MacNeil Jami E, Williams Rod N
Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana, United States of America.
PLoS One. 2014 Dec 17;9(12):e114683. doi: 10.1371/journal.pone.0114683. eCollection 2014.
Balancing timber production and conservation in forest management requires an understanding of how timber harvests affect wildlife species. Terrestrial salamanders are useful indicators of mature forest ecosystem health due to their importance to ecosystem processes and sensitivity to environmental change. However, the effects of timber harvests on salamanders, though often researched, are still not well understood. To further this understanding, we used artificial cover objects to monitor the relative abundance of terrestrial salamanders for two seasons (fall and spring) pre-harvest and five seasons post-harvest in six forest management treatments, and for three seasons post-harvest across the edge gradients of six recent clearcuts. In total, we recorded 19,048 encounters representing nine species of salamanders. We observed declines in mean encounters of eastern red-backed salamanders (Plethodon cinereus) and northern slimy salamanders (P. glutinosus) from pre- to post-harvest in group selection cuts and in clearcuts. However, we found no evidence of salamander declines at shelterwoods and forested sites adjacent to harvests. Edge effects induced by recent clearcuts influenced salamanders for approximately 20 m into the forest, but edge influence varied by slope orientation. Temperature, soil moisture, and canopy cover were all correlated with salamander counts. Our results suggest silvicultural techniques that remove the forest canopy negatively affect salamander relative abundance on the local scale during the years immediately following harvest, and that the depth of edge influence of clearcuts on terrestrial salamanders is relatively shallow (<20 m). Small harvests (<4 ha) and techniques that leave the forest canopy intact may be compatible with maintaining terrestrial salamander populations across a forested landscape. Our results demonstrate the importance of examining species-specific responses and monitoring salamanders across multiple seasons and years. Long-term monitoring will be necessary to understand the full impacts of forest management on terrestrial salamanders.
在森林管理中平衡木材生产与保护需要了解木材采伐如何影响野生动物物种。由于陆地蝾螈对生态系统过程的重要性以及对环境变化的敏感性，它们是成熟森林生态系统健康状况的有用指标。然而，尽管木材采伐对蝾螈的影响经常被研究，但仍未得到充分理解。为了进一步了解这一点，我们使用人工遮蔽物在六个森林管理处理中收获前的两个季节（秋季和春季）以及收获后的五个季节监测陆地蝾螈的相对丰度，并在六个近期皆伐地的边缘梯度上收获后的三个季节进行监测。我们总共记录了19048次相遇，涉及九种蝾螈。我们观察到，在群状择伐和皆伐中，从收获前到收获后，东部红背蝾螈（Plethodon cinereus）和北方黏蝾螈（P. glutinosus）的平均相遇次数有所下降。然而，我们没有发现庇护林和采伐附近的森林地区蝾螈数量下降的证据。近期皆伐引起的边缘效应影响森林内约20米范围内的蝾螈，但边缘影响因坡向而异。温度、土壤湿度和树冠覆盖都与蝾螈数量相关。我们的结果表明，去除森林树冠的造林技术在收获后的几年里会对当地尺度上蝾螈的相对丰度产生负面影响，并且皆伐对陆地蝾螈的边缘影响深度相对较浅（<20米）。小规模采伐（<4公顷）和保持森林树冠完整的技术可能与在森林景观中维持陆地蝾螈种群相兼容。我们的结果证明了检查物种特异性反应以及跨多个季节和年份监测蝾螈的重要性。有必要进行长期监测以了解森林管理对陆地蝾螈的全面影响。
