@article{discovery10149177,
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         journal = {Proceedings of The National Academy of Sciences of the United States of America (PNAS)},
          number = {6},
            year = {2022},
           title = {The number of tree species on Earth},
       publisher = {NATL ACAD SCIENCES},
           month = {January},
          volume = {119},
        keywords = {Science \& Technology, Multidisciplinary Sciences, Science \& Technology - Other Topics, biodiversity, forests, hyperdominance, rarity, richness, BIODIVERSITY, RICHNESS, DIVERSITY, SAMPLE, PATTERNS, HETEROGENEITY, COMPLETENESS, ABUNDANCE, COVERAGE, ECOLOGY},
          author = {Gatti, Roberto Cazzolla and Reich, Peter B and Gamarra, Javier GP and Crowther, Tom and Hui, Cang and Morera, Albert and Bastin, Jean-Francois and de-Miguel, Sergio and Nabuurs, Gert-Jan and Svenning, Jens-Christian and Serra-Diaz, Josep M and Merow, Cory and Enquist, Brian and Kamenetsky, Maria and Lee, Junho and Zhu, Jun and Fang, Jinyun and Jacobs, Douglass F and Pijanowski, Bryan and Banerjee, Arindam and Giaquinto, Robert A and Alberti, Giorgio and Almeyda Zambrano, Angelica Maria and Alvarez-Davila, Esteban and Araujo-Murakami, Alejandro and Avitabile, Valerio and Aymard, Gerardo A and Balazy, Radomir and Baraloto, Chris and Barroso, Jorcely G and Bastian, Meredith L and Birnbaum, Philippe and Bitariho, Robert and Bogaert, Jan and Bongers, Frans and Bouriaud, Olivier and Brancalion, Pedro HS and Brearley, Francis Q and Broadbent, Eben North and Bussotti, Filippo and Castro da Silva, Wendeson and Gomes Cesar, Ricardo and Cesljar, Goran and Moscoso, Victor Chama and Chen, Han YH and Cienciala, Emil and Clark, Connie J and Coomes, David A and Dayanandan, Selvadurai and Decuyper, Mathieu and Dee, Laura E and Del Aguila Pasquel, Jhon and Derroire, Geraldine and Djuikouo, Marie Noel Kamdem and Tran, Van Do and Dolezal, Jiri and Dordevic, Ilija D and Engel, Julien and Fayle, Tom M and Feldpausch, Ted R and Fridman, Jonas K and Harris, David J and Hemp, Andreas and Hengeveld, Geerten and Herault, Bruno and Herold, Martin and Ibanez, Thomas and Jagodzinski, Andrzej M and Jaroszewicz, Bogdan and Jeffery, Kathryn J and Johannsen, Vivian Kvist and Jucker, Tommaso and Kangur, Ahto and Karminov, Victor N and Kartawinata, Kuswata and Kennard, Deborah K and Kepfer-Rojas, Sebastian and Keppel, Gunnar and Khan, Mohammed Latif and Khare, Pramod Kumar and Kileen, Timothy J and Kim, Hyun Seok and Korjus, Henn and Kumar, Amit and Kumar, Ashwani and Laarmann, Diana and Labriere, Nicolas and Lang, Mait and Lewis, Simon L and Lukina, Natalia and Maitner, Brian S and Malhi, Yadvinder and Marshall, Andrew R and Martynenko, Olga V and Mendoza, Abel L Monteagudo and Ontikov, Petr V and Ortiz-Malavasi, Edgar and Camacho, Nadir C Pallqui and Paquette, Alain and Park, Minjee and Parthasarathy, Narayanaswamy and Peri, Pablo Luis and Petronelli, Pascal and Pfautsch, Sebastian and Phillips, Oliver L and Picard, Nicolas and Piotto, Daniel and Poorter, Lourens and Poulsen, John R and Pretzsch, Hans and Ramirez-Angulo, Hirma and Correa, Zorayda Restrepo and Rodeghiero, Mirco and Gonzales, Rocio Del Pilar Rojas and Rolim, Samir G and Rovero, Francesco and Rutishauser, Ervan and Saikia, Purabi and Salas-Eljatib, Christian and Schepaschenko, Dmitry and Scherer-Lorenzen, Michael and Seben, Vladimir and Silveira, Marcos and Slik, Ferry and Sonke, Bonaventure and Souza, Alexandre F and Sterenczak, Krzysztof Jan and Svoboda, Miroslav and Taedoumg, Hermann and Tchebakova, Nadja and Terborgh, John and Tikhonova, Elena and Torres-Lezama, Armando and van der Plas, Fons and Vasquez, Rodolfo and Viana, Helder and Vibrans, Alexander C and Vilanova, Emilio and Vos, Vincent A and Wang, Hua-Feng and Westerlund, Bertil and White, Lee JT and Wiser, Susan K and Zawila-Niedzwiecki, Tomasz and Zemagho, Lise and Zhu, Zhi-Xin and Zo-Bi, Irie C and Liang, Jingjing},
        abstract = {One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are {$\sim$}73,000 tree species globally, among which {$\sim$}9,000 tree species are yet to be discovered. Roughly 40\% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness.},
             url = {https://doi.org/10.1073/pnas.2115329119}
}