease on a state-wide scale which exists. There has been no attempt to make the present account a technical one. It is rather the object of this report to show how the plan of after-care now in operation in Vermont developed, what difficulties were encountered, and how they were met. In the years 1910, 1911, 1912 and 1913, cases of poliomyelitis were reported in Vermont, but in 1914 there occurred an epidemic of great severity, with a very high incidence across the northern half of the state, and from this epidemic 306 cases were reported. Undoubtedly, not all of the cases were reported; but of those that were, the mortality