The hosts of vascular epiphytes differ in many ways, not least in leaf phenology. We hypothesized that differences in microclimatic conditions in evergreen vs. deciduous trees would affect epiphytes at various levels, from organ physiology to community structure. Indeed, deciduous tree species hosted less abundant and species-poorer epiphyte assemblages. Physiologically, epiphyte assemblages differed in the proportion of CAM species and individuals, and in SLA and δ13C values. Effects were also detectable at a demographic level, i.e. in growth and survival rates. Although not all studied epiphyte species showed these effects, the data generally support our basic hypothesis.
The genus Wulfenia (Plantaginaceae) demonstrates a striking disjunction between the southeastern Alps (Carnic Alps), the southeastern Dinaric Alps (Prokletije Mountains, Balkan Peninsula) and the Amanos mountains of southern Turkey. This puzzling biogeographic pattern has interested botanists for more than 100 years and Wulfenia has been widely regarded as a Tertiary relict of at least Miocene age in southeastern Europe. Specifically, the identity of populations in the Prokletije Mountains either referred to as disjunct populations of W. carinthiaca or a separate species, “W. blecicii”, has been much debated. Here we analyze AFLP, plastid and nuclear ribosomal sequence data in conjunction with a morphometrical analysis to clarify the taxonomy of the genus and the relationships of the populations to one another. Furthermore, we employ a molecular dating strategy to put these results in a time frame to assess the Miocene relict–hypothesis. Our results provide evidence for a new classification of the genus with four species, W. orientalis, W. glanduligera comb. & stat. nov., W. baldaccii and W. carinthiaca. The split of the last species into populations disjunctly distributed in the southeastern Alps (W. carinthiaca s.str.) and southeastern Dinaric Alps (“W. blecicii”), is not supported either by molecular or morphological data, while we find enough evidence in DNA sequence data, growth site specifics and morphology for W. orientalis var. glanduligera to be treated at the species rank. Our dating analysis suggests that the extant genus is rather young with a crown node age of only about 1.24 Ma and 0.61 Ma for the European populations despite a stem node age of about 10.69 Ma. Thus, Wulfenia as a genus is likely a Miocene relict but its uninterrupted presence on the Balkan Peninsula cannot be demonstrated.
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.