Abstract
Microbial carbon use efficiency (CUE) describes the partitioning of carbon (C) between respiration and growth, and this defines the soil-atmosphere C balance. Despite its importance, CUE is not properly represented in soil biogeochemical models. Here, we estimated how CUE varied in soil along a continental gradient. Through a structural equation model, we found that bacterial growth, fungal community composition, and SOM quality were the main drivers of CUE variation. Biotic factors controlled CUE directly, while soil properties and climate indirectly controlled CUE via biotic factors. Surprisingly, we found that microbial assimilability of SOM had a negative relationship with CUE. High rates of microbial SOM-use coincided with a greater growth-fraction used for respiration suggesting decoupled catabolism and anabolism, probably due to nutrient limitation. Our study highlights the importance of the microbial community composition to predict CUE and that interactions between bacterial and fungal communities can have implications for CUE.
Originalsprog | Engelsk |
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Artikelnummer | 109394 |
Tidsskrift | Soil Biology and Biochemistry |
Vol/bind | 193 |
Antal sider | 5 |
ISSN | 0038-0717 |
DOI | |
Status | Udgivet - jun. 2024 |
Udgivet eksternt | Ja |
Bibliografisk note
Funding Information:We thank colleagues from the Microbial Ecology Group at Lund University for help with soil sampling, and Dániel Tájmel for his help conducting microbial growth measurements. This work was supported by the Danmarks Frie Forskningsfond (DFF, grant no. 9036-00004B ), the Swedish Research Council Vetenskapsrådet (VR, grant no. 2020-04083 ) and the Knut and Alice Wallenberg Foundation (grant no. KAW 2017.0171 , KAW 2022.0175 ). The research is a contribution to the strategic research area Biodiversity and Ecosystems in a Changing Climate (BECC) at Lund University.
Emneord
- Carbon use efficiency
- Fungal growth
- Microbial community composition