Mollusc diversity patterns in Central European fens: hotspots and conservation priorities

Aim To assess mollusc species composition and diversity patterns of treeless fen sites and to find simple environmental parameters that characterize diversity hotspots and priority sites for conservation. Location Western Carpathian Mountains, Europe. Methods Mollusc communities were sampled quantitatively from a homogeneous area of 16 m² in the central part of each of 145 treeless fen sites. Water conductivity and pH, geographical coordinates, altitude and habitat size of the sites studied, mean annual rainfall, mean annual temperature and mean January temperature were compiled for each plot. Nestedness in species composition was tested using the binmatnest program to confirm the ‘nested habitat‐quality hypothesis’. Patterns in species diversity were analysed using the regression trees method to isolate the main predictors of species diversity. Results Nested subset patterns of species composition were found along the gradient of mineral richness. Species distribution was highly nested (T_obs = 11.21, P << 0.001) in mineral‐poor sites (with water conductivity < 300 μS cm^?1, n = 42) and was highly correlated with the site’s mineral richness (r_s = 0.76, P << 0.001). By contrast, species distribution and richness of mineral‐rich sites (c.≥ 300 μS cm^?1, n = 103) were not controlled by mineral richness. Variation in species richness was further explained by January temperature, landscape geomorphology, and total habitat area. The southern mineral‐rich low altitude fens were the most species rich, especially those of larger total area (23 species on average). These 24 sites (17% of all sites) harboured 90% of all recorded species, including all highly endangered ones. Mineral‐rich fens in montane valleys were the second most important group because they hosted the majority of populations of two rare glacial relict species (Vertigo geyeri and Pupilla alpicola). Main conclusions The significant nestedness raises the possibility of conserving the whole fen‐mollusc species pool within the most species‐rich sites. Thus, to select the conservation priority sites, easily available site characteristics for the prediction of species richness are needed. This knowledge can help us maintain fen biodiversity, which has become closely dependent on conservation management practices after the cessation of traditional mowing of fens for haymaking.     

Farm characteristics and the vegetative diversity of grasslands in the North of England: a policy perspective

A survey of 36 fields across 11 farms in the North of England was conducted to record the plant species diversity of grassland communities under various base conditions. Data pertaining to topographical advantage, farm management strategy and soil type were also collected for each field site. The relationship between management inputs and base environmental conditions and the resultant diversity of flora were identified through ordination techniques. The results show a total of 111 species being observed across the sample and some expected relationship emerge, but they also suggest that complementary management techniques can have opposing or conflicting effects on species prevalence. The study argues that provision or use of such information should be paramount within environmental policy formulation where site-specific management plans are used to produce environmental goods.     

Host diversity and latitude drive trematode diversity patterns in the European freshwater fauna

Aim We investigated the relationship between host and parasite diversity as well as latitudinal gradients in parasite diversity on a continental scale in European freshwater trematodes. Location European freshwaters. Methods We extracted distributional data for 564 freshwater trematodes across 25 biogeographical regions in Europe from the Limnofauna Europaea and used multiple regression analyses to test for correlations between the diversity of definitive (vertebrates) or first intermediate (gastropods) hosts and that of trematodes, and for latitudinal gradients in trematode diversity. In particular, we investigated patterns in beta diversity among latitudinal bands and between trematode species that parasitize host groups with low (autogenic) and high (allogenic) dispersal capacity. We also tested for a latitudinal gradient in the proportional representation of these two trematode groups within regional faunas. Results Latitude or first intermediate host richness had no effect on trematode richness, but definitive host richness was a strong predictor of trematode richness, among both allogenic and autogenic parasites. We found that beta diversity of trematode faunas within latitudinal bands decreased to the north, with similar values for allogenic and autogenic trematodes. Finally, we observed an increasing proportion of autogenic species toward the north of Europe. Main conclusions The richness of definitive hosts appears to be the driver of trematode diversity at a continental scale. The latitudinal gradient in beta diversity reflects patterns observed in free‐living species and probably results from recolonization in the aftermath of the ice ages. The similar beta‐diversity patterns of allogenic and autogenic trematodes and the increasing proportion of autogenic trematodes with increasing latitude are surprising. We suggest that the geographical scale of our analysis or confounding factors such as differences in habitat utilization and specialization may partly explain these patterns.     

