Abstract:Leaf functional traits are pivotal for reflecting how plant communities access resources and adapt to their environment. Studies on plant functional traits based at the local-scale plant communities level is important for understanding and predicting species assemblages and adaptation strategies of plant communities in response to regional habitat changes. Due to the significant environmental heterogeneity at the local scale in the desert-oasis transition zone,differences in community-establishing species and community composition across different environments lead to variations in plant community functional traits. However,the distribution characteristics of desert plant community functional traits along environmental gradients and the interplay with soil factors remain unclear. In this study,we investigated the effects of habitat heterogeneity on leaf functional traits in the transition zone of desert oasis in Linze with different stages of fixation in the sand dunes,conducted community surveys and measurements of leaf functional traits,and decomposed plant community-level leaf functional traits using trait gradient analysis. The results showed that: (1) Leaf functional traits such as degree of fleshing,leaf total water content,relative water content,saturat water content,leaf dry matter content,specific leaf area,tissue density,leaf phosphorus content,and leaf nitrogen to phosphorus ratio varied significantly in heterogeneous habitats (different stages of dune fixation),and plants in fixed dunes dominated by shrubs and perennials tended to adopt a "slow repayment" strategy. Plants in fixed dunes dominated by shrubs and perennials tended to adopt a "slow payback" strategy,while plants in semi-fixed and fixed dunes dominated by annuals tended to adopt a "fast payback" strategy,and plants in stabilized dunes were more likely to transition from P- to N-limitation. (2) Tissue density,leaf carbon to phosphorus ratio,and leaf nitrogen to phosphorus ratio had the highest plasticity and variability,and soil compactness,soil phosphorus content,and soil water content were the main drivers of variability. (3) The range of α values of the leaf functional trait gradient was larger than that of β values,suggesting that biological competition is more important than environmental filtration for community building; the strong negative correlation of the β component and the lack of correlation of the α component between specific leaf area and leaf dry matter content suggests that the species adopt different ecological strategies for adapting to their environments within and among the communities. (4) The primary constraints on plant community functional traits differed among habitats,with trait interconnections strengthening as habitat conditions worsened. In summary,plant communities at different stabilization stages of sand dunes exhibit significant adaptive differences through leaf functional traits. As the degree of dune stabilization increases,the adaptive strategies of plant communities shift gradually from phosphorus limitation to nitrogen limitation. This suggests that the roles of environmental filtering and biotic competition in community assembly adjust according to habitat heterogeneity. These findings provide important theoretical insights into the adaptive mechanisms of plant communities in the desert-oasis transition zone under different habitat conditions.