Appraisal of the vegetation-based services for cropland ecosystems: a case study of a high-yielding county in North Chin

As people become increasingly aware of the irreplaceability of ecosystem services, defined as "the natural environmental conditions and effects upon which people rely forexistence that are formed and maintained by ecosystems and ecological processes", more emphasis is being placed on these services. In recent years, numerous studies havefocused primarily on the services of natural ecosystems. This paper expands the scope of this field from natural ecosystems to semi-natural ecosystems, i.e. cropland ecosystems, which are closely associated with human productivity and life. Taking Huantai County in Shandong Province as an example, the vegetation-based services of winter wheat/summer maize rotation systems and cotton cropland ecosystems were systematically analyzed, including the material production,carbon dioxide fixation, oxygen release, water conservation, and nutrient recycling. These services were then evaluated in terms of economics through the applications of a market value technique, a substitution engineering method,and a shadow price method. The results indicated that the total economic value of cropland ecosystem vegetation-based services in Huantai County is 124,827.3 × l04 yuan, which is equivalent to 15.63% of the GDP of Huantai County (798,491 × 104 yuan). Among these services, the gas regulation value is 82,698.3 × 104yuan (66.25%), the material production value is 38, 049. 4 × 104 yuan (30. 48% ), the nutrient cycling value is 3257.3 × 104 yuan (2.61% ), and the water conservation value is 822.3 × 104yuan (0,66%). In addition, through the comparison between winter wheat/summer maize rotation systems and cotton cropland ecosystems, we conclude that the economic value of vegetation-based services provided by the former is much higher than that of the latter, which could provide a scientific guideline for adjusting the agricultural structure. Our study may facilitate the conservation of cropland ecosystems and promote effective use of vegetation-based services to achieve sustainable development of agriculture and guarantee nationwide food security.

作 者： Bao Yonghong Wu Wenliang Wang Mingxin Liu Wenna   作者單位： College of Resources and Environmental Science, China Agricultural University, Beijing 100094, P. R. China  刊 名： 生態(tài)經(jīng)濟(jì)（英文版）  英文刊名： ECOLOGICAL ECONOMY  年，卷(期)： 2006 2(2)  分類號(hào)： F1  關(guān)鍵詞： Cropl and ecosystems   Ecosystem vegetation-based services   Economic valuation