Climate change affects Arctic ecosystems. This includes thawing of permafrost (ground below 0 °C) and an increase in rainfall. Both have substantial impacts on the chemical composition of river water. We compared the composition of small rivers in the low and high Arctic with the large Arctic rivers. In comparison, dissolved organic matter in the small rivers is more susceptible to degradation; thus, it could potentially increase carbon dioxide emissions. Rainfall events have a similar effect.

Organic soils drained for crop production or grazing land have high potential for nitrous oxide emissions. The present study investigated the regulation of N₂O emissions in a raised bog area drained for agriculture. It seems that archaeal ammonia oxidation and either chemodenitrification or nitrifier denitrification were considered to be plausible pathways of N₂O production in spring, whereas in the autumn heterotrophic denitrification may have been more important at arable sites.

Our study illustrates that the competition processes for light and soil resources in a game-theoretic vegetation demographic model can substantially change the prediction of the contribution of ecosystems to the global carbon cycle. The model that tracks the competitive allocation strategies can generate significantly different ecosystem-level predictions than those with fixed allocation strategies.

We investigated the potential for chemical reduction of nitrite into nitrous oxide (N₂O) in soils from tropical peat. Among treatments, irradiation resulted in the lowest biological interference and least change of native soil chemistry (iron and organic matter). Nitrite depletion was as high in live or irradiated soils, and N₂O production was significant in all tests. Thus, nonbiological production of N₂O may be widely underestimated in wetlands and tropical peatlands.

This calibration study shows that despite isotope heterogeneity along grass leaves, the triple oxygen isotope composition of bulk leaf phytoliths can be estimated from the Craig and Gordon model, a mixing equation and a mean leaf water–phytolith fractionation exponent (lambda) of 0.521. The results strengthen the reliability of the ¹⁷O–excess of phytoliths to be used as a proxy of atmospheric relative humidity and open tracks for its use as an imprint of leaf water ¹⁷O–excess.

The effect of soil water availability (SWA) on emissions of isoprenoids by trees was studied by setting up a parameterization from published data. SWA impact on isoprene emissions can be described by a growth type curve, while monoterpene emissions display a pattern reflecting plants’ stomata opening. Sesquiterpene fluxes tend to increase at the start of severe drought until resources decline. Feedbacks on atmospheric processes such as ozone and aerosol particles are further studied.

A screening of more than 100 strains from 65 different species revealed that the ice nucleation activity within the fungal genus Fusarium is more widespread than previously assumed. Filtration experiments suggest that the single cell-free Fusarium IN is smaller than 100 kDa (~ 6 nm) and that aggregates can be formed in solution. Exposure experiments, freeze–thaw cycles, and long-term storage tests demonstrate a high stability of Fusarium IN under atmospherically relevant conditions.

Interdisciplinary teams can only capitalize on innovative ideas if members work well together through collegial and efficient use of field sites, instrumentation, samples, data, and model code. Thus, biogeoscience teams may benefit from developing a set of best practices for collaboration. We present one such example from a the Susquehanna Shale Hills critical zone observatory. Many of the themes from our example are universal, and they offer insights useful to other biogeoscience teams.

Sea level rise alters hydrology and vegetation in coastal wetlands. We studied effects of freshwater, saltwater, and wood on soil microbial activity in a freshwater forested wetland. Saltwater reduced CO₂/CH₄ production compared to freshwater, suggesting large changes in greenhouse gas production and microbial activity are possible due to saltwater intrusion into freshwater wetlands but that the availability of C in the form of dead wood (as forests transition to marsh) may alter the magnitude.

We collated peer-reviewed publications presenting GHG flux data for drained organic forest soils in boreal and temperate climate zones, focusing on data that have been used, or have the potential to be used, for estimating net annual soil GHG emission/removals. We evaluated the methods in data collection and identified major gaps in background/environmental data. Based on these, we developed suggestions for future GHG data collection to increase data applicability in syntheses and inventories.

Our results demonstrate the importance of oxygen in regulating the fate of nitrogen (N) in the sediments of Lake Lugano south basin, Switzerland. Hence, our study suggests that, by changing oxygen concentration in bottom waters, the seasonal water column turnover may significantly regulate the partitioning between N removal and N recycling in surface sediments, and it is likely that a similar pattern can be expected in a wide range of environments.

Across North America and Europe, goose populations have increased exponentially in response to agricultural intensification. By using an experimental approach, we empirically demonstrated that geese act as bio-vectors, making terrestrial nutrients more bioavailable to freshwater systems. The study revealed that the nutrient loading from goose faeces has the potential to change phytoplankton community composition, with a shift toward an increased presence of cyanobacteria.

Commonly used nitrogen fertilisers, ammonium nitrate, urea and urea coated with a urease inhibitor, were applied to experimental plots. Fertilisation with ammonium nitrate supported the largest yields but also resulted in the largest nitrous oxide emissions. Urea was the largest emitter of ammonia. The coated urea did not significantly increase yields; however, ammonia emissions were substantially smaller than urea. The coated urea was the best environmentally but is economically unattractive.