10.5061/DRYAD.6WWPZGMWM
König, Christian
0000-0003-0585-5983
University of Potsdam
Weigelt, Patrick
University of Göttingen
Taylor, Amanda
University of Göttingen
Stein, Anke
University of Konstanz
Dawson, Wayne
Durham University
Essl, Franz
University of Vienna
Pergl, Jan
Academy of Sciences of the Czech Republic
Pysek, Petr
Academy of Sciences of the Czech Republic
van Kleunen, Mark
University of Konstanz
Winter, Marten
German Center for Integrative Biodiversity Research
Chatelain, Cyrille
Conservatory and Botanical Garden of the City of Geneva
Wieringa, Jan
Naturalis Biodiversity Center
Krestov, Pavel
Far East Branch of the Russian Academy of Sciences
Kreft, Holger
University of Göttingen
Source pools and disharmony of the world’s island floras
Dryad
dataset
2020
Assembly processes
ecological filtering
source regions
island disharmony
generalized dissimilarity modeling
FOS: Biological sciences
2020-08-20T00:00:00Z
2020-08-20T00:00:00Z
en
https://doi.org/10.1111/ecog.05174
96342926 bytes
5
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Island disharmony refers to the biased representation of higher taxa on
islands compared to their mainland source regions and represents a central
concept in island biology. Here, we develop a generalizable framework for
approximating these source regions and conduct the first global assessment
of island disharmony and its underlying drivers. We compiled vascular
plant species lists for 178 oceanic islands and 735 mainland regions.
Using mainland data only, we modelled species turnover as a function of
environmental and geographic distance and predicted the proportion of
shared species between each island and mainland region. We then quantified
the over- or under-representation of families on individual islands
(representational disharmony) by contrasting the observed number of
species against a null model of random colonization from the mainland
source pool, and analysed the effects of six family-level functional
traits on the resulting measure. Furthermore, we aggregated the values of
representational disharmony per island to characterize overall taxonomic
bias of a given flora (compositional disharmony), and analysed this second
measure as a function four island biogeographical variables. Our results
indicate considerable variation representational disharmony both within
and among plant families. Examples of generally over-represented families
include Urticaceae, Convolvulaceae and almost all pteridophyte families.
Other families such as Asteraceae and Orchidaceae were generally
under-represented, with local peaks of over-representation in known
radiation hotspots. Abiotic pollination and a lack of dispersal
specialization were most strongly associated with an insular
over-representation of families, whereas other family-level traits showed
minor effects. With respect to compositional disharmony, large,
high-elevation islands tended to have the most disharmonic floras. Our
results provide important insights into the taxon- and island-specific
drivers of disharmony. The proposed framework allows overcoming the
limitations of previous approaches and provides a quantitative basis for
incorporating functional and phylogenetic approaches into future studies
of island disharmony.
Data collection and processing is described in detail in the article.