Habitat Types Research Articles

Spatial and temporal predictability drive foraging movements of coastal birds

BackgroundTemporal and spatial predictability of food resources are critical to the foraging efficiency of central place foragers. While site fidelity is often assessed in this context, route fidelity, or the repeated use of the same path while traveling, and temporal aspects of habitat predictability have received less attention. We examined how the use of urban, coastal, and offshore habitats influenced spatiotemporal predictability in the foraging patterns of herring gulls (Larus argentatus) and great black-backed gulls (L. marinus). Since gulls show higher site fidelity when foraging in urban habitats, we predicted that these trips would also show higher route fidelity. Similarly, we predicted that gulls foraging in coastal habitats would adapt the timing of foraging trips relative to tides.MethodsWe analyzed GPS tracks of herring gulls (n = 79) and great black-backed gulls (n = 37)—between 2016–2022 from four nesting colonies whose surrounding areas varied in their degree of urbanization. Fréchet distance, which is defined as the repeated use of the same path while traveling, was used to assess route fidelity, within colonies and between habitat types. We also compared the consistency of foraging trip timing relative to tidal stage and day of week, respectively, across habitat types.ResultsNeither herring nor great black-backed gulls showed higher route fidelity in urban habitats. Herring gulls showed direct travel between urban foraging sites but revisited sites in different orders, suggesting that a mosaic map may be used to navigate between known urban foraging sites. Herring and great black-backed gulls that foraged at coastal sites exhibited patterns in trip timing in relation to the tidal cycle, with foraging primarily occurring at or around low tide. Herring gulls in urban environments foraged more on Fridays and weekends, possibly due to increased or altered human activities on these days.ConclusionsOur results demonstrate the importance of spatial memory and spatiotemporal predictability of gull foraging habitats and highlight the extent to which gulls adjust their movements based on their foraging habitats.

Status of coral, giant clam and sea cucumber communities including CITES listed species on a remote Australian coral reef atoll and the potential impact of illegal fishing.

Following a recent dramatic increase in illegal fishing by Indonesian fishing vessels in Australian waters in 2022, we conducted an extensive survey of coral reef communities covering 33,000m2at Mermaid Reef Marine Park in the Rowley Shoals off north-western Australia in July 2022. Species richness of sea cucumbers was 13 species (three CITES listed) and 6 species of giant clams (all CITES listed). The most abundant sea cucumber species were the low or intermediate value, asexually reproducing species Holothuria atra and H. edulis. Seventy-one percent of all sea cucumbers were found in the deep lagoon habitat despite this habitat comprising only about one-third of total survey effort. Most of the higher value species, such as CITES listed Thelenota ananas, were more abundant in the deep lagoon habitat. The exceptions to this pattern were H. whitmaei (CITES listed) and Actinopyga mauritiana (high value) and Bohadschia marmorata (intermediate value) that were most abundant on the reef flat, reef slope and shallow lagoon habitats respectively. The burrowing giant clam Tridacna crocea was abundant in all habitat types, whereas T. squamosa and Hippopus hippopus were most abundant on the western outer slope, T. gigas on the reef flat and T. derasa in the deep lagoon. The results of previous and subsequent surveys in 2003, 2018 and 2023 were compared with our 2022 survey. High value species that mainly occur in shallow water (e.g., H. whitmaei) were more abundant in 2003 while T. ananas and Stichopus herrmanni were more abundant in the deep lagoon habitat in 2022 and less abundant in the shallow habitats than they were in 2003 while there was no change in the more abundant, low to intermediate value species (e.g., H. atra, H. edulis). There were no significant differences in sea cucumber densities between 2022 and 2018 or 2023, however the comparison was confounded by the small number of 2018 and 2023 survey sites which were spread over multiple habitat types. Survey results were consistent with the expectation that illegal fishing by free-diving occurs predominantly in shallow and intertidal habitats and that sea cucumbers in those habitats are more vulnerable to fishing than those in deep water habitats. We were unable to ascertain levels of catches from Mermaid Reef or the Rowley Shoals as a whole, however there were numerous reports of vessels being intercepted with catches of many tonnes of sea cucumbers. At Mermaid Reef, to remove one tonne of sea cucumbers, from reef flat and shallow lagoon habitats would require harvesting all sea cucumbers from 38ha (2037 individuals). This represents about 9% of the total area of reef flat and shallow lagoon at Mermaid Reef Marine Park and indicates how rapidly sea cucumber populations can be depleted through illegal fishing. Coral communities at Mermaid Reef were healthy, consistent with previous surveys over two decades with mean hard coral cover highest (40-50 %) on the exposed western outer reef slope and lowest on the reef flat (<10 %). Evidence of damage to coral communities from illegal fishing operations, bleaching or crown-of-thorns sea stars was negligible.

