Montane Sub-Tropical Forests of India
These forests grow along the lower slopes of the Himalayas and other hills at elevations of 1000–2000 m, where climate shifts from tropical to temperate.
They are classified into three distinct subtypes, based on moisture availability, topography, and dominant species:
1. Sub-Tropical Broad-Leaved Hill Forests
Moist, moderate-altitude forests dominated by broad-leaved evergreen trees.
🌦️ Climatic Conditions
- Rainfall: 75–125 cm
- Temperature: 18–21 °C
📍 Distribution
- Eastern Himalayas, east of 88°E longitude (e.g., Sikkim, Arunachal, Bhutan border)
- South India: Nilgiris, Palni Hills
- Also: Mahabaleshwar, Satpura & Maikal Ranges, Bastar Highlands, Mt. Abu
🌳 Characteristics
- Evergreen broad-leaved trees
- Common species: Oak, Chestnut, Ash, Beech, Sal, Pine
- Dense undergrowth: Climbers and epiphytes prominent
- Not very luxuriant — often called “stunted rain-forests”
Analogy: Like a “light version” of a tropical rainforest, tucked away in the hills.
2. Sub-Tropical Moist Pine Forests
Dominated by Chir Pine (Pinus roxburghii), adapted to slopes and moderate rainfall.
📍 Distribution
- Western Himalayas: 73°E to 88°E (Uttarakhand, Himachal Pradesh, J&K)
- Also found in Khasi, Naga, Manipur Hills, and parts of Arunachal Pradesh
🌲 Tree Dominance
- Chir Pine (Chil) forms pure stands — highly uniform forest
🪵 Economic Importance
- Timber used for furniture, construction
- Resin & Turpentine extracted
UPSC Tip: Moist pine = Chir pine = Resin source = Western Himalayas
3. Sub-Tropical Dry Evergreen Forests
Found in lower elevations, drier zones, especially western Himalayas & Shiwaliks.
🌦️ Climatic Conditions
- Rainfall: 50–100 cm
- Winter Rainfall: 15–25 cm (Dec–March)
- Temperature: Hot summers & cold winters
📍 Distribution
- Bhabar, Shiwalik Hills, and parts of Western Himalayas (up to 1000 m)
🌳 Characteristics
- Low scrub forests
- Small, stunted, evergreen trees & shrubs
- Dominant species: Olive, Acacia modesta, Pistacia
These forests reflect a Mediterranean-like ecology — dry summers, some winter rains.
✅ Comparison Table: Montane Sub-Tropical Forests
| Forest Type | Rainfall (cm) | Dominant Trees | Distribution | Key Features |
| Broad-Leaved Hill Forests | 75–125 | Oak, Chestnut, Sal, Ash | Eastern Himalayas, Nilgiris, Mahabaleshwar | Moist, stunted evergreens, climbers |
| Moist Pine Forests | Moderate | Chir Pine (pure stands) | Western Himalayas, Khasi & Naga Hills | Resin source, used for timber |
| Dry Evergreen Forests | 50–100 | Olive, Acacia modesta, Pistacia | Shiwaliks, Western Himalayas | Low scrub, dry, sparser |
