Evaluating the role of local and landscape factors on the resilience of mixed-species forest ecosystems under climate uncertainty

评估气候不确定性下当地和景观因素对混合物种森林生态系统恢复力的作用

• 批准号: RGPIN-2016-06438
• 负责人: Elkin, Che
• 金额: $ 2.04万
• 依托单位: University of Northern British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710292
• 关键词: Evaluating; role; local; landscape; factors

In boreal and sub-boreal mixed-species forests, interactions between coniferous and deciduous trees entail competition for limiting resources, such as light, water and nutrients. However, under some conditions the presence of multiple species is hypothesized to facilitate tree growth. My research aims to improve our understanding of the conditions under which competition or facilitation will occur, and what the concomitant impacts on long-term forest dynamics, the resilience of forests to disturbances, and the provision of forest ecosystem services, such as timber production, carbon storage and biodiversity will be. In particular, I will focus on testing how interactions between species are projected to change under novel future climate conditions. My students and I will examine how forest composition and structure impacts the availability of resources essential for tree growth. By evaluating how resource availability changes within and between years, we will gain insights into where and when competition for resources will be most important, and how projected changes in climate will alter the prevalence of competition or facilitation. Tree and forest development is expected to be influenced not only by the current growth environment, but also by past environmental conditions. We will test for differences in the sensitivity of conifers and deciduous species to past environmental conditions to improve our understanding of how current growth conditions will influence the vulnerability of forests to disturbances and climate-dependent stress, such as drought. Specifically, we will test the hypothesis that under some conditions, mixed-species forest will be more resilient to environmental change and extreme weather events. The long-term dynamics of mixed-species forests are hypothesized to be driven by the interplay of landscape disturbances, environmental conditions including climate, and the developmental state of the forest at the time of disturbance. However, climate change will likely alter the relative competitive ability of species, and the prevalence and intensity of different disturbance types. Therefore, large uncertainty remains regarding how the relative importance of each of these factors, and their interactions, will change under future climate conditions. Using process-based forest models we will examine the mechanisms that drive mixed-species forest dynamics, and project how these processes will change in the future. We will also test how the timing and intensity of different forest management practices influences the dynamics of mixed-species forests at stand and landscape scales. Specifically we will evaluate if forest management can increase the resilience of forests to climate changes, and test how to most effectively trade-off short- and long-term management goals to maintain a diversity of forest ecosystem services under future climate uncertainty.

在北方和亚北方混种森林中，针叶树和落叶树之间的相互作用导致竞争有限的资源，如光、水和养分。 然而，在某些条件下，假设存在多个物种，以促进树木的生长。我的研究旨在提高我们对竞争或促进将发生的条件的理解，以及对长期森林动态，森林对干扰的恢复力以及森林生态系统服务的提供（如木材生产，碳储存和生物多样性）的伴随影响。 特别是，我将专注于测试物种之间的相互作用是如何预测在未来新的气候条件下发生变化的。 我和我的学生将研究森林的组成和结构如何影响树木生长所必需的资源的可用性。通过评估资源可用性如何在年内和年与年之间变化，我们将深入了解资源竞争在何处和何时最重要，以及预计的气候变化将如何改变竞争或促进的普遍性。 预计树木和森林的发展不仅受到当前生长环境的影响，而且还受到过去环境条件的影响。 我们将测试针叶树和落叶树种对过去环境条件的敏感性差异，以提高我们对当前生长条件如何影响森林对干扰和气候依赖性压力（如干旱）的脆弱性的理解。具体来说，我们将测试的假设，在某些条件下，混合物种的森林将更适应环境变化和极端天气事件。 混合物种森林的长期动态被假设为驱动的景观干扰，环境条件，包括气候，和干扰时的森林的发展状态的相互作用。然而，气候变化可能会改变物种的相对竞争能力，以及不同干扰类型的普遍性和强度。 因此，在未来气候条件下，这些因素中每一个的相对重要性及其相互作用将如何变化，仍存在很大的不确定性。 使用基于过程的森林模型，我们将研究驱动混合物种森林动态的机制，并预测这些过程将如何在未来发生变化。 我们还将测试不同的森林管理措施的时间和强度如何影响林分和景观尺度上的混种林的动态。 具体而言，我们将评估森林管理是否可以提高森林对气候变化的适应能力，并测试如何最有效地权衡短期和长期管理目标，以在未来气候不确定性下保持森林生态系统服务的多样性。