This study compares the accuracy of two genomic approaches in estimating genetic diversity levels, which could be useful for informing species conservation assessments of abundant, exploited fish species. The first approach (SNP-calling-based) is the commonly used pipeline of SNP calling followed by SNP filtering at a determined Minor Allele Frequency (MAF). The second approach (genotype-likelihood-based) does not perform SNP calling but estimates the Site Spectrum Frequency (SFS) based on alignment quality and sample size. The results show up to two-fold differences in the magnitude of the estimated nucleotide diversities among the analyzed datasets. The SNP-calling-based approach produces overestimates when missing data are considered in the analysis and shows pronounced deviations of the SFS towards high-frequency SNPs when filtering by MAF > 5%. The genotype likelihood-based approach showed that nucleotide diversity estimates significantly deviated from neutral expectations, as expected based on the known history of the case-study fish population analyzed here, regardless of whether missing data were considered. In contrast, the SNP-calling-based approach only shows this expected difference when no missing data are included and no MAF filtering is performed. Overall, the results indicate that using the SNP-calling-based approach may hide the effects of population size declines in abundant exploited fish species, while genotype-likelihood-based estimates of nucleotide diversity can effectively contribute to informing conservation assessments.
As an emerging pollutant, microplastics (MPs) pose a potential risk to ecosystem health due to recycling technology’s limitations and long-term durability. Wood chip amendments can enhance the holding capacity of water and nutrients and improve the soil structure and quality of terrestrial ecosystems. However, the effects of wood chip amendments on MPs-contaminated soil-plant systems are still unclear. In this experiment, we employed a combination of field experiments, soil and plant measurements, molecular techniques (DNA extraction and sequencing), and advanced statistical analyses. A comprehensive assessment was conducted on the effects of Low-density polyethylene (LDPE) MPs on soil properties, wheat growth, and soil microbial communities, and the potential of wood chips as a mitigating agent was also evaluated. The results indicated that wood chips improved soil nutrient content, enhanced the activity of enzymes related to carbon, nitrogen, and phosphorus cycling, and promoted crop growth, all of which were negatively affected by LDPE. The effect of MPs on fungi was greater than that on bacterial communities, and adding wood chips could improve the α-diversity of fungal communities rather than bacteria. LDPE may increase the abundance of pathotrophic fungal groups, such as Stachybotrys and Alternaria. However, certain pathotrophic groups have been found to potentially facilitate the degradation of LDPE-MPs. LDPE reduced the symbiotroph groups and increased the competitiveness and complexity of the community in the microbial co-occurrence network. LDPE treatment inhibited the N-cycling bacteria group, while adding wood chips could promote most of the N-cycling bacteria groups. Wood chips increased saprotroph groups such as Trichoderma, which are able to degrade plastics. Wood chips emerge as a cost-effective and environmentally friendly solution to improve soil quality and mitigate the negative impacts of microplastics on crop growth.
The construction of hydroelectric dams for power generation causes environmental alterations and ecosystem restructuring in directly and indirectly affected areas. This study aimed to survey the ant fauna in the indirect area of influence of a small hydroelectric plant located in Mangueirinha, Paraná State, Brazil. Seven sampling campaigns were conducted, two before and five during the project’s implementation, using pitfall traps as the sampling method. A total of 72 ant species were recorded, belonging to 26 genera and six subfamilies. Species richness and abundance did not differ significantly between the pre-implementation and implementation phases. The Chao1 estimator indicated that actual species richness may be approximately 7.6% higher than observed. These findings contribute to understanding ant biodiversity in areas subject to land-use change in Paraná State. The results highlight the value of using insect species richness and abundance, particularly of bioindicator groups such as ants, for environmental impact monitoring.
Biodiversity is essential for human well-being, and serves as the green engine for education, science, technology and health. China’s prosperous private entrepreneurs have established hundreds of private colleges and universities with several newcomers positioned as world-class research universities. Unfortunately, biodiversity conservation education and researches appear overlooked in these institutions. Universities, particularly the top-tier universities, serve as critical hubs where talent, knowledge, and technology concentrate. Private capital’s flexible management framework and rapid response to emerging academic disciplines enable universities, enterprises, and markets to collaborate effectively in developing tools and equipment for biodiversity assessment and monitoring. Expanding huge private capital investment in universities to biodiversity conservation could spur broader investment in ecological products in the future, while would also offer an opportunity for the universities to achieve their ambitions.
Patches of open water (polynyas) persist throughout six-month winters on many ice-covered lakes in boreal mountain ecoregions of northwestern North America. We explored their distribution, hydrological correlates, and the diversity of species using them from freeze-up to break-up. In headwater drainages, lakes with outflow polynyas were significantly larger than those without, but many small lakes also had polynyas. There was a consistent threshold in upstream catchment size below which outflow polynyas were absent and above which they persistently occurred in downstream lakes. Outflow polynyas depend on winter-long through-flow of water, likely maintained by the hydraulic head of higher elevation ground water in perched water tables in this region of very limited permafrost. Based on camera trapping, two species, the American dipper and river otter, used polynyas heavily throughout winter foraging. Polynyas likely provided crucial forage for at least 9 species of migratory waterfowl (Anatidae) to complete their spring migration or to prepare for reproduction on local lakes. Cameras recorded additional 5 bird and 11 mammal species, as foragers, scavengers, or incidentally. We report previously undocumented significance of these spatially-limited and seasonal polynya ecosystems in expanding the diversity of winter ecological opportunity for numerous species on small to medium-sized lakes.