LTER: Microbial Ecology of Ectomycorrhizal Mats in a Douglas-Fir Ecosystem

LTER：花旗松生态系统中外生菌根垫的微生物生态学

• 批准号: 8717849
• 负责人: Kermit Cromack
• 金额: $ 23.37万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-02-15 至 1992-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8717849&HistoricalAwards=false
• 关键词: LTER; Microbial; Ecology; Ectomycorrhizal; Mats

At least two ectomycorrhizal fungi, Hysterangium setchellii and Gautieria monticola, form extensive hyphal mats in the soils of coniferous forests of the Pacific Northwest. Other Hysterangium species form similar mats in coniferous and deciduous forests throughout the world, including H. gardneri in association with Eucalyptus. Preliminary research has demonstrated that the rhizosphere communities dominated by the first two fungi have significantly elevated microbial biomass, respiration rates and altered levels of seven enzymes responsible for organic matter decomposition when compared to adjacent uncolonized soils. Since these mats offer discrete units to study the influence of ectomycorrhizae on the microbial ecology of the rhizosphere community, we propose to compare the above three mat communities with uncolonized soils in terms of: fungal and bacterial biomass, community respiration and enzyme activities; the partitioning of nitrogen and phosporus into labile and recalcitrant pools; the effects of mat chemistry on enzyme activities; enzyme production by pure fungal cultures; and the role of phenolic-coupling enzymes in rhizosphere processes.

至少有两种外生菌根真菌，Hysterangium setchellii和Gautieria monticola，在太平洋西北部针叶林的土壤中形成了广泛的菌丝垫。世界各地的针叶林和落叶林中的其他Hysterangium物种形成了类似的垫子，包括与桉树相关的H.gardneri。初步研究表明，与邻近的未定居土壤相比，由前两种真菌主导的根际群落显著提高了微生物生物量、呼吸速率和负责有机质分解的七种酶的水平。由于这些垫子提供了独立的单元来研究外生菌根对根际群落微生物生态的影响，我们建议从真菌和细菌生物量、群落呼吸和酶活性、氮和磷的分配到不稳定池和顽固池等方面来比较上述三种垫子群落与未定居土壤的差异。MAT化学对酶活性的影响；纯真菌培养产生的酶；以及酚偶联酶在根际过程中的作用。