by Jagath Gunawardana
It would surprise many to know that a short, narrow strip of privately owned swamp forest is the only known place in the world where two critically endangered and endemic plants, amongst another large number of endemic species, are found.
The existence of this forest speaks volumes not only of the critical situation of some of our biodiversity, but more importantly, how the preservation of even a small extent of habitat can ensure the survival of one or more endangered endemic species, and how the initiatives taken by a family or individual can cause the survival or the demise of such species.
This unique swamp forest is located in the Bulathsinhala Divisional Secretary’s division in the Kalutara District and is part of the private property known as the Walawwewatta, owned by the members of the Wijesekara family. It is a narrow strip of forest, 1.3 kilometres along the Batapota Ela, about 100 metres to 120 metres in width, and bordering the Batapota Ela and Kukulu Ela canals which join the Kuda Ganga.
Rediscovery of endangered species
The importance of Walawwewatta Waturana came to prominence due to the efforts of Professor A.J. Kostermans and Professor Nimal Gunatilleka who rediscovered the endemic plant known as Stemanoporus mooni in October 1979, till then considered extinct from Sri Lanka. This rediscovery was made 159 years since the initial collection of specimens and 121 years after it was described as a new species. This expedition also revealed the habitat of Mesua stylosa, until then known only through several cultivated trees in botanical gardens and presumed extinct in the wild. Following their discovery, the two professors were successful in getting the two species declared as protected plants in 1993 with the amendment to the Fauna and Flora Protection Ordinance. The area of the habitat has been declared an Environment Protection Area under the provisions of Sections 24C and 24D of the National Environmental Act by the Minister of Environment and Natural Resources by an order published in Gazette Extraordinary No.1598/21 of 24.04.2009. It is officially known as ‘Walawwewatta Waturana Environment Protection Area’ and covers an extent of 6.2045 hectares.
The plant Hora-wel (Stemanporus mooni) was not known to have been found in the wild since they were first collected by Moon in 1820 and deposited in the National Herbarium in the Royal Botanical Gardens at Peradeniya. It was named in 1858 after him. It grows up to four to five metres in height, usually as an un-branched woody stem. A mop of long, lance-shaped leaves are at the apex of the stems. A leaf is about 45 centimetres long, but only about eight centimetres in width. The tender leaves are reddish and droop down along the stem. The small flowers are white, and the small fruit is globular and about three centimetres in diameter. There are less than fifty plants in this habitat.
A refuge for endemic plants
Suwanda (Mesua stylosa) is related to the Na-tree and is a large, woody tree. The trees found at present are rather small but it could be that all the larger trees would have been poached, as is evident by the cutting down and sawing of one large tree that was witnessed in 1988.This species bears white flowers similar to Na and have a very pleasant smell. Several large trees are in the Henarathgoda Botanical Gardens in Gampaha and the Royal Botanical Gardens in Peradeniya.
This small forest is a refuge for more than 20 other endemic plants, including a wild Cinnamon known as Sewala-Kurundu (Cinnamomum dubium), Lene-Thari (Areca concinna), a Wild Durian known as Katu Boda (Cullenia rosayroana),three species of Rattan vines or We-wel (Calamus species) and Wesak-Orchid (Dendrobium maccarthiae).The swamp and canals are the habitats of more than 35 species of fish including 12 endemics, and over 70 species of birds with around 12 endemics. There is a constant need for more surveys and we have been adding new species to the lists following every visit to the area since 1988. A noteworthy addition I made in 2009 is the rare, critically endangered and endemic species of Water Trumpet (Cryptocoryne bogneri). It was described and named only in 1978, but was presumed to have become extinct in the wild by 1980 due to over-collection for the aquarium fish and ornamental plant trade.
An increasingly looming threat is posed by invasive alien plants including aggressively growing trees such as Havari-Nuga (Alstonia macrophylla) and Para (Dillenia suffruticola). Other invasives found encroaching into the habitat are the Koster’s Curse (Clidemia hirta), Kaha-karabu (Wedalia trilobata), Guinea Grass (Panicum maximum) and the Drunken Sailor (Quisqualis indica). These trees are still in the fringes and have not penetrated into the deep forest areas. However, this could happen rather quickly as the forest is a thin strip and needs prompt attention from the authorities.
The Wijesekara legacy
A recurrent but intriguing question that may probably never be answered is the reason as to why this patch was left by the predecessors of the Wijesekara family when they initially planted rubber in the estate and was never ever touched by their descendents. Either they may have been aware of the unique species or it could well have been that they wanted to preserve part of the initial habitat.
Whatever the reason, we are indeed eternally grateful to the generations of the Wijesekara family including present family members for taking all necessary care and effort towards preserving this forest patch. It is the care they provided that has allowed Sri Lanka to be fortunate and proud to be endowed with the existence of at least two unique plants in their original habitat. courtesy: The Ceylon Today