Broadly Bhutan can be divided into three eco-floristic Zones. The Alpine Zone comprises areas above 4,000m. The Temperate Zone, lying between 2,000m and 4,000 and the subtropical zone, which lies between 150 m and 2,000 m,
Forest ecosystem is the most dominant ecosystem in the country with 70.46 percent of the total area under forest cover. Mixed conifer and broad leaf forests are the two dominant forest types, constituting 32.43 and 22.69 percent of the total forest cover respectively.
The alpine ecosystem comprises areas above 4000 masl, with no tree cover but scrub vegetation and meadows. This area is rich in many species of grasses and herbs with over 200 medicinal plants used for traditional medicine are found in this region. It is also the habitat of the famous chinese caterpillar fungus (Ophiocordyceps sinensis), and other wild fauna, such as the snow leopard, blue sheep and takin.
Bhutan has different forms of aquatic habitats scattered through out the country, ranging from rivers, lakes, marshlands to hot springs.
The country is known to have six major agro-ecological zones corresponding with altitudinal range and climatic conditions ranging from the Wet Subtropical Zone at 150 to 600m above sea level to the Alpine zone at 3,600 – 4,600 m above sea level.
Source: National Biodiversity Centre, Thimphu