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ABSTRACT Aim Location Taxon Methods Results Main Conclusions Ferns are globally distributed, yet the number of studies examining the historical evolution of African taxa is relatively low. Investigation of the evolution of African fern diversity is critical in order to understand patterns and processes that have global relevance (e.g., the pantropical diversity disparity [PDD] pattern). This study aims to examine when and from where a globally distributed fern lineage arrived in sub‐Saharan Africa, to obtain a better understanding of potential processes contributing to patterns of diversity across the region.Global, sub‐Saharan Africa.Asplenium (Aspleniaceae).We analysed five loci from 537 Asplenium taxa using a maximum likelihood (IQ‐Tree) phylogenetic framework. For age estimation, we performed penalised likelihood as implemented in treePL, and executed a Bayesian analysis using BEAST. Biogeographical analyses were carried out using BioGeoBEARS.Most dispersals into Africa occurred within the last ~55 myr, with the highest diversity of sub‐Saharan African taxa concentrated in two clades, each of which descended from an Asian ancestor. Additional dispersals to sub‐Saharan Africa can be found throughout the phylogeny. Lastly, potential cryptic species diversity exists within Asplenium as evidenced by several polyphyletic taxa.We recover multiple dispersals of Asplenium to sub‐Saharan Africa, with two major lineages likely diversifying after arrival. [ABSTRACT FROM AUTHOR]

Aim: How spatial, historical and ecological processes drive diversity patterns remains one of the main foci of island biogeography. We determined how beta diversity varies across spatial scales and among organisms, disentangled the drivers of this variation, and examined how, consequently, biogeographic affinities within and among archipelagos vary among land plants. Location: Macaronesia. Taxon: Bryophytes, pteridophytes, spermatophytes. Methods: Species turnover and nestedness were compared within and among archipelagos across taxonomic groups. The relationship between species turnover and nestedness, climatic, geological and geographic factors was analysed using generalized dissimilarity models. Results: Species turnover, but not nestedness, increased with the geographic scale. This increment decreased from spermatophytes, pteridophytes and bryophytes, wherein the median turnover was less than half that in spermatophytes. Bryophytes exhibited a significantly higher nestedness and lower turnover than spermatophytes. Extant climatic conditions and island age contributed the most to all models but the importance of island age for bryophyte and pteridophyte turnover was marginal. Spermatophyte floras clustered by archipelago, whereas the clustering patterns in pteridophyte and bryophyte floras reflected macroclimatic conditions. Main Conclusions: The lower increment of species turnover with spatial scale and the higher nestedness in bryophytes and pteridophytes than in spermatophytes reflect the variation in dispersal capacities and distribution ranges among land plants. Accordingly, extant climatic conditions contributed more to explain turnover in bryophytes and pteridophytes than in spermatophytes, whereas factors associated with dispersal limitations, including island age, geographic distance and archipelago structure, exhibited the reverse trend. The differences in beta diversity patterns, caused by different responses of Macaronesian land plant lineages to the main factors shaping their community composition, explain their different biogeographic affinities. These differences reflect a distinct origin and different mechanisms of speciation among Macaronesian land plant lineages and archipelagos. [ABSTRACT FROM AUTHOR]

Aim: It is well known that the distribution of species diversity is spatially heterogeneous, but understanding the factors contributing to this heterogeneity and to the formation of biodiversity hotspots remains a challenge. Here, we seek to improve our understanding of how historical, ecological and evolutionary processes contribute to current patterns of global fern diversity. Location: Worldwide. Taxon: Ferns. Methods: To evaluate the drivers of global fern diversity, we integrate over 800,000 georeferenced species occurrence records of nearly 8000 species, a time‐calibrated phylogeny and seven climate and environmental layers. We use these data to summarize diversity and evolutionary patterns at a resolution of 100 × 100 km, and identify hotspots of fern species richness and endemism. We compare these hotspots to neighbouring non‐hotspot regions to provide insight into the factors controlling global patterns of fern diversity. Results: Tropical and subtropical mountains harbour a disproportionate amount of species relative to the land area they occupy; 58% of global species richness occur in eight principally montane hotspots together comprising just 7% of Earth's land area. We identify hotspots of fern species richness and endemism that are universally characterized by disproportionately high ecological variation. We demonstrate that total fern species richness scales linearly with available climate space at regional and global scales. Main Conclusions: Areas of high environmental heterogeneity harbour a disproportionate amount of fern species, and global patterns of extant fern diversity reflect the distribution of these areas, especially in mountains at lower latitudes. Persistence of ancient lineages in areas with long‐term climatic stability helps explain exceptional endemism in regions such as Malesia. [ABSTRACT FROM AUTHOR]

