Flora

Wetlands are one of habitat types of Yala

Yala National Park has a variety of ecosystems including moist monsoon forests, dry monsoon forests, semi deciduous forests, thorn forests, grasslands, fresh water and marine wetlands, and sandy beaches.^[3] The area under forest cover mainly consists of Block I and rangelands of open parkland (Pelessa grasslands) including some extensive grasslands. The forest area is restricted to around the Menik River while rangelands are found towards the sea side. Other habitat types of the Block I are tanks and water holes, lagoons and mangroves and chena lands. The mangrove vegetation in the Buthuwa lagoon is largely Rhizophora mucronata while Avicennia spp. and Aegiceras spp. are less abundant. The vegetation of Block II is similar to those of Block I, and Yalawela, once a fertile paddy field, represents Pitiya grasslands. The mangroves of Block II occur around the estuary of Menik River, which extent to 100 hectares (0.39 sq mi). The common mangrove plants are Rhizophora mucronata, Sonneratia caseolaris, Avicennia spp., and Aegiceras corniculatum. The lagoons of Pilinnawa, Mahapothana, and Pahalapothana are also located in this block.^[3] The other common mangrove species are Sonneratia caseolaris, Acanthus ilicifolius, Excoecaria agallocha, and Lumnitzera racemosa. In the bare sand Crinum zeylanicum is found.^[9]

In the Blocks III, IV, and V, forests are more widespread. The canopy of the forest manly contains Drypetes sepiaria and Manilkara hexandra plant species. The Pitiya grasslands are important for grazing animals. The Cynodon barberi is the common grass in Pitiya grasslands while Zoysia matrella becomes dominant near the beach. Among 300 odd floral species are Manilkara hexandra, Drypetes sepiaria, Ceylon Satinwood, Terminalia arjuna, Limonia, Berrya cordifolia, Randia dumetorum, Pleurostylia opposita, Gymnema sylvestre, Bell mimosa, Neem, Banyan, Toothbrush tree, Schleichera oleosa, Vitex pinnata, Indian blackberry, Gmelina asiatica, Carissa spinarum, Euphorbia antiquorum, and Acacia eburnea.^[2] In the seasonally flooded areas of Block II, a wild species of rice (Oryza sp.) is found. The Glenniea unijuga is an endemic plant species found around the wetlands of the park. The Munronia pumila, Salacia reticulata, and Asparagus racemosus are the medicinal plants.^[3]

[edit] Fauna

Fauna

Fauna

The Great Stone-curlew is a waterbird found in the park

Yala is one of the 70 Important Bird Areas (IBAs) in Sri Lanka.^[10] Of 215 bird species of the park, six are endemic to Sri Lanka.^[2] They are Sri Lanka Grey Hornbill, Sri Lanka Junglefowl, Sri Lanka Wood-pigeon, Crimson-fronted Barbet, Black-capped Bulbul, and Brown-capped Babbler. The number of waterbirds inhabiting wetlands of Yala is 90 and half of them are migrants.^[3] Waterfowls (Lesser Whistling Duck, Garganey), Cormorants (Little Cormorant, Indian Cormorant), large waterbirds (Grey Heron, Black-headed Ibis, Eurasian Spoonbill, Asian Openbill, Painted Stork), medium-sized waders Tringa spp., and small waders Charadrius spp. are among the common waterbirds. Black-necked Stork and Lesser Adjutant are the rare birds that can be seen in the park. The migrant Great White Pelican and resident Spot-billed Pelican are also have been recorded. Other waterbirds attracted to the Yala lagoons include Lesser Flamingo, and Pelicans, and rare species such as Purple Heron, Night herons, Egrets, Purple Swamphen, and Oriental Darter. Thousands of waterfowls migrate to the lagoons of Yala during the northeast monsoon. They are Northern Pintail, White-winged Tern, Eurasian Curlew, Whimbrel, Godwits, and Ruddy Turnstone. The visiting species mingled with residing Lesser Whistling Duck, Yellow-wattled Lapwing, Red-wattled Lapwing, and Great Stone-curlew. Rock Pigeon, Barred Buttonquail, Indian Peafowl, Black Stork, Black-winged Stilt, and Greater Flamingo are among the other bird species. Crested Serpent-eagle and White-bellied Sea Eagle are the raptors of the park. The forest birds are Orange-breasted Green Pigeon, Hornbills, Old World flycatchers, Asian Paradise-flycatcher, Asian barbets, and Orioles.^[9]

