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1 Published on: 1 st Aug 2010 STATUS OF MATURE TREES, SEEDLINGS AND SAPLINGS IN TROPICAL THORN FOREST (TTF) OF NORTH GUJARAT REGION (NGR), GUJARAT, INDIA S. Rajendrakumar 1 and S. Kalavathy 2 1. Research Scholar, P & G. Research Department of Environmental Sciences, Bishop Heber College, Trichirappalli, Tamil Nadu Associate Professor, Department of Botany, Bishop Heber College, Trichirappalli, Tamil Nadu meen_rajendrakumar@yahoo.co.in; kalavathy55@yahoo.co.in ABSTRACT: Here we enumerated the status and ongoing disturbance of Tropical Thorn Forest in North Gujarat Region. A total of 58 tree species were recorded, the reason behind for forest degradation is mainly extraction of resources for fuel wood, fodder for animals and home furnishing by local community. Due to that, the low or less regeneration potential of dominant thorny were observed. KEY WORDS: Regeneration, Disturbance, Thorn Forest INTRODUCTION: The North Gujarat Region is said to be a home of diverse vegetation types, within protected areas and reserve forests. It extended into to N and to E with a total forest cover of 1638 km 2 (8.7%) (Joshua et al., 2007). As literature survey suggested, over 1200 plant species were recorded from NGR. But, recently the forest region faces continuous human intervention especially extraction of resources, which disturbs the natural mechanism of reproduction of tree species (SRISTI, 2000; Joshua et al., 2005). Tropical Thorn forest is the third largest forest type, spread over an area of 213 (13%) km 2 (Joshua et al., 2007). This forest is dominated by Acacia raddiana, A.sengal, A.leucopholeia, A.catchu, Zizphus mauritina, Z.nummlaria, Maytenous emarginata & Prosopis cineraria. Page 188

2 Sandy soil is the main substratum of this forest, which significantly influences the establishment, distribution and dominance of tree species, and the uniqueness of the forest. Further, the on going human interventions also influence the reproduction of the tree species. So, studies on trees species in TTF would help to maintain and preserve the uniqueness of the forest type. MATERIALS AND METHODS: The entire study was carried out from May 2007 to Dec During this period nested plots were used to enumerate trees and its components. A total of 171 plots were sampled in the entire study area. The plot varied from 10m radius for trees and 8m radius for the regenernts (seedlings) & recruits (saplings). The name of the species under each category and the number were determined. The criteria for each category were: Tree - > 20cm Girth at Breast Height (GBH) at 1.3m height Seedlings - young-one of tree species with < 50 cm height Saplings - < 20 cm GBH at 1.3m height and > 50 cm height The Shannon Wiener Index (Shannon and Wiener, 1949) was used to calculate the diversity of mature trees, seedlings and saplings. H = P i log e P i Where Pi = ni / Ni (ni is the number of individuals of the species i, and N is the total number of individuals. Density was estimated as follows, π - 22/7 or 3.14; r - plot size Area (ha) = πr 2 X Total number of plots/10000 Density = number of individuals of the species i / Area (ha) RESULTS AND DISCUSSIONS: A total of 44 mature trees species (23 families and 33 genera) were recorded, with a density of 498 trees/ha (3204 individuals) and a diversity index of The dominant tree species were Acacia raddiana (279/ha), A.senegal (42/ha), Anogeissus pendula (38/ha), Zizyphus mauritiana (25/ha) and Holarrhena pubscens (17/ha) seedlings belonging to 41 species (24 families and 32 genera) with a density of 453/ha and a diversity index of 3.42 were recorded. The dominant species were Acacia raddiana (121/ha), Anogeissus pendula (58/ha), Holarrhena pubscens (47/ha), Zizyphus mauritiana (38/ha) and Butea monosperma (29/ha). Page 189

3 Similarly, the saplings (1410 individuals) of 32 species (21 families and 26 genera) with a density of 354/ha and a diversity index of 2.43 were observed. The dominant species were Acacia raddiana (110/ha), Anogeissus pendula (48/ha), Aegle marmelos (32/ha), Butea monosperma (26/ha) and Acacia senegal (25/ha). Comparatively, the number of mature trees were higher than the seedlings / saplings (Table 1), probably because of the trees in TTF could not produce enough new individuals. Even the represented dominant trees were facing severe cutting and lopping pressure for fuel wood and fodder for animals (Joshua et al., 2007). The cut or lopped trees could not maintain a maximum structure. The rate or magnitude of the interaction between the physical components, potential for producing new individuals, maturation of flowers and fruits are all impaired when compared to uncut trees (Rykicl. 1985). Chapman & Chapman (1997) supported this by view reporting, lower seedling and sapling density in the heavily logged tropical forest at Kibale National Park, Uganda. Deficiency of regeneration and recruitment was also observed in heavily as well as lightly logged-over sites in Mt Elgon lower montane forest in Western Kenya (Hitimana et. al., 2004). Table 1: Status of Mature Trees, Seedlings and Saplings in Tropical Thorn Forest of North Gujarat Region TTF Mature Trees Seedlings Saplings Family Genus Species Total no of individual Density/ha Shannon Weaver index (H) The occurrences of maximum diversity among seedlings than the other foms may be due to the immigration of species from other forest types. The dominant species of all the three categories (Annexure 1) supports this view. On an overall view, the landscape structure of TTF is influenced by human interventions, such as resources extraction. The present disturbance regime changes the species composition, through total loss or lessening of regeneration potential of the dominant thorny species (Annexure 1). In order to conserve the originality of TTF, the area needs proper fortification, creation of series protected area or regeneration plots for at least certain period without any human intervention. This could be improving the restoration potential of the thorn forest. Page 190

