ALBERT

Beschreibung: In 2005 and 2010 the Amazon basin experienced two strong droughts, driven by shifts in the tropical hydrological regime possibly associated with global climate change, as predicted by some global models. Tree mortality increased after the 2005 drought, and regional atmospheric inversion modelling showed basin-wide decreases in CO2 uptake in 2010 compared with 2011 (ref. 5). But the response of tropical forest carbon cycling to these droughts is not fully understood and there has been no detailed multi-site investigation in situ. Here we use several years of data from a network of thirteen 1-ha forest plots spread throughout South America, where each component of net primary production (NPP), autotrophic respiration and heterotrophic respiration is measured separately, to develop a better mechanistic understanding of the impact of the 2010 drought on the Amazon forest. We find that total NPP remained constant throughout the drought. However, towards the end of the drought, autotrophic respiration, especially in roots and stems, declined significantly compared with measurements in 2009 made in the absence of drought, with extended decreases in autotrophic respiration in the three driest plots. In the year after the drought, total NPP remained constant but the allocation of carbon shifted towards canopy NPP and away from fine-root NPP. Both leaf-level and plot-level measurements indicate that severe drought suppresses photosynthesis. Scaling these measurements to the entire Amazon basin with rainfall data, we estimate that drought suppressed Amazon-wide photosynthesis in 2010 by 0.38 petagrams of carbon (0.23-0.53 petagrams of carbon). Overall, we find that during this drought, instead of reducing total NPP, trees prioritized growth by reducing autotrophic respiration that was unrelated to growth. This suggests that trees decrease investment in tissue maintenance and defence, in line with eco-evolutionary theories that trees are competitively disadvantaged in the absence of growth. We propose that weakened maintenance and defence investment may, in turn, cause the increase in post-drought tree mortality observed at our plots.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Doughty, Christopher E -- Metcalfe, D B -- Girardin, C A J -- Amezquita, F Farfan -- Cabrera, D Galiano -- Huasco, W Huaraca -- Silva-Espejo, J E -- Araujo-Murakami, A -- da Costa, M C -- Rocha, W -- Feldpausch, T R -- Mendoza, A L M -- da Costa, A C L -- Meir, P -- Phillips, O L -- Malhi, Y -- England -- Nature. 2015 Mar 5;519(7541):78-82. doi: 10.1038/nature14213.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Environmental Change Institute, School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, UK. ; Department of Physical Geography and Ecosystem Science, Lund University, Solvegatan 12, 223 62 Lund, Sweden. ; Universidad Nacional San Antonio Abad de Cusco, Apartado Postal Nro 921, Cusco, Peru ; Museo de Historia Natural Noel Kempff Mercado, Universidad Autonoma Gabriel Rene Moreno, Av. Irala 565, Casilla 2489, Santa Cruz, Bolivia. ; Universidade Federal do Para, Instituto de Geociencias, Faculdade de Meteorologia, Rua Augusto Correa, n degrees 01, CEP 66075 - 110, Belem, Para, Brazil. ; IPAM Instituto de Pesquisa Ambiental da Amazonia Rua Horizontina, 104, Centro, 78640-000 Canarana, Mato Grosso, Brazil. ; Department of Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK. ; 1] School of Geosciences, University of Edinburgh, Edinburgh EH9 3FF, UK [2] Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia. ; School of Geography, University of Leeds, Leeds LS2 9JT, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25739631" target="_blank"〉PubMed〈/a〉

Beschreibung: The climatic impact of CO2 and other greenhouse gases is usually quantified in terms of radiative forcing, calculated as the difference between estimates of the Earth's radiation field from pre-industrial and present-day concentrations of these gases. Radiative transfer models calculate that the increase in CO2 since 1750 corresponds to a global annual-mean radiative forcing at the tropopause of 1.82 +/- 0.19 W m(-2) (ref. 2). However, despite widespread scientific discussion and modelling of the climate impacts of well-mixed greenhouse gases, there is little direct observational evidence of the radiative impact of increasing atmospheric CO2. Here we present observationally based evidence of clear-sky CO2 surface radiative forcing that is directly attributable to the increase, between 2000 and 2010, of 22 parts per million atmospheric CO2. The time series of this forcing at the two locations-the Southern Great Plains and the North Slope of Alaska-are derived from Atmospheric Emitted Radiance Interferometer spectra together with ancillary measurements and thoroughly corroborated radiative transfer calculations. The time series both show statistically significant trends of 0.2 W m(-2) per decade (with respective uncertainties of +/-0.06 W m(-2) per decade and +/-0.07 W m(-2) per decade) and have seasonal ranges of 0.1-0.2 W m(-2). This is approximately ten per cent of the trend in downwelling longwave radiation. These results confirm theoretical predictions of the atmospheric greenhouse effect due to anthropogenic emissions, and provide empirical evidence of how rising CO2 levels, mediated by temporal variations due to photosynthesis and respiration, are affecting the surface energy balance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Feldman, D R -- Collins, W D -- Gero, P J -- Torn, M S -- Mlawer, E J -- Shippert, T R -- England -- Nature. 2015 Mar 19;519(7543):339-43. doi: 10.1038/nature14240. Epub 2015 Feb 25.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Road, MS 74R-316C, Berkeley, California 94720, USA. ; 1] Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Road, MS 74R-316C, Berkeley, California 94720, USA [2] University of California-Berkeley, Department of Earth and Planetary Science, 307 McCone Hall, MC 4767, Berkeley, California 94720, USA. ; University of Wisconsin-Madison, Space Science and Engineering Center, 1225 W. Dayton Street, Madison, Wisconsin 53706, USA. ; 1] Lawrence Berkeley National Laboratory, Earth Sciences Division, 1 Cyclotron Road, MS 74R-316C, Berkeley, California 94720, USA [2] University of California-Berkeley, Energy and Resources Group, Berkeley, 310 Barrows Hall, MC 3050, California 94720, USA. ; Atmospheric and Environmental Research, Inc., 131 Hartwell Avenue, Lexington, Massachusetts 02141, USA. ; Pacific Northwest National Laboratory, Fundamental and Computational Sciences, 902 Battelle Boulevard, Richland, Washington 99354, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25731165" target="_blank"〉PubMed〈/a〉

