Taking the pulse of Earth's tropical forests using networks of highly distributed plots

Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of funding agencies. Here we show how a global community is responding to the challenges of tropical ecosystem research with diverse teams measuring forests tree-by-tree in thousands of long-term plots. We review the major scientific discoveries of this work and show how this process is changing tropical forest science. Our core approach involves linking long-term grassroots initiatives with standardized protocols and data management to generate robust scaled-up results. By connecting tropical researchers and elevating their status, our Social Research Network model recognises the key role of the data originator in scientific discovery. Conceived in 1999 with RAINFOR (South America), our permanent plot networks have been adapted to Africa (AfriTRON) and Southeast Asia (T-FORCES) and widely emulated worldwide. Now these multiple initiatives are integrated via ForestPlots.net cyber-infrastructure, linking colleagues from 54 countries across 24 plot networks. Collectively these are transforming understanding of tropical forests and their biospheric role. Together we have discovered how, where and why forest carbon and biodiversity are responding to climate change, and how they feedback on it. This long-term pan-tropical collaboration has revealed a large long-term carbon sink and its trends, as well as making clear which drivers are most important, which forest processes are affected, where they are changing, what the lags are, and the likely future responses of tropical forests as the climate continues to change. By leveraging a remarkably old technology, plot networks are sparking a very modern revolution in tropical forest science. In the future, humanity can benefit greatly by nurturing the grassroots communities now collectively capable of generating unique, long-term understanding of Earth's most precious forests.Additional co-authors: Susan Laurance, William Laurance, Francoise Yoko Ishida, Andrew Marshall, Catherine Waite, Hannsjoerg Woell, Jean-Francois Bastin, Marijn Bauters, Hans Beeckman, Pfascal Boeckx, Jan Bogaert, Charles De Canniere, Thales de Haulleville, Jean-Louis Doucet, Olivier Hardy, Wannes Hubau, Elizabeth Kearsley, Hans Verbeeck, Jason Vleminckx, Steven W. Brewer, Alfredo Alarcón, Alejandro Araujo-Murakami, Eric Arets, Luzmila Arroyo, Ezequiel Chavez, Todd Fredericksen, René Guillén Villaroel, Gloria Gutierrez Sibauty, Timothy Killeen, Juan Carlos Licona, John Lleigue, Casimiro Mendoza, Samaria Murakami, Alexander Parada Gutierrez, Guido Pardo, Marielos Peña-Claros, Lourens Poorter, Marisol Toledo, Jeanneth Villalobos Cayo, Laura Jessica Viscarra, Vincent Vos, Jorge Ahumada, Everton Almeida, Jarcilene Almeida, Edmar Almeida de Oliveira, Wesley Alves da Cruz, Atila Alves de Oliveira, Fabrício Alvim Carvalho, Flávio Amorim Obermuller, Ana Andrade, Fernanda Antunes