OOS 31-2 - Tree mortality and growth among topographical habitats in a diverse tropical rain forest in Cameroon

Wednesday, August 8, 2012: 1:50 PM
B110, Oregon Convention Center
David Kenfack, Center for Tropical Forest Science & Smithsonian Global Earth Observatory, Washington, DC, George B. Chuyong, Plant and Animal Sciences, University of Buea, Buea, Cameroon and Duncan Thomas, Oregon State University, Corvallis, OR
Background/Question/Methods

Topographic microhabitats determined by altitude, slope and convexity have been hypothesized to be at a local scale, one of the main drivers of tree species diversity and distribution in tropical forests. We examined the patterns of tree mortality and growth among five topographically defined habitats for all stems with dbh ≥ 1cm in a 50-ha plot in Korup National Park, Cameroon and provide answers to the following questions: 1) how do demographic rates in Korup vary among habitat categories? 2) How do habitat specialists perform in their preferred as opposed to their non-preferred habitats? We expect that with a high level of habitat specificity in Korup, demographic rates of tree species will vary in the different habitats, with the habitat specialists performing better in their preferred habitats as opposed to the generalists.

Results/Conclusions

Forest-wide mortality and growth rates were 1.2% yr-1 and 0.36 mm yr-1 respectively for all stems ≥1 cm dbh during a 10-year census interval. Mortality was significantly lower on low flat habitat compared to the remaining habitats that did not show any significant difference. Growth rates were more variable among habitats, higher on slope and high gully, and lowest in low flat habitat. Except for the species positively associated to the ridge top habitat, mortality and growth rates were higher for generalists compared to species positively associated to the remaining habitats. Within each habitat type, mortality and growth rates were not significantly different between specialists and non-specialists.