According to the forest cover survey carried out by the Forest Department in year 1999 based on the satellite imageries of 1996, the dense natural forest cover in Sri Lanka was (1.47 million ha) 22.4% of the land area of the country, though all forests including " sparse natural forests" (which cover 7.2% of the land area) brings the forest cover in the country excluding forest plantations and other forms of tree vegetation) to (1.94 million ha) 29.6% of the land area10. The total extent of forest plantations established for commercial or protective purposes amounts to 93,000 ha (around 1.4% of the land area) (Figure 2.3) It is therefore, the total forest cover in Sri Lanka (1996) including forest plantations amounts to 2.035 million ha (31% of the land area of the country).

In addition to these natural forests and forest plantations, a wide range of non-forest tree resources are available in the form of home gardens, rubber plantations, coconut plantations, and shade trees on tea plantations, tress on farmlands etc. These non-forest tree resources provide more than 70% of the industrial timber requirement in the country. Of this production, over 45% is produced from home gardens11.

Natural Forests by Forest Type in 1999

Forest Type	Total Forest Area (ha) 1999	Percentage of the Land Area
Montane forests	3,099.5	0.5
Sub-montane forests	65,792.3	1.00
Lowland wet evergreen forests	124,340.8	1.89
Moist evergreen forests	221,977.0	3.38
Dry mixed evergreen forests	1,027,544.1	15.66
Riverine forests	18'352.1	0.28
Mangroves	9,530.5	0.15
Total of Closed  Canopy Forests	1,470,636.2	22.41
Open Canopy Forests	471,583.2	7.19
Total forest cover	1,942,219.5	29.60

Natural Forests by Forest Type in 2010

Forest Type	Total Forest Area (ha) 2010	Percentage of the Land Area
Montane forests	44,758	0.68
Sub-montane forests	28,513	0.43
Lowland wet evergreen forests	123,302	1.87
Moist evergreen forests	117,885	1.79
Dry mixed evergreen forests	1,121,392	17.09
Riverine forests	2425	0.036
Mangroves	15669	0.24
Savannah forest	68,043	1.04
Total of Closed  Canopy Forests	1521987	23.19
Open Canopy Forests	429,485	6.55
Total forest cover	1,951,472	29.74

Sri Lanka has a striking variety of forest types brought about by spatial variations in rainfall, altitude and soil.  Based on the angiosperm flora and their endemicity , a total of  15 distinct floristic regions (Appendix D) have been recognized in Sri Lanka 12.  The forests that containmuch of the biodiversity of Sri Lanka range from Tropical wet lowland evergreen forest (Lowland rain forests) in the wet zone, Tropical moist evergreen forest (Moist monsoon forests) in the intermediate zone and Tropical moist evergreen forests (Dry monsoon forests) in the dry zone at elevations between 1000 – 1500 m in the wet zone); Tropical montane forests (at elevations of 1500-2500m in the wet zone); with Riverine forest along river banks; Tropical thorn forest in the
arid areas; and Mangrove swamps in the coastal areas13. The percent composition of Sri Lanka's main natural forest categories in 1999 and the forest cover map of Sri Lanka (1999) are shown in figure 2.1 and figure 2.2 respectively.

Tropical lowland wet evergreen forests of Lowland rain forests

Tropical lowland wet evergreen forests represent 6.4% of the island's natural forest cover and 1.9% of its total land area of the country. This forest type is restricted to the wet zone in the southwest of the island, up to a mean elevation of 1000 m, and is at present highly fragmented. These forests are now represented mainly by isolated and very fragmented forest patches scattered over the wet zone.  Most individual forests amount to less than 10,000 ha2. These forests are of particular importance as they, constitute the last remnants exceptionally rich in biodiversity and high in endemism (about 60 – 75% of the tree species are endemic to Sri Lanka) especially among the Dipterocarps which constitute the characteristic tree flora and dominate the structural and floristic composition of this ecosystem.  Lowland wet evergreen forests harbor nearly all the country's woody end endemic flora, about 75 per cent of the endemic fauna and all the endemic genera.  The level of endemism in these forests ranges from 37- 64% for woody plants and 14- 52% for animals, compared with 10 – 16% for species in the Dry Zone forests.  All endemic genera and over 90 per cent of the woody endemic species and about 75 per cent of the endemic animals occur in these forests. In the lower slopes and valleys, these forests are characterized by a dense forests.  In the lower slopes and valleys, these forests are characterized by a dense canopy of tree species reaching 30-40 m in height, with emergents rising to about 45 m, and woody lianas that form an intricate net work6.

