Dissertation Research: The Effects of Riverine Prey and Cover Availability on Riparian Lizards: River Subsidized Population and Community Dynamics

在一个栖息地（隔间）的种群和群落动态往往与单独但相邻的栖息地的动态密切相关。通过这种方式，一个栖息地实际上可以补贴第二个栖息地中的某些生物。最近的几项实证研究表明，空间补贴导致人口密度膨胀或改变接收栖息地的生物体的相互作用强度。在河流生态系统中，水生昆虫有翅成虫的出口可能是一个跨隔室的联系，补贴流域消费者和改变他们的社区动态。 在加利福尼亚州北方的河流中，蜥蜴（Sceloporus，鬣蜥科）的密度至少是非河流高地栖息地同类动物的7倍。在同一条河流上，随着距离河流-陆地界面的距离增加，气生无脊椎动物的丰度几乎呈指数下降。Sceloporus主要吃陆生无脊椎动物，但其食物中5-25%的昆虫是水生动物。Sceloporus追踪水生资源的能力可能会受到河流附近覆盖物可用性的限制。PI建议调查1）水生昆虫的河流补贴对Sceloporus种群和群落动态的影响，以及2）近河覆盖的可用性如何调节Sceloporus跟踪这些资源的能力。

9700834 Power Population and community dynamics in one habitat (compartment) are often strongly linked to dynamics in separate but adjacent habitats. In this way, one habitat may in effect, subsidize certain organisms in a second habitat. Several recent empirical studies suggest that spatial subsidies lead to inflated population densities or altered interaction strengths of organisms in recipient habitats. In river ecosystems, the export of winged adults of aquatic insects may be a cross-compartmental link, subsidizing watershed consumers and altering their community dynamics. In rivers of northern Califomia, lizards (Sceloporus, Iguanidae) are at least seven times more dense than congeners in non-river, upland habitats. On the same rivers, the abundance of aerial invertebrates declines nearly exponentially with increasing distance from the river-land interface. Sceloporus eat primarily terrestrial invertebrates, but 5-25% of the insects in their diet are of aquatic origin. The ability of Sceloporus to track aquatic resources may be limited by cover availability near rivers. The PIs propose to investigate 1) the effect of riverine subsidies of aquatic insects on Sceloporus population and community dynamics and 2) how near-river cover availability may modulate the ability of Sceloporus to track these resources.