BMC ecology and evolution最新文献

Background: Ekebergia capensis is a valuable tropical tree occurring on highlands of Ethiopia and used for traditional medicines, fodder for livestock and fruits are eaten by birds and other wild animals. However, it faces climate change threats and increased anthropogenic pressure, mainly, selective cutting for timber, firewood and expansions of agriculture across its range. Understanding the impacts of climate change on its suitable ranges is crucial to identify high-priority areas for its effective conservation and management plans. The study aimed to predict suitable habitats of Ekebergia capensis and examine factors influencing its distribution under current climate and future climate scenarios.

Methods: We used an ensemble modeling approach with 10 replications of five algorithms: BRT (boosted regression trees), RF (random forest), GLM (generalized linear model), GAM (generalized additive model), and Maxent (maximum entropy). Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), the true skill statistic (TSS), and visual assessment of ROC curves.

Results: The AUC and TSS of the ensemble model are 0.88 and 0.68, respectively, showing a very good performance. The currently predicted suitable habitat for Ekebergia capensis covers an area of approximately 215,869.87 km², representing 19.05% of the country. Under climate projections for the 2050s based on emission scenarios, the range of this species will decline by 31.71% under the medium (SSP2-4.5) and by 33.56% under the worst-case (SSP5-8.5) scenario. In the 2070s, the suitable habitats of this species will decrease by 45.44% and 47.14% under SSP2-4.5 and SSP5-8.5, respectively. Ekebergia capensis will lose a large portion of its suitable habitats between 2050s and 2070s, i.e., 16.92% under SSP2-4.5 and 15.24% under SSP5-8.5. This study suggests that southern, central, southwestern, and eastern highlands of Ethiopia provide suitable areas for the species. In contrast, suitable habitats in the northern part of the country will be either lost or fragmented in the future.

Conclusions: Our findings show that climate change significantly affects the suitable habitats of Ekebergia capensis. Only selected parts of its current habitat will remain suitable, while others will be lost or become isolated in the future. This species has recalcitrant seeds and cannot be stored ex-situ. Therefore, conservation efforts should prioritize in situ strategies such as habitat restoration, reintroduction, and assisted migration across its range. In addition, combining in situ efforts with carefully selected ex situ methods could offer a more comprehensive approach to conserving this species.

This study examined the ecological impact of the invasive shrub Amorpha fruticosa in marsh meadows and assessed the effectiveness of combined conservation management practices, i.e., mowing and cattle grazing, in on restoring native vegetation. Conducted in the Mártély Landscape Protection Area (Hungary), the research used a multiscale approach to compare treated non-invaded and treated invaded wetland vegetation. Information theory-based diversity metrics were employed to evaluate the impact of A. fruticosa on structural complexity and species composition. Results revealed that although A. fruticosa can significantly altered plant community structure, the implemented management strategies effectively reduced its impact. The treated invaded vegetation exhibited diversity levels compareable to native marshland communities, suggesting that mowing and grazing contributed to decreasing A. fruticose dominance. However, in the absence of untreated control stands, this pattern must be interpreted cautiously, as the observed similarity could be conclusively attributed to the applied management alone. A slight, but non-significant shift in structural diversity was also observed, implying a residual effect of invasion. This study underscores the value of active, combined conservation strategies in maintaining biodiversity and ecosystem resilience in wetland habitats. The results contribute to broader discussions on invasive species control, emphasizing the role of traditional land-use practices in mitigating the ecological effects of biological invasions.

Background: Evolutionary fitness is determined by the match between an organism's phenotype and its local environment. When mismatched, individuals may disperse to more suitable habitats. For flightless insects, however, the range of dispersal is typically limited. Numerous flightless species have, therefore, evolved a dispersal dimorphism, that is, some individuals in otherwise short-winged populations develop long wings. Wing development may be genetically or environmentally determined, but these two drivers have rarely been analysed together.

Results: We studied the inheritance and density-dependent plasticity in the dispersal dimorphism of the meadow grasshopper Pseudochorthippus parallelus. Using a full-sib half-sib breeding design, we found that the development of long wings strongly depends on rearing density, with tactile stimulation being the most likely proximate cause. Additionally, we found heritable variation in the development of long wings, both in the propensity to produce long wings and in response to density (genotype-by-environment interactions). While at high and low densities, the environmental effect dominates, genetic variation is most consequential at intermediate densities.

Conclusions: Our results have implications for the phenotype-environment match and ultimately the evolution of individualised niches. Induced dimorphisms represent a form of adaptive phenotypic plasticity by offering a much greater potential for active niche choice and both genetic and induced dispersal dimorphisms facilitate niche choice in allowing individuals to sample a greater range of environments. Our study shows that niche-related polymorphisms can evolve via selection on the sensitivity threshold.

Accurate three-dimensional localisation of ultrasonic bat calls is essential for advancing behavioural and ecological research. I present a comprehensive, open-source simulation framework-Array WAH-for designing, evaluating, and optimising microphone arrays tailored to bioacoustic tracking. The tool incorporates biologically realistic signal generation, frequency-dependent propagation, and advanced Time Difference of Arrival (TDoA) localisation algorithms, enabling precise quantification of both positional and angular accuracy. The framework supports both frequency-modulated (FM) and constant-frequency (CF) call types, the latter characteristic of Hipposiderid and Rhinolophid bats, which are particularly prone to localisation errors due to their long-duration emissions. A key innovation is the integration of source motion modelling during call emission, which introduces Doppler-based time warping and phase shifts across microphones-an important and often overlooked source of error in source localisation. I systematically compare four array geometries-a planar square, a pyramid, a tetrahedron, and an octahedron-across a volumetric spatial grid. The tetrahedral and octahedral configurations demonstrate superior localisation robustness, while planar arrays exhibit limited angular resolution. My simulations reveal that spatial resolution is fundamentally constrained by array geometry and the signal structure, with typical localisation error ranging between 5-10 cm at 0.5 m arm lengths. By providing a flexible, extensible, and user-friendly simulation environment, Array WAH supports task-specific design and deployment of compact, field-deployable localisation systems. It is especially valuable for investigating the acoustic behaviour of free-flying bats under naturalistic conditions, and complements emerging low-power multichannel ultrasonic recorders for field deployment and method validation.

Background: Heteroplasmy, the presence of more than one type of mitochondrial DNA (mtDNA) within an individual, is an exception to the maternal transmission of mtDNA and has been observed in several animal species. A central question is whether heteroplasmy among individuals and across generations is mainly influenced by genetic drift or by selection.

Results: We quantified heteroplasmy in eight males, eight females and eight unfertilized eggs per female from a natural population of the hybrid frog species Pelophylax esculentus (between P. ridibundus and P. lessonae). After excluding sequencing error and potential sources of contamination, we found that all individuals and most of the eggs were heteroplasmic, containing 2-5 different haplotypes, from which one was very common and the rest appeared at very low frequencies (at maximum 2%). We observed a single lessonae haplotype, which was present in females and in their eggs but absent from all males. On the other hand, we observed four different ridibundus haplotypes that were present in males, females and eggs. Eggs had significantly lower heteroplasmy levels than their mothers.

Conclusions: The distribution of haplotypes between males and females, the difference of heteroplasmy levels between mothers and their eggs, and results from simulations suggest that drift alone is not sufficient to explain the observed patterns of heteroplasmy.