1
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Hogan KFE, Jones HP, Savage K, Burke AM, Guiden PW, Hosler SC, Rowland-Schaefer E, Barber NA. Functional consequences of animal community changes in managed grasslands: An application of the CAFE approach. Ecology 2024; 105:e4192. [PMID: 37878728 DOI: 10.1002/ecy.4192] [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: 03/28/2023] [Revised: 08/23/2023] [Accepted: 09/19/2023] [Indexed: 10/27/2023]
Abstract
In the midst of an ongoing biodiversity crisis, much research has focused on species losses and their impacts on ecosystem functioning. The functional consequences (ecosystem response) of shifts in communities are shaped not only by changes in species richness, but also by compositional shifts that result from species losses and gains. Species differ in their contribution to ecosystem functioning, so species identity underlies the consequences of species losses and gains on ecosystem functions. Such research is critical to better predict the impact of disturbances on communities and ecosystems. We used the "Community Assembly and the Functioning of Ecosystems" (CAFE) approach, a modification of the Price equation to understand the functional consequences and relative effects of richness and composition changes in small nonvolant mammal and dung beetle communities as a result of two common disturbances in North American prairie restorations, prescribed fire and the reintroduction of large grazing mammals. Previous research in this system has shown dung beetles are critically important decomposers, while small mammals modulate much energy in prairie food webs. We found that dung beetle communities were more responsive to bison reintroduction and prescribed fires than small nonvolant mammals. Dung beetle richness increased after bison reintroduction, with higher dung beetle community biomass resulting from changes in remaining species (context-dependent component) rather than species turnover (richness components); prescribed fire caused a minor increase in dung beetle biomass for the same reason. For small mammals, bison reintroduction reduced energy transfer through the loss of species, while prescribed fire had little impact on either small mammal richness or energy transfer. The CAFE approach demonstrates how bison reintroduction controls small nonvolant mammal communities by increasing prairie food web complexity, and increases dung beetle populations with possible benefits for soil health through dung mineralization and soil bioturbation. Prescribed fires, however, have little effect on small mammals and dung beetles, suggesting a resilience to fire. These findings illustrate the key role of re-establishing historical disturbance regimes when restoring endangered prairie ecosystems and their ecological function.
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Affiliation(s)
- Katharine F E Hogan
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Holly P Jones
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
- Institute for the Study of the Environment, Sustainability, and Energy, Northern Illinois University, DeKalb, Illinois, USA
| | - Kirstie Savage
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Angela M Burke
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Peter W Guiden
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Sheryl C Hosler
- Department of Biological Sciences, University of Illinois Chicago, Chicago, Illinois, USA
| | - Erin Rowland-Schaefer
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Nicholas A Barber
- Department of Biology, San Diego State University, San Diego, California, USA
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2
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Martins IS, Schrodt F, Blowes SA, Bates AE, Bjorkman AD, Brambilla V, Carvajal-Quintero J, Chow CFY, Daskalova GN, Edwards K, Eisenhauer N, Field R, Fontrodona-Eslava A, Henn JJ, van Klink R, Madin JS, Magurran AE, McWilliam M, Moyes F, Pugh B, Sagouis A, Trindade-Santos I, McGill BJ, Chase JM, Dornelas M. Widespread shifts in body size within populations and assemblages. Science 2023; 381:1067-1071. [PMID: 37676959 DOI: 10.1126/science.adg6006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 08/10/2023] [Indexed: 09/09/2023]
Abstract
Biotic responses to global change include directional shifts in organismal traits. Body size, an integrative trait that determines demographic rates and ecosystem functions, is thought to be shrinking in the Anthropocene. Here, we assessed the prevalence of body size change in six taxon groups across 5025 assemblage time series spanning 1960 to 2020. Using the Price equation to partition this change into within-species body size versus compositional changes, we detected prevailing decreases in body size through time driven primarily by fish, with more variable patterns in other taxa. We found that change in assemblage composition contributes more to body size changes than within-species trends, but both components show substantial variation in magnitude and direction. The biomass of assemblages remains quite stable as decreases in body size trade off with increases in abundance.
