Operational Geographic Units Research Articles

New perspectives, additions, and amendments to plant endemism in a North African flora

BackgroundEndemism is essential in biodiversity, biogeography, and conservation tasks. Based on herbarium specimens kept in some local herbaria, many published literature, and available information, we compiled a comprehensive list and an updated assessment of the Egyptian endemic and near-endemic taxa. The application of quantitative approaches to the distribution patterns, conservation status, and habitat preference of endemic taxa in Egypt was provided. Comparisons of the near-endemic taxa with other neighbouring flora were explained. For each taxon, the distribution patterns, most preferable habitat, biological spectrum, and taxa among 14 phytogeographical regions (Operational Geographical Units; OGUs) of Egypt were determined.ResultsIn this study, 19 endemics (out of 70) and 76 near-endemics (out of 181) are newly added taxa. Differentiation indices represented the taxonomic degrees of differentiation among endemic taxa. Two different indices were used to assess endemism: single-region endemic taxa (SRET) and multiple-region endemic taxa (MRET). Most endemic and near-endemic taxa were recorded from the mountainous Sinai (S) and the Mareotis sector of the Mediterranean coastal land (Mm). Generally, the most represented families in endemic and near-endemic areas were Asteraceae, Caryophyllaceae, Lamiaceae, and Fabaceae. More than 60% of the endemic taxa occurred in the sandy plains, wadis (desert valleys), and rocky plains and mountains. Applying hierarchical cluster analysis to the occurrences of 70 endemic taxa in the 14 studied OGUs revealed five main floristic groups (I–V), each characterized by certain OGUs. We provided eight groups of near-endemic taxa that represented their extension in neighbouring countries.ConclusionsThe presented data will help to fill the gap in our knowledge of endemism, provide baseline information to understand biogeographical processes and facilitate further cooperation toward conservation purposes.

Areas of Endemism and Biogeographic Regionalization of the Iberian Peninsula Based on Ants (Hymenoptera: Formicidae)

Based on the distribution of 275 species of ants native to the Iberian Peninsula (IP), we identified areas of endemism (AE) within its geographical limits and present a biogeographic regionalization using two complementary methods and two types of operational geographical units. For endemicity analysis (EA), we used a 100 km2 grid cell, and for parsimony analysis of endemicity (PAE), we used hydrological basins as natural units. The EA revealed twelve areas of endemism that were grouped into five consensus areas. These are the Northeastern area, South plateau, Guadalquivir Valley, Baetic System, and Iberian Peninsula (whole). PAE resulted in a cladogram that classified hydrological basins into at least two successively nested subsets: an Atlantic group that is more related to northern European fauna and an Iberian subset that is well supported by synapomorphies. The Iberian subset was differentiated into four main areas: (a) a Northeastern area formed by the Pyrenees and the Catalan Coastal Range, (b) a mainland area containing the Central System and Guadiana and Tajo valleys, (c) a Southern area consisting of the Guadalquivir Valley and the Baetic System, and (d) a Northern coastal area. The results showed congruence between the two methods since many of the synapomorphies are shared among the diagnostic and IP endemic species of the EA. Both EA and PAE showed the relevance of the heterogeneous peninsular orography that combines mountainous regions with valleys and plateaus, which have acted as historical barriers or corridors. The presence of numerous endemic species, particularly in the southern third of the IP, suggests that several Iberian refuges for ants originated during glacial periods. These areas constitute priority sites for the conservation of ants in particular and biodiversity in general on the IP and allow further research about the processes that generated these distributional patterns.