Lowland wet evergreen forests are dominated by the families Dipterocapaceae, Clusiaceae, Sapotaceae, Bombacaceae and Myrtaceae.  At the lower elevations (<100m), Dipterocarpus zeylanicus and D. hispidus, and at higher elevations (>100 m) Mesua ferrea and shorea trapezifolia, dominate the canopy of these forests.  In the sub – canopy, the common species are Cullenia rosayroana, C, zeylanica and Myristica dactyloides, and in the understorey tree layer Xylopia champinoii and Garcinia hermonii.  large leaves, drip tips on leaves, buttresses,  cauliflory, drooping young twigs, colourful young leaves, drip tips on leaves and fewer lianas and epiphytes characterize its vegetation

The southern lowland hills and plains extending from the east of Kalutara to the southeast are exceptionally rich in plant diversity, and this area is believed to be, floristically, the richest in South Asia6.   Another interesting feature is that many endemices are restricted to a single forest or a single cluster of forest blocks. Some of the most important wet zone forests in terms of biodiversity are the peak Wilderness Sanctuary (22,379 ha) the Kanneliya- Dediyagala-Nakiyadeniya (KDN) forest complex (10,139 ha) , the Sinharaja world Heritage Forest Reserve (11,280 ha), the Knuckles Range of Forests (21,650 ha) and the Horton plains National park (3,159 ha). These forests are also important hydrologically as they protect the headwaters of all of Sri Lanka's main rivers.

Tropical moist evergreen forest or Moist monsoon forests

Tropical moist evergreen forests represent 11.4% of the island's natural forest cover and 3.4% of its total land area of the country.  Tropical moist evergreen forests constitute a distinct group in the lowland intermediate zone. Trees in these forests are about 25-30 m tall; represent the transition or ecotone between forests in the aseasonal and seasonal climates.  They bear similarities in species composition to both the tropical lowland wet evergreen forests and the tropical dry mixed evergreen forests and some species of their own. The dominant families here are Anacardiaceae, Sapinsaceae, Euphorbiaceae and Moraceae. The dominant species are Mangifera zeylanica, Canarium zeylanicum, Filicium decipiens, Dimorcarpus longan, Nothopegia beddomei and Gironniera parvifolia.  Lianas are abundant in this forest type. Only about 17% of the tree species in them are endemic to Sri Lanka. One of these endemics is Hopea brevipetiolaris on the crest of Doluwakanda , which is its only habitat. A few of the characteristic elements of this wcosystem are Tetrameles nudiflora, Antiaris toxicaria, Arotocarpus gomezianus and pterygota  thwaitesii.  Fragments of this forest type are seen at Barogoda near Kurunegala and Daragoda near Moneragala, and more extensive areas in Randenigala and Samanalawewa.

Tropical dry mixed evergreen forest or dry monsoon forests

Tropical dry mixed evergreen forests  represent  53% of the island's natural forest cover and 16% of its total land area.  These forests are the characteristic vegetation of the dry zone.  Generally, the trees are about 25 m tall, but shorter in those to words the arid zone. About 13% of the tree species in these forests are endemic to Sri Lanka.

