Maximizing the profitability of forestry projects under the Clean Development Mechanism using a...
-
Upload
independent -
Category
Documents
-
view
4 -
download
0
Transcript of Maximizing the profitability of forestry projects under the Clean Development Mechanism using a...
Maximizing the profitability of forestry projects under the Clean
Development Mechanism using a forest management optimization model
Vıctor Hugo Gutierrez *, Mauricio Zapata, Carlos Sierra,William Laguado, Alı Santacruz
Research Center on Ecosystems and Global Change, Carbono & Bosques (C&B),
Calle 51 # 72-07, Int. 708, Medellın, Colombia
Received 14 September 2005; received in revised form 3 February 2006; accepted 3 February 2006
Abstract
Forestry projects under the Clean Development Mechanism (CDM) may provide several benefits for developing countries. Under the current
rules, these projects can participate in both timber and carbon markets. Thus, project developers need to know what the optimal forest management
design would be to maximize their revenues according to timber and carbon market expectations while at the same time complying with
international rules adopted for carbon sequestration projects under the CDM.
We developed Carbomax, a management optimization model that simulates forest growth under different forest management regimes (intensity
and frequency of thinnings and rotation lengths). A genetic algorithm was used to find the management regime that maximizes the Annual
Equivalent Value (AEV) of projects under different market scenarios.
We tested our model under a wide variety of possible scenarios for forestry projects. Five tropical plantation species (Alnus jorullensis, Cordia
alliodora, Pinus patula, Cupressus lusitanica and Eucalyptus grandis) were evaluated, at discount rates of 4, 7 and 10%, and certified emissions
reduction (CER) prices of US$3, 7, 10 and 13. Temporary CERs (tCERs) and long-term CERs (lCERs) prices were considered in the evaluation and
were calculated as a variable proportion of CER price.
Results showed that optimal forest management is sensible to carbon and timber market conditions. Under each discount rate, as CER price
increased, frequency and intensity of thinnings tended to decrease and optimal thinnings and rotation lengths tended to be reached at older ages.
The largest AEV were obtained with discount rates of 10%, CER prices of US$13 and rotation lengths of 40 years for all species. For those species
with higher timber prices, thinnings tended to be more frequent and at early ages of the plantation. For all species optimal thinnings were found at
35 years of plantation age. tCERs was selected by the model as the best choice to maximize the profitability of the projects.
# 2006 Elsevier B.V. All rights reserved.
Keywords: Forest management; Simulation; Profitability; Optimization; lCERs; tCERs; Genetic algorithm; CDM; Growth equations; Carbon sequestration
www.elsevier.com/locate/foreco
Forest Ecology and Management 226 (2006) 341–350
1. Introduction
According to the Kyoto Protocol, projects under the Clean
Development Mechanism (CDM) have to be designed to
promote sustainable development in developing countries
while at the same time can be used to assist developed
countries to reach their emission reduction targets (UNFCCC,
1997). Forestry activities can help to achieve these objectives
because well-designed projects generate important environ-
mental and social collateral benefits like water regulation,
erosion amelioration, habitat improvement and employment
* Corresponding author. Tel.: +57 4 230 08 76; fax: +57 4 230 08 76.
E-mail address: [email protected] (V.H. Gutierrez).
0378-1127/$ – see front matter # 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.foreco.2006.02.002
generation, among others (Ji and Junfeng, 2000; Garcia et al.,
2005; IUCN, 2006).
However, forest activities have detractors because CO2
absorbed by forests is not permanently sequestered. This
‘‘crunch’’ issue was addressed in the ninth Conference of the
Parties (COP9), in which modalities and procedures for forestry
projects under the CDM were approved. According to COP9
rules, forestry credits are issued for a limited period of time, at
the end of which, they have to be renewed or replaced for other
valid units (AAUs, CERs, ERUs and RMUs) before their expiry
date (UNFCCC, 2003).
Decisions adopted about non-permanence in COP9 allow
forestry projects to obtain revenues from both certified
emission reductions (CERs) and timber. Nevertheless, timber
and CERs prices will be variable and, as it will be shown below,
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350342
decisions made in forest management to favor revenues from
one of these two sources of incomes, will affect negatively the
incomes received from the other. This is the reason why project
developers need appropriate tools to know what could be the
forest management regime (frequency and intensity of
thinnings and rotation lengths) to maximize their revenues
from these two sources of incomes.
We developed Carbomax as a management optimization
model for forestry projects under the CDM. Carbomax
simulates different management regimes and finds the one
that maximize the profitability of projects, depending on
carbon sequestration and timber production capacity of the
species considered and expectancies about carbon and timber
markets.
The first part of this paper describes the general structure of
the model. In the second part, the following two basic
hypotheses were tested through its application to a case study in
Colombia: (1) optimal forest management is strongly
influenced by carbon and timber market scenarios. (2) tCERs
will be more profitable for forestry projects under the CDM
because they give more flexibility to forest management.
2. Model structure
Carbomax is comprised of three modules (Fig. 1). The first
one simulates carbon growth and timber yield under different
management regimes according to a structure of costs and
incomes. The second one calculates the profitability obtained
with each simulated regime. The last module finds, through an
iterative process, the regime that maximizes the profitability of
projects under each of the market scenarios simulated.
Carbomax was developed in S language, using R Version
2.0, an open source software available on the internet (R
Development Core Team, 2004).
2.1. Module 1: growth simulation
Under this module, total timber production is predicted
using volume yield equations reported in the literature. Using
taper equations, the module calculates timber production for
Fig. 1. Graphical representation of th
different end-use products. This information is needed to
calculate the incomes obtained from timber sales because
different end-uses have different timber prices.
To estimate carbon dynamics, Carbomax uses biomass or
carbon growth equations. If only volume equations are
available, volume estimates are transformed to aboveground
biomass using adequate Biomass Expansion Factors (BEF)
chosen by the user. These factors are defined as the ratio of
total aboveground biomass of trees to biomass of the stem
volume, calculated as the product of stem volume and wood
density.
