Nature conservation in Sri Lanka (Ceylon)

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  • Nature Conservation in Sri Lanka (Ceylon)*

    HILARY CRUSZ, Ph .D . (London)

    Professor and Head, Department of Zoology, University of Sri Lanka, Peradeniya, Sri Lanka (Ceylon)

    ABSTRACT

    Sri Lanka (Ceylon) was once part of an Indo-Malayan and Afro-Madgascan complex, and has three peneplains. These circumstances are reflected in her fauna and flora, of which 28"5 per cent of the vascular plants and 16 per cent of the land vertebrates are endemic, inhabiting mostly the central montane and southwestern regions. Such figures could provide indices or coefficients of insularity of islands of the nature of Sri Lanka and Madagascar. The parasites of the endemics and relicts could also point to the relation- ships of the hosts and the antiquity of the geographical regions. Nearly all the wildlife reserves are in the dry northern and eastern halves of the island, in areas of monsoon scrub-jungle, monsoon forest, or grassland. Further strict natural reserves are urgently needed in the montane and southwestern rain-forest and grassland areas. Significant conservation measures have been taken since 1885 by the Government and by what in 1971 was renamed the Wildlife and Nature Protection Society of Ceylon. Constitutional changes have also had their impact, while human population increase has affected land utilization and the extents of nature reserves. Twenty-seven mammal, 340 bird, 7 reptile, and 9 plant, species are absolutelyprotected. Despite such efforts, conservation science and practice, based on ecological studies, have lagged behind, but some progress is being made through the work of foreign and local scientists, and the new interest taken by Government and the universities. That Sri Lanka is well suited to effective nature conservation is shown also by the ethos of her people, as shaped by Buddhist teachings and by the concern of kings during her long history.

    INTRODUCTION

    Sri Lanka (Ceylon) is a pear-shaped island lying in the Indian Ocean between longitudes E 7939 ' and 815Y, and latitudes N 554 ' and 9052 '. It is 434 km (270 miles) long and 225 km (140 miles) at its widest, and has an area of 65,584 km 2 (25,332 sq miles), of which 64,742 km 2 (24,997 sq miles) are land and the rest is inland water.

    * A revised and updated version of a paper presented at the First International Conference on the Rational Use and Conservation of Nature, Tananarive, Madagascar, 7-11 October 1970.

    That the island was once part of India is evidenced by its continental shelf and rock-formations. Geo- logically it is essentially an Archaean complex, a synclinorium of fundamental gneisses, outcropping widely at the surface in the eastern sector and more narrowly in the west. Above these lie the highly metamorphosed khondalite group of rocks, which include crystalline limestones and quartzites, and also the charnockites of the central hills. In them are found graphite and gems, which are the chief mineral deposits of Sri Lanka. Granites and other rocks have intruded into the fundamental gneisses and khondalites in some parts of the island.

    There are no rocks of more recent age, apart from two small plant-fossiliferous Jurassic beds near the southernmost region of the northwestern sector, and Miocene limestones along the extreme north-west, with a patch, probably of similar age, in the extreme south-east. Plio-Pleistocene gravels occur as isolated patches in the north-west and south-east. Quaternary deposits line the island for some distance along the east and west coasts.

    Sri Lanka became an island probably in late Miocene times, the southwestern sector having been the first to separate from India, with alternate shallow floodings and elevations at various times thereafter. There are also indications that parts of the island have, through subsidence, elevation, erosion, and even faulting, produced three peneplains, or erosion levels, at 0 to 122 m (400 ft), 305 to 762 m (1,000 to 2,500ft), and 914m (3,000ft) to over 2,438m (8,000 ft), respectively, above mean sea-level. All this, together with its climatic and vegetational conse- quences, would account for the fact that the greatest endemicity of fauna and flora is shown in the central montane and southwestern region of the island.

    DISTRIBUTION OF FAUNA AND FLORA

    Analyses of the distribution of Sri Lanka's fauna and flora have been made for many years on the

    199

    Biological Consercation, Vol. 5, No. 3, July 1973-- 0 Applied Science Publishers Ltd, England, 1973--Printed in Great Britain

  • 200 Biological Conservation

    basis of climatic factors alone. Phillips (1942), for instance, based his study of the mammals of Sri Lanka on three climatic zones, namely the Low Country Dry Zone, the southwesterly Low Country Wet Zone, and the central Hill Zone. More recently, however, Eisenberg & McKay (1970), following Gaussen et al. (1964), Mueller-Dombois & Sirisena (1967), and Fernando (1968), have recognized seven vegetational zones (see Fig. 1 and below) for basing their analysis of mammalian distribution in Sri Lanka. They argue that climate and, to some extent, soil, interact to determine vegetation form, which in turn influences mammalian distribution in a given area. This sound principle would apply to the life- forms as well, both plant and animal. The seven vegetational zones are, with symbols referring to the caption to the map:

