Epiphytic Habit Research Articles

The structure of epiphytic and planktonic bacterial assemblages under two contrasting lake regimes

Abstract In contrast to the macrophyte‐dominated regime (MDR), the phytoplankton‐dominated regime (PDR) in shallow lakes is characterized by relatively high nutrient concentrations, excessive phytoplankton growth and turbid water column. Some floating‐leaved plants can grow under both regimes and aid in reducing nutrient concentrations in water bodies. Their epiphytic bacterial assemblages play an essential role in the health and adaptation of these plants; however, there is limited understanding of this plant‐bacteria interaction. Here, we used 16S rRNA gene‐based high‐throughput sequencing to compare the diversity, composition and co‐occurrence patterns of planktonic and epiphytic bacterial assemblages associated with the submerged roots and floating leaves of Trapa natans, growing under the PDR and MDR in Lake Taihu, China. Alpha diversity of PDR epiphytic bacterial assemblages was lower than in MDR. The opposite trend was observed for planktonic bacterial assemblages. We detected a strong compositional difference between epiphytic and planktonic bacterial assemblages. Bacterial assemblages found on root and leaf surfaces showed only minimal compositional overlap with those in the water column. The composition of epiphytic bacterial assemblages differed more between the two regimes than did planktonic bacterial assemblages. The PDR co‐occurrence network of bacterial assemblages was more complex than that of the MDR, with the PDR epiphytic habitats enriched more network keystone taxa. The proportion of positive edges was also greater in the PDR networks of epiphytic bacterial assemblages than in the epiphytic MDR networks, whereas it was lower in the planktonic bacterial network from the PDR than from the MDR. The comprehensive view of the diversity, composition and co‐occurrence patterns of epiphytic and planktonic bacterial assemblages of MDR and PDR in large shallow lakes provided by our results showed that the structure of epiphytic bacterial assemblages was mediated by both host and water properties, and the observed core taxa and network keystone species may play an important role in maintaining plant growth and adaptation to environmental change.

The effect of urbanization on planktonic and biofilm bacterial communities in different water bodies of the Danube River in Hungary

Freshwaters play an essential role in providing ecosystem services worldwide, however, the water quality of different water bodies is strongly influenced by human activities such as urbanization, industry and agriculture. In this study, water and biofilm samples were collected from the main channel of the Danube River upstream and downstream of a metropolitan, from a regulated side arm within an urbanized area, and from two differently separated oxbow lakes located in nature conservation areas. The taxonomic diversity of bacterial communities was revealed by 16S rRNA gene-based amplicon sequencing using Illumina MiSeq platform. The results showed that all samples were dominated by phyla Pseudomonadota, Actinobacteriota and Bacteroidota. The bacterial community structures, however, clearly differentiated according to planktonic and epilithic or epiphytic habitats, as well as by riverine body types (main channel, side arm, oxbow lakes). The taxonomic diversity of biofilm communities was higher than that of planktonic ones in all studied habitats. Human impacts were mainly reflected in the slowly changing biofilm composition compared to the planktonic ones. Genera with pollution tolerance and/or degradation potential, such as Acinetobacter, Pseudomonas and Shewanella were mainly detected in biofilm communities of the highly urbanized section of the river side arm.

Species Richness, Abundance, and Vertical Distribution of Epiphytic Bromeliads in Primary Forest and Disturbed Forest.

Epiphytes represent a key component in tropical forests. They are affected by anthropogenic and natural disturbances suffered by forests, since they depend on their hosts and the microclimatic conditions they generate. We analyzed differences in abundance, species richness, and vertical distributions of epiphytic bromeliads in primary and disturbed forests. We found a higher abundance (5316 individuals) and species richness (8 species) of bromeliads in disturbed forest than in primary forest (1360 individuals and 4 species, respectively). Most bromeliads (97%) were found on Taxodium mucronatum, a dominant tree with rough bark in the disturbed forest (gallery forest). Bromeliads were more abundant in the middle of the tree and diminished towards the trunk base and the upper crown. Tillandsia baileyi was the most abundant bromeliad, and the size categories of this species differentially colonize trees in gallery forest according to Johansson zones; seedlings of T. baileyi abundantly colonize the upper canopy, and juveniles colonize the middle canopy or secondary branches. Gallery forest represents an important reservoir for epiphytic bromeliads. Hence, it is important to extend this kind of study to wetland sites to understand the role they play as a habitat for epiphytes, as well as the dynamics and ecological processes that occur in such habitats.

