Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures;crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transe...Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures;crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transects were located at random in woody vegetation using quadrats 20 m × 20 m which were located every 100 m along 1 km long transects. For every host tree substrate sampled, tree species was identified and bark texture was determined. Presence and location of epiphytes were determined through direct observation. Epiphytes were collected, dried and weighed, so as to apportion biomass between rough and smooth bole textures, crown and trunk as well as stem inclination. Rough bole textured stems had more epiphytes of 1967 kg (89%) than smooth bole substrates of 313.48 kg (11%) and also inclined stems had higher biomass of 85% than vertical stems of 14.64% (χ2 = P < 0.005). Trunk had less biomass of 32% and crown had higher biomass of 68% (Mann Whitney U test 0.002 < P < 0.05). It was concluded that epiphytes were more abundant on rough bole textured substrates and in crown than stem. It would appear that rough bole textured substrates provided better physical anchorage and stability against dislodging forces of wind and rain water, hence being suitable for epiphyte establishment and survival. Inclined substrates on the other hand provided a suitable habitat for accumulation of debris and moisture retention, seed settling, germination, and maximum exposure to sunlight all of which support germination and growth of epiphytes. Further research is required to determine successional colonization, incidences of host species specificity, rain water interception and retention and impact of fire on epiphyte biomass as these are important water catchment attributes.展开更多
Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a com...Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.展开更多
Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes.Little is known about the processes and rates of their death and decomposition when ...Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes.Little is known about the processes and rates of their death and decomposition when they fall from the canopy,which limits our understanding of their role in forest carbon sequestration and nutri-ent cycling.In the temperate rainforest of the Quinault River Valley,Washington State,our aim was to test hypotheses regarding four elements of disturbance that might contribute to their decline.Methods We established set of experiments in which we placed samples of canopy epiphytes and their branch segments:(i)in the canopy versus forest floor microenvironment(stratum);(ii)attached to live versus dead branch substrates;(iii)subjected to physical disruption and‘jarring’;and(iv)in direct versus indirect con-tact with the forest floor.Over the 2-year study,we assigned a non-destructive‘vitality index’(based on color and appar-ent mortality and dryness)to each sample every 2-3 months to compare effects of the experimental treatments and analyzed with a statistical model and post hoc pairwise comparisons of treatments.Important Findings The canopy versus ground stratum and live/dead branch status sig-nificantly affected epiphyte vitality.Effects of physical disruption and ground contact were not significant.There were seasonal effects(low vitality during the sampling times in the summer,revitalization upon sampling times in the winter)for all treatments except samples in contact with the ground.One implication of these results relates to effects of climate change,which is predicted to shift to hotter,drier summers and wetter winters.Climate change may affect forest dynamics and nutrient cycling in unpredictable ways.Results also point to future experiments to understand biotic and abiotic effects on epiphyte disturbance and dynamics.展开更多
The effects of climatic warming on phyllosphere microbial communities remain uncertain.In this study,the effects of long-term(>10 years)experimental warming on phyllosphere epiphytic bacterial and fungal communitie...The effects of climatic warming on phyllosphere microbial communities remain uncertain.In this study,the effects of long-term(>10 years)experimental warming on phyllosphere epiphytic bacterial and fungal communities of Carex alrofusca,Kobresia pygmaea,Potentilla bifurca and Stipa capillacea were examined in the northern Xizang.Overall,warming increased bacterialα-diversity,but reduced fungalα-diversity across the four host plants.Warming altered the bacterial and fungal community compositions mainly by increasing Actinobacteria,Firmicutes and pathotrophsaprotroph fungi,and reducing Basidiomycota and symbiotroph fungi across the four host plants.Warming increased the relative effect of the‘drift&others’process in the bacterial community,but reduced the relative effect of the‘dispersal limitation’process in the bacterial community and the relative effect of the‘homogeneous selection’process in the fungal community across the four host plants.The overall warming effects on the bacterial and fungal communities may be due to overall warming effects on temperature,leaf morphology structure and physicochemical properties,ecological processes of community assembly and topological parameters of species co-occurrence networks of bacteria and fungi.Warming altered the bacterial species co-occurrence network mainly by increasing the vertex,clustering coefficient and heterogeneity,while reducing the average path length and network diameter across host species.Warming altered the fungal species co-occurrence network mainly by increasing the network diameter and reducing the vertex across host species.Warming effects on bacterial and fungal communities varied among host plants,which may be due to the diverse responses to warming of plant height,leaf malondialdehyde,ecological processes of community assembly and topological parameters of species co-occurrence network.Therefore,warming can alter phyllosphere epiphytic bacterial and fungal communities of alpine plants.Such changes varied among host plants and may cause adverse effects on the host plants.展开更多
Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observin...Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observing the patterns of species richness, abundances and species composition of epiphytic orchids and ferns in two subtropical forests in Nepal. We also studied the relationship of host plants(Schima wallichii and Quercus lanata) and epiphyte species. Data were collected in Naudhara community forest(CF) and the national forest(NF) in Shivapuri Nagarjun National Park. The data were analyzed using univariate and multivariate tests. In total, we recorded 41 species of epiphytes(33 orchid and 8 fern species). Orchid species abundance is significantlyhigher in CF compared to NF. Orchid species richness and abundance increased with increasing southern aspect whereas it decreased with increasing canopy cover, and fern species richness increased with host bark roughness. Orchid abundance was positively correlated with increasing bark p H, stem size, tree age and tree height and negatively correlated with increasing steepness of the area. Likewise, fern abundances were high in places with high canopy cover, trees that were tall and big, but decreased with increasing altitude and southern aspect. The composition of the orchid and fern species was affected by altitude, aspect, canopy cover, DBH, number of forks and forest management types. We showed that the diversity of orchid and fern epiphytes is influenced by host characteristics as well as host types. The most important pre-requisite for a high epiphyte biodiversity is the presence of oldrespectively tall trees, independent of the recent protection status. This means:(i) for protection, e.g.in the frame of the national park declaration, such areas should be used which host such old tall trees;and(ii) also in managed forests and even in intensively used landscapes epiphytes can be protected by letting a certain number of trees be and by giving them space to grow old and tall.展开更多
In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC)...In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.展开更多
A study on the spatial and seasonal variations of the associate macroalgae and epiphytes of Thalassia testudinum was carried out in Bahía de Nuevitas. Sixty-two species were identified: 3 Cyanophyta, 25 Chlorophy...A study on the spatial and seasonal variations of the associate macroalgae and epiphytes of Thalassia testudinum was carried out in Bahía de Nuevitas. Sixty-two species were identified: 3 Cyanophyta, 25 Chlorophyta, 8 Phaeophyceae, 23 Rhodophyta and 3 Magnoliophyta, with two new records for Cuba and 43 for the area. The differences in the specific composition of the macroalgae communities are determined by a space component related to the type of affectation in each area. The morpho-functional groups of macroalgae in the station with more nutrient influence were mainly foliaceous and filamentous. In the stations far from the city, the predominant morpho-types were the leathery and articulate calcareous indicators of lower nitrification levels. The abundance and diversity of macroalgae in the site affected by fisheries were lower due to the damage by bottom trawls. Seasonal variations were found in the relative abundance of the species, not in the diversity, which makes evident seasonal changes in the structure of the seaweeds, where some species replace others in the community.展开更多
Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canop...Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.展开更多
In our trials, from 2007 to 2008, of mass production of seedlings of Hizikiafusiformis using synchronization techniques, problems of a ＂dark thalli＂ phenomenon and epiphytes contamination severely threatened the hea...In our trials, from 2007 to 2008, of mass production of seedlings of Hizikiafusiformis using synchronization techniques, problems of a ＂dark thalli＂ phenomenon and epiphytes contamination severely threatened the health of juvenile seedlings. In this investigation, we optimized conditions for improving the growth of juvenile seedlings. Seven string collectors were seeded with zygotes and a series of experiments were conducted including direct exposure to solar irradiance, co-culture with Ulva spp. and treatment with sodium hypochlorite. It was found that direct exposure to solar irradiance （maximum： 1 740 μmol photons/（m2.s）） for 2 h per day could efficiently enhance the growth of young seedlings and simultaneously inhibit the growth of epiphytic algae. In this treatment, 50-day old seedlings could reach an average of 0.44 cm in length and possess up to nine leaflets. However, a single treatment with 18-mmol/L sodium hypochlorite for 10 rain severely harmed 15-day old seedlings. In comparison, weekly treatment with 2.2-mmol/L sodium hypochlorite for 10 rain brought no apparent harm to seedlings and eliminated epiphytic algae efficiently. However, this treatment significantly increased the detachment rate of seedlings, Inoculating Ulva spp. onto the collector caused a dramatic decrease in the number of seedlings. However, the growth of the remaining seedlings appeared unhampered. All collectors except the control were daily sprayed with a high pressure water jet from the 84 day post fertilization. From the first day to 50th day, no ＂dark thallus＂ was observed on any of the seven collectors. We believe that well-timed daily exposure to solar irradiance would favor H. fusiformis in its early growing stages.展开更多
Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is c...Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is consistently threatened by illegal trade and habitat transformation.Here,we identified areas critical for orchid conservation in the biogeographic province of Megamexico.For this purpose,we evaluated orchid endemism,phylogenetic diversity,and phylogenetic endemism within Megamexico and characterized orchid life forms.Our results indicate that the majority of the regions with the highest estimates of endemism and phylogenetic endemism are in southern Mexico and northern Central America,mostly located on the Pacific side of Megamexico.Among the most important orchid lineages,several belong to epiphytic lineages such as Pleurothallidinae,Laeliinae and Oncidiinae.We also found that species from diverse and distantly related lineages converge in montane forests where suitable substrates for epiphytes abound.Furthermore,the southernmost areas of phylogenetic diversity and endemism of Megamexico are in unprotected areas.Thus,we conclude that the most critical areas for orchid conservation in Megamexico are located in southern Mexico and northern Central America.We recommend that these areas should be given priority by the Mexican system of natural protected areas as complementary conservation areas.展开更多
