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The stability of inverse nonpremixed oxygen (O2)/methane (CH4) coaxial jet flames near blowout limits in a model combustor is studied by analyzing signals for their local combustion phenomena using high-speed imaging and dynamic pressure. The power spectral analysis and the statistical analysis are conducted to delineate the stability of the inverse nonpremixed flames. Depending on the O2 to CH4 momentum flux ratio ((O/F)mom), two distinguished combustion phenomena which lead to different liftoff mechanisms are observed in the same burner configuration: the partial liftoff related to the aerodynamic mechanism and the local extinction related to the flame–turbulence interaction. The results of the power spectral density (PSD) show that on approaching the near-blowout limits, the local extinction or the partial liftoff occurs not in a specific frequency, but in a time-varying random distribution. The normalized root mean square (NRMS) based on the frame-integrated visible light signal (SVL) is found to be effective for quantifying the local extinction and the partial liftoff and particularly delineating the stability of the present inverse nonpremixed flames with the partial liftoff. [ABSTRACT FROM AUTHOR]

Urban ecological reserves are large green areas immersed within cities where native and exotic species of plants and animals coexist. Here, we examined the environmental features that facilitate the occurrence of nine species of native birds in an urban ecological reserve located within one of the largest cities in the world, Mexico City. We also searched for changes in occupancy rates among the three distinct climatic seasons that occur in central Mexico: warm-dry, rainy, and cold-dry. Using data collected during four years and multi-season occupancy models, we found that most of our study species prefer the urbanized sites that surround the reserve over the core conservation areas. This urban affinity can be explained by the diverse vegetation that prevails in such urban sites, which offers a high habitat heterogeneity that facilitates the presence of bird species with distinct ecological needs. In contrast, the reserve consists of a relatively homogeneous xerophytic scrubland where a few species of shrubs and small trees are dominant. We also detected seasonal changes in five species, with highest occupancy during the warm-dry season of each year, which coincides with both their breeding season and the driest period of the year. This finding indicates that these birds find in the reserve and surrounding urban areas enough food and water during this limiting season as well as safe nesting sites. Our study provides evidence that some native birds can become urban exploiters and that the benefits that they obtain from urban settings are greatest during their breeding season. [ABSTRACT FROM AUTHOR]

Understanding which species will be extirpated in the aftermath of large‐scale human disturbance is critical to mitigating biodiversity loss, particularly in hyperdiverse tropical biomes. Deforestation is the strongest driver of contemporary local extinctions in tropical forests but may occur at different tempos. The 2 most extensive tropical forest biomes in South America—the Atlantic Forest and the Amazon—have experienced historically divergent pathways of habitat loss and biodiversity decay, providing a unique case study to investigate rates of local species persistence on a single continent. We quantified medium‐ to large‐bodied mammal species persistence across these biomes to elucidate how landscape configuration affects their persistence and associated ecological functions. We collected occurrence data for 617 assemblages of medium‐ to large‐bodied mammal species (>1 kg) in the Atlantic Forest and the Amazon. Analyzing natural habitat cover based on satellite data (1985–2022), we employed descriptive statistics and generalized linear models (GLMs) to investigate ecospecies occurrence patterns in relation to habitat cover across the landscapes. The subregional erosion of Amazonian mammal assemblage diversity since the 1970s mirrors that observed since the colonial conquest of the Atlantic Forest, given that 52.8% of all Amazonian mammals are now on a similar trajectory. Four out of 5 large mammals in the Atlantic Forest were prone to extirpation, whereas 53% of Amazonian mammals were vulnerable to extirpation. Greater natural habitat cover increased the persistence likelihood of ecospecies in both biomes. These trends reflected a median local species loss 63.9% higher in the Atlantic Forest than in the Amazon, which appears to be moving toward a turning point of forest habitat loss and degradation. The contrasting trajectories of species persistence in the Amazon and Atlantic Forest domains underscore the importance of considering historical habitat loss pathways and regional biodiversity erosion in conservation strategies. By focusing on landscape configuration and identifying essential ecological functions associated with large vertebrate species, conservation planning and management practices can be better informed. [ABSTRACT FROM AUTHOR]

The steam-diluted oxyfuel combustion of the hydrogen-enriched fuels is promising to attain zero-emission in the energy system. One critical challenge for this technology is the flame stabilization, which was examined in this work mainly through the flame structure analysis. The burner adopted three swirlers to enhance the mixing, which leads to V-shaped diffusion-like flames. Starting from the purely hydrogen fuel, the CH 4 addition effects with fractions of 20% and 40% were studied. Meanwhile, combustion with different equivalence ratios were also compared, when the volume flowrate ratio of the O 2 and steam was kept constantly at 1:4. For these diffusion-like flames, the reaction zone was obtained using the OH-PLIF. Then, the flame structure statistics, such as the number and area of the broken reaction zone and its thickness, were all examined. Results show that the fuel properties and steam flowrate intensively affect the flame stabilization. With increased CH 4 addition in the hydrogen fuel, the reaction zone tends to be broken seriously. This is characterized by frequently appeared small reaction zone fragments, along with largely decreased reaction zone area. With a larger stream flow rate, the local flame extinction is also increased obviously and the flame branches can be completely distinguished due to the intensive straining effects. The extinction upstream is observed to promote an enveloped reaction zone downstream, due to the unburned fuel leakage. It is found that the mean reaction zone thickness is overall close, which varies from 1 to 2 mm, but can be modified by different factors. An analogical comparison of the reaction thickness to the laminar counter-flame thickness reveals that the CH 4 addition and flow straining can decrease the reaction zone thickness, but the accompanied turbulence effects can broaden it to at least about 1.2 times. These results are beneficial to attain a stable ultra-clean combustion utilizing hydrogen-based flexible fuels. [Display omitted] • Steam-diluted swirling CH 4 /H 2 /O 2 flames are studied. • The flame is a diffusional type and can be unstable. • Extinction is increased with either CH 4 addition or high steam flowrate. • Extinction and fuel leakage lead to enveloped reaction zone downstream. • The reaction zone thickness can be broadened by turbulence. [ABSTRACT FROM AUTHOR]

