UNEP WCMC

Name Silent Valley National Park

IUCN Management Category II (National Park)

Biogeographical Province 4.01.01 (Malabar Rainforest)

Geographical Location Situated in the Kundali Hills of the Western Ghats, at the south-western corner of the Nilgiri Hills in Palghat District. Mannarghat, the nearest town and location of park headquarters, is 40km by road to the south. The park is bounded by Attappadi Reserved Forest to the east, and the vested forests of Palghat Division and Nilambur Division to the south and the west, respectively. The northern boundary is largely contiguous to the Nilgiri Forests. 11°04'-11°13'N, 76°24'-76°29'E

Date and History of Establishment Originally declared a national park on 26 December 1980 (Notification No. 96731/FSB/80/AD), but this excluded the site of a proposed hydro-electric project that was subsequently dropped. The area to be submerged was included later within the national park on 30 March 1984 (Notification No. 5462/FS-AS/82/AD), and the entire Silent Valley area was renotified as a national park on 15 November 1984 (Notification No. 5462/FSA3/82/AD). The same area was originally constituted reserved land under Section 26 of the Forest Act in 1888 and subsequently notified as reserved forest by the Government of Madras on 18 May 1914 (Notification No. 291). The park is included as a core area within the Nilgiri Biosphere Reserve declared as per Letter No. J.22010/6/86/CSC of 1 September 1986 from the Ministry of Environment and Forests, New Delhi. This biosphere reserve, has yet to be officially accepted by Unesco.

The Silent Valley Forests, locally known as 'Sairandhrivanam' and considered by many to be one of the last representative tracts of virgin tropical evergreen forest in India, became the focus of India's perhaps fiercest and most widely-publicised environmental debate in the late 1970s, when the Kerala State Electricity Board decided to go ahead with a hydro-electric project in the valley (Anon., 1982; Agarwal et al., 1985). The project would generate 240MW of electricity and irrigate some 100,000ha of land in the relatively underdeveloped Palghat and Malappuram districts. It entailed the submergence of 830ha, including 500ha of prime tropical evergreen forest (Anon., 1982). A task force of the National Committee on Environmental Planning and Coordination, under Dr M S Swaminathan, the then Secretary of Agriculture of the Government of India, and several non-governmental conservation organisations, including the Bombay Natural History Society, Kerala Sastra Sahitya Parishad (Kerala Science and Literature Society) and the Indian Science Congress, urged the Government of Kerala to abandon the scheme but to no avail (Anon., 1982). The dispute became highly politicised and innumerable state and national organisations, as well as international organisations such as IUCN and WWF, became involved in the 'Save Silent Valley' campaign (Variava, 1983; IUCN, 1986). In a bid to placate conservationists, the Government of Kerala created a national park in December 1980 which excluded the proposed project site from the area. In November 1983 the hydro-electric project was finally shelved and the present national park declared a year later, in deference to the weight of public opinion and the sentiments of the then Prime Minister, Mrs Indira Gandhi. The Government of Kerala, however, refused to endorse the Joint Committee's findings (Agarwal et al., 1985). Further details about the park's establishment are summarised by Unnikrishnan (1990).

Area 8,951.65ha. The park is contiguous to the proposed Karimpuzha National Park (22,500ha) in the north and to Mukurthi (Nilgiri Tahr) Sanctuary (7,846ha) to the north-east in Tamil Nadu.

Land Tenure State Government of Kerala

Altitude Ranges from 658m to 2,383m (Balakrishnan, 1984). Most of the park lies between 880m and 1,200m (Anon., n.d.). High peaks such as Anginda (2,383m), Sispara (2,206m) and Kozhipara (1,904m) occur in the northern part of the park.

