Species-specific Distribution Research Articles

Habitat-based species distribution modelling of the Hawaiian deepwater snapper-grouper complex

Deepwater snappers and groupers are valuable components of many subtropical and tropical fisheries globally and understanding the habitat associations of these species is important for spatial fisheries management. Habitat-based species distribution models were developed for the deepwater snapper-grouper complex in the main Hawaiian Islands (MHI). Six eteline snappers (Pristipomoides spp., Aphareus rutilans, and Etelis spp.) and one endemic grouper (Hyporthodus quernus) comprise the species complex known as the Hawaiian Deep Seven Bottomfishes. Species occurrence was recorded using baited remote underwater video stations deployed between 30 and 365m (n=2381) and was modeled with 12 geomorphological covariates using GLMs, GAMs, and BRTs. Depth was the most important predictor across species, along with ridge-like features, rugosity, and slope. In particular, ridge-like features were important habitat predictors for E. coruscans and P. filamentosus. Bottom hardness was an important predictor especially for the two Etelis species. Along with depth, rugosity and slope were the most important habitat predictors for A. rutilans and P. zonatus, respectively. Models built using GAMs and BRTs generally had the highest predictive performance. Finally, using the BRT model output, we created species-specific distribution maps and demonstrated that areas with high predicted probabilities of occurrence were positively related to fishery catch rates.

Submerged aquatic vegetation, topography and flow characteristics in the upper, tidal Hudson River: Progress toward a predictive habitat model

Submerged aquatic vegetation (SAV) plays a critical role in biogeochemical cycling, primary productivity, sediment dynamics and current flow within the systems they inhabit. SAV communities in the Upper Hudson River Estuary are comprised of species assemblages dominated by two very morphologically distinct species: the native Vallisneria americana, which has wide-strap shaped leaves that are completely submerged underwater, and the invasive Trapa natans, which produces leaf rosettes that float at the water’s surface. Using characteristics of modeled tidal/riverine flow, we examined the distribution and composition of the predominant SAV in the estuary. SAV habitat space was, on average, well described by depth and flow. From a hydrodynamic standpoint however, the two species occupied very similar niche spaces. Species-specific distribution patterns and co-occurrence rates did not appear to be strongly controlled by physical tolerances of topography or flow. Other ecological drivers such as disturbance regimes, dispersal strategies, plant-animal interactions, and sediment chemistry and composition might explain distribution patterns and T. natans expansion more accurately, rather than hydrodynamics alone. Sixty years after reaching the Hudson River Estuary, T. natans appears unable to fully displace V. americana, despite significant overlap in habitat space and spatial distribution. Future management of the exotic T. natans should consider its role as an ecosystem engineer, adding to overall habitat diversity, rather than the current focus on its perceived invasibilty.

Modeling nonbreeding distributions of shorebirds and waterfowl in response to climate change.

To identify areas on the landscape that may contribute to a robust network of conservation areas, we modeled the probabilities of occurrence of several en route migratory shorebirds and wintering waterfowl in the southern Great Plains of North America, including responses to changing climate. We predominantly used data from the eBird citizen‐science project to model probabilities of occurrence relative to land‐use patterns, spatial distribution of wetlands, and climate. We projected models to potential future climate conditions using five representative general circulation models of the Coupled Model Intercomparison Project 5 (CMIP5). We used Random Forests to model probabilities of occurrence and compared the time periods 1981–2010 (hindcast) and 2041–2070 (forecast) in “model space.” Projected changes in shorebird probabilities of occurrence varied with species‐specific general distribution pattern, migration distance, and spatial extent. Species using the western and northern portion of the study area exhibited the greatest likelihoods of decline, whereas species with more easterly occurrences, mostly long‐distance migrants, had the greatest projected increases in probability of occurrence. At an ecoregional extent, differences in probabilities of shorebird occurrence ranged from −0.015 to 0.045 when averaged across climate models, with the largest increases occurring early in migration. Spatial shifts are predicted for several shorebird species. Probabilities of occurrence of wintering Mallards and Northern Pintail are predicted to increase by 0.046 and 0.061, respectively, with northward shifts projected for both species. When incorporated into partner land management decision tools, results at ecoregional extents can be used to identify wetland complexes with the greatest potential to support birds in the nonbreeding season under a wide range of future climate scenarios.

