Seedling survival in Manilkara butugi Chiov. along a dispersal gradient in Kakamega forest, Kenya

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 relation 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 5 m 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 seedlings 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.