1
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Fan C, Zhu D, Zhang T, Wu R. Efficient keystone species identification strategy based on tabu search. PLoS One 2023; 18:e0285575. [PMID: 37167265 PMCID: PMC10174581 DOI: 10.1371/journal.pone.0285575] [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: 02/11/2023] [Accepted: 04/25/2023] [Indexed: 05/13/2023] Open
Abstract
As species extinction accelerates globally and biodiversity declines dramatically, identifying keystone species becomes an effective way to conserve biodiversity. In traditional approaches, it is considered that the extinction of species with high centrality poses the greatest threat to secondary extinction. However, the indirect effect, which is equally important as the local and direct effects, is not included. Here, we propose an optimized disintegration strategy model for quantitative food webs and introduced tabu search, a metaheuristic optimization algorithm, to identify keystone species. Topological simulations are used to record secondary extinctions during species removal and secondary extinction areas, as well as to evaluate food web robustness. The effectiveness of the proposed strategy is also validated by comparing it with traditional methods. Results of our experiments demonstrate that our strategy can optimize the effect of food web disintegration and identify the species whose extinction is most destructive to the food web through global search. The algorithm provides an innovative and efficient way for further development of keystone species identification in the ecosystem.
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Affiliation(s)
- Chuanjin Fan
- School of Mathematics and Statistics, Shandong University, Weihai, Shandong, China
| | - Donghui Zhu
- School of Mathematics and Statistics, Shandong University, Weihai, Shandong, China
| | - Tongtong Zhang
- SDU-ANU Joint Science College, Shandong University, Weihai, Shandong, China
| | - Ruijia Wu
- School of Law, Weihai, Shandong University, Weihai, Shandong, China
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2
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García-Callejas D, Godoy O, Buche L, Hurtado M, Lanuza JB, Allen-Perkins A, Bartomeus I. Non-random interactions within and across guilds shape the potential to coexist in multi-trophic ecological communities. Ecol Lett 2023; 26:831-842. [PMID: 36972904 DOI: 10.1111/ele.14206] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/12/2023] [Accepted: 02/05/2023] [Indexed: 03/29/2023]
Abstract
Theory posits that the persistence of species in ecological communities is shaped by their interactions within and across trophic guilds. However, we lack empirical evaluations of how the structure, strength and sign of biotic interactions drive the potential to coexist in diverse multi-trophic communities. Here, we model community feasibility domains, a theoretically informed measure of multi-species coexistence probability, from grassland communities comprising more than 45 species on average from three trophic guilds (plants, pollinators and herbivores). Contrary to our hypothesis, increasing community complexity, measured either as the number of guilds or community richness, did not decrease community feasibility. Rather, we observed that high degrees of species self-regulation and niche partitioning allow for maintaining larger levels of community feasibility and higher species persistence in more diverse communities. Our results show that biotic interactions within and across guilds are not random in nature and both structures significantly contribute to maintaining multi-trophic diversity.
