17 - Productivity of Tropical Rain Forests

Abstract

Tropical rain forests exist in a broad band across the Earth's warm, moist equatorial regions. They are characterized by their great stature, a wide range of life forms (including many trees with buttresses, thick stemmed climbers, and herbaceous epiphytes), and a large number of tree species. Despite the importance of tropical rain forests as a store of carbon, their role in the carbon cycle is not well understood because they are extensive, variable, and generally more difficult to study than other vegetation types. This chapter discusses the progress in understanding the controls on net primary productivity and the related quantity, and the net ecosystem productivity, which requires close collaboration between disciplines. Studies at the leaf and stand scale, using eco physiological and eddy covariance techniques, are advancing one's understanding of the temporal changes. Thereafter, scaling up to whole regions and biomes still requires remotely sensed data on the distribution of land-surface cover, as well as the use of interpolated climatological data from the ground or from global circulation models to drive the models. There is a need to develop new approaches to this difficult problem, perhaps using large-scale experimentation and observation. One aspect of environmental change that has received attention is the influence of forest edges that are created during logging and burning.