1
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Sigdel SR, Zheng X, Babst F, Camarero JJ, Gao S, Li X, Lu X, Pandey J, Dawadi B, Sun J, Zhu H, Wang T, Liang E, Peñuelas J. Accelerated succession in Himalayan alpine treelines under climatic warming. NATURE PLANTS 2024; 10:1909-1918. [PMID: 39558135 DOI: 10.1038/s41477-024-01855-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 10/18/2024] [Indexed: 11/20/2024]
Abstract
Understanding how climate change influences succession is fundamental for predicting future forest composition. Warming is expected to accelerate species succession at their cold thermal ranges, such as alpine treelines. Here we examined how interactions and successional strategies of the early-successional birch (Betula utilis) and the late-successional fir (Abies spectabilis) affected treeline dynamics by combining plot data with an individual-based treeline model at treelines in the central Himalayas. Fir showed increasing recruitment and a higher upslope shift rate (0.11 ± 0.02 m yr-1) compared with birch (0.06 ± 0.03 m yr-1) over the past 200 years. Spatial analyses indicate strong interspecies competition when trees were young. Model outputs from various climatic scenarios indicate that fir will probably accelerate its upslope movement with warming, while birch recruitment will decline drastically, forming stable or even retreating treelines. Our findings point to accelerating successional dynamics with late-successional species rapidly outcompeting pioneer species, offering insight into future forest succession and its influences on ecosystem services.
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Affiliation(s)
- Shalik Ram Sigdel
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Xiangyu Zheng
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Flurin Babst
- School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ, USA
| | | | - Shan Gao
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Xiaoxia Li
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Xiaoming Lu
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Jayram Pandey
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Binod Dawadi
- Central Department of Hydrology and Meteorology, Tribhuvan University, Kathmandu, Nepal
| | - Jian Sun
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Haifeng Zhu
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Tao Wang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
| | - Eryuan Liang
- State Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China.
| | - Josep Peñuelas
- CREAF, Barcelona, Spain
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Barcelona, Spain
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2
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LaManna JA, Hartig F, Myers JA, Freckleton RP, Detto M, Surendra A, Doolittle CJ, Bachelot B, Bagchi R, Comita LS, DeFilippis DM, Huanca-Nunez N, Hülsmann L, Jevon FV, Johnson DJ, Krishnadas M, Magee LJ, Mangan SA, Milici VR, Murengera ALB, Schnitzer SA, Smith DJB, Stein C, Sullivan MK, Torres E, Umaña MN, Delavaux CS. Consequences of Local Conspecific Density Effects for Plant Diversity and Community Dynamics. Ecol Lett 2024; 27:e14506. [PMID: 39354892 DOI: 10.1111/ele.14506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 08/05/2024] [Accepted: 08/11/2024] [Indexed: 10/03/2024]
Abstract
Conspecific density dependence (CDD) in plant populations is widespread, most likely caused by local-scale biotic interactions, and has potentially important implications for biodiversity, community composition, and ecosystem processes. However, progress in this important area of ecology has been hindered by differing viewpoints on CDD across subfields in ecology, lack of synthesis across CDD-related frameworks, and misunderstandings about how empirical measurements of local CDD fit within the context of broader ecological theories on community assembly and diversity maintenance. Here, we propose a conceptual synthesis of local-scale CDD and its causes, including species-specific antagonistic and mutualistic interactions. First, we compare and clarify different uses of CDD and related concepts across subfields within ecology. We suggest the use of local stabilizing/destabilizing CDD to refer to the scenario where local conspecific density effects are more negative/positive than heterospecific effects. Second, we discuss different mechanisms for local stabilizing and destabilizing CDD, how those mechanisms are interrelated, and how they cut across several fields of study within ecology. Third, we place local stabilizing/destabilizing CDD within the context of broader ecological theories and discuss implications and challenges related to scaling up the effects of local CDD on populations, communities, and metacommunities. The ultimate goal of this synthesis is to provide a conceptual roadmap for researchers studying local CDD and its implications for population and community dynamics.
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Affiliation(s)
- Joseph A LaManna
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Florian Hartig
- Theoretical Ecology, University of Regensburg, Regensburg, Germany
| | - Jonathan A Myers
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Robert P Freckleton
- Ecology and Evolutionary Biology, School of Biosciences, University of Sheffield, Sheffield, UK
| | - Matteo Detto
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Akshay Surendra
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Cole J Doolittle
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Bénédicte Bachelot
- Department of Plant Biology, Ecology, and Evolution, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Robert Bagchi
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Liza S Comita
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | - David M DeFilippis
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | | | - Lisa Hülsmann
- Ecosystem Analysis and Simulation (EASI) Lab, University of Bayreuth, Bayreuth, Germany
- Bayreuth Center of Ecology and Environmental Research (BayCEER), University of Bayreuth, Bayreuth, Germany
| | - Fiona V Jevon
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Daniel J Johnson
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, Florida, USA
| | - Meghna Krishnadas
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Lukas J Magee
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, Florida, USA
| | - Scott A Mangan
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, Arkansas, USA
| | - Valerie R Milici
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA
| | | | - Stefan A Schnitzer
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - Daniel J B Smith
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona, USA
| | - Claudia Stein
- Department of Biology and Environmental Sciences, Auburn University at Montgomery, Montgomery, Alabama, USA
| | - Megan K Sullivan
- School of the Environment, Yale University, New Haven, Connecticut, USA
| | - Ethan Torres
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
| | - María Natalia Umaña
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Camille S Delavaux
- Institute of Integrative Biology, ETH Zurich (Swiss Federal Institute of Technology), Zurich, Switzerland
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3
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Song X, Katabuchi M, Chase JM, Johnson DJ, Zhang W, Deng X, Cao M, Yang J. Drought tolerance and species abundance mediate dry season negative density dependence in a tropical forest. Ecology 2024; 105:e4382. [PMID: 39056489 DOI: 10.1002/ecy.4382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 04/10/2024] [Accepted: 05/20/2024] [Indexed: 07/28/2024]
Abstract
Conspecific negative density dependence (CNDD) is thought to be a key process in maintaining plant diversity. However, the strength of CNDD is highly variable in space and time as well as among species, and correlates of this variation that might help to understand and explain it remain largely unquantified. Using Bayesian hierarchical models, we took advantage of 10-year seedling monitoring data that were collected annually in every dry and rainy season in a seasonal tropical forest. We quantified the interspecific variation in the strength of CNDD and its temporal variation. We also examined potential correlates of this interspecific and temporal variation, including species functional traits (such as drought-tolerant traits, defense-related traits, and recourse acquisition traits) and species abundances. In the dry season, we found a negative relationship between the density of neighboring conspecific seedlings on seedling survival, while in the rainy season, there was a negative relationship between the density of neighboring conspecific adults on seedling survival. In addition, we found that interspecific variation in CNDD was related to drought-tolerant traits in the dry season but not in the rainy season. Across years, we found that drought-intolerant species suffer less CNDD during the dry seasons that have higher rainfall, whereas drought-tolerant species suffer less CNDD when the dry season has lower rainfall. We also found that rare species suffered stronger CNDD in the dry season. Overall, our study highlights that CNDD is highly variable among species and through time, necessitating a deeper appreciation of the environmental and functional contexts of CNDD and their interactions.
