seeing the urban forest for the trees
TRANSCRIPT
Seeing the Urban Forest
for the TreesDavid J. Nowak
US Forest Service
Syracuse, NY
Early Morning Test – What is this?
Perception of ValueWe take care of things we value
New red car – What are you willing to pay?
Ferrari 488 GTB - Features: Twin-turbocharged 3.9-liter V8, 660 horsepower
Yugo - Features: Rear-window defogger so owner can keep hands warm while pushing vehicle
Five General Messages about Urban Forests
There are global problems
UrbanizationWorld = 54% urban (3.9 billion urban inhabitants)
By 2050 = 66% urban (6.4 billion urban inhabitants)
www.globalchange.umich.edu
Projected urban land increase (2010-2060):+2 million acres/year
Urban land (conterminous U.S.)
2010 = 67.8 million acres (3.6%)
2060 = 163.1 million acres (8.7%)
Increase greater than size of Montana
Urban population increase
Approximately 90% urban population (2060)
Delaware land area = 1.2 million acres
Growth in Percent Urban (2010 – 2060)
Urbanization Issues – Energy Use
One trillion BTU =~ 250,000 tonnes of TNTDaily world energy use = 60 million tons of coal
= pile of coal: 10 ft x 1 mile x 4.4 miles
theenergyharginger.com
Urbanization Issues – Air Pollution3.7 million deaths from outdoor air pollution (2012)
World’s largest single environmental health risk
Air pollution mortality (2010) – Nature, 2015
Urbanization Issues - Others
Increased air temperatures
Water flow / quality issues
Crowding
Stress…
Source: NASA: Bright red = 65oC; Dark green / blue ~ 25oC
Five General Messages about Urban Forests
There are global problems
Trees can help
Tree Benefits - TangibleShade / Cool Air
Aesthetics
Wildlife
Tree Benefits – Less TangiblePocket book ($)
Altered building energy use / altered emissions
Products (26M t wastewood/yr), jobs
Human Health
Water quality
Air quality, UV radiation
Physiological changes
Environmental Quality / Regulations
Air quality, water quality, carbon, air temperature
Other
Biodiversity, neighborhoods, crime…
Tree CostsMaintenance / planting / removal
Leaf clean-up
Damaged sidewalks
Blocked views
Branch drop
Crime perception
Pollen
Increased energy use
VOC emissions
Maintenance emissions, pesticides, excess fertilization
Annual U.S. Urban Forest Values > $18 billion/yrAvoided energy use = $7.8 billion*
39 million Mwh/year; 246 million MMBTU /year
Air pollution removal = $4.7 billion
717,000 tons/year; ~580 avoided deaths / year
Carbon sequestration = $3.7 billion
29.4 million tons / year
Avoided emissions = $2.2 billion*
21.5 million t CO2; 93,000 t pollutants /year
Oxygen production = $0
75 million tons per year
Total = $18.4 billion
$770 per acre of tree cover *preliminary results
Five General Messages about Urban Forests
There are global problems
Trees can help
Nature and people interact
Tree Cover Urban / Community Land
~80% of U.S. urban land is within forested areas
Nature and Humans
What percent of trees in cities are planted?
Nowak, D.J. 2012. Contrasting natural regeneration and tree planting in 14 North American cities. Urban Forestry and Urban Greening. 11: 374 – 382
Planting varies by city population density and region
Nowak, D.J. 2012. Contrasting natural regeneration and tree planting in 14 North American cities. Urban Forestry and Urban Greening. 11: 374 – 382
Percent planting varies by land use
Nowak, D.J. 2012. Contrasting natural regeneration and tree planting in 14 North American cities. Urban Forestry and Urban Greening. 11: 374 – 382
Percent of Total Tree Cover in Cities by Land Use
Forest(40% TC)
Grass(20% TC)
Desert(10% TC)
Why Don’t We Have More Urban Trees?
Why Don’t We Have More Urban Trees?
It is expensive to keep trees out
US mowing ~$49-134 billion / year
Why Don’t We Have More Urban Trees?
It is expensive to keep trees out
Five General Messages about Urban Forests
There are global problems
Trees can help
Nature and people interact
Costs are unavoidable
Costs are Unavoidable
People in association with trees = costs
Goal = reduce costs; increase values
No trees ≠ no costs
Costs of gray infrastructure and mowing
What if we didn’t maintain gray infrastructure?
What if we didn’t maintain gray infrastructure?
Five General Messages about Urban Forests
There are global problems
Trees can help
Nature and people interact
Costs are unavoidable
Change is coming
Major Drivers of Change in the Future
Development
Major Driver of Change in the Future
Development
Climate Change
Major Driver of Change in the Future
Development
Climate Change
Insects and DiseasesEmerald ash borer range (2013)
Ash dieback (Hymenoscyphusfraxineus)
Major Driver of Change in the Future
Development
Climate Change
Insects and Diseases
Invasive species
Tree Cover Change
In the U.S., urban tree cover dropping:
20,000 acres per year
4.0 million trees per year
Steps to SustainabilityAssess resource – what do you have?
Understand resource – what can it do?
Plan – what do you want?
Right location, right tree, right time; across scales
Implement Plan
Monitor – did you get there?
Demonstrating Tree Value
Summary
[email protected] nrs.fs.fed.us/units/urban
Trees and forests provide significant value to society
Understanding and communicating the resource value is essential to improve management and community well-being