The article presents information about the taxonomy and ecology of lichens in the Ohaliksai River basin. According to the conducted studies, 11 families <span>of the Lecanoromycetes class (Parmeliaceae, </spa...The article presents information about the taxonomy and ecology of lichens in the Ohaliksai River basin. According to the conducted studies, 11 families <span>of the Lecanoromycetes class (Parmeliaceae, </span></span><span style="font-size:10.0pt;font-family:"">Lecanoraceae</span><span style="font-size:10.0pt;font-family:"">, Ramalinaceae, M</span><span style="font-size:10.0pt;font-family:"">e<span>gasporaceae, Physciaceae, Teloschistaceae, Peltigeraceae, Collemataceae, Ca</span>n<span>delariaceae, Umbilicariaceae, Physciaceae), 1 family of the Eurotiomycetes cla</span>ss (Verrucariaceae) and 1 family Lichinaceae of the class Lichinomycetes were identified, 18 groups and 23 species were noted as widespread. The taxonomic<span> analysis and ecological characteristics of the identified specie</span>s are presented.展开更多
Immigrant bacteria located on leaf surfaces are important to the health of plants as well as to people who consume fresh fruits and vegetables. However, the spatial distribution and organization of these immigrant bac...Immigrant bacteria located on leaf surfaces are important to the health of plants as well as to people who consume fresh fruits and vegetables. However, the spatial distribution and organization of these immigrant bacteria on leaf surfaces are still poorly understood. To examine the spatial organization of these strains, two bacterial strains on tobacco leaves： （1） an indigenous strain, Pseudomonas stutzeri Nov. Y2011 labeled with green fluorescent protein, and （2） an immigrant strain Pantoea agglomerans labeled with cyan fluorescent protein isolated from pear, were studied. Under moist conditions, P. agglomerans cells quickly disappeared from direct observation by laser- scanning confocal microscopy, although elution results indicated that large amounts of live cells were still present on the leaves. Following exposure to desiccation stress, particles of cyan fluorescent protein-labeled P. agglomerans were visible within cracked aggregates of P. stutzeri Nov. Y2011. Detailed observation of sectioned aggregates showed that colonies of immigrant P. agglomerans were embedded within aggregates of P. stutzeri Nov. Y2011. Furthermore, carbon-resource partitioning studies suggested that these two species could coexist without significant nutritional competition. This is the first observation of an immigrant bacterium embedding within aggregates of indigenous bacteria on leaves to evade harsh conditions in the phyllosphere.展开更多
Vascular epiphytes are one of the most important forest components,contributing to microclimatic maintenance.These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high t...Vascular epiphytes are one of the most important forest components,contributing to microclimatic maintenance.These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high temperature and humidity typical of this biome.In recent years,the Brazilian Amazon has undergone dramatic changes in its landscape,mainly due to the increase in deforestation and fire rates.We present here the floristic composition and analyze the community structure of epiphytic angiosperms of an urban forest fragment in Eastern Amazon.A total of 71 epiphytic individuals were recorded belonging to eight species and four families.Orchidaceae was the most representative family,corroborating the pattern for surveys of epiphytic diversity in the Neotropical region.Epiphytic species were found on 24 individuals of 10 tree species.The epiphytic importance value(IVe)was low for all species,except for Aechmea tocantina and Rhipsalis baccifera.Cactaceae was the family with the highest IVe.Most epiphytes were found in the crown of trees(83.1%).The diversity index of the fragment was H’=1.80 and the equity index was J=0.87,reflecting the absence of highly dominant species.Conservation of urban forest fragments is necessary for the maintenance of epiphytic flora and ecosystem services.展开更多
Various species of mangrove trees thrive in the mangrove forests of Calabarzon,Philippines including species of Avicennia marina,Rhizophora mucronata,and Rhizophora apiculata,which house various lichen species but ver...Various species of mangrove trees thrive in the mangrove forests of Calabarzon,Philippines including species of Avicennia marina,Rhizophora mucronata,and Rhizophora apiculata,which house various lichen species but very little available information on the diversity of these epiphytes is known.A survey of 90 decaying mangrove woods from 3 mangrove sites in Calabarzon including Laiya Batangas,Tanza Cavite and Pagbilao Quezon recorded a total of 40 lichen species classified under 25 genera and 14 families.Rhizophora apiculata(bakawang lalaki)was found the most preferred lichen establishment host as it housed 23 lichen species followed by Rhizophora mucronata(bakawang babae)with 17 lichen species and Avicenia marina with 7 lichen species.Lichens that belong to family Arthoniaceae,Caliciaceae,Parmeliaceae,Collemataceae,and Graphidaceae were the highest recorded.Most of these manglicolous lichens were classified as crustose(60%)and foliose(40%)lichens.Out of these manglicolous lichens identified,29 species were found to be new records of lichens in the Philippines.展开更多
This study describes the anatomy of sterile leaves of Elaphoglossum discolor (Kuhn) C. Chr., E. flaccidum (Fée) T. Moore and E. laminarioides (Bory ex Fée) T. Moore, the most representative species of the ge...This study describes the anatomy of sterile leaves of Elaphoglossum discolor (Kuhn) C. Chr., E. flaccidum (Fée) T. Moore and E. laminarioides (Bory ex Fée) T. Moore, the most representative species of the genus in the Ecological Park of Gunma in Pará State. It reports the main diagnostic characters and provides new systematic data for the group. In addition, it locates the production and accumulation sites of bioactive compounds to determine possible adaptive strategies of these species in the Amazon rainforest environment. Diagnostic structural features include stoma typology, central veins and margin forms, type of mesophyll, and the presence of schlerenchymatous sheaths in the cortex, among others. Among the bioactive compounds related to defense adaptation are phenolic compounds, which occur in all three species, and alkaloids and mucilage, which are exclusive to E. laminarioides. Of the three species studied, E. laminarioides has features that make it the best suited to the rainforest environment.展开更多
