RIPARIAN VEGETATION ALONG THE MIDDLE AND LOWER ZONES OF THE CHALAKKUDY RIVER, Kerala, India (Survey, mapping, community studies and identification of the residual pockets for conservation.) By Amitha bachan K.H Limnological Association of Kerala, Iringalakkuda Project Report May 2003 Project 26/2000 Sponsored by Kerala Research Programme on Local Level Development, CDS, Thiruvananthapuram Contents List of tables and figures v Acknowledgement vii Glossary ix Chapter I: - Introduction .1. Introduction 1 1.2. Riparian Vegetation 3 Chapter II: - Study area, Objectives and Methodology 2.1. Study Area 2.1.1. Chalakudy River and the Basin 7 2.1.2. Physiography 7 2.1.3. Climate 10 2.1.4. Biodiversity Potential and Ecological Importance 10 2.1.5. Human relations and Interventions 11 2.1.6. Study Area 12 2.2. Main Objectives 14 2.3. Materials and Methods 14 2.3.1. Collection and identification of plant components 14 2.3.2. Phytosociological analysis 15 2.3.3. Mapping 15 2.3.4. People’s Perceptions 15 2.3.5. Review of literature 16 Chapter III: Preliminary survey and Analysis 3.1. Zonation 19 3.1.1. Zone 1 23 3.1.2 Zone 11 25 3.1.3 Zone 111 Chapter IV: Phytosociological and Floristic Analysis of the Riparian Vegetation 4.1 Status of existing riparian vegetation in the study area 28 4.2 Phytosociological analysis 31 4.2.1. Species composition and its significance 42 4.2.2. Dominant species in the Riparian zone 42 4.2.3. Distribution of the species along the river 47 4.3. Floristic analysis 49 4.4. Ecological analysis of the flora 49 4.4. Structure and development of the riparian vegetation 51 4.5.1. The structure of the riparian vegetation of the islets 54 Chapter V:- Assessment of Biodiversity Potential 5.1. Flora 57 5.2. Fauna 57 5.2.1. Animal corridor 58 5.2.2. Birds and butterflies 59 5.2.3. Fish diversity in the Chalakkudy River 60 Chapter VI :- Human perceptions and Anthropogenic influences 6.1. Kadar tribals of the Vazhachal area and the riparian habitat 62 6.1.1. History and culture 62 6.1.2. Habit and Habitat 63 6.1.3. Traditional Skills 63 6.1.4. Water requirements 64 6.1.5. Food 64 6.1.6. Fishing 65 6.1.7. Non-Wood Forest Products 66 6.1.8. Other income resources 69 6.1.9. Dynamics of change 70 6.2. Fishermen in the lowlands 72 6.2.1. Methods of fishing 72 6.2.2. Perceptions of the people 72 6.2.3. Relation with riparian vegetation 80 6.3. Major human interventions in the riparian zone 82 6.3.1. Reclamation of the riparian and adjacent landuse 82 6.3.2. Encroachment 85 6.3.3. Sand mining 87 6.3.4. Quarrying and clay mining 90 6.3.5. Felling of the trees and clearing of the riparian forest 90 6.3.6. Over use of resources 91 6.3.7. Poaching and illegal fishing 91 6.3.8. Fire 91 6.3.9. Grazing 92 6.3.10. Tourism. 92 Chapter VII: -Findings and Discussion 7.1. Structure, composition and configuration of riparian vegetation 94 7.2. Importance of riparian vegetation 96 7.2.1. Ecological significance 96 7.2.2. Social significance 99 7.3. Factors affecting riparian vegetation 100 7.2.1. Fragmentation 100 7.3.2. Dams and other constructions 100 7.3.3. Overuse of resources 101 7.3.4. Sandmining 101 7.3.5. Tourism 102 Chapter VIII Important areas, its status and recommendations based on identified problems 8.1. Zone-I (Poringalkuthu dam to Athirappilly waterfalls:) 103 8.1.1. Area from Poringalkuthu dam upto the powerhouse 103 8.1.2. Area just after Poringal powerhouse to the Vazhachal waterfalls 103 8.1.3. Area from Vazhachal to the Ittiany 104 8.1.4. Area from Ittiany to the Athirappilly waterfalls 105 8.2. Zone-II Athirappilly water falls to the Thumboormuzhi (100-50m) 105 8.3. Zone-III Area after Thumboormuzhi to Elanthikkara (50-sea level) 106 8.3.1. Area from Thumboormuzhi up to Chalakudy 106 8.3.2. Area after Chalakudy upto Elanthikkara of Puthenvelikkara Panchayath107 Chapter IX :- Recommendations and Conclusion 9.1. Recommendations and plans for conservation and regeneration of the riparian vegetation for the protection of the riverbanks. 108 (a). Important riparian plant species for replanting 108 9.1.1. Pioneer species 108 9.1.2. Other tree species that can be planted mainly in the forest area listed below. 