Little is known about how hypoxia influences mangrove fish assemblages. In situ video observations reveal species-specific avoidance strategies in response to developing hypoxia in a mangrove forest. Taxa commonly using mangroves could withstand hypoxia, while others usually associated with reef habitats were not recorded below 70 % saturation. These results suggest that hypoxia is an important factor shaping mangrove fish assemblages and could explain the low species richness usually observed.

In this study, a new model is presented, which was specifically designed to study the development and carbon storage of blanket peatlands since the last ice age. In the past, two main processes (declining forest cover and rising temperatures) have been proposed as drivers of blanket peatland development on the British Isles. The simulations performed in this study support the temperature hypothesis for the blanket peatlands in the Cairngorms Mountains of central Scotland.

N₂O concentrations were subject to strong variations accompanying glacial–interglacial but also rapid climate changes over the last 21 kyr. The sources of these N₂O changes can be identified by measuring the isotopic composition of N₂O in ice cores and using the distinct isotopic composition of terrestrial and marine N₂O. We show that both marine and terrestrial sources increased from the last glacial to the Holocene but that only terrestrial emissions responded quickly to rapid climate changes.

To better understand time-series data in lake sediment cores in times of rapidly changing climate, we study within-lake spatial variabilities of environmental indicator data in 38 sediment surface samples along spatial habitat gradients in the boreal deep Lake Bolshoe Toko (Russia). Our methods comprise physicochemical as well as diatom and chironomid analyses. Species diversities vary according to benthic niches, while abiotic proxies depend on river input, water depth, and catchment lithology.

The tundra plays a pivotal role in Arctic mercury cycling by storing atmospheric mercury deposition and shuttling it to the Arctic Ocean. We used the isotopic fingerprint of mercury to investigate the processes controlling atmospheric mercury deposition. We found that the uptake of atmospheric mercury by vegetation was the major deposition source. Direct deposition to snow or soils only played a minor role. These results improve our understanding of Arctic mercury cycling.

Taking a 2-year atmospheric record of atmospheric oxygen and the greenhouse gases N₂O, CO₂, and CH₄, made at a coastal site in the Namib Desert, we estimated the fluxes of these gases from upwelling events in the northern Benguela Current region. We compared these results with flux measurements made on a research vessel in the study area at the same time and found that the two approaches agreed well. The study region was a source of N₂O, CO₂, and CH₄ to the atmosphere during upwelling events.

This study demonstrates the implications of Molinia caerulea colonization in Sphagnum peatland on the C fluxes by enhancing the CO₂ uptake by photosynthesis (but which led to higher CO₂ and CH₄ emissions) and also on the parameters controlling it (by increasing the temperature sensitivity of the CH₄ emissions). Furthermore, roots and litter of Molinia caerulea could provide additional substrates for C emissions and should be taken into account in further works.

Monthly measurements of nitrous oxide (N₂O), a potent greenhouse gas and ozone depletion agent, were conducted at Boknis Eck (BE), a time series station in the southwestern Baltic Sea, since July 2005. Low N₂O concentrations were observed in autumn and high in winter and early spring. Dissolved nutrients and oxygen played important roles in N₂O distribution. Although we did not observe a significant N₂O trend during 2005–2017, a decrease in N₂O concentration and emission seems likely in future.

We investigated abundance, potential activity, and diversity of soil ammonia-oxidizing archaea (AOA) and bacteria (AOB) in five Antarctic tundra patches, including penguin colony, seal colony, and tundra marsh. We have found (1) sea animal colonization increased AOB population size.; (2) AOB contributed to ammonia oxidation rates more than AOA in sea animal colonies; (3) community structures of AOB and AOA were closely related to soil biogeochemical processes associated with animal activities.

Marine algae might contribute to the observed methane oversaturation in oxic waters, but so far direct evidence for methane production by marine algae is limited. We investigated three widespread haptophytes for methane formation. Our results provide unambiguous evidence that all investigated marine algae produce methane per se and at substantial rates. We conclude that each of the three algae studied here could substantially account for the methane production observed in field studies.