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Affiliation(s)
- Xiaoyang Song
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Masatoshi Katabuchi
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Jonathan M Chase
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Daniel J Johnson
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, Florida, USA
| | - Wenfu Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Xiaobao Deng
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Min Cao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
| | - Jie Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan, China
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4
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Pak U, Guo Q, Liu Z, Wang X, Liu Y, Jin G. Spatial Distribution of Pinus koraiensis Trees and Community-Level Spatial Associations in Broad-Leaved Korean Pine Mixed Forests in Northeastern China. PLANTS (BASEL, SWITZERLAND) 2023; 12:2906. [PMID: 37631117 PMCID: PMC10459911 DOI: 10.3390/plants12162906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/28/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023]
Abstract
Investigating the spatial distributions and associations of tree populations provides better insights into the dynamics and processes that shape the forest community. Korean pine (Pinus koraiensis) is one of the most important tree species in broad-leaved Korean pine mixed forests (BKMFs), and little is known about the spatial point patterns of and associations between Korean pine and community-level woody species groups such as coniferous and deciduous trees in different developmental stages. This study investigated the spatial patterns of Korean pine (KP) trees and then analyzed how the spatial associations between KP trees and other tree species at the community level vary in different BKMFs. Extensive data collected from five relatively large sample plots, covering a substantial area within the natural distribution range of KP in northeastern China, were utilized. Uni- and bivariate pair correlation functions and mark correlation functions were applied to analyze spatial distribution patterns and spatial associations. The DBH (diameter at breast height) histogram of KP trees in northeastern China revealed that the regeneration process was very poor in the Changbai Mountain (CBS) plot, while the other four plots exhibited moderate or expanding population structures. KP trees were significantly aggregated at scales up to 10 m under the HPP null model, and the aggregation scales decreased with the increase in size classes. Positive or negative spatial associations were observed among different life stages of KP trees in different plots. The life history stages of the coniferous tree group showed positive spatial associations with KP saplings and juvenile trees at small scales, and spatial independence or negative correlations with larger KP trees at greater scales. All broad-leaved tree groups (canopy, middle, and understory layers) exhibited only slightly positive associations with KP trees at small scales, and dominant negative associations were observed at most scales. Our results demonstrate that mature KP trees have strong importance in the spatial patterns of KP populations, and site heterogeneity, limited seed dispersal, and interspecific competition characterize the spatial patterns of KP trees and community-level spatial associations with respect to KP trees, which can serve as a theoretical basis for the management and restoration of BKMFs in northeastern China.
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Affiliation(s)
- Unil Pak
- Center for Ecological Research, Northeast Forestry University, Harbin 150040, China; (U.P.); (Q.G.); (Z.L.)
| | - Qingxi Guo
- Center for Ecological Research, Northeast Forestry University, Harbin 150040, China; (U.P.); (Q.G.); (Z.L.)
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin 150040, China
| | - Zhili Liu
- Center for Ecological Research, Northeast Forestry University, Harbin 150040, China; (U.P.); (Q.G.); (Z.L.)
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin 150040, China
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
| | - Xugao Wang
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China;
| | - Yankun Liu
- Heilongjiang Forestry Engineering and Environment Institute, Harbin 150040, China;
- Key Laboratory of Forest Ecology and Forestry Ecological Engineering of Heilongjiang Province, Harbin 150040, China
| | - Guangze Jin
- Center for Ecological Research, Northeast Forestry University, Harbin 150040, China; (U.P.); (Q.G.); (Z.L.)
- Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education, Northeast Forestry University, Harbin 150040, China
- Northeast Asia Biodiversity Research Center, Northeast Forestry University, Harbin 150040, China
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5
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Dispersal success of a specialized tropical tree depends on complex interactions among diverse mammalian frugivores. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2022.e02312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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6
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Idbella M, Abd‐ElGawad AM, Mazzoleni S, Bonanomi G. Microclimate, soil chemistry, and microbiota fail to explain
Euphorbia dendroides
Janzen‐Connell
pattern in a shrubland. Ecosphere 2022. [DOI: 10.1002/ecs2.4296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Mohamed Idbella
- Department of Agricultural Sciences University of Naples Federico II Naples Italy
- Laboratory of Biosciences, Faculty of Sciences and Techniques Hassan II University Casablanca Morocco
| | - Ahmed M. Abd‐ElGawad
- Department of Botany, Faculty of Sciences Mansoura University Mansoura Egypt
- Plant Production Department, College of Food and Agriculture Sciences King Saud University Riyadh Saudi Arabia
| | - Stefano Mazzoleni
- Department of Agricultural Sciences University of Naples Federico II Naples Italy
- Task Force on Microbiome Studies University of Naples Federico II Naples Italy
| | - Giuliano Bonanomi
- Department of Agricultural Sciences University of Naples Federico II Naples Italy
- Task Force on Microbiome Studies University of Naples Federico II Naples Italy
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7
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Liu H, Liang M, Yang Q, Zhang J, Shen G, Zhang Z, Wang X. Responses of tree seedlings to understory filtering by the recalcitrant fern layer in a subtropical forest. FRONTIERS IN PLANT SCIENCE 2022; 13:1033731. [PMID: 36507462 PMCID: PMC9730283 DOI: 10.3389/fpls.2022.1033731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/07/2022] [Indexed: 06/17/2023]
Abstract
The recalcitrant understory fern layer is an important ecological filter for seedling regeneration, yet how the fern layer influences seedling regeneration dynamics remains unclear. Here we transplanted 576 seedlings of four dominant tree species, Castanopsis fargesii, Lithocarpus glaber, Schima superba and Hovenia acerba, to the treatments of Diplopterygium glaucum retention and removal under an evergreen broad-leaved forest in eastern China. We monitored the survival, growth and biomass data of these seedlings for 28 months, and then used generalized linear mixed models to evaluate the treatment effects on seedling survival, growth, biomass and root-shoot ratio. Our results showed that fern retention significantly inhibited the seedling establishment of all four species. During the seedling development stage, the seedling relative growth rate of L. glaber decreased under fern retention, which was not the case for the other three species. Root-shoot ratio of C. fargesii and L. glaber increased significantly under fern retention. Our findings provide new evidence of the filtering effect of a recalcitrant fern understory. Notably, we observed that the response of tree seedlings to the recalcitrant fern understory was more sensitive in the establishment stage. Finally, our work highlights that the filtering effect of the recalcitrant fern understory changes depending on the regeneration stages, and that shade-tolerant species, C. fargesii and L. glaber were even more affected by fern disturbed habitats, suggesting that effective management should attempt to curb forest fern outbreaks, thus unblocking forest recruitment.
