Seedling establishment of Acacia tortilis and Hyphaene compressa in the Turkwel riverine forest, Kenya |
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Authors: | Jø rn Stave ,Gufu Oba,Inger Nordal, Nils Chr. Stenseth |
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Affiliation: | Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, PO Box 1050 Blindern, N-0316 Oslo;, Noragric, Department of International Environment and Development Studies, Norwegian University of Life Sciences, PO Box 5003, N-1432 Ås;and Department of Biology, University of Oslo, PO Box 1066 Blindern, N-0316 Oslo, Norway |
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Abstract: | This study reports on the spatial and temporal patterns of seedling establishment in the Turkwel riverine forest, Kenya. Seedlings of the dominant tree species Acacia tortilis and Hyphaene compressa were mapped and monitored to assess the underlying causes of seedling recruitment and mortality. The broad‐scale distribution of A. tortilis was not correlated with any environmental variables, while H. compressa seedlings were confined to flood‐exposed sites in the arid downstream section of the floodplain. One year of monitoring showed that seedling recruitment of A. tortilis was evoked by prolonged rainfall, while seedling mortality was caused by desiccation, browsing and trampling. In contrast, seedling recruitment and mortality of H. compressa was largely unaffected by rainfall and livestock, probably due to the high moisture requirements of seeds and the tolerance of seedlings to disturbance. There were no effects of soils, light, or seedling density on the establishment of A. tortilis and H. compressa seedlings. This study demonstrates the importance of parallel mapping and monitoring of riverine seedlings in order to understand patterns and processes of forest regeneration in arid and semi‐arid floodplains. |
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Keywords: | floodplain forest regeneration herbivory rainfall seedling dynamics Turkana |
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