Question

Altitude has a tremendous impact on the distribution and growth of vegetation because this effect the tree line in Western and eastern Himalaya are at a different height. The Uppermost boundary of the tree line on Eastern Himalaya is

• A. 4000 m
• B. 4500 m
• C. 3500 m
• D. 5000 m

Hint:

In India, the tree line is higher in the East (4000m) and lower in the West (3500m). This is a standard comparison in Himalayan ecology.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question focuses on the "tree line"—the highest elevation where trees can grow—and asks for its specific limit in the Eastern Himalayan region.

Step 2: Detailed Explanation:

• Tree Line Concept: The tree line is the edge of the habitat at which trees are capable of growing. Beyond this point, climatic conditions (cold, lack of oxygen, high winds) are too severe for tree survival.

• Western vs. Eastern Himalaya: The Eastern Himalayas are generally warmer and much more humid than the Western Himalayas. This higher moisture availability and higher snow line allow trees to grow at higher elevations in the East.

• Elevation Difference: In the Western Himalayas, the tree line is typically found at around 3,300 to 3,600 meters. In the Eastern Himalayas, it extends much higher, reaching up to 4,000 meters.

• Species Composition: Near the tree line in the East, common species include Birch (Betula utilis), Silver Fir (Abies densa), and various Rhododendrons.

• Factors: The lower latitude and higher rainfall of the Eastern region are the primary reasons for this higher elevational limit of vegetation.

Step 3: Final Answer:
The uppermost boundary of the tree line on the Eastern Himalaya is 4000 m.