Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
http://www.ijsk.org/ijrafs.html
AN EVALUATION OF EXTERNALITIES LINKED TO NIGERIAN
FORESTS
.
Sulaiman AdesinaYusuf, Mistura Adedoyin Rufai , Joseph Oluwaseun Komolafe
Department of Agricultural Economics,University of Ibadan, Nigeria
e-mail: [email protected], [email protected], [email protected]
ABSTRACT:
Forests produce goods and services (externalities) which are not reflected in conventional market
transactions and are rarely considered in government plans. Externalities can be positive (benefits) or
negative (loss) with values often difficult to assess. The identification and valuation of forest externalities
are essential for proper policy formulations and sustainable forest development in Nigeria. Using different
evaluation methods positive externalities and negative externalities were valued. Positive externalities
included are grazing, carbon sequestration, fuel wood and charcoal and biodiversity conservation. On the
other hand negative externalities identified for Nigeria were erosion floods and landslides and forest fires.
The positive externalities had a Total Economic Value (TEV) of N265.883 billion with fuel wood and
charcoal having the highest contribution of 41.62 percent while the negative ones had a TEV
ofN4.201billion. Both types of externalities had a net value of N261.682billion.From the foregoing,
Nigerian forests made net positive externalities to the Nigerian economy. In order to sustain these net
positive externalities to the Nigerian economy, there is need for forest conservation.
Key Words: Evaluation, Externalities, Nigeria, and Forest
INTRODUCTION
an estimated forest area of 4.11 million hectares,
comprising 2.72 million hectares of natural
production forests, 1.01 million hectares of
protection forest and 375,000 hectares of planted
forest.
Nigeria is characterized by different
ecological zones ranging from a belt of
mangrove swamps and tropical forest along the
coast to open woodlands and savannah on the
low plateau which extends through much part of
the country to the semi-arid plains in the north
and highlands in the east. The combined effect of
temperature, humidity and rainfall and
particularly the variations that occur in the
rainfall pattern of the natural vegetation zone
exerts a major influence on the types of
indigenous plants that grow or can be introduced
in any part of the country. However of all the
ecological zones in Nigeria, forests harbor the
bulk of the globally important biodiversity of the
nation even though they are small in extent when
compared to other ecosystems (USAID,
2008).According to the International Tropical
Timber Organization (ITTO 2011), Nigeria has
Nigeria’s forest provides significant
economic, social and ecological benefits for
citizenry. It is also of global importance as the
canopies of its multiple plant species help in
temperature modulation thus reducing the effects
of climate change while the various crop races of
grains originating from its core help feed the
world. Nigeria’s forests have continued to make
economic contributions to agriculture and the
nation’s national income even though the real
contributions from forestry may not have been
totally captured due to data paucity within the
country (Adekunle et al, 2010). Nigeria has lost a
vast amount of its forests as a result of various
human activities. Forests are cleared for
1
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
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environmental activities such as road projects,
agriculture, subsistence activities, logging,
mining and dam construction among others.
Timber concessions have been granted in
national parks and oil palm plantations are
replacing the natural forest. Wild life populations
decrease from poaching and destruction of their
habitats as a result of increasing desertification
and soil loss. Extreme activities such as forest
fires, tractor logging and other methods of land
clearing contribute to soil erosion and the
reduction in forest productivity. The biodiverse
ecosystems (old growth forests) are disappearing
at an even faster rate and presently, forests now
occupy about 923,767km2 or about 10 million ha
which is about 10 percent of the Nigerian forest
land area (IITA, 2010). Over dependence on
forest resources and the subsequent prolonged
deforestation has seriously threatened and
depleted the biodiversity resource of the
country’s forest ecosystem (Aremu et al, 2009).
threshold value of these externalities for the year
2010.
CONCEPTUAL
FRAMEWORK
FORESTRY EXTERNALITY
FOR
As forests, forestry and the environment
are concerned, externalities, public goods and
market failures are closely related. Externalities
and public goods represent two types of market
failure i.e. situations where the assumptions of
welfare theorems do not hold and as such market
equilibrium cannot be relied upon to yield pareto
optimal outcomes.
The distinction between private and public or
collective goods is often affiliated by
externalities. Public goods are nondepletable and
are mostly services (although sometimes called
goods) with such characteristic that one persons
use does not decrease the amount available to
others while private goods are goods where
consumption
by
one
person
prevents
consumption by another. Pure public goods are
non-excludable and non-rivalrious with external
cost or benefits (externalities) not represented in
markets. The examples of externalities and
public goods tend to overlap (Miller, 2006).