When carbon equations in other pools (root biomass, dead
wood and fine litter) are not available, these values are
calculated as a proportion of total tree biomass per hectare. If
there is no data about carbon content in biomass, the universal
constant of 0.5 is used (IPCC, 2003). Carbon values are
transformed to CO2, multiplying them by 44/12.
Soil carbon is not considered in the modeling, because
although it could accumulate high quantities of carbon, its net
rate of accumulation is difficult to predict (Bashkin and
Binkley, 1998; Lopera et al., 2003) and its spatial variability at
both micro and macro-scale is high. However, COP9 decisions
indicate that project developers are allowed ‘‘not to account for
one or more carbon pools . . ., while avoiding double counting’’
(UNFCCC, 2003).
Growth after thinnings is projected using the method to
predict future growth, based on the present condition of the
stand as described by Clutter et al. (1983). Carbomax was built
to simulate forest growth without thinnings or considering one
or two thinnings with intensities varying between 20 and 60%
of basal area.
2.2. Module 2: profitability assessment
2.2.1. Profitability indicator
The Annual Equivalent Value (AEV) (1) is used as the
profitability indicator (Benitez et al., 2001). AEV can be
obtained from the Net Present Value (NPV) formula (Eq. (2)). It
was adopted because NPV is not appropriate for comparisons
of economic feasibility of projects with different lifetimes
e Carbomax modeling structure.
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350 343
Table 1
Default values for transaction costs
Costs Causation year Value
Pre-implementation
Search (US$) 0 15,000
Preparation and formulation
of project design (US$)
0 180,000
Approval by host country
and holding in
national registry (US$)
0 40,000
Validation (US$) 0 20,000
Total pre-implementation (US$) 225,000
Implementation
Monitoring (first) (US$/ha) 5 12.4
Monitoring (following periods)
(US$/ha)
Every 5 years 6.3
Verification and certification
(first) (US$)
5 17,000
Verification and certification
(following periods) (US$)
Every 5 years 8500
Trading
Registration by the
executive board (US$)
0 10,000
Brokerage
(% of total CERs traded)
Every 5 years 5
Other transaction costs
Adaptation fund
(% of total CERs traded)
Every 5 years 2
Baseline actualization (US$) Every 20 years 50,000
Validation of baseline
actualization (US$)
Every 20 years 20,000
(Fabrycky and Thuesen, 1981; Valencia, 1988; Tarkin and
Blank, 1992).
AEV ¼ NPV� i
1� ð1þ iÞ�n (1)
where n is the lifetime of the project and i is the discount rate.
NPV ¼Xn
t¼0
It � Et
ð1þ iÞt(2)
where It is the incomes incurred in year t (US$) and Et is the
costs incurred in year t (US$).
2.2.2. Costs
2.2.2.1. Establishment, management and administration cost-
s. In this module, projected costs incurred over the whole
lifetime of the plantation are considered. Operational costs
include salaries related to planting and management (ground
preparation, laying-out, digging, transportation of seedlings,
planting, pest control, fertilization, replanting, weeding, road
maintenance, fire protection, pruning and thinning) materials
(seedlings, fertilizers, insecticides and tools), administration
and others. These costs are calculated on a hectare/year basis.
Administration costs are assumed to be a percentage of the total
annual costs.
2.2.2.2. Land price. Referential price of land is not con-
sidered because the model was built to compare the profitability
obtained by several species under different silvicultural
management regimes in the same land. This assumption
assumes that forest management is not influenced by land
prices (Benitez et al., 2001).
2.2.2.3. Transaction costs. Transaction costs refer to the time,
effort and other resources needed to search out, initiate,
negotiate and complete a deal (Lile et al., 1998). The estimation
of transaction costs in CDM projects is not trivial but they are
likely to be quiet high as there is not much experience in the
development of this kind of projects.
If there are no data available on transaction costs, the model
provides default values based on an extensive review of the
most recent literature (Milne, 2001; Benitez et al., 2001;
Michaelowa and Stronzik, 2002; Locatelli and Pedroni, 2003;
Michaelowa and Jotzo, 2003). According to Michaelowa and
Stronzik (2002), transaction costs are classified in the model as
pre-implementation, implementation and trading (Table 1).
Monitoring costs were based on our own experience in forest
inventories and monitoring. These costs were calculated
assuming a sampling intensity of 0.5% of the total eligible area.
Other transaction costs included the 2% charge on the total
CERs issued, that is destined to assist developing countries to
climate change adaptation, as specified in paragraph 15 of
decision 17/CP.7 (UNFCCC, 2002). Additionally, baseline
actualization costs are included once every 20 years for all of
those management scenarios which rotation lengths are longer
than 20 years. This actualization implies additional costs
related to acquisition and analysis of new data and validation:
‘‘. . . for each renewal a DOE [Designated Operational Entity]
determines and informs the Executive Board that the original
project baseline is still valid or has been updated taking account
of new data where applicable’’ (UNFCCC, 2003).
2.2.3. Incomes
2.2.3.1. Options for addressing non-permanence. According
to COP9 rules, project participants shall select one of the
following optional forestry credits (fCERs): temporary CERs
(tCERs) which expire at the end of the commitment period for
which they were issued and long-term CERs (lCERs), expiring
at the end of the crediting period. It is assumed in this analysis
that all the commitment periods will be of 5 years. According to
COP9 decisions, crediting periods can be of 20 years with two
possible renewals or 30 years without renewals. Once fCERs
expire, developed countries have to renew or replace them with
other valid units approved in the Kyoto Protocol (CERs, AAUs
or ERUs) (UNFCCC, 2003). Because of the uncertainty on
what kind of fCERs will be more profitable for forestry
projects, Carbomax evaluates the profitability obtained under
each management regime for the case of both tCERs and
lCERs.
