Malabar Shola Forest
These so-called shola forest are basically high altitude evergreen forests confined to high altitude plateaus and can become stunted at the highest elevations. They include both tropical and temperate elements and constitute one of the main natural plant formations of Kerala occurring in the regions of Anamalai (Eravikulam and Munnar), Vavul Malai (North Nilambur) and upper reaches of New Amarambalam (South Nilambur). The plant families Lauraceae (including Litsea species) and Myrtaceae (including Syzygium species) along with Microtropis species (Celastraceae) usually characterize these forests. In the Konkan area they typically have three or four tiers. In the first of these, trees such as the endemic Amoora lawii and Dysoxylum malabaricum (Meliaceae), Dipterocarpus indicus (Dipterocarpaceae) and Elaeocarpus tuberculatus (Elaeocarpaceae) reach heights of up to 45 m. The second tier between 15-23 m includes Alstonia scholaris and Hardwickia pinna, while the third tier includes small trees of between 10-15m such as Callicarpa tomentosa and Leea indica. There is also usually a dense thicket of shrubs and climbers including the mysterious climbing gymnosperm Gnetum ula. The Gnetinae, which also include Ephedra and Welwitschia, are a group of unusual gymnosperms with certain features in common with flowering plants. For example, they have vessels in the xylem and lack archegonia (multicellular female sex organs). It has been suggested therefore that these may be primitive descendants of flowering plants. Between 650-1000m the forests become entirely dominated by deciduous trees such as Bridelia squamosa, Dillenia pentagyna and Grewia tiliaefolia. Other endemics found in the Konkan area include Aporosa lindleyana (Euphorbiaceae), Lamprochaenium microcephalum, Nanothamnus sericeus (Asteraceae) and Oxytenanthera monostigma (Poaceae). In the Nigiri Hills the shola forests are interspersed among rolling downs. Conspicuous shrubs and trees include Berberis tinctoria, Hydnocarpus alpina and the endemic Garcinia cambogia (Hypericaceae) and Michelia nilgirica (Magnoliaceae), while less common endemics are Actinodaphne lanata (Lauraceae), Aglaia anamallayana (Meliaceae) and Apodytes beddomei (Icacinaceae). These shola forests are also notable for their many orchids such as Aerides ringens, Calantha veratrifolia and Habenaria longicornu.
The surrounding downlands are dominated by many herbaceous species such as the endemic Campanula wightii (Campanulaceae) and Impatiens nilgirica (Balsaminaceae). Endemic genera found in the Nilgiri include Campbellia represented by Campbellia cytinoides (Orobanchaceae) and Baeolepis represented by Baeolepis nervosa (Asclepiadaceae). Shola forests further south in the Anamalai, Cardamom and Palni hills are also richly endowed with species with at least 26 trees contributing to the upper tiers including the gigantic endemic Palaquium ellipticum (Sapotaceae). Other endemics in this area include Antistrophe serratifolia and Ardisia blatteri (Myrsinaceae) and the unusual saprophyte Haplothismia exannulata (Burmanniaceae). The flora in this part of the Western Ghats has much in common with Sri Lanka. For example, the monotypic genus Kendrickia (Kendrickia walkeri) of the Melastomataceae is restricted to the Anamalai hilltops and Adam’s Peak on Sri Lanka. This supports the idea that the island was connected to the Indian sub-continent in ancient times. Other common species in the shola include Actinodaphne bourdillonii, Berberis tinctoria, Daphniphyllum neilgherrense, Elaeocarpus recurvatus, Photonia notoniana, Rhodomyrtus tomentosa, Symplocos pendula, Turpinia cochinchinensis and the endemic Michelia nilagirica (Magnoliaceae) and Rhododendron nilagiricum (Ericaceae).
