Spatiotemporal evolution in species richness patterns and future conservation prioritization of Chenopodiaceae in Xinjiang, China under climate change

Xinjiang serves as a distribution center for Chenopodiaceae species in China and a key region for global research on their ecological adaptation. Clarifying the spatiotemporal patterns of Chenopodiaceae species richness in Xinjiang helps develop strategies for scientific conservation. Using species occurrence data and environmental variables, this study employed ensemble species distribution models to simulate historical, current, and future richness patterns across Xinjiang. Multidimensional climate velocities were calculated via nearest-neighbor search algorithms. Priority conservation areas (PCAs) were identified by integrating species richness as the feature layer and climate velocity as the cost layer using the Zonation model and overlaid with existing protected areas(PAs) for analysis. First, the mean species richness was relatively high during the Last Glacial Maximum and Mid-Holocene but declined markedly by the current period, with fragmentation of the hotspots along the western and northern Tarim Basin.By the future periods (2050 s and 2090 s), the mean richness will continue to decline under both SSP1-2.6 and SSP5-8.5 climate scenarios, with a more pronounced reduction under SSP5-8.5. Secondly, under SSP1-2.6, the mean climate velocity will increase slightly from 2.89 km/yr (current-2050s) to 2.96 km/yr (2050s-2090s), with stable high-velocity zones in eastern Xinjiang and western Tarim Basin. Under SSP5-8.5, the mean climate velocity will increase from 4.54 km/yr (current-2050s) to 6.23 km/yr(2050s-2090s), and the high-velocity zones will expand significantly across eastern Xinjiang and the western Tarim Basin. The accelerated future climate velocity will exacerbate the decline in Chenopodiaceae species richness. Third, the current PCAs are concentrated in western Junggar Basin. Under SSP1-2.6, the PCAs are primarily distributed in the eastern Junggar Basin, the northern margin and southwestern part of the Tarim Basin, with an increasing trend in area. Under SSP5-8.5, the PCAs are primarily located in the western and southeastern Junggar Basin, with a decreasing trend in area. Both currently and in the future, the overlap between PCAs for Chenopodiaceae species and existing PAs in Xinjiang remains limited.