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Affiliation(s)
- Inês S Martins
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- Leverhulme Centre for Anthropocene Biodiversity, University of York, York YO10 5DD, UK
| | - Franziska Schrodt
- School of Geography, University of Nottingham, University Park, Nottingham NG7 2RD
| | - Shane A Blowes
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Amanda E Bates
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Anne D Bjorkman
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg 40530, Sweden
- Gothenburg Global Biodiversity Centre, Gothenburg 41319, Sweden
| | - Viviana Brambilla
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- MARE, Guia Marine Laboratory, Faculty of Sciences, University of Lisbon, Cascais 2750-374, Portugal
| | - Juan Carvajal-Quintero
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Institute of Biology, Leipzig University, Leipzig 04103, Germany
| | - Cher F Y Chow
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Gergana N Daskalova
- International Institute for Applied Systems Analysis (IIASA), Laxenburg 2361, Austria
| | - Kyle Edwards
- Department of Oceanography, University of Hawai''i at Mānoa, Honolulu, HI 96822, USA
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Institute of Biology, Leipzig University, Leipzig 04103, Germany
| | - Richard Field
- School of Geography, University of Nottingham, University Park, Nottingham NG7 2RD
| | - Ada Fontrodona-Eslava
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Jonathan J Henn
- Department of Evolution, Ecology, and Organismal Biology, University of California Riverside, Riverside, CA 92521, USA
- Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO 80303, USA
| | - Roel van Klink
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Joshua S Madin
- Hawai''i Institute of Marine Biology, University of Hawai''i at Manoa, Kāne'ohe, Hawai''i 96744, USA
| | - Anne E Magurran
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Michael McWilliam
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Faye Moyes
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
| | - Brittany Pugh
- School of Geography, University of Nottingham, University Park, Nottingham NG7 2RD
- University College London, School of Geography, Gower Street, London WC1E 6AE, UK
| | - Alban Sagouis
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Isaac Trindade-Santos
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- Macroevolution Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1, Tancha, Onna-son, Kunigami-gun 904-0495, Okinawa, Japan
| | - Brian J McGill
- School of Biology and Ecology and Mitchell Center for Sustainability Solutions, University of Maine, Orono, ME 04469, USA
| | - Jonathan M Chase
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig 04103, Germany
- Department of Computer Science, Martin Luther University Halle-Wittenberg, Halle (Saale) 06099, Germany
| | - Maria Dornelas
- Centre for Biological Diversity, School of Biology, University of St Andrews, St Andrews KY16 9TH, Scotland
- Leverhulme Centre for Anthropocene Biodiversity, University of York, York YO10 5DD, UK
- MARE, Guia Marine Laboratory, Faculty of Sciences, University of Lisbon, Cascais 2750-374, Portugal
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3
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Diaz RM, Ernest SKM. Maintenance of community function through compensation breaks down over time in a desert rodent community. Ecology 2022; 103:e3709. [PMID: 35362169 PMCID: PMC9287087 DOI: 10.1002/ecy.3709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 01/27/2022] [Accepted: 02/08/2022] [Indexed: 11/08/2022]
Abstract
Understanding the ecological processes that maintain community function in systems experiencing species loss, and how these processes change over time, is key to understanding the relationship between community structure and function and predicting how communities may respond to perturbations in the Anthropocene. Using a 30‐year experiment on desert rodents, we show that the impact of species loss on community‐level energy use has changed repeatedly and dramatically over time, due to (1) the addition of new species to the community, and (2) a reduction in functional redundancy among the same set of species. Although strong compensation, initially driven by the dispersal of functionally redundant species to the local community, occurred in this system from 1997 to 2010, since 2010, compensation has broken down due to decreasing functional overlap within the same set of species. Simultaneously, long‐term changes in sitewide community composition due to niche complementarity have decoupled the dynamics of compensation from the overall impact of species loss on community‐level energy use. Shifting, context‐dependent compensatory dynamics, such as those demonstrated here, highlight the importance of explicitly long‐term, metacommunity, and eco‐evolutionary perspectives on the link between species‐level fluctuations and community function in a changing world.
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Affiliation(s)
- Renata M Diaz
- School of Natural Resources and Environment, University of Florida, Gainesville, FL
| | - S K Morgan Ernest
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL
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4
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Dallas TA, Kramer AM. Temporal variability in population and community dynamics. Ecology 2021; 103:e03577. [PMID: 34714929 DOI: 10.1002/ecy.3577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 07/15/2021] [Accepted: 08/23/2021] [Indexed: 11/12/2022]
Abstract
Populations and communities fluctuate in their overall numbers through time, and the magnitude of fluctuations in individual species may scale to communities. However, the composite variability at the community scale is expected to be tempered by opposing fluctuations in individual populations, a phenomenon often called the portfolio effect. Understanding population variability, how it scales to community variability, and the spatial scaling in this variability are pressing needs given shifting environmental conditions and community composition. We explore evidence for portfolio effects using null community simulations and a large collection of empirical community time series from the BioTIME database. Additionally, we explore the relative roles of habitat type and geographic location on population and community temporal variability. We find strong portfolio effects in our theoretical community model, but weak effects in empirical data, suggesting a role for shared environmental responses, interspecific competition, or a litany of other factors. Furthermore, we observe a clear latitudinal signal - and differences among habitat types - in population and community variability. Together, this highlights the need to develop realistic models of community dynamics, and hints at spatial, and underlying environmental, gradients in variability in both population and community dynamics.
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Affiliation(s)
- Tad A Dallas
- Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA.,Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Andrew M Kramer
- Department of Integrative Biology, University of South Florida, Tampa, Florida, 33620, USA
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5
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Junker JR, Cross WF, Benstead JP, Huryn AD, Hood JM, Nelson D, Gíslason GM, Ólafsson JS. Resource supply governs the apparent temperature dependence of animal production in stream ecosystems. Ecol Lett 2020; 23:1809-1819. [PMID: 33001542 PMCID: PMC7702057 DOI: 10.1111/ele.13608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 06/06/2020] [Accepted: 08/17/2020] [Indexed: 11/27/2022]
Abstract
Rising global temperatures are changing how energy and materials move through ecosystems, with potential consequences for the role of animals in these processes. We tested a central prediction of the metabolic scaling framework-the temperature independence of animal community production-using a series of geothermally heated streams and a comprehensive empirical analysis. We show that the apparent temperature sensitivity of animal production was consistent with theory for individuals (Epind = 0.64 vs. 0.65 eV), but strongly amplified relative to theoretical expectations for communities, both among (Epamong = 0.67 vs. 0 eV) and within (Epwithin = 1.52 vs. 0 eV) streams. After accounting for spatial and temporal variation in resources, we show that the apparent positive effect of temperature was driven by resource supply, providing strong empirical support for the temperature independence of invertebrate production and the necessary inclusion of resources in metabolic scaling efforts.
