Ecology and Evolution最新文献

Environmental pressures, particularly those driven by anthropogenic activity, can induce rapid behavioural and physiological adaptation. Insects, due to their ecological importance, are especially affected by the widespread use of insecticides. While physiological resistance to insecticides is well documented, less is known about how such resistance influences behaviour, particularly oviposition site choice, a decision with direct consequences for offspring survival. Using Drosophila melanogaster, we investigated whether genetic resistance conferred by the detoxification gene Cyp6g1 affects oviposition preferences and survival across life stages when exposed to insecticides. We presented resistant and susceptible female flies with a choice between food laced with acetone, insecticides to which they are resistant, or insecticides to which Cyp6g1 does not confer resistance, and examined larval and adult survival under matching exposure conditions. We found that resistant females differ from susceptible flies by avoiding laying eggs on food containing DDT, an insecticide they are resistant to, suggesting that resistance is associated with a parallel shift in behaviour. Larval survival was closely tied to maternal oviposition choice, with Cyp6g1-mediated resistance conferring survival benefits only against insecticides it can detoxify. In contrast, adult survival was less affected by genotype, highlighting the importance of oviposition site selection in shaping transgenerational fitness. Our results suggest that resistance alleles can impact not only physiological resistance but also incur behavioural adaptations such as toxin avoidance that act synergistically to mitigate insecticide exposure. Furthermore, our results show that these resistance alleles influence behaviour in ways that affect their frequency in natural populations.

Community biomass allocation is jointly determined by habitat conditions and plant functional traits. Studies of biomass allocation patterns in topographic-soil climax communities of karst ecosystems remain scarce. According to the trait-driven paradigm, topographic gradients and soil properties indirectly influence karst forest biomass, via their control over community-level functional structure. In the 25-ha Maolan Dynamic Plot of the Karst Forest Ecosystem in South China, we compiled 1255 high-quality trait records for six key plant functional traits related to biomass from 48 dominant species, individual biomass data for 12,354 stems, and fine-scale environmental variables. Partial least-squares structural equation modeling (PLS-SEM) was used to quantify the direct and indirect factors affecting biomass allocation in this climax karst forest community. We observed that the trade-offs in biomass among different forest layers were more effective in predicting the biomass status of natural communities (R ² = 0.69). Topographic heterogeneity acted as an environmental filter, driving the assembly of distinct karst climax communities. Community-level trait distributions and abiotic variables significantly influenced both community biomass and its trade-offs, although trait patterns explained biomass trade-offs more effectively than environmental factors. PLS-SEM identified slope position as the primary driver of biomass trade-offs in the karst climax communities, with community-level variation in specific leaf area (SLA) mediating biomass allocation. Slope position decline reduced the community-weighted mean of functional traits (SLA, Wood density, Leaf nitrogen content) and concurrently increased biomass of the stable layer. In parallel, lower community-weighted variance of traits (SLA) attenuated biomass loss in the regeneration layer. These results underscore the pivotal role of trait composition in mediating biomass partitioning at the community scale.

Summer programs are a powerful educational tool for increasing student interest in science, technology, engineering, and mathematics (STEM) careers. However, barriers such as lack of awareness, transportation challenges, and financial constraints can hinder participation. This study examines Water Dawgs, a paid summer initiative designed to provide high school students with hands-on freshwater science education while ensuring accessibility for all interested students. Using Water Dawgs as a case study, we explore how proactive planning and budgeting can help mitigate these participation barriers. Water Dawgs successfully engaged 16 participants, and survey results indicate increased self-efficacy in STEM as well as greater awareness of how environmental science impacts daily life and career opportunities. We identify five key barriers-information gaps, resource deficiencies, transportation disparities, food insecurity, and economic limitations-and offer practical recommendations for addressing them through proactive planning and budgeting of direct costs. Strategies include planning and engagement well in advance of the event, allocating direct expenditures to compensate teacher partners and participants for their work, providing all necessary supplies for both classroom and field activities, offering transportation options for all participants, and ensuring access to meals. Our case study highlights the importance of thoughtful program planning and budget development that fully accounts for direct costs associated with removing barriers, making STEM summer programs an option for all interested students.