Global paleobiogeography of Albian–Cenomanian (mid-Cretaceous) marine ostracods

Despite their potential for providing important information for paleobiogeography, studies using ostracod assemblages compiled from global datasets have been scarce so far. In this study, the paleogeographic implications of the relationship between different ostracod assemblages are analyzed and discussed for the Albian and Cenomanian. We compiled an ostracod dataset at the genus level, with 168 genera for the Albian and 174 for the Cenomanian, to which different multivariate statistical methods of grouping were applied. The affinity between different ostracod assemblages from different regions allowed for the delineation of 30 operational geographic units (OGUs) for the Albian, and 32 OGUs for the Cenomanian, grouped in three paleobiogeographic units (PBUs; Megatethys, Persia, and Austral) and one sub-unit (PBSU; Maghreb associated to the Megatethys). The Maghreb PBSU showed minor changes between the Albian and Cenomanian. The relationship among the OGUs grouped in each PBU is related to different factors, such as eustatic sea level events, similar climatic zones, and marine current circulation patterns. A relationship was observed between the Gabon and Nigeria OGUs with the Persia PBU, which suggests a direct east–west connection between them during the Cenomanian. The affinity observed in the Austral PBU between the South American, South African, and Australian regions during the Albian can be explained by their relative geographic isolation due to the Walvis Ridge barrier. The eventual flooding of this barrier led to the relationship observed between the SE Brazilian and Bolivian regions with the Austral PBU. Finally, the data also suggested that the separation of the Indian subcontinent from the Austral PBU took place during the Cenomanian.

Diversity patterns of echinoids (Echinodermata: Echinoidea) in shallow waters of the Mexican Pacific

The Mexican Pacific hosts a large diversity of echinoids occupying different habitats and ecological niches; nevertheless, the group remains scarcely studied in terms of their spatial patterns of biodiversity and variation in the region. This work evaluated the alpha, beta, and gamma diversity of echinoids living in the Mexican Pacific's shallow waters (0–200 m) at three spatial scales: Operational geographic units (OGUs), ecoregions, and provinces. Alpha diversity was evaluated through the standardized coverage values of 0D, 1D, and 2D, while the contribution of alpha and beta diversity components to gamma diversity was estimated with additive partitioning. Finally, we evaluated whether beta diversity resulted from overlap, species replacement, or richness differences. A total of 45 species and 2,232 incidences were registered in the 150 OGUs distributed throughout the Mexican Pacific. Cluster completeness in the ecoregions of the Warm Temperate Northeast Pacific (WTNP) province was higher (> 95 %) than in the ecoregions of the Eastern Tropical Pacific (TEaP) province. Standardized coverage values of the 0D, 1D, and 2D indices showed differences between the ecoregions Cortezian and Magdalena Transition in the WTNP province. At the ecoregion and province level, alpha diversity might be influenced by sampling techniques and habitat availability, which limits the distribution of regular and irregular echinoids. Gamma diversity is mainly determined by beta diversity at the ecoregion scale, where species overlap and richness differences were the major contributing components, probably resulting from substrate dependence, habitat availability, and mesoscale ocean circulation patterns.

Ophiuroidea (Echinodermata) diversity partitioning across the eastern tropical Pacific

Ophiuroidea is one of the most suitable marine groups for exploring diversity partitioning in the ocean due to its wide distribution and particular lifestyles. Nevertheless, diversity and its variation have yet to be investigated, and even basic information for large areas such as the eastern tropical Pacific (ETP) is still lacking. The present contribution explores α, β, and γ-diversity patterns of Ophiuroidea from the ETP at four spatial scales (Operational Geographic Units, Ecoregions, Provinces, and Realms). Based on literature records, databases, and scientific collections, an occurrence matrix was constructed for 69 shallow water (0–200 m) Ophiuroidea of the ETP (Mexico–Peru). Diversity evaluation based on rarefaction curves indicated that the observed richness tends to reach the asymptote. At the province and the ecoregion levels, β-diversity was the most important component explaining γ-diversity. The components that mainly contributed to the differentiation between provinces and ecoregions were the intersection of nestedness and β-diversity. PERMANOVA and SIMPER results showed that species composition presented significant differences at all spatial levels. The PCO ordination indicated that the first component (PCO1) explained the variation in species composition in a longitudinal gradient between coastal and oceanic ecoregions, while PCO2 showed a latitudinal gradient. The shade plot yielded three clusters (northern, southern, and widely distributed species). In general, α-diversity was explained by differences in sampling effort and methods; in contrast, β-diversity and its components were mainly explained by patterns and processes occurring at different spatial scales (provinces and ecoregions) such as oceanographic conditions, geographic extension, dispersal, and environmental heterogeneity. This work represents the first attempt to analyze the distribution patterns of shallow-water Ophiuroidea from the ETP.

