The role of mycorrhizae and mycorrhizal networks in tree species range shifts with climate change nad disturbance

菌根和菌根网络在树种范围随着气候变化和干扰而变化的作用

• 批准号: 298271-2009
• 负责人: Simard, Suzanne
• 金额: $ 3.64万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=571463
• 关键词: role; mycorrhizae; mycorrhizal; networks; tree

Tree species ranges are predicted to shift dramatically in Canada with climate change, typically with northward migration at the leading edges and extensive mortality at the trailing edges. The ability of trees to migrate will depend not only on their genetic suitability, but also the hospitability of the new environment, including the presence of compatible ectomycorrhizal fungi (EMF) in soil, the severity of site disturbance, and the intensity of plant competition. Whereas previous research predicting tree species range shifts has focused on climatic and genetic factors, my program makes the novel contribution of examining the contributing biotic effects of EMF and mycorrhizal networks (MNs) in real species migration experiments using cutting edge techniques in isotope tracers, molecular biology (metagenomics, microsatellites, and DNA sequencing) and network analysis. Across a regional drought-stress gradient serving as a spatial proxy for climate change, I will study the roles of: (1) local EMF in facilitating migration of tree genotypes to new environments; (2) MNs formed by mature trees in facilitating natural regeneration, particularly of closely related (kin) genotypes; (3) disturbance severity in reorganizing the MN and affecting natural regeneration patterns; and (4) shifting interplant carbon source-sink gradients in transfer of carbon from dying to establishing trees. For (1), I will examine the role of EMF in establishment of non-local tree genotypes within assisted migration field and growth chamber experiments. For (2) and (3), I will plant kin and non-kin seed in mesh bag treatments (controlling for the formation and complexity ot MNs) either in natural gaps or within harvesting treatments that remove different levels of hub (highly connected) trees. For (4), I will manipulate seedling carbon source-sink gradients using defoliation treatments emulating natural tree senescence. The contributions of my program on the roles and mechanisms by which EMF and MNs facilitate tree range shifts, and how these affect plant community and soil carbon dynamics, will help scientists to predict forest ecosystem responses to climate change and managers to design practices for maintaining the resilience, carbon storage, and adaptive capacity of Canada's forests.

预计随着气候变化，树种范围将在加拿大发生巨大变化，通常在领先的边缘向北迁移，并且在后缘边缘处于广泛的死亡率。树木迁移的能力不仅取决于它们的遗传适用性，而且还取决于新环境的热情，包括在土壤中存在兼容的外生菌血真菌（EMF），现场障碍的严重程度以及植物竞争的强度。尽管以前预​​测树种范围转移的研究集中在气候和遗传因素上，但我的计划使研究了实际物种迁移实验中使用同位素轨迹中的切削缘技术，研究EMF和霉菌网络（MNS）的生物效应的新颖贡献。生物学（宏基因组学，微卫星和DNA测序）和网络分析。在区域干旱压力梯度中，我将研究以下空间代理，我将研究：（1）局部EMF在促进树木基因型迁移到新环境方面的迁移； （2）成熟树形成的MN在促进自然再生方面，特别是密切相关（KIN）基因型的MN； （3）重组MN并影响自然再生模式时的干扰严重程度； （4）在碳转移中转移碳源 - 晶体梯度从死亡转移到建立树木中。 对于（1），我将研究EMF在辅助迁移场和生长室实验中建立非本地树基因型的作用。对于（2）和（3），我将在自然间隙或收获处理中，在网格袋处理中种植亲属和非金属种子（控制构成和复杂性MN），以去除不同水平的枢纽（高度连接）树木。对于（4），我将使用模仿天然树衰老的脱叶处理处理幼苗碳源 - 螺旋梯度。我的计划对EMF和MN促进树范围的角色和机制的贡献以及它们如何影响植物群落和土壤碳动态，将帮助科学家预测森林生态系统对气候变化的反应，以及管理人员设计实践，以维护维持森林生态系统。加拿大森林的弹性，碳存储和适应能力。