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1. Dissipative Tunneling Rates through the Incorporation of First-Principles Electronic Friction in Instanton Rate Theory II: Benchmarks and Applications

Author

Litman, Y., Pós, E. S., Box, C. L., Martinazzo, R., Maurer, R. J., and Rossi, M.

Subjects
Physics - Chemical Physics
Abstract

In part I, we presented the ring-polymer instanton with explicit friction (RPI-EF) method and showed how it can be connected to the \textit{ab initio} electronic friction formalism. This framework allows the calculation of tunneling reaction rates that incorporate the quantum nature of the nuclei and certain types of non-adiabatic effects (NAEs) present in metals. In this second part, we analyze the performance of RPI-EF on model potentials and apply it to realistic systems. For a 1D double-well model, we benchmark the method against numerically exact results obtained from multi-layer multi-configuration time-dependent Hartree calculations. We demonstrate that RPI-EF is accurate for medium and high friction strengths and less accurate for extremely low friction values. We also show quantitatively how the inclusion of NAEs lowers the cross-over temperature into the deep tunneling regime, reduces the tunneling rates, and in certain regimes, steers the quantum dynamics by modifying the tunneling pathways. As a showcase of the efficiency of this method, we present a study of hydrogen and deuterium hopping between neighboring interstitial sites in selected bulk metals. The results show that multidimensional vibrational coupling and nuclear quantum effects have a larger impact than NAEs on the tunneling rates of diffusion in metals. Together with part I, these results advance the calculations of dissipative tunneling rates from first principles.

Published
2022
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2. Dissipative Tunneling Rates through the Incorporation of First-Principles Electronic Friction in Instanton Rate Theory I: Theory

Author

Litman, Y., Pós, E. S., Box, C. L., Martinazzo, R., Maurer, R. J., and Rossi, M.

Subjects
Physics - Chemical Physics, Condensed Matter - Materials Science
Abstract

Reactions involving adsorbates on metallic surfaces and impurities in bulk metals are ubiquitous in a wide range of technological applications. The theoretical modelling of such reactions presents a formidable challenge for theory because nuclear quantum effects (NQEs) can play a prominent role and the coupling of the atomic motion with the electrons in the metal gives rise to important non-adiabatic effects (NAEs) that alter atomic dynamics. In this work, we derive a theoretical framework that captures both NQEs and NAEs and, due to its high efficiency, can be applied to first-principles calculations of reaction rates in high-dimensional realistic systems. In more detail, we develop a method that we coin ring polymer instanton with explicit friction (RPI-EF), starting from the ring-polymer instanton formalism applied to a system-bath model. We derive general equations that incorporate the spatial and frequency dependence of the friction tensor, and then combine this method with the \textit{ab initio} electronic friction formalism for the calculation of thermal reaction rates. We show that the connection between RPI-EF and the form of the electronic friction tensor presented in this work does not require any further approximations, and it is expected to be valid as long as the approximations of both underlying theories remain valid.

Published
2022
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3. Nothing lasts forever: Dominant species decline under rapid environmental change in global grasslands

Author

Wilfahrt, P.A., Seabloom, E.W., Bakker, J.D., Biederman, L., Bugalho, M.N., Cadotte, M.W., Caldeira, M.C., Catford, J.A., Chen, Q., Donohue, I., Ebeling, A., Eisenhauer, N., Haider, S., Heckman, R.W., Jentsch, A., Koerner, S.E., Komatsu, K.J., Laungani, R., MacDougall, A., Martina, J.P., Martinson, H., Moore, J.L., Niu, Y., Ohlert, T., Venterink, H.O., Orr, D., Peri, P., Pos, E., Price, J., Raynaud, X., Ren, Z., Roscher, Christiane, Smith, N.G., Stevens, C.J., Sullivan, L.L., Tedder, M., Tognetti, P.M., Veen, C., Wheeler, G., Young, A.L., Young, H., Borer, E.T., Wilfahrt, P.A., Seabloom, E.W., Bakker, J.D., Biederman, L., Bugalho, M.N., Cadotte, M.W., Caldeira, M.C., Catford, J.A., Chen, Q., Donohue, I., Ebeling, A., Eisenhauer, N., Haider, S., Heckman, R.W., Jentsch, A., Koerner, S.E., Komatsu, K.J., Laungani, R., MacDougall, A., Martina, J.P., Martinson, H., Moore, J.L., Niu, Y., Ohlert, T., Venterink, H.O., Orr, D., Peri, P., Pos, E., Price, J., Raynaud, X., Ren, Z., Roscher, Christiane, Smith, N.G., Stevens, C.J., Sullivan, L.L., Tedder, M., Tognetti, P.M., Veen, C., Wheeler, G., Young, A.L., Young, H., and Borer, E.T.

Abstract

Dominance often indicates one or a few species being best suited for resource capture and retention in a given environment. Press perturbations that change availability of limiting resources can restructure competitive hierarchies, allowing new species to capture or retain resources and leaving once dominant species fated to decline. However, dominant species may maintain high abundances even when their new environments no longer favour them due to stochastic processes associated with their high abundance, impeding deterministic processes that would otherwise diminish them.Here, we quantify the persistence of dominance by tracking the rate of decline in dominant species at 90 globally distributed grassland sites under experimentally elevated soil nutrient supply and reduced vertebrate consumer pressure.We found that chronic experimental nutrient addition and vertebrate exclusion caused certain subsets of species to lose dominance more quickly than in control plots. In control plots, perennial species and species with high initial cover maintained dominance for longer than annual species and those with low initial cover respectively. In fertilized plots, species with high initial cover maintained dominance at similar rates to control plots, while those with lower initial cover lost dominance even faster than similar species in controls. High initial cover increased the estimated time to dominance loss more strongly in plots with vertebrate exclosures than in controls. Vertebrate exclosures caused a slight decrease in the persistence of dominance for perennials, while fertilization brought perennials' rate of dominance loss in line with those of annuals. Annual species lost dominance at similar rates regardless of treatments.Synthesis. Collectively, these results point to a strong role of a species' historical abundance in maintaining dominance following environmental perturbations. Because dominant species play an outsized role in driving ecosystem processes, their a

Published
2023

4. Biased-corrected richness estimates for the Amazonian tree flora

Author

ter Steege, H., Prado, P. I., de Lima, R. A. F., Pos, E., Coelho, L. D., Lima, D. D., Salomao, R. P., Amaral, I. L., de Almeida Matos, F. D., Castilho, C. V., Phillips, O. L., Guevara, J. E., Carim, M. D. J., Lopez, D. C., Magnusson, W. E., Wittmann, F., Martins, M. P., Sabatier, Daniel, Irume, M. V., Guimaraes, J. R. D., Molino, Jean-François, and Engel, Julien

Abstract

Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just similar to 50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come.

