Occurrence In Habitats Research Articles

Enhancing monitoring to promote early detection and eradication of invasive species

Ecological niche models are often used to predict the distribution of invasive species before or after they have been detected in new regions. Such models should also be used to guide surveys to promote the early detection and eradication of invasive species. Here we propose a practical framework that seamlessly uses ecological niche models to develop sampling routes that promote detection of invasive species. Our framework uses habitat suitability predictions and occurrence data on incursion populations to generate potential survey sites, which are then prioritized for sampling based on their size and suitability. The generated survey route is then displayed on an open street map platform. Our framework was developed into the ‘enmRoute' R package and a user‐friendly website to facilitate its application, and we validated our framework with a case study. We show that integrating ecological niche models with human transport routes promotes identification of survey sites that are predicted to collect more individuals and have a greater potential for species detection than traditional sampling approaches. Our framework may help industries, invasion biologists, and regulators develop economical and efficient survey programs for invasive pest monitoring that make eradication programs more attainable.

Molecular Screening for Cyanobacteria and Their Cyanotoxin Potential in Diverse Habitats.

Cyanobacteria are adaptable and dominant organisms that exist in many harsh and extreme environments due to their great ecological tolerance. They produce various secondary metabolites, including cyanotoxins. While cyanobacteria are well studied in surface waters and some aerial habitats, numerous other habitats and niches remain underexplored. We collected 61 samples of: (i) biofilms from springs, (ii) aerial microbial mats from buildings and subaerial mats from caves, and (iii) water from borehole wells, caves, alkaline, saline, sulphidic, thermal, and iron springs, rivers, seas, and melted cave ice from five countries (Croatia, Georgia, Italy, Serbia, and Slovenia). We used (q)PCR to detect cyanobacteria (phycocyanin intergenic spacer-PC-IGS and cyanobacteria-specific 16S rRNA gene) and cyanotoxin genes (microcystins-mcyE, saxitoxins-sxtA, cylindrospermopsins-cyrJ), as well as amplicon sequencing and morphological observations for taxonomic identification. Cyanobacteria were detected in samples from caves, a saline spring, and an alkaline spring. While mcyE or sxtA genes were not observed in any sample, cyrJ results showed the presence of a potential cylindrospermopsin producer in a biofilm from a sulphidic spring in Slovenia. This study contributes to our understanding of cyanobacteria occurrence in diverse habitats, including rare and extreme ones, and provides relevant methodological considerations for future research in such environments.

Applying landscape ecological principles in comprehensive landscape protection: Šumava National Park as a case study

In the face of ongoing anthropogenic pressure and biodiversity loss, there is a need to protect nature more effectively. Therefore, we propose a comprehensive and consecutive approach utilising landscape ecological principles and methods for effective landscape protection and spatial nature conservation. Methods applicable in various conditions are exemplified through case studies from the Šumava National Park, the largest NP in Czechia. Using a set of spatial environmental, landscape ecological and geographical data we can: Characterise the area of interest from the physical-geographical, socioeconomic, and management point of view to create the concept´s framework and review important background information for analysis of the area. Therefore, the key factors for landscape protection and biodiversity conservation are defined. Analyse trends and processes of landscape dynamics in terms of land cover, landscape structure and habitat fragmentation and connectivity, which helps us to set main objectives of landscape protection and nature conservation. Use data about environment conditions and key species and habitat occurrence to model habitat suitability, identify their suitable areas, and thus improve their protection. As a result, areas of high conservation value are distinguished. Synthetize outputs of the above-mentioned steps and prioritise the target goals of landscape protection and biodiversity conservation in the area of interest. This leads to the effective zonation, which is a necessary condition for the application of appropriate management measures.