An analytically derived delineation of the West African Coastal Province based on bivalves

AbstractAimTo assess the pattern of biotic regions (BR) and their boundaries, to detect chorotypes and to relate these patterns to key environmental factors.LocationEastern Atlantic Ocean.Time periodRecent.Taxon studiedBivalvia.MethodsDistributions were scored for 595 species. Operational geographical units are classified hierarchically using Baroni‐Urbani & Buser similarity index, clusters were assessed for statistical significance with the ‘RMacoqui 1.0’ software using G tests of independence, and chorotypes were inferred likewise from similarity between species distributions.ResultsThree strong biotic boundaries delimit four BR: (1) European Atlantic and Mediterranean; (2) West African, from western Sahara to southern Angola; (3) Baia dos Tigres/Namibia; and (4) Saint Helena/Ascension. The West African BR is subdivided by two weak boundaries into three subordinate BR: the tropical region proper, the north‐western African transition zone and the cluster (southern Angola/São Tomé/Cape Verde Islands). Of the 429 species present in West Africa, 261 (60.7%) are endemic, and 19 genera (7.2%) are endemic. Sixteen chorotypes were identified; the European BR is correlated with chorotypes C5 (149 species mostly European and Mediterranean) and C3 (38 species mostly in northern Europe), whereas the West African BR is mainly characterized by chorotype C6 (221 species). Some discontinuous distribution patterns of tropical West African species were identified as chorotypes, but subordinate to chorotype C6. The West African BR is mainly characterized by sea surface temperature and chlorophyll; characterization without the islands also involved the extensive sandy coast. The north‐western African transition region is characterized by an arid climate and few rivers and influenced by seasonal upwelling. The cluster of southern Angola, Sao Tomé and Cape Verdes contrasts with the remainder of West Africa in having a predominantly rocky shore.Main conclusionsThe present analyses provide an objective regionalization based on species occurrences, which supports the traditional recognition of West Africa as a major biotic region with a high level of endemism. Attention is called on that the unique endemic component is insufficiently represented in current marine protected areas.

Hot-spots of the genus Aconitum in the Ukrainian Carpathian Region

Basing on 2054 georeferenced occurrences of ten Aconitum species, the initial map of the species richness per each of 57 operational geographic units (OGU) of the Ukrainian Carpathian Region (UCR) has been developed. Next, to avoid unequal data distribution, we counted absolute species presence per OGU, based on which we calculated ‘rarity-weighted richness’ (RWR) and performed parsimony analysis. As a result, we found that Chornohora and Svydovets made a strongly supported cluster with the highest Aconitum species diversity and demonstrated the highest RWR values, hence being the main hot-spot of the genus distribution in the UCR. This main hot-spot also spreads to adjacent mountain ranges, including Maramures and Gorgany. Probably, a continuous gradient of Aconitum taxonomic richness from southeast toward northwest of the UCR existed before. The gap in Polonyna Borzhava, located between Polonyna Rivna and Polonyna Rivna, can be secondarily resulted by the high level of anthropogenic transformation of this region. Contrary, the high RWR value and distinct clustering of the Polonyna Rivna supported the presence of a local isolated Aconitum hot-spot related to two prominent mountain peaks located here – Runa-Plai Mt. (in Polonyna Rivna) and Pikui Mt. (in adjacen Waterdivided Mountain Range).

Macroclimatic structuring of spatial phylogenetic turnover in liverworts

Phylogenetic turnover has emerged as a powerful tool to identify the mechanisms by which biological communities assemble. When significantly structured along environmental gradients, phylogenetic turnover evidences phylogenetic niche conservatism, a critical principle explaining patterns of species distributions at different spatio–temporal scales. Here, we quantify the contribution of geographic and macroclimatic drivers to explain patterns of phylogenetic turnover in an entire phylum of land plants, namely liverworts. We further determine whether climatic niche conservatism has constrained the distribution of liverworts in the course of their evolutionary history. Two datasets, one insular, focused on 60 archipelagos and including 2346 species, and the second global, including 6334 species in 451 oceanic and continental operational geographic units (OGUs) worldwide, were assembled. Phylogenetic turnover among OGUs was quantified through πststatistics. πst‐through‐time profiles were generated at 1 Myr intervals along the phylogenetic time‐scale and used to compute the correlation between πst, current geographic distance and macroclimatic variation with Mantel tests based on Moran spectral randomization to control for spatial autocorrelation. The contribution of macroclimatic variation to phylogenetic turnover was about four‐times higher than that of geographic distance, a pattern that was consistently observed in island and global geographic settings, and with datasets including or excluding species‐poor OGUs. The correlation between phylogenetic turnover and geographic distance rapidly decayed at increasing phylogenetic depth, whereas the relationship with macroclimatic variation remained constant until 100 Mya. Our analyses reveal that changes in the phylogenetic composition among liverwort floras across the globe are primarily shaped by macroclimatic variation. They demonstrate the relevance of macroclimatic niche conservatism for the assembly of liverwort floras over very large spatial and evolutionary time scales, which may explain why such a pervasive biodiversity pattern as the increase of species richness towards the tropics also applies to organisms with high dispersal capacities.

