极端干旱区防护林地土壤微生物多样性

土壤微生物在森林土壤中有重要功能.采用传统培养、脂肪酸鉴定和PCR-DGGE 3种方法分别研究了塔里木沙漠公路防护林地土壤微生物数量、脂肪酸种类和细菌DNA片段的多样性,从微生物学角度为塔里木沙漠公路防护林的管理提供理论依据.结果表明,塔里木沙漠公路防护林的建设促进了风沙土土壤微生物的发育,随着防护林定植年限的增加,土壤微生物数量、脂肪酸和细菌DNA片段的多样性指数明显增大;土壤微生物区系组成中,细菌是优势类群,占微生物总数80%以上,而真菌很少,不到微生物总数1%,但在不同土层间有所差异;传统培养法与现代生物标记和分子生物学方法对塔里木沙漠公路防护林地土壤微生物多样性的研究结果基本一致,说明塔里木沙漠公路防护林的建设使林地土壤生物活性有所增强,有利于林地土壤养分循环与利用.

Microbial diversities of shelter\|forest soils in the extreme arid area

Soil microbe has an important role in forest land. In this study, methods of conventional culture, identifying fatty acid and PCR-DGGE were utilized to analyze soil microbial quantity, fatty acid and bacterial DNA segment in Tarim desert highway forest land, which can provide theoretical foundation for managing Tarim desert highway shelter-forest scientifically. The main results are: construction of Tarim desert highway shelter-forest promoted soil microbial development, and with increase of plantation time of the shelter-forest, the quantity, fatty acid diversity index of soil microbe and diversity index of bacterial DNA segment enhanced notably. As to soil microbial community structure, bacteria are dominant population with amounting for over 80% of total soil microbe, and fungi is not more than 1% of total soil microbe, but soil microbial community structure was different among three soil layers. The conclusions from study methods of conventional culture, biological marker and molecule biology were almost identical, which illuminates that construction of Tarim desert highway made soil microbial activity enhance and so promote nutrient cycle and utilization of Tarim desert highway shelter-forest land.