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Diversity and Biogeography of Neotropical Vascular Epiphytes
... 1,2 This group of epiphyte splants contribute greatly to global plant diversity, because they represent between 8% and 10% of all known vascular plant species, where 80% of all vascular epiphytes are concentrated in the families' Orchidaceae, Bromeliaceae, Polypodiaceae and Araceae. 3,4 The importance of these plants in the ecosystems is notable, because epiphytes can considerably increase the retention of atmospheric water in tropical forests, 5 in addition to playing a predominant role in the contribution of biomass and the nutrient recycling in upland forests. 6 Information on the diversity of epiphytes in forests under different successional stages is still insufficient according to their response capabilities to environmental changes. ...
... An factors is atmospheric humidity, where environments in conditions of high humidity present, for example, a greater richness and abundance of epiphytes. 3 Consequently, epiphytes reach their greatest diversity and abundance in tropical humid montane forests, where moderate temperatures together with constant high humidity favor growth and the accumulation of organic matter. 6,11,12 The degree of forest succession affects climatic factors such as light, humidity, temperature and evapotranspiration, affecting forest dynamics, and but also epiphytic species and their growth forms. ...
... These results corroborate what was expected for a family that contains two thirds of the vascular epiphytes in the world and the Neotropics, standing out for their morphological, physiological and distribution adaptations. 3,40 It seems that the nomads were the group most affected by the natural disturbance, where no individuals were recorded in the initial successional stage, probably because it is a group that grows only in humid environments. 1 True epiphytes presented the greatest richness in the initial successional stage, but it was affected by the conditions of said stage, given the decrease in richness in relation to the intermediate and late stages. ...
Our objective was to determine the relationship of different successional stages with the diversity, assimilation rates and net productivity of different growth forms of vascular epiphytes in a humid montane forest in Andean Colombian. Three successional stages were selected according to the site conditions. The 30 trees sampled in the three successional stages 4,610 epiphytic individuals to 54 species. A main finding was that species richness, abundance and biomass increased with stage age. Additionally true epiphytes were the growth form with the greatest richness, abundance and biomass. Regarding photosynthesis rates decreased with stage age and were higher for treelets, shrubs and lower for true epiphytes. According the analysis of the ordering of the epiphytes found by stages shows the existence of a successional trajectory with the presence of representative species of each stage. This research can contribute as a basis to the knowledge of epiphytes, with the purpose of enriching and supporting management measures for these species
... This well-documented pattern applies to several groups of organisms in nature (Rahbek 1995), including ferns and lycophytes (Kessler et al. 2001;Kluge et al. 2006;Watkins et al. 2006;Paciencia 2008). The general trend is that epiphytes are better represented in cloud forests and at intermediate elevations (Gentry & Dodson 1987;Zotz 2016). Our data align with this trend. ...
... Our data showed Polypodiaceae to be the main family along the altitudinal gradient on both slopes. Several studies have also identified Polypodiaceae as one of the most numerous families in the world, particularly among the neotropical epiphytic flora (Madison 1977;Gentry & Dodson 1987; Figure 8 -a-c. Floristic composition layout of epiphytic pteridophytes on both slopes in the Parque Nacional (PN) da Serra dos Órgãos, as generated from a principal coordinates analysis -a. both slopes; b. eastern slope; c. western slope. ...
... In this study, there was little variation in the taxonomic diversity of families along altitudinal zones, and no clear pattern was found on either slope (except for among Aspleniaceae on the eastern slope). Gentry & Dodson (1987) reported similar findings along an altitudinal gradient for epiphytic flora in the neotropical region. Sundue et al. (2015) proposed that the epiphytic richness of some groups in tropical forests (particularly some Polypodiaceae, Elaphoglossum, and Hymenophyllaceae species containing green spores) can be linked to ecological convergence and rapid diversification. ...
Gradual climatic changes caused by mountains’ altitudinal variation promote alterations in the structure of ecological communities. Environmental changes are also expected according to the slope’s position in relation to the sea. In this study, we aimed to compare epiphytic pteridophyte communities along altitudinal gradients on opposite slopes in a section of the Atlantic Forest. We sampled a total of 10 sites in the montane and upper montane zones from the eastern (facing the sea) and western (facing away from the sea) slopes. A total of 1,742 individuals from 62 epiphytic species were recorded. The slopes showed similar epiphytic abundances and richness. Species richness showed a tendency to decrease with an increase in altitude on the western slope, and abundance was higher at intermediate altitudes, with no altitudinal trend in dominance. Conversely, on the eastern slope, there was no clear altitudinal pattern in richness or abundance; however, dominance increased with an increase in altitude from 1,200 to 1,800 m. Species compositions differed among altitudinal zones and between slopes. The eastern slope had lower species richness and no clear altitudinal gradient, although it was better preserved than the western one. Thus, there are differences in the community structure of epiphytic pteridophytes from the forest understory due to altitudinal variation and slope orientation, and these findings corroborate our hypotheses.
... O dossel das florestas é uma parte importante para o funcionamento dos ecossistemas e, nas últimas décadas, tem havido um grande e rápido aumento nas pesquisas sobre esse ambiente (Barker;Pinard, 2001). Dentre as comunidades que fazem parte do dossel, destacam-se as epífitas vasculares (Gentry;Dodson, 1987;Zotz, 2016). Plantas epífitas são definidas como aquelas que, em todas as fases da vida, germinam e enraízam de forma não parasitária sobre outras plantas (Madison, 1977;Zotz, 2016). ...
... O dossel das florestas é uma parte importante para o funcionamento dos ecossistemas e, nas últimas décadas, tem havido um grande e rápido aumento nas pesquisas sobre esse ambiente (Barker;Pinard, 2001). Dentre as comunidades que fazem parte do dossel, destacam-se as epífitas vasculares (Gentry;Dodson, 1987;Zotz, 2016). Plantas epífitas são definidas como aquelas que, em todas as fases da vida, germinam e enraízam de forma não parasitária sobre outras plantas (Madison, 1977;Zotz, 2016). ...
... O epifitismo ocorre em torno de 28.000 espécies (Gentry;Dodson, 1987;Zotz et al., 2021), o que corresponde a quase 10% de toda a flora de traqueófitas. O epifitismo ocorre em 73 famílias, com 913 plantas vasculares (Zotz, 2013a), porém, de acordo com Zotz et al. (2021a), a maioria das famílias é de monocotiledôneas e ressalta-se que a distribuição do número de espécies nos táxons é realmente bastante desigual. ...
Epiphytes constitute important plant communities in the Atlantic Forest, however, many areas do not even have floristic and ecological data on the species. Here,
we gather information about the diversity, ecology, and conservation status of vascular epiphytes from Ilha Grande, RJ. The data were collected through a systematic bibliographical review, collections and data from herbariums. 253 species were inventoried. The richest families in species were Orchidaceae, Bromeliaceae, and Polypodiaceae. Most are holoepiphytic, pollinated by insects, and dispersed through anemochory. The best-preserved ombrophilous forests present a higher diversity and unique composition. Epiphytes are affected by tree density and size and canopy cover. There is vertical stratification of the community with the higher diversity occurring in the trunk of the trees and the least in the high crown. Four species are endemic to Rio de Janeiro, seven are in the Red Book of Flora of Brazil and in the National List of Endangered Species, as well as two in the Red Book of Endemic Flora of Rio de Janeiro. Thus, Ilha Grande is an important area for preserving epiphytes in the state. We reiterate that more botanical incursions are needed in poorly sampled areas and population studies that can support the elaboration of strategies for the conservation of species and ecosystems.
... Vascular epiphytes (hereafter epiphytes) are plants that germinate and grow non-parasitically on other plants, mainly trees and shrubs (Zotz, 2016). They are important elements in tropical forests due to their contribution to richness and biomass (Gentry and Dodson, 1987), their relationship with water and nutrient cycles (Benzing, 2008;Mendieta-Leiva et al., 2020a), and their interaction with other taxa (Zotz, 2016). In addition, epiphytes provide habitat and food resources to vertebrates, invertebrates, and microorganisms (Frank, 2008;Cruz-Angón et al., 2009;Woods et al., 2015). ...
... Mountainous ecosystems occupy about 25% of the Earth's terrestrial surface area (Rahbek et al., 2019), nevertheless, they harbor disproportionately high richness and endemism of vascular epiphytes, especially in the tropics (Küper et al., 2004;Suissa et al., 2021;Taylor et al., 2022). At a large scale, this high richness and endemism may be explained by geological, geographical, evolutionary, and climatic factors (Suissa et al., 2021;Taylor et al., 2022), while at a regional scale climate and topography variation along elevational gradients are positively linked to richness and endemism of vascular epiphytes, especially at mid-elevation (Gentry and Dodson, 1987;Küper et al., 2004;Krömer et al., 2005;Ding et al., 2016;Jiménez-López et al., 2020;Furtado and Menini Neto, 2021). In tropical mountains, epiphytes show consistent general richness patterns at local and regional scales, with highest richness commonly found at mid-elevations (between 1500 and 3000 m) and decreasing diversity towards both high and low elevations (Küper et al., 2004;Krömer et al., 2005Krömer et al., , 2013aHernández-Rojas et al., 2020). ...
... In tropical mountains, epiphytes show consistent general richness patterns at local and regional scales, with highest richness commonly found at mid-elevations (between 1500 and 3000 m) and decreasing diversity towards both high and low elevations (Küper et al., 2004;Krömer et al., 2005Krömer et al., , 2013aHernández-Rojas et al., 2020). This hump-shaped distributional trend has been explained by climatic factors, especially temperature, precipitation, and fog frequency (Gentry and Dodson, 1987;Krömer et al., 2013a;Furtado and Menini Neto, 2021). ...
Mesoamerican mountains are important centers of endemism and diversity of epiphytes. The Sierra Madre of Chiapas in southeastern Mexico is a mountainous region of great ecological interest due to its high biological richness. We present the first checklist of epiphytes for this region based on a compilation of various information sources. In addition, we determined the conservation status for each species based on the Mexican Official Standard (NOM-059-SEMARNAT-2010), endemism based on geopolitical boundaries, spatial completeness with inventory completeness index, richness distribution with range maps, and the relationship between climatic variables (temperature and rainfall) with species richness using generalized additive models. Our dataset includes 9,799 records collected between 1896-2017. Our checklist includes 708 epiphytes within 160 genera and 26 families; the most species-rich family was Orchidaceae (355 species), followed by Bromeliaceae (82) and Polypodiaceae (79). There were 74 species within a category of risk and 59 species considered endemic. Completeness of epiphyte richness suggests that sampling is still largely incomplete, particularly in the lower parts of the mountain system. Species and family range maps show the highest richness at high elevations, while geographically richness increases towards the southeast. Epiphyte richness increases with increased rainfall, although a unimodal pattern was observed along the temperature gradient with a species richness peak between 16-20 C°. The Sierra Madre of Chiapas forms a refuge to more than 40% of all epiphytes reported for Mexico and its existing network of protected areas overlaps with the greatest epiphyte richness.