Geographical variation in the bill–flower fit in a plant–pollinator interaction in western Mexico

AbstractFew studies have examined geographical variation in traits involved in biotic interactions, although such variation is likely key in the evolution of interactions. The fit between hummingbird bills and the flowers they feed on suggests mutual selection pressures. We tested for geographical variation in the pollinator–flower fit in the Mexican hermit Phaethornis mexicanus and Heliconia spp. flowers by analyzing the morphospaces of the interacting species and the ways they vary. To analyze the geographical variation in the morphology of P. mexicanus and Heliconia spp. flowers, we grouped samples into three operational geographic units (OGUs). Within each OGU, we assessed pollinator–flower specificity by analyzing floral resource preference, and morphological data using correlations and principal component analysis. Our data on floral preferences and morphology indicate geographical variation in the P. mexicanus–Heliconia interaction in all of the OGUs. Heliconia was the preferred floral resource (83% of the samples), suggesting a preference for these flowers as a food source. We also detected morphological overlap between the bill of P. mexicanus and the corollas of both Heliconia species, at least in the two westernmost OGUs. That P. mexicanus morphology tracked variation in the different Heliconia spp. across the hummingbird's range suggests that the specificity of the hummingbird–plant interaction exerts a significant selection pressure on hummingbird morphology. The morphological overlap observed in the two northernmost OGUs is probably due to the evolution of a close biotic interaction, which is reflected in the high correlation values in the morphological characters involved.Abstract in Spanish is available with online material.

Land snail biogeography and endemism in south-eastern Africa: Implications for the Maputaland-Pondoland-Albany biodiversity hotspot.

Invertebrates in general have long been underrepresented in studies on biodiversity, biogeography and conservation. Boundaries of biodiversity hotspots are often delimited intuitively based on floristic endemism and have seldom been empirically tested using actual species distributions, and especially invertebrates. Here we analyse the zoogeography of terrestrial malacofauna from south-eastern Africa (SEA), proposing the first mollusc-based numerical regionalisation for the area. We also discuss patterns and centres of land snail endemism, thence assessing the importance and the delimitation of the Maputaland-Pondoland-Albany (MPA) biodiversity hotspot for their conservation. An incidence matrix compiled for relatively well-collected lineages of land snails and slugs (73 taxa in twelve genera) in 40 a priori operational geographic units was subjected to (a) phenetic agglomerative hierarchical clustering using unweighted pair-group method with arithmetic means (UPGMA), (b) parsimony analysis of endemicity (PAE) and biotic element analysis (BEA). Fulfilling the primary objective of our study, the UPGMA dendrogram provided a hierarchical regionalisation and identified five centres of molluscan endemism for SEA, while the PAE confirmed six areas of endemism, also supported by the BEA. The regionalisation recovers a zoogeographic province similar to the MPA hotspot, but with a conspicuous westward extension into Knysna (towards the Cape). The MPA province, centres and areas of endemism, biotic elements as well as the spatial patterns of species richness and endemism, support the MPA hotspot, but suggest further extensions resulting in a greater MPA region of land snail endemism (also with a northward extension into sky islands—Soutpansberg and Wolkberg), similar to that noted for vertebrates. The greater MPA region provides a more robustly defined region of conservation concern, with centres of endemism serving as local conservation priorities.

