The soil microclimate and microbial characteristics jointly drive the response of vegetation productivity to changes in snow cover — A global meta-analysis

Recent climate warming has greatly shaped snow-cover patterns globally. Variances in snow cover are expected to affect soil microclimate and microorganisms, which may cause vegetation productivity to vary. However, exactly how snow cover influences the productivity of terrestrial vegetation remains unclear. In this study, we conducted a global meta-analysis of the response of vegetation productivity to variances in snow cover from near-complete depletion to increasing snow depth. Globally, complete snow-cover depletion was shown to reduce vegetation productivity by about 33.6 %, with cropland productivity decreasing the most. In contrast, increasing snow depth did not have an observable effect on vegetation productivity. The response of vegetation productivity to snow-depth variations was shown to be controlled by in-situ soil temperature and moisture and variations in soil-microbial-generated differences in soil carbon (C) and nitrogen (N) content. Based on modelled future snow-cover change (from present to the start of the 22nd century), cropland productivity is projected to decline, especially under a high CO2-emission scenario, such as IPCC's emission scenario SSP5–8.5. Our findings advance our understanding of future implications of snow-cover depletion on vegetation productivity. © 2024