Genetic divergence during long-term isolation in highly diverse populations of tropical trees across the Eastern Arc mountains of Tanzania

Alistair S. Jump, Martin Carr, Antje Ahrends, Rob Marchant

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The Eastern Arc Mountains are believed to support some of the oldest tropical forest in the world. The current distribution of this forest is highly fragmented due to a combination of long-term effects of past changes in global climate and more recent deforestation. We sought to explore the hypothesized antiquity and long-term isolation of the Eastern Arc montane forests based on an assessment of the geographical distribution and interspecies similarity of chloroplast DNA sequence variation in five forest trees. Data were used to investigate regional patterns of diversity and population structure based on intraspecific phylogenies, and results were interpreted against hypotheses on ecosystem age and connectivity. Regional diversity was high, with up to 22 chloroplast DNA haplotypes being recorded within a species across the sampled populations. Geographical concordance of genetic and geographic structure was weak to absent in all species and there was little similarity of genetic structure between species. Haplotype sharing between mountain blocks was extremely limited. The generally weak phylogeographical structure, in conjunction with high regional diversity and genetic uniqueness of individual mountain forests does not support the assumption of widespread genetic connectivity of the mountain forests, indicating instead a pattern of past isolation and ongoing diversification. Our findings substantially add to understanding patterns of diversity in this region and lend weight to calls to use more sophisticated biodiversity assessments when setting regional conservation and research funding priorities.

LanguageEnglish
Pages565-574
Number of pages10
JournalBiotropica
Volume46
Issue number5
DOIs
Publication statusPublished - 2014

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montane forest
montane forests
Tanzania
divergence
mountains
chloroplast DNA
chloroplast
genetic variation
mountain
connectivity
haplotypes
DNA
research support
regional pattern
deforestation
forest trees
geographical distribution
tropical forests
genetic structure
tropical forest

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Genetic divergence during long-term isolation in highly diverse populations of tropical trees across the Eastern Arc mountains of Tanzania. / Jump, Alistair S.; Carr, Martin; Ahrends, Antje; Marchant, Rob.

In: Biotropica, Vol. 46, No. 5, 2014, p. 565-574.

Research output: Contribution to journalArticle

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