新疆猪毛菜属植物多样性地理分布格局及其环境解释

猪毛菜属(Salsola)是新疆干旱区分布最为丰富的被子植物属之一，是盐碱和荒漠区的先锋种和建群种，对西北干旱区植被恢复与建设具有巨大生态价值。基于新疆自然分布的33种猪毛菜属物种共741个分布数据，整合利用点格局法和物种分布模型法构建了物种丰富度(SR)、加权特有性指数(WE)和校正加权特有性指数(CWE)的分布格局。选取环境能量、水分可获得性、气候季节性、生境异质性、土壤条件和历史气候变化共6类19种生态因子，利用地理加权回归模型(GWR)探究了环境异质性对猪毛菜属物种丰富度的影响。结果显示：(1)基于现实点位模型和物种分布模型构建的物种丰富度具有一致性，均呈北高南低、西高东低的破碎化分布趋势，但物种分布模型的结果在空间上比点格局法更连续，物种丰富度的高值区主要分布于准噶尔盆地南缘、准噶尔西部山地、天山西端和天山南脉南缘；(2)加权特有性指数和校正加权特有性指数的分布格局与物种丰富度分布格局具有一定差异，其最大值集中分布于准噶尔盆地南缘、伊犁河谷和塔里木盆地西南缘；(3)GWR模型结果表明，海拔变幅、土壤酸碱度和最干月降水量是制约新疆分布的猪毛菜属丰富度和特有性分布的最重要因素。

Geography distribution pattern and the environmental interpretation of plant species of Salsola genus in Xinjiang

Salsola is one of the most abundant angiosperm genera in the arid area of Xinjiang. Most species of Salsola are pioneer species and constructive species in saline-alkali and desert areas, and have great ecological values for vegetation construction and restoration in the arid area of Northwest China. In this study, we integrated the point grid method and species distribution model to construct the distribution patterns of species richness (SR), weighted endemism (WE), and corrected weighted endemism (CWE) based on 741 occurrence points of 33 species of Salsola in Xinjiang. By selecting 19 ecological factors including 6 types of environmental energy, water resource availability, climate seasonality, habitat heterogeneity, soil conditions and historical climate change, we explored the effects of heterogeneity of environment on Salsola genus species richness based on a geographically weighted regression (GWR) model. The results show that:(1) the species richness constructed based on the actual points and species distribution models are consistent, showing a fragmented distribution trend of high in the north and low in the south, and high in the west and low in the east, but the modeled results are more continuous than the results of point pattern method. The high-value areas of species richness are mainly distributed in the southern margin of the Junggar Basin, the Junggar Xibu Shandi, the western end of the Tianshan Mountains, the southern edge of the Tianshan Mountains southern vein, and the southern margin of the Tarim Basin; (2) the distribution patternof the weighted endemism index and the corrected weighted endemism index are differs from the distribution pattern of richness. The maximum value is concentrated in the southern margin of the Junggar Basin, the Ili River Valley and the southwestern margin of the Tarim Basin; (3) The results of the GWR model show that the altitude variation, soil pH and the driest month precipitation are the constraints of Salsola genus in Xinjiang.