The distribution of N₂O in fjord-like estuaries is poorly described in the Southern Hemisphere. Our study describes N₂O distribution and its drivers in one such system in Macquarie Harbour, Tasmania. Water samples were collected seasonally in 2022 and 2023. Results show the system removes atmospheric N₂O when river flow is high, whereas the system emits N₂O when the river flow is low. N₂O generated in basins is intercepted by the surface water and exported to the ocean during high river flow.

We present a fully automatic, low-cost soil–plant enclosure system to monitor CO₂ and evapotranspiration fluxes within greenhouse experiments. It operates in two modes: independent, using low-cost sensors, and dependent, where multiple chambers connect to a single gas analyzer via a low-cost multiplexer. This system provides precise, accurate measurements and high temporal resolution, enabling comprehensive monitoring of plant–soil responses to various treatments and conditions.

We investigated the formation of early Archean (~3.5–3.4 Ga) carbonates in the Pilbara Craton, Western Australia, demonstrating the presence of an oceanic crust, an organo-carbonate, and a microbial carbonate factory. Notably, (a)biotic organic matter and hydrothermal fluids were centrally involved in carbonate precipitation. Since carbonates were widespread in the Archean, they may have constituted major carbon sinks that modulated early Earth’s carbon cycle and, hence, climate system.

Despite interest in modeling the biogeochemical uptake and cycling of the trace metal zinc (Zn), measurements of Zn uptake in natural marine phytoplankton communities have not been conducted previously. To fill this gap, we employed a stable isotope uptake rate measurement method to quantify Zn uptake into natural phytoplankton assemblages within the Southern Ocean. Zn demand was high and rapid enough to depress the inventory of Zn available to phytoplankton on seasonal timescales.

This study exposed a natural community to two non-CO₂-equilibrated ocean alkalinity enhancement (OAE) deployments using different minerals. Adding alkalinity in this manner decreases dissolved CO₂, essential for photosynthesis. While photosynthesis was not suppressed, bloom formation was mildly delayed, potentially impacting marine food webs. The study emphasizes the need for further research on OAE without prior equilibration and on its ecological implications.

In the boreal humic waters of a forest lake and bog, the rate of dissolved organic matter photodegradation is 4 times higher than that of biodegradation. However, given the shallow, light-penetrating layer, the biodegradation provides the largest contribution to CO₂ emissions from water surfaces. Trace metals were partially removed (1–10 %) during photodegradation and biodegradation via precipitation of Fe(III) hydroxides after destabilization of organoferric colloids and organic complexes.

Drainage of boreal peatlands strongly influences soil methane fluxes, with important implications for climatic impacts. Here we simulate methane fluxes in forestry-drained and restored peatlands during the 21st century. We found that restoration turned peatlands into a source of methane, but the magnitude varied regionally. In forests, changes in the water table level influenced methane fluxes, and in general, the sink was weaker under rotational forestry compared to continuous cover forestry.