Quality control of CarboEurope flux data – Part 1: Coupling footprint analyses with flux data quality assessment to evaluate sites in forest ecosystemsBiogeosciences - Tập 5 Số 2 - Trang 433-450
Mathias Göckede, Thomas Foken, Marc Aubinet, Minna Aurela, J. Banza, Christian Bernhofer, Jean-Marc Bonnefond, Yves Brunet, Arnaud Carrara, R. Ceulemans, Ebba Dellwik, A. J. Dolman, W. Eugster, Jürg Fuhrer, Thomas Grünwald, Bernard Heinesch, Ivan A. Janssens, Alexander Knohl, Renate Koeble, Denis Loustau, Giovanni Manca, Michal V. Marek, Barbara Marcolla, J. Mateus, Gioṙgio Matteucci, Matthias Mauder, Mirco Migliavacca, Stefano Minerbi, F. Miglietta, Leonardo Montagnani, E.J. Moors, Jean‐Marc Ourcival, Dario Papale, J. S. Pereira, Kim Pilegaard, Gabriel Pita, Serge Rambal, Corinna Rebmann, Abel Rodrigues, Eyal Rotenberg, M. J. Sanz, Pavel Sedlák, G. Seufert, Lukas Siebicke, Jean‐François Soussana, Riccardo Valentini, Timo Vesala, Hans Verbeeck, Dan Yakir
Abstract. We applied a site evaluation approach combining Lagrangian Stochastic footprint modeling with a quality assessment approach for eddy-covariance data to 25 forested sites of the CarboEurope-IP network. The analysis addresses the spatial representativeness of the flux measurements, instrumental effects on data quality, spatial patterns in the data quality, and the performance of th...... hiện toàn bộ
Modelling post-fire vegetation recovery in PortugalBiogeosciences - Tập 8 Số 12 - Trang 3593-3607
Ana Bastos, Célia M. Gouveia, Carlos C. DaCamara, Ricardo M. Trigo
Abstract. Wildfires in Mediterranean Europe have been increasing in number and extension over the last decades and constitute one of the major disturbances of these ecosystems. Portugal is the country with more burnt area in the last decade and the years of 2003 and 2005 were particularly devastating, the total burned areas of 425 000 and 338 000 ha being several times higher than the corr...... hiện toàn bộ
Heavy metal incorporation in foraminiferal calcite: results from multi-element enrichment culture experiments with <i>Ammonia tepida</i>Biogeosciences - Tập 7 Số 8 - Trang 2339-2350
D. Munsel, U. Kramar, Delphine Dissard, Gernot Nehrke, Zsolt Berner, Jelle Bijma, Gert‐Jan Reichart, Thomas Neumann
Abstract. The incorporation of heavy metals into carbonate tests of the shallow water benthic foraminifer Ammonia tepida was investigated under controlled laboratory conditions. Temperature, salinity, and pH of the culture solutions were kept constant throughout the duration of this experiment, while trace metal concentrations were varied. Concentrations of Ni, Cu, and Mn were set 5-, 10-,...... hiện toàn bộ
Copper incorporation in foraminiferal calcite: results from culturing experimentsBiogeosciences - Tập 4 Số 4 - Trang 493-504
Lennart de Nooijer, Gert‐Jan Reichart, Adriana Dueñas-Bohórquez, Mariëtte Wolthers, Sander Ernst, Paul R.D. Mason, G.J. van der Zwaan
Abstract. A partition coefficient for copper (DCu) in foraminiferal calcite has been determined by culturing individuals of two benthic species under controlled laboratory conditions. The partition coefficient of a trace element (TE) is an emperically determined relation between the TE/Ca ratio in seawater and the TE/Ca ratio in foraminiferal calcite and has been established for many dival...... hiện toàn bộ
Calibration of δ<sup>18</sup>O of cultured benthic foraminiferal calcite as a function of temperatureBiogeosciences - Tập 7 Số 4 - Trang 1349-1356
Christine Barras, Jean‐Claude Duplessy, Emmanuelle Geslin, Élisabeth Michel, Frans Jorissen