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Affiliation(s)
- Heming Liu
- Tiantong National Station for Forest Ecosystem Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Mengfang Liang
- Department of ecology and climate, Shanxi Academy of Eco-Environmental Planning and Technology, Shanxi, China
| | - Qingsong Yang
- Tiantong National Station for Forest Ecosystem Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Jian Zhang
- Tiantong National Station for Forest Ecosystem Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Guochun Shen
- Tiantong National Station for Forest Ecosystem Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Zhenzhen Zhang
- Tiantong National Station for Forest Ecosystem Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
| | - Xihua Wang
- Tiantong National Station for Forest Ecosystem Research, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, China
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8
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Wang F, Mi X, Chen L, Xu W, Durka W, Swenson NG, Johnson DJ, Worthy SJ, Xue J, Zhu Y, Schmid B, Liang Y, Ma K. Differential impacts of adult trees on offspring and non-offspring recruits in a subtropical forest. SCIENCE CHINA. LIFE SCIENCES 2022; 65:1905-1913. [PMID: 36098896 DOI: 10.1007/s11427-021-2148-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
An important mechanism promoting species coexistence is conspecific negative density dependence (CNDD), which inhibits conspecific neighbors by accumulating host-specific enemies near adult trees. Natural enemies may be genotype-specific and regulate offspring dynamics more strongly than non-offspring, which is often neglected due to the difficulty in ascertaining genetic relatedness. Here, we investigated whether offspring and non-offspring of a dominant species, Castanopsis eyrei, suffered from different strength of CNDD based on parentage assignment in a subtropical forest. We found decreased recruitment efficiency (proxy of survival probability) of offspring compared with non-offspring near adult trees during the seedling-sapling transition, suggesting genotype-dependent interactions drive tree demographic dynamics. Furthermore, the genetic similarity between individuals of same cohort decreased in late life history stages, indicating genetic-relatedness-dependent tree mortality throughout ontogeny. Our results demonstrate that within-species genetic relatedness significantly affects the strength of CNDD, implying genotype-specific natural enemies may contribute to population dynamics in natural forests.
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Affiliation(s)
- Fang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiangcheng Mi
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Lei Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Wubing Xu
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstrasse 4, 04103, Leipzig, Germany
| | - Walter Durka
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Puschstrasse 4, 04103, Leipzig, Germany
- Department Community Ecology, Centre for Environmental Research-UFZ, Theodor-Lieser-Str. 4, Halle, 06120, Germany
| | - Nathan G Swenson
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana, 46556, USA
- University of Notre Dame Environmental Research Center, Land O'Lakes, Wisconsin, 54540, USA
| | - Daniel J Johnson
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, Florida, 32611, USA
| | - Samantha J Worthy
- Department of Biology, University of Maryland, College Park, Maryland, 20742, USA
| | - Jianhua Xue
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Yan Zhu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Bernhard Schmid
- Department of Geography, Remote Sensing Laboratories, University of Zürich, Zürich, CH-8006, Switzerland
- Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100085, China
| | - Yu Liang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
| | - Keping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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9
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Garzon‐Lopez CX, Barcenas EM, Ordoñez A, Jansen PA, Bohlman SA, Olff H. Recruitment limitation in three large‐seeded plant species in a tropical moist forest. Biotropica 2022. [DOI: 10.1111/btp.13063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Carol X. Garzon‐Lopez
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen The Netherlands
- Ecology and plant physiology group (Ecofiv) Universidad de los Andes Bogota Colombia
| | | | - Alejandro Ordoñez
- Section for Ecoinformatics and Biodiversity Department of Bioscience Aarhus University Aarhus C Denmark
- Department of Bioscience Centre for Biodiversity Dynamics in a Changing World (BIOCHANGE) Aarhus University Aarhus C Denmark
| | - Patrick A. Jansen
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen The Netherlands
- Smithsonian Tropical Research Institute Ancon Panama
- Department of Environmental Sciences Wageningen University Wageningen The Netherlands
| | - Stephanie A. Bohlman
- Smithsonian Tropical Research Institute Ancon Panama
- School of Forest, Fisheries and Geomatics Sciences University of Florida Gainesville Florida USA
| | - Han Olff
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences (GELIFES) University of Groningen Groningen The Netherlands
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10
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Huang T, Huang C, Lin Y, Sun I. Seedling survival simultaneously determined by conspecific, heterospecific, and phylogenetically related neighbors and habitat heterogeneity in a subtropical forest in Taiwan. Ecol Evol 2022; 12:e8525. [PMID: 35136563 PMCID: PMC8809428 DOI: 10.1002/ece3.8525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 12/08/2021] [Accepted: 12/14/2021] [Indexed: 01/31/2023] Open
Abstract
Density dependence and habitat heterogeneity have been recognized as important driving mechanisms that shape the patterns of seedling survival and promote species coexistence in species-rich forests. In this study, we evaluated the relative importance of density dependence by conspecific, heterospecific, and phylogenetically related neighbors and habitat heterogeneity on seedling survival in the Lienhuachih (LHC) Forest, a subtropical, evergreen forest in central Taiwan. Age-specific effects of different variables were also studied. We monitored the fates of 1,642 newly recruited seedlings of woody plants within a 25-ha Forest Dynamics Plot for 2 years. The effects of conspecific, heterospecific, and phylogenetically related neighbors and habitat heterogeneity on seedling survival were analyzed by generalized linear mixed models. Our results indicated that conspecific negative density dependence (CNDD) had a strong impact on seedling survival, and the effects of CNDD increased with seedling age. Heterospecific positive density dependence (HPDD) and phylogenetic positive density dependence (PPDD) had a significant influence on the survival of seedlings, and stronger HPDD and PPDD effects were detected for older seedlings. Furthermore, seedling survival differed among habitats significantly. Seedling survival was significantly higher in the plateau, high-slope, and low-slope habitats than in the valley. Overall, our results suggested that the effects of CNDD, HPDD, PPDD, and habitat heterogeneity influenced seedling survival simultaneously in the LHC subtropical forest, but their relative importance varied with seedling age. Such findings from our subtropical forest were slightly different from tropical forests, and these contrasting patterns may be attributed to differences in abiotic environments. These findings highlight the importance to incorporate phylogenetic relatedness, seedling age, and habitat heterogeneity when investigating the impacts of density dependence on seedling survival that may contribute to species coexistence in seedling communities.
