Read the passage and answer the following questions:
Adding to the grim scenario of extinctions is the fact that more than 15,500 species world-wide are facing the threat of extinction. From a study of the history of life on earth through fossil records, we learn that large-scale loss of species like the one we are currently witnessing have also happened earlier, even before humans appeared on the scene. During the long period (> 3 billion years) since the origin and diversification of life on earth there were five episodes of mass extinction of species. How is the 'Sixth Extinction' presently in progress different from the previous episodes? The difference is in the rates; the current species extinction rates are estimated to be 100 to 1,000 times faster than in the pre-human times and our activities are responsible for the faster rates. Ecologists warn that if the present trends continue, nearly half of all the species on earth might be wiped out within the next 100 years.
A plant species of a forest is now facing a very high risk of extinction in the wild in the near future and needs urgent measures to save it from extinction. Which of the following gives the desirable approach for it, along with a correct way of carrying it out?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Ex situ conservation, by keeping it in a botanical garden
There are two ways to conserve biodiversity. In in situ (on site) conservation, the whole ecosystem is protected and the species stays in its natural habitat, as in biosphere reserves, national parks and sanctuaries. In ex situ (off site) conservation, the species is taken out of its habitat and cared for in a special setting, such as a zoo or a botanical garden. When a species is endangered and cannot wait, it is moved to safety outside its habitat, so ex situ is the approach to choose here.
Option (1) In situ conservation, by declaring its area a biosphere reserve — Incorrect. A biosphere reserve is a real in situ method, but in situ is not the desirable approach here. The plant is endangered and needs urgent help, and protecting its area alone may not save it in time.
Option (2) Ex situ conservation, by keeping it in a botanical garden — Correct. The approach is right for an endangered species needing urgent measures, and the method fits it too. A botanical garden takes the plant out of the wild and gives it protection and special care.
Option (3) In situ conservation, by growing it in a botanical garden — Incorrect. Growing a plant in a botanical garden means moving it away from its natural habitat. That is ex situ, not in situ.
Option (4) Ex situ conservation, by declaring its forest a wildlife sanctuary — Incorrect. A wildlife sanctuary protects the species in its own habitat. That is in situ, so it is not a way of carrying out ex situ conservation.
NCERT Extract:
How do we conserve Biodiversity? – “When we conserve and protect the whole ecosystem, its biodiversity at all levels is protected - we save the entire forest to save the tiger. This approach is called in situ (on site) conservation. However, when there are situations where an animal or plant is endangered or threatened (organisms facing a very high risk of extinction in the wild in the near future) and needs urgent measures to save it from extinction, ex situ (off site) conservation is the desirable approach.”
How do we conserve Biodiversity? – “Ex situ Conservation– In this approach, threatened animals and plants are taken out from their natural habitat and placed in special setting where they can be protected and given special care. Zoological parks, botanical gardens and wildlife safari parks serve this purpose.”