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LECTURE XIV
FORESTRY DEVELOPMENT
Planning Forestry Development
 The
world's natural forests are
experiencing land use change due to
both direct and indirect causes.
 However forest related land use
changes have complex socio-economic,
cultural and political foundations.
 Thus one cannot assume simple and
static cause-effect relationships.
Direct causes of change

Direct causes include immediate human land
use activities that change forest cover in a
local area.
 Key drivers include:
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Agricultural expansion
Infrastructure development
Wood extraction
Climate change
Fire and
Alien invasive species.
Agricultural expansion

Agricultural expansion has been identified as
a major factor in almost all studies on
deforestation.
 In the 1990s, according to the United Nations
Environment Programme (UNEP), 70% of
total deforested areas were converted to
permanent agriculture systems.
 Increases in food production have been at the
expense of millions of hectares of forest.
Infrastructure development
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Infrastructure development (road construction, dams,
mining, power stations, etc.) is an important direct
cause of forest-related land use change.
Road construction particularly, is a key factor in
triggering deforestation as it tends to open up areas
of undisturbed, mature forests to pioneer settlements,
logging, and occasionally unsuitable forms of
agriculture.
The ensuing fragmentation also increases the
exposure of forests to the dangers of poaching, alien
invasive species, fires and pest outbreaks.
Infrastructure development
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Large dams construction has led to the loss of forests
and wildlife habitat, species populations and the
degradation of upstream catchment areas.
Mining corporations and individual miners are also
notably responsible for the clearance of large areas
of forest in some countries.
Wood Extraction

Another direct cause of forest land use change is
wood extraction from natural forests.
 Despite the growing importance of plantations as a
source of wood supply, wood extraction in the form of
commercial timber, poles, fuelwood, and charcoal
continues to degrade mature natural forests in many
parts of the world.
 In the case of commercial logging, tree removal
methods are frequently destructive and
unsustainable.
 This is often the case on steep slopes and in
sensitive ecosystems such as mangroves.
Fire

Fires are a key driver of forest land use
change.
 Yet, fire is a paradox as while it can cause
extensive ecological, economic, and social
damage it can also be extremely beneficial
through nutrient recycling and regeneration.
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Fire is a natural part of the forest cycle with some
tree species, notably Lodgepole Pine and Jack
Pine being able to germinate only after they have
been exposed to fire.
Burning quickly decomposes organic matter into
mineral components that cause a spurt of plant
growth, and can also reduce disease in the forest.
Fires in contrast cause considerable
environmental, health, economic and social
damages and cause forest loss and degradation.
Climate Change
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Today's fragmented and degraded forests are
vulnerable to climate change with up to 30% of
forests likely to be affected by climate change by the
year 2050 according to an Intergovernmental Panel
on Climate Change report.
Higher temperatures and changes in rainfall threaten
tropical montane forests, boreal forests and
Mediterranean-type, fire-prone forests.
Effects of greenhouse gases can affect the
processes of budding, flowering, fruiting, leaf
senescence, frost hardiness, wood quality, branching
and insect susceptibility.
The risk of serious pest and disease infestations
increase with more changes in climate.
Extreme weather events, such as droughts and
floods, pose other risks to forest ecosystems.
Alien invasive species
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As the global movement of people and products
spreads, so does the movement of plant and animal
species from one part of the world to another.
Often these alien species are economically important
and enhance the production of forest commodities in
many parts of the world.
In some cases species introduced intentionally
become established in the wild and spread at the
expense of native species, affecting entire
ecosystems.
Alien invasive species
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Worse still is invasive by alien species that are
introduced unintentionally, such as disease
organisms that can devastate an entire tree species
(e.g. Dutch elm disease and chestnut blight in North
America) or pests that can have a major effect on
native forests or plantations (e.g. gypsy moths and
long-horned beetles).
As global trade grows, so does the threat from
devastating invasive species of insect and pathogen.
These could fundamentally alter natural forests and
wipe out tree plantations, the latter being especially
vulnerable because of their lower species diversity
Indirect causes of change

Result from social and institutional processes
that may indirectly impact forest cover from a
local, national, or international level.
 Forest land use change is seldom
straightforward, often being driven through a
complex mix of socio-economic, cultural, and
political factors.
 Such factors in turn result from the combined
actions, decisions and behavior of multiple
agents ranging from national governments to
international financiers to impoverished
landless people.
Indirect causes of change
 Prominent
Indirect causes include:
 Poverty.
 Market
failure and perverse incentives,
 Corruption
 Inappropriate state policies and institutional
failure
 Population pressure and
Poverty

Poverty is popularly cited as a principal driver
of forest loss and degradation.
 In reality, however, the evidence for such a
straight-forward relationship is weak and
sometimes conflicting.
 The empirical evidence for the historical
relationship between economic growth, a
growing middle class, consumption levels and
forest decline is perhaps a little better
understood but also remains weak and
fragmented.
Poverty
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What is evident however is that there is a
causal relationship, or more accurately
several relationships, that need to be better
understood.
 More reassuringly, there is some, yet again
fragmented, evidence that no single trajectory
is necessarily predetermined and that forest
resources, under a range of circumstances,
can be managed and utilized in such a way
as to contribute to poverty reduction while
keeping future options open to retain more
and lose less forest biodiversity.
Imperfect local, National and
International Markets

