Trong việc tìm kiếm các cách để đo lường tính bền vững của agroecosystems, đất ĐÃ beens thường bị bỏ qua. Tuy nhiên, đất hỗ trợ chức năng hệ sinh thái thiết yếu, như vậy là Thúc đẩy năng suất cây trồng, Tăng cường quan hệ nước, chất dinh dưỡng khoáng hoà, Cho phép phân hủy, và hành động như bộ đệm Một môi trường | CHAPTER 7 Nematode Communities as Ecological Indicators of Agroecosystem Health Deborah A. Neher CONTENTS Nematodes and Their Role in the Soil Nematode Community Maturity Indices. 107 Trophic Diversity Relationship of Nematode Communities to Ecosystem Nutrient Decomposition of Organic Index Calibration . 111 Perennial Organic Confounded Disturbance Regional Scale Future Research . 116 References. 117 INTRODUCTION In the search for ways to measure the sustainability of agroecosystems the soil has often been ignored. However soil supports essential ecosystem functions such as promoting plant productivity enhancing water relations regulating nutrient mineralization permitting decomposition and acting as an environmental buffer Neher 105 2001 by CRC Press LLC 106 AGROECOSYSTEM SUSTAINABILITY DEVELOPING PRACTICAL STRATEGIES 1999a . The relative health and quality of an agroecosystem s soil especially its biological and ecological components should correlate closely with the overall health and sustainability of the system. Biologically soil ecosystems support a great diversity of both microfauna fungi bacteria protozoa and algae and mesofauna protozoa arthropods and nematodes . The author s research suggests that measures of the community structure of one of these biological components namely nematodes may serve as useful indicators of the health of agricultural soils and therefore have promise as indicators of sustainability. NEMATODES AND THEIR ROLE IN THE SOIL ECOSYSTEM Soil nematodes roundworms are relatively abundant 6 X 104 to 9 X 106 per m2 small 300 pm to 4 mm animals with short generation times days to a few weeks that allow them to respond to changes in food supply Wasilewska 1979 Bongers 1990 . Relative to other soil micro and mesofauna
