We studied how invertebrate communities of mudflats are affected by sudden deposition of sediment. We applied sediment layers of different thickness to mudflat communities and studied how their densities, diversity, and behaviour and the exchange of oxygen between the bottom and the water column changed. We found that some species easily diminish in numbers, while others become more active after deposition. The interaction of all species effects influences the environment, i.e. oxygen exchange.

Plant traits are characteristics of plants that are easy to measure and that show how plants function. Values of these traits for many species and locations worldwide are available in trait databases, but these are often incomplete. Here we use different statistical methods to fill the gaps in a trait database of Mediterranean and temperate tree species. Combining traits and environmental information provides more plausible gap-filled databases and preserves the observed trait variability.

The spatial distribution of biological N₂ fixation fluxes to the ocean remains poorly constrained. Here we use nitrogen isotope budgets to identify significant N₂ fixation inputs to the western tropical South Pacific (WTSP), where N₂ fixation supports > 50 % of export production at stations proximal to iron sources. The significant N₂ fixation inputs in the WTSP may offset nitrogen loss in the oxygen-deficient zones of the eastern tropical South Pacific.

The Main Endeavour vent field, a Marine Protected Area, is a target site for the cabled observatory Ocean Networks Canada, providing unprecedented opportunities to better understand vent ecosystem functioning. We report the diversity and food webs of six faunal communities associated with siboglinid tubeworms of the Grotto edifice. Better knowledge of the ecological functioning of these communities will help in assessing the role of the MPA as a management tool for hydrothermal vents ecosystems.

We use an estuarine-watershed modeling system of the Chesapeake Bay to examine the impact climate change may have on the ability of nutrient reduction regulations to increase dissolved oxygen. We find that climate change will move the onset of hypoxia ~7 days earlier, while also decreasing oxygen in the bay primarily due to increased temperature. While this effect is smaller than the increase in oxygen due to nutrient reduction, it is enough to limit the regulation's future effectiveness.

The western tropical South Pacific Ocean has recently been shown to be a hotspot for biological nitrogen fixation. In this study, we examined the horizontal and vertical distribution of heterotrophic prokaryotic production alongside photosynthetic rates, nitrogen fixation rates and phosphate turnover times across the western tropical South Pacific Ocean, in order to relate these fluxes to bottom–up controls (related to nitrogen, phosphate and labile C availability).

We present year-round methane emissions from wetlands in Northeast Siberia that were simulated with a land surface model. Ground-based flux measurements from the same area were used for evaluation of the model results, finding a best agreement with the observations in the summertime emissions that take place in this region predominantly through plants. During winter, methane emissions through the snow contribute 4 % of the total annual methane budget, but these are still underestimated.

Nitrogen (N) is an essential nutrient for plant growth. It would be interesting to detect it using satellite data. The goal was to investigate if it is possible to remotely sense the canopy nitrogen concentration and content of Mediterranean trees using a product calculated from satellite reflectance data, the MERIS Terrestrial Chlorophyll Index (MTCI). The tree plots were located in Catalonia, NE Spain. The relationship between MTCI and canopy N was present but dependent on the type of trees.

We tested a current theory, which proposes an upper limit for organic carbon (OC) stocks independent of increasing carbon input for a soil with already large OC stocks. The soil received a large additional carbon input as sawdust. In response, only the OC stock in 25–50 cm depth increased significantly. We assume, that due to saturation in 0–25 cm, added OC migrates downwards and becomes retained in 25–50 cm. This indicates the possibility to sustainably increase already large OC stocks further.

To bridge the missing links between variable marine elemental stoichiometry, phytoplankton physiology and carbon cycling, we embed four environmentally controlled stoichiometric models into a five-box ocean model. As predicted each model varied in its influence on the biological pump. Surprisingly, we found that variation can lead to nonlinear controls on atmospheric CO₂ and carbon export, suggesting the need for further studies of ocean C : P and the impact on ocean carbon cycling.

To support C exchange measurements, we examined plant and soil attributes in Siberian Arctic tundra. Our results illustrate a typical tundra ecosystem with great spatial variation. Mosses dominate plant biomass and control many soil attributes such as temperature, but variation in moss biomass is difficult to capture by remote sensing. This indicates challenges in spatial extrapolation of some of those plant and soil attributes that are relevant for regional ecosystem and global climate models.

To understand ecological impacts of CO₂-induced ocean acidification and temperature rise, a key question is if organisms become more vulnerable under multiple stressors. Here we tested heart rate and gene expression levels of a limpet under varying pCO₂ and temperature. Results showed that while many individuals are more vulnerable to heat stress under high CO₂ and increased temperature, some animals have the ability to alter their physiology to help them survive under future conditions.