Published
2020

5. General destabilizing effects of eutrophication on grassland productivity at multiple spatial scales

Author

Hautier, Yann, Zhang, P., Loreau, Michel, Wilcox, Kevin, Seabloom, Eric W., Borer, Elizabeth T., Byrnes, Jarrett, Koerner, Sally, Komatsu, Kimberly, Lefcheck, Jonathan, Hector, Andrew, Adler, Peter B., Alberti, Juan, Arnillas, Carlos A., Bakker, J.D., Brudvig, Lars A., Bugalho, M.N., Cadotte, Marc W., Caldeira, Maria, Carroll, Oliver, Crawley, Michael J., Collins, Scott, Daleo, Pedro, Dee, Laura, Eisenhauer, N., Isbell, Forest, Knops, Johannes M. H., MacDougall, Andrew S., McCulley, Rebecca L., Moore, J.L., Morgan, J.W., Mori, Akira S., Peri, P.L., Pos, E., Power, S.A., Price, Jodie, Reich, Peter B., Risch, Anita C., Roscher, Christiane, Sankaran, Mahesh, Schütz, Martin, Smith, Melinda, Stevens, Carly, Tognetti, P.M., Virtanen, R, Wardle, Glenda M., Wilfahrt, Peter, Wang, Shaopeng, Hautier, Yann, Zhang, P., Loreau, Michel, Wilcox, Kevin, Seabloom, Eric W., Borer, Elizabeth T., Byrnes, Jarrett, Koerner, Sally, Komatsu, Kimberly, Lefcheck, Jonathan, Hector, Andrew, Adler, Peter B., Alberti, Juan, Arnillas, Carlos A., Bakker, J.D., Brudvig, Lars A., Bugalho, M.N., Cadotte, Marc W., Caldeira, Maria, Carroll, Oliver, Crawley, Michael J., Collins, Scott, Daleo, Pedro, Dee, Laura, Eisenhauer, N., Isbell, Forest, Knops, Johannes M. H., MacDougall, Andrew S., McCulley, Rebecca L., Moore, J.L., Morgan, J.W., Mori, Akira S., Peri, P.L., Pos, E., Power, S.A., Price, Jodie, Reich, Peter B., Risch, Anita C., Roscher, Christiane, Sankaran, Mahesh, Schütz, Martin, Smith, Melinda, Stevens, Carly, Tognetti, P.M., Virtanen, R, Wardle, Glenda M., Wilfahrt, Peter, and Wang, Shaopeng

Abstract

Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant diversity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species composition within sites (higher beta diversity) have greater spatial asynchrony of productivity among communities, resulting in greater stability at the larger scale (gamma stability). Importantly, fertilization consistently weakens the contribution of plant diversity to both of these stabilizing mechanisms, thus diminishing the positive effect of biodiversity on stability at differing spatial scales. Our findings suggest that preserving grassland functional stability requires conservation of plant diversity within and among ecological communities.

Published
2020

6. General destabilizing effects of eutrophication on grassland productivity at multiple spatial scales

Author

Hautier, Y. (Yann), Zhang, P. (Pengfei), Loreau, M. (Michel), Wilcox, K. R. (Kevin R.), Seabloom, E. W. (Eric W.), Borer, E. T. (Elizabeth T.), Byrnes, J. E. (Jarrett E. K.), Koerner, S. E. (Sally E.), Komatsu, K. J. (Kimberly J.), Lefcheck, J. S. (Jonathan S.), Hector, A. (Andy), Adler, P. B. (Peter B.), Alberti, J. (Juan), Arnillas, C. A. (Carlos A.), Bakker, J. D. (Jonathan D.), Brudvig, L. A. (Lars A.), Bugalho, M. N. (Miguel N.), Cadotte, M. (Marc), Caldeira, M. C. (Maria C.), Carroll, O. (Oliver), Crawley, M. (Mick), Collins, S. L. (Scott L.), Daleo, P. (Pedro), Dee, L. E. (Laura E.), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Fay, P. A. (Philip A.), Gilbert, B. (Benjamin), Hansar, A. (Amandine), Isbell, F. (Forest), Knops, J. M. (Johannes M. H.), MacDougall, A. S. (Andrew S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Morgan, J. W. (John W.), Mori, A. S. (Akira S.), Peri, P. L. (Pablo L.), Pos, E. T. (Edwin T.), Power, S. A. (Sally A.), Price, J. N. (Jodi N.), Reich, P. B. (Peter B.), Risch, A. C. (Anita C.), Roscher, C. (Christiane), Sankaran, M. (Mahesh), Schutz, M. (Martin), Smith, M. (Melinda), Stevens, C. (Carly), Tognetti, P. M. (Pedro M.), Virtanen, R. (Risto), Wardle, G. M. (Glenda M.), Wilfahrt, P. A. (Peter A.), Wang, S. (Shaopeng), Hautier, Y. (Yann), Zhang, P. (Pengfei), Loreau, M. (Michel), Wilcox, K. R. (Kevin R.), Seabloom, E. W. (Eric W.), Borer, E. T. (Elizabeth T.), Byrnes, J. E. (Jarrett E. K.), Koerner, S. E. (Sally E.), Komatsu, K. J. (Kimberly J.), Lefcheck, J. S. (Jonathan S.), Hector, A. (Andy), Adler, P. B. (Peter B.), Alberti, J. (Juan), Arnillas, C. A. (Carlos A.), Bakker, J. D. (Jonathan D.), Brudvig, L. A. (Lars A.), Bugalho, M. N. (Miguel N.), Cadotte, M. (Marc), Caldeira, M. C. (Maria C.), Carroll, O. (Oliver), Crawley, M. (Mick), Collins, S. L. (Scott L.), Daleo, P. (Pedro), Dee, L. E. (Laura E.), Eisenhauer, N. (Nico), Eskelinen, A. (Anu), Fay, P. A. (Philip A.), Gilbert, B. (Benjamin), Hansar, A. (Amandine), Isbell, F. (Forest), Knops, J. M. (Johannes M. H.), MacDougall, A. S. (Andrew S.), McCulley, R. L. (Rebecca L.), Moore, J. L. (Joslin L.), Morgan, J. W. (John W.), Mori, A. S. (Akira S.), Peri, P. L. (Pablo L.), Pos, E. T. (Edwin T.), Power, S. A. (Sally A.), Price, J. N. (Jodi N.), Reich, P. B. (Peter B.), Risch, A. C. (Anita C.), Roscher, C. (Christiane), Sankaran, M. (Mahesh), Schutz, M. (Martin), Smith, M. (Melinda), Stevens, C. (Carly), Tognetti, P. M. (Pedro M.), Virtanen, R. (Risto), Wardle, G. M. (Glenda M.), Wilfahrt, P. A. (Peter A.), and Wang, S. (Shaopeng)

