Large uncertainties exist in carbon sequestration and water exchange process in wetland ecosystems under climate change. Beihai wetland is a very rare special type of alpine marsh with plants floating on the water surface located in the southeast margin area of the Tibetan Plateau. Based on the eddy covariance measurements from July 2015 to December 2016 over Baihai wetland, we have investigated the patterns of energy and carbon dioxide fluxes between the air and the alpine marsh and their main drivers. The latent heat flux (LE) was the main consumer of available radiation which accounted for 63% of net radiation (R_n) in 2016. R_n was the main factor determining H at both wet and dry season. Air temperature (T_a) and vapor pressure deficit (VPD)were most influenced with half-hourly LE during both wet and dry season, and VPD showed a larger influence on NEE in dry season than that in wet season. The total evapotranspiration (ET) in wet season occupied 60% of annual ET with an amount of 762.3 mm yr⁻¹ in 2016, which was much lower than the annual total precipitation (1780.2 mm yr⁻¹). Photosynthetic active radiation (PAR) was the main controller in the half-hourly net ecosystem exchange (NEE), while T_a mainly controlled the seasonal variations in NEE. The annual total NEE, gross primary production (GPP) and ecosystem respiration (RE) were -233.8, 796.6 and 562.8 g C m⁻² yr⁻¹ in 2016. The fraction of vegetation to water surface changed from 66% to 74% in the study period. A positive linearly relationship was both found between the fraction of vegetation to water surface and CO₂ uptake and evapotranspiration. The fraction of vegetation to water surface could explain 40% variation of ET and 62% variation of NEE, respectively.

气候变化下湿地生态系统的固碳和水交换过程存在较大的不确定性。北海湿地位于青藏高原东南缘地区，是一种非常罕见的特殊类型的高山沼泽，水面上漂浮着植物。基于2015年7月至2016年12月白海湿地涡旋协方差测量，我们研究了空气与高山沼泽之间的能量和二氧化碳通量模式及其主要驱动因素。潜热通量 (LE) 是可用辐射的主要消耗者，占2016 年净辐射 (R _n ) 的63% 。 R _n是决定雨季和旱季H的主要因素。气温（T _a) 和水汽压差 (VPD) 在雨季和旱季受半小时 LE 的影响最大，并且 VPD 在旱季对 NEE 的影响大于雨季。2016年雨季总蒸散量（ET）占全年蒸散量的60%，为762.3 mm yr ^-1，远低于全年总降水量（1780.2 mm yr ^-1）。光合有效辐射（PAR）是半小时净生态系统交换（NEE）_的主要控制者，而T _a主要控制NEE的季节变化。年总 NEE、初级生产总值 (GPP) 和生态系统呼吸 (RE) 分别为 -233.8、796.6 和 562.8 g C m ^-2 yr ^-12016年。研究期间植被对水面的比例从66%变为74%。发现植被与水面的比例与CO ₂吸收和蒸发量之间均呈正线性关系。植被与水面的比例可以分别解释 40% 的 ET 变化和 62% 的 NEE 变化。