Competitive exclusion, a mechanism for local extinction of organisms, has been well established among taxonomically related species, including those within the same genus, family, or class in animal communities. This study, however, focuses on competitive exclusion that occurs across phyla, exemplified by the exclusion of a native insect by an invading exotic mammal, where food resources overlap. The hypothesis proposed in this study is that the small Indian mongoose (Urva auropunctata) has caused the local extinction of a burying beetle (Nicrophorus nepalensis) on Okinawa Is., Japan due to competition for carcasses of small vertebrates. To test this hypothesis, a comparison of beetle abundance was conducted between the area intensively controlled for mongoose and the area where mongoose control was weak or nonexistent. The former situated north of the boundary to prevent mongoose from crossing, and the latter located south of the boundary. To determine the user of carcasses on the forest floor, mouse carcasses were laid and their consumers were observed in each area. The results showed that the beetle abundance was clearly higher in the former than in the latter, and no beetles were collected where mongoose have never been controlled. The beetles often buried the mouse carcasses for their reproduction in the former, whereas in the latter, mongoose frequently consumed the mouse carcasses. These results provide evidence of competitive exclusion of the burying beetle by mongoose. This conclusion represents the first demonstration of competitive exclusion across phyla in an animal community. [ABSTRACT FROM AUTHOR]

To determine the present-day community composition of siliceous Rhizaria (Radiolaria and Phaeodaria) in Norwegian fjords, plankton tows were conducted in south-western and northern Norwegian fjords in September 2016. The mean total abundance of radiolarians was 306 m–3 in the Sognefjord complex, which was the southern research site, and, in the north, 945 m–3 in Malangen and 89 m–3 in Balsfjord, both above the Arctic Circle. Sticholonche zanclea was the most abundant radiolarian in the Sognefjord complex and Malangen, accounting for 78–100% (mean 89%) of radiolarian abundance. The mean total abundance of phaeodarians was 1554 m–3 in the Sognefjord complex, 51 m–3 in Malangen and 11 m–3 in Balsfjord. Medusetta arcifera was the most abundant phaeodaria in the Sognefjord complex, accounting for >99% of phaeodarian abundance, but was absent in Malangen and Balsfjord, where Protocystis tridens accounted for >96% of phaeodarian abundance. The carbon biomass of S. zanclea and M. arcifera was 188 and 438 µg C m–3, respectively, which is similar to and 8.6 times higher than, respectively, that of phaeodarians >1 mm in the western North Pacific, suggesting that M. arcifera contributes to organic carbon transport in the Sognefjord complex. Amphimelissa setosa (Nassellaria, Radiolaria), which was a dominant species in the study area in 1982–83, was absent in the present study in all sampled fjords. This could have been caused by the approximately 2 °C increase in water temperature that has occurred since 1990 and can be taken as evidence of a climate-change-associated local temperature rise linked to the warming of advected Atlantic Water.

Fireflies (Coleoptera, Lampyridae) are a globally threatened group of insects due to habitat loss and fragmentation, light pollution, climate change and pesticides. However, against all odds, some firefly populations persist in urbanized environments where all four of these factors are present simultaneously. In this work, we compiled several data sources to document the diversity of fireflies in the urbanized area of Morelia, characterize their current habitats, and determine the main stressors affecting these bioluminescent insects. We found seven genera and 26 species of fireflies (19 nocturnal, seven diurnal) associated with 32 urban, peri-urban and extra-urban areas; at least, 14 are new records for Michoacán, and the list for the state now includes nine genera and 41 species. Five additional sites were documented as extinction sites. We compared the characteristics of these five sites with those of the sites with extant populations. We found that in Morelia, fireflies are mainly associated with areas that have high to moderate proportions of vegetation cover, are near water bodies, have very gentle to moderate slopes, and are exposed to low levels of light pollution. In contrast, the extinction sites showed high proportions of artificial surfaces and high levels of light pollution. Because some fireflies are considered bioindicators of ecosystem integrity as they are associated to specific habitats, are highly diverse and due to their sensitivity to environmental changes, we consider that sites from Morelia's urban core and extinction sites show the highest levels of environmental degradation, threatening most fireflies and other insects living in the urban core with local extinction. At the same time, our results also suggest that implementing conservation strategies and sustainable planning for the urban development of Morelia in the short term could allow fireflies and other vital elements of the city's insect communities to persist for future generations. Restoration and conservation of green areas and nighttime environments are essential for biodiversity and human health, especially in intra-urban zones. [ABSTRACT FROM AUTHOR]

Temporal patterns of biodiversity are often difficult to interpret because of our limited understanding of how communities vary through time and how processes drive this variation. A further challenge with dynamic systems is choosing an appropriate baseline against which biodiversity change is judged. We used abundance time series of breeding waterbirds in eutrophic lakes in Finland for 1946–2022 to study the dynamics of biodiversity change in local communities and the relative role of two presumed main drivers, i.e. eutrophication and alien predators, in contributing to historical and recent trends in local abundances and biodiversity. We set the cut-off for the historical and recent study periods in the mid-1980 s, because the systematic monitoring of breeding waterbirds in Finland started in 1986 and recent analyses of biodiversity change and population trends in European boreal waterbird communities are mainly based on time series and data gathered since 1986. Both species richness and the total abundance of waterbirds in local communities showed contrasting trends between historical (gathered before the mid-1980 s) and current (gathered after the mid-1980 s) community time series, with the current time series indicating a decline and the historical time series indicating an increase. The abundances of habitat specialists (species preferring eutrophic lakes) and habitat generalists (species using both eutrophic and oligotrophic lakes) showed a corresponding difference between the current and historical time series. The local extinction rates were higher among habitat specialists than among habitat generalists. The trend indices for wetland-nesting species (highly vulnerable to predation by two alien species (the raccoon dog, Nyctereutes procyonoides, and American mink, Neovison vison) in terms of nest site) abundances were more negative than the trend indices of species nesting further away from waterbodies (less vulnerable to predation by two alien species). In addition, bottom-feeding species (presumably more sensitive to negative impacts of eutrophication) did not show more negative population trends than surface-feeding species (presumably less sensitive to negative impacts of eutrophication). Regardless of equal sensitivity to negative impacts of eutrophication, two species highly vulnerable to two alien predators showed more negative population trends than a less vulnerable species. The results suggest that increased predation has been an important driver of the population and biodiversity declines in the studied waterbird communities. The mid-1980 s may not provide an ecologically appropriate baseline against which changes in the populations and biodiversity of boreal waterbird communities are judged.

Reservoirs are fundamental for human well-being but can cause landscape changes (e.g., habitat fragmentation and loss), altering biodiversity and ecosystem services. However, we know little about reservoir long-term effects on bird communities of tropical rainforests at different temporal scales. We assessed species richness and composition changes in four consecutive periods in a reservoir area in the Colombian Tropical Andes. After 20 years of monitoring avifauna within the reservoir, we recorded 360 bird species along with 47 local extinction and 184 colonization events. We found that species richness increased by 42% during the first 11 years after reservoir establishment. After that, changes in species bird composition were largely explained by species turnover. Eighty-two percent of the expected species in the region were recorded within the reservoir area. Also, forests surrounding the reservoir are a habitat for several threatened bird species. Bird community changes observed can be explained by secondary succession, changes in vegetation cover (i.e., increase in forest area), the transformation of aquatic ecosystems, forest protection, and restoration programs focused on biodiversity conservation. Long-term systematic bird sampling in tropical forests is key to understanding biodiversity dynamics and the effectiveness of conservation actions.

