DiversiTree: diversifying our woodlands to increase resilience

英国政府计划增加林地覆盖，作为其储存更多碳、缓解气候变化计划的一部分。然而，英国的许多树木受到气候变化和一系列病虫害的威胁，这可能会限制它们为碳储存做出贡献的能力，以及林地带来的广泛其他好处。因此，我们需要使我们的林地能够抵御这些未来的威胁。恢复力是一个系统，如林地，从干扰中恢复的能力。增加森林恢复力的一种常用方法是增加树木的多样性。因此，将风险分散到许多不同的树木中，因为我们不知道每种树木将如何应对气候变化，也不知道它们在未来几十年可能面临的病虫害威胁。然而，林地管理者对多样性有不同的看法，以及管理如何最好地实现多样性，我们知道不同的树种将以不同的方式支持林地生态系统。因此，重要的是将利益相关者的知识与生态知识结合起来，以确定哪些树种和管理方法最能实现多样化，从而提高恢复力。DiversiTree关注的是两种针叶树物种，苏格兰松和锡特卡云杉，因为在截至2021年3月的一年中，54%的新林地是针叶树。苏格兰松是英国唯一具有经济意义的本土针叶树。它被种植用于木材生产，但也是文化标志性的本地加里多尼亚松林中的优势物种。苏格兰松有患树木病Dothistroma的危险。锡特卡云杉并非原产于英国，但却是我们最具经济价值的树种，它正面临树皮甲虫入侵和气候变化的威胁。该项目解决了与林地多样化相关的四个知识缺口：1)利益相关者如何理解森林多样性、他们的多样化战略以及他们对未来多样化森林的愿景和抱负？2)在混合树种的林地中，树木叶子上的微生物是否更加多样化，这是否有助于树木更好地抵御疾病？3)森林内树种的多样化如何使林地生物多样性得到持续的支持？4)我们如何实施和沟通管理策略以提高林地的恢复力？为了解决这些知识差距，我们跨学科合作，汇集了生态学家、微生物学家、社会科学家和林地管理者。林地信托是我们项目的核心，使我们能够与从业者共同开发和检查我们结果的可行性。与林地管理者面谈、焦点小组和政策文件分析的结果将用于提高对林地多样化备选办法的认识，以及对执行多样化战略的热情和能力的认识。叶子上的微生物对植物健康很重要。利用现有的长期实验，我们将检查生长在单一栽培和混合林中的苏格兰松叶子上的微生物。我们将评估叶片上微生物的多样性是否随着树种多样性的增加而增加，以及这是否使树木能够抵抗现有的疾病。令人惊讶的是，我们没有列出哪些物种使用哪些树木。如果我们要种植能够继续支持林地生物多样性的树木，就需要这些信息。我们将整理由苏格兰松和锡特卡云杉承载的生物多样性数据，并评估哪些其他树种也可以支持相同的生物多样性。最后，我们将结果汇集在一起，与从业者共同开发多样化的管理策略和案例研究，说明如何实施结果。除了科学文献中的出版物外，研究结果还将通过视频、播客、社交媒体和从业者笔记进行分享。

The UK government plans to increase woodland cover as part of its plans to store more carbon, to mitigate climate change. However, many of the UK's trees are threatened by climate change and a range of pests and diseases, which might limit their ability to contribute to carbon storage and the wide range of other benefits delivered by woodlands. We therefore need to make our woodlands resilient to these future threats. Resilience is the ability of a system, such as a woodland, to recover from a disturbance. One commonly proposed approach to increase the resilience of woods is to increase their tree diversity. Thus, spreading the risk amongst many different trees, as we don't know exactly how each tree species will respond to climate change, nor what threats from pests and diseases they may face decades into the future. However, woodland managers have different perceptions of diversity, and how management may best deliver it, and we know that different tree species will support the woodland ecosystem in different ways. Therefore, it is important to combine stakeholders' knowledge with ecological knowledge to identify which tree species and management approaches best deliver diversification that increases resilience.DiversiTree focuses on woods dominated by two conifer species, Scots Pine and Sitka Spruce, as in the year to March 2021 54% of all new woodland was coniferous. Scots Pine is the UK's only native conifer of economic significance. It is planted for timber production but is also the dominant species in the culturally iconic native Caledonian pinewoods. Scots Pine is at risk from the tree disease Dothistroma. Sitka Spruce is not native to Britain but is our most economically valuable tree species and is at risk from invasive bark beetles and climate change.This project addresses four knowledge gaps related to the diversification of woodlands: 1) How do stakeholders understand forest diversity, their diversification strategies, and their visions and ambitions for diverse future forests? 2) Are the microbes found on the leaves of trees more diverse in woodlands with mixed tree species and does this help trees to better defend themselves against diseases? 3) How may diversification of tree species within a wood allow the continued support of woodland biodiversity? 4) How do we implement and communicate management strategies to increase woodland resilience?To address these knowledge gaps, we work across disciplines bringing together ecologists, microbiologists, social scientists, and woodland managers. The Woodland Trust is embedded at the heart of our project to enable us to co-develop and check the feasibility of our results with practitioners. Results from interviews with woodland managers, focus groups and analyses of policy documents, will be used to improve knowledge of the options for woodland diversification, and both the enthusiasm for, and capacity to, implement diversification strategies.The microbes on leaves are important for plant health. Utilizing existing long-term experiments, we will examine the microbes on the leaves of Scots Pine grown in monocultures and in mixed woods. We will assess if the diversity of microbes on a leaf increases as the diversity of tree species increases, and whether this enables the trees to resist existing diseases.Surprising we don't have lists of which species use which trees. This information is required if we are to plant trees that will continue to support woodland biodiversity. We will collate data on the biodiversity hosted by Scots Pine and Sitka Spruce and assess which other tree species could also support the same biodiversity.Finally, we bring the results together to co-develop with practitioners, management strategies for diversification and case studies illustrating how the results can be implemented. The results will be shared via videos, podcasts, social media, and practitioner notes in addition to publications in the scientific literature.