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1.In many tropical areas, forests have almost undergone complete decline. In this context, agroforestry has often been acknowledged as fostering compromises between crop production, local income diversification and the preservation of forest ecosystem services. 2.Cocoa agroforestry capacity to provide ecosystem services has mainly been studied through a management intensification gradient summed up as a shade rate. This paper proposes an alternative reading grid based on different trees origins that agroforests often combine: (i) Remnants,left-alive during deforestation, (ii) Recruits that have colonized the agroforest and (iii) Planted trees. This grid has been applied to 137 cocoa fields in the south of Ivory Coast to assess the impact of farmers management on provisioning trees ecosystem services (i.e.: carbon storage, diversity, food, medicine, timber and agronomic services to cocoa trees). 3. (i) Little environmental effect was found to explain ecosystem services provisioning. (ii) However, with regard to their origins, trees provide different services: remnants stock most above-ground carbon, recruits are the most diverse and provide medicinal resources and planted trees bring food resources. (iii) According to their origin, trees belong to different species or are at different stages of maturity so that trees from different origins play a complementary role in providing ecosystem services. Our results suggest that Ivorian cocoa agrosystems are so shaped by human management of associated trees that ecosystem services are weakly linked to environmental variables. Two neighboring fields in similar environmental conditions will provide very different services according to farmers’ management. 4. Synthesis and applications Preserving remnants while clearing forest is irreplaceable for large-scale climate mitigation while providing farmers with trees seedlings may have only little impact on carbon stocks. To strengthen complementarities between human-brought and human-selected trees, private companies providing trees to farmers should supply them with different valued trees from the ones they already plant or easily find in recruits. At landscape scale, policy should encourage remnants preservation to ensure that those remnants can feed the cohort of recruits with propagules thus allowing the survival of the species throughout several cycles of perennial crops.
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Local farmers shape ecosystem service provisioning in West
African cocoa agroforests
E. Sanial .F. Ruf .D. Louppe .M. Mietton .B. Hérault
Received: 14 May 2020 / Accepted: 13 December 2021
©The Author(s), under exclusive licence to Springer Nature B.V. 2022
Abstract 1.In many tropical areas, forests have
almost undergone complete decline. In this context,
agroforestry has often been acknowledged as foster-
ing compromises between crop production, local
income diversification and the preservation of forest
ecosystem services. 2.Cocoa agroforestry capacity to
provide ecosystem services has mainly been studied
through a management intensification gradient
summed up as a shade rate. This paper proposes an
alternative reading grid based on different trees
origins that agroforests often combine: (i) Rem-
nants,left-alive during deforestation, (ii) Recruits that
have colonized the agroforest and (iii) Planted trees.
This grid has been applied to 137 cocoa fields in the
south of Ivory Coast to assess the impact of farmers
management on provisioning trees ecosystem ser-
vices (i.e.: carbon storage, diversity, food, medicine,
timber and agronomic services to cocoa trees). 3.
(i) Little environmental effect was found to explain
ecosystem services provisioning. (ii) However, with
regard to their origins, trees provide different ser-
vices: remnants stock most above-ground carbon,
recruits are the most diverse and provide medicinal
resources and planted trees bring food resources. (iii)
According to their origin, trees belong to different
species or are at different stages of maturity so that
trees from different origins play a complementary
role in providing ecosystem services. Our results
suggest that Ivorian cocoa agrosystems are so shaped
by human management of associated trees that
ecosystem services are weakly linked to
Supplementary Information The online version
contains supplementary material available at
https://doi.org/10.1007/s10457-021-00723-6.
E. Sanial (&)
Nitidae N’lab, Lyon, France
e-mail: e.sanial@nitidae.org
F. Ruf
CIRAD, UMR Art-dev, c/o Universite
´Houphoue
¨t-
Boigny, Abidjan, Co
ˆte d’Ivoire
D. Louppe
CIRAD, Montpellier, France
Present Address:
M. Mietton
Universite
´Lyon 3 Jean Moulin, UMR 5600 CNRS, Lyon,
France
B. He
´rault
CIRAD, UPR Fore
ˆts et Socie
´te
´s, Yamoussoukro, Co
ˆte
d’Ivoire
B. He
´rault
Fore
ˆts et Socie
´te
´s, Univ Montpellier, CIRAD,
Montpellier, France
B. He
´rault
Institut National Polytechnique Fe
´lix Houphoue
¨t-Boigny,
INP-HB, Yamoussoukro, Co
ˆte d’Ivoire
123
Agroforest Syst
https://doi.org/10.1007/s10457-021-00723-6(0123456789().,-volV)(0123456789().,-volV)
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
environmental variables. Two neighboring fields in
similar environmental conditions will provide very
different services according to farmers’ management.
4. Synthesis and applications Preserving remnants
while clearing forest is irreplaceable for large-scale
climate mitigation while providing farmers with trees
seedlings may have only little impact on carbon
stocks. To strengthen complementarities between
human-brought and human-selected trees, private
companies providing trees to farmers should supply
them with different valued trees from the ones they
already plant or easily find in recruits. At landscape
scale, policy should encourage remnants preservation
to ensure that those remnants can feed the cohort of
recruits with propagules thus allowing the survival of
the species throughout several cycles of perennial
crops.
Keywords Agroforestry · Cocoa ·
Farming systems · Ecosystem services ·
Management
Introduction
Public attention is often drawn to threats that tropical
forest ecosystems encounter and to the importance of
hyper-diverse irreplaceable tropical ecosystems’ con-
servation Gibson et al. (2011); Barlow et al. (2018).
Although, in some tropical areas, stakes are already
beyond limiting deforestation because forests have
undergone almost complete decline. Nowadays, more
than 80% of 1900’s forests are lost in West Africa.
Smallholders agriculture was the main driver of tree
cover reduction. This loss reaches 90% in East Africa
Aleman et al. (2018). Commercial and smallholders
agriculture accounts for 80% of global deforestation
FAO (2016). Each additional forest lost accelerates
fragmentation: forests fragments get smaller and their
number increases Taubert et al. (2018). Post-forest
landscapes are important for the conservation/restora-
tion of present and future ecosystem services. For this
reason, they are an object of close attention for
environmental and aid organizations, politicians,
scientists and the agricultural sector Gibbs and
Salmon (2015); de Carvalho et al. (2015); Saqib et al.
(2019). Seeking and accompanying local people’s
practices in reforestation to ensure their livelihoods
and maintain or restore ecosystems’ capacity to
provide forests’ services is at stake in post-forest
tropical areas FAO (2018). Such approaches should
not ignore political economy of deforestation Pollini
(2009); Burgess et al. (2012) nor divert attention from
how to reduce global demand for land-intensive
export commodities Gibbs and Salmon (2015).
In this context, agroforestry has often been
acknowledged as fostering promising compromises
between production, local income diversification and
the preservation of ecosystem services (i.e. benefits
that ecosystems provide to human societies) Bene
et al. (1977). Often targeted as being deforestation
drivers, tropical perennial crops are also suitable for
such agroforestry associations Kusters et al. (2008).
For example, although cocoa cultivation has widely
contributed to deforestation in West Africa Oswald
(2005), it raises hopes for a better conciliation
between trees and agriculture in post-forest land-
scapes Tscharntke et al. (2011); Vaast and Somarriba
(2014). Wild cocoa (Theobroma cacao) is an under-
storey Amazonian specie: it tolerates shade and it
could be suited for agroforestry systems.
Ecosystem services these agroforests provide are
commonly studied through a management intensifi-
cation gradient Beer et al. (1997); Steffan-Dewenter
et al. (2007); Babin et al. (2009); Tscharntke et al.
(2011); Blaser et al. (2018) summed up as a shade
rate decreasing along a process of forest trees’ cover
reduction. Recently, 30–40% shade cover has been
identified as being an acceptable trade-off between
cocoa production and provisioning of several ecosys-
tem services (i.e. species richness of plants and
animals and aboveground carbon (C)) Steffan-
Dewenter et al. (2007); Blaser et al. (2018). However,
particularly in anthropogenic and specialized agro-
forestry systems, different shade cover rates would be
poorly linked to biodiversity, for example orange
trees/cocoa association in Cameroon or leguminous
trees/cocoa in Central America. Despite consistent
results, shade cover is thus an acute proxy for only
few ecosystem services: mainly (i) carbon stocks and
(ii) cocoa yields that are logically linked to shade
cover. Provisioning of other ecosystem services, such
as medicine or agronomic services, may be more
dependent on the real nature of associated trees Bos
et al. (2007), itself depending on introduction and
management strategies by farmers. Agroforestry
systems often combine at least three different types
of trees: (i) Remnants that were left-alive, i.e. saved,
Agroforest Syst
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during deforestation, (ii) Recruits that have naturally
colonized the established agroforest and that have
been selected by farmers (iii) Planted trees that
farmers intentionally bring to the agroforest Ordonez
et al. (2014). As they are the direct outcome of
management choices, these three cohorts of trees may
constitute a powerful reading grid to analyze the
importance of farmers’ management choices on the
ecosystem services provision in cocoa agroforests.
