Photosynthetic parameters of peatland plant species were measured over one growing season in an ombrotrophic bog. Based on these measurements, ecosystem-level photosynthesis was calculated for the whole growing season and compared with an estimate derived from micrometeorological measurements. These two estimates corresponded well. Species with low areal cover at the site but high photosynthetic efficiency appeared to be potentially important for the ecosystem-level carbon balance.

Understanding nitrogen (N) cycling mechanisms in the ocean is crucial for improving ecosystem management. Here we study N processes by in situ lander and isotope tracer techniques in – so far overlooked – sediments with low organic loads. Denitrification and anammox are the main N transformation processes. However, we demonstrate high contribution of dissimilatory nitrate reduction to ammonium, which recycles a major portion of fixed N to the water column and sustains primary production.

Vegetated coastal habitats (mangroves, seagrass meadows, salt marshes and macroalgal beds) are key contributors to the marine carbon budget, but remain hidden in the representation of the coastal carbon budget. While they have been acknowledged to play an important role in carbon burial, this is small compared to the export flow, which may lead to carbon sequestration beyond these habitats. The carbon fluxes supported by vegetated coastal habitats are globally relevant.

Endoliths are a prominent bioerosive component of intertidal marine habitats, traditionally thought to be formed by a few cyanobacteria, algae and fungi. Using molecular techniques, however, we found that endoliths from Mona Island, Puerto Rico, were of high diversity, well beyond that reported in traditional studies. We also found evidence for substrate specialization, in that closely related cyanobacteria seem to have diversified to specialize recurrently to excavate various mineral substrates

The biogeochemistry of methane was studied in high-latitude fjord-type estuarine sediment in the Baltic Sea from April 2012 to April 2013. A large variability in methane-producing and methane-oxidizing processes was observed over the year. Oxygen was the most important regulator for the methane flux. In addition to eutrophication effects, free gas movement is suggested as a factor controlling methane concentrations.

The present study investigated the vertical profiles of sediment methanogenic potential and communities in two plateau freshwater lakes. Hydrogenotrophic methanogenesis was the major methane production pathway in the freshwater lakes. Lake trophic status was found to influence sediment methanogen community and activity. This work could provide some new insights into methane production in freshwater sediment ecosystem.

Natural gap disturbances are the dominant form of forest regeneration and dynamics in tropical forests. We highlight strong links between gap size distribution and environment, primarily hydrological conditions and topography, with large gaps being more frequent on floodplains and in wind-exposed areas.

Much of the western US is projected to become warmer and drier over the coming century. We examined how tree productivity, biomass, and carbon residence time varied with average water availability across this region using field and satellite measurements. Each forest characteristic increased markedly with increasing water availability between the dry woodlands and temperate rain forests, underscoring that water availability is a key environmental constraint on forests in the region.

Phytoplankton in the ocean's stratified layer are limited by mineral nutrients, normally nitrogen, phosphorus, or iron. It is important to know not only which element is limiting, but also the surplus of the secondary limiting element. We explore here, in temperate mesotrophic waters, a bioassay based on alkaline phosphatase that provides information on both of these.

Leaf stomata influence both photosynthesis and transpiration, coupling the carbon and water cycles, but there is no direct method for estimating stomatal behavior on the ecosystem scale. We use the ecosystem–atmosphere exchange of water, heat, and carbonyl sulfide to estimate canopy-integrated stomatal conductance by two independent methods. We then use that conductance to show that the seasonal dynamics of transpiration and evaporation are different than represented in current biosphere models.

Marine biota drives a number of climate-relevant mechanisms, not all of which are included in current Earth system models (ESMs) used for climate projections. We identify three classes of mechanisms and argue that, to adequately resolve these mechanisms and to ensure links to and feedbacks with other Earth system components, ESMs need to account for five marine organism groups.

To calculate the seawater carbonate system, proxies for 2 out of 7 parameters are required. The boron isotopic composition of foraminifera shells can be used as a proxy for pH and it has been suggested that B / Ca ratios may act as a proxy for carbonate ion concentration. However, differentiating between the effects of pH and [CO₃²⁻] is problematic, as they co-vary in natural systems. To deconvolve the effects, we conducted culture experiments with the planktonic foraminifer Orbulina universa.

Global change, specifically sea-level rise and longer growing seasons, have the potential to affect how much methane is emitted from coastal wetlands. Our study found that sea-level rise is likely to reduce methane emissions in the long term, but longer growing seasons could provide more plant matter that fuels and thereby enhances methane production. Future methane emissions from wetlands will be shaped by the quality and quantity of plant matter as well as the microbial communities present.

We conducted a large-scale field experiment using 55 m³ floating containers (mesocosms) to investigate consequences of near-future projected CO₂ elevations (ocean acidification) on a Baltic Sea plankton community in Storfjärden (Finland). The focus of our study was on single- and multicelled small-sized organisms dwelling in the water column. Our results suggest that increasing CO₂ concentrations may change the species composition and promote specific food web interactions.

The nitrogen content of leaves is a key quantity for understanding ecosystem function. We analysed variations in nitrogen per unit leaf area among species at sites along a transect across Australia including many climates and ecosystem types. The data could be explained by the idea that leaf nitrogen comprises two parts, one proportional to leaf mass, the other (metabolic) part proportional to light intensity and declining with CO₂ drawdown and temperature, as optimal allocation theory predicts.