Automated Visual Fin Identification of Individual Great White Sharks

This paper discusses the automated visual identification of individual great white sharks from dorsal fin imagery. We propose a computer vision photo ID system and report recognition results over a database of thousands of unconstrained fin images. To the best of our knowledge this line of work establishes the first fully automated contour-based visual ID system in the field of animal biometrics. The approach put forward appreciates shark fins as textureless, flexible and partially occluded objects with an individually characteristic shape. In order to recover animal identities from an image we first introduce an open contour stroke model, which extends multi-scale region segmentation to achieve robust fin detection. Secondly, we show that combinatorial, scale-space selective fingerprinting can successfully encode fin individuality. We then measure the species-specific distribution of visual individuality along the fin contour via an embedding into a global ‘fin space’. Exploiting this domain, we finally propose a non-linear model for individual animal recognition and combine all approaches into a fine-grained multi-instance framework. We provide a system evaluation, compare results to prior work, and report performance and properties in detail.

Flight Morphology, Compound Eye Structure and Dispersal in the Bog and the Cranberry Fritillary Butterflies: An Inter- and Intraspecific Comparison.

Understanding dispersal is of prime importance in conservation and population biology. Individual traits related to motion and navigation during dispersal may differ: (1) among species differing in habitat distribution, which in turn, may lead to interspecific differences in the potential for and costs of dispersal, (2) among populations of a species that experiences different levels of habitat fragmentation; (3) among individuals differing in their dispersal strategy and (4) between the sexes due to sexual differences in behaviour and dispersal tendencies. In butterflies, the visual system plays a central role in dispersal, but exactly how the visual system is related to dispersal has received far less attention than flight morphology. We studied two butterfly species to explore the relationships between flight and eye morphology, and dispersal. We predicted interspecific, intraspecific and intersexual differences for both flight and eye morphology relative to i) species-specific habitat distribution, ii) variation in dispersal strategy within each species and iii) behavioural differences between sexes. However, we did not investigate for potential population differences. We found: (1) sexual differences that presumably reflect different demands on both male and female visual and flight systems, (2) a higher wing loading (i.e. a proxy for flight performance), larger eyes and larger facet sizes in the frontal and lateral region of the eye (i.e. better navigation capacities) in the species inhabiting naturally fragmented habitat compared to the species inhabiting rather continuous habitat, and (3) larger facets in the frontal region in dispersers compared to residents within a species. Hence, dispersers may have similar locomotory capacity but potentially better navigation capacity. Dispersal ecology and evolution have attracted much attention, but there are still significant gaps in our understanding of the mechanisms of dispersal. Unfortunately, for many species we lack detailed information on the role of behavioural, morphological and physiological traits for dispersal. Our novel study supports the existence of inter- and intra-specific evolutionary responses in both motion and navigation capacities (i.e. flight and eye morphology) linked to dispersal.

Overlapping expression of anion exchangers in the cochlea of a non-human primate suggests functional compensation

Ion homeostasis in the inner ear is essential for proper hearing. Anion exchangers are one of the transporters responsible for the maintenance of homeostasis, but their expression profile in the primate cochlea has not been fully characterized. However, species-specific overlapping expression patterns and functional compensation in other organs, such as the kidney, pancreas and small intestine, have been reported. Here, we determined the expression patterns of the anion exchangers SLC26A4, SLC26A5, SLC26A6, SLC26A7, SLC26A11, SLC4A2 and SLC4A3 in the cochlea of a non-human primate, the common marmoset (Callithrix jacchus). Although the pattern of expression of SLC26A4 and SLC26A5 was similar to that in rodents, SLC26A7, SLC4A2, SLC4A3 exhibited different distributions. Notably, five transporters, SLC26A4, SLC26A6, SLC26A11 SLC4A2 and SLC4A3, were expressed in the cells of the outer sulcus. Our results reveal a species-specific distribution pattern of anion exchangers in the cochlea, particularly in the outer sulcus cells, suggesting functional compensation among these exchangers. This “primate-specific” pattern may be related to the human-specific hearing loss phenotypes of channelopathy disorders, including the SLC26A4-related diseases Pendred syndrome/DFNB4.

