How water transfer could promote the carbon sink in reed wetland

Abstract

The hydrologic condition is the basic attribute of the wetland ecosystem, which affects the carbon exchange process between the wetland soil and the vegetation atmosphere, and then affects the change of carbon sink. Artificial water transfer or ecological replenishment is one of the most direct and effective measures used to control wetland saturation levels. The relationship was established, between water flux, water level fluctuation and the influence of artificial water transfer, to discuss the variation of carbon sink and when to implement water transfer and how to control water (water level) to achieve carbon sink in Baiyangdian reed (Phragmites australis) wetland under the influence of artificial water transfer. The research results show the amount of carbon sink is changed only-0.72 gC/m2 (-0.08%) in spring, and the influence is minimal, which is changed -19.49 kgC/m2 (-2.10%) in summer, and the adverse effect was great, which is changed 133.85 kgC/m2 (14.41%) in autumn, but the carbon sink increases and decreases, and the carbon sequestration is unstable, which is changed 17.89 kgC/m2 (1.93%) in winter, and the effect is favorable. Therefore, according to the effect of carbon sink in reed wetland, the time in the early spring of winter (February to March) is the best water transfer time in Baiyangdian. When the water level fluctuation is controlled at 0.3 m, the carbon sink change is 230.79 kgC/m2 (9.07%), which is beneficial to the increase of carbon sink in reed wetland. The model established in this study can be helpful to understand the mechanism of carbon sink in reed wetland through artificial water transfer in Reed wetlands, also can be used in the optimal design of the ecological service function for the restoration of damaged wetland.