四川农业大学学报 ›› 2010, Vol. 28 ›› Issue (03): 285-290.

• 研究论文 • 上一篇    下一篇

天然常绿阔叶林人工更新后枯落物对土壤微生物和养分的影响

王景燕   

  1. 四川农业大学林学院
  • 收稿日期:2010-05-28 修回日期:2010-08-27 出版日期:2010-09-30 发布日期:2010-09-30
  • 通讯作者: 王景燕
  • 基金资助:

    国家“十五”科技攻关项目

Impacts of litter on soil microbe and nutrient in soils of natural evergreen broadleaved forest after artificial regeneration

Wang JingYan   

  1. Forestry college, Sichuan agricultural university
  • Received:2010-05-28 Revised:2010-08-27 Online:2010-09-30 Published:2010-09-30
  • Contact: Wang JingYan

摘要:

天然常绿阔叶林及其人工更新成檫木林、柳杉林后0~20 cm土层土壤在25 ℃、自然含水量和添加不同枯落物条件下,培养15、30、45、60、75和90 d测定土壤细菌、真菌、放线菌数量及碱解氮、有效磷和速效钾含量的差异。结果表明:微生物数量随培养时间延长而增加,当达到最大值后又随培养时间延长而降低,不添加枯落土壤细菌数量在45 d达到最大值,而添加枯落物后细菌在60 d达到最大值,各处理真菌和放线菌数量分别在60 d和45 d达到最大值。土壤养分含量均随培养时间延长而增加。各培养时间土壤微生物数量和养分含量,在不添加枯落物时均为天然常绿阔叶林>檫木林>柳杉林,各林分土壤添加其自身林地枯落物高于不添加枯落物,而且在檫木林、柳杉林土壤中添加天然常绿阔叶林枯落物比添加其自身林地枯落物高。土壤微生物数量和养分含量三者间具有较好的相关性。说明天然常绿阔叶林人工更新后土壤微生物数量和养分含量下降,枯落物组成与质量对土壤肥力具有重要影响。

关键词: 天然常绿阔叶林, 人工更新, 枯落物, 微生物, 养分

Abstract:

Soil bacteria, fungi and actinomycetes counts, and hydrolysis N, available P and K contents in soils were determined to understand the effects of litter on soils in natural evergreen broadleaved forest, Sassafras tzumu plantation and Cryptomeria fortunei plantation. Soils were collected in the 0~20 cm layer and incubated for 15, 30, 45, 60, 75 and 90 days in the laboratory at 25 ℃ with natural water content and different litters. The results indicated that microbial counts increased and decreased with incubation time pre- and post- reached the max values, respectively. Bacteria counts reached the max value in 45 and 60 days incubation in soils with and without forest litter addition, respectively; fungi and actinomycetes counts reached the max value in 60 and 45 days incubation, respectively. Soil nutrient contents increased continuously with incubation time. Microbial counts and nutrient contents in soils showed the ranked order of natural evergreen broadleaved forest > Sassafras tzumu plantation > Cryptomeria fortunei plantation when the forest litter was not added to the soil. The added forest litter increased the microbial counts and nutrient contents in soils regardless of the forests. Added the litter from the natural evergreen broadleaved forest in soils of the Sassafras tzumu plantation and Cryptomeria fortunei plantation led to higher microbial counts and nutrient contents, as compared with added the litter from the Sassafras tzumu plantation and Cryptomeria fortunei plantation, respectively. There were close relationships between soil microbial counts and nutrient contents. The results suggested that the artificial regeneration of the natural evergreen broadleaved forest into the Sassafras tzumu plantation and Cryptomeria fortunei plantation might lead to the decrease of soil microbial counts and nutrient contents; in addition, the composition and quality of forest litter have important impacts on soil fertility.

Key words: natural evergreen broadleaved forest, artificial regeneration, litter, microbe, nutrient