The families Euphorbiaceae, Sapindaceae, Ebenaceae, Sapotaceae, and Rutaceae dominate this foresr type. The dominant canop species are Manikara hexandra, chloroxylon swietenia, Schleichera oleosa, and Pleurostylia opposite, while those in the unserstorytree layer are pterospermum suberifolium, Drypetes sepiaria and Dimorphocalyx glabellus.  They comprise a mixtyre of evergreen and deciduous canopy species. In general, the latter are found in the canopy, shedding their leaves during the late dry period, allowing much light to filter to the forest floor.  This enables grass and herbaceous species to flourish at the onset of the rainy season before new foliage on denuded canopy tress emerges.  Leaves of plant species here are small, without drip tips; many have compound leaves.  The tree trunks branch lower down and show no buttresses, compares with those in rainforests.  Epiphytes and lianas are relatively sparse in this forest type.

Although dry zone forests, are less diverse than wet zone forests floristically, are more extensive spatially, and they are important as habitats for large mammals (leopard, elephants, spotted deer,  sambhur, wild pig, primates etc)  Faunal groups such as carnivores, ungulates and primates show their highest species diversity in tropical dry mixed evergreen forests.

Tropical thorn forests:

Tropical thorn forests are found in the arid zone in the southeast and northwestern parts of the country, which have very long dry period. Temperatures here are high being over 34C and the rainfall is below 1250 mm.  As the name implies, thorny species are abundant in these forests and reach to about 5 m in height showing no species stratification. The thorny species have adaptations to store water and are able to live on very little water. Its dominant famlilles are Salvadoraceae, Mimosaceae, Euphorbiaceae and Rhamnaceae.  The racemosa, Eugenia bracteata, Phyllanthus polyphyllus, and Zizyphus oenoplia.  Endemic plant species are almost absent in these forests.

Riverine forests:

Riverine forests are found along flood plains and river valleys in the dry and intermediate zones in elevations up to about 600 m.

Tropical sub montane forests:

The natural vegetation type of tropical sub montane  forests a transitional biological belt between highlands and lowlands.  Tropical sub montane forests are confined to middle elevations (1000-1500 m) in the wet zone. Their canopies are about 20-25 m high, dominated by the families Diptreocarpaceae, Clusiaceae and Mytaceae, with the following soft and medium hardwood species being dominant: Shorea gardneri, Calophyllum spp. Cryptocarya wightiana, Myristica dactyloides and Syzygium spp.  The proporation of endemic tree species here is about 50%. Most species of the endemic genus Stemonoporus show a localized distribution in these montane forests.  The major forest areas of this catefory include peak Wilderness, Lnuckles (Dumbara hills), Namunukula and the Rakwana Deniyaya ranges.

Tropical montane forest

The montane forests, restrictes to the upper,ost elevations of the country (> 1500 m), are dominated by the Clusiaceae, Myrtaceae, Lauraceae, Symplocaceae and Rubiaceae. The common tree species in them are Calophyllum walker, C. trapezifolium, Syzygium revolutum, S. rotundifolium, Litsea ovalifolia and Actinodaphne speciosa. The forest floor harbours many species of frens.  In most areas, the understory of the forest is dense and dominated by species of Strobilanthes, bamboo and Coleus.  These forests have about 8 – 10 m tall, short – statured trees with gnarled twisted branches, an abundance of epiphytes dominated by mosses, leafy liverworts, ferns and orchids, colourful young foliage, relatively small, thick, leathery leaves and absence of drip tips are distinguishing features of its vegetation. With increase in elevation and windy conditions the canopy species become quite stunted giving way to pygmy forests.

Forest Plantations:

Forest plantation establishment was commenced in Sri Lanka as far back as 187s.  Over the past 100 years the Forest Department has established nearly 93,000 ha of forest plantations mainly with Teak, Eucalyptus, pines and Mahogany.

The forest plantation establishment expanded with the policy to establish forest plantations for production of fuelwood and timber in order to alleviate the pressure on natural forests for timber and fuelwood.  As  a result large scale planting of Teak and Eucalypts in the dry zone and pines in the wet zone taken place.  Currently the total ate under productive forest plantations is around 93,000 ha including 16,440 ha of Conifers (mainly pine species), 27,500 ha of Eucalypts & Acacias, 31,713 ha of Teak, 2,800 ha of Mahogany and 14,547 ha of Miscellaneous species.  Figure 1.3 shows the forest species in the FD forest plantations.  Timber and fuelwood from these forest plantations are extracted on sustainable basis based on the management plans.  These plantations produce 120,000 cubic meters of timber annually which account for over 8% of the national demand of timber.

