Plant-mycorrhizal fungal interaction networks: understanding their role in the resilience and adaptation of forests to climate change

加强具有生产力和抗扰动能力的森林的再生将是加拿大减缓和适应气候变化努力的一项关键战略。弹性森林的特点是地上和地下物种多样性、健康的生物和非生物相互作用以及连通性，从而使它们能够抵御破坏并从干扰中迅速恢复。然而，生态学理论认为，地上竞争是驱动资源吸收、物种共存、生产力和其他森林生态过程的主导机制，这阻碍了提高森林恢复力和适应能力的新应用的发展。缺乏对互惠共生的促进作用，特别是菌根真菌及其在树木之间形成的地下网络如何影响树木行为和对森林生态系统的后果的理解。本研究的基本前提是，森林的恢复力和适应能力植根于物种之间的积极和消极的地上和地下相互作用的平衡。在此框架内，我将重点关注(I)结果，（ii）机制和（iii）森林生态系统中这些相互作用的驱动因素。

Enhancing regeneration of forests that are productive and resilient to perturbations will be a crucial strategy in Canada’s efforts to mitigate and adapt to climate change. Resilient forests are characterized by above and belowground species diversity, healthy biotic and abiotic interactions, and connectivity, thus enabling them to resist damage and recover quickly from disturbance. However, ecological theory that aboveground competition is the dominant mechanism driving resource uptake, species coexistence, productivity and other forest ecological processes, is hindering the development of novel applications for increasing the resilience and adaptive capacity of regenerating forests. Lacking is an understanding of how facilitation by mutualists, in particular mycorrhizal fungi and the belowground networks they form among trees, influences tree behaviour and consequences for forest ecosystems. The underlying premise of this research is that resilience and adaptive capacity of forests is rooted in the balance of positive and negative above- and belowground interactions among species. Within this framework, I will focus on (i) outcomes, (ii) mechanisms and (iii) drivers of these interactions in forest ecosystems. Over the next five years, I will meet four short-term objectives: 1. Test whether forest responses to climate change are dependent upon competitive and facilitative interactions among trees mediated by mycorrhizal networks, roots, and root-shoot relations; 2. Determine whether climate, tree relatedness and tree stress influence mycorrhizal network effects on tree behavior and forest structure; 3. Investigate how above and belowground legacies affect the plurality of interactions and resilience of forests to climate stress and disturbance; 4. Integrate understanding of shoot, root and fungal interaction effects on forest structure and function with theory that forest ecosystems behave as complex adaptive systems. To meet these objectives, I will train and mentor HQP at the MSc, PhD and PDF levels in science and professional skills, building on my strong track record. The research will include experimental manipulations in the field and greenhouse; natural experiments across environmental gradients; plant and fungal ecophysiology; molecular tools; statistical and structural equation modeling; and development of concepts and theory. This proposal tests basic ecological theory, but it has broad practical implications for management of forests in Canada and world-wide. This is evidenced by wide applications of my ongoing research on species interactions in today’s forest harvesting and reforestation practices and policies in western Canada, as well as numerous speaking invitations in the public and private forest sectors. This DG will not cover applications directly, but these will be addressed through ongoing collaborations over the next five years.