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Montane Forests, Mangroves, and Wetlands
Montane Forests
Montane forests occur at higher altitudes in the Himalayas and other mountain ranges, where temperature decreases with elevation, creating distinct vegetation zones.
Himalayan Vegetation Zones
| Elevation | Forest Type | Key Species |
|---|---|---|
| 1,000-1,500 m | Sub-tropical broadleaf | Sal, teak, terminalia, bamboo |
| 1,500-3,000 m | Temperate coniferous | Pine (chir), deodar (Himalayan cedar), fir, spruce, oak, rhododendron |
| 3,000-3,600 m | Temperate mixed | Blue pine, silver fir, birch, juniper, rhododendron shrub |
| 3,600-4,500 m | Sub-alpine | Birch, rhododendron (krummholz — stunted growth), juniper |
| >4,500 m | Alpine | Alpine meadows (bugyals), mosses, lichens, cushion plants |
Characteristics
- Deodar (Cedrus deodara) — National tree of Pakistan; prized timber of the western Himalayas
- Chir pine (Pinus roxburghii) — dominates in the 1,500-2,000 m zone; resin extraction
- Oak forests (Quercus) — in the 1,500-2,500 m zone of the central and eastern Himalayas
- Rhododendron — colorful flowering trees and shrubs; State tree of Uttarakhand and Nagaland
- Alpine meadows (Bugyals) — rich in medicinal herbs (brahmakamal, keeda jadi — Yarsagumba)
Peninsular Montane Forests
- Found in the Nilgiris, Palani hills, Anaimalai, and Cardamom hills
- Shola forests: Stunted tropical forests found in high-altitude valleys of the Western Ghats (1,500-2,500 m)
- Grasslands: Shola-grassland mosaic — grassy meadows alternating with patches of forest
- Key species: silver oak, acacia, eucalyptus (planted), rhododendron
Mangrove Forests
Mangroves are salt-tolerant forest ecosystems found in intertidal zones along the coast.
Distribution
| Location | Area (sq km) | Key Species |
|---|---|---|
| Sundarbans (WB) | 4,226 | Sundari (Heritiera fomes), goran, gewa, keora |
| Bhitarkanika (Odisha) | 672 | Sundari, avicennia, rhizophora |
| Gulf of Khambhat (Gujarat) | 2,000+ | Avicennia, rhizophora |
| Andaman & Nicobar | 617 | Rhizophora, bruguiera, ceriops |
| Godavari-Krishna delta | 350 | Avicennia, excoecaria |
Characteristics
- Prop roots: Support roots that emerge from the trunk (Rhizophora)
- Pneumatophores: Breathing roots projecting upward from mud (Avicennia)
- Salt excreting glands: Remove excess salt through leaves
- Vivipary: Seeds germinate while still attached to parent tree
Importance
- Coastal protection: Absorb wave energy; reduce cyclone/tsunami damage
- Biodiversity: Nursery grounds for fish, shrimp, crabs; habitat for Bengal tiger (Sundarbans)
- Carbon sequestration: Store 3-5x more carbon per hectare than tropical forests
- Livelihood: Honey, wax, timber, fish for local communities
Threats
- Coastal development (aquaculture, urban expansion)
- Climate change-induced sea level rise
- Pollution from agriculture and industry
- Overharvesting of timber and fisheries
Wetlands
India has over 700,000 hectares of wetlands, including 49 designated Ramsar sites.
Major Wetland Types
| Type | Examples |
|---|---|
| Glacial lakes | Wular, Dal (J&K) |
| Brackish lagoons | Chilika (Odisha), Pulicat (AP) |
| Freshwater lakes | Loktak (Manipur), Kolleru (AP) |
| Coral reefs | Lakshadweep, Andaman, Gulf of Mannar |
| Man-made | Keoladeo (Rajasthan), Harike (Punjab) |
Ecological Significance
- Water purification and flood control
- Migratory bird habitats (Siberian cranes in Keoladeo, flamingos in Chilika)
- Groundwater recharge
- Livelihoods: fishing, agriculture, tourism