This study aims at inspecting organic matter dynamics affecting the survival and carbon sink potential of salt marshes, which are valuable yet endangered wetland environments. Measuring the organic matter content in marsh soils and its relationship with environmental variables, we observed that the organic matter accumulation varies at different scales, and it is driven by the interplay between sediment supply and vegetation, which are affected, in turn, by marine and fluvial influences.

We measured nutrients and dissolved organic matter for 1 year in a eutrophic tropical estuary to understand their sources and cycling. Our data show that the dissolved organic matter originates partly from land and partly from microbial processes in the water. Internal recycling is likely important for maintaining high nutrient concentrations, and we found that there is often excess nitrogen compared to silicon and phosphorus. Our data help to explain how eutrophication persists in this system.

A hydraulic model approach is presented that can be added to any physiologically based ecosystem model. Simulated plant water potential triggers stomatal closure, photosynthesis decline, root–soil resistance increases, and sapwood and foliage senescence. The model has been evaluated at an extremely dry site stocked with Aleppo pine and was able to represent gas exchange, soil water content, and plant water potential. The model also responded realistically regarding leaf senescence.

The study investigates the impact of decreasing oxygen in the ocean on macrofaunal communities using the BUS as an example. It identifies distinct shifts in community composition and feeding guilds across oxygen zones, with nematodes dominating dysoxic areas. These findings underscore the complex responses of benthic organisms to oxygen gradients, crucial for understanding ecosystem dynamics in hypoxic environments and their implications for marine biodiversity and sustainability.

Do-it-yourself hardware is a new way to improve measurement resolution. We present a low-cost, automated system for field measurements of low nitrate concentrations in soil porewater and open water bodies. All data hardware components cost USD 1100, which is much cheaper than other available commercial solutions. We provide the complete building guide to reduce technical barriers, which we hope will allow easier reproducibility and set up new soil and environmental monitoring applications.

The ratio between atmospheric O₂ and CO₂ can be used to characterize the carbon balance at the surface. By combining a model and observations from the Hyytiälä forest (Finland), we show that using atmospheric O₂ and CO₂ measurements from a single height provides a weak constraint on the surface CO₂ exchange because large-scale processes such as entrainment confound this signal. We therefore recommend always using multiple heights of O₂ and CO₂ measurements to study surface CO₂ exchange.

Biologically available (fixed) nitrogen (N) is a limiting nutrient for life in the ocean. Under low-oxygen conditions, fixed N is either removed via denitrification or retained via dissimilatory nitrate reduction to ammonia (DNRA). Using in situ incubations in the Santa Barbara Basin, which undergoes seasonal anoxia, we found that benthic denitrification was the dominant nitrate reduction process, while nitrate availability and organic carbon content control the relative importance of DNRA.

This paper explores the climate processes that drive increasing global average temperatures in zero-emission commitment (ZEC) simulations despite decreasing atmospheric CO₂. ACCESS-ESM1.5 shows the Southern Ocean to continue to warm locally in all ZEC simulations. In ZEC simulations that start after the emission of more than 1000 Pg of carbon, the influence of the Southern Ocean increases the global temperature.

The tropical Andes contains unique landscapes where forest patches are surrounded by tussock grasses and cushion-forming plants. The aboveground vegetation composition informs us about belowground nutrient availability: patterns in plant-available nutrients resulted from strong biocycling of cations and removal of soil nutrients by plant uptake or leaching. Future changes in vegetation distribution will affect soil water and solute fluxes and the aquatic ecology of Andean rivers and lakes.