The Comparison of turbulent fluxes between a marsh wetland and a lake ecosystem

Abstract

<p>Wetlands are “hot spot” area of global climate change, which are obviously sensitive to climate change. Under climate change, the carbon sequestration potential and carbon balance over wetland ecosystems are greatly altered, and large uncertainties are still existed in carbon budgets over these areas. Tengchong Beihai wetland is the only highland “floating blanket” lake wetland which is located in Southwest of China. As this land surface is composed by both water and terrestrial land surface, it’s doubted whether this type of wetland behaves more like lake or the latter one. Based on one year continuous observation measured with eddy covariance technique over Beihai wetland and Erhai Lake in 2016, the patterns of CO<sub>2</sub> flux and energy fluxes over Tengchong wetland and Erhai lake are analyzed. The results show the diurnal variation of H and LE are both similar to Rn, which is different with Erhai lake. Erhai lake has a higher evaporation rate even in nighttime, which is much larger than Beihai wetland, due to the “floating blanket” vegetation could obviously reduce the evaporation rate. Beihai wetland acts as CO<sub>2</sub> sink for the most time of the year, with an annual CO<sub>2</sub> flux of -202.2 g C m<sup>-2</sup>, while Erhai Lake acted as CO<sub>2</sub> source with an annual CO<sub>2</sub> flux of 143.7 g C m<sup>-2</sup>. The results indicate the carbon and water exchange process in Beihai wetland behaves more like vegetated land surface.</p>