Temperature sensitivity of termites determines global wood decay rates

Abstract

Animals, such as termites, have largely been overlooked as global-scale drivers of biogeochemical cycles1,2, despite site-specific findings3,4. Deadwood turnover, an important component of the carbon cycle, is driven by multiple decay agents. Studies have focused on temperate systems5,6, where microbes dominate decay7. Microbial decay is sensitive to temperature, typically doubling per 10°C increase (decay effective Q10 = ~2)8–10. Termites are important decayers in tropical systems3,11–13 and differ from microbes in their population dynamics, dispersal, and substrate discovery14–16, meaning their climate sensitivities also differ. Using a network of 133 sites spanning 6 continents, we report the first global field-based quantification of temperature and precipitation sensitivities for termites and microbes, providing novel understandings of their response to changing climates. Temperature sensitivity of microbial decay was within previous estimates. Termite discovery and consumption were both much more sensitive to temperature (decay effective Q10 = 6.53), leading to striking differences in deadwood turnover in areas with and without termites. Termite impacts were greatest in tropical seasonal forests and savannas and subtropical deserts. With tropicalization17 (i.e., warming shifts to a tropical climate), the termite contribution to global wood decay will increase as more of the earth’s surface becomes accessible to termites.

Why are trees hollow? Termites, microbes, and tree internal stem damage in a tropical savanna

“…CH4 has a greater climate warming potential compared to CO2, meaning shifts between microbial-and termite-mediated wood decay may have different feedbacks in the Earth system. Investigation of such questions is an important next step given that global climate models predict increased termite-driven wood decomposition in savanna ecosystems under hotter, drier conditions (Zanne et al, 2022).…”

“…Microbes are important biotic wood decomposers in ecosystems around the globe (Cornwell et al, 2009; Ulyshen 2016), while termites are especially important in dry tropical ecosystems, both in living trees which they frequently hollow (Werner & Prior 2007) and in fallen deadwood (Zanne et al, 2022;Wijas, Flores-Moreno et al, 2024). However, microbes and termites differ in wood decomposition strategies, which impacts wood C storage and release.…”