Abstract

Eutrophication is a widespread environmental change that usually reduces the stabilizing effect of plant diversity on productivity in local communities. Whether this effect is scale dependent remains to be elucidated. Here, we determine the relationship between plant diversity and temporal stability of productivity for 243 plant communities from 42 grasslands across the globe and quantify the effect of chronic fertilization on these relationships. Unfertilized local communities with more plant species exhibit greater asynchronous dynamics among species in response to natural environmental fluctuations, resulting in greater local stability (alpha stability). Moreover, neighborhood communities that have greater spatial variation in plant species composition within sites (higher beta diversity) have greater spatial asynchrony of productivity among communities, resulting in greater stability at the larger scale (gamma stability). Importantly, fertilization consistently weakens the contribution of plant diversity to both of these stabilizing mechanisms, thus diminishing the positive effect of biodiversity on stability at differing spatial scales. Our findings suggest that preserving grassland functional stability requires conservation of plant diversity within and among ecological communities.

Published
2020

10. Antibiotics with antibiofilm activity - rifampicin and beyond.

Author

Ferreira L, Pos E, Nogueira DR, Ferreira FP, Sousa R, and Abreu MA

Abstract

The management of prosthetic joint infections is a complex and multilayered process that is additionally complicated by the formation of bacterial biofilm. Foreign material provides the ideal grounds for the development of an intricate matrix that hinders treatment and creates a difficult environment for antibiotics to act. Surgical intervention is often warranted but requires appropriate adjunctive therapy. Despite available guidelines, several aspects of antibiotic therapy with antibiofilm activity lack clear definition. Given the escalating challenges posed by antimicrobial resistance, extended treatment durations, and tolerance issues, it is essential to ensure that antimicrobials with antibiofilm activity are both potent and diverse. Evidence of biofilm-active drugs is highlighted, and alternatives to classical regimens are further discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Ferreira, Pos, Nogueira, Ferreira, Sousa and Abreu.)

Published
2024
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11. One sixth of Amazonian tree diversity is dependent on river floodplains.

Author

Householder JE, Wittmann F, Schöngart J, Piedade MTF, Junk WJ, Latrubesse EM, Quaresma AC, Demarchi LO, de S Lobo G, Aguiar DPP, Assis RL, Lopes A, Parolin P, Leão do Amaral I, Coelho LS, de Almeida Matos FD, Lima Filho DA, Salomão RP, Castilho CV, Guevara-Andino JE, Carim MJV, Phillips OL, Cárdenas López D, Magnusson WE, Sabatier D, Revilla JDC, Molino JF, Irume MV, Martins MP, Guimarães JRDS, Ramos JF, Rodrigues DJ, Bánki OS, Peres CA, Pitman NCA, Hawes JE, Almeida EJ, Barbosa LF, Cavalheiro L, Dos Santos MCV, Luize BG, Novo EMML, Núñez Vargas P, Silva TSF, Venticinque EM, Manzatto AG, Reis NFC, Terborgh J, Casula KR, Costa FRC, Honorio Coronado EN, Monteagudo Mendoza A, Montero JC, Feldpausch TR, Aymard C GA, Baraloto C, Castaño Arboleda N, Engel J, Petronelli P, Zartman CE, Killeen TJ, Rincón LM, Marimon BS, Marimon-Junior BH, Schietti J, Sousa TR, Vasquez R, Mostacedo B, Dantas do Amaral D, Castellanos H, Medeiros MB, Simon MF, Andrade A, Camargo JL, Laurance WF, Laurance SGW, Farias ES, Lopes MA, Magalhães JLL, Mendonça Nascimento HE, Queiroz HL, Brienen R, Stevenson PR, Araujo-Murakami A, Baker TR, Cintra BBL, Feitosa YO, Mogollón HF, Noronha JC, Barbosa FR, de Sá Carpanedo R, Duivenvoorden JF, Silman MR, Ferreira LV, Levis C, Lozada JR, Comiskey JA, Draper FC, Toledo JJ, Damasco G, Dávila N, García-Villacorta R, Vicentini A, Cornejo Valverde F, Alonso A, Arroyo L, Dallmeier F, Gomes VHF, Jimenez EM, Neill D, Peñuela Mora MC, Carvalho FA, Coelho de Souza F, Feeley KJ, Gribel R, Pansonato MP, Ríos Paredes M, Barlow J, Berenguer E, Dexter KG, Ferreira J, Fine PVA, Guedes MC, Huamantupa-Chuquimaco I, Licona JC, Pennington T, Villa Zegarra BE, Vos VA, Cerón C, Fonty É, Henkel TW, Maas P, Pos E, Silveira M, Stropp J, Thomas R, Daly D, Milliken W, Pardo Molina G, Vieira ICG, Albuquerque BW, Campelo W, Emilio T, Fuentes A, Klitgaard B, Marcelo Pena JL, Souza PF, Tello JS, Vriesendorp C, Chave J, Di Fiore A, Hilário RR, Pereira LO, Phillips JF, Rivas-Torres G, van Andel TR, von Hildebrand P, Balee W, Barbosa EM, Bonates LCM, Doza HPD, Gómez RZ, Gonzales T, Gonzales GPG, Hoffman B, Junqueira AB, Malhi Y, Miranda IPA, Mozombite-Pinto LF, Prieto A, Rudas A, Ruschel AR, Silva N, Vela CIA, Zent S, Zent EL, Cano A, Carrero Márquez YA, Correa DF, Costa JBP, Flores BM, Galbraith D, Holmgren M, Kalamandeen M, Nascimento MT, Oliveira AA, Ramirez-Angulo H, Rocha M, Scudeller VV, Sierra R, Tirado M, Umaña MN, van der Heijden G, Vilanova Torre E, Ahuite Reategui MA, Baider C, Balslev H, Cárdenas S, Casas LF, Farfan-Rios W, Ferreira C, Linares-Palomino R, Mendoza C, Mesones I, Parada GA, Torres-Lezama A, Urrego Giraldo LE, Villarroel D, Zagt R, Alexiades MN, de Oliveira EA, Garcia-Cabrera K, Hernandez L, Palacios Cuenca W, Pansini S, Pauletto D, Ramirez Arevalo F, Sampaio AF, Valderrama Sandoval EH, Valenzuela Gamarra L, and Ter Steege H

