Transcript Environmental Impact Assessment (EIA)

BRE 211: Principles of
Agriculture and Forestry
LECTURE 9
FORESTRY
Introduction
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World is faced with the problem of managing
the forest environment in a complex social,
economic and political setting.
 In the past human triumph over the
environment was dependent upon the ability
to find food, a means of protection from other
animals and find shelter from other elements
of the environment.
 The benefits of forests and tree resources
cannot be over emphasised.
Introduction
 With
the rapid human population growth
the quest for greater productivity has
intensified the exploitation of the limited
forest resources.
 This has consequently entailed the
encroachment into forestlands and the
subsequent pushing of forest resource
out of humid zone to marginal areas.
Meaning of Forestry

Is the business of managing forestlands and
the forest resources to produce economically
useful goods and services.
 The trees and other vegetation as well as the
soil, which supports them, are important
bases for forest management.
 The nature of the forest is diverse depending
on the soil and climatic conditions prevailing
over a specific region of the world.
Meaning of Forestry
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Involves several disciplines in the biological
and social sciences such as
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Chemistry
Biology
Physics
Mathematics
Economics
Sociology
political science and
law
Meaning of Forestry
 The
physical and biological sciences
constitute the foundation on which
forestry must be laid, whereas
application of forestry principles is
limited by the socio-economic
phenomena.
 Forestry production depends
increasingly on the availability of
resource inputs such as land, capital
and labour.
Scope of Forestry
 Embraces
the production, distribution
and consumption of forest products and
services.
 Forestry production includes the raising
of forest crops such as timber in artificial
plantations, or the maintenance of
naturally occurring resources to
upgrade their productive potential.
Scope of Forestry
 Forestry
practised for timber production
is known as silviculture.
 Production decisions are based on
information about the soil and ecology
of the forest; the pests and diseases
(pathology) and growth and yield
(mensuration) of the trees and the
general climatic conditions.
Scope of Forestry
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The intangible output of forestry production
includes:
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Protection of soils against erosion and flooding
Use of tree vegetation to protect against harsh
local climates and in the improvement of
precipitation.
Identification, preservation and maintenance of
recreational sites
Landscaping and tree planting in urban areas
Prevention of wild bush fires.
Scope of Forestry
 Distribution
is the primary function of
forest industries.
 It provides the link between the
resource and the user.
 Distribution includes:
 Harvesting and extraction of the
material from the production sites
 Processing and transportation of the
product to the point of use and
 Marketing forest products.
Scope of Forestry
 For
some forestry output, such as
recreation, distribution is reversed;
consumers are moved to points of
production where consumption takes
place.
 Some physical outputs are consumed
without processing e.g. fruit or wood
fuel.
Scope of Forestry
 Consumption
of forest products and
services should be carefully studied to
take into account the effects of
substitute and complementary products.
 Consumption information is crucial in
determining the scale, form and timing
of production.
Scope of Forestry
 In
the case of wood products,
production of raw material takes many
years to complete, and accurate
estimation of consumption is essential.
 In order to meet the needs of the
society, forestry cannot ignore the
systematic analysis of consumption
requirements and the creation of wider
opportunities for the utilization of forest
products.
Forest Classification
 Categories
include:
 Rural Forest Plantations:
 Aim
at promoting and maintaining sound
environment and growing sustained stock
of trees to produce enough fuel-wood,
charcoal and other wood products for the
population.
 The larger part of Kenya's forests is rural
forests that are mostly indigenous.
Forest Classification
 Industrial
Forest plantations:
 Mainly
privately owned for purposes of
wood production for paper manufacturing,
building or and furniture making e.g.
Webuye Paper Mills with its nucleus
plantation for its paper factory.
 Urban
forest plantations:
 Include
forests such as the Arboretum and
the City Park in Nairobi for environmental
protection, aesthetic and recreation.
Forest Benefits
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Forests provide a wide range of benefits at
the local, national, regional and global levels.
 Some of these benefits depend on the forest
being left untouched or subject to minimal
interference.
 Others can only be realized by harvesting the
forest for wood and other products.
 Yet other benefits from the forests, despite
being frequently claimed, are illusionary
Forest Benefits
 Include:
 Wood
products
 Non-wood products
 Forests as dwelling places
 Environmental benefits
 Genetic Resources
 Biodiversity (Biological Diversity)
 Global climate
Wood products
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Wood and the products derived from it are
found in every area of modern existence.
