DISSERTATION RESEARCH: Belowground Bud Bank Populations as Regulators of Vegetation Responses to Ecosystem Drivers in African Grasslands

论文研究：地下芽库种群作为非洲草原植被对生态系统驱动因素反应的调节者

• 批准号: 0608008
• 负责人: David Hartnett
• 金额: $ 1.13万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0608008&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Belowground; Bud; Bank

In grassland and savanna ecosystems, the population of belowground vegetative buds (the bud bank) plays a key role in local plant population persistence and dynamics. In many grasslands, this bud bank, rather than seeds, is the primary source for plant reproduction, the seasonal regeneration of stems, and local population sustainability. In fact, in tallgrass prairie as many as 99.6% of plant stems are derived from buds, not seeds. Bud banks may play a key role in the response of grasslands to global environmental change. Unlike soil seed banks, whose general ecology has been well studied, the importance of bud banks remains under-appreciated and poorly understood. This research addresses four questions about the effects of bud banks on vegetation and ecosystem dynamics, and test the hypothesis that in North American grasslands, the effects of key factors such as fire, grazing, and climatic variability on plant community diversity and productivity may be mediated principally through their effects on belowground bud bank dynamics. This dissertation enhancement project tests the generality of these ecological hypotheses and the roles of fire and grazing across North American grasslands, and extends the research to test the key role of bud banks in the grass-dominated ecosystem of the Okavango Delta region of Botswana, an area of great ecological and socio-economic importance in southern Africa. Understanding bud bank dynamics will help predict responses of grasslands and savannas to long-term environmental change and to alterations in their three main ecological drivers: fire, grazing, and hydrologic regimes.

在草原和稀树草原生态系统中，地下营养芽（芽库）的种群数量对当地植物种群的持续性和动态起着关键作用。在许多草原上，这种芽库，而不是种子，是植物繁殖，茎的季节性再生和当地人口可持续性的主要来源。事实上，在高草草原上，多达99.6%的植物茎是由芽而不是种子生长出来的。芽库可能在草地对全球环境变化的响应中起着关键作用。土壤种子库的一般生态学已经得到了很好的研究，与之不同的是，芽库的重要性仍然没有得到充分的认识和理解。本研究解决了四个问题芽银行对植被和生态系统动态的影响，并测试的假设，在北美草原，关键因素，如火灾，放牧和气候变化对植物群落多样性和生产力的影响可能介导的主要是通过其影响地下芽银行动态。本论文增强项目测试这些生态假设的一般性和北美草原的火灾和放牧的作用，并扩展研究，以测试芽银行在博茨瓦纳的奥卡万戈三角洲地区，在南部非洲具有重要的生态和社会经济意义的地区的草为主的生态系统中的关键作用。 了解芽库动态将有助于预测草原和稀树草原对长期环境变化的反应，以及对三个主要生态驱动因素（火灾、放牧和水文制度）的改变的反应。