Ecology and Evolution最新文献

Climate change poses a serious threat to global species distributions and has significantly altered the distribution patterns of invasive species. Coreopsis spp. are widely distributed invasive plants with strong adaptability and reproductive capacity, whose invasion has become a major ecological concern in China. Using three climate change scenarios (SSP-126, SSP-245, SSP-585), combined with the Maximum Entropy (MaxEnt) model and Geographic Information System (ArcGIS), this study delineated the potential distribution areas and distribution centroids of invasive Coreopsis plants in China. The results indicated that temperature (especially isothermality BIO3 and mean temperature of the warmest quarter BIO10) and moisture are the primary climatic factors influencing the distribution of Coreopsis spp., while human activity (HA) also plays a key role in shaping their distribution. Coreopsis drummondii exhibited the largest suitable habitat area (4.138 × 10⁶ km²), whereas Coreopsis verticillata had the smallest (9.53 × 10⁵ km²). Under current climatic conditions, the six Coreopsis species are mainly distributed in southern China. In future climate scenarios, their distributions are projected to shift northward and toward plateau regions. Moreover, high niche and range overlap was observed among Coreopsis grandiflora, Coreopsis lanceolata, and Coreopsis tinctoria, suggesting potential intensified interspecific competition. This study systematically reveals the invasion potential and spatial dynamics of Coreopsis spp. under climate change, providing a scientific basis for early warning, regional management, and ecological control. It also offers perspectives for future research on the interaction mechanisms between invasive and native species.

The composition and function of animal gut microbiota are influenced by various intrinsic and extrinsic factors. Hibernation represents a significant physiological challenge for heterothermic mammals, yet the effects on gut microbiota in bats remain understudied. This study investigated seasonal variations in the gut microbiota of Rhinolophus sinicus between summer activity and winter hibernation using 16S rRNA gene sequencing (n = 12 per group). Sequencing analysis identified 907 ASVs in the hibernation group and 555 ASVs in the summer group, with only 27 ASVs shared between groups, suggesting substantial seasonal turnover in microbial community membership. At the phylum level, Pseudomonadota (formerly Proteobacteria) dominated the gut microbiota, but no significant difference was found between seasons (77.52% during hibernation vs. 57.15% during summer). Bacillota (formerly Firmicutes) decreased significantly, while Actinomycetota (formerly Actinobacteriota) increased significantly in the hibernation group compared to the summer group. Genus-level composition exhibited seasonal variation, with distinct microbial communities characterizing each period. Alpha diversity analysis revealed significant differences in Faith's phylogenetic diversity between seasons, suggesting shifts in phylogenetic composition, while Chao1, Shannon, and Simpson indices remained unchanged. Beta diversity analyses revealed significant structural divergence between seasonal groups. Functional prediction using PICRUSt2 suggested seasonal shifts in metabolism-related pathways, with putative enrichment of lipid metabolism and xenobiotic biodegradation pathways during hibernation, while carbohydrate metabolism appeared more prominent during the active period. These findings suggest that winter fasting may alter intestinal microbial metabolic functions, potentially shifting the microbiota from carbohydrate-oriented to lipid-oriented metabolism. This study enhances our understanding of host-microbiome crosstalk in hibernating mammals and highlights the potential adaptive role of gut microbes in facilitating survival under extreme physiological conditions.

Climate change alters the oceans' temperature, pH, and oxygen concentration. These changes are expected to increase globally over the coming decades, affecting a wide range of marine organisms. Coastal upwelling zones, characterized by their high environmental variability, serve as ideal natural laboratories to study the potential impacts on marine organisms and ecosystems of temperature change, acidification, and ocean deoxygenation. The estimation of survival using capture-mark-recapture (CMR) data has been commonly applied to vertebrates, and to date, very few studies have been done on marine invertebrate organisms. In this study, we combined field CMR data and laboratory measurements to assess the physiological responses (metabolic rate and heart rate) and survival probability of individuals in two populations of intertidal mollusks, Chiton granosus and Scurria zebrina, in contrasting upwelling environments (i.e., semi-permanent vs. seasonal). We found that (1) there are no differences between the two studied populations for heart rate in both species, (2) the S. zebrina population subjected to seasonal upwelling has a higher metabolism, (3) there are no differences in the calcification rate between the two studied populations of both species, and (4) survival is significantly higher in the semi-permanent upwelling location for both species. Our findings highlight species-specific responses to contrasting upwelling regimes, suggesting that phenotypic plasticity and survival differences may influence resilience under ongoing climate change.