Fireflies (Coleoptera, Lampyridae) are a globally threatened group of insects due to habitat loss and fragmentation, light pollution, climate change and pesticides. However, against all odds, some firefly populations persist in urbanized environments where all four of these factors are present simultaneously. In this work, we compiled several data sources to document the diversity of fireflies in the urbanized area of Morelia, characterize their current habitats, and determine the main stressors affecting these bioluminescent insects. We found seven genera and 26 species of fireflies (19 nocturnal, seven diurnal) associated with 32 urban, peri-urban and extra-urban areas; at least, 14 are new records for Michoacán, and the list for the state now includes nine genera and 41 species. Five additional sites were documented as extinction sites. We compared the characteristics of these five sites with those of the sites with extant populations. We found that in Morelia, fireflies are mainly associated with areas that have high to moderate proportions of vegetation cover, are near water bodies, have very gentle to moderate slopes, and are exposed to low levels of light pollution. In contrast, the extinction sites showed high proportions of artificial surfaces and high levels of light pollution. Because some fireflies are considered bioindicators of ecosystem integrity as they are associated to specific habitats, are highly diverse and due to their sensitivity to environmental changes, we consider that sites from Morelia’s urban core and extinction sites show the highest levels of environmental degradation, threatening most fireflies and other insects living in the urban core with local extinction. At the same time, our results also suggest that implementing conservation strategies and sustainable planning for the urban development of Morelia in the short term could allow fireflies and other vital elements of the city’s insect communities to persist for future generations. Restoration and conservation of green areas and nighttime environments are essential for biodiversity and human health, especially in intra-urban zones.

Phylogeographic patterns in large mammals result from natural environmental factors and anthropogenic effects, which in some cases include domestication. The grey wolf was once widely distributed across the Holarctic, but experienced phylogeographic shifts and demographic declines during the Holocene. In the 19th–20th centuries, the species became extirpated from large parts of Europe due to direct extermination and habitat loss. We reconstructed the evolutionary history of the extinct Western European wolves based on the mitogenomic composition of 78 samples from France (Neolithic‐20th century) in the context of other populations of wolves and dogs worldwide. We found a close genetic similarity of French wolves from ancient, medieval and recent populations, which suggests the long‐term continuity of maternal lineages. MtDNA haplotypes of the French wolves showed large diversity and fell into two main haplogroups of modern Holarctic wolves. Our worldwide phylogeographic analysis indicated that haplogroup W1, which includes wolves from Eurasia and North America, originated in Northern Siberia. Haplogroup W2, which includes only European wolves, originated in Europe ~35 kya and its frequency was reduced during the Holocene due to an expansion of haplogroup W1 from the east. Moreover, we found that dog haplogroup D, currently restricted to Europe and the Middle East, was nested within the wolf haplogroup W2. This suggests European origin of haplogroup D, probably as a result of an ancient introgression from European wolves. Our results highlight the dynamic evolutionary history of European wolves during the Holocene, with a partial lineage replacement and introgressive hybridization with local dog populations. [ABSTRACT FROM AUTHOR]

The initial mechanism of cellular instabilities on the flame surface was investigated experimentally. Firstly, mono-dispersed ethanol droplets were created via the Wilson cloud principle in a spherical combustion chamber, and aerosol ethanol/air flame propagation was tracked under microgravity conditions. Schlieren images revealed that at the beginning of the cellular structure formation, dark spots formed linking to the signal loss in a density gradient. This phenomenon is assumed to be local extinction and quenching on the flame front due to either liquid droplets’ presence or evaporation. To further investigate the observed phenomenon, stagnation flame experiments were performed for rich propane/air gaseous flames with isolated ethanol droplet injection. The evidence for the local extinction on the flame surface due to droplet passage was found via the Chemiluminescence method. The intrinsic instabilities were found to be triggered by the droplets in cases where the flame cannot recover its initial state.

Abstract Background Temperature, as one of the effective environmental stimuli in many aspects of species life and ecosystems, can affect amphibians in many ways. Knowing and predicting temperature change and its possible effects on the habitat suitability and movements of amphibians have led many researchers to use climate change scenarios and species distribution models (SDMs). One of the important remote-sensing products that received less attention of conservation biologists is the land surface temperature (LST). Due to the small difference between LST and air temperature, this component can be used to investigate and monitor the daily and seasonal changes of habitats. This study aims to investigate the seasonal trend of LST in the habitat suitability and connectivity of the critically endangered newt (Neurergus derjugini) in its small distribution range, using the MODIS LST time series (2003 to 2021) and with the help of SDMs, Mann–Kendall (MK) and Pettitt non-parametric tests. Results In the last decade, the increasing trend of LST versus its decreasing trends is obvious. Based on MK and Pettitt tests, in the winter and spring, with the decrease in latitude of 35.45° and increase in longitude of 46.14°, the core populations which are located in the southeast have experienced an increase in temperature. Considering the period time of breeding and overwintering, the continuity of winter and spring can be effective on the survival of adult newts as well as larvae in the microclimate. Linkages with the highest current flow between core populations in the winter and summer are the most likely to be vulnerable. At the level of habitat, the increase in LST is proportional to the trend of thermal landscape changes, and all seasons have had an increase in LST, but in winter and summer, the largest area of the habitat has been involved. By continuing the current trend, many high-altitude southern habitats in Iran will be endangered, and the species will be at risk of local extinction. Conclusion The increasing trend of temperature in all seasons such as winter will affect many adaptations of the species and these effects are mostly evident in the southern parts of its distribution range therefore, captive breeding and reintroduction are recommended for the populations of these areas.

Abstract Background Ponerine ants are almost exclusively predatory and comprise many of the largest known ant species. Within this clade, the genus Neoponera is among the most conspicuous Neotropical predators. We describe the first fossil member of this lineage: a worker preserved in Miocene-age Dominican amber from Hispaniola. Results Neoponera vejestoria sp. nov. demonstrates a clear case of local extinction—there are no known extant Neoponera species in the Greater Antilles. The species is attributable to an extant and well-defined species group in the genus, which suggests the group is older than previously estimated. Through CT scan reconstruction and linear morphometrics, we reconstruct the morphospace of extant and fossil ants to evaluate the history and evolution of predatory taxa in this island system. Conclusions The fossil attests to a shift in insular ecological community structure since the Miocene. The largest predatory taxa have undergone extinction on the island, but their extant relatives persist throughout the Neotropics. Neoponera vejestoria sp. nov. is larger than all other predatory ant workers known from Hispaniola, extant or extinct. Our results empirically demonstrate the loss of a functional niche associated with body size, which is a trait long hypothesized to be related to extinction risk.

