中国农田生态系统的服务功能及其经济价值

Ecological Services and Their Values of Chinese Agroecosystem

采用生态经济学的方法。对中国农田生态系统的服务功能进行了价值化评估。结果表明。2003年中国农田生态系统提供的总服务价值为19121．8×10^8元（2003年现价）．其中．正面服务价值为22334．1×10^8元．由于灌溉、化肥及农药的使用．给人类福利造成的损失为3212．3×10^8元；单位面积农田提供的服务价值为18960．6元／hm^2。其中。农产品生产的价值为14788．7元／hm^2。其它服务价值为4171．9元／hm^2，灌溉等给人类福利造成的损失为3185．2元／h矗；各地区农田的生态服务功能差别较大。其价值量波动在86．8～5050．8×10^8元之间．黄淮海和长江中下游地区所占比重较大。二者合计占总量的52．2％；各地区单位面积农田提供的服务价值为5159～34984．3元／hm^2。华南和长江中下游地区相对较大，内蒙古和东北地区相对较低。

Agroecesystem not only provides people with grains, vegetables, fibre, etc., but also plays an important role in gas regulation, soil and water conservation, environmental decontamination, etc. Furthermore, Agroecosystem has negative effects on our environment, such as, soil and water pollution caused by fertilizer and pesticide utilization. So, the ecological services of farmland are more complicated than grassland and forest. So far, there are a few of research findings about Chinese farmland＇ s ecological services but only part of ecological services were involved in these documents. An integrated research is needed now in order to understand agroecosystem comprehensively. This paper gave a primary result of ecological services and their monetary values of Chinese agroecosystem. The results showed that the total monetary value of ecological services provided by Chinese agroecosystem is 1 912.18 billion yuan RMB in 2003（presont price in 2003）; the positive value is 2 233.41 billion yuan and negative is - 321.23 billion ynan. The services value per hectare is 18 960.6 yuan/hm^2; the value of farm products is 14 788.7 yuan/hm^2, others are 4 171.9 yuan/hm^2 and negative value is 318.52 yuan/hm^2. There is great distinction of farmland ecological services in different regions. The values range from 8.68 - 505.08 billion yuan and Huang-Hnai-Hai Region and Middle and Lower Reaches of Yangtse River are bigger than other regions. The values of per hectare range from 515.90 - 3 498.43 yuan/ hm^2. South China and Middle and Lower Reaches of Yangtse River are bigger and Inner Mongolia and Northeast region are smaller.