According to COP9 rules, if the lCERs option is selected,
carbon stocks at the end of a commitment period should have
increased since the previous certification report (UNFCCC,
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350344
2003). Carbomax introduces this rule as a restriction in this
module. If any management regime does not guarantee this
condition, the solution is discarded by the model.
2.2.3.2. fCERs valuation. Current approaches concerning
fCERs values are based on expectancies about future price
of permanent CERs (Dutschke and Schlamadinger, 2003;
Locatelli and Pedroni, 2003; Dutschke et al., 2004). Depending
on the expected discount rate and the value of a fCER, incomes
expected from 1 t of CO2 stored in vegetation at the end of the
commitment period i + 1 are calculated as follows:
fCERiþ1 ¼CERi
ð1þ IiÞi� CERed
ð1þ IedÞed(3)
where ed is the expiring date of the credits. For tCERs, ed is
equal to i + 1. For lCERs, ed is equal to the crediting period for
which fCERs will be issued (20 which may be renewed at twice
or 30 years without renewals).
Carbomax gives the option to assume constant or variable
CER prices, according to market tendencies. Also, it is possible
to discount a percentage of the CERs issued attributable to
leakage.
Discount rate employed for fCERs valuation ‘‘expresses
price expectances of the market participants. It is influenced by
the interest rate as well as expectations on the stringency of
future emission-limitation commitments’’ (Dutschke and
Schlamadinger, 2003). Under this model, it is possible to
assume constant or dynamic discount rates, according to market
tendencies.
To calculate revenues from timber, Carbomax requires timber
prices for different end-uses (lumber, pulpwood, etc.) for each
one of the species considered. This value can be constant or
dynamic over time, depending upon market expectances.
2.3. Module 3: optimization
This module uses a genetic algorithm to optimize forest
management. This is an adaptive, stochastic model which
incorporates principia of natural selection to find optimal
solutions. It is very useful to solve large optimization problems
with multiple local optima (Ansari and Hou, 1997; Fouskakis
and Draper, 2002).
In this case, solutions from the previous two modules are
evaluated by a fitness function, defined in this case as the AEV
Table 2
Ecological description of the species considered in the application of the model
Species Height (m) Altitude (m.a.s.l) T (8C) P (
P. patula 20–30 2000–2800 13–18 160
C. lusitanica 30 1500–2800 14–20 150
A. jorullensis 30 2200–2800 7–14 100
C. alliodora 15–20 0–1900 18–25 150
E. grandis 43–55 100–1800 15–32 100
T: temperature; P: precipitation.
to find the optimal values. Different combinations of the
parameters are evaluated by the algorithm until the optimal
solution is found. For a complete description and formulation of
the genetic algorithms please refer to Fouskakis and Draper
(2002).
3. Application of the model to the case study
Carbomax was tested and validated in a case study in
Colombia. PROCUENCA (Forestry Project in the Basin of the
Chinchina River) reforestation and afforestation project is an
initiative formulated in 2001 by the City of Manizales
(Colombia) and its public services utility company Aguas de
Manizales, the United Nations Food and Agriculture Organiza-
tion (FAO) and the Corporation for the Development of Caldas
(CDC).
This umbrella project is designed to assist multiple
landowners in several forest activities. The project attempts
to consolidate a sustainable development process to assure
long-term fresh water supply by reforesting the regional
watersheds. Activities consist on the establishment and
management of forest plantations in areas currently dedicated
to extensive cattle grazing and perennial coffee cultivations.
The species considered in the simulation were Pinus patula,
Cupressus lusitanica, Alnus jorullensis, Cordia alliodora and
Eucalyptus grandis. A brief botanical description and soil
requirements of the species is detailed below. Also in Table 2,
other ecological characteristics are described.
P. patula is a closed cone pine, with straight stem form,
reddish flaky bark, and pale, green pendent foliage. It grows
on fertile well-drained soils on mountain ridges and slopes. A.
jorullensis has a straight and cylindrical trunk, and smooth
bark. Its crown is oval and its leaves are shiny-light, green and
alternate with a serrated edge. It grows best on deep, sandy
and well-drained soils of volcanic origin. C. alliodora is a tall
thin tree with a narrow, open crown and shows minimal
forking with simple alternate leaves. It grows best on well-
drained and medium-textured soils (Vozzo, 2003). C.
lusitanica has a crown broadly pyramidal. Bark thick, reddish
brown, with longitudinal fissures and bluish green foliage. It
grows on deep, rocky, sandy and well-drained soils with a
slightly low pH. E. grandis has a straight stem and its bark is
either white, gray or green, smooth, shedding in long narrow
strips. The leaves are alternate, lanceolate and glabrous. It is
adapted to a wide range of soil types but grows well in moist,
well-drained soils.
mm/year) Life zones Source
0–2500 LM-mf, M-mf CONIF (1995, 1998)
0–3000 LM-wf, M-hf CONIF (1995, 1998)
0–2500 M-df, M-mf, LM-wf Del Valle and Gonzalez (1988),
CONIF (1998)
0–3000 T-mf, PM-mf CONIF (1998), Vozzo (2003)
0–3000 PM-mf, T-mf CONIF (1998)
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350 345
Table 3
List of parameters considered in the application of the model to the case study
Parameters (unit) Value/source
AEV (US$/ha) Calculated by the model
using Eq. (1)
Total eligible area (ha) 57,721
Forest site (m/reference age) Table 3
Leakage (% of CERs) 2
Tree initial density (trees/ha) 1111
Mortality (% of standing trees) 2
Biomass in the baseline (t/ha) Coffee: 44
(van Noordwijk et al., 2002);
cattle grazing: 22
(Boscolo et al., 2000)
Management and
administration (US$)
PROCUENCA
Transactions costs (US$) See Table 1
Monitoring periodicity (years) 5
Verification periodicity (years) 5
Certification period (years) 5
Price of lumber (US$) PROCUENCA
Price of pulpwood (US$) PROCUENCA
Discount rates (%) 4, 7, 10
CER prices (US$) 3, 7, 10, 13
Non-permanence options tCERs or lCERs
fCER price Eq. (3)
Mutation probability
(proportion)
0.4
Data about establishment, management and administration
costs were provided by the project. Total eligible area was
obtained from a pre-feasibility study concluded recently (Black
et al., 2004). The parameters and variables considered in the
application are shown in Tables 3 and 4.
