Chapter 7 ANALYSIS of the FLORA
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Chapter 7 ANALYSIS OF THE FLORA . ANALYSIS OF THE FLORA Gorumara National Park (GNP) is a virgin broadleaf forest but the vegetation is very much disturbed. The Park belongs to the Bio-Geographical zone 7B (Lower Gangetic Plain) as recognized by Rodgers and Panwar (1988). Total area of this bottle shaped National Park is only 79.99 sq km. The National Park is located in the flood plains of Jaldhaka and Murti rivers and other medium and small rivers and rivulets which have created pockets of grassland. As it is not possible to control the movement of big wild animals like Rhinos, Gaurs and Elephants within the legally demarcated boundary of the National Park, it is seen that the ecological boundary extends up to the Sibchu, Khumani and Jaldhaka blocks of Jalpaiguri and Kalimpong Forest Divisions respectively. In the South too it extends into the Bichabhanga, Lataguri and Ramsai areas of Jalpaiguri Forest Division. The ecological boundary in the eastern fringe extends well beyond Gairkata, Central Diana upto Moraghat blocks of Jalpaiguri forest division whereas in the western part it assumes an area beyond Sursuti, Lataguri blocks of Jalpaiguri forest division up to the Apalchand and Kathambari forests of Baikunthapur forest division. The GNP has immense significance in view of it being situated in the middle of the elephant migratory route between the rivers Teesta and Torsa in North Bengal. Gorumara can become one part of the Managed Elephant ranges for containing and sustaining the wild elephant population of North Bengal. Especially, the Tondu, Selka, Gorumara, Panjhora and Indong blocks serve as a major habitat of elephant population and with more scientific management of these are as follows by development of fodder, cover and water resources, the Elephant depredation problem can be substantially reduced. The same is true for the ever increasing population of gaurs in the area. However, inspire of having a good habitat for large carnivores, with plenty of food, water and covered the area is not having much tigers which it once had, though still today it is quite rise in Leopard population. In view of the ever dwindling number of great Indian one horn rhinoceros, any area harbouring a natural population of this animal assumes immense significance, even if the population is small, yet with increasing population of one horn rhinoceroses in west Bengal, other than its much larger counterpart, Jaldapara National Park (JNP). Besides rhinos, GNP serves as an important corridor for sustaining the population of wild elephants in North Bengal, between Teesta and Torsa rivers. A large number of Indian Bison also utilize this national park along with other herbivore species. Though the presence of Royal Bengal Tiger is debatable but the national park can boast of a good population of leopards and few other small carnivores. The area also has a great significance in the forested landscape of the Jalpaiguri district along with its forest and riverine ecosystem. GNP has approximately 48 species of carnivores and herbivores, approximately 193 species of birds, 22 species of reptiles, 7 species of turtles, 27 species of fishes and other macro and micro fauna. The complete flora and the vegetation structure of GNP are not known. So, an attempt was initiated in 2006 to record the flora of this area that has enough potential for conservation. 7.1. Recorded Flora: After the comprehensive floristic survey, it is noted that the Gorumara National Park is housing enormously rich flora. A total of 670 species of spermatophytes has been recorded from the intensive survey since the year 2006. Of these, angiosperms are represented by 666 species 338 Goutam Saha under 431 genera belonging to 104 families (Table 7.1). In addition, 4 species of 4 genera from 4 families of gymnosperms have been recorded from the GNP during the present exploration. The reason for sustentation of enormous richness in floral diversity within the forest is basically due to the Natural Habitation areas and suitable climate of Terai and Duars foothills. The area receives annual precipitation of 200 – 400 cm, the major amount of which is received mainly during the monsoon months. However, little amount of rain is received almost in all other months. This type of distribution of precipitation helpful to maintains a very good broadleaf floristic wealth. The analysis of the flora revealed that there are numerous tropical, subtropical and even temperate elements those are common with the East Himalayan region. The beels, nalahas, other low-laying areas, scrubs, forests etc. provided enormous variety of habitats and that is reflected in the richness of its flora. The detailed analysis of the total spermatophytic flora of the forest distribution and variation in dicots have much dominance over the monocots. An analysis of the flora of GNP further revealed the existence of numerous important plant species which are directly or indirectly beneficial for the human sustenance. Many of the species have been recorded for having varied potential as food, medicines, etc. for humanity, besides an extraordinarily rich repository of various plant resources including the large number of valuable and durable timber-yielding trees. 