东灵山3种落叶阔叶林的碳氮元素含量及比率

Content and Ratio of Carbon and Nitrogen of Three Types of Warm Temperate Deciduous Broadleaf Forests in Dongling Mountain

研究暖温带东灵山3种落叶阔叶林的碳氮元素含量和C∶N比率的化学计量特征。结果表明:1)土壤和乔木层的碳元素含量表现为白桦林>辽东栎+棘皮桦混交林>辽东栎林,氮元素含量在辽东栎+棘皮桦混交林中最高,为另外2种林型含量的2倍,而3种林型的土壤微生物碳氮元素含量之间没有显著差异;2)不同林型土壤微生物的C∶N比率变动很小,并且不受土壤碳氮含量变化的影响;3)3种林型土壤和土壤微生物的C∶N比率变化不大,表现出受限制的化学计量学特征。

The contents of carbon and nitrogen and C ： N ratio stoichiometry in three warm temperate deciduous broadleaf forest types were investigated in Dongling Mountains, northern China. The results showed that： 1 ） The carbon concentrations of soil and tree layer decreased successively from Betula platyphylla （birch） forest （BF）, Quercus liaotungensis （oak） and Betula dahurica mixed deciduous broadleaf forest（MF）, to Quercus liaotungensis （oak） forest （OF）. The tree layer in the mixed forests had the highest nitrogen concentration, which was more than twice that of the others. However, no significant difference was found in the carbon and nitrogen contents in soil microbial among the three forest types. 2） The variation of C：N ratio in the soil microbial was smaller than that in the tree layer among the three forest types, regardless of the soil C and N concentrations. 3） The C ： N ratios of both the soil and the soil microbial were not significantly changed and appeared well-constrained in the three forest types.