Effects of snowpack changes on functional traits and reproductive allocation of four perennial plants in an alpine meadow.

BACKGROUND

Global climate change has led to dynamic changes in snow and ice cover, exerting a profound impact on the functional traits and reproductive adaptation strategies of perennial plants in alpine meadows. However, the underlying response mechanisms remain unclear. Through the field simulation experiments with different snowpack thicknesses in the alpine meadows of Qinghai-Tibet Plateau, we systematically analyzed the response patterns and regulatory mechanisms of the organ functional traits and reproductive allocation of four perennial plants: Saussurea nigrescens, Anaphalis lactea, Elymus nutans, and Koeleria macrantha.

RESULTS

Changes in snowpack significantly affected resource allocation strategies of plants. In snow removal condition, S. nigrescens and A. lactea significantly reduced the biomass of vegetative organs, while K. macrantha significantly decreased its reproductive allocation under multi-fold snowpack. E. nutans maintained stable reproductive allocation under different snowpack treatments, demonstrating its high adaptability. Compared with the stability of carbon (TC) content, the nitrogen (TN) and phosphorus (TP) contents in various plant organs were more sensitive to changes in snowpack, and there were significant differences in nutrient responses among different organs and species. We found that Apart from E. nutans, the reproductive allocation of the other three plant species showed significant responses to soil temperature and/or moisture. The impact of changes in snowpack on reproductive traits was partially dependent on individual size, suggesting that plants had diverse adaptation strategies in resource allocation.

CONCLUSION

Significant changes in snowpack profoundly influence plant resource allocation patterns among different functional organs, highlighting the diverse adaptation strategies plants employ under resource scarcity and environmental stress. Soil temperature and moisture are key factors influencing reproductive allocation in four plant species. The relationship between reproductive allocation and individual size varies across species. This study provides a scientific basis for understanding ecosystem functions and plant population maintenance mechanisms in alpine meadow ecosystems under climate change.