Non-use value trends analysis of wetland ecosystem in the Sanjiang Plain, Northeast China

The total economic value of wetland ecosystem services can be separated into use value and non-use value. The non-use value assessment on a large time scale is insignificant for the wetland management policies. This paper uses an economic model to analyze the non-use value trends based on the former willingness to pay survey of the non-use value in the Sanjiang Plain. The assessment results show that under the combined effect of the discount rate and the change of relative price, the curve of the non-use value displays a gradually rising at first and then declining trend. The non-use value curve reaches a maximum after 42 years when the non-use value is $55.01 and the remaining wetland areas is 56.35 % of the situation in 2007. The elasticity of marginal utility of consumption and the elasticity of substitution substantially affect the assessment results. As they become larger, the combined effect of the discount rate and the change of relative price becomes larger too. This will result in a relative lower result of the non-use value assessment and minor supports for today measures of the wetland ecosystem conversation. Speeding up the recovery rate of wetland ecosystem is in favor of bringing down the costs of wetlands conservation, and if the wetland ecosystem in the Sanjiang Plain enter into a healthy state, people will not have to worry about whether or not others or future generations have the opportunity to use it in the future.