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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 ∼73,000 tree species globally, among which ∼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.
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2
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Kerr MR, Alroy J. Marine diversity patterns in Australia are filtered through biogeography. Proc Biol Sci 2021; 288:20211534. [PMID: 34753352 PMCID: PMC8580438 DOI: 10.1098/rspb.2021.1534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/19/2021] [Indexed: 11/12/2022] Open
Abstract
Latitudinal diversity gradients are among the most striking patterns in nature. Despite a large body of work investigating both geographic and environmental drivers, biogeographical provinces have not been included in statistical models of diversity patterns. Instead, spatial studies tend to focus on species-area and local-regional relationships. Here, we investigate correlates of a latitudinal diversity pattern in Australian coastal molluscs. We use an online database of greater than 300 000 specimens and quantify diversity using four methods to account for sampling variation. Additionally, we present a biogeographic scheme using factor analysis that allows for both gradients and sharp boundaries between clusters. The factors are defined on the basis of species composition and are independent of diversity. Regardless of the measure used, diversity is not directly explained by combinations of abiotic variables. Instead, transitions between regions better explain the observed patterns. Biogeographic gradients can in turn be explained by environmental variables, suggesting that environmental controls on diversity may be indirect. Faunas within provinces are homogeneous regardless of environmental variability. Thus, transitions between provinces explain most of the variation in diversity because small-scale factors are dampened. This explanation contrasts with the species-energy hypothesis. Future work should more carefully consider biogeographic gradients when investigating diversity patterns.
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Affiliation(s)
- Matthew R. Kerr
- Centre for Environment, Fisheries and Aquaculture Science, Lowestoft NR33 0HT, UK
| | - John Alroy
- Department of Biological Sciences, Macquarie University, Sydney 2109, Australia
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3
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Kuyper TW. Networks of friends and foes and the fate of tree seedlings. THE NEW PHYTOLOGIST 2021; 230:1688-1689. [PMID: 33843064 DOI: 10.1111/nph.17337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Thomas W Kuyper
- Soil Biology Group, Wageningen University & Research, PO Box 47, Wageningen, 6700 AA, the Netherlands
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4
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Dietzel A, Bode M, Connolly SR, Hughes TP. The population sizes and global extinction risk of reef-building coral species at biogeographic scales. Nat Ecol Evol 2021; 5:663-669. [PMID: 33649542 DOI: 10.1038/s41559-021-01393-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 01/14/2021] [Indexed: 01/31/2023]
Abstract
Knowledge of a species' abundance is critically important for assessing its risk of extinction, but for the vast majority of wild animal and plant species such data are scarce at biogeographic scales. Here, we estimate the total number of reef-building corals and the population sizes of more than 300 individual species on reefs spanning the Pacific Ocean biodiversity gradient, from Indonesia to French Polynesia. Our analysis suggests that approximately half a trillion corals (0.3 × 1012-0.8 × 1012) inhabit these coral reefs, similar to the number of trees in the Amazon. Two-thirds of the examined species have population sizes exceeding 100 million colonies, and one-fifth of the species even have population sizes greater than 1 billion colonies. Our findings suggest that, while local depletions pose imminent threats that can have ecologically devastating impacts to coral reefs, the global extinction risk of most coral species is lower than previously estimated.
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Affiliation(s)
- Andreas Dietzel
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.
| | - Michael Bode
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.,School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Sean R Connolly
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.,College of Science and Engineering, James Cook University, Townsville, Queensland, Australia.,Smithsonian Tropical Research Institute, Balboa, Republic of Panama
| | - Terry P Hughes
- ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia
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5
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Ter Steege H, Sabatier D, Mota de Oliveira S, Magnusson WE, Molino JF, Gomes VF, Pos ET, Salomão RP. Estimating species richness in hyper-diverse large tree communities. Ecology 2018; 98:1444-1454. [PMID: 28419434 DOI: 10.1002/ecy.1813] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 01/24/2017] [Accepted: 03/03/2017] [Indexed: 11/09/2022]
Abstract
Species richness estimation is one of the most widely used analyses carried out by ecologists, and nonparametric estimators are probably the most used techniques to carry out such estimations. We tested the assumptions and results of nonparametric estimators and those of a logseries approach to species richness estimation for simulated tropical forests and five data sets from the field. We conclude that nonparametric estimators are not suitable to estimate species richness in tropical forests, where sampling intensity is usually low and richness is high, because the assumptions of the methods do not meet the sampling strategy used in most studies. The logseries, while also requiring substantial sampling, is much more effective in estimating species richness than commonly used nonparametric estimators, and its assumptions better match the way field data is being collected.
