Forest management shapes forest structure and in turn surface–atmosphere interactions. We used Fennoscandian forest maps and inventory data to develop a classification system for forest structure. The classification was integrated with the ESA Climate Change Initiative land cover map to achieve complete surface representation. The result is an improved product for modeling surface–atmosphere exchanges in regions with intensively managed forests.

Organic carbon processing at the seafloor is studied by geologists to better understand the sedimentary record, by biogeochemists to quantify burial and respiration, by organic geochemists to elucidate compositional changes, and by ecologists to follow carbon transfers within food webs. These disciplinary approaches have their strengths and weaknesses. This award talk provides a synthesis, highlights the role of animals in sediment carbon processing and presents some new concepts.

Global estimates of freshwater greenhouse gas emissions are usually based on simple gas transfer models that underestimate the emissions. Thus, comparison of different gas transfer models is required for evaluating the uncertainties. This study compares three commonly used methods for estimating greenhouse gas emissions over lakes. We conclude that simple gas transfer models underestimate the emissions and more recent models should be used for global freshwater greenhouse gas emission estimates.

The Amazon rainforest produce large quantities of carbon, a portion of which is deposited in floodplain lakes. This research shows a potentially important spatial dependence of the carbon deposition in the Amazon lacustrine sediments in relation to deforestation rates in the catchment. The findings presented here highlight the effects of abrupt and temporary events in which some of the biomass released by the deforestation reach the depositional environments in the Amazon floodplains.

The quality of dissolved organic carbon (DOC), especially its color, is a defining feature of freshwater ecosystems. We found that colored DOC fractions are surprisingly resistant to natural degradation during water transit through many brown-water lakes. This is explained by the dominance of microbial processes that appear to selectively remove noncolored DOC. However, in lakes where sunlight degradation plays a relatively larger role, significant DOC bleaching occurs.

We determined the aerobic and anaerobic degradation rates of land- and marine-derived organic material in East Siberian shelf sediment. Marine plankton-derived organic carbon was the main source for the oxic dissolved carbon dioxide production, whereas terrestrial organic material significantly contributed to the production of carbon dioxide under anoxic conditions. Our direct degradation rate measurements provide new constraints for the present-day Arctic marine carbon budget.

We report on the net primary productivity of a biological soil crust from the Boodjamulla NP, Queensland. Metabolic activity lasted from September 2010 to mid-April 2011, referring to 23.6 % of the total time of the year. The first months of activity had a respiratory loss of CO₂. Of the metabolic active period, 48.6 % were photosynthesis and 51.4 % dark respiration. Carbon gain was 1.72 g m⁻² yr⁻¹. The gas exchange pattern was divided into metabolically inactive winter and active summer month.

The Arabian Sea has one of the most severe oxygen minima of the world's oceans between about 100 and 1200 m of water depth and is therefore a major oceanic nitrogen sink. Stable nitrogen isotopic ratios in sediments record changes in oxygen concentrations and were studied for the last 25 kyr. Oxygen concentrations dropped at the end of the last glacial and became further reduced during the Holocene, probably due to the increasing age of the low-oxygen water mass.

Few studies have investigated the atmospheric deposition of nitrate in the Arctic or its impacts on Arctic ecosystems. We collected late-season snowpack from three regions in western Greenland from the coast to the edge of the ice sheet. We found major differences in nitrate concentrations (lower at the coast) and deposition load (higher). Nitrate in snowpack undergoes losses and isotopic enrichment which are greatest in inland areas; hence deposition impacts may be greatest at the coast.

We examine the effects of elevated CO₂ on bacterioplankton community during a mesocosm experiment in subtropical, eutrophic coastal waters in southern China. We found that the elevated CO₂ hardly altered the network structure of the bacterioplankton taxa present with high abundance but appeared to reassemble the community network of taxa with low abundance. Results suggest that the bacterioplankton community in this subtropical, high-nutrient coastal environment is insensitive to elevated CO₂.

The Qinghai–Tibet Plateau is sensitive to climate change. We documented seasonal and interannual dynamics of soil microbial and available N in an alpine meadow in this region. Consistently increasing trends of microbial biomass and available N pools were observed during the nongrowing season. Significant shifts in microbial communities largely contributed to microbial reduction during soil thaw. Divergent seasonal dynamics of different N forms showed a complementary nutrient supply pattern.

We conducted a series of incubation experiments to understand how the changes in five environmental drivers will affect the elemental composition of the calcifying phytoplankton species Emiliania huxleyi. These findings provide new diagnostic information to aid our understanding of how the physiology and the related marine biogeochemistry of the ecologically important species Emiliania huxleyi will respond to changes in different environmental drivers in the global climate change scenario.

Previous studies have shown that differences in soil carbonic anhydrase (CA) activity are found in different biomes and seasons, but our understanding of the drivers responsible for those patterns is still limited. We artificially increased the soil CA concentration to test how soil pH affected the relationship between soil CA activity and concentration. We found that soil pH was the primary driver of soil CA activity.

This study provides a demonstration that a biogeochemical/ecosystem/optical computer model which explicitly captures how light is radiated at the surface of the ocean and can be used as a laboratory to explore products (such as Chl a) that are derived from satellite measurements of ocean colour. It explores uncertainties that arise from data input used to derive the algorithms for the products, and issues arising from the interplay between optically important constituents in the ocean.

We proposed a new data processing technique to reduce the uncertainty of H₂O fluxes measured using the eddy covariance method, which is widely used to observe mass/energy fluxes between biosphere and atmosphere. A special feature of the proposed technique is the merging of two existing methods a new method. Such a strategy strengthens the strength and makes up for the weakness of the original methods. It will contribute to the standardization of eddy covariance data processing.

Our isoprene data from field measurements in the mixed layer from the Indian Ocean and the eastern Pacific Ocean show that the ability of different phytoplankton functional types to produce isoprene seems to be mainly influenced by light, ocean temperature, salinity, and nutrients. By calculating in-field isoprene production rates, we demonstrate that an additional loss is needed to explain the measured isoprene concentration, which is potentially due to degradation or consumption by bacteria.

Carbon leaching to streams represents a very small (~ 2 %) fraction of forest net ecosystem exchange (NEE). Such weak export of carbon from forest ecosystems, at least in temperate regions, is at odds with recent studies that attempt to integrate the contribution of inland waters in the continent carbon budget. Understanding why local and global carbon mass balances strongly diverge on the proportion of land NEE exported to aquatic systems is a major challenge for research in this field.