The European Far West: Miocene mammal isolation,diversity and turnover in the Iberian Peninsula

Aim To analyse the diversity dynamics of Miocene mammalian faunas in the Iberian Peninsula in order to determine whether the patterns are related to the dispersal of taxa from other areas into this region. Location Mainly the Iberian Peninsula, but two close geographical areas (Central Europe and the Eastern Mediterranean) are also considered in some of our calculations. Methods Genus‐level faunal lists for a total of 299 localities from the Iberian Peninsula, covering 10 successive biochronological units [Mammal Neogene (MN) zones] that span from the latest Early Miocene to the early Pliocene (about 17–4 Ma), were compiled. The dataset was expanded with a further 331 localities in Central Europe and the Eastern Mediterranean for the same time span. Next, a taxonomically standardized database was used to create composite faunal lists of micro‐ and macromammalian genera present during each MN zone. Separate genera‐by‐MN‐zone matrices for both micro‐ and macromammals were built for each region. Mean standing diversity as well as origination and extinction rates were calculated for the Iberian Peninsula, and their correlation with preservation rates is discussed. Simpson’s coefficient of faunal similarity with Central Europe and the Eastern Mediterranean was calculated in order to evaluate whether diversity patterns were related to changes in the affinity of the Iberian mammalian faunas with those of other regions. Results Diversity changes in the Iberian macromammalian faunas coincide with periods of increased faunal similarity with other regions, suggesting a relationship to the expansions and contractions of the geographical ranges of the constituent taxa. This pattern is not recognized for micromammals; that is, their diversity trends are not related to changes in geographical ranges. Main conclusions Climatic shifts result in expansions or contractions in the geographical ranges of macromammals, owing to changes in the distribution of their preferred habitats. The lower dispersal ability of micromammals results in a higher extinction risk when habitat fragmentation confines their populations to relatively small environmental patches. Hence, they are more severely affected by climatic changes. Our results thus emphasize the role of climatic forcing in mammalian biogeography and diversity.     

Distance decay of similarity among European urban floras: the impact of anthropogenic activities on β diversity

Aim We examine how two categories of non‐native species (archaeophyte and neophyte, introduced before and after ad 1500, respectively) have had different impacts on β diversity across European urban floras. Our goal is to use the unique biological perspective provided by urban areas, and the contrasting historical and geographical perspectives provided by archaeophytes and neophytes, to infer how non‐native species will impact upon β diversity in the future. Location Twenty‐two urban areas located in seven European countries. Methods We used the β‐sim dissimilarity index to estimate the level of β diversity for 231 unique pair‐wise combinations of 22 urban floras. We examined bivariate plots of dissimilarity by geographical separation of city centres to evaluate distance decay of similarity for native species, archaeophytes and neophytes. Results Based on average percentages, 52.8% (SD = 8.2%) of species in the urban floras were identified as non‐native with 28.3% (SD = 6.9%) classified as neophytes and 24.5% (SD = 4.9%) as archaeophytes. Relative to native species, across urban floras, archaeophytes were associated with higher compositional similarity and weaker distance decay patterns, whereas neophytes were associated with lower compositional similarity and stronger distance decay patterns. Main conclusions Across European urban floras, archaeophytes and neophytes occurred in similar numbers but archaeophytes were consistently associated with lower β diversity and neophytes with higher β diversity. Thus, the impact of non‐native species on β diversity can be determined, at least in part, through their historical and geographical associations with anthropogenic activities. If archaeophytes represent the long‐term biogeographical outcome for human commensal species, neophytes could develop similar patterns. The consequences, however, are likely to be more substantial ecologically and geographically due to the increasing numbers of neophytes and their global anthropogenic associations. Nevertheless, at present, our findings suggest that, based on occurrence information, neophytes have not achieved this state with European urban floras retaining regionally distinct assemblages of neophytes.     

New specimens of Allodaposuchus precedens from France: intraspecific variability and the diversity of European Late Cretaceous eusuchians

A series of cranial remains as well as a few postcranial elements attributed to the basal eusuchian Allodaposuchus precedens are described from Velaux‐La Bastide Neuve, a Late Cretaceous continental locality in southern France. Four skulls of different size represent an ontogenetic series and permit an evaluation of the morphological variability in this species. On this basis, recent proposals that different species of Allodaposuchus inhabited the European archipelago are questioned and A. precedens is recognized from other Late Cretaceous deposits of France and Romania. A dentary bone is described for the first time in A. precedens and provides a basis to reconsider the validity of two taxa, Ischyrochampsa meridionalis and Musturzabalsuchus buffetauti, which are interpreted as possible junior synonyms of Allodaposuchus. These results allow the diversity of Late Cretaceous eusuchians from Europe to be refined and recognize a basal stock known as the Hylaeochampsidae sharing an absence of external mandibular fenestrae. Within this family, Allodaposuchus occupies a basal position relative to Acynodon, Iharkutosuchus and Hylaeochampsa. © 2015 The Linnean Society of London     

