High-latitude cooling associated with landscape changes from North American boreal forest fires Biogeosciences DOI 10.5194/bg-10-699-2013 1 February 2013 Here we simulated changes in forest composition due to altered burn area using a stochastic model of fire occurrence, historical fire data from national inventories, and succession trajectories derived from remote sensing. Read more
Identifying urban sources as cause of elevated grass pollen concentrations using GIS and remote sensing Biogeosciences DOI 10.5194/bg-10-541-2013 29 January 2013 We examine here the hypothesis that during flowering, the grass pollen concentrations at a specific site reflect the distribution of grass pollen sources within a few kilometres of this site. We perform this analysis on data from a measurement campaign in the city of Aarhus (Denmark) using three pollen traps and by comparing these observations with a novel inventory of grass pollen sources. Read more
Management, regulation and environmental impacts of nitrogen fertilization in northwestern Europe under the Nitrates Directive; a benchmark study Biogeosciences DOI 10.5194/bg-9-5143-2012 14 December 2012 Implementation of the Nitrates Directive (NiD) and its environmental impacts were compared for member states in the northwest of the European Union (Ireland, United Kingdom, Denmark, the Netherlands, Belgium, Northern France and Germany). The main sources of data were national reports for the third reporting period for the NiD (2004–2007) and results of the MITERRA-EUROPE model. Read more
Internal respiration of Amazon tree stems greatly exceeds external CO2 efflux Biogeosciences DOI 10.5194/bg-9-4979-2012 6 December 2012 Here, we studied gas exchange from stems of tropical forest trees using a new approach to better understand respiration in an ecosystem that plays a key role in the global carbon cycle. Read more
Ocean acidification limits temperature-induced poleward expansion of coral habitats around Japan Biogeosciences DOI 10.5194/bg-9-4955-2012 4 December 2012 Using results from four coupled global carbon cycle-climate models combined with in situ observations, we estimate the effects of future global warming and ocean acidification on potential habitats for tropical/subtropical and temperate coral communities in the seas around Japan. Read more
Activity and abundance of denitrifying bacteria in the subsurface biosphere of diffuse hydrothermal vents of the Juan de Fuca Ridge Biogeosciences DOI 10.5194/bg-9-4661-2012 22 November 2012 Based on our rate measurements, and on published data on hydrothermal fluid fluxes and residence times, we estimated that up to ~10 Tg N yr−1could globally be removed in the subsurface biosphere of hydrothermal vents systems, thus, representing a small fraction of the total marine N loss (~275 to > 400 Tg N yr−1). Read more
Bioerosion by microbial euendoliths in benthic foraminifera from heavy metal-polluted coastal environments of Portovesme (south-western Sardinia, Italy) Biogeosciences DOI 10.5194/bg-9-4607-2012 20 November 2012 We found that carbonate dissolution induced by euendoliths is selective, depending on the Mg content and morpho-structural types of foraminiferal taxa. This study provides evidences for a connection between heavy metal dispersion, decrease in pH of the sea-water and bioerosional processes on foraminifera. Read more
High-resolution interpolar difference of atmospheric methane around the Last Glacial Maximum Biogeosciences DOI 10.5194/bg-9-3961-2012 16 October 2012 Here we present new high-resolution methane records from the North Greenland Ice Core Project and the European Project for Ice Coring in Antarctica Dronning Maud Land ice cores covering Termination 1, the Last Glacial Maximum, and parts of the last glacial back to 32 000 years before present. Read more
Marine bacteria in deep Arctic and Antarctic ice cores: a proxy for evolution in oceans over 300 million generations Biogeosciences DOI 10.5194/bg-9-3799-2012 5 October 2012 Ice cores offer the opportunity to study evolution of marine microbes over ~ 300 million generations by analysing their genomes vs. depth in glacial ice over the last 700 000 yr as frozen proxies for changes in their genomes in oceans. Read more
The carbon budget of terrestrial ecosystems in East Asia over the last two decades Biogeosciences DOI 10.5194/bg-9-3571-2012 7 September 2012 We estimate the current terrestrial carbon balance of East Asia and its driving mechanisms during 1990–2009 using three different approaches: inventories combined with satellite greenness measurements, terrestrial ecosystem carbon cycle models and atmospheric inversion models. Read more