Beschreibung: Coral bleaching events threaten the sustainability of the Great Barrier Reef (GBR). Here we show that bleaching events of the past three decades have been mitigated by induced thermal tolerance of reef-building corals, and this protective mechanism is likely to be lost under near-future climate change scenarios. We show that 75% of past thermal stress events have been characterized by a temperature trajectory that subjects corals to a protective, sub-bleaching stress, before reaching temperatures that cause bleaching. Such conditions confer thermal tolerance, decreasing coral cell mortality and symbiont loss during bleaching by over 50%. We find that near-future increases in local temperature of as little as 0.5 degrees C result in this protective mechanism being lost, which may increase the rate of degradation of the GBR.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ainsworth, Tracy D -- Heron, Scott F -- Ortiz, Juan Carlos -- Mumby, Peter J -- Grech, Alana -- Ogawa, Daisie -- Eakin, C Mark -- Leggat, William -- New York, N.Y. -- Science. 2016 Apr 15;352(6283):338-42. doi: 10.1126/science.aac7125.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4810, Australia. ; Coral Reef Watch, U.S. National Oceanic and Atmospheric Administration (NOAA), College Park, MD 20740, USA. Marine Geophysical Laboratory, College of Science, Technology and Engineering, James Cook University, Townsville 4811, Australia. ; Marine Spatial Ecology Lab, School of Biological Sciences, University of Queensland, Brisbane 4072, Australia. Australian Research Council Centre of Excellence for Coral Reef Studies, University of Queensland, Brisbane 4072, Australia. ; Department of Environmental Sciences, Macquarie University, Sydney 2109, Australia. ; Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville 4810, Australia. The College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville 4810, Australia. ; Coral Reef Watch, U.S. National Oceanic and Atmospheric Administration (NOAA), College Park, MD 20740, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27081069" target="_blank"〉PubMed〈/a〉