However, forests provide biodiversity, attractive
landscape, clean air which can be referred to as
public goods.
As the Nigerian forests disappear,
poverty continues to force people to exploit even
the relics of the remaining forest. With the high
rate of depletion, the importance of forest
resources have become more apparent and
people have become more sensitive about the
benefits they get from forests and the possible
losses if forest resources were destroyed. These
contributions are made up of benefits and losses
some of which are usually not priced at the
market price and are referred to as externalities.
Externalities associated with forest resources
create a gap between the value and the notional
price of forests either positively or negatively
(Ozturk, 2009). The determination of negative
and positive externalities in forests and forestry
in Nigeria is an essential ingredient in promoting
sustainable forestry developmentas there is an
inadequate recognition of public goods and
externalities for forestry (Croitoru, 2007) and as
a result, governments often allocate inadequate
funds for the maintenance of forests (Mathur and
Sachdeva, 2003).This study therefore aims to
examine some of the positive and negative
externalities related to the Nigerian forest
resources and forestry by determining the
The idea of externality is quite complex and
many definitions are found in literature (Merlo
and Croitoru, 2005). In economics, an externality
is a cost or benefit which results from an activity
or transaction and which affects an otherwise
uninvolved party which did not choose to incur
that cost or benefit. Externalities are the actions
of other agents in the economy which affect the
preference of a consumer (Mas – collel et al,
1995). Pearse (1990) indicated that externalities
are the market imperfections that occur when the
impacts of actions are not compensated through
markets. Such actions exclude those mediated by
price and those which affect profitability
(pecuniary externalities) which causes no
inefficiency.
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Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
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© 2013 IJRAFS & K.A.J. All rights reserved
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In environmental economics, an externality
exists when an agents utility or production
function depends directly on inputs chosen by
another agent without any particular attention
given to the latter’s well being. For goods with
externalities, unregulated market prices do not
reflect the full social costs or benefits of the
transaction as the benefits and overall cost of
such goods do not reflect the total costs inflicted
upon the society as a whole. Externalities can
have both desirable and undesirable impacts and
some have both. An externality favorable to the
recipient is usually called a positive externality
and conversely for a negative externality. The
existence of positive externalities will lead
markets to produce a smaller quantity of goods
than is socially desirable while negative
externalities will lead markets to produce a larger
quantity of goods and services than is socially
desirable. This refers to the market failure
associated with externalities and implies a
legitimate ground for government intervention
(Friedman, 1955).
and carbon sequestration. In erosion control they
serve as shelter belts, dune fixation rehabilitation
of eroded terrain and in land bank for soil
nutrient and structure maintenance (Oriola,
2009).Nigerian forests are also known for
wildlife and tourism, wildlife is particularly
varied because of the country’s location, size and
the ecological zones. The various species of trees
and plants serve as raw materials for very many
industries in the country and the wood, wax and
oils generated from the trees could also be
produced for export. Cash crops mainly cocoa,
rubber and oil palm dominate agriculture in the
forests as the area best supports the growing of
commercial trees crops while roots and tuber
crops are produced at subsistence levels.Forests
are also a major source of fuel wood and
charcoal (Oriola, 2009) and other non timber
forest products such as leaves, fruits, nuts, resins,
honey, mushrooms, chewing sticks, and cane
among others.
externalities and the total economic value of
nigerian forests
The total economic value is a concept in cost
benefit analysis that refers to the value derived
by people from a natural resource, a man made
heritage resource or an infrastructure system,
compared to not having it. The underlying logic
is to assess all the different benefits and
contributions of an asset into a single value
estimate. The TEV value can be broken down
into the use value, non use value, option value,
bequest value and existence value.
externalities associated with Nigerian forests
Externalities are those forest goods and services
which are not actively marketed but are also
valuable to other people other than forest
owners. Such goods and services are known to
have value but the value is often difficult to
assess. There are many positive and negative
externalities associated with forests which are
not normally reflected in conventional market
transactions.
Forests perform natural functions such as
watershed protection to control run off, soil
nutrient maintenance and contribute to
atmospheric regulation as in evapotranspiration
3
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
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Fig 1: Total Economic value of forests adapted from Croitoruet al, (2007).