The south Ivory Coast is a typical post-forest
region and producer of first-world cocoa where light
agroforestry systems are the most represented in
cocoa orchards. As the willingness of a majority of
farmers to introduce trees in their fields has been
recently highlighted Smith Dumont et al. (2014);
Sanial and Ruf (2018), this paper aims to understand
the impact of tree introduction management on
agroforests’ capacities to deliver ecosystem services
(carbon, diversity, food, timber, medicine and agro-
nomic support to cacao trees). More specifically, we
asked the following questions: (i) what is the
magnitude of the effect of the local environmental
factors alone, i.e. without any management, on
ecosystem services provisioning? (ii) What is the
relative role of each cohort in provisioning the
selected ecosystem services? (iii) For a given
ecosystem service, do the cohorts play a comple-
mentary role in optimizing the service provisioning?
This in-depth analysis builds an understanding of the
farmers’ rationale behind the wide diversity of cocoa
agroforestry systems. This understanding is precious,
as cocoa farmers are mainly smallholders and cocoa
production is organized at their level. Any policy
aiming to enhance ecosystem services provisioning
would thus have to deal with farmer’s management
practices and preferences.
Material and methods
Study area
Data were collected in Ivory Coast between January
2015 and April 2018 on four regions: Akoupe
´(20
fields), Divo (49 fields), Gue
´yo (19 fields) and
Meagui (49 fields) located along a climatic (from
1200 to 1500 mm annual rainfall), forest vegetation
(from semi-deciduous to evergreen forest) and his-
torical (from the old cocoa zone of the East to 1970s’
pioneer fronts of the West) gradient (Fig. 1).
Fig. 1 Location of the study regions along a climatic, forest vegetation and historical gradient
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Paradoxically, the old cocoa zone has the youngest
plot (10–20 years old) as farmers have already
planted two or three times cocoa on the same field
and the West has the oldest fields: farmers started
planting cocoa in the 1970s’. In each region, fields
were located in one to three neighboring villages.
Data collection
Ethnobotanic inventories were established in 137
sampled cocoa fields covering 210 hectares in total.
Single field areas ranged between 1 and 2 hectares.
Every associated tree that farmers didn’t have the
intention to fall during next field’s weeding was
inventoried. Botanical names, introduction mode (i.e.
cohorts’ belonging) and uses were recorded. Species
characteristics have been found in Ake Assi (2011)
flora (Raunkiaer biological types) and PROTA4U
online database (specie habitat; more details in
Supplementary material). Diameters at Breast Height
(DBH) and heights were measured on a subset of 40
fields. A large set of associated local (7), landscape
(7) and historical (3) variables were simultaneously
recorded (see Table 1). Each sampled field was GPS
mapped to measure its area, average altitude and
slope. Fields’ history (age, previous land use, timber
logging) was recorded during farmers’ interviews.
Fields’ surroundings land use (in a 300m radius) was
collected with a GPS field map to accurately
discriminate cocoa agroforests, secondary forests
and secondary fallows. GPS way-points were then
drawn into polygons on Google Earth images. Soil
data at local scale were extracted from CNRA
Table 1 Local, landscape and historical environmental variables recorded for the 137 sampled cocoa fields
Category Variable Source Unit Range
Local Altitude GPS Meters 66–203
Slope GPS % 0.01–10.5
Soil Carbon Soil sampling g.100g11.19–1.85
Soil N Soil sampling g.100g10.10–0.17
pH Soil sampling 5.5–6.75
Average annual temperature WorldClim oC 25.6–26.5
Precipitation (dryest trimester) WorldClim Millimeters 75–139
Landscape Forest GPS, Google Earth % area 0–49
Marshes GPS, Google Earth % area 0–96
Other perennial crops GPS, Google Earth % area 0–38
Forested fallow GPS, Google Earth % area 0-60
Cocoa GPS, Google Earth % area 0.5–95
Urban GPS, Google Earth % of land 0–15
Annual crops GPS, Google Earth % of land 0–33
History Previous land use Farmers interviews Category
Field age Farmers interviews years 1–64
Forest logging Farmers interviews Category
Logging (1) or not (0)
Table 2 Description of the studied cocoa agroforestry sys-
tems: age and density of the cocoa plantation and values of the
ecosystem services
Variables Units Median [5%;95%]
Cocoa Fields
Age years 29 [7;50]
Density cocoa trees.ha
-1
30 [4;98]
Ecosystem Services
Carbon (other trees) MgC.ha
-1
8,2 [0.8;30]
Shannon adiversity 2,22 [1.05;2.99]
Food use trees.ha
-1
14 [1;57]
Agronomic use trees.ha
-1
20 [0;41]
Medicinal use trees.ha
-1
2,5 [0;22]
Timber use trees.ha
-1
1 [0;10]
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database (2015) and local climate data was extracted
from Worldclim database Fick and Hijmans (2017)at
field scale with a 2.5 minutes resolution (Table 2).
Quantifying ecosystem services
Carbon
DBH and Height measurements were used to estimate
the tree Above-Ground Biomass (AGB) using the
BIOMASS package Rejou-Mechain (2018). AGB
values were then converted into carbon using the 0.48
conversion factor value according to IPCC (2013).
Diversity
We used two measures of diversity aand b, both
estimated at order q=1, i.e. Shannon diversity Marcon
et al. (2014). adiversity was calculated for each field
and for each cohort in each field. bdiversity was
calculated between pairs of cohorts at field scale to
assess the cohort complementarity Marcon et al.
(2012). All calculations were made using the
Entropart package Marcon and He
´rault (2015).
Use values
Use values were calculated on four main uses: food,
timber, medicine and agronomic services to cocoa
trees (fertility, shade, water availability, etc...). Based
on farmers declarations and for each use, every tree
was coded 0 if the farmer and his household did not
use it and 1 if the tree was actually used. Then, for
each use, the use value was the number of trees.ha1
coded 1. These values were calculated by cohort and
by field. bdiversity was also calculated between pairs
of cohorts at field scale to assess cohort complemen-
tarity in furnishing a given service.
Data analysis
Effect of environmental factors on service
provisioning
The ability of the recorded environmental factors to
predict the 6 evaluated ecosystem services was
assessed under a normal linear modeling framework.
For each ecosystem service, the best model was
selected using a stepwise selection procedure based
on the Akaike Information Criterion. Variance par-
titioning Legendre and Legendre (2012) was then
applied to the final models to decipher the relative
importance of historical, landscape and local envi-
ronment variables in shaping the values of the
selected ecosystem services.
The relative role of cohorts in service provisioning
To assess the role of each cohort in provisioning each
ecosystem service, we regressed the values of the
ecosystem service of interest of a targeted cohort
against the summed values for the non-targeted
cohorts. In doing so, we were able (i) to rank the
cohorts in terms of ecosystem services provisioning
and (ii) to test for positive, negative or absent links
between the values of a targeted cohort and the two
others. In other words, we were able to see if, when a
given service is high in a given field for a given
cohort, this service is high, low or averaged for the
other cohorts in this field.
Cohort complementarities in provisioning services
To evaluate the complementarity of the 3 cohorts in
storing carbon, we computed the ratio between the
carbon stocked by each individual tree over the
maximum carbon stock recorded for the species it
belongs to. We used this ratio as a proxy of tree
maturity and then compared the distribution of tree
maturity between cohorts.
To evaluate the complementarity of the 3 cohorts
in the total diversity of the field, we computed the
taxonomic bdiversity between all pairs of cohorts for
each field. We then compared the distribution of
taxonomic beta diversity between the 3 possible pairs
of cohorts.
To evaluate the complementarity of the 3 cohorts
in shaping the use values, we calculated, for each
field, the beta diversity of the 4 use values (food,
agronomic, medicinal, timber) between pairs of
cohorts. For instance, the beta diversity of two
cohorts having respectively use values of (10, 10, 0,
0) and (0,0,10,10) respectively is 2 while for use
values of (5, 5, 5, 5) and (5, 5, 5, 5) respectively, beta
diversity is 1. We then compared the distribution of
use values’ beta diversity between the 3 possible pairs
of cohorts.
