This document discusses threats to biodiversity from various causes such as habitat loss, introduction of invasive species, overexploitation, diseases, and climate change. It provides details on different types of habitat loss including deforestation, destruction of wetlands, and habitat fragmentation. Other threats covered include genetic pollution, hybridization, and human overpopulation. Specific threats like poaching and man-wildlife conflicts are also summarized. The document emphasizes that any disturbance to natural ecosystems can reduce biodiversity and lists some remedial measures that can be taken to help conserve biodiversity.
2. Causes for loss of biodiversity
Habitat loss or destruction / deforestation
Introduction of invasive species
Genetic pollution
Over exploitation
Hybridization
Climate change
Diseases
Human over-population
• Any disturbance in an natural ecosystem tend to reduce its biodiversity.
• The waste generated due to increase in human population and industrialization,
spoils the environment and leads to a major imbalance and threatens the normal
ecological cycle.
3. Causes for loss of biodiversity
INTRODUCTION OF INVASIVE SPECIES:
Invasive species eliminate native species by:
Occupying their niches
By using the resources of native species
By competing with native species
Causing diseases to native species
GENETIC POLLUTION:
It is caused by uncontrollable hybridization
Genetic pollution is detrimental to rare species that
come into contact with more abundant species which immediately colonize the
area eliminating the rare species
4. Causes for loss of biodiversity
OVER EXPLOITATION:
Occurs when resources are consumed at unsustainable rate.
Occurs in form of:
• Overhunting
• Excessive logging
• Poor soil conservation in agriculture
• Illegal trading of wildlife
5. HABITAT LOSS
The loss of populations of interbreeding organisms is caused by habitat loss . Habitat
loss threatened a wide range of animals and plants.
Habitat loss occurs when natural habitats are modified for human needs.
Habitat size and number of species are systematically related.
Major reasons for habitat destruction are:
Large scale industrial and commercial activities
Mining
Cattle rearing
Commercial fishing
Plantation and agriculture
Dam construction
Encroaching
6. FACTORS INFLUENCING HABITAT LOSS:
DEFORESTATION:-
The loss of habitat is mainly caused by deforestation activities.
The forests and grasslands are the natural homes of thousands of species.
Forests and grasslands have been cleared for conversion into agricultural lands, or
settlement areas or developmental projects.
DESTRUCTION OF WETLANDS:-
The wetlands, estuaries and mangroves are destroyed due to draining, filling and pollution,
which causes huge bio-diversity loss.
7. FACTORS INFLUENCING HABITAT LOSS:
HABITAT FRAGMENTATION:-
Sometimes the habitat is divided into small and sacred patches due to human
constructional activities. This phenomenon is known as habitat fragmentation.
This is harmful to large animals like elephants as their breeding occurs only in large
habitats. Due to this many wild animals and plants are vanishing.
DEVELOPMENTAL ACTIVITIES:-
Construction of massive dams in the forest areas, discharge of industrial effluents which kill
the birds and other aquatic organisms.
AGRICULTURAL AND PLANTATION: -
Clearing the forests for areas for agricultural and plantation activities has a huge impact on
the wild habitat.
8. RAW MATERIALS:-
For production of hybrid seeds, the wild plants are used as raw materials .
As a result, many plant species become extinct.
PRODUCTION OF DRUGS:-
Many pharmaceutical companies collect wild plant for production of drugs.
Therefore several medicinal plants species are on the verge of extinction.
ILLEGAL TRADE:-
Illegal trade on wild life also reduces the bio-diversity and leads to habitat loss.
9. POACHING(OVER HARVESTING) OF WILDLIFE
Poaching means killing animals or commercial hunting. It leads to loss of animal
biodiversity.
I. SUBSISTENCE POACHING:- Killing animals (or) commercial hunting leads to loss of
animal biodiversity.
II.COMMERCIAL POACHING:- Hunting and killing animals to sell their products is called
commercial poaching
10. POACHING(OVER HARVESTING) OF WILDLIFE
FACTORS INFLUENCING POACHING:
HUMAN POPULATION;
Increased human population has increased the pressure on forest resources, which
ultimately causes degradation of wildlife habitats.