Carvalho, Simone Aparecida Vieira, Ana Carla Aquino, Luiz Aragão, Ana Claudia Araújo, Marco Antonio Assis, Jose Ataliba Mantelli Aboin Gomes, Fabrício Baccaro, Plínio Barbosa de Camargo, Paulo Barni, Jorcely Barroso, Luis Carlos Bernacci, Kauane Bordin, Marcelo Brilhante de Medeiros, Igor Broggio, José Luís Camargo, Domingos Cardoso, Maria Antonia Carniello, Andre Luis Casarin Rochelle, Carolina Castilho, Antonio Alberto Jorge Farias Castro, Wendeson Castro, Sabina Cerruto Ribeiro, Flávia Costa, Rodrigo Costa de Oliveira, Italo Coutinho, John Cunha, Lola da Costa, Lucia da Costa Ferreira, Richarlly da Costa Silva, Marta da Graça Zacarias Simbine, Vitor de Andrade Kamimura, Haroldo Cavalcante de Lima, Lia de Oliveira Melo, Luciano de Queiroz, José Romualdo de Sousa Lima, Mário do Espírito Santo, Tomas Domingues, Nayane Cristina dos Santos Prestes, Steffan Eduardo Silva Carneiro, Fernando Elias, Gabriel Eliseu, Thaise Emilio, Camila Laís Farrapo, Letícia Fernandes, Gustavo Ferreira, Joice Ferreira, Leandro Ferreira, Socorro Ferreira, Marcelo Fragomeni Simon, Maria Aparecida Freitas, Queila S. García, Angelo Gilberto Manzatto, Paulo Graça, Frederico Guilherme, Eduardo Hase, Niro Higuchi, Mariana Iguatemy, Reinaldo Imbrozio Barbosa, Margarita Jaramillo, Carlos Joly, Joice Klipel, Iêda Leão do Amaral, Carolina Levis, Antonio S. Lima, Maurício Lima Dan, Aline Lopes, Herison Madeiros, William E. Magnusson, Rubens Manoel dos Santos, Beatriz Marimon, Ben Hur Marimon Junior, Roberta Marotti Martelletti Grillo, Luiz Martinelli, Simone Matias Reis, Salomão Medeiros, Milton Meira-Junior, Thiago Metzker, Paulo Morandi, Natanael Moreira do Nascimento, Magna Moura, Sandra Cristina Müller, Laszlo Nagy, Henrique Nascimento, Marcelo Nascimento, Adriano Nogueira Lima, Raimunda Oliveira de Araújo, Jhonathan Oliveira Silva, Marcelo Pansonato, Gabriel Pavan Sabino, Karla Maria Pedra de Abreu, Pablo José Francisco Pena Rodrigues, Maria Piedade, Domingos Rodrigues, José Roberto Rodrigues Pinto, Carlos Quesada, Eliana Ramos, Rafael Ramos, Priscyla Rodrigues, Thaiane Rodrigues de Sousa, Rafael Salomão, Flávia Santana, Marcos Scaranello, Rodrigo Scarton Bergamin, Juliana Schietti, Jochen Schöngart, Gustavo Schwartz, Natalino Silva, Marcos Silveira, Cristiana Simão Seixas, Marta Simbine, Ana Claudia Souza, Priscila Souza, Rodolfo Souza, Tereza Sposito, Edson Stefani Junior, Julio Daniel do Vale, Ima Célia Guimarães Vieira, Dora Villela, Marcos Vital, Haron Xaud, Katia Zanini, Charles Eugene Zartman, Nur Khalish Hafizhah Ideris, Faizah binti Hj Metali, Kamariah Abu Salim, Muhd Shahruney Saparudin, Rafizah Mat Serudin, Rahayu Sukmaria Sukri, Serge Begne, George Chuyong, Marie Noel Djuikouo, Christelle Gonmadje, Murielle Simo-Droissart, Bonaventure Sonké, Hermann Taedoumg, Lise Zemagho, Sean Thomas, Fidèle Baya, Gustavo Saiz, Javier Silva Espejo, Dexiang Chen, Alan Hamilton, Yide Li, Tushou Luo, Shukui Niu, Han Xu, Zhang Zhou, Esteban Álvarez-Dávila, Juan