Simulation of Forest System Response and Feedbacks to Global Change - Abstract

Large shifts in the response and feedbacks of forest systems are implied by models and systems analysis driven by global change scenarios of General Circulation Models (GCMs). Prior climate change analyses and modelling efforts have been reported at a global scale and in a few developed countries but relatively few developing country or national assessments have been successfully completed.

Under the auspices of the U:S. Country Studies Program, analysts from 55 countries employed a common set of methods and models to characterise current carbon pools in forest, future impacts of global change on forest distribution, and management options to conserve and sequester carbon dioxide in forest system. The analysis revealed the response and feedbacks of forest system to global climate change will be profound in the 55 countries studied on five continents. Globally, forest vegetation and soil contain about 1,146 Pg C, with approximately 37% of this C in low-latitude forest, 14 % in mid-latitudes, and 49% at high latitudes.

The impacts of future global change on forest distribution and productivity will be most significant at high latitudes, with more modest changes in distribution an productivity at low latitudes. Future opportunities to conserve and sequester carbon dioxide in forest system are potentially significant, but future land-use practices and global change will both influence the size of this carbon pool and carbon dioxide sink. In the future, a great proportion of forests at all latitudes could become a greenhouse gas (GHG) source if sustained management and conservation policies are not employed. The timing and magnitude of future changes in forest system are dependent on global environmental factors (for example, global change, biogeochemical sulphur and nitrogen cycles), as well as human factors such as demographics, economic growth, technology, and resource management policies.