Partial Harvesting Regimes as Management Tools for Forested Landscape Mosaics

了解个别树木之间的相互作用的影响是发展森林生态系统的可持续管理的关键，特别是在混合物种，年龄不等的林分。制定可持续林业处方战略的独特挑战之一是管理采伐和剩余树木分布的斑块以及这种斑块如何影响未来的林分动态。任何给定的部分采伐的长期后果将是剩余林分的即时配置和剩余树木随后的生长的函数。预测这些长期的，部分采伐的间接影响，需要使用基于数据的森林动态模拟模型。建议的研究将收获的影响到一个空间明确的森林动态模型（SORTIE）。我建议使用在南部新英格兰森林获得的数据，探讨不同的采伐制度的影响，竞争性的相互作用，确定增长和生存的残留树木，因此对不同的采伐制度所产生的景观格局。这是发展造林制度的一个关键组成部分，这种制度要保持林分组成和结构的多样性，同时提供经济上可行的产量。森林管理者需要帮助来确定给定林分的部分采伐的最佳空间格局。该格局将是现有林分结构和组成以及未来期望的林分结构和组成的函数。 拟议的研究将探讨树种多样性和丰富度对森林动态和林分生物量生产的影响。这是生态学中一个重要的理论问题，很少用树木群落来探讨。SORTIE提供了一个机制框架来量化物种特异性过程的贡献（即，补充、生长或死亡率）对物种丰度和林分生物量的影响。了解物种间相互作用的群落后果对于联系植物群落的过程和格局至关重要。量化这些相互作用的大小和意义也是生态学中一个重要和正在进行的辩论的核心，特别是竞争的重要性（即，生态位分化）在构建自然植物群落中的作用。

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 structuringnatural plant communities.