While the contribution of forest goods and services
for local livelihoods, national economic growth and as
a global public good are regularly highlighted, there is
a considerable gap between the acknowledgment of
these benefits and how they are actually "valued".
 In many countries forests goods and services
continue to be undervalued because in the absence
of suitable markets, forests, as a land-use, are
unable to compete, either with other land-uses or with
other sectors such as energy.
Imperfect local, National and
International Markets

New markets could arise if the provision of
key public utilities was viewed slightly
differently.
 For example, clean and reliable water supply
requires not only the hard infrastructure of
pipes and reservoirs, but also the "green"
infrastructure in watershed catchments.
 Equally production-based incentives for other
land-use activities, notably agriculture may
also help
Absence of Good Governance
and Rule of Law
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Government policies, and how those policies are
enforced, both within and outside the forest sector,
also ultimately impact on forest land use change.
Forest land is still all too often seen as a nationallyowned asset, irrespective of the stewardship that
local communities have exercised over the same
resource for many years.
Inequities in titling and use rights can result in forests
becoming a major source of conflict and / or illegal
activity.
Absence of Good Governance
and Rule of Law
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While illegal logging and corruption may exist
because of pure criminality it can, in some situations,
be driven by inappropriate governance structures that
turn legitimate concerns or entitlements into illegal
activities.
Demographic factors

A common myth of the 1990s was that
increasing populations was a major
underlying cause of forest decline.
 Available evidence shows that there is no
general relationship between population
growth and density and deforestation.
 Indeed there are a number of examples in
both developed and developing countries of
how population increase has been
accompanied by increasing tree cover.
Demographic factors
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Where fuelwood and agricultural land is in
much demand and other livelihood options
are limited population growth and density can
result in increased pressure on forests but
this can tend to be quite localized.
 Importantly, demographic factors associated
with mortality and morbidity, particularly
where the HIV/AIDS pandemic is concerned,
may be just significant when it come to forestrelated land-use change
Forest Land use and Agriculture

Due to increasing population forest land has
been increasingly converted into agricultural
land
 The conversion of forest to agricultural land
has had numerous repercussions on the
physical and biological environment such as :
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Increasing the proportion of light energy which is
reflected from the land surface
Increasing heat transfer to the atmosphere
Reduces evapotranspiration from plants and trees
Compacting soil (which increases rainfall runoff)
Increases erosion, and affects air turbulence (and
therefore air movements and winds).
Forest Land use and Agriculture
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Conversion has led to a loss of biodiversity,
movements of species around the world,
shifts in local plant and animal populations,
the destruction of ecosystems, and the
invasion of exotic organisms and diseases
into areas where they are not endemic.
 Agricultural land differs in almost every
respect from the original forested land.
Forest Land Conversion Results
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Chemical, physical and biological alterations
in soil
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After forest conversion, the soil environment is
seriously perturbed. The soil structure often
becomes compacted, chemical processes in the
soil are disrupted, and the diversity and quantity of
soil microbes declines.
Reductions in biodiversity
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Very complex ecosystems of the forest are
reduced to a simple system of only one or a few
crops – cattle, oil palm, or rubber.
Forest Land Conversion Results
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Depletion of forest ecosystems because of
the spread of pathogens and the incursion of
exotic species.
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Because of the prevalence of monocultures and
the importation of exotics, agriculture is an inviting
feast for pathogens, because there are large
stands of uniform hosts.
Epidemics in agricultural areas can spread to
nearby forests, particularly when they are
fragmented.
An unexpected effect is that forests may be cut in
an attempt to find areas which are not
contaminated with the pathogen.
Forest Land Conversion Results
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Chemical contamination of soil and water and
alterations of natural mineral cycles (carbon,
nitrogen, phosphorus):
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In a natural tropical rainforest system, the input of
gases and chemicals from the environment is
approximately equal to the outgo, but these
connections to the outside environment are small
compared to the internal cycling of chemicals from
vegetation/animals to soil and back again.
This cycling is severely altered in agricultural
systems since the quantity of vegetation is much
reduced and the crop is removed from the system,
thus depleting it of essential organic matter.
Forest Land Conversion Results
 Detrimental
alterations in water supplies
and in waterways:
 Irrigation
of converted lands leads to
salinization (salt deposits), water logging of
soil, high nutrient levels in waterways in the
vicinity of agricultural areas and water
depletion in streams, rivers and other
waterways.
Forest Land Conversion Results
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Displacement of native species and disruption of
ecosystems by the introduction of exotic species:
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Many forest species are threatened by the invasion of exotic
species introduced either deliberately as crops and livestock
or inadvertently.
Many of these have no natural enemies in forest systems
and are able to invade the habitats of native species, driving
them to population declines or to local extinction.
Others act as pathogens, parasites and predators of local
species.
These biological “invasions” are very extensive and many
are irreversible.
They at the least disrupt local ecosystems and drive losses
in the biodiversity of native species and populations.
Forest Land Conversion Results
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Soil depletion and loss of productivity:
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Many farms are established by small-scale cultivators who
follow logging roads into the forest.
Once roads have penetrated the forest, access becomes
easy, and people who are fleeing the poverty of cities or
worn-out farms (often rain forest land which has been
degraded by agricultural activities) follow and establish small
agricultural or ranching operations.
When the nutrient level of the land decreases sufficiently,
they abandon these farms and penetrate farther into the
virgin forest, leaving degraded fields behind.
Often this deserted land is unable to regenerate forest and
becomes scrub or wasteland.
Forest Land Conversion Results
 Increase
in surface the proportion of
light energy which is reflected from the
land surface and decrease in surface
roughness
 Leading
to temperature increases and
decreases in precipitation.
 All
of these consequences are related.