9717116 Coley Monodominant forests are unusual communities in the lowland tropics, but their origin and maintenance is not well understood. This study tests a number of mechanisms that may allow Gilbertiodendron dewevrei to form monodominant forests in eastern Zaire. The first hypothesis is that ectomycorrhizae (fungal-plant root symbioses) are important to the origin and maintenance of these extensive, monodominant forests. Secondly, to test the hypothesis that Gilbertiodendron competitively excludes other species by creating an inhospitable environment. This study will determine if mixed-forest species are unable to establish in the Gilbertiodendron forest because they do not encounter their appropriate, vesicular-arbuscular mycorrhizal fungi. Furthermore, a number of other mechanisms will be tested (e.g. deep leaf litter, shade and low nutrient availability) by which Gilbertiodendron could exclude mixed-forest species from the monodominant forest. This study will conclusively test a number of mechanisms for monodominance and provide preliminary tests of other potential mechanisms. This study is important because an understanding of monodominant forests is essential to our understanding of the processes controlling lowland tropical tree diversity. Finally, it appears likely that no single character will explain monodominance. The proposed multifaceted analysis should provide the first empirically supported framework for understanding the origin and maintenance of tropical monodominant forests.
