PROGRAM
SYNOPSIS
The data reported
here came out of a pilot study performed by 8th grade students in Portland,
Oregon, during 1998.?The program is continuing through Fall, 1999 with two high
schools and three middle schools.?The goal of the program is to educate youth
about urban ecosystems within the context of an over-looked, everyday segment of
the urban ecosystem -- the street trees -- and how the trees relate to other
entities within the urban environment.?The major steps in the program for the
students include:
- Learning fundamental concepts of botany and
ecology, as related to the urban forest.
- Performing a street tree inventory and developing
a computer database of their findings.
- Analyzing their data preparing a written that
outlines findings and recommendations.
- Reporting their data and promoting their
recommendations to the local community.
THE URBAN FOREST
CONTINUUM
The urban forest consists of a variety of
vegetated sites that fall along an ecological continuum. At one end of the
continuum is a diverse, multi-layered forest composed of a soil layer, ground
covers, shrubs, small trees, and an upper canopy. At the other end of the
continuum is a landscape of isolated trees over a nearly continuous surface of
concrete and asphalt, frequently surrounded by a canyon wall of
buildings.
Typical urban features along the continuum
include:
- natural / native forest remnants
- naturalistic park environments
- yard plantings
- landscaping around commercial buildings
- parking lot plantings
- street trees
In addition to their role as aesthetic and psychological
elements of an urban area, the ecological values of trees are
substantial:
- micro-climate moderation
- storm water interception and retention
- wildlife habitat
- carbon sequestering
- oxygen production
For many people, the most visible portion of the urban
forest is the street tree segment.?While few people would likely think of
street trees when the subject of ecology is raised, this segment of the urban
environment offers a readily-accessible "field site" with great potential for
illustrating urban ecology process to students.?
STEPS IN THE EVOLUTION OF THE
INVENTORY METHODOLOGY
The methodology has evolved from what was
originally conceived as an adult volunteer program aimed at educating the public
about the ecology of the urban forest, to a largely school age program that
works with students in grades 7-12.
1993 Portland State University students in an
Urban Forest class perform
a pilot inventory.
1994 A graduate student implements a methodology that
georeferences
the data to a
GIS-based digital map.
1995 A graduate
student coordinates a full-scale implementation and
analysis for a community of 13,600
people.
1998 Eighth graders from
Portsmouth Middle School collect and analyze
street tree data in the Cathedral Park
neighborhood.
1999 The program is
expanded to include a total of five middle and high schools.?
UNDERSTANDING URBAN ECOLOGY
THROUGH STREET TREES
The education process begins with traditional
lecture and demonstrations on topics such as:
- Water, Light and Soil / Nutrient Needs of
Plants
- Tree Structure and Growth
- Soils / Compaction / Stress of Tree Roots
- Proper Pruning / Maintenance / Tree Health
- Plant-People Conflicts (e.g., overhead wires,
street signs, root-lifted sidewalks)
- Diseases and Pests / Tree Health
- Species Site Selection / Right Tree in the Right
Place
The student's understanding of
the traditionally-learned material is reinforced and amplified through the
inventory and analysis experience:
- Field Observation
- Discussion of the Range of Observed
Situations
- Data Recording
- Data Entry
- Analysis, Discussion and Recommendations
- Formal Written Report and Oral
Presentation
ECOLOGY?CONCEPT:?SPATIAL
PATTERN
An important aspect of the data compilation
process is the ability to enter the data to a Geographical Information System
(GIS). The manipulative ability of a GIS means that a variety of map themes are
possible, such as maps by species, or tree size, or health
condition.
This example presented here illustrates the
potential value of the map as visualization tool for identifying patterns and
assisting in analysis.
In addition to the educational value, the tangible
nature of the physical map product can capture the interest of students and
serve as a motivator.
