TY - JOUR
T1 - Grassland responses to elevated CO2 determined by plant–microbe competition for phosphorus
AU - Keane, Ben
AU - Hartley, Iain
AU - Taylor, Christopher R
AU - Leake, Jonathan R
AU - Hoosbeek, Marcel R
AU - Miglietta, Franco
AU - Phoenix, Gareth K
N1 - This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details
PY - 2023/7/10
Y1 - 2023/7/10
N2 - Rising atmospheric CO2 has stimulated plant productivity, with terrestrial ecosystems currently absorbing nearly one-third of anthropogenic CO2 emissions. Increases in photosynthesis can subsequently lead to increased carbon (C) storage in plants and soil. However, there is growing evidence that nitrogen (N) availability constrains elevated CO2 (eCO2) responses, yet we know much less about the role of phosphorus (P) limitation on productivity under eCO2. This is important because P-limited ecosystems are globally widespread, and the biogeochemical cycles of N and P differ fundamentally. In the Peak District National Park of northern England, we conducted a free-air CO2 enrichment (FACE) experiment for three years on two contrasting P-limited grasslands under long-term nutrient manipulation. Here we show that competition between plants and microbes for P can determine plant productivity responses to eCO2. In a limestone grassland, aboveground productivity increased (16%) and microbial biomass P remained unchanged, whereas in an acidic grassland, aboveground productivity and P uptake declined (11% and 20%, respectively), but P immobilization into microbial biomass increased (36%). Our results demonstrate that strong competition with microbes can cause plant P uptake to decline under eCO2, with implications for the future productivity of P-limited ecosystems in response to climate change.
AB - Rising atmospheric CO2 has stimulated plant productivity, with terrestrial ecosystems currently absorbing nearly one-third of anthropogenic CO2 emissions. Increases in photosynthesis can subsequently lead to increased carbon (C) storage in plants and soil. However, there is growing evidence that nitrogen (N) availability constrains elevated CO2 (eCO2) responses, yet we know much less about the role of phosphorus (P) limitation on productivity under eCO2. This is important because P-limited ecosystems are globally widespread, and the biogeochemical cycles of N and P differ fundamentally. In the Peak District National Park of northern England, we conducted a free-air CO2 enrichment (FACE) experiment for three years on two contrasting P-limited grasslands under long-term nutrient manipulation. Here we show that competition between plants and microbes for P can determine plant productivity responses to eCO2. In a limestone grassland, aboveground productivity increased (16%) and microbial biomass P remained unchanged, whereas in an acidic grassland, aboveground productivity and P uptake declined (11% and 20%, respectively), but P immobilization into microbial biomass increased (36%). Our results demonstrate that strong competition with microbes can cause plant P uptake to decline under eCO2, with implications for the future productivity of P-limited ecosystems in response to climate change.
U2 - 10.1038/s41561-023-01225-z
DO - 10.1038/s41561-023-01225-z
M3 - Article
SN - 1758-678X
JO - Nature Climate Change
JF - Nature Climate Change
ER -