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Show Ecosystem Introduction Great Salt Lake ecosystem is of worldwide importance for migratory bird populations, brine shrimp and mineral extraction industries. GSL is one of the premier wetlands areas of the United States and is a major recreational and aesthetic resource for Utah. ( Science Review Committee ( SRC), 1999c) GSL ecosystem is comprised of many sub- ecosystems ( SRC, 1999b and c) and each is strongly influenced by changing lake levels and lake chemistry. Shallow water, wetland areas and deep water portions of the lake are spatially and temporally dynamic in response to changing environmental conditions. Variations in precipitation and fresh water inflows together create a dynamic mosaic of habitat types along the shores of the lake. Variations in salinity affect species community composition and structure which also varies across all of the lake's ecosystems. There is a distinct difference in salinity between the north and south arms of GSL and this directly influences species distribution and abundance. There is also a strong east- to- west ecosystem gradient in regard to GSL habitat and productivity ( SRC, 1999b). Natural and human- induced inputs and outputs occur via inflow, atmosphere and other mechanisms ( SRC, 1999c). There are many other components and interactions which determine ecosystem function and productivity. GSL resources are inter- connected and human use influences ecosystem response. GSL components and interactions are closely associated, thus making the management of GSL ecosystems complex and challenging. Great Salt Lake Subsystems GSL and its watershed represent a complex web of interacting physical, socioeconomic and ecological systems and subsystems ( SRC, 1999c). Current understanding of the complexity of GSL ecosystems and lake dynamics limits the ability to accurately describe and forecast the dynamics of the various system components ( SRC, 1999c) such as hydrology, landscape, chemistry, biology, water and air. A subsystem analysis emphasizes the linkages between these components and human interactions from a large- scale perspective. Subsystems and their interactions are usually represented by using a Venn Diagram. ( See Figure 11.) The subsystems approach can be a management tool for resource planners and managers to identify issues, limitations and areas of uncertainty. These linkages are best depicted by studying cause- and- effect chains. ( Figure 12 is a simplified example of GSL systems biological linkages.) Understanding cause- and- effect chains and their interconnected linkages helps resource managers identify potential methods of altering conditions or managing a system. |