Abstract: Poyang Lake is a permanent fresh water lake,with water level changing with the seasonal variation of flooding and drying.The benefits of Poyang Lake include direct products,ecological functions and wetland characteristics.Three types of methods were used to evaluate the wetland ecosystem service value:direct market evaluation,replacement market,and stating partiality method.This paper stressed on the main serve functions of Poyang Lake,and provided monetary evaluations on the functions of water storage,flood regulation,soil protection,CO₂ fixation, O₂ release,soil and water purification,and habitats.The results revealed that the total monetary value of the main functions of Poyang Lake was 3.627?10¹⁰ yuan.The most important function was flood regulation,which was about 43.98% of the whole value.The second was soil and water purification,about 38.49% of all.

Key words: Larix chinensis, Fractal dimension, Spatial distribution pattern, Pattern intensity, Pattern scale