Climax epiphytic communities in Mediterranean Spain

The Antitrichetalia curtipendulae epiphytic climax communities of Šmarda & Hadàč from the Spanish Mediterranean area have been classified by numerical and traditional floristic methods. Ninety-eight phytosociological relevés have been recorded from a number of Iberian forests. Our results indicate two clusters that can be easily related to two different alliances: Lobarion pulmonariae (Nephrometum resupinati) and Pterogonio gracile-Antitrichion californicae (Antitrichielum californicae). A phytogeographical and syntaxonomical discussion is followed by a suggested Red List of threatened lichens and bryophytes occurring in these communities in the Spanish Mediterranean area with the aim of advancing conservation of endangered and vulnerable species.     

Beta diversity of frogs in the forests of New Guinea, Amazonia and Europe: contrasting tropical and temperate communities

Aim To test the hypothesis that animal communities within environmentally relatively uniform lowland forests are characterized by low beta diversity, both in tropical and in temperate areas. Location Lowland forests in the basins of the Sepik and Ramu rivers in New Guinea, the Amazon river in Bolivia, and the Elbe and Dyje rivers in the Czech Republic. Methods A network of 5–6 study sites spanning distances from 20–80 to 300–500 km in each study area was systematically surveyed for all frogs, using visual detection and call tracking. The community data were analysed for alpha and beta diversity. Results Local (alpha) diversity of frog communities was similar in the two tropical areas, New Guinea (mean ± SE of 22 ± 1.4 species per site) and Amazonia (24 ± 1.7 species), but was significantly lower in Europe (8 ± 0.8 species). In Amazonia, 36 of the total of 70 species were recorded from single sites. In contrast, widespread species dominated in Europe, whereas New Guinea exhibited an intermediate pattern with both local and widespread species well represented. The rate of species accumulation across different sites was lowest in Europe, intermediate in New Guinea and highest in Amazonia. The regional species diversity, expressed as the combined number of species from five study sites, was 1.5 times higher than the local species diversity at a single site in Europe, 2.0 times higher in New Guinea and 2.7 times higher in Amazonia. The proportion of species shared between communities decreased with geographic distance in New Guinea and Europe, but not in Amazonia. Main conclusions Frog communities in the lowland tropical rain forests of New Guinea and Amazonia had similar numbers of species, but differed in their beta diversity. More species in Amazonia had restricted distributions than in New Guinea. Both tropical areas had markedly higher alpha and beta diversity than the temperate area in Europe.     

Warming increases plant biomass and reduces diversity across continents,latitudes, and species migration scenarios in experimental wetland communities

Atmospheric warming may influence plant productivity and diversity and induce poleward migration of species, altering communities across latitudes. Complicating the picture is that communities from different continents deviate in evolutionary histories, which may modify responses to warming and migration. We used experimental wetland plant communities grown from seed banks as model systems to determine whether effects of warming on biomass production and species richness are consistent across continents, latitudes, and migration scenarios. We collected soil samples from each of three tidal freshwater marshes in estuaries at three latitudes (north, middle, south) on the Atlantic coasts of Europe and North America. In one experiment, we exposed soil seed bank communities from each latitude and continent to ambient and elevated (+2.8 °C) temperatures in the greenhouse. In a second experiment, soil samples were mixed either within each estuary (limited migration) or among estuaries from different latitudes in each continent (complete migration). Seed bank communities of these migration scenarios were also exposed to ambient and elevated temperatures and contrasted with a no‐migration treatment. In the first experiment, warming overall increased biomass (+16%) and decreased species richness (?14%) across latitudes in Europe and North America. Species richness and evenness of south‐latitude communities were less affected by warming than those of middle and north latitudes. In the second experiment, warming also stimulated biomass and lowered species richness. In addition, complete migration led to increased species richness (+60% in North America, + 100% in Europe), but this higher diversity did not translate into increased biomass. Species responded idiosyncratically to warming, but Lythrum salicaria and Bidens sp. increased significantly in response to warming in both continents. These results reveal for the first time consistent impacts of warming on biomass and species richness for temperate wetland plant communities across continents, latitudes, and migration scenarios.     

