Bird Communities in Forest Openings at Harvard Forest 2014-2015

Currently, many of the most severely declining neotropical migrants in the northeastern United States are disturbance dependent, early-successional species. Much of their decline is attributed to loss of suitable habitat. Large clearcuts (>5.0 ha) are widely considered to be optimal habitat for most shrubland bird species. However, it is well documented that certain species are capable of breeding within significantly smaller patches of habitat (less than 2.0 ha), which are most commonly created through group selection harvest cuttings. The goal of this research is to determine habitat characteristics translatable to habitat value for shrubland birds for use in conservation programs to maximize biological value. This research will provide an assessment of the value of forest openings for shrubland birds, helping to define the suitability of forest canopy openings for specific bird species. This project will describe the conservation value of shrubland openings deemed too small to sustain full suites of specialist shrubland birds by providing threshold patch area values for individual species able to use these smaller patches.

当前，美国东北部种群衰减最为显著的新热带界迁徙鸟类（Neotropical Migrant）多为依赖干扰的早期演替物种。其种群数量下降多归因于适宜栖息地的丧失。学界普遍认为，面积大于5.0公顷的大型皆伐迹地是多数灌丛鸟类的最优栖息地。但已有充分文献证实，部分物种可在面积显著更小的栖息地斑块（<2.0公顷）内繁殖，这类小型斑块通常通过分组择伐作业（group selection harvest cuttings）形成。本研究旨在明确可用于表征灌丛鸟类栖息地价值的生境特征，服务于以最大化生物价值为目标的保护项目。本研究将评估林隙对灌丛鸟类的保育价值，助力界定林冠间隙对特定鸟类物种的适宜性。本项目将为可利用此类小型斑块的单个物种划定斑块面积阈值，以此阐明被认为过小、无法维持完整特化灌丛鸟类类群的灌丛林隙的保护价值。