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Results
In the 137 fields sampled, 6747 trees belonging to 45
different families, 129 genders and 213 species were
recorded. Among these trees, 500 are remnants
(7.4%), 2472 are recruits (36.6%) and 3771 have
been planted (56%). Among the non-exotic forest
species (n= 185), less than 12% have a strict
evergreen forest habitat. 41% can be found in semi-
deciduous forest and 32% in dry forests. 30% of all
forest species are typical secondary forest species
(Tables 3 and 4 in Supplementary material).
Median tree density is 30 trees.ha1, it varies
between 0 and 232. Aboveground C stocked by
associated trees also differs a lot from one field to
another and ranges between almost no carbon stock to
nearly 50 MgC.ha1with a median of 8.2 MgC.ha1.
Regarding use values, an average field gathered 14
food trees, 2.5 medicinal trees, 0.6 timber trees and
farmers expect from 5 trees to support cocoa
production (bring soil fertility, shade, maintain soil
humidity during dry periods, host ants to struggle
against cocoa pests...) but with high variability
between fields.
Effects of environmental factors
All together, environmental variables alone explained
between 0.02% (timber) and 28% (diversity) of the
service provisioning. The local physical environment
gather the main group of predictors (Fig. 2). The
main environmental variables retained include alti-
tude, average temperature and soil properties. Any
historical variable is retained only once (field age for
medicinal service). For diversity service, two land-
scape variables are retained: the proportion of land
occupied by cocoa and by other perennial crops
(Table 5 in Supplementary material for detailed
results). Use values are less linked to environmental
variables than adiversity or carbon.
Cohorts and service provisioning
For each service, one cohort stands out for its
overwhelming contribution (Fig. 3). Remnants stock
the most carbon (Fig. 3A). Even if 35% of fields have
known past logging, remnants still stock 54% of the
total carbon on average while recruits and planted
trees stock 28% and 18% respectively.
Recruits belong to 173 different species and are
the most diverse cohort (remnants present 77 differ-
ent species and planted ones, 76) (Fig. 3B). On
average, they are almost twice more diverse than
planted trees and over 3 times more diverse than
remnants. Farmers expect that they deliver agronomic
services to cocoa trees (Fig. 3D) and are also the main
providers of medicinal products (Fig. 3E).
Planted trees have a clear specific function. They
are the main providers of food (Fig. 3C). There is a
quartet of planted food trees found in almost all cocoa
fields: Mango (Mangifera indica,n= 407), Orange
(Citrus sinensis,n= 907), Avocado (Persea ameri-
cana,n= 638) and Kola tree (Cola nidita,n= 725).
These four species represent almost 40% of all
inventoried trees.
Finally, farmers find timber wood in recruits and to
a lesser extent in remnants (Fig. 3F).
0
25
50
75
100
Agronomic
Alpha diversity
Carbon
Food
Medicine
Timber
Services
Proportion of variance explained
Nature of variables
Covariance
History
Landscape
Local
Fig. 2 Proportion of the variance in ecosystem services
provisioning explained by local, landscape and history
variables
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Complementarities between cohorts in service
provisioning
In 96% of fields at least two different cohorts are
present and all the 3 cohorts are found in more than
65% of fields.
For carbon provisioning, each cohort brings trees
with different stages of maturity (Fig. 4A). Remnants
are the most mature (the median ratio of the carbon
stocked by each individual tree over the maximum
carbon stock recorded for the species it belongs to is
0.45), planted trees are mostly less mature (median
ratio of 0.16) and recruits are the least mature
(median ratio of 0.05).
For diversity, when each cohort is present, it is
complementary to others (Fig. 4B). Planted trees are
characterized by 26 species not found in other cohorts
and recruits bring 86 original species. These two
groups are the most complementary. Remnants bring
14 original species and are highly complementary to
planted trees (median bdiversity of 1.9). Remnants
and recruits are, in comparison with other pairs, less
complementary. Nevertheless, the bdiversity is, on
average 1.8 (Table 7 of the ten most frequent species
present in each cohort in Supplementary material).
Given that almost 60% of all species in our dataset
are present in only one cohort, each cohort brought an
original contribution to the agroforestry system.
Recruits comprise a lot of shrubs (37%) with some
having a pioneer strategy (16%) (Table 6 in Supple-
mentary material). Their habitat is mostly dense
humid forests and 42% of these species are secondary
forest species (Table 6 in Supplementary material).
Remnants are tall tree species without any pioneer
species nor any species of secondary forests. Their
habitat is dense humid forests. Finally, specific
planted species are exotic species, savanna food
species quoted beforehand and also medicinal species
whose seeds where brought by migrant farmers from
their region of origin such as Nauclea pobeguinii,
Acacia nilotica,Annona senegalensis,Detarium sene-
galense and Cassia sieberiana. Therefore, 42% of
specific planted species have a dry forest habitat
(Table 6 in Supplementary material).
Fig. 3 The importance of tree cohorts to understand service
provisioning in cocoa field. The observed values (dots) of a
targeted cohort are regressed (dashed lines) against the
summed values of the non-targeted cohorts with 95%
confidence intervals reported in shaded areas
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For use values, remnants and recruits are the most
similar (Fig. 4C) with a median bdiversity of 1.22.
When complementarity is high between uses, it is
thus due to planted trees. Yet, even if all levels of
complementarity are possible between planted trees
and other cohorts, the median bdiversity is high (1.6
between remnants and planted trees and 1.5 between
recruits and planted trees). Even if 67% of fields
present at least 3 of the 4 main declared uses, this
multifunctionality is not necessarily provided by
cohorts’ complementarity. Low complementarity is
marked in fields where farmers chose specialization
towards one single use (22% of fields): either only
one cohort is present or different cohorts are present
but provide the same use.
Discussion
Our results suggest that Ivorian cocoa agrosystems
are so shaped by human management of associated
trees (clearing forest, planting trees, selecting recruit,
logging) that ecosystem services are weakly linked to
environmental variables. In other words, two neigh-
boring fields in similar environmental conditions will
provide very different services according to farmers’
management approach and whether they have chosen
to associate trees to cocoa or not. Socio-economic
variables influencing farmers’ decisions about trees
association (market access, farmers’ knowledge about
trees, risks mitigation strategy, local governance,
non-forest tree products (NFTP) commercial
0.25
0.50
0.75
1.00
Planted Recruits Remnants
Origin of trees
Carbon stocked/Maximum carbon
Carbon
A
1.25
1.50
1.75
2.00
Planted/Remnants Planted/Recruits Remnants/Recruits
Pairs of cohorts
Beta diversity
Diversity
B
1.00
1.25
1.50
1.75
2.00
Planted/Remnants Planted/Recruits Remnants/Recruits
Pairs of cohorts
Beta diversity
Uses
C
Fig. 4 Testing for cohort complementarities in service provisioning (ADot density of Carbon stocked over maximum carbon for
each cohort. BDot density of bdiversity between pairs of cohorts. CDot density of use values’ bdiversity between pairs of cohorts.)
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opportunities) are thus more determinant than envi-
ronmental variables to predict the values of
ecosystem services. This “black box” of farmers’
decisions is investigated by social sciences. For
example, the latter show that land scarcity or risk
aversion are determining factors for agroforestry
adoption Gyau et al. (2015); Meijer et al. (2015).
Recent works in remote sensing have also attempted
to integrate large-scale mapping of fine socio-eco-
nomic data Watmough et al. (2016) in order to
upscale small scale results. However, even fine
remote sensing could not totally replace fieldwork
and data enabling the understanding of farmers’
decisions. This understanding is central to predict the
values of ecosystem services in cocoa fields at every
scale.
Cohorts provide different ecosystem services
Remnants play a major role in carbon storage. Large
trees are already known for their significant storage
contribution Saj et al. (2013); Andreotti et al. (2018);
Bastin et al. (2018). The median values (6.2 MgC.
ha1) have to be compared to carbon stocks of
evergreen (144 MgC.ha1) and semi-deciduous (88
MgC.ha1) forests in Ivory Coast FAO (2017).
Considering that cocoa trees store about 19 MgC.
ha1N’Gbala et al. (2017), the carbon content of the
agroforest represents, on average, one fifth of that
stocked in the anterior forest. As remnants come from
the former old-growth forest, one could expect that
their timber would be of interest for farmers.