Carlos Andrés Escobar, Henry Arellano-Peña, Jaime Cabezas Duarte, Jhon Calderón, Lina Maria Corrales Bravo, Borish Cuadrado, Hermes Cuadros, Alvaro Duque, Luisa Fernanda Duque, Sandra Milena Espinosa, Rebeca Franke-Ante, Hernando García, Alejandro Gómez, Roy González-M., Álvaro Idárraga-Piedrahíta, Eliana Jimenez, Rubén Jurado, Wilmar López Oviedo, René López-Camacho, Omar Aurelio Melo Cruz, Irina Mendoza Polo, Edwin Paky, Karen Pérez, Angel Pijachi, Camila Pizano, Adriana Prieto, Laura Ramos, Zorayda Restrepo Correa, James Richardson, Elkin Rodríguez, Gina M. Rodriguez M., Agustín Rudas, Pablo Stevenson, Markéta Chudomelová, Martin Dancak, Radim Hédl, Stanislav Lhota, Martin Svatek, Jacques Mukinzi, Corneille Ewango, Terese Hart, Emmanuel Kasongo Yakusu, Janvier Lisingo, Jean-Remy Makana, Faustin Mbayu, Benjamin Toirambe, John Tshibamba Mukendi, Lars Kvist, Gustav Nebel, Selene Báez, Carlos Céron, Daniel M. Griffith, Juan Ernesto Guevara Andino, David Neill, Walter Palacios, Maria Cristina Peñuela-Mora, Gonzalo Rivas-Torres, Gorky Villa, Sheleme Demissie, Tadesse Gole, Techane Gonfa, Kalle Ruokolainen, Michel Baisie, Fabrice Bénédet, Wemo Betian, Vincent Bezard, Damien Bonal, Jerôme Chave, Vincent Droissart, Sylvie Gourlet-Fleury, Annette Hladik, Nicolas Labrière, Pétrus Naisso, Maxime Réjou-Méchain, Plinio Sist, Lilian Blanc, Benoit Burban, Géraldine Derroire, Aurélie Dourdain, Clement Stahl, Natacha Nssi Bengone, Eric Chezeaux, Fidèle Evouna Ondo, Vincent Medjibe, Vianet Mihindou, Lee White, Heike Culmsee, Cristabel Durán Rangel, Viviana Horna, Florian Wittmann, Stephen Adu-Bredu, Kofi Affum-Baffoe, Ernest Foli, Michael Balinga, Anand Roopsind, James Singh, Raquel Thomas, Roderick Zagt, Indu K. Murthy, Kuswata Kartawinata, Edi Mirmanto, Hari Priyadi, Ismayadi Samsoedin, Terry Sunderland, Ishak Yassir, Francesco Rovero, Barbara Vinceti, Bruno Hérault, Shin-Ichiro Aiba, Kanehiro Kitayama, Armandu Daniels, Darlington Tuagben, John T. Woods, Muhammad Fitriadi, Alexander Karolus, Kho Lip Khoon, Noreen Majalap, Colin Maycock, Reuben Nilus, Sylvester Tan, Almeida Sitoe, Indiana Coronado G., Lucas Ojo, Rafael de Assis, Axel Dalberg Poulsen, Douglas Sheil, Karen Arévalo Pezo, Hans Buttgenbach Verde, Victor Chama Moscoso, Jimmy Cesar Cordova Oroche, Fernando Cornejo Valverde, Massiel Corrales Medina, Nallaret Davila Cardozo, Jano de Rutte Corzo, Jhon del Aguila Pasquel, Gerardo Flores Llampazo, Luis Freitas, Darcy Galiano Cabrera, Roosevelt García Villacorta, Karina Garcia Cabrera, Diego García Soria, Leticia Gatica Saboya, Julio Miguel Grandez Rios, Gabriel Hidalgo Pizango, Eurídice Honorio Coronado, Isau Huamantupa-Chuquimaco, Walter Huaraca Huasco, Yuri Tomas Huillca Aedo, Jose Luis Marcelo Peña, Abel Monteagudo Mendoza, Vanesa Moreano Rodriguez, Percy Núñez Vargas, Sonia Cesarina Palacios Ramos, Nadir Pallqui Camacho, Antonio Peña Cruz, Freddy Ramirez Arevalo, José Reyna Huaymacari, Carlos Reynel Rodriguez, Marcos Antonio