Subjects
Brazil, Forests, Biodiversity, Trees, Rivers, Floods
Abstract

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function., (© 2024. The Author(s).)

Published
2024
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12. Author Correction: One sixth of Amazonian tree diversity is dependent on river floodplains.

Author

Householder JE, Wittmann F, Schöngart J, Piedade MTF, Junk WJ, Latrubesse EM, Quaresma AC, Demarchi LO, de S Lobo G, Aguiar DPP, Assis RL, Lopes A, Parolin P, Leão do Amaral I, Coelho LS, de Almeida Matos FD, Lima Filho DA, Salomão RP, Castilho CV, Guevara-Andino JE, Carim MJV, Phillips OL, Cárdenas López D, Magnusson WE, Sabatier D, Revilla JDC, Molino JF, Irume MV, Martins MP, Guimarães JRDS, Ramos JF, Rodrigues DJ, Bánki OS, Peres CA, Pitman NCA, Hawes JE, Almeida EJ, Barbosa LF, Cavalheiro L, Dos Santos MCV, Luize BG, Novo EMML, Núñez Vargas P, Silva TSF, Venticinque EM, Manzatto AG, Reis NFC, Terborgh J, Casula KR, Costa FRC, Honorio Coronado EN, Monteagudo Mendoza A, Montero JC, Feldpausch TR, Aymard C GA, Baraloto C, Castaño Arboleda N, Engel J, Petronelli P, Zartman CE, Killeen TJ, Rincón LM, Marimon BS, Marimon-Junior BH, Schietti J, Sousa TR, Vasquez R, Mostacedo B, Dantas do Amaral D, Castellanos H, Medeiros MB, Simon MF, Andrade A, Camargo JL, Laurance WF, Laurance SGW, Farias ES, Lopes MA, Magalhães JLL, Mendonça Nascimento HE, Queiroz HL, Brienen R, Stevenson PR, Araujo-Murakami A, Baker TR, Cintra BBL, Feitosa YO, Mogollón HF, Noronha JC, Barbosa FR, de Sá Carpanedo R, Duivenvoorden JF, Silman MR, Ferreira LV, Levis C, Lozada JR, Comiskey JA, Draper FC, Toledo JJ, Damasco G, Dávila N, García-Villacorta R, Vicentini A, Cornejo Valverde F, Alonso A, Arroyo L, Dallmeier F, Gomes VHF, Jimenez EM, Neill D, Peñuela Mora MC, Carvalho FA, Coelho de Souza F, Feeley KJ, Gribel R, Pansonato MP, Ríos Paredes M, Barlow J, Berenguer E, Dexter KG, Ferreira J, Fine PVA, Guedes MC, Huamantupa-Chuquimaco I, Licona JC, Pennington T, Villa Zegarra BE, Vos VA, Cerón C, Fonty É, Henkel TW, Maas P, Pos E, Silveira M, Stropp J, Thomas R, Daly D, Milliken W, Pardo Molina G, Vieira ICG, Albuquerque BW, Campelo W, Emilio T, Fuentes A, Klitgaard B, Marcelo Pena JL, Souza PF, Tello JS, Vriesendorp C, Chave J, Di Fiore A, Hilário RR, Pereira LO, Phillips JF, Rivas-Torres G, van Andel TR, von Hildebrand P, Balee W, Barbosa EM, Bonates LCM, Doza HPD, Gómez RZ, Gonzales T, Gonzales GPG, Hoffman B, Junqueira AB, Malhi Y, Miranda IPA, Mozombite-Pinto LF, Prieto A, Rudas A, Ruschel AR, Silva N, Vela CIA, Zent S, Zent EL, Cano A, Carrero Márquez YA, Correa DF, Costa JBP, Flores BM, Galbraith D, Holmgren M, Kalamandeen M, Nascimento MT, Oliveira AA, Ramirez-Angulo H, Rocha M, Scudeller VV, Sierra R, Tirado M, Umaña MN, van der Heijden G, Vilanova Torre E, Ahuite Reategui MA, Baider C, Balslev H, Cárdenas S, Casas LF, Farfan-Rios W, Ferreira C, Linares-Palomino R, Mendoza C, Mesones I, Parada GA, Torres-Lezama A, Urrego Giraldo LE, Villarroel D, Zagt R, Alexiades MN, de Oliveira EA, Garcia-Cabrera K, Hernandez L, Palacios Cuenca W, Pansini S, Pauletto D, Ramirez Arevalo F, Sampaio AF, Valderrama Sandoval EH, Valenzuela Gamarra L, and Ter Steege H

Published
2024
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13. Mycobacterium szulgai Pulmonary Infection in an Immunocompromised Patient.

