Epiphytic Diversity Research Articles

Post-stripping recolonization of vascular epiphytes in cloud-forest fragments in Mexico

Abstract:The response of vascular epiphyte communities following natural or human disturbance has been little studied. Over 5 y, we evaluated the post-stripping recolonization of vascular epiphytes in cloud forest. Vascular epiphytes were experimentally removed from branch and trunk plots (1 m in length) on five trees in two secondary cloud forest fragments in southern Mexico. Similarity between colonizer and established communities was compared in each fragment using a further five trees with no stripping. All seedlings were recorded yearly. Non-vascular epiphyte cover was estimated in each plot. The recolonization rate was very high; after 5 y, epiphyte density of the colonizer community (27.4 ± 6.8 individuals per segment) reached similar values to those of the established community (26.7 ± 3.3) in nearby trees. While similarity (composition and abundance) between the colonizer community and established community was high (81%), diversity accumulation curves indicated that the colonizer community presents a lower diversity of epiphytes (5.5 equivalent species) than the established community (11.4). Colonization of xerophytic bromeliads was high, while pteridophytes and orchids presented reduced recovery. The immediately surrounding source of propagules had a strong influence on recolonization. In both the colonizer and established communities, dominance rank was bromeliads > peperomias > pteridophytes. The results show that the recovery capacity of epiphytic vegetation in secondary forest is high, if propagule sources are close by. However, at 5 y after disturbance, it is unclear whether the colonizer community would present the same species composition as the established community or if it would give rise to a different community.

Microlejeunea miocenica sp. nov. (Porellales, Jungermanniopsida) in Dominican amber, the first fossil of a subcosmopolitan genus of leafy liverworts

We describe a lejeuneoid liverwort preserved in Miocene Dominican amber. The plants creep on bark, have zig-zagged stems, entire-margined suberect leaves with large lobules with a curved apical tooth at the free margin, small, bifid underleaves with forward-directed lobes, and winged female bracts. They are assigned to the extant genus Microlejeunea and classified as Microlejeunea miocenica sp. nov., representing the first fossil of this genus. So far 17 extant genera of Lejeuneaceae have been recognized in Dominican amber, pointing to generic stasis of the regional epiphytic diversity since the Miocene.

Large trees and dense canopies: key factors for maintaining high epiphytic diversity on trunk bases (bryophytes and lichens) in tropical montane forests

Large trees and dense canopies: key factors for maintaining high epiphytic diversity on trunk bases (bryophytes and lichens) in tropical montane forests

Defense mechanisms of sargassacean species against the epiphytic red alga Neosiphonia harveyi.

Flora diversity and abundance of epiphytes are specific to their basiphyte species and may relate to variations in the defensive abilities of basiphytes. Thus, investigating the interactions between epiphytes and basiphytes is useful for a better understanding of the biological impact of epiphytism and the survival strategies of basiphytes. We examined the epiphyte density on five sargassacean species at six locations between two study sites, which showed that the epiphytic red alga Neosiphonia harveyi was remarkably less abundant on Sargassum siliquastrum at all locations. To assess its defense mechanism against N.harveyi, we performed bioassays of phlorotannins, which are considered effective in deterring fouling, by culturing sargassacean blades with N.harveyi carpospores and observed the process by which sargassacean blades remove epiphytes. When the carpospores were incubated with various concentrations of dissolved phlorotannins, settlement and germination were inhibited only at the highest concentrations (>0.1g·L(-1) ), and this effect did not significantly differ among the five sargassacean species. When the carpospores were combined with blades from the five species, many of the spores attached and germinated on every blade. Because N.harveyi penetrated rhizoids into basiphyte tissues, cuticle peeling observed in all five sargassacean species could not remove this epiphyte after germination. However, in S.siliquastrum, the blade tissues around the germlings became swollen and disintegrative, and were removed together with the germlings. The spores normally grew on the dead blades, suggesting that the tissue degradation of S.siliquastrum is triggered by the infection of N.harveyi.

