Shola Forests


The hill forests are locally known as Sholas.    The term ‘shola’ is a corrupt form of the Tamil word ‘cholai’ borrowed and incorporated into forest typology. In Tamil the term ‘cholai’ (Malayalam: ‘chola’) refers to a cold place, a thicket etc. Both ‘shola’ and ‘sholai vanam’ are literally glorified in ancient Tamil literature, songs and films. All these connotations refer to streams, rivulets and the associated forests. The shola forests actually represent continuation of the evergreen forests in response to elevational gradient, the sequence being: Wet Evergreen Forests - Subtropical Hill Forests -  Montane Wet Temperate Forests.

The shola forests as redefined by Meher-Homji (1986) include forests vegetations of the Peninsular India, growing above 1500 m msl approximately. In terms of this broader definition, shola forests are found all along the upper reaches of the Western Ghats where the elevation goes beyond 1500 m msl.

The first floristc account of Shola Forests was that of Fyson(1915-21). It was the pioneering study of Shetty and Vivekanandan(1968,1970,971,1972,1973,1991) that gave a good floristc account of Sholas of Kerala. Blasco (1971) provided an account of flora and ecology of Sholas of Western Ghats.

 The shola forests in the upper plateau are dense and floristically rich with many endemic and rare species. The trees in the sholas form a continuous canopy usually not exceeding 10-15m. There is no marked differentiation into canopy layers. The tree bark is covered with lichens, orchids, mosses and climbers. The crowns are generally rounded and dense.


Common tree species in the shola forests are Pithecellobium subcoriaceum, Ixora notoniana, Syzygium arnottianum, Ilex denticulata, I. wightiana, Michaelia nilagirica, Elaeocarpus recurvatus, Microtropis ramiflora, Actinodaphne bourdellonii, and Symplocos pendula. The edges of the shola are marked by trees such as Rhododendron arboreum var. nilagiricum, Ternstroemia japonica, Ligustrum perrottettii, Turpinia cochinchinensis, Mahonia leshenaultii, Rhodomyrtus tomentosa, Berberis tinctoria, Vaccinium neilgherrense etc. and herbs and shrubs include Gaultheria fragrantissima, Moonia heterophylla, Jasminum bignoneacium, Smithia blanda, Valeriana hookeriana and a few species of Strobilanthes.

The undergrowth in the shola is represented by Strobilanthes sp., Impatiens phoenicea, I. coelotropis, Psychotria congesta, Viola patrinii, V. serpens, Asplenium sp., and Arundinaria densifolia. Epiphytic orchids in the sholas include Aerides ringens, Coelogyne nervosa, C. mossiae, Eria dalzelli, E. pauciflora, and Schoenorchis filiformis. The common climbers are Piper schmidtii, Rubia cordifolia, and Connarus wightii. Rapanea capillata, Vaccinium leschenaultii, Impatiens tangachee, Sonerila grandiflora, Osmunda regalis and Eurya japonica are usually found along streams.


Broad-leaved forests are found on the slopes descending from the plateau. The dominant tree species found in the broad-leaved forests are Pittosporum tetraspermum, Elaeocarpus munroii, Apollonias arnotti, Symplocos spicata, Gomphandra coriacea, Garcinia gummi-gutta, Litsea coreacea, Prunus ceylanica and Photinia notoniana. Major shrubs include Begonia subpeltata, Osbeckia lineolata, Polygala arillata, Strobilanthes homotropus, Maesa perrottetiana etc.

The Shola Forests are important phytogeographically also. A very important species in this regard is Rhododendron arboreum All other members of the of the genus Rhododendron in India are confined to the Himalayan region. The flora also shows an affinity to that of Sri Lanka which has tracts of Shola forests.

The study of micro flora of the Shola Forests has come up with promising results. 34 genera and 101 species have been identified from Munnar areas. The abundance of rare species like penicillium is a portent for future biotechnological studies. There is a treasure trove waiting to be tapped. This gives all the more reason for conserving Shola Forests for the future generations.

