Articles | Volume 14, issue 3
Research article 02 Feb 2017
Research article | 02 Feb 2017
Environmental conditions for alternative tree-cover states in high latitudes
Beniamino Abis and Victor Brovkin
No articles found.
Alexander J. Winkler, Ranga B. Myneni, Alexis Hannart, Stephen Sitch, Vanessa Haverd, Danica Lombardozzi, Vivek K. Arora, Julia Pongratz, Julia E. M. S. Nabel, Daniel S. Goll, Etsushi Kato, Hanqin Tian, Almut Arneth, Pierre Friedlingstein, Atul K. Jain, Sönke Zaehle, and Victor Brovkin
Preprint under review for BGShort summary
Satellite observations since the early 1980s show that Earth's greening trend is slowing down and that browning clusters are emerging, especially in the last two decades. A collection of model simulations in conjunction with causal theory points at climatic changes as a key driver of vegetation changes in natural ecosystems. Most models underestimate the observed vegetation browning, especially in tropical rainforests, which could be due to an excessive CO2 fertilization effect in models.
Aaron Spring, István Dunkl, Hongmei Li, Victor Brovkin, and Tatiana Ilyina
Earth Syst. Dynam. Discuss.,
Preprint under review for ESDShort summary
Numerical carbon cycle prediction models usually do not start from observed carbon states due to sparse observations. Instead, only physical climate is reconstructed before, assuming that the carbon cycle follows indirectly. Here, we test in an idealized framework how well this indirect and direct reconstruction with perfect observations works. We find that indirect reconstruction works quite well and that improvements from the direct method are limited, strengthening the current indirect use.
Lena R. Boysen, Victor Brovkin, Julia Pongratz, David M. Lawrence, Peter Lawrence, Nicolas Vuichard, Philippe Peylin, Spencer Liddicoat, Tomohiro Hajima, Yanwu Zhang, Matthias Rocher, Christine Delire, Roland Séférian, Vivek K. Arora, Lars Nieradzik, Peter Anthoni, Wim Thiery, Marysa M. Laguë, Deborah Lawrence, and Min-Hui Lo
Biogeosciences, 17, 5615–5638,Short summary
We find a biogeophysically induced global cooling with strong carbon losses in a 20 million square kilometre idealized deforestation experiment performed by nine CMIP6 Earth system models. It takes many decades for the temperature signal to emerge, with non-local effects playing an important role. Despite a consistent experimental setup, models diverge substantially in their climate responses. This study offers unprecedented insights for understanding land use change effects in CMIP6 models.
Taraka Davies-Barnard, Johannes Meyerholt, Sönke Zaehle, Pierre Friedlingstein, Victor Brovkin, Yuanchao Fan, Rosie A. Fisher, Chris D. Jones, Hanna Lee, Daniele Peano, Benjamin Smith, David Wårlind, and Andy J. Wiltshire
Biogeosciences, 17, 5129–5148,
Claudia Tebaldi, Kevin Debeire, Veronika Eyring, Erich Fischer, John Fyfe, Pierre Friedlingstein, Reto Knutti, Jason Lowe, Brian O'Neill, Benjamin Sanderson, Detlef van Vuuren, Keywan Riahi, Malte Meinshausen, Zebedee Nicholls, George Hurtt, Elmar Kriegler, Jean-Francois Lamarque, Gerald Meehl, Richard Moss, Susanne E. Bauer, Olivier Boucher, Victor Brovkin, Jean-Christophe Golaz, Silvio Gualdi, Huan Guo, Jasmin G. John, Slava Kharin, Tsuyoshi Koshiro, Libin Ma, Dirk Olivié, Swapna Panickal, Fangli Qiao, Nan Rosenbloom, Martin Schupfner, Roland Seferian, Zhenya Song, Christian Steger, Alistair Sellar, Neil Swart, Kaoru Tachiiri, Hiroaki Tatebe, Aurore Voldoire, Evgeny Volodin, Klaus Wyser, Xiaoge Xin, Rong Xinyao, Shuting Yang, Yongqiang Yu, and Tilo Ziehn
Earth Syst. Dynam. Discuss.,
Revised manuscript accepted for ESDShort summary
We present a broad overview of CMIP6 ScenarioMIP outcomes from a multi-model ensemble according to the new SSP-based scenarios. Average temperature and precipitation projections according to a wide range of forcings, spanning a wider range than the CMIP5 projections, are documented as global averages and geographic patterns. Times of crossing various warming levels are computed, together with benefits of mitigation for selected pairs of scenarios. We also document results from large ensembles.
Vivek K. Arora, Anna Katavouta, Richard G. Williams, Chris D. Jones, Victor Brovkin, Pierre Friedlingstein, Jörg Schwinger, Laurent Bopp, Olivier Boucher, Patricia Cadule, Matthew A. Chamberlain, James R. Christian, Christine Delire, Rosie A. Fisher, Tomohiro Hajima, Tatiana Ilyina, Emilie Joetzjer, Michio Kawamiya, Charles D. Koven, John P. Krasting, Rachel M. Law, David M. Lawrence, Andrew Lenton, Keith Lindsay, Julia Pongratz, Thomas Raddatz, Roland Séférian, Kaoru Tachiiri, Jerry F. Tjiputra, Andy Wiltshire, Tongwen Wu, and Tilo Ziehn
Biogeosciences, 17, 4173–4222,Short summary
Since the preindustrial period, land and ocean have taken up about half of the carbon emitted into the atmosphere by humans. Comparison of different earth system models with the carbon cycle allows us to assess how carbon uptake by land and ocean differs among models. This yields an estimate of uncertainty in our understanding of how land and ocean respond to increasing atmospheric CO2. This paper summarizes results from two such model intercomparison projects that use an idealized scenario.
Philipp de Vrese, Tobias Stacke, Thomas Kleinen, and Victor Brovkin
The Cryosphere Discuss.,
Revised manuscript accepted for TC
Matteo Puglini, Victor Brovkin, Pierre Regnier, and Sandra Arndt
Biogeosciences, 17, 3247–3275,Short summary
A reaction-transport model to assess the potential non-turbulent methane flux from the East Siberian Arctic sediments to water columns is applied here. We show that anaerobic oxidation of methane (AOM) is an efficient filter except for high values of sedimentation rate and advective flow, which enable considerable non-turbulent steady-state methane fluxes. Significant transient methane fluxes can also occur during the building-up phase of the AOM-performing biomass microbial community.