... Although temperate forest has a significant role in species diversity, knowledge about the distribution and ecological importance of vascular epiphytes in this forest system is insufficient (Dawson, 1988;Dickinson et al., 1993;Munoz et al., 2003). Some earlier work reports the diversity of vascular epiphytes rarely outside the tropical region (Benzing, 1995;Gentry & Dodson 1987;Barthlott et al., 2001;Zotz & Hietz, 2001). Over the years, extensive research has been done to estimate the epiphytic diversity patterns (Kromer et al., 2005;Guzman-Jacob et al., 2020;Marcusso et al., 2022). ...
... Vascular epiphytes contribute significantly to forest ecologies such as water and nutrient inputs, also numerous taxa depend on them since they provide habitat and resources (Gotsch et al., 2016;Angelini & Silliman, 2014;Mendez-Castro et al., 2018). Additionally, they are well known for their contribution to primary productivity, biomass, litterfall and species diversity (Gentry & Dodson, 1987;Benzing, 1995;Barthlott et al., 2001;Munoz et al., 2003). They can also contribute considerably to other plant biomass (Zotz, 2016). ...
... Thus, finding highest epiphytic species richness and abundance in sites I and II is a well-known fact that epiphyte flourishes well in warmer and wetter areas than the colder and drier areas. In addition to this, epiphytic plant responds to variation in humidity more than other life forms as they lack access to soil (Gentry & Dodson, 1987). Although relative humidity showed little difference across our study sites, relative humidity plays a key role in epiphytic adaptation (Aragon et al., 2015;Sanger & Kirkpatrick, 2017;Williams et al., 2020). ...
The focus of ongoing research in forest ecosystems is highly biased towards vascular epiphytes that grow non-parasitically on host trees and contribute substantially in shaping biodiversity. In this communication, an effort has been made to understand the vascular epiphytic assemblage and richness along the altitudinal gradients in temperate forests of Darjeeling Himalaya. Additionally, influence of environmental variables was also analyzed. Orchidaceae was the dominant family followed by Polypodiaceae and Ericaceae in terms of species abundance. The epiphytic richness and diversity were greater towards lower altitudinal tier compared to the higher. The epiphytic diversity was positively correlated with host tree CBH (circumference at breast height) and bark texture, while bark pH showed a negative correlation. The outcome of this study establishes a baseline of epiphytic characteristics with respect to elevational range and environmental variables in temperate Himalaya. However, a detailed study on population dynamics, habitat evaluation and geographic aspects with further development on monitoring and conservation effort is of utmost necessity.
... On tree trunk, the vertical distribution of vascular epiphytes is not random and perhaps influenced by branch properties, humidity, and photon-flux densities. Vascular epiphytes present upon this stretched fertile area are a conspicuous and highly diverse group in nature and also a significant component of tropical and subtropical forests, not just because of its diverse species, but also for its huge biomass accumulation (Gentry and Dodson 1987, Benzing 1987, 1990, Nadkarni 1994, Isaza et al. 2004. Many authors presented different definitions for vascular epiphyte during the course of time. ...
... This finding is in agreement with Flores-Argüelles (2022) in natural and disturbed forest on the northern coast of Jalisco, Mexico. The vertical distribution of vascular epiphytes is depended upon the microclimatic gradients such as temperature, wind velocity, humidity and light intensity(Gentry and Dodson 1987). The outer canopy i.e., zone 6 to 7 have low VEA because of extreme microclimate, due to exposure of high light intensities from direct sunlight. ...
Vascular epiphyte makes a significant contribution to the tropical and subtropical diversity. In this study vertical distribution of vascular epiphytes and their significance presence were analysed within the Chapramari Wildlife Sanctuary. Tree species were sampled upon which VEA (Vascular epiphytic assemblage) were studied by using binocular and rope climbing method. A total of 1057 individual epiphytes representing 59 species belonging to 10 families were sampled. Trees were grouped over heights, DBH and Vertical distribution according to zonation pattern confirmed by Detrended Correspondence Analysis (DCA). Orchids and ferns were found dominant species of the study area.
... Evolutionary explanations for epiphyte niche differentiation also exist, but have been scarcely tested (Gentry & Dodson, 1987b;Lüttge, 2012;Sundue et al., 2015). In addition to biogeography and founder effects contributing to the patterns of evolution of epiphytism on the global scale (e.g. ...
... In addition to biogeography and founder effects contributing to the patterns of evolution of epiphytism on the global scale (e.g. Gentry & Dodson, 1987b), several hypotheses highlight biotic interactions as potential drivers of epiphyte differentiation (Baguette et al., 2020;Bermudes & Benzing, 1989;Dodson, 1975;Janzen, 1974;reviewed in Spicer & Woods, 2022). Epiphytism itself may have evolved in part to escape biotic enemies in the soil, rather than strictly for abiotic reasons such as access to light (Zotz, 2016), a proposal recently coined the epiphyte enemy escape hypothesis (Spicer et al., 2020;Spicer & Woods, 2022). ...
Epiphytes are characterized by their ability to survive without a root connection to the ground, but many basic life‐history traits and ecological trade‐offs of this unique aerial growth habit remain largely uncharacterized. Mortality causes are still not well understood, but falling from the host tree has been suggested as a leading cause of epiphyte mortality and community dynamics. Little empirical evidence exists for why epiphytes do not survive when forced to become terrestrial, and few studies exist that transplant epiphytes between high‐ and low‐forest strata to test trade‐offs between thriving in canopy environments and survival in the forest understorey.
Here, we experimentally test two hypotheses regarding the drivers of epiphyte mortality in a cloud forest of central Panama. We test whether simple contact with terrestrial soil is deleterious to epiphytes, preliminarily testing the epiphyte enemy escape hypothesis, and test the vertical niche differentiation hypothesis, wherein epiphytes are specifically adapted for microsites throughout the vertical forest strata. By monitoring survival, leaf loss and health status of 270 transplanted epiphytes for a year and a half, we pinpoint the extent to which soil contact and height of origin regulate epiphyte performance.
We found that contact with terrestrial soil itself was detrimental to epiphytes in situ, providing some of the first empirical data to explain why falling onto the ground, versus falling into the understorey, is particularly fatal to epiphytes. However, we also found that mortality rates vary substantially among taxonomic groups and among epiphytes that originally came from different height strata.
Synthesis. Plants that are adapted for the canopy experience a trade‐off with higher mortality when in contact with terrestrial soil. Follow‐up studies should explore the role of terrestrial soil microbes and physiological constraints as potential drivers of decreased grounded epiphyte survival.
... Epiphytic species represent approximately 10% of vascular plants (Zotz et al. 2021). The Neotropics, particularly, are home to the largest richness and abundance of epiphytes accounting for up to 39% of the global vascular epiphytic flora, especially in humid montane forests (Gentry and Dodson, 1987;Taylor et al. 2022). These plants play crucial roles in the hydrology and mineral cycling of forests, redistributing moisture and nutrients in aboveground components (Stanton et al. 2014;Victoriano-Romero et al. 2023). ...
... They are also a vulnerable group rapidly affected by deforestation (Hietz et al. 2006;Köster et al. 2009) and are highly sensitive to air pollution (Benzing et al. 1992;Wannaz & Pignata, 2006;Gradstein, 2008). Due to their dependence on atmospheric water and particular microclimatic conditions (Gentry & Dodson, 1987), vascular epiphytes are considered a good bioindicator to monitor disturbances (Zotz 2016a). Among Neotropical epiphytes, the Bromeliaceae family is an example of high diversity, with 58 genera and about 3140 species (Givnish et al. 2011). ...
... A composição e a distribuição dos epífitos são influenciadas por características do forófito, como arquitetura, altura, diâmetro, textura, estabilidade e porosidade do ritidoma, toxinas presentes e húmus acumulado (GENTRY; DODSON, 1987;FONTOURA et al. 1997;NIEDER et al. 2000). Características que podem estar presentes ou não sobre os cáudices de xaxins. ...
... Tais resultados demonstram a importância das duas espécies hospedeiras para epífitas no ambiente florestal, revelando uma tendência de uso um pouco maior para um dos tipos de forófito (substrato) analisados. A composição e distribuição dos epífitos podem ter sido influenciadas por características do forófito, como arquitetura, altura, diâmetro, textura, estabilidade e porosidade do ritidoma, toxinas presentes e húmus acumulado (GENTRY; DODSON, 1987;FONTOURA et al. 1997;NIEDER et al. 2000). ...
Nesta pesquisa foram avaliados alguns tópicos, como riqueza, composição e estrutura comunitária de epífitos vasculares em cáudices de Dicksonia sellowiana Hook . e Cyathea phalerata Mart . em um fragmento de Floresta Ombrófila Mista no município de Porto União, extremo norte de Santa Catarina, sul do Brasil (26° 14’ 16’’ S, 51° 4’ 40’’ W). O clima da região é subtropical mesotérmico úmido, com temperaturas variando entre 18 e 21 °C, precipitação média mensal 125 mm e altitude média de 820 m. Na área de estudos, foram selecionados 40 forófitos (20 para cada espécie hospedeira), e seus cáudices foram divididos em intervalos de 1m, a partir do solo, chegando até três intervalos de altura. Foram encontradas sete espécies, distribuídas em seis gêneros e cinco famílias de samambaias epífitas. Blechnum L . e Polypodium L. ocorreram em todos os intervalos de altura dos cáudices de D. sellowiana. Em C. phalerata , somente o gênero Blechnum L. esteve presente nos três intervalos levantados. No estudo quantitativo, foram registradas 503 ocorrências de pteridófitas epifíticas sendo n=346 (68,78%) sobre cáudices de D. sellowiana e n=157 (31,22%) sobre cáudices de C. phalerata. Tal diferença foi estatisticamente significativa (t = 1,586; p< 0,05). Isso demonstra a importância das duas espécies hospedeiras para epífitas no ambiente florestal e revela uma tendência um pouco maior de ocupação epifítica nos cáudices de D. sellowiana .
