基于综合指数法的白龙江流域生物多样性空间分异特征研究

大中区域尺度上生物多样性空间分布格局识别是制定和实施区域生物多样性保护计划的前提条件,也是生物多样性保护确定优先区域研究工作迫切需要解决的关键问题之一。拟以甘肃白龙江流域为例,结合InVEST模型和遥感、GIS技术,以区域生境质量、植物净初级生产力和景观状态指数为评价指标,应用归一化处理方法,构建区域生物多样性空间格局综合评估方法,在栅格像元尺度上开展白龙江流域生物多样性评价及其空间分异特征分析。结果表明:白龙江流域生物多样性较为丰富,空间分异特征明显。生物多样性较高的区域(Ⅰ和Ⅱ级以上)面积约占39.80%,且主要集中在自然保护区和林业管护区。生物多样性较低的地区主要分布在舟曲-武都-文县的白龙江两岸及其以北区域、宕昌县岷江沿岸、高寒稀疏植被区和高山积雪-裸岩区。

Assessment and spatial variation of biodiversity in the Bailong River Watershed of the Gansu Province

The loss of biodiversity has become one of the major global environmental problems, with strengthening of biodiversity conservation and protection urgently required. The first step in solving this problem is the identification and understanding of the spatial variation of biodiversity on a regional scale, with the formulation and implementation of biodiversity protection schemes imperative. This has become the focus of biodiversity assessments over both large and medium scales. The Bailong River Watershed of the Gansu Province (BRWGP), one of the most abundant biodiversity regions in China, is located in the transitional ecotone along the Tibet Plateau, Loess Plateau, and Qinba Mountains. The BRWGP was selected in the present study to analyze the spatial heterogeneity of biodiversity. Inclusion of three assessment indicators (habitat quality, vegetation net primary productivity, and landscape state index) enabled the construction of a comprehensive index system of biodiversity spatial patterns and application of spatial differentiation analysis under the landscape geography perspective. Our goal was to revise the biodiversity evaluation module of the InVEST model and demonstrate biodiversity spatial patterns on a grid cell. The results indicated that biodiversity was high and had obvious spatial pattern variations in the BRWGP. The land area containing higher biodiversity accounted for 39.8% of the total watershed area, which was mainly distributed in the national nature reserve and forest. The relatively poor biodiversity areas were mainly distributed in the valleys of the BRWGP between Zhouqu-Wudu-Wenxian, the valley of Minjiang in Tanchang County, alpine mountain snow regions, and bare rock zones.