Transcript GEOG 346: Day 13

Open Space, Green Space, and Green
Infrastructure
Housekeeping Items

 These dates for this week are incorrect on the outline.
They should be February 17 and 19th. Remember to
reference image sources in projects.
 Any questions about the self-guided field trip?
 The first article, by Ken Tamminga, focuses on the
challenge of restoring ecological health, diversity, and
integrity in an urbanizing region. The author starts with
some definitions: “Ecological health is a capacity of the
land (and all its organisms) for self-renewal. Ecological
integrity is the capacity of an area to support and
maintain assemblages of organisms that have a
composition and functional organization comparable to
that of the region’s natural habitat.”
Urban Ecology

 Tamminga seems to argue that, in the past, planners
and other decision-makers have assumed that
urbanization necessitated a policy of ecological nihilism
– the eradication of ecological function in
undeveloped areas (what developers have cavalierly
referred to as “raw land,” much as a painter might
see a plain canvas as a ‘blank slate’ to be worked up).
This can be witnessed in Nanaimo to the present day.
 He also notes that remnant natural areas are usually
too small to maintain ecological processes and
biodiversity.
Urban Ecology

 Tamminga seems to argue that, in the past, planners
and other decision-makers have assumed that
urbanization necessitated a policy of ecological nihilism
– the eradication of ecological function in
undeveloped areas (what developers have cavalierly
referred to as “raw land,” much as a painter might
see a plain canvas as a ‘blank slate’ to be worked up).
This can be witnessed in Nanaimo to the present day.
 He also notes that remnant natural areas are usually
too small to maintain ecological processes and
biodiversity.
Urban Ecology

 Impacts of society on nature in an urban context:
 Removal of vegetation (especially forests)
 Removal of topsoil and compaction thereof
 Filling in of wetlands (which, together with forests, etc.,
removes and/or fragments valuable habitat)
 Elimination of riparian areas, thus compromising wildlife
movement corridors and fish habitat
 Introduction of exotic species
 Channeling and/or culverting of streams
 Reduction in infiltration capacity of the soil, leading to a
diminution of groundwater resources, and more…
Urban Ecology

 Forests, which have an immense practical value in an
urban context, can be largely maintained, rather than clearcut to be replaced with lollipop trees.
 Soil can be stockpiled and then returned to construction
sites.
 Wetlands can be retained and turned into an amenity
feature, and stormwater retention and purification
systems.
 Setbacks can be rigorously enforced in riparian areas.
 Exotic species can be removed.
 Streams can be kept on the surface or daylighted.
 Infiltration capacity of surfaces can be maintained.
Conservation Subdivisions and
Urban Forests
In a conservation subdivision,
there are supposed to be an
equal number of homes as in a
standard subdivision, but on
smaller lots.

Soil Retention and Wetland
Conservation

Riparian Setbacks and Corridors

Eradication of Exotics

Daylighted Streams

Cheonggyecheon River in Seoul, South Korea
Maintaining or Adding
Infiltration Capacity

Urban Ecology

 See p. 245 for Tamminga’s distinction between
anthropocentric and biocentric values. Where do you
find yourself on this spectrum?
 Some barriers to taking more of an ecosystem approach
include:
 The sanctity of private property
 The “silos” in which decision-makers find themselves
 The lack of support for more proactive planning by the
public and/or an ambivalence towards have more
natural elements woven into the urban fabric.
 Others?
Urban Ecology

 Tamminga suggests a specific model involving
relatively robust ecological cores and corridors linking
these that allow migration from one to another, and the
repopulation of areas low in species diversity or in need
of mates of reproduction.
The corridors can also serve as alternative
transportation greenways. The idea is not
new but goes back to Frederick Law
Olmsted, the creator of New York’s
Central Park. At least in the 1990s,
Markham, Ontario was one community
committed to applying a variation of this
model.
Urban Ecology

 One example of an
“urban wilderness”
park is Rouge River
Park in northeast
Toronto. It is over 40
square km in size
and stretches from
the Oak Ridges
Moraine 50 km north
of Toronto to the
wetland estuary at
the mouth of the
Rouge River.
Urban Ecology

 The park is home to 17
federally endangered
species, more than 225
birds, 25 reptiles, and 30
mammal species. In
addition, there are 800
flora, a quarter of all
those to be found in
Ontario.
 The park also
incorporates cultural
heritage – evidence of
past settlement.
The Watershed Approach

 Tamminga makes
reference to the
“watershed
approach” as a
unifying concept for
ecological planning.
 Experts have noted
that once 10% of a
watershed loses its
permeability, its
health is
compromised.
Stewardship

http://www.railforthevalley.com/wpcontent/uploads/2011/03/ReallyBigMap.jpg
 Fern Heitkamp’s article focuses on stewardship. She talks
about the region of the Fraser River from Vancouver to Hope,
and how much of the habitat for salmon has been destroyed in
the last century-plus (see her description of the changes on p
251).
 She offers a definition from Fisheries and Oceans Canada that
“Stewardship refers to co-operative forms of planning and
management of environmental resources in which all users and
managers share the responsibility for management and
conservation… [see the rest]”
Stewardship

 Not only has habitat been lost but, in cities like Richmond,
which had vast quantities of high quality of farmland –
itself a product of diking and removal of wetlands – large
quantities of agricultural land have been lost:
www.youtube.com/watch?v=c8rZtC6vblE
 Hietkamp’s five stewardship lessons are that 1) It
involves a commitment to cooperation and partnership; 2)
It is essential for the health of humans and fish; 3)It in
involves comprehensive planning for human settlements;
4) Community groups and non-government organizations
(NGOs) are essential to realizing its goals, and 5)
Stewardship requires strategic planning.