LTER: Succession, Biodiversity and Ecosystem Functioning at the Prairie-Forest Border

小行星9411972 雪松溪自然历史区是重要的，因为它的位置在草原和森林之间的气候和土壤控制的边界。 森林和草原之间的这一“紧张地带”对气候变化高度敏感，并受到土壤因素的强烈影响，特别是土壤氮的供应、火灾频率以及食草动物和捕食者的影响。 该地区的主要植被橡树稀树草原本身就具有异常高的物种丰富度，因为其植物群和动物群既包括草原物种，也包括森林物种。 正是这些生态系统的多样性和动态构成了他们研究的重点。 三个主要问题指导他们的研究： (1)什么因素，相互作用和积极和消极的反馈效果控制我们的演替草原和原生稀树草原生态系统的物种组成和物种动态？ (2)什么力量决定了有多少物种可以在我们的生态系统中的各种营养水平上生存，即，是什么控制了生物多样性？ (3)物种组成和生物多样性对这些生态系统的功能有哪些影响？ 生物多样性与生物多样性密切相关。 他们对演替感兴趣，因为这是生态系统组装的过程。 干扰往往造成当地物种的损失。 因此，驱动演替过程的因素是控制和维持多样性的过程。 他们进行了许多长期实验，深入了解了生物多样性对这些生态系统的稳定性和功能的影响。 他们将继续寻找潜在的机制，导致大规模的生态系统组成，多样性和生产力的演替草原和草原开口的模式，并将扩大他们的努力在橡树稀树草原。 他们正在进行的研究将进一步量化生物多样性对生态系统抵御气候变化的能力和复原力的影响。 他们的新的生物多样性实验应该提供物种和功能多样性对人口和生态系统稳定性和功能的许多方面的影响的第一批直接实地证据。

9411972 Tilman The Cedar Creek Natural History Area is important because of its location on the climatically and edaphically controlled boundary between prairie and forest. This "tension zone" between forest and prairies is highly sensitive to climatic variation and strongly impacted by edaphic factors, especially soil nitrogen availability fire frequency and by herbivores and predators. The dominant vegetation of the region, oak savanna, itself has unusually high species richness because its flora and fauna include both prairies and forest species. It is the diversity and dynamics of these ecosystems that form the focus of their research. Three major questions guide their research: (1) What factors, interactions and positive and negative feedback effects control the species composition and species dynamics of our successional grasslands and native savanna ecosystems? (2) What forces determine how many species can persist on various trophic levels within our ecosystems, i.e., what controls biodiversity? (3) What are the impacts of species composition and biodiversity on the functioning of these ecosystems? Succession and biodiversity are tightly linked. They are interested in succession because it is the process of ecosystem assembly. Disturbances often cause the local loss of species. The factors that drive the successional processes, are thus the processes that control and maintain diversity. They have performed numerous long-term experiments that have provided insights into the impacts of biodiversity on the stability and functioning of these ecosystems. They will continue to seek the underlying mechanisms that cause broad scale patterns in ecosystem composition, diversity, and productivity in their successional grasslands and prairie openings, and will expand their efforts in oak savannas. Their ongoing studies will further quantify the effects of biodiversity on ecosystem resistance to and resilience from climatic variability. Their new biodiversity e xperiment should provide some of the first direct field evidence of the effects of species and functional diversity on numerous aspects of population and ecosystem stability and functioning.