110 9.1.3. Riparian species found only in the lower area 113 9.1.4. Mangrove and associated species 114 (b). Plan for the regeneration of riparian vegetation 114 9.2. Important areas and initiative steps for the rehabilitation and regeneration of riparian vegetation on along the Chalakudy River 116 (a). Zone –I and II forest areas 117 9.2.1. Necessary actions required 117 9.2.2. Role of Forest Department 117 9.2.3. Local bodies 118 9.2.4. Plantation Corporation of Kerala 118 9.2.5. Role of local people 118 9.2.6. Role of NGO’s 119 (b). Lower area (zone-III from Thumboormuzhi to Elanthikkara) 119 9.3. Conclusion 120 Bibliogrpahy 123 Appendix 1. - List of Plants 126 Appendix 2. - List of Animals 130 Appendix 3. - List of Birds 131 Appendix 4. - List of Fishes 136 Appendix 5. - Individual quadrat analysis 137 Appendix 7. - Map showing status of riparian vegetation 145 Appendix 8. - Map showing major human interventions in the riparian zone 146 List of tables and figures Tables Table 1 Study area 19 Table 2 List of riparian local bodies 19 Table 3 Zonation of the area 20 Table 4 Total areas having riparian vegetation 28 Table 4.1 Shows area of sampling 31 Table 5 Species richness, density and basal area of quadrats having high density 32 Table 6 Top 10 Quadrats in the case of basal area 33 Table 7 Top 10 Quadrats in the case species richness 33 Table 8 Comparison of areas under different altitudinal ranges 33 Table 9.1&9.2 Phytosociological analysis of zone-I 35 Table 10.1& 10.2 Phytosociological analysis of zone – II 37 Table 11.1&11.2 Phytosociological analysis of zone – III 38 Table 12 Comparison of three zones 40 Table 13 Population density of most abundant tree species in the three zones 46 Table 14 Status of houses (Vazhachal tribals) 62 Table 15 Non-Wood Forest Products (NWFP) 67 Table 16 Daily labour distribution of V.S.S. in Vazhachal 68 Table 17 Plantations under Vazhachal 82 Table 18 List of economically valuable fish and other aquatic species 77 Graphs Chart 1 Comparison of area having vegetation in the three zones 28 Chart 2 Comparison of riparian vegetation in the river margin and the islets 29 Chart 4.1 Stand density 34 Chart 4.2 Species richness 34 Chart 4.3 Basal area 34 Chart 5 Comparison of three zones 41 Chart 6 Important Value Index (IVI) of Zone-I 43 Chart 7 Important Value Index (IVI) of Zone-II 44 Chart 8 Important Value Index (IVI) of Zone-III 45 Chart 9 Diagram showing distribution of important plant species on riparian zone of the study area in an altitudinal gradient 48 Chart 10 Top ten families 49 Chart 11 Monocot dicot ratio 49 Chart 12 Different life forms 50 Chart 13 Raunkiaer’s Life forms 50 Chart 14 Species richness of various growth forms in two important quadrats 51 Chart 15 Ecological status 50 Diagram Diagram 1 Structure of river margin vegetation 52 Diagram 2 Islet type – I 55 Diagram 3 Islet type – II 55 Diagram 4 Evolution of sandmining methods 89 Maps Map –1 Map of Kerala showing Chalakudy River 8 Map - 2 Chalakudy river basin 9 Map – 3 Map showing study area 13 Map – 4 Map showing Local bodies 21 Map – 5 Map of study area showing different zones 23 Map – 6 Map showing the status of riparian vegetation (Appendix - 7) 145 Map – 7.1 & 7.2 Map showing quadrat locations 31 Map - 8 Map showing major human interventions in the riparian zone(Appendix - 8) 146 ACKNOWLEDGEMENTS I have received considerable help and support from many people during this study that it is not possible to name and thank all of them individually in a few words. However, I wish to remember all of them and express my deepest gratitude. This project is funded by the Kerala Research Programme for Local Level Development (KRPLLD), of the Centre for Development Studies (CDS), Thiruvananthapuram. I am very grateful to Dr.K.Narayanan Nair, Programme Coordinator, KRPLLD for his support, timely advice and suggestions. I am also thankful to Dr.P.R.Gopinathan Nair, Dr.G.Christopher and other members of the KRPLLD for their encouragement and support in many ways. I am thankful to Dr.C.K.Gopinathan Nair, President, Limnological Association of Kerala (LAK), Chalakudy, Dr.Sunny George, Adv.Vinod Jabbar, Prof.John Thomas, Christ College, Irinjalakkuda and other members of LAK for all their support. This study was in fact a part of a larger study on all aspects of the Chalakudy river basin undertaken by Dr.Sunny George through LAK. I wish to thank Dr.A.K.Pradeep, Department of Botany, University of Calicut, Dr.Sasidharan, Kerala Forest Research Institute, Peechi, Dr.C.N.Sunil, S.N.M.College, Maliankara and Smt.K.K.Vaheeda, Lecturer, Department of Botany, M.E.S Asmabi College, Vemballur for their valuable advice and help especially in the identification of plants.