Growth equations were obtained from the literature (Del
Valle, 1979; Velez, 1982; Gonzalez, 1983; Del Valle and
Gonzalez, 1988; Lopera and Gutierrez, 2000) and corresponded
to the Schumacher model (Table 5). To calculate volume of
wood for lumber and pulpwood, taper equations from the
literature were employed (Del Valle and Gonzalez, 1988; Velez,
1982; Lopera and Gutierrez, 2000) following the method
proposed by Gutierrez and Lopera (2003). Equations are
summarized in Table 5.
Because of the lack of growth equations for C. alliodora, a
Mean Annual Increment (MAI) of 15 m3/ha/year was used for
Table 4
List of variables considered in the application of the case study
Type of variable Variable (unit)
Continuous variables Basal area (m2/ha)
Volume (m3/ha)
Sapwood and pulpwood volume (m3/ha)
Aboveground biomass (t/ha)
Belowground biomass (t/ha)
Fine litter mass (% of tree biomass)
Soil carbon (Mg/ha)
Optimizing variables Rotation length (years)
Frequency of thinnings (# thinnings/rotation le
Time of thinning (years)
Intensity of thinnings (%)
this species, corresponding to the growth rate expected by
PROCUENCA. Belowground biomass carbon and carbon in
other pools were calculated as a proportion of aboveground
carbon using values obtained from the literature (Flint and
Richards, 1994; Brown, 1997; Herrera et al., 2003).
Site values used in the simulations corresponded to the mean
site in which the equations used in the simulations were
developed. Wood density values of the species were obtained
from Brown (1997), except for A. jorullensis, which was obtained
from Del Valle and Gonzalez (1988) (Table 6). BEF values were
calculated, using the equation reported by Brown (1997), which
is a function dependent of stem biomass and allows to calculate
the proportion of aboveground biomass related to the stem
volume of a forest per hectare (see Section 2.1). For P. patula
carbon dynamics were calculated using carbon growth equations,
so wood density and BEF values were not needed in the
estimations. Wood prices were calculated for standing trees
(excluding logging and transportation costs). Lumber price for E.
grandis is not reported because all the commercial volumewill be
destined to pulpwood production (Table 6).
4. Results and validation of the model
4.1. Growth simulation
Using the equations reported in Table 5, Carbomax projected
volume growth and carbon sequestration for each of the species
considered (Fig. 2). Table 7 shows Mean Annual Increments
calculated for each of the species modeled considering a
reference age of 25 years.
4.2. Convergence of the fitness function
For each species, CERs price and discount rates considered,
the model evaluated the effect of different management regime
in the fitness function (AEV) across generations until the
moment at which the fitness function converges to a maximum.
4.3. Optimal management scenarios
Table 8 shows that as CER prices increase, thinnings tend to
be applied at older stages of the plantation. Similarly, thinnings
Value/source
Table 3
Table 3
Table 3
Brown (1997), Lopera et al. (2003)
Flint and Richards (1994), Brown (1997)
Brown (1997), Herrera et al. (2003), Lopera et al. (2003)
Not considered
5–40 intervals of 5 years
ngth) 1 or 2
5–40 in intervals of 5 years
20–60 respect to basal area
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350346
Table 5
Growth and taper equations used in the application of the model to the case study
Species Equationa Parameters R2 Source
A B C D
A. jorullensis lnðhÞ ¼ Aþ B � d�1 3.584 �10.377 0.72 Del Valle and Gonzalez (1988)
dcc ¼ Aþ B � d � ð1� ðhc � h�1ÞÞ 0.016 1.099 0.95 Del Valle and Gonzalez (1988)
dsc ¼ Aþ B � d � ð1� ðhc � h�1ÞÞ 0.014 1.071 0.95 Del Valle and Gonzalez (1988)
lnðGÞ ¼ Aþ B � t�1 þ C � ðS � t�1Þ 3.455 �12.628 0.296 0.91 Del Valle and Gonzalez (1988)
lnðVCCÞ ¼ Aþ B � t�1 þ C � Sþ D � lnðGÞ 2.393 �1.452 0.005 0.990 0.99 Del Valle and Gonzalez (1988)
C. lusitanica lnðhÞ ¼ Aþ B � d�1 3.183 �6.173 0.68 Gonzalez (1986)
dc ¼ Aþ B � d � ð1� ðhc � h�1ÞÞ 0.677 1.067 0.97 Gonzalez (1983)
PC ¼ A � eB�d 0.136 �0.021 0.68 Gonzalez (1986)
lnðGÞ ¼ Aþ B � t�1 þ C � Sþ D � ðS � t�1Þ 2.505 �8.745 0.077 0.152 0.65 Del Valle (1979)
lnðVCCÞ ¼ Aþ B � t�1 þ C � Sþ D � ðS � t�1Þ 3.560 �5.889 0.125 �0.049 0.72 Del Valle (1979)
Eucalyptus sp. lnðhÞ ¼ Aþ B � lnðd � 100�1Þ 4.032 0.589 0.80 Velez (1982)
lnðvccÞ ¼ Aþ B � lnððd � 100�1Þ2 � hÞ �1.051 0.922 0.98 Velez (1982)
lnðvscÞ ¼ Aþ B � lnððd � 100�1Þ2 � hÞ �1.234 0.925 0.97 Velez (1982)
lnðGÞ ¼ Aþ B � t�1 þ C � ðS � t�1Þ 3.824 �8.530 0.223 0.71 Velez (1982)
lnðVCCÞ ¼ Aþ B � t�1 þ C � Sþ D � ðS � t�1Þ 5.480 �10.272 0.018 0.315 0.75 Velez (1982)
P. patula lnðhÞ ¼ Aþ B � lnðdÞ 0.751 0.659 0.38 Lema and Parra (1995)
dsc ¼ Aþ B � lnð1� ðhc � h�1ÞÞ 2.221 0.996 0.90 Gutierrez and Lopera (2003)
lnðGÞ ¼ Aþ B � t�1 þ C � ðS � t�1Þ 4.289 �12.552 0.218 0.92 Lopera and Gutierrez (2000)
lnðVSCÞ ¼ Aþ B � t�1 þ C � lnðGÞ 3.572 �6.663 0.703 0.73 Lopera and Gutierrez (2000)
lnðCBqTÞ ¼ Aþ B � t�1 þ C � lnðGÞ 3.230 �9.061 0.666 0.80 Lopera and Gutierrez (2000)
a d: diameter at breast height in cm; dc: diameter at any height (hc in m) in cm; dcc: diameter at any height with bark in cm; dsc: diameter at any height without bark
in cm; vcc: total volume of a tree, including bark in m3; vsc: total volume of a tree, without bark in m3; G: basal area in m2/ha; h: total height in m; PC: proportion of
bark in the stem; S: site index (m/reference age); t: age in years; VCC: total volume with bark in m3/ha; VSC: total volume without bark in m3/ha; CBqT: total carbon
in the carbon pools except soil (tC/ha).
