Substrate availability and not thermal acclimation controls microbial temperature sensitivity response to long-term warming.

Autor: Domeignoz-Horta LA; Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA.; Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland., Pold G; Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden., Erb H; Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA., Sebag D; IFP Energies Nouvelles, Rueil-Malmaison, France.; Faculty of Geosciences and the Environment, Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland., Verrecchia E; Faculty of Geosciences and the Environment, Institute of Earth Surface Dynamics, University of Lausanne, Lausanne, Switzerland., Northen T; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.; The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA., Louie K; The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA., Eloe-Fadrosh E; The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA., Pennacchio C; The DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, California, USA., Knorr MA; School of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA., Frey SD; School of Natural Resources and the Environment, University of New Hampshire, Durham, New Hampshire, USA., Melillo JM; The Ecosystems Center, Marine Biological Laboratories, Woods Hole, Massachusetts, USA., DeAngelis KM; Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA.
Jazyk: angličtina
Zdroj: Global change biology [Glob Chang Biol] 2023 Mar; Vol. 29 (6), pp. 1574-1590. Date of Electronic Publication: 2022 Dec 14.
DOI: 10.1111/gcb.16544
Abstrakt: Microbes are responsible for cycling carbon (C) through soils, and predicted changes in soil C stocks under climate change are highly sensitive to shifts in the mechanisms assumed to control the microbial physiological response to warming. Two mechanisms have been suggested to explain the long-term warming impact on microbial physiology: microbial thermal acclimation and changes in the quantity and quality of substrates available for microbial metabolism. Yet studies disentangling these two mechanisms are lacking. To resolve the drivers of changes in microbial physiology in response to long-term warming, we sampled soils from 13- and 28-year-old soil warming experiments in different seasons. We performed short-term laboratory incubations across a range of temperatures to measure the relationships between temperature sensitivity of physiology (growth, respiration, carbon use efficiency, and extracellular enzyme activity) and the chemical composition of soil organic matter. We observed apparent thermal acclimation of microbial respiration, but only in summer, when warming had exacerbated the seasonally-induced, already small dissolved organic matter pools. Irrespective of warming, greater quantity and quality of soil carbon increased the extracellular enzymatic pool and its temperature sensitivity. We propose that fresh litter input into the system seasonally cancels apparent thermal acclimation of C-cycling processes to decadal warming. Our findings reveal that long-term warming has indirectly affected microbial physiology via reduced C availability in this system, implying that earth system models including these negative feedbacks may be best suited to describe long-term warming effects on these soils.
(© 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz: