Introduce and amphibian and reptile diversity relative to habitats. Enormous basalt flows from large volcanoes in eastern Oregon. Pleistocene glaciation and associated fluctuations in climate. C. Climate 1. Rainfall a. Rainshadow effect of the Cascades reduces amount of moisture from storms over the Pacific.
Fault scarps create local rain shadow effects.
Temperature a. Moderating influence of the Pacific Ocean is removed. Result is much greater temperature fluctuations on seasonal and daily basis. Low elevations in southeastern Oregon get warmer than high elevations. D. Habitats 1. Open areas with sandy soils 1.