LAn Assessment of the Environmental Impact of Genetically Modified Crops in the US

摘要

Genetically modified (GM) crops have become important components of modern agriculture in the past ten years. The United States had over 39 million hectares of GM crops grown in 2002 with much of these hectares comprised of Bt corn, Bt cotton, and herbicide tolerant (HT) soybeans. Commercialization of GM crops has been more limited in other areas, such as the EU. This paper describes the information collected to address ecological risks in the US as part of the initial regulatory process and providesa review of new information derived since commercialization, with a focus on field data. Field studies for Bt corn, Bt cotton, and HT crops in the US are reviewed specifically for impacts on arthropod populations and results show no consistent unexpected findings in abundance. Indeed, the adoption of these products can have direct and indirect benefits for the environment by the replacement of broad-spectrum insecticides and the facilitation of reduced tillage. The results of the field studies are discussed within the context of overall biodiversity in agroecosystems.