Hasil untuk "Natural history (General)"

J. Schumpeter

I. Zagorodniuk, O. Nikolaichuk

An analysis of the southern distribution limit of the lynx in the Middle Dnipro region, in the area from Zhytomyr to Nizhyn, i.e. in the Ukrainian part of Polissia known as Prydniprovske Polissia, is presented. This area is a zone of natural growth in abundance and expansion of the species' range and represents an important model for analysing the potential of indicator species in the Polissia natural zone to restore their former presence and role in the faunal communities of the Polissia. In total, the southern range of the lynx in the region is described in 17 locations, most of which are the southernmost for the entire Polissia segment of the lynx's geographical range within Ukraine. All locations where the species has been recorded, delineating the southern edge of its range, are in areas where the lynx had not been known to occur previously. The analysis includes only data on findings of the species in the last 25 years, and all such marginal findings are essentially new, dating no earlier than 2010–2020. This is a result of the growing lynx population in the Polissia and shows how the species is spreading in the region. Factors limiting and supporting population growth and species expansion into new areas are considered. The three key supporting factors are the development of the food base, a decrease in anthropogenic pressure, and the presence of natural eco-corridors with powerful natural cores covering an area of 1–2 thousand hectares. An important factor in the population growth and dispersal of the lynx was the high (restored) abundance of species that are potential prey for the lynx, primarily roe deer and wild boar. One of the triggers for the restoration of the geographical ranges of large mammals in the Polissia region, including the lynx, was the significant reduction of human impact on the natural complexes of Central Polissia, a substantial decrease in economic activity and the virtual cessation of hunting (and, to a certain extent, poaching), which was essentially facilitated by the existence of the Chernobyl Exclusion Zone, the war in Ukraine, and the resulting increased control of frontier areas, as well as significant restrictions on any human activity in forested areas. If the current minimum levels of anthropogenic pressure on the region's natural complexes are maintained, the species may advance southward by another 50–70 km.

Hans-Dieter Sues, Rainer R. Schoch

Triassic strata in the portion of the Central European Basin (CEB) that cover parts of conterminous Germany have yielded a long if discontinuous record of continental tetrapods spanning this period. The classic Germanic Triassic succession comprises two mostly terrestrial units, the Buntsandstein and Keuper groups, separated by the predominantly marine Muschelkalk Group (Fig. 1). Thus, it is not possible to trace lineages of terrestrial tetrapods continuously through the entire Triassic Period. Skeletal remains of Early and early Middle Triassic (Induan-early Anisian) reptiles are rare in the Buntsandstein Group and mainly known from the Upper Buntsandstein Subgroup. The Middle Triassic (Anisian-Ladinian) marine carbonates of the Muschelkalk Group have yielded a considerable diversity of sauropterygians together with a few ichthyopterygians, a possible thalattosaurian, and the long-necked tanysaurian archosauromorph Tanystropheus. The late Middle and Late Triassic continental deposits of the Keuper Group preserve a substantial record of the rapidly diversifying crocodile-line and bird-line archosaurs together with stem-forms of some tetrapod crown clades such as turtles and lepidosaurs. In recent years, many new discoveries have greatly increased our knowledge of reptiles from the Keuper Group, especially from the Ladinian-age Lower Keuper Subgroup. The latest Triassic (Rhaetian) is represented by bonebeds containing bones and teeth of marine and continental vertebrates including reptiles that were deposited before the Early Jurassic transgression completely inundated the CEB. This paper provides a detailed overview of the currently known taxa of reptiles from the Triassic of conterminous Germany and explores some more general aspects of this fossil record.

Aura M. Alonso‐Rodríguez, Pablo E. Gutiérrez‐Fonseca, Scott E. Miller et al.