Physical Features Silent Valley is a rectangular tableland enclosed by a high contiguous ridge along its northern and eastern borders and by a lower, irregular ridge along its western and southern borders. It is flanked by steep escarpments to the south and west, which descend some 1,000m to the plains of Kerala, and by sheer cliffs to the north and east which rise a further 1,000m to the Upper Nilgiri Plateau. Kuntipuzha River flows southwards through the entire 15km length of the park, dividing it into a narrow western sector of less than 2km and a wider eastern sector of 5km. The valley is drained by five main tributaries of the Kuntipuzha which originate near the eastern border and flow westwards. Only a few minor streams drain into the Kuntipuzha from the western sector. The river is uniformly shallow, with no flood plains or meanders. Its bed falls from 1,861m to 900m over a distance of 12km, the last 8km being particularly level with a fall of only 60m. Kuntipuzha is one of the less torrential rivers of the Western Ghats, with a pesticide-free catchment area. Soils are blackish and slightly acidic in evergreen forests where there is good accumulation of organic matter. The underlying rock in the area is granite with schists and gneiss, which give rise to the loamy laterite soils on slopes (Anon., n.d., 1981, 1982; Unnikrishnan, 1989).

Climate Conditions vary greatly, becoming progressively wetter with increasing altitude and diminishing from west to east due to rainshadow effects. Prevailing winds are from the west and south-west in April-September and from the east in October-March. Most rain (80%) falls during the south-west monsoon from June to September, and least in December and January. Rainfall is significant during the north-east monsoon, from October to November. Mean annual rainfall based on data for 1965-1973 is 3180mm, with a range of 2800-3450mm (Balakrishnan, 1984). This is considerably less than that of 5750mm, based on data for 1958-1963 (Anon., 1981). Hills in the west of the park receive about 4550mm annually, and those in the east about 3200mm (Unnikrishnan, 1989). Mean annual temperature is 20.2°C. Conditions are hottest in April and May, with a monthly mean of up to 23.5°C, and coolest in January and February with a monthly mean of about 18°C. Relative humidity is consistently high from June to December, often about 95% (KFD, 1990).

Vegetation Four main types of vegetation can be recognised: tropical evergreen forest, which forms extensive dense stands along hills and valleys between 900m and 1300mm; sub-tropical hill forest between 1,500m and 2,000m; temperate forest, popularly referred to as 'sholas' and characterised by unrelated evergreen species with a dense closed canopy; and grasslands, which are restricted to the narrow sector west of the Kunthipuzha and to the higher slopes and hill tops in the eastern sector. Associations characterised by predominant tree species are exceptional for tropical rain forests, but they are an unusual feature of the forests of Silent Valley. Seven associations can be recognised: Palaquium ellipticum-Cullenia exarillata, Palaquium ellipticum-Mesua ferrea, Pallaquium ellipticum-Poeciloneuron indicum, Mesua-Calophyllum elatum, Mesua-Cullenia, Ochlandra-Calophyllum, and Ochlandra-Poeciloneuron (KFD, 1990; Unnikrishnan, 1989). Further details of the vegetation are given elsewhere (Singh, et al., 1984; Unnikrishnan, 1989).

The angiosperm flora comprises 966 species belonging to 134 families and 559 genera. Dicotydedons total 701 species, distributed among 113 families and 420 genera, and monocotyledons 265 species within 21 families and 139 genera. Families best represented are the Orchidaceae (with 108 species), Poaceae (56), Fabaceae (55), Rubiaceae (49) and Asteraceae (45) (Manilal, 1988). Seven new plant species have been recorded from Silent Valley (Manilal, 1988), as well as many rare, endemic and economically valuable species, such as cardamom Ellettaria cardamomum, pepper Piper nigrum, yams Dioscorea spp., beans Phaseolus sp., a pest-resistant strain of rice (species unknown), and 110 plant species of importance in Ayurvedic medicine (Nair et al., 1980).

Fauna Faunal diversity is very high and includes a number of endemic and threatened species. Many new species were recorded by the Zoological Survey of India during its expedition in 1980 (Records of the Zoological Survey of India, 1986). These include 15 species of invertebrates, two fishes (Holaloptera pillae and Garra menini) and two amphibians (the primitive caecilian Ichthyophis longicephalus and Malabar tree toad Nectophryne tuberculosa).

Some 26 species of mammals, excluding bats, rodents and insectivores, have been recorded (Balakrishnan, 1984). Notable species include Nilgiri leaf monkey Trachypithecus johnii (E), lion-tailed macaque Macaca silenus (E), tiger Panthera tigris (E), leopard Panthera pardus (T), Jerdon's palm civet Paradoxurus jerdoni (E), wild dog Cuon alpinus (V), Nilgiri marten Martes gwatkinsi (I), Asian elephant Elephas maximus (E), gaur Bos gaurus (V), and Nilgiri tahr Hemitragus hylocrius (V), some of which are endemic to the western Ghats. Estimates of large mammals populations are provided by Balakrishnan (1984). Six species of bats have been recorded, of which Peshwa's bat Myotis peshwa and hairy-winged bat Harpiocephalus harpia lasyurus are considered to be rare.

