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1. Historical Aerial Surveys Map Long-Term Changes of Forest Cover and Structure in the Central Congo Basin

Author

Koen Hufkens, Thalès de Haulleville, Elizabeth Kearsley, Kim Jacobsen, Hans Beeckman, Piet Stoffelen, Filip Vandelook, Sofie Meeus, Michael Amara, Leen Van Hirtum, Jan Van den Bulcke, Hans Verbeeck, and Lisa Wingate

Subjects
aerial survey, data recovery, cnn, deep learning, sfm, congo basin, Science
Abstract

Given the impact of tropical forest disturbances on atmospheric carbon emissions, biodiversity, and ecosystem productivity, accurate long-term reporting of Land-Use and Land-Cover (LULC) change in the pre-satellite era (

Published
2020
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2. Resistance of African tropical forests to an extreme climate anomaly

Author

Hans Verbeeck, Jacques Mukinzi, Hermann Taedoumg, Connie J. Clark, Kofi Affum-Baffoe, Peter M. Umunay, John R. Poulsen, John T. Woods, Pascal Boeckx, Armandu K. Daniels, Vianet Mihindu, David Harris, Yannick Enock Bocko, Serge K. Begne, Thalès de Haulleville, Greta C. Dargie, C. Amani, Terry Sunderland, Miguel E. Leal, Stephen Adu-Bredu, Elizabeth Kearsley, Terry Brncic, Suspense Averti Ifo, Martin J. P. Sullivan, Jean-Louis Doucet, Kathryn J. Jeffery, Yadvinder Malhi, Jefferson S. Hall, Vincent P. Medjibe, Olivier J. Hardy, Ted R. Feldpausch, Jean-Remy Makana, Darlington Tuagben, Jan Reitsma, Natacha Nssi Begone, Bonaventure Sonké, Aida Cuni-Sanchez, Sam Moore, Jan Bogaert, Joey Talbot, Lise Zemagho, Marie-Noël Djuikouo Kamdem, Eric Chezeaux, Declan L. M. Cooper, Christelle Gonmadje, Oliver L. Phillips, Georgia Pickavance, Faustin Mbayu Lukasu, Amy C. Bennett, Hannsjoerg Woell, John Tshibamba Mukendi, Lee J. T. White, Lindsay F. Banin, Hans Beeckman, Fidèle Evouna Ondo, Simon L. Lewis, Wannes Hubau, Jason Vleminckx, Aurora Levesley, Corneille E. N. Ewango, and Ernest G. Foli

Subjects
Agriculture and Food Sciences, Hot Temperature, 010504 meteorology & atmospheric sciences, Environmental change, DIVERSITY, drought, 01 natural sciences, Trees, BIOMASS, Soil respiration, CARBON STORAGE, El Nino-Southern Oscillation, 0303 health sciences, Biomass (ecology), Multidisciplinary, Ecology, PRODUCTIVITY, Biological Sciences, Droughts, GROWTH, TREES, CO2, Seasons, ENSO, Biologie, SOIL RESPIRATION, El Nino, Rainforest, Climate Change, MODELS, Climate change, Ecology and Environment, Carbon Cycle, Carbon cycle, 03 medical and health sciences, parasitic diseases, carbon cycle, Humans, El Niño, Precipitation, 030304 developmental biology, 0105 earth and related environmental sciences, Tropical Climate, temperature, Tropics, 15. Life on land, 13. Climate action, cavelab, Environmental science, Tropical rainforest
Abstract

The responses of tropical forests to environmental change are critical uncertainties in predicting the future impacts of climate change. The positive phase of the 2015–2016 El Niño Southern Oscillation resulted in unprecedented heat and low precipitation in the tropics with substantial impacts on the global carbon cycle. The role of African tropical forests is uncertain as their responses to short-term drought and temperature anomalies have yet to be determined using on-the-ground measurements. African tropical forests may be particularly sensitive because they exist in relatively dry conditions compared with Amazonian or Asian forests, or they may be more resistant because of an abundance of drought-adapted species. Here, we report responses of structurally intact old-growth lowland tropical forests inventoried within the African Tropical Rainforest Observatory Network (AfriTRON). We use 100 long-term inventory plots from six countries each measured at least twice prior to and once following the 2015–2016 El Niño event. These plots experienced the highest temperatures and driest conditions on record. The record temperature did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality, but the record drought did significantly decrease net carbon uptake. Overall, the long-term biomass increase of these forests was reduced due to the El Niño event, but these plots remained a live biomass carbon sink (0.51 ± 0.40 Mg C ha −1 y −1 ) despite extreme environmental conditions. Our analyses, while limited to African tropical forests, suggest they may be more resistant to climatic extremes than Amazonian and Asian forests., info:eu-repo/semantics/published

Published
2021

3. Fourteen years of anthropization dynamics in the Uapaca bojeri Baill. forest of Madagascar

Author

Gabrielle Lalanirina Rajoelison, Jan Bogaert, Marc Poncelet, Hans Beeckman, Yves Brostaux, François Verheggen, François Malaisse, Thalès de Haulleville, Jean-François Bastin, Eric Haubruge, Olivia Rakotondrasoa, and Harifidy Rakoto Ratsimba

Subjects
0106 biological sciences, 010504 meteorology & atmospheric sciences, Ecology, Biodiversity, Fragmentation (computing), Anthropization, Management, Monitoring, Policy and Law, 010603 evolutionary biology, 01 natural sciences, Fractal dimension, Geography, Deforestation, Uapaca bojeri, Physical geography, Segmented regression, Landscape ecology, 0105 earth and related environmental sciences, Nature and Landscape Conservation
Abstract

Anthropization of forest landscapes is a major threat to ecosystems and biodiversity. To gather comprehensive information on anthropization dynamics in forest landscapes, fine-scale surveys of deforestation are required, coupled with detailed analysis of both spatial transformation processes and forest patch geometry. We conducted such a comprehensive study in a monospecific Uapaca bojeri (Baill.) forest of Madagascar, between 1999 and 2013. A diachronic set of four maps was produced and deforestation rates were calculated. Spatial transformation processes were described using Bogaert et al. (2004) typology. Forest patch geometry was monitored using largest patch index, mean patch size, and squared mean patch size to describe patch size dynamics, mean shape index and area weighted mean shape index to describe patch compactness, and fractal dimension analysis to describe patch outline complexity. For fractal dimension analysis, an innovative segmented regression model (Muggeo 2008) was used to separately quantify fractal dimensions for multiple ranges of patch sizes. Our results showed a growing anthropization of the U. bojeri forest landscape in the area, through a strong yet decelerating deforestation (from − 59.5% year−1 between 1999 and 2005 to − 2.84% year−1 between 2009 and 2013), clear forest fragmentation, and a subtle yet growing-in-scale simplification of patch geometry for small forest patches. Deforestation was artisanal in nature and, in 2013, large patches were withdrawing to less accessible topographic features. Our results forecast a medium-term loss of resilience of the U. bojeri forest in the area, if no direct forest conservation measures are taken.

