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
Tree height integrated into pantropical forest biomass estimates Biogeosciences DOI 10.5194/bg-9-3381-2012 27 August 2012 Aboveground tropical tree biomass and carbon storage estimates commonly ignore tree height (H). We estimate the effect of incorporating H on tropics-wide forest biomass estimates in 327 plots across four continents using 42 656 H and diameter measurements and harvested trees from 20 sites to answer various questions. Read more
A synthesis of carbon in international trade Biogeosciences DOI 10.5194/bg-9-3247-2012 23 August 2012 In a globalised world, the transfer of carbon between regions, either physically or embodied in production, represents a substantial fraction of global carbon emissions. The resulting emission transfers are important for balancing regional carbon budgets and for understanding the drivers of emissions. Read more
Photoproduction of ammonium in the southeastern Beaufort Sea and its biogeochemical implications Biogeosciences DOI 10.5194/bg-9-3047-2012 10 August 2012 During the August 2009 Mackenzie Light and Carbon (MALINA) Program, the absorbed photon-based efficiency spectra of NH4+photoproduction (i.e. photoammonification) were determined using water samples from the SE Beaufort Sea, including the Mackenzie River estuary, shelf, and Canada Basin. Read more
Detecting anthropogenic carbon dioxide uptake and ocean acidification in the North Atlantic Ocean Biogeosciences DOI 10.5194/bg-9-2509-2012 11 July 2012 Fossil fuel use, cement manufacture and land-use changes are the primary sources of anthropogenic carbon dioxide (CO2) to the atmosphere, with the ocean absorbing approximately 30% (Sabine et al., 2004). Ocean uptake and chemical equilibration of anthropogenic CO2 with seawater results in a gradual reduction in seawater pH and saturation states (Ω) for calcium carbonate (CaCO3) minerals in a process termed ocean acidification. Read more
Bioerosion by euendoliths decreases in phosphate-enriched skeletons of living corals Biogeosciences DOI 10.5194/bg-9-2377-2012 2 July 2012 While the role of microboring organisms, or euendoliths, is relatively well known in dead coral skeletons, their function in live corals remains poorly understood. They are suggested to behave like ectosymbionts or parasites, impacting their host’s health. However, the species composition of microboring communities, their abundance and dynamics in live corals under various environmental conditions have never been explored. Read more
Novel water source for endolithic life in the hyperarid core of the Atacama Desert Biogeosciences DOI 10.5194/bg-9-2275-2012 26 June 2012 Our results explain how life has colonized and adapted to one of the most extreme environments on our planet, expanding the water activity envelope for life on Earth, and broadening the spectrum of possible habitats for life beyond our planet. Read more
Towards a merged satellite and in situ fluorescence ocean chlorophyll product Biogeosciences DOI 10.5194/bg-9-2111-2012 12 June 2012 Understanding the ocean carbon cycle requires a precise assessment of phytoplankton biomass in the oceans. In terms of numbers of observations, satellite data represent the largest available data set. However, as they are limited to surface waters, they have to be merged with in situ observations. Read more
Organic matter dynamics and stable isotope signature as tracers of the sources of suspended sediment Biogeosciences DOI 10.5194/bg-9-1985-2012 4 June 2012 Suspended sediment (SS) and organic matter in rivers can harm brown trout Salmo trutta by affecting the health and fitness of free swimming fish and by causing siltation of the riverbed. The temporal and spatial dynamics of sediment, carbon (C), and nitrogen (N) during the brown trout spawning season in a small river of the Swiss Plateau were assessed and C isotopes as well as the C/N atomic ratio were used to distinguish autochthonous and allochthonous sources of organic matter in SS loads. Read more