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Affiliation(s)
- James R Junker
- Department of Ecology, Montana State University, Bozeman, MT, 59717, USA
| | - Wyatt F Cross
- Department of Ecology, Montana State University, Bozeman, MT, 59717, USA
| | - Jonathan P Benstead
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Alexander D Huryn
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, 35487, USA
| | - James M Hood
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Translational Data Analytics Institute, The Aquatic Ecology Laboratory, Columbus, OH, 43212, USA
| | - Daniel Nelson
- Department of Biology, University of Oklahoma, Norman, OK, 73019, USA
| | - Gísli M Gíslason
- University of Iceland, Institute of Life and Environmental Sciences, Reykjavík, Iceland
| | - Jón S Ólafsson
- Institute of Marine and Freshwater Fisheries, Reykjavík, Iceland
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6
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A Perspective on Body Size and Abundance Relationships across Ecological Communities. BIOLOGY 2020; 9:biology9030042. [PMID: 32111083 PMCID: PMC7150794 DOI: 10.3390/biology9030042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/21/2020] [Accepted: 02/23/2020] [Indexed: 12/27/2022]
Abstract
Recently, several studies have reported relationships between the abundance of organisms in an ecological community and their mean body size (called cross-community scaling relationships: CCSRs) that can be described by simple power functions. A primary focus of these studies has been on the scaling exponent (slope) and whether it approximates -3/4, as predicted by Damuth's rule and the metabolic theory in ecology. However, some CCSR studies have reported scaling exponents significantly different from the theoretical value of -3/4. Why this variation occurs is still largely unknown. The purpose of our commentary is to show the value of examining both the slopes and elevations of CCSRs and how various ecological factors may affect them. As a heuristic exercise, we reanalyzed three published data sets based on phytoplankton, rodent, and macroinvertebrate assemblages that we subdivided according to three distinctly different ecological factors (i.e., climate zone, season, and trophic level). Our analyses reveal significant variation in either or both the CCSR slopes and elevations for marine phytoplankton communities across climate zones, a desert rodent community across seasons, and saltwater lagoon macroinvertebrate communities across trophic levels. We conclude that achieving a comprehensive understanding of abundance-size relationships at the community level will require consideration of both slopes and elevations of these relationships and their possible variation in different ecological contexts.
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7
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Christensen EM, Simpson GL, Ernest SKM. Established rodent community delays recovery of dominant competitor following experimental disturbance. Proc Biol Sci 2019; 286:20192269. [PMID: 31822258 PMCID: PMC6939914 DOI: 10.1098/rspb.2019.2269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/13/2019] [Indexed: 12/04/2022] Open
Abstract
Human activities alter processes that control local biodiversity, causing changes in the abundance and identity of species in ecosystems. However, restoring biodiversity to a previous state is rarely as simple as reintroducing lost species or restoring processes to their pre-disturbance state. Theory suggests that established species can impede shifts in species composition via a variety of mechanisms, including direct interference, pre-empting resources or habitat alteration. These mechanisms can create transitory dynamics that delay convergence to an expected end state. We use an experimental manipulation of a desert rodent community to examine differences in recolonization dynamics of a dominant competitor (kangaroo rats of the genus Dipodomys) when patches were already occupied by an existing rodent community relative to when patches were empty. Recovery of kangaroo rat populations was slow on plots with an established community, taking approximately 2 years, in contrast with rapid recovery on empty plots with no established residents (approx. three months). These results demonstrate that the presence of an established alternate community inhibits recolonization by new species, even those that should be dominant in the community. This has important implications for understanding how biodiversity may change in the future, and what processes may slow or prevent this change.
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Affiliation(s)
- Erica M. Christensen
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, FL 32611, USA
- New Mexico State University, Jornada Experimental Range, Wooton Hall, 2995 Knox Street, Las Cruces, NM 88003, USA
| | - Gavin L. Simpson
- Institute of Environmental Change and Society, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan, CanadaS4S 0A2
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan, CanadaS4S 0A2
| | - S. K. Morgan Ernest
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, FL 32611, USA
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8
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9
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O’Connell MA, Hallett JG. Community ecology of mammals: deserts, islands, and anthropogenic impacts. J Mammal 2019. [DOI: 10.1093/jmammal/gyz010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
| | - James G Hallett
- Department of Biology, Eastern Washington University, Cheney, WA, USA
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10
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Lyons SK, Smith FA, Ernest SKM. Macroecological patterns of mammals across taxonomic, spatial, and temporal scales. J Mammal 2019. [DOI: 10.1093/jmammal/gyy171] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- S Kathleen Lyons
- University of Nebraska–Lincoln, School of Biological Sciences, St. Lincoln, NE
| | - Felisa A Smith
- University of New Mexico, Department of Biology, Albuquerque, NM
| | - S K Morgan Ernest
- University of Florida, Department of Wildlife Ecology and Conservation, Gainesville, FL
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11
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Sundstrom SM, Angeler DG, Barichievy C, Eason T, Garmestani A, Gunderson L, Knutson M, Nash KL, Spanbauer T, Stow C, Allen CR. The distribution and role of functional abundance in cross-scale resilience. Ecology 2018; 99:2421-2432. [PMID: 30175443 PMCID: PMC6792002 DOI: 10.1002/ecy.2508] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 05/29/2018] [Accepted: 07/20/2018] [Indexed: 12/30/2022]
Abstract
The cross-scale resilience model suggests that system-level ecological resilience emerges from the distribution of species' functions within and across the spatial and temporal scales of a system. It has provided a quantitative method for calculating the resilience of a given system and so has been a valuable contribution to a largely qualitative field. As it is currently laid out, the model accounts for the spatial and temporal scales at which environmental resources and species are present and the functional roles species play but does not inform us about how much resource is present or how much function is provided. In short, it does not account for abundance in the distribution of species and their functional roles within and across the scales of a system. We detail the ways in which we would expect species' abundance to be relevant to the cross-scale resilience model based on the extensive abundance literature in ecology. We also put forward a series of testable hypotheses that would improve our ability to anticipate and quantify how resilience is generated, and how ecosystems will (or will not) buffer recent rapid global changes. This stream of research may provide an improved foundation for the quantitative evaluation of ecological resilience.
