Deep diversity: patterns, mechanisms, and effects in below-ground vegetation

我的研究计划的目标是探索地下植被如何促进物种多样性的模式，地下机制如何控制多样性，以及多样性的丧失如何影响生态系统服务，如土壤固碳。****物种多样性和物种丰富度是所有生态系统的基本特征，但我们对植被多样性的认识仅基于地上数据。我们研究了生物入侵后地下多样性变化的预测，以及沿着草原-森林边界等环境梯度。地下和地上的多样性可能不同，因为根和芽的结构和寿命不同。关于地下多样性的新信息有可能挑战长期以来关于植被结构和功能背后过程的观点。****空间斑块性是一个被广泛认可的多样性原因，但很少有植被类型下的斑块性比较，在与根相关的尺度上也没有。先前对斑块的研究是基于尺度（cm - m），相对于细根的大小，它是粗的(*生物入侵是由具有高生物量的速生物种完成的，它们可能会增加土壤中的碳储量。另一方面，我们发现一种广泛传播的入侵物种的根系营养丰富，易于分解，因此土壤碳不会在入侵后增加。我们将通过实地研究和实验来检验这一结果的普遍性。****我的研究考察了在加拿大主导植被和影响多样性的地下过程的功能生态学。该计划的意义在于，在温带、干旱和北极植被中，根系占植物质量的80-90%。此外，地下生产和分解对大气中二氧化碳通量的调节大约是化石燃料燃烧的10倍。美国国家科学院建议优先资助六个生态学领域。其中五个（生物多样性，生物地球化学循环，气候变化，入侵物种和栖息地交替）是由该计划解决的。我们的项目也将有助于保护不同的原生草地免受入侵，并提供不同植物在土壤中固碳和养分的相对能力的理解

The objectives of my research program are to explore how below-ground vegetation contributes to patterns of species diversity, how below-ground mechanisms control diversity, and how the loss of diversity affects ecosystem services such as soil carbon sequestration.****Species diversity and species richness are basic features of all ecosystems, but our knowledge of vegetation diversity is based only on above-ground data. We examine predictions about variation in below-ground diversity following biological invasion, and along environmental gradients such as prairie-forest boundaries. Below- and above-ground diversity are likely to differ because of differences in the architecture and life spans of roots and shoots. New information about below-ground diversity has the potential to challenge long-held ideas about the processes that underlie vegetation structure and function.****Spatial patchiness is a widely-recognized cause of diversity, yet there are few comparisons of patchiness beneath vegetation types, and none at root-relevant scales. Previous studies of patchiness are based on scales (cm - m) that are coarse relative to the size of fine roots (*Biological invasions are accomplished by fast-growing species with high biomass that might be expected to increase carbon storage in soil. On the other hand, we have found that the roots of one wide-spread invasive species are nutrient-rich and easily decomposed, so that soil carbon does not increase following invasion. We will test the generality of this result with both field studies and experiments.****My research examines the functional ecology of below-ground processes that dominate vegetation and influence diversity in Canada. The significance of the program is that roots account for 80-90% of plant mass in temperate, arid and arctic vegetation. Further, below-ground production and decomposition regulate CO2 fluxes to the atmosphere approximately 10 times greater than those from fossil fuel combustion. The US National Academy of Sciences recommended six areas of ecology for priority funding. Five of these (biodiversity, biogeochemical cycles, climate change, invasive species and habitat alternation) are addressed by this program. Our program will also contribute to the conservation of diverse native grassland from invasion, and provide an understanding of the relative abilities of different plants to sequester C and nutrients in soil.**