Tropical forests are thermally buffered despite intensive selective logging

• Published in: Global change biology Vol. 24; no. 3; pp. 1267 - 1278
• Main Authors: Senior, Rebecca A., Hill, Jane K., Benedick, Suzan, Edwards, David P.
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.03.2018
• Subjects: Availability; Biodiversity; Borneo; Buffers; Climate change; Dead wood; Forest floor; forest litter; forest types; Forests; Global warming; land‐use change; Leaf litter; Leaves; Logging; Microclimate; microhabitat; microprocessors; primary forests; Rainforests; refuge habitats; Refugia; selective logging; Temperature; Temperature effects; thermal buffering; thermal camera; Thermal stability; tree cavities; Tropical climate; Tropical forests; tropical rain forests; tropics; Borneo; selective logging; microclimate; microhabitat; thermal buffering; thermal camera; tropics; land-use change; climate change
• ISSN: 1354-1013; 1365-2486; 1365-2486
• DOI: 10.1111/gcb.13914

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. Selectively logged tropical forests harbour much of the world's terrestrial biodiversity; their ability to do so in the long term will depend in part on the extent to which temperature‐sensitive species can respond to climate change in situ. Using thermal images and temperature dataloggers, we found that—despite major differences in forest structure—thermal buffering potential in intensively logged forest on Borneo was comparable to that of undisturbed primary forest. Selectively logged forests can therefore play a crucial role in the long‐term maintenance of global biodiversity