However, this cohort presents a low timber use value
(Fig. 3F), meaning that the farmers’ intention is not to
harvest these trees even if 56% of remnants are listed
as commercial species according to Dupuy (1998) list
and hold thus a potential in terms of future timber
provisioning. If farmers’ interest in timber was to
increase due to better market conditions and secured
tenure rights, farmers could value these remnants as
timber trees. However, forest logging by industry
often happened without farmers’ consent and without
any compensation Ruf and Bini (2010). This dis-
courages farmers to introduce timber trees Sanial
(2018). Improving tree tenure security could partly
fill the gap between potential uses for timber (1262
trees from all cohorts belong to commercial species)
and farmers actual declared intentions (464 trees).
Recruits are the most diverse. The range of species
offered by recruit is remarkably wider than (i) what is
locally available for plantation in cooperative or
farmers nurseries (fruit trees, common timber trees,
exotic leguminous species) and (ii) what is saved by
farmers at the time of clear-cutting. This high
diversity may also be an indirect consequence of
the uses these trees are selected for: agronomy and
medicine. For instance, species that provide good
shade (Terminalia superba,Milicia excelsa,Termina-
lia ivorensis) are different from those used to cure
Malaria (Morinda lucida,Alstonia boonei,Monodora
myristica). Globally, 48% of recruits are expected to
support cocoa production (Fig. 3plot D). This
confirms the importance of agronomic service in the
choice of the trees to be preserved by West African
farmers Smith Dumont et al. (2014). Even if 81% of
fields have at least one agronomic service tree.ha1
in our dataset, the median value is only 5.6 trees.ha1
and this confirms that there is no large-scale re-
adoption of high-density traditional agroforestry
systems in this country Ruf (2011). Indeed, many
farmers seem to seek the optimal balance between
limiting dry period impact, enhancing their fields’
longevity and getting rid of what they perceive as dis-
services from traditional tree-rich agroforests (ro-
dents, black pod) Ruf (2011). In their view,
agronomic services are not expected from dense
and complex agroforests but from finely selected and
well-known recruits. Recruits also bring medicinal
resources (Fig. 3E). In our data set, malaria is the
main target of these medicinal trees with Morinda
lucida (n= 223) being the most used ( Table 7 in
Supplementary material). Its properties are known by
both local people and migrant farmers as it grows
everywhere from evergreen to Guinean dry forests
PROTA4U (2018). In Ivory Coast, where allopathic
medicine and drugs are available and consumed in
most rural areas, this finding, although already
documented by botanists Herzog (1994); Vroh et al.
(2015); Adou Yao et al. (2016), confirms that
allopathic and traditional medicines still coexist in
West African countries Diallo et al. (2006).
Planted trees play an important role in providing
food (Fig. 3C) with two distinct strategies: planting
food trees (i) when farmers planted cocoa trees or (ii)
when former monoculture cocoa fields aged Sanial
and Ruf (2018). In the latter case, dying cocoa trees
leave open spaces where farmers introduce fruit trees.
Agroforest Syst
123
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
In doing so, (i) they keep trunks of cocoa trees from
being directly exposed to sunlight, (ii) they alleviate
the decrease of cocoa revenues and (iii) they allow
the introduction of new cocoa seedlings under the
shade of these fruit trees. In fields close to urban
market opportunities, these trees may give birth to
local, informal and specialized fruit value chains as
shown by orange trees in Cameroon Dury and
Temple (1999). Elsewhere, food trees are a domestic
resource with some local fruit forest trees (Ricin-
odendron heudelotii (n= 84), Irvingia gabonensis
(n= 7)) coexisting with non-indigeneous species such
as Tamarind (Tamarindus indica,n= 13), Ne
´re
´
(Parkia biglobosa,n= 15) or Baobab (Adansonia
digitata,n= 9) brought by migrant farmers. Planted
trees are mainly introduced by direct seed sowing but
some farmers experiment with other strategies, for
example taking cuttings, preparing trees seedlings in
nurseries or grafting. Sometimes certified coopera-
tives provide farmers with forest or exotic
leguminous seedlings and future transformation of
the composition of planted trees may be expected
with the development of massive environmental
certification standards (UTZ, Rainforest Alliance).
However, such initiatives represent for the time only
131 trees of the whole dataset (1.9% of all trees and
3.5% of planted trees). This may be due to (i) the low
interest of farmers for trees they might not know or
not value, (ii) high mortality rates of seedlings not
adapted to the local environment combined with (iii)
strong uncertainties on premium benefits Ruf et al.
(2013); Sanial and Ruf (2018).
Advantages of diversifying trees’ origins
Regarding carbon stocks, each cohort is characterized
by a specific maturity level (Fig. 4A), which makes
their contribution to the present and future carbon
stocks highly complementary. Long term, recruits
could take over remnants in carbon stocking N’Gues-
san et al. (2019). However, given that after one cycle
of cocoa (30–50 years) farmers usually grow other
perennial crops, this long-term substitution may be
challenged in future by oil palm or rubber tree
monocultures where associated trees are not usually
kept. In other words, trees introduced nowadays
might not be remnant trees tomorrow. If this rotation
from cocoa to another perennial crop is not changed,
the impact of planting new trees may be very little at
short-term as compared to encouraging tree preser-
vation at the clearing step. Overcoming this
constraint would require halting the classical boom
and bust cycles of cocoa leading to the continuous
conquest of forest frontiers Ruf (1995) and finding
sustainable ways to maintain cocoa fields (and
companion trees) in the long-term. The cocoa sector
is facing a global challenge to meet growing demand
by increasing or maintaining cocoa production with-
out expanding the area under cocoa Vaast and
Somarriba (2014). As several authors show, some
farmers have already engaged in this transition Smith
Dumont et al. (2014); Gyau et al. (2015); Sanial
(2015) and adopt rehabilitation practices Jagoret et al.
(2017) that could ensure longevity to associated trees
and therefore the renewal of carbon stocks.
Regarding species diversity, the overall system
diversity is maximised by the coexistence of the 3
cohorts (Fig. 4B). Therefore, our results nuance the
hypothesis that farmers will tend to associate trees
with an overwhelming presence of low diversity food
and commercial trees that will lead to the disappear-
ance of complex agroforests Ruf (2011). Indeed, the
predominance of planted trees with a dietary function
does not imply low overall diversity of this cohort
and the species it brings in the system are original and
complementary to the species brought by other
cohorts. Moreover, the species brought and planted
by migrant farmers enrich the overall diversity. The
presence of these dry forest species in the South of
Ivory Coast might be of high interest for further
research, i.e adaptation of these species in different
environmental conditions, relative importance of
these human-introduced and functionally-different
species in future ecosystem trajectories He
´rault and
Piponiot (2018), behaviour of the enriched system to
future climate changes Aguirre-Gutie
´rrez et al.
(2019).
Regarding uses, the rather even distribution of b
diversity on uses for planted/remnants and planted/
recruits cohorts illustrates the high variety of agro-
forests’ profiles in the studied fields. When beta
diversity is high, farmers usually complement the tree
species (i) found at the clearing step and (ii) selected
in recruits with well-chosen planted trees to get the
range of uses they wish. Cohorts’ specialization in
providing one or several specific uses (Fig. 3) does
not mean that they do not participate at all in
providing other uses. (i) Food trees, predominantly
Agroforest Syst
123
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
provided by planted trees, may be found in the
recruits. For example, Irvingia gabonensis and
Garcinia kola can’t be planted by farmers as they
have not been widely domesticated. Indeed, Garcinia
kola dormancy lasts several months and is rarely
available in local nurseries. (ii) Agronomic services,
predominantly provided by recruits may sometimes
be expected from planted trees. Gliricidia sepium is
an exotic leguminous tree. (iii) Medicinal trees
predominantly provided by recruits may also be
planted. Local population has raised medicinal
knowledge on exotic species, like Psidium guayava
or Mangifera indica, introduced in West Africa
centuries ago. These agronomic and medicinal
planted trees are exotic species that farmers can’t
find in the recruits.
Synthesis and applications
The overriding role of human management on
ecosystem services provisioning, the importance of
specific cohorts in each service provisioning and the
existence of complementarities between cohorts
should be taken into consideration to set future
policies on environmental services for both local
population, global climate mitigation and diversity
preservation.
First, in order to enhance timber use potential and
favour contractualisation between timber industry
and cocoa farmers, securing trees outside forests’
tenure through national policy (land and tree rights)
and local arrangements’ framing (added-value shar-
ing) would provide economic diversification for
farmers and timber provision for the industrial sector.
If this value chain was to be developed, attention
should be given either to preserving remnants from
being logged down or to renewing trees. For farmers,
a real and strong economic interest to invest in timber
might be a sufficient incentive to grant this renewal.
