Multiple stressors of ocean ecosystems in the 21st century: projections with CMIP5 models Biogeosciences DOI 10.5194/bg-10-6225-2013 2 October 2013 Ocean ecosystems are increasingly stressed by human-induced changes of their physical, chemical and biological environment. Here, we use the most recent simulations performed in the framework of the Coupled Model Intercomparison Project 5 to assess how stressors such as warming, acidification deoxygenation and changes in primary productivity by marine phytoplankton, may evolve over the course of the 21st century. Read more
Increased soil temperature and atmospheric N deposition have no effect on the N status and growth of a mature balsam fir forest Biogeosciences DOI 10.5194/bg-10-4627-2013 11 July 2013 Nitrogen (N) is a major growth-limiting factor in boreal forest ecosystems. Increases of temperature and atmospheric N deposition are expected to affect forest growth directly and indirectly by increasing N availability due to higher rates of N mineralization. We conducted experiments on a mature balsam fir stand in Canada to understand the potential impacts of these changes. Read more
Impact of change in climate and policy from 1988 to 2007 on environmental and microbial variables at the time series station Boknis Eck, Baltic Sea Biogeosciences DOI 10.5194/bg-10-4529-2013 4 July 2013 The temporal development of phytoplankton was monitored from 1988 to the end of 2007 at the time series station Boknis Eck in the western Baltic Sea. Read more
Seasonal measurements of total OH reactivity emission rates from Norway spruce in 2011 Biogeosciences DOI 10.5194/bg-10-4241-2013 26 June 2013 One way to investigate the chemical interplay between biosphere and atmosphere is through the measurement of total OH reactivity, the total loss rate of OH radicals. This study presents the first determination of total OH reactivity emission rates based on a branch cuvette enclosure system mounted on a Norway spruce throughout spring, summer and autumn 2011. Read more
Iodine-129 concentration in seawater near Fukushima before and after the accident at the Fukushima Daiichi Nuclear Power Plant Biogeosciences DOI 10.5194/bg-10-3839-2013 14 June 2013 Anthropogenic radionuclides were released into the environment in large quantities by the Fukushima Daiichi Nuclear Power Plant (1FNPP) accident. To evaluate accident-derived 129I, the 129I concentrations in seawater before and after the accident were compared. Read more
Surface pathway of radioactive plume of TEPCO Fukushima NPP1 released 134Cs and 137Cs Biogeosciences DOI 10.5194/bg-10-3067-2013 7 May 2013 134Cs and 137Cs were released to the North Pacific Ocean by two major likely pathways, direct discharge from the Fukushima NPP1 accident site and atmospheric deposition off Honshu Islands of Japan, east and northeast of the site. High density observations of 134Cs and 137Cs in the surface water were carried out by 17 cruises of cargo ships and several research vessel cruises from March 2011 till March 2012. TEPCO Fukushima NPP1 released 134Cs and 137Cs">Read more
Bacteriohopanepolyols record stratification, nitrogen fixation and other biogeochemical perturbations in Holocene sediments of the central Baltic Sea Biogeosciences DOI 10.5194/bg-10-2725-2013 23 April 2013 We studied bacteriohopanepolyols (BHPs), lipids of specific bacterial groups, in a sediment core from the central Baltic Sea (Gotland Deep) and found considerable differences between the distinct stages of the Baltic Sea’s history. Read more
Nitrous oxide emissions from European agriculture – an analysis of variability and drivers of emissions from field experiments Biogeosciences DOI 10.5194/bg-10-2671-2013 22 April 2013 Nitrous oxide emissions from a network of agricultural experiments in Europe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared within replicated experimental designs in plot-based experiments. Read more
Vertical distributions of plutonium isotopes in marine sediment cores off the Fukushima coast after the Fukushima Dai-ichi Nuclear Power Plant accident Biogeosciences DOI 10.5194/bg-10-2497-2013 15 April 2013 To obtain the vertical distribution of Pu isotopes in marine sediments and to better assess the possible contamination of Pu from the Fukushima Dai-ichi Nuclear Power Plant accident in the marine environment, we determined the activities of 239+240Pu and 241Pu as well as the atom ratios of 240Pu/239Pu and 241Pu/239Pu in sediment core samples collected in the western North Pacific off Fukushima from July 2011 to July 2012. Read more
Inverse estimation of source parameters of oceanic radioactivity dispersion models associated with the Fukushima accident Biogeosciences DOI 10.5194/bg-10-2349-2013 9 April 2013 With combined use of the ocean–atmosphere simulation models and field observation data, we evaluate the parameters associated with the total caesium-137 amounts of the direct release into the ocean and atmospheric deposition over the western North Pacific caused by the accident of Fukushima Daiichi nuclear power plant that occurred in March 2011. Read more