An illustrated guide for the identification of ant subfamilies and genera in Brazil

Abstract In this guide we present taxonomic keys for the 12 subfamilies and 117 genera of ants known to occur in Brazil, along with an illustrated glossary of technical terms. The identification keys presented here are accompanied by high-resolution photographs of representative specimens for each taxon covered, including details that aid in the understanding of complex characters. Additionally, we provide comparative information for each genus, including diagnostic morphological traits, predominant habitat occurrence, nesting and foraging strata, collection frequency, and reproductive strategy. We also provide a synopsis of the taxonomic status of each genus, including the number of known species in Brazil in comparison to their global distribution, as well as the occurrence of the ant genera across biomes and the most recent study including taxonomic tools for species identification. The main objective of this guide is to facilitate the accurate identification of ants in Brazil, providing a systematic and practical approach in accessible language for researchers, students, and entomology enthusiasts. We hope to contribute to the advancement of taxonomic, ecological, and applied knowledge of Brazilian ants, as well as provide a tool for diversity studies and environmental education, contributing to the understanding and preservation of ants in the country with the highest biodiversity on the planet.

Occurrence patterns of sympatric forest wallabies: assessing the influence of structural habitat attributes on the coexistence of Thylogale thetis and T.stigmatica.

We studied the occurrence of two sympatric wallabies, the red-necked pademelon (Thylogale thetis) and the red-legged pademelon (T. stigmatica) in northeastern New South Wales, Australia in relation to structural habitat attributes. At our study site, both species inhabit closed forest environments and have overlapping distributions, but T. thetis leaves the forest at night to graze adjacent grassy forest edges whereas T. stigmatica remains within the forest and browses forest vegetation. The objectives of the study were to investigate how structural attributes of two forest types, wet sclerophyll forest and rainforest, relate to the fine-scale occurrence of these two wallaby species within the forested environment. We gathered occurrence data from 48 camera trap stations divided equally between rainforest and wet sclerophyll forest. At each camera point, we also measured a range of structural habitat attributes to determine habitat affiliations for the two Thylogale species. Principal component analyses were used to describe major trends in habitat, and generalised linear models were used to describe the efficacy of the variables in predicting habitat occurrence of each species. The number of occurrences of Thylogale thetis was significantly greater than occurrences of T. stigmatica, which was driven by significantly greater occurrences of T. thetis in wet sclerophyll forest. There was both spatial and temporal partitioning between the two species; there was a significant difference in the occurrences of the two species at individual cameras and T. stigmatica had a different activity schedule than T. thetis in wet sclerophyll forest, where the latter reached its greatest rate of occurrence. At a finer (camera station) scale, occurrences of T. thetis increased with proximity to roads and grassy edges and at sites that were less rocky and less steep. T. stigmatica occurrence increased in the presence of rainforest elements like vines, palms and ferns, more ground-level cover and tree-fall gaps and at sites with fewer emergent eucalypts. Our findings have implications for managing these pademelons and their habitats. T. thetis is a common species that was encountered more often than T. stigmatica, and it responded positively to human disturbance like roadsides and grassy edges, presumably because these areas provided good grazing opportunities. By comparison, T. stigmatica is a threatened species, and it responded to natural disturbance like tree-fall gaps where lateral cover was greater, and where rainforest food plants may be more abundant. Our results suggest, therefore, that conservation of the threatened T. stigmatica requires the preservation of intact rainforest.

Explaining inter-individual differences in habitat relationships among wildcat hybrids in Scotland

Little is known about the factors that drive nonstationarity and inter-individual differences in realized habitat niches and species-environment relationships. We explored this topic by developing individual habitat selection models for 14 wildcat hybrids distributed across Scotland, and assessed how differences in their predicted probabilities of occurrence were related to factors including (1) geographic distance, (2) multivariate ecological distance, (3) difference in degree of hybridization and (4) difference in sex (male vs female). We found that the individual models were exceptionally effective in predicting the habitat use and occurrence of the particular individuals on whose data they were trained, but were generally highly divergent and not transferable among individuals. We conducted a reciprocal validation approach where we calculated the AUC for each individual model, predicting the occurrence patterns of the 13 other individuals. We then fit regression and nonparametric splines to evaluate the impacts of geographical distance, ecological distance, hybridization distance and difference in the sex of individuals in the ability of individual wildcat hybrid habitat models to predict the occurrences of other individuals. We found that, of the four factors assessed, ecological distance was supported as being inversely related to ability of a model from one individual to predict occurrence of another individual. The other three factors were not strongly related to differences in reciprocal model predictive ability. This suggests that ecological differences where individual wildcat hybrids reside drive differences in their habitat selection, but that geographical distance, degree of genetic hybridization and difference in the sex of individuals are not consistently associated with differences in model prediction or reciprocal validation performance. These results highlight the effect of ecological limiting factors, and the importance of nonstationary limiting factors in determining the habitat they select, their expressed species-environment relationship and the description of their realized habitat niches.

