Institution
Swiss Federal Institute for Forest, Snow and Landscape Research
Facility•Birmensdorf, Switzerland•
About: Swiss Federal Institute for Forest, Snow and Landscape Research is a facility organization based out in Birmensdorf, Switzerland. It is known for research contribution in the topics: Climate change & Soil water. The organization has 1256 authors who have published 3222 publications receiving 161639 citations. The organization is also known as: WSL.
Topics: Climate change, Soil water, Geology, Biodiversity, Environmental science
Papers published on a yearly basis
Papers
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361 citations
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TL;DR: In this paper, the authors present estimated ranges in carbon (C) sequestration per kg nitrogen (N) addition in above-ground biomass and in soil organic matter for forests and heathlands, based on: (i) empirical relations between spatial patterns of carbon uptake and influencing environmental factors including nitrogen deposition (forests only), (ii) 15N field experiments, (iii) long-term low-dose N fertilizer experiments and (iv) results from ecosystem models.
359 citations
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TL;DR: This review starts from the rather well understood processes at the leaf level such as photosynthetic carbon isotope fractionation, leaf water evaporative isotope enrichment and the issue of the isotopic composition of inorganic sources (CO2 and H2O), though it focuses on the less explored 'downstream' processes related to metabolism and transport.
Abstract: The mechanistic understanding of isotope fractionation processes is increasing but we still lack detailed knowledge of the processes that determine the isotopic composition of the tree-ring archive over the long term. Especially with regard to the path from leaf photosynthate production to wood formation, post-assimilation fractionations/processes might cause at least a partial decoupling between the leaf isotope signals that record processes such as stomatal conductance, transpiration and photosynthesis, and the wood or cellulose signals that are stored in the paleophysiological record. In this review, we start from the rather well understood processes at the leaf level such as photosynthetic carbon isotope fractionation, leaf water evaporative isotope enrichment and the issue of the isotopic composition of inorganic sources (CO2 and H2O), though we focus on the less explored 'downstream' processes related to metabolism and transport. We further summarize the roles of cellulose and lignin as important chemical constituents of wood, and the processes that determine the transfer of photosynthate (sucrose) and associated isotopic signals to wood production. We cover the broad topics of post-carboxylation carbon isotope fractionation and of the exchange of organic oxygen with water within the tree. In two case studies, we assess the transfer of carbon and oxygen isotopic signals from leaves to tree rings. Finally we address the issue of different temporal scales and link isotope fractionation at the shorter time scale for processes in the leaf to the isotopic ratio as recorded across longer time scales of the tree-ring archive.
358 citations
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Goddard Institute for Space Studies1, Columbia University2, Foundation for Research & Technology – Hellas3, University of Crete4, Carnegie Mellon University5, University of São Paulo6, University of California, San Diego7, University of Reading8, Met Office9, European Centre for Medium-Range Weather Forecasts10, Finnish Meteorological Institute11, University of Oslo12, North-West University13, University of Maryland, College Park14, University of Leeds15, Goddard Space Flight Center16, University of L'Aquila17, Universities Space Research Association18, Pacific Northwest National Laboratory19, Meteorological Service of Canada20, National Center for Atmospheric Research21, Paul Scherrer Institute22, Swiss Federal Institute for Forest, Snow and Landscape Research23, Norwegian Meteorological Institute24, University of Colorado Boulder25, Max Planck Society26, University of Michigan27, University of Wyoming28, State University of New York System29, Environment Canada30, Belgian Institute for Space Aeronomy31, Georgia Institute of Technology32, Istanbul Technical University33, Duke University34, Kyushu University35, University of Eastern Finland36, University of Mainz37, Royal Netherlands Meteorological Institute38, China Meteorological Administration39, University of California, Davis40
TL;DR: In this article, the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations.