Streptococci Engage TLR13 on Myeloid Cells in a Site-Specific Fashion.

Streptococci are common human colonizers with a species-specific mucocutaneous distribution. At the same time, they are among the most important and most virulent invasive bacterial pathogens. Thus, site-specific cellular innate immunity, which is predominantly executed by resident and invading myeloid cells, has to be adapted with respect to streptococcal sensing, handling, and response. In this article, we show that TLR13 is the critical mouse macrophage (MΦ) receptor in the response to group B Streptococcus, both in bone marrow-derived MΦs and in mature tissue MΦs, such as those residing in the lamina propria of the colon and the dermis, as well as in microglia. In contrast, TLR13 and its chaperone UNC-93B are dispensable for a potent cytokine response of blood monocytes to group B Streptococcus, although monocytes serve as the key progenitors of intestinal and dermal MΦs. Furthermore, a specific role for TLR13 with respect to MΦ function is supported by the response to staphylococci, where TLR13 and UNC-93B limit the cytokine response in bone marrow-derived MΦs and microglia, but not in dermal MΦs. In summary, TLR13 is a critical and site-specific receptor in the single MΦ response to β-hemolytic streptococci.

Neuroanatomical distribution of oxytocin receptor binding in the female rabbit forebrain: Variations across the reproductive cycle

Oxytocin receptors (OTR) have been characterized in the brains of several mammals, including rodents, carnivores, and primates. Their species-specific distribution in the brain has been associated with species differences in social organization, including mating strategy and parenting behavior. In several species, the density of OTR binding in specific brain regions varies according to reproductive condition, including ovarian cycle, pregnancy and lactation. Rabbits are induced ovulators, polygamous, and monoparental but their distribution and regulation of brain OTR has not been described. Here we used receptor autoradiography to quantitatively characterize OTR binding in the brains of estrous, ovariectomized, late pregnant, and lactating does. Intense binding occurred in the prefrontal cortex (PFC), preoptic area (POA), lateral septum (LS; dorsal and ventral), hippocampus, and medial amygdala. Variations among the experimental groups were seen only in PFC, POA, LS. Ovariectomy increased OTR density in PFC but had the opposite effect in POA. Lactating does had significantly reduced OTR density, relative to late pregnancy, in PFC and POA. Our results are consistent with a possible role of OT in modulating social and maternal behavior in rabbits since the brain regions sensitive to OT have been implicated in social interaction, learning and memory, olfactory processing and maternal behavior.

Positive selection in development and growth rate regulation genes involved in species divergence of the genus Radix.

BackgroundLife history traits like developmental time, age and size at maturity are directly related to fitness in all organisms and play a major role in adaptive evolution and speciation processes. Comparative genomic or transcriptomic approaches to identify positively selected genes involved in species divergence can help to generate hypotheses on the driving forces behind speciation. Here we use a bottom-up approach to investigate this hypothesis by comparative analysis of orthologous transcripts of four closely related European Radix species.ResultsSnails of the genus Radix occupy species specific distribution ranges with distinct climatic niches, indicating a potential for natural selection driven speciation based on ecological niche differentiation. We then inferred phylogenetic relationships among the four Radix species based on whole mt-genomes plus 23 nuclear loci. Three different tests to infer selection and changes in amino acid properties yielded a total of 134 genes with signatures of positive selection. The majority of these genes belonged to the functional gene ontology categories “reproduction” and “genitalia” with an overrepresentation of the functions “development” and “growth rate”.ConclusionsWe show here that Radix species divergence may be primarily enforced by selection on life history traits such as (larval-) development and growth rate. We thus hypothesise that life history differences may confer advantages under the according climate regimes, e.g., species occupying warmer and dryer habitats might have a fitness advantage with fast developing susceptible life stages, which are more tolerant to habitat desiccation.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-015-0434-x) contains supplementary material, which is available to authorized users.

