Ecology and Evolution最新文献

This study demonstrates significant ecological-linguistic overlap between the distribution of the giant panda (Ailuropoda melanoleuca) and Southwestern Mandarin in China. Analysis of data from China's 4th National Giant Panda Survey reveals that 1745 of the 1864 recorded wild individuals (93.62%) reside in counties where Southwestern Mandarin is the predominant dialect. Spatial analysis confirmed a strong and statistically significant congruence (Schoener's D = 0.92, p = 0.04). Paleontological records further indicate that approximately 80%–90% of giant panda fossils are clustered within these linguistic zones. This ecological-linguistic overlap may be attributed to shared environmental drivers and bamboo's dual ecological-cultural role, providing a regional-scale empirical case consistent with the core tenets of the ecological risk hypothesis. Our findings highlight the potential of linguistic maps as a supplementary layer of information for identifying conservation priorities.

Urban shrinkage, driven by population decline rather than expansion, is an emerging concern in many developed countries. This demographic shift increases the prevalence of novel green spaces, such as vacant lots, prompting interest in their potential to enhance urban biodiversity and ecosystem multifunctionality. However, biodiversity-ecosystem multifunctionality relationships in vacant lots remain largely unexamined. We investigated 69 vacant lots in Yokohama, Japan, a city facing potential population decline, by quantifying six environmental factors, five ecosystem functions, and taxonomic and functional diversity and composition of plants, bacteria, and fungi. We used structural equation modelling to analyse the direct and indirect effects of environmental and ecological variables on ecosystem function and multifunctionality. Additionally, to account for trade-offs and synergies among ecosystem functions, we examined the relationships between environmental factors and multifunctionality using a multiple-threshold approach and generalized linear mixed models. Our results indicate that environmental factors exerted a dominant influence on ecosystem functions, although all components (environment, plants, and microbes) played a role. Specifically, soil moisture directly enhanced several ecosystem functions and average multifunctionality. In contrast, spatial aggregation of vacant lots indirectly impaired them, mediated by increased plant richness and altered fungal composition. Moreover, urbanization indirectly affected all ecosystem functions and exerted a direct negative effect on average multifunctionality, with its negative effects intensifying at elevated multifunctionality thresholds. These findings highlight that the multifunctionality of urban vacant lots is intricately shaped by environmental factors mediated by diverse taxa. Given that dispersed vacant lot configurations in less urbanized areas may enhance multifunctionality but reduce plant diversity, future urban planning in shrinking cities should balance biodiversity conservation with the enhancement of ecosystem multifunctionality through strategic spatial configuration.

The degree of connectivity across ecosystems is a key determinant of resilience, directly influencing recovery potential after disturbance and long-term ecosystem stability. In reef-building corals, there is added complexity to these processes because both the coral host and their symbiotic dinoflagellates determine resilience. Given these complexities, we investigated the connectivity of a broadcast spawning coral and its associated algal symbiont communities along the Ningaloo Reef Marine Park and Muiron Island Management Area. Using reduced representation sequencing and DNA metabarcoding in 158 colonies of Acropora cf. tenuis across 14 sampling sites, we detected significant spatial genetic structure in the coral host consistent with a pattern of isolation by distance (IBD). Spatial Autocorrelation analyses revealed that the genetic neighbourhood extends up to 50 km suggesting that this coral species has multiple demographically independent populations across Ningaloo Reef. Symbiont communities were dominated by Cladocopium and followed a similar IBD pattern of between-site differences in community composition. We did not identify a significant correlation between host genetic diversity and symbiont community diversity at the colony level. However, spatial patterns of genetic differentiation between sample sites for the host and symbiont community composition were significantly associated suggesting that connectivity along a fringing reef system for both coral hosts and their symbionts is driven by similar biogeographic factors.

