Ecoregional Dominance in Spatial Distribution of Avian Influenza (H5N1) Outbreaks

Recent articles in Emerging Infectious Diseases (1,2) and elsewhere (3,4) have highlighted the role of Anatidae migration in dispersal of the H5N1 subtype of highly pathogenic avian influenza (HPAI) virus. Although these articles point out that identifying the geographic origin of migrating waterfowl is needed to understand and predict pathogen dispersal, study analyses have been limited to pathways with nominal reference to climatic and vegetation patterns that control spatiotemporal patterns of this migration

Quantitative Soil Descriptions for Ecoregions of the United States

Researchers have defined and mapped ecological regions of the United States based on similar patterns of ecosystems such as deserts, forests, and croplands. These studies are useful in regional research, monitoring, and environmental management because data can be more readily extrapolated within the same ecoregion and to regions with similar characteristics. The description of ecoregions is largely holistic and qualitative. Conversely, quantitative information for soil are abundant and soil is an important ecosystem component related to many ecoregion properties. We used the nationwide State Soil Geographic database(STATSGO) to describe the soils of 84 Level III ecoregions in the United States. Among the 24 soil characteristics studied were texture, rock fragments, available water capacity, bulk density, and organic matter content. For each ecoregion we developed ranks to describe (i) its similarity to the U.S. average soil characteristics, (ii) the accuracy of predicting those characteristics, (iii) how well the soil map unit boundaries fit within ecoregion boundaries, (iv) the spatial relationship of soils across neighboring ecoregion boundaries, and (v) the homogeneity of texture-rock patterns. We present a national map of soil texture and rock fragments and five soil ranks for each ecoregion, and examine relationship between soils and other ecological components for selected ecoregions. Because soils relate to other ecosystem components such as vegetation, geology, and land use, the soil ranks complement and enrich the qualitative ecoregion descriptions. Similar analyses of physical or biological components of ecoregions will expand the understanding of the ecosystem patterns

Ecoregions and Subregions of Iowa: A Framework for Water Quality Assessment and Management

Ecoregion frameworks are valuable tools for inventorying and assessing environmental resources, for setting resource management goals, and for developing biological criteria and water quality standards. In a collaborative project between the Iowa Department of Natural Resources (DNR) and the U.S. Environmental Protection Agency (EPA), we have refined boundaries of the EPA\u27s five ecological regions of Iowa and defined six subregions of the Western Corn Belt Plains ecoregion within the state. Lists of candidate stream reference sites have been developed to date for the seven largest regions, and the sites were visited and evaluated by Iowa DNR and U.S. EPA personnel to determine their suitability for sampling aquatic biota. The Iowa DNR plans to use the ecoregions and reference sites to better understand regional variations in stream quality, to help define best-attainable conditions, to develop biological criteria, and as a framework to report on water quality

Regionalizing Aquatic Ecosystems Based on the River Subbasin Taxonomy Concept and Spatial Clustering Techniques

Aquatic ecoregions were increasingly used as spatial units for aquatic ecosystem management at the watershed scale. In this paper, the principle of including land area, comprehensiveness and dominance, conjugation and hierarchy were selected as regionalizing principles. Elevation and drainage density were selected as the regionalizing indicators for the delineation of level I aquatic ecoregions, and percent of construction land area, percent of cultivated land area, soil type and slope for the level II. Under the support of GIS technology, the spatial distribution maps of the two indicators for level I and the four indicators for level II aquatic ecoregion delineation were generated from the raster data based on the 1,107 subwatersheds. River subbasin taxonomy concept, two-step spatial clustering analysis approach and manual-assisted method were used to regionalize aquatic ecosystems in the Taihu Lake watershed. Then the Taihu Lake watershed was divided into two level I aquatic ecoregions, including Ecoregion I1 and Ecoregion I2, and five level II aquatic subecoregions, including Subecoregion II11, Subecoregion II12, Subecoregion II21, Subecoregion II22 and Subecoregion II23. Moreover, the characteristics of the two level I aquatic ecoregions and five level II aquatic subecoregions in the Taihu Lake watershed were summarized, showing that there were significant differences in topography, socio-economic development, water quality and aquatic ecology, etc. The results of quantitative comparison of aquatic life also indicated that the dominant species of fish, benthic density, biomass, dominant species, Shannon-Wiener diversity index, Margalef species richness index, Pielou evenness index and ecological dominance showed great spatial variability between the two level I aquatic ecoregions and five level II aquatic subecoregions. It reflected the spatial heterogeneities and the uneven natures of aquatic ecosystems in the Taihu Lake watershed