Abstract. The geochemical composition of deep-sea benthic foraminiferal calcite is widely used to reconstruct sea floor paleoenvironments. The calibration of the applied proxy methods has until now been based on field observations in complex natural ecosystems where multiple factors are interfering. However, laboratory experiments with stable physico-chemical conditions appear to be the id...... hiện toàn bộ
A new model for biomineralization and trace-element signatures of Foraminifera testsBiogeosciences - Tập 10 Số 10 - Trang 6759-6767
Gernot Nehrke, Nina Keul, Gerald Langer, Lennart de Nooijer, Jelle Bijma, Anders Meibom
Abstract. The Mg/Ca ratio of Foraminifera calcium carbonate tests is used as proxy for seawater temperature and widely applied to reconstruct global paleo-climatic changes. However, the mechanisms involved in the carbonate biomineralization process are poorly understood. The current paradigm holds that calcium ions for the test are supplied primarily by endocytosis of seawater. Here, we co...... hiện toàn bộ
Processes of ammonia air–surface exchange in a fertilized <i>Zea mays</i> canopyBiogeosciences - Tập 10 Số 2 - Trang 981-998
John T. Walker, Matthew R. Jones, Jesse O. Bash, LaToya Myles, Tilden P. Meyers, Donna Schwede, Jeffrey D. Herrick, Eiko Nemitz, Wayne P. Robarge
Abstract. Recent incorporation of coupled soil biogeochemical and bi-directional NH3 air–surface exchange algorithms into regional air quality models holds promise for further reducing uncertainty in estimates of NH3 emissions from fertilized soils. While this represents a significant advancement over previous approaches, the evaluation and improvement of such modeling systems for fertiliz...... hiện toàn bộ
Temporal variability in bioassays of the stomatal ammonia compensation point in relation to plant and soil nitrogen parameters in intensively managed grasslandBiogeosciences - Tập 6 Số 2 - Trang 171-179
Marie Mattßon, B. Herrmann, M. David, Benjamin Loubet, M. Riedo, Mark R. Theobald, Mark A. Sutton, Dan Bruhn, A. Neftel, Jan K. Schjøerring
Abstract. The exchange of ammonia between crop canopies and the atmosphere depends on a range of plant parameters and climatic conditions. However, little is known about effects of management factors. We have here investigated the stomatal ammonia compensation point in response to cutting and fertilization of a grass sward dominated by Lolium perenne. Tall grass had a very low NH3 compensa...... hiện toàn bộ
Evaluation of a regional air-quality model with bidirectional NH<sub>3</sub> exchange coupled to an agroecosystem modelBiogeosciences - Tập 10 Số 3 - Trang 1635-1645
Jesse O. Bash, Ellen J. Cooter, Robin L. Dennis, John T. Walker, Jonathan Pleim
Abstract. Atmospheric ammonia (NH3) is the primary atmospheric base and an important precursor for inorganic particulate matter and when deposited NH3 contributes to surface water eutrophication, soil acidification and decline in species biodiversity. Flux measurements indicate that the air–surface exchange of NH3 is bidirectional. However, the effects of bidirectional exchange, soil bioge...... hiện toàn bộ
Advances in understanding, models and parameterizations of biosphere-atmosphere ammonia exchangeBiogeosciences - Tập 10 Số 7 - Trang 5183-5225
Christophe Fléchard, Raia Silvia Massad, Benjamin Loubet, Erwan Personne, David Simpson, Jesse O. Bash, Ellen J. Cooter, Eiko Nemitz, Mark A. Sutton
Abstract. Atmospheric ammonia (NH3) dominates global emissions of total reactive nitrogen (Nr), while emissions from agricultural production systems contribute about two-thirds of global NH3 emissions; the remaining third emanates from oceans, natural vegetation, humans, wild animals and biomass burning. On land, NH3 emitted from the various sources eventually returns to the biosphere by d...... hiện toàn bộ