COMMERCIAL ACTIVITIES:
There is an international ban on trading products of endangered species, but trading these
wildlife products are highly profitable.
Poaching makes the poachers to hunt these prohibitable wildlife and smuggle it to other
countries.
Wild life products: furs, horns, tusks, live specimens, herbal products.
Developing countries in Asia, Latin America and
Africa has the richest source of biodiversity.
The rich countries in Europe and North America, Japan
Taiwan, Hongkong are the major importer of wildlife
and their products.
11. Causes for loss of biodiversity
CLIMATE CHANGE:
Global warming is one of the major threat to global
biodiversity.
Coral reefs will be lost in 20 – 40 years if global warming
continues at the current trend.
Carbon dioxide concentration in atmosphere affects the
morphology of plants. Higher carbon dioxide concentration
can acidify oceans.
In 2004, an international collaborative study on four
continents estimated that 10% of species would become
extinct by 2050 due to global warming.
Climate changes induces change in raining pattern and also
affects migratory animals and birds.
Biodiversity in polar and mountain region are more
vulnerable to climate change.
12. Causes for loss of biodiversity
DISEASES:
Diseases can eliminate species from earth.
The cause of disease maybe natural or anthropological.
Human activities sometimes speedup the severity of natural diseases.
Introduced species may carry pathogens along with them.
Viral epidemics in animals is a major threat.
Animals are more prone to disease than plants.
Animals in captivity are also prone to diseases.
13. Causes for loss of biodiversity
HUMAN OVER-POPULATION:
World population (by 2020): 7.8 million.
In 1950 the population was 2.5 billion.
Population will reach 9 billion during the 21st century.
Increase in population leads to over exploitation of
resources.
Forest area gets reduced.
Population increase ultimately increase pollution.
Population explosion thus form the prime factor
biodiversity depletion.
HYBRIDIZATION:
Popularized during green revolution , hybridization of hybrid species
with local varieties increased yields and desirable characters.
These species might cause genetic erosion and gene pollution in wild
species destroying the unique genotypes
14. MAN - WILDLIFE CONFLICTS
Man – wildlife conflict arises, when wildlife starts causing immense damage and danger to the man.
Under such conditions it is very difficult for the forest department to compromise the affected
villagers and to gain the villagers support for wildlife conservation.
The conflict between man and wildlife started with the evolution of man, but intensity increased due
to the activities of modern man.
Due to the lack of stable food and disruption of movement, wild animals came out of forest area and
attack the agricultural field and humans and in turn got killed by the humans.
15. FACTORS INFLUENCING MAN – ANIMAL CONFLICTS
Shrinking of forest cover compels wildlife to move outside the forest and attack the fields and
humans.
Human encroachment into wildlife area induces a conflict between man and the wildlife.
Injured animals have a tendency to attack man.
Usually the female attacks the human if she feels that her newborn cubs are in danger.
Often the villagers put electric wiring around their crop fields.
The elephants get injured, suffer in pain and start violence.
16. FACTORS INFLUENCING MAN – ANIMAL CONFLICTS
The cash compensation paid by the government for the damage caused by the wild animals, is
not enough (About 400 rupees quintal).
Therefore the agonized farmers gets revengeful and kill wild animals.
Garbage near human settlements or food crops near forest areas attracts wild animals.
Earlier, forest departments used to cultivate sugarcane, paddy, coconut trees in the sanctuaries.
When the favorite food of elephants( i.e. bamboo leaves) were not available, they feed them to the
elephants.
But, now due to lack of such practices the wild animals move out of the forest for searching of
food.
17. REMEDIAL MEASURES (OR) CONSERVATIVE OF BIODIVERSITY
1. Adequate crop and cattle compensation schemes must be started.
2. Solar powered fencing must be provided along with electric proof electric current proof trenches to
prevent the animals from entering into the fields.
3. Cropping pattern should be changed near the forest borders.
4. Adequate food and water should be made available for the wild animals within the forest zones.
5. The development and construction work in and around forest region must be stopped.
6. Existing laws should be implemented more strictly and people should be educated about them
7. Government should provide alternate source of livelihood for people who depend on forest and
hunting.
8. Proper education about forest and wildlife should be
provided to people near the forests