Andrew H. MacDougall, Thomas L. Frölicher, Chris D. Jones, Joeri Rogelj, H. Damon Matthews, Kirsten Zickfeld, Vivek K. Arora, Noah J. Barrett, Victor Brovkin, Friedrich A. Burger, Micheal Eby, Alexey V. Eliseev, Tomohiro Hajima, Philip B. Holden, Aurich Jeltsch-Thömmes, Charles Koven, Nadine Mengis, Laurie Menviel, Martine Michou, Igor I. Mokhov, Akira Oka, Jörg Schwinger, Roland Séférian, Gary Shaffer, Andrei Sokolov, Kaoru Tachiiri, Jerry Tjiputra, Andrew Wiltshire, and Tilo Ziehn
Biogeosciences, 17, 2987–3016,Short summary
The Zero Emissions Commitment (ZEC) is the change in global temperature expected to occur following the complete cessation of CO2 emissions. Here we use 18 climate models to assess the value of ZEC. For our experiment we find that ZEC 50 years after emissions cease is between −0.36 to +0.29 °C. The most likely value of ZEC is assessed to be close to zero. However, substantial continued warming for decades or centuries following cessation of CO2 emission cannot be ruled out.
Thomas Kleinen, Uwe Mikolajewicz, and Victor Brovkin
Clim. Past, 16, 575–595,Short summary
We investigate the changes in natural methane emissions between the Last Glacial Maximum and preindustrial periods with a methane-enabled version of MPI-ESM. We consider all natural sources of methane except for emissions from wild animals and geological sources. Changes are dominated by changes in tropical wetland emissions, high-latitude wetlands play a secondary role, and all other natural sources are of minor importance. We explain the changes in ice core methane by methane emissions only.
Georgii A. Alexandrov, Victor A. Brovkin, Thomas Kleinen, and Zicheng Yu
Biogeosciences, 17, 47–54,
Alexander J. Winkler, Ranga B. Myneni, and Victor Brovkin
Earth Syst. Dynam., 10, 501–523,Short summary
The concept of
emergent constraintsis a key method to reduce uncertainty in multi-model climate projections using historical simulations and observations. Here, we present an in-depth analysis of the applicability of the method and uncover possible limitations. Key limitations are a lack of comparability (temporal, spatial, and conceptual) between models and observations and the disagreement between models on system dynamics throughout different levels of atmospheric CO2 concentration.
Victor Brovkin, Stephan Lorenz, Thomas Raddatz, Tatiana Ilyina, Irene Stemmler, Matthew Toohey, and Martin Claussen
Biogeosciences, 16, 2543–2555,Short summary
Mechanisms of atmospheric CO2 growth by 20 ppm from 6000 BCE to the pre-industrial period are still uncertain. We apply the Earth system model MPI-ESM-LR for two transient simulations of the climate–carbon cycle. An additional process, e.g. carbonate accumulation on shelves, is required for consistency with ice-core CO2 data. Our simulations support the hypothesis that the ocean was a source of CO2 until the late Holocene when anthropogenic CO2 sources started to affect atmospheric CO2.
Anne Dallmeyer, Martin Claussen, and Victor Brovkin
Clim. Past, 15, 335–366,Short summary
A simple but powerful method for the biomisation of plant functional type distributions is introduced and tested for six different dynamic global vegetation models based on pre-industrial and palaeo-simulations. The method facilitates the direct comparison between vegetation distributions simulated by different Earth system models and between model results and the pollen-based biome reconstructions. It is therefore a powerful tool for the evaluation of Earth system models.
Thomas Schneider von Deimling, Thomas Kleinen, Gustaf Hugelius, Christian Knoblauch, Christian Beer, and Victor Brovkin
Clim. Past, 14, 2011–2036,Short summary
Past cold ice age temperatures and the subsequent warming towards the Holocene had large consequences for soil organic carbon (SOC) stored in perennially frozen grounds. Using an Earth system model we show how the spread in areas affected by permafrost have changed under deglacial warming, along with changes in SOC accumulation. Our model simulations suggest phases of circum-Arctic permafrost SOC gain and losses, with a net increase in SOC between the last glacial maximum and the pre-industrial.
Thomas Riddick, Victor Brovkin, Stefan Hagemann, and Uwe Mikolajewicz
Geosci. Model Dev., 11, 4291–4316,Short summary
During the Last Glacial Maximum, many rivers were blocked by the presence of large ice sheets and thus found new routes to the sea. This resulted in changes in the pattern of freshwater discharge into the oceans and thus would have significantly affected ocean circulation. Also, rivers found routes across the vast exposed continental shelves to the lower coastlines of that time. We propose a model for such changes in river routing suitable for use in wider models of the last glacial cycle.
Sandy P. Harrison, Patrick J. Bartlein, Victor Brovkin, Sander Houweling, Silvia Kloster, and I. Colin Prentice
Earth Syst. Dynam., 9, 663–677,Short summary
Temperature affects fire occurrence and severity. Warming will increase fire-related carbon emissions and thus atmospheric CO2. The size of this feedback is not known. We use charcoal records to estimate pre-industrial fire emissions and a simple land–biosphere model to quantify the feedback. We infer a feedback strength of 5.6 3.2 ppm CO2 per degree of warming and a gain of 0.09 ± 0.05 for a climate sensitivity of 2.8 K. Thus, fire feedback is a large part of the climate–carbon-cycle feedback.
Maarit Raivonen, Sampo Smolander, Leif Backman, Jouni Susiluoto, Tuula Aalto, Tiina Markkanen, Jarmo Mäkelä, Janne Rinne, Olli Peltola, Mika Aurela, Annalea Lohila, Marin Tomasic, Xuefei Li, Tuula Larmola, Sari Juutinen, Eeva-Stiina Tuittila, Martin Heimann, Sanna Sevanto, Thomas Kleinen, Victor Brovkin, and Timo Vesala
Geosci. Model Dev., 10, 4665–4691,Short summary
Wetlands are one of the most significant natural sources of the strong greenhouse gas methane. We developed a model that can be used within a larger wetland carbon model to simulate the methane emissions. In this study, we present the model and results of its testing. We found that the model works well with different settings and that the results depend primarily on the rate of input anoxic soil respiration and also on factors that affect the simulated oxygen concentrations in the wetland soil.
Andrey Ganopolski and Victor Brovkin
Clim. Past, 13, 1695–1716,Short summary
Ice cores reveal that atmospheric CO2 concentration varied synchronously with the global ice volume. Explaining the mechanism of glacial–interglacial variations of atmospheric CO2 concentrations and the link between CO2 and ice sheets evolution still remains a challenge. Here using the Earth system model of intermediate complexity we performed for the first time simulations of co-evolution of climate, ice sheets and carbon cycle using the astronomical forcing as the only external forcing.
Daniel S. Goll, Alexander J. Winkler, Thomas Raddatz, Ning Dong, Ian Colin Prentice, Philippe Ciais, and Victor Brovkin
Geosci. Model Dev., 10, 2009–2030,Short summary
The response of soil organic carbon decomposition to warming and the interactions between nitrogen and carbon cycling affect the feedbacks between the land carbon cycle and the climate. In the model JSBACH carbon–nitrogen interactions have only a small effect on the feedbacks, whereas modifications of soil organic carbon decomposition have a large effect. The carbon cycle in the improved model is more resilient to climatic changes than in previous version of the model.
