Research on seed germination, seedling survival, and establishment of alpine plants in response to climate change: A review

The natural regeneration of alpine plants is an important prerequisite for the maintenance of plant community diversity and the productivity of the community in alpine regions. Investigation of the characteristic response to climate change can provide data to support the accurate assessment of the evolution direction and pattern of alpine ecosystem response to climate change, and provide a theoretical basis for exploring the mechanisms of internal evolution. This research starts with the three key regeneration stages of seed germination, seedling survival, and establishment of alpine plants, and summarizes how biological factors (such as plant factors, plant interactions, animal disturbances, and insect pollination) and abiotic factors (such as temperature, moisture, and soil properties) affect these key regeneration stages. During the seed germination stage, extreme drought and alpine snow melt in advance have changed the relationship of plant and pollination insect and nutrient structure network. Increased temperature and precipitation increase the seed germination of plants. This warming can break the dormancy of seeds and change their physiological status. An increase in soil moisture can provide an adequate water supply for seed germination. Excessive temperature and moisture hinder seed germination, which is attributable to high-temperature stress, caused by temperature above the germination threshold, and the production of pathogens by excessive soil moisture. Seedling survival and establishment stage, plant animal disturbance, and plant interspecific competition are both advantageous and disadvantageous for seedling survival and settlement. Appropriate animal disturbance increases seedling growth space, and plant interspecific competition in resource-poor mountainous areas promotes seedlings to coordinate with each other and promote survival and establishment. High-intensity feeding by animals and disturbance of seedlings and inter-species competition among resource-rich regions hinder the acquisition of plant resources and inhibit the survival and settlement of seedlings. At present, the impact of warming on the survival of alpine plant seedlings is still unconfirmed (it may promote survival or have no effect), but the conclusion that warming and increased precipitation can promote seedling growth is well accepted, showing that warmer and more moist soil allows better seedling growth. Good environmental conditions are conducive to the absorption and utilization of nutrients. This research clarifies the effects of biotic and abiotic factors on the three stages of early regeneration of alpine plants, and indicates the deficiency of research not accounting for multiple effects of biotic and abiotic factors, and proposes scientific issues that require further investigation. Thus, this study has provided a reference on the impact of climate change on alpine ecosystems for future studies.