Dissertation Research: Moisture-mediated Predation in an Underground Trophic Cascade

论文研究：地下营养级联中水分介导的捕食

• 批准号: 0206602
• 负责人: Donald Strong
• 金额: $ 1万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0206602&HistoricalAwards=false
• 关键词: Dissertation; Research; Moisture; mediated; Predation

I am researching how moisture influences a multi-predator trophic cascade in asoil system. At my research site on the California coast, the entomophagous fungusBeauveria bassiana is the most potent predator of root-feeding insects in dry summersoil. During the rainy winter and spring, however, soil moisture increases sharply and theentomopathogenic nematode Heterorhabditis marelatus becomes the primary predator asB. bassiana decreases in predatory efficiency. Both prey on ghost moth (Hepialuscalifornicus) larvae, root-feeding herbivores that feed on the bush lupine Lupinusarboreus. The lupine shows increased growth, seed set, and survivorship in the presenceof the nematode, which preys on H. californicus that would otherwise eat the lupine'sroots. The wet-season interactions in this food chain are known as an important exampleof a terrestrial trophic cascade. My research seeks to develop a complete picture of thisfood web by understanding predation on the herbivore during the dry season, and the rolethat moisture plays in both predators' activities. I also propose testing whether the twopredators have equivalent impacts on the prey population, possibly leading to cascadesdue to different predators in the wet versus dry season.

我正在研究水分如何影响一个多捕食者的营养级联系统。在我位于加州海岸的研究地点，食虫真菌球孢白僵菌是夏季干燥土壤中食根昆虫最强有力的捕食者。在多雨的冬春季，土壤湿度急剧增加，昆虫病原线虫异小杆线虫成为主要捕食者。捕食效率下降。两者都捕食鬼蛾（加州蝠蛾）的幼虫，这种食根的食草动物以灌木羽扇豆为食。在捕食H的线虫存在的情况下，羽扇豆的生长、结籽和存活率都有所增加。加州人会吃羽扇豆的根这个食物链中的雨季相互作用被认为是陆地营养级联的一个重要例子。我的研究旨在通过了解旱季食草动物的捕食行为，以及水分在这两种捕食者活动中的作用，来全面了解这个食物网。我还建议测试两个捕食者是否对猎物种群有同等的影响，可能会导致不同的捕食者在潮湿和干燥的季节。