Home gardens :

Home gardens are perhaps the best developed afro-forestry system in Sri Lanka. This system of traditional perennial cropping has been practiced for centuries and it can be found all over Sri Lanka, as they are an essential part of the agricultural system in the island. A brief description about the home garden system in Sri Lanka and its diversity are provided under the agricultural biodiversity section of this document.

Grassland Ecosystems:

Generally, forests in Sri Lanka are associated with several different types of grasslands.  Based on elevation, climate, plant composition and degree of disturbance, six types of grassland ecosystems have been recognized.  These include Wet patina grasslands that occur around andm above 1800 m altitude in association with upper montane forests, and these grasslands are best seen in Horton plains and around Nuwara Eliya. Dry patina grasslands are located between 500- 1000 m altitudes, are relatively  widespread, occurring in the Uva basin, and around Gampola, Nawalapitiya, Hantana and Rakwana. These grasslands have resulted from the removel of tree vegetation for shifting cultivation and subsequent abandonment. Savanna grasslands occur in the intermediate and dry zones, between 300-1000 m elevations. Those on the eastern slopes of the central massif and around the Uva basin are calles unland savannas while those in Moneragala and Bibile and in the Gal Oya basin are known as lowland savannas. Yhese frasslands resemble parkland, with scattered, fire-tolerant tree species with medicinal properties.  Savannas are maintained by anthropogenic fires, mostly to facilitace the collection of fallen fruits of the medicinal species.  Damana grasslands also known as dry low country parklands or grasslands occur in the Ampara and Batticoloa districts of the eastern dry zone.  They are dominated by the tussock grass Cymbopogon nardus.  Dammana grasslands provide fodder to wild elephants and buffaloes.  These animals are largely responsible for the maintenance of this vegetation.

Talawa grasslands

Occur in areas where the topsoil is eroded and reduced to some degree.  These grasslands also dominated by tussock grass. These grasslands can be seen around Haldumulla area in Badulla district.  Villus grasslands are found in wetland ecosystems also known as freshwater riverine  marshes. These grasslands are found in the floodplains of the Mahaweli River in the eastern dry zone and in moist depressions with a perennially high flucturating water table.  Flooding and rain water accumulation suppress any tree growth within the villu grasslands. but encourage hydrophilic grasses, sedges and other aquatic plants including some tree species. The villu grasslands are important habitats for resident and migrant water birds which include different kinds of plovers, sandpipers, pipits,  wag-tails. terns, gulls, geese.  ducks, rails, eagles, harries, cormorants, shags, jacanas etc.  

Wetlands, both natural and man-made, currently make up about 15% of the land area of Sri Lanka.  Rivers and streams, riverine floodplains, small isolated freshwater bodies, freshwater springs, seasonal ponds, and fresh water marshes comprise natural inland wetlands. The most important inland wetlands are associated  with Sri Lanka's river system comprising of 103 rivers flowing from the central highlands and making up a total collective length of about 4560 km.  plays a dominant role in shaping the wetland landscape.

This river system covers an area of about 59,245 sq km with their river basins which amounts to about 90 per cent of the island's total land area.  These rivers, associated streams and waterfalls provide special habitats such as marshes and swamps for certain plant species in the reverine and aquatic ecosystems.  The marshes and swamps associated with the Mahaweli Ganga (river) and its tributaries cover about 10,000 ha and they are very rich in biodiversity and are highly productive.