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Affiliation(s)
- Hans Ter Steege
- Naturalis Biodiversity Center, Leiden, The Netherlands.,Museu Paraense Emílio Goeldi, Belem, Para, Brazil.,Systems Ecology, Free University Amsterdam, Amsterdam, The Netherlands
| | - Daniel Sabatier
- AMAP, IRD, Cirad, CNRS, INRA, Université de Montpellier, Montpellier, France
| | | | | | | | | | - Edwin T Pos
- Naturalis Biodiversity Center, Leiden, The Netherlands.,Ecology & Biodiversity Group, Department of Biology, Utrecht University, Utrecht, The Netherlands
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6
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Campos-Sánchez E, González-Espinosa M, Ramírez-Marcial N, Navarrete-Gutiérrez DA, Pérez-Farrera MÁ. Riqueza de especies arbóreas en bosques de montaña de Chiapas: estimaciones a partir de datos de herbarios e inventarios florísticos. REV MEX BIODIVERS 2017. [DOI: 10.1016/j.rmb.2017.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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7
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Chen Y, Shen TJ. Rarefaction and extrapolation of species richness using an area-based Fisher's logseries. Ecol Evol 2017; 7:10066-10078. [PMID: 29238537 PMCID: PMC5723611 DOI: 10.1002/ece3.3509] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 09/03/2017] [Accepted: 09/16/2017] [Indexed: 11/07/2022] Open
Abstract
Fisher's logseries is widely used to characterize species abundance pattern, and some previous studies used it to predict species richness. However, this model, derived from the negative binomial model, degenerates at the zero‐abundance point (i.e., its probability mass fully concentrates at zero abundance, leading to an odd situation that no species can occur in the studied sample). Moreover, it is not directly related to the sampling area size. In this sense, the original Fisher's alpha (correspondingly, species richness) is incomparable among ecological communities with varying area sizes. To overcome these limitations, we developed a novel area‐based logseries model that can account for the compounding effect of the sampling area. The new model can be used to conduct area‐based rarefaction and extrapolation of species richness, with the advantage of accurately predicting species richness in a large region that has an area size being hundreds or thousands of times larger than that of a locally observed sample, provided that data follow the proposed model. The power of our proposed model has been validated by extensive numerical simulations and empirically tested through tree species richness extrapolation and interpolation in Brazilian Atlantic forests. Our parametric model is data parsimonious as it is still applicable when only the information on species number, community size, or the numbers of singleton and doubleton species in the local sample is available. Notably, in comparison with the original Fisher's method, our area‐based model can provide asymptotically unbiased variance estimation (therefore correct 95% confidence interval) for species richness. In conclusion, the proposed area‐based Fisher's logseries model can be of broad applications with clear and proper statistical background. Particularly, it is very suitable for being applied to hyperdiverse ecological assemblages in which nonparametric richness estimators were found to greatly underestimate species richness.
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Affiliation(s)
- Youhua Chen
- Department of Renewable Resources University of Alberta Edmonton AB Canada.,Chengdu Institute of Biology Chinese Academy of Sciences Chengdu China
| | - Tsung-Jen Shen
- Institute of Statistics & Department of Applied Mathematics National Chung Hsing University Taichung Taiwan
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8
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Tovo A, Suweis S, Formentin M, Favretti M, Volkov I, Banavar JR, Azaele S, Maritan A. Upscaling species richness and abundances in tropical forests. SCIENCE ADVANCES 2017; 3:e1701438. [PMID: 29057324 PMCID: PMC5647133 DOI: 10.1126/sciadv.1701438] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/20/2017] [Indexed: 06/07/2023]
Abstract
The quantification of tropical tree biodiversity worldwide remains an open and challenging problem. More than two-fifths of the number of worldwide trees can be found either in tropical or in subtropical forests, but only ≈0.000067% of species identities are known. We introduce an analytical framework that provides robust and accurate estimates of species richness and abundances in biodiversity-rich ecosystems, as confirmed by tests performed on both in silico-generated and real forests. Our analysis shows that the approach outperforms other methods. In particular, we find that upscaling methods based on the log-series species distribution systematically overestimate the number of species and abundances of the rare species. We finally apply our new framework on 15 empirical tropical forest plots and quantify the minimum percentage cover that should be sampled to achieve a given average confidence interval in the upscaled estimate of biodiversity. Our theoretical framework confirms that the forests studied are comprised of a large number of rare or hyper-rare species. This is a signature of critical-like behavior of species-rich ecosystems and can provide a buffer against extinction.