... Vascular epiphytes, non-parasitic plants that are structurally dependent on other plants, have a prominently tropical distribution (Benzing, 1990;Gentry and Dodson, 1987) and contribute about 40% of the vascular flora in neotropical forests (Taylor et al., 2021). Epiphytes are strongly influenced by the vertical gradient of a forest and the three-dimensional structure of tree crowns (Benzing, 1990) and, according to Taylor et al. (2021), the high diversity of tropical forests is precisely due to niche partition in the communities, since the many species of epiphytes present an exceptional variety of functional traits within diverse taxonomic groups. ...
... Epiphytes are strongly influenced by the vertical gradient of a forest and the three-dimensional structure of tree crowns (Benzing, 1990) and, according to Taylor et al. (2021), the high diversity of tropical forests is precisely due to niche partition in the communities, since the many species of epiphytes present an exceptional variety of functional traits within diverse taxonomic groups. Classical studies have already shown that epiphytes do not have a random distribution along tree height zones (Benzing, 1990;1995;Catling and Lefkovitch, 1989;Gentry and Dodson, 1987;Johansson, 1974;Kelly, 1985;Schimper, 1888). Recent research has detected preferential spatial patterns for specific groups of epiphytes in the canopy (Krömer et al., 2007;Martínez-Meléndez et al., 2008;Nieder et al., 2000;Wagner et al., 2013;Woods et al., 2015Woods et al., , 2019 and this is related to the functional characteristics of the species (Graham and Andrade, 2004;Guzmán-Jacob et al., 2022;Miranda et al., 2020;Petter et al., 2016;Rascher et al., 2012;Zotz, 2004). ...
Epiphytes are strongly affected by the microclimate of the forest canopy. Therefore, understanding how microclimatic changes are related to the functional characteristics of taxa and the patterns of communities is essential. Our objective was to examine the stratification of the epiphyte community along the vertical gradient of the forests and to investigate whether the pattern of species distribution in the canopy height zones is similar among forests with different characteristics and between the families of epiphytic plants. The study was carried out in the Atlantic Forest of Ilha Grande, in southeastern Brazil, where we recorded 76 species. The highest richness and abundance were found on tree trunks. The high crown had less diversity and a characteristic set of species. The vertical stratification pattern was similar across forests with different phytophysiognomies. The main epiphytic families exhibited different patterns of diversity along the canopy. The highest richness of Araceae occurred in the trunk zones, while Polypodiaceae, Bromeliaceae, and Orchidaceae were more diverse in the trunk and inner crown, and Cactaceae were more diverse in the inner crown. Tree height zones select epiphytic taxa with distinct characteristics according to the fundamental conditions for their survival and, therefore, we suggest that the ecological niche theory is adequate to explain the assembly of epiphytic communities at a local scale.
... -Facultativas: especies que se dan regularmente tanto en el suelo como en el dosel, en sitios donde convergen las condiciones terrestres y arbóreas; 5%-95% -Las categorías no están bien definidas, los umbrales son artificiales y pocos estudios han cuantificado la abundancia epifítica y terrestre (Hoeber & Zotz, 2022) -Cuantificar el grado de epifitismo de una especie depende de su variación regional; A. distichantha crece epifítica en el extremo húmedo de su distribución, pero terrestre o rupícola en el extremo seco -Cualquier planta terrestre puede crecer como epífita accidental si dispone de un microhábitat adecuado en un árbol y se puede dispersar con éxito -Las holoepífitas pueden crecer en el suelo o sustratos artificiales, si las condiciones abióticas pueden satisfacer sus requerimientos ecológicos El término hemiepífitas ha sido usado sobre todo para las aráceas trepadoras, a veces distinguiendo entre hemiepífitas primarias (HP) y secundarias (HS) como formas de crecimiento diferentes (Putz & Holbrook 1986;Gentry & Dodson 1987;Nadkarni et al. 2001) • Las HP germinan y pasan su estado juvenil como epífitas y posteriormente, establecen contacto con el suelo mediante raíces adventicias ...
Las epífitas son plantas que crecen de forma no parasitaria sobre otra planta, principalmente en troncos o copas de árboles, sin contacto con el suelo durante toda su vida. A diferencia de las plantas parásitas o muérdagos, no obtienen directamente ni agua ni nutrientes de sus hospederos, solo los requieren como soporte para acceder a mejores condiciones lumínicas, son ecológicamente distintos.
... Por su parte, la presencia de estas plantas se ve afectada por ciertos factores como lo es la escasez de precipitaciones [17], lo que hace que las áreas boscosas con precipitación reducida solo se puedan establecer familias más especializadas como Orchidaceae y Bromeliaceae [18]. Particularmente, los bosques tropicales caducifolios con estaciones secas definidas pueden ser considerados ambientes marginales para las orquídeas, mostrando una escasez y distribución irregular de las mismas en estos hábitats [19]. ...
Orchidaceae is one of the most numerous families in the world contributing to tropical forests diversity. In this study, we assessed two permanent sampling plots (PSP), in which five 20 x 20 m subplots were chosen: the four corner plots and one in the center; two 10 x 200 m linear transects (one at each study site) were also monitored. The total sampling area was 0,4 ha per PSP, to assess the presence of orchids and their preference for particular tree species as phorophytes. Data from host tree and orchids found were gathered as orchid density per hectare, IVI based on relative frequency and abundance; specific abundance according to phorophyte, bark type, bark thickness and the associativity degree of the species with the specific host plant were all quantified using RStudio software version 4.1.1. The species Swietenia macrophylla, Rehedera trinervisu, Quercus oleoides and Semialarium mexicanum were found as phorophytes with the presence of the following orchid species; Brassavola nodosa; Encyclia cordigera, Laelia rubescens, Oncidium spp., Prosthechea fragrans and Stilifolium ascendens. The species Sacoila lanceolata was found growing on the forest floor, in the phenological flowering stage. Phorophytes with longitudinally fissured bark, greater thickness and little exfoliation, were those with the highest affinity for orchids, which managed to establish in the upper canopy part.
... The abundance and diversity of epiphytes are strongly influenced by changes in ecological conditions along altitudinal and latitudinal gradients (Gentry & Dodson 1987;Gentry 1988), primarily varying based on light intensity, altitude, characteristics of the host tree bark and water availability (Wolf 1994;Basset et al. 2003;Mucunguzi 2007). The longitudinal gradient and the type of suber define a great differentiation of niches and interactions, such as plant-herbivore, plant-pollinators, mycorrhizae, in addition to providing resources and habitat for vertebrates and invertebrates. ...
Epiphytes represent approximately 10% of vascular plants, or 25,000 species distributed across 84 families. Water deficit is the greatest challenge faced by epiphytes, resulting in anatomical strategies aimed at maximizing water usage and minimizing water loss. This study aimed to characterize the leaf blade anatomy of 40 species of vascular epiphytes occurring in a cloud forest of the Brazilian Atlantic Forest and assess how leaf anatomy is related to the epiphytic life form. Samples were collected, fixed, dehydrated with ethanol, and embedded in paraffin for sectioning using a microtome or freehand technique. Some samples were dissociated for epidermal observation. A clustering analysis (using UPGMA) was conducted using a presence/absence matrix of 16 anatomical characters. The results showed that species within this functional group exhibit different leaf blade anatomical characteristics, which may or may not be adaptive to epiphytism. However, despite the occurrence of some characteristics such as stomata at the same level as other epidermal cells, thick cuticle, fibers, hypodermis, and homogeneous chlorophyllous parenchyma in 50% or more of the species, there is no set of anatomical characteristics that can be used to define an epiphyte.
... Even after proofing that epiphytes are diversifying faster, the exact mechanism(s) behind the origin of the enormous diversity of many holoepiphyte taxa remain(s) largely obscure. Phillips et al. (2012) investigated the hypothesis that small, and disjunct orchid populations experience strong genetic drift due to orogenesis, which ultimately encourages speciation (a hypothesis specifically proposed for orchids by Gentry and Dodson, 1987). However, no evidence for higher levels of population genetic differentiation was found. ...
... Approximately 70% of orchid species are epiphytes, accounting for approximately 72% of epiphyte species in the world (Gentry & Dodson 1987, Gravendeel et al. 2004. Epiphytic orchid conservation and management techniques may include the protection of suitable and existing phorophytes, as well as planting new ones (Adhikari & Fischer 2011). ...
We explore phorophyte suitability for germination and establishment of the epiphytic orchid, Psychilis kraenzlinii. We found that the orchid grows on a subset of the available tree species and shows pref- erence for the endemic Machaonia portoricensis (Rubiaceae). The orchid preferred trees with smoother bark, high water holding capacity and low water retention capacity. Microclimatic conditions under which embryos began pre-germination stages mirrored that of the adult orchid, but germination did not, suggesting that suit- able germination sites are not necessarily the best sites for later stages of development.
Exploramos la utilización de árboles y los patrones de germinación de la orquídea epífita, Psychilis kraenzlinii. Encontramos que P. kraenzlinii crece en un subconjunto de las especies de árboles disponibles y muestra preferencia por la endémica Machaonia portoricensis. La orquídea prefiere árboles con corteza lisa y alta capacidad de sostener agua y baja capacidad de retención de agua. Las condiciones microclimáticas bajo las cuáles los embriones empienzan etapas pre-germinacíon, reflejan los de la orquídea adulta, pero las condiciones bajo las cuáles los embriones llegan a etapas de germinación no. Lo que sugiere que los sitios de germinación adecuados no son necesariamente los lugares donde mejor se producirá el desarrollo a etapas más avanzadas de la germinación.
... Esta gran riqueza pudiera estar relacionada con la ubicación intertropical de este departamento, sumado a los Andes con una evolución geológica y orogenia que se dio en un extenso periodo geológico, la formación de ecotonos en los ecosistemas septentrionales del Norte y los Andes Centrales, que definieron gradientes altitudinales y la presencia de una gran diversidad de ecosistemas y micronichos (Pérez-Escobar et al. 2017) los cuales permitieron el establecimiento de epífitas con diferentes requerimientos ecofisiológicos en los bosques nublados. Así mismo, es uno de los departamentos más cercanos al ecuador que es donde se concentra la mayor diversidad de epífitas vasculares (Gentry & Dodson 1987b, Benzing 2008. Otra explicación es la cercanía del departamento de Amazonas con Ecuador que es el país más rico en epífitas del mundo (Richter et al., 2009, Cascante-Marín & Nivia-Ruíz 2013) y que pudiera estar fungiendo como una fuente de propágulos. ...