Worldwide analysis of multiple microsatellites: language diversity has a detectable influence on DNA diversity

Previous studies of the correlations between the languages spoken by human populations and the genes carried by the members of those populations have been limited by the small amount of genetic markers available and by approximations in the treatment of linguistic data. In this study we analyzed a large collection of polymorphic microsatellite loci (377), distributed on all autosomes, and used Ruhlen's linguistic classification, to investigate the relative roles of geography and language in shaping the distribution of human DNA diversity at a worldwide scale. For this purpose, we performed three different kinds of analysis: (i) we partitioned genetic variances at three hierarchical levels of population subdivision according to language group by means of a molecular analysis of variance (AMOVA); (ii) we quantified by a series of Mantel's tests the correlation between measures of genetic and linguistic differentiation; and (iii) we tested whether linguistic differences are increased across known zones of increased genetic change between populations. Genetic differences appear to more closely reflect geographic than linguistic differentiation. However, our analyses show that language differences also have a detectable effect on DNA diversity at the genomic level, above and beyond the effects of geographic distance.     

The effect of farm policy on production strategies among French family farmers

French farm policy has created incentives for certain production strategies which theoretically require little or no land and which would therefore be particularly suited for small holders. Through credit and subsidies for the construction of pigsties, and through contractual arrangements for the production of hybrid seed corn and tobacco, the government has encouraged these activities. However, because of certain constraints, these activities are more successfully pursued by holders of larger farms. Small holders, because they are small, cannot fully benefit from these strategies which would compensate them for their smallness.Funds for fieldwork were provided by the National Science Foundation, the Social Science Research Council, the National Institute of Mental Health, and Columbia University, all of whom I thank. I owe special thanks to Henri Mendras for suggesting the village which I call Alunhac as the site for my fieldwork, and to Pierre Boisseau for introducing me to its inhabitants. Alunhac is one of the ten communities studied by theGroupe de Sociologie Rural du CNRS, and has been described in Boisseau (1966) and Jollivet and Mendras (1971, pp. 120–130). All proper names of people and places are pseudonyms. I want to thank Susan Carol Rogers for comments on an earlier version of this paper, and I am grateful to the editors and the anonymous readers ofHuman Ecology for helpful criticisms.     

Putting flesh to the bone: looking for solidarity in diversity,here and now

In many Western European countries, concern rises that both formal mechanisms of redistribution and informal acts of charity, reciprocity and support are challenged by ethnic and cultural diversity. Against such gloomy perspectives, this paper draws on insights from sociology, geography, pedagogy and political science to argue that four traditional sources of solidarity (interdependence, shared norms and values, struggle and encounter) remain relevant, but require a rethinking of their spatial and temporal framing to capture today's intricate engagements of solidarity. More specifically, we draw on theories from the aforementioned disciplines to claim that our understanding of solidarities grounded in the spatial boundedness of territorial states and the intergenerational continuity of supposedly culturally homogeneous nations should be complemented and enriched with an in-depth knowledge of solidarities developing in an entirely different spatio-temporal register, namely that of the everyday places and practices in which people engage across ethnic and cultural boundaries.     

Models of the influence of predation on aspect diversity in prey populations

By considering a model incorporating behavioral changes by predators and prey evolution, we demonstrate how under certain conditions apostatic predation influences the maintenance of diversity within prey populations, and among different prey species. Further, we estimate the intrinsic diversity wavelength of the system when apostasy combines with other factors to lead to nonuniform distributions of prey along aspect gradients.     