Bacterial community composition and metabolic characteristics of three representative Marine areas in northern China

Bacteria are essential components of ecosystems, participating in nutrient cycling and biogeochemical processes, and playing a crucial role in maintaining the stability of marine ecosystems. However, the biogeographic distribution patterns of bacterial diversity and metabolic functions in the estuarine and coastal areas of northern China remain unclear. Here, we used metagenomic sequencing to investigate the bacterial community composition and metabolic functions in sediments from the adjacent waters of the Yellow River Estuary, the Yellow Sea Cold Water Mass, and the adjacent waters of the Yangtze River Estuary. Among the 9164 species that were found, the most dominant microbial communities are Pseudomonadota, Actinomycetota, Bacteroidota, and Bacillota, but there are significant differences in the species composition in these three typical habitats. Amino acid metabolism and carbohydrate metabolic pathways were highly enriched. Glycoside hydrolases (GHs) predominate in carbon metabolism across all samples. In nitrogen metabolic pathway, genes related to organic degradation and synthesis are more abundant in the Yellow River Estuary than the other two habitats. In sulfur metabolic pathway, genes involved in assimilatory sulfate reduction are significantly enriched. Assimilatory sulfate reduction might be crucial for sulfur metabolism in coastal regions, with a full assimilatory nitrate reduction pathway found in Desulfobacterota. This research offers insights into the compositional diversity, metabolic functions, and biogeographic distribution patterns of bacterial communities in sediments from typical marine areas of northern China.

Exploring the causal relationships between environmental factors and benthos distributions in an intertidal algal reef ecosystem via a structural equation model

Algal reefs are unique and valuable yet poorly understood marine ecosystems. The causal relationships between environmental driving forces and biotic community distributions in an algal reef ecosystem were assessed to fill large scientific gaps. Using a structural equation model (SEM) coupled with factor analysis, we established a well-fitted algal reef SEM. This model revealed that there were two subsystems, one operating primarily above the reef laminated substratum and the other beneath the surface. The crustose coralline algae (CCA) and non-CCA cover areas were affected, with an inverse trend between the two, by river inputs, as indicated by NH3-N concentrations, and by the seasonal rhythm of riverine NO3-N concentrations. The trends revealed spatial competition between the two algal groups. The CCA coverage and epifaunal gastropod density responded positively to the presence of pebble habitat. Notably, sand coverage and its variation did not hinder the coverage of the two macrophytes. However, the epifaunal gastropod and arthropod densities were negatively regulated by the sand coverage variability. The infaunal arthropod density was positively influenced by the sediment heavy metal content. Among the biotic communities, the non-CCA cover area negatively affected the infaunal polychaeta density. Furthermore, the increasing infaunal polychaete density increased those of sipunculans, bivalves, and arthropods, implying co-occurrence. This SEM revealed that riverine nutrients, pebble habitat type and sand coverage variability were significant environmental drivers in organizing the biotic communities in an algal reef ecosystem.

