Cocoa agroforestry for increasing forest connectivityin a fragmented landscape in Ghana
Richard Asare • Victor Afari-Sefa •
Yaw Osei-Owusu • Opoku Pabi
Received: 11 December 2013 / Accepted: 12 March 2014 / Published online: 29 March 2014
� Springer Science+Business Media Dordrecht 2014
Abstract In Ghana, farmers perceive protected forests
as land banks for increasing agricultural productivity to
support subsistence living. This has led to fragmentation
of existing protected forests. Two of such reserve forests
namely Bia Conservation Area and Krokosua Hills
Forest Reserve have been encroached through lumbering
for timber and area expansion of no-shade cocoa
production systems. The purpose of this study was to
develop a multi-disciplinary strategy to increase forest
connectivity using cocoa agroforest corridors. Biophys-
ical assessments involving satellite images for vegetation
patterns, and expert data from a decision support system
were used to select suitable sites for the corridor within a
Geographic Information System framework. Socio-eco-
nomic assessments of the opportunity costs of alternative
farming systems to cocoa agroforestry in the delineated
corridors show that while timber trees planted within
cocoa agroforests settings would help offset the yield
losses in cocoa shade-yield relationships compared to full
sun-production systems, the on-farm benefits of cocoa
agroforestry alone are insufficient to justify the adoption.
Paying farmers premium prices for cocoa and substantial
off-farm environmental and ecosystem services under
agroforestry systems can tip the balance towards
adoption.
Keywords Forest corridors �Protected forests �Biodiversity � Cost-benefit analysis �Geographic
information system
Introduction
Cocoa cultivation is a major economic activity and
land use in Ghana. Traditionally, cocoa was planted
under partially cleared forest with remaining trees
providing shade to the cocoa trees (Asare 2005;
R. Asare (&)
Department of Geoscience and Natural Resource
Management, University of Copenhagen-Denmark and
International Institute of Tropical Agriculture (IITA),
Private Mail Bag (PMB) L56 University of Ghana-Legon,
Accra, Ghana
e-mail: [email protected]; [email protected];
V. Afari-Sefa
AVRDC—The World Vegetable Center, Eastern and
Southern Africa Regional Office, Duluti, P. O. Box 10,
Arusha, Tanzania
e-mail: [email protected]
Y. Osei-Owusu
Conservation Alliance International, 5 Odum Street,
North Dzorwulo, P. O. Box KIA 20436, Accra,
Greater Accra, Ghana
e-mail: [email protected]
O. Pabi
Institutes for Environment and Sanitation, University of
Ghana, Legon, Accra, Ghana
e-mail: [email protected]
123
Agroforest Syst (2014) 88:1143–1156
DOI 10.1007/s10457-014-9688-3
Anglaaere et al. 2011). In recent times management
practices in new cocoa fields in Ghana particularly by
migrant farmers have been associated with wide
spread forest clearings where little or no shade is
maintained (Ruf 2011). Given how fast agricultural
activities diminish biodiversity, the major challenge
for conservationists and agriculturists in biodiversity
areas in Ghana is how to balance the economically
driven agricultural expansion with strategies neces-
sary for conserving natural resources, and maintaining
ecosystem integrity and species viability (Asare
2006).
Results of work by Owubah et al. (2001) in Ghana
on forest tenure systems and sustainable forest man-
agement confirms farmers use of protected forests as
land banks for increasing agricultural productivity to
support subsistence living. It is estimated that
50–70 % of the total areas of protected forestlands in
Ghana have been illegally encroached (England 1993;
Ministry of Science and Environment 2002). In the
process, two protected areas [Bia Conservation Area
(Reserve A) and Krokosua Hills Forest Reserve
(Reserve B)] of biodiversity importance in the
Western region of Ghana have been encroached
through lumbering for timber, cocoa production and
other agricultural land expansions (Oates et al. 2000;
Oates 2006). These forest reserves are the last domain
for two of the most endangered primates in Africa—
the Roloway Guenon (Cercopithecus diana roloway)
and the white-naped mangabey (Cercocebus atys
lunulatus) (Oates 2006).
To address the impact of increased land expansion
for cocoa cultivation (i.e., cocoa extensification) in the
two protected forest areas, a multidisciplinary study
was undertaken to identify corridor options and
strategies compatible with cocoa agroforestry systems
to overcome forest and habitat fragmentation while
providing households with appreciable farm income.
To this end, biophysical and socio-economic assess-
ments within a geographic information systems (GIS)
framework were undertaken to delineate possible
candidate’s sites for cocoa agroforest corridors to link
the two forest reserves. In order to achieve this,
emphasis was placed on identifying a socio-economic
justification that offers appropriate incentives for
farmers who undertake cocoa agroforestry. This was
done by analyzing hypothetical cocoa agroforestry
systems based on ex-ante assumptions of the situation
as is likely to occur under different farming systems
with regards to cocoa certification schemes that have
recently been introduced in the study area.