Marielle Saunois, Philippe Bousquet, Ben Poulter, Anna Peregon, Philippe Ciais, Josep G. Canadell, Edward J. Dlugokencky, Giuseppe Etiope, David Bastviken, Sander Houweling, Greet Janssens-Maenhout, Francesco N. Tubiello, Simona Castaldi, Robert B. Jackson, Mihai Alexe, Vivek K. Arora, David J. Beerling, Peter Bergamaschi, Donald R. Blake, Gordon Brailsford, Victor Brovkin, Lori Bruhwiler, Cyril Crevoisier, Patrick Crill, Kristofer Covey, Charles Curry, Christian Frankenberg, Nicola Gedney, Lena Höglund-Isaksson, Misa Ishizawa, Akihiko Ito, Fortunat Joos, Heon-Sook Kim, Thomas Kleinen, Paul Krummel, Jean-François Lamarque, Ray Langenfelds, Robin Locatelli, Toshinobu Machida, Shamil Maksyutov, Kyle C. McDonald, Julia Marshall, Joe R. Melton, Isamu Morino, Vaishali Naik, Simon O'Doherty, Frans-Jan W. Parmentier, Prabir K. Patra, Changhui Peng, Shushi Peng, Glen P. Peters, Isabelle Pison, Catherine Prigent, Ronald Prinn, Michel Ramonet, William J. Riley, Makoto Saito, Monia Santini, Ronny Schroeder, Isobel J. Simpson, Renato Spahni, Paul Steele, Atsushi Takizawa, Brett F. Thornton, Hanqin Tian, Yasunori Tohjima, Nicolas Viovy, Apostolos Voulgarakis, Michiel van Weele, Guido R. van der Werf, Ray Weiss, Christine Wiedinmyer, David J. Wilton, Andy Wiltshire, Doug Worthy, Debra Wunch, Xiyan Xu, Yukio Yoshida, Bowen Zhang, Zhen Zhang, and Qiuan Zhu
Earth Syst. Sci. Data, 8, 697–751,Short summary
An accurate assessment of the methane budget is important to understand the atmospheric methane concentrations and trends and to provide realistic pathways for climate change mitigation. The various and diffuse sources of methane as well and its oxidation by a very short lifetime radical challenge this assessment. We quantify the methane sources and sinks as well as their uncertainties based on both bottom-up and top-down approaches provided by a broad international scientific community.
Thomas Kleinen, Victor Brovkin, and Guy Munhoven
Clim. Past, 12, 2145–2160,Short summary
We investigate trends in atmospheric CO2 during three recent interglacials – the Holocene, the Eemian and MIS 11 – using an earth system model of intermediate complexity. Our model experiments show a considerable improvement in the modelled CO2 trends for all three interglacials if peat accumulation and shallow water CaCO3 sedimentation are included, forcing the model only with orbital and sea level changes. The Holocene CO2 trend requires anthropogenic emissions of CO2 only after 3 ka BP.
Sylvia S. Nyawira, Julia E. M. S. Nabel, Axel Don, Victor Brovkin, and Julia Pongratz
Biogeosciences, 13, 5661–5675,Short summary
We introduce an approach applicable to dynamic global vegetation models for evaluating simulated soil carbon changes from land-use changes against meta-analyses. The approach makes use of the large spatial coverage of the observations, and accounts for different ages of the sampled land-use transitions. The evaluation offers an opportunity for identifying causes of model–data discrepancies. Applied to the model JSBACH, we find that introducing crop harvest substantially improves the results.
Ana Bastos, Philippe Ciais, Jonathan Barichivich, Laurent Bopp, Victor Brovkin, Thomas Gasser, Shushi Peng, Julia Pongratz, Nicolas Viovy, and Cathy M. Trudinger
Biogeosciences, 13, 4877–4897,Short summary
The ice-core record shows a stabilisation of atmospheric CO2 in the 1940s, despite continued emissions from fossil fuel burning and land-use change (LUC). We use up-to-date reconstructions of the CO2 sources and sinks over the 20th century to evaluate whether these capture the CO2 plateau and to test the previously proposed hypothesis. Both strong terrestrial sink, possibly due to LUC not fully accounted for in the records, and enhanced oceanic uptake are necessary to explain this stall.
David M. Lawrence, George C. Hurtt, Almut Arneth, Victor Brovkin, Kate V. Calvin, Andrew D. Jones, Chris D. Jones, Peter J. Lawrence, Nathalie de Noblet-Ducoudré, Julia Pongratz, Sonia I. Seneviratne, and Elena Shevliakova
Geosci. Model Dev., 9, 2973–2998,Short summary
Human land-use activities have resulted in large changes to the Earth's surface, with resulting implications for climate. In the future, land-use activities are likely to expand and intensify further to meet growing demands for food, fiber, and energy. The goal of LUMIP is to take the next steps in land-use change science, and enable, coordinate, and ultimately address the most important land-use science questions in more depth and sophistication than possible in a multi-model context to date.
Chris D. Jones, Vivek Arora, Pierre Friedlingstein, Laurent Bopp, Victor Brovkin, John Dunne, Heather Graven, Forrest Hoffman, Tatiana Ilyina, Jasmin G. John, Martin Jung, Michio Kawamiya, Charlie Koven, Julia Pongratz, Thomas Raddatz, James T. Randerson, and Sönke Zaehle
Geosci. Model Dev., 9, 2853–2880,Short summary
How the carbon cycle interacts with climate will affect future climate change and how society plans emissions reductions to achieve climate targets. The Coupled Climate Carbon Cycle Model Intercomparison Project (C4MIP) is an endorsed activity of CMIP6 and aims to quantify these interactions and feedbacks in state-of-the-art climate models. This paper lays out the experimental protocol for modelling groups to follow to contribute to C4MIP. It is a contribution to the CMIP6 GMD Special Issue.
Ulrike Port, Martin Claussen, and Victor Brovkin
Earth Syst. Dynam., 7, 535–547,
Fabio Cresto Aleina, Benjamin R. K. Runkle, Tim Brücher, Thomas Kleinen, and Victor Brovkin
Geosci. Model Dev., 9, 915–926,Short summary
This study presents the hotspot parameterization, a novel approach to upscaling methane emissions in a boreal peatland from the micro-topographic scale to the landscape scale. We based this new parameterization on the analysis of water table patterns generated by the Hummock–Hollow (HH) model. We show how the hotspot parameterization successfully upscales the micro-topographic controls on methane emissions for both present-day conditions and for the next century under three different scenarios.
F. Cresto Aleina, B. R. K. Runkle, T. Kleinen, L. Kutzbach, J. Schneider, and V. Brovkin
Biogeosciences, 12, 5689–5704,Short summary
We developed a process-based model for peatland micro-topography and hydrology, the Hummock-Hollow (HH) model, which explicitly represents small-scale surface elevation changes. By coupling the HH model with a model for soil methane processes, we are able to model the effects of micro-topography on hydrology and methane emissions in a typical boreal peatland. We also identify potential biases that models without a micro-topographic representation can introduce in large-scale models.