Despite the high diversity of vascular epiphytes (VE) reported in Peru, there is no updated checklist that is in line with the new taxonomic delimitations and the new concepts of epiphytes. In this study, we update the list of VE in Peru, based on a bibliographic search and visits to local herbaria. Species names were updated according to the World Flora Online, their presence in the EpiList was confirmed, as well as their altitudinal distribution and distribution by department, risk category, and endemism. Finally, the epiphyte coefficient was estimated. We found 2462 species, belonging to 18 orders, 25 families, and 249 genera. The families with the highest richness were Orchidaceae (1606), Bromeliaceae (201), and Piperaceae (139 spp.); 85% of the species were in the EpiList (2088 spp.). The department with the highest richness was Amazonas (709) and the lowest were Ica and Tacna (2 spp.). The altitudinal range with the highest richness is between 1501 – 2000 m (649); 689 species are endemic and 220 are in some risk category; the epiphyte quotient is 13.12. This update represents an approximate 40% increase, positioning Peru as the third country with the highest VE diversity. A more comprehensive list was obtained, in line with the concept of epiphytism, highlighting the need to include 384 species in the EpiList, which would help complement the global list of VE worldwide.
... Neotropical cloud forests exhibit exceptional diversity, particularly in certain groups of birds, amphibians, and vascular epiphytes, notably orchids (Carmona-Higuita et al. 2023, Gentry & Dodson 1987, Pérez-Escobar et al. 2017. Among orchids, the Pleurothallidinae subtribe show one of the highest evolutionary diversification rates, representing a significant portion of the orchid flora found in montane forests (Pérez-Escobar et al. 2017). ...
Two new pleurothallid species of the genera Lepanthes and Pleurothallis, native to cloud forest remnants of the eastern Andes of Colombia, are described and illustrated. Lepanthes pseudoabitaguae is compared with Lepanthes abitaguae, from which it differs by the color of the flowers and by the oblong and biglandular appendix. Pleurothallis falcata is similar to Pleurothallis suspensa, but can be recognized by the falcate to lanceolate leaves, denser inflorescences, longer sepals, and the lip completely recurved with the apical margins erose. We also provide comparisons with similar species and offer comments on their ecology. Furthermore, we discuss the significance of this highly anthropized region and its richness in orchid species.
... Las orquídeas son plantas monocotiledóneas que pertenecen a la familia Orchidaceae, estas plantas son muy valorizadas por su atractivo ornamental, siendo así llamativas en el comercio y ecoturismo (Cozzolino & Widmer, 2005;Giraldo & Betancur, 2011;Ballantyne & Pickering, 2012;Parra, 2013), también son consideradas como indicadores de las condiciones de los ecosistemas (Gentry & Dodson, 1987;Pineda, 2004). Las Orchidaceae en el mundo comprenden aproximadamente 925 géneros y 27,000 especies siendo el grupo más diverso de las plantas vasculares; para el Perú se cataloga aproximadamente 2,800 especies (Goicochea, et al., 2016), y de ellas 21 especies corresponden al género Sobralia de las cuales seis son endémicas (Brako & Zarucchi, 1993;Roque & León, 2006). ...
Resumen: El género Sobralia (Orchidaceae) tiene un alto valor ornamental y ecológico, pero sus poblaciones están actualmente disminuyendo por la pérdida de su hábitat y su venta ilegal en Perú. Se realizó el estudio taxonómico, fenológico de Sobralia y sus relaciones con algunas variables climáticas en el bosque Amazónico del valle de Kosñipata del departamento de Cusco. Se desarrolló el tratamiento taxonómico de las especies, para la fenología se realizó el monitoreo de los patrones de floración en los meses del año desde el 2010 al 2022, y para conocer alguna relación se aplicó el análisis de regresión y correlación entre la riqueza, fenología y las variables de temperatura, precipitación y humedad. Los resultados muestran para en el bosque Amazónico del valle de Kosñipata están presentes 6 especies: Sobralia candida, S. crocea, S. fimbriata, S. rosea, S. setigera y S. violacea; los patrones fenológicos revelan que florecen la mayor parte del año: S. violacea (9meses),S. rosea(8meses), S. fimbriata y S. setigera(6), las especies con las mayores poblaciones en floración fueron: S. rosea en enero y diciembre (4), S. violacea (4) en enero y S. fimbriata (4) en mayo; se evidencia mejor correlación entre la floración con la humedad relativa (R²=0,69y P=0,012). La riqueza de especies del género Sobraliaen el bosque Amazónico de Kosñipata es alta con 6 especies con ellas se actualiza a 25 especies para el Perú. Los periodos de floración aparentemente son dependientes de la humedad. Enfatizamos que el género Sobralia por su alta riqueza y potencial de aprovechamiento deben de ser conservado e incluidos en una legislación más estricta.
... The distribution of vascular epiphytes is determined by both abiotic and biotic factors. Macro and microclimatic conditions, including humidity luminosity, temperature, and precipitation play a critical role in shaping their distribution (Gentry and Dodson, 1987a;Kreft et al., 2004;Krömer et al., 2013;Weigand et al., 2020;Elias et al. in Press). Biotic factors, such as dispersal syndromes, bryophyte coverage, and tree characteristics such as crown volume, area, deciduousness, phorophyte size and architecture, bark chemistry, stability, and roughness, also significantly influence their distribution (Burns and Dawson, 2005;Arévalo and Betancur, 2006;Wagner et al., 2015;Tay et al., 2023). ...
... En cuanto a la riqueza de bromeliáceas epífitas, se encontró que el lugar más húmedo, la selva mediana subperennifolia, obtuvo el mayor número de especies (10), mientras que el manglar, con menor precipitación anual, tuvo la menor diversidad (dos) (cuadro 3), lo cual coincide con lo reportado para epífitas y otros grupos de plantas (Gentry y Dodson, 1987;Adler y Levine, 2007;Kluge y Kessler, 2010). En los sitios de estudio de SMSC se registró un menor número de especies comparado con los de las SBC y SMSP, aun cuando esta selva tuvo una precipitación intermedia. ...
La península de Yucatán comprende el continuo de selva tropical más conservada de México y uno de los acuíferos de karst más extensos del mundo. En el presente trabajo proponemos monitorear la salud de los ecosistemas de esta zona geográfica utilizando los grupos funcionales (tanques CAM, C3 y somero, así como nebulofitas y pseudobulbosas) de las bromeliáceas epífitas. Se muestrearon cinco tipos de vegetación: matorral de duna costera, manglar chaparro y tres tipos de selva. Encontramos una distribución desigual de los grupos entre los sitios de estudio. Un análisis asoció la abundancia diferencial de los grupos con variables ambientales relacionadas con la temperatura, el déficit de presión de vapor y la precipitación. Proponemos utilizar estas mediciones como línea base y continuar su monitoreo a
largo plazo para registrar los efectos del cambio global sobre los ecosistemas.
... En este estudio, En el río Siraín, es una especie bastante común, fue colectado en el transecto 2, donde hay impacto antrópico del hábitat, pero este parece ser muy tolerante al ambiente degradado. En este estudio, fue una especie muy activa durante la estación lluviosa, concentrándose muy cercana a la zona ribereña, lo cual coincide con el trabajo de (Gentry y Dodson, 1987). ...
En el río Siraín, distrito de Kankintú, comarca Ngäbe Buglé se determinó la distribución espacial de los anfibios utilizando tecnologías SIG. Se encontraron 11 especies pertenecientes a seis familias en seis muestreos durante los años 2016, 2018 y 2022. A diferencia de la estructura de las comunidades de anfibios para tipos de bosque similares en América Central, se obtuvo una baja riqueza específica, con pocos individuos y con diversidad de Shannon (H= 2.02), lo que puede estar relacionado con el impacto antrópico a los bosques y a los ríos de Kankintú. De las especies encontradas D. auratus y O. pumilio, presentaron estado de conservación con medida de vulnerabilidad según ley nacional.
... They are particularly conspicuous in tropical and subtropical regions, considered among the world's most diverse areas (Mittermeier et al. 1999;Myers et al. 2000), where epiphytes may represent 20-40% of the flora (Taylor et al. 2021). The Neotropics (tropical America) is one of the most diverse biogeographic realms (Zizka 2019;Raven et al. 2020) and is home to 60% of all vascular epiphyte species currently known, represented most prominently in the families Orchidaceae, Bromeliaceae, Araceae, Polypodiaceae, and Piperaceae (Gentry and Dodson 1987;Taylor et al. 2021). ...
The Neotropical realm hosts some of the Earth's most species-rich biodiversity hotspots, with vascular epiphytes significantly contributing to this diversity, regionally accounting for up to 39% of the vascular flora. However, many regions of the Neotropics where epi-phytic species of restricted distribution are reported coincide with threatened ecosystems, such as the tropical montane cloud forest. Moreover, epiphytes may be especially vulnerable to land use and climate change impacts due to their dependence on host trees. We assessed the conservation status of vascular epiphytes in the Neotropics for the families that represent over 80% of the global epiphyte diversity (Araceae, Bromeliaceae, Orchidaceae, Piperaceae, and Polypodiaceae) and identified geographical centres of accumulation of threatened epiphyte species. We gathered information from free-access web repositories, specific epiphytic plant databases, and scientific and grey literature. We assessed the extinction risk of 11,446 epiphyte species following IUCN Red List guidelines, using Criterion B (geographic range size). We found nearly 60% (6,721 species) to be threatened, with 1,766 critically endangered (CR), 3,537 endangered (EN), and 1,418 vulnerable (VU). The threatened species are mainly found in the centres of endemism of vascular epiphytes in Central America, the northern Andes, and the Atlantic Forest. Our study emphasises that the centres of threatened species largely coincide with diversity hotspots, highlighting epiphytes as an especially vulnerable group that requires urgent conservation actions.