A Multimetric Assessment of Stream Condition in the Northern Lakes and Forests Ecoregion Using Spatially Explicit Statistical Modeling and Regional Normalization

We sampled fish communities, water temperature, water chemistry, physical habitat, and catchment characteristics for 94 stream sites selected randomly throughout the Northern Lakes and Forests ecoregion and used those data to explicitly model reference conditions and assess ecological stream condition at each site via a regional normalization framework. The streams we sampled were first order through fourth order, and the catchments ranged from 0.9 to 458 km2. We developed multiple linear regression (MLR) models that predicted fish community metrics, water chemistry characteristics, and local physical habitat from catchment characteristics; we used these models to compare existing conditions with the conditions that would be expected based on the regression models. Our results indicated that the fish communities were relatively unimpaired because the catchment variables associated with human‐induced land use change were important in only 1 of the 10 fish metric models. Agricultural land use was a significant variable in the MLR equation for species of Lepomis (sunfish). Agricultural land use and urban land use were both significant variables in all of the MLR models predicting water chemistry variables; urban land use was a significant variable in the MLR model predicting the percent coverage of all instream cover types. Regional normalization indicated that none of the sites were impaired based on fish community attributes. However, our analysis based on water chemistry metrics indicated that 22– 35% of the sites were impaired and that, based on physical habitat, 6–14% of the sites were impaired. A comparison with other published studies of the ecoregion suggested that the regional normalization process correctly characterized stream condition.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141590/1/tafs0697.pd

Supplemental Information 6: Data S1.

Microorganisms that reside on and in mammals, such as bats, have the potential to influence their host’s health and to provide defenses against invading pathogens. However, we have little understanding of the skin and fur bacterial microbiota on bats, or factors that influence the structure of these communities. The southwestern United States offers excellent sites for the study of external bat bacterial microbiota due to the diversity of bat species, the variety of abiotic and biotic factors that may govern bat bacterial microbiota communities, and the lack of the newly emergent fungal disease in bats, white-nose syndrome (WNS), in the southwest. To test these variables, we used 16S rRNA gene 454 pyrosequencing from swabs of external skin and fur surfaces from 163 bats from 13 species sampled from southeastern New Mexico to northwestern Arizona. Community similarity patterns, random forest models, and generalized linear mixed-effects models show that factors such as location (e.g., cave-caught versus surface-netted) and ecoregion are major contributors to the structure of bacterial communities on bats. Bats caught in caves had a distinct microbial community compared to those that were netted on the surface. Our results provide a first insight into the distribution of skin and fur bat bacteria in the WNS-free environment of New Mexico and Arizona. More importantly, it provides a baseline of bat external microbiota that can be explored for potential natural defenses against pathogens

Simulated responses of soil organic carbon stock to tillage management scenarios in the Northwest Great Plains

© 2007 Tan et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Effects of grade control structures on the macroinvertebrate assemblage of an agriculturally impacted stream

Nearly 400 rock rip-rap grade control structures (hereafter GCS) were recently placed in streams of western Iowa, USA to reduce streambank erosion and protect bridge infrastructure and farmland. In this region, streams are characterized by channelized reaches, highly incised banks and silt and sand substrates that normally support low macroinvertebrate abundance and diversity. Therefore, GCS composed of rip-rap provide the majority of coarse substrate habitat for benthic macroinvertebrates in these streams. We sampled 20 sites on Walnut Creek, Montgomery County, Iowa to quantify macroinvertebrate assemblage characteristics (1) on GCS rip-rap and at sites located (2) 5–50 m upstream of GCS, (3) 5–50 m downstream of GCS and (4) at least 1 km from any GCS (five sites each). Macroinvertebrate biomass, numerical densities and diversity were greatest at sites with coarse substrates, including GCS sites and one natural riffle site and relatively low at remaining sites with soft substrates. Densities of macroinvertebrates in the orders Ephemeroptera, Trichoptera, Diptera, Coleoptera and Acariformes were abundant on GCS rip-rap. Increases in macroinvertebrate biomass, density and diversity at GCS may improve local efficiency of breakdown of organic matter and nutrient and energy flow, and provide enhanced food resources for aquatic vertebrates. However, lack of positive macroinvertebrate responses immediately upstream and downstream of GCS suggest that positive effects might be restricted to the small areas of streambed covered by GCS. Improved understanding of GCS effects at both local and ecosystem scales is essential for stream management when these structures are present