ABSTRACT Extreme climatic events are expected to increase in frequency and severity under climate change, with lasting consequences for ecological communities worldwide. Global insect declines have raised concerns for biodiversity conservation and ecosystem stability, as shifts in insect communities can trigger cascading effects across trophic levels. Yet insect responses to large‐scale disturbances remain poorly understood, particularly in tropical forests where long‐term datasets are scarce and taxonomic knowledge is limited. We examined the response trajectories and stability of moth communities in two forest types in Puerto Rico following the September 2017 hurricanes Irma and María. Using monthly surveys conducted 5 months before and 6 months after the storms, followed by annual surveys over 5 years, we tracked changes in moth abundance, richness, and composition. We also evaluated ecological stability across multiple dimensions (i.e., resistance, resilience, recovery, and temporal stability) for the entire community and separately for Crambidae, Erebidae, and Geometridae. Despite initial declines, abundance and richness surpassed baseline levels within the first year, especially in old‐growth tabonuco stands, which may have provided more stable microhabitats and resources than palm stands. Resistance varied by family, with grass‐feeding crambids increasing in abundance and arboreal‐feeding geometrids experiencing the greatest species loss. Abundance and richness stabilized within 2 years, likely influenced by trophic interactions that regulated insect outbreaks. Species composition continued to shift over time, reflecting ongoing reassembly, while compositional and functional stability metrics suggested recovery within 5 years. This highlights both the resilience of the moth community and the dynamic nature of post‐disturbance reassembly. Our findings underscore the value of multi‐year, post‐disturbance datasets for uncovering recovery pathways and enhancing our understanding of ecological stability. As extreme events intensify across biomes, insights into resilience dynamics will be critical for sustaining insect biodiversity and the ecological functions they provide.

Guillermo Folguera

A partir del año 2015, aumentó considerablemente la demanda y el precio del litio debido a su rol central en la producción de baterías. América Latina posee alrededor del 60% de las reservas de litio a nivel mundial. Los yacimientos se ubican, principalmente, en la puna que comparten Chile, Bolivia, Perú y Argentina. La posibilidad de extraer litio de los salares es promocionada por gobiernos y empresas como una oportunidad irrenunciable. A su vez, la minería de litio es presentada como clave para la solución a la crisis climática, ante la necesidad de disminuir los gases de efecto invernadero y favorecer la transición energética. En oposición, la extracción de litio es considerada por las comunidades locales como perniciosa porque involucra la pérdida de grandes volúmenes de agua, en la medida en que el litio se encuentra disuelto en los salares y de que una gran cantidad de agua dulce es utilizada durante el proceso y por la contaminación química que genera. En este trabajo se abordará la construcción discursiva y argumentativa de la extracción de litio. La hipótesis general es que la extracción de litio se presenta como inevitable en tanto no hay otras alternativas posibles frente a la crisis climática, impidiendo su discusión en términos políticos.

Tianqi Huang, Peter J. Morin, Sara Ruane

In response to the surge of urbanization in the modern era, many organisms have undergone various changes, such as the shift of their morphological traits to face the challenges brought by this drastic environmental transformation. Rapid adaptive evolution in the morphology of urban-dwelling organisms has been documented in a broad array of taxa, such as lizards and birds, by comparing urban populations with their nonurban counterparts. However, relevant studies concerning more elusive and secretive organisms that also occur in both natural and urbanized habitats (e.g., snakes), are still lacking. Snakes lack appendages, which are often the trait of interest in other morphological studies, but factors such as head shape play a critical role in snakes, as it determines the prey size of these gape-limited predators. In this study, we apply both linear and geometric morphometric analyses to examine interpopulation morphological differences and sexual dimorphism in a small, semi-fossorial snake, Dekay’s brownsnake (Storeria dekayi). We focus on head shape in six different populations across the rural-urban gradient in New Jersey and New York, USA. We find evidence of increased morphological divergence and decreased sexual dimorphism in populations inhabiting more urbanized areas. Our study suggests the occurrence of an adaptive morphological shift in this common species in the urban environments, and lays the path for further investigation of urban adaptation in snakes and similar secretive species.

Issaad Kawther Ezzine, Houria Bouaziz-Yahiatene, Willy De Mattia et al.

Recent sampling efforts in northern Algeria and the investigation of some collection material has revealed the presence of taxa with conchological and genital morphological similarities to the “<i>Candidula</i>-like” group. A detailed investigation of the anatomy of the genitalia combined with the analysis of two mitochondrial and two nuclear markers of representatives of the known genera as well as two Algerian taxa has been conducted. The result confirms the affiliation of the latter in the “<i>Candidula</i>-like” complex. Comparative anatomical analysis led to the description of a new genus, <i>Kherattolactea</i> gen. nov., endemic to northern Algeria with <i>Xerophila keratae</i> Kobelt 1892 as the type species. The anatomical distinction corroborates the result of the molecular analysis that reveals apomorphic nucleotide substitution. Moreover, the result of the combined analysis provides the first confirmed record of the genus <i>Orexana</i> Chueca, Gómez-Moliner, Madeira & Pfenninger, 2018, in north Africa, represented by the species <i>Orexana lemoinei</i> (Kobelt, 1882) nov. comb. A new <i>Xerogyra</i> species, <i>Xerogyra hallgassi</i> nov. sp., from the Apennine Mountain has been described based on the combination of morphoanatomical and molecular traits. For the first time, the morphoanatomical description of the known <i>Xerogyra</i> species has been presented.

