关键词: 增氮, 增温, 亚高山森林, 凋落物分解, 矿质元素

Abstract: [Objective] The aim of the study was to examine impacts of warming and nitrogen additionon release of mineral elements in fresh litter of L. potaninii in an alpine forest of the western Sichuan, China. [Method] Fresh litter of L. potaninii was bagged and incubated in situ under different treatments (control, T₁;nitrogen addition, T₂;warming, T₃;nitrogen addition and warming, T₄)to investigate cumulative percentage of release of mineral elements (K, Ca, Mg and Cu. [Results] Warming significantly affected the release of mineral elements (K, Ca, Mg and Cu)in the early period of the experiment. The interaction of nitrogen addition and warming was significant on release of Mg (P<0.05). However, nitrogen addition had no significant effect in any other treatment. Release rate was ranked in an order of Mg > Cu > K > Ca. [Conclusion] ① Release of mineral elements in fresh litter of L. potaninii was correlated closely with the initial substrate quality and transfer capacity. High initial content and strong transfer capacity may stimulate release of mineral elements. ② Litter decomposition of L. potaninii and release of mineral elements were primarily affected by warming rather than nitrogen addition in the alpine ecosystems, especially in low temperature seasons. Global warming could have more considerable impacts onrelease of mineral elements in fresh litter of L. potaninii compared to nitrogen deposition.

Key words: nitrogen addition, warming, subalpine forest, litter decomposition, mineral elements