Chapter: Environmental Science and Engineering

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Threats to Biodiversity

Extinction is a natural event and, from a geological perspective, routine.


THREATS TO BIODIVERSITY


v   Extinction is a natural event and, from a geological perspective, routine.


v   In last century, human impact has been so severe that thousands of species and varieties are becoming extinct annually.


v   Some of the main causes are:


v   Habitat loss, degradation, fragmentation.


v   Habitat loss & degradation are major causes of species extinction, affecting 89% of all threatened birds, 83% of mammals & 91% of all threatened plants assessed globally (IUCN, 2000)


v   The main causes of habitat are agriculture activities, Mining, development of human settlement, industry etc.


v   According to ICUN, UNEP report, more than 50% of wildlife habitat has been destroyed in 49 out of 61 old world tropical countries.


POACHING OF WILDLIFE

 

v   Poaching is another threat that has emerged in recent decades as one of the primary reason for decline in number of species.


v   Wildlife is sold and traded in many countries for live specimens, folk medicines, furs, Skin, and other products such as Ivory, horns etc amounting to millions of dollars.


MAN – WILDLIFE CONFLICTS

 

v   The conflict between man and wildlife started with the evolution of man, but intensity increased due to the activities of modern man


v   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.

 

1 Introduction of Exotic species

v   Organisms introduced into habitats where they are not native are termed as exotics.

 

v They can be thought of as Biological Pollutants and are considered to be among the most damaging agents of habitat alteration and degradation the world.

 

2 Climate change

A changing global climate threatens species and ecosystems.

v   The distribution of species (biogeography) is largely determined by climate.

v   Climate change may simply shift these distributions but, for a number of reasons, plants and animals may not be able to adjust.

 

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