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Affiliation(s)
- Teng‐He Huang
- Department of Life ScienceTunghai UniversityTaichungTaiwan
| | - Chun‐Lin Huang
- Department of BiologyNational Museum of Natural ScienceTaichungTaiwan
| | - Yi‐Ching Lin
- Department of Life ScienceTunghai UniversityTaichungTaiwan
| | - I‐Fang Sun
- Department of Natural Resources and Environmental StudiesNational Dong Hwa UniversityHualienTaiwan
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11
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Liu Y, He F. Warming intensifies soil pathogen negative feedback on a temperate tree. THE NEW PHYTOLOGIST 2021; 231:2297-2307. [PMID: 33891310 PMCID: PMC8456973 DOI: 10.1111/nph.17409] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 04/07/2021] [Indexed: 05/05/2023]
Abstract
The soil pathogen-induced Janzen-Connell (JC) effect is considered as a primary mechanism regulating plant biodiversity worldwide. As predicted by the framework of the classic plant disease triangle, severity of plant diseases is often influenced by temperature, yet insufficient understanding of how increasing temperatures affect the JC effect contributes uncertainty in predictions about how global warming affects biodiversity. We conducted a 3-yr field warming experiment, combining open-top chambers with pesticide treatment, to test the effect of elevated temperatures on seedling mortality of a temperate tree species, Prunus padus, from a genus with known susceptibility to soil-borne pathogens. Elevated temperature significantly increased the mortality of P. padus seedlings in the immediate vicinity of parent trees, concurrent with increased relative abundance of pathogenic fungi identified to be virulent to Prunus species. Our study offers experimental evidence suggesting that global warming significantly intensifies the JC effect on a temperate tree species due to increased relative abundance of pathogenic fungi. This work advances our understanding about changes in the JC effect linked to ongoing global warming, which has important implications for predicting tree diversity in a warmer future.
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Affiliation(s)
- Yu Liu
- ECNU‐Alberta Joint Laboratory for Biodiversity StudyTiantong National Station for Forest Ecosystem ResearchSchool of Ecology and Environmental SciencesEast China Normal UniversityShanghai200241China
- Shanghai Institute of Pollution Control and Ecological SecurityShanghai200092China
| | - Fangliang He
- ECNU‐Alberta Joint Laboratory for Biodiversity StudyTiantong National Station for Forest Ecosystem ResearchSchool of Ecology and Environmental SciencesEast China Normal UniversityShanghai200241China
- Department of Renewable ResourcesUniversity of AlbertaEdmontonAlberta,T6G 2H1Canada
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12
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Fibich P, Novotný V, Ediriweera S, Gunatilleke S, Gunatilleke N, Molem K, Weiblen GD, Lepš J. Common spatial patterns of trees in various tropical forests: Small trees are associated with increased diversity at small spatial scales. Ecol Evol 2021; 11:8085-8095. [PMID: 34188873 PMCID: PMC8216943 DOI: 10.1002/ece3.7640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 04/07/2021] [Indexed: 02/04/2023] Open
Abstract
Tropical forests are notable for their high species diversity, even on small spatial scales, and right-skewed species and size abundance distributions. The role of individual species as drivers of the spatial organization of diversity in these forests has been explained by several hypotheses and processes, for example, stochastic dilution, negative density dependence, or gap dynamics. These processes leave a signature in spatial distribution of small trees, particularly in the vicinity of large trees, likely having stronger effects on their neighbors. We are exploring species diversity patterns within the framework of various diversity-generating hypotheses using individual species-area relationships. We used the data from three tropical forest plots (Wanang-Papua New Guinea, Barro Colorado Island-Panama, and Sinharaja-Sri Lanka) and included also the saplings (DBH ≥ 1 cm). Resulting cross-size patterns of species richness and evenness reflect the dynamics of saplings affected by the distribution of large trees. When all individuals with DBH ≥1 cm are included, ~50% of all tree species from the 25- or 50-ha plot can be found within 35 m radius of an individual tree. For all trees, 72%-78% of species were identified as species richness accumulators, having more species present in their surroundings than expected by null models. This pattern was driven by small trees as the analysis of DBH >10 cm trees showed much lower proportion of accumulators, 14%-65% of species identified as richness repellers and had low richness of surrounding small trees. Only 11%-26% of species had lower species evenness than was expected by null models. High proportions of species richness accumulators were probably due to gap dynamics and support Janzen-Connell hypothesis driven by competition or top-down control by pathogens and herbivores. Observed species diversity patterns show the importance of including small tree size classes in analyses of the spatial organization of diversity.