TEV
Use value
Non use value
DIRECT
INDIRECT
OPTION VALUE
BEQUEST VALUE
EXISTENCE VALUE
(Removable
products from
nature e.g fish,
timber, water
e.t.c)
(Non removable
products in nature
e.g watershed, soil
conservation e.t.c)
(Potential/ diverse
use e.g source of
energy, raw
material,
recreation e.t.c)
(Potential source of
energy, raw
materials and
biodiversity for
future generations
(Conservation of
biodiversity habitat
and species for future
generation)
Damages by forest fires
Erosion, floods and avalanches due to poor or no forest management
Pollen and other allergic factors
While there is a widespread consensus on the
TEV concept, the boundaries between its various
components remain somewhat less clear (Randall
1997, Bateman 1994)
made up of both positive values (which add to
the TEV) and negative values (which decrease
the TEV) generated from forest activities.
Benefits such as biodiversity conservation, direct
use values (such as raw materials, fish, timber
etc) and carbon sequestration are named positive
externalities while all social costs incurred from
damages caused by forest fires, erosions and
floods etc. are negative externalities.
externalities as a component of the tev:
Externalities are an important consideration in
cost benefit analysis as both positive and
negative externalities and other forest outputs are
related to the TEV of forests (Croitoru et al,
2001). Within the theoretical concept of the
TEV, the entire range of forest outputs can be
more practically seen as markets, potential
markets and non market values. The TEV is
METHODOLOGY
Following Ozturket al, (2009) the major
externalities estimated in this study are carbon
sequestration, biodiversity conservation, grazing,
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Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
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fuel wood and charcoal, erosion, floods and
landslides and forest fires.
relative weight to attach to carbon compared
with other positive and negative impacts of
potential policies (Friends of the Earth, 2008).
sources of data: Data was gotten from various
literature and sources which include the
(FAOSTAT), National Biodiversity Strategy and
Action plan 2010, International Food policy
Research Institute, USDA National Agricultural
statistics and the Agricultural Development
Project (ADP) Annual Report 2010.
cost based approach: This method involves the
use of market prices and the quantity of the good
traded in the market. Market prices reflect the
willingness to pay for costs and benefits of forest
land use options. This may be affected by market
imperfections and seasonal variations (FAO,
1996)
VALUATION METHODS:
Different methods were used in this study to
estimate the values for externalities related to
Nigerian forest. The valuation methods include
substitute goods, shadow price, cost based
approach, benefit transfer approach, replacement
cost approach and restoration cost approach.
benefit transfer approach: This method entails
valuation using similar but extraneous
information. It involves the use of information
obtained on the valuation of environmental
goods and services elsewhere. Context or
locational attributes of the initial study may not
fully match the exercise at hand it may however
provide some measure to the importance and
benefits of environmental goods and services
(Mishra, 2006).
substitute goods: Substitute goods are goods
that are similar and can be used to satisfy the
same needs (Piana, 2005). The prices of
substitute methods are used to impute value for a
good or service when there is no developed
market or when market fails to capture its total
value, (Hutschimdt et al, 1983; Emerton, 2001).
As fodder grazed in forests does not have prices,
it is converted using the value of hay or barley
based on a comparism of their nutrient contents
and then its value is estimated using the price of
those products (Croitoru, 2008).
replacement cost: The replacement cost
technique generates a value for environmental
goods or services by estimating the cost of
replacing them i.e. they attempt to estimate the
additional cost that would be incurred were the
forest not present compared with the situation in
which forests are present,(Center for Agricultural
Bioscience International, 2005).
shadow price: This method of valuation uses
restoration cost: This method measures the
market prices but adjusts for transfer payments,
value of environmental goods by using the cost
market imperfections and policy distortions
of
recreating
(restoring)
the
original
(FAO, 1996). The use of shadow prices in
environmental goods or services. It is a variant of
carbon valuation are applied by governments in
the replacement cost technique,(Center for
policy and project appraisal to determine the
Agricultural Bioscience International, 2005).
