[Illustration: effects of channalization on meanders]
The original diverse habitat arrangement provided spawning and food-producing riffles, and importantly, deep "resting" pools.
Fish community surveys done by the Michigan Department of Natural Resources in 1988 showed
The Dowagiac systems' fish communities have been significanly affected by fishery management practices from as early as 1873. Dowagiac Creek has been managed for trout since 1933. Watershed fishery management practices have relied periodically upon the use of piscicides to eliminate potential competitor species prior to stocking trout.
MDNR-FD's management goal for Dowagiac Creek is to maintain the creek's excellent trout fishing without relying on chemical treatments to control competitor species. Because the Creek's habitat supports a high-quality brown trout community several barriers have been constructed. A rough fish barrier was constructed in 1977 on the creek at the lower edge of the trout designated water just upstream from Lake LaGrange. this barrier has been very successful, allowing a longer-than usual period between chemical treatments. (U of M)
The Dowagiac River Rehabilitation Team proposed rehabilitation of the functional ecology of the entire Dowagiac River system, recreating some of the characteristics of the original channel, and thereby improving the diversity of fisheries and wildlife habitats.
It was highly recommended in the feasibility study that some connections with the floodplain be reestablished in order to recreate a more natural riparian ecosystem with first bottoms or back swamps and second bottoms. Since the river is incised, reconstruction efforts may involve excavating or bringing the floodplain down to the level of the river in places.
It would be helpful for rehabilitation planners to visit and examine the character and functioning of similar river systems that have remained more natural.
The plant community along the Dowagiac River are remnants of Southern Mesic Forest (Beech-Maple dominants) exemplified in Dowagiac Woods, and Southern Flood Plain Forest (which can be seen where Dowagiac Creek joins the main tributary in southern Silver Creek Township).
In pre-settlement times, the southern floodplain forest provided an extensive corridor along most rivers in southern Michigan. The origianl vegetation of the St. Joseph River basin was forest, interspersed with rivers, streams and prairies. Today only small fragmented remnants of original riparian communities exist. Somewhat less fragmented is a wooded corridor that extends along the middle portion of the Dowagiac River in Cass County, including Dowagiac Woods.
A narrow strip of woods is owned by the Michigan Department of Natural Resources at Sink Road and another strip is owned by Cass County at Dodd Park. However most floodplain forests are privately owned.
Riparian ecosystems are one of the most important in terms of biological productivity and diversity. Biotic productivity is often high due to good soil water availability and high nutrient status of alluvial soils due to periodic enrichment (from natural flooding) promoting taxonomic diversity.
Benefits from riparian vegitation include:
Current studies (which are minimal) suggest that we look out for the small whorled progonia (Isotria medeoloides) among plant species, which is only known from Berrien county and is listed as Federally threatened and State endangered. Of the 395 plant species recommended for protection in Michigan, 71 are on Cass County's list. Few plants occurring in the watershed are federally protected and there are no federally listed plant species other than the small whorled progonia.
State threatened plants found adjacent to the Dowagiac River include the log fern, ginseng, goosefoot corn-salad, prairie trillium, and showy coneflower. Historical plant records also cite the praire false indigo and cut-leafed water-parsnip shortly after dredging.
No threatened fish, aquatic invertebrates or aquatic plants were listed for the Dowagiac River watershed by studies, although several aquatic protected species were previously present within the DRS historically.
Two mamals are protected in the Dowagiac watershed under the Michigan Endangered Species Act: the Indiana bat (Federally and State Endangered) and the prarie vole (State Threatened). In May, the Indiana bat migrates north and forms colonies near stream and river floodplains, therefore it would seem that restoration would be advantageous to Indiana bats. Since the prairie vole has not been seen for over thirty years and favors upland habitats, it is unlikely to be a concern in the restoration efforts.
In theory, restoration efforts would be neutal to any threatened or protected bird species which rely on riparian habitat. It is expected that restoration would enhance the presence and diversity of common riparian birdlife. During restoration, it is believed that migrating birds would be able to adjust and use other tributaries of the larger St. Joseph River watershed.
