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More than 1.2 million distribution records were used to create species distribution models for 402 Palaearctic species of dragonflies and damselflies. On the basis of these diversity maps of total, lentic and lotic diversity for the whole of the Palaearctic (excluding China and the Himalayan region) are presented. These maps show a clear pattern of decreasing diversity longitudinally, with species numbers dropping in the eastern half of Europe and remaining low throughout a large part of Russia, then increasing again towards Russia’s Far East and Korea. There are clear differences in diversity patterns of lentic and lotic species, with lentic species being dominant in colder and more arid areas. Areas with a high diversity of species assessed as threatened on the IUCN red list are largely restricted to the Mediterranean, Southwest Asia, and Japan, with clear hotspots found in the Levant and the southern half of Japan. The diversity at species, generic, and family level is higher in the south of Japan than in areas at a similar latitude in the western Mediterranean. This is likely to be the result of the more humid climate of Japan resulting in a higher diversity of freshwater habitats and the stronger impact of the glacial periods in the Western Palaearctic in combination with the Sahara, preventing tropical African lineages dispersing northwards.

Despite the fact that South East (SE) Asia is considered as a biodiversity hotspot, knowledge of sessile invertebrates such as freshwater sponges (Porifera: Haplosclerida: Spongillina) in this region is poor and scarcely reported. For this synopsis, diversity and distribution of SE Asian inland water sponges is reported on the basis of available literature and a recent biodiversity assessment of the Lower Mekong basin. A diagnostic key of families/genera from SE Asia is provided together with Light Microscopy and Scanning Electron Microscopy protocols to prepare the basic spicular complement for taxonomic identification. So far, SE Asian freshwater sponges consist of widespread and/or endemic species belonging to the families Metaniidae, Potamolepidae, and Spongillidae. The highest diversity is recorded from Indonesia, Philippines, Thailand, and Myanmar, respectively. Data from the other countries are necessary for our understanding of their diversity and distribution. Biodiversity in SE Asia is strongly underestimated, as indicated by recent new records and the discovery of new species of freshwater sponges in Thailand. Further investigations should reveal higher values of taxonomic richness, highlighting biogeographic patterns at the family/genus/species levels. A cooperative network involving Thai, Laotian and Italian researchers, was set up to contribute and fulfil knowledge on taxonomy, ecology and biotechnological potentialities of these neglected filter feeders, playing a key role in water purification and biomass production in both lentic and lotic ecosystems in the tropics.

• Seed dormancy is an important life history state that increases survival and fitness of seed plants, and thus it has attracted much attention. However, global biogeography, effects of paleoenvironment, evolutionary roles of dormancy transitions, and differences in adaptations of seed dormancy between life-forms are poorly understood. • We compiled global distribution records for seed dormancy of 12 743 species and their phylogeny to explore the biogeographic patterns, environmental drivers, and evolutionary transitions between seed dormancy and nondormancy. • Biogeographic patterns reveal a low proportion of dormancy in tropical rainforest regions and arctic regions and a high proportion of dormancy in remaining tropical, subtropical, and temperate regions for all species and woody species. Herbaceous plants show a greater proportion of dormancy in most global regions except arctic regions. Seasonal environments have a consistent positive influence on the dormancy pattern for both life-forms, but precipitation and temperature were important driving factors for woody and herbaceous plants, respectively. Seed dormancy was the dominating state during the evolutionary history of seed plants, and dormancy transitions had a significant relationship with paleotemperatures. Dormancy and nondormancy transitions in response to fluctuating environments during long-term evolutionary history may have played important roles in the diversification of seed plants. • Our results add to the current knowledge about seed dormancy from macro-adaptive perspectives and the potential adaptive mechanisms of seed plants.

Increasing speed and magnitude of global change threaten the world's biodiversity and particularly coral reef fishes. A better understanding of large-scale patterns and processes on coral reefs is essential to prevent fish biodiversity decline but it requires new monitoring approaches. Here, we use environmental DNA metabarcoding to reconstruct well-known patterns of fish biodiversity on coral reefs and uncover hidden patterns on these highly diverse and threatened ecosystems. We analysed 226 environmental DNA (eDNA) seawater samples from 100 stations in five tropical regions (Caribbean, Central and Southwest Pacific, Coral Triangle and Western Indian Ocean) and compared those to 2047 underwater visual censuses from the Reef Life Survey in 1224 stations. Environmental DNA reveals a higher (16%) fish biodiversity, with 2650 taxa, and 25% more families than underwater visual surveys. By identifying more pelagic, reef-associated and crypto-benthic species, eDNA offers a fresh view on assembly rules across spatial scales. Nevertheless, the reef life survey identified more species than eDNA in 47 shared families, which can be due to incomplete sequence assignment, possibly combined with incomplete detection in the environment, for some species. Combining eDNA metabarcoding and extensive visual census offers novel insights on the spatial organization of the richest marine ecosystems.

1. Carbon (C), nitrogen (N) and phosphorus (P) stoichiometries play critical roles in the function and structure of ecosystems by affecting important ecological processes. Yet, most studies to date have concentrated on foliar stoichiometry of phylogenetically distantly related species. 2. Here, we hypothesized that (i) plant stoichiometry of closely related species still shows biogeographic patterns because of the geographic patterns of abiotic environment at the regional scale and (ii) even related species still differ strongly in their stoichiometry owing to inherent differences in the absorption and retention of different elements. 3. To test the hypotheses, we analysed the C:N:P stoichiometry of 48 species of Artemisia and its close relatives from 65 sites across northern China. 4. Elemental concentrations and stoichiometry had no correlation with latitude or longitude but showed clear altitudinal trends. Climate had a weak effect on plant elemental concentrations and stoichiometry but not on C concentration. Soil chemistry had significant effects on C and P concentrations, C:P and N:P. Nested models revealed that species identity accounted for more than 30% of the total variance of all elemental concentrations and stoichiometric ratios, and different species responded differently to environmental gradients. 5. Synthesis. Our results highlight that even closely related species can vary importantly in plant elemental stoichiometry. This suggests that ecologists and global change researchers should be careful not to simply take a species' stoichiometry as representative of an entire taxonomic group for upscaling of plant chemical responses to climatic and edaphic variation in our fast changing world.

