岷江上游山区聚落生态位空间分布特征研究

基于岷江上游山区藏-羌-回-汉聚落生态位和植被生境适宜性的空间分布,借助分形和贝叶斯模型,定量刻画聚落生态位的民族属性对山区聚落生态位的空间分布特征的影响。结果表明：① 岷江上游藏-羌-回-汉聚落生态位间隙度维数分别为0.949、0.942、0.890、0.960,汉族聚落生态位的高间隙度维数,揭示了山区汉族聚落封闭性特点。同时,流域内1 667个聚落生态位间隙度维数（0.946）与藏族（0.949）相似,表明藏族聚落生态位空间异质性特征能够反映整个流域山区聚落生态位空间分异程度。② 岷江上游藏-羌-汉-回聚落生态位内的植被生境适宜性指数均值分别为：2.816、2.622、2.529、2.644,说明山区聚落生态位的空间分布与植被生境相适宜。同时,流域内1 667个聚落生态位几何特征对植被生境的敏感程度（0.601）与羌族（0.610）相似,表明羌族聚落生态位的几何特征具有典型性。③ 藏-羌-回-汉聚落生态位的空间聚簇性地域分异明显、地理边界清晰,说明聚落生态位的民族属性对聚落区位、规模和形态具有显著影响。

Spatial Distribution Characteristics of Mountainous Settlement Ecological Niche in the Upper Reaches of the Minjiang River

The settlement ecological niche is the basic element for studying human-land relationship in the mountainous area, which could reflect located spatial position of the settlement vertically along the mountain and resources space available to the settlement for sustenance. It is an effective approach of studying mountainous environmental change and how the human adapted to its change by revealing inner mechanisms about spatial structure of settlement ecological niche and vegetation habitat suitability. Based on the spatial distributions of mountainous settlement ecological niche of individual nationality categories and vegetation habitat suitability in the Upper Reaches of the Minjiang River, this study quantified the affect of nationality category on spatial distributed characteristics of mountainous settlement ecological niche by use of Fractal and Bayesian Models. The detailed results are as following: 1) The values of lacunarity dimensions of Tibetan, Qiang, Hui, and Han nationalities settlement ecological niches were 0.949, 0.942, 0.889, and 0.960, respectively. The maximum value of lacunarity dimension appeared in the Han nationality settlement ecological niche, and indicated that its spatial cluster was lowest and spatial differentiation was highest. The minimum value of lacunarity dimension occurred in the Hui nationality settlement ecological niche, and indicated that its spatial structure was highest and spatial differentiation was lowest. It also suggested that spatial distribution of Hui nationality settlement ecological niche possessed closeness characteristic. Meanwhile, the lacunarity dimension of all 1 667 settlement ecological niches in the studied watershed was 0.946, which approximated to the lacunarity dimension of Tibetan nationality settlement ecological niche (0.949). It indicated that the spatial heterogeneity of Tibetan nationality settlement niche played an important role in the spatial differentiation of all mountainous settlement ecological niches. 2) The average values of vegetation habitat suitability index of Tibetan, Qiang, Han, and Hui nationality settlement ecological niches were 2.816, 2.622, 2.529, and 2.644, respectively, which revealed that the harmony between spatial distribution of mountainous settlement ecological niche and vegetation habitat suitability was high. The sensitivity of all 1 667 settlement ecological niches in the studied watershed to vegetation habitat suitability (0.601) was close to that Qiang nationality settlement ecological niche (0.610), which indicated that Qiang nationality settlement ecological niche can reflect the whole geometrical characteristics of all settlement ecological niches in the studied site. 3) Nationality type significantly impacted on the spatial location, scale, and pattern of mountainous settlement ecological niche, which led to stronger spatial differentiation, and clearer geographical boundaries of Tibetan, Qiang, Hui, and Han different nationality settlement ecological niches. In summary, the study on quantifying of mountainous settlement ecological niche in the upper reaches of the Minjiang River could provide the data support for spatial reconstruction and ecological construction of mountainous settlement. The proposed research framework in this study could be extended to other coexistent area of multiple nationality categories to identify spatial distributed characteristics of settlements.