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CONSERVATION ISSUES IN THE ABODE OF NEELAKURINJI AND NILGIRI TAHR

Sholas and grasslands of the high altitudes in the Western Ghats are highly threatened

E. Kunhikrishnan, Lecturer, Department of Zoology, University College,

Thiruvananthapuram, 695 034

 

It was an amazing sight that welcomed the early European settlers in Ooty when the neelekurinji bloomed, making the meadows mauve once in every 12 years. They called these hills ‘the blue mountains’ It was the gregarious blooming of the plant Phlebophyllum kunthianum(Strobilanthes kunthianus), which is endemic to the high altitudes of the southern Western Ghats, that turned the hill tops apparently blue. The recent flowering of the kurinji was in 1994. Because of the prominence during the gregarious blooming in the high altitude grasslands, this plant got identification as the type species of the high altitudes in the minds of the commons. Other than this, there are many species of plants and animals, which are endemic to the high altitude ecosystem.

The high altitude ecosystem differs from all other ecosystems in that high mountains constitute a unique habitat. It is an environmental complex on the mountains, which are high enough to rise in to the semi- attenuated upper parts of the atmosphere. Altitudinal changes of climate should sort and sift species according to their climatic tolerance ranges, and so produce elevational belts of vegetation in the same way that latitudinal differences in climate produce latitudinal bands of vegetation.

High up on the Western Ghats we have three high altitude regimes namely the Nilgiris, Palnis and Anamalais . Nilgiris rising from the north of Attappady plateau, north of Palakkad gap(Palghat gap ), which culminate in to peaks like Mukurthi, Nilgiri, Anginda, Sispara and Doddabetta. Anamalais and Palnis are immediately south to the Palakkad gap. Anamalais rise from the plains of the gap sharply as a vertical rock wall and expands from the Nelliampathis to the Anamudi peak, which stands at 2695 m above msl forming the highest peak in the Indian peninsula. Palnis is the Kodaikanal hills, comprising the eastern spur of the Western Ghats east to Munnar hills.

In all these regimes large part of the mountains remain 1800 m above msl which afforded a subtropical ecoclimatic zone in the tropics. The forests situated in the tropical latitudes cannot be strictly considered in par with vegetation in the subtropical and temperate latitudes. The mountain tops nave rugged rocky outcrops and pricipituous cliffs and a veil of mist. Down to the cliffs there are vast expanse of grasslands interspersed with small and large islands of dark green stunted forests, namely the ‘sholas’. These are found mainly in sheltered valleys, depressions and ravines. ‘Shola’ might have have come from ‘chola’ which signifies the dark shades of the thick stunted forest or a small or large stream that emerges from the floor of the forest, flowing down to the valleys. As the altitude increases, the trees become more stunted and the branches of neighbouring trees are interlocked and have a thick covering of epiphytes. Champion and Seth who classified the vegetation of the Indian region taking into consideration many parameters, have included the sholas under ‘Southern Montane Wet Temperate Forests’.

  In Kerala we had vast expanse of sholas and high altitude grasslands in the Munnar region of the Anamalai regime. A major share of this came under the Kannan Devan concession land and had been cleared for raising the tea plantation a century ago. After legislation in the early 1970s the excess land was taken from the company and is now with the Kerala Forest Department. The prime grassland of the Eravikulam, Poovar and Hamilton plateau were declared a national park in 1974 and it harbours the largest population of the highly endangered and only wild goat in south India, the Nilgiri tahr, Hemitragus hylocrius.

Factors influencing animal and plant species distribution along elevation gradients are complex, and not solely climatic or even ecological. In some cases evolutionary aspects of the species may be important. Controversies are still going on regarding the presence of the Himalayan taxa in the south Indian hill tracts. Continuity with a more or less climatic unity between the Himalayas and the Western Ghats during the ice ages has been suggested. Many scientists think that the conditions that prevailed then facilitated continuity in the distribution of plants and animals. After the retreat of the ice in the warm period, the temperate condition remained only on the hilltops with substantial altitude to maintain a low temperature, which supported the relict taxa. The high plateaus above 1500m above msl imparted an extra tropical aura for the continued survival of many species in the postglacial era. The Nilgiri and the Palni-Anamalai tracts remain as islands with species common to these and also with endemic species belonging to each of these regions. There were many species of caprinids in the Himalayas. Some animals were supposed to have migrated to the south during a glacial period  eons back and evolved in isolation, to a different species we now call as  Nilgiri tahr. Interglacial warm periods pushed these animals to the crests of the mountains up in the sky, the remnants of which we see as the isolated populations along the cliffs and meadows of the Nilgiris, Anamalais, Kodaikanal, Pampa, Highwavys and  the Ashambu hills. The closest relative of this animal, the Himalayan tahr, Hemitragus jemlahicus, is seen in the upper reaches of the Himalayas.  A third species, the Arabian tahr, H. jayakari is in Sultanate of Oman. The Nilgiri marten, Martes gwatkinsi, a member of the weasel family, is endemic to the forests of the high altitude of the Southern Western Ghats. The immediate relative, the Himalayan yellow throated marten, M.flavigula enjoys a wider distribution in the Himalayas, the Assam hill ranges, Burma, China and the Malay countries. There are at least 14 species of birds which are endemic to the shola grasslands of the high altitude of the Western Ghats in Kerala. The close relatives of the thrushes in these regions are seen in the eastern Himalayas. Salea anamallayana  is an agamid lizard endemic to  Anamalais and Palni hill ranges of the southern Western Ghats and  Salea horsfieldii is confined to the Nilgiris, Anamalais and Palnis. There are two more species of Salea existing in the world, but seen in south China and Myanmar. There are some butterfly species, which are endemic to the mountains 1500m above msl on the Western Ghats. The Nilgiri grass yellow( Eurema nilgiriensis), Nilgiri clouded yellow (Colias nilgiriensis), Red disk bushbrown  (Mycalesis oculus), Red eye bushbrown (Mycalesis adolphei ) , Palni bushbrown(Mycalesis mamerata davisoni), Nilgiri fourring (Ypthima chenui )PALNI FOURRING (Ypthima ypthimoides) are the examples.

