نتایج جستجو برای: biotic index
تعداد نتایج: 408379 فیلتر نتایج به سال:
Marine ecosystem protection and conservation initiatives rely on the assessment of ecological integrity and health status of marine environments. The AZTI's Marine Biotic Index (AMBI), which consists on using macroinvertebrate diversity as indicator of ecosystem health, is used worldwide for this purpose. Yet, this index requires taxonomic assignment of specimens, which typically involves a tim...
—From 1993 to 1996, fish assemblage data were collected from 309 wadeable streams in the U.S. Mid-Atlantic Highlands region as part of the U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program. Stream sites were selected with a probabilistic sampling design that allowed regional estimates of stream condition. We examined responses of 58 fish assemblage metrics t...
The Chesapeake Bay benthic index of biotic integrity (B-IBI) was developed to assess benthic community health and environmental quality in Chesapeake Bay. The B-IBI provides Chesapeake Bay monitoring programs with a uniform tool with which to characterize bay-wide benthic community condition and assess the health of the Bay. A probability-based design permits unbiased annual estimates of areal ...
In southern California, most estuarine wetlands are gone, and what little habitat remains is degraded. For this reason, it is often of interest to assess the condition of estuaries over time, such as when determining the success of a restoration project. To identify impacts or opportunities for restoration, we also may want to know how a particular estuary, or area within an estuary, compares w...
/ Fish and macroinvertebrate assemblage composition, instream habitat features and surrounding land use were assessed in an agriculturally developed watershed to relate overall biotic condition to patterns of land use and channel structure. Six 100-m reaches were sampled on each of three first-order warm-water tributaries of the River Raisin in southeastern Michigan. Comparisons among sites and...
Members of the ERF transcription factor family play important roles in regulating gene expression in response to biotic and abiotic stresses. In soybean (Glycine max L.), however, only a few ERF genes have been studied so far. In this study, 98 unigenes that contained a complete AP2/ERF domain were identified from 63,676 unique sequences in the DFCI Soybean Gene Index database. The phylogeny, g...
The present investigation of forest ecosystem was undertaken during May 2010 to Dec 2010. The main aim of the study was to analyze the impact of biotic interferences on Yousmarg forest ecosystem. The cumulative effect of the biotic interferences was signif icantly seen in the reduction of vegetation cover. The present study revealed that the prominent factor for the exploitation of the vegetati...
Application of the index of biotic integrity methodology to New Zealand freshwater fish communities.
An index of biotic integrity (IBI) was developed for freshwater fish in New Zealand streams. Data on freshwater fish occurrence for 5497 sites over the entire country were obtained from the New Zealand freshwater fish database for the period 1980-2002. Environmental habitat descriptors for the stream watersheds above or at each of these sites were obtained from an existing river environment cla...
The index of biotic integrity (IBI) is a commonly used bioassessment tool that integrates abundance and richness measures to assess water quality. In developing IBIs that are both responsive to human disturbance and resistant to natural variability and sampling error, water managers must decide how to weigh information about rare and abundant taxa, which in turn requires an understanding of the...
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