Rickettsia is an endosymbiotic bacterium that infects various arthropods, affecting the host's biology, ecology, and evolution. Leptocybe invasa is an invasive pest that severely damages eucalyptus plants. A comprehensive investigation of Rickettsia in 313 female L. invasa individuals from 17 Chinese populations revealed a 100% infection prevalence. Sequencing of three host molecular markers-mitochondrial COI, nuclear ITS, and 28S-led to the identification of a novel L. invasa haplotype, designated Haplotype 1 × 2, which exhibits mito-nuclear discordance. Concurrently, sequencing of four Rickettsia genes (16S rRNA, gltA, atpA, rpmE) revealed two distinct strains, termed STRiA and STRiB. These strains demonstrated a specific association with the host lineages, where STRiA was exclusively associated with lineage A (comprising Haplotype 1 and Haplotype 1 × 2), and STRiB was linked to lineage B. Phylogenetic analysis of the multigene datasets from both the host and Rickettsia revealed a high degree of topological congruence between their inferred trees. Correlation analysis further demonstrated a moderate positive association (r = 0.307). The significance of this relationship was supported by a Mantel test (p < 0.005), suggesting coevolution. Low-dose tetracycline treatment effectively eliminated Rickettsia from L. invasa. L. invasa treated with tetracycline exhibited a significantly higher proportion of male offspring, reduced Rickettsia expression, and decreased body length and lifespan in female offspring. Transcriptome analysis comparing Rickettsia-free and Rickettsia-infected L. invasa following antibiotic treatment identified 178 differentially expressed genes (122 up-regulated, 56 down-regulated). These genes were enriched in GO terms related to metabolic processes, cellular processes, cellular components, binding functions, and catalytic activities. KEGG pathway analysis revealed enrichment of differentially expressed genes primarily in metabolic pathways, insect hormone biosynthesis, and thermogenesis. Additionally, enrichment was observed in key signaling pathways, including Ras, MAPK, NF-κB, TGF-β, TNF, and Apelin. These findings elucidate the coevolutionary relationship and functional roles of Rickettsia in L. invasa, providing a foundation for symbiont-mediated biological control.

Gyrodactylus nigeri Zhou & Chen, 2024 was merely distributed in Yunnan Province, Southwest China; meanwhile, its mitochondrial genome remains unclear. This study aims to sequence the mitogenome of G. nigeri and clarify its phylogenetic relationship within the Gyrodactylidea. The mitogenome of G. nigeri was sequenced using the next-generation sequencing (NGS) method, annotated, and analyzed using bioinformatic tools. The mitochondrial genome of G. nigeri is 14,903 bp in length, containing 12 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs), two ribosomal RNA genes (rRNAs), and two major non-coding regions (NCR: NC1 and NC2). The overall A + T content of the mitogenome is 76.6%, a higher content compared with all reported mitochondrial genomes of monogeneans. The mitogenome of G. nigeri presents a clear bias in nucleotide composition with a negative AT-skew and a positive GC-skew. All tRNAs have the typical cloverleaf secondary structure except for tRNA ^Cys , tRNA ^Ser1 , and tRNA ^Ser2 , which lack the dihydrouridine (DHU) arm. Furthermore, two different repetitive non-coding regions of 88 bp repeats occurred in the NCR regions (NC1 and NC2) with a poly-T stretch, two stem-loop structures with obvious differences in the first loop, and a G(A)n motif. The gene order is identical to the mitochondrial genomes reported from other Gyrodactylus species except Gyrodactylus sp. FZ-2021. Co-phylogenetic analyses showed phylogenetic divergence patterns of Gyrodactylus correspond to those of their fish hosts, and the overall coevolutionary fit between the parasites and hosts was consistently significant. Meanwhile, the results supported the sister relationship between G. nigeri and Gyrodactylus sp. FY-2015 from the hosts within the Nemacheilidae cluster together with high nodal support based on 12 PCGs sequences and amino acid sequences. Gyrodactylidae forms an independent and monophyletic clade within Gyrodactylidea.

