UPSC Prelims 2012 · Question 96 of 98

UPSC Prelims 2012 question on Biodiversity Threats

Which of the following can be threats to the biodiversity of a geographical area?

1. Global warming

2. Fragmentation of habitat

3. Invasion of alien species

4. Promotion of vegetarianism

Select the correct answer using the codes given below:

  1. 1, 2 and 3 only
  2. 2 and 3 only
  3. 1 and 4 only
  4. 1, 2, 3 and 4
Show answer

Answer: A. 1, 2 and 3 only

Verdict

Correct Answer: 1, 2 and 3 only

Analysis

Biodiversity of a geographical area can be threatened by factors that disturb habitats, alter climate conditions or introduce harmful non-native species.

Promotion of vegetarianism is not a threat to biodiversity; it may reduce pressure on ecosystems by lowering demand for land-intensive livestock farming.

Statement by statement

1. Global warming — Correct

Global warming changes temperature, rainfall patterns and habitat conditions.

It can force species to migrate, disturb breeding cycles, cause coral bleaching and increase extinction risk for species unable to adapt quickly.

2. Fragmentation of habitat — Correct

Habitat fragmentation occurs when large habitats are broken into smaller isolated patches due to roads, agriculture, mining or urbanisation.

It restricts movement of animals, reduces access to food and mates, and lowers genetic diversity.

3. Invasion of alien species — Correct

Alien species are non-native species introduced into a new ecosystem.

Some become invasive and outcompete native species for food, space and resources, causing decline or extinction of local biodiversity.

4. Promotion of vegetarianism — Incorrect

Promotion of vegetarianism is not a direct threat to biodiversity.

In fact, reduced dependence on livestock may reduce pressure on land, forests and water resources.

This is not a biodiversity-loss factor.

Extra UPSC info

* The major causes of biodiversity loss are often remembered as the Evil Quartet.

* The Evil Quartet includes habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction.

* Habitat loss and fragmentation is considered one of the most important causes of species extinction.

* Examples of invasive alien species in India include Lantana, Water Hyacinth and Parthenium.

* Co-extinction occurs when the extinction of one species leads to the extinction of another dependent species.

* Do not confuse lifestyle changes like vegetarianism with ecological threats such as habitat loss or invasive species.

How to crack it

Global warming, habitat fragmentation and alien species invasion threaten biodiversity, while promotion of vegetarianism is not a biodiversity threat.

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