Around 150 to 200 years ago ,
tropical rain forests stretched as an unbroken green belt over the humid tropics,in theere blocks in the Amazonian, African and Far-Estern regions. Today the are greatly reduced and are in a fragmented state . The rain forests of Sri Lanka belong to the far-estern group which includes the rain forests of South and South-East Asia. The centre of this bli\ock is the Malayan Archipelago stretching eastward to New Guina. Althouth, the rain forests of south-west Sri Lanka share meny features common to this goup, they also contain elements that are peculiar to themselves alone.
The origin of Sri Lankan rain forests and their unique species composition a large proportion of endemics,have been explained in relation to the island's geological history. During the paleozonic era, Sri Lanka was part of the Southern super continent or Gondvanaland. About 140 millions eyars ago this continent began to break up and 55 million years ago, during the mid Cretaceous period, the fregment known as the Deccan plate which comprised Indian and Sri Lanka drifted off towards the equator to collide with thw Nothern continent of Laurasia. Under equatorial climetic conditions, a troppical community was established on the Deccan Plate. These conditions how ever did not remain stable,for continuous fluctuations of climet and sea level in the tropics occured during the Glacial and Interglacial which the Indian sub continent 20 millions ago, Sri Lanka separated out as an island. Since then, temporary land connections with the sub continent have been formed from time to time. The glacial periods have resulted in alternating climetic conditions of ever-wet and seasonally drt ,cool weather prevailing on the island.As these occurred , rain forests expanded over the main land and contracted back in to the ever-wet pockets we have today.
The rain foersts specirs presently found in Sri Lanka therefore have affinities to Gondiwanic flora and fauna as well as to those of the Deccan Plate. While some elements may have been maintained without change, others have envolved in to new plants and animals. From a biogeograpic points of view therefore the species found in the rain forests of Sri Lanka are extraodinary interest,a fact which ha still not been widely recognised. Together with therain forests of the Mascarene Islands (Rodriguez,Reunion and Mauritious), East Madagascar, the Seychelles, and the Andamans, the rain forests of Sri Lanka represents the few surviving links between the rain forests of one major block, (the African) and another (SouthEast Asian).
tropical rain forests stretched as an unbroken green belt over the humid tropics,in theere blocks in the Amazonian, African and Far-Estern regions. Today the are greatly reduced and are in a fragmented state . The rain forests of Sri Lanka belong to the far-estern group which includes the rain forests of South and South-East Asia. The centre of this bli\ock is the Malayan Archipelago stretching eastward to New Guina. Althouth, the rain forests of south-west Sri Lanka share meny features common to this goup, they also contain elements that are peculiar to themselves alone.
The origin of Sri Lankan rain forests and their unique species composition a large proportion of endemics,have been explained in relation to the island's geological history. During the paleozonic era, Sri Lanka was part of the Southern super continent or Gondvanaland. About 140 millions eyars ago this continent began to break up and 55 million years ago, during the mid Cretaceous period, the fregment known as the Deccan plate which comprised Indian and Sri Lanka drifted off towards the equator to collide with thw Nothern continent of Laurasia. Under equatorial climetic conditions, a troppical community was established on the Deccan Plate. These conditions how ever did not remain stable,for continuous fluctuations of climet and sea level in the tropics occured during the Glacial and Interglacial which the Indian sub continent 20 millions ago, Sri Lanka separated out as an island. Since then, temporary land connections with the sub continent have been formed from time to time. The glacial periods have resulted in alternating climetic conditions of ever-wet and seasonally drt ,cool weather prevailing on the island.As these occurred , rain forests expanded over the main land and contracted back in to the ever-wet pockets we have today.
The rain foersts specirs presently found in Sri Lanka therefore have affinities to Gondiwanic flora and fauna as well as to those of the Deccan Plate. While some elements may have been maintained without change, others have envolved in to new plants and animals. From a biogeograpic points of view therefore the species found in the rain forests of Sri Lanka are extraodinary interest,a fact which ha still not been widely recognised. Together with therain forests of the Mascarene Islands (Rodriguez,Reunion and Mauritious), East Madagascar, the Seychelles, and the Andamans, the rain forests of Sri Lanka represents the few surviving links between the rain forests of one major block, (the African) and another (SouthEast Asian).
