Tropical Biology Section
Valverde, Oscar J , Rocha, Oscar J. .
Effects of traditional logging on seedlings survival and levels of genetic diversity in the tropical lowland swamp forests in the Atlantic coast of Talamanca, Costa Rica: the case of the dominant species, Prioria copaifera.
We studied the impact of traditional logging on seedling survival and levels of genetic diversity of cativo (Prioria copaifera) in the Atlantic tropical lowland swamp forest in Costa Rica. The exploitation effects were examined in two forests that were logged two and twelve years before, and were compared with an undisturbed forest (UDF). We found that seedlings of cativo represent between 58-76% of the seedlings found in the study sites. We also found that seedling survivorship and growth was higher in places with low seedling densities and high light intensity, being the most recently disturbed site the most favorable environment. In addition, plant growth, as measured by height increments between two measurements, was also higher in plants growing in logged forest than in undisturbed forests. However, the number of seedlings in of P. copaifera present in each site was higher in undisturbed forests than the other two sites. Analysis of hemispherical photographs revealed significant differences in the light environment between the three sites. We also conducted an experiment in which seedlings of P. copaifera were planted in the center of a light gap, the edge of the gap and in the understory. Our results also support the notion that seedlings survive and grow better in more open habitats. Finally, we also examined the impact of logging on the levels of genetic diversity using AFLP markers. Our data indicates that logging does not reduce genetic diversity. On the contrary, logged sites show higher diversity than undisturbed sites. Our findings revealed a positive response in growth and survivorship for seedlings in open areas. However, our data also suggests that Carapa guianensis that exhibited a marginal regeneration, and is threatened to disappear from this ecosystem. Consequences of these results for the appropriate management and the conservation of this ecosystem are discussed.
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1 - Iowa State University, Department of Ecology, Evolution & Organismal Biology, 253 Bessey Hall, Ames, Iowa, 50011-1020, USA
2 - Kent State University, Department of Biological Sciences, Po Box 5190, Kent, Ohio, 44242-0001, USA
Presentation Type: Oral Paper
Date: Monday, August 15th, 2005
Time: 10:45 AM