Sri Lanka does not have large natural lakes.  The man- made wetlands are the rice paddies, irrigation tanks, large reservoirs, canals, and aquaculture ponds. They together make up about two-thirds of the total area of all wetlands.  Rice paddies consist of about 525,000 ha and are distributed throughout the country.  Around 12,000 reservoirs constructed for agricultural purposes during the past two millennia, ranging in size from 1-6,500 ha, harbor a rich aquatic flora and fauna.  Most of these tanks are located mainly in the Dry Zone covering a total area over 170,000 ha.
Three wetlands (Bundala National Park, Anaiwilundawa and Madu Ganga) have been recognized internationally as Ramsar sites.  The Wetland Directory of Sri Lanka lists 62 sites of which 24 are listed as moderately threatened and 18 are listed as highly threatened.

Coastal and marine ecosystems

Sri Lanka’s coastal zone is defined by statute as a 02 km wide band of ocean, and an adjoining strip of land extending 300 m. inland; except that where a water body connected to the sea occurs, the zone extends 02 km inwards from the mouth of the water body.  Sri Lanka’s varied coastal habitats include estuaries and lagoons (126,989 ha), mangroves (6083 ha), sea grass beds, salt marshes (23,797 ha), coral reefs and large extents of beaches including barrier beaches, spits (5621 ha) and dunes (15,546 ha)17.   These habitats contain a rich component of the country’s biodiversity.  Many coastal and inshore resources associated with the coastal habitats support a thriving export industry based on export of shrimp, lobster, chank, ornamental fish, etc.  Natural causes and human interventions, accelerated by the increased coastal population during the last several decades, have combined to cause considerable degradation of the coastal habitats, resulting in the decline of their resources as well as extents at an unprecedented rate.

Coral Reefs  

Coral reefs are rich in biodiversity and are important as habitats for flora and fauna, for containing coastal erosion, and for sustaining the coastal fishery.  Coral reefs are among Sri Lanka’s most valuable shallow water marine ecosystems.  Three types of reefs are comprising coral, sandstone, and rocky reefs have been identified around the island, occurring separately or mixed together.  Fringing coral reefs are found along 2% of the coastline.  The most extensive coral reefs in Sri Lankan waters are the patchy coral reefs in the northwestern coastal and offshore waters, occurring within the Gulf of Manar and west of Kalpitiya Peninsula18.   A  total of 68 indigenous coral genera and 183 species have been recorded in the country.  Invertebrates that occur among reefs consist mainly of mollusks, sea anemones and sea cucumbers.  Coral reefs may also support around 350 species of reef fishes, such as groupers, snappers, sweetlips7, emperor fish, parrot fish, rabbit fish, surgeon fish, butterfly fish, and damsel fish.  Together these reefs support around 72 reef fishes some of which are important in the ornamental as well as the food fishery12. 

Reefs in Sri Lanka are now degraded at many sites, due to both natural causes and human impacts.  Especially near shore coral reefs are severely degraded, mainly in the western and southern region, due to coral mining in the past for production of lime.

Seagrass beds

The shoreline and near shore areas contain extensive seagrass beds that often occur in association with coral reef ecosystems or within estuaries and lagoons such as the basin estuaries and lagoons of Puttalam, Negambo, Mawella, Koggala, Kokilai, Jaffna and Batticoloa.  Very extensive seagrass beds are reported from the Dutch Bay (in Kalpitiya) to the western end of the Jaffna Peninsula, and from Mannar to the northwest across the Palk Bay to Rameswaram Island on the Indian coast19.

17 Joseph, L, National Report of Sri Lanka on the Formulation of a Transboundary Diagnostic Analysis and Strategic Action Plan for the Bay of Bengal Large Marine Ecosystem Programme, Ministry of Fisheries and Ocean Resources 18 Rajasuriya et al., 2000 Status of coral reefs in South Asia: Bangladesh, India, Maldives and Sri Lanka.  In status of coral reefs of the world: 2000 A GCRMN publicataion Edited by C. Wilkinson. 19 Samarakoon and Pinto, 1988 – Synthesis report for information of critical habitats in the coastal zone: Workshop on Critical Habitats in the Coastal Zone, CCD/US AID/URI

