农田生态系统服务及其价值的研究进展

Review of agro-ecosystem services and their values

农田生态系统在人类控制下已逐渐演变成了提供农产品的集约化生产系统。尽管与自然生态系统相比,农田生态系统服务功能有所下降,但其在提供农产品的同时还在向人类提供大量的生态服务。近年来,生态系统服务稀缺性变得越来越突出,农田生态系统的多功能性受到了空前的重视。本文首先明确了农田生物多样性是农田提供多种生态系统服务的基础,然后回顾了2000年以来国内外农田生态系统服务及其价值化领域取得的主要研究进展,包括对农田产品供给、碳汇、土壤保持和养分循环、水调节等功能的评价以及对农田生态系统服务及其价值化的综合研究。与此同时,我们也应该注意到农业生产还对人类社会和自然环境产生了各种消极影响,认识到权衡农田生态系统在农业生产中的各项利弊的重要性。通过对比不同农业生产模式对农田生态系统服务供给的影响,提出未来发展多功能农业将是实现农田对人类福祉最大化的重要方向。最后,文章指出我国发展多功能农业的主要措施是:(1)确保18亿亩耕地在空间上的存在;(2)与森林、草地、湿地、水域等其他自然生态系统在空间上合理配置;(3)在农业区域充分发展以观光休闲功能为主的休闲农业,实现农田生态系统社会文化价值;(4)逐步实施农业生态补偿。

Agro-ecosystem has become an integrated crop production system with significant human disturbances.Compared with natural ecosystems,the crop production function of agro-ecosystem has intensified while impairing other ecosystem services such as gas/water regulation,soil conservation and biodiversity maintenance.In recent years,agro-ecosystem services have become more and more scarce because of large demand by the rapid global development.This has resulted in an increasing concern about the values and services of agro-ecosystems across the globe.This study argued that biodiversity of agro-ecosystem was the physical basis for ecosystem services.The study reviewed classical studies on agro-ecosystem services,including production supply,carbon sequestration,soil conservation,nutrient cycle and water regulation,and on the comprehensive assessment of agro-ecosystem services.The study further discussed the passive effects（e.g.,non-point pollution,CH4/N2O emissions and heavy metal pollution） of agricultural production on human society and the environment.It was necessary that farmers and government organs realized the importance of the tradeoff between the advantages and disadvantages of agricultural production.The various effects of agricultural production systems（e.g.,integrated,conventional and organic agro-ecosystems,and combined food/forest systems） on the services of different agro-ecosystems were further compared.It was noted that only multi-functional agricultural production systems maximized welfare supported by agro-ecosystem services.Four key measures for developing multi-functional agro-ecosystems in China were eventually listed.The measures included：（1） ensuring the existence of farmlands of 120 million hm2;（2） reasonable arrangements of the distribution of forests,grasslands,wetlands and water resources;（3） encouraging tourism in farming regions in order to strengthen the cultural functions of agro-ecosystems;and（4） stepwise implementation of ecological compensation strategies for adoption of agro-ecosystems.