Restoring Native Habitats to Urban Landscapes
Ian Noyes, Katey Westergren, and Dr. David Warners, Calvin College
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Urbanization’s pressure on biodiversity
Methods
A study done by the U.N. in 2007 reported “that
humans are building a city the size of Vancouver every
week.” The result? Biodiversity loss. Biodiversity is
declining the world over at an unprecedented rate,
currently extinction is proceeding more than 1,000
times faster than the natural background rate.
To understand how best to restore shortgrass prairie
habitat to an area that was previously lawn, we
created half-meter-square experimental plots that will
assess the effects of soil compaction and composition
on plant performance (Table 1).
Results
Table 1. Breakdown of test plot treatments.
How do we combat the loss of native landscapes and
their associated biodiversity? One goal is to replace
biodiversity-poor lawn areas with biodiversity-rich
native landscaping. In our project we introduced
shortgrass prairie habitat in a low-use lawn area north
of the Prince Conference Center (Figure 1). This
replacement is beneficial for at least three reasons:
1. Lawn is a monoculture, and a single ‘producer’
species supports only the simplest of food chains.
1. The shallow root system of lawn doesn’t aerate
and loosen the soil, so it becomes compacted and
does a poor job of absorbing stormwater runoff.
1. Maintaining lawn requires regular use of fossil
fuels, water for irrigation, as well as potentially
harmful chemical inputs (pesticides, fertilizers).
Restoring the Land
1. We planted our shortgrass prairie with replicated
test plots, each containing 5 native species. We
also included 14 other native species in areas
outside the test plots, creating multiple niches for
pollinators and other organisms to inhabit.
Sand to Compost Roto-tilled
ratio
90:10
10 plots
70:30
10 plots
50:50
10 plots
Untilled
10 plots
10 plots
10 plots
In the large planting area
we:
1. Removed the sod and
put down a 6-inch
layer of 70:30 sandto-compost mix.
2. Located our 60 plots
randomly.
3. Planted each plot
Fig. 1. Site location in red.
identically (see
Figure 2).
4. Took baseline data of each plot: birds-eye view
photograph, height of tallest point on each plant,
health rating on standardized 0-5 scale.
1. The root systems of these native species are
extensive and will loosen the soil, creating
channels for water absorption and filtration.
1. The native species have all been grown from
locally collected seed and therefore are adapted
to this climate and will not require irrigation,
fertilization, or mowing.
Fig. 3. Photograph of the prairie after planting.
For accessibility and aesthetic purposes we installed
a woodchip path beside the prairie and two stone
paths transecting it.
The data collected will serve as a baseline resource
for future students who will monitor the progress of
this prairie’s growth in subsequent years.
Conclusions
We predict that the test plots treated with 90:10 ratio
and roto-tilled will perform best. Sandy soil is nutrient
poor which favors the adapted native species over the
weedy species. Tilling will also allow quicker root
establishment. But only time will tell…
Fig. 4. Established shortgrass prairie at Catalyst Partners in
Grand Rapids. Photo credit: Ed Post Photography.
References
Fig. 2. Photo of a single test plot containing the 5 experimental
species: Carex brevior, Coreopsis lanceolata, Rosa carolina,
Liatris scariosa, and Schizachyrium scoparium.
The Nature Conservancy. "Global Impact Of Urbanization Threatening World's
Biodiversity And Natural Resources." Science Daily, 17 Jun. 2008. Web. 6 Aug. 2013.