Spontaneous regeneration of dry grasslands on set-aside fields

Dry grasslands are among the most threatened plant communities of Central Europe. We explore the time scale of spontaneous regeneration of dry grasslands on abandoned fields in an area of Central Europe, where also ancient grassland communities occur (Saxony-Anhalt, Germany). On three permanent plots with shallow soils we monitored during 10 years change of species composition and analysed whether spontaneous succession leads to assemblages similar to the ancient dry grassland communities in the direct surroundings. We found that dry grassland species are able to invade the permanent plots and during the 10 years of succession the number of dry grassland species increased. But even after 10 years there was a clear difference between ancient dry grassland communities and the assemblages on the permanent plots. Our findings suggest two important conclusions: First, spontaneous succession on abandoned fields is a cheap possibility for the conservation of some dry grassland species, at least on shallow soils. Second, the time scale of the regeneration process, however, is rather long. Hence, conservation of remnants of ancient grassland communities needs special attention.     

Where are the glacial refugia in Europe? Evidence from pteridophytes

In this paper we demonstrate that, by investigating polyploid complexes in Asplenium, it is possible to locate the areas in Europe that are southern glacial rcfugia, and arc likely to have been so since the beginning of the Pleistocene during the consecutive cold and warm periods in Europe. Identification and conservation of these specific areas that serve as safe havens for plants, and perhaps animals, is of paramount importance for the maintenance of European biodiversity because Man's activities arc resulting in an ever-increasing loss of natural habitats and putting diversity at risk. The genus Asplenium in Europe comprises some 50 taxa: half of these are diploid while the other half arc polyploids derived from the diploids. All aspleniums in Europe are (small) rock ferns with high substrate specificity. Today, most of mainland Europe, Scandinavia and the British Isles has been colonized by polyploid Asplenium species, while the diploids that gave rise to these polyploids are distributed around (and more or less confined to) the Mediterranean Basin. In the tetraploids genetic variation is partitioned mostly between sites, whereas diploids show a high degree of genetic variation both within and between sites. The tctraploid taxa seem capable of single spore colonization via intragametophytic selfing, but the diploid taxa appear to be predominantly outbreeding. For most diploids at least two gametophytes, produced by different spores, have to be present to achieve fertilization and subsequent sporophyte formation for the successful colonization of a new site. This results in a slower rate of colonization. The formation of auto- and allopolyploid taxa from diploid communities appears to have been a recurrent and common feature in Europe. Minority cytotypc exclusion is likely to prevent the establishment of tetraploids within the diploid communities, but spores from tetraploids can establish populations outside the diploid communities. The differences between colonization abilities of tctraploid and ancestral diploid taxa, resulting from their different breeding systems, has prevented the merging and mingling of their ranges and led to the establishment of contact/ hybrid zones. This has resulted in the restriction of diploid populations to ancient glacial rcfugia and the colonization of the rest of Europe by polyploids. Mapping the current distribution of these diploid communities and comparing the genetic diversity within and between outbreeding diploid Asplenium taxa allows us to define the area, age and historical biogcography of these rcfugia and to assess their importance for present day genetic and species diversity in Europe.     