Geographic isolation and climate govern the functional diversity of native fish communities in European drainage basins

Aim In times of biodiversity crisis, it is extremely important to understand diversity gradients. In particular, the study of the diversity of ecological functions is a key issue for the management of ecosystem integrity. Here we identify areas of low functional diversity of the native fish fauna in European drainage basins and we determine the relative importance of three underlying mechanisms: environmental filtering, geographic isolation and climatic history. Location The European continent. Methods Based on 14 morphological traits that are closely related to fish function (habitat and dietary niches), three independent functional diversity indices [functional richness (FR), functional evenness (FE), functional divergence (FD)] were calculated for 128 European drainage basins with a total of 230 fish species. The indices were standardized for species richness using null models. The patterns of the standardized indices are described and three potentially underlying mechanisms are tested using variance partitioning and multi‐linear regression models. Results FR and FD were highest in eastern European drainage basins and in Great Britain and lowest in the Mediterranean. FE patterns were less pronounced. All observed patterns were mainly governed by geographic isolation and present environmental conditions. Within the environmental conditions, average annual temperature and precipitation were good predictors for functional diversity. The role of habitat diversity and size was negligible. Main conclusions Geographic isolation coupled with harsh environmental conditions such as extreme temperatures and low precipitation, as in Mediterranean regions, can lead to low FR and FD. This can be explained by extinction that could not be compensated by re‐colonization and high speciation. Due to their high functional redundancy, communities in these areas might better withstand further species extinctions on a small scale. Over the short term, however, their often extremely low FR suggests a less flexible functioning that can hinder their ability to withstand today's rapid environmental and anthropogenic threats.     

Potential impacts of climate change on the distributions and diversity patterns of European mammals

The Intergovernmental Panel on Climate Change (IPCC) predicts an increase in global temperatures of between 1.4°C and 5.8°C during the 21st century, as a result of elevated CO₂ levels. Using bioclimatic envelope models, we evaluate the potential impact of climate change on the distributions and species richness of 120 native terrestrial non-volant European mammals under two of IPCC’s future climatic scenarios. Assuming unlimited and no migration, respectively, our model predicts that 1% or 5–9% of European mammals risk extinction, while 32–46% or 70–78% may be severely threatened (lose > 30% of their current distribution) under the two scenarios. Under the no migration assumption endemic species were predicted to be strongly negatively affected by future climatic changes, while widely distributed species would be more mildly affected. Finally, potential mammalian species richness is predicted to become dramatically reduced in the Mediterranean region but increase towards the northeast and for higher elevations. Bioclimatic envelope models do not account for non-climatic factors such as land-use, biotic interactions, human interference, dispersal or history, and our results should therefore be seen as first approximations of the potential magnitude of future climatic changes.     

Partitioning the turnover and nestedness components of beta diversity

Aim  Beta diversity (variation of the species composition of assemblages) may reflect two different phenomena, spatial species turnover and nestedness of assemblages, which result from two antithetic processes, namely species replacement and species loss, respectively. The aim of this paper is to provide a unified framework for the assessment of beta diversity, disentangling the contribution of spatial turnover and nestedness to beta-diversity patterns.
Innovation  I derive an additive partitioning of beta diversity that provides the two separate components of spatial turnover and nestedness underlying the total amount of beta diversity. I propose two families of measures of beta diversity for pairwise and multiple-site situations. Each family comprises one measure accounting for all aspects of beta diversity, which is additively decomposed into two measures accounting for the pure spatial turnover and nestedness components, respectively. Finally, I provide a case study using European longhorn beetles to exemplify the relevance of disentangling spatial turnover and nestedness patterns.
Main conclusion  Assigning the different beta-diversity patterns to their respective biological phenomena is essential for analysing the causality of the processes underlying biodiversity. Thus, the differentiation of the spatial turnover and nestedness components of beta diversity is crucial for our understanding of central biogeographic, ecological and conservation issues.     

Dispersal ability modulates the strength of the latitudinal richness gradient in European beetles

Aim A debate exists as to whether present‐day diversity gradients are governed by current environmental conditions or by changes in environmental conditions through time. Recent studies have shown that latitudinal richness gradients might be partially caused by incomplete post‐glacial recolonization of high‐latitude regions; this leads to the prediction that less mobile taxa should have steeper gradients than more mobile taxa. The aim of this study is to test this prediction. Location Europe. Methods We first assessed whether spatial turnover in species composition is a good surrogate for dispersal ability by measuring the proportion of wingless species in 19 European beetle clades and relating this value to spatial turnover (β_sim) of the clade. We then linearly regressed β_sim values of 21 taxa against the slope of their respective diversity gradients. Results A strong relationship exists between the proportion of wingless species and β_sim, and β_sim was found to be a good predictor of latitudinal richness gradients. Main conclusions Results are consistent with the prediction that poor dispersers have steeper richness gradients than good dispersers, supporting the view that current beetle diversity gradients in Europe are affected by post‐glacial dispersal lags.     

