大青山不同森林结构与根际土壤微生物数量变化研究

大青山不同林龄根际土壤微生物数量变化规律是细菌、放线菌数量和微生物的总数均随着树龄的增长呈现减少趋势。不同林木树种组成,根际土壤微生物数量变化呈现出一定的规律性,在榆林地区的土壤细菌数量及微生物总量分布依次为山杏〉油松×沙棘〉油松×山杏〉油松×柠条〉油松〉沙棘〉柠条;劈柴沟地区不同树种组成土壤微生物总量及土壤细菌数量变化为山杨〉白桦×落叶松〉落叶松〉油松〉白桦。不同密度的根际土壤微生物数量的规律是2 m×3 m≥3 m×3.5 m〉1.5 m×2 m〉1 m×3 m≥1.5 m×2 m,基本上是随密度增加土壤微生物数量减少。

Study on Different Forest Structures and Quantity Change of Microbial in Rhizosphere Soil in Daqingshan Mountains

With the increase of tree ages, the quantity of bacteria, actinomycetes and total microbial are in a tendency of decrease in rhizosphere soil. For different forest tree species composition, the quantity changes of microbial in rhizosphere soil have some regularity, that is, in Yulin district, the sequence of quantity of soil bacteria and total microbial is Prunus sibirica 〉 Pinus tabulaeformis ×Hippophae rhamnoides 〉 Pinus tabulaeformis × Prunus sibirica 〉 Pinus tabulaeformis ×Caragana korshinskii 〉 Pinus tabulaeformis 〉 Hippophae rhamnoides 〉 Caragana korshinskii ; in Pichaigou district, the sequence of quantity of soil bacteria and total microbial is Populus davidiana 〉 Betula ptatyphylla ×Larix gmelinii 〉 Larix gmelinii 〉 Pintts tabulaeformis 〉 Betula platyphylla. The rule of quantity of microbial in rhizosphere soil at different density is 2 m×3 m≥3 m×3.5 m1.5 m×2 m1 m×3 m≥1.5 m×2m, which the quantity of soil microbial is decreasing with the increase of density.