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: qra@life.ku.dk; wjz479@ign.ku.dk;

r.asare@cgiar.org

V. Afari-Sefa

AVRDC—The World Vegetable Center, Eastern and

Southern Africa Regional Office, Duluti, P. O. Box 10,

Arusha, Tanzania

e-mail: victor.afari-sefa@worldveg.org

Y. Osei-Owusu

Conservation Alliance International, 5 Odum Street,

North Dzorwulo, P. O. Box KIA 20436, Accra,

Greater Accra, Ghana

e-mail: yosei-owusu@conservealliance.org

O. Pabi

Institutes for Environment and Sanitation, University of

Ghana, Legon, Accra, Ghana

e-mail: oppabi@gmail.com

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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