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Affiliation(s)
- David García-Callejas
- Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
- Instituto Universitario de Ciencias del Mar (INMAR), Departamento de Biología, Universidad de Cádiz, E-11510, Puerto Real, Spain
- School of Biological Sciences, University of Canterbury, 8140, Christchurch, Private Bag 4800, New Zealand
| | - Oscar Godoy
- Instituto Universitario de Ciencias del Mar (INMAR), Departamento de Biología, Universidad de Cádiz, E-11510, Puerto Real, Spain
| | - Lisa Buche
- Instituto Universitario de Ciencias del Mar (INMAR), Departamento de Biología, Universidad de Cádiz, E-11510, Puerto Real, Spain
| | - María Hurtado
- Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
- Instituto Universitario de Ciencias del Mar (INMAR), Departamento de Biología, Universidad de Cádiz, E-11510, Puerto Real, Spain
| | - Jose B Lanuza
- Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
| | - Alfonso Allen-Perkins
- Estación Biológica de Doñana (EBD-CSIC), Seville, Spain
- Departamento de Ingeniería Eléctrica, Electrónica, Automática y Física Aplicada, ETSIDI, Technical University of Madrid, 28040, Madrid, Spain
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3
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Martins LP, Stouffer DB, Blendinger PG, Böhning-Gaese K, Buitrón-Jurado G, Correia M, Costa JM, Dehling DM, Donatti CI, Emer C, Galetti M, Heleno R, Jordano P, Menezes Í, Morante-Filho JC, Muñoz MC, Neuschulz EL, Pizo MA, Quitián M, Ruggera RA, Saavedra F, Santillán V, Sanz D'Angelo V, Schleuning M, da Silva LP, Ribeiro da Silva F, Timóteo S, Traveset A, Vollstädt MGR, Tylianakis JM. Global and regional ecological boundaries explain abrupt spatial discontinuities in avian frugivory interactions. Nat Commun 2022; 13:6943. [PMID: 36376314 PMCID: PMC9663448 DOI: 10.1038/s41467-022-34355-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 10/20/2022] [Indexed: 11/16/2022] Open
Abstract
Species interactions can propagate disturbances across space via direct and indirect effects, potentially connecting species at a global scale. However, ecological and biogeographic boundaries may mitigate this spread by demarcating the limits of ecological networks. We tested whether large-scale ecological boundaries (ecoregions and biomes) and human disturbance gradients increase dissimilarity among plant-frugivore networks, while accounting for background spatial and elevational gradients and differences in network sampling. We assessed network dissimilarity patterns over a broad spatial scale, using 196 quantitative avian frugivory networks (encompassing 1496 plant and 1004 bird species) distributed across 67 ecoregions, 11 biomes, and 6 continents. We show that dissimilarities in species and interaction composition, but not network structure, are greater across ecoregion and biome boundaries and along different levels of human disturbance. Our findings indicate that biogeographic boundaries delineate the world's biodiversity of interactions and likely contribute to mitigating the propagation of disturbances at large spatial scales.
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Affiliation(s)
- Lucas P Martins
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private bag 4800, Christchurch, 8140, Aotearoa New Zealand.
| | - Daniel B Stouffer
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private bag 4800, Christchurch, 8140, Aotearoa New Zealand
| | - Pedro G Blendinger
- Instituto de Ecología Regional, Universidad Nacional de Tucumán and CONICET; CC 34, 4107, Tucumán, Argentina
- Facultad de Ciencias Naturales e Instituto Miguel Lillo, Universidad Nacional de Tucumán, Miguel Lillo 2005, 4000, Tucumán, Argentina
| | - Katrin Böhning-Gaese
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
- Institute for Ecology, Evolution and Diversity, Goethe University Frankfurt, Max-von-Laue-Straße 13, Frankfurt am Main, 60439, Germany
| | - Galo Buitrón-Jurado
- Laboratorio de Biología de Organismos, Centro de Ecología, Instituto Venezolano de Investigaciones Científicas (IVIC), Carretera Panamericana, km 11, Altos de Pipe, Edo, Miranda, Venezuela
