【摘要】 为探讨物种多样性及功能多样性沿地下水埋深的变异格局及其相互关系，以塔里木荒漠河岸林为研究对象，基于野外群落调查与采样分析。结果显示：（1）物种多样性、功能多样性指数随地下水埋深（GWD）梯度的增加总体呈下降趋势，GWD 4.0～4.5 m以下显著降低，于6.5 m左右出现拐点；（2）不同GWD间群落加权性状平均值(CWM_LDT、CWM_HV)无显著差异（P>0.05）,物种多样性、功能多样性指数及其他群落加权性状平均值均差异显著（P<0.05）;（3）功能多样性指数与Shannon-Wiener、Margalef、Simpson指数，CWM_LI与Shannon-Wiener、Margalef、FDis、RaoQ指数呈显著正相关（P<0.05）;（4）Shannon-Wiener多样性指数对功能多样性的影响最大，Pielou均匀度指数对其影响最小。结论表明：荒漠河岸林地下水埋深直接影响了物种多样性和功能多样性，而物种多样性决定了功能多样性，环境过滤作用间接降低了功能多样性。因此，维持塔里木荒漠河岸林植物群落物种、功能多样性的GWD<6.5 m,维持较高的物种多样性是提高功能多样性的有效措施。更多还原

【Abstract】 This study, focusing on the desert riparian forests in Tarim, investigated the variation patterns of species and functional diversity along a groundwater depth(GWD)gradient and their interrelationships, based on field community surveys and sample analyses.The results revealed that both species and functional diversity indices generally declined with increasing GWD,with a significant reduction observed below a GWD of 4.0-4.5 m and a tipping point at approximately 6.5 m.Among different GWD levels, community-weighted mean trait values(CWM-LDT,CWM-HV)showed no significant differences(P>0.05),whereas significant differences were detected for species diversity indices, functional diversity indices, and other CWM traits(P<0.05).Functional diversity indices were significantly positively correlated with the Shannon-Wiener, Margalef, and Simpson indices(P<0.05).CWM-LI was significantly positively correlated with the Shannon-Wiener, Margalef, FDis, and Rao’s Q indices(P<0.05).The Shannon-Wiener index had the greatest influence on functional diversity, while the Pielou evenness index had the least.In conclusion, groundwater depth directly affects both species diversity and functional diversity in the desert riparian forest.Species diversity plays a determining role in shaping functional diversity, while environmental filtering indirectly reduces it.Therefore, maintaining a GWD below 6.5 m is critical for preserving plant community species and functional diversity in the Tarim desert riparian forest.Enhancing species diversity is an effective strategy for improving functional diversity.These findings provide a scientific basis for biodiversity conservation and ecological restoration in degraded desert riparian areas.更多还原