The physiological response of oriental river prawn Macrobrachium nipponense to starvation-induced stress

Environmental stresses play critical roles in the physiology of crustaceans. Food deprivation is an important environmental factor and a regular occurrence in both natural aquatic habitats and artificial ponds. However, the underlying physiological response mechanisms to starvation-caused stress in crustaceans are yet to be established. In the present study, the hepatopancreas tissue of Macrobrachium nipponense was transcriptome analyzed and examined for starvation effects on oxidative stress, DNA damage, autophagy, and apoptosis across four fasting stages (0 (control group), 7, 14, and 21 days). These results indicated that a ROS-mediated regulatory mechanism is critical to the entire fasting process. At the initial stage of starvation (fasting 0 d ~ 7 d), ROS concentration increased gradually, activating antioxidant enzymes to protect the cellular machinery from the detrimental effects of oxidative stress triggered by starvation-induced stress. ROS content production (hydrogen peroxide and superoxide anion) then rose continuously with prolonged starvation (fasting 7 d ~ 14 d), reaching peak levels and resulting in autophagy in hepatopancreas cells. During the final stages of starvation (fasting 14 d ~ 21 d), excessive ROS induced DNA damage and cell apoptosis. Furthermore, autophagolysosomes and apoptosis body were further identified with transmission electron microscopy. These findings lay a foundation for further scrutiny of the molecular mechanisms combating starvation-generated stress in M. nipponense and provide fishermen with the theoretical guidance for adopting fasting strategies in M. nipponense aquaculture.

ARAapp: filling gaps in the ecological knowledge of spiders using an automated and dynamic approach to analyze systematically collected community data.

The ARAMOB data repository compiles meticulously curated spider community datasets from systematical collections, ensuring a high standard of data quality. These datasets are enriched with crucial methodological data that enable the datasets to be aligned in time and space, facilitating data synthesis across studies, respectively, collections. To streamline the analysis of these datasets in a species-specific context, a suite of tailored ecological analysis tools named ARAapp has been developed. By harnessing the capabilities of ARAapp, users can systematically evaluate the spider species data housed within the ARAMOB repository, elucidating intricate relationships with a range of parameters such as vertical stratification, habitat occurrence, ecological niche parameters (moisture and shading) and phenological patterns. Database URL: ARAapp is available at www.aramob.de/en.

Holocene transformation of natural steppe into an agricultural landscape in the Polabí and Pojizeří Lowlands, Czech Republic, based on mollusc evidence

Recent zonal steppes of Eastern Europe and South-West Asia have their origin in the glacial steppe with its specific continental climate. The westernmost edge of the steppe belt in Central Europe has been climatically shifted from a continental course during the Last Glacial to a rather oceanic one during the Holocene. Steppe enclaves could survive only locally in the driest parts of this area, but as we have confirmed, early arrival of Neolithic agriculture played a significant role in their preservation as well. While pollen analyses can provide the main pattern of landscape development, mollusc successions provide more information about landscape details we need for a better understanding of a steppe transformation towards the recent agricultural ecosystems. Based on the study of 18 mollusc successions in two neighbouring lowlands in the chernozems and alluvial areas of Central and North Bohemia, we described a postglacial development of these two climatically different agricultural landscapes. Based on mollusc evidence, we illustrated the impoverishment of forest communities and the continual occurrence of open habitats throughout the forest climatic optimum of the Holocene. Since the Neolithic colonisation, several erosion events were observed in many profiles documented by a lack of preserved fossil molluscs and layer redeposition which are in excellent agreement with the reconstruction of the fluvial sedimentation and vegetation in the Elbe River floodplain and with the continual settlement of this area. Because we have evidence of a fully developed forest fauna in the Eem interglacial from the Polabí lowland we know that the impoverishment of forest communities and the occurrence of open habitats during the interglacial forest climatic optimum is characteristic only of the Holocene.

