Title: MITIGATED WETLAND IPFW Plant Community Profile Landscape Data
1MITIGATED WETLANDIPFW Plant Community
ProfileLandscape Data
- Overview
- This man-made wetland (purportedly 3.60 acres in
size) was installed during the Summer of 1998
as mitigation for the loss of 0.83 acres of
wetland bordering the Stoney Run Stream that was
filled to accommodate the construction of an
automobile bridge was built over the stream in
conjunction with the development of the McKay
soccer complex. The goal of the mitigation was
to create a mixed cover type wetland, with both
herb and tree-shrub dominated regions, of similar
composition and diversity to other wetlands on
the mitigation site. In addition, since the
wetland would serve retain surface water runoff
prior to its entry into the St. Joseph River
sediment fences were installed along the
margins of the wetland at points of water input
from adjacent more upland sites to facilitate
water treatment i.e., nutrient and particulate
removal. It was also anticipated that the
wetland would be used for environmental science
instruction at IPFW, as an outdoor education
facility. - Prior to wetland installation the mitigation
site was classified as an old field. The
wetland basin was created through shallow
excavation to a elevation of 755-756 ft above sea
level, compared with a starting elevation from
760-765 ft. The elevation of the basin floor was
chosen to correspond with the topography of
adjacent wetlands on the St. Joseph River
floodplain including a lagoon (NW Lagoon) and
forested wetlands. The depth of excavation was
expected to be sufficient to create deep water
pool complexes at the lowest elevations
supporting aquatic vegetation including both
floating leaf species, such as water lily, and
broadleaf emergents, such as Arrow arum and
Pickerelweed, in the lowest regions. However,
the remainder of the basin was anticipated to
develop as a shallow marsh, with the margin
supporting wetland trees and shrubs. Following
excavation the wetland was planted using a
combination of seed mixes and transplanting (for
aquatics and woody plants). - The fact that the wetland was artificially
vegetated facilitates plant identification and
the utility of the site for field botany and
plant taxonomy instruction. In addition, many of
the plant species that were sown are not known to
occur naturally in other wetlands on campus,
contributing to the overall floristic diversity
of the campus. However, the wetland is not a
static community and several of the plants that
were planted are no longer present. These plants
either failed to established or showed initial
growth, but have subsequently been extirpated.
Since the seed mixes included cover crops some
of the plants were anticipated to be temporary at
the site. However, the failure of deep water
complexes to establish at the site was not
expected. Similarly, many of the marsh species
included in the planting mix that prefer
relatively longer periods of saturation or
submergence, such as bulrushes and some of the
sedges and rushes, are doing relatively at the
site. On the other hand, several wetland species
that were not present in the seed mixes have
seeded naturally. Purple loosestrife and
cat-tails are included among the list of
volunteers at the site however, the population
levels of all three species remain in check. The
vegetation, and possibly also the hydrology of
the site, is still in flux providing an
interesting opportunity for studying the
succession of mitigated wetlands.
2 Geographic Coordinates and Elevation Latitude
41º 0715.00 N, approximate center
position Longitude 85º 0645.79 W,
approximate center position County, Township
Allen, St. Joseph Township, Range,
Section T31N, R13E, Section 19, N ½ of SW ¼
Elevation 755-756 ft above sea level at the
lagoon base, compared with starting elevations
from 760-765 ft. According to construction
plans the elevation at the margins of the
wetland should range from 761-762 ft.
3- Location (Aerial Photograph)
4- Location (Aerial Photograph)
5A Western edge of the wetland as seen from the
north in mid-Summer B Wetland as seen from its
northwest margin, looking southeast. The Science
Building is visible in the background (across the
river) C Also from the northwest, looking
east across the wetland basin towards the river.
D Wetland as seen from its eastern edge
(closest to the river), looking north E
Wetland as seen from the south. The arrow shows
the position of the wetland. The forested
wetland that feeds into the mitigated wetland is
also seen F Also from the south showing the
mitigated wetland to the west (arrow) and river
to the east.
6 7The construction site for the mitigated wetland
included two soil types, Eel silt loams (closer
to the river) and Martinsville loams, on its more
upland edge, with some soil mixing presumably
occurring during excavation. Eel silt loams
(Es) are part of the Eel-Martinsville-Genesee
association. This association consists of deep,
well drained to moderately well-drained, level to
moderately sloping, medium-textured to moderately
fine textured alluvial soils on bottom lands and
stream terraces. The Eel and Genesee soils are
located on the bottom lands and the Martinsville
soils are on the stream terraces. Eel soils have
a 20-inch surface layer of dark grayish-brown,
friable silt loam. The underlying material is
firm silty clay loam that is brown in the
uppermost 4 inches and dark yellowish brown
mottled with gray in the lower part. The C
horizon may contain calcareous material at a
depth of more than 38 inches. The native
vegetation was mostly water-tolerant hardwood
trees. The soils bordering the construction site
to the NW are classified as Martinsville loam
soils with 2-6 slopes (McB). The Martinsville
soil series consists of deep, well-drained nearly
level to moderately sloping soils found on
terraces along the major streams, on beach
ridges, and on outwash plains. The soils in this
series have a 13 inch surface layer of friable
loam that is dark, grayish brown in the upper 9
inches and graying brown in the lower part. The
35 inch subsoil is yellowish brown and reddish
brown, friable and firm sandy clay loam in the
uppermost 22 inches and reddish brown friable
fine sandy loam in the lower 13 inches. The
underlying (parent) material is yellowish-brown,
friable, calcareous fine sand that contains thin
lenses of silt and a few pebbles. The native
vegetation was hardwood forests and erosion is
the major hazard, and controlling runoff is a
problem