Peppara Wildlife Sanctuary

Transcription

1 8 STUDY AREA Kerala is the smallest state located in the western part of peninsular India and eastern side of Western Ghats facing the Arabian Sea. Geographically, Kerala is classified into three planes: coastal land, middle land and high land. High lands denote the hilly tracts, which comprise four districts, viz., Thiruvananthapuram (Agastyamala), Idukki, Wyanad and Palaghat. Thiruvananthapuram is built on hills by the sea shore and is located at 8 30 N E / 8.5 N 76.9 E / 8.5; 76.9 on the west coast, near the southern most tip of Kerala State. The city and the suburbs covers an area of about 250 square kilometers, sandwiched between the Western Ghats and the Arabian Sea. The average elevation is 16 ft from the sea level. The area can be divided into two geographical regions, the midlands and the lowlands. The midland region comprises low hills and valleys adjoining the Western Ghats. The lowland is a narrow stretch comprising sea shore, rivers and deltas, dotted with coconut palms. The major rivers that flow through the city are the Karamana river, and the Killi river originating from Neyyar Wildlife Santuary. There are highlands, which form the eastern suburbs of the city. There are three wildlife sanctuaries in the district, namely, Neyyar, Peppara and Shendurny. Well planned field collection tours were conducted to study are so as to cover all places and seasons. Earlier collections made from the study area and deposited in the Tropical Botanic Garden and Research Institute, Palode (TBGT) were studied in addition to the collections made by me. Peppara and Neyyar are the twin and adjacent Wildlife Sanctuaries, include the hot spot area of Agastyamala, located in the southern tip and western slope of southern Western Ghats in Thiruvananthapuram district of Kerala State. These sanctuaries lie between 70 o 4 and 77 o 17 east and 8 o 7 and 8 o 53 north, surrounded by Kalakkad and Mundandurai Wildlife Sanctuaries in the east, Palode and Paruthipalli forest range in the north. Both sanctuaries together have an area of 181 sq. km., with an altitudinal range from m, temperature from 16 to 35 o C,

2 9 annual rain fall about 2800 mm. Agastiar peak (1864 m), Pongalapara (1500 m) and Chemunji (1000 m) are the continuous hill ranges, located towards the eastern side of the study area and steeply descend towards western side. It is drained with Neyyar and Karamanayar perennial rivers by supporting rich riparian vegetation. Since Chemunji is the continuous hill range of Pongalapara, it has been included in the study (Plate I). Peppara Wildlife Sanctuary Location Peppara Wildlife Sanctuary was constituted during the year It spread over an area of 53 km 2 is nestled in the western slope of southern region of the Western Ghats, in Nedumangadu Taluk of Thiruvananthapuram District and the entire area lies within the catchment area of Karamana River, which originates from the slope of Chemmunjimottai, the highest peak of the sanctuary. The area lies between 8 34' 30" to 8 41' 25" N latitude and 77 6' 50" to 77 14' 5" E longitude. The terrain is undulating with elevation ranging from 100m to 1717m (Chemmunjimottai). The important peaks of the sanctuary are Koviltherimalai (1313m.), Athirumala (1594m,), Nachiyadikunnu (957m.), Arumukhamkunnu (1457m.) and adirumudimalai. Except some isolated hillocks, the area generally falls in the moderately to highly undulating terrain units and low rolling zones and the reservoir of 5.82 km 2, formed by the construction of a dam at Peppara. Steep slopes, cliffs and rocky outcrops characterize the eastern region of the wildlife sanctuary. The whole area of the sanctuary is rugged in nature. There are several waterfalls in the sanctuary, the important ones are Bona falls and Azhvanthol falls. (Plate II).

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5 10 Neyyar Wildlife Sanctuary Location Neyyar Wildlife Sanctuary was constituted as per notification No.G.O.(MS) 781/58/AD dated The boundaries were subsequently modified vide GO No.2305/F2/71/AD dated It is located on the western slopes of the southern Western Ghats along the southeast corner of Kerala in Neyyattinkara Taluk of Thiruvananthapuram district and the entire area lies within the catchment area of Neyyar River, which originates from the slopes of Agasthyarkoodam, the highest peak of the sanctuary. This forest area is lying more or less continuous with a vast stretch of reserved forests in Kerala and Tamil Nadu, and lies between 8 17' and 8 53'N latitude and 76 40' and 77 17'E longitude. The terrain is undulating with elevation ranging from 100 to 1868m (Agasthyarkoodam). The important peaks of the sanctuary are Athirumala (1594m.) and Varayattumudi. Except some isolated hillocks, the area generally falls under moderately to highly undulating terrain units. The other geomorphologic units include low rolling zone and the reservoir formed by the construction of a dam at Neyyar. Steep slopes, cliffs and rocky outcrops characterize the eastern region of the sanctuary. The eastern portion of the sanctuary is very steep and comprises of numerous waterfalls. The terrain on the western side is rather gentle. Most of the tribal settlements are located on the western portion. Neyyar Wildlife Sanctuary consists of the following reserved forests: Klamala Reserved Forests Kottoor Reserved Forests Kottoor Extension Reserved Forest Nettukaltherikunnu Reserved Forests (Plate III)