Over the Quaternary, the geographic distributions of many species have experienced shifts in response to climatic changes. We examined the range-shift patterns of six oak (Quercus) species occupying different climatic zones of the western Palearctic under both past and future climate conditions. Using ecological niche models, we reconstructed distributions during the Last Glacial Maximum (LGM, ~22,000 years before present), compared them to the Present, and projected future changes under two scenarios for 2081-2100 (SSP1-2.6 and SSP5-8.5). Quantitative metrics of latitudinal centroid movement, range limits, and area change revealed consistent contrasts among climatic groups. During the LGM, temperate (Q. robur and Q. petraea) and transition-zone (Q. cerris and Q. pubescens) species contracted strongly, persisting in southern refugia across Anatolia, the Balkans, and the western Mediterranean, whereas Mediterranean oaks (Q. coccifera and Q. suber) retained more stable ranges. Future projections suggest that temperate and transition-zone species will undergo substantial range loss and poleward shifts, particularly under the pessimistic scenario, whereas Mediterranean oaks will experience limited latitudinal shifts but pronounced expansion in to northern latitudes and temperate regions. These findings indicate Mediterranean oaks are ecologically distinct from temperate and transition-zone species, which show similar climate sensitivities. Our results emphasize the need for climate-zone-specific conservation strategies, including enhancing connectivity and genetic diversity for temperate and transition-zone species, and prioritizing drought-resilient populations and adaptive management for Mediterranean species, to support the long-term resilience of European oak forests under ongoing and future climate change.

Understanding the early life-stage responses of tree species to climate change is critical for predicting forest regeneration success and guiding conservation and management efforts. We investigated the effects of temperature, cold stratification, and light on germination and early seedling performance of Abies nordmanniana subsp. equi-trojani (Trojan fir), an endangered endemic tree from north-western Anatolia (Türkiye). Germination was tested under fixed (10°C, 15°C, 20°C, 25°C, 30°C) and alternating (15°C/25°C, 20°C/30°C) incubation temperatures with and without cold stratification. Early seedlings were monitored for 10 days under controlled, nutrient-free agar conditions. Our results show that while higher fixed and alternating temperatures enhance germination, early seedling survival declined at the warmest temperature (30°C), and root growth peaked at 20°C and decreased at higher temperatures. Cold stratification significantly improved germination across all temperature regimes, reducing the need for warmer incubation temperatures to achieve high germination. Light had a limited effect on overall germination. These findings indicate stage-specific responses to warming, as warmer conditions favor germination, whereas cooler conditions favor early seedling survival and root allocation. Consequently, successful regeneration assessments and conservation planning should consider both germination and early seedling stages, alongside local thermal contexts, when evaluating the impacts of climate change on Trojan fir.

Hyalomma rufipes is a widely distributed tick species and a competent vector of Crimean-Congo Hemorrhagic Fever Virus (CCHFV), a serious zoonotic pathogen endemic to over 30 countries. Despite the epidemiological importance of CCHFV and H. rufipes in East Africa, little is known about the genetic structure and movement of H. rufipes populations, limiting the understanding of CCHFV transmission dynamics in this region. This study developed and characterized 14 polymorphic microsatellite markers to support population genetic studies of H. rufipes. H. rufipes ticks were collected from livestock in Garissa and Isiolo counties in northern Kenya. Morphological identification was confirmed using 16S rRNA Sanger sequencing and phylogenetic analysis. Low-pass whole genome sequencing was performed on representative samples, and the Quality and Diversity of DNA (QDD) pipeline was used to identify and design microsatellite primers. Of 59,201 candidate loci, 30 were selected for initial screening; 14 loci consistently amplified and were polymorphic. These included mostly tetranucleotide repeats and showed high allelic richness and gene diversity. Several loci showed signs of null alleles, but no evidence of stuttering or allelic dropout was found. These newly developed microsatellite markers provide a valuable tool for investigating H. rufipes population dynamics and dispersal, with the ultimate goal of understanding CCHFV transmission dynamics in East Africa.

Miridae is the most species-rich family of true bugs and plays an important role in both natural and agricultural ecosystems. However, contemporary controversies surrounding their phylogenetic relationships and subfamily classification still lack consensus. This study employs molecular systematics to resolve Miridae phylogeny, utilizing mitochondrial genomes from 42 species spanning 39 genera across six of the seven currently recognized subfamilies. Four outgroup species from Tingidae (2 species) and Thaumastocoridae (2 species) were also included in the analyses. Our results demonstrate that: (1) Bryocorinae is paraphyletic as the stem groups of Miridae; and (2) the clade ((Deraeocorinae + Mirinae) + (Orthotylinae + Phylinae)) is consistently and strongly supported as a monophyletic group across all datasets and analytical methods. We report newly sequenced mitochondrial genomes based on high-throughput sequencing platforms for four Miridae genera and species: Chlamydatus sp. (Phylinae), Deraeocoris punctulatus (Deraeocorinae), Scirtetellus sp. (Orthotylinae), and Prodromus clypeatus (Bryocorinae). These findings provide a progressive phylogenetic framework with new significance for the future phylogenetic improvement and taxonomic revision of Miridae.

