期刊
SOIL BIOLOGY & BIOCHEMISTRY
卷 73, 期 -, 页码 69-83出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.soilbio.2014.02.008
关键词
Soil moisture; Heterotrophic respiration; Decomposition; Microbial biomass; Dormancy; Osmoregulation; Water stress
类别
资金
- Faculty of Natural Resources and Agricultural Sciences
- vice-chancellor of the Swedish University of Agricultural Sciences
- US National Science Foundation [DEB-1145875/1145649, CBET 1033467, EAR 1331846, EAR 1316258]
- US Department of Energy (DOE) through the Office of Biological and Environmental Research (BER) Terrestrial Carbon Processes (TCP) program [DE-SC0006967]
- Agriculture and Food Research Initiative from the USDA National Institute of Food and Agriculture [2011-67003-30222]
- Directorate For Geosciences
- Division Of Earth Sciences [1316258] Funding Source: National Science Foundation
- Division Of Environmental Biology
- Direct For Biological Sciences [1145875] Funding Source: National Science Foundation
- Division Of Environmental Biology
- Direct For Biological Sciences [1145649] Funding Source: National Science Foundation
- Div Of Chem, Bioeng, Env, & Transp Sys
- Directorate For Engineering [1033467] Funding Source: National Science Foundation
Soil microbes face highly variable moisture conditions that force them to develop adaptations to tolerate or avoid drought. Drought conditions also limit the supply of vital substrates by inhibiting diffusion in dry conditions. How these biological and physical factors affect carbon (C) cycling in soils is addressed here by means of a novel process-based model. The model accounts for different microbial response strategies, including different modes of osmoregulation, drought avoidance through dormancy, and extra-cellular enzyme production. Diffusion limitations induced by low moisture levels for both extracellular enzymes and solutes are also described and coupled to the biological responses. Alternative microbial life-history strategies, each encoded in a set of model parameters, are considered and their effects on C cycling assessed both in the long term (steady state ahalysis) and in the short term (transient analysis during soil drying and rewetting). Drought resistance achieved by active osmoregulation requiring large C investment is not useful in soils where growth in dry conditions is limited by C supply. In contrast, dormancy followed by rapid reactivation upon rewetting seems to be a better strategy in such conditions. Synthesizing more enzymes may also be advantageous because it causes larger accumulation of depolymerized products during dry periods that can be used upon rewetting. Based on key model parameters, a spectrum of life-history strategies thus emerges, providing a possible classification of microbial responses to drought. (C) 2014 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据