Forests in virtually all regions of the world are being affected by invasions of non-native insects. We conducted an in-depth review of the traits of successful invasive forest insects and the ecological processes involved in insect invasions across the universal invasion phases (transport and arrival, establishment, spread and impacts). Most forest insect invasions are accidental consequences of international trade. The dominant invasion ‘pathways’ are live plant imports, shipment of solid wood packaging material, “hitchhiking” on inanimate objects, and intentional introductions of biological control agents. Invading insects exhibit a variety of life histories and include herbivores, detritivores, predators and parasitoids. Herbivores are considered the most damaging and include wood-borers, sap-feeders, foliage-feeders and seed eaters. Most non-native herbivorous forest insects apparently cause little noticeable damage but some species have profoundly altered the composition and ecological functioning of forests. In some cases, non-native herbivorous insects have virtually eliminated their hosts, resulting in major changes in forest composition and ecosystem processes. Invasive predators (e.g., wasps and ants) can have major effects on forest communities. Some parasitoids have caused the decline of native hosts. Key ecological factors during the successive invasion phases are illustrated. Escape from natural enemies explains some of the extreme impacts of forest herbivores but in other cases, severe impacts result from a lack of host defenses due to a lack of evolutionary exposure. Many aspects of forest insect invasions remain poorly understood including indirect impacts via apparent competition and facilitation of other invaders, which are often cryptic and not well studied.

ABSTRACT Geographic patterns of bacteria and microeukaryotes have attracted increasing attention. However, mechanisms underlying geographic patterns in the community composition of both microbial groups are still poorly resolved. In particular, knowledge of whether bacterial communities and microeukaryotic communities are subject to the same or different assembly mechanisms is still limited. In this study, we investigated the biogeographic patterns of bacterial and microeukaryotic communities of 23 lakes on the Tibetan Plateau and quantified the relative influence of assembly mechanisms in shaping both microbial communities. Results showed that water salinity was the major driving force in controlling the community structures of bacteria and microeukaryotes. Although bacterial and microeukaryotic communities exhibited similar distance-decay patterns, the bacterial communities were mainly governed by environmental filtering (a niche-related process), whereas microeukaryotic communities were strongly driven by dispersal limitation (a neutral-related process). Furthermore, we found that bacteria exhibited wider niche breadths and higher dispersal ability but lower community stabilities than microeukaryotes. The similar distribution patterns but contrasting assembly mechanisms effecting bacteria and microeukaryotes resulted from the differences in dispersal ability and community stability. Our results highlight the importance of considering organism types in studies of the assembly mechanisms that shape microbial communities in microbial ecology. This study demonstrates that bacterial communities are mainly governed by environmental filtering whereas microeukaryotic communities are more strongly driven by dispersal limitation in Tibetan lakes.

  Upwelling may generate unique hydrological and environmental heterogeneity, leading to enhanced diffusion to reshape microbial communities. However, it remains largely unknown how different microbial taxa respond to highly complex and dynamic upwelling systems. In the present study, geographic patterns and co-occurrence network of different microbial communities in response to upwelling were examined. Our results showed that coastal upwelling shaped prokaryotic and eukaryotic microbial community and decreased their diversity. In addition, bacteria and microeukaryote had similar biogeographical patterns with distinct assembly mechanisms. The impact of stochastic processes on bacteria was significantly stronger compared with microeukaryote in upwelling. Lower network complexity but more frequent interaction was found in upwelling microbial co-occurrence. However, the upwelling environment increased the robustness and modularity of bacterial network, while eukaryotic network was just the opposite. Co-occurrence networks of bacteria and microeukaryote showed significant distance-decay patterns, while the bacterial network had a stronger spatial variation. Temperature and salinity were the strongest environmental factors affecting microbial coexistence, whereas the topological characteristics of bacterial and eukaryotic networks had different responses to the upwelling environment. These findings expanded our understanding of biogeographic patterns of microbial community and ecological network and the underlying mechanisms of different microbial taxa in upwelling.

Recently, an increasing number of studies have focused on the biogeographic distribution of marine microorganisms. However, the extent to which geographic distance can affect marine microbial communities is still unclear, especially for the microbial communities in well-connected surface seawaters. In this study, the bacterial community compositions of 21 surface seawater samples, that were distributed over a distance of 7800 km, were surveyed to investigate how bacterial community similarity changes with increasing geographical distance. Proteobacteria and Bacteroidetes were the dominant bacterial phyla, with Proteobacteria accounting for 52.6–92.5% and Bacteroidetes comprising 3.5–46.9% of the bacterial communities. A significant bacterial distance-decay relationship was observed in the well-connected Southern Ocean surface seawater. The number of pairwise shared operational taxonomic units (OTUs), and community similarities tended to decrease with increasing geographic distance. Calculation of the similarity indices with all, abundant or rare OTUs did not affect the observed distance-decay relationship. Spatial distance can largely explain the observed bacterial community variation. This study shows that even in well-connected surface waters, bacterial distance-decay patterns can be found as long as the geographical distance is great enough. The biogeographic patterns should then be present for marine microorganisms considering the large size and complexity of the marine ecosystem.