A noteworthy feature of Sri Lanka's biodiversity is the remarkable high proportion of endemic species among its flora and fauna: 23% of the flowering plants and 16% of the mammals in the island are endemic. Even more interesting is distribution of endemics. A large proportion is found in the wet zone in the south western region of the island.
Flora - Twenty three percent of the flowering plants are endemic and most of them are confined to the wet evergreen and wet montane forests of the central and southwest part of the country.
Vegetational analysis has resulted in the identification of fifteen different floristic regions with the great majority being found in the wet and intermediate zones. The presence of many floristic regions within a relatively small area is a reflection of the high level of ecosystem diversity in the country.
Fauna - The fauna of Sri Lanka is as diverse as the flora. While sharing common features with the neighboring subcontinent, the fauna exhibits very high endemism among the less mobile groups. With taxonomical revisions and descriptions of new species the number of species in each group keeps changing.
For endemic species, the distribution patterns are similar to the flora: the wet zone has many more endemic species than the dry zone. In terms of mammals, birds and fishes, the three major groups that are well studies in Sri Lanka, each group has a different distribution pattern.
Biodiversity Hot Spot in the world
Sri Lanka has been identified by the environment activist group Conservation International (CI) as one of 25 biodiversity hot spots in the world, reported the Time weekly early January 2006. These hot spots could have maximum benefit by preservation efforts, the magazine said in a cover story titled "Heroes for the Planet: Earth Angles". The U.S.-based CI said that together with Western India, Sri Lanka, the island in the Indian ocean, accounts for 2,180 plant species that are unique to each hot spot.
Sri Lanka's tropical rain forest ecosystem is considered as an area which is disturbed by human activity, but still exceptionally rich in animal and plant species found nowhere else.
For those especially interested in a more in-depth study of Sri Lanka's rich and diverse flora and fauna, Sri Lanka has Eco Teams, who can arrange tours with specialist guides in a variety of different locations all around the island.
In terms of flora, the wet zone is one of the best places to explore due to its huge variety of spectacular orchids, hardwood trees (including ebony, teak and silkwood), and many plants used in Sri Lankan ayurvedic medicine. Sri Lanka's central hill country is home to some fascinating cloud and dwarf (pygmy) forests as well as extensive grassland areas (such as the famous "Horton Plains National Park"). Even the dry zone, though usually arid, can erupt with colour after a spell of rain.
The most ancient type of plant area in Sri Lanka is Namal Uyana. The sanctuary at Ulpothagama, Madatugama famous for its pink quartz mountain could be the home of one of the world's largest beds of fossilized plants. The accidental find of a massive fossil bed by a para archaeologist led to a team of government officials visiting the site and submitting a report to Prime Minister recommending that the area be declared a "strict natural reserve" and a high security zone. The plant fossil area is believed to cover over 300 acres. It is easy to see from the rich diversity that anyone interested in plant life would find Sri Lanka a fascinating place. Just one more reason to visit the beautiful and friendly nation of Sri Lanka.