Articles | Volume 11, issue 16
Research article 19 Aug 2014
Research article | 19 Aug 2014
Evaluating remote sensing of deciduous forest phenology at multiple spatial scales using PhenoCam imagery
S. T. Klosterman et al.
No articles found.
Xin Huang, Dan Lu, Daniel M. Ricciuto, Paul J. Hanson, Andrew D. Richardson, Xuehe Lu, Ensheng Weng, Sheng Nie, Lifen Jiang, Enqing Hou, Igor F. Steinmacher, and Yiqi Luo
Geosci. Model Dev. Discuss.,
Preprint under review for GMDShort summary
In the data-rich era, data assimilation is widely used to integrate abundant observations into models to reduce uncertainty in ecological forecasting. However, applications of data assimilation are restricted by highly technical requirements. To alleviate this technical burden, we developed a model-independent data assimilation (MIDA) module which is friendly to ecologists with limited programming skills. MIDA also supports flexible switch of different models or observations in DA analysis.
Kyle B. Delwiche, Sara Helen Knox, Avni Malhotra, Etienne Fluet-Chouinard, Gavin McNicol, Sarah Feron, Zutao Ouyang, Dario Papale, Carlo Trotta, Eleonora Canfora, You-Wei Cheah, Danielle Christianson, M. Carmelita R. Alberto, Pavel Alekseychik, Mika Aurela, Dennis Baldocchi, Sheel Bansal, David P. Billesbach, Gil Bohrer, Rosvel Bracho, Nina Buchmann, David I. Campbell, Gerardo Celis, Jiquan Chen, Weinan Chen, Housen Chu, Higo J. Dalmagro, Sigrid Dengel, Ankur R. Desai, Matteo Detto, Han Dolman, Elke Eichelmann, Eugenie Euskirchen, Daniela Famulari, Thomas Friborg, Kathrin Fuchs, Mathias Goeckede, Sébastien Gogo, Mangaliso J. Gondwe, Jordan P. Goodrich, Pia Gottschalk, Scott L. Graham, Martin Heimann, Manuel Helbig, Carole Helfter, Kyle S. Hemes, Takashi Hirano, David Hollinger, Lukas Hörtnagl, Hiroki Iwata, Adrien Jacotot, Joachim Jansen, Gerald Jurasinski, Minseok Kang, Kuno Kasak, John King, Janina Klatt, Franziska Koebsch, Ken W. Krauss, Derrick Y. F. Lai, Ivan Mammarella, Giovanni Manca, Luca Belelli Marchesini, Jaclyn Hatala Matthes, Trofim Maximon, Lutz Merbold, Bhaskar Mitra, Timothy H. Morin, Eiko Nemitz, Mats B. Nilsson, Shuli Niu, Walter C. Oechel, Patricia Y. Oikawa, Keisuke Ono, Matthias Peichl, Olli Peltola, Michele L. Reba, Andrew D. Richardson, William Riley, Benjamin R. K. Runkle, Youngryel Ryu, Torsten Sachs, Ayaka Sakabe, Camilo Rey Sanchez, Edward A. Schuur, Karina V. R. Schäfer, Oliver Sonnentag, Jed P. Sparks, Ellen Stuart-Haëntjens, Cove Sturtevant, Ryan C. Sullivan, Daphne J. Szutu, Jonathan E. Thom, Margaret S. Torn, Eeva-Stiina Tuittila, Jessica Turner, Masahito Ueyama, Alex C. Valach, Rodrigo Vargas, Andrej Varlagin, Alma Vazquez-Lule, Joseph G. Verfaillie, Timo Vesala, George L. Vourlitis, Eric J. Ward, Christian Wille, Georg Wohlfahrt, Guan Xhuan Wong, Zhen Zhang, Donatella Zona, Lisamarie Windham-Myers, Benjamin Poulter, and Robert B. Jackson
Earth Syst. Sci. Data Discuss.,
Preprint under review for ESSDShort summary
Methane is an important greenhouse gas, yet we lack knowledge about its global emissions and drivers. We present FLUXNET-CH4, a new global collection of methane measurements and a critical resource for the research community. We use FLUXNET-CH4 data to quantify the seasonality of methane emissions from freshwater wetlands, finding that methane seasonality varies strongly with latitude. Our new database and analysis will improve wetland model accuracy and inform greenhouse gas budgets.