Author

Neves S, Pos E, Horta A, and Vasconcelos AL

Abstract

Mycobacterium szulgai is a slow-growing nontuberculous mycobacterium (NTM). It was first described in 1972 and is responsible for less than 0.2% of all NTM infections. The most common presentation resembles pulmonary tuberculosis, but it may also present as an extrapulmonary disease. It primarily affects individuals with underlying lung disease or immunocompromising conditions. The increasing use of tumor necrosis factor-alpha inhibitors, such as adalimumab, is associated with an increased risk of serious infections. We report a case of Mycobacterium szulgai infection in a 23-year-old woman with a history of childhood pneumonia and Crohn's disease on adalimumab., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Neves et al.)

Published
2023
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14. Mapping density, diversity and species-richness of the Amazon tree flora.

Author

Ter Steege H, Pitman NCA, do Amaral IL, de Souza Coelho L, de Almeida Matos FD, de Andrade Lima Filho D, Salomão RP, Wittmann F, Castilho CV, Guevara JE, Veiga Carim MJ, Phillips OL, Magnusson WE, Sabatier D, Revilla JDC, Molino JF, Irume MV, Martins MP, da Silva Guimarães JR, Ramos JF, Bánki OS, Piedade MTF, Cárdenas López D, Rodrigues DJ, Demarchi LO, Schöngart J, Almeida EJ, Barbosa LF, Cavalheiro L, Dos Santos MCV, Luize BG, de Leão Novo EMM, Vargas PN, Silva TSF, Venticinque EM, Manzatto AG, Reis NFC, Terborgh J, Casula KR, Honorio Coronado EN, Monteagudo Mendoza A, Montero JC, Costa FRC, Feldpausch TR, Quaresma AC, Castaño Arboleda N, Zartman CE, Killeen TJ, Marimon BS, Marimon-Junior BH, Vasquez R, Mostacedo B, Assis RL, Baraloto C, do Amaral DD, Engel J, Petronelli P, Castellanos H, de Medeiros MB, Simon MF, Andrade A, Camargo JL, Laurance WF, Laurance SGW, Maniguaje Rincón L, Schietti J, Sousa TR, de Sousa Farias E, Lopes MA, Magalhães JLL, Nascimento HEM, de Queiroz HL, Aymard C GA, Brienen R, Stevenson PR, Araujo-Murakami A, Baker TR, Cintra BBL, Feitosa YO, Mogollón HF, Duivenvoorden JF, Peres CA, Silman MR, Ferreira LV, Lozada JR, Comiskey JA, Draper FC, de Toledo JJ, Damasco G, García-Villacorta R, Lopes A, Vicentini A, Cornejo Valverde F, Alonso A, Arroyo L, Dallmeier F, Gomes VHF, Jimenez EM, Neill D, Peñuela Mora MC, Noronha JC, de Aguiar DPP, Barbosa FR, Bredin YK, de Sá Carpanedo R, Carvalho FA, de Souza FC, Feeley KJ, Gribel R, Haugaasen T, Hawes JE, Pansonato MP, Ríos Paredes M, Barlow J, Berenguer E, da Silva IB, Ferreira MJ, Ferreira J, Fine PVA, Guedes MC, Levis C, Licona JC, Villa Zegarra BE, Vos VA, Cerón C, Durgante FM, Fonty É, Henkel TW, Householder JE, Huamantupa-Chuquimaco I, Pos E, Silveira M, Stropp J, Thomas R, Daly D, Dexter KG, Milliken W, Molina GP, Pennington T, Vieira ICG, Weiss Albuquerque B, Campelo W, Fuentes A, Klitgaard B, Pena JLM, Tello JS, Vriesendorp C, Chave J, Di Fiore A, Hilário RR, de Oliveira Pereira L, Phillips JF, Rivas-Torres G, van Andel TR, von Hildebrand P, Balee W, Barbosa EM, de Matos Bonates LC, Dávila Doza HP, Zárate Gómez R, Gonzales T, Gallardo Gonzales GP, Hoffman B, Junqueira AB, Malhi Y, de Andrade Miranda IP, Pinto LFM, Prieto A, Rudas A, Ruschel AR, Silva N, Vela CIA, Zent EL, Zent S, Cano A, Carrero Márquez YA, Correa DF, Costa JBP, Flores BM, Galbraith D, Holmgren M, Kalamandeen M, Lobo G, Torres Montenegro L, Nascimento MT, Oliveira AA, Pombo MM, Ramirez-Angulo H, Rocha M, Scudeller VV, Sierra R, Tirado M, Umaña MN, van der Heijden G, Vilanova Torre E, Reategui MAA, Baider C, Balslev H, Cárdenas S, Casas LF, Endara MJ, Farfan-Rios W, Ferreira C, Linares-Palomino R, Mendoza C, Mesones I, Parada GA, Torres-Lezama A, Urrego Giraldo LE, Villarroel D, Zagt R, Alexiades MN, de Oliveira EA, Garcia-Cabrera K, Hernandez L, Cuenca WP, Pansini S, Pauletto D, Ramirez Arevalo F, Sampaio AF, Valderrama Sandoval EH, Gamarra LV, Levesley A, Pickavance G, and Melgaço K

Subjects
Forests, Soil, Temperature, Trees, RNA, Long Noncoding
Abstract

Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution., (© 2023. The Author(s).)

Published
2023
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15. Unraveling Amazon tree community assembly using Maximum Information Entropy: a quantitative analysis of tropical forest ecology.