Kerala's avifauna is well represented within the park. Some 120 species of birds have been recorded (Jayson, 1990), a number of which are endemic to the Western Ghats including the Nilgiri woodpigeon Columba elphinistonii (V).

Amphibians total 19 species, lizards 9 species and snakes 11 species (KFD, 1990). Lepidoptera comprise about 100 species of butterflies and about 400 of moths, of which 13 are endemic to South India and now have very restricted distributions, mostly within the western Ghats (Mathew, 1990).

Cultural Heritage Although the area is believed never to have been settled, even by hunter-gatherers (Anon., 1982; Variava, 1983), the Mudakar tribals are indigenous to the area (R. Whitaker, cited in Rahmani, 1980).

Local Human Population There is no official record of any settlement in the area (Anon., 1982). Tribals live in the adjacent valley of Attappady Reserved Forest. The nearest habitation is a 200ha cardamom and coffee plantation in Panthanthodu Valley, 2km to the south-east of the park boundary. Five kilometres to the south-west are some settlements and rubber estates, and there are more settlements to the north, including Kunhali Colony in the vested forests of Nilambur (Unnikrishnan, 1989).

Visitors and Visitor Facilities Visitors are relatively few and number about 1,000 per year. Visitors may walk from Mukkali to the park, where there are about 80km of bridlepaths, but cannot stay there overnight. There are no visitor facilities at Mukkali, although an Inspection Bungalow is available for visiting officials. There are plans to establish an interpretation centre and dormitory accommodation at Mukkali (Unnikkrishnan, 1989).

Scientific Research and Facilities A considerable amount of research has been conducted in Silent Valley, including several environmental impact assessments which have been generated by the controversy over the hydro-electric project (Vijayan and Balakrishnan, 1977; Anon., 1981; Ramakrishnan and Singh, 1981; Nair and Balasubramanyan, 1984). Vegetation studies include those of Singh et al. (1984), Chand Basha (1987) and Manilal et al., 1988). The flora has been examined by the Botanical Survey of India (Nair et al., 1980; Vohra et al., 1982) and Manilal (1988), and the fauna by the Zoological Survey of India (various papers in ZSI, 1986). The ecology of the lion-tailed macaque has been studied by Kumar (1987) and Anitha (1989), and a number of other ecological studies have been undertaken as part of a research programme carried out by the Kerala Forest Research Institute (KFRI, 1990). There is a building at Sairandhri which is used by the Kerala Forest Research Institute for research purposes.

Conservation Value Silent Valley comprises one of the least disturbed extensive patches of tropical rain forest remaining in the Western Ghats. Tree diversity is high and comparable to the rain forests of Barro Colorado Island, Panama (Ramakrishnan and Singh, 1981), but the presence of several distinct tree associations is an unusual feature, reflecting local differences in edaphic and other factors (Unnikrishnan, 1989). Together with the adjacent Nilgiri Plateau and Karimpuzha forest block to the north, this constitutes some of the finest forested habitat for wildlife in India (Rodgers and Panwar, 1988). A considerable number of rare, threatened or economically important plants or animals are found in Silent Valley, some of which are endemic to the Western Ghats and others new to science (Anon., 1982; Unnikrishnan, 1989; KFD, 1990). The Kuntipuzha is one of only two rivers in the southern Western Ghats having extensive riparian vegetation and, with no record of permanent human settlement or interference in the form of plantations, is an undisturbed, pesticide-free catchment area (Anon., 1982; Variava, 1983). Silent Valley is an integral part of the Nilgiri ecosystem, forming part of a 39,000ha forest tract in conjunction with Attappady (12,000ha), Kundas (10,000ha) and New Amurambalam (8,000ha) reserved forests (Anon., 1982; Variava, 1983). It is also one of the core areas of the 552,000ha Nilgiri Biosphere Reserve.