Gradual ocean warming combined with stronger marine heatwaves (MHWs) can reduce abundances of foundation species that control community structures, biodiversity, and ecosystem functioning. However, few studies have documented long‐term succession trajectories following the more extreme events that cause localized extinctions of foundation species. Here, we documented long‐term successional changes to marine benthic communities in Pile Bay, New Zealand, following the Tasman 2017/18 MHW, which caused localized extinctions of dominant southern bull kelp (Durvillaea sp.). Six years on, multiscale annual and seasonal surveys show no sign of Durvillaea recolonization. Instead, the invasive annual kelp (Undaria pinnatifida), rapidly colonized areas previously dominated by Durvillaea, followed by large changes to the understory community, as Durvillaea holdfasts and encrusting coralline algae were replaced by coralline turf. Between 3 and 6 years after the total loss of Durvillaea, smaller native fucoids colonized in high densities. Although Undaria initially colonized plots throughout Durvillaea's tidal range, later in the succession Undaria only retained dominance in the lower intertidal zone and only in spring. Ultimately, the tidal zone was slowly replaced by alternative foundation species, composed of different canopy‐forming brown seaweeds that dominated different intertidal elevations, resulting in a net increase in canopy and understory diversity. This study is a rare example of long‐term effects following an extreme MHW that caused extinctions of a locally dominant canopy‐former, but these events and their associated dramatic changes to community structures and biodiversity are expected to become increasingly common as MHWs continue to increase in strength, frequency, and duration. [ABSTRACT FROM AUTHOR]

This paper focuses on the reaction zone and soot emission characteristics of swirl spray flames of iso-pentanol and blends. OH planar laser induced fluorescence (PLIF) measurements were used to study the lift-off and local extinction features. Soot emission was investigated using the planar time-resolved two-colour laser induced incandescence (2C-LII) diagnostic technique. Fuels used in this study were n-heptane, iso-pentanol, ethanol and blends of n-heptane/iso-pentanol and n-heptane/ethanol. Different operating conditions were tested and categorized into three flame types including stable, near blow-off, and far away from blow-off. A clear double flame sheet structure appeared in most flames, referred to as the inner and outer regions in this study. Also, all flames other than pure iso-pentanol displayed an open-up spray in a cone-like "V" shape. Results of stable and near blow-off conditions showed that the addition of iso-pentanol to an n-heptane flame caused the flame to become more attached to the bluff-body. In stable flames, the addition of iso-pentanol to n-heptane increased the occurrence of local extinctions. Whereas the addition of ethanol to n-heptane decreased occurrences of local extinction. Across near blow-off conditions, the impact on lift-off height caused by the addition of ethanol to n-heptane was less than that of the addition of iso-pentanol to n-heptane. In the far from blow-off conditions, less local extinction in pure iso-pentanol was found compared to the n-heptane/iso-pentanol mixture. Soot volume fraction of the iso-pentanol flame was less than the n-heptane flame, and the addition of iso-pentanol to the n-heptane flame reduced the soot volume fractions to a lower level than in the pure n-heptane flame. [ABSTRACT FROM AUTHOR]

Savanna plant communities are highly diverse, characterized by an open-canopy structure with rich herbaceous diversity, and maintained by frequent low-intensity fire and grazing. Due to habitat loss and fragmentation, savannas are globally threatened, with less than 1% of former oak savanna land cover found in the Midwestern United States remaining. In remnant oak savannas, loss of fire and grazing has led to woody encroachment and canopy closure over the past century with cascading consequences for the taxonomic composition. Whether these taxonomic changes can be broadly predicted using species functional traits (morpho-physio-phenological characteristics that impact the fitness of a species) is a key question. We ask whether the impacts of woody encroachment on herbaceous species can be predicted from species' abilities to persist (avoid extinction) and disperse (colonize new areas). Specifically, we pair persistence traits (e.g., clonality, belowground storage) and dispersal traits (e.g., seed mass, dispersal mode, flowering height) with a rare 60-year dataset from oak savannas in Wisconsin, USA to understand how the representation of these traits has changed in the herbaceous community over time. Over 60 years, change in species composition was explained both by dispersal abilities and persistence traits; small-seeded species reliant on unassisted dispersal and moderately clonal species experienced the greatest losses. These changes in functional composition are likely due to increased woody encroachment, which may impede propagule production and movement. Restoration efforts need to prioritize species that are dispersal limited and those that create fine fuels, which aid the persistence of fire-maintained open habitat savannas. [ABSTRACT FROM AUTHOR]

Background: Temperature, as one of the effective environmental stimuli in many aspects of species life and ecosystems, can affect amphibians in many ways. Knowing and predicting temperature change and its possible effects on the habitat suitability and movements of amphibians have led many researchers to use climate change scenarios and species distribution models (SDMs). One of the important remote-sensing products that received less attention of conservation biologists is the land surface temperature (LST). Due to the small difference between LST and air temperature, this component can be used to investigate and monitor the daily and seasonal changes of habitats. This study aims to investigate the seasonal trend of LST in the habitat suitability and connectivity of the critically endangered newt (Neurergus derjugini) in its small distribution range, using the MODIS LST time series (2003 to 2021) and with the help of SDMs, Mann–Kendall (MK) and Pettitt non-parametric tests. Results: In the last decade, the increasing trend of LST versus its decreasing trends is obvious. Based on MK and Pettitt tests, in the winter and spring, with the decrease in latitude of 35.45° and increase in longitude of 46.14°, the core populations which are located in the southeast have experienced an increase in temperature. Considering the period time of breeding and overwintering, the continuity of winter and spring can be effective on the survival of adult newts as well as larvae in the microclimate. Linkages with the highest current flow between core populations in the winter and summer are the most likely to be vulnerable. At the level of habitat, the increase in LST is proportional to the trend of thermal landscape changes, and all seasons have had an increase in LST, but in winter and summer, the largest area of the habitat has been involved. By continuing the current trend, many high-altitude southern habitats in Iran will be endangered, and the species will be at risk of local extinction. Conclusion: The increasing trend of temperature in all seasons such as winter will affect many adaptations of the species and these effects are mostly evident in the southern parts of its distribution range therefore, captive breeding and reintroduction are recommended for the populations of these areas. [ABSTRACT FROM AUTHOR]