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Affiliation(s)
- Shana M. Sundstrom
- School of Natural Resources, 103 Hardin Hall, 3310 Holdrege St., University of Nebraska-Lincoln, NE 68583, USA
- Corresponding author:
| | - David G. Angeler
- Swedish University of Agricultural Sciences, Department of Aquatic Sciences and Assessment, Box 7050, SE- 750 07 Uppsala, Sweden
| | - Chris Barichievy
- Zoological Society of London. Regents Park, London NW1 4RY, UK
- Institute for Communities and Wildlife in Africa, University of Cape Town, Rondebosch, Cape Town, 7700, South Africa
| | - Tarsha Eason
- U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH 45268, USA
| | - Ahjond Garmestani
- U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Cincinnati, OH 45268, USA
| | - Lance Gunderson
- Department of Environmental Studies, Emory University, Atlanta, Georgia 30322, USA
| | | | - Kirsty L. Nash
- Centre for Marine Socioecology, Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7000
| | - Trisha Spanbauer
- Department of Integrative Biology, University of Texas-Austin, TX 78712
| | - Craig Stow
- National Oceanographic and Atmospheric Administration Great Lakes Environmental Research Laboratory, Ann Arbor, MI 48108, USA
| | - Craig R. Allen
- U.S. Geological Survey - Nebraska Cooperative Fish & Wildlife Research Unit, University of Nebraska, Lincoln, NE 68583, USA
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12
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Shrub encroachment, productivity pulses, and core-transient dynamics of Chihuahuan Desert rodents. Ecosphere 2018. [DOI: 10.1002/ecs2.2330] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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13
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Christensen EM, Harris DJ, Ernest SKM. Long-term community change through multiple rapid transitions in a desert rodent community. Ecology 2018; 99:1523-1529. [PMID: 29718539 DOI: 10.1002/ecy.2373] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/06/2018] [Accepted: 03/29/2018] [Indexed: 11/08/2022]
Abstract
While studies increasingly document long-term change in community composition, whether long-term change occurs gradually or via rapid reorganization events remains unclear. We used Latent Dirichlet Allocation (LDA) and a change-point model to examine the long-term dynamics of a desert rodent community undergoing compositional change over a 38-yr span. Our approach detected three rapid reorganization events, where changes in the relative abundances of dominant and rare species occurred, and a separate period of increased variance in the structure of the community. These events coincided with time periods, possibly related to climate events, where the total abundance of rodents was extremely low. There are a variety of processes that could link low abundance events with a higher probability of rapid ecological transitions, including higher importance of stochastic processes (i.e., competitive interactions or priority effects) and the removal of structuring effects of competitive dominants or incumbent species. Continued study of the dynamics of community change will provide important information not only on the processes structuring communities, but will also provide guidance for forecasting how communities will undergo change in the future.
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Affiliation(s)
- Erica M Christensen
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, Florida, 32611, USA
| | - David J Harris
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, Florida, 32611, USA
| | - S K Morgan Ernest
- Department of Wildlife Ecology and Conservation, University of Florida, 110 Newins-Ziegler Hall, Gainesville, Florida, 32611, USA
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14
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Padfield D, Buckling A, Warfield R, Lowe C, Yvon-Durocher G. Linking phytoplankton community metabolism to the individual size distribution. Ecol Lett 2018; 21:1152-1161. [PMID: 29797805 PMCID: PMC6849760 DOI: 10.1111/ele.13082] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 02/04/2018] [Accepted: 04/14/2018] [Indexed: 11/30/2022]
Abstract
Quantifying variation in ecosystem metabolism is critical to predicting the impacts of environmental change on the carbon cycle. We used a metabolic scaling framework to investigate how body size and temperature influence phytoplankton community metabolism. We tested this framework using phytoplankton sampled from an outdoor mesocosm experiment, where communities had been either experimentally warmed (+ 4 °C) for 10 years or left at ambient temperature. Warmed and ambient phytoplankton communities differed substantially in their taxonomic composition and size structure. Despite this, the response of primary production and community respiration to long- and short-term warming could be estimated using a model that accounted for the size- and temperature dependence of individual metabolism, and the community abundance-body size distribution. This work demonstrates that the key metabolic fluxes that determine the carbon balance of planktonic ecosystems can be approximated using metabolic scaling theory, with knowledge of the individual size distribution and environmental temperature.