Study context and scope
Despite the increasing body of knowledge on the
benefits of using corridors for landscape connectivity
(Bennett 1998), Laurance (2001) warns of the
potential risks in costs, which include the spread of
biotic and abiotic disturbances to remnant populations
and habitats; the potential for increased wildlife
mortality in corridors and; insufficient information
on whether the financial costs of corridors could be
better invested in other conservation initiatives like
purchasing land. Notwithstanding, Laurance (2001)
argues that despite the risk, it will be far easier to
remove a corridor in the future than to create one
where the original habitat has been destroyed. While
on-going discourse on the importance of corridors is
not a major focus of this paper, emphasis is placed on a
justification of why a corridor via cocoa agroforestry is
beneficial in the context of the present study and the
strategies to develop one.
In order to conserve the landscape and its biodi-
versity, this study considered maintaining migration
corridors for landscape species based on Jones et al.
(2007). The aim was to conserve mammal or bird
populations which need to move over large areas that
cannot realistically be encompassed within protected
forest areas. Three reasons underlined this consider-
ation namely: (i) to reduce human-wildlife conflict in
Reserve A, (ii) to conserve gene flow and demographic
links between populations and (iii) to reduce pressure
on the existing forests.
In this study, forest connectivity is defined in terms
of gene flow between populations of animal and plant
species between the two protected forests. We intro-
duce the community level and national contexts of
connectivity among the two forest areas, explaining
the rationale behind this study in terms of (i) the
general importance of managing cocoa agroforest
corridors to preserve wildlife including the Roloway
Guenon (Cercopithecus diana roloway) and the white-
naped mangabey (Cercocebus atys lunulatus) within
the corridor (ii) the critical situation in the Reserve B,
where the presence of admitted cocoa and food crop
farms continue to increase degradation through rapid
and widespread conversion of forests to farmlands and
(iii) illegal encroachment in Reserve A, where changes
1144 Agroforest Syst (2014) 88:1143–1156
123
over the last 4–5 decades in wildlife habitats and the
absence of buffer zone between the national park and
cocoa farms have led to severe human-wildlife conflict
with elephants causing severe damage to farms.
Cocoa agroforestry as a strategy for biodiversity
conservation
Cocoa cultivation that maintains substantial propor-
tions of shade trees in a diverse structure is viewed as a
sustainable land-use practice that complements the
conservation of biodiversity (Rice and Greenberg
2000; Schroth et al. 2004). By diversifying cocoa
production to focus on other short, medium, or long
term products, and then bridging the whole system to
opportunities in the market chain, diverse trees in
cocoa farms can help to stabilize or improve farm
income and household welfare (Gockowski et al.
2006). In Cameroon, Duguma et al. (2001) argue that
cocoa agroforests are more sustainable than annual
food crop production systems. The authors acknowl-
edge that timber and medicinal species in cocoa farms
can bolster economic returns.
Cocoa agroforests can create forest-like habitats,
which serves as faunal refuges (Griffith 2000).
Research conducted in Central and Latin America
indicates that the capacity of cocoa plantations to
conserve birds, ants and other wildlife is greater than
in any other anthropogenic land use systems (Faria
et al. 2007; van Bael et al. 2007; Rice and Greenberg
2000; Schroth and Harvey 2007). In areas like
Southern Cameroon and Eastern Brazil cocoa agro-
forests are credited with conserving the biological
diversity of the humid forest zone (Ruf and Schroth
2004; Sonwa et al. 2007) and the Atlantic forest
(Rolim and Chiarello 2004), compared to farming
activities that produce food crops like maize and
cereals. In Ghana, cocoa agroforests have been used as
a buffer zone around protected areas like the Kakum
National Park in the Central Region to reduce forest
encroachment (Asare 2005).
It is vital to recognise that even though research
suggests that cocoa agroforests are generally environ-
mentally preferable to other forms of agriculture,
cocoa agroforests do not equate with primary forests
(Donald 2004). According to Rolim and Chiarello
(2004), cocoa agroforests not only support relatively
lower species richness but also impairs natural species
succession and gap dynamics compared to floristically
and climatically similar sites of secondary or primary
Atlantic forest in Brazil. As a result, tree species of late
successions are becoming rare while pioneer and early
secondary species are becoming dominant. Acknowl-
edging these limitations, however, does not dispute the
fact that cocoa agroforestry provide real opportunities,
compared to other agricultural systems (Noble and
Dirzo 1997) and beyond simple conservation, cocoa
agroforests may have positive environmental effects
in landscapes already impoverished by human distur-
bances (Reitsma et al. 2001). This is particularly true
in fragmented landscapes, where cocoa agroforests
have been noted to retain high biomass and carbon
storage (Wade et al. 2010), while providing habitat
and resources for a wide range of plant and animal
species (Schroth and Harvey 2007) and maintaining
connectivity between different land uses (Asare 2006).