Table 1: The use of valuation techniques for forest externalities in Nigeria
Externality
Value type
Output
Positive
externalities
Direct
value
use
Grazing
Indirect
value
use
Carbon
sequestration
Shadow price
Fuel wood and
charcoal
Cost
based
approach
Options value
Valuation
technique
Substitute
goods
5
Physical
indicators
Quantity
of
forage
produced
Net change of
carbon
sequestrated
Quantity
of
wood
Monetary
Indicators
Price of hay
Shadow price
of carbon
Market price of
fuel wood
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
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Negative
externalities
Bequest–
existence
value
-
-
Benefit
–
transfer
approach
Change
in
production
function
and
replacement
cost
Restoration
cost
Biodiversity
conservation
Erosion, floods
and landslides
Damages
forest fires
by
Protected area
Loss of
nutrients
-
soil
Cost
of
preserving
biodiversity
Cost
of
fertilizer
Cost
restoration
of
and grain all year round. It is estimated that only
3 percent of its 101 million animals are reared on
improved pastures while the remaining are
grazed. Veterinary costs are also reduced
because animals on pastures have fewer health
problems than those that feed in the barnyard
(Federal Ministry of Agriculture and water
resources, 2008).
carbon sequestration
Trees in the forest incorporate carbon from the
atmospheric Co2 into biomass. This function is a
component of indirect use value of forests and a
type of positive externality associated to it.
Carbon pricing takes many forms e.g the market
price per ton, shadow price applied by
government in policy and project appraisal or the
relative weight attached to carbon compared with
other positive and negative impacts of potential
policies. The value of Carbon sequestration is
estimated in this study using the shadow price of
carbon which is determined by estimating the
marginal abatement costs and social (damage
costs) for a range of different levels of emissions.
Nigeria has an estimated forest area of about
4.105 million hectares and the average grassland
productivity for the different ecological zones in
Nigeria per season in is 2,626.8kg/ha
(Aregheore, 2009). Total grass production in
Nigerian forests is therefore estimated
conservatively to be approximately 10.783
billion kilograms (10.783 milliontons). The
average price of all hay in US in 2010 was
$109.58 per ton (USDA National Agricultural
Statistics). Following Ozturk (2009), we assume
that hay from pastures have half the value of hay
from meadows i.e $54.79. From this information,
a conservative value of hay produced in Nigerian
forests in 2010 is thus valued.
Momodu el al, 2011 reveals that the cumulative
carbon uptake from Nigerian forests in 2010 is
approximately 10.40mtc while the shadow price
of carbon according to Friends of the Earth, 2008
is ₤26.5/t C , from these information we derive
the economic value of carbon sequestration.
grazing
fuel wood and charcoal
Nigeria has a land area of 92.4 million hectares
of which about 44 percent are under permanent
pastures which supports its domestic ruminants
(Federal Ministry of Agriculture and water
resources, 2008). Nigerian forests provide a
substantial amount of forage and fodder which
are of vital importance in Nation’s drive towards
self
sufficiency
in
agricultural
production.Nigeria still has a vast amount of
forage to be explored and as such feed costs are
reduced as farmers do not have to buy hay and
ranchers do not have to grow or purchase forage
Wood obtained from forests apart from being
used for commercial purposes in various forms
such as saw wood, paper products, furniture
making and electrical poles are also a major
source of energy especially in developing
countries. In Nigeria, wood fuel is an important
source of energy for domestic cooking and
heating in rural areas and the urban poor.
However, the demand for fuel wood in Nigeria’s
urban areas has been on the increase as a result
of major factors such as rural – urban migration,
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Nov. 2013. Vol. 1, No.1
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Biodiversity conservation is a bequest –
existence value of forests i.e. the value that
people place on the existence of forests
independent of the value of other uses. This
study used the benefit transfer approach in
valuing biodiversity conservation. Pearce et al,
2003 suggested that tropical forests have
biodiversity values that range between US $0.01
and US $21 per hectare. Even with the forest
losses, Nigerian forests are still high in
biodiversity and as such a value of US $18 per
hectare was assumed. In the National
Biodiversity Strategy and Action plan 2010, the
Nigerian Government made a commitment to
conserve 25 percent of the country’s forest area
with emphasis on protected areas such as forest
reserves, game reserves, National parks and wild
life sanctuaries and from these values the value
of biodiversity conservation is thus estimated.
urbanization, poverty, hikes in prices of petrol
and cooking gas among others (Babayaro et al,
2010). Fuel wood and charcoal are hardly traded
internationally butits local value however can be
significant in terms of the local economy (Pearse
et al,2001).