Leaves of terrestrial and aquatic plants are home to a wide diversity of bacterial species. However, the diversity and variability of epiphytic bacteria on their submerged plant hosts remains poorly understood. We inv...Leaves of terrestrial and aquatic plants are home to a wide diversity of bacterial species. However, the diversity and variability of epiphytic bacteria on their submerged plant hosts remains poorly understood. We investigated the diversity and composition of epiphytic bacteria from two common submerged macrophytes: Vallisneria natans and Hydrilla verticillata in Taihu Lake, Jiangsu, China, using methods of terminal restriction fragment length polymorphisms (T-RFLP) and clone library analyses targeted at bacterial 16S rRNA genes. The results show that: (1) the libraries of the two waterweeds contain wide phylogenetic distribution of bacteria, and that the sequences of the two libraries can be separated into 93 OTUs (at 97% similar value); (2) Betaproteobacteria, including Burkholderiales, was the most abundant bacterial group on both plants. Cyanobacteria and Gammaproteobacteria were the second largest groups on V. natans and H. verticillata, respectively. Both clone libraries included some sequences related to those of methanotrophs and nitrogen-fixing bacteria; (3) Cluster analysis of the T-RFLP profiles showed two distinct clusters corresponding to the two plant populations. Both ANOSIM of the T-RFLP data and Libshuff analysis of the two clone libraries indicated a significant difference in epiphytic bacterial communities between the two plants. Therefore, the epiphytic bacterial communities on submerged macrophytes appear to be diverse and host-specific, which may aid in understanding the ecological functions of submerged macrophytes in general.展开更多
We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four sp...We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four species of algae:Gracilaria textorii,Ulva pertusa,Laminaria japonica,and Polysiphonia urceolata.The isolated strains of bacteria can be divided into two groups:Halomonas and Vibrio,in physiology,biochemical characteristics and 16S rDNA sequence analyses.The phylogenetic tree constructed based on 16S rDNA sequences of the isolates shows four obvious clusters,Halomonas venusta,Vibrio tasmaniensis,Vibrio lentus,and Vibrio splendidus.Isolates from the surface of P.urceolata are more abundant and diverse,of which strains P9 and P28 have a 16S rDNA sequence very similar(97.5%-99.8%) to that of V.splendidus.On the contrary,the isolates from the surfaces of G.textorii,U.pertusa and L.japonica are quite simple and distribute on different branches of the phylogenetic tree.In overall,the results of this study indicate that the genetic relationships among the isolates are quite close and display a certain level of host species specificity,and alga-associated bacteria species are algal species specific.展开更多
文摘Epiphyte biomass (dry weight kg) placement between rough and smooth bole bark textures;crown and trunk as well as upright and horizontal substrates in Lusenga National Park were examined through ground surveys. Transects were located at random in woody vegetation using quadrats 20 m × 20 m which were located every 100 m along 1 km long transects. For every host tree substrate sampled, tree species was identified and bark texture was determined. Presence and location of epiphytes were determined through direct observation. Epiphytes were collected, dried and weighed, so as to apportion biomass between rough and smooth bole textures, crown and trunk as well as stem inclination. Rough bole textured stems had more epiphytes of 1967 kg (89%) than smooth bole substrates of 313.48 kg (11%) and also inclined stems had higher biomass of 85% than vertical stems of 14.64% (χ2 = P < 0.005). Trunk had less biomass of 32% and crown had higher biomass of 68% (Mann Whitney U test 0.002 < P < 0.05). It was concluded that epiphytes were more abundant on rough bole textured substrates and in crown than stem. It would appear that rough bole textured substrates provided better physical anchorage and stability against dislodging forces of wind and rain water, hence being suitable for epiphyte establishment and survival. Inclined substrates on the other hand provided a suitable habitat for accumulation of debris and moisture retention, seed settling, germination, and maximum exposure to sunlight all of which support germination and growth of epiphytes. Further research is required to determine successional colonization, incidences of host species specificity, rain water interception and retention and impact of fire on epiphyte biomass as these are important water catchment attributes.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB31000000)to D.-Z.L.and J.-B.Y.CAS Pioneer Hundred Talents Program to A.Z.+1 种基金the Project for Innovation Team of Yunnan Province(grant no.202105AE160012)to S.-B.Z.the Science and Technology Basic Resources Investigation Program of China(grant no.2021FY100200)to J.-B.Y.
文摘Epiphytes with crassulacean acid metabolism(CAM)photosynthesis are widespread among vascular plants,and repeated evolution of CAM photosynthesis is a key innovation for micro-ecosystem adaptation.However,we lack a complete understanding of the molecular regulation of CAM photosynthesis in epiphytes.Here,we report a high-quality chromosome-level genome assembly of a CAM epiphyte,Cymbidium mannii(Orchidaceae).The 2.88-Gb orchid genome with a contig N50 of 22.7 Mb and 27192 annotated genes was organized into 20 pseudochromosomes,82.8%of which consisted of repetitive elements.Recent expansions of long terminal repeat retrotransposon families have made a major contribution to the evolution of genome size in Cymbidium orchids.We reveal a holistic scenario of molecular regulation of metabolic physiology using high-resolution transcriptomics,proteomics,and metabolomics data collected across a CAM diel cycle.Patterns of rhythmically oscillating metabolites,especially CAM-related products,reveal circadian rhythmicity in metabolite accumulation in epiphytes.Genomewide analysis of transcript and protein level regulation revealed phase shifts during the multifaceted regulation of circadian metabolism.Notably,we observed diurnal expression of several core CAM genes(especially bCA and PPC)that may be involved in temporal fixation of carbon sources.Our study provides a valuable resource for investigating post-transcription and translation scenarios in C.mannii,an Orchidaceae model for understanding the evolution of innovative traits in epiphytes.