Second, to strengthen complementarities between
human-brought (planted) and human-selected (re-
cruits +remnants) trees, private companies providing
trees to farmers according to their sustainability
commitments could provide them with valued trees
different from the ones they already plant or easily
find in recruits. By doing so, attention would be given
to diversifying the pool of species present in cocoa
fields. Providing what farmers can already find in the
recruit or what they already plant would merely be a
way to increase tree densities in fields. The agro-
forestry standard watched by certification (i.e. UTZ
2015 standard) is often the sole tree density variable
but (i) this might not be optimal to maximize the
studied ecosystem services and (ii) this does not
recognize the diversity of management type made by
local farmers (preserving trees during deforestation,
selecting naturally recruits and planting additional
trees). These management practices should be recog-
nized, acknowledged and correctly valued by
certification programs.
Third, carbon stocks are nowadays almost entirely
linked to management choices made at the clearing
step. This result questions the efficiency of carbon
compensation policies rewarding farmers in function
of the carbon stock. Indeed, such reward is an indirect
way of acknowledging past (sometimes decades ago)
clearing practices. It may lead to a paradoxical policy
rewarding some forms of “better” deforestation for
carbon storage sake. As preserving remnants while
clearing forest is irreplaceable at short and medium
terms for large-scale climate mitigation and as aging
cocoa fields are currently replaced by rubber and
palm monocultures, any policy for carbon sequestra-
tion should then be larger than a sector policy on
cocoa production. At landscape scale, policy should
encourage remnants preservation to ensure carbon
stock permanence. Those trees could even feed the
cohort of recruits with propagules thus allowing the
survival of the species throughout several cycles of
perennial crops.
To conclude, reading agroforestry systems through
the origins of trees provides an understanding of their
capacity to provide ecosystem services that includes
farmers management and decisions. Recent works on
cocoa agroforestry look for management strategies
ensuring trade-offs between ecosystem services
Andreotti et al. (2018). The reading grid we propose
provides a complementary management indicator to
the ones already taken into account in previous
studies (i.e. shade rate, cocoa trees density, forest
trees density, etc ...).
Acknowledgements The authors of this study thank
University Lyon 3, UMR Environnement, Ville et Socie
´te
´s
and CIRAD, UMR Innovations et De
´veloppement for funding
PhD research on this topic and Agropolis foundation for the
funding of field work and data collection (Convention
1502-303).
Agroforest Syst
123
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Author contributions Elsa Sanial, Franc¸ois Ruf, Michel
Mietton, Dominique Louppe and Bruno He
´rault conceived
the ideas and designed methodology. Elsa Sanial collected the
data. Elsa Sanial and Bruno He
´rault analysed the data and led
the writing of the manuscript. All authors contributed critically
to the drafts and gave final approval for publication.
Data availability statement Climatic data available from
https://www.worldclim.org/. Botanic characteristics data
available from https://www.prota4u.org/.
References
Adou Yao C, Kpangui KB, Vroh BTA, Ouattara D (2016)
Pratiques culturales, valeurs d’usage et perception des
paysans des espe
`ces compagnes du cacaoyer dans des
agrofore
ˆts traditionnelles au centre de la Co
ˆte d’Ivoire.
Revue d’ethnoe
´cologie 9:2–17
Aguirre-Gutie
´rrez J, Oliveras I, Rifai S, Fauset S, Adu-Bredu
S, Affum-Baffoe K, Baker TR, Feldpausch TR, Gvozde-
vaite A, Hubau W, Kraft NJB, Lewis SL, Moore S,
Niinemets U
¨, Peprah T, Phillips OL, Ziemin
´ska K,
Enquist B, Malhi Y (2019) Drier tropical forests are
susceptible to functional changes in response to a long-
term drought. Ecol Lett 22(5):855–865
Ake
´Assi L (2001) Flore de la Co
ˆte-d’Ivoire : catalogue
syste
´matique, bioge
´ographie et e
´cologie, I et II. Me
´moires
de botanique syste
´matique. Conservatoire et Jardin Bota-
nique ville de Gene
`ve, Gene
`ve, boissiera edition
Aleman JC, Jarzyna MA, Staver AC (2018) Forest extent and
deforestation in tropical Africa since 1900. Nat Ecol Evol
2(1):26–33
Andreotti F, Mao Z, Jagoret P, Speelman E, Gary C, Saj S
(2018) Exploring management strategies to enhance the
provision of ecosystem services in complex smallholder
agroforestry systems. Ecol Indic 94:257–265
Babin R, Ten Hoopen G, Cilas C, Enjalric F, Lumaret J-P
(2009) Impact of shade on the spatial distribution of
Sahlbergella singularis in traditional cocoa agroforests.
Agric For Entomol 12(1):69–79
Barlow J, Franca F, Gardner TA, Hicks CC, Lennox GD,
Berenguer E, Castello L, Economo EP, Ferreira J, Gue
´-
nard B, Gontijo Leal C, Isaac V, Lees AC, Parr CL,
Wilson SK, Young PJ, Graham NAJ (2018) The future of
hyperdiverse tropical ecosystems. Nature 559(7715):517–
526
Bastin JF, Rutishauser E, Kellner JR, Saatchi S, Pe
´lissier R,
He
´rault B, Slik F, Bogaert J, De Cannie
`re C, Marshall AR,
Poulsen J, Alvarez-Loyayza P, Andrade A, Angbonga-
Basia A, Araujo-Murakami A, Arroyo L, Ayyappan N, de
Azevedo CP, Banki O, Barbier N, Barroso JG, Beeckman
H, Bitariho R, Boeckx P, Boehning-Gaese K, Branda
˜oH,
Brearley FQ, Hockemba Breuer Ndoundou M, Brienen R,
Camargo JLC, Campos-Arceiz A, Cassart B, Chave J,
Chazdon R, Chuyong G, Clark DB, Clark CJ, Condit R,
Honorio Coronado EN, Davidar P, de Haulleville T,
Descroix L, Doucet JL, Dourdain A, Droissart V, Duncan
T, Silva Espejo J, Espinosa S, Farwig N, Fayolle A,
Feldpausch TR, Ferraz A, Fletcher C, Gajapersad K,
Gillet JF, do Amaral IL, Gonmadje C, Grogan J, Harris D,
Herzog SK, Homeier J, Hubau W, Hubbell SP, Hufkens
K, Hurtado J, Kamdem NG, Kearsley E, Kenfack D,
Kessler M, Labrie
`re N, Laumonier Y, Laurance S, Lau-
rance WF, Lewis SL, Libalah MB, Ligot G, Lloyd J,
Lovejoy TE, Malhi Y, Marimon BS, Marimon Junior BH,
Martin EH, Matius P, Meyer V, Mendoza Bautista C,
Monteagudo-Mendoza A, Mtui A, Neill D, Parada
Gutierrez GA, Pardo G, Parren M, Parthasarathy N,
Phillips OL, Pitman NC, Ploton P, Ponette Q, Ramesh
BR, Razafimahaimodison JC, Re
´jou-Me
´chain M, Rolim
SG, Saltos HR, Rossi LMB, Spironello WR, Rovero F,
Saner P, Sasaki D, Schulze M, Silveira M, Singh J, Sist P,
Sonke B, Soto JD, de Souza CR, Stropp J, Sullivan MJ,
Swanepoel B, ter Steege H, Terborgh J, Texier N, Toma
T, Valencia R, Valenzuela L, Ferreira LV, Valverde FC,
Van Andel TR, Vasque R, Verbeeck H, Vivek P, Vlem-
inckx J, Vos VA, Wagner FH, Warsudi PP, Wortel V,
Zagt RJ, Zebaze D (2018) Pan-tropical prediction of forest
structure from the largest trees. Global Ecol Biogeogr 27
(11):1366–1383
Beer J, Muschler R, Kass D, Somarriba E (1997) Shade
management in coffee and cacao plantations. Agrofor Syst
38(1–3):139–164
Bene J, Beall H, Cote A (1977) Trees, food and people: land
management in the tropics. Technical report, CRDI,
Ottawa (Canada)
Blaser WJ, Oppong J, Hart SP, Landolt J, Yeboah E, Six J
(2018) Climate-smart sustainable agriculture in low-to-
intermediate shade agroforests. Nat Sustain 1(5):234–239
Bos M, Steffan-Dewenter I, Tscharntke T (2007) Shade tree
management affects fruit abortion, insect pests and
pathogens of cacao. Agric Ecosyst Ant Environ 120:201–
205
Burgess R, Hansen M, Olken BA, Potapov P, Sieber S (2012)
The political economy of deforestation in the tropics. Q J
Econ 127(4):1707–1754
de Carvalho CM, Silveira S, La Rovere EL, Iwama AY (2015)
Deforested and degraded land available for the expansion
of palm oil for biodiesel in the state of Para in the
Brazilian Amazon. Renew Sustain Energy Rev 44:867–
876
Diallo D, Graz B, Falquet J, Traore
´AK, Giani S, Mounkoro
PP, Berthe
´A, Sacko M, Diakite
´C (2006) Malaria treat-
ment in remote areas of Mali: use of modern and
traditional medicines, patient outcome. Trans R Soc Trop
Med Hyg 100(6):515–520
Dupuy B (1998) Bases pour une sylviculture en fore
ˆt dense
tropicale humide africaine. Technical report, FORAFRI-
CIRAD, Montpellier
Dury S, Temple L (1999) Diversification of peri-urban small
farms toward fruit production in Yaounde
´(Cameroon).
