Impacts of Snowpack Insulation on Winter Ecosystem Respiration: A Synergistic Analysis in the Northern Hemisphere

Abstract. Climate-driven snowpack changes across the Northern Hemisphere introduce substantial uncertainty into the global carbon budget, but how winter ecosystem respiration (Reco_winter) responds to these changes remains unclear. In this study, we investigated the impact of seasonal snowpack on Reco_winter in the Northern Hemisphere (NH, >30° N) from the perspective of snowpack insulation using multi-source datasets. Our analysis revealed that in 30.43 % of NH ecosystems, snowpack (thickness, duration, and density) exerted the most critical impact on respiration, surpassing climatic impacts (by 19.27 %). The positive impact of snowpack on Reco_winter operates through snowpack insulation, with a stronger effect in colder regions. Neglecting the various aspects of the snowpack may systematically underestimate the ecological impacts of snowpack. Accurate assessments of snowpack ecological impacts must account for its synergistic aspects. Consequently, ignoring snowpack ecological processes in future prediction models risk misrepresenting winter carbon fluxes and ecosystem responses to climate change. Our study highlight the importance of snowpack on carbon source in winter ecosystems.