- Universidad Estatal Amazónica-Sede Zamora Chinchipe; Calle Luis Imaicela entre Azuay y Rene Ulloa, El Pangui, Zamora Chinchipe, Ecuador
| | - Marta Correia
- Centre for Functional Ecology, Associate Laboratory TERRA, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - José Miguel Costa
- Centre for Functional Ecology, Associate Laboratory TERRA, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - D Matthias Dehling
- Swiss Federal Research Institute WSL, Zürcherstrasse 111, 8903, Birmensdorf, Switzerland
- Securing Antarctica's Environmental Future, School of Biological Sciences, Monash University, Melbourne, Victoria, 3800, Australia
| | - Camila I Donatti
- Conservation International, 2011 Crystal Dr. Suite 600, Arlington, VA, 22202, USA
- Department of Biological Sciences, Northern Arizona University, 617S. Beaver St., Flagstaff, AZ, 86011-5640, USA
| | - Carine Emer
- Rio de Janeiro Botanical Garden Research Institute, Rua Pacheco Leão 915, Jardim Botânico, Rio de Janeiro, RJ, CEP 22460-030, Brazil
- Department of Biodiversity, São Paulo State University - UNESP, Rio Claro, SP, Brazil
| | - Mauro Galetti
- Department of Biodiversity, São Paulo State University - UNESP, Rio Claro, SP, Brazil
| | - Ruben Heleno
- Centre for Functional Ecology, Associate Laboratory TERRA, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Pedro Jordano
- Estación Biológica de Doñana, CSIC, av. Americo Vespucio 26, 41092, Sevilla, Spain
- Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
| | - Ícaro Menezes
- Applied Conservation Ecology Lab, Santa Cruz State University, Rodovia Ilhéus- Itabuna, km 16, Salobrinho, Ilhéus, Bahia, 45662-000, Brazil
| | - José Carlos Morante-Filho
- Applied Conservation Ecology Lab, Santa Cruz State University, Rodovia Ilhéus- Itabuna, km 16, Salobrinho, Ilhéus, Bahia, 45662-000, Brazil
| | - Marcia C Muñoz
- Programa de Biología, Universidad de La Salle, Carrera 2 # 10-70, Bogotá, Colombia
| | - Eike Lena Neuschulz
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Marco Aurélio Pizo
- Department of Biodiversity, São Paulo State University - UNESP, Rio Claro, SP, Brazil
| | - Marta Quitián
- Systematic Zoology Laboratory, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji-shi, Tokyo, 192-0397, Japan
- Instituto Mediterráneo de Estudios Avanzados (CSIC-UIB), Miquel Marqués 21, Mallorca, Balearic Islands, 07190, Esporles, Spain
| | - Roman A Ruggera
- Instituto de Ecorregiones Andinas (Consejo Nacional de Investigaciones Científicas y Técnicas - Universidad Nacional de Jujuy), Canónigo Gorriti 237, Y4600 San Salvador de Jujuy, Jujuy, Argentina
| | - Francisco Saavedra
- Instituto de Ecología, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Vinicio Santillán
- Centro de Investigación, Innovación y Transferencia de Tecnología (CIITT), Unidad Académica de Posgrado, Universidad Católica de Cuenca, Av. de las Américas, Cuenca, Ecuador
| | - Virginia Sanz D'Angelo
- Laboratorio de Biología de Organismos, Centro de Ecología, Instituto Venezolano de Investigaciones Científicas (IVIC), Carretera Panamericana, km 11, Altos de Pipe, Edo, Miranda, Venezuela
| | - Matthias Schleuning
- Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Senckenberganlage 25, 60325, Frankfurt am Main, Germany
| | - Luís Pascoal da Silva
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661, Vairão, Portugal
- BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vairão, 4485-661, Vairão, Portugal
| | - Fernanda Ribeiro da Silva
- Laboratory of Human Ecology and Ethnobotany, Department of Ecology and Zoology, Federal University of Santa Catarina, UFSC, Campus Trindade, s/n, Florianópolis, SC, 88010-970, Brazil
| | - Sérgio Timóteo
- Centre for Functional Ecology, Associate Laboratory TERRA, Department of Life Sciences, University of Coimbra, Calçada Martim de Freitas, 3000-456, Coimbra, Portugal
| | - Anna Traveset
- Instituto Mediterráneo de Estudios Avanzados (CSIC-UIB), Miquel Marqués 21, Mallorca, Balearic Islands, 07190, Esporles, Spain
| | - Maximilian G R Vollstädt
- Section for Molecular Ecology and Evolution, Globe Institute, University of Copenhagen, Oester Voldgade 5-7, 1350, Copenhagen K, Denmark
| | - Jason M Tylianakis
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private bag 4800, Christchurch, 8140, Aotearoa New Zealand.
