Biocrust contribution to ecosystem carbon fluxes varies along an elevational gradient
- Department of Biology MSC03 2020, 1 University of New Mexico Albuquerque New Mexico 87131 USA
Abstract Understanding how each component of an ecosystem contributes to carbon fluxes across a range of abiotic conditions enables accurate forecasts for future emission scenarios. In drylands, biological soil crust (biocrust) contribution to ecosystem carbon fluxes may vary at a regional scale but is rarely quantified due to the difficulty of parameterizing process‐based models or parsing biocrust (on the soil surface) from whole‐soil flux measurements. We measured excised biocrust carbon fluxes across current and future predicted warmer summertime temperatures from dryland sites (grassland, shrubland, savanna, and woodland) and compared those to the ecosystem and soil fluxes from eddy flux towers. Overall, biocrust fluxes showed net carbon loss during the warm growing season temperatures, suggesting that cool‐season photosynthesis is likely critical for maintaining positive biocrust carbon balance in these sites. Biocrust flux temperature responses differed by site: Grassland and shrubland biocrust gross photosynthesis was relatively invariant, while respiration increased with temperature; in the woodland and savanna, biocrust gross photosynthesis and respiration increased with temperature. Biocrust fluxes contributed <3% to the observed ecosystem gross primary productivity at 26°C and ecosystem respiration at 19°C in grassland, shrubland, and woodland, but contributed >10% of observed soil respiration in grassland and shrubland at 19°C, reinforcing the need to separate biocrust activity from root and subsurface heterotroph activity to understand drivers of fluxes at different sites. Regional resolution of biocrust type and cover will improve predictions of biocrust contribution to global carbon flux with changing temperatures.
- Research Organization:
- Univ. of New Mexico, Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- DE‐SC0008088; SC0008088
- OSTI ID:
- 1457475
- Alternate ID(s):
- OSTI ID: 1458604; OSTI ID: 1509720
- Journal Information:
- Ecosphere, Journal Name: Ecosphere Vol. 9 Journal Issue: 6; ISSN 2150-8925
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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