Inventory of the benthic eukaryotic diversity in the oldest European lake

We have profound knowledge on biodiversity on Earth including plants and animals. In the recent decade, we have also increased our understanding on microorganisms in different hosts and the environment. However, biodiversity is not equally well studied among different biodiversity groups and Earth''s systems with eukaryotes in freshwater sediments being among the least known. In this study, we used high‐throughput sequencing of the 18S rRNA gene to investigate the entire diversity of benthic eukaryotes in three distinct habitats (littoral sediment and hard substrate, profundal sediment) of Lake Ohrid, the oldest European lake. Eukaryotic sequences were dominated by annelid and arthropod animals (54% of all eukaryotic reads) and protists (Ochrophyta and Ciliophora; together 40% of all reads). Eukaryotic diversity was 15% higher in the deep profundal than on either near‐surface hard substrates or littoral sediments. The three habitats differed in their taxonomic and functional community composition. Specifically, heterotrophic organisms accounted for 92% of the reads in the profundal, whereas phototrophs accounted for 43% on the littoral hard substrate. The profundal community was the most homogeneous, and its network was the most complex, suggesting its highest stability among the sampled habitats.     

Testing the impact of climate variability on European plant diversity: 320,000 years of water-energy dynamics and its long-term influence on plant taxonomic richness

Models examining the present-day relationship between macro-scale patterns in terrestrial species richness and variables of water and energy demonstrate that a combined water–energy model is a good predictor of richness in mid-to-high latitude regions. However, the power of the individual water and energy variables to explain this richness through time has never been explored. Here, we assess how well energy and water can predict long-term variations in plant richness using a 320 000-year fossil pollen data set from Hungary. Results demonstrate that a combined water–energy model best explains the variation in plant diversity through time. However, this long temporal record also demonstrates that amplitude of energy variation appears to be a strong determinant of richness. Decreased richness correlates with increased climate variability and certain species appear to be more susceptible according to their ecological traits. These findings have important implications for predicting richness at times of increasing climate variability.     

Spatial gradients in species diversity of microscopic animals: the case of bdelloid rotifers at high altitude

Aim Organisms smaller than 2 mm appear not to follow the spatial patterns in richness and diversity commonly observed in macroscopic organisms. We describe spatial patterns in species diversity in a group of microscopic organisms, bdelloid rotifers, living in moss and lichen patches, in order to test the hypotheses of no relationship between species richness and composition and spatial gradients, suggested by previously published patterns in microscopic organisms. Location Moss and lichen patches as habitats for bdelloids, on high‐elevation peaks at altitudes between 2984 and 4527 m a.s.l. across the Italian, French and Swiss Alps, with distances among sample sites ranging from 1 m to 420 km, in comparison with lower‐elevation samples at altitudes from 850 to 1810 m a.s.l. Methods We sampled species assemblages of bdelloid rotifers living in isolated moss and lichen patches in 47 sites. We described the observed α, β and γ diversities; the heterogeneity of species assemblages; and the estimated number of species (incidence‐based coverage estimator). Patterns in species distribution were analysed at three different levels: (1) habitat, comparing species richness on moss and lichen substrates, testing differences in α diversity and heterogeneity (anova ), species composition (analysis of similarities test), and γ diversity (rarefaction curves); (2) altitude, comparing the observed richness with previously published data from locations well below 2000 m; and (3) distances between sites, correlating the matrix of Jaccard dissimilarities and the matrix of geographical distances with a Mantel test. Results Both species richness and species composition of bdelloid rotifers differed significantly between mosses and lichens at high elevations, but no difference was found in the heterogeneity of species assemblages. Alpha diversity was significantly lower at high‐elevation than at low‐elevation sites, but the estimated number of species was not reduced when compared with sites at low elevations. Geographical distance between sites had no effect on species composition in either mosses or lichens. The distribution of species was highly heterogeneous, with a low similarity among assemblages. Main conclusions As expected, bdelloids appear to occupy habitats selectively. The altitudinal gradient in species richness for bdelloid rotifers is limited to a decrease in α diversity only; such a decrease is not caused by a lower number of species (low γ diversity) being able to tolerate harsh conditions, and high‐altitude species are not a subset of species living at lower elevations. The observed values of α, β and γ diversity at high altitudes in the Alps are compatible with the scenario of a very low number of available propagules because of the low density of patches of favourable habitat. Our results suggest that the geographical distribution of animals, and therefore biodiversity patterns, may be strongly influenced by animal size, as small organisms such as bdelloids appear to show spatial patterns that differ from those known in larger animals. Differences in body size should be taken into account carefully in future studies of biodiversity patterns.