WANG Jian, QI Yuan, CHEN Zheng-hua, MA Ming-guo, LI Jing, HUANG Chun-lin
Ecosystem services are the material base and the headspring of whole resources and environment for human survivorship.In this paper,a dynamic assessing model about ecosystem services and function value is put forwards,based on the knowledge of multidisciplinary.The key points focus on discussing the principal factors,which adjust the function of remote sensing technique in the model,and setting up the frame of dynamic assessing model on ecosystem services and function value.A dynamic monitoring model,which takes the ratio of biomass and index of currency change as adjusting factors,is established.After pre-processing,the input parameters include 10-day maximum composite NDVI,precipitation,temperature,total solar radiation,soil parameters based on Co-Kriging Interpolation. The processing model CASA(Carnegie-Ames-Stanford Approach)has been used to simulate APAR,FPAR,humidity of soil,latent evapotranspiration,and then calculate annual NPP in Gansu province,and then the results are validated by using observation data and other relative outcomes.Afterward,using the dynamic model, the grassland ecosystem services and function value of 1999 and 2002 in Gansu province are assessed,with the input parameters of NPP and the factor of dynamic adjusting currency,respectively.The results show the grassland ecosystem services and function value in Gansu province was 28.36 billion RMB Yuan in 1985,140.37 billion RMB Yuan in 1999 and 130.86 billion RMB Yuan in 2002,with an increasing trend after 1985.However,the ecosystem services and function value have regional characteristics and change with time.At present,ecosystem services and function value assessment research have many uncertain factors,therefore;further accelerating quantitative research and searching solid and validating technique will be an important subject in ecology and other interrelated fields.