Forest Vegetation Studies on the Foothills of Mt. Pangasugan, Leyte/ the Philippines
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Ecology of Tropical Forest Systems Forest Vegetation Studies on the Foothills of Mt. Pangasugan, Leyte/ The Philippines Gerhard Langenberger Eschborn, 2000 TÖB publication number: F-II/10e Published by: Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH Postfach 5180 D-65726 Eschborn, Germany Responsible: Begleitprogramm Tropenökologie (TÖB) Tropical Ecology Support Program Dr. Claus Baetke email: [email protected] Author: Gerhard Langenberger, Friedhofstrasse 11, 66996 Erfweiler, Germany email: [email protected] Layout: Michaela Hammer ISBN: 3-933984- Nominal fee: 10,-DM Produced by: TZ Verlagsgesellschaft mbH, D-64380 Rossdorf © 2000 All rights reserved Preface Tropical ecosystems are the essential life-sustaining basis for the majority of the Earth's human population. Human intervention is destroying the environment and degrading natural resources at an alarming rate, increasingly jeopardising efforts to attain sustainable development and effectively alleviate poverty. The Tropical Ecology Support Program (TÖB) strives, in a development cooperation (DC) setting, to contribute to more effective processing, evaluation and implementation of the knowledge and experience gained on these issues. TÖB provides its services on a supraregional basis. The program is implemented by the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) on behalf of the German Federal Ministry for Economic Cooperation and Development (BMZ). TÖB supports, upon request, back-up studies on issues relating to tropical ecology. The program endeavours to further the development of concepts aimed at protecting and using tropical ecosystems sustainably. It also hopes that innovative tools can be derived from these concepts which can enhance the ecological sustainability of DC projects. By incorporating scientific findings into advisory and consultancy activities, the program helps DC projects implement international agreements such as Agenda 21 and the Convention on Biological Diversity, to which BMZ attaches great importance. It is pivotal to the design of the program that German and partner country scientists work jointly on applications-oriented issues. TÖB thus makes an important contribution to the practical training of counterparts and to the establishment of tropical ecology expertise in partner countries. Through its publication series, TÖB makes the findings and recommendations for action that derive from its back-up studies accessible, in an understandable form, to the organisations and institutions operating in the development cooperation arena, and to a broader public with an interest in environment and development issues. I. Hoven Dr. C. v. Tuyll Head of Division: Head of Division: Environmental Policy, Protection of Natural Rural Development Resources, Forestry; CSD, GDF German Federal Ministry for Economic Deutsche Gesellschaft für Cooperation and Development (BMZ) Technische Zusammenarbeit (GTZ) GmbH Contents Contents FIGURES & TABLES..............................................................................II ABSTRACT............................................................................................III 1 INTRODUCTION..............................................................................1 2 NATURAL SETTINGS......................................................................5 2.1Geography of the Philippines and the Island of Leyte ................5 2.2Geology and Soils....................................................................7 2.3Climate of the Study Area.........................................................8 3 RESULTS......................................................................................11 3.1Methodology..........................................................................11 3.2Plant Diversity........................................................................12 3.3Tree Species, Habitat, and Forest Types.................................16 3.4Additional Observations Concerning the Management of Native Tree Species................................................................20 4 CONCLUSIONS AND RECOMMENDATIONS..................................23 4.1Reforestation with Native Species............................................23 5 REFERENCES...............................................................................27 APPENDICES.......................................................................................31 Appendix 1: Glossary.....................................................................31 Appendix 2: Species Encountered in the Study Area........................33 Appendix 3: Trees and Shrubs on the Foothills of Mt. Pangasugan............................................................................45 Appendix 4: Tree Species Suggested for Inclusion in the Project´s Reforestation Scheme (Rainforestation).....................53 I Forest Vegetation Studies in Leyte, The Philippines Figures Fig 1: The Island of Leyte and the Location of the Study Site ....................6 Fig. 2: Climatic Diagram of ViSCA......................................................... 10 Fig. 3: Number of Genera of the Most Common Families ........................ 13 Fig. 4: Number of Species of the Most Common Families ...................... 14 Fig. 5: Plant Groups in the Study Plots ................................................... 15 Tables Table 1: TOR of TÖB Project "Forest Vegetation Studies on the Foothills of Mt. Pangasugan" (PN: 90.2136.1-03.107) ................4 Table 2: The Occurrence of Dry Periods with a Duration of three months or more since 1976.......................................................9 Table 3: Plant Groups in the Study Plots................................................. 15 II Abstract Abstract The vegetation on the foothills of Mt. Pangasugan, Leyte, The Philippines, has been studied along an environmental gradient from ridge to stream bank. On an overall area of 4900 m2 representing 49 plots, 687 vascular plant species belonging to 111 families and 286 genera could be identified (epiphytes were excluded). About 58 % of the species were trees. A list of all plants identified to species level is given in appendix2. The studied area offers a large source of native species for reforestation. Many species show clear preferences in habitat, which means that a careful selection of species for reforestations is required. To ensure sustainable and economically successful reforestations with native species a lot of research is still needed. This is especially true for species identification in the field, the ecology of species, like habitat, growth dynamics, plant-animal interactions, and finally on the management of mixed species reforestations. A country-wide system of systematic species trials is suggested. Key words: vegetation studies, native tree species, habitat requirements, reforestation, Philippines. III Introduction 1 Introduction During the last decades the Philippines has experienced extensive forest destruction. The island of Leyte, the location of this study, lost about 45 % or 77 000 ha of its forests between the years 1969 to 1984 (Forest Management Bureau, 1987), reducing forest cover to a mere 10 % (Asio 1996) (Fig. 1). In 1987, the Forest Management Bureau calculated that a per capita forest cover of 0.3 ha would be necessary to satisfy the population’s needs for wood products on a sustained base. In 1980, the forest cover on Leyte was 0.04 ha per person. Even without extrapolating the trend to the present day, the situation is obvious. Apart from the ecological consequences of forest destruction, serious economic problems have arisen for local communities because the main raw material for construction, tools, etc. has become a limited resource. Therefore, in 1990, the governments of The Philippines and the Federal Republic of Germany established the "Philippine-German Environmental Research and Development Program" (PN 88.2122.5-01.100) which later on became the "ViSCA- gtz Applied Tropical Ecology Program" (PN 95.2290.5-001.00). The project is based at the Visayas State College of Agriculture (ViSCA) in western Leyte. The overall goal of the project is: `to improve the ecological conditions in Leyte in order to uplift the socio-economic life of the rural poor ‘. 1 Forest Vegetation Studies in Leyte, The Philippines To achieve this goal the project developed a wide range of activities which can be grouped into three categories · education: covering environmental education and training, the development of a curriculum on ecology for ViSCA, and the provision of instructional material. The organisation of farmer communities can also be included in this point. · research: focusing on marine and terrestrial ecosystems · application: e.g. the establishment of a marine sanctuary, island development, eco livelihood activities, and reforestation with native species. The author’s study can be described as a combination of basic research and applied research with the intention of supporting the project’s reforestation activities of which the aim is to: · create stable and sustainable forests with · indigenous and locally adapted tree species, thus to help · preserve local biodiversity and · generate income for local communities and farmers. The problem with such an approach is that the ecology of local forests is still poorly understood. In contrast to the few highly recommended exotic tree species which have been the focus of intense studies in the past (e.g. Gmelina arborea or Swietenia macrophylla) very little is known about site 2