Rui Cheng, Troy S. Magney, Debsunder Dutta, David R. Bowling, Barry A. Logan, Sean P. Burns, Peter D. Blanken, Katja Grossmann, Sophia Lopez, Andrew D. Richardson, Jochen Stutz, and Christian Frankenberg
Biogeosciences, 17, 4523–4544,Short summary
We measured reflected sunlight from an evergreen canopy for a year to detect changes in pigments that play an important role in regulating the seasonality of photosynthesis. Results show a strong mechanistic link between spectral reflectance features and pigment content, which is validated using a biophysical model. Our results show spectrally where, why, and when spectral features change over the course of the season and show promise for estimating photosynthesis remotely.
Istem Fer, Ryan Kelly, Paul R. Moorcroft, Andrew D. Richardson, Elizabeth M. Cowdery, and Michael C. Dietze
Biogeosciences, 15, 5801–5830,Short summary
The computer models we use to understand and forecast the ecosystem changes have multiple components that determine their outcomes. Due to our limited observation capacities, these components bear uncertainties that in return affect our predictions. While there are techniques for reducing these uncertainties, they are not applicable to every model due to computational and statistical barriers. This research presents a method that lowers those barriers and allows us to improve model predictions.
Verónika Ceballos-Núñez, Andrew D. Richardson, and Carlos A. Sierra
Biogeosciences, 15, 1607–1625,Short summary
Will the terrestrial biosphere be a carbon source or sink in the future? Different model simulations cannot reach a consensus, so we need to diagnose the performance of these models. We implemented three models differing in their carbon allocation strategies and assessed their performance using three metrics. The most sensible metric was the distribution of carbon age and transit times. Thus, empirical measurements of these distributions could be key to reduce the model uncertainty.
Paul J. Hanson, Jeffery S. Riggs, W. Robert Nettles, Jana R. Phillips, Misha B. Krassovski, Leslie A. Hook, Lianhong Gu, Andrew D. Richardson, Donald M. Aubrecht, Daniel M. Ricciuto, Jeffrey M. Warren, and Charlotte Barbier
Biogeosciences, 14, 861–883,Short summary
This paper describes operational methods to achieve whole-ecosystem warming (WEW) for tall-stature, high-carbon, boreal forest peatlands. The methods enable scientists to study immediate and longer-term (1 decade) responses of organisms (microbes to trees) and ecosystem functions (carbon, water and nutrient cycles). The WEW technology allows researchers to have a plausible glimpse of future environmental conditions for study that are not available in the current observational record.
M. Verma, M. A. Friedl, A. D. Richardson, G. Kiely, A. Cescatti, B. E. Law, G. Wohlfahrt, B. Gielen, O. Roupsard, E. J. Moors, P. Toscano, F. P. Vaccari, D. Gianelle, G. Bohrer, A. Varlagin, N. Buchmann, E. van Gorsel, L. Montagnani, and P. Propastin
Biogeosciences, 11, 2185–2200,
P. C. Stoy, M. C. Dietze, A. D. Richardson, R. Vargas, A. G. Barr, R. S. Anderson, M. A. Arain, I. T. Baker, T. A. Black, J. M. Chen, R. B. Cook, C. M. Gough, R. F. Grant, D. Y. Hollinger, R. C. Izaurralde, C. J. Kucharik, P. Lafleur, B. E. Law, S. Liu, E. Lokupitiya, Y. Luo, J. W. Munger, C. Peng, B. Poulter, D. T. Price, D. M. Ricciuto, W. J. Riley, A. K. Sahoo, K. Schaefer, C. R. Schwalm, H. Tian, H. Verbeeck, and E. Weng
Biogeosciences, 10, 6893–6909,
Related subject area
Biodiversity and Ecosystem Function: TerrestrialFunctional convergence of biosphere–atmosphere interactions in response to meteorological conditionsMulti-scale assessment of a grassland productivity modelImproving the monitoring of deciduous broadleaf phenology using the Geostationary Operational Environmental Satellite (GOES) 16 and 17Factors controlling the productivity of tropical Andean forests: climate and soil are more important than tree diversityDrought years in peatland rewetting: rapid vegetation succession can maintain the net CO2 sink functionShift of seed mass and fruit type spectra along longitudinal gradient: high water availability and growth allometryRetrieval and validation of forest background reflectivity from daily Moderate Resolution Imaging Spectroradiometer (MODIS) bidirectional reflectance distribution function (BRDF) data across European forestsUnraveling the physical and physiological basis for the solar- induced chlorophyll fluorescence and photosynthesis relationship using continuous leaf and canopy measurements of a corn cropMachine learning estimates of eddy covariance carbon flux in a scrub in the Mexican highlandVariability of the surface energy balance in permafrost-underlain boreal forestVegetation modulates the impact of climate extremes on gross primary productionLandsat near-infrared (NIR) band and ELM-FATES sensitivity to forest disturbances and regrowth in the Central AmazonA survey of proximal