Published
2018
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4. Testing a general approach to assess the degree of disturbance in tropical forests

Author

Jayanth R. Banavar, Filippo Simini, Hans Beeckman, Marijn Bauters, Amos Maritan, Jean-Louis Doucet, Thalès de Haulleville, Giacomo Sellan, and Tommaso Anfodillo

Subjects
0106 biological sciences, Disturbance (geology), 010504 meteorology & atmospheric sciences, Plant Science, 010603 evolutionary biology, 01 natural sciences, Power law, Crown volume, Allometric relationships, Finite size scaling, Operationalization, Restoration strategies, Tree size distribution, Tropical ecology, Ecology, Statistics, Forest protection, 0105 earth and related environmental sciences, Mathematics, Biomass (ecology), Crown (botany), Tree (data structure), Allometry
Abstract

Questions Is there any theoretical model enabling predictions of the optimal tree size distribution in tropical communities? Can we use such a theoretical framework for quantifying the degree of disturbance? Location Reserve of Yangambi, northeast region of the Democratic Republic of Congo. Methods We applied an allometric model based on the assumption that a virtually undisturbed forest uses all available resources. In this condition, the forest structure (e.g. the tree size distribution) is theoretically predictable from the scaling of the tree crown with tree height at an individual level. The degree of disturbance can be assessed through comparing the slopes of the tree size distribution curves in the observed and predicted conditions. We tested this tool in forest stands subjected to different degrees of disturbance. We inventoried trees >1.3 m in height by measuring the DBH in three plots of 1 ha each, and measured tree height, crown radius and crown length in a sub-sample of trees. Results All tree species, independently of the site, shared the same exponents of allometric relationships: tree height vs tree diameter, crown radius vs tree height, crown length vs tree height and consequently crown volume vs tree height, suggesting that similar trajectories of biomass allocation have evolved irrespective of species. The observed tree size distributions appeared to be power laws (excluding the finite size effect) and, as predicted, the slope was steeper in the less disturbed forest (−2.34) compared to the most disturbed (−1.99). The difference in the slope compared to the theoretical fully functional forest (−2.65) represents the metric for assessing the degree of disturbance. Conclusions We developed a simple tool for operationalizing the concept of ‘disturbance’ in tropical forests. This approach is species-independent, needs minimal theoretical assumptions, the measurement of only a few structural traits and requires a low investment in equipment, time and computer skills. Its simple implementation opens new perspectives for effectively addressing initiatives of forest protection and/or restoration.

Published
2017
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5. Long-term thermal sensitivity of Earth's tropical forests