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7 11 Soil Type The soil is almost loamy and assumes sandy or clayey character depending upon the accumulation of wash on the surface. On the slopes of hills and on elevated grounds, there are large proportions of laterite gravel and unbroken pieces of other rocks under different stages of disintegration. The depth of soil varies from place to place. In the valleys and low lying areas, where the wash from the surrounding hills accumulate, the soil is fairly deep and often assumes a dark colour due to the presence of burnt or decomposing vegetable matter. In such places, the soil is of friable and porous character and the trees that come up flourish well. On the slopes of hills and on the elevated grounds subjected to heavy wash, the soil has characteristic yellow or reddishyellow colour. Such soils are generally stiff and heavy, being clayey and containing very little organic matter. On the top and higher slopes of hills where the wash is excessive, the ground is rocky and the soil is shallow and hard. Regarding soil texture, the coarse sand fraction varied from 38.16% to 65.88% and the fine sand fraction from 8.76% to 16.92%. The content of coarse sand fraction increases with depth of the profile while the content of the fine sand exhibit reverse trend. The content of silt and clay decreases uniformly with depth. Climate The difference in elevation between the western side and eastern region ( m.) makes appreciable variations in the climatic conditions of the sanctuaries. Both the sanctuaries consist of tropical and montane subtropical climatic regimes. The climate in the tropical area is moderately hot and humid. Temperature in the plains during the month of March is about 35 C while, it is 20 C, during the month of January. These sanctuaries enjoy both southwest and northeast monsoons. The southwest monsoon brings in greater part of the rainfall from June to August. A few

8 12 pre-monsoon showers in April and May precede the monsoon. The southwest monsoon is steady and gentle from September to November. The Vegetation Types in the Study Area The forests have considerable variations in floristic composition and structure due to variations in the climatic, altitudinal and geographical factors. Floristically, the area has 1117 flowering plant species distributed among 104 Dicotyledonous and 22 Monocotyledonous families. Of these, the area has a status of type locality for 46 plant species. Many plants like Nothopegia aureo-fulva, Psychotria globicephala, Syzygium bourdilloni, etc. are still persisting in the area of their type locality. Further, the area is a source for Wild Relatives of Cultivated Crop Plants and Medicinal Plants (Dhar, 2000; Mohanan & Sivadasan, 2002). The vegetation ranges from southern secondary moist mixed deciduous forest to southern subtropical hill forest. As per the classification of Champion and Seth (1968), twelve forest types are present in these sanctuaries. 1. Southern Hill Top Tropical Evergreen Forest This type of forest confined to altitudes ranging between 1000 and 1300m above mean sea level. Height of the trees are not more than 10 m and rounded crowns and crooked branches. The low stature of trees is mainly due to high wind velocity and less favourable soil conditions. This forest occurs at Peppara, Pandipathal, Athirumala, and Kottoor. 2. West Coast Tropical Evergreen Forest This forest is lofty and dense. Top canopy is with of tall trees, 45m or even more in height and canopy is almost unbroken. This forest is characterized by a luxurious growth of evergreen trees of different sizes and shapes arranged in serial tiers. It is seen between 600m to 1100m.Buttressed roots are characteristic in this type.

9 13 This forest occurs at Thodayar, Kuttiyar, Karamanayar, Vazhaparathiyar, Attayar and under the high peaks of Koviltheri malai, Arumukhamkunnu, Draivyamottai, Adiru malai, Nachiyadi kunnu and Kannan kunnu. This belt occurs as a continuous patch from the point of northeastern boundary of the sanctuary to Kannankunnu near Nachiyadikunnu. The West coast tropical evergreen forest occurs at higher slopes of the ridges along eastern border especially in the upper source of the Neyyar. 3. West Coast Semi-Evergreen Forest It is a closed high forest with heterogeneous mixture of evergreen and deciduous species, the former generally dominating. It is found adjoining the evergreen forest, mostly along the lower slopes. The lower slopes being more easily accessible, have been subjected to heavy interference in the past. Floristic composition of this type depends on the component species of the original evergreen forest and those of the deciduous serai communities with high ecological amplitude occurring around. The following plants are commonly observed in this type of forests: Millettia rubiginosa, Grewia teliaefolia, Goniothalamus rhynchantherus, Trema orientalis, Actinodaphne malabarica, Terminalia paniculata, Aporusa lindleyana, Allophylus serrulatus, Olea dioica etc. This type of forest is seen in the Karadimala, Attayar, Kunnathumala and Idamalathodu areas. 4. Pioneer Euphorbiaceous Scrub Before declaring the area as a sanctuary, the tribals usually move from one place to another and practiced shifting cultivation. Fast growing but short lived euphorbiaceous species like, Macaronga, Mallotus, and Tremo got quickly established in the abandoned areas. The following plants are commonly observed in this type of forests: Macaranga peltata, Mallotus tetracoccus, M. philippensis, Trema orientalis,

