2 SCOPE OF ENVIRONMENTAL SCIENCE o Studying the interrelationship between the components of environment. o Carrying out impact analysis and Environmental Audit o Preventing pollution from existing and new industries o Stopping the use of biological and nuclear weapons o Managing unpredictable disasters etc. PUBLIC AWARENESS Environmental Pollution or problems cannot be solved by mere laws. Public participation is an important aspect which serves the environmental Protection. o Public awareness of environmental issue is at infant stage o 30-40% of public of developing country are aware of environmental. Problems but they do not bother about it. o Ignorance and incomplete knowledge has lead to misconceptions. o Development and improvement in std. of living has lead to serious environmental disasters. o Debates on environmental Issues are treated as anti-developmental. NATURAL RESOURCES Any component of the environment which has intrinsic value of its own is called as resource. Any component which can be transferred in a way such that it becomes more valuable and useful is termed as resource. FOREST RESOURCES A forest can be defined as a biotic community predominant of trees, shrubs or any other woody vegetation usually in a closed canopy. It is derived from latin word ‘foris’ means ‘outside’. India’s Forest Cover is 6,76,000 sq.km (20.55% of geographic area). Scientists estimate that India should ideally have 33% of its land under forests. Today we only have about 12% thus we need not only to protect our existing forests but also to increase our forest cover. Forest Functions: 1) Protective and ameliorative functions a. Watershed protection b. Erosion control
3 c. Land bank d. Atmospheric regulation 2) Productive functions a. Fodder for cattle b. Fuel wood and charcoal c. Poles for building homes d. Food: (consumptive use) e. Sericulture & Apiculture f. Medicinal plants for traditional medicines 3) Recreational and educational functions 4) Development functions a. Employment functions b. Revenue Commercial uses Man depends heavily on a larger number of plant and animal products from forests for his daily needs. The chief product that forests supply is wood, which is used as fuel, raw material for various industries as pulp, paper, newsprint, board, timber for furniture items, other uses as in packing articles, matches, sports goods etc. Indian forests also supply minor products like gums, resins, dyes, tannins, fibers, etc. Many of the plants are utilized in preparing medicines and drugs; Total worth of which is estimated to be more than $300 billion per year. Many forests lands are used for mining, agriculture, grazing, and recreation and for development of dams. Ecological uses The ecological services provided by our forests may be summed up as follows: Production of Oxygen: The main green house gas carbon dioxide is absorbed by the forests as a raw material for photo synthesis. Thus forest canopy acts as a sink for carbon dioxide thereby reducing the problem of global warming caused by green house gas CO2 Wild life habitat: Forests are the homes of millions of wild animals and plants. About 7 million species are found in the tropical forests alone.
4 Regulation of hydrological Cycle: Forested watersheds act like giant sponges, absorbing the rainfall, slowing down the runoff. They control climate through transpiration of water and seed clouding. Soil Conservation: Forests bind the soil particles tightly in their roots and prevent soil erosion. They also act as wind breakers. Pollution moderators: Forests can absorb many toxic gases and can help in keeping the air pure and in preventing noise pollution. OVER EXPLOITATION OF FORESTS Man depends heavily on forests for food, medicine, shelter, wood and fuel. With growing civilization the demands for raw material like timber, pulp, minerals, fuel wood etc. shot up resulting in large scale logging, mining, road- building and clearing of forests. Our forests contribute substantially to the national economy. The international timber trade alone is worth over US $ 40 billion per year. The devasting effects of deforestation in India include soil, water and wind erosion, estimated to cost over 16,400 cores every year. Ecological Significance of Forests 1) Balances CO2 and O2 levels in atmosphere. 2) Regulates earth temperature and hydrological cycle 3) Encourage seepage and reduces runoff losses, prevents drought 4) Reduces soil erosion (roots binding), prevents siltation and landslides thereby floods 5) Litter helps in maintaining soil fertility 6) Safe habitat for birds, wild animals and organisms against wind, solar radiation and rain. DEFORESTATION Deforestation refers to the loss of forest cover; land that is permanently converted from forest to agricultural land, golf courses, cattle pasture, home, lakes or desert. Causes for Deforestation Agriculture: Conversion of forests to agricultural land to feed growing numbers of people. Commercial logging: Destroys
5 The cash crop economy: Raising cash crops for increased economy. Mining Increase in population: The needs also increase and utilize forests resources. Urbanization & industrialization Mineral exploration Construction of dam reservoirs Infrastructure development Forest fires Human encroachment & exploitation Pollution due to acid rain Environmental effects /Consequences of deforestation Food problems Ecological imbalance Increasing CO2 Floods leading to soil erosion Destruction of resources Heavy siltation of dams Changes in the microclimate Loss of biodiversity Desiccations of previously moist forest soil Environmental pollution Global warming CONSERVATION Conservation derived from two Latin words, con – together, servare – to keep or guard measures, i.e. an act of preservation or to keep together. Concepts in conservation Restraining cutting of trees and submerging the forests Reforestation Afforestation Control forest diseases and forest fire Recycling forest products