Brazilian Amazon Coast is an essential habitat for threatened and evolutionarily distinct sharks and rays

Despite the high proportion of endangered species of elasmobranchs occurring in coastal areas subjected to intense fishing pressure, most of the existing habitat use information applies to pelagic species. Recent research efforts have substantially increased the information available on the habitat use of overlooked and often data deficient species. Here, we use vertebrae microchemistry data to study the habitat use patterns of four species of threatened sharks and two species of stingrays occurring in the Brazilian Amazon Coast (BAC). We obtained vertebrae samples from specimens sold in fish markets along the entire BAC area and analyze element:Ca ratios for four elements: Mg, Mn, Sr, and Ba. Our results demonstrate that most species likely complete their entire life cycle in the same region, with little to no use of freshwater habitats, and sympatric occurrence of neonates, juveniles, and adult life stages. The wingfin stingray, the only benthic-restricted species analyzed, differed substantially from all other species, with strong reliance on estuarine areas. The scalloped hammerhead has the largest variability in chemical trace elements, suggesting the use of habitats with wide variations. American cownose ray, daggernose, shovelbill, and smalleye hammerhead sharks showed strong reliance on the same type of habitat throughout their ontogenetic development. Our findings underscore the importance of the BAC as an Essential Fish Habitat for these species, a critical area for improved fisheries management given the widespread population declines and historical overfishing, and the danger of proposed oil exploration in the area can pose to its elasmobranch populations.

Spatial distribution of mammalian fauna in a community forest at Wadrékro, Oumé department, west-central Côte d'Ivoire

The rate at which Ivorian forests are disappearing has become increasingly alarming. It is therefore necessary to conduct investigations in these natural ecosystems to reverse this trend. Accordingly, this study was carried out in a community forest in Wadrékro, in the Oumé department, to determine the spatial distribution of mammalian species recorded there. To achieve this objective, foot surveys were conducted using linear transects and reconnaissance walks or recces. Data analysis revealed that four (4) habitat types were colonized by mammalian fauna in this forest. The orders Artiodactyla and Rodentia showed a wide distribution, while the order Carnivora was restricted to the southern and eastern parts of the forest. At the species level, the Bushbuck and the Greater Cane Rat were the most widespread. These findings could be useful for the restoration of Ivorian forest cover.

Analysis of functional and phylogenetic diversity of bat communities: insights from resource use in the Pantanal and Cerrado

BackgroundAssessing the structure of communities requires analysis of multiple dimensions of biological diversity. Such approaches provide a broader understanding of the ecological and historical factors involved in the formation and maintenance of communities. Metrics such as functional and phylogenetic diversity are crucial as they unveil how communities respond to environmental changes, providing a deeper understanding of their current state and resilience. This goes beyond species richness or community composition, enabling more profound insights into their present condition and resilience. Therefore, analysis in this sense allows accessing differences in the distribution of species, considering different landscape mosaics, and allowing strategic prioritization of conservation initiatives. In this sense, we investigated whether the composition of functional and phylogenetic groups of chiropteran species differs between the Pantanal and Cerrado biomes and various habitat types. We hypothesize that communities with greater conservation integrity are more diverse than communities that suffer anthropogenic influences.MethodsThe surveyed communities include two areas in the Pantanal and two in the Cerrado, with one conservation unit and one that suffers anthropic influence, for each biome. We assessed the composition of bat assemblages by examining functional richness (FRic), functional uniformity (FEve), functional divergence (FDiv), and functional dispersion (FDis). Metrics that reflect phylogenetic richness and divergence were also used, such as phylogenetic diversity (PD), mean pairwise distance (MPD), and mean nearest taxon distance (MNTD).Results and discussionOverall, conservation units sustain higher levels of functional and phylogenetic diversity compared to areas with anthropic influence. In the latter, species occupy fewer ecological niches, indicating that bats can persist in degraded environments, albeit the communities support only a portion of the functional groups.ConclusionOur results showed, through analyses across multiple dimensions of functional and phylogenetic diversity, that bat populations are impacted by environmental degradation and fragmentation. Communities in more conserved areas exhibited higher functional and phylogenetic richness, indicating a greater number of occupied niches. These findings highlight the importance of exploring measures of biological diversity and their spatial scales to advance our understanding of biodiversity dynamics and optimize conservation planning for both species and communities.