Genome size is strongly linked to carbohydrate storage and weakly linked to root sprouting ability in herbs.

Several lines of evidence indicate that carbohydrate storage in plant below-ground organs might be positively related to genome size because both these plant properties represent resource sinks and can affect cell size, cell cycle time, water-use efficiency and plant growth. However, plants adapted to disturbance, such as root sprouters, could be an exception because their strategy would require higher carbohydrate reserves to fuel biomass production but small genomes to complete their cell cycles faster. We used data from a field survey to test the relationship between genome size and the probability of root sprouting ability in 172 Central European herbaceous species. Additionally, we conducted a pot experiment with 19 herbaceous species with different sprouting ability (nine congeneric pairs plus one species), and measured root non-structural carbohydrate concentrations and pools at the end of a growing season. In the Central European flora, the probability of root sprouting ability was lower in large-genome species but this pattern was weak. In the pot experiment, both total non-structural and water-soluble carbohydrates (mainly fructans) were positively and non-linearly related to genome size, regardless of sprouting strategy. The concentrations of mono- and disaccharides and all carbohydrate pools showed no link to genome size, and starch was absent in large-genome species. The link between genome size and carbohydrate storage was less apparent at a small phylogenetic scale because we only observed a higher carbohydrate concentration in species with larger genomes for four of the species pairs. Root sprouters may have smaller genomes because of their frequent occurrence in dry and open habitats. Large-genome species with presumably large cells and vacuoles could accumulate more water-soluble carbohydrates at the end of the growing season to fuel their growth and perhaps protect vulnerable organs from freezing early in the next season.

Variability in leaf traits reveals contrasting strategies between forest and grassland woody communities across southern Brazil

Forests and grasslands often form mosaics in subtropical regions such as in southern Brazil. Currently, we observe the processes of woody species encroachment and forest expansion over grasslands due to changes in climate conditions and disturbance regimes. Woody plants occurring across such mosaics can be specialists from one habitat type (forest or grassland) or a generalist species (those occurring in both of these contrasting habitats). Here, we explore if their occurrence in distinct habitats is coordinated by functional traits, considering both intra- and interspecific variability and phylogenetic relatedness between species, thereby assessing changes between habitats from the individual to the community scale. We surveyed forest and grassland vegetation forming mosaics in nine sites in southern Brazil. We found that grassland-forest communities do not differ in phylogenetic diversity, irrespective of considering or not the gymnosperms of the communities. Furthermore, forests presented lower diversity in leaf area than grasslands, with a predominance of large leaves but higher diversity of specific leaf area and leaf dry matter content, with leaves predominantly with an acquisitive resource strategy. When considering species with different habitat preferences, forest-specialist species showed traits related to resource acquisition, while grassland-specialist species showed trait values associated with resource conservation. Generalist species have trait values according to habitat occurrence, showing high intraspecific variability and trait plasticity to establish on both forest and grassland habitats. Assessing the trait variability from woody individuals is important to understanding the contrasting strategies used by different species in grassland-forest mosaics and can be essential to predict the dynamics of these ecosystems, given the changes in climate and disturbances regimes.

Shedding light on the controversial taxonomic status of Culicoides jamaicensis and Culicoides paolae (Diptera: Ceratopogonidae): an overseas trip among continents.

Culicoides biting midges (Diptera: Ceratopogonidae) are small bloodsucking flies that act as vectors for various pathogens of medical and veterinary importance. This study aimed to examine, using a comprehensive approach, the controversial taxonomic status of 2 Culicoides species that are currently distributed in the Neotropical (Culicoides jamaicensis Edwards) and Palearctic (Culicoides paolae Boorman) areas and possess unique and distinctive features. Previous investigations based on morphological analysis have suggested that these 2 species may be synonyms. Our work updated the current geographical distribution of both species and analyzed new specimens from different geographic origins, together with publicly available sequences. We used 2 universal genetic markers (COI and 28S) to test this hypothesis. Our study reveals evidence that C. paolae and C. jamaicensis belong to the same species due to the following statements: (i) similar morphological features; (ii) low interspecific genetic variation; (iii) association with a single genetic cluster; (iv) inclusion within the subgenus Drymodesmyia, which has only been recorded in the New World; and (v) occurrence in habitats with moderate temperatures. We recommend that European and African specimens of C. paolae be considered from now on as C. jamaicensis. Our comprehensive approach shed new light on the taxonomic status of these 2 Culicoides species and has implications for future studies on their biology and ecology.

