RT journal article
T1 Drivers of the microbial metabolic quotient across global grasslands
A1 Risch, A. C.
A1 Zimmermann, S.
A1 Schutz, M.
A1 Borer, E. T.
A1 Broadbent, A. A. D.
A1 Caldeira, M.C.
A1 Davies, K. F.
A1 Eisenhauer, N.
A1 Eskelinen, A.
A1 Fay, P. A.
A1 Hagedorn, F.
A1 Knops, J. M. H.
A1 Lembrechts, J. J.
A1 MacDougall, A. S.
A1 McCulley, R. L.
A1 Melbourne, B. A.
A1 Moore, J. L.
A1 Power, S.A.
A1 Seabloom, E. W.
A1 Silviera, M. L.
A1 Virtanen, R.
A1 Yahdjian, L.
A1 Ochoa Hueso, Raúl
A2 Biología
K1 anthropogenic management
K1 climate
K1 herbivore exclusion
K1 microbial biomass carbon
K1 microbial respiration
K1 nutrient addition
K1 Nutrient Network: A Global Research Cooperative (NutNet)
K1 soil properties
AB Aim: The microbial metabolic quotient (MMQ; mg CO2-C/mg MBC/h), defined as the amount of microbial CO2 respired (MR; mg CO2-C/kg soil/h) per unit of microbial biomass C (MBC; mg C/kg soil), is a key parameter for understanding the microbial regulation of the carbon (C) cycle, including soil C sequestration. Here, we experimentally tested hypotheses about the individual and interactive effects of multiple nutrient addition (nitrogen + phosphorus + potassium + micronutrients) and herbivore exclusion on MR, MBC and MMQ across 23 sites (five continents). Our sites encompassed a wide range of edaphoclimatic conditions; thus, we assessed which edaphoclimatic variables affected MMQ the most and how they interacted with our treatments. Location: Australia, Asia, Europe, North/South America. Time period: 2015–2016. Major taxa: Soil microbes. Methods: Soils were collected from plots with established experimental treatments. MR was assessed in a 5-week laboratory incubation without glucose addition, MBC via substrate-induced respiration. MMQ was calculated as MR/MBC and corrected for soil temperatures (MMQsoil). Using linear mixed effects models (LMMs) and structural equation models (SEMs), we analysed how edaphoclimatic characteristics and treatments interactively affected MMQsoil. Results: MMQsoil was higher in locations with higher mean annual temperature, lower water holding capacity and lower soil organic C concentration, but did not respond to our treatments across sites as neither MR nor MBC changed. We attributed this relative homeostasis to our treatments to the modulating influence of edaphoclimatic variables. For example, herbivore exclusion, regardless of fertilization, led to greater MMQsoil only at sites with lower soil organic C (< 1.7%). Main conclusions: Our results pinpoint the main variables related to MMQsoil across grasslands and emphasize the importance of the local edaphoclimatic conditions in controlling the response of the C cycle to anthropogenic stressors. By testing hypotheses about MMQsoil across global edaphoclimatic gradients, this work also helps to align the conflicting results of prior studies
PB Wiley
SN 1466-822X
YR 2023
FD 2023-04-04
LK http://hdl.handle.net/10498/29702
UL http://hdl.handle.net/10498/29702
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 05-nov-2026