Updates to the checklist of nocturnal Macroheterocera (Lepidoptera) of the Central High Atlas of Morocco: One new species added for Morocco

This paper provides updates to the checklist of Macroheteroceran moths (Lepidoptera) of the central High Atlas of Morocco, following the initial inventory conducted by Charles Rungs nearly five decades ago. Sampling was carried out using sugar bait traps deployed across various habitat types in the region (natural, semi-natural and agricultural lands). Identification of the collected specimens involved a comprehensive approach, including examination of external morphology, dissections of genitalia and DNA barcoding. In this study, we recorded a total of 123 species belonging to the families Noctuidae, Erebidae, Geometridae, Eutelidae and Drepanidae. Euxoa cos (Noctuidae) was recorded as a new species for Morocco. The presence of Apamea maroccana (Noctuidae) and Chersotis rungsi (Noctuidae), both endemic to Morocco, was verified in the study area. Four of the 123 species were only identified at the genus level. Our inventory also sheds light on species that were previously not known to occur within our study area, reporting twelve species from the High Atlas Mountains for the first time. We also suggest omitting Eupithecia farinosa (Geometridae) from the Moroccan Lepidoptera list. This study significantly contributes to uncovering an overlooked aspect of Lepidopteran biodiversity in Morocco, which is crucial for future conservation efforts.

Lepidopteran Biodiversity in Madagascar’s Eastern Forests: Assessing Species Distribution Across Protected and Anthropized Landscapes

Madagascar, renowned for its unique biodiversity, faces significant environmental threats. Despite their vital ecosystem services, invertebrates, such as Lepidoptera, remain understudied, especially within the Malagasy Island. Indeed, butterflies and moths often serve as biodiversity indicators. This study investigates lepidopteran community structure across different habitat types: protected areas and anthropized areas, represented by forest edges and agroforestry through four expeditions to Madagascar’s moist eastern forests. Both sampling methods were employed including butterfly nets and fermented fruit-baited traps. While nets accounted for 90% of captures, highlighting operator bias, bait traps captured unique species, emphasizing the complementarity of these methods. With over 891 captured specimens, 418 macrolepidopterans were identified at the species level for a total of 50 species. Protected forests hosted 80% of endemic Lepidoptera reliant on specialized ecological niches, while anthropized zones were dominated by common generalist species which are resilient to habitat changes. While the species richness and composition of sampled microlepidoptera are similar, habitat fragmentation created diverse environmental conditions, hosting specific populations. Conservation challenges persist, particularly for endemic species vulnerable to poaching. It is crucial to continue sampling Madagascar’s lepidofauna, as this offers considerable potential for the sustainable maintenance of ecosystems and the long-term preservation of biodiversity of the Malagasy Island.

First density estimates of the Endangered Claire's mouse lemur Microcebus mamiratra and recommendations for its conservation

Abstract Mouse lemurs Microcebus spp. are small, nocturnal primates endemic to Madagascar. The genus is extraordinarily diverse, with 25 extant species, several of which have been described recently. The Endangered Claire's mouse lemur Microcebus mamiratra was first described in 2006, but, similarly to other newly described mouse lemurs, remains understudied, and estimates of its population size are unavailable, hampering effective conservation management. We conducted line transect distance sampling surveys of M. mamiratra across several habitat types in and around Lokobe National Park on the island of Nosy Be in north-western Madagascar. Using a systematic random design we surveyed 15 transects over a 6-week period in 2023, recording 92 detections from a total survey effort of 46.5 km. We estimate the density of M. mamiratra on Nosy Be to be 125.1 individuals/km2, which extrapolates to an estimate of c. 4,700 individuals across the forested areas of its range on the island. Our results indicate that Nosy Be harbours moderately high densities of M. mamiratra, with the highest encounter rates in the unprotected secondary and degraded forests around Lokobe National Park. Our population estimate will inform future conservation status assessments and conservation planning for this range-restricted species and provide a baseline for monitoring population changes over time. We present recommendations for the conservation of M. mamiratra and highlight the potential for lemur watching, sustained by the strong tourism industry on Nosy Be, to help protect lemur habitat and generate economic opportunities for local communities.

