Managing forests for
carbon storage
Bill Keeton
Rubenstein School of Environment
and Natural Resources
University of Vermont
What is the best way to increase
carbon storage in forest ecosystems?
• Intensified forest harvests, favoring fast
rates of uptake and storage in wood
products?
• Reduced harvesting intensity/frequency
and/or passive management (reserves)
favoring carbon storage in extant forests?
Aboveground Tree Biomass (Mg/ha)
Carbon storage in old and
structurally complex forests
400
350
R2 = 0.65
300
250
200
150
100
50
0
0
100
200
300
Dominant Tree Age (yrs)
Keeton et al. 2007. Ecological Applications
400
500
Biomass in Mature vs. Old-growth Forests:
Old Forests Store Large Amounts of Carbon!
Live Tree Biomass (Mg/hectare)
700
Mature
Old-growth
600
500
400
300
200
100
0
Northeastern USA
Pacific Northwest USA
Uholka, Carpathians,
Ukraine
Data Sources:
Ukraine: M. Tchernyavskyy and W. Keeton
U.S. Pacific Northwest: J. Franklin
U.S. Northeast: W. Keeton
Modified from: Schelhaas, M.J. et al. 2004.
CO2FIX V 3.1 – A modelling framework for
quantifying carbon sequestration in forest
ecosystems.
Figure from Ingerson. 2007.
Carbon residence time in wood products
Northern hardwood forests in the U.S. Northeast
1
Total products
Hardwood sawlogs
Fraction of carbon relative to time zero
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
10
20
30
40
50
60
70
Years after clearcut
Data from Smith et al. (2006). USDA
Forest Service GTR NE-343
Figure from Ingerson. 2007.
Modified from: Schelhaas, M.J. et al. 2004.
CO2FIX V 3.1 – A modelling framework for
quantifying carbon sequestration in forest
ecosystems.
Forest Biomass Fuel
Key: how will this be generated?
• Added harvest margin during regeneration harvest.
e.g. whole-tree harvesting or increased removal of
cull
• Stand improvement or thinning to harvest cull.
• Issues and concerns
Coarse Woody Debris in Northern
Hardwood Forests
• Habitat
• Nitrogen Fixation
• Soil organic matter
• Mycorrhizal fungi
• Nurse logs
• Erosion reduction
• Riparian functions
Even-aged
Single-tree Selection
Old-Growth
Figure from McGee et al. (1999)
Modified from: Schelhaas, M.J. et al. 2004.
CO2FIX V 3.1 – A modelling framework for
quantifying carbon sequestration in forest
ecosystems.
Key Points
• Forest carbon sequestration is not a silver bullet solution
• Sustainable forest management is one of many strategies:
– 10% of U.S. CO2 emissions are offset annually by sequestration in
forests
– Deforestation accounts for 20 to 30% of global greenhouse gas
emissions
• Sustainable forest carbon management can provide co-varying ecological
values
• There are management issues that must be resolved
Carbon Credits Through Forest Management
Kyoto Agreement:
•
Reforestation or afforestation (plantations established prior to 1990) in developing
countries
•
In developed countries, 5% of emissions can be offset through forest management.
Developing “Cap and Trade” Markets:
•
•
•
Reforestation/afforestation
Avoided deforestation
NEW! Credits for “improved forest management”
– Have to demonstrate “additionality” in carbon storage over baseline management
– Permanence and leakage issues
Credits for Active Forestry
Credits for Active Forestry
VMC - Vermont Forest Ecosystem
Management Demonstration Project
1. Single-Tree Selection
 BDq modified to enhance post-harvest
structural retention
2. Group Selection
 BDq modified to enhance post-harvest
structural retention
 Mimic opening sizes (0.05 ha) created by finescale disturbances (Seymour et al. 2002)
3. Structural Complexity Enhancement:
 Promotes late-successional/old-growth
characteristics
Mt Mansfield State
Forest
University of Vermont,
Jericho Research Forest
N
100
0
100
200 Meters
40
How much have we
accelerated growth rates?
Normalized cumulative BAI: “treatment BAI”
minus “no treatment BAI” at each time step
Keeton. 2006. Forest Ecology and
Management
35
Cumulative Basal Area Increment (m2 ha-1)
Cumulative
Projected Total
Basal Area
30
25
Structural Complexity Enhancement
20
Conventional Uneven-Aged
Control Units
15
0
5
10
15
20
25
30
35
40
45
50
6
5
4
3
2
1
Structural Complexity Enhancement
Conventional Uneven-aged
0
0
5
10
15
20
25
30
35
Projected Years
40
45
50
Silvicultural Options:
• Even-Aged/Multi-aged systems
Extended Rotations
300
Cubic ft./acre/year
Periodic annual increment
Mean annual increment
0
20
120
Stand age (Years)
From Curtis (1997)
Silvicultural Options:
• Disturbance-based/retention forestry
Aboveground Biomass (Mg/ha)
250
Normal Rotation
200
150
100
75 Mg/Ha
50
0
0
20
40
60
80
100 120 140 160 180 200 220 240 260
Stand Age (Years)
Aboveground Biomass (Mg/ha)
250
Normal Rotation
Extended Rotation
200
150
100
90 Mg/Ha
75 Mg/Ha
50
0
0
20
40
60
80
100 120 140 160 180 200 220 240 260
Stand Age (Years)
Aboveground Biomass (Mg/ha)
250
Normal Rotation
Extended Rotation
Normal with Retention
200
150
100
20
Mg/ha
50
0
0
20
40
60
80
100 120 140 160 180 200 220 240 260
Stand Age (Years)
Aboveground Biomass (Mg/ha)
250
Normal Rotation
Extended Rotation
Normal with Retention
Extended with Retention
200
150
20
Mg/ha
100
50
0
0
20
40
60
80
100 120 140 160 180 200 220 240 260
Stand Age (Years)
Silvicultural Options:
• Uneven-Aged
Stand Structural Complexity
Low
Intermediate
Diameter
40 cm max.
