ABSTRACT
Since the beginning of agriculture, agroecosystems have been altering and displacing naturally occurring terrestrial ecosystems across the face of the earth. The ongoing process of converting land to agricultural production has had a dramatic and usually negative impact on the diversity of organisms and the integrity of ecological processes. Although other forms of human exploitation of the environment, such as urbanization and mining, have also contributed to large-scale habitat modification and the loss of biodiversity and ecosystem function, agricultural production — including grazing and timber production — bears much of the responsibility for causing environmental changes at the biosphere scale that threaten the world’s life-support systems.
