TY - JOUR

T1 - Climate change disrupts the seasonal coupling of plant and soil microbial nutrient cycling in an alpine ecosystem

AU - Broadbent, Arthur A. D.

AU - Newbold, Lindsay K.

AU - Pritchard, William J.

AU - Michas, Antonios

AU - Goodall, Tim

AU - Cordero, Irene

AU - Giunta, Andrew

AU - Snell, Helen S. K.

AU - Pepper, Violette V. L. H.

AU - Grant, Helen K.

AU - Soto, David X.

AU - Kaufmann, Ruediger

AU - Schloter, Michael

AU - Griffiths, Robert I.

AU - Bahn, Michael

AU - Bardgett, Richard D.

N1 - e17245 GCB-24-0178

PY - 2024/3/30

Y1 - 2024/3/30

N2 - Abstract The seasonal coupling of plant and soil microbial nutrient demands is crucial for efficient ecosystem nutrient cycling and plant production, especially in strongly seasonal alpine ecosystems. Yet, how these seasonal nutrient cycling processes are modified by climate change and what the consequences are for nutrient loss and retention in alpine ecosystems remain unclear. Here, we explored how two pervasive climate change factors, reduced snow cover and shrub expansion, interactively modify the seasonal coupling of plant and soil microbial nitrogen (N) cycling in alpine grasslands, which are warming at double the rate of the global average. We found that the combination of reduced snow cover and shrub expansion disrupted the seasonal coupling of plant and soil N-cycling, with pronounced effects in spring (shortly after snow melt) and autumn (at the onset of plant senescence). In combination, both climate change factors decreased plant organic N-uptake by 702 soil microbial biomass N by 1985336 respectively. Shrub expansion also individually modified the seasonality of soil microbial community composition and stoichiometry towards more N-limited conditions and slower nutrient cycling in spring and autumn. In winter, snow removal markedly reduced the fungal:bacterial biomass ratio, soil N pools and shifted bacterial community composition. Taken together, our findings suggest that interactions between climate change factors can disrupt the temporal coupling of plant and soil microbial N-cycling processes in alpine grasslands. This could diminish the capacity of these globally widespread alpine ecosystems to retain N and support plant productivity under future climate change.

AB - Abstract The seasonal coupling of plant and soil microbial nutrient demands is crucial for efficient ecosystem nutrient cycling and plant production, especially in strongly seasonal alpine ecosystems. Yet, how these seasonal nutrient cycling processes are modified by climate change and what the consequences are for nutrient loss and retention in alpine ecosystems remain unclear. Here, we explored how two pervasive climate change factors, reduced snow cover and shrub expansion, interactively modify the seasonal coupling of plant and soil microbial nitrogen (N) cycling in alpine grasslands, which are warming at double the rate of the global average. We found that the combination of reduced snow cover and shrub expansion disrupted the seasonal coupling of plant and soil N-cycling, with pronounced effects in spring (shortly after snow melt) and autumn (at the onset of plant senescence). In combination, both climate change factors decreased plant organic N-uptake by 702 soil microbial biomass N by 1985336 respectively. Shrub expansion also individually modified the seasonality of soil microbial community composition and stoichiometry towards more N-limited conditions and slower nutrient cycling in spring and autumn. In winter, snow removal markedly reduced the fungal:bacterial biomass ratio, soil N pools and shifted bacterial community composition. Taken together, our findings suggest that interactions between climate change factors can disrupt the temporal coupling of plant and soil microbial N-cycling processes in alpine grasslands. This could diminish the capacity of these globally widespread alpine ecosystems to retain N and support plant productivity under future climate change.

KW - alpine ecosystems

KW - climate change

KW - nutrient cycling

KW - plant–soil interactions

KW - seasonality

KW - shrub expansion

KW - snow cover

U2 - 10.1111/gcb.17245

DO - 10.1111/gcb.17245

M3 - Erthygl

VL - 30

SP - e17245

JO - Global Change Biology

JF - Global Change Biology

SN - 1365-2486

IS - 3

ER -