Biological Diversity
In simple term biological diversity means number of species on the earth.
" Biological diversity is referred as the variety and variability of all species (including plants, animals and microorganisms) within and between them and the ecosystem in which they live and interact."
Biological diversity is also termed as biodiversity. Biodiversity is seen at three levels. These are:
- Specie Diversity
- Genetic Diversity
- Ecosystem Diversity
Specie diversity deals with variety of species in any area. The difference within specie and between the species is seen.
Genetic diversity is referred as the variety in genes among the species. Genes reflect the characteristics of species. They carry the information compulsory to live their life.
Ecosystem diversity is defined as the diversity in ecosystems in which the species live. The size of ecosystem varied depending on type of species. Examples of ecosystem are forest or a small pond.
Threats to biodiversity
The threats to biodiversity are as follows:
- Extinction
- Habitat Destruction
- Over Hunting
- Introduction of exotic species
- Pollution
- Climate Change
Extinction
The major threat faced to species is extinction. Extinction is the end of species when any specie no more exist. The causes of extinction of species are the other threats to biodiversity such as habitat loss, introduction of alien species, over exploitation of resources, pollution and climate change. Many species have become extinct and many are at the verge of extinction. It was observed that over past 200 my the rate of extinction of species is 1-2 species per year and 3-4 families per year.
Habitat Destruction
Habitat loss or habitat destruction is another major threat to biodiversity that leads to the extinction of species. Habitat s altered by the human activity such as forests are the habitat of number of species but due to human activity deforestation has been done at an alarming rate. This habitat loss will directly affect the species. Habitat is also altered such as forested land is converted to agricultural land that leads to destruction of species.
Over Hunting
People exploit the natural resources for their use but they have no idea how this exploitation disturbs the species life. Over hunting is one of the other major cause that leads to the extinction. Commercial, legal or illegal hunting cause the species to be endangered. Examples of such endangered species through over hunting in USA are Snowy egret, passenger pigeon and heath hen. Dodo bird is another example of extinct specie.
Introduction of Exotic Species
If we introduce any specie in a ecosystem that is not native to that ecosystem but belongs to another ecosystem that specie is exotic to new ecosystem. Introduction of exotic specie in a ecosystem disturbs the equilibrium of that ecosystem and affects the native species of that ecosystem.
Pollution
Pollution poses a threat to biodiversity. Polluted ecosystem harms the species and as well as cause habitat destruction. It may cause extinction of species as well.
Climate Change
Climate change also affects the species. For example heating of earth surface is an example of climate change. From this the species that are adapted to cold are affected and they would not be able to adapt to hot so they will try to migrate of will die thus leading to endangerment.