Ríos Paredes, Lily Rodriguez Bayona, Rocio del Pilar Rojas Gonzales, Maria Elena Rojas Peña, Norma Salinas Revilla, Yahn Carlos Soto Shareva, Raul Tupayachi Trujillo, Luis Valenzuela Gamarra, Rodolfo Vasquez Martinez, Jim Vega Arenas, Christian Amani, Suspense Averti Ifo, Yannick Bocko, Patrick Boundja, Romeo Ekoungoulou, Mireille Hockemba, Donatien Nzala, Alusine Fofanah, David Taylor, Guillermo Bañares-de Dios, Luis Cayuela, Íñigo Granzow-de la Cerda, Manuel Macía, Juliana Stropp, Maureen Playfair, Verginia Wortel, Toby Gardner, Robert Muscarella, Hari Priyadi, Ervan Rutishauser, Kuo-Jung Chao, Pantaleo Munishi, Olaf Bánki, Frans Bongers, Rene Boot, Gabriella Fredriksson, Jan Reitsma, Hans ter Steege, Tinde van Andel, Peter van de Meer, Peter van der Hout, Mark van Nieuwstadt, Bert van Ulft, Elmar Veenendaal, Ronald Vernimmen, Pieter Zuidema, Joeri Zwerts, Perpetra Akite, Robert Bitariho, Colin Chapman, Eilu Gerald, Miguel Leal, Patrick Mucunguzi, Miguel Alexiades, Timothy R. Baker, Karina Banda, Lindsay Banin, Jos Barlow, Amy Bennett, Erika Berenguer, Nicholas Berry, Neil M. Bird, George A. Blackburn, Francis Brearley, Roel Brienen, David Burslem, Lidiany Carvalho, Percival Cho, Fernanda Coelho, Murray Collins, David Coomes, Aida Cuni-Sanchez, Greta Dargie, Kyle Dexter, Mat Disney, Freddie Draper, Muying Duan, Adriane Esquivel-Muelbert, Robert Ewers, Belen Fadrique, Sophie Fauset, Ted R. Feldpausch, Filipe França, David Galbraith, Martin Gilpin, Emanuel Gloor, John Grace, Keith Hamer, David Harris, Tommaso Jucker, Michelle Kalamandeen, Bente Klitgaard, Aurora Levesley, Simon L. Lewis, Jeremy Lindsell, Gabriela Lopez-Gonzalez, Jon Lovett, Yadvinder Malhi, Toby Marthews, Emma McIntosh, Karina Melgaço, William Milliken, Edward Mitchard, Peter Moonlight, Sam Moore, Alexandra Morel, Julie Peacock, Kelvin Peh, Colin Pendry, R. Toby Pennington, Luciana de Oliveira Pereira, Carlos Peres, Oliver L. Phillips, Georgia Pickavance, Thomas Pugh, Lan Qie, Terhi Riutta, Katherine Roucoux, Casey Ryan, Tiina Sarkinen, Camila Silva Valeria, Dominick Spracklen, Suzanne Stas, Martin Sullivan, Michael Swaine, Joey Talbot, James Taplin, Geertje van der Heijden, Laura Vedovato, Simon Willcock, Mathew Williams, Luciana Alves, Patricia Alvarez Loayza, Gabriel Arellano, Cheryl Asa, Peter Ashton, Gregory Asner, Terry Brncic, Foster Brown, Robyn Burnham, Connie Clark, James Comiskey, Gabriel Damasco, Stuart Davies, Tony Di Fiore, Terry Erwin, William Farfan-Rios, Jefferson Hall, David Kenfack, Thomas Lovejoy, Roberta Martin, Olga Martha Montiel, John Pipoly, Nigel Pitman, John Poulsen, Richard Primack, Miles Silman, Marc Steininger, Varun Swamy, John Terborgh, Duncan Thomas, Peter Umunay, Maria Uriarte, Emilio Vilanova Torre, Ophelia Wang, Kenneth Young, Gerardo A. Aymard C., Lionel Hernández, Rafael Herrera Fernández, Hirma Ramírez-Angulo, Pedro Salcedo, Elio Sanoja, Julio Serrano, Armando Torres-Lezama, Tinh Cong Le, Trai Trong Le, Hieu Dang Tra