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4
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Kortsch S, Frelat R, Pecuchet L, Olivier P, Putnis I, Bonsdorff E, Ojaveer H, Jurgensone I, Strāķe S, Rubene G, Krūze Ē, Nordström MC. Disentangling temporal food web dynamics facilitates understanding of ecosystem functioning. J Anim Ecol 2021; 90:1205-1216. [PMID: 33608888 DOI: 10.1111/1365-2656.13447] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 01/22/2021] [Indexed: 12/17/2022]
Abstract
Studying how food web structure and function vary through time represents an opportunity to better comprehend and anticipate ecosystem changes. Yet, temporal studies of highly resolved food web structure are scarce. With few exceptions, most temporal food web studies are either too simplified, preventing a detailed assessment of structural properties or binary, missing the temporal dynamics of energy fluxes among species. Using long-term, multi-trophic biomass data coupled with highly resolved information on species feeding relationships, we analysed food web dynamics in the Gulf of Riga (Baltic Sea) over more than three decades (1981-2014). We combined unweighted (topology-based) and weighted (biomass- and flux-based) food web approaches, first, to unravel how distinct descriptors can highlight differences (or similarities) in food web dynamics through time, and second, to compare temporal dynamics of food web structure and function. We find that food web descriptors vary substantially and distinctively through time, likely reflecting different underlying ecosystem processes. While node- and link-weighted metrics reflect changes related to alterations in species dominance and fluxes, unweighted metrics are more sensitive to changes in species and link richness. Comparing unweighted, topology-based metrics and flux-based functions further indicates that temporal changes in functions cannot be predicted using unweighted food web structure. Rather, information on species population dynamics and weighted, flux-based networks should be included to better comprehend temporal food web dynamics. By integrating unweighted, node- and link-weighted metrics, we here demonstrate how different approaches can be used to compare food web structure and function, and identify complementary patterns of change in temporal food web dynamics, which enables a more complete understanding of the ecological processes at play in ecosystems undergoing change.
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Affiliation(s)
- Susanne Kortsch
- Environmental and Marine Biology, Åbo Akademi University, Turku, Finland
| | - Romain Frelat
- Wageningen University & Research, Wageningen, The Netherlands
| | - Laurene Pecuchet
- Environmental and Marine Biology, Åbo Akademi University, Turku, Finland.,UiT - The Arctic University of Norway, The Norwegian College of Fishery Science, Tromsø, Norway
| | - Pierre Olivier
- Environmental and Marine Biology, Åbo Akademi University, Turku, Finland
| | - Ivars Putnis
- Institute of Food Safety, Animal Health and Environment BIOR, Riga, Latvia
| | - Erik Bonsdorff
- Environmental and Marine Biology, Åbo Akademi University, Turku, Finland
| | - Henn Ojaveer
- Pärnu College, University of Tartu, Pärnu, Estonia.,National Institute of Aquatic Resources, Technical University of Denmark, Lyngby, Denmark
| | | | | | - Gunta Rubene
- Institute of Food Safety, Animal Health and Environment BIOR, Riga, Latvia
| | - Ēriks Krūze
- Institute of Food Safety, Animal Health and Environment BIOR, Riga, Latvia
| | - Marie C Nordström
- Environmental and Marine Biology, Åbo Akademi University, Turku, Finland
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5
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Zheng J, Brose U, Gravel D, Gauzens B, Luo M, Wang S. Asymmetric foraging lowers the trophic level and omnivory in natural food webs. J Anim Ecol 2021; 90:1444-1454. [PMID: 33666227 DOI: 10.1111/1365-2656.13464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 02/22/2021] [Indexed: 11/29/2022]
Abstract
Food webs capture the trophic relationships and energy fluxes between species, which has fundamental impacts on ecosystem functioning and stability. Within a food web, the energy flux distribution between a predator and its prey species is shaped by food quantity-quality trade-offs and the contiguity of foraging. But the distribution of energy fluxes among prey species as well as its drivers and implications remain unclear. Here we used 157 aquatic food webs, which contain explicit energy flux information, to examine whether a predator's foraging is asymmetric and biased towards lower or higher trophic levels, and how these patterns may change with trophic level. We also evaluate how traditional topology-based approaches may over- or under-estimate a predator's trophic level and omnivory by ignoring the asymmetric foraging patterns. Our results demonstrated the prevalence of asymmetric foraging in natural aquatic food webs. Although predators prefer prey at higher trophic levels with potentially higher food quality, they obtain their energy mostly from lower trophic levels with a higher food quantity. Both tendencies, that is, stronger feeding preference for prey at higher trophic levels and stronger energetic reliance on prey at lower trophic levels are alleviated for predators at higher trophic levels. The asymmetric foraging lowers trophic levels and omnivory at both species and food web levels, compared to estimates from traditional topology-based approaches. Such overestimations by topology-based approaches are most pronounced for predators at lower trophic levels and communities with higher number of trophic species. Our study highlights the importance of energy flux information in understanding the foraging behaviour of predators as well as the structural complexity of natural food webs. The increasing availability of flux-based food web data will thus provide new opportunities to reconcile food web structure, functioning and stability.
