OCR Text |
Show Playas are low flat depressions in the valley floor formed by bottom currents of ancient Lake Bonneville in its last stages of recession. The West Desert is a vast complex of playas laced with irregular bars and local depressions. Salt- tolerant species found on GSL beaches are also found in some playas, depending upon soils, salt gradients and successional stage. Saline plains or uplands extend beyond the playas and beaches around the lake up to the bases of the mountains. The flora is very diverse and includes herbs and smaller scrubs. Their frequency and location depend on the character of the soil surface and rainfall. Slight depressions usually collect water in the spring and support localized changes in plant life. Dunes are formed along the eastern shores of the lake and on the plains and foothills bordering the salt desert. Dunes near the lake are composed of white calcareous oolitic sand formed around mineral particles and fecal material. Beach flora is distinct in some areas but in others it is mixed. Vegetation is usually restricted to the upper edge of the shoreline where wave action is less and flooding by brine laden waters is limited in frequency. Mudflats are a special aquatic site and provide important habitat for some wildlife species, such as the Snowy plover. These areas support pickleweed along the shores of the lake, an important fall and winter forage for geese and other waterfowl. Vegetation on GSL islands is variable, and ranges from no vegetation to broad diversity on Antelope and Stansbury Islands. Some islands are mere sand bars with little vegetation or cover, some have a considerable amount of vegetation including desert shrubs, and others are quite rocky and devoid of vegetation. The eastern shoreline of the lake is dominated by marshlands or wetland type vegetation. This narrow strip of vegetation combined with shallow water is important habitat for wildlife and millions of waterfowl, shorebirds and migratory birds. Relatively small changes in lake level inundate or expose large areas of shoreline so lakeshore flora are characterized by multiple successions. Lake level fluctuations and the shallow gradient of the lake bottom together have a profound affect on the flora and fauna found in this zone of influence. This natural phenomena is critical to maintaining the habitat requirements of many species of birds which inhabit the lake. This mechanism ( lake level fluctuation) must be present to maintain this dynamic system. Around the shores and private lands at the north end of the lake there are extensive stands of sagebrush and this is an important winter grazing area for domestic sheep and deer. Browse- type vegetation located in the Promontory Mountains includes Mountain mahogany, Serviceberry and Bitterbrush, which are valuable to wildlife as food and cover. These areas also have juniper growing on steep and rocky hillsides. Perennial vegetation consists mainly of grasses and various shrubs such as sagebrush, rabbit brush, greasewood and shadscale, particularly along the west side of the lake. Upland and agricultural areas also provide important wildlife habitat and serve as critical habitat when lake levels are high. Reptile and Amphibians Limited work has been done on the amphibians and reptiles in the GSL 74 |