Conservation Management The history of past management practices in Silent Valley is summarised by Unnikrishnan (1989). Ownership of Silent Valley has been at the disposal of the government since 1847, when 400ha of land in the upper reaches (i.e. Walakkad) were leased to private planters. This practice ceased in 1873 and the Walakkad Estate was taken over by the government in 1889. Logging commenced in 1901-1902. Initially worked for selected species, such as Dysoxylum malabaricum, the selection felling system was subsequently introduced in 1928 and regeneration encouraged by planting seeds of native species. Prescriptions for harvesting timber, as well as for conserving the area (though neglected), were detailed in working plans from 1933 onwards (e.g. Aiyar, 1935). Due to the rugged terrain and limited accessibility, many forests of Silent Valley remained intact.

A Forest Division was constituted in 1985-1986 exclusively for the management of the park. The park is managed according to prescriptions outlined in its first management plan (Unnikrishnan, 1989). In view of its relatively small size, the entire park is treated as a core zone, as well as a core of the Nilgiri Biosphere Reserve, within which human influence is kept to a minimum. To this end, tourists are only allowed into peripheral areas of the park (KFD, 1990). It has been proposed in the management plan that the core should be extended to include New Amarambalam Reserved Forest, following the recommendations of the Wildlife Institute of India that Karimpuzha Valley (22,500ha) to the north be established as a protected area. Given that this valley is inhabited by forest-dependent tribes, sanctuary rather than national park status is more appropriate in the short-term (Rodgers and Panwar, 1988). Such proposals have already been submitted to the Kerala Government.

All land surrounding the park, except that to the south, falls within the Nilgiri Biosphere Reserve and is managed as a buffer zone. The risk of fire during the dry season (January-monsoon) is high on all but the eastern boundary of the park. Fire prevention measures include maintaining about 120km of fire breaks, mostly inside and parallel to the park's western boundary, and stationing fire fighting squads in strategic positions. Other management initiatives include protection of soil from erosion along steep water courses and improvement of pastures for wild herbivores (Unnikrishnan, 1989).

Management Constraints Forest fires are a major hazard and account for 20% of the park having been degraded over the last few years. Preventative measures in recent years have helped to reduce the incidence of fire outbreaks (Unnikrishnan, 1989). Some 500ha of forest has been cleared of its larger trees following the intial decision to implement the now abandoned hydro-electric project. Poaching continues to be a problem and minor forest products are collected by local people, both within the park and the adjacent forest estate (Unnikrishnan, 1989). There is a significant amount of agricultural encroachment by relatively affluent persons in the headwaters of the park, a vital corridor linking up with Mukurthi (Nilgiri Tahr) Sanctuary to the north-east. Here, forest is habitually cleared and cultivated for rubber, cardamom, pepper and other crops (A. Robertson, pers. comm., 1986).

Staff Wildlife warden and assistant wildlife warden, with a sanctioned protection staff comprising one deputy ranger, four foresters, eight forest guards and 27 reserve watchers. However, 19 reserve watchers have been diverted elsewhere since 1986 (Unnikrishnan, 1989).

Budget Rs 5,600,000 (1987-1988)

Local Addresses

Assistant Wildlife Warden, Silent Valley National Park, Camp Mukkali, via Mannarghat, Palghat District, Kerala (Tel: Kalkandi 25)

References

A comprehensive bibliography is given in the World Heritage nomination dossier (KFD, 1990)

Agarwal, A. and Narain, S. (Eds) (1985). The State of India's Environment 1984-1985. The Second Citizen's Report. Centre for Science and Environment, New Delhi. 393 pp.

Aiyar, T.V.V. (1935). A working plan for the Ghat forests of the Palghat Division, 1933-34 to 1942-43. (Unseen)

Anitha, S. (1989). Behavioural ecology of lion-tailed macaque (Macaca silenus) in Silent Valley. M.S. thesis. Pondicherry University. 68 pp. (Unseen)

Anon. (n.d.). Report of the Task Force for the ecological planning of the Western Ghats. National Committee on Environmental Planning and Coordination. Government of India, New Delhi. 20 pp.

