240 likes | 327 Vues
Explore the dynamics of Great Salt Lake through the lens of its avian inhabitants, showcasing the interplay between natural and man-caused factors. Discover how climate, historic lake elevations, and anthropogenic influences affect bird populations. Delve into the effects of diking, water consumption, wetland management, and industrial activities on avian ecology. Learn about specific species' responses to environmental changes, from American White Pelicans to Wilson’s Phalarope. Gain insights into the lake's history and the importance of integrated conservation efforts for preserving bird habitats.
E N D
Great Salt Lake Dynamics • Natural • Man caused
Natural Conditions • Climate: a factor in long term trends • Annual variation
Historic Lake ElevationsAn Indicator of the Annual Water Cycle Lake elevation measurement sites
Anthropogenic Influences on Lake Ecology • Highlights from history • Substantive effects
Highlights from History 1850 1870 1880 1890 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990
Substantive Effects: Diking is responsible for the creation of four distinct ecological units. • North Arm • South Arm • Bear River Bay • Farmington Bay
Substantive Effects: Necessary construction to the Southern Pacific causeway in the 1980s has created a salt trap in the North Arm.
Substantive Effects: Current upstream water consumption reduces the standing lake elevation by an estimated five feet (Arnow 1980).
Substantive Effects: Of 400,000 acres of lacustrine wetlands 50% are currently under management by state, federal and non-government organizations.
Substantive Effects: Exotic fish (i.e., carp and gizzard shad) were introduced into managed wetland systems and water storage impoundments.
Substantive Effects: Nearly 200,000 acres on the periphery of Great Salt Lake are leased properties for mineral extraction and other industrial uses (DSLF 1996).
Substantive Effects: In addition to mineral extraction, shorelines have been significantly altered by: • road and railroad construction • WMA diking • power line development • other human activities
Substantive Effects: The commercial harvest of brine shrimp cysts, and other shrimp biomass, at times exceeds 200,000,000 lbs. annually.
Avian Use and Responses to Change • Nine examples of GSL species and their response to change.
Tundra Swan Bear River Refuge 1990s Swan concentration area Ogden Bay WMA 1960-70 Swan concentration area
White-faced IbisStrategic Nesters 1998 1999 2000 2001
Snowy Plover Snowy Plover, master of dynamic habitats: • Double brood in optimum conditions • Long lived ( survival rate 2.7) • Exploiter of ephemeral habitats