    A1- Monsoon Scrub Jungle--extreme north and north-west

    A2- Monsoon Scrub Jungle--extreme south- east

    B - - Monsoon Forest and Grassland

    C - - Intermonsoon Forest

    D 1 - - Rain-forest and Grassland--below 914 m (3,000 ft)

    D 2 - - Rain-forest and Grassland--914 to 1,524 m

    D 3 - - Rain-forest and Grassland--above 1,524 m B (5,000 ft). C

    D1

    Sri Lanka's total forest area in 1956 was 7,165 million D2

    acres (2,900,810ha), comprising 44 per cent of the D3 land area (Andrews, 1961). This area has been de- creasing progressively since. According to Wijesinghe National (1972), the respective figures for 1966 and 1970 are 1. 6.5 million acres (2-63 million ha) and 6-1 million acres (2.47 million ha), respectively.

    DERIVATION OF BIOTA

    The greater number of named forms of Sri Lanka's plants and animals are derived from peninsular India, but there are several endemic genera and numerous endemic species in Sri Lanka, not a few of which latter appear to be true relicts.

    As regards the fauna, there are about 628 known species of terrestrial vertebrates (84 mammal, 379 bird, 133 reptile, and 32 amphibian, species). Sixteen per cent of these are endemic species.

    The animals of the dry zones (A x, A2, B, and C) show the closest affinity with the fauna of the Indian mainland, while those of the wet hill zones (D1, DE, and Da) are more distinctive, although some of them

    Scoh~- I: Z,O00,O00

    MATARA

    Fig. 1. Sketch-map of Sri Lanka (Ceylon) showing vegetational zones, national wildlife reserves, major

    sanctuaries, and other areas.

    Vegetational Zones A1 & Az Monsoon Scrub Jungle (extreme N, NW and SE)

    Monsoon Forest and Grassland Intermonsoon Forest Rain-forest and Grassland--below 914 m

    (3,000 ft) Rain-forest and Grassland--914 to 1,524 m Rain-forest and Grassland--above 1,524 m

    (5,000 ft)

    Wildlife Reserves (blackened areas) Wilpattu National Park--1,095km2 (423 sq

    miles) 2. Ritigala Strict Natural Reserve 3. Gal-Oya National Park--259 km 2 (100 sq miles) 4. Peak Wilderness 5. Horton Plains 6. Hakgala Strict Natural Reserve 7. Yala National Park and Strict Natural Reserve

    --1,090 km2 (421 sq miles) 8. Uda Walawe National Park--308 km2 (119 sq

    miles). This Park, especially its northern half, extends even further westwards into the inter- monsoon forest region (zone C).

    Major Sanctuaries (stippled areas) 9. Giant's Tank

    10. Wilpattu North Sanctuary 11. Wilpattu West Sanctuary 12. Somawathi-Tamankaduwa 13. Gal-Oya Other areas 14. Sinharaja Forest--233 km2 (90 sq miles) (hatched

    area) 15. Elephant corridors (broken lines)

  • Crusz : Conservation

    show affinity with the fauna of the Malabar tract of India (Phillips, 1942). Faunal affinity with Malaysia and Indonesia is indicated by the presence in Sri Lanka of the Mountain Lizard (Cophotis sp.), the Water Lizard (Varanus monitor), and several other species; and, with Africa and Madagascar, by the presence of limbless skinks of the subfamily Acontiani- nae and of a member of the Chamaeleontidae which is also represented in southern India.

    Most of the endemic animal species inhabit the rain-forest (zones D1, D2, and D3). About 25 per cent of them are confined to the upper montane zone (D3) and represent Sri Lanka's most conservative faunal elements which have been least influenced by recent invasion from southern India. A short-list of the more notable endemic tetrapod vertebrates of the montane zone would include the following:

    Mammals: Feroculus feroculus, Solisorex pearsoni, Crocidura miya, Rattus montanus, R. ohiensis. (Feroculus and Solisorex are endemic genera.)

    Birds: Kelaartia penicillata, Muscicapa sordida, Zosterops ceylonensis, Columba torringtoni. (Kelaartia is probably an endemic genus.)

    Reptiles: Lyriocephalus scutatus, Ceratophora stod- darti, C. tennenti, C. aspera, Cophotis ceylanica, Calotes liocephalus, C. nigrilabris, Aspidura trachyprocta. (Lyriocephalus and Ceratophora are endemic genera.)

    Amphibians: Bufo kelaarti, Nannophrys ceylonensis marmorata, Rhacophorus microtympanum, Philau- tus schmardanus, Ramanella palmata, Microhyla zeylanica. (Nannophrys is an endemic genus.)

    As for Sri Lanka's flora, which numbers over 3,100 species of vascular plants (belonging to 1,065 genera and 171 families), about 28.5 per cent of them are endemic, 65 per cent are of Indian and Himalayan affinity, while the balance of 6-5 per cent have come from the Malaysian, African, and Australian, regions (Abeywickrama, 1956, 1959). Some of the endemics, among the inland terrestrial plants, are probably true relicts. One-half of the endemic plants are confined to the wet zones. Of these, more are found at the lower elevations than on the hills. This distribution seems to be somewhat different from that of Sri Lanka's highly endemic hill fauna.

