The ER used phylogenomics to investigate the evolutionary relationships of six plant lineages. The species in the tropical alpine regions of Africa are in most cases monophyletic and the species are often clearly endemic to a single mountain. In contrast, the Andean species show a more complex figure. Species are sometimes not monophyletic and numerous instances of (historical) gene flow were discovered.
Using a newly developed habitat modelling approach, the ER was able to show, that the climatic conditions are similar between the two studied regions. Nevertheless, during the Last Glacial Maximum, the degree of habitat stability varied, with extensive area loss in eastern Africa compared to the northern Andes. Further, in the Andes, usually only the humid areas within tropical alpine regions are considered, the so-called Paramo. The modelling showed that in order to compare regions with similar climates, a region further south, the so-called Puna, which is more arid in comparison to the Paramo should be included into comparisons of tropical alpine ecosystems.
By studying the niche and range characteristics of species within the ecosystem, well known species richness hypothesis were tested: e.g. if species have small niche sizes, it is hypothesized that more species per area can exist. A pattern which could not be confirmed for the tropical alpine regions, as niche sizes were actually larger for the species in the species-poor African mountains. Instead, niche separation of geographically overlapping species is higher in the Paramo, which likely led, in combination with the different degrees of habitat stability in the past, to the diversity differences we can observe today.
Additionally, niche modelling was performed to investigate range changes in the past as well as the future. One prominent hypothesis is, that alpine species will shift their ranges upwards in warming climates. This is not a general pattern observable for the tropical alpine species, as some of them actually shift downwards. Still work in progress is another aspect, to study the phylogenetic community assembly of the isolated tropical alpine regions in Africa to investigate if species are more closely related than expected and how it related to isolation between the different mountains.
Results were published in one open-access article, with three more to be published. The action was further disseminated by several talks given at different institutions and conferences.
