RELATION OF MACROINVERTEBRATE COMMUNITY IMPAIRMENT TO CATCHMENT CHARACTERISTICS IN NEW JERSEY STREAMS1

ABSTRACT: The level of macroinvertebrate community impairment was statistically related to selected basin and water-quality characteristics in New Jersey streams. More than 700 ambient biomonitoring stations were chosen to evaluate potential and known anthropogenic effects. Macroinvertebrate communities were assessed with a modified rapid-bioassessment approach using three impairment ratings (nonimpaired, moderately impaired, and severely impaired). Maximum-likelihood multiple logistic-regression analysis was used to develop equations defining the probability of community impairment above predetermined impairment levels. Seven of the original 140 explanatory variables were highly related to the level of community impairment. Explanatory variables found to be most useful for predicting severe macroinvertebrate community impairment were the amount of urban land and total flow of municipal effluent. Area underlain by the Reading Prong physiographic region and amount of forested land were inversely related to severe impairment. Nonparametric analysis of variance on rank-transformed bioassessment scores was used to evaluate differences in level of impairment among physiographic regions and major drainage areas simultaneously. Rejection of the null hypothesis indicated that the levels of impairment among all six physiographic regions and five major drainage areas were not equal. Physiographic regions located in the less urbanized northwest portion of New Jersey were not significantly different from each other and had the lowest occurrence of severely impaired macroinvertebrate communities. Physiographic regions containing urban centers had a higher probability of exhibiting a severely impaired macroinvertebrate community. Analysis of major drainage areas indicates that levels of impairment in the Atlantic Coastal Rivers drainage area differed significantly from those in the Lower Delaware River drainage area.     

Regional variation in the hierarchical partitioning of diversity in coral-dwelling fishes

The size of the regional species pool may influence local patterns of diversity. However, it is unclear whether certain spatial scales are less sensitive to regional influences than others. Additive partitioning was used to separate coral-dwelling fish diversity to its alpha and beta components, at multiple scales, in several regions across the Indo-Pacific. We then examined how the relative contribution of these components changes with increased regional diversity. By employing specific random-placement null models, we overcome methodological problems with local-regional regressions. We show that, although alpha and beta diversities within each region are consistently different from random-placement null models, the increase in beta diversities among regions was similar to that predicted once heterogeneity in coral habitat was accounted for. In contrast, alpha diversity within single coral heads was limited and increased less than predicted by the null models. This was correlated with increased intraspecific aggregation in more diverse regions and is consistent with ecological limitations on the number of coexisting species at the local scale. These results suggest that, apart from very small spatial scales, variation in the partitioning of fish diversity along regional species richness gradients is driven overwhelmingly by the corresponding gradients in coral assemblage structure.     

AQUATOX: Modeling environmental fate and ecological effects in aquatic ecosystems

AQUATOX combines aquatic ecosystem, chemical fate, and ecotoxicological constructs to obtain a truly integrative fate and effects model. It is a general, mechanistic ecological risk assessment model intended to be used to evaluate past, present, and future direct and indirect effects from various stressors including nutrients, organic wastes, sediments, toxic organic chemicals, flow, and temperature in aquatic ecosystems. The model has a very flexible structure and provides multiple analytical tools useful for evaluating ecological effects, including uncertainty analysis, nominal range sensitivity analysis, comparison of perturbed and control simulations, and graphing and tabulation of predicted concentrations, rates, and photosynthetic limitations. It can represent a full aquatic food web, including multiple genera and guilds of periphyton, phytoplankton, submersed aquatic vegetation, invertebrates, and fish and associated organic toxicants. It can model up to 20 organic chemicals simultaneously. (It does not model metals.) Modeled processes for organic toxicants include chemodynamics of neutral and ionized organic chemicals, bioaccumulation as a function of sorption and bioenergetics, biotransformation to daughter products, and sublethal and lethal toxicity. It has an extensive library of default biotic, chemical, and toxicological parameters and incorporates the ICE regression equations for estimating toxicity in numerous organisms. The model has been implemented for streams, small rivers, ponds, lakes, reservoirs, and estuaries. It is an integral part of the BASINS system with linkage to the watershed models HSPF and SWAT.     

The role of affective traits and affective states in disputants' motivation and behavior during episodes of organizational conflict

This study investigated the effects of individuals' affective traits (i.e., affect intensity and affect disposition) and affective states (i.e., positive and negative mood) on their motivations and behavior during episodes of organizational conflict. Two hundred and twenty‐three student employees from a variety of jobs and organizations kept daily records, for a three day period, of their conflict experiences at work. The results of hierarchical linear modelling indicated that employees' affective traits and affective states had parallel effects on the conflict management process. Subsequent analyses revealed the source of this parallelism: employees' moods on the day of the conflict fully mediated the effects of their affective disposition on the conflict process variables. The results are discussed in terms of their theoretical significance and practical implications. Copyright © 2001 John Wiley & Sons, Ltd.     

Community social capital and individual functioning in the post‐disaster context

Disasters can have severe and long‐lasting consequences for individuals and communities. While scholarly evidence indicates that access to social support can ameliorate their negative impacts, less understood is whether or not neighbourhood social capital can facilitate recovery. This study uses two waves of survey data—collected before and after a significant flood in Brisbane, Australia, in 2011—to examine the relationship between the severity of the event at the individual and neighbourhood level, access to neighbourhood social capital and individual‐level social support, and functioning in the post‐disaster environment. In line with previous research, the results indicate that the severity of the flood is the most salient predictor of post‐disaster functioning. No evidence was unearthed to show that neighbourhood social capital amassed before the flood leads to better functioning subsequently, but the findings do suggest that individual‐level social support can moderate the effect of flood severity on functioning.     

Perfluorinated compounds in a coastal industrial area of Tianjin,China

Perfluorinated compounds (PFC) in water, sediment, soil, and biota from the coastal industrial area of Tianjin, China, were measured to provide baseline information and to determine possible sources and potential risk to wildlife. Perfluorooctanesulfonate (PFOS) was the predominant PFC with maximum concentrations of 10 ng/L in water, and 4.3, 9.4, and 240 ng/g dw in sediment, soil, and fish, respectively. Perfluorooctanoate (PFOA) concentration in water ranged from 3.0 to 12 ng/L. Perfluoroundecanoate (PFUnA) and Perfluorododecanoate (PFDoA) were detected in solid matrices, respectively, at concentrations of 相似文献