Environment and Ecology: UPSC Previous Year Questions (Prelims)

Explanation

The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological species. Great Indian Bustard, Musk Deer, Red Panda and Asiatic Wild Ass (Currently Vulnerable, but as the question is from 2012, we will consider it as Endangered) all are Endangered Species. Important species and their Conservation status are:

Species Particulars Great Indian Bustard State bird of Rajasthan Flagship grassland species, representing the health of the grassland ecology. States: Rajasthan and Gujarat. Small populations occur in Maharashtra, Karnataka and Andhra Pradesh. Conservation Status: Critically Endangered Musk Deer Habitat: J&K, Uttarakhand. Himachal Pradesh, Sikkim and Arunachal Pradesh. Conservation Status: Endangered Red Panda Red panda is endemic to the temperate forests of the Himalayas. Habitat: Sikkim and Assam, northern Arunachal Pradesh. Threats: habitat loss and fragmentation, poaching, and inbreeding depression. Conservation Status: Threatened Species Asiatic Wild Ass Scientific Name: Equus hemionus Also called: Asiatic Wild Ass, Asian Wild Ass, Indian onager or, Ghudkhur and Khur (Gujarati language) Habitat: Western India, southern Pakistan (i.e. provinces of Sindh and Baluchistan), Afghanistan, and south-eastern Iran. Conservation Status:

IUCN: currently listed as Near Threatened (Earlier it was listed under Endangered Category)

Explanation

The Chiru, or Tibetan Antelope, is adapted to the cold, high-altitude regions of the Tibetan Plateau, steppes, and semi-desert areas. These regions are characterized by cold temperatures and sparse vegetation. Chiru is well-suited to survive in these challenging environments. It is primarily poached for its fine wool, known as Shahtoosh rather than for musk. Oryx is a type of antelope that is adapted to hot, arid, and desert regions, such as the Thar Desert in western India and regions in Africa. These antelopes are well-suited to extreme heat and dryness due to their ability to survive with very little water, and they often thrive in desert environments. It is poached for its horns and meat.

Explanation

Option 1 is correct: Black-necked crane is a state bird of Ladakh. It is found in northeastern Ladakh and some parts of Himalayan foothills in India. It is endemic to the Tibetan Plateau and migrates to India during the winter months. It is listed as vulnerable and is considered an important species for conservation.

Option 2 is incorrect: The Cheetah was historically found in India but was declared extinct in India in the 1950s due to hunting and habitat loss. However, the species is now being re-introduced in India, especially in Kuno National Park, Madhya Pradesh.

Option 3 is correct: In India, most of these species are found in the eastern Himalayas and the north-east, at the confluence of two biogeographically significant regions, the Himalayan and the Indo-Malayan regions. These arboreal mammals are adapted to glide between trees in search of food.

Option 4 is correct: The Snow Leopard is found in high-alti-tude regions of Himachal Pradesh, Ladakh, and parts of Uttarakhand and Sikkim. It is classified as vulnerable and is an apex predator in cold mountain ecosystems.

Explanation

Option 1 is correct: Rising temperatures are affecting biodiversity. Global warming induced climate change is causing changing rainfall patterns, extreme weather events, and ocean acidification. These are putting pressure on species already threatened by other human activities.

Option 2 is correct: Mammals and birds that require large territories as well as animals with migratory habitat are adversely affected by fragmentation of Habitat. This results in population decline.

Option 3 is correct: Invasive alien species are animals, plants, fungi and microorganisms entered and established in the environment from outside of their natural habitat. They reproduce rapidly, outcompete native species for food, water and space, and are one of the main causes of global biodiversity loss.

Option 4 is incorrect: Promotion of vegetarianism is not a cause for the loss or threat of biodiversity.

Explanation

Upwelling is a process in which deep, cold water of the ocean rises toward the surface. Winds blowing across the ocean surface push water away. Water then rises up from beneath the surface to replace the water that was pushed away. This process is known as "upwelling."

Statement 1 is incorrect: Decomposer microorganisms primarily reside in the deep ocean and play a role in breaking down organic matter. Upwelling does not bring decomposers to the surface. Most decomposition occurs at depth and decomposer microbes are not significantly transported to the surface by upwelling.

Statement 2 is correct: Upwelling regions bring nutrients like nitrogen, phosphorus, and iron from deep waters to the surface. These nutrients enhance phytoplankton growth which supports higher trophic levels such as fish and marine mammals. Major upwelling zones include the coasts of Peru, California, and West Africa. These regions contribute to high fishery productivity (Ex: Peru-vian anchovy fishery).

Statement 3 is incorrect: Bottom-dwelling (benthic) organisms such as crustaceans and mollusks are not brought to the surface by upwelling. Upwelling affects water movement but does not displace benthic creatures from the ocean floor.

Explanation

Tropical rainforests and tropical deciduous forests differ in their nutrient cycles, soil composition, and regeneration capacity. When a tropical rainforest is removed, it does not regenerate quickly because of the nutrient-poor soil. In tropical rainforests, the warm and humid conditions promote rapid decomposition of organic matter by bacteria and fungi. But due to the high density of plant life the nutrients released are immediately absorbed by plants leaving the soil infertile. In contrast the tropical deciduous forests have richer soils be-cause the leaf litter decomposes and replenishes soil nutrients more effectively. Options (b), (c) and (d) are incorrect:

Propagules (seeds, spores, or other reproductive structures) of rainforest trees generally have high viability. However, the regeneration of rainforests is hindered more by soil nutrient deficiencies than by the viability of propagules. Many rainforest species are fast-growing especially pioneer species that colonize disturbed areas. However, the lack of nutrients in the soil limits their growth and the overall regeneration of the forest. In rainforests slow regeneration is due to nutrient loss and not exotic/invasive species. If soils were fertile, native plants would recover quickly but rainforest soils are typically nutrient-poor which limits their regrowth.

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.