Mean annual temperature mainly drives spatial pattern of plant functional traits in inland arid and semi-arid areas

The distribution pattern of different plant functional traits in arid and semi-arid areas and their environmental impact mechanism are still unclear. The aim of this study is to elucidate the spatial distribution patterns of four key plant functional traits and the effects of environmental factors on their variation in inland arid and semi-arid areas and thus provide a reference for the prediction of species distribution and biodiversity conservation in this region. We focused on wild seed plants naturally distributed in Xinjiang, and by reviewing floras and data sharing platforms, we sorted and compiled the species list and distribution, plant functional traits and environmental data, including 3,953 species information, 44,302 county-level distribution records, 3,892 plant functional traits information and 29 environmental variables. Spatial and statistical analyses were utilized to detect the spatial distribution patterns of four key plant traits in 50 × 50 km grid cells. The spatial variation in different functional traits was explored and environmental drivers were identified. The results showed that there were significant latitudinal and altitudinal gradient patterns of plant functional traits, and there were significant spatial correlations between different traits. Among the three types of environmental factors (climate, soil and habitat heterogeneity), climate factors played the most pronounced role in explaining functional traits. Mean annual temperature (MAT) was the most important driver of the spatial distribution patterns of each trait. Overall, vegetative and reproductive growth of plants is more favorable in areas with higher temperatures, abundant precipitation, fertile soils and high habitat heterogeneity, which is mainly reflected in higher plant height, larger leaves, earlier flowering time and longer flowering duration.