Table 6
Other variables considered in the simulations
Species Site
(m/reference
age)
Wood
density
(g/cm3)
Lumber
price
(US$/t)
Pulpwood
price
(US$/t)
Pinus patula 21.0/20 – 12.0 3.7
Cupressus lusitanica 17.6/15 0.43–0.44 14.6 3.5
Eucalyptus grandis 24.3/10 0.51 – 3.8
Alnus jorullensis 20.7/15 0.23–0.47 12.0 3.7
Cordia alliodora – 0.49 17.3 3.4
tend to be less intensive and less frequent when prices of CERs
are high. For E. grandis, thinning was not simulated because
this kind of plantations is cultivated for pulpwood production
only and does not require commercial thinnings.
Fig. 2. Carbon and volume growth for all the spec
4.4. Non-permanence option selected by the model
For all the management scenarios simulated, the model
selected tCERs as the most profitable non-permanence option
for forestry projects under the CDM. Fig. 3 shows the AEV
obtained with the optimal strategy selected by the model for P.
patula, considering the issuance of tCERs or lCERs separately.
4.5. Sensitivity of project profitability to its size
Because the above analysis was made on a project with a size
of 57,721 ha, a sensitivity analysis for a P. patula plantation was
performed to illustrate the effect of project size on its
profitability. Under a discount rate of 7%, AEV values are
highly sensitive to smaller project sizes (Fig. 4). This tendency
ies considered in the application of the model.
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350 347
Table 7
Mean Annual Increments (MAIs) in volume and carbon calculated for the
species considered considering a reference age of 25 years
Species MAI V (m3/ha/year) MAI C (t/ha/year)
A. jorullensis 11.54 5.73
C. alliodora 15.00 8.37
C. lusitanica 8.90 3.63
Eucalyptus sp. 13.39 8.07
P. patula 17.81 9.93
Mean 12.89 7.14
is more acute when project size is less than 2000 ha. As eligible
area increases, project profitability tends to an asymptote. For
project sizes above 8000 ha, the influence of area on project
profitability is low, with AEV values corresponding to 96–99%
of the maximum AEV depending on the CER prices simulated.
5. Discussion
5.1. Optimal forest management scenarios
Profitability of forestry projects under the CDM is influenced
by timber and fCER prices. Incomes obtained from one of these
Table 8
Annual Equivalent Value (AEV) reached under optimal management regimes outpu
Species Price
(US$)–DR (%)
Thinnings
(age–%)
Rotation
length (years)
AEV
(US$)
S
1 2
P. patula 3–4 12–40 19–40 20 141.4 C
3–7 12–46 15–40 20 110.0
3–10 10–48 15–41 20 82.7
7–4 15–58 20–41 25 195.0
7–7 15–60 25–53 30 202.0
7–10 20–46 30–65 35 203.5
10–4 25–69 35–42 40 246.4
10–7 35–53 40 295.0
10–10 35–77 40 322.2
13–4 35–56 40 311.1
13–7 35–80 40 394.8
13–10 35–80 40 443.3
C. alliodora 3–4 7–40 15–40 30 143.0 A
3–7 6–40 15–40 20 117.5
3–10 6–40 11–40 20 104.2
7–4 6–42 20–40 30 219.3
7–7 20–41 25–40 35 241.6
7–10 20–41 25–40 35 272.8
10–4 6–80 40 285.7
10–7 35–80 40 349.0
10–10 35–66 40 415.6
13–4 6–80 40 357.2
13–7 35–65 40 461.6
13–10 35–80 40 564.7
E. grandis 3–4 43.9 E
3–7 40 75.3
3–10 40 105.9
7–4 40 148.6
7–7 40 256.2
7–10 40 360.7
Thinnings are expressed as a combination of age of thinning and percentage of ba
two sources will affect negatively the other. If a project developer
thins his forest, the fraction of biomass removed will be counted
as instant emissions and will not generate payments from CERs.
On the other hand, if forests are left unthinned, revenues from
timber will not be received until the end of the rotation period,
but the quantity of fCERs generated will be high.
Considering the previous analysis, forest management will
be strongly influenced by wood and CER market dynamics.