The influence of tree architecture, forest remnants, and dispersal syndrome on roadside epiphyte diversity in a highly urbanized tropical environment

Urban environments generally have reduced biodiversity, nevertheless they may contribute to biodiversity conservation. The presence of epiphytes on urban trees indicates viability of urban areas as repositories of biodiversity; however the influence of biophysical and local habitat variables on the occurrence and diversity of epiphytes on urban trees has not been studied. Epiphytes were surveyed on 1170 roadside Albizia saman trees along 39 roads in the tropical city-state of Singapore. Eighty-seven percent of trees were host to at least one epiphyte species. A total of 51 epiphyte species were encountered, 33 of which were native and represented one-third of Singapore’s 113 extant native epiphyte species. Generalized linear mixed models revealed that at the tree level, DBH, fork structure (branch multiplicity), and distance of the host tree from nearest forest patch were associated with epiphyte richness, whereas at the road level, surrounding habitat type, fork structure, and average tree height were associated with epiphyte diversity (Simpson’s reciprocal index [1/λ]). Canonical correspondence analysis showed that the presence of a species was often influenced by a single factor rather than multiple factors, e.g. distance to forest, host tree trunk diameter or height, or host tree branching complexity. This study suggests that an understanding of native epiphytes’ dispersal syndrome, the preservation of forest remnants, and protection of trees—especially large and tall trees exhibiting complex architecture—are crucial for epiphyte conservation in highly urbanized environments.

Changes in epiphyte diversity in declining forests: implications for conservation and restoration

Biodiversity degradation is a serious global problem, and conservation or restoration has been conducted in various ecosystems. The objective of this study was to examine effective conservation measures and restoration goals for epiphytes on the basis of changes in epiphyte flora during the past 30 years on Mt. Odaigahara, Japan. Comparison of epiphyte diversity between 1983 and 2008 indicated that species richness and cover in plots surveyed in 1983 had declined significantly by 2008. The results of nonmetric multidimensional scaling showed that the dominance of hygrophilous species decreased on trees surveyed in 2008 accompanied with forest decline. In addition, total species richness decreased with increasing coverage of wire mesh installed for protection against debarking by deer. We conclude that severe drought stress caused by forest decline after the 1980s and the toxic effects of wire mesh on epiphytes have led to a dramatic decrease in epiphyte diversity during the past 30 years. To conserve epiphyte diversity, first, tree protection without wire mesh should be adopted. In addition, intensive conservation of undamaged forest patches may be necessary to prevent loss of remaining hygrophilous species from this region. The results also indicate that epiphyte diversity can be strongly affected by slight changes in forest structure, and by site-specific environmental factors. Considering that these changes or environmental factors are often not easy to evaluate, comparison of epiphyte diversity before and after disturbance can be an important means of determining appropriate restoration objectives.

Structure of the epiphyte community in a tropical montane forest in SW China.

Vascular epiphytes are an understudied and particularly important component of tropical forest ecosystems. However, owing to the difficulties of access, little is known about the properties of epiphyte-host tree communities and the factors structuring them, especially in Asia. We investigated factors structuring the vascular epiphyte-host community and its network properties in a tropical montane forest in Xishuangbanna, SW China. Vascular epiphytes were surveyed in six plots located in mature forests. Six host and four micro-site environmental factors were investigated. Epiphyte diversity was strongly correlated with host size (DBH, diameter at breast height), while within hosts the highest epiphyte diversity was in the middle canopy and epiphyte diversity was significantly higher in sites with canopy soil or a moss mat than on bare bark. DBH, elevation and stem height explained 22% of the total variation in the epiphyte species assemblage among hosts, and DBH was the most important factor which alone explained 6% of the variation. Within hosts, 51% of the variation in epiphyte assemblage composition was explained by canopy position and substrate, and the most important single factor was substrate which accounted for 16% of the variation. Analysis of network properties indicated that the epiphyte host community was highly nested, with a low level of epiphyte specialization, and an almost even interaction strength between epiphytes and host trees. Together, these results indicate that large trees harbor a substantial proportion of the epiphyte community in this forest.

Diversity of vascular epiphytes in two high altitude biotopes of the Brazilian Atlantic Forest