基金National Science Foundation(EHR 15-14494 and DEB 11-41833 to N.M.N.and DBI 1400456 to K.D.K.).
文摘Aims Epiphytes are an abundant and diverse component of many wet temperate forests and have significant roles in ecosystem processes.Little is known about the processes and rates of their death and decomposition when they fall from the canopy,which limits our understanding of their role in forest carbon sequestration and nutri-ent cycling.In the temperate rainforest of the Quinault River Valley,Washington State,our aim was to test hypotheses regarding four elements of disturbance that might contribute to their decline.Methods We established set of experiments in which we placed samples of canopy epiphytes and their branch segments:(i)in the canopy versus forest floor microenvironment(stratum);(ii)attached to live versus dead branch substrates;(iii)subjected to physical disruption and‘jarring’;and(iv)in direct versus indirect con-tact with the forest floor.Over the 2-year study,we assigned a non-destructive‘vitality index’(based on color and appar-ent mortality and dryness)to each sample every 2-3 months to compare effects of the experimental treatments and analyzed with a statistical model and post hoc pairwise comparisons of treatments.Important Findings The canopy versus ground stratum and live/dead branch status sig-nificantly affected epiphyte vitality.Effects of physical disruption and ground contact were not significant.There were seasonal effects(low vitality during the sampling times in the summer,revitalization upon sampling times in the winter)for all treatments except samples in contact with the ground.One implication of these results relates to effects of climate change,which is predicted to shift to hotter,drier summers and wetter winters.Climate change may affect forest dynamics and nutrient cycling in unpredictable ways.Results also point to future experiments to understand biotic and abiotic effects on epiphyte disturbance and dynamics.
基金funded by the Pilot Project of Chinese Academy of Sciences(XDA26050501)the Youth Innovation Promotion Association of Chinese Academy of Sciences(2020054)+3 种基金the National Natural Science Foundation of China(31600432)the Lhasa Science and Technology Plan Project,China(LSKJ202422)the Tibet Autonomous Region Science and Technology Project,China(XZ202401JD0029)the Construction of Zhongba County Fixed Observation and Experiment Station of First Support System for Agriculture Green Development,China。
文摘The effects of climatic warming on phyllosphere microbial communities remain uncertain.In this study,the effects of long-term(>10 years)experimental warming on phyllosphere epiphytic bacterial and fungal communities of Carex alrofusca,Kobresia pygmaea,Potentilla bifurca and Stipa capillacea were examined in the northern Xizang.Overall,warming increased bacterialα-diversity,but reduced fungalα-diversity across the four host plants.Warming altered the bacterial and fungal community compositions mainly by increasing Actinobacteria,Firmicutes and pathotrophsaprotroph fungi,and reducing Basidiomycota and symbiotroph fungi across the four host plants.Warming increased the relative effect of the‘drift&others’process in the bacterial community,but reduced the relative effect of the‘dispersal limitation’process in the bacterial community and the relative effect of the‘homogeneous selection’process in the fungal community across the four host plants.The overall warming effects on the bacterial and fungal communities may be due to overall warming effects on temperature,leaf morphology structure and physicochemical properties,ecological processes of community assembly and topological parameters of species co-occurrence networks of bacteria and fungi.Warming altered the bacterial species co-occurrence network mainly by increasing the vertex,clustering coefficient and heterogeneity,while reducing the average path length and network diameter across host species.Warming altered the fungal species co-occurrence network mainly by increasing the network diameter and reducing the vertex across host species.Warming effects on bacterial and fungal communities varied among host plants,which may be due to the diverse responses to warming of plant height,leaf malondialdehyde,ecological processes of community assembly and topological parameters of species co-occurrence network.Therefore,warming can alter phyllosphere epiphytic bacterial and fungal communities of alpine plants.Such changes varied among host plants and may cause adverse effects on the host plants.
基金“Bauer-Stiftung und Glaser-Stiftung im Stifterverband für die Deutsche Wissenschaft” Project No. T237/24905/2013/Kg for the research grantgrant number 14-36098G of the Czech Science Foundation and the institutional support RVO 67985939
文摘Epiphytic plant species are an important part of biological diversity. It is therefore essential to understand the distribution pattern and the factors influencing such patterns. The present study is aimed at observing the patterns of species richness, abundances and species composition of epiphytic orchids and ferns in two subtropical forests in Nepal. We also studied the relationship of host plants(Schima wallichii and Quercus lanata) and epiphyte species. Data were collected in Naudhara community forest(CF) and the national forest(NF) in Shivapuri Nagarjun National Park. The data were analyzed using univariate and multivariate tests. In total, we recorded 41 species of epiphytes(33 orchid and 8 fern species). Orchid species abundance is significantlyhigher in CF compared to NF. Orchid species richness and abundance increased with increasing southern aspect whereas it decreased with increasing canopy cover, and fern species richness increased with host bark roughness. Orchid abundance was positively correlated with increasing bark p H, stem size, tree age and tree height and negatively correlated with increasing steepness of the area. Likewise, fern abundances were high in places with high canopy cover, trees that were tall and big, but decreased with increasing altitude and southern aspect. The composition of the orchid and fern species was affected by altitude, aspect, canopy cover, DBH, number of forks and forest management types. We showed that the diversity of orchid and fern epiphytes is influenced by host characteristics as well as host types. The most important pre-requisite for a high epiphyte biodiversity is the presence of oldrespectively tall trees, independent of the recent protection status. This means:(i) for protection, e.g.in the frame of the national park declaration, such areas should be used which host such old tall trees;and(ii) also in managed forests and even in intensively used landscapes epiphytes can be protected by letting a certain number of trees be and by giving them space to grow old and tall.
