Forest resources: Environmental sciences Notes, MCQ, PDF, Books
Forest is an important renewable resource. Forest vary in composition and diversity and can contribute substantially to the economic development of any country. Plants along with trees cover large areas, produce a variety of products and provide food for living organisms, and are also important to save the environment.
It is estimated that about 30% of the world’s area is covered by forest whereas 26% by pastures. Among all continents, Africa has the largest forested area (33%) followed by Latin America (25%), whereas in North America forest cover is only 11%. Asia and the former USSR have 14% area under forest. European countries have only 3% area under forest cover. India’s Forest Cover accounts for 20.6% of the total geographical area of the country as of 2005.
SIGNIFICANCE OF FORESTS
Forest can provide prosperity for human beings and nations. Important uses of forests can be classified as under
✓ Commercial values
✓ Life and economy of tribal
✓ Ecological significance
✓ Aesthetic values
Forests are the main source of many commercial products such as wood, timber, pulpwood etc. About 1.5 billion people depend upon fuel wood as an energy source. Timber obtained from the forest can be used to make plywood, board, doors and windows, furniture, agriculture implements and sports goods. Timber is also a raw material for the preparation of the paper, rayon and film.
Forest can provide food, fibre, edible oils and drugs.
Forest lands are also used for agriculture and grazing.
Forest is an important source of development of dams, recreation and mining.
Life and economy of tribal
Forest provides food, medicine and other products needed for tribal people and plays a vital role in the life and economy of tribes living in the forest.
Forests are habitats for all wild animals, and plants and support millions of species.
They help in reducing global warming caused by greenhouse gases and produce oxygen upon photosynthesis.
Forest can act as a pollution purifier by absorbing toxic gases.
Forest not only helps in soil conservation but also helps to regulate the hydrological cycle.
All over the world people appreciate the beauty and tranquillity of the forest because forests have the greatest aesthetic value.
Forest provides opportunities for recreation and ecosystem research.
Over Exploitation Of Forests
Forests contribute substantially to the national economy. With increasing population and increased demand for fuel wood, expansion of area under urban development and industries has led to over-exploitation of forest.
At the present international level, we are losing forest at the rate of 1.7 crore hectares annually. Overexploitation also occurs due to overgrazing and the conversion of forests to pastures for domestic use.
Forest is burned or cut for clearing of land for agriculture, harvesting of wood and timber, and development and expansion of cities. These economic gains are short term whereas the long-term effects of deforestation are irreversible
The deforestation rate is relatively low in temperate countries than in the tropics If the present rate of deforestation continues, we may lose 90% of tropical forests in the coming six decades For ecological balance 33% area should be under forest cover but our nation has only 20.6% forest cover.
Causes of deforestation
Forest area in some developed areas has expanded. However, in developing countries area under forest is showing a declining trend, particularly in the tropical region. The main causes of deforestation are
a) Shifting cultivation or jhum cultivation
This practice is prevalent in tribal areas where forest lands are cleared to grow subsistence crops. It is estimated that the principal cause of deforestation in the tropics in Africa, Asia and tropical America is estimated to be 70, 50, and 35% respectively. Shifting cultivation which is a practice of slash and burn agriculture possess to clears more than 5 lakh hectares of land annually.
In India, shifting cultivation is prevalent in the northeast and to a limited extent in M.P, Bihar and Andhra Pradesh and is contributing significantly to deforestation.
b) Commercial logging
It is an important deforestation agent. It may not be the primary cause but definitely, it acts as a secondary cause, because new logging lots permit shifting cultivation and fuel wood gatherers access to newly logged areas.
c) Need for fuel wood
Increased population has led to increasing demand for fuel wood which is also acting as an important deforestation agent, particularly in dry forests.
d) Expansion for agribusiness
With the addition of cash crops such as oil palm, rubber, fruits and ornamental plants, there is stress to expand the area for agribusiness products which results in deforestation.
e) Development projects and the growing need for food
The growing demand for electricity, irrigation, construction, mining, etc. has led to the destruction of forests. The increased population needs more food which has compelled the increasing area under agricultural crops compelling for deforestation.
f) Raw materials for industrial use
Forest provides the raw material for industry and it has exerted tremendous pressure on forests. Increasing demand for plywood for backing has exerted pressure on the cutting of other species such as fir to be used as backing material for apple in J&K and tea in northeast states.
Major effects of deforestation
Deforestation adversely and directly affects and damages the environment and living beings.
Major causes of deforestation are
• Soil erosion and loss of soil fertility
• Decrease of rainfall due to the effect of the hydrological cycle
• Expansion of deserts
• Climate change and depletion of the water table
• Loss of biodiversity, flora and fauna
• Environmental changes and disturbance in forest ecosystems
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