Biodiversity: UPSC Previous Year Questions (Environment and Ecology)

Explanation

The IUCN Red List of "threatened species" is the world’s most comprehensive inventory of the global conservation status of plant and animal species, which is a grouping of three categories: Critically Endangered, Endangered, and Vulnerable.

Statement 1 is incorrect: The Red Data Books primary purpose is not to catalog endemic species in biodiversity hotspots. Its focus is on the conservation status of species, particularly those that are threatened (vulnerable, endangered, or critically endangered).

Statement 2 is correct: The purpose of the Red Data Books is to provide a detailed list of threatened species, including plants and animals. These species are categorized based on their risk of extinction, using criteria such as population size, rate of decline, and geographic range.

Statement 3 is incorrect: The Red Data Books do not focus on listing protected sites or conservation areas. Information about protected sites (such as national parks, wildlife sanctuaries, or biosphere reserves) is typically found in other publications or databases, such as the World Database on Protected Areas (WDPA) or national-level conservation reports.

Explanation

Ex Situ Conservation In Situ Conservation Ex situ conservation is the preservation of biodiversity away from their natural habitats. Here, zoological or botanical parks are places where animals and plants are raised or grown. In situ conservation refers to the preservation of plants and animals in their natural environments. Another method of ex situ conservation is the reintroduction of an animal or plant into its former environment. For instance, This includes the establishment of:

1. National parks and sanctuaries

2. Biosphere reserves the extinct Gangetic Gharial has been brought back into the rivers of Uttar Pradesh, Madhya Pradesh, and Rajasthan.

3. Nature reserves

4. Reserved and protected forests

5. Preservation plots

6. Reserved forests Important locations for ex situ conservation include seed banks, botanical, horticultural, and recreational gardens.

Explanation

Biodiversity Hotspot are regions with high species richness and a high degree of endemism. In 1988, the British bi-ologist Norman Myers coined the term "biodiversity hotspot" as a biogeographic region characterized both by exceptional levels of plant endemism and by serious levels of habitat loss and provided certain qualifications for a hotspot. Options 1, 3 and 5 are correct: In 1989, Conservation Inter-national (CI) adopted Myers’ hotspots as its institutional model. Western Ghats-Sri Lanka and Indo-Burma Region meets the Myers’ criterion to qualify as Biodiversity Hotspot:

Species richness and endemism is one of the major criteria which must contain at least 1,500 species of vascular plants (> 0.5% of the world’s total) as endemics. ‘Degree of Threat’ is also a major criteria for the recognition of biological hotspots. It has to have lost at least 70% of its original habitat. (It must have 30% or less of its original natural vegetation). In other words, it must be threatened. Options 2, 4 and 6 are incorrect: Vegetation density, ethno-bo-tanical importance and adaptation of flora and fauna to warm and humid conditions are not part of the criteria for the recognition of Biodiversity Hotspots.

Explanation

The diversity of plants and animals varies widely over the world. The tropics are home to more species than temperate or polar regions.

Statement 1 is correct: Species diversity decreases as we move away from the equator towards the pole. This is due to several reasons:

Lower latitudes experience warmer temperatures and more stable climates, which support a greater variety of life forms. The equatorial regions receive more consistent and intense sunlight throughout the year, leading to higher primary productivity (photosynthesis) and thus more diverse ecosystems. Tropical regions, such as rainforests, have complex habitats with multiple layers (canopy, understory, forest floor) which support a wide range of species. Tropical regions have remained relatively stable over geological time, allowing species to diversify over millions of years.

Statement 2 is correct: Elevational diversity gradient (EDG) is an ecological pattern where biodiversity changes with elevation. The EDG states that species richness tends to increase as elevation increases, up to a certain point, creating a "diversity bulge" at middle elevations, after which it decreases with altitude. Therefore, it is true that along the mountain gradients, biodiversity is normally greater in the lower altitudes as compared to the higher altitudes.

Explanation

Biodiversity provides a number of natural services for human beings which are listed in the table below:

Ecosystem Services Protection of water resources Soil formation and protection Nutrient storage and recycling Pollution breakdown and absorption Contribution to climate stability Maintenance of ecosystems Recovery from unpredictable events Biological Services Food Medicinal resources and pharmaceutical drugs Wood products Ornamental plants Pollination of crops Breeding stocks Diversity in genes, species and ecosystems Social Services Research, education and monitoring Recreation and tourism Cultural values

Explanation

Being a confluence of different biogeographical zones Himalayan Range is very rich in species diversity. The Himalayas act as a natural transition zone between several major bio-geographical regions, leading to high species diversity and endemism. There are ten biogeographic zones in India:

1. Trans-Himalayan zone. 2. Himalayan zone

3. Desert zone. 4. Semi Arid zone.

5. Western ghat zone. 6. Deccan plateau zone.

7. Gangetic plain zone. 8. North east zone.

9. Coastal zone 10. Islands