Aerial and terrestrial root habits influence the composition of the cell walls of Vanilla phaeantha (Orchidaceae).

In response to the restrictions imposed by their epiphytic habit, orchids have developed structural traits that allow greater efficiency in water uptake and use, such as a complex adventitious root system with velamen. The composition of cell wall of this specialized epidermis can be altered according to the substrate to which it is fixed, influencing wall permeability, absorption, and storage of water in roots. The current study aimed to evaluate the cell wall composition of adventitious roots of Vanilla phaeantha (Orchidaceae) that grow attached to the phorophyte, fixed in the soil, or hung free. Immunocytochemical analyses were used to determine the protein, hemicellulose, and pectin composition of the cell walls of aerial and terrestrial roots. We observed that pectins are present in the different tissues of the aerial roots, while in the terrestrial roots, they are concentrated in the cortical parenchyma. The deposition of xyloglucans, extensins, and arabinogalactans was greater in the epidermis of the free side of the roots attached to the phorophyte. The strong labeling of pectins in aerial roots may be related to the influx of water and nutrients, which are generally scarce in this environment. The arrangement of hemicelluloses and proteins with the pectins may be associated with increased cell rigidity and sustainability, a feature of interest for the aerial roots. In summary, the habit of roots can interfere with the non-cellulosic composition of the cell walls of V. phaeantha, possibly related to changes in cell functionality.

Analysis of the Fungal Community Composition in Endemic Orchids with Terrestrial Habitat in Subtropical Regions.

Habenaria and Liparis are well-known orchid genera that grow in terrestrial habitats in the tropics, subtropics or temperate zones. Three species have been found in subtropical regions of China, inhabiting terrestrial to epiphytic habitats. This study focuses on three species, H. dentata (distributed in Asia), H. yachangensis, and L. gigantea. For H. yachangensis and L. gigantea, there is no information about the mycorrhizal community in these species. This study aims to conduct the fungal community screening of Chinese ground orchids from subtropical regions. We performed a comparative analysis of the fungal community among H. dentata, H. yachangensis, and L. gigantea, determining their ITS regions using NGS paired-end sequences. The results clarified the diversity and the predominance of fungal genera. Ascomycota was abundant compared to Basidiomycota or other fungi groups in all communities, with a high dominance in all populations, especially for L. gigantea. At different root spatial locations, the fungal community diversity and richness were higher in the soil than in the rhizosphere or inner root. However, the results suggest that L. gigantea has a different fungal community compared to Habenaria species. In this order, the subtropical terrestrial orchids have a different fungal network compared to the northern terrestrial orchids. Also, there is a high probability of co-existence and co-evolution of endophytic fungi in these terrestrial orchids, indicating the potential role of host plants in selecting an endophytic fungal community. Furthermore, our results highlight the need to elucidate the microbe interactions of these unique orchids for long-term purposes, such as isolating indigenous fungi for suitable inoculants for further orchid propagation, restoration, and conservation.

Environmental factors that influence the germination of Bromeliadsseeds at a physiological level

Bromeliads are plants with epiphytic habits and in smaller quantities they develop on the ground. They are important at an ecological level since they function as indicators of environmental disturbance and intervene in nutrient and hydrological cycles. They also serve as hosts for arthropods and invertebrates, are ornamental,and have medicinal importance, which is why they are vulnerable to extraction by humans. If the germination of these plants in the wild is successful, their abundance and distribution willincrease. This review shows an analysis of the main factors that limit the germination of bromeliad seeds, a detaileddescription of the effect on germination of climatic factors such as light, temperature,and 71Revista Científica Vida NaturalUniversidad Autónoma de Chiriquírevistas.unachi.ac.paRevCient.VidNat, 2 (1) julio -diciembre, 2024, 70-81Revisión BibliográficaISSN L 2992-6424humidity is presented. In addition to some biotic factors that affect germination, which include the characteristics of the bark of the host tree, the allelopathic compounds that the bark can produce act as germination inhibitors, among others. Because bromeliads have very specific germination requirements, it is suggested that future studies explore topics in the physiology and ecology of germination processes, and thus have more detailed information on the factors that affect the germination of these seeds, both in the field and in the laboratory, tocollaborate in the conservation of these species.

