基于生态位理论的厦门市耕地数量演变及驱动力研究

耕地数量变化及其影响的土地利用结构，对理解城市化过程和区域可持续发展具有重要指示意义。基于生态位态势、生态位扩充与压缩等生态位理论，本文测算了1990—2015年厦门市各种土地利用类型和厦门市六区的生态位宽度与熵，分析了厦门市耕地数量的时空演变特征和机制，探讨了厦门市耕地数量变化驱动因素。研究结果表明：1）1990—2015年，厦门市的耕地数量生态位逐渐下降，年均压缩率1.45%，这与建设用地数量生态位的扩充直接相关。综合来看，厦门市耕地数量生态位的演变处于后期滞缓阶段。2）厦门各区的耕地数量生态位变化与厦门市一致，总体呈下降趋势。耕地面积占有率及耕地面积减少速度在各区之间分异较大，根据各区耕地数量生态位的演变特征可以划分为3类，按成熟度递减排序依次为湖里区和思明区、集美区和海沧区、同安区和翔安区。3）厦门市的耕地与建设用地综合效益生态位差逐渐变大，这驱动了耕地数量生态位的演变，其中经济效益是主导效益。研究结果有助于生态位理论在社会生态领域的发展以及城市区域耕地的保护。

Evolution and driving forces of cultivated land quantity in Xiamen City using niche theory

It is vital to identify the changes in cultivated land quantity and its effect on regional land use structure to understand the urbanization process and regional sustainability. To determine the spatiotemporal evolution characteristics and driving mechanism of the cultivated land quantity, the niche was measured for land use types and six districts in Xiamen City from 1990 to 2015. The results identified by the niche ecostate-ecorole, expansion-compression, breadth, and entropy measurements showed that:1) the cultivated land quantity niche in Xiamen declined gradually from 1990 to 2015, with an average annual compression rate of 1.45%, which was directly related to the expansion of the construction land quantity niche. The evolution of cultivated land quantity niche in Xiamen City was in the late stagnating stage. However, it was faster than that of the national cultivated land niche ecostate-ecorole, possibly due to the rapid urbanization process. 2) The change in cultivated land quantity niche in the six urban districts was consistent with that in Xiamen City, and followed an overall decreasing trend. There was a large difference in the cultivated land area occupancy rate and the decrease rate in cultivated land area in each district. The evolution characteristics of the cultivated land quantity niche in each district could be classified into three distinct categories. First, the breadth of cultivated land quantity niche in the Huli and Siming districts were smaller than that of the construction land. The cultivated land ecostate was small in the six districts and had little interannual change, and the construction land ecostate rose steadily. Second, the breadth of the cultivated land quantity niche in the Jimei and Haicang districts had undergone a change from greater to lower than that of the construction land. The cultivated land ecostate was in the middle of the six districts, and the construction land ecostate increased greatly. Third, the range of change in the breadth of cultivated land and construction land quantity niche was the smallest in the Tong''an and Xiang''an districts. The cultivated land ecostate was at a high level among the six districts, and the construction land ecostate in the Tong''an district showed the largest increase. 3) In the context of rapid urbanization and intensive industrialization, the difference in comprehensive benefit niche between the cultivated land and construction land became gradually wider in Xiamen City, which drove the evolution of the cultivated land quantity niche. Among the difference in benefit niche from economic, ecological, and social aspects, the differences in the economic benefit niche for cultivated land and construction land were the largest, which indicated that the economic benefits were the major benefits for the change in the quantity of cultivated land and construction land. This paper attempted to describe the change in cultivated land quantity in Xiamen City by using the niche theory. This study could improve our understanding of cultivated land protection and the changes in land use structure to support sustainable land resource management.