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Homeowners and groundskeepers
battled with the landscape in the
fi rst half of the 20th century—huge
amounts of weed killers, fertilizers, and
pesticides were dumped on the earth.
The dangers of degraded environmental
conditions were brought to the atten-
tion of the American public in 1962 with
the publication of the book Silent Spring
by Rachel Carson. The fi rst Earth Day
celebration, in 1970, also advanced the
foundation of ecological awareness.
Citizens called the government to
action. Key environmental legislation
included the Clean Air Act (1970),
the Clean Water Act (1972), and the
National Environmental Protection Act
(1970), which required that an Environ-
mental Impact Statement be prepared
for all projects receiving government
funding. The design team was required
to evaluate the natural, social, and
economic impact of a project and make
the plans available for review by the
community.
Ecological designers continued the
pioneering work of 18th-century bota-
nists and 19th-century conservationists.
Jens Jensen (1860–1951) was conscious
of environmental themes early in his
professional career. Jensen was born
in Denmark, immigrated to the States
in his early twenties, and established a
landscape design practice in Chicago.
He worked in the naturalistic style and
believed in the social benefi t of public
parks and recreational facilities. Jensen
was a transitional fi gure, infl uenced by
19th-century reformist ideals and 20th-
century Prairie Style design, as exempli-
fi ed by the work of Frank Lloyd Wright.
His sphere of infl uence was centered
around the Midwest, and his practice
consisted of large-scale residential proj-
ects and smaller urban parks. Jensen’s
palette was distinguished by his use of
native plants and local stone, inspired
by the natural meadows and woodland
plantings he treasured. His book Siftings,
from 1933, presented his ideology of
environmental design. He established a
“folk” school of horticulture and the arts
in Wisconsin, called the Clearing, in 1935.
An ecological ideology also drove Ian
McHarg (1920–2001) to advocate a
holistic approach to design. In his book,
Design with Nature (1969), he champi-
oned site analysis techniques based on
the carrying capacity of the land and
its fi tness to intended use. McHarg
developed a methodology based on coor-
dinated overlays of maps, which became
the foundation of geographic informa-
tion systems (GIS) technologies. He pio-
neered the analysis of opportunities and
constraints to assess the many social
and environmental costs of a project.
PIONEERING NEW DIRECTIONS
OPPORTUNITIES AND CONSTRAINTS:
McHarg developed the overlay analysis
process used in GIS.
PRAIRIE STYLE: Jens Jensen’s work fostered an ecological aesthetic.
20th CENTURY
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ENVIRONMENTAL AND ECOLOGICAL DESIGN