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格局，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，如土壤碳固定。*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知识仅基于地面数据。我们检查了关于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的预测。由于根和枝的结构和寿命的不同，地上和地下的多样性可能会有所不同。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基础过程的观点。*空间斑块是一个被广泛认识的多样性原因，但很少有植被类型下的斑块比较，也没有在与根相关的尺度上进行比较。以前对斑块的研究是基于相对于细根的大小较粗的尺度(厘米-米)(*生物入侵是由具有高生物量的快速生长的物种完成的，这些物种可能会增加土壤中的碳储量。另一方面，我们发现一个广布的入侵物种的根部营养丰富，容易分解，因此土壤碳在入侵后不会增加。我们将通过实地研究和实验来检验这一结果的普遍性。*我的研究考察了主导加拿大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，根占植物质量的80%-90%。此外，地下生产和分解调节进入大气的二氧化碳通量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领域。其中五个问题(生物多样性、生物地球化学循环、气候变化、入侵物种和栖息地变化)由该计划处理。我们的计划还将有助于保护不同的本土草原免受入侵，并提供对不同植物在土壤中固定碳和养分的相对能力的了解。**

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.**