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<br /> <br />CHAPTER 2: ECOLOGICAL OVERVIEW-POSTFLOOD RECOVERY AND ECOSYSTEM MANAGEMENT 7 <br /> <br />~ <br />Gl <br />a; <br /><ll <br />Q) <br />'" <br />C <br /><ll <br />Q) <br />E <br />~ <br />o <br />.0 <br /><ll <br />'" <br />~ <br />Q) <br />- <br />Q) <br />E <br />~ <br /> <br />c <br />o <br />.~ <br /> <br />Q) <br />Q) <br /><> <br />.@ <br />::l <br />'" <br />, <br />~ <br />Q) <br />- <br />~ <br /> <br />Upper Mississippi River Hydrographs (RM 218) <br /> <br /> <br /> <br />133 <br />132 <br />131 <br />130 <br />129 <br />128 <br />127 <br />126 <br />125 <br />124 <br />123 <br />133 <br />132 <br />131 <br />130 <br />129 <br />128 <br />127 <br />126 <br />125 <br />124 <br />123 <br />133 <br />132 <br />131 <br />130 <br />129 <br />128 <br />127 <br />126 <br />125 <br />124 <br />123 <br /> <br />1880 1881 <br /> <br />1882 <br /> <br />1883 <br /> <br />~N <br /> <br />1890 1891 <br /> <br />J <br /> <br />1929 <br /> <br />1930 <br /> <br />Predam <br /> <br />1884 1885 <br />Predam <br /> <br />1888 <br /> <br />1889 <br /> <br />1886 <br /> <br />1887 <br /> <br />1931 1932 <br /> <br />1934 <br /> <br />1936 <br /> <br />1935 <br /> <br />1933 <br /> <br /> <br />133 <br />132 <br />131 <br />130 <br />129 <br />128 <br />127 <br />126 <br />125 <br />124 <br />123 <br /> <br />1973 1974 <br /> <br />1975 <br /> <br />1976 <br /> <br /> <br />1983 <br /> <br />1984 <br /> <br />1985 <br /> <br />1986 <br /> <br />Figure 2-3. Upper Mississippi River hydrographs (river mile <br />(RM) 218). Representation of the average hydrologic cycle in fig- <br />ure 2-2 is useful to show general seasonal hydrologic patterns, but <br />it is hydrologic patterns within any particular year that most river- <br />ine flora and fauna respond to in the short term. Long-term gage <br />stations provide prerlam and postdam records necessary to com. <br />pare the two periods near Grafton. Illinois. In any given year. <br /> <br />ANIMALS <br /> <br />Because animals are mobile, they are able to seek out <br />preferred habitats, Species presence is usually specific to a <br />particular habitat type. as defined by geomorphology. <br />hydrology. and vegetation, Five broad categories of animals <br />will be discussed in terms of their ecological relations in the <br />river-floodplain ecosystem: invertebrates. fish, amphibians <br />and reptiles. birds. and mammals, <br /> <br />1977 1978 <br /> <br />1981 <br /> <br />1982 <br /> <br />1979 <br /> <br />1980 <br /> <br />Postdam <br /> <br /> <br />~ <br /> <br />1987 <br /> <br />1988 <br /> <br />1990 <br /> <br />1992 <br /> <br />1991 <br /> <br />1989 <br /> <br />different floral and faunal groups may develop based on hydro- <br />logic patterns. Note how water-surface elevations (river stage) and <br />stage variation have been stabilized at about 128 meters above sea <br />level in the postdam era. High-flow events appear shorter in dura- <br />tion because of stage regulation for navigation (source: John C. <br />Nelson, Illinois Natural History Survey, personal commun., <br />1993), <br /> <br />I!':VERTEBRATES <br /> <br />Terrestrial invertebrates are an important resource for <br />both fish (W.e. Starrett. unpub, data, 1965) and birds <br />(Bellrose. 1980). but lheir role has not been completely <br />evaluated, They are a reliable food resource for terrestrial <br />inhabitants of the floodplain but become available to <br />aquatic animals only when they are inundated by floodwa- <br />ters, fall from flooded vegetation, or are blown in by winds. <br />