matt ritter
TRANSCRIPT
Arbor Day Foundation hardiness
zones reflect warmer climate
1990
2006
Climate Change Projections
% of Human Population
Biodiversity is diminishing at a rate even faster than the last mass extinction at the end of the Cretaceous Period, 65 million years ago, with possibly two-thirds of existing terrestrial species likely to become extinct by the end of this century — the vast majority of them unknown to science at the time they disappear - Peter Raven, 2011
Foreword by Peter Raven
What role can we play in helping the problems facing our planet and our future?
1. Work for more species diversity in California’s
urban forests
Origins of California’s Urban Trees
California Native Trees in Municipal Forests
• 9,100 species of plants in California
• ~6,000 native species• 294 tree species• 78 species are suitable for
urban environments• 20 species commonly used
in urban forests
Evolutionary
Relationships
Among California’s
Commonly
Cultivated Trees
Tree Species in the Urban Forest• All phyla and 83% of orders
with trees are represented in California
• Largest genera in California (most species):• Eucalyptus • Quercus • Acacia • Pinus • Acer
Diversity in Urban ForestsJ.C. Raulston’s Second Law
of Landscape Plant Diversity:
In any given region of the United States, 40 shrubs and trees make up 90% of the landscape plantings.
Diversity in Urban Forests
Muller and BornsteinArb. & Urb. For. 2010. 36(1): 18–27
309 species
Diversity in Municipal Forests• 188 – Average # of species on California
municipality tree surveys• 49 – Average # of species on California
municipality approved planting lists• Only 29% of existing species are approved for
future planting• According to Lawrence Lesser 15 species
account for ~50% of planted trees in Southern California
Lesser, L.M. 1996. Journal of Arboriculture 22:180–185.
Promote Diverse Urban Forests• Diverse urban forests are more resilient to
climate change• Diverse urban forests help conserve
biodiversity• Find undeservedly rare trees in your area• Work with cities and nurseries to grow and
plant more species• Experiment with new, appropriate trees• Add 10 new species to your cities approved
planting list
2. Learn your trees and teach
other people about them
“The average person recognizes more than 1,000 corporate logos, but can identify fewer than 10 plants and animals native to his or her locality.” - David Orr
Promote Tree Knowledge• Relearn the trees in your urban forest• Work on making your area’s tree inventory
accurate and up-to-date• Learn species characteristics and plant
appropriate trees• Learn the correct names of trees• Learn the natural history stories of trees• Share those stories with others
3. Promote a clear educational message
about the value of trees
Life without trees is a lower quality life.
Trees Sequester and Store Carbon
Nowak 1994, USDA FS Technical Report, Radnor, PA, pp. 83-94
Trees Reduce Energy Consumption
Carver, Unger, and Parks, 2004, Environmental Management 34: 650-655
Trees Cool Cities
Wilson et. al., 2003, Remote Sensing of Environment 86: 303-321
More Trees = More Wildlife
Donnelly and Marzluff, 2006, Urban Ecosystems 9: 99-117
More Trees Correlate with Lower Crime
Kuo and Sullivan, 2001, Environment and Behavior 33: 343-367 & 543-571
More Trees Correlate with Lower Crime
Kuo and Sullivan, 2001, Environment and Behavior 33: 343-367 & 543-571
More Trees Correlate with Lower Crime
Kuo and Sullivan, 2001, Environment and Behavior 33: 343-367 & 543-571
Trees Promote Happiness
Fuller et. al., 2007, Biology Letters 3: 390-394
Life without trees is a lower quality life.
Summary1. Work for more diversity in
California’s urban forests2. Learn your trees and teach
other people about them3. Promote a clear educational
message about the value of trees
The beautiful trees that grace our neighborhoods did not sprout at random. Tree-lined streets have been woven into a living fabric that shades and soothes our souls. In a real biological sense, trees are our home. That is the deepest meaning of the urban forest. - David Paul Bayles