Around 12 species of seagrasses have been recorded in Sri Lankan waters.  These habitats are very productive and support a rich diversity of commercially important fish species as well as a large number of other marine organisms.  Among the invertebrate fauna are 201 species of crabs.  There are five species of turtles that come ashore for nesting on Sri Lankan beaches.  Sea grasses are mainly found in the basin estuaries and lagoons of Puttalam, Negambo, Mawlla, Koggala, Kokilai, Jaffna and Batticoloa.  These ecosystems are of particular interest as they are believed to be the main habitat of the endangered dugong (Dugong dugong) and are valuable habitats for the globally threatened sea turtles12.
Estuaries and lagoons

Sri Lanka’s coastline has many picturesque and economically important estuaries and lagoons.  These complex systems contain a diversity of species and a variety of coastal habitats including, mangroves, salt marshes, seagrass beds and mud flats.  Sri Lanka’s estuaries have been defined in the CZMP (2003) as natural systems that are transitional between rivers/streams and the sea, and within which the salinity of the water is measurably different from the salinity in the open ocean.  All estuaries have free connection with the open sea, either continuously or intermittently. 

There are two different types of estuaries; Riverine estuaries where the rivers or streams discharges directly into the sea through relatively narrow channels (e.g.) the Kelani Ganga, Maha Oya, Kalu Ganga and Nilwala Ganga estuaries) and, Basin estuaries where the river or stream first discharges into a relatively shallow basin before entering the sea.  A total area of 88,850 ha for basin estuaries, and about 2,113 ha for riverine estuaries together with 89 lagoons have been recorded in the Coastal Habitat Survey of 200212.

Sri Lanka’s lagoons are defined in the CZMP as coastal bodies of water that may be brackish, fresh or hyper saline, and are separated from the sea over a very long period of time by any of several types of barriers that restrict water circulation.  There are around 89 lagoons ranging from 3 ha to 7,589 ha in extent covering a total extent of 36,364 ha.  Lagoons are more abundant along the southern, southeastern and eastern coasts where the littoral drift causes an accumulation of sand to form barriers and spits at river mouths through which the fresh water discharge is low16.

Mangroves 

The mangrove swamps in Sri Lanka are not extensive as they occur as a narrow inter-tidal belt that extends less than 1 km landward from the mean low water tidal level.  According to the forestry cover inventory of 1999, the total mangrove vegetation in the country covers around 9,530 ha in extent.  The mangrove areas are discontinuous, but are important breeding grounds for marine organisms.  The main mangrove habitats can be seen along the west, northeast and east coasts, but they are most extensive in the Puttalam district20.  Mangrove vegetation comprises around 40 different species of trees, bushes, herbs and vines, of which about 25 are true mangroves.  Occurring within the mangrove habitats are many species of fish, birds and reptiles.

Some relatively undisturbed mangroves have been recorded in the Kala Oya estuary, islands in the Puttalam estuary and Dutch Bay, Kokkilai estuary, Nai Aru estuary, Panama lagoon, the Uppar (Panichchankerni) estuary, Nanthikadal lagoon, Yan Oya estuary and in some areas of the Batticaloa estuary21.

20   MoENR, 2002, State of the Environment in Sri Lanka, Ministry of Environment and Natural Resources
21  Joseph,.  L, 2003, National Report of Sri Lanka on the Formulation of a Transboundary Diagnostic Analysis and Strategic Action Plan for the Bay of Bengal Large Marine Ecosystem Programme.

Salt marshes: There are about 23,797 ha of salt marshes in the arid areas of the country which are subject to long dry periods. The conditions under which salt marshes occur vary,  but more often they are found close to the landward margin of the inter –tidal zone where the soil salinity is relatively high due to insufficient freshwater runoff to flush out the accumulated salts.  These ecosystems contain herbaceous, salt tolerant, plants growing in tidal flats or areas periodically inundated by sea water.  Extensive sail marshes occur along the coast in mannar district where tidal flats contain about 56 species of marsh vegetation.  patchy salt marshes occur mainly in sediment lagoon/estuarine areas such as Hambantota, Puttalam, Kalpitiya and Mundel.

