火烧强度对白桦枝叶生态化学计量特征的影响

Effects of Fire Intensity on Ecological Stoichiometric Characteristics of Twigs and Leaves of Betula platyphylla

以大兴安岭地区典型树种白桦(Betula platyphylla)为研究对象,测定了不同火烧强度下白桦枝叶的碳(C)、氮(N)、磷(P)的质量分数和土壤化学属性,分析了不同火烧强度下植物生态化学计量特征的变化规律,以及火烧强度对土壤与白桦枝叶化学计量特征关系的影响。结果表明:(1)白桦叶C的质量分数、P的质量分数和w(C)∶w(N)均随火烧强度的增加而升高,而N的质量分数、w(C)∶w(P)和w(N)∶w(P)随火烧强度的增加而降低。白桦枝P的质量分数随着火烧强度的增加而升高,w(C)∶w(P)和w(N)∶w(P)随火烧强度的增加而降低,而枝的C的质量分数、N的质量分数和w(C)∶w(N)在不同火烧强度下均无显著差异。(2)白桦枝叶化学计量特征与土壤化学属性显著相关(p<0.05),但两者相关关系在不同火烧强度下存在差异。

Betula platyphylla, a typical tree species in Daxing’an Mountains, was selected as the research object. We measured the contents of C, N and P of twigs and leaves of Betula platyphylla and soil chemical properties under different fire intensities, and explored the influence of fire intensity on the correlation between soil and stoichiometric characteristics of twigs and leaves of B. platyphylla. The results showed that:(1)The content of C, P and C∶N of leaves increased, however, the content of N, C∶P and N∶P of leaves decreased with increasing fire intensity. The P content of twigs increased, C∶P and N∶P of twigs decreased with increasing fire intensity, there was no significant difference in the content of C, N and C∶N of twigs under different fire intensities.(2)The stoichiometric characteristics of twigs and leaves of B. platyphylla were significantly correlated with soil chemical properties, however, the correlation between them varied under different fire intensities.