Regulating mechanisms of calanoid copepods variability in the northern Adriatic Sea: Testing the roles of west-east salinity and phytoplankton gradients

West-east variability of abundance and population structure of calanoid copepods was studied in 2002–2006 period at two stations in the northern Adriatic (NA), influenced to a different degree by the freshwater discharge of the Po River and regional circulation pattern shaped by the Istrian Coastal Countercurrent (ICCC) and Eastern Adriatic Current (EAC). Species-specific calanoid distribution and abundances were related to concurrently obtained salinity, temperature, Po River discharge and phytoplankton data. Significant differences between stations were determined for salinity, phytoplankton biomass and abundance, total calanoid density, total number of species and Shannon–Wiener biodiversity. The paper is especially concentrated to extremes in Po discharge recorded during the investigated period, which are discussed with respect to the observed variability in plankton components at each investigated station. At the western station, the proximity of the freshwater sources and consequent nutrients load was strongly coupled to the phytoplankton cycle and more tightly reflected in the calanoid abundances, whereas at the eastern station this link was appreciably weaker. Analysis of the community structure revealed the lack of true discriminating species between stations, while fairly stable pattern of occurrence and relative abundances was recorded for six key calanoid species (Pseudocalanus elongatus, Paracalanus parvus, Acartia clausi, Ctenocalanus vanus, Temora longicornis and Centropages typicus) at both sites. The role of EAC was significant in transport of open middle Adriatic species into the NA, which were more frequently recorded at the eastern station and extended their areal westwards more often in winter due to strengthening of the EAC.

Predicted Shifts in Small Mammal Distributions and Biodiversity in the Altered Future Environment of Alaska: An Open Access Data and Machine Learning Perspective.

Climate change is acting to reallocate biomes, shift the distribution of species, and alter community assemblages in Alaska. Predictions regarding how these changes will affect the biodiversity and interspecific relationships of small mammals are necessary to pro-actively inform conservation planning. We used a set of online occurrence records and machine learning methods to create bioclimatic envelope models for 17 species of small mammals (rodents and shrews) across Alaska. Models formed the basis for sets of species-specific distribution maps for 2010 and were projected forward using the IPCC (Intergovernmental Panel on Climate Change) A2 scenario to predict distributions of the same species for 2100. We found that distributions of cold-climate, northern, and interior small mammal species experienced large decreases in area while shifting northward, upward in elevation, and inland across the state. In contrast, many southern and continental species expanded throughout Alaska, and also moved down-slope and toward the coast. Statewide community assemblages remained constant for 15 of the 17 species, but distributional shifts resulted in novel species assemblages in several regions. Overall biodiversity patterns were similar for both time frames, but followed general species distribution movement trends. Biodiversity losses occurred in the Yukon-Kuskokwim Delta and Seward Peninsula while the Beaufort Coastal Plain and western Brooks Range experienced modest gains in species richness as distributions shifted to form novel assemblages. Quantitative species distribution and biodiversity change projections should help land managers to develop adaptive strategies for conserving dispersal corridors, small mammal biodiversity, and ecosystem functionality into the future.

Comparative morphological evaluation of domestic animal cornea.

This study described corneal morphology in different domestic animals using histological and immunohistochemical methods. Specifically, we evaluated the species-specific distribution pattern of cytokeratins (CKs) and aquaporins (AQPs) to assess their contribution to the strength and transparency of the cornea, respectively. Corneal sections (2μm thick) were obtained from 28 pigs, 11 cows, two goats, six horses, four dogs, and five cats and stained with hematoxylin-eosin and periodic acid-Schiff (PAS) reaction. Immunohistochemistry was also performed using CK1 to 3 and AQP1 and 5 antibodies. Domestic animal corneas were composed of corneal epithelium, stroma, Descemet's membrane, and corneal endothelium. Bowman's layer was not detected using the PAS reaction. The three-layered epithelium was thinnest in carnivores and thickest in equines and bovines. CKs were demonstrated immunohistochemically in all species examined, especially in the most superficial layer of the corneal epithelium. CKs were more widely distributed in canine and feline corneal epithelial cell layers compared to other species. The corneal monolayer endothelium was immunostained with AQP1 in all species examined, and it was also present in stromal keratocytes in a species-specific manner. In contrast, AQP5 was exclusively localized to the corneal epithelium. Epithelial staining patterns varied markedly between species, and the widest distribution of AQP5 was demonstrated in feline epithelial cell layers. Differences in the distribution of CKs and AQPs in various species suggest species differences in the maintenance of structural integrity and fluid balance.

