地理信息学与地统计学：概述

Plant�??Soil Interactions Management CNP Coupling and Decoupling Processes in Agroecosystems with Perennial Vegetation

Niharika Dvivedi

Agroecosystems are natural ecosystems that have been modified for the production of food and fibre. While they retain many of the characteristics of natural ecosystems, from a toxicological viewpoint they are characterized by the frequent presence of agrochemicals, including pesticides, fertilizers, and plant growth regulators. The nature and extent of the agrochemical contamination will vary considerably, depending upon the nature of the crops and/or livestock. In monocultures, the variety of chemicals will be smaller but the concentrations may well be higher while the reverse could be true in agroecosystems supporting the production of many crops. In highly mechanized agroecosystems, the presence of combustion products from fossil fuels may also present problems