Aim: To assess the range size patterns of ferns and lycophytes along elevational gradients at different latitudes in an ecographical transition zone and search for predictors of range size from a set of environmental factors. Location: Mexico, from 15° to 23° N. Taxon: Ferns and lycophytes. Methods: All terrestrial and epiphytic species were recorded in 658 plots of 400 m2 along eight elevational gradients. To test whether the range size within assemblages increases with elevation and latitude, we calculated the latitudinal range using the northern and southern limits of each species and averaged the latitudinal range of all species within assemblages weighted by their abundances. We related climatic factors and the changes with latitude and elevation with range size using linear mixed‐effects models. Results: Species richness per plot increased with elevation up to about 1,500–2,000 m, with strong differences in overall species richness between transects and a reduction with increasing latitude. The mean weighted range size of species within assemblages declined with elevation, and increased with latitude, as predicted by theory. However, we also found marked differences between the Atlantic and Pacific slopes of Mexico, as well as low range size in humid regions. The best models described about 76%–80% of the variability in range size and included the seasonality in both temperature and precipitation, and annual cloud cover. Main conclusion: Latitudinal and elevational patterns of range size in fern assemblages are driven by an interplay of factors favouring wide‐ranging species (higher latitudes with increasing temperature seasonality; dryer habitat conditions) and those favouring species with restricted ranges (higher elevations; humid habitat conditions), with additional variation introduced by the specific conditions of individual mountain ranges. Climatically stable, humid habitats apparently provide favourable conditions for small‐ranged fern species, and should accordingly be given high priority in regional conservation planning. [ABSTRACT FROM AUTHOR]

Aim: To disentangle the influence of environmental factors at different spatial grains (regional and local) on fern and lycophyte species richness and to ask how regional and plot‐level richness are related to each other. Location: Global. Taxon: Ferns and lycophytes. Methods: We explored fern and lycophyte species richness at two spatial grains, regional (hexagonal grid cells of 7,666 km2) and plot level (300–500 m2), in relation to environmental data at regional and local grains (the 7,666 km2 hexagonal grid cells and 4 km2 square grid cells, respectively). For the regional grain, we obtained species richness data for 1,243 spatial units and used them together with climatic and topographical predictors to model global fern richness. For the plot‐level grain, we collated a global dataset of nearly 83,000 vegetation plots with a surface area in the range 300–500 m2 in which all fern and lycophyte species had been counted. We used structural equation modelling to identify which regional and local factors have the biggest effect on plot‐level fern and lycophyte species richness worldwide. We investigate how plot‐level richness is related to modelled regional richness at the plot's location. Results: Plot‐level fern and lycophyte species richness were best explained by models allowing a link between regional environment and plot‐level richness. A link between regional richness and plot‐level richness was essential, as models without it were rejected, while models without the regional environment‐plot‐level richness link were still valid but had a worse goodness‐of‐fit value. Plot‐level richness showed a hump‐shaped relationship with regional richness. Main conclusions: Regional environment and regional fern and lycophyte species richness each are important determinants of plot‐level richness, and the inclusion of one does not substitute the inclusion of the other. Plot‐level richness increases with regional richness until a saturation point is reached, after which plot‐level richness decreases despite increasing regional richness, possibly reflecting species interactions. [ABSTRACT FROM AUTHOR]