Hermit crabs use gastropod shells for protection from abiotic stressors and predators. However, two sympatric species of hermit crab, Pagurus hirsutiusculus and Pagurus granosimanus, have divergent shell size preferences. Differences in shell size use were evident in the field: for a given body mass, P. granosimanus used shells that were 136%–300% larger than P. hirsutiusculus. The present study examined the possible morphological adaptations associated with the shell size preferences of P. hirsutiusculus and P. granosimanus as well as the costs and benefits associated with the preference of P. hirsutiusculus for shells that are too small to enclose and protect the entire body of the crab. When exposed to desiccation conditions commonly encountered during low tide emersion, P. hirsutiusculus using large shells survived much longer than individuals using small shells. And in motility trials, P. hirsutiusculus moved significantly faster when using a small shell than when using a large shell. It was therefore hypothesized that P. hirsutiusculus might produce a heavier exoskeleton than P. granosimanus to compensate for the reduced protection obtained by P. hirsutiusculus from small shells. Our findings support this hypothesis: relative to body mass, the carapace was 15%–90% heavier in P. hirsutiusculus than in P. granosimanus, a difference further confirmed by the claw mass, which was 59%–81% heavier in P. hirsutiusculus than in P. granosimanus. The use of larger shells in P. granosimanus provides enhanced protection, allowing for the production of a lighter exoskeleton, but likely imposes reduced motility and increased energetic cost. Pagurus hirsutiusculus, on the other hand, uses smaller, lighter shells that impose lesser energetic costs and allow greater motility but leave the animal more vulnerable to stressors; P. hirsutiusculus compensates for this increased vulnerability by producing a heavier carapace and claws. The differences in shell size and exoskeleton mass suggest ecological implications for these species, particularly with regard to microhabitat use.

Studies of the length–weight relationship (LWR) and condition factor (CF) in fish are abundant but often descriptive; yet, most studies overlook how intrinsic and extrinsic drivers structure these metrics. Here, this study tested whether the growth exponent (b) varies across sex, season, and ecological region, and whether CF is elevated in females and before spawning. Over the course of a complete annual cycle, a total of 1436 individuals were collected from four mudflat sites, measured for total length (TL) and weight (W), and analyzed using log10-linear regressions of LWR and CF, along with appropriate parametric or non-parametric tests under false discovery rate control. The TL strongly predicted W (r² = 0.87) with b = 2.46 ± 0.02 SE, (< 3; p < 0.001), indicating negative allometry. Females showed a larger size and higher b value (2.52) than males (2.41). The dry season yielded a higher b value than the wet season, and southern sites showed a non-significant trend towards a higher b value than northern sites. Mean CF was 1.01 ± 0.01 SE, elevated in females (1.09 vs. 0.98) and in the dry season (1.04 vs. 0.99), while monthly fluctuations (0.89–1.08) tracked feeding and reproduction but showed no regional differences. Overall, S. histophorus exhibits consistently negative allometric growth, with systematic variation in b and CF across sex and season. These findings provide hypothesis-driven baselines for monitoring semi-terrestrial gobies and highlight the importance of considering life-history and hydrological context when applying LWR/CF in ecological and evolutionary research and management.

The Delacour's langur (Trachypithecus delacouri) is a Critically Endangered primate, restricted to a small region in northern Vietnam. In view of its very small population and existing threats, frequent population monitoring programs are urgently needed for this species. In this study, we evaluated the utility of handheld thermal imaging devices as a complementary tool to conventional ground-based visual surveys for primate population monitoring efforts. Based on results of past studies, we conducted field surveys in Kim Bang Protection Forest, Ninh Binh Province, Vietnam, where the second most important population of the Delacour's langur inhabits. While we followed protocols from previous ground-based visual surveys, we also used thermal monoculars to facilitate langur detections. By integrating thermal handheld devices, we documented at least 18 langur groups with around 116 individuals, an increase of about 11.5% in total population size compared to the most recent extensive study at the same site. When comparing to the 2022 drone survey in Kim Bang, our results also showed that while the drone platform demonstrates superior performance, the integration of thermal imaging devices substantially reduces survey effort relative to conventional ground-based visual techniques. Given the recent regulations on flying drones in remote areas in Vietnam, our findings suggest that thermal imaging devices offer a viable option to improve the efficacy of ground-based primate population monitoring surveys. Furthermore, when properly deployed, handheld thermal devices may provide key advantages for certain primate research topics.