Low Carbon
Lower vol.
production but large
dimension sawtimber
# stems
Maximized large
sawtimber volume
and value growth
# stems
# stems
Maximized volume
production
High
Diameter
50 cm max.
Medium Carbon
Diameter
80-100 cm max.
High Carbon
400
NE-FVS projections run in NED-2:
Aboveground Tree Biomass (Mg/ha)
350
• “planting” to simulate regeneration
300
• Regeneration based on plot data
• Mixed species, proportions as sampled
250
200
178.9 Mg/ha
150
100
Uneven-Aged (Multiple Entries)
50
0
0
5
10
15
20
25
30
Years
35
40
45
50
55
400
Aboveground Tree Biomass (Mg/ha)
350
300
250
200
150
100
Uneven-Aged (With Treatment)
Uneven-Aged (Multiple Entries)
50
0
0
5
10
15
20
25
30
Years
35
40
45
50
55
216.6 Mg/ha
37.7
178.9 Mg/ha
Mg/ha
400
Aboveground Tree Biomass (Mg/ha)
350
300
292.3 Mg/ha
75.7 Mg/ha
250
216.6 Mg/ha
200
178.9 Mg/ha
150
100
Uneven-Aged Units (No Treatment)
Uneven-Aged (With Treatment)
Uneven-Aged (Multiple Entries)
50
0
0
5
10
15
20
25
30
Years
35
40
45
50
55
114.4
Mg/ha
400
Aboveground Tree Biomass (Mg/ha)
350
300
250
223.8 Mg/ha
216.6 Mg/ha
200
178.9 Mg/ha
150
100
Uneven-Aged Units (No Treatment)
Uneven-Aged (With Treatment)
SCE (Multiple Entries)
Uneven-Aged (Multiple Entries)
50
0
0
5
10
15
20
25
30
Years
35
40
45
50
55
59.9
Mg/ha
400
Aboveground Tree Biomass (Mg/ha)
350
300
251.6 Mg/ha
250
223.8 Mg/ha
200
150
100
Uneven-Aged Units (No Treatment)
SCE (With Treatment)
Uneven-Aged (With Treatment)
SCE (Multiple Entries)
Uneven-Aged (Multiple Entries)
50
0
0
5
10
15
20
25
30
Years
35
40
45
50
55
27.8
Mg/ha
400
Aboveground Tree Biomass (Mg/ha)
350
304.5 Mg/ha
300
292.3 Mg/ha
251.6 Mg/ha
250
223.8 Mg/ha
216.6 Mg/ha
200
178.9 Mg/ha
150
100
55.9
Mg/ha
SCE Units (No Treatment)
Uneven-Aged Units (No Treatment)
SCE (With Treatment)
Uneven-Aged (With Treatment)
SCE (Multiple Entries)
Uneven-Aged (Multiple Entries)
50
80.7
Mg/ha
0
0
5
10
15
20
25
30
Years
35
40
45
50
55
CO2fix Model Simulation:
Scenario = harvest for biomass only, northern hardwood stand,
UVM Jericho Research Forest
125
Carbon (Mg/ha)
100
Total carbon
sequestration +
emissions offset
75
Biofuel offset of fossil
fuel emissions
Soil carbon
50
25
0
100
Carbon in wood
fuel
200
300
400
Years
Data courtesy of Andy Book, Mike Thomas, and
John Shane
500
Carbon in
aboveground
biomass
600
CO2fix Model Simulation
Scenario = low intensity selection harvest for durable
wood products and biomass, northern hardwood stand,
UVM Jericho Research Forest
125
Total carbon
sequestration +
emissions offset
Carbon (Mg/ha)
100
Carbon in
aboveground
biomass
75
50
Soil carbon
25
0
100
200
300
Years
Carbon in
wood
products
Biofuel offset
Data courtesy of Andy Book, Mike Thomas, and
John Shane
400
500
Conclusions
• Even, multi-aged, and uneven-aged silvicultural
options are available for increasing net carbon
storage in managed stands.
• Options include:
– Longer rotations or entry cycles
– Post-harvest retention
– Modified uneven-aged approaches that promote
structural complexity and high biomass conditions
– Passive management: reserves that will develop high
levels of biomass