Obviously, if timber prices are high and fCER prices low, it
will be preferable to obtain revenues from wood. This
situation will stimulate shorter rotation lengths and early and
intensive thinnings. On the other hand if wood prices are low
and fCER prices high, it will be preferable to leave the forest
as unmanaged as possible because thinnings could reduce
growing stock and thus, revenues from fCERs. This explains
why in Table 8 for all the species, except E. grandis, as fCER
prices increase, thinnings tend to be reduced in terms of
frequency and intensity, and final harvests tend to be
performed at older stages of the plantation. In the case of
E. grandis, rotation length in all the scenarios simulated was
the maximum allowed by the model (see Table 8). This is
probably due to the fact that wood price of this species is too
low (see Table 6) to have a significant effect on forest
tted by the model for different species, carbon prices and discount rates (DR)
pecies Price
(US$)–DR (%)
Thinnings
(age–%)
Rotation
length (years)
AEV
(US$)
1 2
. lusitanica 3–4 10–44 20 38.9
3–7 10–44 15–52 25 18.8
3–10 n
7–4 6–80 20 65.2
7–7 20–46 25 63.2
7–10 20–46 25 61.5
10–4 20–50 25 88.5
10–7 20–52 25 102.7
10–10 25–63 30 116.1
13–4 20–60 25 112.0
13–7 35–60 40 145.7
13–10 35–65 40 175.9
. jorullensis 3–4 6–77 20 57.8
3–7 6–77 20 53.7
3–10 6–80 15 53.3
7–4 6–77 20 118.1
7–7 10–80 25 158.3
7–10 20–80 25 201.5
10–4 6–80 25 165.1
10–7 30–78 35 243.4
10–10 35–80 40 319.5
13–4 35–80 40 214.5
13–7 35–80 40 330.8
13–10 35–80 40 438.4
. grandis 10–4 40 227.1
10–7 40 391.9
10–10 40 551.7
13–4 40 305.7
13–7 40 527.6
13–10 40 742.8
sal area left in the forest (n = negative AEV).
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350348
Fig. 3. Maximum AEV obtained from a Pinus patula optimally managed plantations for DR of: 4% (a), 7% (b) and 10% (c), respectively. t/lCER prices were
calculated as a proportion of the CER value (x-axis of the graphs), using Eq. (3).
management, and then fCER price is governing forest
management decisions.
It is important to consider that not all the simulated strategies
could be really applied because there are other constraints in
addition to market conditions that could force a thinning, e.g.,
forest health, longevity of the species and wood requirements
Fig. 4. Effect of size in project profitability for Pinus patula plantations under a
DR of 7% under four scenarios of CER prices. tCER prices were calculated as a
proportion of the CER price, using Eq. (3).
(in the case of an integrated production system), among others.
Carbomax therefore allows the addition of restrictions in the
management to fit particular project requirements.
5.2. tCERs versus lCERs
At the end of each commitment period, tCERs allow project
developers to decide how much CO2 will be committed for the
subsequent period and how much timber will be traded. Then,
forests can be managed according to market expectancies in
terms of both wood and CO2. In contrast, lCERs tend to limit the
quantity of wood sold because according to current rules, carbon
stocks at the end of the commitment for which they are issued
should be higher than the previous. This situation imposes an
additional restriction to forest management compared with
tCERs. This is the reason why tCERs were more profitable in all
the species and market scenarios simulated.
Nevertheless, there are other elements that should be
considered in the selection of the non-permanence option.
lCERs guarantee a more stable investment because they will
assure carbon sales up to the end of the crediting period of the
project, while with tCERs there are uncertainties because the
credits have to be renewed periodically.
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350 349
Another interesting aspect to consider is if tCERs would
imply more transaction costs because project developers
have to find new buyers for their credits at the end of each
commitment period. If the parties decide to renew the credits
it will probably represent lower costs. If the parties do not
agree on a renewal, the costs of finding buyers for new tCERs
will be almost the same than in the case of lCERs because
under this option, project developers have to search buyers for
the net carbon sequester between two certifications. Probably,
buyers would have to incur in additional transaction costs too
because at the end of each commitment period, they will have
to search new carbon credits to comply with their new
commitments. It is hoped that as carbon market becomes more
operational, costs of searching and renewal of credits will
become progressively lower.
5.3. fCERs valuation
The best approach to valuing fCERs involves expectancies
about commitments and CERs prices. This approach needs to
be improved because the real price of fCERs will be strongly
influenced by the demand for this kind of certificates. fCERs
have to be thought of as renting carbon. Buyers will pay for
carbon sequestration during a specific period of time. Why
would a buyer prefer fCERs to permanent CERs? It is true that
expectancies about future commitments would influence the
choice between fCERs or CERs, but if buyers do not have
enough money to comply with their commitments through
domestic emissions reductions or purchasing permanent CERs,
they will be obliged to choose a cheaper option. Since the
fCERs value will be lower than permanent CERs, this kind of
credits could in some case be an attractive option, no matter
what the expectancies about future CER prices are.
5.4. Addressing the scale of projects
In COP9, small-scale projects were defined as those that are
expected to sequester no more than 8 kt of CO2 per year
(UNFCCC, 2003). Using the upper and lower MAIs reported in
Table 7, this sequestration corresponds to an area between
approximately 200 and 600 ha, supposing constant MAIs and
100% areas planted. Under the scenario simulated in Fig. 4,
profitability of projects smaller than 2000 ha but larger than
200–600 ha will be drastically affected by size. Under these
circumstances, project developers should decide if they want to
be registered as small-scale projects or under the current
circumstances. If the first option is selected, they could benefit
from the COP9 decisions that agree to simplified modalities and
procedures for small-scale projects. It is highly probable that
this decision will reduce transaction costs but if the project
sequesters more than 8 kt of CO2 per year, the excess removals
will not be issued as fCERs.
