Multiple constraints cause positive and negative feedbacks limiting grassland soil CO₂ efflux under CO₂ enrichment.

ABSTRACT: Terrestrial ecosystems are increasingly enriched with resources such as atmospheric CO₂ that limit ecosystem processes. The consequences for ecosystem carbon cycling depend on the feedbacks from other limiting resources and plant community change, which remain poorly understood for soil CO₂ efflux, J_CO2, a primary carbon flux from the biosphere to the atmosphere. We applied a unique CO₂ enrichment gradient (250 to 500 µL L^-1) for eight years to grassland plant communities on soils from different landscape positions. We identified the trajectory of J_CO2 responses and feedbacks from other resources, plant diversity [effective species richness, exp(H)], and community change (plant species turnover). We found linear increases in

SUBMITTER: Fay PA 

PROVIDER: S-EPMC7812833 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature