Research progress on the effects of soil freeze-thaw on plant physiology and ecology

Soil freeze-thaw, which mainly refers to repeated freezing and thawing due to changes in soil temperature, is a natural phenomenon in seasonally frozen or permafrost regions. Freeze-thaw not only affects soil physicochemical and biological properties, but also alters the ecophysiological processes of plants. This has been noted to significantly influence the productivity of ecosystems in high latitude and altitude areas with vast frozen grounds. This paper reviewed the effects of freeze-thaw on the physiological and ecological processes of above-ground and below-ground parts of plants and the response characteristics of alpine vegetation ecosystem to different freeze-thaw patterns. The paper summarized the ecophysiological characteristics under different climatic conditions and habitat stresses in terms of photosynthesis, biomass and productivity, root growth and response to moisture and temperature stress. The shortage in studies on soil freeze-thaw and ecophysiological processes of plants were also addressed. It was concluded that frequent soil freezing and thawing dramatically influenced the distribution patterns and ecological functions of vegetation under changing global environment, which was especially stronger in alpine ecosystems.