Developing the GIS-based maps of the geomorphological and phytogeographical division of the Ukrainian Carpathians for routine use in biogeography

The paper introduces GIS-based maps of the geomorphological and phytogeographical division of the Ukrainian Carpathians (a part of Eastern Carpathian Mts.), which were developed for routine use in biogeography and based on the consolidation of the existing publications. The map of geomorphological division includes 57 OGUs (operational geographic units), and the map phytogeographical division – 18 OGUs of the lowest rank. Geomorphological units are supported with available synonyms, which should help in work with different topic-related Ukrainian publications. Both maps follow strict hierarchical classification and are briefly discussed.

Predicting the spatio-temporal spread of West Nile virus in Europe.

West Nile virus is a widely spread arthropod-born virus, which has mosquitoes as vectors and birds as reservoirs. Humans, as dead-end hosts of the virus, may suffer West Nile Fever (WNF), which sometimes leads to death. In Europe, the first large-scale epidemic of WNF occurred in 1996 in Romania. Since then, human cases have increased in the continent, where the highest number of cases occurred in 2018. Using the location of WNF cases in 2017 and favorability models, we developed two risk models, one environmental and the other spatio-environmental, and tested their capacity to predict in 2018: 1) the location of WNF; 2) the intensity of the outbreaks (i.e. the number of confirmed human cases); and 3) the imminence of the cases (i.e. the Julian week in which the first case occurred). We found that climatic variables (the maximum temperature of the warmest month and the annual temperature range), human-related variables (rain-fed agriculture, the density of poultry and horses), and topo-hydrographic variables (the presence of rivers and altitude) were the best environmental predictors of WNF outbreaks in Europe. The spatio-environmental model was the most useful in predicting the location of WNF outbreaks, which suggests that a spatial structure, probably related to bird migration routes, has a role in the geographical pattern of WNF in Europe. Both the intensity of cases and their imminence were best predicted using the environmental model, suggesting that these features of the disease are linked to the environmental characteristics of the areas. We highlight the relevance of river basins in the propagation dynamics of the disease, as outbreaks started in the lower parts of the river basins, from where WNF spread towards the upper parts. Therefore, river basins should be considered as operational geographic units for the public health management of the disease.

Semi-automatic mapping of pre-census enumeration areas and population sampling frames

Enumeration Areas (EAs) are the operational geographic units for the collection and dissemination of census data and are often used as a national sampling frame for various types of surveys. In many poor or conflict-affected countries, EA demarcations are incomplete, outdated, or missing. Even for countries that are stable and prosperous, creating and updating EAs is one of the most challenging yet essential tasks in the preparation for a national census. Commonly, EAs are created by manually digitising small geographic units on high-resolution satellite imagery or physically walking the boundaries of units, both of which are highly time, cost, and labour intensive. In addition, creating EAs requires considering population and area size within each unit. This is an optimisation problem that can best be solved by a computer. Here, for the first time, we produce a semi-automatic mapping of pre-defined census EAs based on high-resolution gridded population and settlement datasets and using publicly available natural and administrative boundaries. We demonstrate the approach in generating rural EAs for Somalia where such mapping is not existent. In addition, we compare our automated approach against manually digitised EAs created in urban areas of Mogadishu and Hargeysa. Our semi-automatically generated EAs are consistent with standard EAs, including having identifiable boundaries for field teams to follow on the ground, and appropriate sizing and population for coverage by an enumerator. Furthermore, our semi-automated urban EAs have no gaps, in contrast, to manually drawn urban EAs. Our work shows the time, labour and cost-saving value of automated EA delineation and points to the potential for broadly available tools suitable for low-income and data-poor settings but applicable to potentially wider contexts.

On the use of nestedness-based similarity functions (NBSF) to classify and/or order operational geographic units (OGUs)

In this paper, we want to support the idea of using a family of indices of similarity, that we call the Simpson’s family indices or nestedness-based similarity functions (NBSF) for comparing operational geographic units (OGUs) (phytosociological releves, animal traps, watersheds, administrative units, industrial areas, islands etc.). In these cases, similarity-dissimilarity depends, in addition to factors that induce replacement, also on factors that produce reduction or increment in the number of features within the same typology of OGUs (e.g., extent, reduction of fertility, anthropogenic pressure etc.). To keep into consideration this aspect, the indices are defined to be equal to 1 when the OGUs are completely nested. The results of the application to four simulated data sets prove that, when the data set does not show clear nested pattern, the use of NBSF produces results similar to the nestedness-free similarity functions, however since NBSF clearly detect nested situations, we should prefer their use in the circumstances where we think important to put in evidence nestedness. In conclusion, we support the idea of using both types of indices in order to improve the knowledge about the structure of any data set.