Consequences for the development process and research.
Planetary Garden, pp. 531–535
FAO (2016) State of the world’s forests Forests and agricul-
ture: land-use challenges and opportunities. Technical
report, FAO, Rome
FAO (2018) The state of the world’s forests Required pathways
to sustainable development. Technical Report CC BY-
NC-SA 3.0 IGO, FAO, Rome
Agroforest Syst
123
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
FAO R (2017) Donne
´es forestie
`res de base pour la REDD+en
Co
ˆte d’Ivoire. Inventaire de la biomasse forestie
`re pour
l’estimation des facteurs d’e
´mission. Technical report,
Organisation des Nations Unies pour l’alimentation et
l’agriculture et Secre
´tariat exe
´cutif permanent REDD +,
Abidjan
Fick S, Hijmans R (2017) Worldclim 2: new 1 km spatial
resolution climate surfaces for global land areas. Int J
Climatol 37(12):4302–4315
Gibbs HK, Salmon JM (2015) Mapping the world’s degraded
lands. Appl Geogr 57:12–21
Gibson L, Ming Lee T, Koh LP, Brook BW, Gardner TA,
Barlow J, Peres CA, Bradshaw CJA, Laurance WF,
Lovejoy TE, Navjot SS (2011) Primary forest are irre-
placeable for sustaining tropical biodiversity. Nature
478:378–381
Gyau A, Smoot K, Diby L, Kouame
´C (2015) Drivers of tree
presence and densities: the case of cocoa agroforestry
systems in the Soubre
´region of Republic of Co
ˆte d’Ivoire.
Agrofor Syst 89:149–161
He
´rault B, Piponiot C (2018) Key drivers of ecosystem
recovery after disturbance in a neotropical forest. For
Ecosyst 5(1):2
Herzog F (1994) Multipurpose shade trees in coffee and cocoa
plantations in Co
ˆte d’Ivoire. Agrofor Syst 27:259–267
Jagoret P, Snoeck D, Bouambi E, Todem Ngnogue H, Nyasse
´
S, Saj S (2017) Rehabilitation practices that shape cocoa
agroforestry systems in central Cameroon: key manage-
ment strategies for long-term exploitation. Agrofor Syst
92(5):1185–1199
Kusters K, Ruiz Perez M, De Foresta H, Dietz T, Ros-Tonen
M, Belcher B, Manalu P, Nawir A, Wollenberg E (2008)
Will agroforests vanish? the case of Damar agroforests in
Indonesia. Hum Ecol 36:357–370
Legendre P, Legendre LF (2012) Numerical ecology, vol 24.
Elsevier, London
Marcon E, He
´rault B (2015) entropart: an R package to mea-
sure and partition diversity. J Stat Softw 67(1):1–26
Marcon E, He
´rault B, Baraloto C, Lang G (2012) The
decomposition of Shannon’s entropy and a confidence
interval for beta diversity. Oikos 121(4):516–522
Marcon E, Scotti I, He
´rault B, Rossi V, Lang G (2014) Gen-
eralization of the partitioning of shannon diversity. PloS
one 9(3):e90289
Meijer S, Catacutan D, Ajayi O, Sileshi G, Nieuwenhuis M
(2015) The role of knowledge, attitudes and perceptions in
the uptake of agricultural and agroforestry innovations
among smallholder farmers in sub-Saharan Africa. Int J
Agric Sustain 13(1):40–54
N’Gbala FN, Martinez Gue
´i A, Tondoh JE (2017) Carbon
stocks in selected tree plantations, as compared with semi-
deciduous forests in centre-west Co
ˆte d’Ivoire. Agric
Ecosyst Environ 239:30–37
N’Guessan AE, N’dja JK, Yao ON, Amani BH, Gouli RG,
Piponiot C, Zo-Bi IC, He
´rault B (2019) Drivers of bio-
mass recovery in a secondary forested landscape of West
Africa. For Ecol Manag 433:325–331
Ordonez J, Luedeling E, Kindt R, Tata H, Jamnadass R, Van
Noordwijk M (2014) Constraints and opportunities for
tree diversity management along the forest transition
curve to achieve multifonctional agriculture. Curr Opinion
Environ Sustain 6:54–60
Oswald J (2005) Dynamique des formations agroforestie
`res en
Co
ˆte d’Ivoire (des anne
´es 1980 aux anne
´es 2000).
Universite
´des Sciences et Technologies de Lille, Lille,
The
`se de doctorat en ge
´ographie
Pollini J (2009) Agroforestry and the search for alternatives to
slash-and-burn cultivation: from technological optimism
to a political economy of deforestation. Agric Ecosyst
Environ 133:48–60
PROTA4U (2018) PROTA4u
Rejou-Mechain M, Tanguy A, Piponiot C, Chave J, He
´rault B
(2018) BIOMASS Estimating aboveground biomass and
its uncertainty in tropical forests
Ruf F (1995) Booms et crises du cacao: les vertiges de l’or
brun. KARTHALA, karthala editions edition
Ruf F (2011) The Myth of complex cocoa agroforests: the case
of Ghana. Hum Ecol 39:373–388. https://doi.org/10.1007/
s10745-011-9392-0
Ruf F, Bini S (2010) Are cocoa farmers ready for timber? the
case of jasikan, ghana. In Technical report
Ruf F, N’dao Y, Lemeilleur S (2013) Certification du cacao,
strate
´gie a
`hauts risques. Inter-re
´seaux De
´veloppement
rural, page 7
Saj S, Jagoret P, Todem Ngogue H (2013) Carbon storage and
density dynamics of associated trees in three contrasting
Theobroma cacao agroforests of Central Cameroon.
Agrofor Syst 87(6):1309–1320
Sanial E (2015) A la recherche de l’ombre: analyse du retour
des arbres associe
´s dans les plantations de cacao ivoiri-
ennes. Me
´moire de master 2, Universite
´Lyon 3, Lyon
Sanial E (2018) L’appropriation de l’arbre, un nouveau front
pour la cacaoculture ivoirienne ? Contraintes techniques,
environnementales et foncie
`res. Cahiers agricultures, 27
Sanial E, Ruf F (2018) Is kola the enemy of cocoa? Critical
analysis of agroforestry recommendations made to ivorian
cocoa farmers. Human Ecology (first online), page 12
Saqib M, Akhtar J, Abbas G, Murtaza G (2019) Enhancing
food security and climate change resilience in degraded
land areas by resilient crops and agroforestry. In Climate
change-resilient agriculture and agroforestry, pp. 283–
297. Springer
Smith Dumont E, Gnahoua G, Ohouo L, Sinclair F, Vaast P
(2014) Farmers in Co
ˆte d’Ivoire value integrating tree
diversity in cocoa for the provision of ecosystem services.