Protected/threatened insect species are of greater concern in the wider watershed than the riparian corridor. One exception is the large (3 inch) grayback dragonfly which is rare and locally occurring over its entire range which includes Indiana, Michigan, Ohio, and New York. The grayback dragonfly is known from one old record in Berrian County and a recent single specimen from Cass County. They are most likely to be found near small streams in wooded valleys.
Among reptiles and amphibians, two snakes found in the watershed area are State endangered, the copperbelly watersnake and Kirkland water snake, both found historically along Dowagiac Creek. One amphibian, the marbled salamander, is listed as a State threatened species because of its inability to overwinter.
The Blanding's turtle, spotted turtle, and eastern box turtle are all listed for special concern. The spotted turtle has been found along Dowagiac Creek in Volinia Township, and along one of the tributaries of the Dowagiac River in Wayne township. The eastern box turtle is known to reside in moist wooded areas of Dowagiac Woods.
Gaps in biological data, such as information on aquatic invertebrates, amphibians, and reptiles found along the DRS, should be identified and assessment studies performed. A long-term monitoring program needs to be established and funded. (U of M)
"Most of Michigan amphibians require an aquatic habitat in their early life stages. Aquatic juvenile amphibians have gills, but most amphibians transform into animals having lungs and are capable of living on land. Tadpoles of some frog species may be found along edges of shallow, slower moving streams with well-vegetated edges. Cut-off meanders of the Dowagiac River function as stagnant pools, providing protection from predatory fish likely to be found in the main river channel. A few frogs were observed jumping back into the former river channel during fieldwork done for vegetation analysis. To assess which species of frogs are using old meanders as breeding ponds, it is recommended a census be done of singing frogs in the spring." (U of M)The source for much of the foregoing on biological data was the Michigan Natural Features Inventory or MNFI, a working partner with The Nature Conservancy (TNC). It is housed within the Wildlife Division of Michigan's Department of Natural Resources (MDNR). MNFI maintains a list of Endangered, Threatened, Special Concern and Probably Extirpated animals (1994), and a similar list for plants. MNFI database contains information on protected species for each county in Michigan along with unique plant community types. A riparian plant survey was conducted along the various reaches of the Dowagiac River during mid-August of 1997 and was an additional resourse for information on plants. Information on amphibians was augmented by local naturalists. (U of M)
The watershed contains interesting and diverse biological community types. Besides the dominant community types, within the corridor there are interesting remnants of Southern Swamp and Coastal Marsh Plain; beyond the riparian corridor are examples of dry sand and mesic prairies and Oak Openings, all of relatively high priority status according to MNFI and TNC.
Average bird densities in this area are twice as high in riparian areas as in more upland areas. Four riparian species are considered to be strongly characteristic of our area, belted kingfisher (a bank nester), spotted sandpiper (one of the few sandpipers to breed in our area rather than the far north), and the Northern and Louisiana (warbler species) waterthrush. Also characteristic, wood duck, mallard and several herons.
The great blue heron, one of our most picturesque species, relies on the river primarily as a source of food and nests in rookeries in nearby forested areas.
A 1915 Dowagiac Daily News report indicated that the "area on the west side of the Dowagiac Creek near Crystal Springs was low and it had a "crane town" located near the river among the trees. The ancient nests, which adorned the tree tops, had been the nesting place the Great Blue Herons for a long time. After the logging in 1915, only a few pair of cranes returned. It was estimated that as many as 20 families of cranes made up the old colony." (quoted in Cook and Cook)
Two birds of prey are associated with mature bottomland forests: the red-shouldered hawk (State threatened status - a bottom land preditor) and the barred owl. They can occupy the same territory since the owl is nocturnal.
Woodpeckers, eastern kingbirds, eastern phoebes, veery and Acadian flycatcher all use the natural and man-made structures of the riparian habitat.
Several warblers use river floodplain areas for their nesting sites. Yellow-throated warblers (a state theatened species) nest primarily in sycamores growing naturally along the front slick of a river (noted in the Galien River basin, just outside the watershed). The prothonitory warbler has been confirmed as a breeder for Cass county.
The belted kingfisher is a bank nester that feeds on fish in the river. Other birds such as bank swallows, rough-winged swallows, Acadian flycatchers, and many warblers nest in river floodplains. Many species are associated with riparian bottomland forests because they have lost other habitat. For instance, the whip-poor-will and veery are associated with riparian bottomland forests in southern Michigan.