What is more cocoa agroforests maintain the capacity
to reduce household vulnerability to climate stress,
pests’ outbreak and food security due to their social
and economic values (Tscharntke et al. 2011).
Materials and methods
Study area
The area lies within latitude 3.2720�N and latitude
2.5870�W. The western boundary of the area forms
part of the western boundary with Cote d’Ivoire. The
north and southern boundaries are delineated by
longitudes 6.6360�N and 6.1560�N respectively. It
covers two administrative districts, namely Juaboso
and Bia (Fig. 1). The area lies across two of Ghana’s
vegetation categories, namely Moist Evergreen Forest
in the south and Moist Semi-deciduous in the north,
which corresponds with the Lophira-Triplochiton
association and the Celtis-Triplochiton association
(Hall et al. 1976). It is marked by high rainfall
(averaging 1,600 mm per annum) and warmer tem-
peratures ranging between 22 and 34 �C. It experi-
ences double rainfall maxima characterized by two
rainy seasons. The major rainy season occurs between
April and October, peaking in May/July, and the minor
rainfall occurring between August and October,
peaking in September/October. The high rainfall and
the proximity to the sea create moist atmospheric
condition that result in high humidity, ranging
between 70–90 %. The climatic conditions provide
Agroforest Syst (2014) 88:1143–1156 1145
123
optimum conditions for biomass production, due to the
high rainfall coupled with fertile ochrosol soil. This
enables the establishment of high forest vegetation
with the characteristic multi-tier vertical stratification.
It is habitat to some of the tallest trees species in West
Africa. Settlements within the area are at different
levels of development, and differentially distributed
throughout the area, with a high density within the off-
reserved areas.
There are settlements and admitted farms within
Reserve B. These were in existence before the
boundaries for the protected areas were established
by legislation. Whereas some of the settlements have
existed for many years, others are new. According to
the Ghana Statistical Service (2012), Bia and Juabeso
have populations of 116,332 and 111,749 people
respectively. Reserve A comprises the Bia National
Park (77.7 km2) in the north and the adjoining Bia
Resource Reserve (227.9 km2) in the south with fringe
communities within 5–7 km from the reserve bound-
aries [see UICN-PACO (2010)]. Reserve B lies to the
east of Reserve A within the moist semi-deciduous
forest. Floristically, Reserve B contains species rarely
found elsewhere in Ghana. Of the 3,600 known species
of plants in Ghana over 1,379 plants have been
recorded within the study area and their adjoining
forest reserves. Reserves A and B are both under the
management of the Forestry Commission of Ghana.
The two forests are endowed with a wide range of non-
timber forest products and non-wood forest products
[see UICN-PACO (2010)].
Cocoa agroforest corridor delineation
A number of relevant spatial information including water
bodies, land-use/cover, topography, forest reserves, set-
tlements, population, and spatial data for roads, streams,
contours and settlements were procured as shape files
Fig. 1 Study area showing administrative districts, settlements, roads and protected forest reserves
1146 Agroforest Syst (2014) 88:1143–1156
123
generated from analogue topographic maps with a scale
of 1:50,000 and transformed to the adopted coordinate
system. Details of data used depended on the extent of
decision space. Knowledge and information systems in
the form of expert and decision support systems, which
included local knowledge, were also deployed [see
Chalmers and Fabricius (2007)]. Inputs from the Forestry
Commission of Ghana created a basis that informed a
Geographic Information System based definition for a
spatial analysis for delineating the area that falls within
the boundaries of the area of influence. The corridor
delineation relied on the use of remote sensing and
models. The analysis was carried out in ArcGIS 9.3.1
software (Environmental System Research Institute,
Redlands, California) in a raster format.
Landsat Enhanced Thematic Mapper Plus (ETM?)
data was used to develop the land-use/cover map. This
was captured on January 23, 2008, with practically no
cloud cover. The satellite data (requested from the United
States Geological Survey), was geometrically corrected
and projected using local parameters and transformed
using the decimal degree coordinate system.
