MODELING AGRICULTURAL AND PASTORAL SYSTEMS UNDER ENVIRONMENTAL-CHANGE

Agricultural and pastoral systems are dynamic entities, responsive to physical, chemical and biological changes in their environment. The im portance of agriculture to human welfare and national economies, and t he variability of production within and between years, has led to the construction of mathematical models to study the impacts of climate va riability, farm management and environmental change on such systems. T he value and adequacy of these models in providing a sound framework f or planning changes in land use and management are discussed.