Agriculture and biological conservation

Abstract

Since its beginning about ten thousand years age, agriculture has spread steadily around the world to become a dominant form of land management on all continents. Agricultural practices have affected the welfare of many organisms other than the primary targets of its manipulations. Prior to the 1960's, with the slow rate at which new land was brought under cultivation, there was little concern about the relation between agriculture and conservation. Low intensity agricultural management systems allowed survival of nontarget economic species which also gave relatively higher value to their indirect benefits (recreational, aesthetic, economic). But the dramatic increase in intensity of management and capital investment in agriculture after World War II heralded in a new era in which the multiple use of the land declined as the intensity of management, and, hence, the value of the market crop, increased. Little attention has been paid to ways changes in agricultural practices might have beneficial consequences for conservation. Agricultural practices can be used as key experimental variables and as laboratories to provide conservation biology with systems to investigate many ecological processes. The goal of the discussion is to provide an overview of conservation biology and agriculture and the relationships that could help determine how agricultural objectives and practices could be modified to enhance the conservation of biological resources for the long-term viability of agriculture. Traditional and modern technological practices both can contribute to the development of new systems. A provisional classification of organisms is offered to assist in the analysis of the interactions between agricultural practices and the organisms. Agricultural systems are classified into monoculture, mixed farming, pastures and rangelands, forestry, intensive animal production systems, and integrated systems. An identification of key techniques and practices within each type of agriculture, the spatial scale of agriculture, lead to a clarification of how agricultural operations could be changed and how such changes would affect non-target species, management options, and research opportunities.