To minimize undue influence of the forest reserves
on the classification, a segmented classification was
implemented. In this case, the forest reserves were
masked, leaving essentially, the off-reserve cultivated
lands, fallows, thickets and fragmented forests. The
composite of bands 3, 4 and 5 were enhanced in the
ENVI 4.8 software (Exelis Visual Information Solu-
tions, Boulder Colorado), initially classified by unsu-
pervised classification using Iterative Self-Organizing
Data Analysis Technique (Ball and Hall 1965), pur-
posely to identify existing possible land-use/cover
types. The final supervised classification was verified
and validated by data collected geo-referenced in the
field using a Garmin Geographic Positioning System
device. The classification scheme adopted was a hybrid
of land use and land cover. Short fallows were put in the
same class as annual crops such as maize, cassava and
plantain due to rapid inter-conversion arising from short
fallow cycles. Almost all the arable lands have been
converted to either cocoa farms or occupied by islands
of protected forest reserves, making them unavailable
for annual food cropping. Figure 2 is a direct output of
the classification process, which include the following:
• Built-up areas like settlements and exposed
grounds
• Annual cropping and fallow lands
• Cocoa-tree formations with different densities of
native trees
• Riverine vegetation
• Closed forest (more than 70 %) or moderately
closed forest (less than 70 %) which were mainly
remnants of pristine forests.
Since the proposed corridor will be an integral part
of a network of socio-economic and biophysical
systems, the potential candidates’ sites were examined
in the light of the following local consideration:
• The level of land-use intensification
• Population/settlement density
• Presence of water bodies
• Landscapes with protective legislation and policy
instruments
• Corridor length
• Current cropping systems
• Land with low monetary or land-use value
• Landscape with high biodiversity importance
• Traditional and cultural practices in the area
Suitability value of the corridor area depended on its
aggregated estimation for all the factors. Trade-offs
were accepted, but not to the point of discounting
factors considered indispensable. The factors above
informed the GIS-based decision processes to delineate
the corridor as in decision support and experts’ systems.
Economics and financial analysis of cocoa
agroforest corridor creation
Using primary data collected from 100 randomly
stratified selected farm-households, we combine a
representative farm-household typology via focus
group discussions using enterprise budgets of alterna-
tive farm production activities to estimate the oppor-
tunity costs of cocoa agroforests vis-a-vis a restricted
food access and no-shade cocoa farming as well as
non-timber forest product resources in the protected
area. A standard cost-benefit analysis of a cocoa
agroforests with cocoa as the dominant crop (Goc-
kowski et al. 2013; Gockowski et al. 2011; Obiri et al.
2007) was applied to analyze the opportunity costs of
alternative farming systems by including revenues
accrued from shade trees used as permanent shade in
the production cycle using the representative farm
approach. A district farm enterprise budget obtained
from Ministry of Food and Agriculture (2006) was
Agroforest Syst (2014) 88:1143–1156 1147
123
validated with data from a survey of 60 cocoa farming
households, 20 oil palm farming households and 20
rice farming households to assess the opportunity costs
of developing cocoa agroforests in the area. Data
averages from the 60 cocoa fields investigated were
consistent with those obtained from a larger baseline
survey of over 4,500 cocoa producers from across
West Africa (including about 1,000 Ghanaian cocoa
farms) conducted by the Sustainable Tree Crops
Program in 2001 (STCP 2003).
Primary and secondary data collected between July
and August 2010 was used to estimate the cost-benefit
analysis of the representative farms, which are distin-
guished by six data categories namely: farmer demo-
graphic and household characteristics, individual farm
characteristics, labor and agrochemical application
levels, crop yield parameters, GPS field measurements
and farmers general perception of biodiversity conser-
vation. Cocoa field measurements involving a total of
six transect walks of 50 9 2.67 m was systematically
undertaken in three different locations resulting in a
total area of 801 m2 on each of the randomly selected
60 cocoa farms to identify and count number of forest
and cocoa trees. The representative crop farms inves-
tigated allowed for the sole production of oil palm, rice
or cocoa with timber trees, along with food or income
from managing various staple crops for subsistence, all
of which compete for farm resources. Notwithstanding,
rice, oil palm and cocoa do not necessarily compete for
land resources. Oil palm grown in this region is usually
non-hybrids. Other by-products from the oil palm tree
such as felling of trees for preparation of local wine are
not included in the analysis. Rice is usually grown in
marshy areas close to water bodies, whiles oil palm is
grown on lands that are marginal for cocoa production.
For purposes of comparison with perennial crops, it was
assumed that rice was grown over two production
seasons per year.