Author

Bruno Herault, Peter J. Van Der Meer, Jean-François Bastin, Aurora Levesley, Michael D. Swaine, Rodolfo Vásquez Martínez, Martin Dančák, Matt Bradford, Frans Bongers, Stuart J. Davies, Reuben Nilus, Adriano José Nogueira Lima, Lip Khoon Kho, Edmar Almeida de Oliveira, Joey Talbot, Richard F. Preziosi, Jagoba Malumbres-Olarte, James A. Comiskey, Thalès de Haulleville, José Luís Camargo, Terese B. Hart, Juliana Schietti, Peter S. Ashton, Thomas E. Lovejoy, Ophelia Wang, Kanehiro Kitayama, Francis Q. Brearley, Peter van der Hout, Amy C. Bennett, Janvier Lisingo, Luis Valenzuela Gamarra, Lily Rodriguez Bayona, Zorayda Restrepo Correa, Jérôme Chave, Connie J. Clark, Christopher Baraloto, Gerardo Aymard, Serge K. Begne, Kofi Affum-Baffoe, Abel Monteagudo-Mendoza, Geertje M. F. van der Heijden, Fernanda Coelho de Souza, Timothy R. Baker, Rahayu Sukmaria Sukri, Julie Peacock, Hermann Taedoumg, Simon L. Lewis, Yahn Carlos Soto Shareva, Greta C. Dargie, Murielle Simo-Droissart, David Harris, Faizah Metali, Hans ter Steege, Richard Lowe, Géraldine Derroire, Benoit Burban, Camila Silva Valeria, Martin Svátek, Wannes Hubau, Sarah A. Batterman, Vincent A. Vos, Elizabeth Kearsley, Peter M. Umunay, Martin J. P. Sullivan, Flávia R. C. Costa, Hans Verbeeck, Maria Cristina Peñuela Mora, John R. Poulsen, Simon Willcock, Simone Aparecida Vieira, Jean-Louis Doucet, Foster Brown, Yadvinder Malhi, Luisa Fernanda Duque, Ronald Vernimmen, Miguel E. Leal, Alan Hamilton, Martin Gilpin, Colin R. Maycock, Carlos Cerón, Radim Hédl, Oliver L. Phillips, Walter Huaraca Huasco, Jon C. Lovett, Beatriz Schwantes Marimon, Roderick Zagt, Ted R. Feldpausch, Gabriela Lopez-Gonzalez, Ima Célia Guimarães Vieira, Pascal Boeckx, Roel J. W. Brienen, Marcelo F. Simon, Keith C. Hamer, Alberto Vicentini, Corneille E. N. Ewango, Clément Stahl, Javier Silva Espejo, Ana Andrade, Anand Roopsind, Erika Berenguer, Pieter A. Zuidema, Vianet Mihindou, Murray Collins, Simone Matias Reis, Emilio Vilanova Torre, Kathryn J. Jeffery, Marie Noël Kamdem Djuikouo, Terry Brncic, Percy Núñez Vargas, John Terborgh, Paulo S. Morandi, Bonaventure Sonké, Jan Bogaert, William E. Magnusson, Lilian Blanc, Terry L. Erwin, Ervan Rutishauser, Anthony Di Fiore, Isau Huamantupa-Chuquimaco, Edward T. A. Mitchard, Massiel Corrales Medina, Nicholas J. Berry, Juliana Stropp, Maureen Playfair, Luzmila Arroyo, Douglas Sheil, Armando Torres-Lezama, David A. Neill, Sean C. Thomas, Eric Arets, Ernest G. Foli, Lola da Costa, Ricardo Keichi Umetsu, Lan Qie, James Singh, Lise Zemagho, Agustín Rudas, Richard B. Primack, Jan Reitsma, Annette Hladik, Alexander K. Koch, Colin A. Pendry, Walter A. Palacios, Sabina Cerruto Ribeiro, Nicolas Labrière, Fernando Elias, Eric Chezeaux, William Milliken, Manuel Gloor, Romeo Ekoungoulou, Jefferson S. Hall, Henrique E. M. Nascimento, Susan G. Laurance, Axel Dalberg Poulsen, Marcos Silveira, Carolina V. Castilho, Plínio Barbosa de Camargo, Eurídice N. Honorio Coronado, Kamariah Abu Salim, Joeri A. Zwerts, Marcelo Brilhante de Medeiros, Jos Barlow, Georgia Pickavance, Joice Ferreira, Mark van Nieuwstadt, Jorcely Barroso, Andrew R. Marshall, Miguel Alexiades, Lindsay F. Banin, Terry Sunderland, Lourens Poorter, Alejandro Araujo-Murakami, Varun Swamy, Rafael Herrera, Hans Beeckman, Gerardo Flores Llampazo, Shin-ichiro Aiba, Adriane Esquivel-Muelbert, Michelle Kalamandeen, Adriana Prieto, Ben Hur Marimon, Casimiro Mendoza, Victor Chama Moscoso, Eliana Jimenez-Rojas, Hirma Ramírez-Angulo, Maxime Réjou-Méchain, Vincent Droissart, Nigel C. A. Pitman, Hannah L. Mossman, Everton Cristo de Almeida, Fernando Cornejo Valverde, Ângelo Gilberto Manzatto, Aurélie Dourdain, Luiz E. O. C. Aragão, Raquel Thomas, David W. Galbraith, Kenneth R. Young, Nallaret Davila Cardozo, Timothy J. Killeen, Rafael de Paiva Salomão, Bente B. Klitgaard, James Taplin, Damien Bonal, Karina Melgaço, William F. Laurance, Jason Vleminckx, Esteban Alvarez Dávila, Verginia Wortel, Richarlly da Costa Silva, Thaiane Rodrigues de Sousa, Sophie Fauset, Nadir Pallqui Camacho, Wendeson Castro, Toby R. Marthews, Fabricio Beggiato Baccaro, John T. Woods, David Taylor, Patricia Alvarez Loayza, Andrew Ford, Niro Higuchi, Aida Cuni Sanchez, Aline Pontes Lopes, Laszlo Nagy, John Pipoly, Lee J. T. White, Jhon del Aguila Pasquel, European Research Council, European Commission, Royal Society (UK), Leverhulme Trust, Gordon and Betty Moore Foundation, David and Lucile Packard Foundation, Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Agence Nationale de la Recherche (France), Missouri Botanical Garden, Smithsonian Institution, Wildlife Conservation Society, National Geographic Society, Centre for International Forestry Research, Agence Nationale Des Parcs Nationaux (Gabon), University of Leeds, Mensurat Unit, Forestry Research Institute of Ghana, Centro de Pesquisa Agroflorestal de Roraima, Brazilian Agricultural Research Corporation (Embrapa), Sch Geog, University of Nottingham, Department of Biology, Higher Teachers Training College (HTTC), Université deYaoundé I, School of Geography [Leeds], University of Edinburgh, School of Geography and the Environment, Environmental Change Institute, University of Oxford [Oxford], Grad Sch Sci & Engn, Kagoshima University, University of Kent [Canterbury], Universidade Federal do Mato Grosso (UFMT), Universidad Nacional de Colombia, Duke University [Durham], Instituto Nacional de Pesquisas da Amazônia (INPA), University of Campinas [Campinas] (UNICAMP), National Institute for Space Research [Sao José dos Campos] (INPE), Universidad Autonoma Gabriel René Moreno (UAGRM), Wageningen University and Research [Wageningen] (WUR), Dept Organism & Evolutionary Biol, Harvard University [Cambridge], Ecologie des forêts de Guyane (ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université des Antilles et de la Guyane (UAG)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Universidade de São Paulo (USP), Universidade Federal do Acre (UFAC), Research Unit of Landscape Ecology and Plant Production Systems, Université libre de Bruxelles (ULB), School of Engineering and Science, Jacobs University [Bremen], Lancaster Environment Centre, Lancaster University, Sch Geosci, Laboratory of Applied Physical Chemistry, Universiteit Gent = Ghent University [Belgium] (UGENT), Biodiversité et Paysage, Université de Liège - Gembloux, Ecologie et Ecophysiologie Forestières [devient SILVA en 2018] (EEF), Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL), Forest Ecol & Forest Management Grp, CSIRO Land and Water, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Woods Hole Research Center, Partenaires INRAE, Herbario Alfredo Paredes, Universidad Agraria del Ecuador, Universidad Nacional de San Antonio Abad del Cusco (UNSAAC), Evolution et Diversité Biologique (EDB), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Rougier Gabon, Andes to Amazon Biodiversity Program, Federal University of Para - Universidade Federal do Para [Belem - Brésil], Smithsonian Tropical Research Institute, Universidad Nacional de la Amazonía Peruana [Loreto, Perou] (UNAP), AgroParisTech, University of Texas at Austin [Austin], Université de Liège, Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Laboratoire des Milieux Désordonnés et Hétérogènes (LMDH), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Commonwealth Scientific & Industrial Research Organisation (CSIRO), Royal Botanic Gardens, Czech Academy of Sciences [Prague] (CAS), Commissariat général du Plan (CGP), Premier ministre, Instituto Nacional de Pequisas da Amazônia, Instituto National de Pequisas da Amazonia Brazil, Éco-Anthropologie (EAE), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale des Parcs Nationaux, Agence Nationale des Parcs Nationaux, BP 30 379 Libreville, Gabon, Malaysian Palm Oil Board, Kyoto University, Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], James Cook University (JCU), Laboratoire d'Etude de l'Apprentissage et du Développement [Dijon] (LEAD), Centre National de la Recherche Scientifique (CNRS)-Université de Bourgogne (UB), Coordenac Bao de Pesquisas em Ecologia, Universidade do Estado de Mato Grosso (UNEMAT), University of Mary Washington, Chercheur indépendant, Royal Botanic Garden , Kew, Department of Biochemistry and Molecular Biology, Medical and Health Science Center, Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Universidad Estatal Amazonica, Forest Research Centre (FRC), Forest Ecology and Forest Management Group, Natural History Museum [Oslo], University of Oslo (UiO), Bur Waarderburg, Iwokrama International Centre for Rainforest Conservation and Development, CarboForExpert, Museu Paraense Emílio Goeldi [Belém, Brésil] (MPEG), Center for International Forestry Research (CIFOR), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), University of Yaoundé [Cameroun], JRC Institute for Environment and Sustainability (IES), European Commission - Joint Research Centre [Ispra] (JRC), Institute of Biological and Environmental Sciences, School of Biological Sciences, University of Aberdeen, Plant Systemat & Ecol Lab, Université de Yaoundé I, Department of Neurology, Great Ormond Street Hospital for Children [London] (GOSH), Naturalis Biodiversity Center [Leiden], Division of Marine Science and Conservation, Nicholas School of the Environment, Instituto de Investigaciones para el Desarrollo Forestal, Universidad de los Andes [Bogota] (UNIANDES), University of Wisconsin - Milwaukee, Van der Hout Forestry Consulting, University Medical Center Groningen [Groningen] (UMCG), Computational & Applied Vegetation Ecology (CAVElab), Department of Integrative Biology [Berkeley] (IB), University of California [Berkeley], University of California-University of California, Sch Earth Sci & Environm Sustainabil, Northern Arizona University [Flagstaff], University of Stirling, Biol Sci, Liverpool John Moore University (ljmu), Biodiversity Department, Center for Agricultural Research in Suriname (CELOS), Sub Ecology and Biodiversity, Sub Animal Ecology, Ecology and Biodiversity, Animal Ecology, and Systems Ecology

