Can spatial variation in epiphyte diversity and community structure be predicted from sampling vascular epiphytes alone?

Abstract

Aim Non-vascular epiphytes have been largely ignored in studies examining the biotic and abiotic determinants of spatial variation in epiphyte diversity. Our aim was to test whether the spatial patterning of species richness, biomass and community composition across geographic regions, among trees within regions, and among branches within trees is consistent between the vascular and non-vascular components of the temperate rain forest flora.Location Coastal lowland podocarp-broadleaved forests on the west coast of the South Island of New Zealand.Methods We collected single samples (30 · 25 cm) from 96 epiphyte assemblages located on the inner branches of 40 northern rata (Metrosideros robusta) trees. For each sample, branch characteristics such as branch height, branch diameter, branch angle, branch aspect, and minimum and maximum epiphyte mat depth were recorded. The biomass for each individual epiphyte species was determined.Results Northern rata was host to a total of 157 species, comprising 32 vascular and 125 non-vascular species, with liverworts representing 41% of all species. Within epiphyte mats, the average total organic biomass of 3.5 kg m )2 of branch surface area consisted largely of non-living biomass and roots. Vascular and non-vascular epiphytes showed strikingly different spatial patterns in species richness, biomass and composition between sites, among trees within sites, and among branches within trees, which could not be explained by the branch structural characteristics we measured. The two plant groups had no significant association in community composition (r = 0.04, P = 0.08). However, the species richness of vascular plant seedlings was strongly linked to the presence/ absence of lichens.Main conclusions Non-vascular plants contributed substantially to the high species richness and biomass recorded in this study, which was comparable to that of some tropical rain forests. High variability in community composition among epiphyte mats, and very low correlation with any of the environmental factors measured possibly indicate high levels of stochasticity in seed or spore colonization, establishment success or community assembly among branches in these canopy communities. Although we found some evidence that vascular plant seedling establishment was linked to the presence of lichens and the biomass of non-living components in the epiphyte mats, there was no correlation in the spatial patterning or determinants of species richness between non-vascular and vascular plants. Consequently, variation in total epiphyte biodiversity could not be predicted from the measurement of vascular

Islands in the trees: A biogeographic exploration of epiphyte‐dwelling spiders

“…We sorted collected spiders into morphotypes according to their morphological traits and, when possible, we identified adults to species following taxonomic keys available in the literature (Jocqué & Dippenaar‐Schoeman, ; Ubick, Paquin, Cushing, & Roth, ; World Spider Catalog, ). Spider vouchers are located at the Laboratorio de Aracnología de la Facultad de Ciencias, Universidad Nacional Autónoma de México (UNAM). We dried the epiphytes for two days at 70°C and weighed them (Affeld, Sullivan, Worner, & Didham, ).…”

“…5. We dried the epiphytes for two days at 70°C and weighed them (Affeld, Sullivan, Worner, & Didham, 2008). Before collecting epiphytes (or "canopy islands"), we conducted a pilot analysis (nearest-neighbour clustering) on 17 Inga jinicuil trees to identify those with the highest structural similarity.…”

A preliminary survey of epiphytes in some tree canopies in Zambia and the Democratic Republic of Congo

“…The aspect of the branch, the slope and the roughness of the bark are thought to be often important factors in shaping epiphyte communities within phorophytes (Marmor, Tõrra & Randlane, ; Nadkarni, ; Affeld et al., ). Tree bark in particular is one of the most commonly used substrates of epiphytes and can affect the epiphyte's ability to establish, attach and grow.…”

Cross Taxon Congruence Between Lichens and Vascular Plants in a Riparian Ecosystem

“…Structurally complex and more mature habitats, indeed, provide more niches and diverse ways of exploiting the environmental resources, thus increasing species diversity [86]. However, a weak degree of association in community composition of vascular plants and cryptogams was evidenced in other studies from Australian [36], Canadian [84], and New Zealand forests [87] and dry grasslands in Sweden [88]. In relation to our data, a previous study pointed out that the five habitats can be well defined and characterized using plant communities [46].…”