Montane environments create unique conditions that favour the development of remarkably rich and endemic biotas. The Serra da Mantiqueira is an important Brazilian mountain range and is recognised globally for certain groups of living organisms, whereas gaps in knowledge exist for other groups, such as epiphytes, which have been poorly studied in the region. The Serra da Mantiqueira contains rare fragments of a vegetation formation, the mixed ombrophilous forest (MOF), which is typical of the Southern Region of Brazil and is very threatened. The present study aimed to analyse the epiphytic communities occurring on individuals of Podocarpus lambertii Klotzsch ex Endl. (Podocarpaceae) in two biotopes: natural patches and continuous alluvial forest. We sampled 60 phorophytes, equally divided between the sites, and established five strata according to stem ramification. This phorophyte species is ecologically relevant, since it harbours 92 species and 19 families, and a single individual may support up to 30 % of the total richness of the studied community. The Shannon diversity index was 3.86, which is comparable to that found in other studies dealing with several phorophyte species and is the highest found to date for the MOF. The biotopes and strata did not show significant differences in the calculated diversity indices, except in richness (80 species in the alluvial forest and 60 in the patches). The most representative ecological categories were characteristic holoepiphytes (73 species) and accidental holoepiphytes (nine species). The present study shows the importance that a single species can have in an ecosystem and contributes to our knowledge concerning epiphytic synusia in mountainous environments.

Microhabitat associations of vascular epiphytes in a wet tropical forest canopy

Summary In tropical forests, vascular epiphyte diversity increases with tree size, which could result from an increase in area, time for colonization or an increase in microhabitat heterogeneity within‐tree crowns if vascular epiphyte species are specialized to particular microhabitats within the crown. The importance of microhabitats in structuring epiphyte communities has been hypothesized for more than 120 years but not yet confirmed. We tested the importance of microhabitats in structuring epiphyte communities by examining microhabitat heterogeneity and epiphyte communities within the crowns of different‐sized Virola koschnyi (Myristicaceae) emergent trees in a Costa Rican tropical wet forest. We tested the degree to which epiphyte species composition was associated with environmental conditions and resources (i.e. microhabitats) using multivariate analyses and a null model that compared the observed epiphyte assemblages amongst different‐sized trees and crown zones with assemblages generated randomly. This study is the first to rigorously examine the degree of microhabitat specialization in epiphyte communities. Microhabitat heterogeneity, epiphyte species richness and abundance increased with tree size. The largest trees had the highest microhabitat and epiphyte diversity and a unique inner crown microhabitat with canopy humus. The few epiphytes found on small trees were mostly bark ferns. Large trees had different epiphyte communities in different parts of the crown; the inner crown contained species not abundant in any other microhabitat (i.e. aroids, cyclanths and humus ferns), and the outer crown contained bark ferns and atmospheric bromeliads. Variation in species composition amongst tree size classes was significantly related to the mean daily maximum vapour pressure deficit and tree diameter, while variation within large tree crowns was significantly related to canopy humus cover. Microhabitat specialization of epiphyte species increased with tree size with 6% of species significantly associated with small trees and 57% significantly associated with large trees. Of the species present in large tree crowns, 23% were specialized to the unique inner crown microhabitat. Synthesis. The increase in microhabitat heterogeneity within tree crowns as trees grow contributes to changes in epiphyte community structure, which supports decades‐old hypotheses of the importance of microhabitat diversity and specialization in structuring tropical epiphyte communities.

Biotic Factors Affecting the Abundance of Vascular Epiphytic Bromeliads Growing in Cloud Forest in Reserva Biologica Los Cedros, Ecuador

Aims: In this paper we investigate whether the abundance of epiphytic bromeliads growing in cloud forest was affected by: (1) phorophyte family; (2) phorophyte size; and (3) the abundance of other epiphytes. Study Design: The abundance of bromeliads was compared on 35 random trees from each of the three most abundant tree families (Burseraceae, Moraceae and Clusiaceae) present within a study site consisted of a 25 m x 25 m riverine area, situated along the Rio Los Cedros, within the Reserva Los Cedros Biological Reserve. All trees and bromeliad species within the study area had previously been identified by staff from the National Herbarium of Ecuador and this information was made available to the authors. Verification of botanical identification was further supported on-site. Place and Duration of Study: A one month study at Reserva Biologica Los Cedros, near the town Original Research Article Brown et al.; ARRB, 6(6): 355-363, 2015; Article no.ARRB.2015.095 356 of Chontal, Pichincha Province NW Ecuador. Methodology: For each of the 105 trees sampled we recorded the following data: total number of bromeliads, number of each of the five most abundance species of bromeliads in the study area; tree family, tree diameter at breast height (DBH), tree height, percent cover of vascular epiphytes; percent cover of non-vascular epiphytes. Data were collected non-invasively from ground level by using binoculars. Results: The results showed no evidence of phorophyte specificity amongst epiphytic bromeliads. However, larger phorophytes held more bromeliads irrespective of phorophyte family and even when supporting high abundances of other vascular epiphytes. Conclusion: We conclude that it is tree size and not the phorophyte species that is most important in driving high abundance and diversity in bromeliad communities. We also conclude that the bromeliad component of epiphyte communities is not affected by competition from other cooccurring epiphytes. Further research is needed to understand how species interactions within epiphyte communities drive epiphyte community assembly, dynamics and diversity.

