Impact of forest policies to promote
new plantations and stand density
increase in future availability of cork
in Portugal
Margarida Tomé, Joana Amaral Paulo,
João H N Palma
Universidade Técnica de Lisboa
Instituto Superior de Agronomia
Centro de Estudos Florestais
 Outline
 Brief introduction to cork oak in Portugal
 The SUBER model and the STANDIS simulator
 The scenarios/policies
– Stand density increase
– New plantations
 Results
– Cork oak production
– Carbon sequestration
 Conclusions and future work
Brief introduction to cork oak in
Portugal
The cork oak system in Portugal
 Traditional cork oak stands are usually managed as an
agroforestry system, with a relatively small number
of trees per ha (sparse forest)
The cork oak system in Portugal
 Traditional cork oak stands are usually managed as an
agroforestry system, with a relatively small number of
trees per ha (sparse forest)
Stand type
Area
(103 ha)
N trees
(ha-1)
G
(m2 ha-1)
Crown
cover
Pure
548
66
4.9
18
Mixed, cork oak dominant
121
47
3.5
13
Mixed, other sp dominant
85
41
2.4
9
Young plantations
47
-
-
-
The cork oak system in Portugal
 The main product is not the wood but the cork (bark)
Tree production per harvest
7 - 11 kg / m2 debarked area
Up to 150 kg per tree in one harvest
After extraction, the cork is usually stored in
the farm in large stacks
14
The cork oak system in Portugal
 Cork oak stands may be managed for cork
production as the main objective (70%)
The cork oak system in Portugal
 But they can also be managed as a silvo-
pastoral system (30%)
The cork oak system in Portugal
 Large areas of new plantations have been
established in the last years
The SUBER model
 The SUBER model
 Individual tree model
 Statistical model (growth and yield model)
 Makes the synthesis of available knowledge to
support forest management decisions
 Allowed for the identification of gaps in the
knowledge
 It is connected to a data base of economic
data (mainly CAOF) that allows
computation of socio-economic indicators
the
SUBER model – modules
 Estimation of site productivity
 Model
initialisation
–
the model simulates
characteristics that are not available from forest inventory
the
 Simulation of the growth of each tree (individual tree
model)
 Simulation of cork parameters – cork growth, evolution of
cork thickness, cork weight prediction, cork quality
 Simulation of silvicultural practices
Thinning (uniform system, selection system)
Regeneration
 Non-cork products and services
Stages of tree development
h=3.00 m
Regeneration
Juvenile
Intermediate
Mature
Present status
of the stand
Number of trees (ha-1)
40
2003
30
Net present value ha-1
13975.1
20
10
95
85
75
65
55
45
35
25
<7.5
15
0
Diameter class (cm)
Year
2030
2040
50
8
7
6
2010
2020
2030
2040
40
35
2010
2020
Year
Year
2030
2040
100
2026
2030
2035
2039
2044
)
7
6
2008
2012
2017
2021
Diameter class (cm)
2030
2035
2039
Net present value ha-1=16238
2050
35
2010
2020
2030
Year
100
2044
2003
2048
2008
2012
2017
2021
20
Number of trees (ha-1)
40
2035
2039
2044
2048
50
2028
40
30
20
10
95
85
0
<7.5
0
75
95
85
75
65
55
45
35
25
Diameter class (cm)
60
65
20
2030
Mature
50
2052
80
55
40
2026
Year
45
60
<7.5
95
85
75
65
55
Diameter class (cm)
2040
40
200
100
2028
80
0
0
2050
45
30
2000
2050
Virgin
35
10
Number of trees (ha-1)
20
45
95
85
75
65
55
45
35
25
15
<7.5
0
35
10
30
25
20
2040
Mature
100
2052
40
15
30
Number of trees (ha-1)
50
2028
40
2026
Virgin
Mature
<7.5
50
2030
Year
15
Virgin
2020
2040
0
2003
2048
Year
25
2021
15
2017
Number of trees (ha-1)
2012
-1
50
8
2010
2030
300
<7.5
2008
2020
Year
55
0
2003
2010
Year
200
0
50
2000
2050
9
Year
Cork weight (15 kg)
Cork weight (15 kg)
100
2040
10
5
2000
2050
300
200
Number of trees (ha-1)
45
30
2000
2050
Stand density (ha
-1
55
9
5
2000
2050
300
Cork weight (15 kg)
10
2030
Year
Diameter class (cm)
Diameter class (cm)
Net present value ha-1=13539
2052
40
30
20
10
0
95
2020
2020
85
2010
2010
75
40
2050
65
45
2040
55
50
2030
Year
45
55
30
2000
2050
2020
35
2040
2010
95
2030
2050
70
25
60
35
2020
2040
85
6
2030
75
7
Mean crown diameter (m)
Percent crown cover
8
2010
2020
Year
65
9
5
2000
2010
90
15
2050
Percent crown cover
2040
70
10
Mean crown diameter (m)
2030
Year
Number of trees (ha-1)
2020
Gu
110
<7.5
2010
0
2000
65
2050
50
2000
55
2040
Year
Gu
G
45
2030
G
0
2000
5
35
2020
50
2000
70
10
25
2010
Gu
Percent crown cover
0
2000
5
90
130
15
15
G
5
70
10
110
Mean crown diameter (m)
10
90
20
130
15
Stand density (ha
Basal area (m 2ha -1)
)
-1
15
110
)
20
130
20
Stand density (ha
Basal area (m 2ha -1)
25
FMA OPTION 3
FMA OPTION 2
Basal area (m 2ha -1)
FMA OPTION 1
Diameter class (cm)
Net present value ha-1=14174
The STANDIS simulator
 The STANDsim simulator
 is a computer program that uses forest
models to predict the evolution of a set of
plots within a certain area (management unit,
region, country)
Forest inventory
Plot1
Plot2
....
Forest
Plot management
n
alternatives
FMA1
FMA2
....
FMAk
STANDsim
Evolution of the
plots over a
planning horizon
 The STANDsim simulator
 it
computes a series of indicators of
sustainable forest management for each plot
and for the whole area
– Economic
– Social
– Environmental
 The SUBER model is one of the models
implemented in STANDsim
The scenarios / policies
 Objectives
 Study the impact of forest policies to
– Increase cork production
– Increase carbon stock and carbon sequestration
– Increase employment
 Four scenarios/policies:
– Buisiness as usual
– Increase stand density in existing stands
– Promote new plantations
 Details on the scenarios
1. Buisiness as usual
– Keep the percent cover found at the inventory,
replanting of burned areas and of areas with all
trees dead
2. Increase density to 58% in stands managed for
cork
3. 2 plus increase density to 40% in stands
managed with grassland under the trees
4. 2 + 3 plus 5650 ha of new plantations between
2015 and 2021 (new PAC)
Results
Cork
production
Carbon
stock
 Conclusions
 Forest policies to promote new plantations and
to increase stand density may have a strong
impact
on
cork
production,
carbon
sequestration and employment
 Forest models and simulators are powerful
tools to support decisions on forest policies
Questions
?