Author

Pos E, de Souza Coelho L, de Andrade Lima Filho D, Salomão RP, Amaral IL, de Almeida Matos FD, Castilho CV, Phillips OL, Guevara JE, de Jesus Veiga Carim M, López DC, Magnusson WE, Wittmann F, Irume MV, Martins MP, Sabatier D, da Silva Guimarães JR, Molino JF, Bánki OS, Piedade MTF, Pitman NCA, Mendoza AM, Ramos JF, Hawes JE, Almeida EJ, Barbosa LF, Cavalheiro L, Dos Santos MCV, Luize BG, de Leão Novo EMM, Vargas PN, Silva TSF, Venticinque EM, Manzatto AG, Reis NFC, Terborgh J, Casula KR, Coronado ENH, Montero JC, Marimon BS, Marimon-Junior BH, Feldpausch TR, Duque A, Baraloto C, Arboleda NC, Engel J, Petronelli P, Zartman CE, Killeen TJ, Vasquez R, Mostacedo B, Assis RL, Schöngart J, Castellanos H, de Medeiros MB, Simon MF, Andrade A, Camargo JL, Demarchi LO, Laurance WF, Laurance SGW, de Sousa Farias E, Lopes MA, Magalhães JLL, Nascimento HEM, de Queiroz HL, Aymard GAC, Brienen R, Revilla JDC, Costa FRC, Quaresma A, Vieira ICG, Cintra BBL, Stevenson PR, Feitosa YO, Duivenvoorden JF, Mogollón HF, Ferreira LV, Comiskey JA, Draper F, de Toledo JJ, Damasco G, Dávila N, García-Villacorta R, Lopes A, Vicentini A, Noronha JC, Barbosa FR, de Sá Carpanedo R, Emilio T, Levis C, de Jesus Rodrigues D, Schietti J, Souza P, Alonso A, Dallmeier F, Gomes VHF, Lloyd J, Neill D, de Aguiar DPP, Araujo-Murakami A, Arroyo L, Carvalho FA, de Souza FC, do Amaral DD, Feeley KJ, Gribel R, Pansonato MP, Barlow J, Berenguer E, Ferreira J, Fine PVA, Guedes MC, Jimenez EM, Licona JC, Mora MCP, Peres CA, Zegarra BEV, Cerón C, Henkel TW, Maas P, Silveira M, Stropp J, Thomas-Caesar R, Baker TR, Daly D, Dexter KG, Householder JE, Huamantupa-Chuquimaco I, Pennington T, Paredes MR, Fuentes A, Pena JLM, Silman MR, Tello JS, Chave J, Valverde FC, Di Fiore A, Hilário RR, Phillips JF, Rivas-Torres G, van Andel TR, von Hildebrand P, Barbosa EM, de Matos Bonates LC, Doza HPD, Fonty É, Gómez RZ, Gonzales T, Gonzales GPG, Guillaumet JL, Hoffman B, Junqueira AB, Malhi Y, de Andrade Miranda IP, Pinto LFM, Prieto A, Rudas A, Ruschel AR, Silva N, Vela CIA, Vos VA, Zent EL, Zent S, Albuquerque BW, Cano A, Correa DF, Costa JBP, Flores BM, Holmgren M, Nascimento MT, Oliveira AA, Ramirez-Angulo H, Rocha M, Scudeller VV, Sierra R, Tirado M, Umaña MN, van der Heijden G, Torre EV, Vriesendorp C, Wang O, Young KR, Reategui MAA, Baider C, Balslev H, Cárdenas S, Casas LF, Farfan-Rios W, Ferreira C, Linares-Palomino R, Mendoza C, Mesones I, Torres-Lezama A, Giraldo LEU, Villarroel D, Zagt R, Alexiades MN, Garcia-Cabrera K, Hernandez L, Milliken W, Cuenca WP, Pansini S, Pauletto D, Arevalo FR, Sampaio AF, Sandoval EHV, Gamarra LV, Boenisch G, Kattge J, Kraft N, Levesley A, Melgaço K, Pickavance G, Poorter L, and Ter Steege H

Subjects
Entropy, Forests, Plants, Ecology, Tropical Climate, Ecosystem, Biodiversity
Abstract

In a time of rapid global change, the question of what determines patterns in species abundance distribution remains a priority for understanding the complex dynamics of ecosystems. The constrained maximization of information entropy provides a framework for the understanding of such complex systems dynamics by a quantitative analysis of important constraints via predictions using least biased probability distributions. We apply it to over two thousand hectares of Amazonian tree inventories across seven forest types and thirteen functional traits, representing major global axes of plant strategies. Results show that constraints formed by regional relative abundances of genera explain eight times more of local relative abundances than constraints based on directional selection for specific functional traits, although the latter does show clear signals of environmental dependency. These results provide a quantitative insight by inference from large-scale data using cross-disciplinary methods, furthering our understanding of ecological dynamics., (© 2023. The Author(s).)

Published
2023
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16. Biased-corrected richness estimates for the Amazonian tree flora.

Author

Ter Steege H, Prado PI, Lima RAF, Pos E, de Souza Coelho L, de Andrade Lima Filho D, Salomão RP, Amaral IL, de Almeida Matos FD, Castilho CV, Phillips OL, Guevara JE, de Jesus Veiga Carim M, Cárdenas López D, Magnusson WE, Wittmann F, Martins MP, Sabatier D, Irume MV, da Silva Guimarães JR, Molino JF, Bánki OS, Piedade MTF, Pitman NCA, Ramos JF, Monteagudo Mendoza A, Venticinque EM, Luize BG, Núñez Vargas P, Silva TSF, de Leão Novo EMM, Reis NFC, Terborgh J, Manzatto AG, Casula KR, Honorio Coronado EN, Montero JC, Duque A, Costa FRC, Castaño Arboleda N, Schöngart J, Zartman CE, Killeen TJ, Marimon BS, Marimon-Junior BH, Vasquez R, Mostacedo B, Demarchi LO, Feldpausch TR, Engel J, Petronelli P, Baraloto C, Assis RL, Castellanos H, Simon MF, de Medeiros MB, Quaresma A, Laurance SGW, Rincón LM, Andrade A, Sousa TR, Camargo JL, Schietti J, Laurance WF, de Queiroz HL, Nascimento HEM, Lopes MA, de Sousa Farias E, Magalhães JLL, Brienen R, Aymard C GA, Revilla JDC, Vieira ICG, Cintra BBL, Stevenson PR, Feitosa YO, Duivenvoorden JF, Mogollón HF, Araujo-Murakami A, Ferreira LV, Lozada JR, Comiskey JA, de Toledo JJ, Damasco G, Dávila N, Lopes A, García-Villacorta R, Draper F, Vicentini A, Cornejo Valverde F, Lloyd J, Gomes VHF, Neill D, Alonso A, Dallmeier F, de Souza FC, Gribel R, Arroyo L, Carvalho FA, de Aguiar DPP, do Amaral DD, Pansonato MP, Feeley KJ, Berenguer E, Fine PVA, Guedes MC, Barlow J, Ferreira J, Villa B, Peñuela Mora MC, Jimenez EM, Licona JC, Cerón C, Thomas R, Maas P, Silveira M, Henkel TW, Stropp J, Paredes MR, Dexter KG, Daly D, Baker TR, Huamantupa-Chuquimaco I, Milliken W, Pennington T, Tello JS, Pena JLM, Peres CA, Klitgaard B, Fuentes A, Silman MR, Di Fiore A, von Hildebrand P, Chave J, van Andel TR, Hilário RR, Phillips JF, Rivas-Torres G, Noronha JC, Prieto A, Gonzales T, de Sá Carpanedo R, Gonzales GPG, Gómez RZ, de Jesus Rodrigues D, Zent EL, Ruschel AR, Vos VA, Fonty É, Junqueira AB, Doza HPD, Hoffman B, Zent S, Barbosa EM, Malhi Y, de Matos Bonates LC, de Andrade Miranda IP, Silva N, Barbosa FR, Vela CIA, Pinto LFM, Rudas A, Albuquerque BW, Umaña MN, Carrero Márquez YA, van der Heijden G, Young KR, Tirado M, Correa DF, Sierra R, Costa JBP, Rocha M, Vilanova Torre E, Wang O, Oliveira AA, Kalamandeen M, Vriesendorp C, Ramirez-Angulo H, Holmgren M, Nascimento MT, Galbraith D, Flores BM, Scudeller VV, Cano A, Ahuite Reategui MA, Mesones I, Baider C, Mendoza C, Zagt R, Urrego Giraldo LE, Ferreira C, Villarroel D, Linares-Palomino R, Farfan-Rios W, Farfan-Rios W, Casas LF, Cárdenas S, Balslev H, Torres-Lezama A, Alexiades MN, Garcia-Cabrera K, Valenzuela Gamarra L, Valderrama Sandoval EH, Ramirez Arevalo F, Hernandez L, Sampaio AF, Pansini S, Palacios Cuenca W, de Oliveira EA, Pauletto D, Levesley A, Melgaço K, and Pickavance G

