Intensively Managing
Plantations for Carbon
Jianwei Zhang
PSW Research Station
Redding, California
Why do we care?
™ Global climate change is unequivocal
™ One of causes is an increase of greenhouse
gases (GHGs) due to human activities
™ Carbon dioxide (CO2) is the most important
anthropogenic GHG and has increased
significantly since 1750
™ Forest stores large amount of carbon (C)
™ Intensively managed plantations play an
active role in C sequestration and storage
1
Globally, forest stores 638 Gt of C, slightly
less than 760 Gt of C in the atmosphere
(1 Gt = 1 billion metric tons)
World
USA
Carbon Stock (Gt)
350
300
317
283
250
200
150
100
50
19
38
Live Biomass
16
7
0
Dead wood
Soils
Global Forest Resources Assessment (FAO 2006)
Million metric tons C/yr
Annual C sequestration by the US forests
equals 10% of US CO2 emissions
180
160
140
120
35%
38%
36%
Product
Biomass
Debris
Soil
100
80
60
40
20
0
1990
1999
2005
Year
Woodbury et al. (2007)
2
Why Intensively Managed Plantations?
Provide 1/3 the
world’s wood supply
Plantation forests
(≈140 million ha) 3.8%
World Forests
≈ 4 billion ha
Global Forest Resources Assessment (FAO 2006)
Loblolly pine
Eucalyptus
3
Cottonwood
Ponderosa pine
McCloud 87-yr-old
Show plantation
Fountain Fire large-scale
14-yr-old plantations
Whitmore small-scale
21-yr-old experiment
4
The Whitmore Garden of Eden
HF
F
FI
HFI
HF
Ctrl
F
H
HI
H
I
HFI
Ctrl
HF
F
H
The Whitmore Garden of Eden
HF
HF
F
Ctrl
F
H
HF
Ctrl
F
H
HF
H
Ctrl
F
H
Ctrl
5
Whitmore measured volume:
(1 m3/ha = 14.3 ft3/ac)
HF at age 15
HF_ ob s
H_ obs
400
F _ obs
Ctrl_ ob s
300
200
172
40
0
0
10
20
30
40
50
Stand age
Control at age 15
118
94
100
Let’s extend predictions to 50-yrs at all
treatments:
500
Stem volume (m 3 /ha)
Stem volume (m 3/ha)
500
HF_ m
HF_obs
H_ m
400
H_ obs
F_m
300
F_obs
Ctrl_ m
Ctrl_ obs
200
100
0
0
10
20
30
Stand age
40
50
6
C
TRANSLATING TO BIOMASS
OR C MASS ISN’T EASY
There are more !C
Lateral roots can be long
Forest floor is massive
Sinker roots can be deep
7
C
Understory shrubs
are big part of forest C
WHITMORE: WILDFIRE EXCLUDED
300
5 Mg/ha/yr
TREES
Mg CARBON ha-1
250
SHRUBS
FOREST FLOOR
200
ROOTS
150
100
50
0
C H HF
C H HF
C H HF
C H HF
C H HF
10
20
30
40
50
PLANTATION AGE (yrs)
8
WHITMORE: WITH WILDFIRE
300
TREES
Mg CARBON ha-1
250
SHRUBS
FOREST FLOOR
200
ROOTS
150
100
50
0
C H HF
C H HF
10
20
C H HF
C H HF
30
40
C H HF
50
PLANTATION AGE (yrs)
WHITMORE: WITH WILDFIRE
300
TREES
Mg CARBON ha-1
250
SHRUBS
SACRIFICED CARBON
FOREST FLOOR
200
ROOTS
150
100
50
0
C H HF
10
C H HF
20
C H HF
30
C H HF
40
C H HF
50
PLANTATION AGE (yrs)
9
How about old plantations?
Show Plantation (1919 – present)
™ McCloud Ranger District
™ Lat 41.32oN, Long 121.98oW, elev 3900’
™ SI = 80 ft at age 50
Compare to a natural
stand at Edson Creek
120-yr-old Natural Stand
87-yr-old Show Plantation
10
Both stands were thinned to
different densities in 1971
(Show plantation example)
Measured (70%)
Measured (40%)
800
600
Before thinning
After thinning
400
200
0
0
20
40
60
80
100
Stand age
Show vs. Edson at age 87
Live tree carbon (Mg/ha)
Stem volume (m 3/ha)
1000
Dead
450
Harvested
400
Current
350
300
250
200
150
100
50
0
Show
Edson
11
Fountain Fire Plantation
Managed
Unmanaged
Live tree C with 3-PG predictions with
inputs used at Whitmore H & Ctrl:
Live tree carbon (Mg/ha)
300
Veg Control
250
No Veg Control
200
150
100
50
0
0
10
20
30
40
50
60
70
Stand age
12
What about natural stands?
(regional estimates for mixed conifer in this region)
(Smith et al. 2006, FS GTR-343, Northern Research Station)
Live tree carbon (Mg/ha)
300
Veg Control
No Veg Control
250
FORCARB2
200
150
100
50
0
0
10
20
30
40
50
60
70
Stand age
Conclusions
™ Intensively managed plantation (IMP)
sequestrates about 100% more
carbon than unmanaged plantation
™ If wildfire is considered, 600% more
carbon was sequestrated by IMP than
by unmanaged plantation at age 50
™ At longer rotation age, MP stores 60%
more carbon than natural stand; these
real data prove our model predictions
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Carbon stock (Mg/ha) if climate is
drier or wetter
Precipitation and ASW
Site (age)
-25%
0
+25%
94 (-12%)
107
116 (+8%)
Veg. C
180 (-8%)
195
201 (+3%)
No Veg. C
116 (-1%)
117
117 (0%)
Veg. C
229 (-2%)
234
234 (0%)
No Veg. C
133 (-6%)
142
148 (+4%)
Veg. C
223 (-14%)
258
258 (0%)
Whitmore (50) No Veg. C
F. Fire (70)
Show (87)
Thank you!
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