Impacts of climate-induced permafrost degradation on vegetation: A review

Abstract

Under a warming climate, degrading permafrost profoundly and extensively affects arctic and alpine ecology. However, most existing relevant studies are more focused on the hydrothermal impacts of vegetation on the underlying permafrost, or symbiosis between vegetation and permafrost, only very few on ecological impacts of permafrost degradation. Additionally, there are much more pertinent investigations in arctic and boreal regions than those in alpine and high-plateau regions at mid- and low latitudes. This study emphasizes on the impact mechanisms of permafrost degradation on vegetation both at high and mid-to low latitudes, addressing vegetation succession trajectories and associated changes in soil hydrology and soil nutrient above degrading permafrost. Permafrost degradation influences vegetation by altering soil hydrology, soil biogeochemical processes and microbial communities, which further improve soil nutrient availability. Furthermore, under a warming climate, vegetation may take two successional trajectories, towards a wetter or drier ecosystem within a certain time period, but to a drier ecosystem in the end upon the thaw of permafrost in case of permeable soils and good drainage. Thus, with rapidly developing remote-sensing and other space- and ground-based and air-borne observational networks and numerical predictive models, the impacting mechanisms of permafrost degradation on vegetation should be timely and better monitored, evaluated and modeled at desired spatiotemporal scales and resolutions by terrestrial or integrated ecosystem models.

Keywords

• Degrading permafrost
• Vegetation
• Impact mechanisms
• Climate warming
• Ecological impacts