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We applied a microbial-explicit model – the CLM-Microbe – to investigate the dynamics of C in vegetation, litter, soil, and microbes during 1901-2016. The CLM-Microbe model was able to reproduce global averages and latitudinal trends of gross (GPP) and net (NPP) primary productivity, heterotrophic (HR) and soil (SR) respiration, biomass C in fungi (FBC) and bacteria (BBC) in the top 30 cm and 1 m, dissolved (DOC) and soil organic C (SOC) in the top 30 cm and 1 m. In addition, the CLM-Microbe model captured the grid-level variation in GPP (R2=0.78), NPP (R2=0.63), SR (R2=0.26), HR (R2=0.23), DOC in 0-30 cm (R2=0.2) and 0-1 m (R2=0.22), SOC in 0-30 cm (R2=0.36) and 0-1 m (R2=0.26), FBC (R2=0.22) and BBC (R2=0.32) in 0-30 cm, and MBC in 0-1 m (R2=0.21). From the 1900s to 2007-2016, simulated C variables increased by approximately 30 PgC yr-1 for GPP, 15 PgC yr-1 for NPP, 12 PgC yr-1 for HR, 25 PgC yr-1 for SR, 1.0 PgC for FBC and 0.4 PgC for BBC in 0-30 cm, 1.5 PgC for FBC, 0.8 PgC for BBC, 2.5 PgC for DOC, 40 PgC for SOC, and 5 PgC for litter C in 0-1 m, and 40 PgC for vegetation C. The relative increases in C fluxes and pools varied across the globe. Increases in vegetation C were closely related to warming and increased precipitation, while C accumulation in microbes and soils was jointly governed by vegetation C input and soil temperature and moisture.
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Macroecology Differentiation Between Bacteria and Fungi in Topsoil Across the United States
Abstract Bacteria and fungi possess distinct physiological traits. Their macroecology is vital for ecosystem functioning such as carbon cycling. However, bacterial and fungal biogeography and underlying mechanisms remain elusive. In this study, we investigated bacterial versus fungal macroecology by integrating a microbial‐explicit model—CLM‐Microbe—with measured fungal (FBC) and bacterial biomass carbon (BBC) from 34 NEON sites. The distribution of FBC, BBC, and FBC: BBC (F:B) ratio was well simulated across sites, with variations in 99% (P < 0.001), 97% (P < 0.001), and 99% (P < 0.001) being explained by the CLM‐Microbe model, respectively. We found stronger biogeographic patterns of FBC relative to BBC across the United States. Fungal and bacterial turnover rates showed similar trends along latitude. However, latitudinal trends of their component fluxes (carbon assimilation, respiration, and necromass production) were distinct between bacteria and fungi, with those latitudinal trends following inverse unimodal patterns for fungi and showing exponential declining responses for bacteria. Carbon assimilation was dominated by vegetation productivity, and respiration was dominated by mean annual temperature for bacteria and fungi. The dominant factor for their necromass production differs, with edaphic factors controlling fungal and mean annual temperature controlling bacterial processes. The understanding of fungal and bacterial macroecology is an important step toward linking microbial metabolism and soil biogeochemical processes. Distinct fungal and bacterial macroecology contributes to the microbial ecology, particularly on microbial community structure and its association with ecosystem carbon cycling across space.
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- Award ID(s):
- 2145130
- PAR ID:
- 10470984
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Global Biogeochemical Cycles
- Volume:
- 37
- Issue:
- 11
- ISSN:
- 0886-6236
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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