Spatiotemporal patterns and environmental drivers of eastern redcedar (Juniperus virginiana) abundance along the Missouri River, USA

Changes in disturbance regimes, including reductions in flooding and geomorphic dynamism from dam construction and flow regulation, have facilitated invasion by eastern redcedar (Juniperus virginiana L.), an upland tree species, in the understory of floodplain forests along the Missouri National Recreational River (MNRR). Our aim was to determine the spatiotemporal patterns and environmental drivers of redcedar invasion along the MNRR. We used the Normalized Difference Vegetation Index (NDVI) calculated from winter Landsat imagery to construct a time series of maps showing spatial changes in redcedar abundance and distribution from 1982 to 2017 in both riparian and upland habitats along the MNRR. We determined how environmental factors (e.g., soil drainage ability, flood recurrence interval, 1980s LULC, lateral distance to the river, and channel incision) have influenced current (2017) redcedar occurrence and abundance in riparian habitats using random forest models (RFM). Time-series maps indicated that detectable redcedar cover occurred over less than 5% of the study area before 1985, increased steadily from 1985 to 2000, and more than tripled from 2000 to 2010. After 2010, redcedar abundance continued to increase in upland areas but declined following the 2011 Missouri River flood in the floodplain. RFMs indicated that river incision, distance to the river, soil drainage, 1984 LULC, and flood recurrence interval were important features influencing redcedar occurrence and abundance in the floodplain. Unless preventive measures are implemented, lack of floods and ongoing flow regulation will enable the continued spread of redcedar along the MNRR and other regulated rivers in the eastern Great Plains.

Resiliency of Apache Trout habitats in a warmer and drier climate future

AbstractObjectiveThe Southwest has the hottest and driest climate in the United States, and projections show that it will only get hotter and drier into the 2100s. The Apache Trout Oncorhynchus apache is native to the Southwest and is currently listed as threatened under the U.S. Endangered Species Act. Our goals were to understand how climate factors influence the distribution of juvenile Apache Trout (<125 mm TL) and how climate change will influence the suitability of Apache Trout habitat into the 2080s.MethodsWe used a species distribution model to evaluate how climatic and other factors influence the distribution of juvenile Apache Trout. We used predictions from the model to evaluate how climate change might impact the suitability of streams designated for recovery of the species into the 2080s.ResultJuvenile Apache Trout occurrence was predicted well by mean July stream temperature (°C), mean annual precipitation (dm), stream slope (%), and the presence of nonnative trout (area under the receiver operating characteristic curve = 0.85). Standardized parameter estimates showed that Rainbow Trout O. mykiss presence and annual precipitation influenced occupancy the most. Model predictions for the 2080s showed suitable habitat (occurrence probability ≥ 0.25) to increase for 11 (of 45) Apache Trout streams in the increased temperature (+3°C) only scenario (scenario 1), as headwater reaches that are currently too cold warmed to become more suitable. When we also included projected declines in annual precipitation (−5%) for the 2080s (scenario 2), the amount of suitable habitat decreased for eight Apache Trout streams and remained unchanged in all other streams.ConclusionMost Apache Trout populations are isolated upstream of barriers to nonnative trout in stream reaches that are currently thermally suitable with respect to mean July temperatures and would remain suitable into the 2080s. Cold headwater reaches are projected to warm, becoming more suitable in the 2080s. Thus, intentional isolation and the resultant truncated downstream distributions of Apache Trout populations in headwater streams explain the nominal effect of projected temperature increases due to climate change on this cold‐adapted salmonid. Standardized model parameters suggest that future declines in precipitation, manifested through reduced snowpack and its influence on streamflows, will play a larger role than temperature in the suitability—and, thus, resiliency—of Apache Trout habitats at least into the 2080s.