Epiphyte diversity on host trees in an urban environment, eThekwini Municipal Area, South Africa

Vascular epiphytes live non-parasitically on other plants and are a distinctive and intergral component of tropical forests. There is a general lack of studies examining epiphyte diversity in urban settings. The aim of this study was to document the diversity of epiphytes on host trees in the eThekwini Metropolitan Area (EMA). In addition, the number of individuals of each epiphyte, host tree circumference at breast height and height were recorded. In total, 30 epiphyte species from 12 families were recorded, with most epiphyte species belonging to the Moraceae (n = 8) and Araliaceae (n = 5). A total of 34 host species from 15 families were recorded. These numbers did not increase when considering herbarium material within the EMA sensu stricto. The highest epiphyte richness (n = 13) was reported on the palm Raphia australis. The high number of both alien host and epiphytic taxa are of concern. More studies are needed to understand how epiphyte/host interactions in the urban landscape are established and maintained.

Epiphyte homogenization and de-diversification on alien Eucalyptus versus native Quercus forest in the Colombian Andes: a case study using lirellate Graphidaceae lichens

In many tropical areas, monospecific tree plantations are replacing natural forest. The ecology of these plantations is quite different from that of natural forests, including the diversity and community structure of vascular and cryptogamic epiphytes. Few studies have looked at the ecology of guilds of epiphytes in plantations versus natural forest. Here, we investigated epiphytic, lirellate species of the family Graphidaceae, the largest family of tropical lichen fungi, which are widely distributed and abundant in tropical regions. We compared species richness and community structure in a monospecific plantation of the introduced tree species Eucalyptus globulus versus native oak forest dominated by Quercus humboldtii. Overall species richness was substantially higher in the natural oak forest (41 vs. 14 species, with eight shared between both stands, for a total of 47), whereas species abundance was significantly higher in the gum plantation. While species richness per tree (alpha diversity) was comparable between both stands, average species turnover between trees within each stand (beta diversity) was significantly higher in the natural oak forest, resulting in substantially higher overall species richness (gamma diversity). We conclude that the monospecific gum plantation exhibits both de-diversification (lower overall species richness) and homogenization (more similar communities between trees) of these epiphytic lichen guilds. This is not an effect of phorophyte diversity since in both stands, only a single tree species each was considered. Among the lichens identified, we detected six new to the Neotropics and 29 new records for Colombia.

Epiphyte assemblages respond to host life-form independently of variation in microclimate in lower montane cloud forest in Panama

Abstract:We investigated the effects of host tree on epiphyte diversity, controlling for microclimate. We measured the light profiles of the lower trunks of 20 individuals, each from three host groups (tree ferns, dicots, palms) occupying the understorey in a tropical montane forest in Panama. The per cent cover and species richness of vascular and non-vascular epiphytes were surveyed on the lower trunks of each understorey host. Light varied considerably between trees (5–21% total transmitted light) but mean light level did not vary between types of host. Light was not significant as a covariate with host in any model. Tree ferns had higher covers than dicots and palms of filmy ferns (15%, 0.02% and 0.2%), other ferns (7%, 0% and 0.5%) and other vascular epiphytes (16%, 3% and 3.4%), and greater species richness of vascular epiphytes (filmy ferns: 3, 0.4 and 0.5; other ferns: 2, 0.2 and 0; other vascular: 7, 2 and 2). Dicots had a higher cover of liverworts (53%) than palms (18%) and tree ferns (27%). Palms and tree ferns were the compositional extremes. We conclude that the differences in species composition and cover between the three host groups relate better to physical differences between hosts than differences in light climate.

Air Pollution Influences Epiphytic Lichen Diversity in the Northeast of Thailand

This work aimed to investigate epiphytic lichens on mango trees (Mangifera indica L.) in the municipality habitats of the Northeast of Thailand based on the Verein Deutscher Ingenieure protocol and define the factors that influence their diversity. Ninety-one taxa were observed, 21 of them are macrolichens, 87 species found outside municipality and 70 species found inside municipality. The factors that most affected epiphytic lichen diversity were tree circumference, days of rainfall, bark pH, area surrounding and annual rainfall and negatively affected by population size, temperature, and distance from road. This work concluded that traffic density and human population size reduce air quality and influenced epiphytic diversity in the municipal habitats in the Northeast of Thailand, and lichens are bioindicators of air pollution in this region.