Background: Ponerine ants are almost exclusively predatory and comprise many of the largest known ant species. Within this clade, the genus Neoponera is among the most conspicuous Neotropical predators. We describe the first fossil member of this lineage: a worker preserved in Miocene-age Dominican amber from Hispaniola. Results: Neoponera vejestoria sp. nov. demonstrates a clear case of local extinction—there are no known extant Neoponera species in the Greater Antilles. The species is attributable to an extant and well-defined species group in the genus, which suggests the group is older than previously estimated. Through CT scan reconstruction and linear morphometrics, we reconstruct the morphospace of extant and fossil ants to evaluate the history and evolution of predatory taxa in this island system. Conclusions: The fossil attests to a shift in insular ecological community structure since the Miocene. The largest predatory taxa have undergone extinction on the island, but their extant relatives persist throughout the Neotropics. Neoponera vejestoria sp. nov. is larger than all other predatory ant workers known from Hispaniola, extant or extinct. Our results empirically demonstrate the loss of a functional niche associated with body size, which is a trait long hypothesized to be related to extinction risk. [ABSTRACT FROM AUTHOR]

Small patches of habitat for indigenous species that remain in developed landscapes are predicted to lose species over time as extinction debts are paid off and to become transformed by spillover from intensive land uses. In December 2020 we searched for plants of three inland South Island-endemic species of Lepidium (Brassicaceae; L. kirkii, L. sisymbrioides, and L. solandri) at previously known locations in Central Otago, the Waitaki Valley, the Mackenzie Basin, and Kura Tāwhiti (Castle Hill, North Canterbury). We recorded whether Lepidium populations remained and identified the vascular plant flora of each location. Lepidium kirkii was found at six of 14 locations where formerly known and at one new location, but numbered over 50 individuals at only one of these locations. Lepidium sisymbrioides was found at five of six locations visited, but we found fewer than four individuals at three of these locations. L. solandri was found at five of 12 formerly known locations in Central Otago (but numbered over 50 individuals at only one), at five of five formerly known locations on public land in the Mackenzie Basin, and at the one known location at Kura Tāwhiti. Exotic vascular plant species outnumbered native species at all but one Lepidium location in Central Otago and at Kura Tāwhiti, but not in the Mackenzie Basin, where there had been the least habitat loss and land-use intensification. Our results are consistent with theoretical predictions of more local plant extinctions at Lepidium locations, and greater transformation of their habitats, in landscapes dominated by intensive land uses and non-indigenous vegetation. We conclude that intensive ex situ and in situ management is now needed to avoid global extinctions of L. kirkii and L. sisymbrioides, and local extinctions of L. solandri at remaining Central Otago locations and at Kura Tāwhiti. We do not know whether landscape-scale processes still provide for the persistence of L. solandri and other dryland species in the Mackenzie Basin or whether intensive land use has already crossed ecological thresholds. [ABSTRACT FROM AUTHOR]

Local populations of marine benthic macro‐invertebrates with planktonic larvae are believed to be in source–sink relationships via larval dispersal in a regional population complex. Practically, such a region is definable only after connectivity of constituent local populations is explored. Numerical simulations abound for hydrodynamic connectivity by larvae between local/regional populations. Empirical studies have scarcely integrated inter‐local connectivity and intra‐local population dynamics into demographic connectivity analysis. I review the current research and indicate fundamental and technical problems to demonstrate that some source–sink systems in intertidal shores, which are most accessible among benthic habitats, are a good model. The challenge in benthic source–sink research comes from that existent local populations may not be self‐sustaining because of low larval self‐seeding rates and/or low benthos' survival rates and yet can persist as latent sinks. They may receive larvae leaking from sources at good‐quality habitat patches with stationary larval retention areas for self‐recruitment. On an intertidal sandflat in an estuary–coastal ocean region, Kyushu, Japan during 1979–2019, the population of a trochid gastropod with 3‐ to 9‐day larval duration became extinct and recovered. The extinction was caused by sediment destabilization by a callianassid shrimp population which increased in the early 1980s. The gastropod recovery was owing to the shrimp decline by stingray predation and the transport of larvae from some self‐sustainable populations with lower shrimp densities 30 km away. It was estimated that the gastropod population before the shrimp proliferation on that sandflat might be a latent sink requiring allochthonous larval subsidy due to epi‐benthic predation on juveniles. [ABSTRACT FROM AUTHOR]

To date, only two Cherax species have been reported to occur in Italy, i.e., C. destructor Clark, 1936 and C. quadricarinatus (von Martens, 1868), both in the wild and in aquaculture farms. Therefore, we aimed to update their current status and distribution in Italian mainland and Sicily. In addition, we investigated the origin of their known populations, and their possible routes of invasion. In order to genetically characterize the Cherax populations occurring in Italian inland waters and aquaculture facilities, the barcode region of the mtDNA gene cytochrome oxidase subunit I was sequenced in the available specimens originating from an aquaculture facility and a museum collection. The sampling campaigns conducted in 2021 did not lead to the collection of any Cherax individuals in the sites where the species was formerly reported to occur. The recent failures to detect Cherax spp. from Italian inland waters might be due to the inability of the species to cope with the Italian climate, which is likely for C. quadricarinatus but less so for C. destructor, to the possible impact of the alien red swamp crayfish Procambarus clarkii (as well as its indirect impact i.e., the spread of the crayfish plague for which yabby is susceptible), which occurs in both the sites where C. destructor was reported in Italy, or to the burrowing habits of the species, which might lead to overlook their presence when present at low densities. In the light of the well-known impact of invasive crayfish and considering the scant knowledge about the current distribution and status of Cherax species in Italy, a regular monitoring of their possible presence is recommended. [ABSTRACT FROM AUTHOR]

The Sydney partially premixed flame FJ200-5GP-Lr75-103 case with the local extinction phenomenon is studied by large eddy simulation (LES) coupled with the dynamic k equation sub-grid scale model and the dynamic thickened flame (DTF) combustion model. To account for the influence of non-uniform equivalence ratio on the laminar flame speed and thickness, two fitting functions are introduced in the DTF model to automatically adjust these two parameters in the wrinkling functions, according to the local value of mixture fraction in the flow field. The results show that the dynamic k equation model can predict the mixture fraction of the non-uniform premixed gas in the flow field well. In the middle and downstream with more flame extinction, the temperature, the species profiles, and the scatter plot of temperature versus mixture fraction calculated by LES agree well with the experiment data. This demonstrates that the improved DTF model can capture the local extinction phenomenon in partially premixed flame, but for the CO mass fraction, discrepancy between the LES results and experiment data is presented.

