雪被期川西高山林线交错带凋落物可溶性有机碳的淋失特征  

Leaching of dissolved organic carbon from decomposing litter during the snow cover period at an alpine timberline ectone in Western Sichuan,China

作　　者：邓长春[1] 陈亚梅[1] 和润莲 刘洋[1] 张健[1] 宋小艳[1] 李建平[1] 

机构地区：[1]四川农业大学生态林业研究所/林业生态工程重点实验室,成都611130

出　　处：《生态学杂志》2014年第11期2921-2929,共9页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31200345;31170423);教育部博士点基金项目(20115103120003);国家科技支撑计划项目(2011BAC09B05);四川省教育厅重点项目(11ZA079)资助

摘　　要：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。Dissolved organic carbon （DOC） in plant litter is one of the main sources of soil DOC, and the DOC leaching process of plant litter plays an important role in the ecosystem C cy- cle. Alpine timberline ecotone responses sensitively to climate change in the terrestrial ecosystem. Differences in decomposition microenvironment caused by different vegetation zones may af- fect DOC leaching from litter at alpine timberline ectone, which further have important impacts on C cycle in alpine ecosystem. In this study, field litterbag technology was taken to investigate the potential effects of three decomposition habitats on the DOC leaching from decomposing litter of 12 plant species at an alpine timberline ectone of Miyaluo, western Sichuan, China between Oc- tober 2012 and May 2013. The results showed that ： 1 ） the initial concentrations of DOC in litter of the 12 plant species ranged from 22.78 to 178.8 g ~ kg-1 , and showed a significant difference among species ; 2） after a snow-covered season （ 182 d） , litter DOC leaching loss rate was in the range of 18.92% and 62.33% , which responded differently to decomposition habitats; 3） decomposition habitats had significant effects on the litter DOC leaching loss, and the litter DOC leaching loss rate in the coniferous forest habitat was higher than that in the timberline and the alpine meadow; 4） snow cover was the most important factor controlling litter DOC leaching during winter at the alpine timberline ecotone. Our results suggested that the differences in snow distri bution contributed to the spatial variability of leaching of DOC from decomposing litter, and the thicker snow cover favored more leaching of DOC from decomposing litter during the snow cover period at the alpine timberline ectone.

关 键 词：高山林线交错带 可溶性有机碳 凋落物 雪被 

分 类 号：S714[农业科学—林学]