Application of a catalytic oxidation method for the simultaneous determination of total organic carbon and total nitrogen in marine sediments and soils

Designers of Nature's Subterranean Abodes: Insights into the Architecture and Utilization of Burrow Systems of Thomas' Pine Vole, Microtus thomasi (Rodentia: Arvicolinae)

Microtus thomasi (Rodentia: Arvicolinae), a fossorial vole endemic to the SW Balkans, uses a variety of substrates but its underground behavior remains poorly understood. This study examines the architecture and utilization of M. thomasi burrow systems in NW Peloponnese, Greece. In particular, eight burrow systems were meticulously excavated and studied, with comprehensive measurements taken of key characteristics, including length, depth, soil mounds, and surface openings. Key coordinates were recorded using a differential GPS device for detailed mapping and fractal dimension analysis using the box-counting method was employed to assess burrow system complexity. Soil samples were analyzed for particle size and chemical composition, and vegetation types at each site were identified. We did not find statistically significant correlations between size and complexity of the burrow systems and soil composition, altitude, or specific soil components. On the other hand, we did observe statistically significant differences in tunnel diameter between two burrow systems and in tunnel depth between more. Moreover, our study showed that more than one same-sex individual can occupy a single burrow system and not just an adult male-female pair, that was previously recorded, indicating the need for further study of the social behavior of this vole species. This study provides valuable insights into the underground behavior of M. thomasi by providing information on the features of its burrow systems, thus contributing to our understanding of its biology.

Microplastic characteristics and microplastic-heavy metal synergistic contamination in agricultural soil under different cultivation modes in Chengdu, China

Microplastics have significant implications for global ecosystems. The microplastic distribution, types, sources, and quantified microplastic-heavy metal synergistic pollution in agricultural soil in Chengdu, China were analyzed. The microplastics were detected in all soil samples collected from 103 sites, with concentrations ranging from 1333 to 15067 particle kg-1. The abundance of microplastics in grassland (12,667 ± 3394 particle kg-1) was more than twice higher than that in open field, vegetable field, orchard, and woodland. The main morphological types of microplastics included fibers, films, and granules (all "3-Dimensional" microplastics), with the colors red, blue, and transparent. Granular and fiber microplastics were predominantly in particles < 500 mm, while film microplastics were uniformly distributed at all sizes. The plastic compositions were mainly polypropylene and polyethylene plastics, accounting for 20.73% and 27.90% of the soil microplastic, respectively. Agricultural plastic applications and irrigation water were the sources of soil microplastics. The concentration of Cd, Cr, and Cu in the microplastics was strongly correlated with the corresponding concentration in the soils (p < 0.01), and the microplastic-heavy metal synergistic pollution might deteriorate the soil environment. The results of soil TOC measurements were influenced by microplastics in the soil. The results provide important data for the characteristics of microplastics in the agroecosystem.