Transcript Are you getting your fair share? That depends on what bias

UFORE
Overview and Process
Overview & Process I
What is UFORE?
= Urban Forest Effects
Science-based computer model that
quantifies urban forest structure, functions,
and values
Collection of analysis tools
Specialized analysis for urban ecosystems
More at www.ufore.org
Overview & Process
Ecosystem
“Functional units of interacting abiotic, biotic, and
cultural (anthropogenic) components”
Includes all trees
 Public/private
 Native/exotic/”utopian”
No systematic management of individuals, but we
can manage the population
Population contributes to common good at much
lower cost/benefit ratio than street trees
Overview & Process
Status of UFORE
Fully operational as program
 Over 10 years in development
 In SAS code at FS Syracuse
 Direction: David Nowak, Project Leader
 Programmer: Dan Crane
 Being converted to desktop app (Windows)
i-Tree 1.0: UFORE “shell” makes
everything now much easier
Overview & Process
UFORE calculates
Structure, e.g.
 Leaf area and biomass
 Species and DBH distribution
Function, e.g.
 VOC emissions
 Pollution removal
 Effect on building energy use
 Total carbon stored
Value based on structure, function
1 metric ton (“tonne”) = 1.10231131 US (short) ton
Sounds like STRATUM…
Similarities
 Similar questions
 Structure, function, value
 Implications for management
 Similar goals
Differences
 Different populations
 STRATUM: street trees
 UFORE: whole ecosystem
 Some differences in methods,
often b/c of differing populations
Overview & Process
What good is it?
Aid planning and management
Improve forest designs
Project future impacts
Assess impact of catastrophic events
Justify programs
Source: http://www.houstonregionalforest.org/Report/
Overview & Process
How does it work?
Uses field data to calculate structure
Uses structure data to calculate
function
Uses function data to calculate value
Uses value data to draw conclusions
and make recommendations
The Devil lurks, as always, in the
details
Does this help? (Not!)
3 questions
I ask when evaluating models:
Do I understand the numbers?
Can I trust the numbers?
Can I use the numbers?
I want to drill down one level in
an effort to answer these
questions, “peek under the hood”
Overview & Process VI
Let’s examine one relatively *simple* set of
calculations: CARBON
Start with allometric¹ equations estimating
above-ground biomass from species and
DBH
¹ = relation of the growth of a part of an organism to
the growth of the whole
Convert with species-specific factor:
above-ground biomass  whole tree
biomass
Regression of DBH as predictor of biomass
http://www.greenhouse.gov.au/ncas/reports/pubs/tr05afinal.pdf
Overview & Process VI
Adjustment
 80% less biomass for open-grown urban
trees than regression formulae compute
 Based on field measurements of 30 street trees
(1994 Chicago study)
 Probably due to pruning
How much of biomass is carbon?
Stored C  biomass x 0.5
 Chow and Rolfe 1989, et al
Is this too MUCH??!!
http://tell.fll.purdue.edu/JapanProj/FLClipart/Adjectives/heavy.gif
Overview & Process VI
Use growth and mortality rates for annual
 Start with published and/or field data for each
species and DBH class
 Adjust growth (C storage) for
 Site (e.g., park 1.78 times less growth than street)
 Growing season length
 Condition of tree
 Adjust mortality (C release) for
 % of condition class
 Rapid release (above ground, populated areas)
 Slow release (below ground, unpopulated areas)
Growth - Mortality  net annual C storage
Overview & Process VI
Value
Multiply net annual stored C by
$22.80/tC
 Based on the estimated marginal
social costs of carbon dioxide
emissions (Fankhauser, 1994).
 Stochastic model provides a
distribution of outcomes from which
means can be calculated.
“Rough order-of-magnitude
assessment”
Nature 443 (October 5, 2006)
http://coreacademy.usu.edu/04_Materials/Clip_Art/
What’s the point?!
We can begin to understand and
therefore trust the numbers
Because of that, we can use the numbers
Advocacy
Strategic planning
Action
UFORE, like STRATUM, is a powerful
tool for promoting sustainable
management of urban forest resource.
Are
me?