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Affiliation(s)
- Daniel Padfield
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK
| | - Angus Buckling
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Ruth Warfield
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK
| | - Chris Lowe
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Gabriel Yvon-Durocher
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9EZ, UK
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15
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D'Souza ML, Hebert PDN. Stable baselines of temporal turnover underlie high beta diversity in tropical arthropod communities. Mol Ecol 2018; 27:2447-2460. [DOI: 10.1111/mec.14693] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 03/12/2018] [Accepted: 03/19/2018] [Indexed: 01/24/2023]
Affiliation(s)
- Michelle L. D'Souza
- Centre for Biodiversity Genomics; University of Guelph; Guelph ON Canada
- Department of Integrative Biology; College of Biological Science; University of Guelph; Guelph ON Canada
| | - Paul D. N. Hebert
- Centre for Biodiversity Genomics; University of Guelph; Guelph ON Canada
- Department of Integrative Biology; College of Biological Science; University of Guelph; Guelph ON Canada
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Deacon AE, Jones FAM, Magurran AE. Gradients in predation risk in a tropical river system. Curr Zool 2018; 64:213-221. [PMID: 30402062 PMCID: PMC5905555 DOI: 10.1093/cz/zoy004] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 01/05/2018] [Indexed: 01/30/2023] Open
Abstract
The importance of predation risk as a key driver of evolutionary change is exemplified by the Northern Range in Trinidad, where research on guppies living in multiple parallel streams has provided invaluable insights into the process of evolution by natural selection. Although Trinidadian guppies are now a textbook example of evolution in action, studies have generally categorized predation as a dichotomous variable, representing high or low risk. Yet, ecologists appreciate that community structure and the attendant predation risk vary substantially over space and time. Here, we use data from a longitudinal study of fish assemblages at 16 different sites in the Northern Range to quantify temporal and spatial variation in predation risk. Specifically we ask: 1) Is there evidence for a gradient in predation risk? 2) Does the ranking of sites (by risk) change with the definition of the predator community (in terms of species composition and abundance currency), and 3) Are site rankings consistent over time? We find compelling evidence that sites lie along a continuum of risk. However, site rankings along this gradient depend on how predation is quantified in terms of the species considered to be predators and the abundance currency is used. Nonetheless, for a given categorization and currency, rankings are relatively consistent over time. Our study suggests that consideration of predation gradients will lead to a more nuanced understanding of the role of predation risk in behavioral and evolutionary ecology. It also emphasizes the need to justify and report the definition of predation risk being used.
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Affiliation(s)
- Amy E Deacon
- Department of Life Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago
- School of Biology, University of St Andrews, Fife, KY16 9TH Scotland, UK
| | - Faith A M Jones
- School of Biology, University of St Andrews, Fife, KY16 9TH Scotland, UK
| | - Anne E Magurran
- School of Biology, University of St Andrews, Fife, KY16 9TH Scotland, UK
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17
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Giacomini HC. Body Size and the Energetics of Food Chain Length: (A Comment on McGarvey et al., “Longer Food Chains in Pelagic Ecosystems: Trophic Energetics of Animal Body Size and Metabolic Efficiency”). Am Nat 2018. [DOI: 10.1086/695845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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18
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Tabak MA, Poncet S, Passfield K, Goheen JR, Martinez del Rio C. The ghost of invasives past: rat eradication and the community composition and energy flow of island bird communities. Ecosphere 2016. [DOI: 10.1002/ecs2.1442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Michael A. Tabak
- Department of Zoology and Physiology University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
- Program in Ecology University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
| | - Sally Poncet
- Beaver Island LandCare P.O. Box 756 Stanley FIQQ IZZ Falkland Islands
| | - Ken Passfield
- Beaver Island LandCare P.O. Box 756 Stanley FIQQ IZZ Falkland Islands
| | - Jacob R. Goheen
- Department of Zoology and Physiology University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
- Program in Ecology University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
| | - Carlos Martinez del Rio
- Department of Zoology and Physiology University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
- Program in Ecology University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
- Wyoming Biodiversity Institute University of Wyoming 1000 E. University Avenue Laramie Wyoming 82071 USA
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Energy flow and functional compensation in Great Basin small mammals under natural and anthropogenic environmental change. Proc Natl Acad Sci U S A 2015; 112:9656-61. [PMID: 26170294 DOI: 10.1073/pnas.1424315112] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Research on the ecological impacts of environmental change has primarily focused at the species level, leaving the responses of ecosystem-level properties like energy flow poorly understood. This is especially so over millennial timescales inaccessible to direct observation. Here we examine how energy flow within a Great Basin small mammal community responded to climate-driven environmental change during the past 12,800 y, and use this baseline to evaluate responses observed during the past century. Our analyses reveal marked stability in energy flow during rapid climatic warming at the terminal Pleistocene despite dramatic turnover in the distribution of mammalian body sizes and habitat-associated functional groups. Functional group turnover was strongly correlated with climate-driven changes in regional vegetation, with climate and vegetation change preceding energetic shifts in the small mammal community. In contrast, the past century has witnessed a substantial reduction in energy flow caused by an increase in energetic dominance of small-bodied species with an affinity for closed grass habitats. This suggests that modern changes in land cover caused by anthropogenic activities--particularly the spread of nonnative annual grasslands--has led to a breakdown in the compensatory dynamics of energy flow. Human activities are thus modifying the small mammal community in ways that differ from climate-driven expectations, resulting in an energetically novel ecosystem. Our study illustrates the need to integrate across ecological and temporal scales to provide robust insights for long-term conservation and management.