Understanding the mechanisms of coral calcification is limited by the isolation of the calcifying environment. The boron systematics (B / Ca and δ11B) of aragonite have recently been developed as a proxy for the carbonate chemistry of the calcifying fluid, but a variety of approaches have been utilized. We assess the available experimental B / Ca partitioning data and present a computer code for deriving calcifying fluid carbonate chemistry from the boron systematics of coral skeletons.

Here we analyze seasonal cycle of CO₂ biases in 10 CMIP5 models in the SO. We find two main model biases; exaggeration of primary production such that biologically driven DIC changes mainly regulates FCO₂ variability, and an overestimation of the role of solubility, such that changes in temperature dominantly drive FCO2 seasonal changes to an extent of opposing biological CO₂ uptake in spring. CMIP5 models show greater zonal homogeneity in the seasonal cycle of FCO₂ than observational products.

Shallow coastal waters are increasingly experiencing increased nutrient loading. Sediment algae within these systems are responsible for a large portion of C production, but we have limited knowledge of what happens to sediment microbial processing of MPB-C under increased nutrient conditions. This work examines how C-processing pathways change after increased short-term nutrient exposure, finding shifts in processing between microbial groups and increased export of algal C from the sediment.

This paper highlights dynamic nitrogen cycling in a freshwater estuary, with implications for harmful algal blooms and downstream nitrogen loading. Phytoplankton and microbes actively consumed nitrogen in this system, contributing to recycling of nitrogen within the system and permanent nitrogen removal, respectively. However, delivery of nitrogen from the river and fixation of atmospheric nitrogen by phytoplankton outweighed nitrogen uptake, resulting in variable downstream nitrogen delivery.

Deforestation, shifting cultivation and wood harvesting cause large carbon emissions, altering climate. We apply a dynamic global vegetation model in a probabilistic framework. Diverse observations are assimilated to establish an optimally performing model and a large ensemble of model versions. Land-use carbon emissions are reported for individual countries, regions and the world. We find that parameter-related uncertainties are on the same order of magnitude as process-related effects.

Using mesocosms we investigated the effect of the increase in the allochthonous and autochthonous sources of DOM in a tropical lake, in order to simulate its effects on the characteristics of lakes caused by anthropogenic impacts. The seasonal allochthonous input has much larger effects on the lake and, in addition to increasing nutrients, alters the transparency of water and consequently controls the seasonal dynamics of phytoplankton (autochthonous source) and lake ecology.

The ecosystem is a significant sink of carbon dioxide. To quantify this sink, very complex and validated models are required. However, the comparison of modeled and measured energy and matter fluxes in a heterogeneous landscape is still a challenge. On the one hand, models must be applied for various surface types, while on the other hand the comparison of the fluxes is only possible based on the flux source areas. This paper treats the potential aggregation of modeled fluxes and its validation.

Surface waters of the western tropical South Pacific were sampled along a longitudinal 4000 km transect during the stratified period between the Melanesian Archipelago and the western part of the South Pacific gyre. We found a significant biological carbon pump sustained almost exclusively by N₂ fixation and essentially controlled by phosphate availability in the iron-rich Melanesian Archipelago waters which appears to be a net sink for atmospheric CO₂ while the gyre is in a quasi-steady state.

Karst is a kind of typical calcium-rich environment, which is widely distributed. We measured the Ca²⁺ content of 41 plant species, as well as soil total Ca²⁺ and exchange Ca²⁺. We found out that different plants have different ways to high Ca²⁺ adaptation. According to the different high Ca²⁺ adaptation of the 17 dominant species, we divided them into 3 categories: Ca-indifferent plants, high-Ca plants and low-Ca plants. Our results can provide a theoretical basis for vegetation restoration.

Phosphorus (P) release from sediments can delay recovery of eutrophicated waters. For the Stockholm inner archipelago (Baltic Sea), a P budget shows that legacy P release was small and restricted to the 20 years following the large P load reduction in 1975. Current P release is largely a seasonal P recycling in oxic conditions and the area is still a poor P sink. Short P turnover time in the area means that measures binding P in sediments will not be very effective in improving water quality.

We report detailed sections of radium-226 (²²⁶Ra, T1/2 = 1602 y) activities and barium (Ba) concentrations determined in the North Atlantic (Portugal–Greenland–Canada) in the framework of the international GEOTRACES program (GA01 section–GEOVIDE project, May–July 2014). Dissolved ²²⁶Ra and Ba are strongly correlated along the section, which may reflect their similar chemical behavior.

Human activities are drastically altering water and material flows in river systems across Asia. This review provides a conceptual framework for assessing the human impacts on Asian river C fluxes and an update on anthropogenic alterations of riverine C fluxes, focusing on the impacts of water pollution and river impoundments on CO₂ outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia.