Permafrost and alpine grasslands mutually influence each other and coevolve, with permafrost temperatures serving as essential indicators for understanding their interactions and changes. 

A research team led by Professor WU Qingbai from the Northwest Institute of Eco-Environment and Resources of the Chinese Academy of Sciences sheds light on the intricate relationship between permafrost temperature, climate change, and alpine grasslands. 

The study was published in CATENA on Apri. 30. 

The researchers examined the permafrost underlying alpine meadows, alpine steppes, alpine desert grasslands, and barren lands to uncover their connections to climate change and identify the climate factors that influence their changes using time-frequency domain analysis. 

The researchers observed distinct periodic characteristics in permafrost temperatures across various zones relative to the level of the permafrost table (above, near, and below it). 

The temperature dynamics in the active layer above the permafrost table primarily respond to monthly climate changes, while permafrost dynamics below this boundary are predominantly influenced by annual climate fluctuations. 

In the time domain, the influence of air temperature, precipitation, and wind speed on permafrost dynamics suggests that air temperature has the most significant impact on permafrost temperature across various depths.  

However, different climate factors control permafrost temperature at various depths in the time-frequency domains. Particularly at deeper levels, it is crucial to consider the impact of wind speed on permafrost. 

Among the four alpine grasslands studied, permafrost beneath alpine meadows emerges as the most responsive to climate change, exhibiting distinct periodic fluctuations in intensity compared to the other three grassland types. 

Finally, the researchers discussed the reaffirmed protective influence of vegetation on underlying permafrost. However, further data are needed to fully comprehend the role of the sand layer. 

Contact: 

GAO Siru 

e-mail: gaosiru@lzb.ac.cn