The alpine treeline ecotones represent one of the most sensitive ecosystems, functioning as first responder of global climate change. However, the soil nutrient dynamics within the alpine ecotone across varying altitudinal gradients remain insufficiently explored. The present study investigated soil physical and biochemical properties in the forest, ecotone and meadow zone in three soil depths: 0–10, 10–20, and 20–30 cm. Our findings revealed soil moisture, pH, organic carbon (SOC), total nitrogen (TN), available phosphorus (AP), SOC/TN and SOC/AP were higher in meadow compared to forest. The SOC (mean) was higher in the meadow (5.68 %) and ecotone (5.02 %) than in forest (4.08 %). The TN increased in order: forest (0.33 %) < ecotone (0.47 %) < meadow (0.52 %). The AP decreased in order: forest (0.048 %) > ecotone (0.037 %) and > meadow (0.035 %). The soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbial biomass phosphorus (MBP) ranged from 125 to 400 µg g, 3–12 µg g and 0.12–4.63 µg g, respectively with higher values in ecotone, possibly due to warming-induced increased shrubification in alpine ecosystem. Principal component analysis (PCA) showed ecotone influenced by most of the soil parameters. ANOVA reveals significant differences in soil physical, chemical, biological, and stoichiometry due to soil layers, sites, and sites × depths interaction (. The results indicated SOC, TN, AP, MBC, MBN, and MBP decreased with soil layers. Significant correlations between soil nutrients and microbial biomass showed strong linkages. Compared to forest and ecotone, the higher MBC/MBN ratio in meadow region indicated shifting of microbes towards the fungal community dominance. Our findings indicated changes in the ecosystem along an altitudinal gradient directly influence the cycling of soil and microbial nutrients and stoichiometry. Thus, our findings will improve understanding for managing and conserving alpine ecosystems in long run.

中文翻译：

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林线交错带影响印度喜马拉雅山西部高山生态系统的土壤物理、生物化学和化学计量特性

高山林线交错带是最敏感的生态系统之一，是全球气候变化的第一响应者。然而，高山交错带内不同海拔梯度的土壤养分动态仍未得到充分探索。本研究调查了森林、交错带和草甸带三个土壤深度（0-10、10-20 和 20-30 厘米）的土壤物理和生化特性。我们的研究结果显示，与森林相比，草地的土壤湿度、pH、有机碳 (SOC)、总氮 (TN)、速效磷 (AP)、SOC/TN 和 SOC/AP 较高。草地 (5.68%) 和交错带 (5.02%) 的 SOC（平均值）高于森林 (4.08%)。 TN增加顺序为：森林(0.33%)<交错带(0.47%)<草甸(0.52%)。 AP下降的顺序为：森林(0.048%)>交错带(0.037%)>草甸(0.035%)。土壤微生物生物量碳（MBC）、微生物生物量氮（MBN）和微生物生物量磷（MBP）分别为125~400 µg·g、3~12 µg·g和0.12~4.63 µg·g，在交错带中值较高，可能由于变暖导致高山生态系统灌木化增加。主成分分析（PCA）显示交错带受到大多数土壤参数的影响。方差分析揭示了由于土层、场地和场地 × 深度相互作用而导致的土壤物理、化学、生物和化学计量的显着差异。结果表明 SOC、TN、AP、MBC、MBN 和 MBP 随着土层的增加而降低。显着相关土壤养分和微生物生物量之间显示出很强的联系。与森林和交错带相比，草甸地区较高的 MBC/MBN 比率表明微生物向真菌群落优势转变。我们的研究结果表明，生态系统沿海拔梯度的变化直接影响循环因此，我们的研究结果将提高对长期管理和保护高山生态系统的理解。