Premium
Population and genetic structure of the West African rain forest liana Ancistrocladus korupensis (Ancistrocladaceae)
Author(s) -
Foster Paul F.,
Sork Victoria L.
Publication year - 1997
Publication title -
american journal of botany
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.218
H-Index - 151
eISSN - 1537-2197
pISSN - 0002-9122
DOI - 10.2307/2446151
Subject(s) - biology , liana , population , genetic diversity , biological dispersal , ecology , genetic structure , genetic variation , seed dispersal , in situ conservation , range (aeronautics) , demography , genetics , materials science , sociology , gene , composite material
Ancistrocladus korupensis D. W. Thomas & Gereau (Ancistrocladaceae) is a recently described liana from Cameroon. Its leaves yield the alkaloid michellamine B, which shows in vitro activity against HIV. The only known population is limited to ~ 15 000 ha within Korup National Park and its immediate surroundings. This study: (1) describes ecological patterns (geographic range, population density, stage and size class distributions, host tree characteristics, and seed dispersal patterns) of A. korupensis; (2) quantifies patterns of genetic variation on species and subpopulation levels and fine‐scale genetic structure; (3) describes variation in michellamine B content; and (4) makes conservation recommendations based on ecological and genetic data. Ecological data from 457 individuals from seven sites indicate that the A. korupensis population is dominated by canopy‐climbing individuals. Population densities are low with values ranging from 2.5 to 12.9 individuals/ha. Reproduction data suggest limited seed dispersal, episodic fruiting, and no vegetative reproduction. Allozyme data indicate low genetic diversity with only 7.1% of the 14 loci polymorphic. Values for H obs and H e were 0.022 (± 0.000 SE) and 0.041 (± 0.000 SE), respectively. Wright's F statistics analysis suggests that A. korupensis is highly inbred ( F IS = 0.455) with moderate levels of subpopulation differentiation ( F ST = 0.1153). Michellamine B content was best predicted by leaf type but also showed a significant relationship for stage class. The occurrence of rare, private alleles in most of the sites, low overall population size and density, and low availability of individuals for recruitment into the adult stage class are important considerations for the rational management of A. korupensis .