@misc{FrankReichsteinBahnetal.2015,
  author    = {Frank, Dorothe A. and Reichstein, Markus and Bahn, Michael and Thonicke, Kirsten and Frank, David and Mahecha, Miguel D. and Smith, Pete and Van der Velde, Marijn and Vicca, Sara and Babst, Flurin and Beer, Christian and Buchmann, Nina and Canadell, Josep G. and Ciais, Philippe and Cramer, Wolfgang and Ibrom, Andreas and Miglietta, Franco and Poulter, Ben and Rammig, Anja and Seneviratne, Sonia I. and Walz, Ariane and Wattenbach, Martin and Zavala, Miguel A. and Zscheischler, Jakob},
  title     = {Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts},
  series = {Global change biology},
  volume    = {21},
  journal   = {Global change biology},
  number    = {8},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1354-1013},
  doi       = {10.1111/gcb.12916},
  pages     = {2861 -- 2880},
  year      = {2015},
  abstract  = {Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global upscaling of the impacts of climate extremes on global carbon-climate feedbacks.},
  language  = {en}
}
@article{KnoblauchBeerLiebneretal.2018,
  author    = {Knoblauch, Christian and Beer, Christian and Liebner, Susanne and Grigoriev, Mikhail N. and Pfeiffer, Eva-Maria},
  title     = {Methane production as key to the greenhouse gas budget of thawing permafrost},
  series = {Nature climate change},
  volume    = {8},
  journal   = {Nature climate change},
  number    = {4},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {1758-678X},
  doi       = {10.1038/s41558-018-0095-z},
  pages     = {309 -- 312},
  year      = {2018},
  abstract  = {Permafrost thaw liberates frozen organic carbon, which is decomposed into carbon dioxide (CO2) and methane (CH4). The release of these greenhouse gases (GHGs) forms a positive feedback to atmospheric CO2 and CH4 concentrations and accelerates climate change(1,2). Current studies report a minor importance of CH4 production in water-saturated (anoxic) permafrost soils(3-6) and a stronger permafrost carbon-climate feedback from drained (oxic) soils(1,7). Here we show through seven-year laboratory incubations that equal amounts of CO2 and CH4 are formed in thawing permafrost under anoxic conditions after stable CH4-producing microbial communities have established. Less permafrost carbon was mineralized under anoxic conditions but more CO2-carbon equivalents (CO2Ce) were formed than under oxic conditions when the higher global warming potential (GWP) of CH4 is taken into account(8). A model of organic carbon decomposition, calibrated with the observed decomposition data, predicts a higher loss of permafrost carbon under oxic conditions (113 +/- 58 g CO2-C kgC(-1) (kgC, kilograms of carbon)) by 2100, but a twice as high production of CO2-Ce (241 +/- 138 g CO2-Ce kgC(-1)) under anoxic conditions. These findings challenge the view of a stronger permafrost carbon-climate feedback from drained soils1,7 and emphasize the importance of CH4 production in thawing permafrost on climate-relevant timescales.},
  language  = {en}
}
@misc{ManzoniCapekPoradaetal.2018,
  author    = {Manzoni, Stefano and Capek, Petr and Porada, Philipp and Thurner, Martin and Winterdahl, Mattias and Beer, Christian and Bruchert, Volker and Frouz, Jan and Herrmann, Anke M. and Lindahl, Bjorn D. and Lyon, Steve W. and Šantrůčkov{\´a}, Hana and Vico, Giulia and Way, Danielle},
  title     = {Reviews and syntheses},
  series = {Biogeosciences},
  volume    = {15},
  journal   = {Biogeosciences},
  number    = {19},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {1726-4170},
  doi       = {10.5194/bg-15-5929-2018},
  pages     = {5929 -- 5949},
  year      = {2018},