The land snail species Drymaeus virgulatus (Férussac, 1821) is recorded in St. Kitts in the form of 21 complete or fragmented shells collected on the island in November 2019. The complete shells were collected on the backshores of South Frigate Bay and Majors Bay, while shell fragments come from naturally exposed sections of the North Frigate Bay sand ridge, where they date to the pre-Columbian period. This evidence therefore attests to the past presence of this species on the island. The absence of this taxon from recent malacological surveys points to it having been extirpated from St. Kitts. Apertural fragments of a large bulimulidae collected in the caves of Tintamarre Island, near St. Martin, are also related to this taxon, adding a second West Indian island from which this species apparently disappeared in recent centuries.

Abstract Species losses and local extinctions are alarmingly common, frequently as a consequence of habitat destruction. Nevertheless, many intact habitats also face species losses, most likely due to environmental changes. However, the exact drivers, and why they affect some species more than others in apparently intact habitats, are still poorly understood. Addressing these questions requires data on changes in occurrence frequency of many species, and comparisons of the responses of those species to experimental manipulations of the environment. Here, we use historic (1911) and contemporary (2017) data on the presence–absence of 42 plant species in 14 seemingly intact Molinia meadows around Lower Lake Constance to quantify changes in occurrence frequency. Then, we performed a common‐garden experiment to test whether occurrence frequencies in 1911 and changes therein by 2017 could be explained by responses of the 42 species to nutrient addition and competition with the acquisitive generalist grass Poa pratensis. Within the 14 still intact Molinia meadows, 36 of the 42 species had declined since 1911. As expected, nutrient addition generally led to increased biomass production of the 42 target species, and competition with P. pratensis had a negative effect. The latter was stronger at high nutrient availability. The more frequent species were in 1911 and the more they declined in frequency between 1911 and 2017, the less above‐ground biomass they produced in our experiment. Competition with P. pratensis magnified this effect. Our work highlights that environmental change can contribute to local extinction of species in otherwise intact habitat remnants. Specifically, we showed that increased nutrient availability negatively affected formerly widespread Molinia‐meadow species in competition with P. pratensis. Our study thus identified a likely mechanism for the decline in occurrence frequency of species in the remaining Molinia meadows.

Screwbean Mesquite (Stromocarpa pubescens), an ecologically and culturally important riparian tree in the North American desert southwest, has experienced a precipitous decline over the past two decades with several documented die-off events resulting in local extinctions. The decline has received little attention, however. To better understand causes of the die-offs, we surveyed 29 populations across the species' range for patterns of decline and found that 16 populations contained trees exhibiting identical disease symptoms (gummosis, cankers). Diseased populations were clustered in the western portion of the range where local extinction has occurred. The fungus Neoscytalidium dimidiatum was isolated and identified molecularly in 100 % of diseased tissue samples taken from 24 trees at six sites. Pathogenicity tests were performed by inoculating 10 naive trees with isolated N. dimidiatum. Inoculations produced identical disease symptoms and the fungus was reisolated from all infections. Branch canker symptoms were present at all but two sites experiencing active decline and sites with branch canker had experienced roughly 30 % more recent mortality than disease-free sites. More intensive monitoring of 244 trees at six sites throughout 2022 revealed that trees with branch canker symptoms showed more than four times new dieback (i.e. tissue death) through the growing season than non-diseased trees and ended the 2022 growing season with 29 % more dieback than non-diseased trees. Neoscytalidium dimidiatum is endemic to the region but this is the first documented example of widespread and aggressive infection by the species across the range of a native tree species. [ABSTRACT FROM AUTHOR]

To verify the effectiveness of continuous habitat-level monitoring survey in identifying species of conservation concern on a local scale, it has been conducted a continuous monitoring survey over five years for butterfly communities in a local area at the foot of Mount Fuji, a special zone of Fuji-Hakone-Izu National Park in Japan. The results showed that the butterfly community was divided roughly into two species groups (i.e. yearly constant appearing species and yearly sporadic appearing species). The former was characterized by relatively high density with more variability. While, the latter showed the reverse characteristics, suggesting that they are the species more prone to extinction in the area. Among the yearly sporadic appearing species, Red Listed species and the species with characteristics vulnerable to extinction (i.e. uni-voltines and/or larval food specialists) could be thought of particularly as species of conservation concern with high priority and urgency on a local scale. This is evidenced by the fact that, in the continuous monitoring survey conducted previously in nearly the same area, the Red Listed species thought to belong to yearly constant appearing species were all alive in the present survey, but the two Red Listed species thought to belong to yearly sporadic appearing species were already extinct between the both surveys. Consequently, results confirmed the effectiveness of continuous habitat-level monitoring survey in identifying species of conservation concern on a local scale. Thus, it has been recommended continuous monitoring surveys at a local (habitat) level in order to prevent the rapid progression of extinction of local populations. [ABSTRACT FROM AUTHOR]

Invasive snakes represent a serious threat to island biodiversity, being responsible for far-reaching impacts that are noticeably understudied, particularly regarding native reptiles. We analysed the impact of the invasive California kingsnake, Lampropeltis californiae--recently introduced in the Canary Islands--on the abundance of all endemic herpetofauna of the island of Gran Canaria. We quantified the density in invaded and uninvaded sites for the Gran Canaria giant lizard, Gallotia stehlini, the Gran Canaria skink, Chalcides sexlineatus, and Boettger's wall gecko, Tarentola boettgeri. We used spatially explicit capture-recapture and distance-sampling methods for G. stehlini and active searches under rocks for the abundance of the other two reptiles. The abundance of all species was lower in invaded sites, with a reduction in the number of individuals greater than 90% for G. stehlini, greater than 80% for C. sexlineatus and greater than 50% for T. boettgeri in invaded sites. Our results illustrate the severe impact of L. californiae on the endemic herpetofauna of Gran Canaria and highlight the need for strengthened measures to manage this invasion. We also provide further evidence of the negative consequences of invasive snakes on island reptiles and emphasize the need for further research on this matter on islands worldwide. [ABSTRACT FROM AUTHOR]