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Affiliation(s)
- Junjie Zheng
- Institute of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Ulrich Brose
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
| | - Dominique Gravel
- Département de Biologie, Universite de Sherbrooke, Sherbrooke, QC, Canada
| | - Benoit Gauzens
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.,Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
| | - Mingyu Luo
- Institute of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Shaopeng Wang
- Institute of Ecology, College of Urban and Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
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6
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Semenchenko VP, Moroz MD. Species and Trophic Structure of Macrozoobenthos Community in Different Types of Littoral Zones in a Mesotrophic Lake. CONTEMP PROBL ECOL+ 2021. [DOI: 10.1134/s1995425521010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Sulliván SMP, Bohenek JR, Cáceres C, Pomeroy LW. Multiple urban stressors drive fish-based ecological networks in streams of Columbus, Ohio, USA. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:141970. [PMID: 32920387 DOI: 10.1016/j.scitotenv.2020.141970] [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: 06/04/2020] [Revised: 08/11/2020] [Accepted: 08/23/2020] [Indexed: 06/11/2023]
Abstract
Integrating a network perspective into multiple-stressor research can reveal indirect stressor effects and simultaneously estimate both taxonomic and functional community characteristics, thus representing a novel approach to stressor paradigms in rivers. Using six years of data from twelve streams of Columbus, Ohio, USA, the effects of nutrients (N:P), impervious surface (%IS), and sedimentation on network properties were quantified. Variability in the strength and distribution of trophic interactions was assessed by incorporating biomass into networks. All stressors impacted some properties of network topology - linkage density (average number of links per species), connectance (fraction of all possible links realized in a network), and compartmentalization (degree to which networks contain discrete sub-webs), including synergistic interactive effects between sedimentation and stream size. We also found support for antagonistic effects between (1) sedimentation and %IS and between %IS and N:P on the weighted index mean link weight, which represents the magnitude of trophic interactions among species in a network, and (2) %IS and stream size on strength standard deviation, a measure of the distribution of total magnitude of all trophic interactions per species in a network. Overall, our results point to the potential for urban stressors such as impervious surfaces and sedimentation - alone and as interactions - to decrease network complexity, compartmentalization, and stability, likely through homogenizing habitat and limiting food resources. The observation that larger streams often buffered the negative effects of these stressors suggests that restoration and other management approaches might be most beneficial in smaller headwater streams of urban catchments.
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Affiliation(s)
- S Mažeika Patricio Sulliván
- Olentangy River Wetland Research Park, School of Environment and Natural Resources, The Ohio State University, Columbus, OH 43202, USA.
| | - Jason R Bohenek
- Olentangy River Wetland Research Park, School of Environment and Natural Resources, The Ohio State University, Columbus, OH 43202, USA
| | - Carlos Cáceres
- Olentangy River Wetland Research Park, School of Environment and Natural Resources, The Ohio State University, Columbus, OH 43202, USA
| | - Laura W Pomeroy
- Division of Environmental Health Sciences, College of Public Health, Ohio State University, Columbus, OH 43210, USA; Translational Data Analytics Institute, Ohio State University, Columbus, OH 43210, USA
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8
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Batáry P, Rösch V, Dormann CF, Tscharntke T. Increasing connectivity enhances habitat specialists but simplifies plant-insect food webs. Oecologia 2020; 195:539-546. [PMID: 33367959 PMCID: PMC7882472 DOI: 10.1007/s00442-020-04830-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 12/09/2020] [Indexed: 11/02/2022]
Abstract
Strong declines of grassland species diversity in small and isolated grassland patches have been observed at local and landscape scales. Here, we study how plant-herbivore interaction webs and habitat specialisation of leafhopper communities change with the size of calcareous grassland fragments and landscape connectivity. We surveyed leafhoppers and plants on 14 small (0.1-0.6 ha) and 14 large (1.2-8.8 ha) semi-natural calcareous grassland fragments in Central Germany, differing in isolation from other calcareous grasslands and in the percentage of arable land in the surrounding landscape (from simple to complex landscapes). We quantified weighted trophic links between plants and their phytophagous leafhoppers for each grassland fragment. We found that large and well-connected grassland fragments harboured a high portion of specialist leafhopper species, which in turn yielded low interaction diversity and simple plant-leafhopper food webs. In contrast, small and well-connected fragments exhibited high levels of generalism, leading to higher interaction diversity. In conclusion, food web complexity appeared to be a poor indicator for the management of insect diversity, as it is driven by specialist species, which require high connectivity of large fragments in complex landscapes. We conclude that habitat specialists should be prioritized since generalist species associated with small fragments are also widespread in the surrounding landscape matrix.