The total amount of fuel wood generated from
Nigerian forests can be determined by summing
the amount of fuel wood produced and the
amounts of wood used for charcoal making,Ojo
et al, 2011. According to the FAOSTAT, the
amount of wood fuel produced in 2010 is about
63,214,728m3 which is about 19,754,602.5 tons
while the amount of charcoal produced was
about 3,940,089 tons. Following Ojo et al, 2011
a weight related conversion factor of 4.5 is
applied for charcoal to give 17,730,400.5 tons of
wood. Fuel wood in the US south sold for an
average of $19.55 per ton in 2010, (Stuber,
2012) and from this the value of fuel wood
produced in Nigeria in 2010 can be determined.
erosion floods and landslides
The Forest canopies provide undisturbed covers
for soils below it and as such they are kept in the
steady state with the thickness of the top soil
maintained. Deforestation comes with negative
implications on the soil as they are exposed to
factors such as rainfall (which could lead to
waterlogging, salinization and alkanization,
floods and landslides), wind and human
activities such as land clearing for domestic
purposes, agriculture and mechanized farming.
All of which contribute to the loss of soil
nutrients.
biodiversity conservation
Biodiversity refers to the variety of life at all
levels (from genes to ecosystems) and the
ecological and evolutionary processes that
sustain it. Biological diversity in forests allows
species to evolve and dynamically adapt to
changing environmental conditions, maintain the
potentials for tree breeding and improvement and
to support their ecosystem functions (FAO,
2010). The forests zones in Nigeria are known to
serve as habitats for different mammals and
various species of birds. The wild life in Nigeria
is particularly varied because of the country’s
location, size and the ecological zones. There are
also many endemic plant species some of which
are economically viable while many are yet to be
scientifically discovered and utilized (USAID,
2008).High human activities in forests have led
to rapid alterations of ecosystems and as such
there is massive loss of biodiversity. The high
rates of deforestation and poaching activities
have led to the destruction of wild life habitats
and loss of wild life populations.
To estimate the value of such negative
externality, the replacement cost of soil
protection is employed. Erosion costs were
estimated with the amount of fertilizer need to
replace nutrients lost from the soil. The quantity
of fertilizer imported to Nigeria in 2010 was
900,000 tons (International Food Policy
Research Institute IFPRI, 2012) and the average
price of fertilizer was N86.705/kg (ADP, 2010).
The total cost of fertilizer imported is thus
estimated to be 78.035 billion naira.This amount
cannot be related to forests as there are no data
relating them. Following Orztuck et al, 2001 we
7
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
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assume that poor forest management induces just
5% of the total erosion in Nigeria. However, it is
worthy to note that the assumption of 5% of
erosion to forestry is very beyond the real share
considering that Nigeria has lost 95% of its
forest cover and irreversible soil losses are not
considered in this assessment.
slash and burn and land clearing has been
identified as a principal cause of fires. Fires
areused for pasture management for livestock,
honey gathering, animal tracking and hunting
and disposal of wastes among others in
agriculture and for other purposes such as land
clearing
for
infrastructural
and
estate
development. Annually cash crops such as
rubber and cocoa, grasses, timber and other
useful and non useful vegetation are destroyed
by fires and as such the economic impact of
forest fires cannot be overlooked in analyzing
forest externalities. However, there are no forest
fire statistics allowing for an analysis of the
causes, risks and extent of damage done by fires
(IFFN, 2006). Deforestation and environmental
degradation costs the country over 6 billion naira
annually (Butler, 2006) and as such this study
conservatively assumes that 5% of this cost is as
a result of forest fires. Forests fires in Nigeria are
not managed and so no extra costs are incurred
for controlling them.
forest fires
In Nigerian forests and savannah bush lands,
wild fires are a constant threat particularly in the
dry season. Majority of these fires are caused by
human activities as lightening fires are rare and
occur in the rainy season. Nigeria is losing up to
400,000 hectares of forest land annually to
deforestation (IITA, 2010b) and selective
exploitation of forests for economic and social
reasons. Fire is used as a work tool generally by
rural populations and the expansion of low input small holder agriculture that depends on
environmentally destructive practices such as
Table 2: Summary of information used for valuing externalities. (Exchange rates: N 151 to $1,
N 229.4 to £1, Source CBN, 2010)
Carbon Sequestration
Cumulative carbon uptake
26.5 million tons
Shadow price of carbon
£ 10.40 per ton
Local value
N 2,385.76
Grazing
Grass productivity
10.783 million tons
Price of hay from pastures( half price of hay from $54.79/ton
meadows
Local value
N 8,273.29
Fuel wood and charcoal
Wood fuel
19,754,602.5 tons
Charcoal (conversion factor of 4.5 to wood)
17,730,400.5 tons
Price of wood
$ 19.55
Local value
N 2,952.05
Biodiversity conservation
Area of forest conserved
25% of forest area
Value of conservation per hectare
$ 18
Local value
N 2,718.00
Erosion, Floods and Landslides
Quantity of fertilizer imported
900,000 tons
Value of fertilizer imported
N 78.035 billion
Forest Fires
Annual cost of deforestation and environmental N 6 billion
degradation
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RESULTS
Table 3: Some positive and negative externalities in Nigerian forests and their values.
