Stoichiometry of microbial carbon use efficiency in soils

作者：Robert L. Sinsabaugh, Benjamin L. Turner, Jennifer M. Talbot, Bonnie G. Waring, Jennifer S. Powers, Cheryl R. Kuske, Daryl Moorhead, Jennifer J. Follstad Shah · 发表于：Ecological Monographs · 年份：2016 · DOI：10.1890/15-2110.1 · 被引用次数：559 · 研究领域：Soil Carbon and Nitrogen Dynamics、Soil and Water Nutrient Dynamics、Peatlands and Wetlands Ecology

Abstract The carbon use efficiency ( CUE ) of microbial communities partitions the flow of C from primary producers to the atmosphere, decomposer food webs, and soil C stores. CUE , usually defined as the ratio of growth to assimilation, is a critical parameter in ecosystem models, but is seldom measured directly in soils because of the methodological difficulty of measuring in situ rates of microbial growth and respiration. Alternatively, CUE can be estimated indirectly from the elemental stoichiometry of organic matter and microbial biomass, and the ratios of C to nutrient‐acquiring ecoenzymatic activities. We used this approach to estimate and compare microbial CUE in >2000 soils from a broad range of ecosystems. Mean CUE based on C:N stoichiometry was 0.269 ± 0.110 ( mean ± SD ). A parallel calculation based on C:P stoichiometry yielded a mean CUE estimate of 0.252 ± 0.125. The mean values and frequency distributions were similar to those from aquatic ecosystems, also calculated from stoichiometric models, and to those calculated from direct measurements of bacterial and fungal growth and respiration. CUE was directly related to microbial biomass C with a scaling exponent of 0.304 (95% CI 0.237–0.371 ) and inversely related to microbial biomass P with a scaling exponent of −0.234 (95% CI −0.289 to −0.179 ). Relative to CUE , biomass specific turnover time increased with a scaling exponent of 0.509 (95% CI 0.467–0.551). CUE increased weakly with mean annual temperature....