Abstract: . This paper evaluates the current status of global modeling of the organic aerosol (OA) in the troposphere and analyzes the differences between models as well as between models and observations. Thirty-one global chemistry transport models (CTMs) and general circulation models (GCMs) have participated in this intercomparison, in the framework of AeroCom phase II. The simulation of OA varies greatly between models in terms of the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used (2 to 62), the complexity of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemical and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom experiments, mainly due to the increasing complexity of the SOA parameterization in models, and the implementation of new, highly uncertain, OA sources. Diversity of over one order of magnitude exists in the modeled vertical distribution of OA concentrations that deserves a dedicated future study. Furthermore, although the OA / OC ratio depends on OA sources and atmospheric processing, and is important for model evaluation against OA and OC observations, it is resolved only by a few global models. The median global primary OA (POA) source strength is 56 Tg a−1 (range 34–144 Tg a−1) and the median SOA source strength (natural and anthropogenic) is 19 Tg a−1 (range 13–121 Tg a−1). Among the models that take into account the semi-volatile SOA nature, the median source is calculated to be 51 Tg a−1 (range 16–121 Tg a−1), much larger than the median value of the models that calculate SOA in a more simplistic way (19 Tg a−1; range 13–20 Tg a−1, with one model at 37 Tg a−1). The median atmospheric burden of OA is 1.4 Tg (24 models in the range of 0.6–2.0 Tg and 4 between 2.0 and 3.8 Tg), with a median OA lifetime of 5.4 days (range 3.8–9.6 days). In models that reported both OA and sulfate burdens, the median value of the OA/sulfate burden ratio is calculated to be 0.77; 13 models calculate a ratio lower than 1, and 9 models higher than 1. For 26 models that reported OA deposition fluxes, the median wet removal is 70 Tg a−1 (range 28–209 Tg a−1), which is on average 85% of the total OA deposition. Fine aerosol organic carbon (OC) and OA observations from continuous monitoring networks and individual field campaigns have been used for model evaluation. At urban locations, the model–observation comparison indicates missing knowledge on anthropogenic OA sources, both strength and seasonality. The combined model–measurements analysis suggests the existence of increased OA levels during summer due to biogenic SOA formation over large areas of the USA that can be of the same order of magnitude as the POA, even at urban locations, and contribute to the measured urban seasonal pattern. Global models are able to simulate the high secondary character of OA observed in the atmosphere as a result of SOA formation and POA aging, although the amount of OA present in the atmosphere remains largely underestimated, with a mean normalized bias (MNB) equal to −0.62 (−0.51) based on the comparison against OC (OA) urban data of all models at the surface, −0.15 (+0.51) when compared with remote measurements, and −0.30 for marine locations with OC data. The mean temporal correlations across all stations are low when compared with OC (OA) measurements: 0.47 (0.52) for urban stations, 0.39 (0.37) for remote stations, and 0.25 for marine stations with OC data. The combination of high (negative) MNB and higher correlation at urban stations when compared with the low MNB and lower correlation at remote sites suggests that knowledge about the processes that govern aerosol processing, transport and removal, on top of their sources, is important at the remote stations. There is no clear change in model skill with increasing model complexity with regard to OC or OA mass concentration. However, the complexity is needed in models in order to distinguish between anthropogenic and natural OA as needed for climate mitigation, and to calculate the impact of OA on climate accurately.
355 citations
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Autonomous University of Barcelona1, University of Edinburgh2, Institut national de la recherche agronomique3, Blaise Pascal University4, Wageningen University and Research Centre5, University of Granada6, University of Helsinki7, Spanish National Research Council8, Durham University9, Swiss Federal Institute for Forest, Snow and Landscape Research10
TL;DR: The adjustment of Scots pine's hydraulic system to local climatic conditions occurred primarily through modifications of A(L) : A(S) and direct stomatal control, whereas intraspecific variation in vulnerability to embolism and leaf physiology appears to be limited.
Abstract: Summary • The variability of branch-level hydraulic properties was assessed across 12 Scots pine populations covering a wide range of environmental conditions, including some of the southernmost populations of the species. The aims were to relate this variability to differences in climate, and to study the potential tradeoffs between traits. Traits measured included wood density, radial growth, xylem anatomy, sapwoodand leaf-specific hydraulic conductivity (KS and KL), vulnerability to embolism, leaf-to-sapwood area ratio (AL : AS), needle carbon isotope discrimination (Δ 13 C) and nitrogen content, and specific leaf area. Between-population variability was high for most of the hydraulic traits studied, but it was directly associated with climate dryness (defined as a combination of atmospheric moisture demand and availability) only for AL : AS, KL and Δ 13 C. Shoot radial growth and AL : AS declined with stand development, which is consistent with a strategy to avoid exceedingly low water potentials as tree size increases. In addition, we did not find evidence at the intraspecific level of some associations between hydraulic traits that have been commonly reported across species. The adjustment of Scots pine’s hydraulic system to local climatic conditions occurred primarily through modifications of AL : AS and direct stomatal control, whereas intraspecific variation in vulnerability to embolism and leaf physiology appears to be limited.
352 citations
Authors
Showing all 1333 results
Name | H-index | Papers | Citations |
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Peter H. Verburg | 107 | 464 | 34254 |
Bernhard Schmid | 103 | 460 | 46419 |
Christian Körner | 103 | 376 | 39637 |
André S. H. Prévôt | 90 | 511 | 38599 |
Fortunat Joos | 87 | 276 | 36951 |
Niklaus E. Zimmermann | 80 | 277 | 39364 |
Robert Huber | 78 | 311 | 25131 |
David Frank | 78 | 186 | 18624 |
Jan Esper | 75 | 254 | 19280 |
James W. Kirchner | 73 | 238 | 21958 |
David B. Roy | 70 | 250 | 26241 |
Emmanuel Frossard | 68 | 356 | 15281 |
Derek Eamus | 67 | 285 | 17317 |
Benjamin Poulter | 66 | 255 | 22519 |
Ulf Büntgen | 65 | 316 | 15876 |