Malabar Wet Evergreen Forest
Tropical evergreen forests constitute the climax vegetation of Kerala characterized by at least three tiers, the highest often attaining a height of 40-45 m. Many species develop plank buttresses. The middle stratum is more or less candle shaped and the lower characteristically conical. Buttressing and fluting are common. These forests represent the most important vegetation between altitudes of about 600 and 1100 m, while under favorable conditions with regard to as availability of shelter and moisture; they can extend to elevations of 1200 m or so. However, they generally require an annual rainfall of more than 2000 mm, temperatures between 15°-30°C and humidity between 70 -100%. The upper storey consists chiefly of Artocarpus heterophyllus, Bischofia javanica, Calophyllum elatum, Canarium strictum, Cullenia exarillata, Drypetes elata, Mesua ferrea, Persea macrantha, Poeciloneuron indicum, Polyalthia coffeoides, Vateria Indica and the endemic Dysoxylum malabaricum (Meliaceae), Elaeocarpus tuberculatus (Elaeocarpaceae), Holigarna arnottiana, H. grahamii, (family?)and Palaquium ellipticum (Sapotaceae). The second storey is characterized by species such as Aglaia elaeagnoidea, Actinodaphne hookeri, Baccaurea courtallensis, Dimocarpus longan, Elaeocarpus serratus, Garcinia morella, Gomphandra polymorpha, Litsea wightiana, Meliosma pinnata, Myristica dactyloides, Oreocnide integrifolia and the endemic Cinnamomum malabaricum (Lauraceae)attaining heights of 15 to 30 m. The third storey, which is usually less than 15 m, consists of small trees like Agrostistachys meeboldii, Euonymus angulatus, Memecylon sisparense, Syzygium munroii, Syzygium laetum, Xanthophyllum flavescens the endemic Turpinia malabarica (Staphyleaceae)and a profusion of shrubs like Dendrocnide sinuata, Sarcococca brevifolia, Solanum surattense, Thottea siliquosa and many others. Monocots are few in number and typically have localized distributions. Important species include Calamus gamblei, Pandanus furcatus, Pinanga dicksonii, Ochlandra travancorica, O. rheedii and the endemic Arenga wightii and Calamus thwaitesii (Arecaceae).At ground level, herbs like Elettaria cardamomum and species of Amorphophallus and Hackeria are common together with various ferns. Climbers like Pothos scandens, Caesalpinia bonduc and many species of Piper are also common. The epiphytic flora is rich and many of the trees are heavily infested with epiphytic orchids, aroids, mosses, and ferns. These forests are also storehouses of medicinal plants (about 180 species) and support many wild relatives of cultivated plants. About 25% of the forests of Kerala belong to this category with the forests of Silent Valley National Park and Periyar tiger reserve represents some of the richest stands.
Malabar Semi-Evergreen Forests
West coast semi-evergreen forests are considered to be a transitional stage between evergreen and moist deciduous forests, and are sometimes associated with high levels of disturbances. They usually occur between altitudes of about 600 to 800 m and in some places extending up to 900 m. The main evergreen species include Artocarpus heterophyllus, Bischofia javanica, Calophyllum elatum, Euvodia lunuankenda, Mangifera indica, Mesua ferrea, Myristica dactyloides and the endemic Hopea ponga (Dipterocarpaceae) while the important deciduous elements are Acrocarpus fraxinifolius, Bombax ceiba, Chukrasia tabularis, Dalbergia latifolia, Grewia tiliaefolia, Terminalia bellirica, Toona ciliata and the endemic Lagerstroemia microcarpa (Lythraceae). Species composition at sub-canopy and ground level is similar to evergreen forests.