Maslim As-singkily, Maslim As-singkily, Maslim As-singkily et al.

Leatherback turtles (Dermochelys coriacea) are highly migratory and globally distributed, yet exhibit low overall genetic diversity. Currently, the species is divided into seven Regional Management Units (RMUs), and significant gaps remain in understanding genetic connectivity within the Indo-Pacific, particularly the Northeast Indian Ocean. Here, we investigate the genetic diversity and population structure of leatherback turtles sampled from five nesting sites in Sumatra, Indonesia. Using mitochondrial DNA (mtDNA) control region sequences from 57 individuals, we identified eight haplotypes, including one novel variant, with Sumatra exhibiting the highest haplotype (h = 0.786) and nucleotide diversity (π = 0.0040) among regional rookeries. There was a lack of significant stock structure based on our haplotype frequency data among rookeries in Sumatra (p&gt;0.05). Phylogenetic and haplotype network analyses revealed that Sumatra contains lineages from both Indian and West Pacific Ocean clades, suggesting its role as a genetic bridge between these populations. Our results on population genetic structure support the recognition of Sumatra as a distinct Management Unit (MU), separate from other Northeast Indian Ocean populations. Our findings highlight the need to refine existing RMU boundaries and prioritize conservation actions in Sumatra to preserve its unique genetic composition and enhance connectivity across the Indo-Pacific.

Enric Gomis, Enric Gomis, Enric Gomis et al.

Seagrass meadows provide important ecosystem services including carbon sequestration, coastal protection from erosion, and sustained biodiversity and fisheries thereby improving the wellbeing and livelihoods of coastal communities. The erosion of millenary deposits of intertwined roots and rhizomes of Posidonia results in the formation of three-dimensional structures named escarpments that constitute a biogenic reef habitat. However, the natural history of seagrass escarpments including their formation processes and their role as habitat for reef fauna and flora remains poorly understood. This research located and characterized Posidonia oceanica escarpments in Menorca (Balearic Islands) and compared structural complexity and fish assemblages among seagrass escarpments, seagrass meadows, rocky substrates and bare sand with emphasis on its role as habitat and shelter for typical rocky fish. Fish abundance and biomass were similar between seagrass escarpments and rocky substrates (P &gt; 0.05), but significantly lower in seagrass meadows (P &lt; 0.001). The large number of caves found along seagrass escarpments provide shelter to fish, including species only associated to rocky substrates. Seagrass meadows form a rather homogenous habitat within their canopy, but the presence of seagrass escarpments enhances habitat heterogeneity and structural complexity along with fish abundance and biomass at the seascape level. This study enhances understanding on the ecological importance of seagrass escarpments.

Kai Zhu, Kaida Xu, Wenbin Zhu

IntroductionPelagic cephalopods play a key role in the Chinese food supply. The market value of seafood frequently fluctuates based on its geographical origin and species, making it imperative to trace the origin and distinguish forms to guarantee food quality and accurate information.MethodsIn this study, we used biochemical tracers, including stable isotope analysis and fatty acid composition profiling, to trace the origin of purpleback flying squid (Sthenoteuthis oualaniensis) from the Indian Ocean and South China Sea. We measured the δ13C and δ15N values and fatty acid (FA) contents in samples from different forms of S. oualaniensis obtained from these two oceanic regions. We analyzed the feeding and nutritional differences among these populations and conducted discriminant analysis.Results and discussionSignificant regional and form differences were observed in both isotopic values and FA profiles in the muscle tissues of S. oualaniensis. Forms with larger sizes exhibited higher δ13C and δ15N values, potentially resulting from different feeding preferences and geographical environments. The discriminant analysis revealed that isotopic composition could effectively distinguish individuals from different oceanic regions, whereas FA composition was more effective in distinguishing different forms within the same oceanic region. The combination of isotopes and FAs could accurately discriminate S. oualaniensis of different forms and from different oceanic regions, achieving a discrimination accuracy of 100%. This study provides a reference for tracing the origin of pelagic cephalopods with complex form structures.