    It is interesting here to reflect on some of the figures available for endemism of plants and animals in Madagascar, where 86 per cent of the plant species are endemic (Nicholson, 1970, after Bathie, 1936). Among animals, 95 per cent of the reptile species and subspecies (Blanc, 1970), and 65 per cent of the bird species, are endemic (Nicholson, 1970), and there are several endemic genera and species, and even families,

    in Sri Lanka (Ceylon) 201

    among the 70 Malagasy mammals, a good many others of which are introduced species (Nicholson, 1970). These figures, compared with those for Sri Lanka (28.5 per cent of the vascular plants and 16 per cent of the terrestrial vertebrates), would seem to reflect the age and degree of isolation undergone by these islands and their faunas. They could provide an 'index or coefficient of insularity'.

    An interesting complementary field of study that could help to throw light on animal relationshil:s, and even on the antiquity of several species on islands such as Sri Lanka and Madagascar and their neigh- bouring continents, is comparative parasitology-- particularly of relict faunas. These studies are pro- ceeding, and the data obtained are being evaluated (Chabaud & Brygoo, 1964; Crusz & Mills, 1970; Crusz & Sanmugasunderam, 1971).

    The importance of distributional studies, and, more significantly, of sound ecological investigations, can- not be overemphasized. It is on the basis of such studies that warnings could be given that if there were to be adequate conservation of the island's fast- diminishing abundance of fauna and flora, and if the more interesting and important species were to be saved from extinction, national reserves would have to be provided, and even other means such as the setting up of arboreta, wildlife cropping, and so on, would have to be adopted, in each of the main zones involved. The dry region, particularly zones A1, A2, and B, already has such reserves, but hardly any really scientifically-based wildlife management. These meas- ures are even more urgently needed in the upper montane zone (D3) and in the southwesterly wet zones (D1 and D2). The Peak Wilderness-Horton Plains- Hakgala complex, and the more southerly Sinharaja Forest, see Fig. 1--perhaps Sri Lanka's only true primary tropical rain-forest, which is almost a relict biome--have yet to receive the care and concern they deserve. There were hopeful signs that the report of the Land Utilization Committee (Government Ses- sional Paper XI of 1968) would result in some early action in this direction, but the recent introduction of potato cultivation on the Horton Plains, and of timber extraction in the Sinharaja Forest, has con- siderably shaken these hopes.

    CONSERVATION ACTION

    Although Sri Lanka's pioneer zoologist, E. F. Kelaart, had published his Prodromus Faunae Zey- lanicae in 1852, seven years before Darwin's Origin of Species, and J. Emerson Tennent wrote on Sri Lanka's natural history in 1859 and 1868, it was not until 1885

  • 202 TABLE I

    Summary of Main Conservation Steps Taken in Sri Lanka (formerly Ceylon)

    Government sessional papers, ordinances, acts, and proclamations

    Title and/or objects Other significant events for Outlook nature conservation

    Ordinance No. 10 of 1885 The Forest Ordinance Government Department of Forestry established in 1887, which administered wildlife affairs up to 1950

    From 1885 to 1929, the main outlook of both Government and the Game Protection Society was 'conservation for sport'

    Ordinance No. 10 of 1891 To prevent the wanton destruction of elephants, buffaloes, and other game

    Ordinance No. 11 of 1891 To readjust the customs duties leviable on firearms and to impose an export duty on certain hides and horns

    Act No. 6 of 1893 To prevent the wanton destruction of non- indigenous birds, beasts, and fishes

    Proclamation in 1894 Prohibiting export of hides of sambpur and deer for a period of 5 years (later amended to read 'for an indefinite period')

    Game Protection Society (GPS) inaugurated in 1894

    Proclamation in 1900 (March 20)

    Under the Forest Ordinance, Yala (150 sq miles = 389 sq km) proclaimed a game sanctuary. (The word sanctuary then had the same meaning as a strict natural reserve)

    Act No. 11 of 1902 The Game Protection Act

    Act No. 14 of 1905 The Fishes (Dynamite) Act

    Proclamation in 1905 (September 15)

    Under the Forest Ordinance, Wilpattu (217 sq miles = 562 sq km) proclaimed a game sanctuary in the same sense as Yala was proclaimed in 1900

    Act No. 10 of 1906 The Wild Bird Protection Act

    Ordinance No. 16 of 1907 To consolidate and amend the law relating to forests and the felling and transport of timber

    Ordinance No. 19 of 1908 The Dried Meat Ordinance (Sections 1 and 4 prohibit the transport of more than 15 lb (6.8 kg) of dried meat from prohibited areas). Originated and drafted by t...

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