Subjects
0106 biological sciences, Tropical trees, Hot Temperature, 010504 meteorology & atmospheric sciences, Earth, Planet, Climate, Acclimatization, Tropical forest carbon stocks, Bos- en Landschapsecologie, Growth, Forests, Atmospheric sciences, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 01 natural sciences, Trees, Tropical climate, SDG 13 - Climate Action, Forest and Landscape Ecology, Biomass, Photosynthesis, Hectare, Productivity, Biomass (ecology), Multidisciplinary, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, PE&RC, Wood, Productivity (ecology), Vegetatie, Bos- en Landschapsecologie, C180 Ecology, Tree, Leaf Respiration, Carbon-Cycle Feedbacks, Climate Change, Climate change and forestry, Climate change, 010603 evolutionary biology, Carbon cycle, Carbon Cycle, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Life Science, Bosecologie en Bosbeheer, Vegetatie, 0105 earth and related environmental sciences, Tropical Climate, Vegetation, Global warming, Tropics, 15. Life on land, Forest Ecology and Forest Management, Carbon, CO₂ Fertilization, 13. Climate action, Environmental science, Vegetation, Forest and Landscape Ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Acclimation
Abstract

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (-9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth's climate., Our plot monitoring networks havebeen supported by multiple grants from a large number of funding bodies: European Research Council; Natural Environment Research Council; European Union’s Fifth, Sixth, and Seventh Framework Programme; Royal Society, Leverhulme Trust; Gordon and Betty Moore Foundation; David and Lucile Packard Foundation; State of São Paulo Research Foundation (FAPESP); National Council for Science and Technology Development of Brazil (CNPq); Agence Nationale de la Recherche; Conservation International; Missouri Botanical Garden; Smithsonian Institution; Wildlife Conservation Society; National Geographic Society; Centre for International Forestry; and Gabon’s National Park Agency.

Published
2020
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6. Asynchronous carbon sink saturation in African and Amazonian tropical forests

Author

Gabriela Lopez-Gonzalez, David A. Coomes, Connie J. Clark, Hannsjörg Wöll, Douglas Sheil, Kofi Affum-Baffoe, Geertje M. F. van der Heijden, Katharine Abernethy, Hans Verbeeck, John Tshibamba Mukendi, Ted R. Feldpausch, Terese B. Hart, Sam Moore, Robert Bitariho, Francesco Rovero, Joey Talbot, Lise Zemagho, C. Amani, Jefferson S. Hall, Sean C. Thomas, Amy C. Bennett, Pascal Boeckx, Aida Cuni-Sanchez, Armandu K. Daniels, Fabrice Bénédet, Yadvinder Malhi, Alusine Fofanah, John R. Poulsen, David Kenfack, Lindsay F. Banin, Janvier Lisingo, Hans Beeckman, Jean-Louis Doucet, Eric Chezeaux, Emanuel Gloor, Mireille Breuer-Ndoundou Hockemba, Timothy R. Baker, Jan Reitsma, Vincent P. Medjibe, Christelle Gonmadje, Axel Dalberg Poulsen, Marie Noel Djuikouo Kamdem, Fidèle Baya, Serge K. Begne, Patrick Boundja, Adriane Esquivel-Muelbert, Lucas Ojo, Roel J. W. Brienen, Hermann Taedoumg, Natacha Nssi Bengone, Benjamin Toirambe, Lan Qie, Jon C. Lovett, Greta C. Dargie, Elizabeth Kearsley, Darlington Tuagben, George B. Chuyong, Sylvie Gourlet-Fleury, Fidèle Evouna Ondo, Terry Brncic, Pantaleo K. T. Munishi, Martin J. P. Sullivan, Tommaso Jucker, Simon Willcock, Yannick Enock Bocko, Emanuel H. Martin, Vianet Mihindou, Kelvin S.-H. Peh, Kathryn J. Jeffery, Simon L. Lewis, Emmanuel Kasongo Yakusu, Jean-Remy Makana, Andrew R. Marshall, Martin Gilpin, Bonaventure Sonké, Jeremy A. Lindsell, Faustin M. Mbayu, Corneille E. N. Ewango, Wannes Hubau, Suspense Averti Ifo, Peter M. Umunay, Duncan W. Thomas, Edward T. A. Mitchard, Ernest G. Foli, Lee J. T. White, Jaccques M. Mukinzi, Georgia Pickavance, James Taplin, Terry Sunderland, Annette Hladik, Stephen Adu-Bredu, Jason Vleminckx, Oliver L. Phillips, Sophie Fauset, Alexander K. Koch, David Harris, Miguel E. Leal, Alan Hamilton, Aurora Levesley, Michael D. Swaine, James A. Comiskey, Thalès de Haulleville, John T. Woods, David Taylor, Jim Martin, and Murray Collins

Subjects
0106 biological sciences, Carbon Sequestration, 010504 meteorology & atmospheric sciences, Rainforest, Carbon sequestration, Forests, Atmospheric sciences, 010603 evolutionary biology, 01 natural sciences, History, 21st Century, Sink (geography), Trees, chemistry.chemical_compound, Forest ecology, Tropical climate, Life Science, Biomass, 0105 earth and related environmental sciences, Carbon dioxide in Earth's atmosphere, geography, Tropical Climate, Multidisciplinary, geography.geographical_feature_category, Atmosphere, Temperature, Carbon sink, Carbon Dioxide, History, 20th Century, Models, Theoretical, Droughts, chemistry, Carbon dioxide, Africa, Environmental science, C180 Ecology, Brazil
Abstract

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions1,2,3. Climate-driven vegetation models typically predict that this tropical forest ‘carbon sink’ will continue for decades4,5. Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53–0.79), in contrast to the long-term decline in Amazonian forests6. Therefore the carbon sink responses of Earth’s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature7,8,9. Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth’s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass10 reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth’s climate.

Published
2019
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7. Historical Aerial Surveys Map Long-Term Changes of Forest Cover and Structure in the Central Congo Basin

Author

Sofie Meeus, Jan Van den Bulcke, Piet Stoffelen, Hans Beeckman, Leen Van Hirtum, Filip Vandelook, Lisa Wingate, Koen Hufkens, Michael Amara, Hans Verbeeck, Thalès de Haulleville, Elizabeth Kearsley, Kim Jacobsen, Faculty of Bioscience Engineering [Ghent], Universiteit Gent = Ghent University [Belgium] (UGENT), Interactions Sol Plante Atmosphère (UMR ISPA), Ecole Nationale Supérieure des Sciences Agronomiques de Bordeaux-Aquitaine (Bordeaux Sciences Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Royal Museum for Central Africa [Tervuren] (RMCA), Botanic Garden Meise, and National Archives of Belgium

