Model Answer
0 min readIntroduction
The Oriental region, also known as the Indo-Malayan realm, is one of the eight biogeographic realms dividing the Earth's land surface. It encompasses South and Southeast Asia, extending from the Himalayas and the Indian subcontinent to southern China, the Malay Archipelago, and parts of Indonesia and the Philippines. Characterized by a monsoon climate and diverse habitats ranging from tropical rainforests to temperate forests and grasslands, the Oriental region boasts a rich and unique biodiversity. Understanding its sub-regions and faunistic distribution is vital for conservation efforts and biogeographical studies.
Defining the Oriental Region
The Oriental region is defined by a unique combination of geological history, climate, and evolutionary processes. It is bounded by the Himalayas to the north, the Pacific Ocean to the east, the Wallace Line (a biogeographical boundary separating Asian and Australian fauna) to the south, and the Iranian Plateau and the Indian Ocean to the west. This region represents a transition zone between the Palearctic and Australian realms, exhibiting elements of both.
Sub-Regions of the Oriental Region
The Oriental region can be further divided into several sub-regions, each with distinct ecological and faunal characteristics:
- Indian Subregion: This includes the Indian subcontinent (India, Pakistan, Bangladesh, Nepal, Bhutan, Sri Lanka). It’s characterized by the monsoon climate, diverse habitats like tropical rainforests, deciduous forests, grasslands, and deserts.
- Indo-Chinese Subregion: Covering Myanmar, Thailand, Laos, Cambodia, Vietnam, and parts of southern China, this subregion features a complex mosaic of forests, mountains, and river systems.
- Sundaic Subregion: This encompasses the Malay Peninsula, Sumatra, Java, Borneo, and surrounding smaller islands. It’s dominated by tropical rainforests and is a hotspot for biodiversity.
- Philippines Subregion: Comprising the Philippine Islands, this subregion is characterized by volcanic islands, rainforests, and high endemism.
- Wallacea: A transitional zone between the Oriental and Australian realms, Wallacea includes islands like Sulawesi, Lombok, and Timor. It exhibits a mix of Asian and Australian fauna.
Faunistic Distribution in the Oriental Region
The Oriental region is renowned for its diverse fauna, including numerous endemic species. Key faunal groups and their distribution patterns are:
- Mammals: The region is home to iconic mammals like tigers (Panthera tigris), elephants (Elephas maximus), rhinoceroses (Rhinoceros unicornis, Dicerorhinus sumatrensis), orangutans (Pongo pygmaeus), gibbons (various species), and various deer species. Tigers are primarily found in India, Nepal, Bhutan, and parts of Southeast Asia. Elephants are distributed across India, Sri Lanka, and Southeast Asia.
- Birds: The Oriental region boasts a rich avifauna, including peacocks (Pavo cristatus), hornbills (various species), pheasants (various species), and numerous migratory bird species.
- Reptiles: The region is home to diverse reptiles, including crocodiles (Crocodylus porosus, Crocodylus palustris), snakes (including cobras, pythons, and vipers), and lizards (including monitor lizards and geckos).
- Amphibians: The Oriental region has a high diversity of amphibians, particularly frogs and salamanders, many of which are endemic to specific regions.
- Fish: Freshwater ecosystems in the region support a rich fish fauna, including various carp species, catfish, and loaches.
- Invertebrates: The region is incredibly diverse in invertebrates, including insects, spiders, and mollusks.
Faunal Distribution Patterns:
- Latitudinal Gradients: Species richness generally decreases with increasing latitude.
- Altitudinal Zonation: Fauna varies with altitude, with different species adapted to different elevations.
- Habitat Specificity: Many species are restricted to specific habitats, such as rainforests, grasslands, or wetlands.
- Endemism: High levels of endemism are found in islands like Sri Lanka, the Philippines, and Wallacea.
The Wallace Line is a particularly important biogeographical feature, marking a sharp transition in faunal composition. West of the line, the fauna is predominantly Asian in origin, while east of the line, it is predominantly Australian. This line reflects the geological history of the region and the long-term isolation of different landmasses.
Conclusion
The Oriental region is a globally significant biodiversity hotspot, characterized by its unique biogeographical history, diverse habitats, and rich fauna. Understanding the region’s sub-regions and faunistic distribution is crucial for effective conservation planning and management. Threats such as habitat loss, poaching, and climate change pose significant challenges to the region’s biodiversity, necessitating collaborative efforts to protect its unique natural heritage. Continued research and monitoring are essential to track changes in faunal distribution and inform conservation strategies.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.