Abstract
On the southeastern Ivory Coast, two coconut plantations were compared with regard to the frequency of the epiphytic fern Platycerium stemaria on coconut trees as influenced by plant collecting for commercial purposes. At each of the two sites, 250 coconut trees were investigated for the presence of P. stemaria and signs of collecting activity. General species richness of vascular epiphytes at the study sites was low, with only three other epiphytic ferns (Asplenium sp., Microgramma owariensis, Phymatodes scolopendria ) being present. At study site no. 1, which was located directly behind several flower stalls offering P. stemaria for sale, the number of coconuts bearing living P. stemaria was significantly lower than at site no. 2 with no flower stalls in the immediate surroundings. At site no. 1, the frequency of P. stemaria was lowest in the neighbourhood of the flower stalls and increased with distance. Within a distance of less than 50 m from the flower stalls, ca. 70 % of the coconuts showed signs of P. stemaria collecting activity. Compared with site no. 1, the number of palm trees with living P. stemaria at site no. 2 was considerably higher (ca. 20 %) and only three coconut trees showed signs of Platycerium collection. Over much of the Ivorian rain forest region where the forest has been cut or converted into agricultural land, plantation trees are important phorophytes (in particular cocoa trees). In many West African regions plantation trees form the last remaining sites for vascular epiphytes, which often occur with considerable abundance. In the Ivory Coast, the collecting of P. stemaria in coconut plantations causes locally a drastic decline in the population size. However, much more threatening to the long-term maintenance of epiphyte communities in plantations is their conversion into non-tree plantations (e.g., pineapples, bananas) or their replacement by urban structures and tourist facilities.
Key words
Conservation - disturbance - epiphytes - ferns - plant trade - West Africa
References
Zeitlicher Vegetations- und Klimawandel in Côte d'Ivoire. Veränderungen der Vegetationsbedeckung in Côte d'Ivoire. Lauer, W., ed. Erdwissenschaftliche Forschung Bd. 30 pp. 7-299
Ethnobotany and economic botany of epiphytes, lianas, and other host-dependent plants: an overview. Forest Canopies. Lowman, M. D. and Nadkarni, N. M., eds. San Diego; Academic Press pp. 547-586
The evolution of epiphytism. Vascular Plants as Epiphytes, Ecological Studies, Vol. 76. Lüttge, U., ed. Berlin Heidelberg New York; Springer pp. 15-41
Platycerium stemaria et Platycerium angolense.
.
Ann. Sci. Nat..
12
87-228
Gas exchange and water relations in epiphytic orchids. Vascular Plants as Epiphytes, Ecological Studies, Vol. 76. Lüttge, U., ed. Berlin Heidelberg New York; Springer pp. 139-166
Gas exchange and water relations in epiphytic tropical ferns. Vascular Plants as Epiphytes, Ecological Studies, Vol. 76. Lüttge, U., ed. Berlin Heidelberg New York; Springer pp. 87-108
Theobroma cacao in Nigeria in relation to the incidence of Black pod diseases (Phytophthora palmivora).
.
J. Ecol..
40
125-142
Anthropogene Veränderungen der Vegetationsbedeckung in Côte d'Ivoire seit der Kolonialisierung. Veränderungen der Vegetationsbedeckung in Côte d'Ivoire. Lauer, W., ed. Erdwissenschaftliche Forschung, Bd. 30 pp. 301-480
stefan.porembski@biologie.uni-rostock.de
Section Editor: G. Gottsberger
