Urban Ecosystems
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The Plant Identification Field Guide for the
College of St. Catherine Woods was created for a senior honors project. The purpose of this guide is to offer the
opportunity for students of the college to identify the plant species within
the woods. The field guide is limited
to only those species found at the college and in this way reduces
misidentification and confusion. This
website was created in conjunction with printed field guide. The printed field guide allows students to
rapidly identify plants while in the field.
The web-based identification can be done with an unknown branch away
from the woods and offers a step-by-step example of using a dichotomous
key.
The field guide
was created through research within the woods.
Using a collection of field guides by other authors, the trees, shrubs
and wildflowers were identified from June 1, 2003 to September 12, 2003. The identification was continued throughout
the summer to ensure that all species would be identified despite differences
in flowering time. All individual plant species found were identified,
described and photographed. A few species were also dried and pressed. The
species were then organized by significant characteristics and a key to the
plants was created. A glossary of key terms was created, in addition to an
introduction to identification.
The woods at the
College of St. Catherine are located within St. Paul, Minnesota. Surrounded by
the campus, the woods features twenty-nine different species of trees, shrubs
and wildflowers. Within the Twin
Cities, the college is part of an urbanized metropolitan area.
Urban Ecosystems
An urban forest
ecosystem, the woods provide an example of the importance of education about
the natural environment. Because half of world’s human population exists in
urban communities (1), a better understanding of the
wildlife communities that are closely associated with human society can improve
the general life of the average citizen.
There are
essential components of an urban ecosystem that help to define the
concept. An ecosystem is composed of
interacting species and their environment that function together to sustain
life (2). All
cities are composed of heterogeneous components. There are often parks, parking lots, shopping malls and wetlands
located in a short distance from each other. There are several types of
ecosystems that exist in an urban community.
Examples of such ecosystems are street trees, lawns, parks, urban forests,
cultivated land, wetlands, lakes, and streams (3). The woodlands at the college fit into the
category of urban forest.
Woodlands within a
metropolitan environment are found throughout the United States. Consisting of 3% of the land, there is
approximately twenty-eight million hectares of urban forest in the U.S. (4). Urban forest
developed through the survival of remnant trees, the deliberate planting of
trees and the unmanaged reproduction of native and exotic trees (5). The woods studied
for this field guide were created through all three factors. The urban forests of the United States have
been inextricably connected to human actions.
Ecosystems in
urban areas are an essential component of a city. Current ecological research has recognized metropolitan areas as
integration between ecological, social and commercial factors (6). There has been long-term research conducted
in Phoenix, Arizona and Baltimore, Maryland to better understand the
contributing factors to urban ecosystems (7). Humanity cannot be excluded from the
research and other factors must be included to effectively conserve and protect
the urban forests.
Challenges
Facing Urban Ecosystems
The close
interactions with the human populations have resulted in a variety of
challenges related to the conservation of these urban ecosystems. The wildlife species are under constant
human activity, because they are near high-density human habitation and
industrial and commercial centers (1). The indigenous ecosystem is only composed of
remnants of the original populations due to the fragmentation and isolation that
occurred during urbanization. The woods
at the College of St. Catherine are no longer connected to a larger ecosystem
that is now the city of St. Paul.
Another challenge
facing the urban forests is the invasive plant species that were originally
planted by human populations. Invasive
species affect the indigenous ecosystem by reducing the native species
diversity, changing the composition of soil nutrients, and altering the
geomorphology of the environment (8). The woods studied for this field guide have
many examples of invasive plant species, such as Common buckthorn and White
Sweet clover.
In addition to
invasive species, pollution and human traffic affect species diversity in urban
ecosystems. The species diversity applies to both plant and animal communities
and can be detrimental to the entire ecosystem. There has been shown to be a decrease in species richness in
arthropods, fungal populations and poorer quality leaf litter in urban forests
compared to equal environments in rural areas (1, 9). Also many urban
environments have less diversity in tree species, which can be unhealthy to the
entire ecosystem. Low diversity tree
stands are more susceptible to pest outbreaks, such as Dutch elm disease (4). Recent policies
involving native species restoration offer the possibility of reducing
extensive plant loss due to disease and increase the diversity of indigenous species.
