Mixed forests management for enhancing adaptation to climate change

背景面对前所未有的气候变化对森林和以森林为生的社区的影响，迫切需要新的战略来提高复原力和减少气候变化的影响。研究人员和管理人员正将注意力转向混交林，因为有证据表明，通常用于最大化利润的单一树种森林更容易出现健康问题，导致生产率下降。我们可以设计特定的物种组合，以提高适应的生态和经济效益--但如何呢？自20世纪70年代S以来，在不列颠哥伦比亚省进行了许多长期的混合物种实验。然而，尽管这种长期数据对于开始检验混合物种是必要的，但由于缺乏精细的时空数据，在理解森林对干旱事件或虫害的反应方面取得的真正进展严重受限。目标我的长期目标是确定物种组成和森林结构中的哪些营林选择能促进预期的生态系统功能。在未来五年内，12个HQP将开发和应用新的监测工具，以量化各种混合、物种安排和场地条件对以下方面的影响：(1)林分结构，特别是光利用和木材质量的空间互补；(2)生物量分配、碳储存和资源利用的时间互补；以及(3)对干旱、昆虫和病原体的脆弱性。为了产生最大的实际影响，拟议的工作将侧重于加拿大西部常见的树种混合，既包括云杉与樟子松混合的内陆森林，也包括道格拉斯-冷杉与杉木混合的沿海森林。方法该项目将使用森林结构的高度详细的空间信息和高分辨率的时间生长和水分利用数据与基于过程的建模的新组合。将使用陆地激光扫描这一非破坏性方法收集树冠和树枝的三维结构，收集范围涉及一系列受各种干扰类型和强度影响的不同树种混合的林木。这些数据将与树级模型结合使用，以量化对光吸收和生产力的影响。树芯和树干测量仪将分别提供年分辨率和小时分辨率的生长数据。生长数据将与用树液流量传感器和同位素获得的水分利用效率测量相结合。影响这项研究将建立新的营林技术，旨在推动关于未来准备就绪的混交林的种植和管理的决策，以满足林业部门和社会的需要。我的研究团队将开发新的方法，以量化资源使用的互补性和对干旱、昆虫和病原体混合物的复原力，供国际研究界使用。这项研究将使包括森林机构和森林工业在内的大量利益攸关方参与进来。

Background In the face of unprecedented climate change impacts on forests and forest-dependent communities, new strategies to enhance resilience and reduce the impacts of climate change are urgently needed. Researchers and managers are turning their attention to mixed forests, as evidence shows that single- species forests, often used to maximize profit, are more prone to health problems resulting in reduced productivity. We can design specific mixtures of species to enhance ecological and economic benefits for adaptation- but how? Many long--term mixed- species experiments have been installed in BC since the 1970's. However, while such long-term data is necessary to begin to examine mixtures, true advances in understanding how forests react to drought events or insect attacks are severely limited by a lack of fine-scale spatial and temporal data. Objectives My long-term objective is to determine which silvicultural choices in species compositions and forest structures promote desired ecosystem functions. Within the next five years, 12 HQP will develop and apply novel monitoring tools to quantify how various mixtures, arrangement of species and site conditions affect:(1) Stand structure, specifically spatial complementarity in light use and wood quality;(2) Biomass allocation, carbon storage and temporal complementarity in resource use; and (3) Vulnerability to drought, insects and pathogens. To have maximum practical impact, the proposed work will focus on species mixtures that are common in western Canada, both in interior forests such as spruce mixed with lodgepole pine, and coastal forests such as Douglas-fir mixed with alder. Methods This program will use a novel combination of highly detailed spatial information of forest structure and high-resolution temporal growth and water-use data with process-based modelling. Crown and branch 3-D structure will be collected using terrestrial laser scanning, a non-destructive method, across a range of forest stands with varying species mixtures, which have been subject to a range of disturbance types and intensities. This data will be used in combination with a tree-level model to quantify the implications for light absorption and productivity. Tree cores and point dendrometers will provide growth data with yearly and hourly resolution respectively. Growth data will be coupled with water-use efficiency measurements obtained with sap-flow sensors and isotopes. Impact This research will establish novel silvicultural techniques designed to drive decisions around planting and management of future-ready mixed-species forests that meet the needs of the forest sector and society. My research team will develop new methodologies to quantify complementarity of resource use and resilience to drought, insects and pathogens in mixtures, that will be used by the international research community. This research will engage a large number of stakeholders including forest agencies and the forest industry.