Tentative of determination of the acidity level in room temperature ionic liquids by electrochemical methods

peer reviewe

Alkene Oligomerization via metallacycles: Recent Advances and Mechanistic Insights

International audienceThe transformation of ethylene and alkenes is of high importance for the chemical industry. In this review, we focus on selective alkenes transformation where metallacyclopentane is suspected or demonstrated to be involved in the reaction mechanism. In addition to the alkenes, the "classical" products of ethylene oligomerization, we also cover articles dealing with the synthesis of cyclobutane and butadiene derivatives, through the common metallacycle intermediate. We also present studies that help decipher the precise mechanism of the transformations, i.e. involving synthesis of postulated intermediates, labelling experiments and DFT calculations

Role of Homogeneous Catalysis in Oligomerization of Olefins : Focus on Selected Examples Based on Group 4 to Group 10 Transition Metal Complexes

International audienceHomogeneous olefin oligomerization plays a pivotai role in the field of petrochemistry. Through catalysts, technology and process developments, market requirements in terms of productivity, selectivity and sustainability have been addressed. Over more than 50 years, an intensive research has been devoted to the design of new Group 4 to Group 10 transition metal complexes and to the study of their reactivity towards olefins leading to severa! breakthroughs of prime importance for academy as for industry. Since the early sixties, IFPEN contributed to bring innovative industrial solutions to different targets from gasoline production to alpha-olefin on purpose processes with over 100 production units built worldwide . Based on nickel, titanium, zirconium or chromium, the catalytic systems for such processes and their next generation are subject to a continuous research where the adaptation of the ligand architecture to the nature of the metal and its mode of activation, play a crucial role to control the reaction selectivity and the catalyst lifetime. lnteresting relationships between the complex structure and their reactivity have been drawn and will be discussed on selected examples

Hammett Acidity Scale in Ionic Liquids : An Indication of Their Weak Dissociating Character

Ionic liquids are salts with the particularity to exhibit melting points near room temperature (below 100°C, by convention) with no vapour tension. For this last reason, ionic liquids are sometimes called “green solvents”. In addition, their exclusive materials and solvent properties has led to an amazing increase of interest from both academic and industrial community, confirmed by the explosion of the number of published papers in the last decade. The many combinations of organic and inorganic cations and anions allow an infinity of new ionic solvents then permitting the selection of the desired properties for a given application. Nevertheless, it is impossible to investigate all these combinations and the unusual complexity of these new solvents gives rise to many controversies. Consequently, the development of the general rules for understanding the chemistry in ionic liquids is crucial. A fundamental property of solvent is its solvating power, for instance towards the proton. Therefore, we are interested to investigate the acid-base properties in ionic liquids in order to ultimately find a correlation with the acidic catalysis activity. We then have proposed a colorimetric method to determine the acidity levels accessible in these new media: the Hammett acidity function H0. This spectroscopic method is based on the protonation equilibrium for a family of coloured indicator with pKa’s assumed as solvent independent (following the Hammett proposition). This presentation will summarize our Hammett acidity measurements in several ionic liquids. - At first, we will show that it is possible to evaluate the Hammett acidity function with two different coloured indicators, in the same ionic liquid. Since the Hammett acidity of a given mixture was found to depend on the choosen coloured indicator, this suggests the formation of ions associations in ionic liquids. As a result, the ionic liquids are clearly not as dissociating as initially thought and the Hammett acidity function is in fact an apparent function, underestimating the real acidity level. - The apparent acidity functions have then been compared for several ionic liquids to which an acid has been added ([BMIm][NTf2], [BMIm][BF4], [BMIm][OTf], [BHIm][NTf2], [BMIm][PF6], [HNEt3][NTf2]). The conclusions are as follows: 1) the accessible acidity level is not influenced by the nature of the cation; 2) on the contrary, the nature of anion is very critical and the solvating power towards the proton follows the order: OTf- > NTf2- > BF4- > PF6-. The more the proton is solvated, the less it is acidic. - Finally, the difference of acidity of two acids, HOTf and HNTf2 (both strong acids in water), has been investigated in [BMIm][BF4], [BMIm][NTf2] and [BMIm][OTf]. In [BMIm][OTf], these two acids show the same acidity (they behave as strong acids) due to the solvent levelling effect; on the other hand, in [BMIm][NTf2] and [BMIm][BF4] allowing higher acidity levels, HNTf2 is stronger than HOTf . The observed difference is also another indication of the lower proton solvation in [BMIm][BF4] or [BMIm][NTf2] versus that in [BMIm][OTf]