Phenological responses to climate change across taxa and local habitats in a high‐Arctic arthropod community

AbstractClimate change has led to pronounced shifts in phenology, varying across taxa. The Arctic is experiencing particularly rapid warming, but long‐term data on phenological changes are rare in this region, especially for arthropods—a diverse taxonomic group that form important links to other trophic levels. Understanding the environmental drivers of arthropod phenological variation is necessary for predicting future trends across taxa and habitats to climate change. Here, we analyze temporal trends and climate associations in arthropod phenology using 25 years of standardized monitoring data from four habitat types in high‐Arctic Greenland. We observed earlier peak activity in the arthropod community, with responses varying considerably among families and habitats. Snowmelt timing was a key driver of peak activity, especially for late‐active taxa, while temperature was a less important driver, but arthropods generally exhibited earlier activity with warming. Responses in the duration of activity were more complex, with family‐ and habitat‐specific responses to climate variation. Notably, taxa in habitats with late snowmelt responded strongly to snowmelt timing, while those in the pond habitat responded strongly to temperature. Mixed feeders and parasitoids showed rapid peak phenological shifts to earlier snowmelt and warming; however, mixed feeders shortened their activity periods, while parasitoids extended theirs. Our findings highlight the complexity of arthropod community phenological responses to climate change, with potential implications for trophic interactions dependent on temporal overlap. By analyzing phenological metrics across entire activity seasons for taxa with different functional and life‐history traits, we identify general trends and consistent patterns that enhance our understanding of arthropod responses to climate change.

Population structure, distribution pattern and habitat utilization of Yellow-wattled Lapwing, Vanellus malabaricus (Boddaert, 1783), in Northern India

This field study investigated the population structure, distribution pattern and habitat utilization of Yellow-wattled Lapwings. The line transect method was used to estimate the density of Yellow-wattled Lapwings. An average of 394 individuals including 77 chicks of Yellow-wattled Lapwings have been registered with an average density of 38 birds per km. The outcome of the GLM analysis exhibited, that Bakshi Ka Talab had the highest lapwing count while, Malihabad had the lowest lapwing count. A significant lapwing count in the year 2021 was confirmed. The winter season had the lowest lapwing counts, whereas the summer season had the highest values. Moreover, the largest lapwing counts were estimated in uncultivated while, the lowest lapwing count was documented in river habitat types. There was a significant difference in the mean flock size across the seasons and the habitat types. Being sighted in flocks of various sizes the distribution pattern was found to be clumped in Yellow-wattled Lapwings. The results of the factorial ANOVA showed a significant difference in the habitat utilization of Yellow-wattled Lapwings across study sites, years, seasons and habitat types. Uncultivated habitat types were the most utilized habitat types during summer seasons.

Hot child in the city: Drivers of urban buffelgrass presence in Tucson, Arizona

AbstractInvasive species distributions and ecological impacts in natural ecosystems have been broadly studied, but invasive species urban distributions and impacts on human populations warrant further investigation. Urban areas are highly disturbed environments at high risk of invasion by non‐native species, and urban infrastructure can influence the dispersal and abundance of invasive species. Furthermore, in areas with concentrated human populations, invasive species may pose a risk to human as well as native biota. Here, we examine (1) how high‐traffic roadways and the presence of suitable habitat influence buffelgrass abundance in residential areas and (2) whether buffelgrass differentially invades residential areas across socioeconomic levels and racial diversity indices in Tucson, Arizona. We found that, within residential areas, the presence of vacant lots was positively associated with buffelgrass abundance; however, there was no relationship between other suitable habitat types and buffelgrass abundance. We found no relationship between road type and buffelgrass abundance in residential areas. We found that lower‐income communities were more likely to be invaded by buffelgrass, but there was no relationship between racial diversity index and buffelgrass abundance. Understanding drivers of invasive species presence and abundance in urban areas is necessary to inform urban management strategies to prevent spread to surrounding wildlands.

Physiological effects of suspended sediments on marine fish across habitat, development, and behavioral factors.

This study evaluated the physiological responses of four marine fish species (Lateolabrax japonicus, Sebastes schlegelii, Platichthys stellatus, and Paralichthys olivaceus) to suspended sediments (SS) generated by marine sand mining. Using oxygen consumption rate (OCR), osmolality, and mortality as endpoints, the effects of SS concentrations ranging from 0 to 10,000mgL-1 were assessed. L. japonicus exhibited the highest sensitive in OCR, with an EC50 of 15,812mgL-1 responding more rapidly to SS exposure. In contrast, S. schlegelii demonstrated the highest mortality, with an LC50 of 340,921mgL-1. SS exposure caused diel variations in OCR across species, highlighting the necessity of accounting for such differences. Based on the results of this study and review, species sensitivity to SS is influenced by habitat type, activity patterns, and developmental stage, emphasizing the importance of incorporating species-specific traits to accurately evaluate the ecological impacts of SS on marine ecosystems.

