CRB: Mechanisms of Persistence in Tallgrass Prairie Forbs: An Experimental Approach Coupled with a Retrospective Analysis of Long-term Patterns

大多数植物群落由许多不同的生长形式组成，其中一种通常以生物量为主。生态学研究倾向于关注主要的生长形式和物种，主要是因为它们处理流经系统的大部分能量。然而，当考虑物种丰富度时，对多样性贡献最大的通常是从属生长型内的物种。除了稀有物种外，人们对从属物种，特别是长寿多年生物种在群落中维持自身的机制知之甚少。对这些不太常见的物种的持久性机制进行全面评估，对于维持自然和恢复的群落内的多样性至关重要。这项研究将在Konza草原研究自然区对Tallgras草原杂草(非木本多年生草本植物)的持久性机制进行实验研究。该地点的主要特点是只有两种生长形式(主要的牧草和杂草)，这便于比较主要和次要的生长形式之间的资源利用和对火、放牧、光照和氮素的反应。杂交种有许多共同的生活史特征，并将其在Tallgras基质中的持久性归因于已建立的个体/无性系的长驻留时间。描述性研究和涉及水、氮和光处理的完整析因实验相结合，将用来阐明长寿杂草在地形和火灾历史上不同的“草海”中保持其存在的过程。

Most plant communities are comprised of many different growth forms with one that usually dominates in biomass. Ecological studies tend to focus on the dominant growth form and species, primarily because they process most of the energy that flows through the system. However, when species richness is considered, it is usually species within the subordinate growth forms that contribute most to diversity. With the exception of ruderal species, relatively little is known about the mechanisms by which subordinate species, especially long-lived perennials, maintain themselves in communities. A comprehensive evaluation of the mechanisms of persistence of these less common species is critical to maintaining diversity within natural and restored communities. This study will experimentally examine the mechanisms of persistence of tallgrass prairies forbs (non-woody, perennial herbs) at the Konza Prairie Research Natural Area. This site is characterized primarily by just two growth forms (the dominant grasses and forbs) and this facilitates comparisons of resource use and responses to fire, grazing, light regime, and nitrogen between dominant and subordinate growth forms. The forbs share many life history characteristics and owe their persistence within the tallgrass matrix to the long residence times of established individuals/clones. A combination of descriptive studies and a full factorial experiment involving water, N and light manipulations will be used to elucidate the processes by which long-lived forbs maintain their presence in a "sea of grass" that varies topographically and in fire history.