Streams in the park can sustain a large heard of Sri Lankan Elephants

Including Sri Lankan Elephant, 44 species of mammals are resident in Yala National Park,^[2] and it has one of the highest leopard densities in the world.^[11] 25 individual leopards are estimated to roam in Block I.^[12] The elephant herd of Yala contains 300–350 individuals.^[13] Sri Lankan Sloth Bear, Sri Lankan Leopard, Sri Lankan Elephant, Wild water buffalo are threatened species that Yala is harbouring. Although water buffaloes are indigenous to Sri Lanka, most populations contain genes of the domestic stock or are descended from feral stock. Toque Macaque, Golden Palm Civet, Red Slender Loris, and Fishing Cat are among the other mammals that can be seen in Yala. The elephant population of the park varies seasonally.^[9]

The reptile fauna recorded from the park is 46 and five of them are endemic. Sri Lankan Krait, Boulenger's Keelback, Sri Lankan Flying Snake, Painted-lip Lizard and Wiegmann's Agama are the endemic species.^[2] The coastal line of the park is visited by the all five globally endangered sea turtles (Leatherback turtle, Olive Ridley, Loggerhead Sea Turtle, Hawksbill turtle, and Green turtle) that visit Sri Lanka.^[2][3] The two breeding crocodile species of Sri Lanka, Mugger crocodile and Saltwater Crocodile inhabit the park. The Indian Cobra and Russell's viper are among the other reptiles.^[9] There are 18 amphibians species that have been recorded from Yala while Bufo atukoralei and Adenomus kelaartii are endemic to Sri Lanka. In the water courses of Yala, 21 fresh water fishes are found.^[2] The fish population in the perennial reservoirs contain mostly exotic food fish Mozambique tilapia.^[3] The Stone sucker and Esomus thermoicos are endemic among other species. The Blackspot barb, Olive Barb, Orange chromide and Common Spiny Loach are the common fish species. Crabs and prawns include the fauna in the lagoons of the park.^[9] A variety of butterfly species is found here. The Common bluebottle, Common Lime Butterfly, Crimson Rose, Common Jezebel, and Common Mormon are the common species.^[

Cultural importance

Yala had been a centre of past civilisations.^[9] Demon King Ravana established his kingdom here with Ravana Kotte, now submerged in the sea, as its boundary. Seafaring traders brought Indo-Aryan civilisation with them, as Yala is situated in their trading route. A large number of ancient although disrepaired tanks are the evidence of a rich hydraulic and agricultural civilisation dating back to 5th century BC.^[3] Situlpahuwa, which was the home for 12,000 arahants, is situated within the park area along with Magul Vihara, which built in 87 BC and Akasa Chaitiya, which constructed in 2nd century BC. Agriculture flourished in area during the period of Ruhuna Kingdom. According to Mahavamsa, the Kingdom of Ruhuna began to decline by the end of the 13th Century AD. During the colonial period Yala became a popular hunting ground. Yala is annually visited by 400,000 pilgr

Threats and conservation

tourism generates noise and air pollution in the par

Poaching, gem mining, logging, encroachment by agriculture, and free-roaming domestic livestock entering are the main threats to the park.^[9] Three wardens have been killed in clashes with poachers. Gems are mined along the Menik River and holes created by gem mining which extend up to 30 metres (98 ft) can be seen along the Kumbukkan Oya. In Blocks III and IV, the encroachment is severe as chena cultivation and burning, to provide grazing in the dry season, collide with the boundary. A large grove of Sonneratia caseolaris is faced with forest dieback in the Menik River's estuary. Cultivation of tobacco, noise and air pollutions caused by uncontrolled tourism are the other conservation issues. The growth of invasive alien species such as Lantana camara, Opuntia dillenii, Chromolaena odorata is threatening the native plants.^[3]