C. D. Koven, J. Q. Chambers, K. Georgiou, R. Knox, R. Negron-Juarez, W. J. Riley, V. K. Arora, V. Brovkin, P. Friedlingstein, and C. D. Jones
Biogeosciences, 12, 5211–5228,Short summary
Terrestrial carbon feedbacks are a large uncertainty in climate change. We separate modeled feedback responses into those governed by changed carbon inputs (productivity) and changed outputs (turnover). The disaggregated responses show that both are important in controlling inter-model uncertainty. Interactions between productivity and turnover are also important, and research must focus on these interactions for more accurate projections of carbon cycle feedbacks.
T. J. Bohn, J. R. Melton, A. Ito, T. Kleinen, R. Spahni, B. D. Stocker, B. Zhang, X. Zhu, R. Schroeder, M. V. Glagolev, S. Maksyutov, V. Brovkin, G. Chen, S. N. Denisov, A. V. Eliseev, A. Gallego-Sala, K. C. McDonald, M.A. Rawlins, W. J. Riley, Z. M. Subin, H. Tian, Q. Zhuang, and J. O. Kaplan
Biogeosciences, 12, 3321–3349,Short summary
We evaluated 21 forward models and 5 inversions over western Siberia in terms of CH4 emissions and simulated wetland areas and compared these results to an intensive in situ CH4 flux data set, several wetland maps, and two satellite inundation products. In addition to assembling a definitive collection of methane emissions estimates for the region, we were able to identify the types of wetland maps and model features necessary for accurate simulations of high-latitude wetlands.
S. Kloster, T. Brücher, V. Brovkin, and S. Wilkenskjeld
Clim. Past, 11, 781–788,
U. Port, M. Claussen, and V. Brovkin
Clim. Past Discuss.,
Revised manuscript not accepted
F. S. E. Vamborg, V. Brovkin, and M. Claussen
Earth Syst. Dynam., 5, 89–101,
P. Dass, C. Müller, V. Brovkin, and W. Cramer
Earth Syst. Dynam., 4, 409–424,
L. M. Verheijen, V. Brovkin, R. Aerts, G. Bönisch, J. H. C. Cornelissen, J. Kattge, P. B. Reich, I. J. Wright, and P. M. van Bodegom
Biogeosciences, 10, 5497–5515,
M. Claussen, K. Selent, V. Brovkin, T. Raddatz, and V. Gayler
Biogeosciences, 10, 3593–3604,
R. Wania, J. R. Melton, E. L. Hodson, B. Poulter, B. Ringeval, R. Spahni, T. Bohn, C. A. Avis, G. Chen, A. V. Eliseev, P. O. Hopcroft, W. J. Riley, Z. M. Subin, H. Tian, P. M. van Bodegom, T. Kleinen, Z. C. Yu, J. S. Singarayer, S. Zürcher, D. P. Lettenmaier, D. J. Beerling, S. N. Denisov, C. Prigent, F. Papa, and J. O. Kaplan
Geosci. Model Dev., 6, 617–641,
F. Joos, R. Roth, J. S. Fuglestvedt, G. P. Peters, I. G. Enting, W. von Bloh, V. Brovkin, E. J. Burke, M. Eby, N. R. Edwards, T. Friedrich, T. L. Frölicher, P. R. Halloran, P. B. Holden, C. Jones, T. Kleinen, F. T. Mackenzie, K. Matsumoto, M. Meinshausen, G.-K. Plattner, A. Reisinger, J. Segschneider, G. Shaffer, M. Steinacher, K. Strassmann, K. Tanaka, A. Timmermann, and A. J. Weaver
Atmos. Chem. Phys., 13, 2793–2825,
J. R. Melton, R. Wania, E. L. Hodson, B. Poulter, B. Ringeval, R. Spahni, T. Bohn, C. A. Avis, D. J. Beerling, G. Chen, A. V. Eliseev, S. N. Denisov, P. O. Hopcroft, D. P. Lettenmaier, W. J. Riley, J. S. Singarayer, Z. M. Subin, H. Tian, S. Zürcher, V. Brovkin, P. M. van Bodegom, T. Kleinen, Z. C. Yu, and J. O. Kaplan
Biogeosciences, 10, 753–788,
J. Segschneider, A. Beitsch, C. Timmreck, V. Brovkin, T. Ilyina, J. Jungclaus, S. J. Lorenz, K. D. Six, and D. Zanchettin
Biogeosciences, 10, 669–687,
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Florian Beyer, Florian Jansen, Gerald Jurasinski, Marian Koch, Birgit Schröder, and Franziska Koebsch
Biogeosciences, 18, 917–935,Short summary
Increasing drought frequency can jeopardize the restoration of the CO2 sink function in degraded peatlands. We explored the effect of the summer drought in 2018 on vegetation development and CO2 exchange in a rewetted fen. Drought triggered a rapid spread of new vegetation whose CO2 assimilation could partially outweigh the drought-related rise in respiratory CO2 loss. Our study shows important regulatory mechanisms of a rewetted fen to maintain its net CO2 sink function even in a very dry year.
Shunli Yu, Guoxun Wang, Ofir Katz, Danfeng Li, Qibing Wang, Ming Yue, and Canran Liu
Biogeosciences, 18, 655–667,Short summary
As key traits of plants, the mechanisms of diversity of fruit sizes and seed sizes have not been solved completely until now. Therefore, the research related to them will continue to be done in the future. Our research, combined with future works, will provide a profound basis for solving the origin of fleshy-fruited species and seed size diversity.
Jan Pisek, Angela Erb, Lauri Korhonen, Tobias Biermann, Arnaud Carrara, Edoardo Cremonese, Matthias Cuntz, Silvano Fares, Giacomo Gerosa, Thomas Grünwald, Niklas Hase, Michal Heliasz, Andreas Ibrom, Alexander Knohl, Johannes Kobler, Bart Kruijt, Holger Lange, Leena Leppänen, Jean-Marc Limousin, Francisco Ramon Lopez Serrano, Denis Loustau, Petr Lukeš, Lars Lundin, Riccardo Marzuoli, Meelis Mölder, Leonardo Montagnani, Johan Neirynck, Matthias Peichl, Corinna Rebmann, Eva Rubio, Margarida Santos-Reis, Crystal Schaaf, Marius Schmidt, Guillaume Simioni, Kamel Soudani, and Caroline Vincke
Biogeosciences, 18, 621–635,Short summary
Understory vegetation is the most diverse, least understood component of forests worldwide. Understory communities are important drivers of overstory succession and nutrient cycling. Multi-angle remote sensing enables us to describe surface properties by means that are not possible when using mono-angle data. Evaluated over an extensive set of forest ecosystem experimental sites in Europe, our reported method can deliver good retrievals, especially over different forest types with open canopies.
