V. Clausnitzer
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Project ID: 01 LC 0025 (BIOTA AFRICA E07) 01.05.2001-30.04.2004 DIVERSITY AND SPECIES COMPOSITION OF ODONATA AS INDICATORS OF BIOTOPE QUALITY OF EAST AFRICAN RAIN FORESTS AND THEIR REPLACEMENT COMMUNITIES V. Clausnitzer Geographisches Institut, Universität Marburg, Deutschhausstr. 10, 35037 Marburg, Germany [email protected], www.uni-marburg.de, www.biota-africa.org Key words: dragonflies, Odonata, biodiversity, Kenya, Tanzania, Uganda, wetlands, coastal forests Abstract: The principal aim of this project is a comparative study of ecology, diversity and biogeography of dragonflies (Insecta: Odonata) in primary, secondary and fragmented rain forests and different wetland habitats in East Africa. To achieve this an identification key for the dragonflies of eastern Africa is prepared and distribution data as well as data on species specific habitat requirements are collected. These will be used for further applied studies, e.g. the development of indicator systems for environmental disturbances. Results: Utilising both, aquatic and terrestrial habitats, the large, predominantly diurnal dragonflies, who can be readily observed and in most cases easily identified in the field, can contribute much to the evaluation of environmental quality. They are known to be very sensitive to structural habitat quality and thus can be a valuable tool to evaluate landscape degradation and have been used as indicator species. The amphibious larvae of dragonflies are critical in regard to water quality and aquatic morphology of streams. The adults are sensitive to habitat structure and are excellent indicators of river disturbance, e.g. changes in habitat structure. Within this project a throughout inventory of East African dragonflies in various habitats and the collection of species specific ecological data is aimed at. Current activities Data collection has been started in different areas in Kenya, Uganda and Tanzania. In most areas visited, new records for the could be made and a lot of data on various ecological aspects could be collected. The PhD student John Joseph Kisakye, (Makerere University, Kampala, funded through the BIOTA programme) works on dragonflies in different forests. In cooperation with a GEF project in southern Tanzania it is planned to have Master's projects on the impact of habitat degradation on dragonflies from 2002. Coastal forests in Kenya During the last year coastal forests of Kenya were surveyed to a large extend. Coastal forests are listed as important areas in terms of conservation for East Africa [1] and are a major centre of endemism in Africa [2, 3]. Coastal forest areas of Kenya and Tanzania are the primary habitat for a number of highly localised dragonfly species (endemics and/or of unique taxonomy). Detailed studies were carried out on the ecology of the two dendrolimnetic species Coryphagrion grandis and Hadrothemis scabrifrons. Dragonfly communities relative to different habitat types from indigenous forests to cultivated landscapes were described. Most of the forest species are confined to coastal forests of East Africa, being stenotopic and highly sensitive to disturbance. With increasing habitat disturbance eurytopic species which are common and widely distributed in Africa colonise the habitats. The species assemblages between different habitat types (stream, swamp, pool) in the disturbed landscape are identical, the β-diversity being very low, although the diversity of single localities may increase after habitat disturbances. Publicity work Species check-lists for several National Parks and other protected areas of Kenya have been prepared and were presented to the corresponding authorities. Information boards on the local dragonflies were prepared for some visitor centres (Saiwa Swamp NP, Mt. Elgon NP, Arabuke Sokoke Forest, Nairobi NP). For 2002 a small dragonfly workshop is planned in the Institute of Environmental and Natural Resources, Makerere University, Kampala. Cooperations Dragonflies are included in a Wildlife Conservation Society (WCS) project in Tanzania "Southern Highlands Conservation Programme" and in a DANIDA funded project on IBA’s in Uganda. Within all projects national reference collections are build up and local scientists trained. First negotiations have started with Ethiopia to include dragonflies in a planned inventory of insects. Together with BIOTA S08 species assemblages in arid habitats, colonisation strategies in seasonal habitats and population genetics of species with a panafrican distribution and different dispersal types are comparatively studied. Odonatologists working in Africa are linked through the recently started PHAON (Pinhey's Heritage African Odonata Network), which proves to be an excellent tool to exchange views and data, discuss results and present projects. In cooperation with other scientists an atlas for African Odonata and a mapping programme are long term aims. Publications The identification key of East African dragonflies will be published in 2002 or 2003. A regional report on dragonflies of Eastern Africa for the IUCN Odonata Specialist Group has been recently prepared. At least one new species waits for description, while a number of other projects need more field work. Following recent manuscripts could be finished: Clausnitzer, V. 2001a. Notes on the species diversity of East African Odonata, with a checklist of species. Odonatologica 30:49-66 Clausnitzer, V. 2001b. Notes on Trithemis bifida and T. donaldsoni (Odonata: Libellulidae). The International Journal of Odonatologogy 4:179-189 Clausnitzer, V. in press. Reproductive behaviour and ecology in the dendrolimnetic Hadrothemis scabrifrons. The International Journal of Odonatologogy. Clausnitzer, V., Lindeboom, M. submitted. Natural history and description of the dendrolimnetic larvae of Coryphagrion grandis. Clausnitzer, V. submitted. Dragonfly communities in coastal habitats of Kenya: indication of biotope quality and the need of conservation measures. References 1. Stuart, S. N., Adams, R.J., Jenkins, M. S. 1990. Biodiversity in sub-saharan Africa and its islands - conservation, management and sustainable use. IUCN, Gland & Camebridge 2. Fjeldsa, J., and Lovett, J.C. 1997. Geographical patterns of old and young species in African forest biota: the significance of specific montane areas as evolutionary centres. Biodiversity and Conservation 6:325-346 3. Kingdon, J. 1989. Island Africa. Princetown University Press, Princetown .