Malabar Dry Deciduous Forests
These forests are fairly rare in Kerala State and mainly confined to northern slope of Anamalai in Chinnar Wildlife Sanctuary, eastern part of Mannarkad Division, and the South Wayanad Wildlife Sanctuary where rainfall is less than 1200 mm. Their physiognomic structure is highly variable mainly due to impoverished soils, especially on steep slopes, but also due to anthropogenic instigated factors such as fire and grazing. Three types of are recognized. Forest dominated by Albizia amara, Gyrocarpus asiaticus and species of Acacia is found only in Chinnar Wildlife Sanctuary, up to an altitude of about 650 m. Other characteristic species include Erythroxylum monogynum, Dichrostachys cinerea, Chloroxylon swietenia and Hardwickia binata. On the lower slopes, species such as Acacia chundra and A. leucophloea are characteristic of scrub woodland and thickets, but where slopes with skeletal soils predominate tree savannas become an important feature. In such places Gyrocarpus asiaticus, with its metallic-coloured bark, becomes conspicuous together with other slope-loving species, such as Cochlospermum religiosum, Commiphora caudate, Givotia rottleriformis and Sterculia urens. Forest dominated by Anogeissus latifolia, Pterocarpus marsupium and species of Terminalia occurs above 600 m in Mannarkad Division and Chinnar Wildlife Sanctary. Again physiognomy varies ranging from savanna woodland to tree savanna. Other characteristic species include Dalbergia paniculata, D. latifolia, Emblica officinalis, Grewia tiliifolia and Kydia calycina. The third type of forest is dominated by Anogeissus latifolia, Tectona grandis and species of Terminalia. This is confined to the South Wayanad Wildlife Sanctuary where it ranges from dense forest to woodland savanna. Other common species include Careya arborea, Diospyros melanoxylon, Emblica officinalis, Lagerstroemia parviflora and Madhuca latifolia, but in low-lying areas where drainage is impeded Shorea roxburghii become conspicuous.
Malabar Cullenia exarillata-Mesua ferrea-Palaqium ellipticum Forest
These forests occur between the Ariankavu Pass and the Brahmagiri Ghat in Wayanad and South of the Ariankavu Pass. They are mainly defined by the altitudinal preference of Cullenia exarillata, which ranges from about 700m-1400 m but occasionally descends to about 550 m in some moist valleys. Mesua ferrea and the endemic Palaqium ellipticum (Sapotaceae) are widely distributed at both low and medium elevations. In dense forests other common canopy or emergent species are Aglaia lawii, Cinnamomum keralense, Dimocarpus longan, Diospyros sylvatica, Drypetes elata, Litsea oleoides and Syzygium gardneri, and of which are widely distributed. Common third and second layers species include Agrostistachys meeboldii, Homalium travancoricum, Myristica dactyloides, Symphilia mallotiformis, Tricalysia apiocarpa and the endemic Diospyros paniculata (Ebenaceae). However, some species like Aglaia tomentosa, Bhesa indica, Litsea bourdillonii, Litsea keralana, Semecarpus travancorica and the endemic Diospyros nilagirica (Ebenaceae) and Drypetes venusta (Putranjivaceae) are found up to the Palghat Gap. Beyond the Gap they either disappear or become rare. In the fourth layer Ardisia pauciflora, Goniothalamus wightiana, Lasianthus jackianus, Psychotria anamalayana and Tabernaemontana gamblei are common. South of the Ariankavu Passthe local endemic Gluta travancorica (Anacardiaceae) becomes an important canopy species. Other canopy or sub canopy species either exclusive to these forests or rarely found to the north of the Ariankavu pass include Atuna travancorica (Chrysobalanaceae), Calophyllum austroindicum (Clusiaceae), Diospyros barberi (Ebenaceae), Garcinia imbertii, Garcinia rubro-echinata and Garcinia travancorica (Clusiaceae), while exclusive undergrowth species are Diotacanthus grandis (Acanthaceae), Goniothalamus rhynchantherus (Annonaceae), Memecylon gracile, Memecylon subramanii (Melastomataceae), Octotropis travancorica (Rubiaceae), Popowia beddomeana (Annonaceae) and Vernonia travancorica (Asteraceae). At elevations above 1000 m the endemic podocarp Nageia wallichiana (Podocarpaceae) also becomes an important canopy tree and represents the only indigenous gymnosperm tree in South India. Species such as Aglaia bourdilloni, Actinodaphne campanulata, Eugenia floccosa, Syzygium microphyllum and the endemic Bentinckia codapanna (Arecaceae) and Elaeocarpus venustus (Elaeocarpaceae) are found on the margins of these forests particularly near the cliffs.
