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