Environment and Ecology: UPSC Previous Year Questions (Prelims)

Explanation

National Parks are designated protected areas aimed at preserving the natural environment, ecosystems, and wildlife. India’s first national park, i.e Jim Corbett National Park was established in 1936. As of 2023 India has 106 national parks, covering a total area of 44,402.95 km². Valley of Flowers National Park was established in 1982. Located in Chamoli, in the state of Uttarakhand, it is renowned for its meadows of indigenous alpine flowers and the variety of vegetation. The park is entirely inside the temperate alpine region. It is located close to Joshimath in the Garhwal area, tucked in the upper reaches of the Bhyundar Ganga river’s Pushpawati river valley. The Asiatic black bear, snow leopard, musk deer, brown bear, red fox, and blue sheep are among the rare and endangered species that call this area home. Himalayan monal pheasants and other high-altitude birds can also be seen in the park. The Valley of Flowers is one of the most unique ecosystems in the world. It lies within the Nanda Devi Biosphere Reserve and is part of a biodiversity hotspot in the Indian Himalayas. The park’s ecosystem is highly sensitive and provides a home to numerous endangered plant species. The valley plays a significant role in conserving alpine flora and provides a refuge for various Himalayan wildlife species.

Explanation

Agasthyamala Biosphere Reserve was established in 2001. It is located near the southernmost tip of the Western Ghats. It includes the following wildlife sanctuaries: Kalakkad Mundanthurai Tiger Reserve, Shendurney Wildlife Sanctuary, Peppara Wildlife Sanctuary, and Neyyar Wildlife Sanctuary. It comprises the tropical wet evergreen forests of India, the moist deciduous forests of the South Western Ghats, the montane rain forests of the South Western Ghats, and the Shola forests. The Kanikaran tribe, one of the oldest extant ancient tribes in the world, is also found in Agasthyamalai. In 2016, it was added to the World Network of Biosphere Reserves of UNESCO.

Explanation

Statement 1 is correct: The Asiatic lion (Panthera leo persica) is a subspecies of lion that is naturally found only in India. The Gir Forest is a protected area that provides a habitat for these majestic animals, and conservation efforts are in place to protect and manage the Asiatic lion population.

Statement 2 is incorrect: Double-humped camels (Camelus bactrianus) are naturally found in the Central Asian region, particularly in countries like Mongolia, China, and parts of Afghanistan. In India, they are found in the Ladakh region, but their native habitat is not India alone.

Statement 3 is incorrect: The one-horned rhinoceros (Rhinoceros unicornis) is found in India, particularly in Assam and other northeastern states and it is also found in parts of Nepal and Bhutan.

Explanation

Statement 1 is correct: Many species of turtles are herbivores, especially those that live in freshwater or on land. For instance, the green sea turtle (Chelonia mydas) is primarily herbivorous, feeding on seagrass and algae. Similarly, the Aldab-ra giant tortoise is also herbivorous, feeding mainly on grasses and leaves.

Statement 2 is correct: Several species of fish are herbivores, consuming algae, aquatic plants, or detritus. Examples include parrotfish, which graze on algae, and certain species of sur-geonfish, which feed on marine plants.

Statement 3 is correct: Some marine mammals are herbivores, notably the manatee and dugong, which feed on seagrasses. These mammals are specialized to thrive on a plant-based diet.

Statement 4 is correct: Boa Constrictors and Green Anacon-das are examples of viviparous snakes, meaning they give birth to live young with no eggs involved at any stage of development.

Explanation

Pair 1 is correctly matched: Blue Finned Mahseer is found in the Mula-Mutha River close to the Indian city of Pune, a part of the Krishna River basin. It is a freshwater fish. It is also known as Deccan Mahseer or Tor Khudree.

Pair 2 is incorrectly matched: Irrawaddy Dolphin’s habitat extends from the Bay of Bengal to New Guinea and the Philippines. It is found in three rivers namely the Irrawaddy (Myanmar), the Mahakam (Indonesian Borneo) and the Mekong but not in Chambal river. The highest single lagoon population of dolphins is considered to be found in Chilika Lake.

