Breakdown and invertebrate colonization of dead wood in wetland, upland, and river habitats

Breakdown of woody debris in river and upland habitats as well as the interactions between wood and invertebrates have been well described. Studies of wood in wetlands are rare, and far less is known about breakdown and invertebrate use of wood in these transitional habitats. This study experimentally assessed breakdown and invertebrate colonization of wood in a floodplain wetland and directly related patterns in the wetland to adjacent river and upland habitats. Over a 2.7 year period, we monitored breakdown and invertebrate presence in 10 cm diameter × 150 cm long sweetgum (Liquidambar styraciflua L.) logs in a floodplain wetland (n = 8), river (n = 5), and upland (n = 4) habitat. Mass loss, decay condition change, and C/N ratios of wetland wood more closely resembled upland than river wood. The overall invertebrate assemblage associated with wetland wood was also more similar to that associated with upland than river wood. Breakdown and invertebrate colonization of wood in the floodplain wetland shared more characteristics with upland than river wood, perhaps because of the seasonal nature of flooding in the wetland. However, the ecology of wood in wetlands also had unique characteristics compared with either the uplands or the river

Comparison of Best Management Practice Adoption Between Virginia\u27s Chesapeake Bay Basin and Southern Rivers Watersheds

Producers in two regions of Virginia (Chesapeake Bay basin and Southern Rivers region) were surveyed to compare farming practices and agricultural best management practice (BMP) adoption. Objectives were to assess farming operations and determine the extent of cost-share and non-cost-share BMP implementation and gain insight into the impact of selected socioeconomic factors on the BMP adoption. Although farming characteristics and producer attitudes toward pollution and water quality were similar, BMP implementation differed between the two regions. Differences in BMP implementation may be due to a more focused, longer-term NPS pollution control educational effort in the Bay basin

Invertebrates Associated with Coarse Woody Debris in Streams, Upland Forests, and Wetlands: A Review

Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.We reviewed literature on the invertebrate groups associated with coarse woody debris in forests, streams, and wetlands, and contrasted patterns of invertebrate community development and wood decomposition among these ecosystems.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors

Benthic Macroinvertebrate Fauna in Small Streams Used by Cattle in the Blue Ridge Mountains, Virginia

Cattle production is a common land use, and the adverse effects of cattle grazing on stream habitat and macroinvertebrates has been well docu-mented. The purpose of our study was to provide a list of taxa that can be expected to occur in small streams impacted by cattle in the southern Blue Ridge Mountains and to demonstrate how taxon-specific natural history information can be used to gain insight about benthic habitat condition. We identified 97 benthic macroinvertebrate taxa from five cattle-impacted streams that differed in cattle grazing intensity. Our findings suggest that some macroinvertebrate taxa can sustain low levels of cattle grazing and that sedimentation is a major stressor to the macroinvertebrate fauna

Environmental factors accounting for benthic macroinvertebrate assemblage structure at the sample scale in streams subjected to a gradient of cattle grazing

Macroinvertebrate assemblages were related to environmental factors that were quantified at the sample scale in streams subjected to a gradient of cattle grazing. Environmental factors and macroinvertebrates were concurrently collected so assemblage structure could be directly related to environmental factors and the relative importance of stressors associated with cattle grazing in structuring assemblages could be assessed. Based on multivariate and inferential statistics, measures of physical habitat (% fines and substrate homogeneity) had the strongest relationships with macroinvertebrate assemblage structure. Detrital food variables (coarse benthic and fine benthic organic matter) were also associated with assemblage structure, but the relationships were never as strong as those with physical habitat measures, while autochthonous food variables (chlorophyll a and epilithic biomass) appeared to have no association with assemblage structure. The amount of variation explained in taxa composition and macroinvertebrate metrics is within values reported from studies that have examined macroinvertebrate metric–sediment relationships. The % Coleoptera and % crawlers had consistent relationships with % fines during this study, which suggests they may be useful metrics when sediment is a suspected stressor to macroinvertebrate assemblages in Blue Ridge streams. Findings from this study also demonstrate the importance of quantitative sampling through time when research goals are to identify relationships between macroinvertebrates and environmental factors

Macroinvertebrate colonization dynamics on artificial substrates along an algal resource gradient

Riparian canopy removal and land use may introduce multiple stressors that can alter food and habitat for stream organisms, but the influence of these alterations on macroinvertebrate colonization dynamics is less well known. A field study involving the simultaneous placement and removal of artificial substrates was performed to examine how macroinvertebrate colonization rates might vary with algal accumulation within a perennial stream segment in eastern Ohio, USA. The study was conducted over a 60-day summer colonization period in three reaches that were selected to represent an algal resource gradient according to canopy cover and agricultural nutrient sources in the riparian corridor. Total nitrogen, water temperatures, and mean algal biomass from substrates increased along the resource gradient represented by the study sites. Total macroinvertebrate biomass and the abundance and biomass of scrapers also increased according to the gradient. Correlation results indicated that chlorophyll a biomass, rather than time or temperature, was better related to the abundance and biomass of most primary consumers on substrates. These results suggest that the combined effects of elevated temperatures and nutrients can result in relatively rapid algal accrual that may alter the colonization and establishment of macroinvertebrate communities in streams subjected to gradients of riparian disturbances

THE STRUCTURE AND DISTRIBUTION OF STREAM SALAMANDER AND MACROINVERTEBRATE COMMUNITIES ACROSS SOUTHEASTERN KENTUCKY.

Because of stream salamanders’ and macroinvertebrates relatively high abundance and complex life cycles, they are important trophic links and serve a critical role in transferring energy. Despite this importance little research has examined their communities’ structure in aquatic ecosystems of southeastern Kentucky. The primary objective of this research was to determine the structure of these communities across southeastern Kentucky and understand what factors impact their abundances and distributions. To address this, we sampled eight reference quality streams across the region three times during March–June 2014. Within each stream, we sampled a 100-m transect for salamanders, macroinvertebrates, water quality, and habitat measurements, including mesohabitat types, canopy closure, stream temperature, dissolved oxygen, pH, conductivity, and streambed cover types. A principle component analysis (PCA) approach was used to create predictive models from the environmental variables, to predict for salamander and macroinvertebrate abundance and richness. We sampled 390 salamanders (155 adult, 235 larvae; 7 species) and 1,163 macroinvertebrates (8 orders, 33 families, 61 genera). Predictive models revealed trends of association between salamander and macroinvertebrate abundance and richness, as well as with habitat characteristics including stream width, presence of cover objects, and percentage canopy closure. This study provides information on the required habitat characteristics for these important stream taxa, which can be used to influence management decisions. By understanding the factors that influence community composition and distribution within reference quality aquatic ecosystems we can gain insight into what may be lost in Appalachia, a region of high disturbance and anthropogenic land use