Eliza M. M. Mills, Sarah Piwetz, Dara N. Orbach

Anthropogenic activity in coastal areas can damage marine habitats and alter marine mammal behavior and habitat use. Understanding behavioral associations with diverse habitat features in industrialized coastal areas is crucial for marine mammal conservation management. A shore-based digital theodolite was used to assess the behavioral states and habitat use of common bottlenose dolphins (Tursiops truncatus) off Port Aransas, Texas across seasons. The relationship between behavioral states and environmental and geographical variables were analyzed. Behavioral hotspots were identified. Dolphins frequently foraged (46%), indicating the area is an important feeding ground. Dolphins also traveled (25%) and milled (22%), with less frequent occurrences of socializing (6%) and resting (1% of observations). Season, time of day, and distance to shoreline were significant predictors of foraging and traveling behavioral states. Dolphins engaged in all behavioral states closer to seawall shorelines than to mangroves and natural seagrass beds, suggesting that hard shoreline features may influence daily activity patterns. Despite daily anthropogenic operations, bottlenose dolphins use features of the industrialized area (i.e., deeply dredged channels, human-engineered seawalls) to engage in a variety of behaviors. Monitoring of dolphin behavioral states and habitat use in active ship channels are needed to assess changes from baseline data from increasing coastal development and vessel activities.

Matiss Castorena, M. Olson, B. Enquist et al.

Plant life-history variation reflects different outcomes of natural selection given the strictures of resource allocation trade-offs. However, there is limited theory of selection predicting how leaves, stems, roots, and reproductive organs should evolve in concert across environments. Here, we synthesize two optimality theories to offer a general theory of plant carbon economics, named as Gmax theory, that shows how life-history variation is limited to phenotypes that have an approximately similar lifetime net carbon gain per body mass. In consequence, fast-slow economics spectra are the result of trait combinations obtaining similar lifetime net carbon gains from leaves and similar net carbon investment costs in stems, roots, and reproductive organs. Gmax theory also helps explain ecosystem and crop productivity and even helps guide carbon conservation strategies.

J. Cross

Abstract:A map of the potential natural vegetation of Ireland is presented. The concept of potential natural vegetation is briefly outlined, followed by a consideration of the factors affecting its development: these include climate, soil type, vegetation history, land use and biotic factors. This is followed by a brief overview of present day vegetation. Literature sources and methods used in the compilation of the map precede the man body of the text, which consists of a description of twenty vegetation units. The vegetation units, which fall within six Formations or Formation Complexes, include nine forest units, five mire units, two heath units, two sand dune units and one each of salt marsh and polder units. Minor vegetation types are also considered briefly. In conclusion, the general distribution and character of Irish potential natural vegetation and its relationship with the rest of Europe is discussed.

Jiang Yuqi, Yang Yikang, Tian Wenbo et al.

[Objective] The spatial differences and dynamic evolution of carbon ecological security level were analyzed to optimize the overall plan of carbon ecological security in the Yellow River basin (an important “energy basin” in China) in order to objectively reflect the current status and evolution trend of carbon ecological security, and to provide a reference for optimizing the carbon ecological security pattern. [Methods] An evaluation index system for carbon ecological security in the Yellow River basin was constructed under the framework of driving-pressure-state-impact-response (DPSIR) analysis. The technique for order preference by similarity to ideal solution (TOPSIS) model was used to evaluate the level of carbon ecological security, and the spatial-temporal evolution characteristics were analyzed by the kernel density estimation method. [Results] ① Carbon sinks and carbon emissions increased from 2012 to 2021 in the Yellow River basin, and the growth rate of carbon emissions was faster than that of carbon sinks. Carbon sinks were spatially characterized as “higher in the west and lower in the east”, while carbon emissions were “lower in the west and higher in the east”. ② The carbon ecological security level in the Yellow River basin increased over time, from 0.356 in 2012 to 0.639 in 2021. In terms of spatial distribution, the carbon ecological security level in the upstream region was higher than in the middle and downstream regions, and was characterized as “upstream leading, midstream catching up, and downstream surpassing”. In addition, the level of carbon ecological security tended to be good. ③ Based on the kernel density estimation results, the differences in carbon security levels among different regions in the Yellow River basin were gradually narrowing, and were decreasing in the upstream region faster than in the middle and downstream regions. [Conclusion] Based on the current status of carbon ecological security in the Yellow River basin, carbon sink capacity in the upstream region is expected to increase over time, while clean energy industries and technology-intensive industries with high added value should be developed to promote green GDP growth in the middle and downstream regions. In addition, a carbon ecological compensation mechanism should be established to coordinate and resolve cross-regional security issues, and to improve the carbon ecological security level of the entire basin.

André L. Luza, André L. Giles, Pedro J. Bergamo et al.

