BMC ecology and evolution最新文献

Small mammals play crucial roles as seed dispersers and ecosystem engineers in forest ecosystems. This study explores the impact of canopy cover on small mammal communities in the Xiaozhaizigou National Nature Reserve, part of the Giant Panda National Park, Northern Sichuan. Field surveys were conducted across 16 sampling plots (50 × 50 m²) in four canopy cover classes (0-24%, 25-49%, 50-74% and 75-100%) during 2023 and 2024. Forests with lowest canopy cover (Class I) exhibited the highest alpha-diversity due to greater habitat heterogeneity, while highest canopy cover forests (Class IV) supported habitat-specialist species, including endemic species Sciurotamias davidianus and Niviventer excelsior. Rodentia showed significantly higher abundance than Eulipotyphla across all canopy classes. Beta-diversity analysis revealed that species turnover (β_SIM) was the main driver of community differentiation, with non-endemic species exhibiting higher beta-diversity than endemic species. Redundancy analysis demonstrated that endemic species showed positive associations with herb layer complexity, while non-endemic species preferred simpler habitat structures. Phylogenetic and functional diversity analyses revealed predominantly random community assembly processes. Current forest restoration strategies prioritizing canopy closure for flagship species like giant pandas may overlook small mammal habitat requirements. The findings underscore the necessity of balanced forest management strategies maintaining both high- and low-canopy environments in a mosaic approach, maximizing biodiversity conservation and ecosystem resilience.

Background: As key components of insects' energy storage and mobilization systems and their various membranes, lipids are crucial to diverse phenotypes and fitness components of these metamorphic, poikilothermic organisms. Yet little is known about the ecological and evolutionary genetics of insect lipids. Historically, assay methodologies have been unable to resolve the diverse components of their lipidomes.

Results: We have used modern lipidomics to screen for heritable differences in adult male Bactrocera tryoni, examining over 400 lipids in 15 different classes of neutral and phospho- ester and ether lipids. We found substantial differences in most classes between populations recently collected from opposite extremes of the species' range and/or during their subsequent domestication. Differences were found in both newly emerged and sexually mature flies. The differences in the former reflect differential use of resources accumulated in the larval stage during metamorphosis. The differences in the latter also reflect differential utilization of adult food resources. Most of the differences were found in the newly emerged flies and there was no obvious relationship between the differences at the two stages, implying largely independent genetic controls. The differences in lipid compositions seen among the recently collected strains suggest that lipids have played significant roles in ecotypic variation. In particular, differences in the acyl chain compositions of the phospholipids could have underpinned differences in the fluidity of the flies' membranes in the tropical versus temperate populations sampled. There were also many differences between the source populations in the patterns of change in their lipid profiles during domestication, suggesting they adapted in different ways to the 'common garden' laboratory environment; acyl chain compositions in lipids from the different populations converged, but their relative abundances did not.

Conclusion: The diverse patterns of genetic variation described here are consistent with the complex, multi-gene pathways for lipid syntheses and remodeling now being discovered by other insect 'omic' analyses and show that heritable lipid differences could underpin differences in a wide variety of adaptively important insect phenotypes.

The Sardinian wildcat (Felis silvestris lybica) belongs to a felid North-African lineage that reached the Mediterranean island in Neolithic times. While numerous studies have been conducted on the European wildcat (Felis silvestris silvestris), very little is known about the Sardinian wildcat ecology, genetics, and conservation status. Therefore, it is paramount to investigate the current distribution and genetics of the Sardinian population of F. s. lybica, previously described as var. sarda. In this work we assessed morphological and molecular traits of Sardinian wildcats, ascertained areas of species presence on the island, and investigated possible occurrence of hybridization with domestic cats. An integrated approach was adopted, involving questionnaire distribution and interviews to local people, and the morphological evaluation of road-killed individuals combined with their genetic typing using 29 polymorphic autosomal microsatellite loci. Genotypes were then analyzed by Bayesian clustering and assignment analyses. Questionnaires and interviews allowed us to build a preliminary alleged distribution map of the species and select candidate areas for non-invasive monitoring. The morphological and genetic characterization of road kills and museum specimens allowed us to identify pure individuals and recent wild × domestic hybrids, paving the way for better characterizing the Sardinian wildcat. Further steps of the research will allow us to shed light on this elusive presence on the island and enhance its conservation.

