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.

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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.

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Vascular epiphytes are a diverse and conspicuous component of biodiversity in tropical and subtropical forests. Yet, the patterns and drivers of epiphyte assemblages are poorly studied in comparison with soil-rooted plants. Current knowledge about diversity patterns of epiphytes mainly stems from local studies or floristic inventories, but this information has not yet been integrated to allow a better understanding of large-scale distribution patterns. EpIG-DB, the first database on epiphyte assemblages at the continental scale, resulted from an exhaustive compilation of published and unpublished inventory data from the Neotropics. The current version of EpIG-DB consists of 463,196 individual epiphytes from 3,005 species, which were collected from a total of 18,148 relevés (host trees and 'understory' plots). EpIG-DB reports the occurrence of 'true' epiphytes, hemiepiphytes and nomadic vines, including information on their cover, abundance, frequency and biomass. Most records (97%) correspond to sampled host trees, 76% of them aggregated in forest plots. The data is stored in a TURBOVEG database using the most up-to-date checklist of vascular epiphytes. A total of 18 additional fields were created for the standardization of associated data commonly used in epiphyte ecology (e.g. by considering different sampling methods). EpIG-DB currently covers six major biomes across the whole latitudinal range of epiphytes in the Neotropics but welcomes data globally. This novel database provides, for the first time, unique biodiversity data on epiphytes for the Neotropics and unified guidelines for future collection of epiphyte data. EpIG-DB will allow exploration of new ways to study the community ecology and biogeography of vascular epiphytes. K E Y W O R D S biodiversity, community ecology, database, forest plot, hemiepiphytes, Neotropics, nomadic vines, taxonomic diversity, vascular epiphytes, vegetation relevé 520 |

The epiphytic life form characterizes almost 10% of all vascular plants. Defined by their mechanical dependence throughout their life and their non‐parasitic relationship with the host, the term epiphyte describes a very heterogenous and taxonomically diverse group of plants. This article explores the functional ecology of this group, acknowledging from the start that our current knowledge is highly biased, e.g. with a strong focus on particular families like bromeliads or orchids. This bias goes along with a number of problematic and weakly founded generalizations in the literature. Our article covers a set of particularly important aspects of epiphyte ecology, e.g. germination, water and nutrient relationships, and biomechanical aspects of the epiphyte‐host relationship. Throughout our article, we describe ways for future research projects to reach a more comprehensive and representative understanding of the biological responses to the varying challenges of the arboreal habitat, and emphasize that the study of epiphytes should not only be of interest to the narrow expert: a comparison of the functional ecology of epiphytes and ground‐rooted terrestrials offers unique perspectives to understanding both evolutionary and ecological, phenotypic responses to the diverse habitats of vascular plants in general.

The ongoing destruction of old-growth forests puts tropical forest species under great pressure because of the resulting loss of habitat. An important biotic component of these forests are vascular epiphytes, which structurally depend on trees. In human-modified landscapes potential hosts may still be present, e.g. in the form of isolated remnant trees, small groups of planted trees, in patches of secondary forests, or in plantations. For this study, we assessed the potential of timber monocultures and secondary forest patches to function as refuges for vascular epiphytes. We studied epiphyte assemblages in teak and pine plantations and secondary forest patches of unknown age along a rainfall gradient (1100-4200 mm) at the Pacific coast of western Panama and also in a few oil palm plantations. Invariably, rainfall had the expected positive influence on epiphyte diversity and abundance. Individual-based rarefaction curves showed that species richness was significantly lower in timber and oil palm plantations compared to secondary forest patches, which in turn hosted less species-rich epiphyte assemblages than (cultivated and wild grown) pasture trees from the same study region. Our results suggest that the value of timber and oil palm plantations as refuges for vascular epiphytes in human-modified landscapes is limited. Secondary forest patches were more promising in that regard.