Tuesday, March 2, 2010

Beaches, Spits and Dunes

Beaches, Spits and Dunes
Much of the coastline of the island consists of sandy beaches. The soil is loose and sandy and doesn 't retain much water. The plants have deep feeding tap roots which have high osmotic pressure. Plants species are Ipomoes pescaprae, Spinifex littoreus and adapted to store water and minimize transpiration.

Salt Marshes

Salt Marshes
Salt marshes in Sri lanka occur mainly where the dry season is prolonged as in the north, northwest, northeast and southeast. The main salt marsh plant are Salicornia and Arthrocnemum. They stems are modified in to cladodes and are leafless. The major functions of this ecosystem are supply of nutrients to near shore coastal waters, provision of bird habitats.

Mangrooves


Mangroves
Mangrooves occur near the mouths of rivers and on the shores of lagoons and estuaries and are seems in the south ,southwest and northeast coasts Koggala,Kalametiya and Kokilai lagoons and Trincomalee and Jaffna. The totalarea under mangroves in sri lanka is estimated to be between 6000 and 13000 ha. 14 mangrove plant species and 12 associated have been recorded.
Avicennia officinalias
Aegiceras corniculata
Acanthus ilicifolius
Acrostichum aureum
Bruguiera gymnorhiza
Ceriops decandra
Sonneratia caseolaris
Rhizophora apiculata
Xylocarpus granatum.Exoecaria agallocha

Talawa

Talawa
Thease arises as a result of forest and chena cultivation in the wet zone. These grasslands are more evident in the Kalutara, Galle, and Matara distric. The grass in the talawa include Chrysopogon,Cynodon dactylon, Ischaemum sp, Themeda tremula and Cymbopogon nardus. Herbs and low shrubs are also found, indicating that succession has commenced. THese species are Osbeckia aspers (heenbowitiya),Hedyotis fruticosa(Weraniya) Ochlandra stridula ( bata).

Villus

Villus
These are wet grassland found in the flood plains of the rivers in the dry zone. When the river flood the saucer like depressions colled villus becomes inundates with overflow during the rain season. The most extensive villus are found in the Mahaweli flood plains around Polonnaruwa, Tamankaduwa, Maduru oya and Manampitiya. Fimbristylis, Cyperus and Typha are also common. This ecosystem has a diversity of large grazing and browsing animals the deer, buffalo and elephant.

Wet Patana

Wet Patana
They occure elevation around 2000 m. Grasses are tufted coarse and wiry.They occur at Horton plains, Elk plains, Moon plains, Sita Eliya, Bogawanthalawa and Bopatalawa..Plant species are
.
Chrysopogun zeylanicum
Arundinella sp.
Schaemum sp.
Rhododendron arbreum

A munber of flowering plants are also found aere.Endemic bird ( 14 sp) endemic shrimp, is unique to

Dry Patanas

Dry Patanas
these are extensive grasslands totaling 75000 ha. (Best known are of the Uva basin)The characterestic grass is
Cymbopogon nardus (mana). Other associated grasses are Arundinella, Pollinia and Ischaemum.