Background: Plant-pollinator interactions are vital for understanding ecological processes influencing reproductive success in plant communities. While species-level pollinator interactions are important for predicting community stability, it remains equally crucial to understand individual-level interactions of keystone species in the community. This study examined the role of habitat factors and floral traits in shaping pollinator interactions at the individual plant scale of Maytenus senegalensis, a dominant native species in the semi-arid Aravalli Hills. We measured flower production, nectar sugar concentration, flower diameter, and external factors such as soil moisture, distance to habitat edge, and density of co-flowering conspecifics to assess their impact on pollinator interactions and reproductive success.

Results: We found significant variation in reproductive investment in the form of flower production and a trade-off with reward quality, where plants with higher flower production were found to have a lower nectar sugar concentration. Higher flower production negatively influenced reproductive success, suggesting the likelihood of increased within-plant visitation. Eristalinus and Apis were the dominant pollinator genera, and overall, Dipterans were found to play a critical role in maintaining the network stability. The presence of flowering conspecific plants in the neighborhood reduced the pollen deposition, suggesting competitive interactions. Moreover, individual plants were found to show some amount of specialization in their interaction niches. We predict that this could lead to further divergence of interaction niches due to pollinator-mediated competition. Any perturbation to interactions of plants with a high degree of pollinator connectance was found to disproportionately influence the network.

Conclusions: Overall, our results link microhabitat (soil moisture) and neighborhood context to individual interaction niches, demonstrating that allocation trade-offs and conspecific competition jointly shape pollination and fitness. In semi-arid systems, which are undergoing considerable anthropogenic and climatic changes, our study provides insights into individual pollinator interaction niches and the role of microhabitat factors in species persistence within a community.

Pteronotus is a Neotropical genus of mormoopid bats known to form large colonies in caves. Cave selection by Pteronotus is not random, and maternity roosts are characterized by the presence of a hot chamber where females give birth and raise their young. Such bat caves are unique from ecological and conservationist perspectives. Previous studies on bat caves in the drylands of Brazilian northeastern region - some holding up to 150,000 bats - have shown that P. gymnonotus presented no population structuring, with no correlation between geographical and genetic distance, and that bat caves up to 700 km apart form a very dynamic roost network used by that species. P. personatus is a smaller relative found in sympatry with P. gymnonotus. Both species frequently share the same roosts and are exposed to similar environmental conditions when foraging; therefore, they are good candidates for a comparison of their population genetic structuring. Using ddRADseq methodology, 55,836 SNPs from 72 P. personatus (21 females and 51 males) and 37,037 SNPs from 177 P. gymnonotus (93 females and 84 males) were analyzed. We observed that both species presented no strong signs of population genetic structure in the drylands of northeastern Brazil, and geographic distance is not the main factor shaping their genetic connectivity. Furthermore, our results suggest that the two Pteronotus species studied are characterized by very dynamic roost use, meaning that individuals frequently switch among caves within a landscape rather than relying on a single permanent roost. Thus, indicating that conservation initiatives should not rely solely on single-site protection but rather adopt a landscape-scale perspective.

Restoration has become one of the key measures in improving the state of biodiversity. However, restoration outcomes are in many cases not well understood, and species communities have not been monitored long enough to determine whether they can or cannot recover completely to the pristine reference state. So far, it is particularly poorly known how the communities of microscopic fauna vary within and between pristine, drained and restored peatland habitats. We collected 270 moss samples from a replicated restoration experimental set up to study whether tardigrade communities differ between pristine, drained and restored pine mire forests. In addition, we estimated the associations between tardigrade genera and the moss type they live in. We found a weak pattern of tardigrade occupancy probability being lower in drained and restored sites than in pristine sites. Furthermore, some tardigrade genera were less likely to occur at the drained and restored (11 to 16 years after restoration) sites when compared to pristine sites, although no significant differences in community compositions between treatments were found. We found notable within site variation, which is indicative of high patchiness in tardigrade distribution. We also found strong associations between some of the moss types and tardigrade occurrences. Therefore, tardigrade occurrence seems to be more linked to microhabitat changes, such as mosses, than treatment of the sites. Although the differences between treatments were small, our results show that drained and restored pine mire forests may provide less suitable habitat for tardigrades than the pristine sites do. Favorable habitat conditions for tardigrades in these ecosystems are likely to arise from combinations of large- (e.g., hydrology) and small-scale (moss type) environmental variables that are both affected by drainage and restoration.