Understanding the effects of interactions between individual trees is critical to the development of sustainable management of forest ecosystems, particularly in mixed-species, uneven-aged stands. One of the unique challenges to developing prescription strategies for sustainable forestry is the management of patchiness in the distribution of both harvested and residual trees and how that patchiness affects future stand dynamics. The long-term consequences of any given partial harvest will be a function of both the immediate configuration of the residual stand and the subsequent growth of residual trees. Predicting these long-term, indirect effects of partial harvesting requires the use of data-based simulation model of forest dynamics. The proposed research incorporates harvest effects into a spatially-explicit model of forest dynamics (SORTIE). I propose to use data obtained in southern New England forests to explore the implications of different harvesting regimes on the competitive interactions that determine growth and survival of the residual trees, and therefore on the landscape patterns generated by different harvesting regimes. This is a critical component of the development of silvicultural systems that maintain diverse stand composition and structure, while providing economically viable yields. Forest managers need help to determine the optimal spatial pattern of partial cutting in a given stand. The pattern will be a function of existing stand structure and composition, and desired stand structureand composition in the future.
The proposed research will explore the implications of tree species diversity and abundance on forest dynamics and stand biomass production. This is an important theoretical question in ecology which has rarely been explored using tree communities. SORTIE provides a mechanistic framework to quantify the contribution of species-specific processes (i.e., recruitment, growth or mortality) on both species abundance and stand biomass. Understanding the community consequences of interactions between species is essential to linking process and pattern in plant communities. Quantifying the magnitude and significance of these interactions is also at the heart of an important and ongoing debate in ecology, amely the importance of competition (i.e., niche differentiation) in structuring natural plant communities.