Eravikulam national park is the abode of another elusive cat locally known as ‘pohayan’. Many members of the Muthuvan community, the local tribe, swear that there is a plain-coated cat much larger than the jungle cat and lesser than a leopard in the national park. So far there is no scientific record on the existence of such an animal any where in the Indian peninsula. The author has come across such an animal twice in the Eravikulam National Park. The appearance matched with the descriptions given by the Muthuvans and that of Mr. Mohan Alampath who managed the park for a pretty long term and had an opportunity to observe the animal once for a longer duration. I strongly believe that the animal can be a race of the golden cat (Catopuma), which is there  in the mountainous regions of the  northeastern Himalayas and Southeast Asia. Being a rare nocturnal cat it managed to skip form the eyes of the scientists and the guns of shikaris.

During a recent study by the Wildlife Institute of India, in Eravikulam National Park, 308 plant species were collected from the grasslands alone. More than 50 species were found to be endemic to the grasslands and more than 30 species were listed as rare and endangered. There were 64 species common with eastern ghats, 30 species with similar high altitude areas(the patnas) in Srilanka,35 with Western Himalaya and 35 with Naga and Khasi Hills indicating phytogeographic affinities of the high altitudes of the southern Western Ghats with these biogeographic zones.A prominent tree with bunches of bright red flowers, Rhododendron arboreum, a temperate species, is seen in the eastern Himalayas, and in the montane regimes of south India and Srilanka. The tree in south is now considered  as subspecies R. arboreum nilagiricum . Michelia nilagirica is a shola tree with fragrant flowers and is seen growing in similar habitats in Srilanka. The endemic and endangered orchids like Brachycorythis wightii, Habenaria perottetiana; the balsams appeared in the Red Data Book of Indian Plants published by the Botanical Survey of India, like Impatiens johnii, I. anamudica,  I. macrocarpa, I. munnarensis, were reported from Eravikulam National Park and the neighbouring areas and I. neo-barnesi, and I. nilgirica were reported from Nilgiris

The percentage of endemism is high and so the conservation value of the high altitude grasslands is also very high. But due recognition has been denied to this unique ecosystem. The degradation of the meadows and saholas of the Nilgiris and Kodaikanal has started along with the arrival of the European settlers during the early 19th century. Now the exotic trees like black wattle, eucalyptus and pines have already replaced the natural vegetation of Ooty and Kodaikanal. The major part of the grasslands of the Mukurthi tahr sanctuary in the Nilgiris is under black wattle plantation. The second spell of doom of the Munnar hills began with the planting of black wattle in the grasslands of this area in the early 1980s.Most stretches of grasslands that were in blues during the kurinji bloom of 1982 were choked with the profusely proliferating black wattle when the gregarious flowering imparted the hills shades of blue again in1994. The wattle was introduced as part of ‘afforestation of the wastelands’ programme in the forests of Kerala. The high quantity of tannin in the bark of the black wattle virtually burnt all other plants in the vicinity.