New foraging grounds for hawksbill (Eretmochelys imbricata) and green turtles (Chelonia mydas) along the northern Pacific coast of Costa Rica, Central America

<p>Existe poca información disponible sobre los sitios de forrajeo de las poblaciones de tortugas marinas del Pacífico Oriental, lo cual dificulta el diseño de estrategias de conservación tanto en el ámbito nacional como internacional. Realizamos observaciones en cinco sitios a lo largo del Pacífico Norte de Costa Rica (Cabo Blanco, Punta Coyote, Punta Pargos, Punta Argentina y Bahía Matapalito) entre el 2010-2013, utilizando redes de enmalle tortugueras con luz de malla de 45 cm, con el objetivo de explorar y documentar nuevos sitios de forrajeo. Estandarizamos la Captura Por Unidad de Esfuerzo (CPUE) como tortugas capturada por 100m de relinga superior por hora de inmersión, el cual varió de 0.06 en Punta Pargos hasta 0.58 en Bahía Matapalito para tortugas carey (Eretmochelys imbricata), y de 0.01 en Punta Coyota hasta 0.10 en Cabo Blanco para tortugas verde del Pacífico (Chelonia mydas). Encontramos rangos de tamaño específicos por sitio para E.imbricata en Bahía Matapalito y Cabo Blanco, con promedio ± Desviación Estándar (SD) del Largo Curvo de Caparazón (CCL) de 42.46 ± 17.66cm y 61.25±13.08cm respectivamente. Tan solo se encontró un individuo en los demás sitios con CCL de 49.6cm hasta 60.5 cm. Se capturaron tortugas verde en tres de los sitios observados, con CCL de 67.67±19.44cm en Cabo Blanco, 69.40±9.40cm en Punta Coyote. y un único individuo en Bahía Matapalito con un CCL de 56.2cm. La ausencia de clases de tamaño de adultos para E.imbricata, así como de clases de tamaño de juveniles para la tortuga verde del Pacífico, enfatiza la complejidad de la distribución específica por especies durante las distintas fases de vida de las tortugas marinas en el Pacífico Oriental, y la necesidad emergente de implementar monitoreos a largo plazo en diferentes sitios a lo largo del Pacífico Norte del país para comprender la conectividad entre hábitats. El presente estudio revela la existencia de sitios de forrajeo frágiles desprotegidos para la tortuga carey y verde en el Pacífico norte de Costa Rica, y sirve de guía para futuras iniciativas de investigación para fortalecer estrategias de conservación en el ámbito nacional e internacional.</p>

Diastereoisomer- and species-specific distribution of hexabromocyclododecane (HBCD) in fish and marine invertebrates

The levels and distributional characteristics of hexabromocyclododecane (HBCD) diastereoisomers have been largely reported for various fish and select shellfish. In this study, we reclassified a number and variety of marine invertebrates, including shellfish, to further contribute to the comprehensive understanding of the effects and assessment of human exposure to HBCD. Overall, 30 marine invertebrate species (n=188) were investigated and the following order of ∑2HBCD (α- and γ-HBCD) was observed: fish>chordata>cephalopoda>echinodermata>bivalve>crustacea. The marine invertebrates that were reclassified into nektonic and benthic organisms showed similar concentration of ∑2HBCD. The feeding habits and modes of the marine organisms were considered to compare the degree of bioaccumulation and diastereoisomer-specific distribution of HBCD due to the effects of the environment in and around pollution sources, as well as the organisms’ metabolic capacities. To the best of our knowledge, this is the first study to examine the species-specific distribution patterns of HBCD for both fish and marine invertebrates. We expect to significantly expand the understanding of the environmental fate of HBCD for marine organisms.