A case of accidental epiphytes that supports the notion of the evolution of epiphytes from ancestors living in open environments.

Approximately 10 % of vascular plants can grow as epiphytes, but the impact of epiphytism is more remarkable because there is an unknown percentage of re-terrestrialized taxa that evolved from epiphytic ancestors. Two main hypotheses have been proposed to explain the evolution of epiphytes: one suggests that they evolved from humid, umbrophilous environments (i.e., forest understory; Schimper hypothesis), and the other that they came from an open-infertile environment (Tietze-Pittendrigh hypothesis). The core evidence supporting these hypotheses is the frequency of terrestrial plants that accidentally grow as epiphytes (i.e., accidental epiphytes), because these plants should be abundant in the habitats that promote the colonization of the canopy by the terrestrial plants (i.e., the early state of epiphyte evolution). In a landscape with both environments (humid and umbrophilous vs. open and infertile), we tested the affinity of the flora to the epiphytic habitat and the association of the accidental epiphytes with each environment. We found 71 plant species. Forty-one percent were terrestrial; among the rest, 39 %, 3 %, and 17 % were accidental, facultative (growing equally as terrestrial or arboreal), and true epiphytes (preferentially living as arboreal), respectively. Discounting plants that exclusively grow terrestrially in the sample, in this landscape, a large proportion of the species living in tree crowns are accidental epiphytes (28), and 16 species belong to Asteranae and Rosanae, superorders where epiphytism is infrequent. Nine accidental epiphytes were associated with the open environment and none with the forest, supporting only the Tietze-Pittendrigh hypothesis. Our results support the idea that species from open environments could be preadapted to grow as epiphytes, and landscapes combining forested areas with open environments (e.g., xerophytic scrub, savanna) could promote the colonization of the canopies from terrestrial plants.

Prevalent arbuscular mycorrhizae in roots and highly variable mycobiome in leaves of epiphytic subtropical fern Ophioderma pendulum.

Endophytic and mycorrhizal fungi are crucial in facilitating plant nutrition acquisition and stress tolerance. In epiphytic habitats, plants face nutrition and water stress, but their roots are mostly nonmycorrhizal and especially lacking in arbuscular mycorrhizal associations. Ophioderma pendulum is an epiphytic fern with a partially mycoheterotrophic lifestyle, likely heavily reliant on symbiotic fungi. To characterize fungal associations in the sporophyte of O. pendulum, we focused on leaves and roots of O. pendulum, seeking to reveal the fungal communities in these organs. Roots and leaves from O. pendulum in a subtropical forest were examined microscopically to observe the morphology of fungal structures and determine the percentage of various fungal structures in host tissues. Fungal composition was profiled using metabarcoding techniques that targeted ITS2 of the nuclear ribosomal DNA. Roots were consistently colonized by arbuscular mycorrhizal fungi (Glomeromycota), especially Acaulospora. Unlike previous findings on epiphytic ferns, dark septate endophytes were rare in O. pendulum roots. Leaves were predominantly colonized by Ascomycota fungi, specifically the classes Dothideomycetes (46.88%), Eurotiomycetes (11.51%), Sordariomycetes (6.23%), and Leotiomycetes (6.14%). Across sampling sites, fungal community compositions were similar in the roots but differed significantly in the leaves. Ophioderma pendulum maintains stable, single-taxon-dominant communities in the roots, primarily featuring arbuscular mycorrhizal fungi, whereas the leaves may harbor opportunistic fungal colonizers. Our study underlines the significance of mycorrhizal fungi in the adaptation of epiphytic ferns.