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Affiliation(s)
- Pavel Fibich
- Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzech Republic
- Biology Centre CASInstitute of EntomologyČeské BudějoviceCzech Republic
| | - Vojtěch Novotný
- Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzech Republic
- Biology Centre CASInstitute of EntomologyČeské BudějoviceCzech Republic
| | - Sisira Ediriweera
- Department of Science and TechnologyUva Wellassa UniversityBadullaSri Lanka
| | | | | | - Kenneth Molem
- New Guinea Binatang Research CenterMadangPapua New Guinea
| | - George D. Weiblen
- Department of Plant BiologyBell MuseumUniversity of MinnesotaSt PaulMNUSA
| | - Jan Lepš
- Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzech Republic
- Biology Centre CASInstitute of EntomologyČeské BudějoviceCzech Republic
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13
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Hou J, Nan Z, Baskin C, Chen T. Effect of seed size and fungicide on germination and survival of buried seeds of two grassland species on the Loess Plateau, China. ACTA OECOLOGICA 2021. [DOI: 10.1016/j.actao.2021.103716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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14
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Ribeiro KFO, Martins VF, Wiegand T, Santos FAM. Habitat filtering drives the local distribution of congeneric species in a Brazilian white-sand flooded tropical forest. Ecol Evol 2021; 11:1797-1813. [PMID: 33614004 PMCID: PMC7882942 DOI: 10.1002/ece3.7169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/08/2020] [Accepted: 12/10/2020] [Indexed: 01/29/2023] Open
Abstract
The investigation of ecological processes that maintain species coexistence is revealing in naturally disturbed environments such as the white-sand tropical forest, which is subject to periodic flooding that might pose strong habitat filtering to tree species. Congeneric species are a good model to investigate the relative importance of ecological processes that maintain high species diversity because they tend to exploit the same limiting resources and/or have similar tolerance limits to the same environmental conditions due to their close phylogenetic relationship. We aim to find evidence for the action and relative importance of different processes hypothesized to maintain species coexistence in a white-sand flooded forest in Brazil, taking advantage of data on the detailed spatial structure of populations of congeneric species. Individuals of three Myrcia species were tagged, mapped, and measured for diameter at soil height in a 1-ha plot. We also sampled seven environmental variables in the plot. We employed several spatial point process models to investigate the possible action of habitat filtering, interspecific competition, and dispersal limitation. Habitat filtering was the most important process driving the local distribution of the three Myrcia species, as they showed associations, albeit of different strength, to environmental variables related to flooding. We did not detect spatial patterns, such as spatial segregation and smaller size of nearby neighbors, that would be consistent with interspecific competition among the three congeneric species and other co-occurring species. Even though congeners were spatially independent, they responded to differences in the environment. Last, dispersal limitation only led to spatial associations of different size classes for one of the species. Given that white-sand flooded forests are highly threatened in Brazil, the preservation of their different habitats is of utmost importance to the maintenance of high species richness, as flooding drives the distribution of species in the community.
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Affiliation(s)
- Kelly F. O. Ribeiro
- Programa de Pós‐Graduação em EcologiaInstitute of BiologyUniversity of Campinas ‐ UNICAMPCampinasBrazil
| | - Valéria F. Martins
- Department of Natural Sciences, Maths and EducationFederal University of São Carlos ‐ UFSCarArarasBrazil
- Department of Plant BiologyInstitute of BiologyUniversity of Campinas ‐ UNICAMPCampinasBrazil
| | - Thorsten Wiegand
- Department of Ecological ModellingHelmholtz Centre for Environmental Research – UFZLeipzigGermany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Flavio A. M. Santos
- Department of Plant BiologyInstitute of BiologyUniversity of Campinas ‐ UNICAMPCampinasBrazil
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15
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LaManna JA, Mangan SA, Myers JA. Conspecific negative density dependence and why its study should not be abandoned. Ecosphere 2021. [DOI: 10.1002/ecs2.3322] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Joseph A. LaManna
- Department of Biological Sciences Marquette University Milwaukee Wisconsin53201USA
- Departments of Botany & Zoology Milwaukee Public Museum Milwaukee Wisconsin USA
| | - Scott A. Mangan
- Department of Biological Sciences Arkansas State University Jonesboro Arkansas72467USA
| | - Jonathan A. Myers
- Department of Biology & Tyson Research Center Washington University in St. Louis St. Louis Missouri63110USA
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Hülsmann L, Chisholm RA, Hartig F. Is Variation in Conspecific Negative Density Dependence Driving Tree Diversity Patterns at Large Scales? Trends Ecol Evol 2020; 36:151-163. [PMID: 33589047 DOI: 10.1016/j.tree.2020.10.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 02/06/2023]
Abstract
Half a century ago, Janzen and Connell hypothesized that the high tree species diversity in tropical forests is maintained by specialized natural enemies. Along with other mechanisms, these can cause conspecific negative density dependence (CNDD) and thus maintain species diversity. Numerous studies have measured proxies of CNDD worldwide, but doubt about its relative importance remains. We find ample evidence for CNDD in local populations, but methodological limitations make it difficult to assess if CNDD scales up to control community diversity and thereby local and global biodiversity patterns. A combination of more robust statistical methods, new study designs, and eco-evolutionary models are needed to provide a more definite evaluation of the importance of CNDD for geographic variation in plant species diversity.
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Affiliation(s)
- Lisa Hülsmann
- Theoretical Ecology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany.
| | - Ryan A Chisholm
- Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543, Singapore
| | - Florian Hartig
- Theoretical Ecology, University of Regensburg, Universitätsstraße 31, 93053 Regensburg, Germany
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17
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Abstract
Abstract
Fifty years ago, Janzen (1970) and Connell (1971) independently published a revolutionary idea to explain the hyperdiverse tree communities of the tropics. The essential observations were that seedfall is concentrated in the vicinity of fruiting trees, whereas saplings recruit at a distance from reproductive conspecifics. These observations were encapsulated in a simple focal-tree model constructed of intersecting curves for seedfall and escape from host-specific enemies postulated to attack propagules (seeds and seedlings) in the vicinity of reproductive conspecifics. In conflict with the thinking of the times, the mechanism operates from the top down rather than from the bottom up. A deterrent to broad acceptance has been the giant intuitive leap required to generalize the focal tree model to an entire forest community. Recent theoretical and empirical results have succeeded in bridging the gap between the focal tree model and its community-level implications. With these new findings, Janzen–Connell has come of age.
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Affiliation(s)
- John Terborgh
- Department of Biology and with the Florida Museum of Natural History, University of Florida, Gainesville and with the College of Science and Engineering, James Cook University, Cairns, Queensland, Australia
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18
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Perea AJ, Garrido JL, Fedriani JM, Rey PJ, Alcántara JM. Pathogen life-cycle leaves footprint on the spatial distribution of recruitment of their host plants. FUNGAL ECOL 2020. [DOI: 10.1016/j.funeco.2020.100974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Song X, Zhang W, Johnson DJ, Yang J, Asefa M, Deng X, Yang X, Cao M. Conspecific negative density dependence in rainy season enhanced seedling diversity across habitats in a tropical forest. Oecologia 2020; 193:949-957. [PMID: 32851493 DOI: 10.1007/s00442-020-04729-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 08/10/2020] [Indexed: 11/25/2022]
Abstract
Conspecific negative density dependence (CNDD) could be one of the most important local-scale mechanisms shaping plant species coexistence. However, the spatial and temporal changes in the strength CNDD and the implications for the plant diversity remain unknown. We used 10 years of seedling data, in a seasonal tropical rainforest, to discover how CNDD influences tree seedling survival across habitats and seasons. We also evaluated the relation between CNDD and species diversity. We found the strength of CNDD in the valley habitat was significantly stronger than in ridge habitat in rainy season, but not significantly different in dry season. Corresponding to expectations of CNDD as mechanism of diversity maintenance, seedling species diversity was significantly higher in valley habitat than in ridge habitat and significantly correlated with CNDD. Additionally, conspecific and heterospecific seedling neighbour densities positively affected the survival of tree seedlings, but heterospecific adult neighbour density had a weak effect. Our study finds that CNDD varied significantly across habitats and was correlated with local seedling diversity. Our results highlight the importance of CNDD in driving species diversity at the local scale. Recognizing the spatial and temporal variation in the strength of CNDD will aid efforts to model and understand species coexistence.