Living on the edge: British and Irish woodland birds in a European context

This paper reviews broad geographical patterns in the species composition of breeding woodland bird communities from Ireland to eastern Europe and outlines how processes affecting woodland birds in Britain and Ireland may differ from those operating in mainland Europe. Bird communities in British and Irish woodlands consist of a subset of the species occurring within European forests at similar latitudes. The occurrence of virtually all groups of forest birds is lower in Britain, and strikingly lower in Ireland, than in other temperate areas of mainland Europe. This phenomenon appears to form part of a west–east gradient in species diversity and is probably not just a consequence of insularity. Across this gradient there appears to be broad geographical constancy in the types (taxonomic, ecological and life-history groups) of species present. There is considerable spatial variation in habitat use by forest species within Europe. Some species in Britain probably use habitats in different ways to elsewhere for reasons related to competition, predation and historical adaptation to landscape change. Several species appear to reach the limits of their geographical ranges within Britain (i.e. in the absence of physical barriers). We suggest that range contraction of one of these species, the Common Nightingale Luscinia megarhynchos , in Britain may partially reflect redistribution into the highest quality areas in response to a wider population decline. It is argued that conclusions drawn from studies of forest birds in Britain do not necessarily apply in other regions and vice versa. There is a need for large-scale studies in Europe of the spatial variation in organization of forest bird assemblages, habitat use and the genetic structure of populations.     

Vegetation of trampled soil dominated by C4 plants in Europe

Abstract. Plant communities of trampled soil dominated by plants characterized by the C4-assimilation syndrome were investigated in Europe. These species, belonging to genera such as Chamaesyce, Amaranthus, Eleusine, Eragrostis and Setaria, are thermophilous, late-germinating, prostrate herbs or grasses. The centre of their distribution is in the (Sub)Tropics. A syntaxonomic revision of the phytosociological material from Europe (incl. the Macaronesian Archipelago) revealed three alliances: the Euphorbion prostratae from Spain, the Polycarpo-Eleusinion indicae from Italy, and Slovenian and Croatian Istria, and the Eragrostio-Polygonion arenastri from temperate regions of Europe. The latter two syntaxa are described as new. All three alliances belong to the order Eragrostietalia (class Stellarietea mediae). Vicarious (ecologically analogous) communities occur also in southern Africa, eastern Asia and North America. The communities studied in the present paper are considered to be an impoverished form of highly diversified trampled plant communities typical of (sub)tropical areas.     

Species richness of migratory birds is influenced by global climate change

Aim  Global climate change is increasingly influencing ecosystems. Long-term effects on the species richness and composition of ecological communities have been predicted using modelling approaches but, so far, hardly demonstrated in the field. Here, we test whether changes in the composition of bird communities have been influenced by recent climate change.
Location  Europe.
Methods  We focus on the proportion of migratory and resident bird species because these groups are expected to respond differently to climatic change. We used the spatial relationship between climatic factors and bird communities in Europe to predict changes in 21 European bird communities under recent climate change.
Results  Observed changes corresponded significantly to predicted changes and could not be explained by the effects of spatial autocorrelation. Alternative factors such as changes in land use were tested in a first approximation as well but no effects were found.
Main conclusions  This study demonstrates that global climate change has already influenced the species richness and composition of European bird communities.     

Long-term stability in the richness and structure of helminth communities in eels,Anguilla anguilla,in Lough Derg,River Shannon,Ireland

A data set on intestinal helminth parasites was collected in the course of an 18 year investigation into the biology of eels in Meelick Bay, Lough Derg, River Shannon. This was used to test two hypotheses relating to the composition and structure of intestinal helminth communities, namely that eels in large rivers do not harbour richer and more diverse communities than those in small rivers but that community composition and structure are more stable over time than in small rivers. The helminth community was species poor, with only six species comprising the component community and a maximum infracommunity richness of three species. The community was overwhelmingly dominated by the acanthocephalan Acanthocephalus lucii, reflecting the importance of its intermediate host Asellus aquaticus in the eels' diet. The remaining helminth species contributed to species richness but made very little contribution to community diversity. Population levels of Acanthocephalus lucii fell and remained low between 1992 and 2000, probably reflecting increased movement of eels from other parts of the lough into Meelick Bay. Diversity values were low, but similar to those reported from other rivers in Britain and Europe. The results provided support for both hypotheses and indicated that in respect of richness, diversity and dominance, the helminth communities of eels in the River Shannon were typical of, and comparable to, those of other large rivers throughout Europe.     

