Forest Ecosystem

Forest Ecosystem

Intended
Learning Outcomes

At
the end of this Lecture, students will be able to

• Explain forest ecosystem

• Explain the types of forest ecosystem

• Discuss the characteristic features of
forest ecosystem

• Discuss the structure and functional of
the forest ecosystem

Content

• Introduction to forest ecosystem

• Types of forest ecosystem

• Characteristic features of forest
ecosystem

• Structure and functional of the forest
ecosystem

Forest
Ecosystem

• Forests are formed by a community of
plants which is predominantly structurally defined by its trees, shrubs,
climbers and ground cover

• Their distinctive appearance is a
fascinating aspect of nature

• Each forest type forms a habitat for a
specific community of animals that are adapted to live in it

• Forest ecosystem has two parts:

       
Non-living or abiotic aspects of the forest

       
Living or the biotic aspects of the forest

Forest
types in India

• Type of forest depends upon the abiotic
factors such as climate and soil characteristics of a region

• Forests in India can be broadly divided
into Coniferous forests and Broadleaved forests

• They can also be classified according to
the nature of their tree species

– Evergreen, deciduous, xerophytic or thorn
trees, mangroves, etc

• They can also be classified according to
the most abundant species of trees such as Sal or Teak forests

• In many cases a forest is named after the
first 3 or 4 most abundant tree species

Coniferous
forests
grow in the Himalayan mountain region, where the temperatures are
low

• These forests have tall stately trees
with needle like leaves and downward sloping branches so that the snow can slip
off the branches

• They have cones instead of seeds and are
called gymnosperms


Broadleaved forests
have several types, such as
evergreen forests, deciduous forests, thorn forests and mangrove forests

• Broadleaved forests have large leaves of
various shapes

• Evergreen forests grow in the high
rainfall areas of the Western Ghats,

• These forests grow in areas where the
monsoon lasts for several months

• There is no dry leafless phase as in a
deciduous forest

• An evergreen forest thus looks green
throughout the year

• The trees overlap with each other to form
a continuous canopy, thus very little light penetrates down to the forest floor

• The forest abounds in animal life and is
most rich in insect life

Deciduous
forests
are found in regions with a moderate amount of seasonal rainfall
that lasts for only a few months

• Deciduous trees shed their leaves during
the winter and hot summer months

• The forest frequently has a thick
undergrowth as light can penetrate easily onto the forest floor


Thorn forests
are found in the semi- arid regions
of India

• The trees, which are sparsely
distributed, are surrounded by open grassy areas

• Thorny plants are called xerophytic
species and are able to conserve water

• These plants have waxy leaves to reduce
water losses during transpiration


Mangrove forests
grow along the coast especially in
the river deltas

• These plants are able to grow in a mix of
saline and fresh water

• The mangrove trees have breathing roots
that emerge from the mudbanks

Forest
utilisation

• Natural forests provide local people with
a variety of products

• Natural forest ecosystems play an
important role in controlling local climate and water regimes

• It is well-known that under the canopy of
a natural forest, it is cooler than outside the forest

• During the monsoon, the forest retains
moisture and slowly releases it through perennial streams during the rest of
the year

• Wood from different species of trees have
special uses. For instance a soft wood is used for the yok of a bullock cart
while a very hard wood is used for its axil

• Traditional types of agriculture needs
forest material such as branches and leaves, which are burnt to form wood ash
which acts as a fertiliser for crops such as rice

• Urban people use these forest resources
indirectly as all their food and other goods come from agricultural areas that
are dependent on the neighbouring forests

Direct uses
of forest products

• Fruits – mango, jamun, amla

• Roots – Dioscoria

• Medicine – Gloriosa, Foxglove

• Fuel wood – many species of trees and
shrubs

• Small timber for building huts and houses

• Wood for farm implements

• Bamboo and cane for baskets

• Grass for grazing and stall feeding
livestock

Indirect
uses of forest

• Building material for construction and
furniture for the urban sector

• Medicinal products collected and
processed into drugs

• Gums and resins processed into a variety
of products

• Raw material for industrial products and
chemicals

• Paper from bamboo and softwoods

What are
the threats to the forest ecosystem?

• As forests grow very slowly, we cannot
use more resources than they can produce during a growing season

• If timber is felled beyond a certain
limit the forest cannot regenerate

• Over utilizing forest resources is an
unsustainable way of misusing our limited forest resources

• Developmental activities such as rapid
population growth together with, urbanisation, industrialisation and the
increasing use of consumer goods, leads to over utilisation of forest produce

What if the
forests disappear?

• When forests are cut down tribal people
who depend directly on them for food and fuel wood and other products find it
very difficult to survive

• Rain that falls on deforested land flows
directly into nearby rivers, thus water is not retained under the ground

• Exposed soil is rapidly washed away
during the rains once the protective forest cover is removed, thus agriculture
is seriously affected.

How can
forest ecosystems be conserved?

• We can conserve forests only if we use
its resources carefully

• Need to grow more trees than are cut down
from forests every year for timber

• The natural forests with all their
diverse species must be protected as National Parks and Wildlife Sanctuaries
where all the plants and animals can be preserved

Summary

• Forests are formed by a community of
plants which is predominantly structurally defined by its trees, shrubs,
climbers and ground cover

• Forests 
in  India  can 
be  broadly  divided 
into  Coniferous  forests 
and Broadleaved forests

• Natural forests provide local people with
a variety of products

• Over utilizing forest resources leads to
forest degradation and finally changes the ecosystem

• We can conserve forests only if we use
its resources carefully