Managing Arid Areas and Sand Dunes in Sri Lanka - Combating Desertification in Asia, Africa and the Middle East - page 313

a significant threat to peoples' livelihood and land degradation is one of the major
challenges facing the people in promoting environmental protection and sustainable
development. But coastal areas are also under threat from mobile sand dunes (see
below).
Sri Lanka was once a heavily forested island. Over the past century its closed
canopy forest cover has dwindled rapidly to less than 23 %. In the 1900s it was
reported that the forest cover is near 90 % of the total land. Historically, much of
the loss was attributed to creation of plantations of tea, rubber, coconut and other
crops during colonial times. Recently, settlement schemes to provide livelihood of
landless poor, slash and burn for agriculture, encroachment for cultivation, village
expansion due to population growth, forest fire and other development activities
have contributed to the decline of island's natural forest cover.
Deforestation on steep slopes of watersheds and removal of grass and other
protective cover both in the wet zone and in the slash and burn cultivation areas
of the dry zone leads to severe soil erosion. Head-ward gully erosion in the plains
of the dry zone is substantial. River bank erosion is confined to flood plain areas
due to undercutting during floods. Overgrazing and trampling by cattle promote
soil erosion in the dry zone. Landslides add further to erosion, especially on
cultivated slopes in the hill country. Deforestation has caused the natural dense
canopy forest cover in the country to dwindle from 80 % at the turn of the 20th
century, to less than 20 % by 2002. Forests have been cleared by government
agencies for agriculture, settlement schemes and other development projects. They
have been cleared illegally for shifting cultivation and for homesteads. Irregular
agricultural activities, deforestation and setting fire to forests have also contributed
to this situation. Deforestation appears to be continuing despite efforts at controlling
the problem and impacts adversely on the environment, the welfare of the rural
sector, agriculture and related sectors and the overall economy of Sri Lanka. Forest
conservation and afforestation is at a low level compared to the rate of forest
destruction.
Sri Lanka is one of the smallest but biologically most diverse countries in Asia.
Consequently, it is recognized as a biodiversity hotspot of global and national
importance. Its varied topography and tropical island conditions have given rise
to extremely high levels of biological diversity and endemism, particularly in
the natural forests. More than 3,650 species of floral plants, 300 species of
pteridophytes, about 400 birds, almost 10 animals and more than 160 reptiles can
be found in Sri Lanka and 26 % of flowering plants, 76 % of land snails, 60 % of
amphibians and 49 % of reptiles are endemic to Sri Lanka. The Sinharaja Forest
Reserve, which protects the largest remaining stand of primary rain forest on the
island, was declared a World Heritage Site in 1988. The government has ratified
international environmental agreements pertaining to climate change, desertification
endangered species, environmental modification, hazardous wastes, law of the sea,
ozone layer protection, and wetlands. Eutrophication of water bodies due to excess
plant nutrition by soil erosion increased the growth rate of aquatic invasive plants
such as Salvinia and Eichornia (“Japan Jabara” - a species of Water Hyacinth).