Mycorrhizal Fungi of Phalaenopsis japonica (Orchidaceae) and Their Role in Seed Germination and Seedling Development

Epiphytic orchids comprise 68% of vascular epiphytes globally; nevertheless, many are endangered. One such epiphytic orchid is Phalaenopsis japonica, which is widely used in the floricultural industry. This study aimed to identify the mycorrhizal fungi of adult P. japonica and their roles in seed germination and seedling development. Root samples were collected from 32 adults across 4 sites in southern Japan, and mycorrhizal fungi were identified using Sanger and high-throughput sequencing (HTS). The results show phylogenetically diverse mycobionts, mainly Ceratobasidiaceae (CE) and Tulasnellaceae (TU), with dominant OTUs designated CE6 and CE22. Sanger sequencing found 9 OTUs, 4 CE, and 5 TU; HTS detected 22 OTUs, 4 CE, 16 TU, and 2 Serendipitaceae. Seeds inoculated with CE6 improved germination and protocorm development compared with other strains. In addition, asymbiotic seedlings inoculated with CE6, CE22, and TU18 displayed varying effects in growth, with CE6 being the most notable. While TU18 did not promote seed germination, it effectively promoted leaf development in seedlings. Overall, Ceratobasidiaceae was predominantly associated with seed germination, seedling growth, and the adult stages, with CE6 and CE22 becoming the primary partners throughout the life history of P. japonica. Our findings illuminate mycorrhizal symbiosis in epiphytic habitats, offering conservation and commercial production insights.

Atributos das árvores hospedeiras, e não a diversidade da comunidade, conduzem a abundância de epífitas em florestas tropicais sazonais

Abstract Epiphytes are considered indicators of forest ecological integrity, but the factors that explain their abundance are still not well understood. We here evaluated tree colonization by epiphytes in old-growth monospecific reforestation stands of Astronium urundeuva (M.Allemão) Engl. (Anacardiaceae) and Eucalyptus saligna Sm. (Myrtaceae), in comparison to a neighbor seasonal tropical forest fragment under similar environmental conditions. In each forest type, we identified and measured all trees (planted and colonizers) from 5-cm stem diameter in five 200 m² plots and quantified all vascular epiphytes per tree. Tree species were categorized by bark roughness, canopy deciduousness and growth rate. The abundance of epiphytes and the frequency of host trees were higher in the A. urundeuva plantation than in the native forest, with the E. saligna stand in an intermediate position. Also, we found that host traits influenced the abundance of epiphytes in their trunks. Host trees had average stem perimeter and height both higher than non-hosts, which indicates that colonization is more likely to occur in older trees. The average abundance of epiphytes per tree was higher in species with rough bark, but no relationship was found with canopy deciduousness or tree growth rate. We evidenced, therefore, that forest plantations, even if monospecific, can provide habitat for epiphytes. However, at community level, colonization success, either in native or restored forest, depends on the relative abundance of species whose bark type favors epiphytes establishment.

Physiological and transcriptome analysis reveal the nitrogen preference and regulatory pathways of nitrogen metabolism in an epiphytic orchid, Cymbidium tracyanum

Epiphytic orchids acquire nutrients elements, including nitrogen, from the atmosphere. However, the nitrogen form preferred by epiphytic orchids Cymbidium tracyanum and adaptive mechanisms that underlie nitrogen metabolism remain unclear. In this study, we determined which nitrogen form the C. tracyanum prefers, and identified adaptive strategies and molecular pathways activated during nitrogen metabolism. For this purpose, we measured the physiological and morphological responses to different ratios of nitrate and ammonium (NO3−/NH4+ = 1:0, 3:1, 1:1, 1:3, 0:1) and used transcriptome analysis to identify genes differentially expressed in response to these nitrogen forms. Physiological and morphological measures of plant growth (i.e., net photosynthetic rate, biomass accumulation, leaf area, root elongation and branching) were highest in plants treated with nitrate. Furthermore, C. tracyanum plants treated with nitrate had a higher root/mass ratio and a lower leaf/mass ratio. Transcriptome analysis identified that several key genes (NRT1.1–2, NRT1.4–4, NRT1.7–2, and CLC-G-2) highly expressed in plants treated with pure nitrate. These genes may be involved in the absorption and transportation of nitrate, and in auxin transportation from leaf to root in C. tracyanum. Our findings suggest that the nitrogen form preferred by C. tracyanum is nitrate and that nitrate alters both root and leaf traits via several molecular pathways, including the plant hormone signal transduction pathway and MAPK signaling pathway. We speculate that the preference of C. tracyanum for nitrate as a nitrogen form may be a result of long-term adaptation to epiphytic habitat via the regulation of leaf and root traits.

