Whitford, Philip; Whitford, Kathryn (ed.) / Transactions of the Wisconsin Academy of Sciences, Arts and Letters
volume 74 (1986)
Keough, Janet R.
The Mink River- a freshwater estuary, pp. 1-11 PDF (4.8 MB)
1986] Keough—Mink River Estuary 7 sampled, and observations were made of submergent species (species are listed in Table 1). Estimates of biomass were made using samples of above- and below-ground material harvested in each community every month during the two growing seasons. Peak biomass values from that period are presented in Table 2, and each community is described below. Deep Marsh The deep marsh complex occurs adjacent to channels of the Mink River. Several species form this community type, but seldom do more than two or three occur together. For example, Sparganium eurycarpum forms monotypic stands near the river mouth and in patches on mud flats in "Rogers Lake." Occasionally, a few individuals of Sagittaria latifolia are intermixed with Sparganium. Zizania aquatica is found in monotypic stands on mudflats. Zizania populations fluctuate widely from year to year; dense populations are found only during years when mudflats are exposed or near the water surface. For example, in 1982, the level of Lake Michigan was 6 inches lower than in 1981. Mud flats were exposed in Rogers Lake, and supported more numerous and dense Zizania populations than the previous year. Scirpus validus occurs over a wide range of water level conditions. This species forms monotypic stands on shallow organic mudflats around Rogers Lake. With Sagittaria latifolia, it forms two-species stands along the Mink River channel. A tall form, probably a hybrid with S. acutus (Galen Smith, pers. comm), grows with Eleocharis smallii around the edge of Rowley Bay. Scirpus americanus also forms monotypic stands in deep water in the open bay, where the populations are exposed to wind and waves. Typha angustifolia also forms single species TABLE 2. Peak biomass of emergent herbaceous communities of the Mink River estuary in 1981. Month of peak biomass occurrence is indicated. Community Type Above Ground g/m2 (month) Below Ground g/m2 (month) Areal Extent km2 Deep Marsh Scirpus validus Community in Rowleys Bay 595.4 (Aug) 1373.6 (Aug) 0.474 along Mink R. channel 204.1 (Aug) 268.6 (Sept) 0.052 shallow marsh edge 194.9 (Aug) 336.6 (Sept) 0.285 edge of Rogers Lake 410.1 (Aug) 493.6 (Sept) 0.050 Sparganium eurycarpum Community at river mouth 512.7 (Aug) 704.0 (Sept) 0.120 Rogers Lake islands 628.2 (Aug) 400.3 (Aug) 0.100 Zizania aquatica Community Rogers Lake islands 545.5 (Sept) 207.7 (Sept) 0.073 Typha angustifolia Community at river mouth 880.6 (Aug) 1626.4 (Sept) 0.041 Shallow Marsh Carex aquatilis/C. prairea Community between headw. creeks 327.1 (Aug) 806.0 (Sept) 0.496 Phragmites communis Community between headw. creeks 686.1 (Sept) 1867.6 (Sept) 0.060 Wet Meadow Calamagrostis canadensis/Carex stricta Community along river 779.7 (Sept) 6486.8 (Sept) 1.968
Copyright 1986 Wisconsin Academy of Sciences, Arts and Letters.| For information on re-use, see http://digital.library.wisc.edu/1711.dl/Copyright