Although microbes have traditionally been used as models for testing ecological theory, research on the organization of these communities has largely been isolated from other areas of community ecology. Early studies ...Although microbes have traditionally been used as models for testing ecological theory, research on the organization of these communities has largely been isolated from other areas of community ecology. Early studies indicated that microbial populations can form dynamic, interacting assemblages. Observations of distributional patterns suggest that certain deterministic forces regulate community structure. It appears that protozoans are tolerant of a wide range of environmental conditions although evidence for this is largely based on gross environmental analyses. Laboratory studies have suggested the importance of negative and positive biotic interactions in determining community membership, but little field evidence for this exists. The importance of transport processes in controlling community composition is being increasingly recognized. All three types of processes likely act to regulate the colonization and successional dynamics of these communities. A simple model is presented to promote the展开更多
The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental impact.Prominent in this change is an increasing emphasis on prote...The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental impact.Prominent in this change is an increasing emphasis on protecting the integrity of natural ecosystems,which incorporate community-and system-level properties as well as organismal and population processes.Consequently,support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as well.The reason for this trend is clear:the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests alone.Many of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or overcome.In particular,the use of natural microbial communities minimizes several shortcomings typically associated with multispecies toxicity testing.This discussion includes the utility of microcosm and mesocosm tests using aquatic microbial communities as hazard assessment tools in conjunction with accumulating information on their performance in toxicity testing protocols.An increasing body of experimental evidence supports an expansion in the use of these tests for a variety of regulatory and research purposes.A shift in research focus is needed,however,to answer remaining questions and further refine standard protocols for these valuable ecotoxicological tools.展开更多
文摘Although microbes have traditionally been used as models for testing ecological theory, research on the organization of these communities has largely been isolated from other areas of community ecology. Early studies indicated that microbial populations can form dynamic, interacting assemblages. Observations of distributional patterns suggest that certain deterministic forces regulate community structure. It appears that protozoans are tolerant of a wide range of environmental conditions although evidence for this is largely based on gross environmental analyses. Laboratory studies have suggested the importance of negative and positive biotic interactions in determining community membership, but little field evidence for this exists. The importance of transport processes in controlling community composition is being increasingly recognized. All three types of processes likely act to regulate the colonization and successional dynamics of these communities. A simple model is presented to promote the
基金This manuscript and specific ex periments discussed within were sponsored,in part,by grants from The Procter&Gamble Company and the du Pont Educational Foundation,altbough the authors take full responsibility for the views ex-pressed herein.
文摘The focus of environmental regulations has changed significantly since the introduction of the bioassay as a standard means of assessing environmental impact.Prominent in this change is an increasing emphasis on protecting the integrity of natural ecosystems,which incorporate community-and system-level properties as well as organismal and population processes.Consequently,support for the use of multispecies testing has widened to include not only ecologists in academia but environmental scientists in the regulatory and industrial sector as well.The reason for this trend is clear:the additional environmental realism gained from tests utilizing communities of organisms allows for greater insight into the potential hazard of chemicals and other forms of human activity to natural ecosystems that cannot be obtained from single species tests alone.Many of the problems cited for multispecies testing early in their evolution as a hazard assessment tool have been refuted or overcome.In particular,the use of natural microbial communities minimizes several shortcomings typically associated with multispecies toxicity testing.This discussion includes the utility of microcosm and mesocosm tests using aquatic microbial communities as hazard assessment tools in conjunction with accumulating information on their performance in toxicity testing protocols.An increasing body of experimental evidence supports an expansion in the use of these tests for a variety of regulatory and research purposes.A shift in research focus is needed,however,to answer remaining questions and further refine standard protocols for these valuable ecotoxicological tools.