Deep within the forest Ganja is cultivated in cleared areas.^[9] The wildlife is poached and disturbed by the fishermen at Patanangala. The turtles are caught in fishing nets and the fishermen also litter the beach with debris. They have also set traps inland and dig up turtle nests. In the absence of hand-weeding which was practiced until the 1950s, the transformation of interior grasslands to scrub jungle is unavoidable. The tourism has created problems in the past, such as vehicles harassing wild animals. The issue is most severe in Sithulpahuwa where thousands of pilgrims are attracted leading to a great degree of commercialisation. Department of Wildlife Conservation has taken some conservation measures such as management of grazing lands, conservation of small water ponds, and irradiation of invasive alien species. A 40 kilometres (25 mi) long electric fence was erected to prevent elephants from moving into nearby villages.^[3

Plant

Plants are living organisms belonging to the kingdom Plantae. They include familiar organisms such as trees, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The scientific study of plants, known as botany, has identified about 350,000 extant species of plants, defined as seed plants, bryophytes, ferns and fern allies. As of 2004, some 287,655 species had been identified, of which 258,650 are flowering and 18,000 bryophytes (see table below). Green plants, sometimes called Viridiplantae, obtain most of their energy from sunlight via a process called photosynthesis.

importance

Potato plant. Potatoes spread to the rest of the world after European contact with the Americas in the late 1400s and early 1500s and have since become an important field crop.

The study of plant uses by people is termed economic botany or ethnobotany; some consider economic botany to focus on modern cultivated plants, while ethnobotany focuses on indigenous plants cultivated and used by native peoples. Human cultivation of plants is part of agriculture, which is the basis of human civilization. Plant agriculture is subdivided into agronomy, horticulture and forestry.

Food

Much of human nutrition depends on land plants, either directly or indirectly.
Human nutrition depends to a large extent on cereals, especially maize (or corn), wheat and rice. Other staple crops include potato, cassava, and legumes. Human food also includes vegetables, spices, and certain fruits, nuts, herbs, and edible flowers.
Beverages produced from plants include coffee, tea, wine, beer and alcohol.
Sugar is obtained mainly from sugar cane and sugar beet.
Cooking oils and margarine come from maize, soybean, rapeseed, safflower, sunflower, olive and others.
Food additives include gum arabic, guar gum, locust bean gum, starch and pectin.
Livestock animals including cows, pigs, sheep, and goats are all herbivores; and feed primarily or entirely on cereal plants, particularly grasses.

Nonfood products

Wood is used for buildings, furniture, paper, cardboard, musical instruments and sports equipment. Cloth is often made from cotton, flax or synthetic fibers derived from cellulose, such as rayon and acetate. Renewable fuels from plants include firewood, peat and many other biofuels. Coal and petroleum are fossil fuels derived from plants. Medicines derived from plants include aspirin, taxol, morphine, quinine, reserpine, colchicine, digitalis and vincristine. There are hundreds of herbal supplements such as ginkgo, Echinacea, feverfew, and Saint John's wort. Pesticides derived from plants include nicotine, rotenone, strychnine and pyrethrins. Drugs obtained from plants include opium, cocaine and marijuana. Poisons from plants include ricin, hemlock and curare. Plants are the source of many natural products such as fibers, essential oils, dyes, pigments, waxes, tannins, latex, gums, resins, alkaloids, amber and cork. Products derived from plants include soaps, paints, shampoos, perfumes, cosmetics, turpentine, rubber, varnish, lubricants, linoleum, plastics, inks, chewing gum and hemp rope. Plants are also a primary source of basic chemicals for the industrial synthesis of a vast array of organic chemicals. These chemicals are used in a vast variety of studies and experiments.