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

9700834一个生境（隔室）内的种群和群落动态往往与不同但相邻生境的动态密切相关。这样一来，一个栖息地实际上可以补贴另一个栖息地的某些生物。最近的一些实证研究表明，空间补贴导致接受者栖息地的种群密度膨胀或生物相互作用强度的改变。在河流生态系统中，有翅水生昆虫成虫的出口可能是一个跨区隔的环节，补贴流域消费者并改变其群落动态。在加利福尼亚北部的河流中，蜥蜴（蜥蜴科，鬣蜥科）的密度至少是非河流高地栖息地的同类的7倍。在同一条河流上，空中无脊椎动物的丰度随着距离河地界面的增加而呈指数下降。棘孔虫主要吃陆生无脊椎动物，但它们的食物中有5-25%是水生昆虫。Sceloporus追踪水生资源的能力可能受到河流附近覆盖物的限制。这些项目建议研究：(1)水生昆虫的河流补贴对螺孔虫种群和群落动态的影响；(2)近河覆盖如何调节螺孔虫追踪这些资源的能力。

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.