Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.
Department of Biology, University of York, York, UK.
Glob Chang Biol. 2018 Mar;24(3):1267-1278. doi: 10.1111/gcb.13914. Epub 2017 Oct 20.
Tropical rainforests are subject to extensive degradation by commercial selective logging. Despite pervasive changes to forest structure, selectively logged forests represent vital refugia for global biodiversity. The ability of these forests to buffer temperature-sensitive species from climate warming will be an important determinant of their future conservation value, although this topic remains largely unexplored. Thermal buffering potential is broadly determined by: (i) the difference between the "macroclimate" (climate at a local scale, m to ha) and the "microclimate" (climate at a fine-scale, mm to m, that is distinct from the macroclimate); (ii) thermal stability of microclimates (e.g. variation in daily temperatures); and (iii) the availability of microclimates to organisms. We compared these metrics in undisturbed primary forest and intensively logged forest on Borneo, using thermal images to capture cool microclimates on the surface of the forest floor, and information from dataloggers placed inside deadwood, tree holes and leaf litter. Although major differences in forest structure remained 9-12 years after repeated selective logging, we found that logging activity had very little effect on thermal buffering, in terms of macroclimate and microclimate temperatures, and the overall availability of microclimates. For 1°C warming in the macroclimate, temperature inside deadwood, tree holes and leaf litter warmed slightly more in primary forest than in logged forest, but the effect amounted to <0.1°C difference between forest types. We therefore conclude that selectively logged forests are similar to primary forests in their potential for thermal buffering, and subsequent ability to retain temperature-sensitive species under climate change. Selectively logged forests can play a crucial role in the long-term maintenance of global biodiversity.
热带雨林受到商业选择性采伐的广泛退化。尽管森林结构发生了普遍变化，但选择性采伐的森林仍是全球生物多样性的重要避难所。这些森林缓冲对温度敏感物种免受气候变暖影响的能力将是其未来保护价值的一个重要决定因素，尽管这个主题在很大程度上仍未得到探索。热缓冲潜力主要由以下因素决定：（i）“宏气候”（局部尺度的气候，m 到 ha）和“微气候”（与宏气候不同的精细尺度气候，mm 到 m）之间的差异；（ii）微气候的热稳定性（例如，日温度的变化）；以及（iii）微气候对生物的可用性。我们在婆罗洲比较了未受干扰的原始森林和密集采伐的森林中的这些指标，使用热图像捕捉森林地面表面的凉爽微气候，并使用放置在枯木、树洞和落叶层内的数据记录器中的信息。尽管在反复选择性采伐后 9-12 年内森林结构仍存在显著差异，但我们发现，就宏气候和微气候温度以及微气候的总体可用性而言，采伐活动对热缓冲的影响很小。对于宏气候升温 1°C，枯木、树洞和落叶层内的温度在原始森林中比在采伐森林中略高，但两种森林类型之间的差异仅为 0.1°C。因此，我们得出结论，选择性采伐的森林在热缓冲潜力及其在气候变化下保留对温度敏感物种的后续能力方面与原始森林相似。选择性采伐的森林可以在长期维护全球生物多样性方面发挥关键作用。
