Ecology of Vascular Epiphytes in West African Rain Forest

About this book

Doctor dissertation. The ecology of 153 species of vascular epiphytes (101 orchids, 39 pteridophytes and 13 others) in the Nimba Mts in Liberia is described. 29 species are recorded in Liberia for the first time including one new species, Rhipidoglossum paucifolium, Orchidaceae. Field characteristics, flowering periods and some pollinators of the orchids are also given. In high forest with the canopy 30 m or more above the ground, 50.4 % of the trees (phorophytes) 10 m or higher carried epiphytes, compared to 14.8 % for the phorophytes in regenerating forest. The ratio between fern and orchid species was 1:3 at 500-700 m alt. and 1:1 at 1 000-1 300 m. Most of the epiphytic species occupy a ± restricted part of the phorophyte, as judged by their occurrence in the five sectors in which the phorophytes were subdivided.

Ten different epiphyte communities are recognized. Their floral composi­tion and development are also described. Certain species of phorophytes, e.g. Heritiera utilis, Lophira alata and Parinari excelsa generally carry an abundance of epiphytes, while others, e.g. Anthocleista nobilis, Fagara tessmannii and Terminalia invorensis are mostly devoid of epiphytes. Colonization by epiphytes begins late in the life of the phorophyte, which is indicated by the higher frequency of epiphytes on the larger specimens. The effect of the epiphytes on their phorophytes is reviewed and obser­ vations from Nimba and East Africa provided. The environmental in­fluences on the occurrence of the epiphytes on the phorophytes are dis­cussed. In addition, field observations and experiments concerning water economy microclimate, substrate properties and light intensities are presented.

Customer Reviews