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11 14 Symplocos macrophylla ssp. zeylanicus, Terminalia paniculata, Aporusa lindleyana, Tabernaemontana divaricata, Olea dioica, Ficus hispida, Albizia odoratissima, Actinodaphne bourdillonii, Euodia lunu-ankenda and Alstonia scholaris. In Peppara Wildlife Sanctuary this type of forest is seen in the southern part of the tract where the tribal settlements are located. The pioneer euphorbiaceous scrub occurs below Nachiyarmottai and along the Muttuparathodu. 5. Moist Bamboo Brake Bamboo, Terminalias and other trees are found in this area. The Natural bamboo brakes also occur along the stream banks, reservoir banks and in sheltered depressions in the sanctuaries. 6. Southern Secondary Moist Mixed Deciduous Forest A closed high forest of about 30 to 36m tall trees with dominant species of deciduous forests. However, moisture a few evergreen species are also seen. Bamboos are commonly seen in the lowlands areas. Epiphytes are seen and large climbers are abundant. 7. Myristica Swamp Forest This is a characteristic edaphic formation found in the bottom of valleys which is subjected to inundation throughout the year. It is a unique forest type with Gymnacranthera farsuhariana and Myristica fatua var. magnifica. It is found in Attayar and Kombe regions. 8. Tropical Sub-Montane Hill Valley Swamp Forest This type occurs in narrow strips of water-logged area continuously wet for a fairly long time during rains and are found mostly in depressions. Soil is rich in humus and continuously wet or at least moist. This type is of restricted in Karikulathukavu, Kuttimuttumambaram, Panagattumothala, Anachira, Mlavitypara, etc.

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13 15 9. Riparian Fringing Forest Riparian forest is an edaphic formation of river banks dependent upon a constant supply of telluric moisture and is a conspicuous association, met with along river banks in certain localities where Vateria indica is the predominant species. 10. Grassland This type of montane wet grasslands are confined to hill-top of Pongalappara, Agastyar peak, Chemunji and Athirumala areas of this sanctuary. The vegetation is dominated by grasses along with several herbaceous and sub-shrubby species. The main species are Arundinella leptochloa, Chrysopogon asper, Cymbopogon flexuosus, Sacciolepis indica, Themeda triandra, Zenkeria elegans etc. Herbaceous plants are Aeginetia pendunculata (Keeripu), Andrographis neesiana, Arisaema tortuosum, Cajanus lineata, Eriocaulon setaceum, Habenaria barbata, H. travancorica, Pogostemon rotundatus, Peucedanum anamallayense, etc. Sub- Shrubby plants are Hypericum mysorense, Lobelia nicotianifolia, Osbeckia cupularis, O. zeylanica, O. glauca, O. aspera etc. Phoenix loureirii, a curious palm is commonly found in this area. 11. Swards Swards are the grasslands at higher altitudes in the hill tops at Chemunji, Pongalapara and Agastiar peak. The Savanna, flanked with sholas, near Attayar is distinctly beautiful. 12. Southern Sub-Tropical Hill Forests The subtropical vegetation exhibits a transitional zone between tropical and temperate vegetation constitute a mixture of those found in the tropical forests and montane temperate forests. These are the 'stunted rainforest'. The trees are smaller in height with less shapely boles and festooned with herbaceous and

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15 16 cryptogamic epiphytes. The low stature of trees are mainly due to elevation, the high velocity of wind and less favourable soil conditions. The subtropical region of this sanctuary is confined to the eastern region as a narrow belt where the interstate boundary coincides with the Peppara Wildlife Sanctuary. Major portion of the subtropical region occur at Chemmunjimottai. 13. Ochlandra Reed Brake The reed grows into impenetrable thickets of 3m to 5m height with scattered over wood of evergreen trees. They are restricted to moist areas. Unlike bamboos, the reed brakes occur in high altitude within evergreen forests. The stream banks and the areas under the shelter of evergreen and semi evergreen forests of Athirumala, Kottoor, Peppara, etc. support reed brakes. The reed does not grow gregariously and its height varies between 2m - 4m. Ochlandra rheedii (Ottal, Kolangi), Ochlandra travancorica (Eetta) and Ochlandra brandisii are found in the sanctuary.

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