Benefits
of Urban Ecosystems
There are many
reasons for human society to protect the natural environment within the
metropolitan area. Urban ecosystems are
an essential component to city planning, because of their benefits to humanity. The ecosystems provide air filtration,
microclimate regulation, noise reduction, rainwater drainage, sewage treatment
and recreation and cultural values (3). It is in the best interest of a community to
ensure the protection of the wildlife within their borders.
The urban
woodlands are a significant component in the lives of human society living near
the borders. The most general use
society has for the urban forests is for recreational experiences (10). Biking, bird
watching, and hiking are activities best conducted within a natural
environment. As the nearest woodlands to the population, it provides important
opportunities for individuals to become more familiar with the natural
world. The urban forest is a
fundamental education tool used to educate the general public about the
environment.
Future
of Urban Ecosystems
Communities, such
as the Twin Cities, are facing significant crossroads in the treatment of the
natural resources. Because the
ecosystems are highly influenced by the human populations, the rapid growth of
the urban spread has placed many ecosystems located within and near the
boundaries of a metropolitan area in danger.
The population cannot continue to view the urban ecosystems as
expendable, because the size and number of these environments are limited. Human intervention to control invasive
species and restore indigenous ecosystems can no longer be viewed as
interfering with the course of natural events. Humanity is an essential
component of the urban environment and should not be excluded. Economic and social forces are as integral
to metropolitan planning as ecological concerns. The responsibilities to conserve the ecosystems within an urban
community reside in the powers of the citizenship.
The main tool that
can be used to encourage the community to protect the urban ecosystem is
education. Citizens in urban areas are
less familiar with natural processes and functions of forest than those in
rural communities (10).
Also, many individuals in urban areas are unfamiliar with the policies
involving their own urban ecosystems. Within a California city, only one third
of the residents surveyed were aware of the actions within the city to protect
the ecosystems (11).
The city employees who maintain much of the urban forests stress
community-level participation and conflict management (12). Citizen support is necessary for urban
forests to remain viable through volunteers to help maintain the species and
residents to encourage the government to include environmental protection in
the budget (13).
For the community to become more involved in the urban ecosystems,
public awareness of the importance of the environment needs to be encouraged.
The main purpose
of my research is to use the field guide as a larger tool. It can serve as an educational tool that
will provide individuals with the opportunity to become better acquainted with
the woods at the College of St. Catherine.
Through the identification of invasive species, their pervasiveness will
be better understood and can encourage involvement in removal programs. The
urban forests can lie within a densely populated community undetected by the
residents. Education and awareness are
the only successful tools that will promote the survival of the ecosystems
within our midst.
Additional
Information on Urban Ecosystems
References
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arthropod community structure in a heterogenous
urban environment. Landscape and Urban Planning 52:
257-274.
- Moll G, and Petit J. 1994. The urban ecosystem: putting nature
back into the picture. Urban Forests Oct/Nov: 8-15.
- Bolund P and Hunhammer S. 1999. Ecosystem services in urban
areas. Ecological Economics 29: 293-301.
- Dreistadt SH, Dahlsten SL, and Frankie GW. 1990. Urban forest
and insect ecology: complex interactions among
trees, insects and people. Bioscience 40(3): 192-9.
- McBride J and Jacobs D. 1976. Urban forest development: a case
study. Urban Ecology 2:1-14.
- Pickett STA, Cadenasso ML, and
Grove JM. 2002. Resilient cities: meaning, models and metaphors for integrating
the ecological,
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pieces together.
Bioscience 48(8):
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- Konijnendijk CC. 2000. Adapting
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- Jetter K and Paine TD. 2004.
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Biological Control. In Press.
- Konijnendijk CC. 2003. A decade of urban forestry in Europe.
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- Davis ND. 1995. Seeing the big picture: New York City’s
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