Abstract Prescribed fire and other forest management practices aimed at restoring longleaf pine (Pinus palustris) communities often focus on the reduction, or removal, of upland hardwoods with the goal of providing habitat for threatened and endangered plant and animal species, including the federally endangered red-cockaded woodpecker (Leuconotopicus borealis), and restoring forests to pre-settlement conditions. Although contemporary restoration and management practices benefit species dependent on the resulting conditions, recent research has called attention to the ecological value of retaining upland hardwoods, especially for mast-dependent wildlife (e.g., fox squirrels [Sciurus niger]). Moreover, retention of indigenous hardwoods in upland longleaf pine communities may benefit a variety of birds. We used fixed-radius, breeding season point counts to sample the presence-absence of 15 avian species and assessed forest composition and structure around each point. We developed single-season single-species occupancy models with an emphasis on the influence of overstory hardwood cover on occupancy. Due to issues with model fit, we were unable to model occupancy for 3 of the 15 focal species. Occupancy probabilities for 6 out of the 12 focal species were positively influenced by overstory hardwood cover or stem density, whereas occupancy probabilities of 4 out of 12 of the focal species was negatively influenced by hardwood cover or stem density. Overstory hardwood cover between 5 and 15% resulted in high occupancy probabilities for the species that were positively influenced but did not result in substantially low occupancy probabilities for the species that were negatively influenced. Longleaf pine uplands with lower and upper bounds of 5% to 15% hardwood overstory cover with hardwood stem densities of ≤250 stems/ha could be targeted to provide habitat for the greatest diversity of birds while avoiding negative impact to species associated with upland longleaf pine communities.

中文翻译：

---

火保持长叶松林旱地阔叶木分布与鸟类占有率的关系

摘要 旨在恢复长叶松（Pinus palustris）群落的规定火灾和其他森林管理实践通常侧重于减少或清除高地硬木，目的是为受威胁和濒临灭绝的动植物物种提供栖息地，包括联邦濒危红松- 冠啄木鸟 (Leuconotopicus borealis)，并将森林恢复到定居前的条件。尽管当代的恢复和管理实践使依赖于所产生条件的物种受益，但最近的研究已引起人们对保留高地硬木的生态价值的关注，特别是对于依赖桅杆的野生动物（例如，狐狸松鼠 [Sciurus niger]）。此外，在山地长叶松群落中保留本地硬木可能有益于多种鸟类。我们使用固定半径，繁殖季节点计数以对 15 种鸟类的存在与否进行抽样，并评估每个点周围的森林组成和结构。我们开发了单季单树种占用模型，重点是上层硬木覆盖对占用的影响。由于模型拟合问题，我们无法模拟 15 个焦点物种中的 3 个的占用情况。12 个焦点树种中有 6 个的占用概率受到上层硬木覆盖或茎密度的积极影响，而 12 个焦点树种中有 4 个的占用概率受到硬木覆盖或茎密度的负面影响。5% 至 15% 的上层硬木覆盖率导致受到正面影响的物种的占用概率较高，但并未导致受到负面影响的物种的占用概率显着降低。长叶松高地的上下界为 5% 至 15% 的硬木覆盖层，硬木茎密度≤250 茎/公顷，可以作为目标，为最多样化的鸟类提供栖息地，同时避免对与高地长叶松相关的物种产生负面影响社区。