基于InVEST模型的生态系统土壤保持功能研究——以福建宁德为例

Study on Soil Conservation Service of Ecosystem Based on InVEST Model——A Case Study of Ningde City,Fujian Province

基于InVEST模型,对宁德地区生态系统土壤保持功能的空间特征及其影响因素进行了分析。结果表明:宁德地区土壤保持总量为9.35×108 t/a,单位面积土壤保持量为695.3t/(hm2·a),空间上呈现中部高,东北部次之,西南部低的分布格局,各县市差异显著;各生态系统土壤保持能力从大到小依次为:灌丛>林地>草丛>旱地>园地>水田>红树林>草本湿地>城镇,自然生态系统优于人工生态系统;除自然因素外,社会经济的迅速发展也是影响土壤保持功能的重要因素,其中单位面积GDP、单位面积第一产业生产总值、人口密度、第一产业劳动力密度、交通网络密度以及耕地比例与单位面积土壤保持量负相关,林地和草地的比例与土壤保持功能正相关。可见,宁德地区土壤保持功能差异性显著,并且与社会经济发展存在紧密联系,因此,在今后的发展中要权衡社会经济发展与土壤保持功能的关系,促进经济和生态环境和谐发展。

Based on the InVEST model,this paper analyzed the spatial characteristics of the soil conservation service of ecosystems and its impact factors in Ningde.The results showed that the amount of soil preserved by ecosystems was approximately 9.35×108 t/a,and the average capacity per unit area was 695.3t/(hm2·a)for the entire region.With regard to the spatial pattern,it displayed the highest capacity in the central part and has the lowest capacity in the southwest,and the difference among the various regions was significant.The soil conservation capacity differed widely across various ecosystems,with a descending order from shrubs,forests,grasslands,dry lands,plantation,paddy lands,mangroves,swamp and city.Natural ecosystems were generally found to perform better than artificial ones in terms of conserving soil resources.Besides natural factors,social and economic development are important factors influencing soil conservation service.Indicators such as gross regional product per area,GDP of primary industry per area,population density,area ratio of farmland and transit network density,showed a negative correlation with soil conservation capacity,while area ratio of forests and grasslands showed a positive correlation with soil erosion rate.In conclusion,the social and economic development in Ningde might impair soil conservation service of ecosystems,as a result,tradeoffs should be made to keep development harmonious.