The landscape of the McMurdo Dry Valleys, Antarctica has been considered quite stable. In 2012, we discovered extensive permafrost degradation along several km of Crescent Stream. Here we document the responses to water quality, specifically changes to dissolved major ion and suspended sediment characteristics. Stream nitrate concentrations were greater than observed in the stream over the previous ~ 20 years, suggesting potentially significant impacts for stream and downstream lake ecosystems.

Simple microbial decomposition models show distinct responses to warming under different assumptions of how complex organic matter is broken down. If there are limitations other than microbial enzyme availability, the short-term respiration response is dampened and the decomposition dynamics resemble traditional first-order decay used in most biogeochemistry models. Further, microbial adjustment to respiratory cost for enzyme production reduces overall sensitivity to temperature.

We reconstruct the observed variability and mean state in pH and aragonite saturation state around Australia at high spatial resolution and reconstruct the changes that have occurred in the Australian region over the last 140 years. We find that large changes in aragonite saturation state and pH have very different spatial patterns, which suggests that the biological responses to ocean acidification are likely to be non-uniform and dependent on the relative sensitivity of organisms to change.

The mean riverine DIN export of 49 watersheds in Taiwan is ∼ 3800 kg N km⁻² yr⁻¹, 18 times the global average. The mean riverine DIN export ratio is 0.30–0.51, which is much higher than the average of 0.20–0.25 of large rivers around the world, indicating excessive N input relative to ecosystem retention capacity. The DIN export ratio is positively related to agriculture input, and levels of human disturbance and watersheds with high DIN export ratios are likely at advanced stages of N excess.

We use stable isotope data from carbonates to provide a palaeoenvironmental reconstruction covering the last 637 kyr at Lake Ohrid (FYROM/Albania). Our results indicate a relatively stable climate until 450 ka, wetter climate conditions at 400–250 ka, and a transition to a drier climate after 250 ka. This work emphasises the importance of Lake Ohrid as a valuable archive of climate change in the northern Mediterranean region.

Soil denitrification is considered the most un-constrained process in the global N cycle due to uncertain in situ N₂ flux measurements, particularly in natural and semi-natural terrestrial ecosystems. The ¹⁵N gas-flux method was adapted by lowering the ¹⁵N tracer application rate to 0.04–0.5 kg ¹⁵N ha⁻¹. The minimum detectable flux rates were 4 μg N m⁻² h⁻¹ and 0.2 ng N m⁻² h⁻¹ for the N₂ and N₂O fluxes respectively. The acetylene inhibition technique underestimated denitrification rates by a factor of 4.

A process-based, weather-driven model for ammonia emission from a urine patch has been developed and its sensitivity to various factors assessed. The model can simulate the ammoniacal nitrogen content, pH and the water content of the soil under a urine patch. The simulated variables were in a good agreement with the measurements. The sensitivity analysis highlighted the vital role of temperature in ammonia exchange. The model is potentially suitable for larger scale application.

Direct human impact on a catchment (fertilizer input, soil disturbance, urbanization) is asymmetrically linked with inherent catchment properties (geology, soil, topography), which together determine catchment vulnerability to human activity. To quantify the influence of physical, hydrologic, and anthropogenic controls on surface water quality, we used a 5-year high-frequency water chemistry data set from three contrasting headwater catchments in western France.

Climate change in western Siberia and permafrost boundary migration will essentially affect the elements controlled by underground water feeding (DIC, alkaline earth elements (Ca, Sr), oxyanions (Mo, Sb, As) and U). The thickening of the active layer may increase the export of trivalent and tetravalent hydrolysates in the form of organo-ferric colloids.

The present manuscript provides an analysis of the interannual variability of the phytoplankton seasonality in the Mediterranean Sea, based on 16 years of ocean color data. Important interannual variabilities at regional scale were highlighted and related to environmental factors. Our results demonstrate also that seasonal patterns retrieved from satellite allow to identify the evolution of an oceanic area and to summarize the huge quantity of information that the satellite data offer.

Methane (CH₄) emissions from hydroelectric reservoirs could represent a significant fraction of global CH₄ emissions from inland waters and wetlands. The first quantification of emissions downstream of a subtropical reservoir shows that they contribute only 10 to 30 % of total CH4 emissions from the reservoir. This surprisingly low contribution is due to the seasonal reservoir overturn and the effect of the turbine on re-aerating the reservoir water column.

Management of forests may be able to mitigate climate change. However, those efforts may be negated by climate change impacts. This project simulated four productivity scenarios for a temperate coniferous forest. The coldest ecoregions were projected to be carbon sinks, but the warmest are at risk of becoming carbon sources to the atmosphere. Effects varied among species and site conditions, indicating that both of these factors need to be considered when planning mitigation and adaptation.

Automated chambers are a promising tool to improve our understanding of short-term dynamics and diurnal cycles of soil greenhouse gas fluxes. Here we compared two commercially available automated chambers systems under a wide range of environmental conditions to test their strengths and weaknesses. Furthermore, the study offers new insights into the potential of automated chambers to provide unbiased nighttime soil respiration measurements.

The water properties of the coastal ocean such as temperature, salt, oxygen, or chlorophyll content vary spatially, and estimates need to be made regarding the scales of variability. Here, we use statistical techniques to determine the spatial variability of ocean properties from high-resolution measurements by gliders. We show that biological activity is patchy compared to the distribution of physical characteristics, and that the size and shape of this is determined by coastal ocean processes.

In a low-oxygen eddy in the tropical Atlantic, total zooplankton biomass was increased. Larger plankton avoided the oxygen minimum zone (OMZ, < 20 µmol O₂ kg⁻¹). We identified four strategies by different plankton groups: (i) shallow OMZ avoidance and compression at surface, (ii) migration to shallow OMZ core during daytime, migration to surface at nighttime, (iii) residing in shallow OMZ day and night and (iv) migration through the shallow OMZ from oxygenated depths to surface and back.