文摘In the coastal ecosystems of the Black Sea,macrophytobenthos and,in particular,the association of Cystoseira crinite,C.barbara,Cladostephus verticillatus,and Corallina mediterranea,with its thick vegetative canopy(VC),is the key contributor to primary production(PP).Though the vertical structure of the canopy,formed by the algal association,is of principal importance to the PP level,this subject has been long-neglected by researchers.The goal of our work was to compare vertical structures of the vegetative canopy of Cystoseira brown algae under diverse hydrodynamical conditions of the Crimean Peninsula coast.Samples were collected using the 50 cm×50 cm counting frame at eight stations positioned in shallow(55-60 cm deep)sites of Sevastopol Bay(Crimean Peninsula).Dry weight biomass of the VC was determined for all algae assemblage and for each algal species individually,per horizontal surface unit,at each height(Z).The study shows that:1)the VC is characterized by unimodal vertical distribution of biomass,with maximum estimate in the lower part,where the biomass increases to 85%of the total biomass;2)a series of single-peaked curves reliably describes the unimodal distribution of the biomass;thalli of different age groups are found along the canopy profile;and 3)algae found in epiphytic synusia prefer inhabiting the upper part of the VC.The role of environmental factors(seawater turbulence and solar radiation)is discussed in reference to the formation of the vertical structure,made up of the associations of the brown algae Cystoseira.
文摘A study on the spatial and seasonal variations of the associate macroalgae and epiphytes of Thalassia testudinum was carried out in Bahía de Nuevitas. Sixty-two species were identified: 3 Cyanophyta, 25 Chlorophyta, 8 Phaeophyceae, 23 Rhodophyta and 3 Magnoliophyta, with two new records for Cuba and 43 for the area. The differences in the specific composition of the macroalgae communities are determined by a space component related to the type of affectation in each area. The morpho-functional groups of macroalgae in the station with more nutrient influence were mainly foliaceous and filamentous. In the stations far from the city, the predominant morpho-types were the leathery and articulate calcareous indicators of lower nitrification levels. The abundance and diversity of macroalgae in the site affected by fisheries were lower due to the damage by bottom trawls. Seasonal variations were found in the relative abundance of the species, not in the diversity, which makes evident seasonal changes in the structure of the seaweeds, where some species replace others in the community.
基金The National Natural Science Foundation of China under contract Nos 32170127 and 42176156the Fundamental Research Funds for the Central Universities under contract No.202141006。
文摘Large numbers of bacteria live on the surface of various brown algae and can produce alginate lyases to consume alginate,an important component of the cell wall of brown algae.Sargassum is a genus of the largest canopyforming brown algae of more than 150 species,which are widely distributed in tropical and subtropical environments.However,our knowledge about the epiphytic bacteria and the alginate lyase-excreting bacteria from Sargassum is still primitive.Here,we investigated the diversity of the culturable epiphytic bacteria and alginate-degrading bacteria from Sargassum samples collected from the coastal seawaters of Shandong Province,China.In total,37 strains belonging to 21 genera in 3 phyla were isolated,including 15 previously unreported genera,of which Vibrio(6/37)and Pseudoalteromonas(5/37)are the dominant genera.Eight strains,mainly Vibrio and Pseudoalteromonas species,were further identified as alginate lyase-excreting strains that can utilize alginate for growth.The extracellular alginolytic activity of the 8 strains was determined,and strains Vibrio sp.C42and Pseudoalteromonas sp.M9 showed the highest activity.These results provide a better understanding of brown algae epiphytes and alginate-degrading bacteria,and are fundamental for further studies on the interactions between brown algae and their epiphytes.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (Nos. 2006AA10A412 2006AA10A416)+1 种基金Main Program of National Science Infrastructure Platform, a project from the Ministry of Science and Technology of China (No. 2006DKA30470-017)a non-profit program from the Ministry of Agriculture of China (No. 200903030)
文摘In our trials, from 2007 to 2008, of mass production of seedlings of Hizikiafusiformis using synchronization techniques, problems of a ＂dark thalli＂ phenomenon and epiphytes contamination severely threatened the health of juvenile seedlings. In this investigation, we optimized conditions for improving the growth of juvenile seedlings. Seven string collectors were seeded with zygotes and a series of experiments were conducted including direct exposure to solar irradiance, co-culture with Ulva spp. and treatment with sodium hypochlorite. It was found that direct exposure to solar irradiance （maximum： 1 740 μmol photons/（m2.s）） for 2 h per day could efficiently enhance the growth of young seedlings and simultaneously inhibit the growth of epiphytic algae. In this treatment, 50-day old seedlings could reach an average of 0.44 cm in length and possess up to nine leaflets. However, a single treatment with 18-mmol/L sodium hypochlorite for 10 rain severely harmed 15-day old seedlings. In comparison, weekly treatment with 2.2-mmol/L sodium hypochlorite for 10 rain brought no apparent harm to seedlings and eliminated epiphytic algae efficiently. However, this treatment significantly increased the detachment rate of seedlings, Inoculating Ulva spp. onto the collector caused a dramatic decrease in the number of seedlings. However, the growth of the remaining seedlings appeared unhampered. All collectors except the control were daily sprayed with a high pressure water jet from the 84 day post fertilization. From the first day to 50th day, no ＂dark thallus＂ was observed on any of the seven collectors. We believe that well-timed daily exposure to solar irradiance would favor H. fusiformis in its early growing stages.
