New insights into global decomposition: Wood decay by termites show high sensitivity to warming

H FLORES-MORENO; A AUSTIN; W CORNWELL; J DALLING; P EGGLETON; J POWELL

New Orleans

Congreso; American Geophysical Union Annual Meeting; 2021

American Geophysical Union

lobally, woody tissue decomposition is a key driver of carbon flux between the biosphere and atmosphere. Woody species represent ~50% of extant plant diversity and store ~457 Gt of carbon. Biotic agents (microbes and invertebrates) are key players in the decomposition of plant woody tissue. The relative contributions of these agents is shaped by abiotic factors and has consequences for both the rate of decomposition and fate of carbon that is released. The interaction among these abiotic and biotic factors is poorly understood within and across ecosystems worldwide and is not modelled explicitly, decreasing the realism and accuracy of dynamic global vegetation and biogeochemical models. In 129 sites on all continents except Antarctica, we replicated a decomposition experiment using a common substrate of Pinus radiata wood, with a common experimental design over a common sampling time-period in which we allowed or excluded soil macrofauna access. Termite discovery of the substrates was greater closer to the equator. Post-discovery termite consumption rates were highly sensitive to temperature (Q10 = 6.5) and much greater than for microbial decay (Q10 = 1.8). Microbial decay and its temperature sensitivity is thought to be governed by enzyme kinetics, but there is little reason to believe that these rules also govern termite activity. The high temperature sensitivity of termite activity is a new mechanism that may lead to much faster decomposition and less carbon storage in tropical forests as the globe warms.