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凋落物可溶性有机碳(dissolved organic carbon,DOC)是土壤DOC的主要来源之一,同时,凋落物DOC的淋失过程是生态系统碳循环的重要环节。本文采用凋落物分解袋法,于2012年10月—2013年5月,以川西高山林线交错带12种代表性植物的凋落物为材料,研究了冬季雪被期凋落物DOC在暗针叶林森林、高山林线和高山草甸3种分解生境中的淋失特征。结果表明:1)凋落物初始DOC含量为22.78~178.8 g·kg-1,物种间差异显著;2)经过一个雪被期(182 d),凋落物DOC淋失率为18.92%~62.33%,各物种DOC的淋失率对分解生境的响应差异较大;3)分解生境差异对凋落物DOC的淋失产生了显著影响,暗针叶林生境中凋落物DOC的淋失率显著高于林线和高山草甸生境;4)雪被是影响冬季高山林线交错带凋落物DOC淋失的主要环境因素。因此,高山林线交错上雪被期DOC淋失的空间变异性主要是景观尺度分布的雪被差异造成的,分解生境中较厚的雪被更利于凋落物DOC的淋失。
Litter DOC (dissolved organic carbon) is one of the main sources of soil DOC. Meanwhile, the leaching process of DOC in litter is an important part of ecosystem carbon cycle. In this paper, litter decomposition bag method, from October 2012 to May 2013, the litter of 12 representative plants in the ecotone between western and northern Sichuan Mountains was used as the material to study the effects of winter littoral litter DOC on dark needles Lin Le Lin, alpine forest line and alpine meadow in three kinds of decomposition of the leaching characteristics. The results showed that: 1) the initial DOC content of litter was 22.78-178.8 g · kg-1 with significant difference among species; 2) after a period of snow (182 days), the DOC leaching rate of litter was 18.92% -62.33% The difference of DOC loss rate in different coniferous forest habitat was significantly higher than that of forest. The leaching rate of litter DOC in dark coniferous forest was significantly higher than that of forest Line and alpine meadow habitat; 4) Snow is the main environmental factor affecting the DOC leaching loss in the ecotone of mountain alpine crosses in winter. Therefore, the spatial variability of DOC leaching staggered in the snowy alpine forest is mainly caused by the difference of the snow distribution in the landscape scale. The thicker snow in the decomposed habitat is more conducive to the leaching of litter DOC.