Allan, J.D., 1995. Stream Ecology: Structure and Function of Running Waters. Chapman and Hall, New York.
Brennan, P.O. and C. Stamm, 1991. Dowagiac River Watershed Non-point Pollution Inventory and Implementation Plan. Sauk Trails Resource Conservation and Development Area Council. Mattawan, Michigan.
Brooks, A. 1987. Restoring the Sinuosity of Artificially Straightened Stream Shannels. Environmental Geology and Water Science 10(1):33-41.
Brooks, A.1995. River Channel Restoratoin: Theory and Practice. in: Changing river Channels, A. Gurnell and g. Petts (Editors). John Wiley & Sons LTD, NY, pp. 369-388.
Burdach, J., 1964. Downstream: A Natural History of the River. Harper and Row Publishers, New York
Daubendiek, Bertha A. and Edna S. Newman, 1988. In Retrospect. Michigan Nature Association. Winton-Swan Associates, Inc. Detroit.
Gordon, N.D., T.A. McMahon, B.L. Finlayson. 1992. Stream hydrology: an introduction for ecologists. John Wiley and Sons, West Sussey, England
Hawkins, C.P., 1991. What are Riparian Ecosystems and Why are We Worried About them in: Riparian Resources. (Eds. Rassmussen and Dobrowolski). Utah State Univeristy at Logan.
Holzman, Richard, Bertha Daubendiek, Lyle Rizor, and Forbes Sibley, 1994. Nature Santuary Guidebook, 7th edition. Michigan Nature Association. Avoca, Michigan.
Kirby, M.J. and D. Hampton 1997. The Hydrology and Hydrogeology of the Dowagiac River Watershed - Southwest Michigan. Department of Geology/Institute for Water Sciences. Western Michigan University; Kalamazoo, Michigan. Decembeer, 1997.
Michigan Department of Environmental Quality (MDEQ). 1997a. A biological survey of the Dowagiac Creek and Dowagiac River watersheds. Berrien, Cass, and Van Buren counties, Michigan. August 27-28, 1990 and July 15-19, 1991 Staff Report No. MI/DEQ/SWZ-96/006, Michigan Department of Environmental Quality, Surface Water Quality Division, Lansing, Michigan.
Michigan Department of Environmental Quality (MDEQ). 1997b. A biological survey of the Dowagiac Creek and Dowagiac River watersheds. Berrien, Cass, and Van Buren counties, Michigan. August 19-20, 1996. Staff Report #MI/DEQ/SWQ-97/074, Michigan Department of Environmental Quality, Surface Water Quality Division, Lansing, Michigan.
MNFI, 1992, Michigan's Special Plants: Endangered, Threatened, Special Concern and Probably Extirpated. Michigan Endangered Species Program. Lansing, Michigan.
MNFI, 1994, Michigan's Special Animals: Endangered, Threatened, Special Concern and Probably Extirpated. Michigan Endangered Species Program. Lansing, Michigan.
MNFI, 1996b, Natural Communities and their Priority Ranks. Lansing, Michigan. p. 1-2.
MNFI, 1997a. Cass County Element List. January 14, 1977. Lansing, Michigan.
Moffet, J.W., Michigan State Conservaation Department, Institute for fisheries Research, 1940. The Dowagic River System, its Trout Possibilities. Report No. 577. Michigan State Conservation Department, Institute for Fisheries Research, Ann Arbor, Michigan.
Toth, L.A., 1995. Principles and Guidelines for Restoration of River/Floodplain Ecosystems -- Kissimmee river, Florida in: J. Cairns (ed.), Rehabilitating Damaged Ecosystems. Lewis Publishers, Ann Arbor, pp. 49-68.
Westrate, William. Volinia township, Cass County. Reported Reptile and Amphibian records (1972-1979).
Wiley, M.J., and P.W. Seelbach. 1997. An introduction to rivers. Michigan Department of Natural Resources, Fisheries Division, Fisheries Special Report 20, Ann Arbor, Michigan.
Note: MNFI material can be obtained from teh State of Michigan, Wildlife Division in Lansing.