Peiqi Yang, Christiaan van der Tol, Petya K. E. Campbell, and Elizabeth M. Middleton
Biogeosciences, 18, 441–465,Short summary
Solar-induced chlorophyll fluorescence (SIF) has the potential to facilitate the monitoring of photosynthesis from space. This study presents a systematic analysis of the physical and physiological meaning of the relationship between fluorescence and photosynthesis at both leaf and canopy levels. We unravel the individual effects of incoming light, vegetation structure and leaf physiology and highlight their joint effects on the relationship between canopy fluorescence and photosynthesis.
Aurelio Guevara-Escobar, Enrique González-Sosa, Mónica Cervantes-Jiménez, Humberto Suzán-Azpiri, Mónica Elisa Queijeiro-Bolaños, Israel Carrillo-Ángeles, and Víctor Hugo Cambrón-Sandoval
Biogeosciences, 18, 367–392,Short summary
All vegetation types can sequester carbon dioxide. We compared ground measurements (eddy covariance) with remotely sensed data (Moderate Resolution Imaging Spectroradiometer, MODIS) and machine learning ensembles of primary production in a semiarid scrub in Mexico. The annual carbon sink for this vegetation type was −283.5 g C m−2 y−1; MODIS underestimated the primary productivity, and the machine learning modeling was better locally.
Simone Maria Stuenzi, Julia Boike, William Cable, Ulrike Herzschuh, Stefan Kruse, Luidmila A. Pestryakova, Thomas Schneider von Deimling, Sebastian Westermann, Evgenii S. Zakharov, and Moritz Langer
Biogeosciences, 18, 343–365,Short summary
Boreal forests in eastern Siberia are an essential component of global climate patterns. We use a physically based model and field measurements to study the interactions between forests, permanently frozen ground and the atmosphere. We find that forests exert a strong control on the thermal state of permafrost through changing snow cover dynamics and altering the surface energy balance, through absorbing most of the incoming solar radiation and suppressing below-canopy turbulent fluxes.
Milan Flach, Alexander Brenning, Fabian Gans, Markus Reichstein, Sebastian Sippel, and Miguel D. Mahecha
Biogeosciences, 18, 39–53,Short summary
Drought and heat events affect the uptake and sequestration of carbon in terrestrial ecosystems. We study the impact of droughts and heatwaves on the uptake of CO2 of different vegetation types at the global scale. We find that agricultural areas are generally strongly affected. Forests instead are not particularly sensitive to the events under scrutiny. This implies different water management strategies of forests but also a lack of sensitivity to remote-sensing-derived vegetation activity.
Robinson I. Negrón-Juárez, Jennifer A. Holm, Boris Faybishenko, Daniel Magnabosco-Marra, Rosie A. Fisher, Jacquelyn K. Shuman, Alessandro C. de Araujo, William J. Riley, and Jeffrey Q. Chambers
Biogeosciences, 17, 6185–6205,Short summary
The temporal variability in the Landsat satellite near-infrared (NIR) band captured the dynamics of forest regrowth after disturbances in Central Amazon. This variability was represented by the dynamics of forest regrowth after disturbances were properly represented by the ELM-FATES model (Functionally Assembled Terrestrial Ecosystem Simulator (FATES) in the Energy Exascale Earth System Model (E3SM) Land Model (ELM)).
Nina Löbs, David Walter, Cybelli G. G. Barbosa, Sebastian Brill, Rodrigo P. Alves, Gabriela R. Cerqueira, Marta de Oliveira Sá, Alessandro C. de Araújo, Leonardo R. de Oliveira, Florian Ditas, Daniel Moran-Zuloaga, Ana Paula Pires Florentino, Stefan Wolff, Ricardo H. M. Godoi, Jürgen Kesselmeier, Sylvia Mota de Oliveira, Meinrat O. Andreae, Christopher Pöhlker, and Bettina Weber
Biogeosciences, 17, 5399–5416,Short summary
Cryptogamic organisms, such as bryophytes, lichens, and algae, cover major parts of vegetation in the Amazonian rain forest, but their relevance in biosphere–atmosphere exchange, climate processes, and nutrient cycling is largely unknown. Over the duration of 2 years we measured their water content, temperature, and light conditions to get better insights into their physiological activity patterns and thus their potential impact on local, regional, and even global biogeochemical processes.
Maitane Iturrate-Garcia, Monique M. P. D. Heijmans, J. Hans C. Cornelissen, Fritz H. Schweingruber, Pascal A. Niklaus, and Gabriela Schaepman-Strub
Biogeosciences, 17, 4981–4998,Short summary
Changes on plant traits associated with climate warming might alter vegetation–climate interactions. We investigated experimentally the effects of enhanced permafrost thaw and soil nutrients on a wide set of tundra shrub traits. We found a coordinated trait response to some treatments, which suggests a shift in shrub resource, growth and defence strategies. This shift might feed back into permafrost thaw – through mechanisms associated with water demand – and into carbon and energy fluxes.
Jürgen Homeier and Christoph Leuschner
Revised manuscript accepted for BG
Shawn D. Taylor and Dawn M. Browning
Revised manuscript accepted for BGShort summary
Grasslands in North America provide multiple ecosystem services and drive production for the majority of grain, beef, and other staples. We evaluated a grassland productivity model using nearly 500 years of grassland camera data and found the areas where the model worked well, and locations where it did not. Long-term grassland forecasts for the suitable locations can be made immediately with the current model, while other areas, such as the Southwest, will need further model development.
Kathryn I. Wheeler and Michael C. Dietze
Revised manuscript accepted for BGShort summary
Monitoring leaf phenology (i.e., seasonality) allows for tracking the progression of climate change and seasonal variations in a variety of organismal and ecosystem processes. Recent versions of the Geostationary Operational Environmental Satellites allow for the monitoring of a phenological-sensitive index at a high temporal frequency (5–10 minutes) throughout most of the western hemisphere. Here we show the high potential of this new data to measure the phenology of deciduous forests.
Juergen Kreyling, Rhena Schumann, and Robert Weigel
Biogeosciences, 17, 4103–4117,Short summary
Temperate forest soils (sites dominated by European beech, Fagus sylvatica) from cold and snowy sites in northern Poland release more nitrogen and phosphorus after soil freeze–thaw cycles (FTCs) than soils from warmer, snow-poor conditions in northern Germany. Our data suggest that previously cold sites, which will lose their protective snow cover during climate change, are most vulnerable to increasing FTC frequency and magnitude, resulting in strong shifts in nitrogen leaching.
Eric R. Beamesderfer, M. Altaf Arain, Myroslava Khomik, Jason J. Brodeur, and Brandon M. Burns
Biogeosciences, 17, 3563–3587,Short summary
Temperate forests play a major role in the global carbon and water cycles, sequestering atmospheric CO2 on annual timescales. This research examined the annual carbon and water dynamics of two similar (age, soil, climate, etc.) eastern North American temperate forests of different species composition (i.e., broadleaf vs. needleleaf). Ultimately, fluxes of the deciduous forest were found to be less sensitive to temperature and water limitations – conditions expected with future climate warming.