Type of externality
Positive
Grazing
externality
Carbon
sequestration
Fuel wood and
charcoal
Biodiversity
conservation
TOTAL
Negative
Erosion, floods
externality
and landslides
Damages
by
forest fires
TOTAL
Quantity (t)
10,783,000
10,400,000
Value (000 N)
89,210,886
63,222,640
Value/ha
21,705.81
15,382.64
percentage
33.55
23.78
21,670,489
110,657,603
26,923.99
41.62
-
2,792,745
679.5
1.05
900
265,883,874
- 3,901,725
64,691.94
-943.39
100
-92.86
-
- 300,000
-72.99
-7.14
-4,201,725
-1,022.32
100
The value of some externalities associated with
Nigerian forests and forestry were estimated
conservatively to arrive at the total economic
value (TEV) of the nation’s forest. Positive
externalities had a value of approximately
N265.833 billion while the negative ones had an
approximate value of N4.201 billion, both with a
net value of N261.682billion.
Erosion, floods and landslides and forest fires
(negative externalities) had contributions of92.8
and 7.14 respectively. Nigeria has lost a major
part of its forests for various commercial
purposes. The continuous destruction of
vegetation in forests reduces infiltration and
increase runoff thus increasing the dangers of
erosion. Erosion generally reduces the
productivity of forests by decreasing the soil
water available for forest growth and through
loss of nutrients in eroded sediment (Elliot et al,
1999). The degradation of the nation’s forests is
also exacerbated by forest fires which contribute
to erosion and reduce the long term productivity
of forests by affecting the soil cover and
structure. (Neriset al, 2012).
The contributions of grazing, biodiversity
conservation and fuel wood and charcoal carbon
sequestration were 33.55, 23.78, 41.62 and 1.05
respectively with fuel wood and charcoal taking
the highest contribution. The importance of the
forage and fodder from Nigeria’s forests cannot
be overemphasized as forests provide a major
source of feed for both ruminant livestock and
wildlife. According to Kallah (2004), ruminant
livestock survival in Nigeria has depended
largely on the extensive native pasture browses
in forest reserves, natural wetlands and
woodlands and farm crop residue across and
within the various ecological zones.Fuel wood
and charcoal also had a high contribution.
According to Oriola (2009), the greatest single of
forests and woodlands is the provision of wood
fuel for domestic cooking and heating in rural
areas and among the urban poor.
CONCLUSION
The results of this study reveal the economic
value of some externalities associated with
Nigerian forests and forestry. Positive
externalities refer to the benefits derived from
forests while negative externalities are the losses
incurred from forest depletion. According to
NBSAP (2010), the commercial value of
biological diversity in Nigeria’s forests exceeds
the cost of conservation and this is reflected with
the high value of positive externalities and low
9
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
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value of negative externalities in the results. The
value of positive externalities estimated in this
study can be considered as underestimated as
other positive externalities such as climate
regulation, soil protection, watershed protection
and other forest products such medicinal plants
and new grain varieties were not considered in
this study. With the high rate of deforestation in
Nigeria, there is the need for the consideration of
these non market forest externalities to promote
the sustainable management of forests. Forests
need to be preserved so they may continue to
generate positive externalities while negative
externalities are prevented or reduced to the
minimum.
A major constraint to this study was the
unavailability of adequate data on forests in
Nigeria. There is the need for an efficient data
collection system for all forest resources and
externalities to promote research and the
development of new conservation techniques for
our forests. This would also assist in proper
policy formulation and the provision of adequate
budgets for forests and their conservation in
Nigeria.
6.
7.
8.
9.
10.
11.
12.
REFERENCES
1.
2.
3.
4.
5.
Adekunle.V.A.J.,Olagoke.A.O.and
Ogundele.L.F. (2012): Rate of timber of
production in a tropical rainforest ecosystem
of south western Nigeria and its implications
on sustainable forest management. Journal
of Forestry research 2010 vol 21(2) Pp 225 –
230.
Agricultural Development Project (ADP),
(2010): Annual Report, 2010.