7.2. Numerical Distribution of Taxa The present floristic work on GNP deals with the recorded 108 Spermatophytic families, out of which 78 are dicotyledonous and the remaining 26 are monocotyledonous; 484 species under 319 genera are recorded from 78 dicotyledons families and 182 species belonging to 112 genera in 26 monocot families. Only 4 species of gymnosperm belonging to 4 genera from 4 families were recorded (Table 7.1). Table 7.1. Numerical representation of different floristic elements in GNP Categories Families Genera Species Magnoliopsida 78 319 484 Liliopsida 26 112 182 Gymnosperms 4 4 4 Total 108 435 670 The Tables 7.2 to 7.5 provided accounts of family-wise numerical distribution of Taxa recorded from the GNP. Table 7.2. Alphabetically family-wise numerical representation of Angiospermic taxa: A. Dicotyledons for the flora of GNP Families No. of genera No. of species Acanthaceae 16 25 Amaranthaceae 9 16 Anacardiaceae 3 4 Annonaceae 5 7 Apiaceae 4 4 Apocynaceae 18 18 Araliaceae 3 3 Aristolochiaceae 1 2 Asteraceae 21 23 Balsaminaceae 1 2 Bignoniaceae 3 3 Bixaceae 1 1 Analysis of the Flora 339 Families No. of genera No. of species Boraginaceae 2 2 Brassicaceae 3 3 Cannabaceae 1 1 Capparaceae 3 4 Caricaceae 1 1 Caryophyllaceae 3 5 Celastraceae 1 1 Chloranthaceae 1 1 Clusiaceae 1 1 Combretaceae 2 7 Convolvulaceae 6 11 Cornaceae 1 1 Crassulaceae 1 1 Cucurbitaceae 7 12 Dilleniaceae 2 3 Dipterocarpaceae 1 1 Droseraceae 1 1 Ebenaceae 1 1 Elaeocarpaceae 1 1 Elatinaceae 1 1 Euphorbiaceae 10 13 Fabaceae 37 62 Hypericaceae 1 1 Icacinaceae 1 1 Lamiaceae 15 20 Lauraceae 4 15 Lecythidaceae 2 2 Lythraceae 5 10 Magnoliaceae 1 3 Malvaceae 19 26 Melastomataceae 2 2 Meliaceae 7 8 Menispermaceae 4 5 Molluginaceae 1 2 Moraceae 4 13 Moringaceae 1 1 Myrtaceae 3 6 Nyctaginaceae 4 5 Nymphaeaceae 1 4 Onagraceae 1 4 Oxalidaceae 2 4 Papaveraceae 2 2 Passifloraceae 1 1 Phyllanthaceae 4 9 Piperaceae 2 6 Plumbaginaceae 1 1 Polygalaceae 2 2 340 Goutam Saha Families No. of genera No. of species Polygonaceae 3 10 Portulacaceae 1 2 Primulaceae 2 2 Ranunculaceae 2 2 Rhamnaceae 3 5 Rosaceae 1 1 Rubiaceae 9 13 Rutaceae 6 8 Salicaceae 1 1 Sapindaceae 2 2 Sapotaceae 1 1 Solanaceae 5 12 Tamaricaceae 1 1 Theaceae 1 1 Ulmaceae 1 1 Urticaceae 7 9 Verbenaceae 5 5 Violaceae 1 1 Vitaceae 5 12 Total (76 Families) 308 461 Table 7.3. Family-wise numerical representation of Angiospermic taxa: B. Monocotyledons for the flora of GNP Families No. of genera No. of species Poaceae 29 45 Cyperaceae 10 29 Araceae 14 20 Orchidaceae 15 17 Commelinaceae 6 13 Zingiberaceae 5 10 Hydrocharitaceae 6 7 Alismataceae 3 6 Arecaceae 5 5 Dioscoreaceae 1 5 Pontederiaceae 2 3 Potamogetonaceae 1 3 Amaryllidaceae 1 2 Eriocaulaceae 1 2 Hypoxidaceae 2 2 Musaceae 1 2 Smilacaceae 1 2 Acoraceae 1 1 Burmanniaceae 1 1 Cannaceae 1 1 Ceratophyllaceae 1 1 Costaceae 1 1 Analysis of the Flora 341 Families No. of genera No. of species Juncaceae 1 1 Marantaceae 1 1 Typhaceae 1 1 Xyridaceae 1 1 Total (26 Families) 112 182 Table 7.4. Family-wise numerical representation of Pinophyta for the flora of GNP Family Genera Species Araucariaceae 1 1 Cupressaceae 1 1 Cycadaceae 1 1 Gnetaceae 1 1 Total 4 4 7.3. High Representation So far, the most comprehensive floristic work for the Indian subcontinent was published by Sir J.D. Hooker (1872 – 1897) in his The Flora of British India. Recently The Flora of Eastern Himalaya, Parts I - III by Hara (1966, 1971) and Ohashi (1975), and Flora of Bhutan, vols. 1 – 3, by Grierson & Long (1983, 1984, 1987, 1991, 1999, 2000), Noltie (1994, 2000) and Pears and Cribb (2002) also presented detailed floristic works on this region. The first flora, i.e. The Flora of British India covers the plants collected from Indian subcontinent, Eastern Himalaya to Pakistan, Bangladesh, Myanmar, Malaysia, etc. The Flora of Eastern Himalaya has engrossed the plant collection from the hilly parts of North Bengal, Sikkim, Eastern Nepal and Bhutan regions in the Eastern Himalaya covering an altitudinal range of 300 m to 4400 m. Flora of Bhutan covered the Terai and Duars of North Bengal. In case of Dicotyledonous flora, In Flora of Eastern Himalaya (FEH), the Fabaceae is represented with highest number of species, which is followed by Asteraceae, Lamiaceae, Rubiaceae, etc. The Flora of Bhutan (FB) recorded Asteraceae as the most represented and is followed by Fabaceae, Rubiaceae, Lamiaceae, etc.