Beschreibung: The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis, exported through sinking particles, and finally sequestered in the deep ocean. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure driving the process remains largely uncharacterized. Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve our understanding of carbon export in the oligotrophic ocean. We show that specific plankton communities, from the surface and deep chlorophyll maximum, correlate with carbon export at 150 m and highlight unexpected taxa such as Radiolaria and alveolate parasites, as well as Synechococcus and their phages, as lineages most strongly associated with carbon export in the subtropical, nutrient-depleted, oligotrophic ocean. Additionally, we show that the relative abundance of a few bacterial and viral genes can predict a significant fraction of the variability in carbon export in these regions.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4851848/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4851848/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guidi, Lionel -- Chaffron, Samuel -- Bittner, Lucie -- Eveillard, Damien -- Larhlimi, Abdelhalim -- Roux, Simon -- Darzi, Youssef -- Audic, Stephane -- Berline, Leo -- Brum, Jennifer R -- Coelho, Luis Pedro -- Espinoza, Julio Cesar Ignacio -- Malviya, Shruti -- Sunagawa, Shinichi -- Dimier, Celine -- Kandels-Lewis, Stefanie -- Picheral, Marc -- Poulain, Julie -- Searson, Sarah -- Tara Oceans Consortium Coordinators -- Stemmann, Lars -- Not, Fabrice -- Hingamp, Pascal -- Speich, Sabrina -- Follows, Mick -- Karp-Boss, Lee -- Boss, Emmanuel -- Ogata, Hiroyuki -- Pesant, Stephane -- Weissenbach, Jean -- Wincker, Patrick -- Acinas, Silvia G -- Bork, Peer -- de Vargas, Colomban -- Iudicone, Daniele -- Sullivan, Matthew B -- Raes, Jeroen -- Karsenti, Eric -- Bowler, Chris -- Gorsky, Gabriel -- England -- Nature. 2016 Apr 28;532(7600):465-70. doi: 10.1038/nature16942. Epub 2016 Feb 10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Sorbonne Universites, UPMC Universite Paris 06, CNRS, Laboratoire d'oceanographie de Villefranche (LOV), Observatoire Oceanologique, 06230 Villefranche-sur-Mer, France. ; Department of Oceanography, University of Hawaii, Honolulu, Hawaii 96822, USA. ; Department of Microbiology and Immunology, Rega Institute, KU Leuven, Herestraat 49, 3000 Leuven, Belgium. ; Center for the Biology of Disease, VIB, Herestraat 49, 3000 Leuven, Belgium. ; Department of Applied Biological Sciences, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Brussels, Belgium. ; Sorbonne Universites, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France. ; Ecole Normale Superieure, PSL Research University, Institut de Biologie de l'Ecole Normale Superieure (IBENS), CNRS UMR 8197, INSERM U1024, 46 rue d'Ulm, F-75005 Paris, France. ; Sorbonne Universites, UPMC Universite Paris 06, CNRS, Laboratoire Adaptation et Diversite en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France. ; LINA UMR 6241, Universite de Nantes, EMN, CNRS, 44322 Nantes, France. ; Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USA. ; Structural and Computational Biology, European Molecular Biology Laboratory, Meyerhofstr. 1, 69117 Heidelberg, Germany. ; Directors' Research European Molecular Biology Laboratory Meyerhofstr. 1, 69117 Heidelberg, Germany. ; CEA - Institut de Genomique, GENOSCOPE, 2 rue Gaston Cremieux, 91057 Evry, France. ; Aix Marseille Universite, CNRS, IGS, UMR 7256, 13288 Marseille, France. ; Department of Geosciences, Laboratoire de Meteorologie Dynamique (LMD), Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris CEDEX 05, France. ; Dept of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. ; School of Marine Sciences, University of Maine, Orono, Maine 04469, USA. ; Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan. ; PANGAEA, Data Publisher for Earth and Environmental Science, University of Bremen, 28359 Bremen, Germany. ; MARUM, Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany. ; CNRS, UMR 8030, CP 5706 Evry, France. ; Universite d'Evry, UMR 8030, CP 5706 Evry, France. ; Department of Marine Biology and Oceanography, Institute of Marine Sciences (ICM)-CSIC, Pg. Maritim de la Barceloneta 37-49, Barcelona E0800, Spain. ; Max-Delbruck-Centre for Molecular Medicine, 13092 Berlin, Germany. ; Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26863193" target="_blank"〉PubMed〈/a〉

Beschreibung: Dataset: Series 3A: cell abundance

Beschreibung: The experiments were designed to test the combined effects of three CO2 concentrations, four temperatures, and three light intensities on growth of the diatom T. pseudonana CCMP1014 in a multifactorial design. This dataset contains measurements of cell abundances measured by forward scatter. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/771421

Beschreibung: NSF Division of Ocean Sciences (NSF OCE) OCE-1538602

Beschreibung: Dataset: Series 3A: Nutrients

Beschreibung: The experiments were designed to test the combined effects of three CO2 concentrations, four temperatures, and three light intensities on growth and photophysiology of the diatom T. pseudonana CCMP1014 in a multifactorial design. This dataset contains measurements of nutrients (phosphate, silicate, and nitrate plus nitrite) made over the course of the experiments. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/771370

Beschreibung: NSF Division of Ocean Sciences (NSF OCE) OCE-1538602

Beschreibung: Dataset: Series 3A: pH

Beschreibung: The experiments were designed to test the combined effects of three CO2 concentrations, four temperatures, and three light intensities on growth and photophysiology of the diatom T. pseudonana CCMP1014 in a multifactorial design. This dataset contains measurements of pH made over the course of the experiments. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/771304

Beschreibung: NSF Division of Ocean Sciences (NSF OCE) OCE-1538602

Beschreibung: Dataset: Series 3A: DIC

Beschreibung: The experiments were designed to test the combined effects of three CO2 concentrations, four temperatures, and three light intensities on growth and photophysiology of the diatom T. pseudonana CCMP1014 in a multifactorial design. This dataset contains measurements of Dissolved Inorganic Carbon (DIC) made over the course of the experiments. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/771333

Beschreibung: NSF Division of Ocean Sciences (NSF OCE) OCE-1538602

Beschreibung: Dataset: Series 3A: cell size

Beschreibung: The experiments were designed to test the combined effects of three CO2 concentrations, four temperatures, and three light intensities on growth of the diatom T. pseudonana CCMP1014 in a multifactorial design. This dataset contains measurements of cell size expressed as forward scatter as well as in equivalent spherical diameter (ESD) in microns. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/771448

Beschreibung: NSF Division of Ocean Sciences (NSF OCE) OCE-1538602

Beschreibung: Dataset: Series 3A: POC, PON, Chl a

Beschreibung: The experiments were designed to test the combined effects of CO2, temperatures, and light on growth and photophysiology of the diatom T. pseudonana CCMP1014 in a multifactorial design. This dataset contains measurements of extracted chlorophyll, particulate organic carbon (POC), and particulate organic nitrogen (PON) made over the course of the experiments. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/771594

Beschreibung: NSF Division of Ocean Sciences (NSF OCE) OCE-1538602