Aremu,O.T., Osayimwem, F.E and Emalue,
G.U. (2009): Estimate of biodiversity
indices in macro flora and fauna resource of
Gele – gele forest reserve, Edo state,
Nigeria. Journal Of Agriculture and
Biological Sciences 5(5): 660 – 667.
Babanyara,Y.Y and Saleh,U.T (2010):
Urbanisation and the choice of fuel wood as
a source of energy in Nigeria. Journal of
human ecology 31(1) Pp 19 – 26 (2010).
Bateman, J. (1994): Research methods of
valuing environmental benefits in Dubgaard,
I.,Bateman and Merlo, M. eds Identification
and valuation of public benefits from
13.
14.
15.
16.
17.
10
farming and countryside stewardship,
WissenschaftsVerlag, Vinkkiel.
Buchanan. J and Stubblepine W.M (1962):
“Externality” Economica 29 (116) Pp371 –
384
Butler,R.A.,
(2006):
Nigeria’s
Environmental profile. Mongabay.com
http://rainforest.mongabay.com/20nigeria.ht
m
Croitoru, L. Gatto, P. And Merlo, M.
(2001): Non-wood forest products (NWFPs)
as a component of the total economic value
(TEV) of
mediterranean forests: First
results of ongoing research, Harvesting of
Non-Wood
Forest
Products-Seminar
Proceedings, FAO ECE-ILO International
Seminar, 2-8 October, MenemenzmirTURKEY.
Croitoru 2008): Value of Mediterranean
Forests.
The
Encyclopedia
of
earth.www.eoearth.org Updated 4,2011
Editor Mark Mc Ginley
Elliot, W.J., Page – Dumroese, D. and Peter,
R. (1999): The effects of forest management
on erosion and soil productivity. USDA
forest service – Moscow Idaho.
Environmental Research and policy Analysis
ERPA (2011): TheTotal Economic Value of
Maasai Mau, Trans Mara and Eastern Mau
Forest Blocks of Mau Forest Kenya. Lake
th
Victoria Basin Commission Secretariat, 6
Floor, Re-insurance Plaza, P.O.Box 151040100, Kisumu, Kenya. www.Ivbcom.org
FAO (2010): Global Forest Resources
Assessment 2010 Main report. FAO
FORESTRY
PAPER
163.http://www.fao.org/docrep/013/i1757e/i
1757e.pdf.
FAO(1996):Valuation
techniques
for
Environmental Assessment of Forest
Projects. FAO Corporate Document
Repository.
http//www.fao.org/docrep/ac625e/625eoo
.htm
Federal Ministry of Agriculture and water
resources
FMAWR
(2008): Federal
Republic of Nigeria, Draft national security
program 2008:107.
Fourth National Biodiversity Report, Abuja
2010 (27 Aug 2010).
Friedman, M. (1955): The role of
government in education in Solo, R.A ED,
Economics and the public interest. New
Brunswick, NJ: Rutgers University press.
Friends of the Earth (2008): The price of
carbon; what should it be and why?
Seminar, Mercer suite, Royal society, 8th
July
2008.http://www.foe.co.uk/resource/reports/
carbonpriceseminar2008.pdf
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
http://www.ijsk.org/ijrafs.html
29. Millar.
N.H
(2006):
Notes
on
microeconomic theory, version; Aug, 2006.
www.hks.havard.edu
30. Mishra (2006): Valuation of environmental
goods and services: An institutionalistic
assessment
a. ISBN: 8t 89233-39-4 in book:
Environmental
and
Natural
Resources:
Ecological
and
economic
b. perspectives First edition ,New
Delhi
31. Momodu, A.S., Siyanbola, W.O., Pelemo,
D.A., Obioh, I.B. and Adesina, F.A. (2011):
Carbon flow pattern in the forest zones of
Nigeria as influenced by land use change.
African Journal of Environmental Science
and Technology Vol 5(9) Pp 700 – 709.
National Adaptation and Strategy plan of
Action on climate change for Nigeria, Nov,
2011.
32. Ojo, O.S, Okonkwo, M.C, Oladele, O.N,
Jaiyeoba,W.A, Suleiman, R.A and Yakubu,
M. (2012): Evaluation of wood fuel
exploitation and its relative consumption
pattern in Kaduna metropolis. Journal of
educational and social research volume 2(7)
October 2012. Pp 134 – 143.
33. Okoye, C.U (2010): Soil Erosion and
Damage control costs in Nigerian small
farms: Implications for farm growth and
sustainability.