For evaluating accurately the NPV returns to the
hypothetical cocoa agroforests and producers’ extant
Fig. 2 Land use cover of the northern part of the BCA, KHFR and Bia North Reserve
1148 Agroforest Syst (2014) 88:1143–1156
123
counterfactual production systems, empirical data was
needed on the agronomic relationships between age of
the tree stock, yields, shade, fertilizer response and pest
and diseases. Farmers for both the hypothetical and
counterfactual scenarios are assumed to follow best
practices and as a result the assumed yields are above
national averages. Best practices in the context of this
paper included recommended levels of fertilizer, use of
integrated crop and pest management practices and
minimum shade levels for cocoa. No shade cocoa and
medium shade cocoa scenarios assume high input
production systems including the use of purchased
fertilizers and the safe and rational use of pesticide as
these elements are deemed fundamental for the sustain-
ability of these production systems. Moreover, model-
ing the returns to a perennial crop such as cocoa is
complicated by the dynamics of yield over time as the
tree stock ages. On the basis of raw data from shade-
yield curves estimated from average annual yields of
longitudinal field age-yield trial data spanning over two
decades by Ahenkorah et al. (1987) in Fig. 3, we
assumed our hypothetical cocoa-agroforest scenario to
be represented by a medium shade cocoa proposed by
the authors and later validated by Gockowski and Sonwa
(2010) and Gockowski et al. (2013) through predicted
cocoa yield regression estimates. In the said trials,
Ahenkorah et al. (1987) identified three yield phases in
the life cycle of an Amazonian cocoa farm—the juvenile
phase from years 4 to 12 which was the period of highest
production, the stable phase from years 13–18 and the
senescent stage from years 19 to 24 when yields were in
decline and signs of ageing evident. According to the
authors cocoa trees over 20 years old on farms in Ghana
may have long passed their economic bearing age.
Moreover, Ofori-Bah and Asafu-Adjaye (2011) con-
firms that the aging cocoa farming population could
reduce farm technical efficiency. A 20-year age-yield
profile (Fig. 3) was assumed as the cutoff point,
particularly for full-sun cocoa production systems,
which are expected to produce sub-optimal yields after
two decades and would require replanting.
For analytical tractability purposes however, the
representative cocoa agroforest was assumed to con-
sist of 70 shade trees of the fast- growing pioneer
Terminalia superba (Gockowski et al. 2013). The
farming system is based on a given year for which the
various enterprises and management strategies are
selected to maximize total gross margin for each
enterprise option. On the basis of work from recent
authors (Gockowski et al. 2013) and sensitivity
analysis for the present cost-benefit study, a discount
rate of 20 % is assumed as the upper limit that
currently best reflects the time value of money in
Ghana. A 10 percent inflation rate (average for Ghana
in recent times) was also assumed. The estimation
procedure considered a 20-year return on operating
cost per hectare. The NPV, BCR and IRR were
calculated based on discounting procedures on a per
hectare basis using the formula (Gittinger 1982):
NPV ¼Xt¼n
t¼1
Bt � Ct
ð1þ iÞt
where Bt = benefit per ha each year; Ct = cost of
production per ha each year t = 1, 2, 3,…n; n = num-
ber of years; i = interest rate.
The Benefit Cost Ratio (BCR):
BCR ¼
Pt¼n
t¼1
Bt
ð1þiÞt
Pt¼n
t¼1
Ct
ð1þiÞt
Costs and returns are estimated for 1 ha of cocoa
trees with a plant population of 1,100 plants ha-1 with
permanent shade provided by timber trees planted and
owned by farmers. Timber trees are assumed to be
sown under the temporary shade canopy provided by
plantains planted at a density of 1,600 per ha. The
modeling do assumed the legality of timber sales that
will occur due to new timber plantings for which
farmers can obtain titles as opposed to the situation
where most trees are not deliberately planted by
farmers as a result of which government is assumed to
0
500
1000
1500
2000
2500
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23Mea
n y
ield
(kg
dry
co
coa
per
ha)
Years after planting
No shade Medium shade cocoa High shade cocoa
Fig. 3 Average annual yield of cocoa for experimental plots
representative of No shade, Medium shade, and High shade
cocoa over 20 years of observation, CRIG-Tafo, Ghana 1959 to
1982 and adapted in Gockowski et al. (2013)
Agroforest Syst (2014) 88:1143–1156 1149
123
own timber (Terminalia superba) trees under conces-
sion in an approach similar to that proposed by
Somarriba et al. (2011) where 50 % of total standing
volume is saleable. For the economic profitability
computation criteria, the annual yields of Terminalia
superba under cocoa agroforestry was assumed to be a
conservative figure of 6 m3 ha-1 year-1, represent-
ing, two-thirds the yield value proposed by Tufour
(1996) under plantations. The study further assumed
that from the trees planted, 330 m3 of T. superba
would be produced and commercialized in the 21st
year of the production cycle (Kimpouni 2009; Tufour
1996). The yield and value of trees were based on
growth rates and projected figures proposed by the FC
(2009) and consistent with projections by other
authors in cocoa growing belts outside West Africa
(see for example, Somarriba et al. 2014). The costs
associated with this certification are arguably assumed
to be covered by the $75 m3 unit cost of harvesting.
We also tested the robustness of our model at
alternative varying discount rates and noted minor
changes in our results.
