寒温带兴安落叶松林不同林型土壤微生物群落特征

Soil Microbial Community Characteristics of the Different Forest Types of Larix gmelini Forest in Cold Temperate Zone

为了研究不同林型兴安落叶松林土壤微生物生物量和群落结构特征,探讨土壤微生物生物量、群落结构的分布规律以及影响因子,选择了4个典型兴安落叶松林,即藓类兴安落叶松林、杜香兴安落叶松林、草类兴安落叶松林和杜鹃兴安落叶松林,采用磷脂脂肪酸生物标记法分析4个林型的土壤微生物量和群落组成。结果表明:4个林型中共检测出10种类型51种不完全分布的磷脂脂肪酸(PLFAs)生物标记,微生物量由多到少的排序为细菌、真菌、放线菌。4个林型中微生物总生物量、细菌生物量是藓类兴安落叶松林最高,草类兴安落叶松林最低;真菌生物量为杜香兴安落叶松林最高,草类兴安落叶松林最低;放线菌生物量为杜鹃兴安落叶松林最高,草类兴安落叶松林最低。冗余分析显示,土壤含水率对细菌影响最大,全钾、速效钾质量分数对真菌影响最大,土壤有机碳和碱解氮质量分数对放线菌影响最大。从而表明,寒温带兴安落叶松林不同林型的土壤微生物生物量和群落存在差异,土壤微生物群落与土壤性质之间具有相关性。

To clarify the characteristics of soil microbial biomass and community structure characteristics and their distribution patterns and influencing factors of different Larix gmelinii forest types, we analyzed the soil microbial biomass and commu- nity structures under four typical plots （ mosses-, Ledumpalustre-, grass-and Rhododendron simsii-larch forest） by using the phospholipid fatty acids （PLFA） method. Ten types, 51 species of incomplete distribution of PLFAs biomarkers were found in four plots, in which the total number of soil microbes was in descending order of bacteria, fungi and actinomyce- tes. The total amount of PLFAs and bacteria in themosses-larch forest was the highest, and lowest in the grass-larch forest. The total amount of the fungi was the highest in the Ledumpalustre-larch forest and lowest in the grass-larch forest. The amount of rhododendron was highest in the Rhododendron simsii-larch forest and the lowest in the grass-larch forest. The redundan- cy analysis showed that soil moisture content had the greatest impact on bacteria, total potassium and available potassium had the greatest impact on fungi, and soil organic carbon and alkali hydrolyzable nitrogen had the greatest impact on acti- nomycetes. There were differences in soil microbial biomass and community among different L. gmelinii forests in the cold temperate zone, and there was a correlation between soil microbial community and soil properties.