Agrofor Syst 88(6):1047–1066
Steffan-Dewenter I, Kessler M, Barkmann J, Bos M, BUchori,
D., Erasmi, S., Faust, H., Gerold, G., Glenk, K., Gradstein,
R., Guhardja, E., Harteveld, M., Hertel, D., Ho
¨hn, P.,
Kappas, M., Ko
¨hler, S., Leuschner, C., Maertens, M.,
Marggraf, R., Migge-Kleian, S., Mogea, J., Pitopang, R.,
Schaefer, M., Schwarze, S., Sporn, S., Steingrebe, A.,
Tjitrosoedirdjo, S., Tjitrosoemito, S., Twele, A., Weber,
R., Woltmann, L., Zeller, M., and Tscharntke, T. (2007)
Tradeoffs between income, biodiversity, and ecosystem
functioning during tropical rainforest conversion and
agroforestry intensification. Proc Natl Acad Sci USA 104
(12):4973–4978
Taubert F, Fischer R, Groeneveld J, Lehmann S, Muller MS,
Rodig E, Wiegand T, Huth A (2018) Global patterns of
tropical forest fragmentation. Nature 554:519
Agroforest Syst
123
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Tscharntke T, Clough Y, Bhagwat SA, Buchori D, Faust H,
Hertel D, Holscher D, Juhrbandt J, Kessler M, Perfecto I,
Scherber C, Schroth G, Veldkamp E, Wanger TC (2011)
Multifunctional shade-tree management in tropical agro-
forestry landscapes: a review. J Appl Ecol 48(3):619–629
Vaast P, Somarriba E (2014) Trade-offs between crop inten-
sification and ecosystem services: the role of agroforestry
in cocoa cultivation. Agrofor Syst 88(6):947–956
Vroh BTA, Cisse
´A, Adou Yao C, Kouame
´D, Koffi Kouao J,
Kpangui KB, Koffi Be
´ne
´JC (2015) Relations entre la
diversite
´et la biomasse ae
´rienne des espe
`ces arbores-
centes dans les agrofore
ˆts traditionnelles a
`base de
cacaoyers: cas de la localite
´de Lakota (Co
ˆte d’Ivoire).
Afr Crop Sci J 23(4):311–326
Watmough GR, Atkinson PM, Saikia A, Hutton CW (2016)
Understanding the evidence base for poverty-environment
relationships using remotely sensed satellite data: an
example from Assam, India. World Dev 78:188–203
Publisher's Note Springer Nature remains neutral with
regard to jurisdictional claims in published maps and
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... carbon storage, biodiversity reservoirs). Notably, they can store more carbon than agricultural fields (N'Guessan et al 2019), even if those fields are conducted in agroforestry (Sanial et al 2022). The main factor that has driven the historical expansion of secondary forests in West Africa is the development of family farming (Bayas et al 2022), linked to rapid demographic growth, which results in a pioneer front dynamic (Pouliot et al 2012). ...
... As such, West African farmers cultivate clear-cut lands for a few decades before migrating elsewhere once soil fertility is depleted and then eventually returning again once fertility is restored after a few decades of fallowing (Ruf et al 2015). Despite the crucial importance of these secondary forests resulting from agricultural fallows in the functioning of human societies (Sanial et al 2022) and in the structuring of West African landscapes, there is still a serious lack of knowledge on the trajectories, and their main local and regional determinants, of forest recovery in this region of the world (Schroeder et al 2010). ...
... Secondary forests resulting from this deforestation represent a large part of the West African landscape and are valuable to local people. These secondary forests provide valuable ecosystem services, including timber and fuelwood, fodder for livestock, non-timber forest products, and also contribute to water purification (Amani et al 2021, Doua-Bi et al 2021, Sanial et al 2022. In order to ensure that these secondary forests can continue to provide these services and cleared land is reduced to a few suitable areas, it would be necessary to • Promote sustainable, i.e. non-shifting, agricultural practices such as agroforestry in an agro-ecological transition to ensure the maintenance of household income • Develop community-based management practices for secondary forests, which do not currently exist, so as not to tie the future of a given forest to an individual decision • Support commercial chains of non-timber forest products to increase economic benefits from secondary forests (which cannot yet produce timber) • Assess soil fertility to decide first the suitability of an area for agriculture, and if the site is not suitable compared to other nearby areas, conserve the area to recover forest. ...
Article
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In West Africa, very poorly documented are the recovery trajectories of secondary forests, and even less is known about the origin of the observed variability in recovery rates. To understand the relative importance of local and regional environmental conditions on these trajectories, we inventoried all trees larger than 2.5 cm DBH on 236 plots (0.2 ha), aged from 0 to 45 years plus controls, on eight chronosequences representing the typical regional North-South climatic gradient of West Africa. In a hierarchical Bayesian framework, we modelled recovery trajectories of biodiversity, aboveground biomass and floristic composition and tested the influence of variability in local (plot history, landscape context, remnant trees) and regional (climate and soil) conditions on recovery rates. Our results show that (a) diversity recovers faster than composition and biomass, (b) among the local variables, the number of remnant trees has a positive impact on recovery rates while the duration of agricultural cultivation has a negative impact, and (c) among the regional variables, the high seasonality of precipitation and climate, typical of the dry forests of the northern West African forest zone, leads to faster secondary successions. Our simulation approaches have indicated that poor regional conditions can be counterbalanced by adequate local conditions and vice versa, which argues strongly in favour of a diagnosis that integrates these two aspects in the choice of more or less active technical itineraries for forest restoration.
... 3.5.8. An urgent need to combine modelling design with the needs of small farmers to improve service supply capacity The optimisation of management practices is the primary way to increase the supply capacity of AFES (Kuyah et al., 2017;Sanial et al., 2022). However, there is a lack of research on optimising the composition, structure, and function of the AF ecosystem and the pathways to enhance service-provisioning capacity, which hinders the related management and decision-making. ...
Article
Agroforestry (AF) has become an important strategy in reconciling the contradictory requirements of environmental protection and economic development in ecologically fragile areas, and whose multiple ecosystem services provide effective ways to promote the restoration of degraded ecosystems in the region. However, agroforestry ecosystem services (AFES) are usually constrained by their generative elements (vulnerability, structure, function, and ecological assets) and service management—both crucial for informed decision-making which enhances AFES supply capacity and AF sustainable management. Karst rocky desertification (KRD) is a typical case in an ecologically fragile area, and within the KRD region greatly relevant for promoting AFES as a strategy for restoring degraded regional ecosystems and for achieving sustainable development goals. In this study, a total of 164 publications related to AFES that met a set of inclusion criteria were obtained through the Scopus database using the literature review method of searching, appraisal, synthesis, and analysis. From the systematic literature review results, (i) we found that the number of relevant publications generally exhibited a year-on-year growth trend, with AFES generation elements being the most common topic (68.11 % of publications), and service management research being the second most common (31.89 % of publications); (ii) we summarised the main progress and landmark results of AFES generation elements and service management research and explored the relevant key scientific questions; and (iii) the above information enlightened the key improvement areas of KRD control ecosystem within three aspects: natural environment, agricultural development, and human-environment relationship. This study provides agroforestry practitioners and relevant decision-makers with information for improving and managing the supply capacity of AFES, and also presents important insights on the KRD control ecosystem to land degradation restoration technicians.
Technical Report
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What are the conditions under which cocoa smallholders may be willing to reverse the trend from deforestation to 'agroforestation'. One of the best ways to answer these questions is to look at farmers' responsiveness to agroforestry/timber projects. This is what is tempted here with a recent agroforestry project launched by Pronatura and the University of Ghana to encourage farmers to plant timber trees in the Jasikan district, in the Volta region of Ghana. Among clear findings, projects are necessary to bring technical and market information and even planting material. However, for the time being, most farmers are not ready to intercrop timber trees in their cocoa farms but rather wish to 'cultivate timber' in separate places. Then cocoa and timber compete for land. Developers and agroforesters may have to accept this situation in the short term while working toward new forms of agroforestry. Farmers and developers/agroforesters will learn by doing. In all cases, the price and revenues drawn from a legal market of timber will be key factors of faster learning.
Article
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Climatic changes have profound effects on the distribution of biodiversity, but untangling the links between climatic change and ecosystem functioning is challenging, particularly in high diversity systems such as tropical forests. Tropical forests may also show different responses to a changing climate, with baseline climatic conditions potentially inducing differences in the strength and timing of responses to droughts. Trait‐based approaches provide an opportunity to link functional composition, ecosystem function and environmental changes. We demonstrate the power of such approaches by presenting a novel analysis of long‐term responses of different tropical forest to climatic changes along a rainfall gradient. We explore how key ecosystem's biogeochemical properties have shifted over time as a consequence of multi‐decadal drying. Notably, we find that drier tropical forests have increased their deciduous species abundance and generally changed more functionally than forests growing in wetter conditions, suggesting an enhanced ability to adapt ecologically to a drying environment.