The Role of Non‐Native Plant Species in Modulating Riverbank Erosion: A Systematic Review

ABSTRACTRiverbank erosion is a naturally occurring process that influences riparian zone habitats. However, anthropogenic activities are increasing rates of riverbank erosion. Climate change and hydrological and physical modifications drive riparian zone perturbations. Whilst native riparian vegetation can reduce riverbank erosion, the proliferation of non‐native riparian plant species has been linked to riverbank instability, with marked changes in fluvial erosional regimes attributed to invasion by species such as Impatiens glandulifera (Himalayan Balsam) or Tamarix (Tamarisk) into riparian zones. Yet, the role of non‐native plant species in modulating riverbank erosion remains unclear, in part due to the lack of investigations that quantify geomorphic change. We systematically assessed the relevant ecological and geomorphological literature to determine current understanding and to offer recommendations for future research on non‐native plant—riverbank erosion. Included articles focused on a limited number of non‐native plant species across a restricted range of habitats types, with dependency on topographic change and generally short study duration obscuring potential causal links or feedback cycles. It is critical in the face of parallel rapid proliferation of riparian non‐native plant species and climate change effects, that we improve mechanistic understanding of their role in riverbank erosion.

Frankenstein matrices: Among-population life history variation affects the reliability and predictions of demographic models.

Population matrix models are routinely used to study the demography of wild populations and to guide management choices. When vital rates are unknown for a specific population or life history stage, researchers often replace them with estimates from other populations of the same species. Such 'hybrid' matrices might ignore among-population life history variation and lead to incorrect inferences. In this study, we examined the real-world effect of using hybrid matrices on demographic inference and management decisions, using a large dataset on yellow-bellied toad (Bombina variegata) populations, an amphibian species whose life history depends on human land use. We estimated stage-specific survival and recruitment for 18 populations across different habitat types. We then assessed how estimated population growth rates and elasticities changed when population-specific vital rates were replaced by estimates from other populations, chosen randomly or based on habitat, demographic or geographic proximity. The use of hybrid matrices mixing demographic estimates from different populations and habitats biased predictions. The mean bias was relatively minor even when sampling randomly across all populations, because our large dataset represented the whole range of life histories and errors cancelled out on average. However, borrowing estimates from geographically close or demographically similar populations substantially reduced the risk of extreme errors. Borrowing from populations from similar habitat types could also reduce bias, but results varied depending on the exact habitat types concerned. Our study illustrates how habitat-specific among-population variation in life history affects the reliability of population matrices commonly used in evolutionary demography, ecology and conservation. When the use of hybrid population matrices cannot be avoided, their creation can be informed by additional information about ecological or demographic patterns, helping reduce bias. When such information is not available, we recommend that studies should consider the whole space of parameter estimates (the complete range of estimates available), thus transparently describing the true uncertainty surrounding demographic estimates.

Age and reproductive status determine spatial niche utilization in Vipera ammodytes (Linnaeus, 1758)

While data on habitat use of Vipera ammodytes are abundant, most studies are purely descriptive and only list the typical habitats in which the species is found. The intraspecific variations (i.e., ontogenetic and intersexual) in habitat and microhabitat utilization remain very poorly studied. In order to assess those intraspecific variations, we studied five different populations in western Bulgaria between 2014–2017, searching for vipers from early spring to late autumn in 24 different habitat types. The ontogenetic and intersexual variations in spatial niche breadth were analysed using several ecological diversity indices, and microhabitat characteristics were estimated by the presence of trees/shrubs, grasses and stones/rocks within a 5 m diameter of each viper’s location. Vipers were found in 17 habitat types. Habitat and microhabitat selection of Vipera ammodytes were age-dependent, with juveniles having the narrowest spatial niche and preferring more open microhabitats. The breadth of the spatial niche gradually increased with age, along with the tendency to inhabit microhabitats with more shrubs. During gestation, female’s spatial niche narrowed significantly and pregnant vipers again tended to use more open microhabitats, known as rookery. The observed results could be explained by a combination of factors, such as 1) the ontogenetic differences in the trophic niche and feeding patterns, 2) different prey type abundance in distinct habitats and microhabitats, 3) the size differences between age groups with all benefits and limitations that come with them, 4) distinct behavioural patterns differing between sex/age groups or 5) a size-related bias in detection probabilities.

