落叶松人工林土壤微量元素的有效性

采用对比分析的方法，研究了落叶松人工林不同发育阶段根际与非根际土壤有效铜、锌、铁微量元素含量的演变及分布规律。结果表明：在落叶松人工林不同发育阶段，根际土壤有效铜和有效铁的含量，从幼龄林到中龄林先降低，后随年龄的增加而增加，而非根际土壤有效铜和有效铁、根际与非根际土壤有效锌随年龄的增加而降低。各林型土壤有效铜、铁含量随着土壤深度的加深而增加，锌含量呈现出中间高、表层和底层低的分布规律。落叶松树种对土壤有效铜、有效铁具有富集作用。落叶松与阔叶树种混交能提高根际与非根际土壤有效铁、有效锌含量。

Availability of Soil Microelements in Larch Plantations

By the method of comparison analysis, evolvement and distribution of soil microelements (available Cu, Zn, Fe) in rhizosphere soil and non-rhizosphere soil were studied in larch plantations at different development stages. The results showed that with stand age increasing, the contents of available Cu and available Fe decreased from the young stand to half-mature stand, then with age increasing the contents increased, but the contents of available Cu and Fe in non-rhizosphere soil, available Zn in rhizosphere soil and non-rhizosphere soil decreased. In various forest types, available Cu and Fe contents increased with soil depth increasing, available Zn content was higher in the middle soil layer and lower in the surface and bottom soil layers. Larch had enrichment impact on available Cu and Fe. The mixture stands of larch and other broadleaved species could improve soil available Fe and Zn status.