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Affiliation(s)
- Anna Tovo
- Dipartimento di Matematica “Tullio Levi-Civita,” Università di Padova, Via Trieste 63, 35121 Padova, Italy
| | - Samir Suweis
- Dipartimento di Fisica e Astronomia, “Galileo Galilei,” Istituto Nazionale di Fisica Nucleare, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
| | - Marco Formentin
- Dipartimento di Matematica “Tullio Levi-Civita,” Università di Padova, Via Trieste 63, 35121 Padova, Italy
| | - Marco Favretti
- Dipartimento di Matematica “Tullio Levi-Civita,” Università di Padova, Via Trieste 63, 35121 Padova, Italy
| | - Igor Volkov
- Department of Physics, University of Maryland, College Park, MD 20742, USA
| | - Jayanth R. Banavar
- Department of Physics, University of Maryland, College Park, MD 20742, USA
- Department of Physics, University of Oregon, Eugene, OR 97403, USA
| | - Sandro Azaele
- Department of Applied Mathematics, School of Mathematics, University of Leeds, Leeds LS2 9JT, UK
| | - Amos Maritan
- Dipartimento di Fisica e Astronomia, “Galileo Galilei,” Istituto Nazionale di Fisica Nucleare, Università di Padova, Via Marzolo 8, 35131 Padova, Italy
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9
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Sosef MSM, Dauby G, Blach-Overgaard A, van der Burgt X, Catarino L, Damen T, Deblauwe V, Dessein S, Dransfield J, Droissart V, Duarte MC, Engledow H, Fadeur G, Figueira R, Gereau RE, Hardy OJ, Harris DJ, de Heij J, Janssens S, Klomberg Y, Ley AC, Mackinder BA, Meerts P, van de Poel JL, Sonké B, Stévart T, Stoffelen P, Svenning JC, Sepulchre P, Zaiss R, Wieringa JJ, Couvreur TLP. Exploring the floristic diversity of tropical Africa. BMC Biol 2017; 15:15. [PMID: 28264718 PMCID: PMC5339970 DOI: 10.1186/s12915-017-0356-8] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/25/2017] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Understanding the patterns of biodiversity distribution and what influences them is a fundamental pre-requisite for effective conservation and sustainable utilisation of biodiversity. Such knowledge is increasingly urgent as biodiversity responds to the ongoing effects of global climate change. Nowhere is this more acute than in species-rich tropical Africa, where so little is known about plant diversity and its distribution. In this paper, we use RAINBIO - one of the largest mega-databases of tropical African vascular plant species distributions ever compiled - to address questions about plant and growth form diversity across tropical Africa. RESULTS The filtered RAINBIO dataset contains 609,776 georeferenced records representing 22,577 species. Growth form data are recorded for 97% of all species. Records are well distributed, but heterogeneous across the continent. Overall, tropical Africa remains poorly sampled. When using sampling units (SU) of 0.5°, just 21 reach appropriate collection density and sampling completeness, and the average number of records per species per SU is only 1.84. Species richness (observed and estimated) and endemism figures per country are provided. Benin, Cameroon, Gabon, Ivory Coast and Liberia appear as the botanically best-explored countries, but none are optimally explored. Forests in the region contain 15,387 vascular plant species, of which 3013 are trees, representing 5-7% of the estimated world's tropical tree flora. The central African forests have the highest endemism rate across Africa, with approximately 30% of species being endemic. CONCLUSIONS The botanical exploration of tropical Africa is far from complete, underlining the need for intensified inventories and digitization. We propose priority target areas for future sampling efforts, mainly focused on Tanzania, Atlantic Central Africa and West Africa. The observed number of tree species for African forests is smaller than those estimated from global tree data, suggesting that a significant number of species are yet to be discovered. Our data provide a solid basis for a more sustainable management and improved conservation of tropical Africa's unique flora, and is important for achieving Objective 1 of the Global Strategy for Plant Conservation 2011-2020. In turn, RAINBIO provides a solid basis for a more sustainable management and improved conservation of tropical Africa's unique flora.