ABSTRACT Aim The aim of this study was to investigate whether the equilibrium theory of island biogeography ( ETIB) is equally applicable at regional and local spatial scales, and whether the 'echo pattern', the correlation between regional species pool and local diversity by which the diversity of the regional species pool 'trickles down' to local scales, influences local diversity equally across a range of sampling scales. Location Twelve mountain regions on islands having different sizes, degrees of isolation and environmental conditions in Indonesia and the Philippines. Methods We sampled ferns in standardized field plots within a fixed spatial design at six spatial scales (with the grain size varying from plot to island). Using ordinary least squares regression and relative variable importance, we tested for the predictive power of area and isolation as well as of local and regional environmental factors for explaining diversity at the chosen spatial scales. Results Consistent with MacArthur and Wilson's ETIB, we found the strongest correlations of area and isolation with diversity at regional scales. The explanatory power of area increased with increasing spatial scale. The strength of the negative relationships among diversity and isolation decreased with increasing spatial scale. We found evidence for an 'echo pattern' at large to intermediate but not at small spatial scales. Main conclusions Area and isolation are strong predictors of biodiversity at regional scales. The size of the species pool has a scale-dependent influence on diversity at smaller scales but is unimportant at the most local scale, where environmental conditions dominate as predictors of diversity. To make predictions about local diversity on islands it is therefore important to take the scale dependence of the 'echo pattern' into account. [ABSTRACT FROM AUTHOR]

To calculate the degree to which differences between local and regional elevational species richness patterns can be accounted for by the effects of regional area. Five elevational transects in Costa Rica, Ecuador, La Réunion, Mexico and Tanzania. We sampled ferns in standardized field plots and collated regional species lists based on herbarium and literature data. We then used the Arrhenius function S = cA to correct regional species richness ( S) for the effect of area ( A) using three slightly different approaches, and compared the concordance of local and regional patterns prior to and after accounting for the effect of area on regional richness using linear regression analyses. We found a better concordance between local and regional elevational species richness after including the effect of area in the majority of cases. In several cases, local and regional patterns are very similar after accounting for area. In most of the cases, the maximum regional richness shifted to a higher elevation after accounting for area. Different approaches to correct for area resulted in qualitatively similar results. The differences between local and regional elevational richness patterns can at least partly be accounted for by area effects, suggesting that the underlying causes of elevational richness patterns might be the same at both spatial scales. Values used to account for the effect of area differ among the different study locations, showing that there is no generally applicable elevational species-area relationship. [ABSTRACT FROM AUTHOR]

Aim To examine the relative importance of long-distance dispersal in shaping the New Zealand pteridophyte (ferns and lycophytes) flora and its relationships with other floras, with the null hypothesis that the extant New Zealand pteridophyte flora has been isolated since New Zealand’s separation from Gondwana. Location New Zealand. Methods rbcL DNA sequences were assembled for 31 New Zealand pteridophyte genera, with each genus represented by one New Zealand species and the most closely related non-New Zealand species for which data were available. Maximum-likelihood, maximum-parsimony, and Bayesian analysis phylograms were constructed and used as input forr8s molecular dating, along with 23 fossil calibrations. Divergence estimates less than conservatively recent ages for New Zealand’s geological isolation, namely Ho > 30 Ma for pairs involving New Caledonian and Norfolk Island species and Ho > 55 Ma for all others, were taken as rejection of the null hypothesis. Results The null hypothesis was rejected for all pairs except, under some parameter conditions, for those involving the New Zealand species Cardiomanes reniforme, Lindsaea trichomanoides, Loxsoma cunninghamii, Lygodium articulatum, Marattia salicina, and Pteris comans. However, the Lindsaea and Pteris results probably reflect the absence in the analyses of closely related non-New Zealand samples, while the Marattia divergence was highly contingent on which fossil calibrations were used. Main conclusions Rejection of the null hypothesis for the majority of pairs implies that the extant New Zealand lineage has undergone long-distance dispersal either into or out of New Zealand. The notion of a long isolation since geological separation can, therefore, be dismissed for much of New Zealand’s pteridophyte flora. The analyses do not identify the direction of the long-distance dispersal, and these New Zealand lineages could have had vicariant origins with subsequent long-distance emigration. However, the alternative that many extant New Zealand pteridophyte lineages only arrived by long-distance immigration after geological isolation seems likely. [ABSTRACT FROM AUTHOR]

