Effects of litter quality and climate change along an elevation gradient on litter mass loss in an alpine meadow ecosystem on the Tibetan plateau
Effects of litter quality and climate change along an elevation gradient on litter mass loss in an alpine meadow ecosystem on the Tibetan plateau
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DOI：
10.1007/s11258-009-9714-0
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发表时间：
2010-08
期刊：
影响因子：
1.7
通讯作者：
Guangping Xu;Yigang Hu;Shiping Wang;Zhenhua Zhang;X. Chang;J. Duan;C. Luo;Z. Chao;Ailing Su;Q. Lin;Ying-nian Li;Mingyuan Du
中科院分区：
文献类型：
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作者：
Guangping Xu;Yigang Hu;Shiping Wang;Zhenhua Zhang;X. Chang;J. Duan;C. Luo;Z. Chao;Ailing Su;Q. Lin;Ying-nian Li;Mingyuan Du
高山生态系统凋落物质量损失对气候变暖和凋落物质量的响应知识仍然很少。在这里，我们进行了一个沿着507天的凋落物分解实验，沿海拔梯度从3200至3800米，使用不同的凋落物类型，以确定凋落物质量和气候变化的影响，对元素的质量损失和对凋落物质量损失的温度敏感性（每年的百分比分解（%）每1°C的温差）。C、N、P、K、Na、Ca和Mg的质量损失随海拔升高而降低。在一般情况下，凋落物中的N和Na浓度和C：N和木质素：N的比例是最好的预测C质量损失。凋落物中较高的N浓度和C：N比导致较大的C质量损失，但较高的木质素：N比导致较小的C质量损失。凋落物分解过程分两个阶段进行。凋落物中碳质量损失主要受分解期第一生长季土壤温度的限制，而分解期第二生长季剩余凋落物中碳质量损失主要受N浓度和C：P和N：P比值的限制。土壤水分对凋落物质量损失的影响不大，高寒地区草地凋落物质量损失的温度敏感性大于灌木凋落物。
Knowledge of the response of litter mass loss to climate warming and litter quality in alpine ecosystems is still sparse. Here, we conducted a 507-day litter decomposition experiment along an elevation gradient from 3200 to 3800 m using different litter types to determine the influences of litter quality and climate change on the elemental mass losses and on the temperature sensitivity of litter mass losses (annual percentage decomposition (%) per 1°C temperature difference). Mass losses of C, nitrogen (N), phosphorus (P), potassium (K), sodium (Na), calcium (Ca), and Magnesium (Mg) decreased with an increase in elevation. In general, N and Na concentrations in litter and ratios of C:N and lignin:N were the best predictors of C mass losses. A higher N concentration and C:N ratio in litter caused greater C mass losses, but higher lignin:N ratio in litter resulted in lower C mass losses. Litter decomposition occurred in a two-stage process. Carbon mass loss in litter was mainly limited by soil temperature in the first growing season of the decomposition period, whereas N concentration and ratios of C:P and N:P limited carbon mass loss in the remaining litter during the second growing season of the decomposition period. Soil moisture appeared not to affect litter mass loss and the temperature sensitivity of litter mass loss of grass litter was greater than that of shrub litter in the alpine region.