Relationship Among Host Tree Species Diversity, Soil Fertility, and Carbon Availability in Maintaining Belowground Ectomycorrhizal Community Structure and Function

寄主树种多样性、土壤肥力和碳有效性在维持地下外生菌根群落结构和功能中的关系

• 批准号: 0211848
• 负责人: Joan Henson
• 金额: $ 30万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0211848&HistoricalAwards=false
• 关键词: Relationship; Among; Host; Tree; Species

Integrated studies of interactions among plants, microbes, and the soils they inhabit arecritical to our understanding of ecosystem function. We propose to use a combination ofbiochemical and molecular-genetic methods to determine effects of artificial defoliation ofPinus contorta (lodgepole pine) on structure and function of ectomycorrhizal (EM)communities in pure P. contorta and mixed P. contorta/Picea engelmannii (Engelmannspruce) stands. We will defoliate only the pine in both pure P. contorta and mixed P.contorta/P. engelmannii patches formed within mixed stands by small-scale disturbance. Wewill then determine how defoliation affects EM fungal community structure, activities ofenzymes that break down litter, and enzymatic function of soil fungal communities. We willsample across a soil fertility gradient created by a transition from relatively nutrient-richandesite, through a transition zone created by glacial activity, to nutrient-poor rhyolite. Bydoing so, we will determine how interactions among carbon flow to roots, tree speciesdiversity, and soil fertility influence ectomycorrhizal fungal diversity and function, for thefirst time.Our preliminary data from this system indicate that defoliation of pine only in a patch of mixedpine/spruce can 1) significantly affect the EM community of mixed P. contorta/P. engelmanniistands, and 2) affect the EM of non-defoliated spruce. Our data also show that soil fertility playsa pivotal role in influencing EM community structure, and the work of others demonstrates thatsoil fertility can moderate effects of defoliation and insect herbivory. We will be the first toinvestigate how alteration of carbon flow to roots affects EM community structure, EMenzymatic function, and below-ground function in a mixed tree species forest, and the first tocombine these factors with soil fertility. We will conduct this study in Yellowstone NationalPark, the centerpiece of the 11-million acre Greater Yellowstone Ecosystem, which includesseveral National Forests in three states. By using a combination of biochemical and molecularmethods, we will provide the most comprehensive picture of these aspects of ecosystem functionto date. Thus, we will add greatly to our understanding of a pristine, economically important, andgeographically dominant ecosystem.Our education/outreach and broader impacts will be far-reaching. For example, Cullings isadjunct at a Hispanic-Serving Institution and will teach classes and seminars there, and studentsfrom that institution will be invited to participate in the study. In addition, Cullings is a memberof the Ames Native American Advisory Council, an education/outreach organization withinNASA dedicated to bringing science education to reservations. Henson has volunteered for 12years as an ASM minority educator/lecturer, and has been a preceptor for NIH (InstitutionalStudent Minority Development) and NSF (Minority Access Program, Science and Engineeringfor All) minority education grants. In addition, and for the past 10 years her lab has hostedNative American high school students and teachers through the American Indian ResearchOpportunities (AIRO) program on campus. Her group also assists YNP park personnel with theirmicrobiology brochures and videotapes for the general public, and maintains a Web site abouttheir work in Yellowstone (www.montana.edu.hotfungi). Henson also participates in ASMs on-line science mentoring project. Students from all programs will be recruited to participate in thisproject.

综合研究植物、微生物和它们栖息的土壤之间的相互作用对我们理解生态系统功能至关重要。本研究拟采用生物化学和分子遗传学相结合的方法，研究人工去叶对扭叶松纯林和扭叶松/欧洲云杉混交林外生菌根（EM）群落结构和功能的影响。我们将在纯扭叶松和通过小规模干扰在混交林中形成的扭叶松/英氏松混合斑块中仅落叶。然后，我们将确定如何落叶影响EM真菌群落结构，酶的活性，分解凋落物，和土壤真菌群落的酶功能。我们将在一个土壤肥力梯度上取样，这个梯度是由相对营养丰富的方铅矿，通过冰川活动产生的过渡区，到营养贫乏的流纹岩的过渡所产生的。初步研究结果表明，仅在松云杉混交林中，松落叶对扭叶松/英氏云杉混交林EM群落和未落叶云杉EM群落均有显著影响。我们的数据还表明，土壤肥力在影响EM群落结构方面起着关键作用，其他人的工作表明，土壤肥力可以缓和落叶和昆虫植食的影响。我们将是第一个调查如何改变碳流到根影响EM群落结构，EM酶的功能，和地下功能在一个混合的树种森林，并首次将这些因素与土壤肥力。我们将在黄石国家公园进行这项研究，黄石国家公园是1100万英亩大黄石生态系统的中心，其中包括三个州的几个国家森林。通过使用生物化学和分子方法的结合，我们将提供迄今为止生态系统功能这些方面的最全面的图片。因此，我们将大大增加我们对一个原始的、经济上重要的、地理上占主导地位的生态系统的理解。我们的教育/推广和更广泛的影响将是深远的。例如，Cullings是一个西班牙裔服务机构的附属机构，将在那里教授课程和研讨会，该机构的学生将被邀请参加这项研究。此外，Cullings还是艾姆斯美洲土著咨询理事会的成员，这是NASA内部的一个教育/外展组织，致力于将科学教育带到保留地。Henson作为ASM少数民族教育者/讲师志愿服务了12年，并一直是NIH（机构学生少数民族发展）和NSF（少数民族访问计划，科学和工程为所有人）少数民族教育赠款的导师。此外，在过去的10年里，她的实验室通过校园内的美国印第安人研究机会（AIRO）计划为美国土著高中学生和教师提供了帮助。她的小组还协助YNP公园工作人员向公众提供微生物学小册子和录像带，并维护一个关于他们在黄石公园工作的网站（www.montana.edu.hotfungi）。Henson还参与了ASMs在线科学指导项目。所有项目的学生都将被招募参加这个项目。