Beromünster tall tower is the flagship of the densely placed Swiss greenhouse gas observation network (CarboCount CH). In this research article we report the first 2 years of the continuous greenhouse gas measurements using cavity ring down spectroscopy analyzer from this tall tower. We have adopted a purely observation based, multi-species and multi-level approach to characterize the site with respect to sources and sinks of natural and anthropogenic origin at diurnal to annual timescales.

Restoration is suggested as a strategy to reduce the large greenhouse gas (GHG) emissions from abandoned peat extraction areas. This study investigated GHG fluxes in restored sites with high and low water table level in comparison to a bare peat area. The results show that on the annual scale, both restored sites acted as similar GHG sources 3 years after restoration. However, their net GHG emissions were only half of those from the bare peat area, indicating considerable mitigation potential.

N₂ fixation rates were measured daily in ~ 50 m³ mesocosms deployed in New Caledonia to investigate the high-frequency dynamics of diazotrophy and the fate of diazotroph-derived nitrogen (DDN) oligotrophic ecosystems. ~ 10 % of UCYN-C from the water column were exported daily to the traps, representing as much as 22.4 ± 5.5 % of the total POC exported at the height of the UCYN-C bloom. 16 ± 6 % of the DDN was released to the dissolved pool and 21 ± 4 % was transferred to non-diazotrophic plankton.

Coral growth rate is known to influence the δ¹⁸O and δ¹³C isotope record to a lesser extent. Recent published data show differences in growth parameters between female and male coral; thus, skeletal δ¹⁸O and δ¹³C are hypothesized to be different in each sex. Our results support the hypothesis of a sex-associated difference in skeletal δ¹⁸O and δ¹³C signal, and suggest that environmental conditions and coral growth parameters affect skeletal isotopic signal differently in each sex.

It is unclear how the nitrogen (N) cycle regulates climate change through influencing carbon sequestration. By using meta-analysis, we tested a popular hypothesis, progressive N limitation (PNL), which postulates that greater N sequestration in organisms leads to declining N availability for further plant growth under elevated CO₂. Our analyses suggest that extra nitrogen supply by increased biological N fixation and decreased leaching may potentially alleviate PNL.

The intensive agriculture is facing environmental problems due to low nitrogen use efficiency (NUE) in China. Integrated soil-crop system management (ISSM) has been developed to increase crop yield and NUE. We investigated greenhouse gas intensity after accounting for CO₂ emissions from all sources, including methane and nitrous oxide emissions, agrochemical inputs and farm operations and sinks. We found that the ISSM strategies are promising for both food security and environmental protection.

Some benthic foraminifera can incorporate chloroplasts from microalgae. We investigated chloroplast functionality of two benthic foraminifera (Haynesina germanica & Ammonia tepida) exposed to different light levels. Only H. germanica was capable of using the kleptoplasts, showing net oxygen production. Chloroplast functionality time was longer in darkness (2 weeks) than at high light (1 week). Kleptoplasts are unlikely to be completely functional, thus requiring continuous chloroplast resupply.

This manuscript presents a detailed analysis of transport and transformation of dissolved organic matter along the Zambezi River and its largest tributary. A particular focus is put on the effects of floodplains/wetlands and reservoirs as well as low-flow vs. high-flow conditions on the longitudinal patterns in DOM concentration and composition. It is the first study to present such a detailed analysis for a whole, large river system, and in particular for a tropical river other than the Amazon.

Coccolithophore Emiliania huxleyi (Haptophyta) strains collected from the subarctic North Pacific and Arctic oceans during the R/V MIRAI cruise in 2010 (MR10-05) were established as clone cultures. This is the first report of a detailed morphometric and morphological investigation of Arctic Ocean coccolithophore strains. Taken together, our results suggest that calcification productivity can be used to predict future oceanic environmental conditions in the polar regions.

Chronology is fundamental in paleoclimatology for understanding timing of events and their origin. In this paper we try to obtain a more detailed chronology for the interval comprised between ca. 140 and 70 ka for the DEEP core in Lake Ohrid using regional independently-dated archives (i.e. speleothems and/or lacustrine succession with well-dated volcanic layers). This allows to insert the DEEP chronology within a common chronological frame between different continental and marine proxy records.

To study the distribution of airborne ragweed pollen in changing environments and associated health risks over Europe, we introduce an approach with explicit treatment of pollen ripening, release and dispersion due to environmental drivers in an online modelling framework where climate is integrated with dispersion and vegetation production. From a simulated pollen season and concentration pattern health risks are evaluated through calculation of exposure time above health-relevant threshold levels.

Lakes play important roles in controlling organic matter derived from watersheds and within-lake production. The organic matter is normally measured by elemental quantities, such as carbon(C) and nitrogen(N), because the two elements are essential for aquatic ecosystems. We observed an decrease of C, but an increase of N in organic matters in a lake. The reason of the different pattern might be that inorganic N in the lake appeared to be recycled to produce organic N due to within-lake processes.

e main goal of the VAHINE project was to study the fate of N₂ fixation in the ocean. Three large-volume (~ 50 m³) mesocosms were deployed in a tropical oligotrophic ecosystem (the New Caledonia lagoon, south-eastern Pacific). This introductory paper describes the scientific objectives of the project in detail as well as the implementation plan: the mesocosm description and deployment, the selection of the study site, and the logistical and sampling strategy.

This work deals with one of the central topics in biogeochemistry, the factors controlling the degradation of organic matter. We found the contribution of dissolved (cell-free) to the total extracellular enzymatic activities follows a strong seasonal pattern, with the largest proportions during cold periods. Our results suggest that temperature changes can have strong implications in the hydrolysis of organic matter, suggesting a link between global warming and the degradation of organic matter.

The marine cycle of calcium carbonate (CaCO₃) influences the distribution of CO₂ between atmosphere and ocean, and thereby climate. We constrain export of biogenic CaCO₃ (globally: 0.72–1.05 Gt C yr⁻¹) and dissolution within the water column (~ 80 %) in a novel Monte Carlo set-up with the Bern3D model based on alkalinity data. Whether CaCO₃ dissolves in the upper ocean remains unresolved. We recommend using constant (saturation-independent) dissolution rates in Earth system models.

Over the past decades large changes have been observed in the biogeographical dispersion of marine life resulting from climate change. To better understand present and future trends it is important to document and fully understand the biogeographical response of marine life during episodes of environmental change in the geological past. Here we investigate the response of phytoplankton, the base of the marine food web, to a rapid cold spell, interrupting greenhouse conditions during the Cretaceous.