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Affiliation(s)
- Marc S M Sosef
- Botanic Garden Meise, Nieuwelaan 38, BE-1860, Meise, Belgium.
| | - Gilles Dauby
- DIADE, Université Montpellier, IRD, Montpellier, France
- Laboratoire d'Évolution biologique et Écologie, Faculté des Sciences, Université Libre de Bruxelles, Brussels, Belgium
- CESAB/FRB, Domaine du Petit Arbois, Av. Louis Philibert, Aix-en-Provence, 13100, France
| | - Anne Blach-Overgaard
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, DK-8000, Aarhus C, Denmark
| | | | - Luís Catarino
- Centre for Ecology, Evolution and Environmental Changes (CE3C), Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016, Lisbon, Portugal
| | - Theo Damen
- Wageningen University, Biosystematics Group, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Vincent Deblauwe
- DIADE, Université Montpellier, IRD, Montpellier, France
- Herbarium et Bibliothèque de Botanique Africaine, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050, Bruxelles, Belgium
- Laboratoire de Botanique systématique et d'Écologie, Département des Sciences Biologiques, École Normale Supérieure, Université de Yaoundé I, Yaoundé, Cameroon
- Center for Tropical Research, Institute of the Environment and Sustainability, University of California, Los Angeles, Box 951496, Los Angeles, CA, 90095, USA
- International Institute of Tropical Agriculture, BP 2008 (Messa), Yaounde, Cameroon
| | - Steven Dessein
- Botanic Garden Meise, Nieuwelaan 38, BE-1860, Meise, Belgium
| | | | - Vincent Droissart
- Herbarium et Bibliothèque de Botanique Africaine, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050, Bruxelles, Belgium
- Missouri Botanical Garden, Africa & Madagascar Department, P.O. Box 299, St. Louis, Missouri, 63166-0299, USA
- AMAP, CNRS, INRA, IRD, Université Montpellier, Montpellier, France
| | - Maria Cristina Duarte
- Centre for Ecology, Evolution and Environmental Changes (CE3C), Faculty of Sciences, University of Lisbon, Campo Grande, 1749-016, Lisbon, Portugal
| | - Henry Engledow
- Botanic Garden Meise, Nieuwelaan 38, BE-1860, Meise, Belgium
| | - Geoffrey Fadeur
- Herbarium et Bibliothèque de Botanique Africaine, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050, Bruxelles, Belgium
| | - Rui Figueira
- CIBIO/InBio, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto, Campus Agrário de Vairão, Vairão, Portugal
- CEABN/InBio, Centro de Ecologia Aplicada "Professor Baeta Neves", Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017, Lisboa, Portugal
| | - Roy E Gereau
- Missouri Botanical Garden, Africa & Madagascar Department, P.O. Box 299, St. Louis, Missouri, 63166-0299, USA
| | - Olivier J Hardy
- Laboratoire d'Évolution biologique et Écologie, Faculté des Sciences, Université Libre de Bruxelles, Brussels, Belgium
| | - David J Harris
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, UK
| | - Janneke de Heij
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, The Netherlands
- Picturae, De Droogmakerij 12, 1851LX, Heiloo, The Netherlands
| | - Steven Janssens
- Botanic Garden Meise, Nieuwelaan 38, BE-1860, Meise, Belgium
| | - Yannick Klomberg
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, The Netherlands
- Department of Ecology, Faculty of Science, Charles University, Vinicna 7, 128 44, Prague 2, Czech Republic
| | - Alexandra C Ley
- Institut für Geobotanik und Botanischer Garten, Im Neuwerk 21, University Halle-Wittenberg, 06108, Halle (Saale), Germany
| | - Barbara A Mackinder
- Royal Botanic Gardens, Kew, Richmond, Surrey, TW9 3AE, UK
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, UK
| | - Pierre Meerts
- Herbarium et Bibliothèque de Botanique Africaine, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050, Bruxelles, Belgium
- Laboratoire d'Ecologie végétale et Biogéochimie, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050, Bruxelles, Belgium
| | - Jeike L van de Poel
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, The Netherlands
| | - Bonaventure Sonké
- Laboratoire de Botanique systématique et d'Écologie, Département des Sciences Biologiques, École Normale Supérieure, Université de Yaoundé I, Yaoundé, Cameroon
| | - Tariq Stévart
- Botanic Garden Meise, Nieuwelaan 38, BE-1860, Meise, Belgium
- Herbarium et Bibliothèque de Botanique Africaine, Université Libre de Bruxelles, Boulevard du Triomphe, B-1050, Bruxelles, Belgium
- Missouri Botanical Garden, Africa & Madagascar Department, P.O. Box 299, St. Louis, Missouri, 63166-0299, USA
| | - Piet Stoffelen
- Botanic Garden Meise, Nieuwelaan 38, BE-1860, Meise, Belgium
| | - Jens-Christian Svenning
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, Ny Munkegade 114, DK-8000, Aarhus C, Denmark
| | - Pierre Sepulchre
- Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, F-91191, Gif-sur-Yvette, France
| | - Rainer Zaiss
- AMAP, CNRS, INRA, IRD, Université Montpellier, Montpellier, France
| | - Jan J Wieringa
- Wageningen University, Biosystematics Group, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, The Netherlands
| | - Thomas L P Couvreur
- DIADE, Université Montpellier, IRD, Montpellier, France.
- Laboratoire de Botanique systématique et d'Écologie, Département des Sciences Biologiques, École Normale Supérieure, Université de Yaoundé I, Yaoundé, Cameroon.
- Naturalis Biodiversity Center, Darwinweg 2, 2333 CR, Leiden, The Netherlands.
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Shem-Tov Y, Danino M, Shnerb NM. Solution of the spatial neutral model yields new bounds on the Amazonian species richness. Sci Rep 2017; 7:42415. [PMID: 28209969 PMCID: PMC5314346 DOI: 10.1038/srep42415] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 01/10/2017] [Indexed: 11/09/2022] Open
Abstract
Neutral models, in which individual agents with equal fitness undergo a birth-death-mutation process, are very popular in population genetics and community ecology. Usually these models are applied to populations and communities with spatial structure, but the analytic results presented so far are limited to well-mixed or mainland-island scenarios. Here we combine analytic results and numerics to obtain an approximate solution for the species abundance distribution and the species richness for the neutral model on continuous landscape. We show how the regional diversity increases when the recruitment length decreases and the spatial segregation of species grows. Our results are supported by extensive numerical simulations and allow one to probe the numerically inaccessible regime of large-scale systems with extremely small mutation/speciation rates. Model predictions are compared with the findings of recent large-scale surveys of tropical trees across the Amazon basin, yielding new bounds for the species richness (between 13100 and 15000) and the number of singleton species (between 455 and 690).
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Affiliation(s)
- Yahav Shem-Tov
- Department of Physics, Bar-Ilan University, Ramat-Gan IL52900, Israel
| | - Matan Danino
- Department of Physics, Bar-Ilan University, Ramat-Gan IL52900, Israel
| | - Nadav M Shnerb
- Department of Physics, Bar-Ilan University, Ramat-Gan IL52900, Israel
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11
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Sfair JC, Arroyo-Rodríguez V, Santos BA, Tabarelli M. Taxonomic and functional divergence of tree assemblages in a fragmented tropical forest. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1816-1826. [PMID: 27755700 DOI: 10.1890/15-1673.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/20/2015] [Accepted: 12/18/2015] [Indexed: 06/06/2023]
Abstract
Tropical forests are being exposed to increasing levels of habitat loss and fragmentation, threatening the maintenance of global biodiversity. However, the effect that land-use change may have on the spatial dissimilarities in taxonomic and functional composition of remaining assemblages (i.e., taxonomic/functional β-diversity) remains poorly understood. We examined a large vegetation database from an old and severely fragmented Atlantic forest landscape to test two alternative hypotheses: (1) tree assemblages experience a taxonomic and functional homogenization (reduced β-diversity) between forest fragments and along forest edges, or alternatively, (2) these edge-affected forests show increased taxonomic and functional differentiation (increased β-diversity) when compared to forest interior (reference) stands. Taxonomic and functional β-diversity were examined via novel abundance-based metrics and considering functional traits related to plant dispersion, recruitment, and growth. Overall, taxonomic β-diversity among fragments was significantly higher than among edge and reference plots. Edge plots also showed higher β-diversity than reference plots, but only when considering dominant species. In functional terms, β-diversity among reference plots was also lower than among forest fragments and among edge plots. These patterns support the landscape-divergence hypothesis, which postulates that variable human disturbances among forest fragments and along forest edges can lead to contrasting trajectories of vegetation changes, thus increasing the compositional and functional differentiation of tree communities in these emerging environments. Our results also show that such differentiation can preserve landscape-wide biodiversity, thus overriding negative effects of habitat fragmentation on local (α) diversity. Therefore, our findings demonstrate that forest fragments and forest edges can be more valuable for maintaining species diversity and ecosystem function in fragmented tropical landscapes than previously thought.
