Biogeochemistry

Abstract A substantial part of terrestrial nitrous oxide (N 2 O) emissions originates from denitrification in wetlands, and this contribution is expected to rise with ongoing land-use changes, such as wetland drainage, agricultural conversion, and peatland degradation, as well as under global warming. Capturing the spatial and temporal dynamics of N 2 O emissions through measurements and numerica…

Abstract The temperature sensitivity of the decomposition of organic carbon pools is of key importance for modelling carbon turnover in soils. Therefore, examining the factors that determine and influence temperature sensitivity is extremely important. The decomposition of organic matter taken from three soil fractions in four land use areas (grass, spruce, oak and arable) was investigated in a 1…

Abstract Tree–soil interactions regulate carbon and nutrient cycling in forest ecosystems, but widespread dieback can disturb these processes with biogeochemical consequences. We investigated how Abies koreana dieback both responds to, and feeds back on, soil properties in subalpine forests on Mt. Jiri, South Korea. Soils were sampled at 0–5, 5–10, and 10–15 cm depths across nine stands, categori…

Assessing nitrogen (N) mass balance and use efficiency is essential for tracking progress toward sustainable agriculture. However, the links between N surpluses or deficits, crop productivity, and environmental N losses remain poorly understood, particularly in rotational cropping systems. In this study, we combined natural abundance N isotope measurements across soil, water, and crop N pools wit…

Nitrite (NO₂⁻) is known to undergo disproportionation into nitric oxide (NO) and nitrogen dioxide (NO₂) via an abiotic pathway in acidic aqueous solutions. However, whether a direct pathway for its conversion to nitrous oxide (N₂O) exists remains unclear. This study investigated this potential pathway under both ambient air and nitrogen-purged conditions. Initial experiments yielded substantial N…

Abstract Plant litter decomposition by microbes plays a major role in soil CO 2 and dissolved organic carbon (DOC) production. Adding reactive nitrogen species is predicted to affect these fluxes, but it’s unclear to what extent since both microbial community composition and abiotic soil and litter chemistry will influence outcomes. We therefore sought to understand broad geochemical trends acros…

Abstract A fraction of organic carbon in beach sands is mobilizable as dissolved organic matter (DOM). The molecular composition of this mobilizable DOM and its relation to microbial metabolism is central for biogeochemical processes in beach ecosystems, yet, still poorly understood. To identify these DOM-microbe interactions, we analyzed two continuous 24-m-long sediment cores from the high-ener…

Abstract Changes in precipitation patterns can influence soil nitrogen (N) cycling by altering the timing and extent of moisture availability. Arid conditions, associated with more frequent and severe droughts, can increase soil inorganic N concentrations when diffusion constraints decouple N sources and sinks, making this N susceptible to loss. Further, shifts in precipitation patterns in one se…

Water limitations are forcing producers to transition large areas of currently irrigated farmland into dryland agriculture across the Western U.S. with unclear effects on global soil carbon (C) dynamics. An experiment established in 2017 in a no-till, maize system in Colorado suggested that soil heterotrophic respiration (Rh) following irrigation retirement was co-regulated by water and available…

Agricultural nitrate pollution, largely associated with high-intensity fertilizer application and untreated or insufficiently treated waste inputs, has become a major driver of water quality degradation worldwide. Agricultural ditches, as key recipients of surface runoff and lateral seepage, function as both transport conduits and biogeochemical hotspots for nitrogen transformation. In salt-affec…

Chemical sequential extraction and high-resolution diffusive gradients in thin-film (DGT) techniques were employed to study the mobilization behavior and underlying mechanisms of phosphorus (P) in estuarine sediments. This study focused on two contrasting subtropical estuaries in the Maowei Sea, northern Beibu Gulf: the Maoling River Estuary (MLRE, dominated by natural processes) and the Qin Rive…

Globally, rivers are vital conduits transporting and processing terrestrial carbon, and are generally considered to act as source of carbon dioxide (CO2) towards the atmosphere. A large amount of soil organic carbon (SOC) is transferred from the land surface to river systems each year, where it mixes and interacts with the autochthonous carbon pool (i.e., produced in-stream via photosynthesis). T…

Wetlands comprise only 5–8% of land surface but hold 20–30% of estimated soil carbon globally. However, wetlands are also significant sources of greenhouse gases such as methane (CH4) and nitrous oxide (N2O). Disturbances such as wildfires can alter the balance between carbon storage and greenhouse gas production in wetland systems; therefore, it is crucial to understand wetland response and reco…

Abstract The substrate production process for the edible mushroom Agaricus bisporus offers a controlled model environment to investigate organic matter transformation. Despite the central role of humic substances (HS) in organic matter dynamics, detailed insights into their compositional changes during decomposition are limited. We investigated the formation and transformation of dissolved and so…

Abstract White-sand forests contribute significantly to dissolved organic matter (DOM) production in the central Amazon, forming blackwater rivers that dominate organic matter export from the Amazon basin to the ocean. Despite their importance in controlling DOM export, white-sand forests are understudied, and it remains unclear whether systematic changes in the formation of blackwater DOM occur …

Shifts in precipitation patterns with less frequent rain events accompanied by global warming will trigger soil drying and rewetting, even in humid regions. Because rewetting of dried soil provokes pulse carbon dioxide (CO2) emissions from soils, the chronic soil dry-wet cycle (DWC) in humid regions may provide positive feedback, contributing to global warming. In this study, we aimed to reveal t…

Understanding and modeling soils and soil organic matter (SOM) are central to a variety of human needs, from food production to ecosystem management. Soil data have been collected for over a century, but the global spatial and process representativeness of soil data remains unclear. We assessed the representativeness of currently available soil data that could be used to understand a variety of S…

The online version contains supplementary material available at 10.1007/s10533-025-01304-w.

Understanding the biogeochemical consequences of fire and land-use history in tropical upland systems is essential for sustainable soil management. We investigated the vertical distribution of stable carbon (δ13C) and nitrogen (δ15N) isotopes in soils under rotational shifting cultivation (RSC) in Northern Thailand. Three fields with distinct land-use histories were analyzed: a continuously fallo…