In these cases, project developers would have to do an
analysis to decide whether they are willing to lower their
transaction costs and lose their additional carbon sequestration
or not be registered as a small-scale project and obtain revenues
for all the tones fixed by the project. This decision will depend
mainly on the expected price of fCERs because if the payment
they could receive for the excess removals is enough to cover
the difference in transaction costs, they probably would prefer
to be registered as a conventional project.
Fig. 4 also showed that projects larger than 8000 ha would
not gain from any additional economies of scale. Thus, for the
discount rate considered, 8000 could be considered as the
optimal project size.
5.5. Uncertainty in the analysis
Information on carbon sequestration in the tropics is scarce.
The simulation module of the model was built in a flexible way
in order to predict carbon dynamics according to the
information available for different species. It can work with
volume and carbon growth equations in different pools, as in
the case of P. patula as well as with only MAI volume values as
in the case of C. alliodora. Obviously, the accuracy of
simulations will vary according to the availability and
reliability of the input data.
6. Conclusions
Results showed that optimal forest management in carbon
sequestration projects under the CDM is strongly influenced by
carbon and timber market dynamics. If carbon prices are high
and timber prices low, it will be more profitable to leave the
stands as unmanaged as possible in order to leave higher carbon
stock in the forest and then, produce more carbon credits to sell.
If the opposite case occurs, optimal management will consist on
earlier and more intensive interventions because it will mean
more revenues near to present and then, more profit.
tCERs were found to be the most profitable option for
forestry projects under the CDM in all the scenarios simulated
because they allow flexibility in silvicultural management of
projects. Under this approach project developers will commit
their carbon stocks for only one period, after which, they can
manage the forest according to the new market circumstances,
both of timber and carbon, without restriction on a minimal
carbon stock to be left in the forest as in the case of lCERs.
Carbomax is useful as a tool to help project developers in
decision-making about selection of species and forest manage-
ment in their projects. It is flexible enough to model carbon
dynamics and to optimize forest management depending on the
quantity and level of accuracy of the information available.
Acknowledgments
This paper was presented in the CASFOR II International
Conference: Modeling Carbon Sequestration at the Landscape
Level: Techniques, Models and Policy Relevance, held in
Palenque-Mexico in November of 2004. It was developed under
the technical and logistical cooperation alliance between the
Research Center on Ecosystems and Global Change (C&B) and
the Andean Center for Economics in the Environment (ACEE).
Thanks to Dr. Francisco Ocampo, National Director of the
PROCUENCA project for facilitating the use of the information.
V.H. Gutierrez et al. / Forest Ecology and Management 226 (2006) 341–350350
We would also thanks to Dr. Sandra Brown, Dr. Margaret Skutsch
and Professor Alvaro Lema for revisions and comments and to
the two anonymous reviewers of this paper for their suggestions
and recommendations.
References
Ansari, N., Hou, E., 1997. Computational Intelligence for Optimization. Kluwer
Academic Publishers, Norwell.
Bashkin, M., Binkley, D., 1998. Changes in soil carbon following afforestation
in Hawai. Ecology 79 (3), 828–833.
Benitez, P., Olschewski, R., de Koning, F., Lopez, M., 2001. Investigacion de
Bosques Tropicales: Analisis Costo Beneficio de Usos del Suelo y Fijacion
de Carbono en Sistemas Forestales de Ecuador Noroccidental. Begleitpro-
gramm Tropenokologie (TOB) – Deutsche Gelleschaft fur Technische
Zusammenarbeit (GTZ). Eschborn.
Black, T., Gutierrez, V., Zapata, M., Gomez, A., Laguado, W., Santacruz, A.,
2004. Estudio de prefactibilidad para implementar el Mecanismo de Desar-
rollo Limpio (MDL) en el proyecto PROCUENCA. Centro Andino para la
Economıa en el Medio Ambiente (CAEMA) – Centro de Investigacion en
Ecosistemas y Cambio Global – Carbono & Bosques (C&B), Bogota.
Boscolo, M., Buongiorno, J., Condit, R., 2000. A model to predict biomass
recovery and economic potential of a tropical forest. Development discus-
sion paper No. 743. Harvard Institute for International Development,
Harvard University.
Brown, S., 1997. Estimating biomass and biomass change of tropical forests.
FAO forestry paper 134. FAO, Rome.
Clutter, J., Forston, J., Pienaar, L., Brister, G., Bailey, R., 1983. Timber
Management: A Quantitative Approach. John Wiley & Sons, New York.
CONIF, 1995. Coniferas. Corporacion Nacional de Investigacion y fomento
Forestal. Bogota.
CONIF, 1998. Guıa para plantaciones forestales comerciales en la Orinoquia.
Corporacion Nacional de Investigacion y fomento Forestal, serie de doc-
umentacion numero 38. Bogota.
Del Valle, J., 1979. Rendimiento y crecimiento de Cupressus lusitanica en
Antioquia, Colombia. Cronica Forestal y del Medio Ambiente 1 (2), 1–42.
Del Valle, J., Gonzalez, H., 1988. Rendimiento y crecimiento del cerezo (Alnus
jorullensis) en la region central andina, Colombia. Facultad Nacional de
Agronomıa 41 (1), 61–91.
Dutschke, M., Schlamadinger, B., 2003. Practical issues concerning temporary
carbon credits in the CDM. HWWA discussion paper 227. Hamburguisches
Welt-Wirtschafts-Archiv (HWWA), Hamburg.
Dutschke, M., Schlamadinger, B., Wong, J., Rumberg, M., 2004. Value and risks
of expiring carbon credits form CDM afforestation and reforestation.
HWWA discussion paper 290. Hamburguisches Welt-Wirtschafts-Archiv
(HWWA), Hamburg.
Fabrycky, W., Thuesen, G., 1981. Decisiones economicas: analisis y proyectos.
Prentice Hall, Colombia.
