Rainfall-induced lateral and vertical microplastic transport of varying sizes in agricultural fields.

Agricultural soils, particularly those utilizing plastic products for crop production, are increasingly recognized as sources of microplastics (MPs) to aquatic ecosystems. In this research, we investigate the transport of polyethylene MPs of three different size ranges (53-63 μm, 125-150 μm and 425-500 μm) in an agricultural soil during a plot-based rainfall simulation. Using a combination of fluorescent particles and high-frequency photography, we tracked the number of MPs on the soil surface throughout the rainfall simulation, measured the depth MPs migrated into the soil profile and the number of MPs which were transported in surface runoff.

The Transport of Microplastics from Soil in Response to Surface Runoff and Splash Erosion.

Erosion is hypothesized to be a significant process transporting microplastics (MPs) from soils to aquatic environments, however, the factors controlling this process are poorly understood. Using a novel combination of high-frequency photography and fluorescent particles, we compared the transport of three MPs to that of a sand particle during rainfall simulations: linear low-density polyethylene (LLDPE), polystyrene (PS), and poly(methyl methacrylate) (PMMA). We measured the "real time" movement of particles on the soil surface alongside the number of particles transported through splash erosion and surface runoff.

To participate or not to participate? A qualitative investigation of students' complex motivations for verbal classroom participation.

Previous research has suggested that making classrooms more active and student centered improves learning, and this usually involves encouraging student talk in the classroom. However, the majority of students remain silent during whole-class discussions, and men's voices are more likely to be heard in science classrooms. Previous interview studies and quantitative studies have discussed the role instructors play in encouraging or discouraging participation, the weight students put into the fear of negative evaluation, and other factors.

Deep denitrification: Stream and groundwater biogeochemistry reveal contrasted but connected worlds above and below.

Excess nutrients from agricultural and urban development have created a cascade of ecological crises around the globe. Nutrient pollution has triggered eutrophication in most freshwater and coastal ecosystems, contributing to a loss in biodiversity, harm to human health, and trillions in economic damage every year. Much of the research conducted on nutrient transport and retention has focused on surface environments, which are both easy to access and biologically active.

Megafire affects stream sediment flux and dissolved organic matter reactivity, but land use dominates nutrient dynamics in semiarid watersheds.

Climate change is causing larger wildfires and more extreme precipitation events in many regions. As these ecological disturbances increasingly coincide, they alter lateral fluxes of sediment, organic matter, and nutrients. Here, we report the stream chemistry response of watersheds in a semiarid region of Utah (USA) that were affected by a megafire followed by an extreme precipitation event in October 2018.