As the global climate changes, there are concomitant changes in global biological productivity. This book is devoted to the assessment of terrestrial Net Primary Productivity ("the total amount of energy acquired by green plants during photosynthesis, minus the energy lost through respiration"--APDS&T, pp. 1457). The book is comprised of three major sections. The first section is a review of the processes that operate globally to influence productivity--these are the initial conditions of any model of primary productivity. The second section is comprised of chapters that assess the contribution of particular ecosystems to global productivity. The final major section contains chapters of a synthetic nature that describe attempts to model global productivity. This book should appeal to both ecologists and environmental scientists.