Measuring the climate benefits
from California’s forests:
Challenges and Opportunities
California FIA Client Meeting May 2008
Bill Stewart
UC Forestry Specialist
stewart@nature.berkeley.edu
510.643.3130
California and our Forests
• We love our trees AND buy lots of cheaper wood from
PNW and BC
• We import over 75% of our wood products from our
neighbors, even a higher percentage than our electrical
imports (imports create ½ of our electricity-based carbon
signature)
• We have very high inventories on government lands
compared to Oregon and Washington and now to beetletagged British Columbia
• About ½ of our private forestlands do not have timber
harvests in their near term management scenarios
• Less than ¼ of our private timberlands are managed in
even aged rotations that are considered the forest
management norm by our northern colleagues
TIME April 25,2008
Trees are the
image of anti-CO2
But many focus on
park-like trees
rather than working
trees
Two Very Different Types of
Benefits
1. In-forest benefits + ε (fire, insects, drought, etc)
2. In-product benefits (a function of
– how much of the potential product lifetime is utilized,
– displacement of more energy intensive alternatives,
– what happens to products after use (landfill, bioenergy,
uncontrolled decomposition)
™ Only national-level accounting will avoid offset shell
games (FIA data is crucial on #1, less so on #2)
Challenges to Modeling
• Fire, insect, disease and drought
mortality factors appear to be
increasing in California
• Infrastructure and businesses needed
to conduct forest treatments that could
reduce risks are shrinking
Opportunities for Modeling
• FIA data provides plot-level info for all
ownerships
• FIA data can be converted into continuous
coverages
• Digital parcel data and ownership characteristics
can be used to develop continuous coverages of
forest management behavioral classes
• FVS variants, ArcFuel, Biosum can run on tree
lists and vegetation/fuel class labels from FIA
New Tools to Go from Fuel Hazards to
Catastrophic Fire Risks
US Forest Service ArcFuels: modeling a fire from road on SW side
Arrival
time
Fire size
potential
High Hazard
BUT
Lower Risk
Burn probability
Fire flow paths
Disturbances alter CO2 fluxes and
need to be included
• Managing to reduce disturbance related
CO2 fluxes often appears too expensive or
counter-intuitive
• Fire risk and other density dependent risks
can be altered with management but will
require expenditures
• 1000’s of decision makers control family
forests – a huge variable
A Very Large Forest Disturbance:
Mountain Pine Beetle in BC and Beyond
Massive Quantities of Dead Trees
and Slash will Decompose: Unlike
Post-Hurricane Cycles in SE USA
Fluxnet Data Trend
Standard Forestry
Textbook Volume Curve
More CO2 losses
Similar
Slower dropoff
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