Q. Which one of the following National Parks has a climate that varies from tropical to subtropical, temperate and arctic? (UPSC Prelims 2015)
Answer: Namdapha National Park
Notes: The correct answer is [D] Namdapha National Park. Located in the Changlang district of Arunachal Pradesh, Namdapha is the largest protected area in the Eastern Himalaya biodiversity hotspot. Its unique geography and massive altitudinal variation create a "vertical stratification" of climates.Why Namdapha is unique:The park's elevation ranges from approximately 200 metres to over 4,500 metres above sea level. This drastic change in height over a relatively short horizontal distance allows for four distinct climatic zones:

• Tropical & Subtropical: Found in the lower reaches and river valleys (Noa-Dihing river), characterized by lush evergreen rain forests.
• Temperate: Occupies the middle altitudes, where mixed deciduous and coniferous forests thrive.
• Arctic (Alpine): The highest peaks remain covered in snow for most of the year, exhibiting an arctic-like tundra climate.

Analysis of the other options:

• Khangchendzonga (Sikkim): While it has a massive range (subtropical to alpine), it is primarily known for its high-altitude temperate and arctic ecosystems rather than a significant "tropical" base like Namdapha.
• Nandadevi (Uttarakhand): This is a high-altitude Himalayan park. Its climate ranges from temperate to arctic/alpine, but it lacks a true tropical climate zone.
• Neora Valley (West Bengal): Located in the Kalimpong district, it possesses a rich range from subtropical to temperate/sub-alpine, but it does not reach the extreme "arctic" heights found in Namdapha.

Key Biodiversity Facts about Namdapha:

• The Big Cats: It is the only park in the world to host four feline species: the Tiger, Leopard, Snow Leopard, and Clouded Leopard.
• Hoolock Gibbons: It is home to India’s only ape, the Hoolock Gibbon.
• Endemism: It is famous for the critically endangered Namdapha Flying Squirrel, which is found nowhere else on Earth.