This program focuses on population and ecosystem level questions within the framework of succession. It capitalizes on a substantial existing base of information and preliminary results from past research to address hypothesized controls of structure and function of successional forest communities. These processes previously have not been examined in a comprehensive manner in the North American taiga. Results of this research will greatly improve understanding of the links between resource (moisture, light, nutrients) supply and plant growth as influenced by herbivores and soil microbial activity. Researchers in interior Alaska have demonstrated their commitment to long-term studies of ecological processes. Several studies have been pursued, essentially by the same scientists for 20 to 25 years. For example a series of plots in various successional stages on the floodplain of the Chena and Tanana rivers established in 1964, are still being monitored for growth and changes in species composition. The USDA Forest Service also is committed to long-term experimentation and encourages these activities through their management of Bonanza Creek Experimental Forest, the principal site of this research. The hypotheses put forth in this proposal address important long- term aspects of forest ecosystem structure and function only initially evaluated in earlier research efforts. During this new phase initial experiments will be continued and new hypotheses will be addressed based on some initial results. Considering questions dealing with taiga forest ecology from a successional standpoint establishes a strong organizational structure for the research and promotes linkage among research projects and feedback of ideas and information among personnel. The structure and objectives of this project take advantage of existing knowledge, current research activities, and an experienced group of investigators, melding them in a combination which will promote the type of interaction necessary for advancing scientific understanding of the ecology of taiga forest ecosystems, and insuring success of a long-term ecological research program.