Aim This paper reports the diversity and endemism patterns of African ferns, and explores the potential role of diversity refuges and environmental and historical factors in the shaping of these patterns. Material and locations The extant fern taxa occupying Africa south of the Sahara, Madagascar and some islands of the South Atlantic. Methods The number of taxa in each area or operational geographical unit (OGU) was scored, and the correlation between this number and physical and climatic variables analysed by standard pairwise and stepwise multiple regression analysis (SPR and SMR). The effects of biological factors such as dispersal capacity, reproductive biology, genetic features and certain physiological adaptations were evaluated by comparing the number of species in each OGU. Floral affinities among OGUs were analysed using non-metric multi-dimensional scaling (NMS) and parsimonic analysis of dispersion (PAD), and compared with 13-turnover and inter-OGU distances. Results OGU area, elevation and the distance between refuges determined the composition of local floras, but only greater OGU area and the existence of higher maximum elevations increased species richness. The distance between refuges also affected the number of endemic species, especially on islands. The biological features studied only slightly influenced fern distribution. The main climatic predictor of species number was humidity. SPR and SMR revealed three main groups of ferns with different ecological trends. NMS and PAD analyses separated the four areas of highest diversity in Africa, three of which are inhabited by ferns with distinct ecological requirements. The fourth area was Madagascar, which shows an accumulation of endemic and relict diversity that is not easy to explain. Main conclusions The distribution of ferns in Africa has been influenced by refuges. These probably allowed many species to recolonize the neighbouring areas after the extinctions of the Pleistocene. Three major components were detected in the African flora: Guinea-Congolian thermophilous, cold-tolerant Afro-montane, and Southern drought-tolerant elements. These are related to the three main refuge areas, i.e. the Gulf of Guinea area, the eastern tropical region, and the Cape region. Endemicity in ferns was found to be lower than that of seed plants due to the higher dispersability of fern spores. The distance between OGUs seems to be the main predictor of the number of endemic fern species these areas contain. [ABSTRACT FROM AUTHOR]

Epiphytes contribute up to 30% to the number of vascular plant species in certain global biodiversity hotspots, e.g. the Ecuadorian Andes. However, their large scale diversity patterns are still discussed on the base of results from a few, local epiphyte inventories. Consequently, explanatory models on epiphyte diversity concentrate on the impact of local climate on small scale epiphyte species richness. Our aim was to analyse large scale elevational patterns of epiphyte diversity integrating data from different geographic scales. Tropical America, with special emphasis on the Ecuadorian Andes. Our study is based on two data sources. First, we analysed the elevational patterns of epiphyte diversity based on the Catalogue of the Vascular Plants of Ecuador and the Libro Rojo de las Plantas Endèmicas del Ecuador. Secondly, the floristic turnover between the epiphyte inventories of seven montane and four lowland study sites in the Neotropics was analysed. The floristic turnover between Neotropical montane epiphyte floras is higher than the one between lowland epiphyte floras. Montane study sites located only a few kilometres apart from each other show considerable differences in their epiphyte species inventories. Irrespectively of their similar dispersal mode, the floristic turnover is much higher for orchids than for Pteridophyta. The Orchidaceae are the species richest group in all of the examined 11 Neotropical epiphyte floras. At the larger scale of the Ecuadorian Flora, c. 50% of the species in the elevational zone with maximum epiphyte diversity (between 1000 and 1500 m) are orchids. Elevational patterns of epiphyte diversity strongly reflect patterns of Orchidaceae. Our results support the observation of a ‘mid-elevation bulge’ of epiphyte diversity by Gentry and Dodson. It has been frequently shown that the high humidity in mid-elevations is suitable to maintan a high epiphyte species richness. Our findings show that in addition, large scale epiphyte diversity in montane rain forest is increased by the high floristic turnover at local and regional scale. Based on the importance of Orchidaceae for epiphyte diversity, we discuss that speciation processes corresponding to the highly diverse environment are a driving force for endemism, floristic heterogeneity and consequently for large scale epiphyte species richness in montane forests. [ABSTRACT FROM AUTHOR]

