Abstract:

From the angle of contribution of eco-system to environmental purification,the value of the environmental purification function of a coastal-terrestrial ecosystem is defined as sum of the values of its functions of pollution purification and air regulation. To establish a model for assessing value of the environmental purification function of a coastal-terrestrial ecosystem,six ecological functions of the system,i. e. release of O₂,fixation of CO₂,purification of sulfides,purification of nitrogen-oxides,purification of fluorides and arrest of dust as evaluation indices. With Huanghua City cited as a case for study. Values of the purification functions of nine categories of eco-systems in the city,such as farmland,garden,grassland,wetland,etc. were assessed using the market price method and shadow price method. Results show that the value of the environmental purification function of the coastal terrestrial eco-system of Huanghua City was quite high,reaching up to 1 634. 54 million Yuan. In terms of purification function value per unit area,the functions followed an order of O₂ release > CO₂ fixation > pollutant purification; and the categories of eco-systems,such as farmland,garden,and grassland were quite high in O₂ release function value,reaching about 0. 67 Yuan·m^-2; and the eco-system of saline land was the lowest in CO₂ fixation function,being about 0. 01 Yuan·m^-2 only.

Key words: coastal-terrestrial ecosystem, purification value, ecosystem service, Huanghua City