9810217

Chapin

The boreal forest plays a crucial role in determining the rate of global climate change because (1) changes in water and energy exchange could affect regional warming and (2) changes in carbon storage might affect the rate of climatic warming at the global scale. This LTER renewal proposal for the Bonanza Creek Long-term Ecological Research program seeks to understand the Alaskan boreal forest as an integrated regional system in which climate, disturbance regime and ecosystem processes are interactive components. The overall objective is to document the major controls over these interactions and their ecological and societal consequences. Disturbances are incorporated as an integral part of the regional system. Research will focus on how different disturbances affect population and ecosystem processes and the mechanisms by which these processes interact with climate to determine probability of insect outbreak and fire. Studies will focus on population processes that are best developed in boreal regions or which have the strongest ecosystem and societal consequences. These processes include plant succession following disturbance and the consequences of these successional changes for (1) species diversity, (2) population dynamics of mammals and insects, and (3) regional disturbance regimes. The ecosystem research focuses on the carbon cycle because changes in boreal carbon cycling have clear global consequences and because a predictive modeling of the carbon cycle requires an understanding of the underlying climatic, population, and ecosystem processes at stand and regional scales. The aquatic research will be integrally tied to the terrestrial program through an emphasis on hydrologic and disturbance impacts on aquatic community structure and function. These processes have immediate social relevance (e.g., regional and global climate, fire, insect outbreaks, timber, game populations, water quality, fish) because these integrate basic understanding and make results useful in influencing what will certainly be an increasing human impact on the boreal region.