库姆塔格沙漠南缘植物物种丰富度格局及主要影响因素

通过对库姆塔格沙漠南缘植被进行实地调查，对该地区植物物种丰富度及其群落组成进行研究，并选取11个影响物种丰富度的气候因子和地形因子，利用PCA分析、方差分解等方法探讨气候、地形因子对物种丰富度的影响。结果显示：该区共有植物15科32属38种，植物群落种类匮乏，物种组成单一，植物生活型主要以灌木、多年生草本为主，占所有物种的80%以上；植物物种丰富度与植物群落组成明显受到水热条件的制约。回归分析结果表明，该区物种丰富度与能量因子呈显著负相关（P<0.05），而与水分因子呈显著正相关（P<0.05）。方差分解结果表明，水分、能量共同制约了该地区的物种丰富度，二者的共同解释率为44.3%。此外，地形因子对研究区物种丰富度也存在一定影响，能进一步提高环境因子对物种丰富度的解释率。总之，库姆塔格南缘物种组成单一、物种丰富度格局受到水热条件的共同制约，同时地形的变化也有重要影响。

Species richness patterns and main influencing factors in the south fringe of Kumtag Desert

In this study, species richness and community composition of vegetation along the southern fringe of the Kumtag Desert were studied, with the effects of 11 climatic and topographic factors also being explored using principal component analysis and variance decomposition. Results showed few plant communities in the study area and single species composition. In total, 38 plant species were recorded, belonging to 15 families and 32 genera. The dominant plant life forms were shrubs and perennial herbs, accounting for more than 80% of all species. Species richness and plant community composition were significantly constrained by hydrothermal conditions. Regression analysis showed that species richness was significantly negatively correlated with the energy factor in the region (P<0.05), but positively correlated with the water factor (P<0.05). Variance decomposition showed that water and energy restricted species richness in the region, with these two variables explaining 44.3% of the variation in species richness. In addition, topographic factors had a certain influence on species richness in the study area, which further improved the interpretation rate of environmental factors on species richness. In short, species composition along the southern fringe of the Kumtag Desert was simple. The species richness pattern was constrained by hydrothermal conditions, with topographical changes also playing an important role.