Brahmaputra Valley semi-evergreen forests

The Brahmaputra Valley semi-evergreen forests is a tropical and subtropical moist broadleaf forests ecoregion located in the Indomalaya biogeographic realm, covering South and Southeast Asia, extending from the Indian subcontinent to southern China, spanning approximately 56,613 km². Classified under the WWF ecoregion code IM0105, this region represents a distinct ecological community shaped by its unique combination of climate, geography, and evolutionary history.

Climate and Vegetation

This ecoregion experiences warm year-round with high annual rainfall, typically exceeding 2,000 mm. The dominant vegetation consists of dense, multi-layered canopy of broadleaf evergreen trees. These conditions create the foundation for the ecological communities found within the Brahmaputra Valley semi-evergreen forests.

Ecological Significance

These forests are the most biodiverse terrestrial ecosystems on Earth, hosting an extraordinary density of plant and animal species per unit area. Epiphytes, lianas, and a rich understorey characterise the complex vertical structure. The Brahmaputra Valley semi-evergreen forests contributes to the broader biodiversity patterns of the Indomalaya realm.

Geographic Distribution

The Brahmaputra Valley semi-evergreen forests extends entirely within Bhutan. This geographic range places it within the Indomalaya realm, one of the eight major biogeographic divisions of the world.

Notable Species

The Brahmaputra Valley semi-evergreen forests supports a range of wildlife, including African bristlegrass (Setaria sphacelata), American carpet grass (Axonopus compressus), Asian house shrew (Suncus murinus), Asian marshweed (Limnophila sessiliflora), Awnless Barnyard Grass (Echinochloa colonum), Awnless Brome (Bromus inermis), Bastard Cress (Thlaspi arvense), Bermudagrass (Cynodon dactylon), and 42 more species.

Conservation

Like many tropical and subtropical moist broadleaf forests ecosystems, the Brahmaputra Valley semi-evergreen forests faces threats from deforestation, agricultural expansion, logging, and climate change. Conservation efforts in this ecoregion focus on habitat preservation, sustainable land management, and protecting corridors that connect fragmented habitat patches.