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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. . Wiley-Blackwell and International Association of Vegetation Science are collaborating with JSTOR to digitize, preserve and extend access to Journal of Vegetation Science. Tel +46 18 182852; Fax +46 18 553419 Ahbstract. Development of planted seedlings of four canopy tree species in recently abandoned pastures (mown and unmown) and in ca. 40-yr old secondary dry forest in Guanacaste National Park, Costa Rica, was studied from July 1989 -June 1992. The species were the light-demanding Cedrela odorata and Swietenia macrophylla, and the shade-tolerant Hymenaea courbaril and Manilkara chicle. Seedling mortality was high and primarily correlated with dry season drought. After the first dry season, M. chicle and C. odorata showed < 5 % survival in the pasture and 20 % in the forest, but after 3 yr survival had decreased to 3% in all plots. Survival of S. macrophylla was highest in the mown pasture (45 % after 3 yr) and lowest in the forest (10 %). For H. courbaril, survival was 40 -55 % under all three conditions.Growth rates were low, with a height increment of < 15 cm/yr, possibly due to low precipitation in 1990 and 1991. All species grew taller in the pasture than in the forest.Differences in soil depth, texture and drainage appeared to contribute to variation in the results both within and between plots. Herbivory contributed to the lower survival of C. odorata and S. macrophylla in the forest.

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