基金The study was carried out with the support of CONACyT,which awarded an M.Sc.scholarship to BEGR(CVU935962)through the Instituto de Ecología,A.C.
文摘Orchid diversity provides a unique opportunity to further our understanding of biotic and abiotic factors linked to patterns of richness,endemism,and phylogenetic endemism in many regions.However,orchid diversity is consistently threatened by illegal trade and habitat transformation.Here,we identified areas critical for orchid conservation in the biogeographic province of Megamexico.For this purpose,we evaluated orchid endemism,phylogenetic diversity,and phylogenetic endemism within Megamexico and characterized orchid life forms.Our results indicate that the majority of the regions with the highest estimates of endemism and phylogenetic endemism are in southern Mexico and northern Central America,mostly located on the Pacific side of Megamexico.Among the most important orchid lineages,several belong to epiphytic lineages such as Pleurothallidinae,Laeliinae and Oncidiinae.We also found that species from diverse and distantly related lineages converge in montane forests where suitable substrates for epiphytes abound.Furthermore,the southernmost areas of phylogenetic diversity and endemism of Megamexico are in unprotected areas.Thus,we conclude that the most critical areas for orchid conservation in Megamexico are located in southern Mexico and northern Central America.We recommend that these areas should be given priority by the Mexican system of natural protected areas as complementary conservation areas.
文摘The article presents information about the taxonomy and ecology of lichens in the Ohaliksai River basin. According to the conducted studies, 11 families <span>of the Lecanoromycetes class (Parmeliaceae, </span></span><span style="font-size:10.0pt;font-family:"">Lecanoraceae</span><span style="font-size:10.0pt;font-family:"">, Ramalinaceae, M</span><span style="font-size:10.0pt;font-family:"">e<span>gasporaceae, Physciaceae, Teloschistaceae, Peltigeraceae, Collemataceae, Ca</span>n<span>delariaceae, Umbilicariaceae, Physciaceae), 1 family of the Eurotiomycetes cla</span>ss (Verrucariaceae) and 1 family Lichinaceae of the class Lichinomycetes were identified, 18 groups and 23 species were noted as widespread. The taxonomic<span> analysis and ecological characteristics of the identified specie</span>s are presented.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences (No. KSCX2YW-JS401, KSCX2-YW-G-072)the National Natural Science Foundation of China (No. 20777089, 21177145)the National High Technology Research and Development Program (863) of China (No. 2007AA06A407)
文摘Immigrant bacteria located on leaf surfaces are important to the health of plants as well as to people who consume fresh fruits and vegetables. However, the spatial distribution and organization of these immigrant bacteria on leaf surfaces are still poorly understood. To examine the spatial organization of these strains, two bacterial strains on tobacco leaves： （1） an indigenous strain, Pseudomonas stutzeri Nov. Y2011 labeled with green fluorescent protein, and （2） an immigrant strain Pantoea agglomerans labeled with cyan fluorescent protein isolated from pear, were studied. Under moist conditions, P. agglomerans cells quickly disappeared from direct observation by laser- scanning confocal microscopy, although elution results indicated that large amounts of live cells were still present on the leaves. Following exposure to desiccation stress, particles of cyan fluorescent protein-labeled P. agglomerans were visible within cracked aggregates of P. stutzeri Nov. Y2011. Detailed observation of sectioned aggregates showed that colonies of immigrant P. agglomerans were embedded within aggregates of P. stutzeri Nov. Y2011. Furthermore, carbon-resource partitioning studies suggested that these two species could coexist without significant nutritional competition. This is the first observation of an immigrant bacterium embedding within aggregates of indigenous bacteria on leaves to evade harsh conditions in the phyllosphere.
文摘Vascular epiphytes are one of the most important forest components,contributing to microclimatic maintenance.These plants find ideal conditions for development in the Amazon due to the spatial heterogeneity and high temperature and humidity typical of this biome.In recent years,the Brazilian Amazon has undergone dramatic changes in its landscape,mainly due to the increase in deforestation and fire rates.We present here the floristic composition and analyze the community structure of epiphytic angiosperms of an urban forest fragment in Eastern Amazon.A total of 71 epiphytic individuals were recorded belonging to eight species and four families.Orchidaceae was the most representative family,corroborating the pattern for surveys of epiphytic diversity in the Neotropical region.Epiphytic species were found on 24 individuals of 10 tree species.The epiphytic importance value(IVe)was low for all species,except for Aechmea tocantina and Rhipsalis baccifera.Cactaceae was the family with the highest IVe.Most epiphytes were found in the crown of trees(83.1%).The diversity index of the fragment was H’=1.80 and the equity index was J=0.87,reflecting the absence of highly dominant species.Conservation of urban forest fragments is necessary for the maintenance of epiphytic flora and ecosystem services.
