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普遍存在于森林地表的粗木质残体(Coarse woody debris,CWD)是森林生态系统的重要组成部分.金属元素不断在CWD中积累—释放—转移,是认识植物-土壤金属元素循环的关键纽带.因此以长江上游高山峡谷区暗针叶林不同类型不同腐烂等级CWD为研究对象,调查其金属元素含量及贮量特征.结果表明:CWD类型和腐烂等级显著影响金属元素含量.CWD中生物必需非重金属元素(K、Ca、Na和Mg)含量分别介于0.29-2.56、2.41-8.13、0.56-1.65和0.34-1.03 g/kg之间,生物必需重金属元素(Cu、Mn和Zn)含量分别介于1.71-6.00、0.03-1.01和0.06-0.73 g/kg之间,非生物必需重金属元素含量(Cr、Cd和Pb)分别介于3.74-34.54、0.07-3.60和0.73-36.10 mg/kg之间.高山峡谷区暗针叶林CWD生物必需非重金属(K、Ca、Na和Mg)总贮量分别为43.77、220.63、40.78和31.37 kg/hm~2,生物必需重金属元素(Cu、Mn和Zn)总贮量分别为0.12、16.11和9.91 kg/hm~2,非生物必需重金属元素(Cr、Cd和Pb)总贮量分别为0.10、0.16和0.72 kg/hm~2.不同类型CWD金属元素贮量表现为倒木>根桩>大枯枝>枯立木,且不同金属元素在相同类型CWD不同腐烂等级之间基本具有相对一致的变化趋势.可见,CWD是高山峡谷区暗针叶林金属元素重要贮存场所之一,其降解过程中金属元素的释放可能是生态系统元素循环的重要途径.
Coarse woody debris (CWD) is a common component of forest ecosystems, and the continuous accumulation, release and transfer of metal elements in CWD is a key link in understanding plant-soil metal cycle. Therefore, the CWD of different types and decay grades of dark coniferous forest in the upper reaches of the Yangtze River were studied, and the metal element content and storage characteristics were investigated.The results showed that the CWD type and decay grade significantly affected the content of metal elements The contents of heavy metals (K, Ca, Na and Mg) ranged from 0.29 to 2.56, 2.41 to 8.13, 0.56 to 1.65 and 0.34 to 1.03 g / kg, respectively. Between 1.71-6.00, 0.03-1.01 and 0.06-0.73 g / kg, the content of non-biogenic heavy metals (Cr, Cd and Pb) were between 3.74-34.54, 0.07-3.60 and 0.73-36.10 mg / kg The total biomass of non - heavy metals (K, Ca, Na and Mg) in the dark coniferous forest of alpine coniferous forest was 43.77, 220.63, 40.78 and 31.37 kg / hm ~ 2, respectively, ) Total reserves were 0.12, 16.11 and 9.91 kg / hm ~ 2, respectively The total reserves of heavy metals (Cr, Cd and Pb) required were 0.10, 0.16 and 0.72 kg / hm ~ 2, respectively.When different types of CWD were stored, The results showed that CWD had a relatively consistent trend among different decay grades of CWD of the same type.It can be seen that CWD is one of the important storage sites for the metal elements in dark coniferous forest in alpine gorge area and the release of metal elements may be the element of ecosystem An important way to cycle.