... DOI: 10.17521/cjpe.2022.0454 森林生态系统中, 高大乔木作为初级基础物种 塑造了最初的物理结构框架, 改善了环境和生物胁 迫源 (Ellison et al., 2005)。在此基础上, 由地表以上 所有植物枝叶集合组成的林冠, 凭借垂直分层的三 维结构, 为动植物提供了更多生存空间以及多样化 的生态位 (刘文耀等, 2006), 支持了大约40%的陆栖 生物物种, 其中10%是林冠专有类群 (Ozanne et al., 2003)。对植物而言, 林冠环境有相对充足的阳光, 但由于无法获得土壤水, 时常会遭受间断性缺水的 影响 (Helbsing et al., 2000), 水分成为限制植物向林 冠扩张的主要因素 (Gentry & Dodson, 1987) ...
... The tropical Andes is considered the largest plant biodiversity hotspot in the world [1,2]. The Orchidaceae significantly contributes to the diverse species comprising the Andean Flora [3], especially epiphytes [4]. In Ecuador, one of the smallest countries in South America, orchids represent the most diverse plant family with 228 genera and more than 4200 species from which 60% are epiphytic [5,6]. ...
Effects of daily temperature fluctuations that mimic on-site environmental conditions were tested on seed germination and development in Dracula felix, a native epiphytic orchid from the neotropics. Mature seeds collected from a native population lost their viability from 60% to 37.78% and 0% after 8 and 16 weeks., respectively, under 22 ± 2 • C. Seed viability was completely lost when seeds were maintained at −10 • C in the dark. Less than 50% germination was observed in D. felix seed across all treatments. Seed germinated regardless of the light or temperature treatment. However, significant improvement in germination was observed at 17/22 • C compared to constant temperature treatments. Early seedling development stages were observed only on 1/2XMS and VW media at 17 • C or 17 • C/22 • C under a 12 h light photoperiod. Neither germination nor seedling development were improved by any fungal strain tested using standard symbiotic germination protocols. Information obtained from this study is critical to ensure the ex-situ conservation of this and other rare Dracula species under current and future climate change scenarios.
... Environmental conditions, particularly temperature and precipitation, are known to determine species distributions and diversity patterns in vascular epiphytes (Gentry and Dodson 1987;Kreft et al. 2004). In this study, epiphytes showed a high correlation with all groups in general. ...
In this work, we contribute to the knowledge of how two environmental gradients (elevation and forest-use intensity) interactively affect the tropical plant diversity of six different vascular plant groups (trees, shrubs, lianas, terrestrial herbs, epiphytes, and ferns). The results were obtained in the frame of the interdisciplinary research project “BIOVERA,” which aims at documenting and understanding biodiversity patterns along gradients of elevation, climate, soil, and disturbance along an eleva
tional transect at the Cofre de Perote mountain in central Veracruz, Mexico.
... Higher epiphyte diversity is more closely related to water availability and optimum temperature (16-20°C) at mid-elevations (Gentry & Dodson, 1987;Khine et al., 2019;Hernández-Rojas et al., 2020;Furtado & Neto, 2021). Study of elevational gradients has deepened our understanding of diversity patterns and how species respond to altitudinal variation, the interaction between climate, topography, K E Y W O R D S elevational patterns, Sierra Madre of Chiapas, thermal range, topographic variation, waterenergy dynamics and human disturbance to explain patterns of diversity for different plant groups remains an active topic of research. ...
Question
Understanding the specific distribution patterns of vascular plants on different spatial scales is central in ecology and conservation. We evaluate distribution patterns of five plant life-forms (climbers, epiphytes, herbs, shrubs, and trees) along the elevation gradient and geographic space of a mountain system, analyzing climate, topography, and human disturbance to explain variation in richness of each life-form, and determine the contribution of each life-form to total richness along the elevation gradient.
Location
Sierra Madre of Chiapas, southeastern Mexico.
Methods
We used linear models to evaluate the elevational pattern of richness for each life-form, as well as total richness, and analyzed the effects of climate (water-energy dynamics, thermal range), topography (topographic heterogeneity), and disturbance (human influence index) on variation in total richness as well as of each life-form using generalized linear models (GLM). We used non-metric multidimensional analysis (NMDS) to determine variation in species composition along the elevation gradient. Finally, the contribution of each life-form to total richness was evaluated using GLM.
Result
We recorded 235 families, 1,439 genera, and 5,196 species. Total richness and richness of each life-form increased with increasing elevation. GLM explained a high proportion of variation in richness of each life-form (34.3% for total richness, climbers 17.2%, epiphytes 44.9%, herbs 20.4%, shrubs 33.5 %, and trees 24.9%). The proportion of richness of herbs and trees to total richness decreased, while the proportion of shrubs, epiphytes, and climbers increased with elevation. Climate largely determined species richness for all life-forms, whereas disturbance was significant only for epiphyte richness.
Conclusions
Results suggest that mechanisms driven by climatic variables (especially thermal range) contribute to maintaining richness of each life-form. However, human disturbance modifies distribution patterns and leads to a decrease in epiphyte richness. The differential contribution of each life-form to total richness along the elevation gradient, presents a challenge for designing conservation strategies applicable to all plant groups.
... Even after proofing that epiphytes are diversifying faster, the exact mechanism(s) behind the origin of the enormous diversity of many holoepiphyte taxa remain(s) largely obscure. Phillips et al. (2012) investigated the hypothesis that small, and disjunct orchid populations experience strong genetic drift due to orogenesis, which ultimately encourages speciation (a hypothesis specifically proposed for orchids by Gentry and Dodson, 1987). However, no evidence for higher levels of population genetic differentiation was found. ...
... El establecimiento de las epífitas depende de las características del árbol huésped como la especie, arquitectura, el tamaño, la edad y el tipo de corteza; así como la variación microclimática, que determinan la estratificación vertical desde la parte alta del dosel hacia el interior del bosque (Jiménez, Roblero, Martínez, Ocampo & Gallardo, 2017). Las epífitas contribuyen significativamente, a la biodiversidad de los trópicos, ya que constituyen hasta 40 % de la flora de una zona tropical, y 10% de todas las plantas vasculares del mundo (Gentry & Dodson, 1987; Mora, Estrada, Pando, de la Rosa Manzano & Jurado, 2018). Las epífitas son importantes en la dinámica de comunidades, porque debido a su distribución vertical, en los troncos de los árboles, ofrecen una variedad de nichos y recursos que son aprovechados por diversos grupos de organismos, contribuyendo a la biodiversidad en las comunidades (Ceja, Espejo, López, Garcia & Mendoza, 2008). ...
... Despite the extraordinary diversity and abundance of epiphytic orchid species in the Andean forest [27,28], most information regarding the mycorrhizal association during seed germination and seedling establishment is well documented for terrestrial orchids in temperate zones [15]. In Ecuador, research on orchid mycorrhizal associations has been focused on the isolation and identification of endophytes isolated from orchid species from the Andean cloud forest of south Ecuador [22,23,29,30]. ...
A greater understanding of the relationship between native orchids and their mycorrhizal symbionts is needed to ensure more effective orchid conservation strategies. A protocol for symbiotic seed germination and seedling development was developed for E. geminiflorum. Mature seeds were collected from a naturally occurring orchid population in Ecuador. Putative mycorrhizal fungi isolated from other native orchid species were used to screen their ability to facilitate germination and seedling development in vitro in either a 0/24 h or 12/12 h light/dark photoperiod at 20 • C. The mycorrhizal fungus Tulasnella calospora (UAMH 9824) isolated from Spiranthes brevilabris in Florida, USA, was also included in this study. Sterilization treatments using 0.3%, 0.5% sodium hypochlorite/ethanol or 2% calcium hypochlorite were tested for their effectiveness as sterilant and their subsequent effects on seed germination percentage. Effective surface seed sterilization was achieved with either 0.5% NaClO/ethanol or 2% calcium hypochlorite. However, significantly higher percentages of germinated embryos developed into protocorms when NaOCl solutions were used compared to the other treatments. Seed germination occurred in both photoperiods tested; however, delayed germination was observed under complete darkness. Seeds of E. geminiflorum germinated without fungal inoculation; however, co-culture with Tulasnella strains improved germination significantly. Seedling development was only observed when seeds were cultured in asymbiotic medium or co-cultured with T. caloscopa (UAMH 9824). Significantly longer seedlings were obtained when T. calospora was present in the culture compared with seedlings cultured in asymbiotic medium. The establishment of mycorrhizal associations was confirmed by the presence of pelotons in the roots of E. geminiflorum seedlings.
... Thus, further studies of herbaceous plant diversity across gradients are needed to determine the main drivers of diversity for different herbaceous plant groups in different tropical forest types. In particular, epiphytes, the vast majority of which are herbaceous angiosperms (Zotz, 2013), can account for up to 30% of plant diversity in tropical forests (Gentry & Dodson, 1987b;Spicer et al., 2020). Because epiphyte diversity tends to increase with increasing MAP and a concomitant increase in tree basal area (Annaselvam & Parthasarathy, 2001;Bartels & Chen, 2012), we likely underestimated overall herb diversity at wetter sites in MNP, since our study only included terrestrial herbs. ...
In tropical forests, understory herbaceous angiosperms (herbs), which can comprise up to 40% of plant species richness, have received relatively little attention compared with trees, and their diversity patterns and drivers remain poorly understood. While tropical tree diversity has been shown to be driven primarily by water availability, we hypothesized that herb diversity may be equally or more limited by light availability.
To test the importance of water and light in shaping herb diversity, we surveyed herb communities in 13 one‐ha plots along a rainfall gradient in a seasonally dry tropical forest landscape in India. In each plot, herbs were censused thrice during the year in 47–50 one‐m² subplots. We examined drivers of herb diversity and ground cover at the landscape scale (across plots) and local scale (among subplots) using simple linear regression and linear mixed models, respectively.
At the landscape scale, herb diversity and ground cover were negatively related to rainfall and soil moisture, in contrast with previous studies of tropical forest trees. This indicates that water was not limiting for herbs. Instead, light availability, which was negatively correlated with rainfall, appears to drive patterns of herb diversity and ground cover across the gradient. Herb diversity and ground cover were uniformly low across the gradient during the dry season, indicating that water limitation does have a seasonal impact. When water was abundant (rainy season), herbs took advantage of higher light availability at more open (lower‐rainfall) plots.
Consistent with landscape‐scale patterns, herb richness at the subplot level was positively related to light availability, with its effect stronger at higher‐rainfall (more closed‐canopy) sites. Herb species richness declined with increasing subplot soil moisture in all sites and seasons, suggesting negative impacts of water logging and high moisture.