Diversity of fungi associated with plants growing in geothermal ecosystems and evaluation of their capacities to enhance thermotolerance of host plants

Diversity and heat-adaptation of endophytic fungi (EF) and rhizospheric fungi associated with plants growing in geothermal ecosystems, Southwest China, as well as their benefit in improving host plant thermotolerances were investigated. A total of 1589 culturable fungi belonging to 38 taxa were isolated, in which Curvularia, Acrophialophora, Penicillium, and Aspergillus were the dominant genera. The Shannon indices of EF and rhizospheric fungi ranged from 1.80 to 2.56 and 0.73 to 2.11, respectively. Phylogenetic analysis indicated that the EF have a close relationship with rhizospheric fungi. However, some fungi exhibited apparently species-specific habitat distribution patterns. Growth temperature tests indicated that 60.22% of the tested isolates were thermotolerant fungi and only 39.78% were mesophiles, and the number of heat-adapted fungi increased with increasing environmental temperatures. The strain G1-29, which was isolated from the roots of Hedyotis diffusa and identified as Curvularia crepinii, significantly improved host plant thermotolerance under laboratory conditions: the death rate of endophyte-infected plants was significantly lower than that of endophyte-free plants (t-test, p = .0158, df = 4). Our results suggested that the EF and rhizospheric fungi associated with plants growing in geothermal ecosystems are diverse, and many of them have adapted to the high environmental temperatures. Some fungi have come to be the dominant endemic inhabitants of specific niches, and some played an important role in improving host plant thermotolerances.

Spatial and temporal variations in the abundance, distribution, and aggregation of krill (Thysanoessa raschii and Meganyctiphanes norvegica) in the lower estuary and Gulf of St. Lawrence

The opportunistic collection of hydroacoustic data during multipurpose, large-scale surveys since 2000 has led to the detection of several, newly-documented krill concentrations throughout the Gulf of St. Lawrence. Based on both historical and these recent results, a series of regional-scale acoustic surveys was initiated in the northwestern Gulf and estuary to quantify the spatial and temporal variations in the regional abundance, distribution and aggregation of northern and Arctic krill. By using a recently-developed multi-frequency method to classify these two krill species, our study re-evaluated the species-specific krill distribution and abundance, previously monitored by plankton-net sampling alone. We show that Thysanoessa raschii is the more coastal species, with its center-of-mass in the shelf and slope habitats. Meganyctiphanes norvegica forms generally less dense aggregations in the slope and channel habitats. Biomass in the northwestern Gulf and estuary was split 60:40 between T. raschii and M. norvegica, and totaled 1.0 million tonnes in August 2009; substantially more than has been reported previously. This re-evaluation should have considerable impact on ecosystem models which have assumed much lower values for these important forage populations. The pattern of krill aggregations identified from large- and regional-scale surveys will have important implications for the interpretation of critical habitat for endangered marine mammals which depend on krill.

Molecular characterization and expression analysis of the complement factor I (CpFI) in the whitespotted bamboo shark (Chiloscyllium plagiosum)

Complement factor I (FI) is a plasma serine proteinase that plays an essential role in the modulation of the complement cascade. In the presence of substrate modulating cofactors (Factor H, C4bp, CR1, etc), FI cleaves the activation products of C3 (i.e. C3b) and C4 (i.e. C4b) to limit complement activity. In this study, the full length cDNA of factor I (CpFI) is isolated from the liver of the whitespotted bamboo shark (Chiloscyllium plagiosum). The CpFI cDNA is 2326 bp in length, encoding a protein of 671 amino acids, which shares 72–80% identity with FI molecules of other sharks, higher than the teleosts (37–40%) and mammals (44–47%). The sequence alignment and comparative analysis indicates the FI proteins are well conserved, with the typical modular architecture and identical active sites throughout vertebrate evolution, suggesting the conserved function. However, the additional sequence present between the leader peptide (LP) and the factor I membrane attack complex (FIMAC) domain in other fishes is also found in CpFI, which consists of two kind of tandem repeats. Phylogenetic analysis suggests that CpFI belongs to the elasmobranch clade, in parallel with the higher vertebrates, to form a sister taxa to teleosts. Expression analysis revealed that CpFI is ubiquitously distributed in a variety of tissues, with the constitutive expression in liver, which might reflect the species-specific distribution patterns of FI. Together with earlier reports, the presence of FI in various sharks might suggest the existence of a well-developed complement regulation mechanism in cartilaginous fish.