34. Oriola, E.O (2009): Forestry for sustainable
development in Nigeria. International
Journal of African studies. Issue 1 (2009) Pp
11 – 16.
35. Ozturk, A., Turker, M. F.and Pak, M.
(2009): Economic valuation of externalities
linked to Turkish forests. African Journal of
Agricultural Research Vol. 4 (11), pp. 12511259,
November,
2009.
http://www.academicjournals.org
ISSN
1991-637X © 2009 Academic Journals.
36. Pearse, P.H (1990): Introductory to forest
economics. The University of British
Colombia press Canada 226p.
37. Piana
V
(2005)
Economic
Web
Institute.www.economicswebinstitute.org
38. Randal, A. (1991): Total and non-use value
in Branden, J.B. and Kolsatd, C.D eds
measuring the demand for environmental
quality, Amsterdam: North Holland.
39. Shiawoya.E and Tsado. D.N (2011): Forage
and Fodder crop production in Nigeria:
Problems and Prospects. World journal life
science and medical research2011 vol 1(4)
Pp 88 – 93.
40. Stuber,D. (2012): Wood fuel prices in US
South continue to fall. F2M market watch
www.forest2market.com
18. Friends of the Environment (2005): Nigeria
Energy Study Report; Enabling urban poor
livelihood policy making, understanding the
role of energy services. Ka R 8348,
University of Twente.
19. IITA (2010a): The state of Nigeria’s forests
by David Ladipo. R4d review Issue 4,
specials 8 April 2010. www.iita.org
20. IITA (2010b): Conservation of Africa’s
forest offers great benefits. Press releases –
2010 archive. www.iita.org
21. International Food Policy Research Institute
(IFPRI), (2012): Impact of fertilizer
subsidies on the commercial fertilizer sector
in Nigeria. Evidence from previous fertilizer
subsuidies. By Hiroyuki Takeshima,
Ephraim Nkoya and Sayon Deb. Nigeria
Strategy Support Program II. Working paper
No. 23/ Dec. 2012.
22. International Forest Fire news (IFFN),
(2006): Fire situation in Nigeria. IFFN,
No.34 (January to June 2006) Pp 89 – 93.
ISSN 1029 – 0864.
23. International Tropical Timber Organization
(ITTO), (2011): Status of tropical rainforest
management (Nigeria). Publication of the
International Tropical Timber Organization.
Sustaining Tropical Forests.
24. Johnson D (2003): Replacement Cost Asset
valuation and the Regulation of Energy
Infrastructure Tariffs Theory and Practice in
Australia. CRI International series 8 (Centre
for the Study of Regulated Industries).
University of Bath, School of Management
25. Kallah, M.S (2004): Rangelands in Nigeria;
A partial resource appraisal towards
improving livestock production. In forage
production and management in Nigeria,
edsGefu, J.O and Amodu, J.T. Nation
animal production research institute,
Ahmadu Bello University, Zaria, Nigeria.
2004;1 – 4.
26. Mas – Colell, A.,Whinston, M.D. and
Green, J.R. (1995): Microeconomic theory,
Oxford University press 198 Madison
Avenue, Newyork, Newyork 10016.
27. Mathur, A.S., Sachdeva, A.S (2003):
Towards an economic approach to
sustainable forest development, working
paper series No 2/2003 – pc, Perspective
Planning Division Planning Commission,
Government of India.
28. Merlo
M,Croitoru
L.(2005):Valuing
Mediterranean Forests: Towards total
economic value.
Edited bycenter for
Agricultural Bioscience International (CABI).
CABI Publishing 875 Massachcusetts
th
Avenue 7 Floor Cambridge, MA02139 USA.
www .cabi-publishing.org
11
Nov. 2013. Vol. 1, No.1
ISSN 2311-2476
International Journal of Research In Agriculture and Food Sciences
© 2013 IJRAFS & K.A.J. All rights reserved
http://www.ijsk.org/ijrafs.html
41. Townbridge. J, (2008): The significance of
biodiversity; Why we should protect the
natural environment. Serendip studio, March
2008.
42. Understanding dairy market prices (2013):
Prices received for hay: Source USDA
National Agricultural Statistics. © Brian
Gould Agricultural and applied economics,
UW.
Madison
http://future.aae.wisc.edu/data/monthly_valu
es/by_area/2053
43. USAID (2008): Nigeria biodiversity and
tropical forestry assessment. Maximizing
agricultural revenue in key enterprises for
targeted sites (markets).
12