Subjects
Brazil, Biodiversity, Classification methods, Forests, Rivers, Trees classification
Abstract

Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just ~50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come.

Published
2020
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17. Scaling issues of neutral theory reveal violations of ecological equivalence for dominant Amazonian tree species.

Author

Pos E, Guevara JE, Molino JF, Sabatier D, Bánki OS, Pitman NCA, Mogollón HF, García-Villacorta R, Neill D, Phillips OL, Cerón C, Ríos Paredes M, Núñez Vargas P, Dávila N, Fiore AD, Rivas-Torres G, Thomas-Caesar R, Vriesendorp C, Young KR, Tirado M, Wang O, Sierra R, Mesones I, Zagt R, Vasquez R, Ahuite Reategui MA, Palacios Cuenca W, Valderrama Sandoval EH, and Ter Steege H

Subjects
Ecosystem, Models, Biological, Species Specificity, Biodiversity, Ecology, Trees
Abstract

Neutral models are often used as null models, testing the relative importance of niche versus neutral processes in shaping diversity. Most versions, however, focus only on regional scale predictions and neglect local level contributions. Recently, a new formulation of spatial neutral theory was published showing an incompatibility between regional and local scale fits where especially the number of rare species was dramatically under-predicted. Using a forward in time semi-spatially explicit neutral model and a unique large-scale Amazonian tree inventory data set, we show that neutral theory not only underestimates the number of rare species but also fails in predicting the excessive dominance of species on both regional and local levels. We show that although there are clear relationships between species composition, spatial and environmental distances, there is also a clear differentiation between species able to attain dominance with and without restriction to specific habitats. We conclude therefore that the apparent dominance of these species is real, and that their excessive abundance can be attributed to fitness differences in different ways, a clear violation of the ecological equivalence assumption of neutral theory., (© 2019 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.)

Published
2019
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18. Species Distribution Modelling: Contrasting presence-only models with plot abundance data.

Author

Gomes VHF, IJff SD, Raes N, Amaral IL, Salomão RP, de Souza Coelho L, de Almeida Matos FD, Castilho CV, de Andrade Lima Filho D, López DC, Guevara JE, Magnusson WE, Phillips OL, Wittmann F, de Jesus Veiga Carim M, Martins MP, Irume MV, Sabatier D, Molino JF, Bánki OS, da Silva Guimarães JR, Pitman NCA, Piedade MTF, Mendoza AM, Luize BG, Venticinque EM, de Leão Novo EMM, Vargas PN, Silva TSF, Manzatto AG, Terborgh J, Reis NFC, Montero JC, Casula KR, Marimon BS, Marimon BH, Coronado ENH, Feldpausch TR, Duque A, Zartman CE, Arboleda NC, Killeen TJ, Mostacedo B, Vasquez R, Schöngart J, Assis RL, Medeiros MB, Simon MF, Andrade A, Laurance WF, Camargo JL, Demarchi LO, Laurance SGW, de Sousa Farias E, Nascimento HEM, Revilla JDC, Quaresma A, Costa FRC, Vieira ICG, Cintra BBL, Castellanos H, Brienen R, Stevenson PR, Feitosa Y, Duivenvoorden JF, Aymard C GA, Mogollón HF, Targhetta N, Comiskey JA, Vicentini A, Lopes A, Damasco G, Dávila N, García-Villacorta R, Levis C, Schietti J, Souza P, Emilio T, Alonso A, Neill D, Dallmeier F, Ferreira LV, Araujo-Murakami A, Praia D, do Amaral DD, Carvalho FA, de Souza FC, Feeley K, Arroyo L, Pansonato MP, Gribel R, Villa B, Licona JC, Fine PVA, Cerón C, Baraloto C, Jimenez EM, Stropp J, Engel J, Silveira M, Mora MCP, Petronelli P, Maas P, Thomas-Caesar R, Henkel TW, Daly D, Paredes MR, Baker TR, Fuentes A, Peres CA, Chave J, Pena JLM, Dexter KG, Silman MR, Jørgensen PM, Pennington T, Di Fiore A, Valverde FC, Phillips JF, Rivas-Torres G, von Hildebrand P, van Andel TR, Ruschel AR, Prieto A, Rudas A, Hoffman B, Vela CIA, Barbosa EM, Zent EL, Gonzales GPG, Doza HPD, de Andrade Miranda IP, Guillaumet JL, Pinto LFM, de Matos Bonates LC, Silva N, Gómez RZ, Zent S, Gonzales T, Vos VA, Malhi Y, Oliveira AA, Cano A, Albuquerque BW, Vriesendorp C, Correa DF, Torre EV, van der Heijden G, Ramirez-Angulo H, Ramos JF, Young KR, Rocha M, Nascimento MT, Medina MNU, Tirado M, Wang O, Sierra R, Torres-Lezama A, Mendoza C, Ferreira C, Baider C, Villarroel D, Balslev H, Mesones I, Giraldo LEU, Casas LF, Reategui MAA, Linares-Palomino R, Zagt R, Cárdenas S, Farfan-Rios W, Sampaio AF, Pauletto D, Sandoval EHV, Arevalo FR, Huamantupa-Chuquimaco I, Garcia-Cabrera K, Hernandez L, Gamarra LV, Alexiades MN, Pansini S, Cuenca WP, Milliken W, Ricardo J, Lopez-Gonzalez G, Pos E, and Ter Steege H

