Microbial carbon use efficiency: accounting for population, community, and ecosystem-scale controls over the fate of metabolized organic matter

By E. Kyker-Snowman, Serita Frey. Biogeochemistry, 2016

368 citations recorded by the source corpus.

Microbial carbon use efficiency (CUE) is a critical regulator of soil organic matter dynamics and terrestrial carbon fluxes, with strong implications for soil biogeochemistry models. While ecologists increasingly appreciate the importance of CUE, its core concepts remain ambiguous: terminology is inconsistent and confusing, methods capture variable temporal and spatial scales, and the significance of many fundamental drivers remains inconclusive. Here we outline the processes underlying microbial efficiency and propose a conceptual framework that structures the definition of CUE according to increasingly broad temporal and spatial drivers where (1) CUEP reflects population-scale carbon use efficiency of microbes governed by species-specific metabolic and thermodynamic constraints, (2) CUEC defines community-scale microbial efficiency as gross biomass production per unit substrate taken up over short time scales, largely excluding recycling of microbial necromass and exudates, and (3) CUEE reflects the ecosystem-scale efficiency of net microbial biomass production (growth) per unit substrate taken up as iterative breakdown and recycling of microbial products occurs. CUEE integrates all internal and extracellular constraints on CUE and hence embodies an ecosystem perspective that fully captures all drivers of microbial biomass synthesis and decay. These three definitions are distinct yet complementary, capturing the capacity for carbon storage in microbial biomass across different ecological scales. By unifying the existing concepts and terminology underlying microbial efficiency, our framework enhances data interpretation and theoretical advances.

Subfields: Ecology, Soil Science

View Paper: https://www.semanticscholar.org/paper/cb2e7f0c3d3d940d2572511e57a8aa58bd39a0ae

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Citations in the corpus

Pathways of mineral‐associated soil organic matter formation: Integrating the role of plant carbon source, chemistry, and point of entry (2018, background): “…by which a substrate is biosynthesized by the microbial community is determined by several factors (Manzoni et al., 2012), but we focus here on the biochemical properties of the substrate that are associated with high carbon‐use efficiency at the microbial community scale (Geyer et al., 2016).”
Microbial carbon use efficiency promotes global soil carbon storage (2023, background): “A high CUE promotes biosynthesis in microbial carbon metabolism 12,13 , causes the accumulation of microbial by-products and nec-romass that favours SOC formation (for example, via the entombing effect) 5,9,29,30 , and could generate a positive relationship between CUE and SOC storage (Fig.”
The Ecology of Soil Carbon: Pools, Vulnerabilities, and Biotic and Abiotic Controls (2017, background): “Microbial CUE is often expressed as the ratio of growth to carbon uptake (Geyer et al. 2016); thus, systems with high CUE have lower respiratory losses of substrate than do systems with low CUE and therefore, presumably, store more soil carbon.”