 Products include:
 Timber used in construction and furniture
making.
 Fuelwood (Charcoal and firewood) for
provision of energy.
 Fibre for industrial and domestic uses
 Chipboard, paper, newsprint and cardboard.
Wood products
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As a construction material, wood
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Is strong, light, durable, flexible and easily worked.
It has excellent insulating properties.
In contrast to the substitutes of wood such as
brick, concrete, metals and plastics
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wood can be produced and transported with little
energy consumed.
wood products are renewable and usually
biodegradable
Non-wood products
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Forests have primarily been seen as woodproducing units and other products have
conventionally been referred to as “minor
forest products”.
 However in recent years importance of these
products have been given much attention
especially in their local context where they
may be considerably more valuable than the
wood obtained from the forest.
 It is recognized that the economic and social
importance of these other forest products
may be the key to the active involvement of
people in forest management.
Non-wood products
 Non-wood
 Plants
forest products include:
for food and medicinal purposes
 Fibre
 Dyes
 Animal
 The
fodder and other necessities.
wildlife in forests can also make a
major contribution to food supplies.
Non-wood products
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Non-wood forest products may also be
commercially important at local level, where
they are traded in markets and shops or sent
to the larger towns and cities
 Some of these products are valuable export
commodities.
 Gums and resins, bamboos, various oils,
turpentine, tanning materials, honey, spices,
bark and leaves and medicinal plants, and
Rattan, the long , thin stem of a climbing palm
have become important export commodities
in Indonesia.
Forests as dwelling places
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Forests and woodlands provide a dwelling place for
more that 200 million people in the tropics including:
 People who have lived there for generations, often
referred to as indigenous or tribal peoples e.g. the
ogiek community
 People who have recently moved into the area,
often described as settlers, squatters or
encroachers
 People who live part-time in the forest working as
small-scale loggers or harvesters of forest
products.
The numbers vary with time and among different
areas, but all need to be taken into account when
forest management is being considered.
Environmental benefits
 Forests
and woodlands play an
important role in protecting the
environment at a local and even
regional level particularly in steeply
sloping watershed areas where the tree
roots are important in binding the soil
and protecting it against erosion and
landslide.
Environmental benefits
 Forests
also play a major part in areas
covered with snow winter.
 During the springs, forests help regulate
the rate at which the snow melts and
also reduce the danger of avalanches.
Environmental benefits
At local levels trees
 provide protection against wind erosion.
 help increase the rate at which rainwater infiltrates
and recharges the ground.
 help maintain soil fertility of the soil as the nutrients
drawn up by their roots are recycled into the top
layers of the soil by leaf fall.
 provide shade for animals and humans; the
microclimate under trees may be several degrees
cooler and more humid than out of their shade.
 In coastal areas, mangroves protect the land against
erosion by the sea as well as providing breeding
grounds for fish and shrimps.
Environmental benefits
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Forests have an increasingly important role as
havens for wildlife and the protection of endangered
species of plants and animals.
Allied to this is their role in recreation, tourism and
“ecotourism”.
Hiking, camping, nature study and simply getting out
of the city are increasingly important to urban people
in their often stressed and polluted world.
Aesthetic appreciation of trees and forests as well as
the cultural and spiritual values that they epitomize
are very important to rural and urban dwellers alike.
Genetic Resources
 Genetic
resources refer to the
economic, scientific or social value of
the genetic variation found among and
between species.
 If properly managed, these resources
are renewable.
Genetic Resources
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Functions of Genetic variation
 Constitutes a buffer against changes in the
environment including those brought about
by pests, diseases and climate change.
 Provides humans with the building blocks
for selection and breeding to adapt plants
and animals to a range of environments
and end uses.
 Provides for intensive selection and
breeding of crop species for increased
yields and uniformity
Genetic Resources
The world’s forests are both laboratories for
natural selection of genetic resources of
plants and animals, on a scale which cannot
be matched by today’s or any conceivable
future research stations, and dynamic storage
banks for those genes.
 In an era of increasing pressure on resources
and significantly changing environmental
conditions, they provide one of humanity’s
most effective ways of buffering itself against
a highly uncertain future.
