Question

What is meant by “ alien species'' invasion ? Name one plant and one animal species that are a threat to our Indian native species.

Answer 1

Hint:Biodiversity losses are the accelerated rates of species extinction that the world is facing now and are largely due to human activities. Ecologists warned that if the present trends of extinction continue nearly half of all species on earth might be wiped out within the next century.

Complete answer:
>Alien species invasions are when the alien species are introduced intentionally or unintentionally for any reason, some of them turn invasive and cause decline or sometimes extinction of indigenous species.
>You must be familiar with the environmental damage caused and threat posed to the native species by invasive weed species like carrot grass also known as Parthenium , Lantana and water hyacinth also known as Terror of Bengal and scientifically known as Eichhornia. Due to which Indian native species of plants are in threat.
>The recent illegal introduction of the African catfish also known as Clarias gariepinus in India for aquaculture purposes posing a threat to the indigenous catfish in our river.

Additional information:
Some other cause of biodiversity losses are :
Habitat loss and fragmentation is the most major cause driving animals and plants to extinction
Over exploitation of animals and plants by humans causes their extinction.
Co-extinction is a process in which a species becomes extinct when the plant and animal species associated with it in an obligatory way also become extinct.

Note:Loss in biodiversity can cause a decrease in the productivity of the plants and also it can cause lowered resistance of plants against environmental crisis.