Nematodes As Environmental Indicators

Nematodes are the most wide spread multicellular animals in nature and analysis of nematodes in terrestrial, freshwater and marine environments as well as their role and function in ecosystems, can be used for environmental monitoring. Compared to other organisms, they offer the greatest potential as bioindicators and can be used to study gene expression in relation to environmental challenges, to monitor changing impacts on the environment and in laboratory ecotoxicity tests. This volume addresses classical and molecular approaches to nematode community analysis, the contemporary field of nematodes as biosensors, as well as genomic aspects of nematode bioindicators. In addition, the case studies stress the importance of these bioindicators and demonstrate the commercial potential of these technologies.

Keoladeo National Park (KNP), a world heritage site, was declared a 'Ramsar site' in October 1981 on the basis of its ecological, biological and limnological importance. It represents a blend of dry grasslands, woodlands, swamps and wetland thus reflecting tremendous diversity in the flora and fauna. It is a fact that KNP has been the focus of many earlier studies and faunal surveys but the nematode faunal diversity has been the aspect virtually neglected in all such work. The second author thus conceived this problem and submitted a proposal to Ministry of Environment and Forests (MEF), New Delhi. The present work has seen the light of the day due to the curious efforts of the second author who executed the pioneering study on the nematodes of the KNP. This book brings about a detailed account of the nematodes and their ecological relevance in the wetland's subterranean food web. Due to their specificity, adaptability and plasticity to cope up diverse environment types, these organisms serve as excellent bioindicators. Thus the degree of disturbance or the enrichment and the maturity status of the environment have been evaluated using these cost-effective biological models.

Nematodes are the most wide spread multicellular animals in Nature and analysis of nematodes in terrestrial, freshwater and marine environments as well as their role and function in ecosystems can be used for environmental monitoring. Classical and molecular approaches to nematode community analysis will be addressed and the contemporary field of nematodes as biosensors and genomic and post genomic aspects of nematode bioindicators will also be included. Case studies stress the importance of these bioindicators and demonstrate the commercial potential of these technologies.

This book contains 22 chapters on various aspects of freshwater nematode ecology and taxonomy. Subjects covered include the techniques for processing freshwater nematodes, the composition and distribution of free living freshwater nematodes, their abundance, biomass and diversity, the production of freshwater nematodes, their feeding ecology, patterns in size structure of freshwater nematode communities, different nematode habitats, and computation and application of nematode community indices. It provides descriptions with figures of each taxon at the genus level and above to currently valid genera. For every genus, a complete list of species, with an emphasis on biogeography, is given for primarily freshwater taxa and a list of only those species reported from freshwater bodies is given for the genera that are considered primarily non-freshwater. This book is intended to provide a useful reference to students, beginners and established researchers in the field of freshwater nematology, benthologists, invertebrate biologists, limnologists, ecologists, microbiologists and soil biologists.

This volume gives a detailed morphology of the dorylaims and provides a thorough overview of their feeding behaviour, reproduction, ecology, and diversity. You will learn what dorylaims are like and how they live.

Greater values of the fungivores to bacterivores ratio (FB) in the forest suggested a shift in the decomposer foodweb. The distribution of nematodes among trophic groups proved to a useful indicator of micro-topography effects, in addition to measures of ecological sucession and genus diversity. Relative abundance of plant-parasites and algivores was greatest along the roadside (grassy areas and ditch, respectively), and omnivores and predators were relatively more abundant in the forest, as well as the ditch. Canonical Correspondence Analysis supported that gravel roads were associated with a less disturbed nematode community, as well as a shift in later succession in the nematode community with distance from the road. Roadside conditions are a complex of chemical and physical soil properties, vegetation, moisture, and other abiotic road conditions.

The offered volume intends to review the biological control theme of phytonematodes from several prospects: ecological; applicative as well as commercial state of the art; understanding the mode-of-action of various biocontrol systems; interaction between the plant host, nematodes’ surface and microorganism’s; candidates for biocontrol; extrapolation of the wide knowledge existed in another systems for understanding biocontrol processes: C. elegans as a model and lessons from other natural systems; and exploiting advanced genomic tools to promote understanding biocontrol processes and thereafter improve specific biological control agents.

Nematodes, as one component of the soil ecosystem, interact with biotic and abiotic factors, as they live in capillary water; their permeable cuticle helps in maintaining direct contact with their micro-environment and any minor change in the environment affect them directly, which can be easily studied by their assemblages using various indices. They are classified on the basis of their feeding behaviour, which helps them to serve as good indicators of soil ecosystem. They also occupy a key position in the soil food webs and may help in regulating it. In the present work, nematodes have been studied under different field stresses involving agro-ecosystems to coal mines and are found to be perfect indicators of soil as reflected by use of faunal profiles and representative indices.

1. Defining and assessing soil health and sustainable productivity 2. The relationship of soil health to ecosystem health 3. Rationale for developing bioindicators of soil health 4. Bioindicators: perspectives and potential for land users, researchers and policy makers 5. Soil microbial biomass, activity and nutrient cycling as indicators of soil health 6. Soil enzyme activities as integrative indicators of soil health 7. Soil microflora as bioindicators of soil health 8. Potential use of plant root pathogens as bioindicators of soil health 9. Soil microfauna as bioindicators of soil health 10. Community structure of soil arthropods as a bioindicator of soil health 11. Can the abundance or activity of soil macrofauna be used to indicate the biological health of soils? 12. Biodiversity of soil organisms as indicators of soil health 13. Biomonitoring of soil health by plants 14. Bioindicators to detect contamination of soils with special reference to heavy metals 15. Chemical and molecular approaches for rapid assessment of the biological status of soils 16. Use of genetically modified microbial biosensors for soil ecotoxicity testing 17. Biological indicators of soil health: synthesis.