Department of Biology, Colgate University, Hamilton, NY, United States of America.
Department of Biology, University of Puget Sound, Puget Sound, WA, United States of America.
PLoS One. 2019 Mar 6;14(3):e0212430. doi: 10.1371/journal.pone.0212430. eCollection 2019.
Land-use change can have profound effects on forest communities, compromising seedling recruitment and growth, and long-term persistence of forests on the landscape. Continued forest conversion to agriculture causes forest fragmentation which decreases forest size, increases edge effects and forest isolation, all of which negatively impact forest health. These fragmentation effects are magnified by human use of forests, which can compromise the continued persistence of species in these forests and the ability of the forests to support the communities that depend on them. We examined the extent and influence of human disturbance (e.g. weedy taxa, native and exotic tree plantations, clearings, buildings) on the ecological status of sacred church forests in the northern highlands of South Gondar, Ethiopia and hypothesized that disturbance would have a negative effect. We found that disturbance was high across all forests (56%) and was negatively associated with tree species richness, density, and biomass and seedling richness and density. Contrary to expectation, we found that forests < 15.5 ha show no difference in disturbance level with distance from population center. Based on our findings, we recommend that local conservation strategies not only protect large forests, but also the small and highly used forests in South Gondar which are critical to the needs of local people, including preserving large trees for seed sources, removing exotic and weedy species from forests, and reducing clearings and trails within forests.
土地利用变化会对森林群落产生深远的影响，破坏幼苗的繁殖和生长，以及森林在景观中长期的持续存在。持续将森林转换为农业用地会导致森林破碎化，减少森林面积，增加边缘效应和森林隔离，所有这些都会对森林健康产生负面影响。人类对森林的利用进一步放大了这些破碎化效应，可能会危及这些森林中物种的持续存在，以及森林维持依赖它们的社区的能力。我们调查了人类干扰（例如杂草类群、本地和外来的人工林、空地、建筑物）对埃塞俄比亚南贡德尔高地北部圣教堂森林生态状况的影响程度和影响，并假设干扰会产生负面影响。我们发现，所有森林的干扰程度都很高（56%），与树种丰富度、密度、生物量以及幼苗丰富度和密度呈负相关。与预期相反，我们发现，距离人口中心较近的小于 15.5 公顷的森林，其干扰水平与距离没有差异。基于我们的发现，我们建议当地保护策略不仅要保护大型森林，还要保护南贡德尔地区的小型和高度使用的森林，这些森林对当地人的需求至关重要，包括为种子来源保护大树、从森林中清除外来和杂草物种，以及减少森林内的空地和小径。