Ecosystem Drivers of Freshwater Mercury Bioaccumulation Are Context-Dependent: Insights from Continental-Scale Modeling.

Significant variation in mercury (Hg) bioaccumulation is observed across the diversity of freshwater ecosystems in North America. While there is support for the major drivers of Hg bioaccumulation, the relative influence of different external factors can vary widely among waterbodies, which makes predicting Hg risk across large spatial scales particularly challenging. We modeled Hg bioaccumulation by coupling Hg concentrations in more than 21,000 dragonflies collected across the United States from 2008 to 2021 with a suite of chemical (e.g., dissolved organic carbon (DOC), pH, sulfate) and landscape (e.g., soil characteristics, land cover) variables representing external drivers of Hg methylation, transport, and uptake. Model predictions explained 85% of the variation in dragonfly Hg concentrations across the United States. Certain predictor variables were more important than others (e.g., DOC, pH, and percent wetland), and they varied among waterbodies. Variation in Hg bioaccumulation was explained by including habitat and ecosystem type in a hierarchical modeling framework, which confirms the context-dependency of external factors in explaining Hg bioaccumulation across disparate freshwater ecosystems. This continent-scale model provides valuable insights into the processes underlying landscape-scale patterns in Hg exposure risk and demonstrates that drivers of Hg methylation and bioaccumulation are habitat- and ecosystem-dependent.

Different Genotypes of the Rare and Threatened Moss Physcomitrium eurystomum (Funariaceae) Exhibit Different Resilience to Zinc and Copper Stress.

The funarioid moss species Physcomitrium eurystomum, which is threatened with extinction, was the subject of this study. The riparian habitat type of this species is often under the influence of contaminated water, and, therefore, we tested the influence of selected potentially toxic elements (PTEs), namely zinc and copper, on the development, physiological features, and survival of the species on two different accessions (German and Croatian). The results obtained showed the different resilience of the two accessions to the PTEs. Flow cytometry analyses revealed that the two accessions differ significantly in terms of genome size. However, the different amplitude of resilience to the tested PTEs, the divergence in physiological responses, and survival within two accessions of the same species are confirmed, as well as the dissimilarity of their genome size, likely associated with ploidy level difference and possibly distinct hybrid origin.

Ecological communities in white‐sand Amazonian rainforests are sensitive to deforestation—A dung beetle case

Abstract Campinarana is a fragile white‐sand rainforest ecosystem in Amazonia, where mining activities have been an important driver of landscape transformation, threatening biodiversity. Despite its importance for biodiversity, few studies have investigated insects' response to environmental disturbance in campinaranas. Here, we assess the differences between the dung beetle assemblages of undisturbed and disturbed campinaranas. The studied campinaranas differ substantially in their vegetation structure, the disturbed one strongly affected by mining activities. Dung beetle taxonomic diversity, abundance, biomass, and assemblage structure (species' distribution and relative abundances) from total and functional group perspective and indicator species were recorded in undisturbed and disturbed campinaranas. A total of 1592 beetles belonging to 42 species were collected in undisturbed campinaranas and 459 beetles from 11 species in disturbed campinaranas. Undisturbed campinaranas encompassed higher diversity, abundance, number of indicator species, and biomass, and their assemblages' structure were distinct from disturbed campinaranas. The abundance of roller dung beetles was the only parameter that was not affected by habitat type. Our results suggest that undisturbed campinaranas host sensitive ecological communities, with most of the species unable to cope with the changes brought by mining activities. In addition, dung beetle species can be a useful indicator for monitoring environmental disturbance in campinaranas. Considering the extension of the latter across the Amazon, this study provides information to support public policies to mitigate losses caused by deforestation in this hyperdiverse area.