  abstract  = {The cycling of carbon (C) between the Earth surface and the atmosphere is controlled by biological and abiotic processes that regulate C storage in biogeochemical compartments and release to the atmosphere. This partitioning is quantified using various forms of C-use efficiency (CUE) - the ratio of C remaining in a system to C entering that system. Biological CUE is the fraction of C taken up allocated to biosynthesis. In soils and sediments, C storage depends also on abiotic processes, so the term C-storage efficiency (CSE) can be used. Here we first review and reconcile CUE and CSE definitions proposed for autotrophic and heterotrophic organisms and communities, food webs, whole ecosystems and watersheds, and soils and sediments using a common mathematical framework. Second, we identify general CUE patterns; for example, the actual CUE increases with improving growth conditions, and apparent CUE decreases with increasing turnover. We then synthesize > 5000CUE estimates showing that CUE decreases with increasing biological and ecological organization - from uni-cellular to multicellular organisms and from individuals to ecosystems. We conclude that CUE is an emergent property of coupled biological-abiotic systems, and it should be regarded as a flexible and scale-dependent index of the capacity of a given system to effectively retain C.},
  language  = {en}
}
@misc{ManzoniČapekPoradaetal.2018,
  author    = {Manzoni, Stefano and Čapek, Petr and Porada, Philipp and Thurner, Martin and Winterdahl, Mattias and Beer, Christian and Br{\"u}chert, Volker and Frouz, Jan and Herrmann, Anke M. and Lindahl, Bj{\"o}rn D. and Lyon, Steve W. and Šantrůčkov{\´a}, Hana and Vico, Giulia and Way, Danielle},
  title     = {Reviews and syntheses},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {1134},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-44638},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-446386},
  pages     = {23},
  year      = {2018},
  abstract  = {The cycling of carbon (C) between the Earth surface and the atmosphere is controlled by biological and abiotic processes that regulate C storage in biogeochemical compartments and release to the atmosphere. This partitioning is quantified using various forms of C-use efficiency (CUE) - the ratio of C remaining in a system to C entering that system. Biological CUE is the fraction of C taken up allocated to biosynthesis. In soils and sediments, C storage depends also on abiotic processes, so the term C-storage efficiency (CSE) can be used. Here we first review and reconcile CUE and CSE definitions proposed for autotrophic and heterotrophic organisms and communities, food webs, whole ecosystems and watersheds, and soils and sediments using a common mathematical framework. Second, we identify general CUE patterns; for example, the actual CUE increases with improving growth conditions, and apparent CUE decreases with increasing turnover. We then synthesize > 5000CUE estimates showing that CUE decreases with increasing biological and ecological organization - from uni-cellular to multicellular organisms and from individuals to ecosystems. We conclude that CUE is an emergent property of coupled biological-abiotic systems, and it should be regarded as a flexible and scale-dependent index of the capacity of a given system to effectively retain C.},
  language  = {en}
}
@article{ReichsteinBahnCiaisetal.2013,
  author    = {Reichstein, Markus and Bahn, Michael and Ciais, Philippe and Frank, Dorothea and Mahecha, Miguel D. and Seneviratne, Sonia I. and Zscheischler, Jakob and Beer, Christian and Buchmann, Nina and Frank, David C. and Papale, Dario and Rammig, Anja and Smith, Pete and Thonicke, Kirsten and van der Velde, Marijn and Vicca, Sara and Walz, Ariane and Wattenbach, Martin},
  title     = {Climate extremes and the carbon cycle},
  series = {Nature : the international weekly journal of science},
  volume    = {500},
  journal   = {Nature : the international weekly journal of science},
  number    = {7462},
  publisher = {Nature Publ. Group},
  address   = {London},
  issn      = {0028-0836},
  doi       = {10.1038/nature12350},
  pages     = {287 -- 295},
  year      = {2013},
  abstract  = {The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Continuing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that climate extremes such as droughts or storms can lead to a decrease in regional ecosystem carbon stocks and therefore have the potential to negate an expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget.},
  language  = {en}
}