Shaded Fuel Break

Reserve






Most of Blodgett harvested in 1913, ~6 trees
per acre left
No management except fire exclusion
Light reaching floor = 6% of what hits canopy
Soil moisture depleted by August
Strong shift in spp. composition to WF and IC
Multiple max fire free intervals skipped
Tradeoffs:
 Good volume production but little
regeneration of shade intolerant species
 Low overall biodiversity but presence of some
“old growth” species
 Low water yield, but high water quality
 No severe wildfires yet, but fuel load is high
and severity predicted to increase in future
 High density = high volume growth, but
individual tree vigor is low
80
20
0
2
Reserve
Thin from below
40
Single tree selection
60
Diameter limit cut
% mortality at 80th percentile weather
Predicted wildfire behavior among management styles

Diameter limit cutting
A suite of treatments to reduce fire hazard:
prescribed burn, pile and burn, masticate,
commercial thin, species preference
Treatment interval ~ 10 years
Tradeoffs:
 Non-commercial treatments are expensive, but
risk of catastrophic loss is extremely low
 Timber production may decrease in future, but
individual tree vigor and resilience against
climatic stress is high
 Mechanical disturbances are imperfect
surrogates for fire, but frequency matches pre
Euro American settlement frequency and
treatment risk is low
 Snag density is low, but aesthetic value is high

Cut the big trees. Wait 15 years, then cut the big
trees again
 Common on small forest ownerships
Tradeoffs:
 Short term profit is high, but long term
Growth is
+ yield
productivity
low:- merchantable volume
1.6
1.4
MBF acre-1 year-1
Stop 1 - Reserve and Shaded Fuel Break
1.2
1.0
0.8
0.6
0.4
0.2
0.0
diameter limit cut
single tree selection
Stop 2 - Single tree selection and diameter
limit cutting
Single tree selection
 Harvest occurs every 10 years
 Light reaching floor after harvest = 32% (12%
right before harvest)
 Groups of trees cut to regenerate all species
Tradeoffs:
 Good stand productivity, but higher logging
costs and higher logging damage
 Little regeneration of pine species, but new
approach might work
 Fire hazard high, but new approach might
work (gap treatments reduces surface loads by
50%)
 Slow but steady income
 As with other methods, treatments can be
modified to meet specific objectives
3
low thin
reserve
treatment
Stop 3: 1- and 11- yr old clearcut





All trees cut : 3 to 20 acre patches
Site prepared with pile and burn
6 species planted, hardwoods encouraged
Use of herbicide and mastication in young stand
Research value has been high
Tradeoffs:
 Fire severity low, except from 10 to 30 years
 Mixed species is good financial hedge, but
uncertainty in mixed species management
 Young tree growth is rapid, but requires
herbicide
 Aesthetically extreme (love/hate relationship)
 High short-term income, but requires long-term
investments
 Highest total species richness, but more exotics
4
Proportion of total number of species (%)
Total diversity and exotics increase with canopy
openness, but late seral species diversity declines:

60
40

20

reserve
single-tree
shelterwood
group
0
plantation
Treatments = control, mechanical thin,
prescribed fire, thin + prescribed fire
Blodgett Forest Research Station
UC Center for Forestry
Tradeoffs
 Treatment costs of initial treatments
o Mechanical earned $1134/acre
o Mechanical + burn earned $887/acre
o Burn only cost $300/acre
o Mortality of large trees in mechanical +
burn and 2nd burn only treatment
% late-seral
% early-seral
% exotic
80
Stop 5 – Fire and Fire Surrogates


Stop 4: Mature clearcuts (thinned)
 Commercial thin ~ 30 years, then periodically
until 100 years
 Young stand investments realized after 2nd
thin
 Whole tree yarded to reduce fire hazard
Post treatment fire severity: Mech+Burn <
Burn < Mech < Control
Carbon loss: Mech+burn > Burn >> Mech >
Control
(Risk of future carbon loss is opposite)
Fires resulted in net loss of nitrogen, but also
resulted in pulse of nitrogen fixing plants
Soil compaction in mechanical treatments, but
limited to skid trails
Seedling response
 Fire treatments resulted in large pulses of seedling
germination:
Tradeoffs:
 Hedge-betting versus big payoff: low versus
high tree diversity
 Whole tree yarding expensive, but fire hazard
low
 Fire hazard low, but landings (and piles) large
 Biomass could produce energy, but no plant is
nearby
5
Blodgett Forest Management: Basic concepts
1. Implement a gradient of management alternatives
(experimental treatments)
2. Replicate each treatment (statistical power)
3. Monitor effects over time (data collection)
4. Diversify structure to diversify research
How it has worked:
 Established a self-sustaining and relatively
productive research station
 Attracted much research, both basic and applied
 Basic framework is in place for understanding
how different forest structure will interact with
an uncertain future.
 Outreach and demonstration value is strong
How it has been limited:
 Physical limit of studies to the stand scale (not
enough acreage for landscape scales)
 Context of research is “working forest,”
although reserves do offer an important “handsoff” treatment alternative
6
1