The shola grasslands are to be protected at any cost. A scientist who studied this ecosystem some decades back, correctly described it as a fossil ecosystem. The relics of an ecoclimatic and geologic past is preserved in its pristine form at least in certain parts of these mist laden canopies of the mountains. Eravikulam is only about100sqkm in area. It was the only protected shola - grassland regime south to the Palakkad Gap. Recently Mannavan shola and neighbouring high altitude grasslands  which are the remaining extensive shola – grassland patches  to north east of Eravikulam were also been notified as protected areas.   Redefining the boundary, taking in to consideration the ecological boundaries of the tahr populations and the distribution of the natural vegetation, can augment the area of the Eravikulam National park and other protected areas in the neighbouring hills. Planting with wattle, pine or eucalyptus and conversion and destruction of this unique ecosystem must be stopped with immediate effect. Let the living fossil, the shola-grassland ecosystem, which survived extremes of the vagaries of nature for eons remain preserved for posterity.

 

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The Sholas and Grasslands in the southern Western Ghats

  E. Kunhikrishnan, Lecturer, Department of Zoology, University College, Thiruvananthapuram, 695 034

In the southern Western Ghats, the hilltops and plateaus 1400m. above the sea level harbour a special kind of ecosystem. H. G. Champion and S. K. Seth in the 1930s and 1960s, while classifying the phytogeographic zones in the Indian subcontinent, identified that the southern montane wet temperate forest and grasslands exist in the high altitudes of southern Western Ghats. The environmental complex that prevailed on these mountains nurtured an ecosystem that could survive in the  semi-attenuated upper parts of the atmosphere. Altitudinal changes of climate could sort and sift species according to their climatic tolerance ranges, and so produce elevation belts of vegetation in the same way that latitudinal differences in climate produce latitudinal bands of vegetation.

The Nilgiris, Anamalais and Kodaikanal(Palnis) are the three important high altitude regimes in the south. The blooming of neelakurinji (Phlebophyllum kunthianum) periodically once in 12 years that imparted a purple hue to the emerald grasslands on the slopes and plateaus were recorded by the  early westerner settlers in the Ootakamund. But the locals had already called this hill range, Nilgiris- meaning, the blue mountains. The first written records by the Britishers about the gregarious blooming phenomenon could be traced  in the volumes of the journal, Indian Forester published in the late 19th century and in the Journal of Bombay Natural History Society of the early 20th century.(The recent gregarious flowering was in 1994.) Much attention had not been given to the special characteristics of the high altitude vegetation in those days. P. F. Fyson was the botanist who seriously ventured to study the plants in these inhospitable terrain and the leech infested forests, during the British regime.  Mehr Homji of the French Institute, Pondichery, made  some observations on the ecology of the hill stations in the south. Studies have  shown that  a unique vegetation exists here which is more comparable with the  Alpine meadows in the Himalayas than the Dipterocarpus and Hopea dominated forests somewhere in the lower altitudes in the Western Ghats.

Tropical montane forests are situated in the higher mountain tracts of the southern Western Ghats, at an altitude above 1500 m, interspersed with rolling grasslands. The montane forests are the stunted ever green forests locally known as sholas. In the sholas the trees are stunted with crooked branches thickly laden with moss and other epiphytes. The shola trees have interlocking branches to withstand the high velocity winds blowing from the west during the monsoon.

During a recent study by the Wildlife Institute of India, in  Eravikulam national park, 308 plant species were collected from the grassland alone. More than 50 species were found to be endemic to the grasslands and more than 30 species were listed as rare and endangered. There were 64 species common with the Eastern Ghats, 30 species with similar high altitude areas in  Srilanka, 35 with Western Himalaya and 35 with Naga and Khasi Hills indicating phytogeographic affinities of the high altitudes of the southern Western Ghats  and of these  biogeographic zones

The plant families Lauraceae and Rubiaceae are well represented in the sholas. Acanthaceae members dominated among the shrubs. Many species of   Strobilanthes and Andrographis (both belonging to Acanthaceae) are endemic to this region. In the Western Ghats, members of the flora  families like Ranunculaceae, Geraniaceae, and Saxifragaceae are seen only in such regimes. Other members of these families are seen in the alpine meadows of the Himalayas and temperate regions which are separated from the Western Ghats by thousands of kilometers. The presence of the typical Himalayan tree Rhododentron arboreum on the south Indian hilltops in the Nilgiris, Kodaikanal and Munnar is much intriguing. It is not present on the Ashambu hills on the southern tip but is there on the  Srilankan hilltops. The Rhododendron in the south and in the  Srilankan 'patnas'(local name for the grasslands of Srilankan hilltops) were earlier considered as separate species, viz. nilagiricum and zeylanicus respectively. Now it has been established that the zeylanic, south Indian and Himalayan  Rhododendron do not have any taxonomic difference to justify granting them separate species status. Rhododendron is considered a native of south west Himalayas, where many species exist.  Michelia nilagirica is a tree in the sholas above an altitude of 2000 m above msl, which is also present in the cloud forests of Srilanka at similar altitudes.