Environments are becoming increasingly more variable, as a function of climate change. As this occurs, species may be exposed to conditions outside their preferred range. Such variability in the environment can influence community abundance as individual species respond either similarly (synchronous dynamics) or differently (asynchronous dynamics) to each other. These fluctuations in abundances are important for understanding the impact of environmental variability on species temporal fluctuations in aquatic macroinvertebrates. This group of organisms is species-rich and highly sensitive to environmental fluctuations. We analyzed 18 stream macroinvertebrate communities sampled by the National Ecological Observatory Network between 2014 and 2022 to understand how community synchrony is related to stream temperature variability, discharge variability, and species turnover. We then quantified individual species contributions to community synchrony. These contributions were aggregated by functional feeding group to understand how resource acquisition strategies influenced species contributions. Species with higher contributions are often more synchronous with many other species. Here, community synchrony was expected to be negatively related to increasing environmental variability and turnover. Opposite our expectation, temperature variability, turnover, and discharge variability were unrelated to community synchrony. Contributions to community synchrony significantly varied among functional feeding groups. Scrapers had the highest proportion of taxa with significant positive contributions, followed by filterers. Shredders had the lowest proportion of species contributing to synchrony. Scrapers and shredders were significantly less synchronous than other functional feeding groups. This suggests that functional feeding group may explain patterns of community synchrony. Using a standardized, long-term dataset, we demonstrated how temperature variability, turnover, and functional feeding groups relate to community synchrony. While identifying the drivers of community synchrony remains challenging, integrating functional groupings provides an approach to identify species that drive community dynamics.

Pacific sea turtle populations primarily inhabit subtropical and tropical waters, making sightings at the edge of their range in colder high-latitude regions of the Canadian Pacific particularly uncommon and even rare. This paper presents a comprehensive summary of known occurrences in British Columbia waters from 1931 to 2024, featuring demographics, spatiotemporal distribution, and pathological findings. The dataset contains 247 sea turtle records from four species including 77 previously unpublished records. Leatherback sea turtles (Dermochelys coriacea) were the most frequently sighted, followed by hard-shelled sea turtle species: 34 green (Chelonia mydas ), three loggerhead (Caretta caretta), the first five olive ridley reports (Lepidochelys olivacea), and 54 unidentified sea turtles. Leatherbacks were primarily observed free-swimming, whereas almost half of the hard-shelled sea turtles were found dead or cold-stunned. This difference may be attributed to the inability of hard-shelled sea turtles to thermoregulate in high latitude waters. Although leatherback sightings predominantly occurred July through October, hard-shelled sea turtle records were distributed widely across all months of the year. There were 16 records involving human interactions, of which 75% were attributed to entanglement in fishing gear. Given the rarity of these occurrences and the conservation status of most sea turtle populations, these records provide important insights into high-latitude habitat use and threats, informing future monitoring and recovery efforts for these at-risk species.

White sharks undergo pronounced ecological and dietary shifts across ontogeny, and their teeth play a central role in mediating these changes. Understanding the complexity within shark tooth and jaw mechanics, plus the fine-scale tooth morphology, can provide insights into how feeding strategies and, hence, dietary niches and ecological function evolve with age and size. These morphological changes underpin ontogenetic niche shifts, revealing how functional adaptations in dentition enable white sharks to exploit different prey resources throughout development. This study provides novel insights into the ontogenetic and positional variation in C. carcharias dentition, integrating both Elliptic Fourier Analysis (EFA) and traditional morphometric approaches. We reveal significant patterns of tooth morphology that vary with jaw position and ontogenetic stage, reflecting functional adaptations to changing dietary and biomechanical demands. A key ontogenetic shift was identified as teeth transitioned from narrow, cuspidate forms with accessory cusplets in juveniles to broader, serrated teeth in larger individuals. We found no significant differences in tooth morphology between sexes, aligning with known similarities in diet and body shape in the eastern Australian white shark population. Significant anterior-to-posterior variation in tooth form was observed within the jaw, with lateral teeth becoming more compressed and recurved, suggesting functional transitions in prey handling throughout the jaw. Additionally, we documented structural changes in jaw morphology at approximately 210 cm PCL, corresponding to broader teeth and increased bite capacity. These shifts likely reflect developmental milestones in feeding capability, supporting the transition from a solely piscivorous diet to the inclusion of marine mammal prey.