The lichens of the Alps – an annotated checklist

This is the first attempt to provide an overview of the lichen diversity of the Alps, one of the biogegraphically most important and emblematic mountain systems worldwide. The checklist includes all lichenised species, plus a set of non- or doubtfully lichenised taxa frequently treated by lichenologists, excluding non-lichenised lichenicolous fungi. Largely based on recent national or regional checklists, it provides a list of all infrageneric taxa (with synonyms) hitherto reported from the Alps, with data on their distribution in eight countries (Austria, France, Germany, Liechtenstein, Monaco, Italy, Slovenia, Switzerland) and in 42 Operational Geographic Units, mostly corresponding to administrative subdivisions within the countries. Data on the main substrates and on the altitudinal distribution are also provided. A short note points to the main ecological requirements of each taxon and/or to open taxonomic problems. Particularly poorly known taxa are flagged and often provided with a short description, to attract the attention of specialists. The total number of infrageneric taxa is 3,163, including 117 non- or doubtfully lichenised taxa. The richness of the lichen biota fairly well corresponds with the percent of the Alpine area occupied by each country: Austria (2,337 taxa), Italy (2,169), France (2,028), Switzerland (1,835), Germany (1,168), Slovenia (890) and Lichtenstein (152), no lichen having ever been reported from Monaco. The number of poorly known taxa is quite high (604, 19.1% of the total), which indicates that, in spite of the Alps being one of the lichenologically most studied mountain systems worldwide, much work is still needed to reach a satisfactory picture of their real lichen diversity. Thirteen new combinations are proposed in the genera Agonimia, Aspicilia, Bagliettoa, Bellemerea, Carbonea, Lepra, Miriquidica, Polysporina, Protothelenella, Pseudosagedia and Thelidium.

Vertebrate endemism in south-eastern Africa numerically redefines a biodiversity hotspot.

We use numerical methods to explore patterns of vertebrate endemism in south-eastern Africa, refining the boundaries of the intuitively-defined Maputaland-Pondoland-Albany biodiversity hotspot, also proposing a zoogeographic regionalisation. An incidence matrix of 300 vertebrate species endemic to south-eastern Africa sensu lato in 37 operational geographic units were used in (a) phenetic cluster analysis (PCA) using the algorithm of unweighted pair-group method with arithmetic averages (phenetic approach), and (b) parsimony analysis of endemicity (PAE; parsimony approach), in order to numerically evaluate the bioregional delimitations. The analyses provide a valid biogeographical entity 37% larger than the Maputaland-Pondoland-Albany hotspot, but substantially (131%) higher in vertebrate endemicity viz. the Greater Maputaland-Pondoland-Albany (GMPA) region of vertebrate endemism. South-east Africa is recognised as a dominion in the global zoogeographical area hierarchy, with subordinate units including the GMPA province. Various spatially-based measures of endemism were mapped for vertebrate species restricted to the dominion, i.e. endemic to south-eastern Africa sensu stricto. Areas and centres of endemism detected respectively from PAE and PCA, within the south-east Africa dominion also support the refined boundary of the GMPA region of endemism, which provides a better spatial conservation priority compared to the Maputaland-Pondoland-Albany hotspot. Reptiles and amphibians are found to be the main drivers of the overall pattern of endemism, while the pattern in freshwater fish is the most distinctive. Our analyses also indicate a good congruence of the centres of endemism across different terrestrial vertebrate taxa.