In the base scenario where we compare cocoa
production systems with other alternative cropping
systems, we assumed farmers would receive only the
standard bulk cocoa prices without any premiums
price on cocoa and no payments for environmental
services. We included payments for environmental
and ecosystems services in our scenario analysis,
given that a number of chocolate industries have
begun adding sustainability criteria in their sourcing
codes and guiding principles (Datamonitor 2010;
WCF 2009).
No-shade cocoa production systems were com-
pared with four hypothetical alternative cocoa agro-
forest scenarios differentiated by price premiums and
varying levels of payments for environmental and
ecosystem services. Scenario one assumed a cocoa
price premium of $200/tonne as proposed by certifi-
cation schemes such as Rainforest Alliance (Rainfor-
est Alliance 2011). Scenario two combined cocoa
premium with carbon sequestration benefits. We
assumed carbon stocks levels of 155 CO2E per ha
(Wade et al. 2010). The 2009 prices of carbon ranged
from $1.20 to $46.90 per tonne of CO2E (with an
average of 3.35 $ per tonne CO2E for agricultural soil
sequestration) from the voluntary market (Hamilton
et al. 2010). However, a conservative price estimate of
$2.05 per tonne CO2E observed in April 2009 by the
Chicago Climate Futures Exchange (2009) to yield
476.63 GHC/ha ($318) of carbon sequestration at an
exchange rate of 1.5 GHC per $1.00 was used. In our
final scenario, we included biodiversity benefits (cor-
ridor creation and plant and animal species diversity)
at a rate of $250.00 per ha based on estimates provided
by Pagiola et al. (2004).
Results and discussions
Delineated cocoa agroforest corridor
There is a management regime within 5 km by the
Forestry Commission beyond the boundaries of the
forest reserves. Accordingly a buffer with a width of
five km was generated beyond the boundaries of the
forest reserves. This zone (shaded light green in
Fig. 4) captured all manner of landforms and land-use/
cover formations in an area of five km radius outside
the forest reserves.
Between Reserve B, Bia National Park and Bia
North Forest Reserves is a central zone (shaded yellow
in Fig. 4), which was considered an area of exclusion
since the Forestry Commision does not have signifi-
cant management interest outside the five km radius.
By examination, the eastern side of the Bia North
Reservation area was excluded due to the existence of
high concentration of settlements, population densities
and extensive annual cropping.
On the other hand more favorable conditions based
on vegetation cover, fewer settlements, and low
annual cropping exist in the area between the Bia
North Reservation area and the Bia National Park
(Fig. 2). The decision for selecting the corridor
favored sites that allowed the development of short,
rather than long corridors. The GIS analysis indicated
that two areas are most favorable (see Fig. 4). These
are i) the gap between the Bia National Park and the
Bia North Forest Reserve referred to as the northern
site (Fig. 2) with a distance of 4 km and, ii) the gap
between the south eastern tip of the Bia Resource
Reserve (south of the Reserve A) and south western tip
of Reserve B referred to as the southern site with a
distance of 5.5 km. The areas between the southern
and the northern sites have high density of rivers and
streams linking the forest blocks. These areas were
considered to be more conducive and therefore
potential candidate sites for locating a corridor to link
1150 Agroforest Syst (2014) 88:1143–1156
123
the forest blocks. The areas also enjoy protection from
the existing water resource policy instrument for
protecting vegetation along water bodies.
The corridor will maintain a central core of pure
natural vegetation along water bodies. It will have a
network of core forest vegetation that will maintain a
high degree of connectivity between the forest
reserves since they will be continuous. This zone will
be maintained as an extension of the forest reserves
that will enhance movements between the forest
reserves and the corridor. The implementation regime
will use the national land and buffer policies as
protective instruments to manage the zone. It is
expected that this area will have a minimum width
of 200 m. Beyond this zone will be an area of cocoa
agroforest on individual farmlands where high indig-
enous tree density are maintained.
Economic analysis and financial incentives
for cocoa agroforest corridor creation
Field survey results confirmed that cocoa is the
dominant cropping activity in the study area with
average farm sizes of 0.89 ha for rice, 0.91 ha for oil
palm and 2.45 ha for cocoa. The dominant tree species
on cocoa farms include Milicia excelsa, Khaya
ivorensis, Entandrophragma angolense, E. cylindri-
cum, Terminalia ivorensis, T. superba, Triplochiton
scleroxylon, Aningeria robusta, Pycnanthus angolen-
sis, Masonia spp., Tiegmella heckelii, Newbodia lavis,
Cocos nucifera, and Elaies guineensis. The transect
analysis indicated that many of the cocoa farms have
less than three forest trees per hectare, similar to what
Ruf (2011) counted on cocoa farms in parts of the
Western region. Baseline scenario results also indicate
Fig. 4 Map showing circled areas of shortest distances for locating corridors
Agroforest Syst (2014) 88:1143–1156 1151
123
that no shade cocoa is the highest in terms of
profitability with a BCR of 1.26 (Table 1).
