Patterns of Carbon and Water Exchange Process over Different Types of Ecosystems in the Southeastern Margin of the Tibetan Plateau

The Hengduan Mountains situated at the southeastern margin of the Tibetan Plateau are in the conjunction area of the south and southeast Asian monsoons and are also heating and sensitive areas, where atmospheric changes occur. Therefore, understanding key processes related to the atmospheric water resources in the Tibetan Plateau is highly essential to investigate the effects and parameterization schemes concerning the interaction between the land surface and atmosphere or water vapor as well as energy exchange processes in this region. This study introduces the land–atmosphere field experiments developed in this area based on continuous eddy covariance measurements. Furthermore, the patterns of the exchange process between the wetland/lake/grassland surfaces and atmosphere around the land surface process observation sites at the Erhai lake, Lijiang alpine grassland, and Tengchong Beihai wetland are analyzed. In addition, the characteristics of the local circulation in mountainous lake areas obtained from simulations using the lake-atmosphere coupled model WRF v3.7.1 are investigated in complex mountainous areas. The characteristics of the land–atmosphere surface exchange process and their factors influencing different types of ecosystems in the southeastern edge of the Tibetan Plateau and Hengduan Mountains have been preliminarily identified and disclosed. The main conclusions from this study are as follows: carbon and water exchange processes in the alpine meadows at the southeastern edge of the Tibetan Plateau are considerably influenced by precipitation distribution. In addition to meteorological factors, carbon and water exchange occurring in the "floating blanket" wetlands, where grass floats on the surface like a blanket throughout the year, is affected by changes in the underlying surface vegetation and water proportion. Factors affecting carbon and water exchange processes in different ecosystems vary at different time scales. Wind speed has crucial impacts on the latent heat and CO₂ exchange in lakes, while precipitation substantially affects CO₂ flux in lakes at longer time scales. Furthermore, the complex terrain at the southeastern edge of the Tibetan Plateau considerably influences the carbon and water exchange processes of ecosystem. Thus, different types of local circulations generated by complex terrains have different effects on the carbon and water exchange processes of ecosystems.