Endemism and conservation of Amazon palms

Endemicity is important for the delimitation of conservation areas. Endemic areas are those that contain two or more taxa with their distribution restricted to the area. The aim of this study was to detect endemic areas for palms in the Amazon region and to determine whether the species that define these endemic areas are protected within conservation units. Records of occurrence were extracted from the global biodiversity information facility (GBIF). The final dataset consisted of 17,310 records, for 177 species of Amazonian palms. For analysis we used parsimony analysis of endemicity (PAE) and NDM-VNDM program, and grid square size of 1° and 3° as operational geographic units (OGUs). The distribution of endemic species was superimposed on occurrence of the conservation units (CUs). PAE did not show endemic areas in grid squares of 1°, but found 10 palm endemic areas in grid squares of 3° in the western Amazon and Andean sub-region. However, the NDM-VNDM program identified an endemic area in grid squares of 1° located at the eastern Guiana with endemicity score = 2.9, and in grid squares of 3° it identified seven consensus areas with endemicity score > 6.0, all in the western Amazon. The combination of PAE and NDM-VNDM analyses resulted in eight endemic palm areas in the combined western Amazon and Andean sub-region. Of the species that define the endemic areas, five are threatened with extinction in one of three IUCN categories (EN, VU, NT), and they are not protected in any conservation units. The western Amazon, besides having high palm richness, also has palm endemic areas, especially, near the Andean sub-region and the Peruvian Amazon.

Historical and ecological drivers of the spatial pattern of Chondrichthyes species richness in the Mediterranean Sea.

Chondrichthyes, which include Elasmobranchii (sharks and batoids) and Holocephali (chimaeras), are a relatively small group in the Mediterranean Sea (89 species) playing a key role in the ecosystems where they are found. At present, many species of this group are threatened as a result of anthropogenic effects, including fishing activity. Knowledge of the spatial distribution of these species is of great importance to understand their ecological role and for the efficient management of their populations, particularly if affected by fisheries. This study aims to analyze the spatial patterns of the distribution of Chondrichthyes species richness in the Mediterranean Sea. Information provided by the studied countries was used to model geographical and ecological variables affecting the Chondrichthyes species richness. The species were distributed in 16 Operational Geographical Units (OGUs), derived from the Geographical Sub-Areas (GSA) adopted by the General Fisheries Commission of the Mediterranean Sea (GFCM). Regression analyses with the species richness as a target variable were adjusted with a set of environmental and geographical variables, being the model that links richness of Chondrichthyes species with distance to the Strait of Gibraltar and number of taxonomic families of bony fishes the one that best explains it. This suggests that both historical and ecological factors affect the current distribution of Chondrichthyes within the Mediterranean Sea.

The use of vegetation series to assess α and β vegetation diversity and their relationships with geodiversity in the province of Almeria (Spain) with watersheds as operational geographic units

With this paper we suggest that vegetation series is a useful conceptual tool to identify a clear level of biodiversity of land systems among the many possible logical levels. The suggestion is supported by the results of a case study carried out for the province of Almeria (Spain) using the watersheds as operational geographic units. The application of standard correlation analysis, simple and partial, the Mantel’s test, and the cluster analysis has shown that α and β vegetation diversities, based on vegetation series, are significantly predictive with respect to environmental heterogeneity expressed by pedodiversity, lithodiversity, and some parameters of digital elevation model. Being a product of the Braun Blanquet’s floristic approach, vegetation series could be the key to enter into vegetation databases for biodiversity analysis of land systems at many other levels of knowledge.

Tropical bryophyte floras: a homogeneous assemblage of highly mobile species? Insights from their spatial patterns of beta diversity

The impact of Pleistocene climate changes substantially varied between tropical regions, resulting in striking differences in angiosperm species richness caused by post-glacial recolonization delays. Tropical bryophytes, which have been perceived as extremely good dispersers due to biased rates of monoecy and hence spore production, differ strikingly from angiosperms in their similar patterns of species richness among tropical regions. Here, we analyse the patterns of beta diversity of tropical bryophytes to determine whether their high dispersal capacities have balanced patterns of species richness and erased any difference of post-glacial recolonization patterns between tropical regions. The partitioning of beta diversity for 7485 tropical moss species among 164 operational geographical units (OGUs) and 3276 liverwort and hornwort species in 154 OGUs revealed a slight, but significantly higher beta diversity among than within tropical regions. The nestedness component of beta diversity did not significantly differ between tropical regions. This indicates that, although regional migration rates were sufficient to erase differences of the impact of Pleistocene climate changes between tropical regions, the similar bryophyte species richness of tropical regions cannot be interpreted in terms of unrestricted migrations and that oceans act as a barrier to routine dispersal, which is sufficient to shape large-scale floristic patterns.