Climate change impacts on organic carbon cycling in European alpine soils

This review focuses on impacts of climate change on soil organic carbon (SOC) cycling in alpine soils, with a specific emphasis on input and loss processes. In alpine regions, low temperatures and variable snow cover govern plant productivity and microbial activity, leading to unique SOC dynamics. However, rising temperatures, altered precipitation patterns, and reduced snow cover threaten to disrupt these processes, potentially leading to significant SOC losses. Changes in vegetation, driven by climatic shifts, further complicate the dynamics of SOC by modifying the quantity and chemical composition of organic inputs into the soil. Furthermore, increased temperatures are expected to accelerate microbial activity, potentially decreasing SOC stocks and increasing carbon losses. How changing loss and input rates alter net effects of climatic changes on SOC stocks remains a persistent knowledge gap. Addressing this gap is critical for predicting carbon cycling in alpine ecosystems and formulating strategies to mitigate climate impacts. This review highlights the urgent need for targeted research on alpine SOC dynamics to better anticipate the response of these susceptible environments in the face of a rapidly changing climate. • Shifts in vegetation communities reshape quantity & chemistry of organic carbon inputs. • Climate extremes shift microbial CUE & decomposition pathways affecting SOC turnover. • Extended drought, freeze–thaw cycles, and warming jointly accelerate SOC loss. • Net SOC losses are expected in alpine soils under future climate scenarios. • Integrating microbe–plant–soil linkages is vital for robust SOC predictions.