Subjects
Brazil, Chrysobalanaceae physiology, Fabaceae physiology, Humans, Polygonaceae physiology, Conservation of Natural Resources statistics & numerical data, Models, Statistical, Plant Dispersal physiology, Trees physiology
Abstract

Species distribution models (SDMs) are widely used in ecology and conservation. Presence-only SDMs such as MaxEnt frequently use natural history collections (NHCs) as occurrence data, given their huge numbers and accessibility. NHCs are often spatially biased which may generate inaccuracies in SDMs. Here, we test how the distribution of NHCs and MaxEnt predictions relates to a spatial abundance model, based on a large plot dataset for Amazonian tree species, using inverse distance weighting (IDW). We also propose a new pipeline to deal with inconsistencies in NHCs and to limit the area of occupancy of the species. We found a significant but weak positive relationship between the distribution of NHCs and IDW for 66% of the species. The relationship between SDMs and IDW was also significant but weakly positive for 95% of the species, and sensitivity for both analyses was high. Furthermore, the pipeline removed half of the NHCs records. Presence-only SDM applications should consider this limitation, especially for large biodiversity assessments projects, when they are automatically generated without subsequent checking. Our pipeline provides a conservative estimate of a species' area of occupancy, within an area slightly larger than its extent of occurrence, compatible to e.g. IUCN red list assessments.

Published
2018
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19. Estimating and interpreting migration of Amazonian forests using spatially implicit and semi-explicit neutral models.

Author

Pos E, Guevara Andino JE, Sabatier D, Molino JF, Pitman N, Mogollón H, Neill D, Cerón C, Rivas-Torres G, Di Fiore A, Thomas R, Tirado M, Young KR, Wang O, Sierra R, García-Villacorta R, Zagt R, Palacios Cuenca W, Aulestia M, and Ter Steege H

Abstract

With many sophisticated methods available for estimating migration, ecologists face the difficult decision of choosing for their specific line of work. Here we test and compare several methods, performing sanity and robustness tests, applying to large-scale data and discussing the results and interpretation. Five methods were selected to compare for their ability to estimate migration from spatially implicit and semi-explicit simulations based on three large-scale field datasets from South America (Guyana, Suriname, French Guiana and Ecuador). Space was incorporated semi-explicitly by a discrete probability mass function for local recruitment, migration from adjacent plots or from a metacommunity. Most methods were able to accurately estimate migration from spatially implicit simulations. For spatially semi-explicit simulations, estimation was shown to be the additive effect of migration from adjacent plots and the metacommunity. It was only accurate when migration from the metacommunity outweighed that of adjacent plots, discrimination, however, proved to be impossible. We show that migration should be considered more an approximation of the resemblance between communities and the summed regional species pool. Application of migration estimates to simulate field datasets did show reasonably good fits and indicated consistent differences between sets in comparison with earlier studies. We conclude that estimates of migration using these methods are more an approximation of the homogenization among local communities over time rather than a direct measurement of migration and hence have a direct relationship with beta diversity. As betadiversity is the result of many (non)-neutral processes, we have to admit that migration as estimated in a spatial explicit world encompasses not only direct migration but is an ecological aggregate of these processes. The parameter m of neutral models then appears more as an emerging property revealed by neutral theory instead of being an effective mechanistic parameter and spatially implicit models should be rejected as an approximation of forest dynamics.

Published
2017
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20. Are all species necessary to reveal ecologically important patterns?

Author

Pos E, Guevara Andino JE, Sabatier D, Molino JF, Pitman N, Mogollón H, Neill D, Cerón C, Rivas G, Di Fiore A, Thomas R, Tirado M, Young KR, Wang O, Sierra R, García-Villacorta R, Zagt R, Palacios W, Aulestia M, and Ter Steege H

Abstract

While studying ecological patterns at large scales, ecologists are often unable to identify all collections, forcing them to either omit these unidentified records entirely, without knowing the effect of this, or pursue very costly and time-consuming efforts for identifying them. These "indets" may be of critical importance, but as yet, their impact on the reliability of ecological analyses is poorly known. We investigated the consequence of omitting the unidentified records and provide an explanation for the results. We used three large-scale independent datasets, (Guyana/ Suriname, French Guiana, Ecuador) each consisting of records having been identified to a valid species name (identified morpho-species - IMS) and a number of unidentified records (unidentified morpho-species - UMS). A subset was created for each dataset containing only the IMS, which was compared with the complete dataset containing all morpho-species (AMS: = IMS + UMS) for the following analyses: species diversity (Fisher's alpha), similarity of species composition, Mantel test and ordination (NMDS). In addition, we also simulated an even larger number of unidentified records for all three datasets and analyzed the agreement between similarities again with these simulated datasets. For all analyses, results were extremely similar when using the complete datasets or the truncated subsets. IMS predicted ≥91% of the variation in AMS in all tests/analyses. Even when simulating a larger fraction of UMS, IMS predicted the results for AMS rather well. Using only IMS also out-performed using higher taxon data (genus-level identification) for similarity analyses. Finding a high congruence for all analyses when using IMS rather than AMS suggests that patterns of similarity and composition are very robust. In other words, having a large number of unidentified species in a dataset may not affect our conclusions as much as is often thought.

Published
2014
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