Subjects
Agriculture and Food Sciences, 0106 biological sciences, Technology, aerial survey, 010504 meteorology & atmospheric sciences, Aerial survey, 01 natural sciences, Remote Sensing, TROPICAL DEFORESTATION, Geosciences, Multidisciplinary, PHOTOGRAPHS, Reforestation, Geology, Vegetation, Geography, SfM, Physical Sciences, CO2, Life Sciences & Biomedicine, CNN, data recovery, Science, CONSERVATION, Atmospheric carbon cycle, Environmental Sciences & Ecology, Context (language use), Land cover, ANTHROPOGENIC DISTURBANCE, 010603 evolutionary biology, Aerial photography, Deforestation, RATES, congo basin, Imaging Science & Photographic Technology, cnn, 0105 earth and related environmental sciences, deep learning, Congo Basin, CARBON EMISSIONS, Science & Technology, Forestry, 15. Life on land, [SDE.ES]Environmental Sciences/Environmental and Society, LAND-COVER, sfm, 13. Climate action, Earth and Environmental Sciences, cavelab, General Earth and Planetary Sciences, VEGETATION, SELF-SIMILARITY, Environmental Sciences
Abstract

Given the impact of tropical forest disturbances on atmospheric carbon emissions, biodiversity, and ecosystem productivity, accurate long-term reporting of Land-Use and Land-Cover (LULC) change in the pre-satellite era (

Published
2020
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8. Pan-tropical prediction of forest structure from the largest trees

Author

Narayanaswamy Parthasarathy, Stephen P. Hubbell, Cintia Rodrigues de Souza, Takeshi Toma, Ben Swanepoel, Raphaël Pélissier, Donatien Zebaze, Luzmila Arroyo, Juliana Stropp, James R. Kellner, Alejandro Araujo-Murakami, Thomas E. Lovejoy, Benoît Cassart, Ben Hur Marimon Junior, James Grogan, Sebastian K. Herzog, Yadvinder Malhi, Krisna Gajapersad, José Luís Camargo, Christelle Gonmadje, Renato Valencia, Connie J. Clark, Denise Sasaki, Fabien Wagner, Francesco Rovero, Katrin Boehning-Gaese, David Kenfack, Olaf Bánki, John Terborgh, Ferry Slik, Arafat S. Mtui, Javier Silva Espejo, Hans Beeckman, Germaine Alexander Parada Gutierrez, Tinde van Andel, Luis Valenzuela, Thalès de Haulleville, Hans ter Steege, Elizabeth Kearsley, Martin J. P. Sullivan, Wilson Roberto Spironello, Rodolfo Vasque, Emmanuel H. Martin, Thomas Duncan, William F. Laurance, Jason Vleminckx, Paulus Matius, Charles De Cannière, Yves Laumonier, Ted R. Feldpausch, Andrew R. Marshall, John R. Poulsen, J. Daniel Soto, Priya Davidar, Jean François Gillet, Iêda Leão do Amaral, Papi Puspa Warsudi, Eurídice N. Honorio Coronado, Vincent A. Vos, Laurent Descroix, Nicolas Texier, Philippe Saner, Roderick Zagt, Marc P. E. Parren, Luiz Marcelo Brum Rossi, Robert Bitariho, Fernando Cornejo Valverde, Jon Lloyd, Nina Farwig, James Singh, Jean-Louis Doucet, Francis Q. Brearley, Leandro Valle Ferreira, Celso Paulo de Azevedo, Ervan Rutishauser, Johanna Hurtado, Bruno Hérault, Albert Angbonga-Basia, Jérôme Chave, David A. Neill, Jean Claude Razafimahaimodison, Pierre Ploton, Hilandia Brandão, Susan G. Laurance, Richard Condit, Roel J. W. Brienen, Jean-François Bastin, Ana Andrade, Marcos Silveira, Oliver L. Phillips, Gauthier Ligot, David B. Clark, Casimero Mendoza Bautista, Narayanan Ayyappan, Robin L. Chazdon, Hans Verbeeck, Santiago Espinosa, Jürgen Homeier, Mireille Breuer-Ndoundou Hockemba, Simon L. Lewis, Patricia Alvarez-Loyayza, Vincent Droissart, Sassan Saatchi, Nigel C. A. Pitman, Victoria Meyer, Nicolas Barbier, Wannes Hubau, Jorcely Barroso, Nicolas Labrière, Plinio Sist, Georges Chuyong, Pascal Boeckx, Hugo Romero Saltos, Antonio Ferraz, David Harris, Verginia Wortel, Pandi Vivek, Mark Schulze, Bonaventure Sonké, Jan Bogaert, Abel Monteagudo-Mendoza, Guido Pardo, Quentin Ponette, Ahimsa Campos-Arceiz, Michael Kessler, Beatriz Schwantes Marimon, Samir Gonçalves Rolim, Maxime Réjou-Méchain, Koen Hufkens, Narcisse Guy Kamdem, Adeline Fayolle, Aurélie Dourdain, Christine Fletcher, Moses Libalah, B.R. Ramesh, Research Unit of Landscape Ecology and Plant Production Systems, Université libre de Bruxelles (ULB), Carbon For Expert, California Institute of Technology (CALTECH), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Ecologie des forêts de Guyane (UMR ECOFOG), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Département Environnements et Sociétés (Cirad-ES), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Université de Liège, University of Mary Washington, Instituto Nacional de Pesquisas da Amazônia (INPA), Universidad Autonoma Gabriel René Moreno (UAGRM), Institut Français de Pondichéry (IFP), Ministère de l'Europe et des Affaires étrangères (MEAE)-Centre National de la Recherche Scientifique (CNRS), Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam [Amsterdam] (UvA), Universidade Federal do Acre (UFAC), School of Engineering and Science, Jacobs University [Bremen], Laboratory of Applied Physical Chemistry, Universiteit Gent = Ghent University (UGENT), School of Geography [Leeds], University of Leeds, Universidad Nacional de San Antonio Abad del Cusco (UNSAAC), Evolution et Diversité Biologique (EDB), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), University of Buea, Department of Computer Science, King‘s College London, Patrimoines Locaux et Gouvernance (PALOC), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD), Gembloux Agro-Bio Tech [Gembloux], Department of Ecology-Conservation Ecology, Faculty of Biology, Philipps Universität Marburg = Philipps University of Marburg, AgroBioTech, Forest Research Institute Malaysia (FRIM), Mount Holyoke College, Royal Botanic Gardens, Georg-August-University = Georg-August-Universität Göttingen, Royal Museum for Central Africa [Tervuren] (RMCA), Smithsonian Conservation Biology Institute, Center for Conservation Education and Sustainability, MRC 705, Box 37012, Washington, DC, VA 20013-7012, USA, Universität Zürich [Zürich] = University of Zurich (UZH), AgroParisTech, Center for International Forestry Research (CIFOR), Consultative Group on International Agricultural Research [CGIAR] (CGIAR), Université de Yaoundé I, Imperial College London, Environmental Science and Policy Department and the Department of Public and International Affairs, George Mason University [Fairfax], Environmental Change Inst., School of Geography and the Environment, University of Oxford, Universidade do Estado de Mato Grosso (UNEMAT), Centre Maurice Halbwachs (CMH), École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS)-Département de Sciences sociales ENS-PSL, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Missouri Botanical Garden, Universidad Estatal Amazonica, Universidad Autonoma del Beni, Analytical and Biophysical Environmental Chemistry (CABE), University of Geneva, Sciences II, Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University [Durham], Université Catholique de Louvain = Catholic University of Louvain (UCL), Département Systèmes Biologiques (Cirad-BIOS), MUSE – Science Museum of Trento, Forêts et Sociétés (UPR Forêts et Sociétés), Amazonia Central, Brazilian Agricultural Research Corporation (Embrapa), JRC Institute for Environment and Sustainability (IES), European Commission - Joint Research Centre [Ispra] (JRC), Department of Forest Vegetation, Forestry and Forest Products Research Institute (FFPRI), Laboratorio de Ecología de Plantas y Herbario QCA, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Chercheur indépendant, Computational & Applied Vegetation Ecology (CAVElab), Instituto Nacional de Pesquisas Espaciais (INPE), Ministério da Ciência, Tecnologia e Inovação, Biodiversity Department, Center for Agricultural Research in Suriname (CELOS), Laboratoire de Botanique systématique et d'Ecologie [ENS Yaoudé], Université de Yaoundé I-École normale supérieure [ENS] - Yaoundé 1, Université Libre de Bruxelles [Bruxelles] (ULB), Université des Antilles (UA)-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA), Centre National de la Recherche Scientifique (CNRS)-Ministère de l'Europe et des Affaires étrangères (MEAE), Ghent University [Belgium] (UGENT), Universidad Nacional San Antonio Abad del Cusco, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Phillips Universität (Marburg), Georg-August-Universität Göttingen, University of Zurich, Université de Yaoundé, École normale supérieure - Paris (ENS Paris)-École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS), Missouri Botanical Garden (USA), Université Catholique de Louvain (UCL), Pontificia Universidad Catolica del Ecuador, Université de Yaoundé I [Yaoundé]-École normale supérieure [ENS] - Yaoundé 1, Systems Ecology, Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud]), Universiteit Gent = Ghent University [Belgium] (UGENT), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Georg-August-University [Göttingen], University of Oxford [Oxford], École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École des hautes études en sciences sociales (EHESS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
P33 - Chimie et physique du sol, 0106 biological sciences, pan-tropical, 010504 meteorology & atmospheric sciences, P40 - Météorologie et climatologie, REDD, Rainforest, F50 - Anatomie et morphologie des plantes, 010603 evolutionary biology, 01 natural sciences, Basal area, [SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry, K01 - Foresterie - Considérations générales, Quadratic mean diameter, Ecology, Evolution, Behavior and Systematics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Changement climatique, Global and Planetary Change, Biomass (ecology), Tree canopy, Ecology, carbon, Diameter at breast height, large trees, Tropics, 15. Life on land, Structure du peuplement, séquestration du carbone, climate change, 13. Climate action, Forêt, Environmental science, Physical geography, tropical forest ecology, REDD+, Woody plant, forest structure
Abstract