Species Diverasity:

The high diversity of ecosystems in the country has provided habitats for rich species diversity and climatic and edaphic variants of individual species, particularly among the plants.  In the island's flora, the highest species diversity is recorded among the flowering plants, followed in decreasing order by the fungi, bryophytes (mosses and liverworts).  freshwater algae and ferns.  Among animals, the diversity of vertebrates is well known compared to that of invertebrates, where only a few groups have been studied in depth.

The wet zone rainforests provide habitats for nearly all of the country's woody endemic plants and for about there-quarters of the endemic animals. Similarly, the country supports a high faunal diversity due to the varied climatic and topographic conditions prevailing in the island.  The inland waters provide habitats for a large number of freshwater species, particularly the fish fauna and also invertebrate fauna.  Inland wetlands, both natural and man-made, are also the habitats of many species of birds, mammals and plants.

Species diversity among selected flora and fauna and the number of endemics in each group

Taxonomic group	Total no. of species	Endemics (%)	Taxonomic group	Total no. of species	Endemics(%)
Flora			Invertebrate Fauna
Flowering plants	3771	927(24.6)		148	21(14.2)
Gymnosperms	1	0(0)		181	??  (?)
Pteridophytes(Ferns only)	348	48(13.8)		243	20 (8.2)
Mosses	561	63(11.2)		501	NA
Liverworts	303	NA		246	204(82.9)
Freshwater algae	560	NA		120	57(47.5)
Fungi	2260	NA		51	51(100)
Lichens	661	NA		23	07(30.4)
Marine Fauna			Vertebrate Fauna
Echinoderms	213	NA		91	16(17.6)
Marine Molluscs	228	NA		482*	33 (6.8)
Sharks	61	NA		183	92 (50.3)
Rays	31	NA		106+	90+(84.9)
Marine Reptiles	18	NA		82	44(53.6)
Marine Mammals	28	NA

Floral Diversity

In terms of floral diversity, the vegetation supports over 3771 species of flowering plants(angiosperms)from 214 families and 1522 genera (of which 24.% are endemic) and 314 species of ferns and fern allies (of which 13.8%are endemic).  Species diversity is also high among mosses (561), liverworts (303), algae (896) and fungi (2260)  Of the island's moss flora, 115 of the species are endemic to the island and all of them are confined to the rain forests.  It is very interesting to note that all 58 species of  Dipterocarps  in Sri Lanka, which form the dominant structural and floristic component in wet Zone rainforests, are endemic (MoENR, 2008)

Faunal Diversity

The country supports a high faunal diversity due to the varied climatic and topographic conditions prevailing in the island. Overall Sri Lanka has 677 indigenous vertebrate species (excluding marine forms), of which 43% are endemic, and a further 262 species of migrant birds.  Endemism among vertebrates is highest among amphibians (85%), freshwater fishes (54%) and reptiles (50%). In addition, there are 22 species of introduced fish which are consumed for food.  There are also about 350 species of marine fish which include ornamental fishes and food species such as seer, tuna and skipjack. Sri Lanka is one of the richest countries for amphibian diversity with 3.9 species per 1000 sq Km. The amphibian fauna number 53 species from 16 genera (of which 85% are endemic).  A majority of the amphibian species has very restricted geographic ranges and is found mainly in specific ecological niches of wet zone forests.

The reptilian fauna of Sri Lanka show considerable diversity, with 02 species of crocodiles, 05 species of marine turtles, 03 species of tortoises, 92 species of snakes (of which approximately 50% are endemic), 21 species of geckoes (of which 06 are endemic), 14 species of agamid lizards (of which 10 are endemic), two species of monitor lizards, and 21 species of skinks (all rare, and 17 endemic).  The rich avifauna of the country is reflected by the presence of 482 species of birds which include about 113 migrants (6.8% are endemic).

Among the invertebrates, a high percentage of endemism is evident among the freshwater crabs (100%) land  snails (83%) and dragon flies (47.5%) with many of them being point endemics.  Most of this endemic fauna are restricted to the wet zone of the island.

