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亚高山森林林窗可能通过改变冬季雪被格局和生长季水热环境影响林窗内凋落物中半纤维素的分解动态,但目前对此还缺乏研究。采用凋落物分解袋法,以亚高山森林5种典型物种岷江冷杉(Abies faxoniana)、红桦(Betula albosinensis)、四川红杉(Larix mastersiana)、方枝柏(Sabina saltuaria)和高山杜鹃(Rhododendron lapponicum)凋落物为研究对象,研究雪被形成期、雪被覆盖期、雪被融化期和生长季节从林窗中心、林冠林窗、扩展林窗到郁闭林下物种凋落物的半纤维素变化特征。经历一年分解后,5种凋落物的半纤维素均呈现净累积现象。针、阔叶凋落物半纤维素分别在雪被覆盖期和融化期表现出相对较高的损失率。在雪被覆盖期和融化期,凋落物半纤维素在林窗中心和林冠林窗具有相对较高的损失率;而在生长季节,林窗中心呈现相对较低的凋落物半纤维素累积率。统计分析结果表明凋落物分解过程中半纤维素损失率与环境因子和凋落物质量因子均显著相关。这些结果表明亚高山森林林窗对凋落物分解过程中半纤维素损失率具有显著影响,分别促进了半纤维素在冬季的损失以及抑制了半纤维素在生长季节的累积,意味着亚高山森林林窗的形成有利于凋落物半纤维素的降解。
Subalpine forest gap may be through the change of winter snow pattern and the growing season of water and heat environment impact litter decomposition of hemicellulose in the dynamics, but the current lack of research. Five typical species of subalpine forest such as Abies faxoniana, Betula albosinensis, Larix mastersiana, Sabina saltuaria and Rhododendron lapponicum ) Litter were used to study the hemicellulose changes of litter in litters during the period of snow formation, snow coverage, snow meltdown and growing season from the center of canopy, forest canopy gap, feature. After a year of decomposition, the five kinds of litter hemicellulose showed a net cumulative phenomenon. Pinus tabulaeformis and broad-leaf litter hemicellulose showed a relatively high loss rate during snow cover and thawing periods, respectively. During snow cover and thawing period, litter hemicellulose had a relatively high loss rate at the center of the gap and in the forest canopy gap. In the growing season, the center of the gap showed a relatively low accumulation rate of litter hemicellulose . Statistical analysis showed that the hemicellulose loss rate during litter decomposition was significantly correlated with environmental factors and litter quality factors. These results show that subalpine forest gaps have a significant effect on hemicellulose loss during litter decomposition, contributing to the loss of hemicellulose in winter and inhibiting the accumulation of hemicellulose in the growing season, respectively, suggesting that subalpine forests The formation of Gaps favors the degradation of litter hemicellulose.