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Scattered populations of the same tree species in montane forests through Africa have led to speculations on the origins of distributions. Here, we inferred the colonization history of the Afromontane tree Prunus africana using seven chloroplast DNA loci to study 582 individuals from 32 populations sampled in a range-wide survey from across Africa, revealing 22 haplotypes. The predominant haplotype, HT1a, occurred in 13 populations of eastern and southern Africa, while a second common haplotype, HT1m, occurred in populations of western Uganda and western Africa. The high differentiation observed between populations in East Africa was unexpected, with stands in western Uganda belonging with the western African lineage. High genetic differentiation among populations revealed using ordered alleles (N ST = 0.840) compared with unordered alleles (G ST = 0.735), indicated a clear phylogeographic pattern. Bayesian coalescence modelling suggested that 'east' and 'west' African types likely split early during southward migration of the species, while further more recent splitting events occurred among populations in the East of the continent. The high genetic similarity found between western Uganda and west African populations indicates that a former Afromontane migration corridor may have existed through Equatorial Africa.

Conservation priorities for Prunus africana, a tree species found across Afromontane regions, which is of great commercial interest internationally and of local value for rural communities, were defined with the aid of spatial analyses applied to a set of georeferenced molecular marker data (chloroplast and nuclear microsatellites) from 32 populations in 9 African countries. Two approaches for the selection of priority populations for conservation were used, differing in the way they optimize representation of intra-specific diversity of P. africana across a minimum number of populations. The first method (S1) was aimed at maximizing genetic diversity of the conservation units and their distinctiveness with regard to climatic conditions, the second method (S2) at optimizing representativeness of the genetic diversity found throughout the species’ range. Populations in East African countries (especially Kenya and Tanzania) were found to be of great conservation value, as suggested by previous findings. These populations are complemented by those in Madagascar and Cameroon. The combination of the two methods for prioritization led to the identification of a set of 6 priority populations. The potential distribution of P. africana was then modeled based on a dataset of 1,500 georeferenced observations. This enabled an assessment of whether the priority populations identified are exposed to threats from agricultural expansion and climate change, and whether they are located within the boundaries of protected areas. The range of the species has been affected by past climate change and the modeled distribution of P. africana indicates that the species is likely to be negatively affected in future, with an expected decrease in distribution by 2050. Based on these insights, further research at the regional and national scale is recommended, in order to strengthen P. africana conservation efforts.

Prunus africana--an evergreen tree found in Afromontane forests--is used in traditional medicine to cure benign prostate hyperplasia. Different bioactive constituents derived from bark extracts from 20 tree populations sampled throughout the species' natural range in Africa were studied by means of GC-MSD. The average concentration [mg/kgw/w] in increasing order was: lauric acid

The genus Warburgia (Canellaceae) contains four tree species that are of valuable medicinal importance and are all found in Africa. Genetic diversity present in wild populations of these species is under great threat due to unsustainable harvesting for medicines and indiscriminate felling for timber and agricultural expansion. There is therefore an urgent need for conservation of these species. Some authors disagree about the taxonomy of the genus and list different species as synonyms. Amplified fragment length polymorphism (AFLP) technique was used to determine the genetic relationships between three species to resolve the taxonomic confusion. The amount of genetic variation within and among populations was assessed to guide strategies for their conservation and sustainable utilization. Four AFLP primer pairs (EcoRI/MseI) generated a total of 185 amplification products. Analysis of molecular variance revealed most variation among individuals within populations (63%, P<0.0001), but variation among populations (37%, P<0.0001) was highly significant as well. Constrained analysis of principal coordinates based on the Jaccard distance confirmed the separation among populations (38.2%, P<0.0001). A phenetic tree and ordination graphs showed a clear distinction of W. ugandensis from W. salutaris and W. stuhlmannii. W. ugandensis populations from Uganda and western Kenya formed a subgroup that clustered away from the rest of the W. ugandensis populations. W. salutaris and W. stuhlmannii populations showed little genetic differentiation. An implication of the data to genetic management and taxonomic clarification is discussed.

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The observed patterns indicate divergent population history across the continent most likely associated to Pleistocene changes in climatic conditions. The high genetic similarity between populations of West Africa with population of East Africa west of the ERV is in agreement with faunistic and floristic patterns and provides further evidence for a historical migration route. Contrasting estimates of recent and historical gene flow indicate a shift of the main barrier to gene flow from the Lake Victoria basin to the ERV, highlighting the dynamic environmental and evolutionary history of the region.