Thomas Janssen, Katrin Fleischer, Sebastiaan Luyssaert, Kim Naudts, and Han Dolman
Biogeosciences, 17, 2621–2645,Short summary
The frequency and severity of droughts are expected to increase in the tropics, impacting the functioning of tropical forests. Here, we synthesized observed responses to drought in Neotropical forests. We find that, during drought, trees generally close their leaf stomata, resulting in reductions in photosynthesis, growth and transpiration. However, on the ecosystem scale, these responses are not visible. This indicates that resistance to drought increases from the leaf to ecosystem scale.
Jessica Hetzer, Andreas Huth, Thorsten Wiegand, Hans Jürgen Dobner, and Rico Fischer
Biogeosciences, 17, 1673–1683,Short summary
Due to limited accessibility in tropical regions, only small parts of the forest landscape can be surveyed in forest plots. Since there is an ongoing debate about how representative estimations based on samples are at larger scales, this study analyzes how many plots are needed to quantify the biomass of the entire South American tropical forest. Through novel computational and statistical investigations we show that the spatial plot positioning is crucial for continent-wide biomass estimations.
Jameson R. Brennan, Patricia S. Johnson, and Niall P. Hanan
Biogeosciences, 17, 1281–1292,Short summary
Prairie dogs have been described as a keystone species and are important for grassland conservation, yet concerns exist over the impact of prairie dogs on livestock production. The aim of this study was to classify plant communities on and off prairie dog towns in South Dakota and determine the utility of using remote sensing to identity prairie dog colony extent. The results show that remote sensing is effective at determining prairie dog colony boundaries.
Simon Scheiter, Glenn R. Moncrieff, Mirjam Pfeiffer, and Steven I. Higgins
Biogeosciences, 17, 1147–1167,Short summary
Current rates of climate and atmospheric change are likely higher than during the last millions of years. Vegetation cannot keep pace with these changes and lags behind climate. We used a vegetation model to study how these lags are influenced by CO2 and fire in Africa. Our results indicate that vegetation is most sensitive to CO2 change under current and near-future conditions and that vegetation will be committed to further change even if CO2 emissions are reduced and the climate stabilizes.
Jonathan R. Moore, Arthur P. K. Argles, Kai Zhu, Chris Huntingford, and Peter M. Cox
Biogeosciences, 17, 1013–1032,Short summary
The distribution of tree sizes across Amazonia can be fitted very well (for both trunk diameter and tree mass) by a simple equilibrium model assuming power law growth and size-independent mortality. We find tree growth to mirror some aspects of metabolic scaling theory and that there may be a trade-off between fast-growing, short-lived and longer-lived, slow-growing ones. Our Amazon mortality-to-growth ratio is very similar to US temperate forests, hinting at a universal property for trees.
Hongying Yu, Zhenzhu Xu, Guangsheng Zhou, and Yaohui Shi
Biogeosciences, 17, 781–792,Short summary
Climate change severely impacts grassland carbon cycling, especially in arid ecosystems, such as desert steppes. The current results highlight the great dependence of soil carbon emission on warming regimes of different duration and the important role of precipitation pulse during growing season in assessing the terrestrial ecosystem carbon balance and cycle.
Rafat Qubaja, Fyodor Tatarinov, Eyal Rotenberg, and Dan Yakir
Biogeosciences, 17, 699–714,Short summary
This paper presents a study of the CO2 fluxes in a pine forest plantation at the dry timberline in the Negev, combining the present time with the long-term perspective. Two key issues that limit our understanding are the need to know the sources of CO2 fluxes and the need for long-term perspectives. We provide evidence that helps explain the forest plantation productivity under stressful conditions, which can assist in predicting the response of forest to future drying climate.
Richard K. F. Nair, Kendalynn A. Morris, Martin Hertel, Yunpeng Luo, Gerardo Moreno, Markus Reichstein, Marion Schrumpf, and Mirco Migliavacca
Biogeosciences, 16, 1883–1901,Short summary
We investigated how nutrient availability affects seasonal timing of root growth and death in a Spanish savanna, adapted to a long summer drought. We found that nitrogen (N) additions led to more root biomass but number of roots was higher with N and phosphorus together. These effects were strongly affected by the time of year. In autumn root growth occurred after leaf production. This has implications for how we understand biomass production and carbon uptake in these systems.
Susanne Wiesner, Christina L. Staudhammer, Paul C. Stoy, Lindsay R. Boring, and Gregory Starr
Biogeosciences, 16, 1845–1863,Short summary
We studied entropy production in longleaf savanna sites with variations in land use legacy, plant diversity, and soil water availability which experienced drought. Sites with greater land use legacy had lower metabolic energy use efficiency, which delayed recovery from drought. Sites with more hardwood captured less solar radiation but more efficiently used absorbed energy. Future management applications could use these methods to quantify energy use efficiency across global ecosystems.
Shaun R. Levick, Anna E. Richards, Garry D. Cook, Jon Schatz, Marcus Guderle, Richard J. Williams, Parash Subedi, Susan E. Trumbore, and Alan N. Andersen
Biogeosciences, 16, 1493–1503,Short summary
We used airborne lidar to map the three-dimensional structure and model the biomass of plant canopies across a long-term fire experiment in the Northern Territory of Australia. Our results show that late season fires occurring every 2 years reduce the amount of carbon stored above-ground by 50 % relative to unburnt control plots. We also show how increased fire intensity removes the shrub layer from savannas and discuss the implications for biodiversity conservation.
Lisa Thieme, Daniel Graeber, Diana Hofmann, Sebastian Bischoff, Martin T. Schwarz, Bernhard Steffen, Ulf-Niklas Meyer, Martin Kaupenjohann, Wolfgang Wilcke, Beate Michalzik, and Jan Siemens
Biogeosciences, 16, 1411–1432,Short summary
To improve our understanding of the effects of tree species selection and management intensity on dissolved organic matter (DOM), we studied solution samples along the water flow path through forests with spectroscopic methods and biodegradation tests. There are distinct changes in DOM composition and biodegradability following the water path. Aboveground DOM was influenced by tree species selection but not by management intensity. Differences became aligned in mineral soil.
Raquel Lobo-do-Vale, Cathy Kurz Besson, Maria Conceição Caldeira, Maria Manuela Chaves, and João Santos Pereira
Biogeosciences, 16, 1265–1279,Short summary
By comparing the cork oak tree vegetative phenology in two contrasting precipitation years in a Mediterranean ecosystem, we showed the critical role of water availability in extending the length of the growing season and determining tree growth. The observed higher transfer of nitrogen from senescent to green leaves in response to drought might compensate for the limited nitrogen uptake by the roots. Our results improve our understanding of the ecosystem's responses to climate change.
