Seaweeds can store carbon in the ocean, but traditional methods in food chemistry fail to measure alginate—a major organic component derived from brown algae—in seafloor mud. We developed a novel extraction method for alginate in marine sediments. This allows for high recovery rates, and we successfully used this method to quantify alginate in marine sediments from northern Japan. Our work establishes a reliable method to track alginate on the ocean floor.

Adjusting Rock-Eval® cycle is needed to avoid the need for post-hoc corrections to estimate soil organic (SOC) and inorganic (SIC) carbon. PYRO520 is a cycle with a pyrolysis ending at 520°C instead of 650°C to avoid SIC decomposition while preserving the SOC characterization during pyrolysis. This cycle corrects the misallocation of the end-of-pyrolysis signals and thus repeatably and accurately estimates SOC and SIC contents without using corrections, while preserving the SOC characterization.

Arable soils emit or absorb greenhouse gases such as carbon dioxide, nitrous oxide and methane. This study compared two gas analysis techniques for determining greenhouse gas fluxes under field conditions using the closed chamber method. Fluxes were measured simultaneously using the widely applied gas chromatography (GC) and the emerging mid-infrared laser absorption spectroscopy (LAS) technique. Our results showed that LAS is a reliable alternative to GC, particularly for low flux rates.

Peatlands are complex and widespread ecosystems that store large amounts of carbon through photosynthesis. Carbon fixation depends on solar irradiance, and the relationship between them is called the photosynthesis-irradiance or “PI” curve. We developed a simple, portable chamber to measure PI curves in peatlands, taking into account complex plant assemblages and microhabitat variability. This tool may help scientists better understand carbon dynamics in these ecosystems.