RT info:eu-repo/semantics/article
T1 Increase of island endemism with altitude – speciation processes on oceanic islands
A1 Steinbauer, Manuel J.
A1 Otto, Rüdiger
A1 Naranjo-Cigala, Agustín
A1 Beierkuhnlein, Carl
A1 Fernández-Palacios, José María
K1 oceanic islands
K1 speciation
K1 island biogeography
K1 pSIE
K1 islas oceánicas
K1 especiación
K1 biogeografía insular
AB Understanding speciation on oceanic islands is a major topic in current research on island biogeography. Within thiscontext, it is not an easy task to diff erentiate between the infl uence of elevation as an indicator for habitat diversity andisland age as an indicator for the time available for diversifi cation. One reason for this is that erosion processes reducethe elevation of islands over time. In addition, the geographic distance to source ecosystems might diff er among habitats,which could lead to habitat-specifi c reduction of species immigration, niche occupation and diversifi cation. We used thepercentage of single island endemic species (pSIE) in fi ve diff erent zonal ecosystems (distributed in altitude) on the CanaryIslands as an indicator for diversifi cation. We tested whether diversifi cation increases with altitude due to a greater ecologicalisolation of high elevation ecosystems on oceanic islands under the assumption of a low elevation source region on themainland. In addition we tested whether the ‘ hump-shaped ’ (unimodal) relationship between pSIE and island age as wellas the linear relationship between species richness and pSIE is consistent across spatial scales. We also analyse a potentialinfl uence of island area and habitat area. We found that pSIE increases with elevation. Th e relations between species richnessas well as age with pSIE are consistent across scales. We conclude that high elevation ecosystems are ecologically isolated.Surprisingly, the altitudinal belt with the strongest human infl uences has the highest values of pSIE. We successfullytransfer the ‘ general dynamic theory of island biogeography ’ to the ecosystem scale, which provides multiple opportunitiesfor future studies. With this approach we fi nd that the eff ects of elevation on diversifi cation can be separated from thoseof island age.
PB Oikos Editorial Office
YR 2012
FD 2012
LK http://riull.ull.es/xmlui/handle/915/18484
UL http://riull.ull.es/xmlui/handle/915/18484
LA en
DS Repositorio institucional de la Universidad de La Laguna
RD 24-abr-2024