Pierre Laurent, Florent Mouillot, Maria Vanesa Moreno, Chao Yue, and Philippe Ciais
Biogeosciences, 16, 275–288,Short summary
Fire propagation and fire size are usually considered to be proportional to fire intensity. We used a global database of fire patch size and fire radiative power, used as a proxy of fire intensity, to test this relationship at a global scale. We showed that in some regions fire size tends to saturate when a regional fire intensity threshold is reached. We concluded that increasing landscape fragmentation limits fire propagation and this effect should be accounted for in global fire modules.
Kerry Cawse-Nicholson, Joshua B. Fisher, Caroline A. Famiglietti, Amy Braverman, Florian M. Schwandner, Jennifer L. Lewicki, Philip A. Townsend, David S. Schimel, Ryan Pavlick, Kathryn J. Bormann, Antonio Ferraz, Emily L. Kang, Pulong Ma, Robert R. Bogue, Thomas Youmans, and David C. Pieri
Biogeosciences, 15, 7403–7418,Short summary
Carbon dioxide levels are rising globally, and it is important to understand how this rise will affect plants over long time periods. Volcanoes such as Mammoth Mountain, California, have been releasing CO2 from their flanks for decades, and this provides a test environment in order to study the way plants respond to long-term CO2 exposure. We combined several airborne measurements to show that plants may have fewer, more productive leaves in areas with increasing CO2.
Tim van Emmerik, Susan Steele-Dunne, Pierre Gentine, Rafael S. Oliveira, Paulo Bittencourt, Fernanda Barros, and Nick van de Giesen
Biogeosciences, 15, 6439–6449,Short summary
Trees are very important for the water and carbon cycles. Climate and weather models often assume constant vegetation parameters because good measurements are missing. We used affordable accelerometers to measure tree sway of 19 trees in the Amazon rainforest. We show that trees respond very differently to the same weather conditions, which means that vegetation parameters are dynamic. With our measurements trees can be accounted for more realistically, improving climate and weather models.
Ricardo Dalagnol, Fabien Hubert Wagner, Lênio Soares Galvão, Bruce Walker Nelson, and Luiz Eduardo Oliveira e Cruz de Aragão
Biogeosciences, 15, 6087–6104,Short summary
We used a time series of MODIS (MAIAC) satellite images from 2000 to 2017 to map the distribution of bamboo-dominated forests in the southwest Amazon and detect when the bamboo populations are suffering massive die-offs. The aim was to test if bamboo die-off is associated with higher fire probability, which could impact other plant species while promoting bamboo dominance. Our findings show 15.5 million ha of bamboo forests which are not directly associated with fire, except in drought years.
Milan Flach, Sebastian Sippel, Fabian Gans, Ana Bastos, Alexander Brenning, Markus Reichstein, and Miguel D. Mahecha
Biogeosciences, 15, 6067–6085,Short summary
Northern forests enhanced their productivity during and before the 2010 Russian mega heatwave. We scrutinize this issue with a novel type of multivariate extreme event detection approach. Forests compensate for 54 % of the carbon losses in agricultural ecosystems due to vulnerable conditions in spring and better water management in summer. The findings highlight the importance of forests in mitigating climate change, while not alleviating the consequences of extreme events for food security.
Anni Vanhatalo, Andrea Ghirardo, Eija Juurola, Jörg-Peter Schnitzler, Ina Zimmer, Heidi Hellén, Hannele Hakola, and Jaana Bäck
Biogeosciences, 15, 5047–5060,Short summary
We analysed the relationships between Scots pine needle monoterpene synthase activities, monoterpene storage pools and emissions of needles. The results showed changes in the monoterpene synthase activity of needles, linked to seasonality and needle ontogenesis, while the pool did not change considerably as a function of needle aging. Monoterpene emissions did not correlate with synthase activity or storage pool size. Additionally, we observed notably high plant-to-plant variation.
Joshua P. Heyer, Mitchell J. Power, Robert D. Field, and Margreet J. E. van Marle
Biogeosciences, 15, 4317–4331,Short summary
A variety of data were explored to better understand relationships among climate, fire, smoke emissions, and human land use in lowland Bolivia. Paleosedimentary work and modern fire records have linked drought to fire in the southern Amazon. From 2000 to 2015, our results indicate drought was the dominant control on wildfire in lowland Bolivia and in Noel Kempff Mercado National Park. Note that fire was most common in the Cerrado and seasonally inundated wetland biomes.
Karin Glaser, Karen Baumann, Peter Leinweber, Tatiana Mikhailyuk, and Ulf Karsten
Biogeosciences, 15, 4181–4192,
Jing Wang, Xuefa Wen, Xinyu Zhang, and Shenggong Li
Biogeosciences, 15, 4193–4203,Short summary
The different contributions of gs, gm, and Vcmax to A indicated that plants utilized diverse trade-offs between CO2 supply and demand to maintain relatively high A. The iWUE was relatively low, but ranged widely, indicating that plants used a "profligate/opportunistic" water use strategy to maintain their survival, growth, and the structure of the community. These findings highlight the importance of covariation of gs, gm, and Vcmax for the adaptation of plants to the harsh karst environment.
Zachary T. Aanderud, Trevor B. Smart, Nan Wu, Alexander S. Taylor, Yuanming Zhang, and Jayne Belnap
Biogeosciences, 15, 3831–3840,Short summary
Besides performing multiple ecosystem services individually and collectively, biocrust constituents may also create biological networks connecting spatially and temporally distinct processes. We found evidence of fungal loops within biocrusts but only in cyanobacteria-dominated crusts for the inorganic N form NH4+. Combined with our sequencing effort, our findings suggest that even localized, minor rainfall events may allow dark septate Pleosporales to rapidly translocate N within biocrusts.
Tommaso Jucker, Gregory P. Asner, Michele Dalponte, Philip G. Brodrick, Christopher D. Philipson, Nicholas R. Vaughn, Yit Arn Teh, Craig Brelsford, David F. R. P. Burslem, Nicolas J. Deere, Robert M. Ewers, Jakub Kvasnica, Simon L. Lewis, Yadvinder Malhi, Sol Milne, Reuben Nilus, Marion Pfeifer, Oliver L. Phillips, Lan Qie, Nathan Renneboog, Glen Reynolds, Terhi Riutta, Matthew J. Struebig, Martin Svátek, Edgar C. Turner, and David A. Coomes
Biogeosciences, 15, 3811–3830,Short summary
Efforts to protect tropical forests hinge on recognizing the ecosystem services they provide, including their ability to store carbon. Airborne laser scanning (ALS) captures information on the 3-D structure of forests, allowing carbon stocks to be mapped. By combining ALS with data from 173 field plots on the island of Borneo, we develop a simple yet general model for estimating forest carbon stocks from the air. Our model underpins ongoing efforts to restore Borneo's unique tropical forests.