4 ACKNOWLEDGEMENT: The authors wish to acknowledge the constant encouragement, supports and facilities provided by Gujarat Institute of Desert Ecology (GUIDE), Bhuj, Kachchh and Foundation for Ecological Security (FES), Anand, Gujarat for successful completion of this work. REFERENCES: Chapman, C. & L.J. Chapman, Forest regeneration in logged and unlogged forests of Kibale National Park, Uganda. Biotropica. 29: pp. Hitimana J., J.L. Kiyiapi and J.T. Njunge, Forest structure characteristics in disturbed and undisturbed sites of Mt. Elgon Moist Lower Montane Forest, Western Kenya. Forest Ecology and Management. 194: pp. Joshua, J., S.F.W. Sunderraj, P.N. Joshi, S.K. Das, J.M. Menon, S. Rajendrakumar., H.K.P. Kala, T. Mewada, Assessment of Biodiversity and Preparation of Conservation Plan for the Forest of North Gujarat Region. A First Progress Report Prepared by a Gujarat Institute of Desert Ecology, Bhuj, Kachchh, Gujarat. 45pp. Joshua, J., S.F.W. Sunderraj, S. Rajendrakumar, H. Kala, P. Manojkumar, L. Muthuandavan, Assessment of Biodiversity and Preparation of Conservation Plan for the Forest of North Gujarat Region. A Final Report Prepared by Gujarat Institute of Desert Ecology, Bhuj, Kachchh, Gujarat. 206pp. Rykicl. E. J Towards a definition of ecological disturbance. Australian Journal Ecology. 10: pp. Shannon, C.E and W. Wiener, The mathematical theory of communication. University of Illinois Press, Urbana 125p. SRISTI, Conservation and Sustainable management of dryland floral biodiversity of Balaram-Ambaji wildlife Sanctuary and Jessore sloth Bear Sanctuary. Report by Society for Research and Initiatives for Sustainable Technologies and Institutions, Ahmedabad, Gujarat, India. Page 191

5 Annexure 1: List of Tree Species were recorded from Tropical Thorn Forest of North Gujarat Region Sr. No Scientific Name Mature Tree_1 Recruitment_1 Regeneration_1 Mature Tree_2 Recruitment_2 1 Acacia catechu (L. f.) Willd Acacia chundra (Roxb. ex Rottler.) Willd Acacia farnesiana (L.) W illd Acacia leucophloea (Roxb.) Willd. Acacia nilotica (L.) Del. subsp. Indica (Bth.) Brenan Acacia raddiana Savi Acacia senegal (L.) Willd Adina cordifolia (Willd. ex Roxb.) Hook. f. ex Brandis Aegle marmelos (L.) Corr Ailanthus excelsa Roxb Alangium salvifolium (L. f.) Wangerin Albizia odoratissima (L. f.) Benth. Anogeissus latifolia (Roxb. ex DC.) Wall. ex Guill. & Perr Anogeissus pendula Edgew Anogeissus sericea Brandis var. nummularia King ex Duthie Anogeissus sericea Brandis var. sericea Azadirachata indica A. Juss Balanites aegyptiaca (L.) Del Bauhinia racemosa Lam Boswellia serrata Roxb. ex Cocls. Butea monosperma (Lam.) Taub Cassia fistula L Clerodendrum multiflorum (Burm. f.) O. Ktez. Commiphora wightii (Arm.) Bhandari Cordia gharaf (Forsk.) Ehrenb. ex Asch Cordia perrottetii Wt Crateva nurvala Buch.-Ham. Var. nurvala Derris indica (Lam.) Bennet Diospyros chloroxylon Roxb Diospyros melanoxylon Roxb Regeneration_2 Page 192

6 31 Ehretia laevis Roxb Emblica officinalis Gaertn Feronia limonia (L.) Swingle Ficus racemosa L Flacourtia indica (Burm. f.) Merrill Flacourtia montana Grah Garuga pinnata Roxb. Hort. Beng. Holarrhena pubscens (Buch.-Ham.) Wall. ex G. Don Holoptelea integrifolia (Roxb.) Planch. Lannea coromandelica (Houtt.) Merrill Maytenus emarginatus (Willd.) Ding Hou Miliusa tomentosa (Roxb.) J. Sinclair Mitragyna parvifolia (Roxb.) Korth. Moringa concanensis Nimmo ex Dalz. & Gibs Moringa oleifera Lam Phoenix sylvestris (L.) Roxb Prosopis cineraria (L.) Druce Sapindus emarginatus Vahl Sapindus laurifolius Vahl Tamarindus indica L Tecomella undulata (Sm.) Seem. Terminalia bellirica (Gaertn.) Roxb Terminalia crenulata Roth Vitex negundo L Wrightia arborea (Denst.) Mabb. Wrightia tinctoria (Roxb.) R. Br Zizyphus mauritiana Lam Zizyphus xylopyra (Retz.) Willd Total Abundance (Number of Individuals); 2 Density/ha Page 193