Malabar Dipterocarpus indicus Forest
These forests vary in composition. In a wide area between Ariankavu Pass and the northern border of the Palaghat Gap dominant canopy species in addition to Dipterocarpus indicus include Strombosia ceylanica and to a lesser extent the gigantic Dipterocarpus bourdillonii. The latter generally occurs at lower limits (<450 m) and as a result of logging is now mainly encountered adjacent to streams and in some inaccessible areas. Other former climax species like Calophyllum polyanthum, Chrysophyllum roxburghii, Otonephelium stipulaceum, Poeciloneuron indicum, Semecarpus auriculata, Vateria indica and the endemic Palaquium ellipticum (Sapotaceae) have also become less frequent. On the other hand, certain widespread species such as Antiaris toxicaria, Artocarpus gomezianus, Bombax ceiba, Polyalthia fragrans and Pterygota alata and have become much more common and monopolize the canopy in places. These forests often surround small swamps especially in Ranni (between Plapally and Erumeli) and Kannur Divisions. Some of these are dominated by Humboldtia vahliana with its looping stilt roots while other species include Gymnacanthera canarica, Myristica dactyloides and the endemic Knema attenuata (Myristicaceae). To the south of the Ariankavu Pass, where the dry season varies from 2 to 3 months, canopy composition changes. Here Dipterocarpus indicus and Strombosia ceylanica are joined by Kingiodendron pinnatum as the main canopy species. However, in the humid valleys between Kallar and Shendurni rivers west of Agastya malai, Hopea racophloeaand and Humboldtia decurrens become common canopy species. The latter is a caulifliorus tree with large winged pinnate leaves and mainly prominent as a third story component. Other common canopy trees here include Artocarpus gomezianus, Ficus beddomei, Holigarna nigra, Otonephelium stipulaceum and Vateria Indica. Poeciloneuron indicum occurs in patches and Semecarpus auriculata and Semecarpus travancorica are common towards the lower limits. Common lower stratum species include Cynometra bedlomei, Fahrenheitia zeylanica, Hydnocarpus macrocarpa and the endemic Diospyros humilis and Diospyros paniculata (Ebenaceae).
Malabar Bhesa indica-Gomphandra coriacea-Litea Montane Forest
This forest is confined to upland zones (1400-1800 m) in the Western Ghats between the Ariyankavu Pass and Palghat Gap. At this altitude several species of lower elevations disappear or become very rare and members of the family Annonaceae disappear altogether. Species that become more important include Acronychia pedunculata, Archidendron clyparia, Cocculus laurifolius, Gomphandra coriacea (a vicariant of Gomphandra tetrandra of low elevations), Hydnocarpus alpina, Mastixia arborea and Schefflera capitata. The family Lauraceae, which tends to become more important with altitude, reaches a high level of diversity here.
Malabar (Nilgiri) Sub-Tropical Hill Forests
Apart from their stunted growth these forests have much in common with lowland tropical rain forest, but they tend to be less luxuriant and the trees usually have shapeless boles often festooned with epiphytes. Apart from the Nigiri Hills they can also be found in Anamalai and Palani hills at altitudes ranging from 1000-1700 m. The main canopy and subcanopy trees include Actinodaphne hookeri, Calophyllum elatum, Canthium dicoccum, Ficus arnottiana and Persia macrantha. The shrub layer is typically dense and usually dominated by species of Strobilanthes, while species of Calamus are the main climbers.
