Lesson 3, Topic 2
Destruction of Ecosystem & Its Impact
- Land use changes are a major reason for transformation of ecosystems.
- Land cover changes occur due to natural as well as manmade forces.
- It has been projected that 60% of the world population will live in urban areas by 2025.
- Irrational use of land has resulted in degradation of land, degradation of surface water as well as acute air pollution.
Reasons for Destruction of Ecosystem
- Population Explosion– This comes with a lot of cost and unnecessary burden on the natural resources. Pressure is added on the existing land surface with increase in urbanization and loss of agricultural land. This causes a disturbance in the ecological balance.
- Migration– People move from rural to urban areas in search of better livelihood, jobs and this leads to over concentration of population in specific areas. A lot of squatter settlements and slums come up in response to this phenomenon again causing a negative impact on the environment.
- Urbanisation & Urban Sprawls– A Sprawl refers to a dispersed development unit outside the compact urban & village centers, along highways and in rural countryside. Excessive land consumption, lack of planned housing, lack of public space etc are some characteristics of a sprawl. The conversion of a natural landscape into an urban area is an irreversible process. Loss of habitat for plants & animals is the main outcome of urbanization.
- Industrialisation– The standard of living we are enjoying today would not have been possible without the products available to mankind. This however comes at a cost. Development of industries leads to degradation of natural environment and also escalates pollution to immeasurable levels. Excessive CO2 released from industries causes global warming & greenhouse effect. A lot of natural disasters like gas leaks can occur causing damage to life & property.
- Immigration & Refugee Burden– People from developing countries migrate to developed ones for better opportunities thus causing a burden on the resources. It is estimated that there are 23 million environmental refugees trying to escape from poverty & lack of opportunity. People from war zones also flee to other counties & take a toll on the environment. Ex– Rohingyas in India.
- Mining- Mining rights are obtained in forest areas to drill gold and diamonds. A handful of people benefit from it at the cost of the environment and the workers. Chemicals that are used deteriorate the ecosystem to a large extent. Studies show that nearly 1/3rd of all active mines are located within areas of ecosystems of high conservation value. Rainforests are immensely harmed as a result of mining. Mercury, cyanide etc leach into the rivers etc and cause pollution.
- Shifting Agriculture or Slash & Burn– This practice of burning a piece of land and eventually abandoning it is not an environment friendly practice. Logging, oil & gas exploration etc have also caused undue damage to the areas. In the north east, shifting agriculture is known as Jhumming.
IMPACT OF ECOSYSTEM DESTRUCTION
The impact of Ecosystem destruction can be listed as follows-
- Loss of habitat
- Habitat destruction & deterioration poses maximum threat to many plant species, sites & other habitats.
- Can be caused due to clearance of forest areas for settlement or agriculture, hydel schemes etc.
- Overexploitation mainly for commercial purposes such as meat, fur, tusks, medicine etc also lead to habitat depletion.
- Introduction of Exotic Species can threaten the native flora & fauna.
- Fragmentation of forests destroys wildlife habitat.
- Deforestation and degraded human waste disposal can affect key ecosystem services such as erosion control, food production etc.
- Water running off from roads is a major point of concern as Salmon fishes are very sensitive to these ‘Flash Flows’.
- Disturbance is also caused due to light, noise, movement and human activity.
- Factors such as Inbreeding, Limited Dispersal, Skewed Sex Ratio that reduce population can also escalate risk of extinction.
- An ever increasing population puts greater demand on an otherwise limited set of resources.
- The rate of exploitation of natural resources increases more rapidly than increase in population.
- This in turn leads to exhaustion of exhaustible resources.
- Other factors that cause resource depletion include Decreasing forest cover, increase in use of Pesticides, Herbicides etc.
- Change in Climatic Conditions-
- On cutting of forest, carbon stored in the tree joins with oxygen to form CO2.
- Burning of fossil fuels also releases CO2 that enhances the greenhouse effect and global warming phenomenon.
- Deforestation affects local climate by reducing the process of evaporative cooling.
- Less evaporation leads to a rise in an area’s temperature.
- Drying up of Rivers & Aquifers
- The rainfall in an area decreases with decreasing forest cover.
- This reduces percolation of water and depletes the underground water table.
- With this, the streams, lakes, aquifers are slowly seen to dry out.
- Floods and Droughts-
- As a result of global warming, there is excessive heat which leads to quicker evaporation.
- Rise in temp also melts the glaciers and imbalance in water flow leads to glacial lake floods.
- The soil devoid of vegetation falls short of water retention and it leads to droughts.
- Removal of Topsoil & Desertification-
- Loss of vegetative cover causes easy runoffs and leads to floods.
- These floods wash away the topsoil cover and the nutrients.
- The soil loses its fertility.
- Loss of soil productivity in turn leads to formation of deserts.
- Loss of Species & Biomass-
- Habitat destruction, land conversion etc result in loss of biodiversity and resultant loss in biomass.
- Agricultural degradation-
- Ecosystem destruction has a substantial impact on agricultural practices.
- Issues like soil erosion, desertification, construction of houses, water logging etc cause significant damage to cultivable land.
- With such unprecedented damage, future food supply & security will be a challenge for mankind.
In order to save the ecosystem from destruction, conservation is the key.
- In recent times, the ecosystem has been at the verge of destruction. This has caused irreparable damage to the wildlife habitat. Comment.
- Mention the impacts caused due to destruction of ecosystem and how can we mitigate the same.