Traits related to species persistence and dispersal explain changes in plant communities subjected to habitat loss

Aim Habitat fragmentation is a major driver of biodiversity loss but it is insufficiently known how much its effects vary among species with different life‐history traits; especially in plant communities, the understanding of the role of traits related to species persistence and dispersal in determining dynamics of species communities in fragmented landscapes is still limited. The primary aim of this study was to test how plant traits related to persistence and dispersal and their interactions modify plant species vulnerability to decreasing habitat area and increasing isolation. Location Five regions distributed over four countries in Central and Northern Europe. Methods Our dataset was composed of primary data from studies on the distribution of plant communities in 300 grassland fragments in five regions. The regional datasets were consolidated by standardizing nomenclature and species life‐history traits and by recalculating standardized landscape measures from the original geographical data. We assessed the responses of plant species richness to habitat area, connectivity, plant life‐history traits and their interactions using linear mixed models. Results We found that the negative effect of habitat loss on plant species richness was pervasive across different regions, whereas the effect of habitat isolation on species richness was not evident. This area effect was, however, not equal for all the species, and life‐history traits related to both species persistence and dispersal modified plant sensitivity to habitat loss, indicating that both landscape and local processes determined large‐scale dynamics of plant communities. High competitive ability for light, annual life cycle and animal dispersal emerged as traits enabling species to cope with habitat loss. Main conclusions In highly fragmented rural landscapes in NW Europe, mitigating the spatial isolation of remaining grasslands should be accompanied by restoration measures aimed at improving habitat quality for low competitors, abiotically dispersed and perennial, clonal species.     

The geographical parallels of lithorheophil biotic community organisation of small streams of eastern Europe and northern Asia

The influence of geographical position on taxonomical composition and structure of communities inhabited stony riffles is considered on a material from 79 small streams situated in four regions of Eastern Europe (Moscow region, Southern Ural, Northern Caucasus and Mountain Crimea), as well as on publishing data on Asia and Northern Ural regions. Litoreophil communities of mentioned regions include different but closely allied species with similar habits. Eight basic living forms of litoreophils are common practically everywhere irrespective of geographical position and taxonomical composition of the community. The average number of species in a sample is also constant and includes 13-14 species. Local relief and climate influence the abundance of living forms and species diversity.     

Rare and threatened plant communitiesof Estonia

This paper introduces the criteria for identifying rare and threatened plant communities in Estonia. An overview of such communities is given and the general problems associated with their protection are briefly discussed. Of forest communities, alvar forests and boreo-nemoral forests must be preserved very carefully. Once widely distributed minerotrophic mobile-water swamp forests and flood plain forests nowadays cover only a small area. Numerous rare communities are associated with coastal regions and islands. Wooded meadows, the most species rich vascular plant communities in northern Europe, as well as flooded meadows and many other communities require continuation of traditional management for their preservation.     

Global distribution of free-living microbial species

Species of large animals and plants have geographically restricted distributions, but it is unclear if this also applies to free-living micro-organisms. We have attempted to clarify this, by investigating the ciliated protozoa living in a habitat that is separated from northern Europe by geographical barriers and great distance - the sediment of a Holocene volcanic crater-lake with brackish water, in Australia. Of the 85 ciliate species recorded, none was 'new', and all (apart from one species previously described only from tropical Africa) are known from northern Europe. All species appear to have reached the crater by passive dispersal from other freshwater and marine environments. The significance of this finding lies in the fact that ciliates are among the largest and most fragile of microbes. If ciliate species have global distributions, it is likely that the same is true for the many smaller, more abundant and more easily dispersed microbial species, including bacteria. There is some support for this in the literature, and most species smaller than ca 1 mm may have global distributions. Biodiversity at the microbial level is fundamentally different from that of macroscopic animals and plants, and it may be difficult to make realistic extrapolations from the attributes of microbial communities, to biodiversity in general.     