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Affiliation(s)
- Julia C Sfair
- Departamento de Botânica, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil.
| | - Víctor Arroyo-Rodríguez
- Instituto de Investigaciones en Ecosistemas y Sustentabilidad, Universidad Nacional Autónoma de México, 58190, Morelia, Michoacán, Mexico
| | - Bráulio A Santos
- Departamento de Sistemática e Ecologia, Universidade Federal da Paraíba, João Pessoa, PB, 58051-900, Brazil
| | - Marcelo Tabarelli
- Departamento de Botânica, Universidade Federal de Pernambuco, Recife, PE, 50670-901, Brazil
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12
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ter Steege H, Vaessen RW, Cárdenas-López D, Sabatier D, Antonelli A, de Oliveira SM, Pitman NCA, Jørgensen PM, Salomão RP. The discovery of the Amazonian tree flora with an updated checklist of all known tree taxa. Sci Rep 2016; 6:29549. [PMID: 27406027 PMCID: PMC4942782 DOI: 10.1038/srep29549] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/17/2016] [Indexed: 11/15/2022] Open
Abstract
Amazonia is the most biodiverse rainforest on Earth, and the debate over how many tree species grow there remains contentious. Here we provide a checklist of all tree species collected to date, and describe spatial and temporal trends in data accumulation. We report 530,025 unique collections of trees in Amazonia, dating between 1707 and 2015, for a total of 11,676 species in 1225 genera and 140 families. These figures support recent estimates of 16,000 total Amazonian tree species based on ecological plot data from the Amazonian Tree Diversity Network. Botanical collection in Amazonia is characterized by three major peaks, centred around 1840, 1920, and 1980, which are associated with flora projects and the establishment of inventory plots. Most collections were made in the 20th century. The number of collections has increased exponentially, but shows a slowdown in the last two decades. We find that a species' range size is a better predictor of the number of times it has been collected than the species' estimated basin-wide population size. Finding, describing, and documenting the distribution of the remaining species will require coordinated efforts at under-collected sites.
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Affiliation(s)
- Hans ter Steege
- Naturalis Biodiversity Center, Vondellaan 55, Postbus 9517, 2300 RA Leiden, The Netherlands
- Coordenação de Botânica, Museu Paraense Emílio Goeldi, Av. Magalhães Barata 376, C.P. 399, Belém, PA 66040–170, Brazil
| | - Rens W. Vaessen
- Naturalis Biodiversity Center, Vondellaan 55, Postbus 9517, 2300 RA Leiden, The Netherlands
| | - Dairon Cárdenas-López
- Herbario Amazónico Colombiano, Instituto SINCHI, Calle 20 No 5-44, Bogotá, DF, Colombia
| | - Daniel Sabatier
- Institut de Recherche pour le Développement (IRD, UMR AMAP), TA A-51/PS2, Bd. de la Lironde, 34398 Montpellier cedex 5, France
| | - Alexandre Antonelli
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 461, SE-405 30 Göteborg, Sweden
- Gothenburg Botanical Garden, Carl Skottsbergs gata 22A, SE-413 19, Göteborg, Sweden
| | | | - Nigel C. A. Pitman
- Science and Education, The Field Museum, 1400 S. Lake Shore Drive, Chicago, IL 60605–2496, USA
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27705, USA
| | | | - Rafael P. Salomão
- Coordenação de Botânica, Museu Paraense Emílio Goeldi, Av. Magalhães Barata 376, C.P. 399, Belém, PA 66040–170, Brazil
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