The theoretical and practical significance of tree species and functional diversity in designing novel forest ecosystems

全世界的自然森林生态系统正因人类的直接和间接干预而以惊人的速度逐渐消失和/或大大简化。剩余的天然森林和管理下的森林正受到与全球变化有关的因素（入侵物种和虫害;气候变化）的影响。由于人口压力的增加和全球变化的加速，这一趋势今后可能会加剧。考虑到森林为65%以上的陆地生物多样性提供栖息地，并且是许多生态系统服务的关键提供者，这些压力更加令人震惊。然而，令人信服的科学证据现在表明，自然生态系统和管理生态系统的生产力和复原力在很大程度上取决于生物多样性和复杂性的维持。在本项目中，我们将重点关注提供两种主要森林生态系统服务的机制：木材和土壤碳固存方面的初级生产力。来自4所加拿大大学（舍布鲁克、拉瓦尔、UQAR和UQAM）的科学家将与来自美国和波兰的合作者共同工作。该研究将比较树种、系统发育和功能性状多样性在以下方面的作用：（1）维持健康的天然森林和管理森林;（2）促进更具生产力和复原力的新型森林生态系统;（3）最大限度地增加碳固存。核心办法将是在美国东北部三个不同地区和波兰的一个地区建立和监测一系列世界独特的高密度单一和混合本地树种和外来树种试验性种植园。该项目将评价各种本地树种和外来树种的混合物如何影响：（1）地上和地下生物量和根系分布;（2）细根生长、形态和结构动态;（3）C、N、P和碱循环、土壤中的储存和沥滤以及分解;（4）营养互补。该项目的成果将为政府和私营利益攸关方提供必要的知识，以制定关于使用混合物种种植园和外来物种的知情创新政策和做法，作为可持续森林管理的一部分。

Natural forest ecosystems worldwide are being gradually eliminated and/or greatly simplified at an alarming rate by direct and indirect human interventions. Remaining natural and managed forests are being impacted by factors associated with global change (invasive species and pests; changing climate). This trend is likely to increase in the future due to increasing human population pressures and accelerating global change. These stresses are even more alarming considering that forests provide habitats for more than 65% of the terrestrial biodiversity and are key providers of many ecosystem services. Yet, compelling scientific evidence now shows that the productivity and resilience of natural and managed ecosystems are greatly dependent on the maintenance of biodiversity and complexity. In this project, we will focus on mechanisms involved in supplying two major forest ecosystem services: primary productivity in terms of wood and soil carbon sequestration. Scientists from 4 Canadian universities (Sherbrooke, Laval, UQAR & UQAM) will work together with collaborators from the US and Poland. The research will compare the role of tree species, phylogenetic and functional trait diversity in (1) maintaining healthy natural and managed forests; (2) contributing to more productive and resilient novel forest ecosystems; and (3) maximizing carbon sequestration. The core approach will be the establishment and monitoring of a series of world-unique experimental high-density single and mixed native and exotic tree species plantations in three different regions of north-eastern America and in one region of Poland. The project will evaluate how various mixtures of native and exotic tree species affect: (1) above and below-ground biomass and root distribution; (2) fine-root growth, morphological and architectural dynamics; (3) C, N, P and base cycling, storage and leaching in soils and decomposition; and (4) trophic complementarity. The results of this project will provide both government and private stakeholders the necessary knowledge to develop well-informed innovative policies and practices regarding the use of mixed species plantations and exotics as part of sustainable forest management.