Synthesis. Diversity of understory herbs is limited by light availability at both local and landscape scales in this region, with the impact of water limitation restricted to the dry season. Our study shows that tree diversity patterns cannot be assumed to hold for other plant lifeforms, and conservation and restoration efforts must consider unique strategies for different lifeforms.
... Altogether, while there remains a wide range of questions about the identity, structure, and function of OMF and other fungi that associate with orchids worldwide, epiphytic orchids remain especially poorly studied despite representing up to 70% of the Orchidaceae (Benzing 1987;Gentry and Dodson 1987;Zotz 2013). Epiphytic orchids also occur in the generally hyper-diverse tropical ecosystems that tend to be hotspots for biodiversity. ...
Mycorrhizal symbiosis has been related to the coexistence and community assembly of coexisting orchids in few studies despite their obligate dependence on mycorrhizal partners to establish and survive. In hyper-diverse environments like tropical rain forests, coexistence of epiphytic orchids may be facilitated through mycorrhizal fungal specialization (i.e., sets of unique and dominant mycorrhizal fungi associated with a particular host species). However, information on the role of orchid mycorrhizal fungi (OMF) in niche differentiation and coexistence of epiphytic orchids is still scarce. In this study, we sought to identify the variation in fungal preferences of four co-occurring epiphytic orchids in a tropical rainforest in Costa Rica by addressing the identity and composition of their endophytic fungal and OMF communities across species and life stages. We show that the endophytic fungal communities are formed mainly of previously recognized OMF taxa, and that the four coexisting orchid species have both a set of shared mycorrhizal fungi and a group of fungi unique to an orchid species. We also found that adult plants keep the OMF of the juvenile stage while adding new mycobionts over time. This study provides evidence for the utilization of specific OMF that may be involved in niche segregation, and for an aggregation mechanism where adult orchids keep initial fungal mycobionts of the juvenile stage while adding others.
... In general, epiphytes at the community level are more affected by drought than any other life form. In their classic study, Gentry and Dodson [31] showed that epiphyte species richness and abundance change much more from dry to moist to wet forest than richness and abundance of co-occurring trees, climbers or shrubs. However, this statement does not mean that epiphytes that do grow in seasonal and drier habitats are particularly vulnerable to drought. ...
As climate change leads to increasing temperatures, tropical dry seasons are expected to become more severe. An overall intensification of drought events may strongly affect vascular epiphytes. Especially at the community level, the response of epiphytes to intense drought events is still poorly understood. Therefore, the severe El Niño event of 2015/16 was used to assess the impact of prolonged drought on an epiphyte community on Annona glabra host trees, around Barro Colorado Island. Prior census data from 2002 and 2015 served as a reference for background community dynamics. Net species changes and net population changes at the species level were determined for both periods. While the total abundance of the community almost doubled during the 13 years of the reference period, individual numbers decreased by c. 17% within the year of the El Niño event. Overall, the El Niño event strongly affected the epiphyte community and led to a strong decrease in epiphyte numbers and species. These findings contrast with most previous studies in tropical lowlands that found epiphyte populations to be rather resistant to similarly severe drought events.
... We know that at the regional scale the epiphytic life form responds more strongly than others (e.g. trees or climbers) to differences in water supply, as demonstrated in the classic study by Gentry and Dodson (1987). However, by far the highest numbers of species and the highest abundances are found at the wet end, where epiphytes are not much affected by water scarcity. ...
Background and Scope
The epiphytic life form characterizes almost 10 % of all vascular plants. Defined by structural dependence throughout their life and their non-parasitic relationship with the host, the term epiphyte describes a heterogenous and taxonomically diverse group of plants. This article reviews the importance of crassulacean acid metabolism (CAM) among epiphytes under current climatic conditions and explores the prospects under global change.
Results and Conclusions
We question the view of a disproportionate importance of CAM among epiphytes and its role as a “key innovation” for epiphytism but do identify ecological conditions under which epiphytic existence seems to be indeed contingent on the presence of this photosynthetic pathway. Possibly divergent responses of CAM and C3 epiphytes to future changes in climate and land use are discussed with the help of experimental evidence, current distributional patterns, and the results of several long-term descriptive community studies. The results and their interpretation aim at stimulating a fruitful discussion on the role of CAM in epiphytes, under current and under altered climatic conditions in the future.
Although epiphytes play a significant role in the functioning of forest ecosystems, their ecological importance has often given less attention. The objective of this study was to assess the floristic composition and diversity of epiphytes in the Farante Forest. A total of sixty (25m x 25m) plots/quadrates were systematically laid. They were laid on the line transacts that were established in the Farante forest for vegetation for data collection. Phorophytes' vertical structure, diameter at breast height, bark texture, abundance of epiphytes and phorophytes, and elevation of each plot were collected as data. Voucher specimens of both epiphytes and phorophytes were collected for identification in the national herbarium of Ethiopia. Twenty-six (26) vascular epiphytes belonging to 22 genera and 10 families were recorded in Farante Forest. Polypodiaceae was the most abundant family. Acacia abyssinica, Ficus vasta, and Olea europaea subsp. cuspidata harbored the highest species richness of epiphytes. The relative distribution of epiphytes on the vertical structure of the phorophyte indicated 37% on the trunk, 36% on the canopy, and 27% on the base. The relative distribution of epiphytes on the texture of the phorophyte indicates 63% on a rough texture and 37% on a smooth texture. A significant (p = 0.002) and positive correlation (r = 0.96) were observed in the abundance of epiphytes and the size of the DBH of phorophytes. The diversity and evenness of epiphytes were 3.01 and 0.924, respectively, in the forest. The finding, therefore, confirmed the dominance of a few epiphytes harbored by a few host species, the highest epiphyte composition in the trunk zone, and the rough bark of phorophytes.
El habia ceniza (Habia gutturalis) y el torito capiblanco (Capito hypoleucus) son aves amenazadas y endémicas de Colombia. Ambas especies tienen rangos geográficos y tamaños poblacionales pequeños posiblemente como resultado de la destrucción y fragmentación de sus hábitats. Con el fin de obtener estimados cuantitativos de los efectos de características del paisaje sobre la ocupación de ambas especies, muestreamos una variedad de configuraciones del paisaje al interior de las zonas de amortiguamiento de dos hidroeléctricas en la cordillera Central de los Andes de Colombia y empleamos modelos de ocupación para estimar la proporción del área ocupada en función de estas covariables. Realizamos 35 puntos de conteo en cada zona de amortiguamiento entre junio y julio del 2014 y 2015. Utilizamos modelos de ocupación de una sola temporada para estimar la ocupación reconociendo la detección imperfecta. Los promedios de ocupación para ambas especies en el área de estudio fueron similares (0.61 SD=0.33 para el habia ceniza y 0.63 SD=0.25 para el torito capiblanco). Sin embargo, la distribución de la ocupación al interior del área de estudio fue muy diferente entre ellas. El mejor modelo para la habia ceniza propone que su ocupación disminuye con la elevación, mientras que el mejor modelo para la ocupación del torito capiblanco propone un aumento en la ocupación con la distancia a quebradas. Las probabilidades de detección fueron similares para ambas especies (<0.4) y declinaron significativamente durante el segundo año. Nuestros resultados proveen lineamientos cuantitativos para evaluar y monitorear el estado de estas poblaciones a corto y largo plazo.
Physical gradients are major natural drivers of global biodiversity. A key question is understanding how biogeographic patterns are impacted by transformation of natural habitats. We aim to elucidate the complex relationships between two core biogeographic drivers of biodiversity—elevation and precipitation—, local deforestation, and their additive and interactive effects on Andean orchid diversity in the Colombian Andes. We sampled understory orchids across 341 plots pairing natural and transformed habitats along a wide elevational (1163–3415 m) and precipitation range (879–3817 mm per year). We found 35,891 adult individuals in 341 species peaking at mid-elevations (∼2500 m) and mid-to-high precipitations (>1600 mm/yr). Conversion of natural to transformed habitats caused substantial orchid diversity loss, with ten-fold fewer species at the plot level equating to a 6-fold loss in overall species richness, and 23-times fewer individuals. The additive and interactive effects better explained the main patterns: conversion reconfigured the natural mid-elevation trends in orchid diversity and positive trend in diversity with precipitation to a quasi-linear trend in transformed habitats. This reflects the inherent dependency of orchid species to a host tree as well as lower resilience to transformed habitats. Our findings highlight the importance of halting deforestation across environmental gradients, but in particular at elevations and precipitations where reshaping of biogeographic patterns maximises the losses of biodiversity.
Reconstruction of the dispersal history and formation of modern ranges of various taxa is one of the actual problems of modern biogeography. Molecular genetic biogeography based on the analysis of phylogenetic relationships of taxa of different levels began to develop actively at the end of the XX century. Currently, this method is the most objective and represents the basis for reconstruction of scenarios of the origin and dispersal of various groups of plants. Due to recent transformation of views on the phylogenetic relationships of Pandanales, the reconstruction of tracks and modes of dispersal of representatives of the order Pandanales becomes an actual task. Representatives of all 5 families of Pandanales sensu APG IV were selected for the study and two cladograms were constructed. Based on the molecular-genetic cladistic method the region of hypothetical origin and probable dispersal scenarios of the families of the order Pandanales were determined. The order Pandanales is treated as originated in Laurasia and its differentiation began on the territory of Tibet. Dispersal of the representatives of the basal family Velloziaceae took place by long-distance transport via the Bering Land Bridge to South America (approximately 115 Mya). Velloziaceae dispersed in the New World vicariously in South America, then it was distributed to sub-Atlantic Africa by long-distance transport, and finally also vicariously to the east, south and north of the continent. It is shown, that the modern range of the representatives of rest Pandanales is the result of both types of dispersal – vicariously and long-distance transport.
