Department of Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, MT, 59717, United States.
Department of Land Resources and Environmental Sciences, Montana State University, 334 Leon Johnson Hall, Bozeman, MT, 59717, United States.
J Environ Manage. 2022 Oct 1;319:115729. doi: 10.1016/j.jenvman.2022.115729. Epub 2022 Jul 16.
Forest roads fragment and degrade ecosystems and many have fallen into disrepair and are underutilized, to address these issues the United States Forest Service is restoring, or "decommissioning," thousands of kilometers of forest roads each year. Despite the prevalence of decommissioning and the importance of vegetation to restoration success, relatively little is known about floristic responses to different forest road decommissioning treatments or subsequent recovery to reference conditions. Over a ten year period, this study assessed floristic cover, diversity, and composition responses to and recovery on forest roads decommissioned using three treatments varying in intensity (abandonment, ripping, recontouring), in Montana, USA. Initially, floristic cover groups were lowest on the recontoured roads, however, they demonstrated the fastest temporal response (e.g. increased litter and vegetative cover). The floristic communities of both active treatments (ripped and recontoured) had more species and were more diverse than the communities of the abandoned (control) treatment. Among the three on-road plant communities, the recontoured treatment was most associated with desirable species, including the native shrubs Rosa woodsii and Spirea betulifolia, while the abandoned treatment was most associated with two non-native species, Taraxacum officinale and Trifolium repens. Assessed using a restoration index, recovery to reference conditions was limited in all treatments, however, the recontoured treatment had a positive restoration trajectory in seven of eight metrics and was the best recovered treatment. Community composition on the recontoured treatment had more native species than the other treatments, and was moving toward, though still substantially different from, reference communities. These findings demonstrate that restoration of forest roads benefit from active restoration methods and, while forest road recontouring facilitates floristic recovery in the first decade after decommissioning, full recovery will likely take years to decades longer.
森林道路会使生态系统破碎化和退化，许多道路已经失修且未被充分利用。为了解决这些问题，美国林务局每年都会修复或“退役”数千公里的森林道路。尽管退役现象普遍存在，植被对恢复成功也很重要，但人们对不同森林道路退役处理方式的植物区系响应以及随后恢复到参考条件的情况知之甚少。在十年的时间里，这项研究评估了蒙大拿州森林道路退役后使用三种不同处理方式（弃置、开沟、重新塑形）的植物覆盖度、多样性和组成的响应和恢复情况。最初，重新塑形道路上的植物覆盖度最低，但它们表现出最快的时间响应（例如，增加了凋落物和植被覆盖）。两种活跃处理（开沟和重新塑形）的植物群落的物种数量和多样性都高于废弃（对照）处理的群落。在三种道路内的植物群落中，重新塑形处理与理想物种的关联度最高，包括本地灌木 Rosa woodsii 和 Spirea betulifolia，而废弃处理与两种非本地物种 Taraxacum officinale 和 Trifolium repens 的关联度最高。使用恢复指数评估，所有处理方式的恢复到参考条件都受到限制，但重新塑形处理在八项指标中的七个指标上具有积极的恢复趋势，是恢复效果最好的处理方式。重新塑形处理的群落组成比其他处理方式具有更多的本地物种，并且正在向参考群落靠拢，尽管仍有很大差异。这些发现表明，森林道路的修复受益于积极的修复方法，虽然森林道路的重新塑形在退役后的头十年促进了植物区系的恢复，但完全恢复可能需要数年到数十年的时间。