In terms of opportunity cost, the second best
enterprise to no shade cocoa is cocoa agroforests,
under the assumption that farmers will sell timber after
the 20 year production cycle. Oil palm and rice
production are break even propositions with low
marginal returns. Thus, the analysis of the opportunity
cost of alternative farming systems and from farmers’
perceptions of biodiversity conservation in the course
of focus group discussions acknowledges the need for
environmental payments to support cocoa agroforest
corridor creation. As shown in Table 1, cocoa agro-
forest premiums alone are not attractive enough for
farmers to shift from no shade cocoa with BCR of 1.26
to cocoa agroforestry (with a BCR of 1.24). The results
show that the only incentive for farmers to shift to
cocoa agroforestry would be when cocoa premiums
are tied with carbon sequestration benefits and by
extension with full environmental benefits (i.e., carbon
sequestration plus biodiversity benefits). Under such
circumstances, cocoa agroforestry is more profitable
than no-shade cocoa production with a BCR of 1.32
with carbon sequestration benefits and 1.40 under full
environmental benefits. If the present assumptions of
the age-yield profile of cocoa shade systems are
relaxed along with increased yields of cocoa under
high input systems, there is the tendency to have lower
than estimated environmental benefits as per our
estimated scenarios.
In the course of focus group discussions during the
community engagement exercise, respondents
acknowledged the strong need for environmental
payments to support cocoa agroforestry corridor
creation. However, this is constrained by a general
lack of robust approaches and tools for pricing
environmental services in Ghana and coupled with
weak institutional capacities to implement appropriate
payments for biodiversity conservation schemes that
have so far been proposed. In addition the persistence
of trans-boundary cocoa smuggling activities between
Ghana and Cote D’Ivoire could distort any suitable
methods for valuation and compensation to spur
payments for environmental services (PES). Never-
theless, identifying and adopting appropriately
designed agroforestry systems as biological corridors
could engender environmentally friendly agriculture
that will promote the need for compensations or
Table 1 Computed economic indicators of scenarios on premium price and selected assumed environmental benefits
Crop/farming system Yield of main crop
in kg ha-1 year-1Total production
cost (¢GHC ha-1)
Total revenue
(¢GHC ha-1)
Economic profitability indicators
NPV
(¢GHC ha-1)
BCR IRR (%)
No shade cocoa 948.88 1,429.15 2,247.33 1,025.12 1.26 45.0
Cocoa-agroforestrya 553.28 896.73 1,489.36 781.12 1.19 40.0
Oil palm 3,745.00 1,152.08 1,498.33 607.13 1.04 36.0
Rice? 881.47 569.66 837.40 345.32 1.02 34.0
Cocoa-agroforestry (with no
premium cocoa price)a553.28 896.73 1,489.36 781.12 1.19 40.0
Cocoa-agroforestry (with
premium cocoa price)a553.28 896.73 2,105.34 945.67 1.24 43.5
Cocoa-agroforestry (with
premium cocoa price plus carbon)b553.28 896.73 2,297.02 1,317.76 1.32 45.9
Cocoa-agroforestry (with premium
cocoa price ? full environmental
benefits)c
553.28 896.73 2,609.22 1,657.41 1.40 51.3
? Production and revenue figures are annualized assuming two production cycles per yeara Yield for cocoa plus value of timber at the end of the 20 year production cycle in the economic profitability analysisb Yield of cocoa plus premium cocoa price and added carbon sequestration benefitsc Full environmental benefits in this scenario are assumed to include carbon sequestration credits and biodiversity
(corridor creation and plant and animal species biodiversity)
1152 Agroforest Syst (2014) 88:1143–1156
123
incentives (e.g. carbon credits, ecotourism, payments
for watershed services) to be economically viable for
farmers.
Based on the scarcity of land in the area for further
cocoa and food crop extensification and the results
from economic and financial analysis, it is suggested
that the cocoa farms in the corridor should be managed
in an ecologically intensive manner to increase yields
per hectare while compensating for the trade-offs. It is
expected that higher income per unit land obtained
from premium certified or payments for biodiversity
conservation can be used to improve the staple food
availability within the households either by market
purchases or by utilizing marginal lands not suitable
for cocoa production for food crop production. Con-
sequently, it is expected that timber trees planted
within cocoa agroforests would offset the yield loses
in the shade-yield relationship compared to full sun-
production systems. This will subsequently help to
reduce the use of ‘forest rent’ of newly cleared land to
establish cocoa farms as asserted by Ruf and Zadi
(1998) and Owubah et al. (2001).