Se presenta un listado de las especies de la familia Meloidae (Coleoptera) de la región Cusco, con base en revisión de material y fuentes bibliográficas. El listado comprende siete géneros y 16 especies incluidas dentro de dos subfamilias, Nemognathinae, con las tribus Nemognathini y Horiini, y la subfamilia Meloinae, con las tribus Tetraonycini, Epicautini y Pyrotini. Se indican como primeros registros para la región a las especies Epicauta (Epicauta) latitarsis (Haag-Rutenberg, 1880), Epicauta (Epicauta) weyrauchi Kaszab 1960, Epicauta (Epicauta) zischkai Martinez 1955, y Pseudomeloe espostoi Escomel 1917. Se provee una clave para la identificación de los géneros de Meloidae presentes en la región Cusco /// A list of the species of the Meloidae (Coleoptera) family of the Cusco region is presented, based on a review of material and bibliographic sources. The list comprises seven genera and 16 species included within two subfamilies, Nemognathinae, with the Nemognathini and Horiini tribes, and the Meloinae subfamily, with the Tetraonycini, Epicautini, and Pyrotini tribes. The species Epicauta (Epicauta) latitarsis (Haag-Rutenberg, 1880), Epicauta (Epicauta) weyrauchi Kaszab 1960, Epicauta (Epicauta) zischkai Martinez 1955, and Pseudomeloe espostoi Escomel 1917 are new records for the region. A key is provided for the identification of the genera of Meloidae present in the Cusco region.
Epiphytes are a large and understudied part of global diversity. Classic work by Gentry and Dodson argued that Neotropical, mid-elevation forests are centers of diversity for this growth form. We assessed this hypothesis with modern global geospatial and climatic datasets. By connecting growth form and occurrence data with climatic records at the same locations, we quantified spatial and climatic distributions of epiphyte species richness. Latitude was a powerful driver of epiphyte distributions, with peaks at the equator; here, epiphytes contributed significantly to vascular plant species richness with greatest prevalence at mid elevations and in the Neotropics. Climatically, precipitation was a stronger determinant than temperature as to where epiphytic species thrive. The study provides robust support for the hypotheses that plant diversity in Neotropical, mid-elevation forests is unusually concentrated in the epiphytic growth form, and the lower proportion of epiphytic diversity elsewhere may have both physiological or biogeographic explanations. The particular features of climate change in Neotropical mid-elevation habitats, and the implications for epiphyte diversity, are worthy of urgent research.
Land cover change threatens biodiversity by reducing species richness, altering species composition, and favouring generalist species. Pasture creation can promote the loss of original species, although this loss can be mitigated by maintaining scattered trees to reduce their structural differences with forests and thus retaining a portion of regional epiphyte diversity. We explore the negative effects of land cover change and potential factors promoting similarity of epiphyte assemblages between forests and pastures. We hypothesize that pasture epiphyte assemblages are characterized by low species richness and are dominated by xerotolerant and generalist species, with a species composition nested from the forest community, indicating a degree of overlap. We hypothesize that two main factors drive the similarity between forest and pasture epiphyte assemblages: “structural dependence”, whereby trees host similar species on their crowns and trunks independent of habitat, and “microclimatic dependence”, where pasture and forest trees are more similar in areas with comparable microclimatic conditions. We found lower species richness and higher abundance of generalist species in the pasture than in the forest, with differing species composition. However, there was still a significant overlap in species composition between the two habitats, indicating that the epiphyte assemblages in the pasture were nested from the forest assemblages. Pasture and forest trees shared more epiphyte species between crown and trunk zones rather than between shaded and sunlight-exposed zones. Hence, the similarity of vascular epiphyte assemblages between habitats is partially driven by structural factors, where certain epiphyte species preferentially occur in specific tree zones regardless of the microclimate or habitat. Considering these findings, we recommend maintaining and planting scattered trees in pastures to enhance structural complexity (e.g., longer trunks and multiple crown branching), which can foster a proportion of the vascular species from forested areas, thus maintaining the similarity in vascular epiphyte assemblages between habitats.
The dispersal and colonization of plant populations allow species to occupy novel habitats, migrate, and undergo range shifts in response to changing environmental factors and, as such, are fundamental ecological processes for ensuring the long‐term persistence of species. Natural landscape disturbance often generates habitats available for colonization. Patterns of colonization and population expansion can be inferred from the levels and partitioning of genetic variation of plant populations with known disturbance histories, such as recent volcanic eruptions. We sampled and mapped 496 individuals from two populations of the colonizing terrestrial orchid, Sobralia chrysostoma , on the 1992 lava flow of Volcán Arenal in central Costa Rica. We used neutral co‐dominant markers to genotype individuals and estimate population genetic statistics. Both populations had high mean levels of genetic diversity ( P = 100%; AP = 3.31; H e = 0.259) suggesting that the lava flow was colonized by numerous individuals that likely originated from multiple source populations. However, significant spatial genetic structure (SGS) was only present in one population at the smallest distance class (≤2 m) and was low ( r = 0.032). That these large and genetically diverse populations had such low SGS and an absence of SGS, respectively is contrary to expectations and differs significantly from the pattern in Epidendrum radicans (Orchidaceae), with which S. chrysostoma is growing sympatrically. Our results suggest that these two populations either consist primarily of immigrant individuals or that seeds produced in situ dispersed over longer distances, thereby producing larger seed shadows and greater overlap of seed shadows.
Aim
Angiosperm epiphytes have long been reported to have larger geographic ranges than terrestrial species, despite evidence of their outstanding diversity and endemism. This apparent contradiction calls for further investigation of epiphytes' poorly understood range size patterns. Here, we address the question of whether epiphytes have larger geographic ranges and different vulnerability to extinction than terrestrial species.
Location
The Atlantic Forest of Brazil, a global centre of tropical epiphyte diversity with relatively well‐known flora, where we can estimate the geographic ranges of a large number of species with reasonable confidence.
Time period
Occurrence records from the 17th century to the year 2021.
Major taxa studied
Flowering plants (angiosperms).
Methods
We downloaded, processed and cleaned all occurrence records for the angiosperm species native to the Atlantic Forest of Brazil available in the speciesLink network and the Global Biodiversity Information Facility. We estimated the extent of occurrence and area of occupancy of 12,679 native flowering plants, including 1251 epiphytic species. We compared the geographic ranges of epiphytes and other life forms at broad (e.g. Angiosperms, Monocots) and more restricted taxonomic scales (e.g. individual families), assuming species are independent entities and also when accounting for species phylogenetic dependence.
Results
We found that epiphytes have among the smallest geographic ranges of flowering plants. We found no consistent evidence that epiphytism leads to differences in geographic ranges between close relatives. However, both epiphytes and non‐epiphytes in epiphyte‐rich lineages have small ranges and likely a high vulnerability to extinction.
Main Conclusions
Our findings contrast with the long‐held hypothesis that epiphytes have larger geographic ranges than terrestrial species. Epiphytes and their close relatives share many diversification mechanisms and ecological adaptations (‘epiphyte‐like traits’), which probably explain why both sets of species have small range sizes and high vulnerability to extinction.
The Neotropical realm hosts some of the Earth’s most species-rich biodiversity hotspots, with vascular epiphytes significantly contributing to this diversity. However, many regions of the Neotropics where epiphytic species of restricted distribution are reported coincide with threatened ecosystems, such as the tropical montane cloud forest. Moreover, epiphytes may be especially vulnerable to land use and climate change impacts due to their dependence on host trees. We assessed the conservation status of vascular epiphytes in the Neotropics for the families that represent over 80% of the global epiphyte diversity (Araceae, Bromeliaceae, Orchidaceae, Piperaceae, and Polypodiaceae) and identified geographical centers of accumulation of threatened epiphyte species. We gathered information from free-access web repositories, specific epiphytic plant databases, and scientific and grey literature. We assessed the extinction risk of 11,446 epiphyte species following IUCN Red List guidelines, using Criterion B (geographic range size). We found nearly 60% (6,721 species) to be threatened, with 1,766 critically endangered (CR), 3,537 endangered (EN), and 1,418 vulnerable (VU). The threatened species are mainly found in the centers of endemism of vascular epiphytes in Central America, the northern Andes, and the Atlantic Forest. Our study emphasises that the centers of threatened species largely coincide with diversity hotspots, highlighting epiphytes as an especially vulnerable group that requires urgent conservation actions.
Las bromelias epífitas albergan en su interior una variedad de microambientes y de recursos para los artrópodos, convirtiéndose en importantes sitios de biodiversidad. En este trabajo se determinó la diversidad de los artrópodos asociados a la bromelia Tillandsia recurvata en tres localidades del municipio de Tecozautla, Hidalgo, México. En la temporada de secas se colectaron 112 ejemplares de T. recurvata en las plantas (forofito) de las especies: Acacia schaffneri, Myrtillocactus geometrizans, Bursera fagoroides y Prosopis laevigata. De cada epífita se extrajeron los artrópodos y cada morfoespecie se determinó taxonómicamente a nivel de orden y familia; por forofito se evaluó la riqueza específica, la diversidad y el número esperado de especies. La mayoría de las especies colectadas son de los órdenes Araneae, Coleoptera, Diptera y Hemiptera. La mayor riqueza se presentó en las bromelias del forofito P. laevigata y una diversidad mayor en el forofito M. geometrizans. En todos los forofitos, el número esperado de especies fue mayor al encontrado. En T. recurvata se forma un microambiente propicio para la presencia de los artrópodos, ya sea como refugio o bien para conseguir alimento. Los resultados establecen la posible influencia de los forofitos en la diversidad de las especies de artrópodos en T. recurvata.
Vascular epiphytes are extraordinarily diverse in the tropical Andean region. Compared to trees and terrestrial herbs, epiphytes are more vulnerable to forest alteration due to their structural dependence on trees and environmental requirements. Based on experimental approaches for ecological purposes, monitoring air pollutants, and seeking propagation alternatives, the rescue and translocation of vascular epiphytes (mainly bromeliads and orchids) from a threatened forest to a safer forest has been recently conducted in Colombia. Preliminary assessments indicate that epiphytes benefit from such well-planned measures, and their mortality and survival might be associated with extrinsic and intrinsic factors, which remain to be understood. We evaluated the survival of 16 vascular epiphyte species after translocation into a secondary forest in Antioquia (Colombia) for 8 years. We assessed the role of intrinsic (foliar area, number of leaves, initial pseudobulbs, stems or rosettes, functional group, and epiphyte species) and extrinsic factors (host tree species, bark water-holding capacity, type of substrate, location on the host tree, nutrients, and hormone addition) and the efect of climatic variables on plant survival. The overall mortality rate in this
study ranked 1–7% per year, and survival decreased annually, reaching 44% by the end of the 8th year. Host tree species and intrinsic factors such as the functional group and epiphyte species significantly afected the probability of survival. Bromeliads, in particular, exhibited high mortality, which their monocarpic growth form could explain. Another group of species showing high mortality were the miniature orchids, Masdevalia amanda and M. platyglossa, and are associated with short life cycles. Five host tree species appear to afect the survival of translocated epiphytes; however, the factors or characteristics involved remain unclear. A higher seasonality of precipitation was related to the percentage of overallmortality. This result indicates that extreme precipitation events or drought reduce epiphyte longevity. In conclusion, our study suggests that a wide range of epiphytes may be successfully translocated to secondary forests in the Colombian Andes and demonstrates that the effective introduction of epiphyte assemblages may be useful for ecological restoration efforts in Andean forests.