Climate change is considered a key driver for shaping ecological and evolutionary processes of Arctic animals. Historical glaciation has profoundly influenced the distribution and genetic differentiation of Arctic vertebrates, and recently Arctic species are facing new and intensifying threats from rapid global warming. Understanding how past, recent and future climate change has, and will influence the evolution of Arctic animals is, therefore, crucial for effective conservation planning. Here we combine whole-genome sequencing, demographic inference, and species distribution modeling (SDM) to assess the eco-evolutionary responses of the gyrfalcon (Falco rusticolus), a resident Arctic apex predator, to climate change. Assembling a genome reference and using samples from three breeding regions across the Eurasian Arctic (Kola, Yamal, and Chukotka peninsulas), we found genetic differentiation of gyrfalcon populations from west to east, that arose during the late Pleistocene (12.9-14.7 thousand years ago (ka)) and subsequently persisted in isolation, until gene flow into the Yamal population resumed during the late Holocene. The extant gyrfalcon populations exhibit low genetic diversity, elevated inbreeding coefficients, and high genetic loads compared to the closely related saker falcon (Falco cherrug), and some other threatened species with small populations, likely due to a population bottleneck about 1 ka, which might compromise the long-term viability of this Arctic raptor. Additionally, the effective population size (Ne) of the Kola gyrfalcon population was inferred to be in decline over the past 165-60 years. SDM based on ensemble models further predicts a substantial reduction of climatically suitable areas for Kola gyrfalcons under future global warming scenarios. Our study highlights how past climatic fluctuations and ongoing warming jointly shape the genomic landscape of endemic Arctic birds and provides insights into making conservation strategies for Arctic animals in a rapidly warming environment.

Oceanic islands have high biodiversity, which is severely threatened by invasive species. Functional traits serve as a framework to investigate invasive-native dynamics, but most studies investigating native-invasive plant functional trait differences on islands focus on live foliage traits, while litter traits remain understudied. It is hypothesized that invasive species produce higher quality litter (e.g., high nutrient content, low tannins and leaf mass per area) than native species, and furthermore, that this high-quality litter decomposes more rapidly, in turn providing a positive feedback that facilitates their expansion. To investigate native vs. invasive plant litter quality in a highly endemic island flora, we conducted a systematic review to synthesize litter trait data from Hawai'i. To account for the extensive heterogeneity that occurs across the Hawaiian Islands, litter trait variability was synthesized with respect to elevation and climate gradients. Litter quality varies extensively across the Hawaiian Islands in native and invasive species. Although invasive plants have higher quality litter than native species overall, species origin accounts for relatively little trait variance, and native and invasive species overlap considerably in litter multivariate trait space. Moreover, intraspecific variation exceeds interspecific variation, highlighting the important role of environmental heterogeneity for widespread species. Climate influences native and invasive litter quality in distinct ways, leading to a reversal in strategy across climate gradients. When controlling for the full direct effects of climate, native and invasive plant litter traits are not significantly different. Climate heterogeneity, more than plant species origin, plays a key role in shaping plant litter trait variation and resource-use strategies at the landscape or archipelago scale. Litter quality could be more commonly sampled as part of the functional syndrome of plants and for a better understanding of how traits differ between native and invasive plants.

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.