Flint, E., Richards, J., 1994. Trends in carbon content of vegetation in south and
southeast Asia associated with changes in land use. In: Dale, V. (Ed.),
Effects of Land-Use Changes on Atmospheric Concentrations. South and
Southeast Asia as a Case Study. Springer-Verlag, New York, pp. 201–299.
Fouskakis, D., Draper, D., 2002. Stochastic optimization: a review. Int. Stat.
Rev. 70 (3), 315–349.
Garcia, J., Deckmyn, G., Moons, E., Proost, S., Ceulemans, R., Muys, B., 2005.
An integrated decision support framework for the prediction and evaluation
of efficiency, environmental impact and total social cost of domestic and
international forestry projects for greenhouse gas mitigation: description
and case studies. For. Ecol. Manage. 207, 245–262.
Gonzalez, C., 1986. La conicidad del cipres (Cupressus lusitanica M) en el
departamento de Antioquia. Thesis. Universidad Nacional de Colombia,
Medellın.
Gonzalez, H., 1983. Cuantificacion y calificacion de la conicidad del cipres
(Cupressus lusitanica M). Research Report. Universidad Nacional de
Colombia, Medellın.
Gutierrez, V., Lopera, G., 2003. El arbol de area basal promedia como predictor
del volumen por usos del rodal. Revista de la Facultad Nacional de
Agronomıa 55 (2), 1683–1693.
Herrera, M., Del Valle, J., Orrego, S., 2003. Biomasa de la vegetacion herbacea
y lenosa pequena y necromasa en bosques primarios intervenidos y secun-
darios. In: Orrego, S., Del Valle, J., Moreno, F. (Eds.), Existencias y flujos de
carbono en ecosistemas forestales tropicales de Colombia. Universidad
Nacional de Colombia, Centro Andino para la Economıa en el Medio
Ambiente, Bogota.
Intergovernmental Panel on Climate Change (IPCC), 2003. Good Practice
Guidance for Land Use, Land-Use Change and Forestry. Institute for Global
Environmental Strategies (IGES), Hayama.
IUCN, 2006. The World Conservation Union, http://www.iucn.org/themes/
carbon/knowcdm/dc_opps.htm (online).
Ji, Z., Junfeng, L., 2000. China: CDM opportunities and benefits. In: Austin,
D., Faeth, P. (Eds.), Financing Sustainable Development with the Clean
Development Mechanism. World Resources Institute, Washington DC.
Lema, A., Parra, R., 1995. Ecuaciones de crecimiento, conicidad y de volumen
para las plantaciones de las Empresas Publicas de Medellın. Universidad
Nacional de Colombia, Medellın.
Lile, R., Powell, M., Toman, M., 1998. Implementing the Clean Development
Mechanism: lessons from U.S. private sector participation in activities
implemented jointly. Discussion paper 99-08. Resources for the Future,
Washington, DC.
Locatelli, B., Pedroni, L., 2003. Accounting methods for carbon credits:
impacts on the minimum size of CDM forestry projects. Working paper.
Global Change Group, CATIE, Turrialba.
Lopera, G., Gutierrez, V., Lema, A., 2003. Fijacion de carbono en plantaciones
tropicales de Pinus patula. In: Orrego, S., Del Valle, J., Moreno, F. (Eds.),
Existencias y flujos de carbono en ecosistemas forestales tropicales de
Colombia. Universidad Nacional de Colombia, Centro Andino para la
Economıa en el Medio Ambiente, Bogota.
Lopera, G., Gutierrez, V., 2000. Viabilidad tecnica y economica de la utilizacion
de plantaciones de Pinus patula como sumideros de CO2. Thesis. Uni-
versidad Nacional, Medellın.
Michaelowa, A., Jotzo, F., 2003. Impacts of transaction costs and institutional
rigidities on the share of the clean development mechanism in the global
greenhouse gas market. Paper fur die Sitzung des Ausschusses Umwelto-
konomie im Verein fur Socialpolitik, Rostock.
Michaelowa, A., Stronzik, M., 2002. Transaction costs of the Kyoto Protocol.
HWWA discussion paper 175. Hamburguisches Welt-Wirtschafts-Archiv
(HWWA), Hamburg.
Milne, M., 2001. Transaction Costs of Forest Carbon Projects. Working paper
CC05. Center for International Forestry Research (CIFOR), Bogor.
van Noordwijk, M., Rahayu, S., Hairiah, K., Wulan, Y.C., Farida, A.,
Verbist, B., 2002. Carbon stock assessment for a forest-to-coffee con-
version landscape in Sumber-Jaya (Lampung, Indonesia): from allo-
metric equations to land use change analysis. Science in China: Series C
45 supp.
R Development Core Team, 2005. R: A Language and Environment for
Statistical Computing. R Foundation for Statistical Computing, Vienna.
Tarkin, A., Blank, L., 1992. Ingenierıa economica. McGraw Hill, Mexico.
UNFCCC, 2003. Report of the Conference of the Parties on its Ninth Session,
held at Milan from 1 to 12 December 2003. FCCC/CP/2003/6/Add.2.
UNFCCC, 2002. Report of the Conference of the Parties on its Seventh Session,
held at Marrakesh from 29 October to 10 November 2001. FCCC/CP/2001/
13/Add.2.
UNFCCC, 1997. Kyoto Protocol to the United Nations Framework Convention
on Climate Change. FCCC/CP/L.7/Add.1.
Valencia, E., 1988. Decisiones economicas en la ingenierıa. Ingenierıa eco-
nomica. Universidad Nacional de Colombia, Medellın.
Velez, G., 1982. Indice de sitio, estimacion edafica y rendimiento del Euca-
lyptus saligna en Antioquia. Thesis. Universidad Nacional de Colombia,
Medellın.
Vozzo, J., 2003. Tropical Tree Seed Manual. United States Department of
Agriculture Forest Service.