Regional and Elevational Patterns in Vascular Epiphyte Richness on an East Asian Island

AbstractThe distribution of species on mountains has been related to various predictor variables, especially temperature. Thermal specialization—presumed to be more pronounced on tropical mountains than on temperate mountains—accounts for the elevational pattern of species richness and varies between organisms and geographic areas. In this study, the elevational and regional distribution patterns of 331 epiphyte species in Taiwan were explored using 39,084 botanic collections, mostly from herbaria. Species richness showed a peak in elevation at 500–1500 m. This peak could not be explained by a null model, the mid‐domain effect, suggesting that environmental variables accounted mostly for the distribution of species on the mountains. Next, species distributions were modeled to assess epiphyte regional and elevational distribution patterns. The model results not only corroborated the position of the mid‐elevation peak in richness, but also identified two mountain areas on the island with exceptionally high species richness. These areas of high epiphyte diversity coincide with areas of high rainfall in relation to the direction of the prevailing winds. Moreover, a subsequent exploratory ordination analysis showed a varied thermal preference between epiphyte subcategories (hemiepiphytes, dicotyledons, orchids, and ferns). In contrast to predictions by the elevational Rapoport's rule, ordination analysis also showed that the degree of thermal specialization increased with elevation, suggesting that highland species may be especially vulnerable to global warming.

Quantifying the loss of lichen epiphyte diversity from the pre-industrial Exmoor landscape (south-west England)

AbstractAcross much of lowland Britain, lichen diversity has been dramatically affected by the Industrial Revolution, including the lasting legacy of pollution, and changes in land use including the loss, intensification, or abandonment of traditional woodland management. We sampled preserved epiphytes on historical timbers in vernacular buildings to reconstruct pre-industrial lichen species occurrence for a site in Exmoor, south-west England, and used these data to quantify biodiversity loss that appears related to shifts in woodland composition. A total of 33 lichen epiphyte species were collected from pre-industrial structural timbers, and these were compared with modern lichen occurrence. Based on a direct comparison with species presence-absence in the same 10 km target grid-square,c. 31% of species recorded from the pre-industrial landscape had disappeared from the post-1960 landscape. Based on statistical inference comparing historical records with present-day biogeographical distributions, up to 38% of species could be inferred to be lost. This study presents a surprisingly high figure for these losses for a region in Britain usually recognized as having a relatively unpolluted environment and a diverse set of lichens. Of 12 species that were inferred to be lost, nine are predominantly found on nutrient-rich bark, and in our study onUlmus, the dominant timber in the archaeological samples. We conclude that shifts in phorophyte distribution and abundance may be more important in this region than previously understood.

The effect of substrate abundance in the vertical stratification of bromeliad epiphytes in a tropical dry forest (Mexico)

Diversity of epiphytes is associated with niche partitioning, through vertical strata and host preferences. However, abundance of substrate offered by hosts differs between vertical strata, misleading if epiphytes prefer a stratum or are randomly distributed. In a tropical dry forest of San Andres de la Cal Morelos, central Mexico, we tested the null hypothesis, that epiphytes follow the abundance of the substrate, rather than showing preference for a particular vertical stratum, and tested whether microclimatic variables, seed germination and seedling survival match with observed epiphyte distribution. Our data show that epiphytes could be randomly distributed inside some host; but in some host species, certain structures presented either a deficit or an excess of all, atmospheric, or tank epiphytes. In the hosts Bursera copallifera and Bursera glabrifolia, distribution of epiphytes was biased towards the upper strata, with a deficit of epiphytes in the lower strata. In Conzattia multiflora, Sapium macrocarpum and Ipomoea pauciflora, epiphyte distribution was biased towards the lower strata. Vertical gradation of light, seed germination and seedling survival did not generally match with epiphyte distribution and did not support the notion that the microclimatic gradient governs the vertical distribution of epiphytes. Our data indicate that vertical distribution of epiphytes in such tropical dry forests is mainly driven by the distribution of the structures, which apparently influence dispersion of the seeds and by the lifespan of branches, which allow the concentration of epiphytes in the stratum that optimizes seed capture and the clonal growth of epiphytes.

