Seedling survival in Manilkara butugi Chiov. along a dispersal gradient in Kakamega forest, Kenya Geoffery M. Wahungu 1 *, Lucy K. Mureu 1 , Yussuf A. Wato 2 , Sarah N. Mureithi 1 and Geoffery G. Karanja 1 1 Department of Wildlife Management, School of Natural Resources Management, Moi University, PO Box 1125, 30100, Eldoret, Kenya; 2 Kenya Wildlife Service, Tsavo East National Park, Voi, Kenya Abstract The spatial patterns of seedling distribution in Manilkara butugi were studied between December 2004 and April 2005 at Kakamega forest, Kenya. Our objectives were to determine the spatial variation in seedling density in rela- tion to distance from the parent tree and the survivorship patterns of M. butugi seedlings. We hypothesized that seedling density and mortality would be highest beneath the parent tree and would reduce with increasing distance from the parent tree. Line transects, radiating along the four compass directions from mature female M. butugi trees were established, and quadrats marked out at intervals of 5m in which seedlings were counted. To determine establishment and survivorship, belt transects 5 m · 40 m running along the northerly compass direction were laid and data collected on seedling variables. Seedling density reduced with increasing distance from the parent plant (F = 25.72, df = 3; P < 0.001). Whereas seedling height (F = 14.806, df = 1; P < 0.05) and the number of leaves (F = 12.45, df = 1; P < 0.05) increased with increasing distance from the parent tree, damage to seed- lings reduced with increasing distance (F = 27.59, P < 0.05). Our results were consistent with the Janzen– Cornell escape hypothesis and have implications for natural regeneration of M. butugi and to maintenance of species diversity. Key words: Kakamega forest, Manilkara butugi, seedling, survival Re ´sume ´ Entre de ´cembre 2004 et avril 2005, on a e ´tudie ´ le sche ´ma spatial de la distribution de jeunes plants de Manilkara butugi dans la fore ˆt de Kakamega, au Kenya. Notre objectif e ´tait de de ´terminer la variation spatiale de la distribution de la densite ´ des jeunes plants en fonction de la distance par rapport a ` l’arbre parent et le sche ´ma de la survie des jeunes plants de M. butugi. Nous avions e ´mis l’hypothe `se que la densite ´ et la mortalite ´ des jeunes plants seraient maximales sous l’arbre parent et qu’elles iraient en dimi- nuant quand la distance augmenterait par rapport a ` lui. Nous avons de ´fini des transects en ligne, rayonnant dans les quatre directions de la boussole a ` partir de M. butugi femelles adultes, et de ´limite ´ tous les cinq me `tres des quadrats ou ` les jeunes plants furent compte ´s. Pour de ´terminer l’e ´tablisse- ment et la survie, des transects en bandes de 5m x 40m ont e ´te ´ de ´finis le long de la direction nord et nous avons re ´colte ´ des donne ´es sur des variables concernant les jeunes plants. La densite ´ des jeunes plants diminuait avec l’e ´loignement par rapport a ` l’arbre parent (F = 25.72; ddl = 3; P < 0.001). Alors que la hauteur des jeunes plants (F = 14.806; ddl = 1; P < 0.05) et le nombre de feuilles (F = 12.45, ddl = 1; P < 0.05) augmentaient avec la distance les se ´pa- rant de l’arbre parent, les dommages cause ´s aux jeunes plants diminuaient (F = 27.59; P < 0.05). Nos re ´sultats concordent avec l’hypothe `se d’e ´vitement de Janzen-Connell et ils ont des implications pour la re ´ge ´ne ´ration naturelle de M. butugi et pour la pre ´servation de la diversite ´ des espe `ces. Introduction Tropical forests are known to have high species diversity with low densities of species, and the mechanism that maintains this high diversity in tropical forest has long fascinated biologists (Denslow, 1980). Since the 1930s, the effect of distance from parent trees on seed and seedlings mortality has been postulated as fundamental to maintaining the higher plant diversity of tropical forest compared to tem- *Correspondence: E-mail: gmwahungu@yahoo.com Ó 2009 The Authors. Journal compilation Ó 2009 Blackwell Publishing Ltd, Afr. J. Ecol., 48, 783–790 783