Evol Ecol Res 9: 283-297 (2007)     Full PDF if your library subscribes.

Plant endemism in the central Namib Desert

Antje Burke*

EnviroScience, PO Box 1722, Oranjemund, Namibia

e-mail: antje@enviro-science.info

ABSTRACT

Questions: Have Namib endemics evolved from old or recent evolutionary lines? What are their phylogenetic patterns at different levels of taxonomic order? What is the role of environmental factors in determining current distributions?

Data description: Distribution of central Namib plant endemics and environmental indices, based on field surveys and published sources.

Method of analysis: Chi-squared and G-tests to examine differences in phylogenetic aspects, growth form, and dispersal spectra between endemic and non-endemic flora. Canonical correspondence analysis to investigate the effect of environmental variables on the distribution of plant endemics in a 15-minute interval geographic grid.

Conclusions: Central Namib endemics have probably descended from old evolutionary lines in contrast to those in the southern Namib. Different selective forces are therefore likely to be driving evolution in different parts of the Namib Desert. Although leaf-succulents are over-represented among both central Namib and southern Namib endemics, leaf-succulents in the central Namib are likely to be a result of former environmental conditions (i.e. winter rainfall) and/or the influence of fog, in contrast to the southern Namib where phylogenetics play a more important role. Species-specific responses are indicated among the Namib endemics, as the influence of fog seems to be important for some, and substrate conditions for others. These need to be taken into account when predictions are made regarding broad-scale biogeographic patterns and when modelling the effect of climate change.

Keywords: arid lands, biogeography, climate change, evolution, growth forms, southern Africa.

DOWNLOAD A FREE, FULL PDF COPY
IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.

 

        © 2007 Antje Burke. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.