Conclusions and policy recommendations
Both biophysical and socio-economic assessments
were undertaken to establish baseline status for the
delineation of potential corridor sites to link Reserves
A and B and provide an economic and financial
paradigm to incentivize farmers in a cocoa agroforestry
setting. In the process the multi-disciplinary approach
employed, proved to be useful. This is because it
provided a diversity of inputs that informed the
delineation process and the mechanisms for compen-
sating farmers for the environmental trade-offs as a
result of the corridor creation and management.
Creating corridors on complex landscapes with
multiple objectives must be carefully negotiated by
considering all relevant factors for effectiveness. The
use of spatial technology, especially GIS, enabled a
commanding and intergraded view and analysis of
complex human-dominated and natural landscapes for
holistic planning and a multi-criteria decision-making.
As a result, this work identified the following critical
factors in a decision process to choose suitable sites for
corridor development and implementation at the gap
between the Bia National Park and the Bia North
Forest Reserve and the gap between the south eastern
tip of the Bia Resource Reserve (south of the Reserve
A) and south western tip of Reserve B. These includes:
level of land use intensification; population density;
presence of resources attractive to wildlife; protective
legislation and policy instrument; short separating
corridors; cropping systems; land use with low
monetary value; biodiversity importance and; tradi-
tional and cultural practices were considered. The
success in the corridor delineation in this study makes
a strong case for similar applications. However, we
acknowledge that the choice of weighting and config-
uration in practice may be site-specific.
The baseline socio-economic study established
that no-shade cocoa production is the most impor-
tant economic activity in the area in comparison
with competing alternatives with cocoa agroforestry,
oil palm and rice. The second best enterprise to no
shade cocoa is cocoa agroforests, under the assump-
tion that farmers will sell timber after the 20 year
production cycle. The scenario analysis showed that,
cocoa agroforest premiums alone are not attractive
enough for farmers to shift from no shade cocoa to
cocoa agroforestry. To encourage no-shade cocoa
farmers to shift to cocoa agroforestry, cocoa premi-
ums from cocoa agro-forestry need to be tied with
payments for full environmental benefits, including,
rewards for carbon sequestration and biodiversity
conservation.
Clearly, there is potential for cocoa-agroforestry to
offer opportunities for developing sustainable land use
systems within fragmented protected forest reserves to
help address land and environmental degradation
problems while ensuring provision of substantial
household income to sustain livelihoods. Effective
management of land use and forest resources would
require measures aimed at improving the integrity of
the landscape while optimizing farmers’ production
levels in combination with necessary compensation
packages to farmers for adopting environmental
stewardship practices. Thus, paying farmers premium
prices for the cocoa produced and substantial off-farm
environmental and ecosystem services under agro-
forestry systems can tip the balance towards the
adoption of sustainable biodiversity friendly and
agricultural practices. The resulting revenue arising
from the payment of premium could help improve
household incomes. Similarly, the timber trees planted
within cocoa agroforests settings could offset the yield
losses in the shade-yield relationship compared to full
Agroforest Syst (2014) 88:1143–1156 1153
123
sun-production systems. Based on this the following
recommendations are made:
1. Given the lack of contemporary data on cocoa age-
yield profiles in Ghana, it is recommended that
further longitudinal trials with different age-yield
profile regimes of cocoa trees under varying shade
management treatments in different agro-ecologi-
cal zones should be undertaken. This should include
varying soil fertility levels and different cultural
management practices to provide more robust
information on yield assumptions under different
set of conditions to improve farmers’ practices and
confidence.
2. Embark on an ecologically intensified cocoa
agroforestry system in which at least 70 Termi-
nalia superba species or more different other
species (i.e., if their growth parameters are known
to be desirable in cocoa) are planted per hectare of
cocoa farm to achieve optimum results. In the
process, improved planting materials should be
used. Fertilizers and other agro-chemicals should
be used in a rational manner.
3. Undertake community education and public aware-
ness on the importance and sustainable use of
biodiversity resources within the target communi-
ties to enhance the ecological integrity of the
production landscape. Determine the most cost-
effective corridor route by analyzing the cost and
benefits associated with establishing a corridor of
different widths—200 m, 500 m, 1 km and
1.5 km—against the predetermined length of 5 km.
4. Delineate corridor routes by conducting a number
of physical and ecological studies within the
delineated sites to help establish the most appro-
priate routes to link the three forest blocks.
5. Undertake further socio-economic and biological
surveys to determine the level of human-wildlife
conflict and establish the most efficient means to
address the conflict.
6. Develop a monitoring protocol based on the five
levels of biodiversity considerations: landscape,
ecosystems, species, genetic and community
(human settlements) to help assess impacts on
delineated corridor.
Acknowledgments The financial support of the European
Union under the Cocoa Sector Support Program Phase II, World
Cocoa Foundation and the Sustainable Tree Crops Program of
the International Institute of Tropical Agriculture is gratefully
acknowledged.
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