© 2018 John Wiley & Sons Ltd Aim: Large tropical trees form the interface between ground and airborne observations, offering a unique opportunity to capture forest properties remotely and to investigate their variations on broad scales. However, despite rapid development of metrics to characterize the forest canopy from remotely sensed data, a gap remains between aerial and field inventories. To close this gap, we propose a new pan-tropical model to predict plot-level forest structure properties and biomass from only the largest trees. Location: Pan-tropical. Time period: Early 21st century. Major taxa studied: Woody plants. Methods: Using a dataset of 867 plots distributed among 118 sites across the tropics, we tested the prediction of the quadratic mean diameter, basal area, Lorey's height, community wood density and aboveground biomass (AGB) from the ith largest trees. Results: Measuring the largest trees in tropical forests enables unbiased predictions of plot- and site-level forest structure. The 20 largest trees per hectare predicted quadratic mean diameter, basal area, Lorey's height, community wood density and AGB with 12, 16, 4, 4 and 17.7% of relative error, respectively. Most of the remaining error in biomass prediction is driven by differences in the proportion of total biomass held in medium-sized trees (50–70 cm diameter at breast height), which shows some continental dependency, with American tropical forests presenting the highest proportion of total biomass in these intermediate-diameter classes relative to other continents. Main conclusions: Our approach provides new information on tropical forest structure and can be used to generate accurate field estimates of tropical forest carbon stocks to support the calibration and validation of current and forthcoming space missions. It will reduce the cost of field inventories and contribute to scientific understanding of tropical forest ecosystems and response to climate change.

Published
2018
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9. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood

Author

Charles De Cannière, Jean-François Bastin, Adeline Fayolle, Frédéric Mortier, Adeline Serckx, Jan Van den Bulcke, Yegor Tarelkin, Thalès de Haulleville, Joris Van Acker, Hans Beeckman, and Jan Bogaert

Subjects
K50 - Technologie des produits forestiers, Production du bois, Psychologie appliquée, TROPICAL FORESTS, lcsh:Medicine, forêt tropicale, Compétition intraspécifique, Trees, Allométrie, K01 - Foresterie - Considérations générales, Biomasse, Densité, ECONOMICS SPECTRUM, Biomass, lcsh:Science, Specific Gravity, Biomass (ecology), Multidisciplinary, geography.geographical_feature_category, U10 - Informatique, mathématiques et statistiques, Ecology, RAIN-FOREST, Sciences bio-médicales et agricoles, RING ANALYSIS, Wood, Compétition végétale, Biologie, Tree species, ABOVEGROUND BIOMASS, Research Article, F40 - Écologie végétale, Modèle linéaire, Dendrology, Rainforest, Biology, Swamp, Intraspecific competition, Bois, Écologie forestière, RADIAL VARIATION, MOIST FORESTS, Africa, Central, Regeneration (ecology), AMAZON FORESTS, Propriété physicochimique, geography, ERROR PROPAGATION, Méthode statistique, lcsh:R, Biology and Life Sciences, Propriété mécanique, DENSITY, Compétition interspécifique, lcsh:Q, Specific gravity
Abstract

Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e. the dominant species, and we quantified the consequences of such variations on the biomass. Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e. the dominant species, and we quantified the consequences of such variations on the biomass. Results Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shadebearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity variance was explained by species only (45%) followed by a redundant part between species and regeneration guilds (36%). Despite substantial variation in wood specific gravity profiles among species and regeneration guilds, we found that values from the outer wood were strongly correlated to values from the whole profile, without any significant bias. In addition, we found that wood specific gravity from the DRYAD global repository may strongly differ depending on the species (up to 40% for Dialium pachyphyllum). Main Conclusion Therefore, when estimating forest biomass in specific sites, we recommend the systematic collection of outer wood samples on dominant species. This should prevent the main errors in biomass estimations resulting from wood specific gravity and allow for the collection of new information to explore the intraspecific variation of mechanical properties of trees., SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2015

11. Functional identity explains carbon sequestration in a 77-year-old experimental tropical plantation

Author

Marijn Bauters, Hans Verbeeck, Elizabeth Kearsley, Giacomo Sellan, Kris Verheyen, Thalès de Haulleville, Pascal Boeckx, Dries Huygens, and Evy Ampoorter