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Meeting demands for agricultural production while maintaining ecosystem services, mitigating and adapting to climate change and conserving biodiversity will be a defining challenge of this century. Crop production in agroforests is being widely imple- mented with the expectation that it can simultaneously meet each of these goals. But trade-offs are inherent to agroforestry and so unless implemented with levels of canopy cover that optimize these trade-offs, this effort in climate-smart, sustainable intensification may simply compromise both production and ecosystem services. By combining simultaneous measurements of production, soil fertility, disease, climate variables, carbon storage and species diversity along a shade-tree cover gradient, here we show that low-to-intermediate shade cocoa agroforests in West Africa do not compromise production, while creating benefits for climate adaptation, climate mitigation and biodiversity. As shade-tree cover increases above approximately 30%, agroforests become increasingly less likely to generate win–win scenarios. Our results demonstrate that agroforests cannot simultaneously maximize production, climate and sustainability goals but might optimise the trade-off between these goals at low-to-intermediate levels of cover.
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Cocoa production in Côte d’Ivoire (40% of the world market) has tripled in the past 35 years even as the country’s forests are depleted. The chocolate industry, concerned about production so concentrated in one country and its dependence on the forest, is trying to convince smallholders to obtain ‘cocoa certification.’ This scheme, while couched in environmental terms, aims to increase cocoa yields and recommends the removal of kola trees from cocoa plots. This advice, ultimately largely ignored by the cocoa farmers, reflects a lack of understanding of farmer practices and kola tree’s economic, social, and cultural role. The chocolate industry reveals its vision for agroforestry as limited to production and demonstrates an unwillingness to participate in the smallholder-driven innovation system that is transforming Ivorian cocoa cultivation.
Article
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Remote sensing enables the quantification of tropical deforestation with high spatial resolution. This in-depth mapping has led to substantial advances in the analysis of continent-wide fragmentation of tropical forests. Here we identified approximately 130 million forest fragments in three continents that show surprisingly similar power-law size and perimeter distributions as well as fractal dimensions. Power-law distributions have been observed in many natural phenomena such as wildfires, landslides and earthquakes. The principles of percolation theory provide one explanation for the observed patterns, and suggest that forest fragmentation is close to the critical point of percolation; simulation modelling also supports this hypothesis. The observed patterns emerge not only from random deforestation, which can be described by percolation theory, but also from a wide range of deforestation and forest-recovery regimes. Our models predict that additional forest loss will result in a large increase in the total number of forest fragments-at maximum by a factor of 33 over 50 years-as well as a decrease in their size, and that these consequences could be partly mitigated by reforestation and forest protection.
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Background Natural disturbance is a fundamental component of the functioning of tropical rainforests let to natural dynamics, with tree mortality the driving force of forest renewal. With ongoing global (i.e. land-use and climate) changes, tropical forests are currently facing deep and rapid modifications in disturbance regimes that may hamper their recovering capacity so that developing robust predictive model able to predict ecosystem resilience and recovery becomes of primary importance for decision-making: (i) Do regenerating forests recover faster than mature forests given the same level of disturbance? (ii) Is the local topography an important predictor of the post-disturbance forest trajectories? (iii) Is the community functional composition, assessed with community weighted-mean functional traits, a good predictor of carbon stock recovery? (iv) How important is the climate stress (seasonal drought and/or soil water saturation) in shaping the recovery trajectory? Methods Paracou is a large scale forest disturbance experiment set up in 1984 with nine 6.25 ha plots spanning on a large disturbance gradient where 15 to 60% of the initial forest ecosystem biomass were removed. More than 70,000 trees belonging to ca. 700 tree species have then been censused every 2 years up today. Using this unique dataset, we aim at deciphering the endogenous (forest structure and composition) and exogenous (local environment and climate stress) drivers of ecosystem recovery in time. To do so, we disentangle carbon recovery into demographic processes (recruitment, growth, mortality fluxes) and cohorts (recruited trees, survivors). Results Variations in the pre-disturbance forest structure or in local environment do not shape significantly the ecosystem recovery rates. Variations in the pre-disturbance forest composition and in the post-disturbance climate significantly change the forest recovery trajectory. Pioneer-rich forests have slower recovery rates than assemblages of late-successional species. Soil water saturation during the wet season strongly impedes ecosystem recovery but not seasonal drought. From a sensitivity analysis, we highlight the pre-disturbance forest composition and the post-disturbance climate conditions as the primary factors controlling the recovery trajectory. Conclusions Highly-disturbed forests and secondary forests because they are composed of a lot of pioneer species will be less able to cope with new disturbance. In the context of increasing tree mortality due to both (i) severe droughts imputable to climate change and (ii) human-induced perturbations, tropical forest management should focus on reducing disturbances by developing Reduced Impact Logging techniques.
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Accurate estimates of historical forest extent and associated deforestation rates are crucial for quantifying tropical carbon cycles and formulating conservation policy. In Africa, data-driven estimates of historical closed-canopy forest extent and deforestation at the continental scale are lacking, and existing modelled estimates diverge substantially. Here, we synthesize available palaeo-proxies and historical maps to reconstruct forest extent in tropical Africa around 1900, when European colonization accelerated markedly, and compare these historical estimates with modern forest extent to estimate deforestation. We find that forests were less extensive in 1900 than bioclimatic models predict. Resultantly, across tropical Africa, ~ 21.7% of forests have been deforested, yielding substantially slower deforestation than previous estimates (35–55%). However, deforestation was heterogeneous: West and East African forests have undergone almost complete decline (~ 83.3 and 93.0%, respectively), while Central African forests have expanded at the expense of savannahs (~ 1.4% net forest expansion, with ~ 135,270 km2 of savannahs encroached). These results suggest that climate alone does not determine savannah and forest distributions and that many savannahs hitherto considered to be degraded forests are instead relatively old. These data-driven reconstructions of historical biome distributions will inform tropical carbon cycle estimates, carbon mitigation initiatives and conservation planning in both forest and savannah systems.
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We created a new dataset of spatially interpolated monthly climate data for global land areas at a very high spatial resolution (approximately 1 km 2). We included monthly temperature (minimum, maximum and average), precipitation, solar radiation, vapour pressure and wind speed, aggregated across a target temporal range of 1970–2000, using data from between 9000 and 60 000 weather stations. Weather station data were interpolated using thin-plate splines with covariates including elevation, distance to the coast and three satellite-derived covariates: maximum and minimum land surface temperature as well as cloud cover, obtained with the MODIS satellite platform. Interpolation was done for 23 regions of varying size depending on station density. Satellite data improved prediction accuracy for temperature variables 5–15% (0.07–0.17 ∘ C), particularly for areas with a low station density, although prediction error remained high in such regions for all climate variables. Contributions of satellite covariates were mostly negligible for the other variables, although their importance varied by region. In contrast to the common approach to use a single model formulation for the entire world, we constructed the final product by selecting the best performing model for each region and variable. Global cross-validation correlations were ≥ 0.99 for temperature and humidity, 0.86 for precipitation and 0.76 for wind speed. The fact that most of our climate surface estimates were only marginally improved by use of satellite covariates highlights the importance having a dense, high-quality network of climate station data.
Article
The tropics contain the overwhelming majority of Earth's biodiversity: their terrestrial, freshwater and marine ecosystems hold more than three-quarters of all species, including almost all shallow-water corals and over 90% of terrestrial birds. However, tropical ecosystems are also subject to pervasive and interacting stressors, such as deforestation, overfishing and climate change, and they are set within a socio-economic context that includes growing pressure from an increasingly globalized world, larger and more affluent tropical populations, and weak governance and response capacities. Concerted local, national and international actions are urgently required to prevent a collapse of tropical biodiversity.
Article
Agroforestry systems (AFS) can provide multiple ecosystem services (ES), partly due to their high (agro)biodi-versity. However, multi-criteria analyses studying trade-offs between multiple ES and exploring AFS management optimization paths are still scarce. Routine methods, such as regressions or weighted/non-weighted scorings, may reveal unsuitable because data collections hardly meet rigorous statistical designs and knowledge about ES can be limited in such complex systems. In this paper, we explore a novel approach based on algorithms identifying Pareto fronts to check for management schemes which favour the multi-functionality of complex agroecosystems. We based our study on the ground truth data from 58 cocoa-based AFS fields in Cameroon and chose to study three ES: cocoa production, aboveground tree carbon storage and natural pest control. The combination of expert knowledge and Pareto front algorithms enabled us to identify four clusters of increasing ES provision among the 58 plots: "bottom", "low-yield intermediate", "high-yield intermediate", and "top". Significant differences in associated tree communities and management strategies were identified across the four clusters. While highlighting clusters of AFS with common management strategies, the use of the Pareto front algorithm enabled us to draw significant lessons on cocoa-based AFS despite their high complexity. We believe that such an approach can be used to design suitable benchmarks for the study and improvement of multiple ES provision in complex agroecosystems.