Genetic Diversity and Spatial Genetic Structure of an Epiphytic Bromeliad in Costa Rican Montane Secondary Forest Patches

AbstractInformation on genetic variation and its distribution in tropical plant populations relies mainly on studies of ground‐rooted species, while genetic information of epiphytic plants is still limited. Particularly, the effect of forest successional condition on genetic diversity and structure of epiphytes is scanty in the literature. We evaluated the genetic variation and spatial genetic structure of the epiphytic bromeliad Guzmania monostachia (Bromeliaceae, Tillandsioideae) in montane secondary forest patches in Costa Rica. The sampling design included plants on the same trees (i.e., populations), populations within forest patches and patches within secondary forest at two different successional stages (early vs. mid‐succession). Six microsatellites revealed low levels of population genetic variation (A = 2.06, AE = 1.61, HE = 0.348), a marked deficiency of heterozygotes (HO = 0.031) and high inbreeding (f = 0.908). Genetic differentiation was negligible among populations within the same forest patch, but moderate (GST = 0.123 ± 0.043) among forest patches. Genetic relatedness between individuals was significantly higher for plants located within the same forest patch and separated by <60 m and decreased as distance between plants increased, becoming significantly negative at distances >400 m. An analysis of molecular variance (AMOVA) showed significant genetic variation between forest patches, but non‐significant variation between successional stages. The selfing breeding system and limited seed dispersal capabilities in G. monostachia could explain the observed levels and partitioning of genetic diversity at this geographic scale. However, these results also suggest that forest fragmentation is likely to influence the degree of local genetic structuring of epiphytic plants by limiting gene flow.

Epiphyte response to drought and experimental warming in an Andean cloud forest.

The high diversity and abundance of vascular epiphytes in tropical montane cloud forest is associated with frequent cloud immersion, which is thought to protect plants from drought stress. Increasing temperature and rising cloud bases associated with climate change may increase epiphyte drought stress, leading to species and biomass loss. We tested the hypothesis that warmer and drier conditions associated with a lifting cloud base will lead to increased mortality and/or decreased recruitment of epiphyte ramets, altering species composition in epiphyte mats. By using a reciprocal transplant design, where epiphyte mats were transplanted across an altitudinal gradient of increasing cloud immersion, we differentiated between the effects of warmer and drier conditions from the more general prediction of niche theory that transplanting epiphytes in any direction away from their home elevation should result in reduced performance. Effects differed among species, but effects were generally stronger and more negative for epiphytes in mats transplanted down slope from the highest elevation, into warmer and drier conditions, than for epiphyte mats transplanted from other elevations. In contrast, epiphytes from lower elevations showed greater resistance to drought in all treatments. Epiphyte community composition changed with elevation, but over the timescale of the experiment there were no consistent changes in species composition. Our results suggest some epiphytes may show resistance to climate change depending on the environmental and evolutionary context. In particular, sites where high rainfall makes cloud immersion less important for epiphyte water-balance, or where occasional drought has previously selected for drought-resistant taxa, may be less adversely affected by predicted climate changes.

Epiphyte response to drought and experimental warming in an Andean cloud forest

The high diversity and abundance of vascular epiphytes in tropical montane cloud forest is associated with frequent cloud immersion, which is thought to protect plants from drought stress. Increasing temperature and rising cloud bases associated with climate change may increase epiphyte drought stress, leading to species and biomass loss. We tested the hypothesis that warmer and drier conditions associated with a lifting cloud base will lead to increased mortality and/or decreased recruitment of epiphyte ramets, altering species composition in epiphyte mats. By using a reciprocal transplant design, where epiphyte mats were transplanted across an altitudinal gradient of increasing cloud immersion, we differentiated between the effects of warmer and drier conditions from the more general prediction of niche theory that transplanting epiphytes in any direction away from their home elevation should result in reduced performance. Effects differed among species, but effects were generally stronger and more negative for epiphytes in mats transplanted down slope from the highest elevation, into warmer and drier conditions, than for epiphyte mats transplanted from other elevations. In contrast, epiphytes from lower elevations showed greater resistance to drought in all treatments. Epiphyte community composition changed with elevation, but over the timescale of the experiment there were no consistent changes in species composition. Our results suggest some epiphytes may show resistance to climate change depending on the environmental and evolutionary context. In particular, sites where high rainfall makes cloud immersion less important for epiphyte water-balance, or where occasional drought has previously selected for drought-resistant taxa, may be less adversely affected by predicted climate changes.