How does habitat influence metabolism? Clues from biomarker response and contaminant profile in Tursiops truncatus (Montagu, 1821) subspecies living in parapatry

In western South America (WSA) two subspecies of bottlenose dolphin are recognized: Tursiops truncatus gephyreus, predominantly found in estuaries and river mouths, and Tursiops truncatus truncatus, occurring along the continental shelf. Despite a partial spatial overlap, both subspecies are considered to occupy different habitats and ecological niches. In the present study, chemical analyzes as well as biochemical and molecular biomarkers were used to investigate the influence of niche partitioning over metabolic pathways associated with the detoxification of persistent organic pollutants (POPs), antioxidant metabolism, immune activity and lipid metabolism in Tursiops truncatus subspecies living in parapatry. Overall, the profile and levels of bioaccumulated PCBs, pesticides and PBDEs were similar between groups, with a greater variety of pesticides, such as γ-HCHs, heptachlor, oxychlordane and o,p'DDT, detected in T. truncatus gephyreus. Multivariate analysis of variance (MANOVA) and non-metric multidimensional scaling (NMDS) results indicated that glutathione reductase (GR) and superoxide dismutase (SOD) enzymatic activities were higher in coastal dolphins, as were the mRNA levels of metallothionein 2A (MT2A), interleukin-1α (IL-1α), ceramide synthase 3 (CERS3) and fatty acid elongase (ELOVL4). In parallel, mRNA levels of fatty acid synthase complex 1 (FASN 1) were higher in oceanic dolphins. These findings suggest that, due to their occurrence in coastal habitats, T. truncatus gephyreus is more exposed to environmental pollutants and pathogenic microorganisms. Likewise, niche partitioning may influence lipid biosynthesis, possibly due to differences on feeding habits, reflecting in an enhanced long chain ceramides biosynthesis in T. truncatus gephyreus. Collectively, these data reinforce the need to address habitat specificities in conservation efforts, since distinct groups can be facing different anthropogenic pressures in WSA.

The Wallacean Shortfall and the role of historical distribution records in the conservation assessment of an elusive Neotropical snake in a threatened landscape

Documenting species distribution is essential to extinction risk asessments and subsequent conservation actions. Historical records are thus essential to understand how species are distributed and how their range has changed over time. However, using historical records might contribute to overestimating the species current range and misrepresent their conservation status. Here, we illustrate the pitfalls of this approach using a widespread but elusive Neotropical snake species, Philodryas livida (Dipsadidae Bonaparte, 1838). We mapped occurrences of this species over time and calculated its Extent of Occurrence and Area of Habitat. Our results show that due to the intense, widespread anthropic land-use transformation since the discovery of P. livida in 1920, most historical localities are now likely unsuitable for its occurrence and both its current Extent of Occurrence and Area of Habitat become remarkably smaller (5.7% and 19.1% remaining, respectively) if only localities from the last 30 years are considered. Apart from the natural elusiveness of the species, intense habitat loss and fragmentation may also explain the low number of recent records of P. livida, all concentrated within or near protected areas, indicating a putative decline in range relevant to its conservation status. We thus highlight how failing to consider the date of records and the associated land-use change over time might underestimate species range reduction and thus threat status. We strongly encourage the inclusion of the date of each occurrence record in conservation assessments, as suggested by the IUCN’s mapping standards, such that historical records are carefully considered, especially in highly dynamic and threatened biomes such as the Cerrado savannas in Brazil.

Spatio-Temporal Variations in the Potential Habitat Distribution of Pacific Sardine (Sardinops sagax) in the Northwest Pacific Ocean

Pacific sardine (Sardinops sagax) is a commercially important species and supports important fisheries in the Northwest Pacific Ocean (NPO). Understanding the habitat distribution patterns of Pacific sardine is of great significance for fishing ground prediction and stock management. In this study, both single-algorithm and ensemble distribution models were established through the Biomod2 package for Pacific sardine by combining the species occurrence data, sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS) and chlorophyll-a concentration (Chla) in the NPO during the main fishing season (June–November) from 2015 to 2020. The results indicated that the key environmental variables affecting the habitat distribution of Pacific sardine were the SSH and SST. The suitable habitat area for Pacific sardine showed significant monthly changes: the suitable habitat range in June was larger than that in July and August, while the suitable habitat range gradually increased from September to November. Furthermore, the monthly geometric centers of habitat suitability index (HSI) for Pacific sardine presented a counterclockwise pattern, gradually moving to the northeast from June, and then turning back to the southwest from August. Compared with single-algorithm models, the ensemble model had higher evaluation metric values and better spatial correspondence between habitat prediction and occurrence records data, which indicated that the ensemble model can provide more accurate prediction and is a promising tool for potential habitat forecasting and resource management.