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Affiliation(s)
- Xiaoyang Song
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, 666303, China
| | - Wenfu Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Daniel J Johnson
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, USA
| | - Jie Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China.
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, 666303, China.
| | - Mengesha Asefa
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Xiaobao Deng
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Xiaofei Yang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
| | - Min Cao
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, 666303, Yunnan, China
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20
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Koga W, Suzuki A, Masaka K, Seiwa K. Conspecific distance-dependent seedling performance, and replacement of conspecific seedlings by heterospecifics in five hardwood, temperate forest species. Oecologia 2020; 193:937-947. [PMID: 32783114 DOI: 10.1007/s00442-020-04725-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 07/29/2020] [Indexed: 12/01/2022]
Abstract
The mechanisms driving species diversity in the context of Janzen-Connell model are best understood by evaluating not only conspecific distance-dependent (CDD) seedling performance, but also replacement of conspecific seedlings by heterospecific seedlings beneath adult trees. We evaluated CDD and replacement as a log response ratio of seedling performance (height, age) directly beneath and at a distance from adult plants in a temperate forest, and examined the log response ratio of that between conspecifics and heterospecifics beneath adults for five hardwood species with different ecological traits (e.g., seed size, mycorrhizal type, relative abundance). CDD was greater in three small-seeded species with arbuscular mycorrhizae (AM) associations than it was in two large-seeded species with ectomycorrhizae (EM) associations. Replacement was also higher for small-seeded AM species compared to large-seeded EM species, resulting in a strong, positive relationship between CDD and replacement. The traits suggest that small-seeded AM seedlings are more likely to be replaced by heterologous seedlings beneath the adults than large-seeded EM seedlings, probably due to that the small-seeded AM species are more susceptible to attack by plant natural enemies (e.g., soil pathogens, leaf diseases). As a result, small-seeded AM species had lower relative abundances compared to large-seeded EM species. This study suggests that either seed size or associations with microorganisms play an important role in driving forest diversity by regulating replacement and CDD, although relative importance of the two traits (i.e., seed size, mycorrhizal type) remains unclear, because of the autocorrelation between the two traits for the five species studied.
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Affiliation(s)
- Wataru Koga
- Graduate School of Agricultural Science, Tohoku University, Naruko-onsen, Osaki, Miyagi, 989-6711, Japan
| | - Aya Suzuki
- Graduate School of Agricultural Science, Tohoku University, Naruko-onsen, Osaki, Miyagi, 989-6711, Japan
| | - Kazuhiko Masaka
- Faculty of Agriculture, Iwate University, Morioka, Iwate, 020-8550, Japan
| | - Kenji Seiwa
- Graduate School of Agricultural Science, Tohoku University, Naruko-onsen, Osaki, Miyagi, 989-6711, Japan.
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21
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Tree species traits affect which natural enemies drive the Janzen-Connell effect in a temperate forest. Nat Commun 2020; 11:286. [PMID: 31941904 PMCID: PMC6962457 DOI: 10.1038/s41467-019-14140-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 12/14/2019] [Indexed: 01/25/2023] Open
Abstract
A prominent tree species coexistence mechanism suggests host-specific natural enemies inhibit seedling recruitment at high conspecific density (negative conspecific density dependence). Natural-enemy-mediated conspecific density dependence affects numerous tree populations, but its strength varies substantially among species. Understanding how conspecific density dependence varies with species’ traits and influences the dynamics of whole communities remains a challenge. Using a three-year manipulative community-scale experiment in a temperate forest, we show that plant-associated fungi, and to a lesser extent insect herbivores, reduce seedling recruitment and survival at high adult conspecific density. Plant-associated fungi are primarily responsible for reducing seedling recruitment near conspecific adults in ectomycorrhizal and shade-tolerant species. Insects, in contrast, primarily inhibit seedling recruitment of shade-intolerant species near conspecific adults. Our results suggest that natural enemies drive conspecific density dependence in this temperate forest and that which natural enemies are responsible depends on the mycorrhizal association and shade tolerance of tree species. The Janzen-Connell hypothesis posits that seedlings may be less likely to establish near conspecifics due to shared natural enemies. Here, Jia et al. show that tree species traits determine whether fungal pathogens or insect herbivores inhibit seedling recruitment and survival in a temperate forest.
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22
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Marchand P, Comita LS, Wright SJ, Condit R, Hubbell SP, Beckman NG. Seed-to-seedling transitions exhibit distance-dependent mortality but no strong spacing effects in a Neotropical forest. Ecology 2019; 101:e02926. [PMID: 31729025 DOI: 10.1002/ecy.2926] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Revised: 09/16/2019] [Accepted: 10/03/2019] [Indexed: 11/10/2022]
Abstract
Patterns of seed dispersal and seed mortality influence the spatial structure of plant communities and the local coexistence of competing species. Most seeds are dispersed in proximity to the parent tree, where mortality is also expected to be the highest, because of competition with siblings or the attraction of natural enemies. Whereas distance-dependent mortality in the seed-to-seedling transition was often observed in tropical forests, few studies have attempted to estimate the shape of the survival-distance curves, which determines whether the peak of seedling establishment occurs away from the parent tree (Janzen-Connell pattern) or if the peak attenuates but remains at the parent location (Hubbell pattern). In this study, we inferred the probability density of seed dispersal and two stages of seedling establishment (new recruits, and seedlings 20 cm or taller) with distance for 24 tree species present in the 50-ha Forest Dynamics Plot of Barro Colorado Island, Panama. Using data from seed traps, seedling survey quadrats, and tree-census records spanning the 1988-2014 period, we fit hierarchical Bayesian models including parameters for tree fecundity, the shape of the dispersal kernel, and overdispersion of seed or seedling counts. We combined predictions from multiple dispersal kernels to obtain more robust inferences. We find that Hubbell patterns are the most common and Janzen-Connell patterns are very rare among those species; that distance-dependent mortality may be stronger in the seed stage, in the early recruit stage, or comparable in both; and that species with larger seeds experience less overall mortality and less distance-dependent mortality. Finally, we describe how this modeling approach could be extended at a community scale to include less abundant species.
