Current Habitat Conditions Sample Clauses

Current Habitat Conditions. ‌ Extant relict leopard frog populations are restricted to narrow habitat corridors (<0.5 - 20 m; 1 – 3 m in most places), with a sharply defined boundary between riparian corridor and desert. Extant populations are restricted to perennial desert springs along the Virgin and Colorado River drainages. Substantial leopard frog habitat in the historical range of the species has been destroyed or modified by activities such as spring capping and diversions and the construction of dams and reservoirs. Modifications have not only changed the amount and quality of habitat available for relict leopard frogs, but have permanently removed connectivity between extant native populations and may also have created habitat for and promoted introduction of non-native predators (Sredl et al. 1997). Tamarisk is prevalent along the Virgin and Xxxxx xxxxxx, and the shorelines of lakes Xxxx and Mohave, as well as in almost every untreated spring. Tamarisk has overgrown the type locality of the relict leopard frog, changing geomorphology, soil chemistry, and available habitat. Tamarisk roots can substantially reduce pool size by growing directly in the water and trapping sediment. Tamarisk also greatly reduces the amount of light available to forbs, which provide cover for relict leopard frogs, and each autumn fallen needles entirely cover pools. Tamarisk control has been maintained at many occupied sites including Lake Xxxx north shore and some Black Canyon and Gold Butte area springs. These treatments will need to be continued, but tamarisk is not a threat in the short term at most sites (RLFCT 2005, 2009).