Artificial sulfur (S) and nitrogen (N) addition experiments often fail to accurately simulate acid deposition in terms of type, composition, intensity, frequency, and duration, potentially leading to biased estimates of deposition impact on plant diversity. Consequently, studying plant diversity patterns around acid emission sources provides a more reliable alternative. Yet, this approach remains understudied in field research, particularly in saline-alkaline regions where high soil buffering capacity may attenuate plant sensitivity to acid deposition. Therefore, we investigated plant functional diversity (PFD) and analyzed its influencing factors in a desert coal-mining region in northwestern China characterized by high pH, abundant CaCO₃ content in soils, and increasing acid deposition. The plant communities were characterized by high leaf thickness, low specific leaf area, and limited leaf total carbon (C) and N concentrations, indicating the preference of the plant communities for a slow investment-returning ecological strategy in the study region. In this context, leaf traits (e.g., thickness and total C and N concentrations), rather than PFD, played a major role in stabilizing plant communities. The intensity of S and N deposition had no effect on PFD. In contrast, exchangeable cation (BC) deposition directly reduced the functional richness, functional dispersion, and the Rao's indices, possibly by exacerbating soil salinity and alkalinity in the study region. Our findings indicate that PFD is mainly influenced by BC deposition in saline-alkaline coal-mining regions. Therefore, the potential risk of BC deposition, which accompanies acid deposition, posed on plant diversity should not be overlooked in these regions.

Monitoring the health of cetaceans is challenging as traditional approaches including vessel-based surveys and necropsies are often opportunistic and limited in their ability to detect subtle physiological changes. Infrared thermography (IRT) offers a non-invasive alternative by detecting surface temperature anomalies that may reflect localised physiological variation, including changes associated with inflammation, scarring, tissue disruption or thermoregulatory processes. Mounted on drones, IRT can enable remote thermal imaging of free-ranging individuals. This case study presented preliminary observations from the exploratory use of drone-IRT to detect localised thermal anomalies in the skin of bottlenose dolphins (Tursiops truncatus) under human care. A total of 14 adult dolphins were monitored across the Austral summer and winter, with two individuals exhibiting consistent thermal hotspots 3°C–5°C warmer than surrounding body surface temperatures. One individual exhibited a transient anomaly that resolved over time, whereas the other displayed persistent hotspots that became more pronounced. These anomalies corresponded with external markings, suggesting localised alterations in skin surface thermal patterns. This case study provided preliminary evidence that drone-IRT can detect localised thermal anomalies in a dolphin's skin and highlights the potential for drone-IRT as a non-invasive tool for monitoring health in both managed and wild dolphin populations. Further quantitative investigations with larger sample sizes and concurrent veterinary assessments may provide validation regarding such observations and to evaluate whether such anomalies are indicative of underlying health issues.

Accurate information underpins successful ecological science and management. Cryptic species, those that are difficult to differentiate, pose challenges to reliable collection of taxon-specific information. Blackbirds, including tricolored blackbirds (Agelaius tricolor), a cryptic species of high conservation concern, and red-winged blackbirds (Agelaius phoeniceus), an abundant congener, are sometimes killed by wind turbines. We used publicly available survey records to evaluate rates at which blackbirds were reported dead at wind energy facilities in California, USA. We then used genetic species identification of carcasses found to estimate true rates of discovery and of misidentification. Of 329 blackbird fatalities in survey records, most were identified as red-winged (n = 149), “unidentified” (n = 90), or Brewer's (Euphagus cyanocephalus; n = 70); only 13 were identified as tricolored. We also genetically analyzed samples from 40 blackbirds. Of 14 carcasses identified in the field to species, two, including one tricolored, were incorrectly called Brewer's blackbirds (14% misidentification rate). Of the 26 birds called “unidentified blackbird” in the field, 17 (65%) were tricolored, leading to a 19× underestimation of true fatality rate. The state-wide population of tricolored blackbirds is < 1% the size of that of red-winged blackbirds. A large proportion of blackbirds found dead were actually tricoloreds, indicating that fatality rates of this state threatened species may be substantially underestimated. The potential for misidentification or nonidentification may create perverse incentives that undermine conservation and have consequences for on-the-ground management, mitigation, and operations of high-priority infrastructure.