Long-Term Ecological Research in Tallgrass Prairie: The Konza Prairie LTER Program

9632851 Knapp一个长期的生态研究计划将在堪萨斯州东北部的Konza Prairie LTER地点继续并扩大。Konza Prairie是一个原始的高草草原，可以说是地球上研究最深入的草原遗址。这项已有15年历史的广泛研究计划涵盖了从人口、社区、生态系统和景观生态层面进行的研究。这些研究通过一个主题联系在一起，该主题包括影响该生态系统的所有主要非生物和生物因素。我们的中心假设是，火、放牧和气候变化是塔尔格拉斯草原的结构和功能的关键和责任。与许多其他草原的生态过程受到单一资源(如水)的限制不同，塔尔草草原的有机体到生态系统的过程和动态是各种限制资源(水、光、氮)的产物。这些主要限制资源的变化和相互转换是由现在和历史上的火灾、放牧和气候制度造成的。由于这种复杂性，而且由于放牧和火制度是在世界各地的草原系统中管理的，来自Konza Prairie LTER项目的数据不仅与了解这一草原有关，而且与更广泛的生态问题有关，如稳定性多样性问题以及土地利用、生物多样性和气候变化之间的相互作用。拟议的研究包括继续进行长期的火灾和放牧研究，以及侧重于关键过程和机制的短期研究。拟议中的新研究包括对火季影响的研究，对每年燃烧或未燃烧20年的流域进行的火灾处理逆转实验，对野牛和牛作为主要草食者的比较研究，以及关于放牧、火灾、气候变化和农业如何影响高草草原年度碳、水和能源收支的长期研究。后一项研究解决的一个关键问题是，高草草原土壤是碳汇还是碳源，以及土地利用(火、牧场)和气候如何影响碳收支。

9632851 Knapp A long-term ecological research program will be continued and expanded at the Konza Prairie LTER site in NE Kansas. Konza Prairie, a pristine tallgrass prairie is, arguably, the most intensively studied grassland site on earth. The 15 year old, broadly-based research program encompasses studies from the population, community, ecosystem and landscape ecology levels. These studies are linked by a theme that includes all the major abiotic and biotic factors influencing this ecosystem. Our central hypothesis is that fire, grazing and climatic variability are essential and responsible for the structure and function of tallgrass prairie. In contrast to many other grasslands where ecological processes are constrained by a single resource (e.g., water), organismic to ecosystem processes and dynamics in tallgrass prairie are products of a variety of limiting resources (water, light, nitrogen). Variability in, and switching among, these primary limiting resources are caused by both present and historical fire, grazing and climatic regimes. As a result of this complexity, and because grazing and fire regimes are managed in grassland systems worldwide, data from the Konza Prairie LTER program have relevance not only for understanding this grassland, but for broader ecological issues such as stability diversity questions and interactions between land-use, biodiversity and climate change. The proposed research includes continuation of long-term fire and grazing studies as well as short-term studies focused on key processes and mechanisms. Proposed new research includes studies of the effect of fire season, a fire-treatment reversal experiment in which watersheds that have been annually burned or unburned for 20 years will have their treatments reversed, comparative studies of bison vs. cattle as the dominant grazers, and a long-term study of how grazing, fire, climatic variability and agriculture affect annual carbon, water and energy budgets in tallgrass prairie. A key question addressed by the latter study is whether or not tallgrass prairie soils are a sink or source for carbon and how land-use (fire, grazing) and climate affects the carbon budget.