基金the College of Science,University of Santo Tomas the Fungal Biodiversity Ecogenomics and Systematics(FBeS)Group for their unwavering support in the performance of this study.
文摘Various species of mangrove trees thrive in the mangrove forests of Calabarzon,Philippines including species of Avicennia marina,Rhizophora mucronata,and Rhizophora apiculata,which house various lichen species but very little available information on the diversity of these epiphytes is known.A survey of 90 decaying mangrove woods from 3 mangrove sites in Calabarzon including Laiya Batangas,Tanza Cavite and Pagbilao Quezon recorded a total of 40 lichen species classified under 25 genera and 14 families.Rhizophora apiculata(bakawang lalaki)was found the most preferred lichen establishment host as it housed 23 lichen species followed by Rhizophora mucronata(bakawang babae)with 17 lichen species and Avicenia marina with 7 lichen species.Lichens that belong to family Arthoniaceae,Caliciaceae,Parmeliaceae,Collemataceae,and Graphidaceae were the highest recorded.Most of these manglicolous lichens were classified as crustose(60%)and foliose(40%)lichens.Out of these manglicolous lichens identified,29 species were found to be new records of lichens in the Philippines.
基金The authors thank Dr.Alejandra Vasco,New York Bo-tanical Garden(NYBG),for information on the systema-tics studies in the groupthe National Council for Sci-entific and Technological Development(CNPq)for the Master scholarship of the first author(CNPq 132809/2009-5).
文摘This study describes the anatomy of sterile leaves of Elaphoglossum discolor (Kuhn) C. Chr., E. flaccidum (Fée) T. Moore and E. laminarioides (Bory ex Fée) T. Moore, the most representative species of the genus in the Ecological Park of Gunma in Pará State. It reports the main diagnostic characters and provides new systematic data for the group. In addition, it locates the production and accumulation sites of bioactive compounds to determine possible adaptive strategies of these species in the Amazon rainforest environment. Diagnostic structural features include stoma typology, central veins and margin forms, type of mesophyll, and the presence of schlerenchymatous sheaths in the cortex, among others. Among the bioactive compounds related to defense adaptation are phenolic compounds, which occur in all three species, and alkaloids and mucilage, which are exclusive to E. laminarioides. Of the three species studied, E. laminarioides has features that make it the best suited to the rainforest environment.
基金Supported by the National Natural Science Foundation of China(No.40730528)the National Basic Research Program of China(973Program)(No.2008CB418104)+2 种基金the Knowledge Innovation Project of Chinese Academy of Sciences(No.KZCX2-YW-JC302)the Jiangsu Provincial Science Foundation(No.BK2009024)the Frontier Foundation of Nanjing Institute of Geography & Limnology,Chinese Academy of Sciences(No.09SL021001)
文摘Leaves of terrestrial and aquatic plants are home to a wide diversity of bacterial species. However, the diversity and variability of epiphytic bacteria on their submerged plant hosts remains poorly understood. We investigated the diversity and composition of epiphytic bacteria from two common submerged macrophytes: Vallisneria natans and Hydrilla verticillata in Taihu Lake, Jiangsu, China, using methods of terminal restriction fragment length polymorphisms (T-RFLP) and clone library analyses targeted at bacterial 16S rRNA genes. The results show that: (1) the libraries of the two waterweeds contain wide phylogenetic distribution of bacteria, and that the sequences of the two libraries can be separated into 93 OTUs (at 97% similar value); (2) Betaproteobacteria, including Burkholderiales, was the most abundant bacterial group on both plants. Cyanobacteria and Gammaproteobacteria were the second largest groups on V. natans and H. verticillata, respectively. Both clone libraries included some sequences related to those of methanotrophs and nitrogen-fixing bacteria; (3) Cluster analysis of the T-RFLP profiles showed two distinct clusters corresponding to the two plant populations. Both ANOSIM of the T-RFLP data and Libshuff analysis of the two clone libraries indicated a significant difference in epiphytic bacterial communities between the two plants. Therefore, the epiphytic bacterial communities on submerged macrophytes appear to be diverse and host-specific, which may aid in understanding the ecological functions of submerged macrophytes in general.
基金Supported by the National Natural Science Foundation of China (No 40376048)the National Basic Research Program of China (973 Program) (No 2006CB400604)
文摘We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four species of algae:Gracilaria textorii,Ulva pertusa,Laminaria japonica,and Polysiphonia urceolata.The isolated strains of bacteria can be divided into two groups:Halomonas and Vibrio,in physiology,biochemical characteristics and 16S rDNA sequence analyses.The phylogenetic tree constructed based on 16S rDNA sequences of the isolates shows four obvious clusters,Halomonas venusta,Vibrio tasmaniensis,Vibrio lentus,and Vibrio splendidus.Isolates from the surface of P.urceolata are more abundant and diverse,of which strains P9 and P28 have a 16S rDNA sequence very similar(97.5%-99.8%) to that of V.splendidus.On the contrary,the isolates from the surfaces of G.textorii,U.pertusa and L.japonica are quite simple and distribute on different branches of the phylogenetic tree.In overall,the results of this study indicate that the genetic relationships among the isolates are quite close and display a certain level of host species specificity,and alga-associated bacteria species are algal species specific.
