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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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Significance of seed dispersal by the largest frugivore for large-diaspore trees. Sci Rep 2022; 12:19086. [PMID: 36411297 PMCID: PMC9678871 DOI: 10.1038/s41598-022-23018-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 10/21/2022] [Indexed: 11/23/2022] Open
Abstract
How do large-bodied frugivores contribute to seed dispersal of large-diaspore plants? This study examined seed dispersal effectiveness for two large-diaspore tree species, Astrotrichilia asterotricha (AA) and Abrahamia deflexa (AD), in a Madagascan forest. I evaluated fruit removal rates through focal tree observations and factors affecting seedling recruitment up to the 2-year-old seedling stage. I confirmed brown lemur (Eulemur fulvus) as the sole disperser, removing 58.8% and 26.0% of fruits produced by AA and AD. Brown lemurs frequently visited large-crowned AA trees with high density of fallen fruits and more adjacent fruiting trees during seasons with low fruit diversity. Most AA seedlings were removed by predators, although canopy openness slightly improved seedling establishment. Although AD seeds were severely attacked by predators under mother trees, the seedlings survived under dispersal conditions distant from the mother trees, and with low density of diaspores. AD had a higher cumulative probability from fruit removal to seedling recruitment (6.5%) than AA (1.5%) in the first rainy season. This study clarifies the significance of seed dispersal to tree recruitment strategies, which vary among different combinations of tree species and large frugivores, i.e. quantitative dispersal to reach suitable microhabitats, and qualitative dispersal to escape from dangerous zones near mother trees.
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Bedessem B, Julliard R, Montuschi E. Measuring epistemic success of a biodiversity citizen science program: A citation study. PLoS One 2021; 16:e0258350. [PMID: 34634086 PMCID: PMC8504750 DOI: 10.1371/journal.pone.0258350] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/25/2021] [Indexed: 12/04/2022] Open
Abstract
This paper offers a comparative evaluation of the scientific impact of a citizen science program in ecology, ‘‘Vigie-Nature”, managed by the French National Museum of Natural History. Vigie-Nature consists of a national network of amateur observatories dedicated to a participative study of biodiversity in France that has been running for the last twenty years. We collected 123 articles published by Vigie-Nature in international peer-reviewed journals between 2007 and 2019, and computed the yearly amount of citations of these articles between 0–12 years post-publication. We then compared this body of citations with the number of yearly citations relative to the ensemble of the articles published in ecology and indexed in the ‘‘Web of Science” data-base. Using a longitudinal data analysis, we could observe that the yearly number of citations of the Vigie-Nature articles is significantly higher than that of the other publications in the same domain. Furthermore, this excess of citations tends to steadily grow over time: Vigie-Nature publications are about 1.5 times more cited 3 years after publication, and 3 times more cited 11 years post-publication. These results suggest that large-scale biodiversity citizen science projects are susceptible to reach a high epistemic impact, when managed in specific ways which need to be clarified through further investigations.
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Affiliation(s)
- Baptiste Bedessem
- Dipartimento di Filosofia e beni culturali, Università Ca’Foscari, Venezia, Italy
- * E-mail:
| | | | - Eleonora Montuschi
- Dipartimento di Filosofia e beni culturali, Università Ca’Foscari, Venezia, Italy
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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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