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Affiliation(s)
- Philippe Marchand
- Institut de recherche sur les forêts, Université du Québec en Abitibi-Témiscamingue, Rouyn-Noranda, QC, J9X 5E4, Canada
| | - Liza S Comita
- School of Forestry & Environmental Studies, Yale University, New Haven, Connecticut, 06511, USA
| | - S Joseph Wright
- Smithsonian Tropical Research Institute, Panama City, 0843-03092, Panama
| | - Richard Condit
- Field Museum of Natural History, Chicago, Illinois, 60605, USA.,Morton Arboretum, Lisle, Illinois, 60532, USA
| | - Stephen P Hubbell
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 90095, California, USA
| | - Noelle G Beckman
- Department of Biology and Ecology Center, Utah State University, Logan, Utah, 84322, USA
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23
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Bergamo PJ, Susin Streher N, Traveset A, Wolowski M, Sazima M. Pollination outcomes reveal negative density-dependence coupled with interspecific facilitation among plants. Ecol Lett 2019; 23:129-139. [PMID: 31650660 DOI: 10.1111/ele.13415] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/07/2019] [Accepted: 10/03/2019] [Indexed: 01/27/2023]
Abstract
Pollination is thought to be under positive density-dependence, destabilising plant coexistence by conferring fitness disadvantages to rare species. Such disadvantage is exacerbated by interspecific competition but can be mitigated by facilitation and intraspecific competition. However, pollinator scarcity should enhance intraspecific plant competition and impose disadvantage on common over rare species (negative density-dependence, NDD). We assessed pollination proxies (visitation rate, pollen receipt, pollen tubes) in a generalised plant community and related them to conspecific and heterospecific density, expecting NDD and interspecific facilitation due to the natural pollinator scarcity. Contrary to usual expectations, all proxies indicated strong intraspecific competition for common plants. Moreover interspecific facilitation prevailed and was stronger for rare than for common plants. Both NDD and interspecific facilitation were modulated by specialisation, floral display and pollinator group. The combination of intraspecific competition and interspecific facilitation fosters plant coexistence, suggesting that pollination can be a niche axis maintaining plant diversity.
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Affiliation(s)
- Pedro J Bergamo
- Graduate Program in Ecology, University of Campinas, Monteiro Lobato St., 255, Campinas, PO Box 13083-862, Brazil.,Mediterranean Institute for Advanced Studies, CSIC-UIB, Miquel Marqués St., 21, Esporles, Mallorca, PO Box 07190, Spain
| | - Nathália Susin Streher
- Graduate Program in Plant Biology, University of Campinas, Monteiro Lobato St., 255, Campinas, PO Box 13083-862, Brazil
| | - Anna Traveset
- Mediterranean Institute for Advanced Studies, CSIC-UIB, Miquel Marqués St., 21, Esporles, Mallorca, PO Box 07190, Spain
| | - Marina Wolowski
- Institute of Natural Sciences, Federal University of Alfenas, Gabriel Monteiro da Silva St., 700, Alfenas, PO Box 37130-000, Brazil
| | - Marlies Sazima
- Department of Plant Biology, Institute of Biology, University of Campinas, Monteiro Lobato St., 255, Campinas, PO Box 13083-862, Brazil
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24
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Fricke EC, Tewksbury JJ, Rogers HS. Linking intra‐specific trait variation and plant function: seed size mediates performance tradeoffs within species. OIKOS 2019. [DOI: 10.1111/oik.06494] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Evan C. Fricke
- National Socio‐Environmental Synthesis Center, Univ. of Maryland Annapolis MD 21401 USA
| | - Joshua J. Tewksbury
- Colorado Global Hub, Future Earth Boulder CO USA
- Sustainability, Energy and Environment Complex, Univ. of Colorado Boulder CO USA
| | - Haldre S. Rogers
- Dept of Ecology, Evolution, and Organismal Biology, Iowa State Univ Ames IA USA
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25
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Liu Y, He F. Incorporating the disease triangle framework for testing the effect of soil‐borne pathogens on tree species diversity. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13345] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Yu Liu
- ECNU‐Alberta Joint Lab for Biodiversity Study, Tiantong Forest Ecosystem National Observation and Research Station, School of Ecology and Environmental Sciences East China Normal University Shanghai China
- Shanghai Institute of Pollution Control and Ecological Security Shanghai China
| | - Fangliang He
- ECNU‐Alberta Joint Lab for Biodiversity Study, Tiantong Forest Ecosystem National Observation and Research Station, School of Ecology and Environmental Sciences East China Normal University Shanghai China
- Department of Renewable Resources University of Alberta Edmonton Alberta Canada
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26
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Evidence of within-species specialization by soil microbes and the implications for plant community diversity. Proc Natl Acad Sci U S A 2019; 116:7371-7376. [PMID: 30842279 DOI: 10.1073/pnas.1810767116] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Microbes are thought to maintain diversity in plant communities by specializing on particular species, but it is not known whether microbes that specialize within species (i.e., on genotypes) affect diversity or dynamics in plant communities. Here we show that soil microbes can specialize at the within-population level in a wild plant species, and that such specialization could promote species diversity and seed dispersal in plant communities. In a shadehouse experiment in Panama, we found that seedlings of the native tree species, Virola surinamensis (Myristicaceae), had reduced performance in the soil microbial community of their maternal tree compared with in the soil microbial community of a nonmaternal tree from the same population. Performance differences were unrelated to soil nutrients or to colonization by mycorrhizal fungi, suggesting that highly specialized pathogens were the mechanism reducing seedling performance in maternal soils. We then constructed a simulation model to explore the ecological and evolutionary consequences of genotype-specific pathogens in multispecies plant communities. Model results indicated that genotype-specific pathogens promote plant species coexistence-albeit less strongly than species-specific pathogens-and are most effective at maintaining species richness when genetic diversity is relatively low. Simulations also revealed that genotype-specific pathogens select for increased seed dispersal relative to species-specific pathogens, potentially helping to create seed dispersal landscapes that allow pathogens to more effectively promote diversity. Combined, our results reveal that soil microbes can specialize within wild plant populations, affecting seedling performance near conspecific adults and influencing plant community dynamics on ecological and evolutionary time scales.