Malabar Montane Thicket
In the montane zones of the Nilgiris and Palni hills are stands of thicket reaching heights of 8-10 m. The upper storey is usually dominated by Syzygium calophyllifolium while other common species include Elaeocarpus recurvatus, Ilex denticulata, Isonandra condolleana, Melicope indica, Microtropis microcarpa, Rapanea wrightiana, Symplocos obtusa, Syzygium montanum and Turpinia cochinchinensis. Occasional upper storey species include the endemic Cryptocaria lawsonii (Lauraceae) and Michelia nilagirica (Magnoliaceae). A lower story is typically dominated by Euonymus crenulatus, Lasianthus capitulatus and Psychotria elongata, but the ground layer is usually species-poor. Among the many epiphytes are Aerides ringens, Eria nana, Oberonia brunoniana, Peperomia reflexa together with the fern Asplenium fulcatum and the lycopod Lycopodium hamiltonii. Lianas, on the other hand, are few in number, but notable species include Clematis theobromina, Gardneria ovata, Gymnema montanum and Piper schmidtii. Thickets in the Nilgiris Hills support a greater number of local endemics compared with the Palni Hills. The few associated with the latter include the ligneous Actinodaphne bourneae (Lauraceae), Elaeocarpus blascoi, E. gausseni (Elaeocarpaceae) and Pittosporum undulatum (Pittosporaceae).
Malabar Myristica Swamp Forest
These dense evergreen forests appear to be restricted to valleys in the tropical evergreen zones of Travancore where they typically form a fringe along slow moving streams on sandy alluvium. They can reach heights of up to 30 m with species such as Carallia brachiata Lagerstroemia speciosa, Laphopetalum wightianum, Myristica magnifica and the endemic Myristica malabarica (Myristicaceae) dominating the canopy and sub canopy. Most of the trees have clean, slender boles. Pandanus represents one of the main shrub layer groups, but it also includes the endemic shrub Nilgirianthus barbatus (Acanthaceae). Species of Calamus appear to dominate the climbers, while the undergrowth is mainly composed of aroids and scitaminae.
Malabar Grasslands
In Kerala grasslands are largely found at altitudes above 1500 m and often take the form shrub-savanna characterized by shrubby and herbaceous species mixed with grasses. Above 1800 m the minimum temperature can drop to below zero degrees centigrade during the colder months. Here in Anamalai region (Eravikulam and Munnar) the grass layer is usually less than 1 m and mainly represented by Andropogon foulkesii, Anthistiria ciliata, Arundinaria villosa, Bothriochloa pertusa, Chrysopogon orientalis, Eragrostis nigra, Heteropogon contortus, Tripogon bromoides, Zenkeria elegans and species of Arundinella, Cymbopogon, Eulalia, Isachne and Themeda. Common herbaceous species include Campanula fulgens, Crotalaria notonii, Indigofera pedicellata, Justicia simplex, Knoxia mollis, Leucas suffruticosa, Lilium neilgherrense, Oldenlandia articularis Polygala sibirica, Striga asiatica, Viola patrinii and Wahlenbergia gracilis, but in the more swampy areas species such as Centella asiatica, Drosera peltata and Fimbristylis uliginosa predominate. Typical shrubby elements are Berberis tinctoria, Gaultheria frangrantissima, Hypericum mysorense, Lobelia excelsa, Oldenlandia stylosa, Osbeckia wightianum, Pteridium aquiilnum, Rubus fairholmianus, Phlebophyllum kunthianus and the endemic Rhododendron arboreum var. nilagiricum may occur in the form of small tree. Grasslands below 1800 m that are mainly interspersed with evergreen forests often characterized by Briedelia crenulata, Careya arborea, Emblica officinalis, Terminalia chebula and Wendlandia thrysoidea. The grasses here are usually tall reaching heights of up to 1.5 m. Common taxa include Agrostis peninsularis, Androprogon lividus, Arundinella purpurea, Chrysopogon zeylanicus, Eulalia phaeothrix, Heteropogon contortus, Ischaemum indicum, Sehima nervosum, Tripogon bromoides and species of Eulalia and Themeda. Intermixed with the grasses are shrubs such as the monocarpic Phlebophyllum kunthianum and herbs of the genera Crotalaria, Desmodium, Hypericum, Knoxia, Leucas, Lobelia and Osbeckia.
Malabar Rivers
The river of the Malabar BioProvince provide habitat for two endemic water plants, Griffithella hookeriana and Willisia selaginoides, both belonging to the unusual aquatic family Podostemaceae.
Further information required.
References
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