Pedicularis is a genus with many species in the meadows of the Himalayas, but only two species, Pedicularis perrotettii and P. zeylanica are reported from the south, from the hills 1300m above msl. The species Pedicularis zeylanica as the name indicates, is found in the 'patnas' of Srilanka also. Geranium nepalense seen in the high altitude grasslands is probably the only member of the family in the south and  in Srilanka. The same species and some more of the genus  are seen in the western Himalayas.

The plants of the family Asteraceae are in good numbers in the grasslands of the hilltops in all the three regimes in the south. Genera like Anaphalis, Conyza, Gnaphalium, Gynura, Cnicus, Artimesia, Senicio, Erigeron, and Picris in south, are exclusive to the high altitude grasslands, where a subtropical climate prevails.

Endangered animals of the high altitudes

The rocky escarpments and rolling meadows are the home for the highly endangered and only wild goat of peninsular India, the  Nilgiri tahr(Hemitragus hylocrius).The total individuals of this caprinid present today would be around two thousand only. Half of the population is in the Eravikulam national park in Kerala  and in the adjoining Grasshills in the Indira Gandhi wildlife sanctuary, Tamilnadu. Another major population of this mountain goat is in the Mukurthi sanctuary in the Nilgiris, where less than 200 individuals survive.

 The Nilgiri marten, Martes gwatkinsi, a member of the weasel family, is endemic to the forests of the high altitudes of the southern Western Ghats. The immediate relative, the  Himalayan yellow throated marten, M. flavigula enjoys a wider distribution in the Himalayas, the Assam hill ranges, Burma, China and the Malay countries. There are at least 14 species of birds which are endemic to the shola grasslands of the high altitudes of the Western Ghats in Kerala and Tamilnadu. The close relatives of the thrushes in these regions are seen in the eastern Himalayas. The lizard genus Salea is endemic to the Nilgiris and Anamalais.

The mountain wine snake, Ahetullah dispar is confined to the high altitude grasslands of Anamalais and Ahetullah perroteti to that of Nilgiris. The butterfly species the Nilgiri clouded yellow, the Palni four ring, the Nilgiri four ring, red disc bush brown, the  red eyed bush brown and the Indian cabbage white are endemic to the mountains 1500 m above  msl in the Western Ghats.

The Ecological holocaust on the mountaintops

The last century saw nothing less than a true ecological disaster in all the three major shola grasslands regimes of the southern Western Ghats.

The history of destruction in the Nilgiris, Kodaikanal and Munnar was started by the initial colonial settlers, more than a century ago. The first discovery of the 'salubrious climate' that best suited the  Europeans in the Nilgiris was by the  then Coimbatore collector Mr. Sullivan who first moved to Ootakamund in the early 19th century. The plateau on the remote misty mountains was the homeland of the pastoral tribe, the Thodas. In 1834, The Governor General of British India spent several months in Nilgiris which was followed by a flood of migration to procure land there. The natural vegetation in the sholas and the grasslands depleted very fast. Introduced exotic temperate trees like Acacia, (wattles) Eucalyptus and pines replaced the plants of the sholas and grasslands. The high content of tannin in the bark of the black wattle virtually burnt off the native endemic plants many of which now are in the list of plants  'presumed to be extinct'. In the Nilgiris, now there is no stretch of grassland free of wattle, Eucaluptus and   pine. The fate of Kodaikanal was not different when it became a major 'Hill Station' in south India. The introduction of tea plantations in the 1870s was the  beginning of onslaught on the sholas and grasslands in Munnar. The planting of black wattle and Eucalyptus in the remaining grasslands in the pretext of social forestry and afforestation of 'wastelands' from the 1980s onwards was the last nail in the coffin.


The vestiges of the pristine grasslands that remain, comprise the Eravikulam national park which escaped destruction by virtue of its special legal status.  Studies have shown that majority of the endemic plants of the Munnar -Kodaikanal tract are highly threatened and many are already extinct because of loss of habitat. In the coming decades conservationists will have to fight very hard to save the remaining endangered native plants from extinction because of the invasion of the black wattle in the grasslands and sholas.