Any disturbance in a natural ecosystem tends to reduce its biodiversity. Waste generated due to increase in human population and industrialization spoils the environment and leads to decreased diversity in biological species.
Causes for loss of biodiversity are:
1. Habitat loss
2. Poaching of wildlife and
3. Man-wildlife conflicts
1. Habitat loss:
The loss of populations of interbreeding organisms is caused by habitat loss. Factors influencing habitat loss are:
a.Deforestation: Loss of habitat is mainly caused by deforestation activities. Forests and grasslands are cleared for conversion into agriculture lands or settlement areas or
b.developmental projects. Forests and grasslands are natural home to thousands of species which disintegrate due to loss of their natural habitat. Destruction of wetlands: Wetlands, estuaries and mangroves are destroyed due to farming, filling and pollution that cause loss of biodiversity
c. Habitat fragmentation: When the habitat is divided into small and scattered patches the phenomenon is called habitat fragmentation. This leads to the disappearance of most wildlife
d. Raw material: To produce hybrid seeds, wild plants are used as raw materials leading to extinction of many wild plant species.
e. Production of drugs: Pharmaceutical companies collect wild plants for the production of drugs leading to extinction of several medicinal plant species.
f. Illegal trade: Illegal trade of wildlife reduces biodiversity leading to habitat loss
g. Developmental activities: Construction of dams in forest areas coupled with the discharge of industrial effluents kills birds and other aquatic life.
2. Poaching of wildlife:
Poaching refers to killing animals or commercial hunting. It contributes to loss of biodiversity.
Poaching can be of two types listed below:
a. Subsistence poaching: This refers to killing animals for survival.
b. Commercial poaching: This refers to hunting animals in order to sell their products. Factors influencing poaching:
Human population: Increased human population in India has led to pressure on forest resources, leading to degradation of wildlife habitats.
Commercial activities: Although a ban has been imposed internationally on the trade of products of endangered species, there is a continued smuggling of wildlife products. Since trading of such products is highly profitable, poachers continue to hunt endangered animals and smuggle their fur, skin and tusks to other countries. Wildlife products include furs, horns, tusks, live specimens and herbal products.
3.Man-Wildlife Conflicts:
Man-wildlife conflicts arise, when wildlife starts causing immense damage and danger to man. Under such conditions it is very difficult for the forest department officials to convince the affected villagers to gain the villagers support for wildlife conservation.
Ex: 1. In Sambalpur, Orissa, several people were killed by elephants. In retaliation, the villagers killed and injured several elephants.
Villagers sometimes hide explosives in their fields to ward-off animals which explode when the elephants enter the fields.
Several people were killed when leopards attacked them in Sanjay Gandhi National Park, Mumbai. Factors influencing man-animal conflicts
1. Shrinking forest cover compels wildlife to move outside the forest
2. Human encroachment into forest area induces a man-wildlife conflict
3. Injured animals have a tendency to attack man
4. Wild animals venture out of the forest area in search of food
5. Villagers set-up electric wiring around their fields. This injures animals (Elephants) who suffer pain and get violent
