MULTIPLE-SCALE SPATIAL-DISTRIBUTION OF THE FUNGAL EPIPHYLL SCOLECOPELTIDIUM ON TRICHILIA SPP. IN 2 LOWLAND MOIST TROPICAL FORESTS

The leaf-inhabiting fungus Scolecopeltidium mayteni (Micropeltaceae) i s common on Trichilia tuberculata in lowland tropical forests on Barro Colorado Island, Panama, and on Trichilia moritzii in Corcovado Natio nal Park, Costa Pica. The sexual reproductive structures (ascomata) of the fungus have a clumped or random distribution on leaflet surfaces. The density of ascomata correlates well with the density of hyphae on the leaf surface and is a good indicator of the intensity of fungal c olonization. Most of the variability in colonization is at a leaf-to-l eaf level rather than among leaflets or among plants. Intensity of fun gal colonization is directly related to the light environment of the l eaflet or plant, but not to the density of hosts. The Scolecopeltidium -Trichilia system is well suited for studies on ecological factors aff ecting host-fungal symbioses in natural plant communities.