The Great Barrier Reef is a diverse ecosystem of outstanding universal value that is under an increasing level of cumulative threat. The status of biodiversity, particularly that of habitat-forming taxa is not known, and more data are needed to evaluate this. Here, we summarize scleractinian coral distribution records in the Lizard Island reef system from 1976 to 2020 to explore the persistence of the local species pool across 44 years. By undertaking replicated spatio-temporal biodiversity surveys (2011, 2015, 2017, 2020) at 14 sites and compiling published species records from this location (1976–2020), we determine that 368 species of hermatypic scleractinian coral have been recorded from Lizard Island and/or nearby reefs over the last 44 years. Two hundred and eighty-four of those species (77.2%) have ongoing records across this time period indicating temporal persistence at the local scale. However, 28 species (7.6%) that were reliably recorded prior to 2011 have not been recorded in subsequent years and may be at risk of local extinction. A further 31 species (8.4%) may be at risk of local range reduction as they have not been recorded at Lizard Island and/or at nearby reefs since 2015. The remaining 25 species (6.8%) were deemed taxonomically unreliable records. Fifty-three species are recorded from Lizard Island for the first time in the 2011–2020 surveys, however, further integrated taxonomic research is required to verify some of these records. At a site level, species diversity has been in a state of flux over the 2011–2020 period with significant declines in species richness notable from 2011 to 2017, and significant recovery from 2017 to 2020. Overall, this dataset indicates local extinction or local range reduction is a tangible risk for 59 species (16% of the species pool) in the Lizard Island region. Additional targeted searching for these species along with temporal monitoring of species abundance and size structure is warranted to better understand the status of coral biodiversity at this globally significant location. [ABSTRACT FROM AUTHOR]

The conservation of species in human-modified landscapes such as agroforestry systems is central to global conservation and sustainable use of biodiversity. Understanding the dynamics of key species in agroforestry systems is important for predicting the sustainability of these systems. However, the population dynamics of agroforestry tree species are often unknown, and planning for the management of these systems is generally grounded on the untested assumption that the tree component will persist over time. Here, we developed an integral projection model for Vitellaria paradoxa (Sapotaceae), one of the most important tree species in traditional agroforestry systems in West Africa. We collected three years of demographic data from six populations around the Pendjari Biosphere Reserve in Benin to parameterize this model and test the effect of populations' proximity to natural habitats on the short- and long-term dynamics of V. paradoxa. However, models suggest that V. paradoxa populations are projected to decline at a yearly rate of 10.6% and within the next two decades, this tree will be locally extinct. We found a significant positive effect of proximity to natural forest on the long-term population dynamics, but this failed to save populations from decline. Elasticity analyses show that the best strategy to slow down such a decline includes preserving the largest mature trees. However, traditional management systems that protect shea butter trees in agroforestry systems are now replaced by increasing tree cutting to produce firewood, charcoal and carve out mortars and pestles. The decline of this key agroforestry tree poses a broader threat to long-term sustainability of agroforestry systems. • The population dynamics of key agroforestry tree is critical to the long-term persistence of agroforests. • Proximity to forests increased shea butter tree long-term population dynamics but not enough to limit decline. • Fast decline of shea butter tree population poses serious threat to local extinction. • Life stages that are important for the persistence of shea butter tree are now cut by local people. • Decline of shea butter tree poses a broader threat to the sustainability of agroforestry systems and food security. [ABSTRACT FROM AUTHOR]

Species losses and local extinctions are alarmingly common, frequently as a consequence of habitat destruction. Nevertheless, many intact habitats also face species losses, most likely due to environmental changes. However, the exact drivers, and why they affect some species more than others in apparently intact habitats, are still poorly understood. Addressing these questions requires data on changes in occurrence frequency of many species, and comparisons of the responses of those species to experimental manipulations of the environment. Here, we use historic (1911) and contemporary (2017) data on the presence–absence of 42 plant species in 14 seemingly intact Molinia meadows around Lower Lake Constance to quantify changes in occurrence frequency. Then, we performed a common‐garden experiment to test whether occurrence frequencies in 1911 and changes therein by 2017 could be explained by responses of the 42 species to nutrient addition and competition with the acquisitive generalist grass Poa pratensis. Within the 14 still intact Molinia meadows, 36 of the 42 species had declined since 1911. As expected, nutrient addition generally led to increased biomass production of the 42 target species, and competition with P. pratensis had a negative effect. The latter was stronger at high nutrient availability. The more frequent species were in 1911 and the more they declined in frequency between 1911 and 2017, the less above‐ground biomass they produced in our experiment. Competition with P. pratensis magnified this effect. Our work highlights that environmental change can contribute to local extinction of species in otherwise intact habitat remnants. Specifically, we showed that increased nutrient availability negatively affected formerly widespread Molinia‐meadow species in competition with P. pratensis. Our study thus identified a likely mechanism for the decline in occurrence frequency of species in the remaining Molinia meadows. [ABSTRACT FROM AUTHOR]

Self-incompatible, non-clonal plant species are especially dependent on the activity of flower visitors for seed production. Therefore, populations of these plants are vulnerable to a reduced flower visitation rates, but also to increased isolation by extinction of local populations. To study how local populations of Centaurea scabiosa, a self-incompatible, bee-pollinated herb species changed over time in the region of Bonn, we collected historical population records in the area and investigated their current status. We found that more than half of the subpopulations mentioned in the literature between 1950 and 2012 (38 of 65) have since disappeared. Small populations were most vulnerable, whereas medium to large populations increased in size. In a second step, we studied visitation frequencies and achene production and weight across 14 extant populations. We found that both flower visitation frequency and achene production were positively related to population size. Achene weight was neither related to the frequency of flower visitors nor to achene production. These results clearly indicate that reduced pollen transfer and lower pollination rates may contribute to local extinction in small populations of Centaurea scabiosa. Overall our results call for an intensified monitoring of the populations of self-incompatible plant species. [ABSTRACT FROM AUTHOR]

The turbulent counter-flow flame (TCF) has proven to be a useful benchmark to study turbulence-chemistry interactions, however, the widely observed bulk flow fluctuations and their influence on the flame stability remain unclear. In the present work, premixed TCFs are studied numerically using a Large Eddy Simulation (LES) method. A transported probability density function (pdf) approach is adopted to simulate the sub-grid scale (sgs) turbulence-chemistry interactions. A solution to the joint sgs-pdf evolution equation for each of the relative scalars is obtained by the stochastic fields method. The chemistry is represented using a simplified chemical reaction mechanism containing 15 reaction steps and 19 species. This work compares results with two meshing strategies, with the domain inside nozzles included and excluded respectively. A conditional statistical approach is applied to filter out the large scale motions of the flame. With the use of digital turbulence, the velocity field in the flame region is well reproduced. The processes of local extinction and re-ignition are successfully captured and analysed together with the strain rate field, and local extinctions are found correlated to the turbulent structures in the reactant stream. The predicted probability of localised extinction is in good agreement with the measurements, and the influence of flame stoichiometry are also successfully reproduced. Overall, the current results serve to demonstrate the capability of the LES-pdf method in the study of the premixed opposed jet turbulent flames. [ABSTRACT FROM AUTHOR]

