新疆草地生物量优势植物地理分布特征

Characteristics of the geographical range size of biomass-dominant species in the Xinjiang grassland

地理分布范围反映物种在一定空间中所占的分布面积,体现着物种适应环境的能力。以2011-2013年对新疆草地397个样地的调查数据为基础,集合全球生物多样性信息网络、中国数字植物标本馆收录的优势种植物分布点位数据,以及《新疆植物志》对其的记录信息,在ArcGIS软件上以县域为基本单位,用生物区划法计算新疆草地优势种地理分布范围并分析其在物种、功能群和分类水平上分布特征。结果显示:1)本研究所涉及的169种优势种植物,按地理分布范围可分为窄布种(0.15万~5.4万km^(2))]、中等分布种(5.5万~13.9万km^(2))、广布种(14.1万~30.8万km^(2))]和极广布种(31.5万~96万km^(2))] 4类。其中,窄布种、广布种和极广布种各包括42个优势种,而中等分布种有43个优势种。2)在科水平上,窄布种和中等分布种主要由菊科植物组成,而广布种和极广布种则由禾本科植物组成。3)在光合途径和生活型方面,窄布种、中等分布种、广布种和极广布种均由C4植物和多年生草本植物占主导。在生态型方面,窄布种主要由中生植物组成,而中等分布种、广布种和极广布种则由旱生植物组成。本研究为深入理解新疆草地优势种植物地理分布范围,提供了可视化的资料和数据支持。

Geographical range size(GRZ) has been defined as the distribution area of a species in a certain space, and it reflects the adaptive ability of a species to the environment. On basis of 397 site surveys from^(2)011-2013 and distribution information recorded by the Global Biodiversity Information Facility, Chinese Virtual Herbarium and Flora of Xinjiang, we calculated the GRZ of dominant species in the Xinjiang grassland using the bioregional method in ArcGIS software, and county-level administrative units were treated as the basic units. Then, we explored GRZ variations in terms of species, plant functional groups, and taxonomic levels. Our results demonstrated that GRZ could be used to group the 169 dominant species into four classes: narrowly(1 500~54 000 km^(2)), moderately(55 000~139 000 km^(2)), widely(141 000~308 000 km^(2)), and extremely widely distributed species(315 000~960 000 km^(2)). Forty-two species were included in the narrowly, widely, and extremely widely distributed species classes, while 43 species were included in the moderately distributed species class. At the family level, the narrowly and moderately distributed species mainly belonged to Asteraceae while the widely and extremely widely distributed species mainly belonged to Poaceae. Among the plant functional groups, the narrowly,moderately, widely, and extremely widely distributed species were mostly composed by C4 plant and perennial forbs in terms of photosynthetic pathways and life forms. Among the ecological groups, the narrowly and moderately distributed species were dominated by mesophytes while the widely and extremely widely distributed species were mainly composed of xerophytes. Our results provide visual material and basic information to better understand the GRZ variations among the dominant species in the Xinjiang grassland.