Subjects
NITROGEN-FIXING TREES, AFRICA, linear mixed effects models, Biodiversity, Carbon sequestration, Basal area, tropics, BENEFITS, Afforestation, STOCKS, functional biodiversity, AGRICULTURAL SOILS, Shade tolerance, Ecology, Evolution, Behavior and Systematics, Pioneer species, CLIMATE-CHANGE, Ecology, Agroforestry, CURRENT KNOWLEDGE, Biology and Life Sciences, Soil carbon, FOREST, forest plantations, Democratic Republic of Congo, carbon sequestration, tree diversity experiments, Agronomy, AFFORESTATION, Environmental science, cavelab, BIODIVERSITY, Species richness, identity effect
Abstract

Planting forests is an important practice for climate change mitigation, especially in the tropics where the carbon (C) sequestration potential is high. Successful implementation of this mitigation practice requires knowledge of the role of species identity and diversity on carbon accrual of plantations. Despite this need, solid data on the long-term development of forest plantations are still very scarce. Monospecific and two species mixture plots of a 77-year-old tree diversity experiment in Yangambi in the Congo basin were fully inventoried. We calculated above-ground C stocks using allometric equations, and soil C stocks by analyzing soil samples at multiple depths. Linear mixed effects models were used to analyze the effect of taxonomic and functional identity and diversity on the aboveground and soil carbon stocks. A high variability in aboveground C stocks across tree species combinations was observed. Apart from a species identity effect, the proportion of planted species in the total stand basal area (BA(pl)) and effective species richness were identified as compositional parameters with a significant effect on the aboveground carbon (AGC), with BApl being more important. Both AGC and BA(pl) were coupled to the functional identity of the planted species; the planting of short-lived pioneers led to low AGC. We found no clear benefits, but also no drawbacks, for AGC of two species mixture plots over monospecific plots or including nitrogen fixing species in the plantation scheme. However, the latter was the only compositional parameter with a significant positive effect on the soil carbon stock up to 1 m depth. We conclude that the different plantation configurations gave rise to a wide range in carbon stocks. This was predominantly caused by large differences in AGC sequestration over the past 77 years. Altogether, short-lived pioneer species had a low BApl resulting in low carbon sequestration, while partial shade tolerant species achieved the highest AGC stocks. Tolerating spontaneous ingrowth during the plantation development can further increase the AGC stock, given that the appropriate functional type is planted.

Published
2015

13. Above-ground biomass and structure of 260 African tropical forests

Author

Lindsay F. Banin, Georgia Pickavance, Gloria Djagbletey, Hans Beeckman, Timothy R. Baker, David Harris, Lise Zemagho, Benjamin Toirambe, James Taplin, Jon Lloyd, Hannsjorg Woell, Miguel E. Leal, Alan Hamilton, Murielle Simo, Jason Vleminckx, Douglas Sheil, Jean-François Bastin, Kelvin S.-H. Peh, Sophie Fauset, Marie Noël Kamdem Djuikouo, Connie J. Clark, Yadvinder Malhi, Koen Hufkens, Hans Verbeeck, Kofi Affum-Baffoe, Geertje M. F. van der Heijden, Serge K. Begne, Cornielle E N Ewango, Philippe Jeanmart, Jean-Remy Makana, Dries Huygens, Elizabeth Kearsley, Terese B. Hart, Simon Willcock, Jan Reitsma, Ted R. Feldpausch, Pascal Boeckx, Murray Collins, Bonaventure Sonké, Jan Bogaert, Andrew R. Marshall, Jon C. Lovett, David Taylor, Jean-Louis Doucet, Kathryn J. Jeffery, John R. Poulsen, Jean François Gillet, Terry Sunderland, Joey Talbot, Ernest G. Foli, Lucas Ojo, Sean C. Thomas, Oliver L. Phillips, Hermann Taedoumg, Eric Chezeaux, Annette Hladik, Kathy Steppe, Charles De Cannière, Gabriela Lopez-Gonzalez, Lee J. T. White, Vincent Droissart, Simon L. Lewis, and Thalès de Haulleville

Subjects
Life Sciences & Biomedicine - Other Topics, 0106 biological sciences, 010504 meteorology & atmospheric sciences, Amazonian, Climate, AMAZONIAN FORESTS, 01 natural sciences, Trees, Basal area, Soil, SD Forestry, Tropical climate, Biomass, Biomass (ecology), CLIMATE-CHANGE, Ecology, 11 Medical And Health Sciences, RAIN-FOREST, Articles, Sciences bio-médicales et agricoles, GROWTH, SENSITIVITY, CARBON STOCKS, General Agricultural and Biological Sciences, Life Sciences & Biomedicine, Biologie, Wood density, Research Article, GE Environmental Sciences, Conservation of Natural Resources, Climate Change, Tree allometry, Rainforest, Biology, SPATIAL-PATTERNS, Models, Biological, 010603 evolutionary biology, General Biochemistry, Genetics and Molecular Biology, Ecology and Environment, Carbon Cycle, Congo basin, West Africa, Bosecologie en Bosbeheer, Precipitation, TREE ALLOMETRY, 0105 earth and related environmental sciences, Evolutionary Biology, Tropical Climate, Science & Technology, Biology and Life Sciences, Forestry, 06 Biological Sciences, 15. Life on land, East Africa, Forest Ecology and Forest Management, SOILS, Africa, Soil fertility
Abstract

We report above-ground biomass (AGB), basal area, stemdensity and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha-1 (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region attaining AGB values (429 Mg ha-1) similar to those of Bornean forests, and significantly greater than East or West African forests. AGB therefore appears generally higher in palaeo- comparedwithneotropical forests.However, mean stem density is low(426±11 stems ha-1 greater than or equal to 100 mm diameter) compared with both Amazonian and Bornean forests (cf. approx. 600) and is the signature structural feature of African tropical forests. While spatial autocorrelation complicates analyses, AGB shows a positive relationship with rainfall in the driest nine months of the year, and an opposite association with the wettest three months of the year; a negative relationship with temperature; positive relationship with clay-rich soils; and negative relationshipswith C:Nratio (suggesting a positive soil phosphorus- AGB relationship), and soil fertility computed as the sum of base cations. The results indicate that AGB is mediated by both climate and soils, and suggest that the AGB of African closed-canopy tropical forests may be particularly sensitive to future precipitation and temperature changes. © 2013 The Authors., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

Published
2013

14. Conventional tree height-diameter relationships significantly overestimate aboveground carbon stocks in the Central Congo Basin

Author

Alidé Kidimbu, Yodit Kebede, Jan Bogaert, Hans Verbeeck, Thalès de Haulleville, Pierre Defourny, Pascal Boeckx, Benjamin Toirambe, Hans Beeckman, Koen Hufkens, Kathy Steppe, Geert Baert, Elizabeth Kearsley, and Dries Huygens

Subjects
Canopy, Aboveground carbon, Conservation of Natural Resources, General Physics and Astronomy, Structural basin, Models, Biological, General Biochemistry, Genetics and Molecular Biology, Trees, Soil, land-use, deforestation, regions, impacts, climate, Stock (geology), tropical forests, Multidisciplinary, Geography, Land use, Agroforestry, emissions, Central africa, Forestry, Farm Systems Ecology Group, General Chemistry, Soil carbon, central-africa, Tropical forest, Carbon, Congo, Regression Analysis, Environmental science, landscape-scale, live biomass
Abstract

Policies to reduce emissions from deforestation and forest degradation largely depend on accurate estimates of tropical forest carbon stocks. Here we present the first field-based carbon stock data for the Central Congo Basin in Yangambi, Democratic Republic of Congo. We find an average aboveground carbon stock of 162 ± 20 Mg C ha(-1) for intact old-growth forest, which is significantly lower than stocks recorded in the outer regions of the Congo Basin. The best available tree height-diameter relationships derived for Central Africa do not render accurate canopy height estimates for our study area. Aboveground carbon stocks would be overestimated by 24% if these inaccurate relationships were used. The studied forests have a lower stature compared with forests in the outer regions of the basin, which confirms remotely sensed patterns. Additionally, we find an average soil carbon stock of 111 ± 24 Mg C ha(-1), slightly influenced by the current land-use change.