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Gese EM, Thompson CM. Does habitat heterogeneity in a multi-use landscape influence survival rates and density of a native mesocarnivore? PLoS One 2014; 9:e100500. [PMID: 24963713 PMCID: PMC4070944 DOI: 10.1371/journal.pone.0100500] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/27/2014] [Indexed: 11/29/2022] Open
Abstract
The relationships between predators, prey, and habitat have long been of interest to applied and basic ecologists. As a native Great Plains mesocarnivore of North America, swift foxes (Vulpes velox) depended on the historic disturbance regime to maintain open grassland habitat. With a decline in native grasslands and subsequent impacts to prairie specialists, notably the swift fox, understanding the influence of habitat on native predators is paramount to future management efforts. From 2001 to 2004, we investigated the influence of vegetation structure on swift fox population ecology (survival and density) on and around the Piñon Canyon Maneuver Site, southeastern Colorado, USA. We monitored 109 foxes on 6 study sites exposed to 3 different disturbance regimes (military training, grazing, unused). On each site we evaluated vegetation structure based on shrub density, basal coverage, vegetation height, and litter. Across all sites, annual fox survival rates ranged from 0.50 to 0.92 for adults and 0.27 to 0.78 for juveniles. Among sites, population estimates ranged from 1 to 7 foxes per 10 km transect. Fox density or survival was not related to the relative abundance of prey. A robust model estimating fox population size and incorporating both shrub density and percent basal cover as explanatory variables far outperformed all other models. Our results supported the idea that, in our region, swift foxes were shortgrass prairie specialists and also indicated a relationship between habitat quality and landscape heterogeneity. We suggest the regulation of swift fox populations may be based on habitat quality through landscape-mediated survival, and managers may effectively use disturbance regimes to create or maintain habitat for this native mesocarnivore.
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Affiliation(s)
- Eric M. Gese
- United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, Department of Wildland Resources, Utah State University, Logan, Utah, United States of America
| | - Craig M. Thompson
- Department of Wildland Resources, Utah State University, Logan, Utah, United States of America
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Ruhl HA, Bett BJ, Hughes SJM, Alt CHS, Ross EJ, Lampitt RS, Pebody CA, Smith KL, Billett DSM. Links between deep-sea respiration and community dynamics. Ecology 2014; 95:1651-62. [DOI: 10.1890/13-0675.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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22
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Hurlbert AH, Stegen JC. When should species richness be energy limited, and how would we know? Ecol Lett 2014; 17:401-13. [DOI: 10.1111/ele.12240] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/02/2013] [Accepted: 12/06/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Allen H. Hurlbert
- Department of Biology; University of North Carolina; Chapel Hill NC 27599-3280 USA
- Curriculum for Environment and Ecology; University of North Carolina; Chapel Hill NC 27599 USA
| | - James C. Stegen
- Pacific Northwest National Laboratory; 902 Battelle Blvd P.O. Box 999, MSIN J4-18 Richland WA 99352 USA
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Allington GRH, Koons DN, Morgan Ernest SK, Schutzenhofer MR, Valone TJ. Niche opportunities and invasion dynamics in a desert annual community. Ecol Lett 2012; 16:158-66. [DOI: 10.1111/ele.12023] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 07/26/2012] [Accepted: 10/02/2012] [Indexed: 11/30/2022]
Affiliation(s)
| | - David N. Koons
- Department of Wildland Resources and the Ecology Center; Utah State University; Logan; UT; 84322; USA
| | - S. K. Morgan Ernest
- Department of Biology and the Ecology Center; Utah State University; Logan; UT; 84322; USA
| | | | - Thomas J. Valone
- Department of Biology; Saint Louis University; St. Louis; MO; 63103; USA
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24
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Influence of vegetation structure on the small mammal community in a shortgrass prairie ecosystem. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s13364-012-0098-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Dochtermann NA, Jenkins SH, Swartz MJ, Hargett AC. The roles of competition and environmental heterogeneity in the maintenance of behavioral variation and covariation. Ecology 2012; 93:1330-9. [PMID: 22834374 DOI: 10.1890/11-1025.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Many models of selection predict that populations will lose variation in traits that affect fitness. Nonetheless, phenotypic variation is commonly observed in natural populations. We tested the influences of competition and spatial heterogeneity on behavioral variation within and among populations of Merriam's kangaroo rats (Dipodomys merriami) and tested for the differential expression of trait correlations. We found that populations of D. merriami exhibited more aggression at sites with more competition. Contrary to theoretical predictions and empirical results in other systems, the sites with the greatest spatial heterogeneity and highest levels of competition did not exhibit the most behavioral variation among individuals. However, the greatest within-individual behavioral variability in boldness (response to cues of predator presence) was exhibited where spatial heterogeneity was highest. Aggression and boldness of D. merriami were highly repeatable, that is, individuals behaved in a consistent manner over time, and the two behaviors were also highly correlated. Interestingly, the strength of this correlation was greatest where the competitive community was least diverse. These findings add to increasing evidence that natural populations of animals exhibit patterns of behavioral covariance, or personality structure, and suggest that competitive variation may act to erode personality structure.
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Affiliation(s)
- Ned A Dochtermann
- Department of Biology, University of Nevada-Reno, MS314, Reno, Nevada 89557, USA.