methods for monitoring leaf phenology in temperate deciduous forestsRecent above-ground biomass changes in central Chukotka (Russian Far East) using field sampling and Landsat satellite dataMicroclimatic conditions and water content fluctuations experienced by epiphytic bryophytes in an Amazonian rain forestPlant trait response of tundra shrubs to permafrost thaw and nutrient additionSoils from cold and snowy temperate deciduous forests release more nitrogen and phosphorus after soil freeze–thaw cycles than soils from warmer, snow-poor conditionsResponse of carbon and water fluxes to meteorological and phenological variability in two eastern North American forests of similar age but contrasting species composition – a multiyear comparisonClimate change and elevated CO2 favor forest over savanna under different future scenarios in South AsiaDrought resistance increases from the individual to the ecosystem level in highly diverse Neotropical rainforest: a meta-analysis of leaf, tree and ecosystem responses to droughtAn analysis of forest biomass sampling strategies across scalesVariable tree rooting strategies improve tropical productivity and evapotranspiration in a dynamic global vegetation modelComparing stability in random forest models to map Northern Great Plains plant communities in pastures occupied by prairie dogs using Pleiades imageryAfrican biomes are most sensitive to changes in CO2 under recent and near-future CO2 conditionsValidation of demographic equilibrium theory against tree-size distributions and biomass density in AmazoniaSoil carbon release responses to long-term versus short-term climatic warming in an arid ecosystemPartitioning of canopy and soil CO2 fluxes in a pine forest at the dry timberline across a 13-year observation periodN : P stoichiometry and habitat effects on Mediterranean savanna seasonal root dynamicsQuantifying energy use efficiency via entropy production: a case study from longleaf pine ecosystemsRapid response of habitat structure and above-ground carbon storage to altered fire regimes in tropical savannaDissolved organic matter characteristics of deciduous and coniferous forests with variable management: different at the source, aligned in the soilDrought reduces tree growing season length but increases nitrogen resorption efficiency in a Mediterranean ecosystemVarying relationships between fire radiative power and fire size at a global scaleEcosystem responses to elevated CO2 using airborne remote sensing at Mammoth Mountain, CaliforniaIdeas and perspectives: Tree–atmosphere interaction responds to water-related stem variationsLife cycle of bamboo in the southwestern Amazon and its relation to fire eventsContrasting biosphere responses to hydrometeorological extremes: revisiting the 2010 western Russian heatwaveLong-term dynamics of monoterpene synthase activities, monoterpene storage pools and emissions in boreal Scots pineThe impacts of recent drought on fire, forest loss, and regional smoke emissions in lowland BoliviaAlgal richness in BSCs in forests under different management intensity with some implications for P cyclingThe strategies of water–carbon regulation of plants in a subtropical primary forest on karst soils in ChinaFungal loop transfer of nitrogen depends on biocrust constituents and nitrogen formEstimating aboveground carbon density and its uncertainty in Borneo's structurally complex tropical forests using airborne laser scanningTechnical note: Rapid image-based field methods improve the quantification of termite mound structures and greenhouse-gas fluxesThermal acclimation of leaf photosynthetic traits in an evergreen woodland, consistent with the coordination hypothesisCanopy area of large trees explains aboveground biomass variations across neotropical forest landscapesGap-filling a spatially explicit plant trait database: comparing imputation methods and different levels of environmental informationWet season cyanobacterial N enrichment highly correlated with species richness and Nostoc in the northern Australian savannahSpecies composition and forest structure explain the temperature sensitivity patterns of productivity in temperate forestsClimate effects on vegetation vitality at the treeline of boreal forests of Mongolia
Christopher Krich, Mirco Migliavacca, Diego G. Miralles, Guido Kraemer, Tarek S. El-Madany, Markus Reichstein, Jakob Runge, and Miguel D. Mahecha
Biogeosciences, 18, 2379–2404,Short summary
Ecosystems and the atmosphere interact with each other. These interactions determine e.g. the water and carbon fluxes and thus are crucial to understand climate change effects. We analysed the interactions for many ecosystems across the globe, showing that very different ecosystems can have similar interactions with the atmosphere. Meteorological conditions seem to be the strongest interaction-shaping factor. This means that common principles can be identified to describe ecosystem behaviour.