Suitable, reachable but not colonised: seasonal niche duality in an endemic mountainous songbird

The realized distribution of animals is often delimited by climatic factors which define, next to the specific habitat and food availability, their species-specific potential distribution. We studied the environmental limi- tations affecting the realized breeding and wintering dis- tributions of the Citril Finch (Carduelis citrinella), one of the few endemic bird species of European mountain ranges. To assess the environmental limits that shape the seasonal distribution, we used species distribution models (SDMs) derived from macroclimate in combination with land cover information. Our data suggest a high congruence between the potential modelled breeding distribution of the Citril Finch and the currently known breeding sites, indicating a high level of niche filling. The unusual absence in several suitable breeding habitats at the eastern and northern range limit (Eastern Alps, Carpathians, Bavarian Forest, Harz Mountains, Fichtelgebirge, Krkonose Mountains) is likely linked to a combination of both missing resources and restricted physiological migration capacities from the available wintering grounds. Since the accomplished migratory distances hardly exceed more than 500 km, it seems likely that the distance to the main wintering areas is too large for exceeding eastern and northern range limits. We discuss the differences in SDM outcomes when including distal predictor variables instead of using proxi- mal predictors alone, and highlight the importance of considering a seasonal niche duality to gain more insights into complex range effects in species with seasonal ranges.

Species-specific dinoflagellate vertical distribution in temperature-stratified waters

Thermal stratification is increasing in strength as a result of higher surface water temperature. This could influence the vertical distribution of vertically migrating dinoflagellates. We studied the diel vertical distribution of the dinoflagellates Heterocapsa triquetra and Prorocentrum minimum using stratified laboratory columns with two thermoclines of different strength (ΔT° = 10 or 17 °C), with below cline temperature of 8 °C. Above the thermocline, nutrient depletion simulated the natural summer conditions in the Baltic Sea. Our study shows that H. triquetra and P. minimum can behave differently in terms of their vertical occurrence, both in space and in time when subjected to thermoclines of different strength. Also, both dinoflagellate species showed species-specific distribution patterns. In the ΔT° = 10 °C treatment, H. triquetra cells performed a diel vertical migration (DVM) behavior just above the thermocline, but not in the ΔT° = 17 °C. In the ΔT° = 17 °C, the cells did not migrate and cell densities in the water column decreased over time. Opposing results were observed for P. minimum, where a DVM pattern was found exclusively below the thermocline of ΔT° = 17 °C, while in the ΔT° = 10 °C treatment, no clear DVM pattern was observed, and the highest number of cells were found in the cold bottom water. These results indicate that an increase in thermal stratification can influence species-specific dinoflagellate distribution, behavior, and survival.

The Edaphobase project of GBIF-Germany—A new online soil-zoological data warehouse

Edaphobase is a non-commercial data warehouse on soil organisms (up to now including Chilopoda, Collembola, Diplopoda, Enchytraeidae, Gamasina, Lumbricidae, Nematoda, Oribatida) integrated in the Global Biodiversity Information Facility (GBIF) network. Edaphobase combines data on taxonomy, zoogeography and ecology of these organisms in a comprehensive manner. Data are derived from publications, unpublished results of field studies (theses, reports) and collection data from German museums and research institutions. Data types (=entities) comprise up-to-date taxonomic thesauri, geographical references, ecological indices, soil composition, vegetation, meteorological data, sampling and extraction methods, quantity of collected organisms, identification methods, preparation techniques and behavioural data. At present, the focus is on Germany and neighbouring countries, but data from other European countries can be incorporated in the future. Edaphobase offers a wide range of tools for data inclusion (data-input client, GIS-tool, semi-automatic literature analysis) and data exploration. Simple queries are possible as well as more sophisticated analyses of different data groups. Specific examples of exploration of multi-source datasets are presented to illustrate the potential of the system for detailed analyses (i.e., for the elucidation of species-specific habitat preferences, distribution patterns or environmental influences on population densities) with different soil invertebrate groups (i.e., Diplopoda, Nematoda and Collembola).