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Biodiversity (Biological Diversity)
 Biodiversity
or biological diversity refers
to the variety of life forms, the ecological
roles they perform and the genetic
diversity they contain.
 It is estimated that the tropical forests
contain at least 50 percent or more of all
the living species on the planet,
including a great proportion of higher
plants and mammals.
Biodiversity (Biological Diversity)
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No financial value can be placed directly on
the almost infinite variety of living species in
the forests.
 Only a tiny proportion are ever likely to be
studied in detail, let alone be found useful to
humanity.
 Yet the loss of each individual species makes
the world a biologically poorer place.
 Such a loss affects the inter-linkages and
symbiotic relationships with other species.
Global Climate
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Because trees absorb carbon dioxide during
photosynthesis, reforestation is seen as a
means of countering the increase in
greenhouse gases in the atmosphere.
 Carbon dioxide uptake is greatest in the early
years when the rate of growth of the tree is at
its maximum and tapers off as the tree
reaches maturity.
 Eventually the trees in the forest simply act as
a carbon store when no further net growth of
the forest is taking place.
Global Climate
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Areas of forest plantations required to have a
significant impact on the amount of carbon
dioxide in the atmosphere are colossal.
 The effect of planting trees outside closed
forests on the global climate and on carbon
sequestration will depend upon its scale.
 Large-scale tree planting projects in
agricultural areas must sequester
considerable quantities of carbon as well as
provide other environmental benefits
Multiple Roles of Forests
 Include:
 Regulating
and optimising the
distribution and flow of water.
 Conserving and protecting the soil
mantle.
 Providing habitat and dry season refuge
for the wildlife complex, that along with
wilderness value, are the foundations of
Kenya's important tourist industry.
Multiple Roles of Forests
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Are a source of virtually all the nations supply
of building and other poles, fuel-wood, sawn
timber, veneers and plywood, pulp and paper.
 Provide fruits and fodder for humans and
animals.
 Provide a wide range of physical and
economic benefits at the farm.
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Managing trees in association with crop and
livestock enterprises enhances the productivity of
these enterprises.
Tree culture provides avenues for diversifying
sources of farm revenues, hence spreading
risk, ensuring
Role of Forests in Economy
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Include:
i) Reservation: The ability to
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Maintain and improve the climatic and physical
conditions of the country
Regulate water supplies by protecting catchment
regions
Conserve the soil by preventing desiccation and
movement of soil caused by water and wind
Reserve timber and other products for the future.
ii) Industry:
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Provide people with fuel-wood and raw materials
for building, tools and implements.
Role of Forests in Economy
 iii)
Employment:
 In
forest management and in forest related
industries such as making furniture.
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Amenity and wildlife
 The
forests provide habitation to the
wildlife and thus are important for tourism
and recreation.
Common Timber species
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Indigenous hardwood species include:
 East African Camphor
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A hardwood species found in Mt Kenya and
Aberdare Forest and Taita Hills.
It is very strong and resistant to fungi and acids,
though not resistant to termites.
It is used for furniture; lorry bodies and boat
building.
Cedar:
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A hardwood found in the Mt. Kenya forest.
It is widely used in making lead pencils, telegraph
posts and fencing posts.
Common Timber species
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Meru oak
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A hardwood found in the Mt. Kenya forest and
plantations.
It is used for furniture.
Mvule
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A hardwood found at the Coast, Meru and
Nyanza.
It is popular in construction work and furniture
making.
It is very resistant to fungi, termites and fire
Common Timber species
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Exotic softwoods include:
 Cypress
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Initially from Mexico and planted in plantations in
Kenya since 1908.
It is popular for joinery/furniture, flush doors,
plywood and boxes.
Pine
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Originally from California, Mexico and Cuba.
Popular for fibreboard, pulp and furniture.
Common Timber species
 Gum/Eucalyptus
 Originally
from Australia.
 Used for electricity poles, joinery,
construction and fuel.
 Wattle
 Widely
grown in East Africa for tannin on
its bark, poles and posts, firewood and
charcoal.
Forestry Industry Problems
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Include:
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Depletion of hardwood stocks
Inaccessibility to some sources leading to overharvesting in accessible areas
Low optimal usage due to lack of integrated forest
industries
Low recovery rates of 30-40 per cent due to
technological and labour inadequacies
Pollution caused by residue disposal problems
and
Specific supply shortages of important types of
wood such as wattle.
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