The Terrestrial Biosphere and Global Change: Implications for Natural and Managed Ecosystems

From the perspective of terrestrial ecosystems, the most important component of global change over the next three or four decades will likely be land-use/cover change. It is driven largely by the need to feed the expanding human population, expected to increase by almost one billion (109) people per decade for the next three decades at least. Much of this increase will occur in developing countries in the low-latitude regions of the world. To meet the associated food demand, crop yields will need to increase, consistently, by over 2% every year through this period. Despite advances in technology, increasing food production must lead to intensification of agriculture in areas which are already cropped, and conversion of forests and grasslands into cropping systems. Much of the latter will occur in semi-arid regions and on lands which are marginally suitable for cultivation, increasing the risk of soil erosion, accelerated water use, and further land degradation.