ABSTRACT
Human beings have gradually increased in numbers and expanded the extent and range of their activity, eventually gaining dominance over, and drastically modifying, entire terrestrial and marine biomes for food production throughout the world. Consequently, numerous other species have been endangered or even eradicated. Recent calculations suggest that rates of species extinctions are now on the order of 100 to 1000 times those before humans dominated the Earth. For some welldocumented groups, extinctions are even greater. Over the past 2000 years, humans have driven to extinction as many as one-quarter of Earth’s bird species (Steadman 1995). Unless checked, the continued increase of human population and the intensified manipulation of the environment for short-term advantage threaten to turn human success into eventual failure. Having tampered with
11.1 Introduction ......................................................................................................................... 167 11.2 Historical Background ......................................................................................................... 168 11.3 Dependence of Agriculture on Biodiversity ........................................................................ 170 11.4 Functions and Effects of Biodiversity in Agriculture.......................................................... 171
11.4.1 Pollinators ................................................................................................................ 171 11.4.2 Insect Pests .............................................................................................................. 172 11.4.3 Disease Control ....................................................................................................... 175 11.4.4 Birds ........................................................................................................................ 176
11.5 Cultivated Plants and Wild Relatives .................................................................................. 176 11.6 Genetic Bases of Agricultural Crops ................................................................................... 178 11.7 Biodiversity in the Soil ........................................................................................................ 178 11.8 Genetic Modification of Food Species ................................................................................ 181
11.8.1 Opportunities and Potential Risks ........................................................................... 181 11.8.2 Biosafety Issues ....................................................................................................... 183
11.9 Climate Change and Agricultural Biodiversity ................................................................... 185 11.9.1 Shifts in Agroecological Zones ............................................................................... 186 11.9.2 Pests and Climate Change ....................................................................................... 187 11.9.3 Climate Change and Biotechnology ........................................................................ 188
11.10 Conserving Biodiversity and Sustaining Food Production ................................................. 188 Acknowledgments .......................................................................................................................... 189 References ...................................................................................................................................... 189
nature in hopes of gaining control over it, humans are now more dependent than ever on its complex workings, in which the diversity and intrinsic mutuality of all life forms are essential factors.