Pair 3 is correctly matched: Rusty Spotted Cat has been observed in eastern Gujarat’s Gir National Park, in Maharashtra’s Tadoba-Andhari Tiger Reserve and along India’s Eastern Ghats.

Explanation

The Himalayan nettle has gained attention as a sustainable source of textile fibre. The fibres extracted from the stems of this plant are strong, durable, and eco-friendly, making them suitable for producing textiles. This has significant potential for promoting sustainable livelihoods in rural and mountainous regions, especially in the Himalayas. Himalayan nettle (Girardinia diversifolia) is not known for its use as an anti-malarial drug. Anti-malarial drugs are derived from plants like Artemisia annua (source of artemisinin) or Cinchona officinalis (source of quinine). Himalayan nettle is not recognized as a source of biodiesel. Biodiesel is usually derived from oil-rich plants like Jatropha, Pongamia, or algae. While Himalayan nettle is a fibrous plant but it is not widely used as a source of pulp for the paper industry. The paper industry primarily relies on wood pulp from trees like Eucalyptus, Bamboo, or agricultural residues like wheat straw and bagasse.

Explanation

Both warm and mid-latitude deserts have a predomi-nance of xerophytic or drought-resistant plants. This comprises cacti, thorny bushes, wiry grasses with extensive roots, and scattered dwarf acacias.

Option (d) is correct: In order to gather moisture and search for ground water, the majority of desert shrubs have lengthy roots that are widely distributed. These plants typically have a few (or no leaves) tiny, needle-shaped, waxy, leathery leaves or hairy foliage to reduce water loss through transpiration.

Explanation

Carbon fertilisation is the artificial enrichment of the atmosphere of greenhouses with carbon dioxide, an essential nutrient for plants and vegetables. It also goes by the name of "Carbon Dioxide Fertilization." It can be used to grow nearly any form of vegetable (asparagus, celery, lettuce, tomatoes, aubergines, etc.), greenhouse fruit (strawberries), and ornamental plants, and is especially suited for cold climates.

Option (a) is correct: Carbon fertilisation results in an increase in the instantaneous rate of photosynthesis in C3 plants; and increases the transpiration efficiency of the leaf (C3 and C4 plants). During high concentration of carbon dioxide, plants maintain narrow openings of leaf surface which protects them from water loss. Faster plant growth enhances food production and allows for the sequestration of more carbon dioxide. Plants distribute a greater proportion of photosynthate to roots under high concentrations of atmospheric carbon dioxide. The reproductive biomass growth, as well as vegetative biomass growth, is usually increased by elevated carbon dioxide.

Explanation

Statement 1 is incorrect: Soil water holding capacity is the amount of water that a given soil can hold for crop use. Soil texture and organic matter are the key components that determine soil water holding capacity. Organic matter influences the physical conditions of a soil in several ways.

Statement 2 is incorrect: Sulphur is one of three nutrients that are cycled between the soil, plant matter and the atmosphere. The sulphur cycle describes the movement of sulphur through the atmosphere, mineral and organic forms, and through living things.

Statement 3 is correct: Salinization is a major problem associated with irrigation, because deposits of salts build up in the soil and can reach levels that are harmful to crops.

Explanation

Conservation Agriculture (CA) is a farming system that promotes minimum soil disturbance (i.e. no tillage), maintenance of a permanent soil cover, and diversification of plant species. It enhances biodiversity and natural biological processes above and below the ground surface, which contribute to increased water and nutrient use efficiency and to improved and sustained crop production. According to FAO’s website there are three principles of Conservation of Agriculture:

1. Minimum mechanical soil disturbance: It refers to low disturbance no-tillage and direct seeding. The disturbed area must be less than 15 cm wide or less than 25% of the cropped area (whichever is lower).

2. Permanent soil organic cover: Three categories are distinguished: 30-60%, >60-90% and >90% ground cover, measured immediately after the direct seeding operation. An area with less than 30% cover is not considered as CA.

3. Species diversification: Rotation/association should involve at least 3 different crop species. The rotation of crops is not only necessary to offer a diverse "diet" to the soil micro organisms, but as they root at different soil depths, they are capable of exploring different soil layers for nutrients.