A new approach to an old problem: how to categorize the habit of ferns and lycophytes.

Substrate preferences are often treated as species traits and are used to distinguish different habits, i.e. an epiphytic, lithophytic or terrestrial habit. Such a categorization, however, ignores substantial intraspecific variation. An approach that takes biological variability within a species into account is needed. We focused on four large genera of ferns and lycophytes and found relevant information in >500 sources, such as online databases, checklists, floras and species descriptions. Translating textual information into a quantitative index, we quantified the propensity to grow on either substrate as a continuous trait for 1475 species. Only a minority of species exhibited strict substrate fidelity, but a majority of them showed clear habitat preferences. The relative frequencies of intermediates between strict lithophytes, epiphytes and terrestrials does not support the frequent notion of ecological similarity of the lithophytic and epiphytic habitat. The compiled data are useful immediately for ecological and evolutionary studies with the focal taxa. More importantly, we propose the replacement of the concept of distinct habits with one of gradual differences. This should have a profound impact on any such study with plants in general.

Mycorrhizal specificity differences in epiphytic habitat: three epiphytic orchids harbor distinct ecological and physiological specificity.

Orchidaceae has diversified in tree canopies and accounts for 68% of vascular epiphytes. Differences in mycorrhizal communities among epiphytic orchids can reduce species competition for mycorrhizal fungi and contribute to niche partitioning, which may be a crucial driver of the unusual species diversification among orchids. Mycorrhizal specificity-the range of fungi allowing mycorrhizal partnerships-was evaluated by assessment of mycorrhizal communities in the field (ecological specificity) and symbiotic cultures in the laboratory (physiological specificity) for three epiphytic orchids inhabiting Japan. Mycorrhizal communities were assessed with co-existing individuals growing within 10cm of each other, revealing that ecological specificity varied widely among the three species, ranging from dominance by a single Ceratobasidiaceae fungus to diverse mycobionts across the Ceratobasidiaceae and Tulasnellaceae. In vitro seed germination tests revealed clear differences in physiological specificity among the three orchids, and that the primary mycorrhizal partners contributed to seed germination. In vitro compatibility ranges of three orchids strongly reflect the mycorrhizal community composition of wild populations. This suggests that differences in in situ mycorrhizal communities are not strongly driven by environmental factors, but are primarily due to physiological differences among orchid species. This study shows that the symbiotic strategy among the epiphytic orchid species varies from specialized to generalized association, which may contribute to biotic niche partitioning.

The genus Cultrobates (Acari: Oribatida: Ceratokalummidae) in the Galapagos Islands and Central America

The species Cultrobates heterodactylus Willmann, 1930 is known from Central America and has erroneously been reported from the Galapagos archipelago. A comparison with findings of this species from Panama has highlighted morphological differences between the specimens from Galapagos and C. heterodactylus. Herein, two new species from Galapagos, Cultrobates ermilovi n. sp. and Cultrobates subiasi n. sp. are described and illustrated. Also, differences in colonization of different islands as well as preferences in occupation of different habitats of the two species in Galapagos were noted, whereby C. subiasi was found almost exclusively in epiphytic habitats, predominantly in moss, and C. ermilovi occurs in various microhabitats in ground litter. Cultrobates heterodactylus occurs in Panama in lowland tropical rainforests, mainly in moist forest floor and litter in epiphytic bromeliads. Additional taxonomical remarks on C. heterodactylus are presented. Corrections to previous distribution data are given.