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The biology and seasonal phenology of Aacanthocnema dobsoni (Froggatt) were studied at a single site in Victoria over a 2 year period between 2013 and 2015. This species is monophagous on the dioecious host, Allocasuarina verticillata (Lam.) L. Johnson (Casuarinaceae). Laboratory studies found that females attained reproductive maturity 24 h post‐eclosion, lived for 28.6 ± 2.8 (mean ± SE) days and laid 182 ± 23 (mean ± SE) eggs each. Egg development was most rapid at 26 °C, ceased below 7 °C and above 33 °C; hatching required 188 degree‐days. Nymphs could not be reared to adulthood on excised host branchlets maintained under controlled conditions, so no developmental data were obtained for these life stages. Seasonal phenology data revealed pronounced developmental asynchrony, i.e. with overlapping generations and multiple life stages occurring simultaneously. Three generations per year were observed, and there was no evidence of either developmental (egg and nymph) or reproductive diapause. A 4 day heat wave in January 2014 drastically reduced psyllid abundance at the study site and the size of the adults that eclosed from the surviving nymphs. These smaller adults produced substrate‐borne vibrational signals with altered characteristics, i.e. with significantly higher intensities and power. The altered signals might have facilitated communication over longer distances and increased mate finding opportunities when populations were low. The abundance of adults had recovered to preheat wave levels 3 months after the heat wave. High fecundity, multivoltinism and effective mate attraction signalling are life history traits that may mitigate against localised extinction of populations as a consequence of extreme weather events. [ABSTRACT FROM AUTHOR]

Lichens, as well as other organisms, should be considered important biodiversity components for the establishment of priorities in conservation biology. In this study, we report six new recent localities of the highly endangered, epiphytic macrolichen Pseudocyphellaria aurata in Spain: two in Navarra and four in A Coruña. Previous Spanish reports based on literature and herbarium specimens suggest a reduction of the distribution area of P. aurata and local extinction. Pseudocyphellaria aurata is known to be extinct in six localities, where it has not been observed since the middle of the 19th century (Cádiz, Pontevedra, Málaga). Four records reported for central Spain (Zaragoza, Salamanca, Teruel) are considered unplausible. The newly discovered populations are located in well-preserved patches of atlantic deciduous forest with strong oceanic influence, whose long-term ecological stability seems evident because of the presence of ancient trees. Nevertheless, these populations are small, fragmentary, and are threatened by habitat degradation, forestry and maybe fungal pathogens. Two populations, Intzola and Beba (Navarra and A Coruña, respectively), account for 75.7% of thalli. The localities with the highest number of trees colonized by P. aurata are Santa Leocadia and Beba in A Coruña. We reassessed the conservation status of this species concluding that conservation initiatives must be implemented to avoid its extinction in mainland Spain.

Forests are the principal terrestrial ecosystem for protected and endangered large carnivores, providing the main habitat for species maintenance and survival. Changes in forest cover influence species distribution. The aim was (1) to test hypotheses on the natural environmental (abiotic) and biological (biotic) factors and human disturbances that determine the colonization and local extinction of three large carnivore species in relation to forest cover, (2) to infer the biotic interactions between these three large carnivore species occupying the same forested areas in Albania. Colonization is estimated to be positively affected by forest cover for brown bear, Balkan lynx and grey wolf. Brown bear and grey wolf tend to compete for the same forested areas. Local extinction increased with decreasing forest cover for brown bear and increased with decreasing mixed broadleaved forests for Balkan lynx. Anthropological variables (proximity to villages and to neighbourhood roads) increased local extinction for brown bear, grey wolf and Balkan lynx. Further studies are recommended for better understanding biotic interactions of large carnivore species in forest habitats in Albania and its neighbouring countries, which could contribute to conservation of large carnivore species on a large scale. [ABSTRACT FROM AUTHOR]

The anthropic effect associated with worldwide European settlements over the last 500 years has caused dramatic environmental changes, modified regional patterns of biodiversity, and often led to local or complete extinctions. The sigmodontine rodents of Bahía Samborombón (Humid Pampas, central-eastern Argentina) constitute a good case study: a late Holocene archaeological site allowed us to compare a pre-European settlement assemblage (12 species) with the extant one (nine species). We used linear morphometrics (16 cranial and ten mandibular measurements) to assess interspecific morphological variations of the masticatory apparatus in relation to dietary habits for each assemblage. Even though sigmodontines have a tendency towards omnivory, groups based on dietary preference only overlapped partially. Size was one of the main variables involved in niche segregation, and shape characteristics such as rostrum elongation or mandible robustness were linked to different diets. We found that a combination of dietary preference and size was associated with extinctions. The main morphospace change between the two assemblages was related to the local extinction of the three greater insectivores and the smallest graminivore, located towards the center of the assemblage's morphospace. An insectivore was incorporated, involving no significant changes in the general morphospace. Graminivores and larvivores were not affected. Our study sheds light on the causes of local extinctions of small mammals at the Humid Pampas, a phenomenon that had never been studied from an ecomorphological approach. [ABSTRACT FROM AUTHOR]

Heterogeneity in quantity and quality of resources provided in the urban matrix may mitigate adverse effects of urbanization intensity on the structure of biotic communities. To assess this we quantified the spatial variation in butterfly richness and abundance along an impervious surface gradient using three measures of urban matrix quality: floral resource availability and origin (native vs. exotic plants), tree cover, and the occurrence of remnant habitat patches. Butterfly richness and abundance were surveyed in 100 cells (500 × 500 m), selected using a random‐stratified sampling design, across a continuous gradient of imperviousness in Melbourne, Australia. Sampling occurred twice during the butterfly flight season. Occurrence data were analyzed using generalized linear models at local and mesoscales. Despite high sampling completeness, we did not detect 75% of species from the regional species pool in the urban area, suggesting that urbanization has caused a large proportion of the region's butterflies to become absent or extremely rare within Melbourne's metro‐area. Those species that do remain are largely very generalist in their choice of larval host plants. Butterfly species richness and abundance declined with increasing impervious surface cover and, contrary to evidence for other taxa, there was no evidence that richness peaked at intermediate levels of urbanization. Declines in abundance appeared to be more noticeable when impervious surface cover exceeded 25%, while richness declined linearly with increasing impervious surface cover. We find evidence that the quality of the urban matrix (floral resources and remnant vegetation) influenced butterfly richness and abundance although the effects were small. Total butterfly abundance responded negatively to exotic floral abundance early in the sampling season and positively to total floral abundance later in the sampling season. Butterfly species richness increased with tree cover. Negative impacts of increased urbanization intensity on butterfly species richness and abundance may be mitigated to some extent by improving the quality of the urban matrix by enhancing tree cover and the provision of floral resources, with some evidence that native plants are more effective. [ABSTRACT FROM AUTHOR]