Published
2013
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15. High aboveground carbon stock of African tropical montane forests

Author

Janvier Lisingo, Tibebu Y. Simegn, Miroslav Svoboda, Murielle Simo-Droissart, Dismas Hakizimana, Charles Kayijamahe, Emanuel H. Martin, Aida Cuni-Sanchez, Jan Altman, Petri Pellikka, Hans Verbeeck, Rob Marchant, Andreas Hemp, Jefferson S. Hall, Jiri Dolezal, Janne Heiskanen, Valerio Avitabile, Pascal Boeckx, Olivier J. Hardy, Vincent Droissart, Roy E. Gereau, Mark Lung, Felix Nchu, Hermann Taedoumg, Philip J. Platts, Charlotte E. Wheeler, Jonathan Timberlake, Colin A. Chapman, Brigitte Nyirambangutse, Andrew J. Plumptre, Demisse Sheleme, Abreham Berta Aneseyee, Joseph Okello, Terese B. Hart, Peter M. Umunay, John Tshibamba Mukendi, Lan Qie, Simon L. Lewis, Mathieu Decuyper, Senbeta Feyera, Teshome Soromessa, Kelvin S.-H. Peh, Corneille E. N. Ewango, Simon Willcock, Wannes Hubau, Aster Gebrekirstos, Edward T. A. Mitchard, Ben DeVries, Gerard Imani, Martin Herold, David Horák, Andrew R. Marshall, Serge K. Begne, Achim Bräuning, Kim Calders, C. Amani, A. C. Hamilton, Marie Noel Djuikouo Kamdem, Jean-Remy Makana, Martin J. P. Sullivan, Mwangi James Kinyanjui, Yadvinder Malhi, Tomáš Albrecht, Tom Muller, Hazel M. Chapman, Robert Bitariho, Julia A. Klein, Alain Senghor K. Ngute, Marijn Bauters, Eustrate Uzabaho, Göran Wallin, Christine B. Schmitt, Hari Adhikari, Iveren Abiem, Franklin Bulonvu, Ulrike Hiltner, Moses Nsanyi Sainge, James Taplin, Amy C. Bennett, John T. Woods, Sean C. Thomas, Jason Vleminckx, David Taylor, Oliver L. Phillips, Alexandra C. Morel, James A. Comiskey, Douglas Sheil, Thalès de Haulleville, Francesco Rovero, Darlington Tuagben, Neil D. Burgess, Jon C. Lovett, Terry Sunderland, Rodrigue Batumike, Martin Gilpin, Bonaventure Sonké, Jan Bogaert, Ondrej Sedlacek, Etienne Zibera, David Kenfack, Lindsay F. Banin, Hans Beeckman, University of York [York, UK], Manchester Metropolitan University (MMU), International Union for Conservation of Nature (IUCN), University of Leeds, Université officielle de Bukavu, Royal Museum for Central Africa [Tervuren] (RMCA), University of Jos [Nigeria], Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Charles University [Prague] (CU), Addis Ababa University (AAU), European Commission - Joint Research Centre [Ispra] (JRC), UK Centre for Ecology & Hydrology, Natural Environment Research Council (NERC), Universiteit Gent = Ghent University (UGENT), Botanique et Modélisation de l'Architecture des Plantes et des Végétations (UMR AMAP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Rwanda, European Project: 328075,EC:FP7:PEOPLE,FP7-PEOPLE-2012-IEF,ASEC-DRYLAND-FORESTS(2014), University of Helsinki, Universiteit Gent = Ghent University [Belgium] (UGENT), Earth Change Observation Laboratory (ECHOLAB), and Department of Geosciences and Geography

Subjects
0106 biological sciences, DIVERSITY, Endangered species, Datasets as Topic, Geographic Mapping, life_on_land, [SDV.BID.SPT]Life Sciences [q-bio]/Biodiversity/Systematics, Phylogenetics and taxonomy, 01 natural sciences, Trees, Laboratory of Geo-information Science and Remote Sensing, Biomass, 0303 health sciences, Biomass (ecology), GLOBAL PATTERNS, Multidisciplinary, Ecology, Reforestation, EASTERN ARC MOUNTAINS, Carbon cycle, [SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics, Biogeochemistry, PE&RC, Geography, MAP, C180 Ecology, climate_action, STORAGE, Carbon Sequestration, Conservation of Natural Resources, Rainforest, Climate Change, Climate change, 010603 evolutionary biology, Ecology and Environment, Earth and environmental sciences, 03 medical and health sciences, [SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, Forest ecology, Life Science, Ecosystem services, Bosecologie en Bosbeheer, Laboratorium voor Geo-informatiekunde en Remote Sensing, Ecosystem, 1172 Environmental sciences, 030304 developmental biology, Tropical Climate, SINK, Forestry, 15. Life on land, Carbon, Forest Ecology and Forest Management, Attitude, 13. Climate action, Africa, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Tropical rainforest
Abstract

Tropical forests store 40–50 per cent of terrestrial vegetation carbon 1. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests 2. Owing to climatic and soil changes with increasing elevation 3, AGC stocks are lower in tropical montane forests compared with lowland forests 2. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network 4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane 2,5,6 and lowland 7 forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa 8. We find that the low stem density and high abundance of large trees of African lowland forests 4 is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse 9,10 and carbon-rich ecosystems.

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16. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood.

Author

Jean-François Bastin, Adeline Fayolle, Yegor Tarelkin, Jan Van den Bulcke, Thales de Haulleville, Frederic Mortier, Hans Beeckman, Joris Van Acker, Adeline Serckx, Jan Bogaert, and Charles De Cannière

Subjects
Medicine, Science
Abstract

Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass.Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood).Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity variance was explained by species only (45%) followed by a redundant part between species and regeneration guilds (36%). Despite substantial variation in wood specific gravity profiles among species and regeneration guilds, we found that values from the outer wood were strongly correlated to values from the whole profile, without any significant bias. In addition, we found that wood specific gravity from the DRYAD global repository may strongly differ depending on the species (up to 40% for Dialium pachyphyllum).Therefore, when estimating forest biomass in specific sites, we recommend the systematic collection of outer wood samples on dominant species. This should prevent the main errors in biomass estimations resulting from wood specific gravity and allow for the collection of new information to explore the intraspecific variation of mechanical properties of trees.

Published
2015
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