Researchers find that soil aging of polyethylene microplastics has only a limited effect on their interactions with organic contaminants. Scientists have long worried that aging microplastics in soil could become increasingly effective at interacting with organic contaminants. But a new study shows that this may not be the case for all plastic types. Researchers found that while polyethylene microplastics modify as they age in soil, those changes have little effect on how they interact with various organic contaminants.

More than 100 shallow lakes along the Atlantic coast of southern Brazil and Uruguay could become one of the world’s most important natural laboratories for tracking climate change and human impact on freshwater ecosystems. An international research team has identified this overlooked subtropical lake network as a global hotspot for monitoring biodiversity, water quality and ecosystem resilience. This was published in the open-access, peer-reviewed journal One Ecosystem.

How dinosaurs digested food has long remained a mystery because soft tissues such as stomachs and intestines are rarely preserved in the fossil record. In a new study, researchers analyzed the shapes and wear patterns of gastroliths—stones preserved in the abdominal cavities of dinosaurs—and compared them with those of living birds and crocodilians. The results suggest that rounded, heavily worn gastroliths indicate the presence of muscular stomachs used to grind food, while angular gastroliths are associated with less muscular stomachs. Applying this framework to dinosaurs, the team found evidence that different groups evolved distinct digestive strategies. Some toothless theropods likely processed plant material using bird-like muscular stomachs, whereas herbivorous dinosaurs such as sauropods and ornithischians may have relied more on their teeth and prolonged intestinal fermentation than on gastrolith-assisted grinding. The study presents a new hypothesis for the evolution of dinosaur digestive systems and provides a framework for reconstructing feeding biology by integrating gastrolith evidence with other dietary indicators.

Erosion removes more than soil

A paper published in Carbon Research reports that water erosion can intensify soil carbon loss not only by transporting soil downslope, but also by changing how microorganisms use the carbon that remains. Working in black soils of northeastern China, the team examined 0–100 cm soil profiles from erosion-prone upper slopes and depositional lower slopes to determine how erosion reshapes soil organic carbon (SOC) decomposition across depth.

The authors found that the strongest biological response occurred in the 0–40 cm topsoil. Upper slopes had lower SOC content and lower colloidal organic carbon, especially in the 2–10 μm fraction, than lower slopes. At the same time, SOC degradation rates in the upper slope were 41%–48% higher during incubation, indicating that erosion was associated with faster microbial conversion of soil carbon to CO₂.

Microbes adapt to carbon scarcity

The work combined field sampling, laboratory incubation, extracellular enzyme assays, 16S rRNA sequencing, and quantification of carbon-cycling functional genes. This integrated design allowed the authors to connect changes in carbon pools with microbial carbon limitation, community composition, and decomposition potential along slope position and soil depth.

According to the results, erosion reduced carbon availability in upper-slope topsoil and increased signs of microbial carbon limitation. Specific activities of carbon-, nitrogen-, and phosphorus-acquiring enzymes per unit SOC were higher in the upper slope, with β-glucosidase activity showing a marked increase. Microbial communities also shifted toward taxa associated with decomposition of more resistant substrates, particularly Streptomyces, which was enriched in the upper slope and positively correlated with SOC decomposition.

Functional genes point to recalcitrant carbon use

The upper slope also showed greater abundance of several genes linked to organic carbon breakdown in the top 40 cm, including genes associated with degradation of plant-derived compounds. The authors interpret this pattern as evidence that microorganisms under erosion stress reallocated effort toward accessing recalcitrant carbon substrates, rather than relying mainly on more readily available carbon pools.

Boston College scientists have determined a newly discovered meteorite from Mars is 1.27-billion years old and derived from a previously unsampled, pristine region of the Red Planet, the team reported recently in the journal Geochimica et Cosmochimica Acta. Revealing the age of the meteorite, discovered in Algeria in 2019, adds a previously uncharacterized rock type within a 1.8-billion year data gap in the magmatic and volcanic history of Mars.

By studying how seismic waves travel through frozen soil on Earth, a University of Maryland geophysicist helped develop a better way to detect water ice on the moon—a critical resource for future astronauts and extended lunar missions.

The gas surrounding biomass during heating may be just as important as temperature in determining the quality of the biochar produced, according to a new review published in Biochar.