Genetic diversity
Sri Lanka is expected to have a very high genetic diversity in view of its varied climate, high species diversity and many other environmental variations.  However, almost all the available information on genetic diversity is confined to economically important agricultural crops and their wild relatives.  Information on genetic diversity of the natural flora and fauna of Sri Lanka is extremely limited.  However among the few studies carried out on natural flora and fauna, reports that the Sri Lankan leopard is a distinct subspecies, one of ten in the world.  Sri Lanka elephant population consists of three distinct subspecies, one of ten in the world.  Sri Lanka elephant population consists of three distinct genetic stocks representing northern, mid-latitude and southern regions of the island.  High genetic diversity has also been reported among freshwater fishes and amphibians26 Among the plants, phylogenetic and population genetic studies have been carried out on some members of Dipterocarpaceae.   The proportion of the total genetic diversity among populations of some of the Dipterocarp  species resulting from higher rates of out-crossing is shown to be similar to the average reported in literature for tropical woody species.  Lower within-population genetic variation for these species have been reported in logged-over forest fragments, suggesting that forest degradation, fragmentation and habitat size reduction have lead to their genetic erosion.

The genetic diversity of wild relatives, traditional cultivars and land races of crop species are being estimated for both in-situ and ex-situ conservation in both within and outside protected areas, in farmlands and home gardens and gene banks, primarily through the initiatives of the Department of Agriculture, Department of Export Agriculture, research institutes for plantation crops and the plant Genetic Resource Centre (PGRC) at  Gannoruwa.  In addition to these institutions, Department of National Museums and National Herbarium at Peradeniya, and  the National Herbarium at Hakgala Botanic Gardens maintain a taxonomic collection of fauna and flora of the island.  The diversity of crop genetic resources in different agro-ecological regions of the island is quite high.  About 645 species of crop wild relatives of Sri Lanka have been catalogued in the National Herbarium at Peradeniya.11

Threatened and Endangered Species

Among the total inland indigenous vertebrate species recorded in Sri Lanka, 223 (33%) species are nationally threatened.  Among the threatened vertebrate species, 138 (62%) are endemic to the island.  Twenty one species of endemic amphibians have been considered as extinct.  Of the surviving total inland vertebrates, 57 species are Critically Endangered (CR), and among the endemic vertebrate species, 34(12%) are Critically Endangered,68 (25%)  are Endangered (EN) and 36(14%) are Vulnerable (VU).  Among the vertebrate fauna, the highest number of threatened species has been recorded among reptiles (56), followed by amphibians (52), birds (46) mammals (41) and fresh water fish (28).  It has been reported that  50%  of mammals and amphibians,  30% of reptiles and fresh water fish, and 20% of birds in the island are currently facing the risk of becoming extinct.

Among the inland invertebrates, the highest number of threatened species has been recorded among the butterflies (66), followed by freshwater crabs (37), land snails (33), dragonflies (20) and theraphosid spiders (01).  Among inland invertebrates, the highest proportion of threatened species is among freshwater crabs where 50%of the species is currently facing extremely high risk of extinction (CR).

Summary of threatened inland indigenous fauna in Sri Lanka.   

According to the IUCN Red List of Threatened Fauna and Flora of Sri Lanka (2007), 6.5% of the angiosperm flora has been assessed as extinct, while 61% were threatened. Among the extinct plant species, nearly 60% are endemic, while among the threatened plant species, 61% are endemic to the island.  It has been reported that about 37% of the threatened plants are Critically Endangered (CR).  They are under considerable risk of extinction in the near future, especially if habitat degradation is not reversed.  Fifty three (53%) of the endemic ferns species are nationally threatened.  The family Orchidaceae had the hifhest number of threatened species (18%), followed by Rubiaceae (15%), Acanthaceae (7.5%), Dipterocarpaceae (6.2%) and Phyllanthaceae (4.6%).  According to IUCN study, these five families harbor more than 50% of the threatened species identified.