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26
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Valdivia N, Golléty C, Migné A, Davoult D, Molis M. Stressed but stable: canopy loss decreased species synchrony and metabolic variability in an intertidal hard-bottom community. PLoS One 2012; 7:e36541. [PMID: 22574181 PMCID: PMC3344890 DOI: 10.1371/journal.pone.0036541] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 04/09/2012] [Indexed: 11/18/2022] Open
Abstract
The temporal stability of aggregate community properties depends on the dynamics of the component species. Since species growth can compensate for the decline of other species, synchronous species dynamics can maintain stability (i.e. invariability) in aggregate properties such as community abundance and metabolism. In field experiments we tested the separate and interactive effects of two stressors associated with storminess--loss of a canopy-forming species and mechanical disturbances--on species synchrony and community respiration of intertidal hard-bottom communities on Helgoland Island, NE Atlantic. Treatments consisted of regular removal of the canopy-forming seaweed Fucus serratus and a mechanical disturbance applied once at the onset of the experiment in March 2006. The level of synchrony in species abundances was assessed from estimates of species percentage cover every three months until September 2007. Experiments at two sites consistently showed that canopy loss significantly reduced species synchrony. Mechanical disturbance had neither separate nor interactive effects on species synchrony. Accordingly, in situ measurements of CO(2)-fluxes showed that canopy loss, but not mechanical disturbances, significantly reduced net primary productivity and temporal variation in community respiration during emersion periods. Our results support the idea that compensatory dynamics may stabilise aggregate properties. They further suggest that the ecological consequences of the loss of a single structurally important species may be stronger than those derived from smaller-scale mechanical disturbances in natural ecosystems.
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Affiliation(s)
- Nelson Valdivia
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
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27
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Kelt DA. Comparative ecology of desert small mammals: a selective review of the past 30 years. J Mammal 2011. [DOI: 10.1644/10-mamm-s-238.1] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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28
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Meserve PL, Kelt DA, Previtali MA, Milstead WB, Gutiérrez JR. Global climate change and small mammal populations in north-central Chile. J Mammal 2011. [DOI: 10.1644/10-mamm-s-267.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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29
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Hernández L, Laundré JW, González-Romero A, López-Portillo J, Grajales KM. Tale of two metrics: density and biomass in a desert rodent community. J Mammal 2011. [DOI: 10.1644/10-mamm-a-175.1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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30
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Rowe RJ, Terry RC, Rickart EA. Environmental change and declining resource availability for small-mammal communities in the Great Basin. Ecology 2011; 92:1366-75. [DOI: 10.1890/10-1634.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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31
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Arim M, Berazategui M, Barreneche JM, Ziegler L, Zarucki M, Abades SR. Determinants of Density–Body Size Scaling Within Food Webs and Tools for Their Detection. ADV ECOL RES 2011. [DOI: 10.1016/b978-0-12-386475-8.00001-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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32
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Magurran AE, Baillie SR, Buckland ST, Dick JM, Elston DA, Scott EM, Smith RI, Somerfield PJ, Watt AD. Long-term datasets in biodiversity research and monitoring: assessing change in ecological communities through time. Trends Ecol Evol 2010; 25:574-82. [DOI: 10.1016/j.tree.2010.06.016] [Citation(s) in RCA: 447] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/24/2010] [Accepted: 06/25/2010] [Indexed: 10/19/2022]
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33
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Thibault KM, Ernest SKM, White EP, Brown JH, Goheen JR. Long-term insights into the influence of precipitation on community dynamics in desert rodents. J Mammal 2010. [DOI: 10.1644/09-mamm-s-142.1] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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34
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Thibault KM, Ernest SKM, Brown JH. Redundant or complementary? Impact of a colonizing species on community structure and function. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2010.18378.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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35
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Henderson PA, Magurran AE. Linking species abundance distributions in numerical abundance and biomass through simple assumptions about community structure. Proc Biol Sci 2010; 277:1561-70. [PMID: 20071388 DOI: 10.1098/rspb.2009.2189] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Species abundance distributions (SADs) are widely used as a tool for summarizing ecological communities but may have different shapes, depending on the currency used to measure species importance. We develop a simple plotting method that links SADs in the alternative currencies of numerical abundance and biomass and is underpinned by testable predictions about how organisms occupy physical space. When log numerical abundance is plotted against log biomass, the species lie within an approximately triangular region. Simple energetic and sampling constraints explain the triangular form. The dispersion of species within this triangle is the key to understanding why SADs of numerical abundance and biomass can differ. Given regular or random species dispersion, we can predict the shape of the SAD for both currencies under a variety of sampling regimes. We argue that this dispersion pattern will lie between regular and random for the following reasons. First, regular dispersion patterns will result if communities are comprised groups of organisms that use different components of the physical space (e.g. open water, the sea bed surface or rock crevices in a marine fish assemblage), and if the abundance of species in each of these spatial guilds is linked to the way individuals of varying size use the habitat. Second, temporal variation in abundance and sampling error will tend to randomize this regular pattern. Data from two intensively studied marine ecosystems offer empirical support for these predictions. Our approach also has application in environmental monitoring and the recognition of anthropogenic disturbance, which may change the shape of the triangular region by, for example, the loss of large body size top predators that occur at low abundance.
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Affiliation(s)
- Peter A Henderson
- Pisces Conservation Ltd., The Square, Pennington, Lymington, Hampshire, UK.
