Abstract：
Sodium (Na), a beneficial mineral element, stimulates plant growth through osmotic adjustment. Previous studies focused on Na content at the individual or species level, however, it is hard to link to ecosystem functions without exploring the characteristics (content, density, and storage) of Na at the community level. We conducted grid-plot sampling of different plant organs in 2040 natural plant communities on the Tibetan Plateau (TP) to comprehensively characterize community-level Na on a regional scale. The Na content was 0.57, 0.09, 0.07, and 0.71 mg g-1 in leaves, branches, trunks, and roots, respectively. Across biomes Na content was higher in deserts under drought stress. Oxygen partial pressure, radiation, precipitation, soil Na supply, and temperature significantly affected the spatial variation in Na content. Furthermore, we accurately simulated the spatial variation in Na density and produced a highly precise 1 km × 1 km spatial map of plant Na density on the TP using random forest algorithm, which demonstrated higher Na density in the southeast of TP. The total plant Na storage on the TP was estimated as 111.80 × 104 t. These findings provide great insights and references for understanding the plant community-level adaptation strategies and evaluating the mineral element status on a large scale, and provide valuable data for ecological model optimization in the future.
摘要：
钠(Na),一种有益的矿物元素,通过渗透调节刺激植物生长。以前的研究集中在个体或物种水平的Na含量，然而,如果不探索特征(内容，密度,和储存)在社区一级的Na。我们在青藏高原（TP）的2040个自然植物群落中对不同植物器官进行了网格图采样，以在区域尺度上全面表征群落水平的Na。叶片中Na含量分别为0.57、0.09、0.07和0.71mgg-1,分支,树干,和根，分别。干旱胁迫下，沙漠中的生物群落Na含量较高。氧分压,辐射,降水,土壤Na供应，和温度显著影响Na含量的空间变化。此外，我们准确地模拟了Na密度的空间变化，并使用随机森林算法在TP上生成了高度精确的1km×1km植物Na密度空间图，这表明TP东南部的Na密度较高。植物在TP上的总Na储量估计为111.80×104t。这些发现为理解植物群落水平的适应策略和大规模评估矿质元素状况提供了很好的见解和参考。为今后的生态模型优化提供有价值的数据。