Ecological notes on Carex aquatilis communities

Carex aquatilis spp. aquatilis grows in mesotrophic fens and has a boreal circumpolar distribution. The species is most frequent in areas north of the 66° N line. In Europe the southern limits of its distribution is ca 53°N. Here Carex aqualitis is found in eutrophic flood plains. However, mesotrophic communities of C. aquatilis have been reported from these areas as well. Nowadays the peripheral populations in NW Europe appear to be relics of former mesotrophic communities which at present are under heavy pressure from human activities such as drainage and fertilizing. In the northern part of the Netherlands C. aquatilis stands are restricted to areas with a steady supply of cool groundwater. A decreased groundwater discharge has a negative influence on the development of inflorescences. It is expected that further interference with the hydrology will promote a further decline of the peripheral populations. The species will not be able to survive in drained, eutrophic, warmed up habitats.     

Distribution of the Forest Dormouse Dryomys nitedula (Pallas, 1779) (Rodentia, Myoxidae) in Europe

A spot distribution map of Dryomys nitedula in Europe is presented, based on a critical evaluation of published information from the various countries of Europe. In addition, maps which are numbered to identify localities were prepared for regions where Dryomys nitedula distribution was largely unknown until now. The species has a unique distribution, ranging from the Alps in the west to the foothills of the Urals in the east, and from southern Latvia in the north as far south as Calabria and Peloponnisos. The species' reported vertical range is from sea level in the Balkans to the subalpine belt in the Alps. The presence of Dryomys nitedula in Europe can be traced back to the beginning of the Pleistocene, but its recent distributional area does not coincide with climatic factors, nor with the distribution of vegetation communities. Possible competition with Eliomys quercinus is discussed as a factor affecting the peripheral range distribution of Dryomys nitedula.     

Diversity and abundance patterns of phytophagous insect communities on alien and native host plants in the Brassicaceae

The herbivore load (abundance and species richness of herbivores) on alien plants is supposed to be one of the keys to understand the invasiveness of species. We investigate the phytophagous insect communities on cabbage plants (Brassicaceae) in Europe. We compare the communities of endophagous and ectophagous insects as well as of Coleoptera and Lepidoptera on native and alien cabbage plant species. Contrary to many other reports, we found no differences in the herbivore load between native and alien hosts. The majority of insect species attacked alien as well as native hosts. Across insect species, there was no difference in the patterns of host range on native and on alien hosts. Likewise the similarity of insect communities across pairs of host species was not different between natives and aliens. We conclude that the general similarity in the community patterns between native and alien cabbage plant species are due to the chemical characteristics of this plant family. All cabbage plants share glucosinolates. This may facilitate host switches from natives to aliens. Hence the presence of native congeners may influence invasiveness of alien plants.     

Bumblebees (Hymenoptera,Apidae) in the forest-tundra and tundra of Northeast Europe

Ways of formation of the topical bumblebee complexes are considered on the basis of long-term research carried out in 2002–2009, in different regions of the Nenets Autonomous Area. The specific features of species distribution are analyzed, and the role of anthropogenic changes in the plant communities for the bumblebees is revealed. The complex of the dominant species in the forest-tundra and tundra zones of Northeast Europe is determined.     

Comparative thermal adaptation in cicadas (Hemiptera: Cicadidae) inhabiting Mediterranean ecosystems

The thermal responses of cicadas inhabiting the Mediterranean ecosystems in Europe, North America, South Africa, and Australia are investigated. A total of 37 species and two subspecies from 17 genera representing eight tribes and three subfamilies of cicadas are investigated. The analysis includes species that are restricted to the Mediterranean ecosystem as well as those which also inhabit additional environments. The data suggest that cicadas adapt to the climate type regardless of particular types of plants within the various Mediterranean communities. Similarly, cicada thermal responses are independent of body size or taxonomic affinities. There is a wider range of body temperatures for the maximum voluntary tolerance temperature than for heat torpor or minimum flight temperatures. This diversity seems to be determined by the subdivision of the habitat used and the behavior of the species. All species possess relatively elevated heat torpor temperatures adapting to the general thermal characteristics of the Mediterranean ecosystem. The data suggest that cicadas adapt to the Mediterranean climate type regardless of the diversity of particular types of plants within the various communities, of body size or of taxonomic position.