The central problem in biogeography is that interactions between different processes result in the formation of historical patterns, such that it is difficult to discriminate the relative roles of vicariance and dispersal. Ferns are distributed by small wind-dispersed propagules that are produced in very large numbers and capable of dispersing thousands of kilometers. Thus, most taxon distributions in ferns are assumed to be a function of dispersal rather than vicariance. Here, we review some case examples that provide good evidence for vicariance and dispersal in ferns. We then ask whether dispersal is so extensive in ferns that vicariance is no longer detectable in most cases. Although we think that too few studies have been carried out to make generalizations at this stage, we outline the criteria for an effective research programme that can address this issue. Phylogenetic and distributional data are needed, not only because they are lacking in an evolutionarily important group of organisms, but also because data from ferns and other cryptogams are likely to be crucial in making broad biogeographic statements. [ABSTRACT FROM AUTHOR]

Abstract To test whether cryptogamic plant communities in tropical Andean rain forests are distributed in floristically discrete communities corresponding to altitudinal belts, I subjected the elevational distribution of pteridophytes along two elevational gradients in Bolivia, and of bryophytes and lichens along two transects in Peru and Colombia (data from;) to an analysis of deviance. All well-defined elevational boundaries in floristic composition were related to marked ecological changes: the transition from the steep mountains to the hilly lowland zone coupled with a change in geological substrate at 400 m along the Bolivian Carrasco transect, a strong humidity gradient at 1000 m at the Bolivian Masicurí transect and at 1250–1980 m along the Colombian transect, and the transition from mixed cloud forests to forests dominated by Polylepis or Podocarpus at 3400–3600 m in Carrasco, at 1650–1800 m in Masicurí, and at 3670 m in Colombia. Consequently, floristic elevational belts appear to be well-defined at strong environmental boundaries and in fairly species-poor forest communities where the presence or absence of one or a few tree species influences the whole ecosystem while they are ill-defined in species-rich communities such as tropical forests at low to mid-elevations. [ABSTRACT FROM AUTHOR]

The aim of this quantitative biogeographical analysis is to identify the existence of specific groups of pteridophytes with significantly similar distribution patterns (chorotypes) in the Iberian Peninsula, as well as to infer the environmental factors that may explain such groupings. We have applied a classification method to the pteridophyte species and have then tested the significance of the resulting groups. This allows the distinction of groups of species that occur together more frequently than expected at random from those which are just a product of the cluster analysis. The majority of the 113 pteridophyte species in the Iberian Peninsula are not distributed independently from each other, but eighteen chorotypes exist that are common to various species and three chorotypes that consist of one species each. Five species are distributed independently of the other species, and so their distribution areas overlap and segregate from the others at random. With the aim of finding a relation between the chorotypes identified and the processes that determine them, we investigated the possible incidence of certain environmental factors on the chorotype distributions by means of logistic regression. Factors that appear most frequently as possible causes of the distribution of the chorotypes are the water availability, climatic stress, availability of environmental energy, and disturbances caused by floods.. El objetivo de este análisis biogeográfico cuantitativo es identificar la posible existencia de grupos de especies de pteridófitos con patrones de distribución significantivamente similares (corotipos) en la Peninsula Ibérica, así como analizar los factores ambientales que explican tales grupos. Hemos aplicado un método de clasificatión biogeográfica de especies y después hemos comprobado la significación de los grupos resultantes. Esto nos ha permitido distinguir los grupos de especies que se asocian con más frecuencia de lo esperado por azar de aquellos grupos que se deben únicamente al análisis de agrupación. La mayoría de las 113 especies de pteridófitos en la Península Ibérica no se distribuyen independientemente unas de otras, sino que existen 18 corotipos que son comunes a varias especies y tres que están formados por una sola especie. Cinco especies se distribuyen independientemente de las restantes, y por tanto, sus áreas de distribución se solapan y se segregan con las demás al azar. Con objeto de encontrar una relación entre los corotipos identificados en el presente trabajo y los procesos que los determinan, investigamos por medio de regresiones logísticas la posible incidencia de ciertos factores ambientales sobre las distribuciones de los corotipos. Los factores que han aparecido más frecuentemente como posibles causas de las distribuciones de los corotipos son la disponibilidad de agua, el estrés climático, la energía ambiental disponible y los disturbios causados por las inundaciones. [ABSTRACT FROM AUTHOR]