Himalayan subtropical broadleaf forests

The Himalayan subtropical broadleaf forests is an ecoregion which extends along the southern foothills of the Himalayas through Nepal, India, Bhutan. It stretches from central Nepal, Bihar along the Nepalese border, eastern Nepal, Darjeeling District of India's West Bengal state, and Bhutan.^[2]

Himalayan subtropical broadleaf forests
Sal forest in Chitwan National Park
Ecoregion territory (in purple)
Ecology
Realm	Indomalayan
Biome	tropical and subtropical moist broadleaf forests
Borders	List Himalayan subtropical pine forests Western Himalayan broadleaf forests Eastern Himalayan broadleaf forests Brahmaputra Valley semi-evergreen forests Terai-Duar savanna and grasslands
Bird species	343[1]
Mammal species	148[1]
Geography
Area	38,200 km2 (14,700 sq mi)
Countries	Bhutan India Nepal
Conservation
Habitat loss	81.553%[1]
Protected	6.77%[1]

Geography

The ecoregion covers an area of 38,200 km² (14,700 sq mi). The soil is alluvium.^[2]

Above 1,000 m (3,300 ft), the broadleaf forests transition to the Himalayan subtropical pine forests. At lower elevations the ecoregion is flanked by the Terai-Duar savannas and grasslands and the tropical monsoon forests of the Gangetic Plain.

Flora

The ecoregion hosts a broad range of plant communities, based on its complex topography, differing soils, and variations in rainfall from the drier west to the more humid east. Its location on the south slope of the Himalaya allows the intermingling of plants and animals from the Indomalayan and Palearctic biogeographic realms. Predominant tree species include sal (Shorea robusta) and species of Terminalia, Bauhinia, Schima, and Castanopsis, which are typical of Asian moist subtropical and tropical forests. Trees grow to 30 meters in height and up to 50 meters in favorable conditions. Climbers and epiphytes are common in the humid forests.^[3] The main forest types include Dodonaea scrub, subtropical dry evergreen forests of Olea europaea subsp. cuspidata, northern dry mixed deciduous forests, dry Siwalik sal (Shorea robusta) forests, moist mixed deciduous forests, subtropical broadleaf wet hill forests, northern tropical semi-evergreen forests, and northern tropical wet evergreen forests.^[2]

Fauna

Several mammals native to the ecoregion are threatened, including the Bengal tiger, Indian elephant, smooth-coated otter, clouded leopard, gaur, Sumatran serow, Irrawaddy squirrel, and particoloured flying squirrel. The chestnut-breasted partridge is endemic.^[2]

Protected areas

Eight protected areas extend into this ecoregion covering 2,710 km² (1,050 sq mi), which is about 7% of the ecoregion's area:^[2]

• in India: Sohagi Barwa Sanctuary and Valmiki National Park;
• in Nepal: Bardia National Park, Chitwan National Park, Parsa National Park;
• in Bhutan: Royal Manas National Park, Khaling Wildlife Sanctuary and Phibsoo Wildlife Sanctuary.

Two high-priority tiger conservation units (TCU) extend across adjacent ecoregions:^[4]

• Chitwan-Parsa-Valmiki TCU covers a 3,549 km² (1,370 sq mi) huge block of alluvial grasslands and subtropical moist deciduous forests;
• Bardia-Banke TCU covers 1,518 km² (586 sq mi).