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36
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Wolverton S, Huston MA, Kennedy JH, Cagle K, Cornelius JD. Conformation to Bergmann's Rule in White-tailed Deer can be Explained by Food Availability. AMERICAN MIDLAND NATURALIST 2009. [DOI: 10.1674/0003-0031-162.2.403] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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37
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Morlon H, White EP, Etienne RS, Green JL, Ostling A, Alonso D, Enquist BJ, He F, Hurlbert A, Magurran AE, Maurer BA, McGill BJ, Olff H, Storch D, Zillio T. Taking species abundance distributions beyond individuals. Ecol Lett 2009; 12:488-501. [DOI: 10.1111/j.1461-0248.2009.01318.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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38
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Abstract
Major shifts in many ecosystem-level properties of tropical forests have been observed, but the processes driving these changes are poorly understood. The forest on Barro Colorado Island (BCI) exhibited a 20% decrease in the number of trees and a 10% increase in average diameter. Using a metabolism-based zero-sum framework, we show that increases in per capita resource use at BCI, caused by increased tree size and increased temperature, compensated for the observed declines in abundance. This trade-off between abundance and average resource use resulted in no net change in the rate resources are fluxed by the forest. Observed changes in the forest are not consistent with other hypotheses, including changes in overall resource availability and existing self-thinning models. The framework successfully predicts interrelated changes in size, abundance and temperature, indicating its utility for understanding changes in the structure and dynamics of ecosystems.
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Affiliation(s)
- S K Morgan Ernest
- Department of Biology and the Ecology Center, Utah State University, Logan, UT 84322, USA.
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39
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Ernest SKM, Brown JH, Thibault KM, White EP, Goheen JR. Zero sum, the niche, and metacommunities: long-term dynamics of community assembly. Am Nat 2009; 172:E257-69. [PMID: 18947326 DOI: 10.1086/592402] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Recent models of community assembly, structure, and dynamics have incorporated, to varying degrees, three mechanistic processes: resource limitation and interspecific competition, niche requirements of species, and exchanges between a local community and a regional species pool. Synthesizing 30 years of data from an intensively studied desert rodent community, we show that all of these processes, separately and in combination, have influenced the structural organization of this community and affected its dynamical response to both natural environmental changes and experimental perturbations. In addition, our analyses suggest that zero-sum constraints, niche differences, and metacommunity processes are inextricably linked in the ways that they affect the structure and dynamics of this system. Explicit consideration of the interaction of these processes should yield a deeper understanding of the assembly and dynamics of other ecological communities. This synthesis highlights the role that long-term data, especially when coupled with experimental manipulations, can play in assessing the fundamental processes that govern the structure and function of ecological communities.
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Affiliation(s)
- S K Morgan Ernest
- Department of Biology and the Ecology Center, Utah State University, Logan, Utah 84322, USA.
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40
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Thibault KM, Brown JH. Impact of an extreme climatic event on community assembly. Proc Natl Acad Sci U S A 2008; 105:3410-5. [PMID: 18303115 PMCID: PMC2265133 DOI: 10.1073/pnas.0712282105] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2007] [Indexed: 11/18/2022] Open
Abstract
Extreme climatic events are predicted to increase in frequency and magnitude, but their ecological impacts are poorly understood. Such events are large, infrequent, stochastic perturbations that can change the outcome of entrained ecological processes. Here we show how an extreme flood event affected a desert rodent community that has been monitored for 30 years. The flood (i) caused catastrophic, species-specific mortality; (ii) eliminated the incumbency advantage of previously dominant species; (iii) reset long-term population and community trends; (iv) interacted with competitive and metapopulation dynamics; and (v) resulted in rapid, wholesale reorganization of the community. This and a previous extreme rainfall event were punctuational perturbations-they caused large, rapid population- and community-level changes that were superimposed on a background of more gradual trends driven by climate and vegetation change. Captured by chance through long-term monitoring, the impacts of such large, infrequent events provide unique insights into the processes that structure ecological communities.
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Affiliation(s)
- Katherine M. Thibault
- *Department of Biology, University of New Mexico, Albuquerque, NM 87131; and
- Department of Biology, Furman University, Greenville, SC 29613
| | - James H. Brown
- *Department of Biology, University of New Mexico, Albuquerque, NM 87131; and
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41
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White EP, Ernest SKM, Kerkhoff AJ, Enquist BJ. Relationships between body size and abundance in ecology. Trends Ecol Evol 2007; 22:323-30. [PMID: 17399851 DOI: 10.1016/j.tree.2007.03.007] [Citation(s) in RCA: 368] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 02/19/2007] [Accepted: 03/15/2007] [Indexed: 11/29/2022]
Abstract
Body size is perhaps the most fundamental property of an organism and is related to many biological traits, including abundance. The relationship between abundance and body size has been extensively studied in an attempt to quantify the form of the relationship and to understand the processes that generate it. However, progress has been impeded by the under appreciated fact that there are four distinct, but interrelated, relationships between size and abundance that are often confused in the literature. Here, we review and distinguish between these four patterns, and discuss the linkages between them. We argue that a synthetic understanding of size-abundance relationships will result from more detailed analyses of individual patterns and from careful consideration of how and why the patterns are related.
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Affiliation(s)
- Ethan P White
- Department of Biology and the Ecology Center, Utah State University, Logan, UT 84322, USA.
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