Synthesis science is an emergent research field for harmonizing different data, concepts, and theories to create new insights and endorse novel approaches. Here we provide a brief general overview of synthesis science, emphasize the geographically biased location of synthesis centers一particularly their paucity in the Global South一and highlight the pioneering role of the Synthesis Center on Biodiversity and Ecosystem Services (SinBiose, CNPq) concerning transdisciplinary aspirations in the Global South. Working with the ecosystem service dimension requires breaking discipline boundaries to approach society, stakeholders, and decision-makers, which SinBiose fosters and is rarely found elsewhere. This article features a “Brazilian experience” of synthesis science through the perception of SinBiose’s postdoctoral researchers, which have a central role in the workflow as the only professionals dedicated exclusively to the projects. As a conclusion, we present recommendations for improving the support for postdoctoral researchers and arguments for a continued funding of synthesis science in Brazil.

Yu Liu, Yu Liu, Jianhui Wang et al.

The East Greenland Polar Front (EGPF) is an important front with strong salinity and temperature gradients in the Nordic Seas. It is formed by the interaction between Arctic-origin and Atlantic-origin water. The variations of EGPF are closely linked with sea ice melting and heat content transport associated with North Atlantic water recirculation. For a three-dimensional (3D) daily analysis, we use the global ocean eddy resolution reanalysis product (GLORYS12V1) from 1993 to 2018 to calculate the salinity and temperature horizontal gradient in the upper ocean and obtain the spatiotemporal distribution and intensity characteristics of EGPF. After assessment, the thresholds of the salinity and temperature fronts are set to 0.04 psu/km and 0.09°C/km, respectively. Compared with satellite observations of sea ice concentration, a significant spatial relationship is observed between the main position of EGPF and the ice edge before the sea ice shrinks to the continental shelf sea area. Affected by the freshening of the Arctic-origin water due to the melting of the sea ice, the intensity and area of EGPF show significant seasonal variations. Against the background of global warming, the sea ice area presents an obvious decreasing trend in the Greenland Sea. The melting of sea ice increased annually every summer from 1998 to 2018. The heat content transport of the Atlantic-origin water has also increased in recent years. The 3D characteristics (intensity and volume) of EGPF as salinity and temperature fronts exhibit increasing trends.

T. Orchard, Bryan Paul Wordsworth, D. Jewell

J. Scott

Sergei V. Shekhovtsov, Sergei V. Shekhovtsov, Sergei V. Shekhovtsov et al.

Eisenia nordenskioldi (Eisen, 1879) is the only autochthonous Siberian earthworm with a large distribution that ranges from tundra to steppe and broadleaved forests. This species has a very high morphological, ecological, karyological, and genetic diversity, so it was proposed that E. nordenskioldi should be split into several species. However, the phylogeny of the complex was unclear due to the low resolution of the methods used and the high diversity that should have been taken into account. We investigated this question by (1) studying the diversity of the COI gene of E. nordenskioldi throughout its range and (2) sequencing transcriptomes of different genetic lineages to infer its phylogeny. We found that E. nordenskioldi is monophyletic and is split into two clades. The first one includes the pigmented genetic lineages widespread in the northern and western parts of the distribution, and the second one originating from the southern and southeastern part of the species' range and representing both pigmented and non-pigmented forms. We propose to split the E. nordenskioldi complex into two species, E. nordenskioldi and Eisenia sp. 1 (aff. E. nordenskioldi), corresponding to these two clades. The currently recognized non-pigmented subspecies E. n. pallida will be abolished as a polyphyletic and thus a non-natural taxon, while Eisenia sp. 1 will be expanded to include several lineages earlier recognized as E. n. nordenskioldi and E. n. pallida.

Edward A. Myers, Daniel G. Mulcahy

The North American nightsnakes in the genus Hypsiglena is composed of nine named and at least two unnamed species. Here, we provide the first mt-genome of H. affinis, an additional mt-genome for H. sp. nov. 1, and four additional mt-genomes from the widespread H. jani. These mtDNA genomes were sequenced using both Illumina and Ion Torrent sequencing technologies. The resulting genomes contained the expected 13 protein coding genes, 22 tRNA genes, 2 rRNA genes, and 2 control regions typical of colubroid snakes. Two of the H. jani samples had partial tRNAIle genes upstream of CR2 which has not been previously documented in colubroid snakes. A maximum likelihood gene-tree based on these data combined with previously published sequence data recovers a well-supported phylogeny and is in concordance with previous estimates of evolutionary relationships in this group.