Philipp A. Nauer, Eleonora Chiri, David de Souza, Lindsay B. Hutley, and Stefan K. Arndt
Biogeosciences, 15, 3731–3742,Short summary
Termites perform important biogeochemical processes in tropical ecosystems, but the complex structure of their mounds impede an accurate quantitative description. We present two novel low-cost field methods, based on photogrammetry and image analysis, to quantify the volume, surface area and porosities of termite mounds. The methods are accurate, rapid to apply and superior to traditional methods, and thus improve biogeochemical rate estimates such as greenhouse-gas fluxes from termite mounds.
Henrique Fürstenau Togashi, Iain Colin Prentice, Owen K. Atkin, Craig Macfarlane, Suzanne M. Prober, Keith J. Bloomfield, and Bradley John Evans
Biogeosciences, 15, 3461–3474,Short summary
Ecosystem models commonly assume that photosynthetic traits, such as carboxylation capacity measured at a standard temperature, are constant in time and therefore do not acclimate. Optimality hypotheses suggest this assumption may be incorrect. We investigated acclimation by carrying out measurements on woody species during distinct seasons in Western Australia. Our study shows evidence that carboxylation capacity should acclimate so that it increases somewhat with growth temperature.
Victoria Meyer, Sassan Saatchi, David B. Clark, Michael Keller, Grégoire Vincent, António Ferraz, Fernando Espírito-Santo, Marcus V. N. d'Oliveira, Dahlia Kaki, and Jérôme Chave
Biogeosciences, 15, 3377–3390,Short summary
This study shows how a simple lidar-derived metric measuring the area covered by large trees (> 27 m) can explain biomass variations across the Neotropics. The importance of this metric is in its relevance to the structural and ecological characteristics of large trees and their unique contribution in determining the biomass of forests. Our results point toward simplified ground data collection and potential algorithms for future space missions focusing on biomass estimation.
Rafael Poyatos, Oliver Sus, Llorenç Badiella, Maurizio Mencuccini, and Jordi Martínez-Vilalta
Biogeosciences, 15, 2601–2617,Short summary
Plant traits are characteristics of plants that are easy to measure and that show how plants function. Values of these traits for many species and locations worldwide are available in trait databases, but these are often incomplete. Here we use different statistical methods to fill the gaps in a trait database of Mediterranean and temperate tree species. Combining traits and environmental information provides more plausible gap-filled databases and preserves the observed trait variability.
Wendy Williams, Burkhard Büdel, and Stephen Williams
Biogeosciences, 15, 2149–2159,Short summary
The northern Australian savannah grasslands encompass 1.5 million square kilometres, where naturally occurring cyanobacteria cover the soil surface. During the wet season, photosynthetic cyanobacteria continually absorb nitrogen from the air and produce a nutrient-rich slime. This bioactive slime formed a protective biofilm on the soil in-between grass plants and provided nitrogen in a plant-available form. Cyanobacterial species richness increased biofertilisation and boosted soil fertility.
Friedrich J. Bohn, Felix May, and Andreas Huth
Biogeosciences, 15, 1795–1813,Short summary
Rising temperature affect the wood production of forests. However, in some cases, we observe positive and in others negative changes. In this study, we used a new simulation approach to generate ~ 400 000 forest stands, which cover various types of temperate forests (low to high divers; young to old; even aged to uneven aged). We treated each forest with different temperature scenarios and analysed, which forest characteristics triggered the different reaction of forest to temperature change.
Michael Klinge, Choimaa Dulamsuren, Stefan Erasmi, Dirk Nikolaus Karger, and Markus Hauck
Biogeosciences, 15, 1319–1333,Short summary
Treelines are one of the most obvious borders between vegetation units and can easily be detected by remote sensing. They provide information on climate conditions and human impact on forest distribution. Performing a GIS analysis by combining different datasets leads to detection of the major determining factors for current forest distribution and helps to evaluate past and future conditions for tree growth. This is especially feasible for regions without extensive forest management.
Aaron M. Sparks, Crystal A. Kolden, Alistair M. S. Smith, Luigi Boschetti, Daniel M. Johnson, and Mark A. Cochrane
Biogeosciences, 15, 1173–1183,Short summary
Through landscape-scale satellite observations we demonstrate that fire intensity has a dose–response relationship with temperate forest net primary productivity. Increasing fire intensity resulted in persisting step-wise reductions in post-fire net primary productivity. Forests with higher proportions of fire-resistant species generally had lower reductions in post-fire net primary productivity. A conceptual framework for assessing spatiotemporal post-fire effects is presented.
Yuewei Guo and Yunge Zhao
Biogeosciences, 15, 797–808,Short summary
This study is a preparatory work for inoculating artificial biological soil crusts (biocrusts). The response of the physiological characteristics and regenerative capacity of three mosses to storage temperatures were studied. Results showed that different temperature significantly influenced the physiological characteristics of the mosses, which caused alteration in their regenerative capacity. More focus should therefore be on the state of moss inocula when restoring biocrusts by inoculation.
Burkhard Büdel, Wendy J. Williams, and Hans Reichenberger
Biogeosciences, 15, 491–505,Short summary
We report on the net primary productivity of a biological soil crust from the Boodjamulla NP, Queensland. Metabolic activity lasted from September 2010 to mid-April 2011, referring to 23.6 % of the total time of the year. The first months of activity had a respiratory loss of CO2. Of the metabolic active period, 48.6 % were photosynthesis and 51.4 % dark respiration. Carbon gain was 1.72 g m−2 yr−1. The gas exchange pattern was divided into metabolically inactive winter and active summer month.
Steffen Seitz, Martin Nebel, Philipp Goebes, Kathrin Käppeler, Karsten Schmidt, Xuezheng Shi, Zhengshan Song, Carla L. Webber, Bettina Weber, and Thomas Scholten
Biogeosciences, 14, 5775–5788,Short summary
This study investigated biological soil crusts (biocrusts, e.g. cyanobacteria and mosses) within an early-stage mesic subtropical forest in China, where they were particularly abundant. Biocrust covers significantly decreased soil erosion and were more effective in erosion reduction than stone cover. Hence, they play an important role in mitigating soil erosion under forest and are of particular interest for erosion control in forest plantations.
Ulises Rodríguez-Robles, Tulio Arredondo, Elisabeth Huber-Sannwald, José Alfredo Ramos-Leal, and Enrico A. Yépez
Biogeosciences, 14, 5343–5357,Short summary
The approach we present has the potential to contribute to the understanding of several types of plant interactions such as coexistence, competition and niche extent. By combining geophysical exploration techniques GPR and ERT we provide experimental evidence of horizontal roots located under exfoliated rocks and in water reservoirs. We also study how the roots access water retained in the weathered rock during droughty periods and the implications for survival and coexistence of forest species.
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We study the link between the boreal tree-cover fraction distribution and eight globally observed environmental factors. We find that they exert a strong control over the tree-cover distribution, generally uniquely determining its state. Furthermore, we show the location of areas with potentially alternative tree-cover states under the same environmental conditions. These areas represent transition zones with reduced resilience, where the forest can shift between different vegetation states.
We study the link between the boreal tree-cover fraction distribution and eight globally...