A Comparison of the Acidity Levels in Room-Temperature Ionic Liquids

The Broensted acidity level was evaluated for several ionic liqs. ([BMIm][BF4], [BMIm][PF6], [BMIm][SbF6], [BMIm][OTf], [BMIm][NTf2], [HNET3][NTf2], and [HBIm][NTf2]) to which a strong acid, such as HNTf2 [NTf2=N(CF3SO2)2] and HOTf (OTf=CF3SO3), has been added. The main purpose is to tentatively measure the influence on the resulting acidity of (i) the solvent anion or cation structure and (ii) the added acid nature. The evaluation method is based on the detn. of the Hammett acidity functions H0 using UV/visible spectroscopy. The acidity of protons is mainly detd. by their solvation state, and consequently, the properties of protons depend on both the nature of the solvent and the nature and concn. of the acid. In practice, for the investigated ionic liqs., the cation as well as the added acid nature does not play a dominant role, whereas changing the anion nature may lead to very different acidities. Indeed, for a similar content of added acid, the measured acidity levels are in the order PF6- > BF4- > NTf2- > OTf-. The problems of the influence of impurities on the final acidity and of the dissocg. character of the ionic liq. are addressed

Synthesis of L2Ni(ORF)2 (RF=C(CF3)3) Complexes and their Reactivity in Ethylene Oligomerization

International audienceA family of L2Ni(ORF)2 (L2: (Cy3PO)24, dcpmS 5, dppf 9, bipyMe210; RF = C(CF3)3) complexes is synthesized via selective substitution of 2 equiv of (DME)NaORF from homoleptic [Ni(ORF)4][Na(DME)]2 complex 1, all characterized by 19F and 1H NMR and SCXRD analyses as well as elemental analyses. These L2Ni(ORF)2 precursors, activated by 2 equiv of PhF → Al(ORF)3, were active in ethylene oligomerization with selectivity toward butenes up to 97% and activities ranging from 10 to 50 kgC2H4·gNi·h–1. Mechanistic investigations, involving experiments with C2H4/C2D4 (1/1) coupled with GC-MS analysis, revealed the formation of a Ni–H fragment in the catalytic process. The L2Ni(ORF)2/2PhF → Al(ORF)3 catalytic system thus dimerizes ethylene through a Cossee–Arlman mechanism

About the Acidity Level in Room Temperature Ionic Liquids

peer reviewedThe Brønsted acidity level was evaluated for ionic liquids to which a strong acid has been added. The evaluation method is based on the determination of the Hammett acidity functions H0, using UV-Visible spectroscopy. The acidity of protons is mainly determined by their solvation state and consequently, the properties of protons depend on both the nature of the solvent and the nature and concentration of the acid. In practice, it was found that, for the investigated ionic liquids, the cation as well as the added acid nature does not play a dominant role, whereas changing the anion nature may lead to very different acidities. Indeed, for a similar content of added acid, the measured acidity levels are in the order: PF6- > BF4- > NTf2- > OTf-. The problems of the influence of impurities on the final acidity and of the weakly dissociating character of the ionic liquid are addressed

Taming the Lewis Superacid Al(OR F )3 (R F =C(CF3)3): DFT Guided Identification of the "Stable yet Reactive" Adduct S i Pr2→Al(OR F )3; Its Use as OR F-Abstractor from a "Ni-OR F " complex

International audienceA DFT study of several L→Al(ORF)3 (L=Lewis bases) adducts allowed the identification of (iPr2S)→Al(ORF)3 1-SiPr2 as a “stable yet reactive” adduct. 1-SiPr2 was shown to act as a masked Lewis superacid able to release Al(ORF)3 under mild conditions. It could be used to abstract a ORF− ligand from (bipyMe2)Ni(ORF)2 (bipyMe2 : 6,6’-dimethyl-2,2’-dipyridyl) and generate the nickel alkoxide complex [(bipyMe2)Ni(ORF)(iPr2S)]+[(RFO)3Al−F−Al(ORF)3]− 5. Ligand exchange of iPr2S by Ph3P yielded [(bipyMe2)Ni(ORF)(PPh3)]+[(RFO)3Al−F−Al(ORF)3]− 6