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27
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Chua SC, Potts MD. The role of plant functional traits in understanding forest recovery in wet tropical secondary forests. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 642:1252-1262. [PMID: 30045506 DOI: 10.1016/j.scitotenv.2018.05.397] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 05/13/2018] [Accepted: 05/31/2018] [Indexed: 05/12/2023]
Abstract
Simultaneous measurement of plant functional traits and the regeneration environment should shed light on the plant-environment interactions and feedbacks as secondary forest regenerates. However, little of such work has been done in the wet tropics, and even fewer studies have examined soil nutrients. We investigated whether plant functional traits and environmental variables explain the varied recovery of secondary forests in Singapore. Our study plots included three primary forest plots and eight approximately 60-year-old secondary forest plots regenerating from intensive agricultural activities. Using 35 seedling quadrats, we asked: Q1) How do environmental variables explain the variation in seedling functional traits observed in primary and secondary forests? Q2) How do seedling traits, adult traits and environmental variables relate and explain variation in species richness and stem density in secondary forests? We found that both light and soil fertility explained the shifts in plants functional traits from poorly recovering secondary forests to primary forests. Poor forest regrowth was correlated with high soil aluminum levels and lower leaf nitrogen concentrations. Low nutrients and high aluminum saturation were also negatively correlated with seedling species richness, but not stem density, in the secondary forests. Forest recovery is probably slowed by positive feedback between slower nutrient returns from slow decaying litter and further recruitment of nutrient conserving species, as indicated by positive correlations among adult leaf CN ratio, litter depth, soil CN ratio and quadrat level CN ratio. Plant functional traits are indicative of the strategies of successful seedlings and do not necessarily relate to overall forest recovery. Hence, while some specialist plant species are able to accrue high nutrients on degraded soils with aluminum toxicity and low nutrients, species richness on these soils was poor. This underscores the need to concurrently measure environmental variables and plant traits when investigating the mechanisms driving changes during forest recovery.
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Affiliation(s)
- Siew Chin Chua
- Ridge View Residential College, National University of Singapore, Singapore; Department of Environmental Science, Policy & Management, University of California, Berkeley, CA, USA.
| | - Matthew D Potts
- Department of Environmental Science, Policy & Management, University of California, Berkeley, CA, USA
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Abstract
An important class of negative feedbacks in population dynamics is the activity of host-specific enemies that disproportionately kill individuals in locations where they are common. This mechanism, called the Janzen–Connell hypothesis, has been proposed as a determinant of the large number of species in tropical forests. A critical but untested assumption of the hypothesis is that density-dependent mortality among juvenile trees reduces the probability of adult recruitment. Here, we show that adult recruitment is negatively density dependent in a low-density tree population using time series from high-resolution remote sensing. However, this density dependence was not strong enough to stabilize the size of the adult population, which increased significantly in size. The Janzen–Connell hypothesis is a well-known explanation for why tropical forests have large numbers of tree species. A fundamental prediction of the hypothesis is that the probability of adult recruitment is less in regions of high conspecific adult density, a pattern mediated by density-dependent mortality in juvenile life stages. Although there is strong evidence in many tree species that seeds, seedlings, and saplings suffer conspecific density-dependent mortality, no study has shown that adult tree recruitment is negatively density dependent. Density-dependent adult recruitment is necessary for the Janzen–Connell mechanism to regulate tree populations. Here, we report density-dependent adult recruitment in the population of Handroanthus guayacan, a wind-dispersed Neotropical canopy tree species. We use data from high-resolution remote sensing to track individual trees with proven capacity to flower in a lowland moist forest landscape in Panama and analyze these data in a Bayesian framework similar to capture–recapture analysis. We independently quantify probabilities of adult tree recruitment and detection and show that adult recruitment is negatively density dependent. The annualized probability of adult recruitment was 3.03% ⋅ year−1. Despite the detection of negative density dependence in adult recruitment, it was insufficient to stabilize the adult population of H. guayacan, which increased significantly in size over the decade of observation.
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Stump SM, Comita LS. Interspecific variation in conspecific negative density dependence can make species less likely to coexist. Ecol Lett 2018; 21:1541-1551. [PMID: 30129216 DOI: 10.1111/ele.13135] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 06/05/2018] [Accepted: 07/15/2018] [Indexed: 01/19/2023]
Abstract
Conspecific negative density dependence (CNDD) is thought to promote plant species diversity. Theoretical studies showing the importance of CNDD often assumed that all species are equally susceptible to CNDD; however, recent empirical studies have shown species can differ greatly in their susceptibility to CNDD. Using a theoretical model, we show that interspecific variation in CNDD can dramatically alter its impact on diversity. First, if the most common species are the least regulated by CNDD, then the stabilising benefit of CNDD is reduced. Second, when seed dispersal is limited, seedlings that are susceptible to CNDD are at a competitive disadvantage. When parameterised with estimates of CNDD from a tropical tree community in Panama, our model suggests that the competitive inequalities caused by interspecific variation in CNDD may undermine many species' ability to persist. Thus, our model suggests that variable CNDD may make communities less stable, rather than more stable.
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Affiliation(s)
- Simon Maccracken Stump
- School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT, 06511, USA
| | - Liza S Comita
- School of Forestry and Environmental Studies, Yale University, 195 Prospect Street, New Haven, CT, 06511, USA.,Smithsonian Tropical Research Institute Balboa, Ancón, Panama
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30
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Martins VF, Seger GDDS, Wiegand T, Santos FAMD. Phylogeny contributes more than site characteristics and traits to the spatial distribution pattern of tropical tree populations. OIKOS 2018. [DOI: 10.1111/oik.05142] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Valéria Forni Martins
- Dept of Natural Sciences, Maths and Education; Centre for Agrarian Sciences, Federal Univ. of São Carlos - UFSCar campus Araras, Rodovia Anhanguera - SP 330, km 174; 13600-970 Araras SP Brazil
- Dept of Plant Biology; Inst. of Biology, Univ. of Campinas - UNICAMP; Campinas SP Brazil
| | | | - Thorsten Wiegand
- Helmholtz Centre for Environmental Research - UFZ; Dept of Ecological Modelling; Leipzig Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Leipzig Germany
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