The correct option is (a).
Explanation
In mountainous areas, the decrease in temperature with increasing altitude leads to a corresponding change in natural vegetation. This results in a distinct succession of natural vegetation belts in the same order as seen from the tropical to the tundra regions.
Altitudinal Zonation Analysis:
- Wet Temperate Forests (1,000–2,000 m): These forests are typically found at lower elevations within the montane ecosystem. They are characterized by evergreen broad-leaf trees such as oaks and chestnuts.
- Temperate Forests with Conifers (1,500–3,000 m): As altitude increases, the vegetation transitions to temperate forests containing coniferous trees. Common species include pine, deodar, silver fir, spruce, and cedar. These are found generally between 1,500 and 3,000 meters.
- Alpine Vegetation (Above 3,600 m): At high altitudes, generally above 3,600 meters, temperate forests and grasslands give way to alpine vegetation. Silver fir, junipers, pines, and birches are common here, eventually transitioning into alpine grasslands as they approach the snowline.
Conclusion:
The correct order from lower to higher altitude is: Wet temperate forests (2) → Temperate forests with conifers (3) → Alpine vegetation (1).
Key Takeaway:
Montane vegetation follows a strict altitudinal gradient: Wet Temperate forests (broad-leaf) occupy lower slopes, followed by Coniferous Temperate forests at mid-altitudes, and Alpine vegetation (shrubs and grasslands) at the highest elevations before the snowline.