Anon. (1981). Flora and fauna of Silent Valley, Attappadi and Sabarigiri forests. Report of the Study Team appointed by the Government of Kerala. Kerala State Electricity Board, Trivandrum. 108 pp.

Anon. (1982). Ecological aspects of the Silent Valley. Report of the Joint Committee. Department of the Environment, Government of India, New Delhi. 44 pp.

Balakrishnan, M. (1984). The larger mammals and their endangered habitats in the Silent Valley forests of South India. Biological Conservation 29: 277-286.

Chand Basha, S. (1987). Studies on the ecology of evergreen forests of Kerala with special reference to Silent Valley and Attappady (South India). Ph.D. thesis, University of Kerala, Trivandrum. 232 pp.

IUCN (1986). A new development paradigm. IUCN Bulletin 17: 123.

Jayson, E.A. (1990). Community ecology of birds in Silent Valley. In: Ecological studies and long-term monitoring of biological processes in Silent Valley National Park. Kerala Forest Research Institute Research Report. Pp. 55-107.

KFD (1990). Silent Valley National Park. Nomination dossier for World Heritage List. Kerala Forest Department, Trivandrum. 66 pp.

KFRI (1990). Ecological studies and long-term monitoring of biological processes in Silent Valley National Park. Kerala Forest Research Institute Research Report.

Kumar, A. (1987). The ecology and population dynamics of the lion-tailed macaque (Macaca silenus) in South India. Ph.D. thesis, University of Cambridge, Cambridge, UK. 174 pp.

Manilal, K.S. (1988). Flora of Silent Valley tropical rainforests of India. The Mathrubhumi (MM) Press, Calicut. 398 pp.

Manilal, K.S., Kandya, A.K. and Sabu, T. (1988). Phytosociological studies on the Silent Valley Forests, Kerala. Journal of Tropical Forests 4: 362-379.

Mathew, G. (1990). Studies on the lepidopteran fauna of Silent Valley. In: Ecological studies and long-term monitoring of biological processes in Silent Valley National Park. Kerala Forest Research Institute Research Report. Pp. 13-53.

Nair, P.V. and Balasubramanyan, K. (1984). Long-term environmental and ecological impacts of multipurpose river valley projects. Wildlife studies in Idukki, Periyar and Silent Valley. Kerala Forest Research Institute Report No. 26. 75 pp.

Nair, V.C., Vajravelu, E., Bhargavan, P. (1980). Preliminary report on the botany of Silent Valley (Palghat District, Kerala). Botanical Survey of India, Coimbatore. (Unseen)

Rahmani, A.R. (1980). Silent Valley: India's last tropical rainforest. Tigerpaper 7(1): 17-19.

Ramakrishnan, P.S. and Singh, J.S. (1981). The Silent Valley forest ecosystem and possible impact of proposed hydroelectric project.

Singh, J.S., Singh, S.P., Saxena, A.K. and Rawat, Y.S. (1984). The forest vegetation of Silent Valley, India. In: Chadwick, A.C. and Sutton, S.L. (Eds), Tropical rain-forest. The Leeds Symposium. Leeds Philosophical and Literary Society, Leeds. Pp. 25-52.

Singh, J.S., Singh, S.P., Saxena, A.K. and Rawat, Y.S. (1984). India's Silent Valley and its threatened rain forest ecosystems. Environmental Conservation 11: 223-233. (Unseen)

Unnikrishnan, P.N. (1989). Silent Valley National Park Management Plan 1990.91-99.2000. Silent Valley National Park Division, Mannarghat. 83 pp.

Variava, D. (1983). Silent Valley: a case study in environmental education. Paper presented at Bombay Natural History Society Centenary Symposium, Powai, Bombay. 12 pp.

Vijayan, V.S. and Balakrishnan, M. (1977). Impact of hydroelectric project on wildlife. Report of the first phase of study. Kerala Forest Research Institute, Peechi. 111 pp.

Vohra, J.N., Roychowdhury, K.N., Ghosh, R.K., Kar, B.D. and Singh, K.P. (1982). Observations on the cryptogamic flora of Silent Valley. In: Botanical Studies on Silent Valley. Part 1. Botanical Survey of India, Howrah. Pp. 1-40.

ZSI (1986). Records of the Zoological Survey of India 84(1-4).

Date March 1988, reviewed March 1991