Relative importance of tree species and genotypic diversity for above- and belowground processes in boreal forest

欧洲的大多数森林都得到管理，在过去几个世纪里，在树种丰富度、物种组成和遗传多样性方面发生了相当大的变化。然而，关于树种和遗传多样性的这些变化对生态系统如何运作及其提供的服务，包括人类福祉的影响，仍然缺乏可靠的科学证据。我们需要这些知识，以便在面对环境变化时有效地保护和利用我们的森林。北方森林的物种特别少，因此，增加或减少一个树种，预计会对生态系统产生更大的影响。此外，树种内的变异最近也被证明是生态系统功能的一个重要决定因素，但树种之间和单一物种内的变异的相对重要性尚未在一项研究中得到解决。在这个项目中，我们利用了我们的团队以前在芬兰西南部的北方森林中建立的两个独特的长期实验。这些实验操纵树种多样性和树种内遗传多样性。我们将研究这种基于树木的生物多样性如何影响与森林相关的动物，微生物和真菌的范围，生态系统如何工作，从地上昆虫到树木的生长以及土壤中看不见但至关重要的生物多样性。树木与其相关的生物多样性之间的一个关键联系是它们含有不同的化学防御物质，这些化学防御物质保护它们免受敌人的侵害，并可能对其他生物和生态系统进程产生影响。了解遗传多样性和物种多样性的相对作用很重要，因为我们需要知道保护和管理工作是否必须集中在物种丰富度或种内多样性上。因此，该项目的结果对于优先考虑保护工作和预测生物多样性下降的后果将是重要的。

The majority of forests in Europe are managed and underwent considerable changes in tree species richness, species composition and genetic diversity over the last few centuries. However, sound scientific evidence of the impact of these changes in tree species and genetic diversity on how the ecosystems work and the services they provide, including human well-being, is still lacking. We need this knowledge in order to effectively conserve and utilise our forests in the face of environmental change. Boreal forests are particularly species-poor, and therefore addition or loss of a single tree species may be expected to have larger effects on the ecosystem. In addition, the variation within tree species has also been recently shown to be an important determinant of ecosystem functioning, but the relative importance of variation between tree species and within a single species has not yet been addressed in a single study. In this project we take advantage of two unique long-term experiments previously established by our team in boreal forests of SW Finland. These experiments manipulate both tree species diversity and tree within-species genetic diversity. We will examine how this tree-based biodiversity affects the range of animals, microbes and fungi associated with the forest, how the ecosystems work, from above-ground insects to the tree's growth and the unseen but crucial biodiversity in the soil. A key connection between the trees and their associated biodiversity is their content of different chemical defences which protect them from their enemies and can have consequences for other organisms and ecosystem processes. Understanding the relative role of genetic and species diversity is important because we need to know whether conservation and management efforts have to be focused on species richness or intraspecific diversity. Therefore, the results of this project will be important for prioritizing conservation efforts and predicting consequences of biodiversity declines.