Shawn D. Taylor and Dawn M. Browning
Biogeosciences, 18, 2213–2220,Short summary
Grasslands in North America provide multiple ecosystem services and drive the production of a lot 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 productivity projections 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
Biogeosciences, 18, 1971–1985,Short 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 min) throughout most of the western hemisphere. Here we show the high potential of these new data to measure the phenology of deciduous forests.
Jürgen Homeier and Christoph Leuschner
Biogeosciences, 18, 1525–1541,Short summary
We studied aboveground productivity in humid tropical montane old-growth forests in two highly diverse Andean regions with large geological and topographic heterogeneity and related productivity to tree diversity and climatic, edaphic and stand structural factors. From our results we conclude that the productivity of highly diverse Neotropical montane forests is primarily controlled by thermal and edaphic factors and stand structural properties, while tree diversity is of minor importance.
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)).
Kamel Soudani, Nicolas Delpierre, Daniel Berveiller, Gabriel Hmimina, Jean-Yves Pontailler, Lou Seureau, Gaëlle Vincent, and Éric Dufrêne
Revised manuscript accepted for BGShort summary
We present an exhaustive comparative survey of eight proximal methods to estimate forest phenology. We focused on methodological aspects and assessed deeply deviations between predicted and observed phenological dates and pointed out their main causes. We show that proximal methods provide robust phenological metrics. They can be used to retrieve long-term phenological series at flux measurement sites and help interpret the interannual variability and trends of mass and energy exchanges.
Iuliia Shevtsova, Ulrike Herzschuh, Birgit Heim, Luise Schulte, Simone Stünzi, Luidmila A. Pestryakova, Evgeniy S. Zakharov, and Stefan Kruse
Revised manuscript accepted for BGShort summary
In the light of climate changes of subarctic regions, notable general increase in above-ground biomass for the past 15 years (2000 to 2017) was estimated along a tundra-taiga gradient of central Chukotka (Russian Far East). The greatest increase occurred in the northern taiga in the areas of larch closed-canopy forest expansion with Cajander larch as a main contributor. For the estimations, we used field data (taxa-separated plant biomass, 2018) and upscaled it based on Landsat satellite data.
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.
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.
Dushyant Kumar, Mirjam Pfeiffer, Camille Gaillard, Liam Langan, and Simon Scheiter
Revised manuscript accepted for BGShort summary
In this paper, we investigated the impact of climate change and rising CO2 on biomes using a vegetation model in South Asia, a region that is often neglected in global modeling studies. Understanding these impacts guide ecosystem management and biodiversity conservation. Our results indicate that savanna regions are at high risk of woody encroachment and transitioning into the forest, and the bioclimatic envelopes of biomes need adjustments to account for shifts caused by climate change and CO2.
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.
Boris Sakschewski, Werner von Bloh, Markus Drüke, Anna A. Sörensson, Romina Ruscica, Fanny Langerwisch, Maik Billing, Sarah Bereswill, Marina Hirota, Rafael S. Oliveira, Jens Heinke, and Kirsten Thonicke
Revised manuscript accepted for BGShort summary
This study shows how local adaptations of tree roots across tropical and sub-tropical South America explain patterns of biome distribution, productivity and evapotranspiration on this continent. By allowing for a high diversity of tree rooting strategies in a dynamic global vegetation model (DGVM) we are able to mechanistically explain patterns of mean rooting depth and the effects on ecosystem functions. The approach can advance DGVMs and Earth System Models.
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.
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