Impacts of Climate Change on the Biogeography of Three Amnesic Shellfish Toxin Producing Diatom Species

Harmful algal blooms (HABs) are considered one of the main risks for marine ecosystems and human health worldwide. Climate change is projected to induce significant changes in species geographic distribution, and, in this sense, it is paramount to accurately predict how it will affect toxin-producing microalgae. In this context, the present study was intended to project the potential biogeographical changes in habitat suitability and occurrence distribution of three key amnesic shellfish toxin (AST)-producing diatom species (i.e., Pseudo-nitzschia australis, P. seriata, and P. fraudulenta) under four different climate change scenarios (i.e., RCP-2.6, 4.5, 6.0, and 8.5) up to 2050 and 2100. For this purpose, we applied species distribution models (SDMs) using four abiotic predictors (i.e., sea surface temperature, salinity, current velocity, and bathymetry) in a MaxEnt framework. Overall, considerable contraction and potential extirpation were projected for all species at lower latitudes together with projected poleward expansions into higher latitudes, mainly in the northern hemisphere. The present study aims to contribute to the knowledge on the impacts of climate change on the biogeography of toxin-producing microalgae species while at the same time advising the correct environmental management of coastal habitats and ecosystems.

Structural elements enhanced by retention forestry promote forest and non-forest specialist bees and wasps

Retention forestry promotes certain forest structural elements to enhance biodiversity. It is unclear however to what extent retention measures are suited to enhance the biodiversity of bees and wasps, and how relationships to structural elements promoted by retention may differ when habitat-based classifications are accounted for. Here, we analyze the abundance, diversity and species richness of forest and non-forest specialist cavity-nesting bees and wasps collected on 127 plots in the southern Black Forest, Germany. Our aim was to use habitat-based classifications, or groupings based on habitat occurrence of cavity-nesting bees and wasps to evaluate the effectiveness and importance of forest structural elements that are prioritized in biodiversity-focused conservation. We found that canopy cover, stand structural complexity and standing deadwood were principally important for abundance, diversity and species richness of bees and wasps, with differing responses among habitat classifications. Forest specialist biodiversity metrics and composition were related to forest structural variables indicating greater feeding and nesting resource availability, namely herb cover, standing deadwood and stand structural complexity. Non-forest specialist biodiversity metrics were related to primarily canopy cover and elevation while community composition was structured by only forest cover and understory species richness. Our results indicate the importance of considering habitat specializations of cavity-nesting bee and wasp communities for meaningful evaluation of retention forestry structural elements. The presence and arrangement of these forest elements can be altered by stand level management practices utilizing the cascading effects of structural changes, such as increasing herb cover and sun exposed standing deadwood via canopy opening, and high stump retention during tree harvesting.

Temporal distribution, reproductive synchrony, and mating patterns of the explosive breeder frog Dermatonotus muelleri (Anura: Microhylidae)

The knowledge about natural history of a species is fundamental for the proposition of theories in population, community, and behavioral ecology. Dermatonotus muelleri (Boettger, 1885) is one of the several Neotropical anuran species that still lacks basic information. These frogs are widely distributed in South America and present many peculiar morphological features, such as a reduced head size and a tongue morphology that suggests a specialized diet in ants and termites. However, D. muelleri is rare in anuran surveys, because of the explosive breeding behavior, which restrict its occurrence in aquatic habitats to few days a year, and the semi-fossorial habit, making the individuals inactive during most part of the year. In this study, we describe the reproductive ecology of Dermatonotus muelleri, with special attention to the mechanisms that regulates (i) the reproductive synchrony between males and females and (ii) the operational sex ratio (OSR), and (iii) if size is a good predictor of pairs formation (assortative mating).