Age-related differences in physiological and metabolic responses of Pleione aurita (Orchidaceae) pseudobulbs to drought stress and recovery

The pseudobulb is a storage organ for water and nutrients that plays a crucial role in the growth and survival of epiphytic orchids. However, the role of water and metabolites in pseudobulb during adaptation to environmental stress are rarely detected through control experiments. In the present study, water-related physiological traits and metabolite changes in the pseudobulbs at the flowering stage and full leaf expansion stage for Pleione aurita were investigated after drought stress and recovery treatments. We found that the composition of non-structural carbohydrates (starch vs. soluble sugar) varied over the lifetime of pseudobulbs, and older pseudobulbs stored more water, whereas younger pseudobulbs stored more dry matter. When plants were subjected to drought stress and subsequent recovery, multiple metabolites in the pseudobulbs including non-structural carbohydrates, flavonoids, phenolic acids, as well as amino acids and their derivatives responded positively to these water level fluctuations. For those metabolites that differently accumulated in both stress and recovery processes, old pseudobulbs contained a higher number of these key metabolites than did the connected younger pseudobulbs. In addition, young and old pseudobulbs use different metabolic pathways to both respond and recover to drought. These results indicate that orchid pseudobulbs cope with water level fluctuations by mobilizing metabolite reserves and that pseudobulbs of different ages exhibit different physiological and metabolic responses to drought stress. These findings broadens our understanding of the role pseudobulbs play in the survival of orchids growing in epiphytic habitats.

A new Species of Anthurium section Calomystrium, subsection Rupicola (Araceae) from Peru

Anthurium is a highly diverse neotropical genus, in which many species remain undescribed. Here, we describe a new species of Anthurium (sect. Calomystrium, subsect. Rupicola) from Central Peru, which we name Anthurium huaytae. The species is also the first record for subsect. Rupicola for Peru. Anthurium huaytae resembles A. amnicola but differs by its epiphytic habit (vs. epipetric habit), white or light lavender spathe (vs. purple spathe), persistent cataphylls (vs. promptly deciduous cataphylls) and slimmer flowers in relation to its length (ratio 1:1.1) (vs. flowers with a length-width ratio of 2:3). We provide a description, photographs and the floral scent composition of the new species. In addition, an updated identification key including all the known species of Anthurium subsect. Rupicola is also provided.

The phylogeny of Syntrichia: An ecologically diverse clade of mosses with an origin in South America.

To address the biodiversity crisis, we need to understand the evolution of all organisms and how they fill geographic and ecological space. Syntrichia is one of the most diverse and dominant genera of mosses, ranging from alpine habitats to desert biocrusts, yet its evolutionary history remains unclear. We present a comprehensive phylogenetic analysis of Syntrichia, based on both molecular and morphological data, with most of the named species and closest outgroups represented. In addition, we provide ancestral-state reconstructions of water-related traits and a global biogeographic analysis. We found 10 major well-resolved subclades of Syntrichia that possess geographical or morphological coherence, in some cases representing previously accepted genera. We infer that the extant species diversity of Syntrichia likely originated in South America in the early Eocene (56.5-43.8 million years ago [Mya]), subsequently expanded its distribution to the neotropics, and finally dispersed to the northern hemisphere. There, the clade experienced a recent diversification (15-12 Mya) into a broad set of ecological niches (e.g., the S. caninervis and S. ruralis complexes). The transition from terricolous to either saxicolous or epiphytic habitats occurred more than once and was associated with changes in water-related traits. Our study provides a framework for understanding the evolutionary history of Syntrichia through the combination of morphological and molecular characters, revealing that migration events that shaped the current distribution of the clade have implications for morphological character evolution in relation to niche diversity.

