Abstract: Understanding plant diversity in the Tarim River Basin is of great significance for the assessment of regional ecological restoration. However, current studies mostly focused on vegetation restoration in the downstream ecological water conveyance area, lacking a comprehensive analysis of the distribution pattern of plant diversity and its influencing factors across the entire basin. In this study, combining field survey with the measurement of soil physicochemical properties, we investigated the distribution patterns of plant diversity and its influencing factors along the Tarim River. The results showed that: (1) Among the seven plots (50 m×50 m) established along the upper, middle, and lower reaches, a total of 13 plant species, belonging to 13 genera and 8 families, were recorded. The overall plant diversity distribution followed a pattern of upper reaches > middle reaches > lower reaches. Plots near the Daxihaizi Reservoir in the lower reaches exhibited relatively high plant diversity indices. (2) Results of redundancy analysis (RDA) and canonical correlation analysis (CCA) revealed that soil physicochemical properties directly governed the distribution of plant diversity. The mean variation of soil water content was consistent with the change trend of plant diversity. Except for total soil phosphorus (TP), the contents of total salt (TS), total carbon (TC), and total nitrogen (TN) exhibited similar variation patterns. (3) The artificial ecological water conveyance project effectively improved soil environment in the lower reaches of the Tarim River and promoted the restoration of plant diversity in the basin, while also highlighted the spatial imbalance of ecological restoration in the upper, middle, and lower reaches. This study deepens the understanding of the distribution pattern of plant diversity and its influencing factors in the Tarim River Basin, providing a theoretical basis for the effectiveness evaluation of the artificial ecological water conveyance scheme in the lower reaches.

Key words: plant diversity, soil physicochemical property, Tarim River, artificial ecological water conveyance