Mesoamerican mountains are important centers of endemism and diversity of vascular epiphytes. The Sierra Madre of Chiapas in southeastern Mexico is a mountainous region of great ecological interest due to its high biological richness. We present the first checklist of epiphytes for this region based on a compilation of various information sources.
Recognizes three distinct components of flower function: attraction, reward, and filtering mechanisms, and discusses their functioning in an ecological context, and as they relate to the genetic system or 'pollination unit' of the plant. Discusses nectar-feeding birds (not only morphological, but ecological and behavioral specializations to flowers as a food source). Different bird groups vary widely in their degrees of specialization for flower-feeding; bird-flower coevolution has followed very different courses, and has led to widely divergent ecological systems in different geographical areas. The hummingbirds are the most specialized avian nectarivores, although they are approached in this regard by some members of certain passerine groups, notably among the sunbirds. Several groups of passerine nectarivores also occur with the hummingbirds in many New World areas. Patterns of ornithophily and nectarivory are examined in detail for this area, concentrating on Southern Central America, especially Costa Rica. The altitudinal and geographical distributions of the two main groups of hummingbirds, the hermits and nonhermits, differ, as are the taxonomic and ecological affinities of their primary foodplants. Hermits are most numerous in wet lowlands and the adjacent foothills, and are primarily associated with large monocotyledonous herbs, notably Heliconia. Nonhermits reach their greatest taxonomic and ecological diversity in the lower middle elevations, and are the only group present at high elevations; they seem to have coevolved with the flowers of a variety of dicot families, and the bromeliads among the monocots. Passerine nectarivores occur primarily as parasites on the hummingbird-flower system (Coerebidae) and are important as pollinators only in seasonally dry areas when the hummingbirds are poorly represented.-from Author nectar feeding birds Costa Rica hummingbirds hermits Heliconia Coerebidae
Species pollinated by medium-sized to large bees were most frequent, followed by those pollinated by moths, small diverse insects and small bees, in that order. Almost a half the total species had pollinators with wide foraging ranges. Species pollinated by various groups of pollinators were distributed non-randomly. The greatest diversity of pollination systems was found in the subcanopy. As compared to the subcanopy, pollination mechanisms in the canopy were monotonous, consisting primarily of species pollinated by bees and small diverse insects. The hummingbird- and sphingid moth-pollinated species were found mainly in the subcanopy. The factors underlying the non-random distribution of pollinators are discussed and the potential implications of such distribution of the forest structure are explored.-from Authors Dept of Biol, Univ of Massachusetts, Boston, MA 02125, USA.
Nine sections are currently recognized in the genus Fuchsia, consisting of approximately 100 species. Morphological and biogeographical evidence indicates a Paleogene origin of the genus in temperate South America, with two early lines diverging to New Zealand and North America. Within South America, sects. Quelusia and Kierschlegeria have remained in the southern part of the continent, while the two largest sections, Fuchsia and Hemsleyella, have developed in the tropical Andes.
The Florida Caverns State Park, an area which is unique both in its flora and its physiography, is treated floristically with emphasis upon its geologic history and past climates. Evidence is presented which supports the theory that the area has been continuously available for occupancy by plants throughout the period of Pleistocene glaciations, possibly since the deposition of early Pliocene alluvia. Discussions of disjunct and endemic populations of both vascular plants and mosses point out the importance of fluctuating glacial and interglacial climates as well as the significance of edaphic and genetic factors in the synthesis and preservation of the relic flora. Disjunction and endemism are also discussed in the light of recent collections in the southeastern United States, and distribution maps are provided for many species. A check list of the Bryophytes and an annotated check list of the vascular plants of the 1187-acre park supplement the text.
The substance of this article was delivered as the Presidential Address to the Society for the Study of Evolution, December 30, 1969, in Boston, Massachusetts. Attention is drawn to evolutionary studies in the tropics which appear to be advancing the subject significantly. Then, detailed attention is given to the possible evolutionary bases of the most striking biological characteristic of the tropics: the extraordinary floristic and faunistic diversity of tropical ecosystems. Because most contributions to the discussion of this topic have come from zoologists, the emphasis here is placed on botanical aspects. It is concluded that each of several potential explanations for the diversity may be valid and that a great need for the future is synthesis rather than arbitration between theories.
Several species of rodents have been observed visiting the flowers of an undescribed species ofBlakea (Melastomataceae) in a cloud forest in Costa Rica. The rodents drink the copious nectar secreted at the base of the stamens
and are dusted with pollen. The first report of pollination by non-flying mammals in the neotropics suggests that this type
of pollination may be important where there is little competition with bats.
"Wright's views about population genetics and evolution are so fundamental and so comprehensive that every serious student must examine these books firsthand. . . . Publication of this treatise is a major event in evolutionary biology."-Daniel L. Hartl, BioScience
The founder principle has been used to explain many instances of rapid speciation. Advances from theoretical population genetics are incorporated into MAYR's original founder-effect genetic-revolution model to yield a newer model called the genetic transilience. The basic theoretical edifice lies upon the fact that founder event can sometimes lead to an accumulation of inbreeding and an induction of gametic disequilibrium. This, in turn, causes alleles to be selected more for their homozygous fitness effects and for their effects on a more stable genetic background. Selection occurring in multi-locus systems controlling integrated developmental, physiological, behavioral, etc, traits is particularly sensitive to these founder effects. If sufficient genetic variability exists in the founder population, such multilocus genetic systems can respond to drift and the altered selective forces by undergoing a rapid shift to a new adaptive peak known as the genetic transilience. A genetic transilience is, therefore, most likely to occur when the founder event causes a rapid accumulation of inbreeding without a severe reduction in genetic variability. The implications of this model are then examined for three aspects of the founder-effect genetic-transilience model: the attributes of the ancestral population, the nature of the sampling process used to generate the founders and the attributes of the founder population. The model is used to explain several features of the evolution of the Hawaiian Drosophila, and experimental designs are outlined to test the major predictions of the theory. Hence, this theory of speciation can be tested in the laboratory, using systems and techniques that already exist--a rare attribute of most models of speciation.
The Piperales and the monocots: alternate hypotheses for the origin of monocoty-ledonous flowers
- W Burger
BURGER, W. 1977. The Piperales and the monocots: alternate hypotheses for the origin of monocoty-ledonous flowers. Bot. Rev. 43: 345-393.
Flora y Vegetaci6n del Fundo Tesis Lic. Fac. Ciencias, Univ Flora of Barro Colorado Island Middle-latitude rainforests in the southern hemisphere
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Relationships between polli-BOTANICAL GARDEN
- C H Dodson
DODSON, C. H. 1967. Relationships between polli-BOTANICAL GARDEN [VOL. 74 in the arthropod community along an elevational transect in the Venezuelan Andes. Biotropica 8: 193-203.
Flora del Parque Nacional Puye-hue. Editorial Universitaria Epiphyte biomass and nu-trient capital of a neotropical elfin forest
- S Munoz
MuNoz S., M. 1980. Flora del Parque Nacional Puye-hue. Editorial Universitaria, Santiago. NADKARNI, N. M. 1984. Epiphyte biomass and nu-trient capital of a neotropical elfin forest. Biotro-pica 16: 249-256.
Las utilidades de los generos de antofitas del nordeste del Valle de Lerma (Salta, Republica Argentina) Facultad de Ciencias Na-turales
- L Novara
NOVARA, L. 1984. Las utilidades de los generos de antofitas del nordeste del Valle de Lerma (Salta, Republica Argentina). Facultad de Ciencias Na-turales, Universidad Nacional de Salta, Salta. RAMiREZ, C. 1978. Estudio floristico y vegetacional del Parque Nacional Tolhuaca (Malleco-Chile).
Angiosperm biogeog-raphy and past continental movements. Ann. Mis-souri Bot
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& D. AXELROD. 1974. Angiosperm biogeog-raphy and past continental movements. Ann. Mis-souri Bot. Gard. 61: 539-673.
Fitocenosis epi-fitas de la asociaci6n Lapagerio-Aextoxiconetum en el fundo
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RIVEROS, M. & C. RAMiREZ. 1978. Fitocenosis epi-fitas de la asociaci6n Lapagerio-Aextoxiconetum en el fundo San Martin (Valdivia-Chile). Act. Cient. Venezolana 29: 163-169.
Seed size and plant habit in seven families from Panama and Costa Rica The Botany and Natural History of Panama Missouri Botanical Garden Plant-Geography upon a Physiological Basis The abundance and diversity of the herpetofauna of tropical forest litter
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ROCKWOOD, L. L. 1985. Seed size and plant habit in seven families from Panama and Costa Rica. Pp. 197-205 in W. D'Arcy & M. Correa (editors), The Botany and Natural History of Panama. Missouri Botanical Garden, St. Louis. SCHIMPER, A. F. W. 1888. Die epiphytische Vegeta-tion Amerikas. Bot. Mitt. Trop. 2. 1903. Plant-Geography upon a Physiological Basis. Clarendon Press, Oxford. [English transla-tion, revised edition.] SCOTT, N. J., JR. 1976. The abundance and diversity of the herpetofauna of tropical forest litter. Bio-tropica 8: 41-58.
Las pterid6fitas y el epifitismo en el Departamento del Choc6 (Colombia)
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SOTA, E. DE LA. 1972. Las pterid6fitas y el epifitismo en el Departamento del Choc6 (Colombia). Ann. Soc. Cient. Arg. 194: 245-278.
Vegetation of the Earth Tropical Rain Forests of the Far East A synopsis of the neotropical Ges-neriaceae
- H Walter
- Berlin
- T C Whitmore
WALTER, H. 1985. Vegetation of the Earth, 3rd edi-tion. Springer-Verlag, Berlin. WHITMORE, T. C. 1984. Tropical Rain Forests of the Far East, 2nd edition. Clarendon Press, Oxford. WIEHLER, H. 1983. A synopsis of the neotropical Ges-neriaceae. Selbyana 6: 1-219.