KAJIAN FITOGEOGRAFI TUMBUHAN ANGGREK ENDEMIK DI HUTAN PENELITIAN UNIVERSITAS BORNEO TARAKAN

The purpose of this study is to examine the phytogeography of endemic orchid plants in the University of Borneo Tarakan research forest. In this sort of exploratory research, the sampling point is chosen by the researcher using an adaptive sampling sample. This study was conducted in the University of Borneo Tarakan’s Research Forest, which has an area of around 70 ha. The sample site has a 120,617 m² location area. According to the study’s findings, there are two different species of orchids, including Bromhedia finlaysoniana, which has a terrestrial habitat, and Dendrobium crumenatum, which has an epiphytic habitat. From the results of these values, the average distribution value is 1, which means that the distribution pattern is random. Orchid growth can also be affected by different environmental parameters in each location. Bromhedia finlaysoniana and Dendrobium crumenatum, two types of orchids that were discovered as a result of the research, are endemic to tropical southeast Asian countries and are common in many regions of Indonesia, including Kalimantan, Maluku, java, the Lesser Sunda Islands, Sulawasi, and Sumatra. Keywords: phytogeography study, Bromheadia finlaysoniana, Dendrobium crumenatu, Endemic

New Proposal of Epiphytic Bromeliaceae Functional Groups to Include Nebulophytes and Shallow Tanks.

The Bromeliaceae family has been used as a model to study adaptive radiation due to its terrestrial, epilithic, and epiphytic habits with wide morpho-physiological variation. Functional groups described by Pittendrigh in 1948 have been an integral part of ecophysiological studies. In the current study, we revisited the functional groups of epiphytic bromeliads using a 204 species trait database sampled throughout the Americas. Our objective was to define epiphytic functional groups within bromeliads based on unsupervised classification, including species from the dry to the wet end of the Neotropics. We performed a hierarchical cluster analysis with 16 functional traits and a discriminant analysis, to test for the separation between these groups. Herbarium records were used to map species distributions and to analyze the climate and ecosystems inhabited. The clustering supported five groups, C3 tank and CAM tank bromeliads with deep tanks, while the atmospheric group (according to Pittendrigh) was divided into nebulophytes, bromeliads with shallow tanks, and bromeliads with pseudobulbs. The two former groups showed distinct traits related to resource (water) acquisition, such as fog (nebulophytes) and dew (shallow tanks). We discuss how the functional traits relate to the ecosystems inhabited and the relevance of acknowledging the new functional groups.

The epiphytic bryophyte succession of Buxus sempervirens forests in the Fırtına Valley, Rize (North Türkiye)

In this study, the epiphytic bryophyte succession of the Buxus sempervirens L. forests in Fırtına Valley (Çamlıhemşin-Rize, North Türkiye), one of the nine biodiversity hotspots in Türkiye, were investigated. For this purpose, a total of 60 sampling plots were taken from the live trunks of the B. sempervirens trees of different ages. Twenty-nine epiphytic bryophyte species were determined (24 mosses and 5 liverworts) within the sample plots. Also, six different life form types and four different habitat affinity categories were determined. The mat type life form is in the first place with 34.4% whereas the and cortico-saxicolous species are the most common with 51.7%. Two-Way Indicator Species Analysis (TWINSPAN) classified the epiphytic bryophyte communities on the trunks of the B. sempervirens at the second level into two main clusters (A and B) and three sub-clusters (A1, B1 and, B2). Detrended Correspondence Analysis (DCA) axis 1 was interpreted as gradient along the height of the epiphytic habitat (from the lower base to the upper zone) on trunks and the DCA axis 2 was interpreted as gradient of moisture (from mesic to xeric). Exsertotheca crispa (Hedw.) S.Olsson, Enroth & D.Quandt was the species with the highest Index of Ecological Significance (IES) value on the lower bases of the aged trees. Species diversity and epiphytic cover in the upper zones were lower than in the basal and middle zones in the study area. While Metzgeria furcata, (L.) Corda, Oxyrrhynchium hians (Hedw.) Loeske, Plagiothecium nemorale (Mitt.) A.Jaeger, and Radula lindenbergiana Gottsche ex C.Hartm were only found on old trees, Ctenidium molluscum (Hedw.) Mitt. and Pseudoleskeella nervosa (Brid.) Nyholm were only found on middle-aged trees.