四川农业大学学报

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巨桉人工林不同林龄阶段土壤微生物生物多样性特征

陈礼清1,张健2   

  1. 1.
    2. 四川农业大学林学院
  • 收稿日期:2011-10-31 修回日期:2011-11-30 出版日期:2011-12-25 发布日期:2011-12-26
  • 通讯作者: 张健

Soil microbial biodiversity across a range of Eucalyptus grandis plantation ages

Lin qingChen1, 2   

  1. 1. Faculty of Forestry & Horticulture, Sichuan Agricultural University
    2.
  • Received:2011-10-31 Revised:2011-11-30 Online:2011-12-25 Published:2011-12-26

摘要:

人工林体现出显著经济和社会效益的同时存在着生态效益的争议。目前,国内外对于人工林生物多样性的研究大多集中于地上部分植物多样性的研究,很少涉及土壤生物,土壤微生物是森林生态系统的重要组成部分,在分解有机质、吸收固定释放养分等方面起着十分重要的作用。本文对1~10年生巨桉人工林林下土壤微生物数量及其生物量进行了研究,结果显示,土壤细菌在土壤微生物类群中占绝对优势,放线菌次之、真菌数量最低,土壤细菌、放线菌、真菌、及微生物总数随土层加深而降低,偶尔出现逆向分布;各微生物类群及微生物数量呈现1-4年降低,而后显著增加的趋势。土壤微生物多样性指数,Pielou和Shannon-wiener指数轮伐期前(1-3或4年)有波动的增加,而后随林龄逐渐减小; Simpson 指数呈相反趋势。

关键词: 巨桉人工林, 年龄系列, 土壤微生物, 生物多样性

Abstract:

Issues around the loss of diversity caused by fast-growing tree plantations have aroused controversy for many years. In recent years, most of the studies focused on the aboveground biodiversity, little information was available for the below-ground biodiversity in plantations. Soil microbial was an important component of the forest ecosystem, the changes of microbial was closely contacted with nutrient cycling and decomposition. Soil microbial biodiversity in the Eucalyptus grandis plantations with a range of plantation ages (1-10 years) converted from cropland, therefore, were simultaneously measured in order to obtain an understanding of eucalypt effects on biodiversity. The results showed that bacteria quantitatively dominated the soil microbe in E. grandis regardless of plantation age, follwed by actinomycete and fungi. The counts of the microbes were higher in organic horizons and decreased with soil depths except for the converse distribution in certain year old stands. The microbial counts decreased before rotation and then increased with the plantation age. The diversity indices generally represent the following trend viz. Shannon-wiener and Pielou index increased in the first 3 or 4 years and then decrease with forest age. Simpson index showed a converse trend.

Key words: Eucalyptus grandis plantation, Chronosequence, Soil microbes, biodiversity.