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Affiliation(s)
- Péter Batáry
- "Lendület" Landscape and Conservation Ecology, Institute of Ecology and Botany, Centre for Ecological Research, Alkotmány u. 2-4, 2163, Vácrátót, Hungary.
| | - Verena Rösch
- Ecosystem Analysis, Institute for Environmental Sciences, University of Koblenz-Landau, Fortstr. 7, 76829, Landau, Germany
| | - Carsten F Dormann
- Biometry and Environmental System Analysis, University of Freiburg, Tennenbacher Str. 4, 79106, Freiburg, Germany
| | - Teja Tscharntke
- Agroecology, University of Goettingen, Grisebachstr. 6, 37077, Göttingen, Germany
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9
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Ceron K, Oliveira‐Santos LGR, Souza CS, Mesquita DO, Caldas FLS, Araujo AC, Santana DJ. Global patterns in anuran–prey networks: structure mediated by latitude. OIKOS 2019. [DOI: 10.1111/oik.06621] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Karoline Ceron
- Programa de Pós Graduação em Ecologia e Conservação, Inst. de Biociências, Univ. Federal de Mato Grosso do Sul, Cidade Universitária CEP 79002‐970 Campo Grande Mato Grosso do Sul Brazil
| | | | - Camila S. Souza
- Programa de Pós Graduação em Ecologia e Conservação, Inst. de Biociências, Univ. Federal de Mato Grosso do Sul, Cidade Universitária CEP 79002‐970 Campo Grande Mato Grosso do Sul Brazil
- Campus Centro Politécnico, Depto de Botânica, Univ. Federal do Paraná Curitiba Paraná Brazil
| | - Daniel O. Mesquita
- Depto de Sistemática e Ecologia, Univ. Federal da Paraíba, Cidade Universitária João Pessoa Paraíba Brazil
| | | | - Andréa C. Araujo
- Inst. de Biociências, Univ. Federal de Mato Grosso do Sul, Cidade Universitária Campo Grande Mato Grosso do Sul Brazil
| | - Diego J. Santana
- Inst. de Biociências, Univ. Federal de Mato Grosso do Sul, Cidade Universitária Campo Grande Mato Grosso do Sul Brazil
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10
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Biological Health Assessments of Lotic Waters by Biotic Integrity Indices and their Relations to Water Chemistry. WATER 2019. [DOI: 10.3390/w11030436] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Biological health assessment (BHA) has developed as an imperative gauge in efficient management of freshwater resources and fish assemblages. The principal objective of this research is directed at the development and application of a new index under the umbrella of the famous index of biological integrity (IBI). Further, we intended to carry out comparative assessments of the new index with two existing indices and testified to their rational in Geum River watershed, which is the third largest river water basin in South Korea. We analyzed the biotic integrity of 149 different study sites in the streams and rivers of Geum River watershed, perusing fish assemblages and water quality data. The results revealed the newer index, i.e., multi-metric (mm) IBI 06 (mmIBI 06 metrics), as comparatively more efficient than previously used indices, i.e., mmIBI 08 and mmIBI 11. Furthermore, the linear regression and correlational analyses indicated harmonic relation of mmIBI 06 with mmIBI 08 (R2 = 0.85) and mmIBI 11 (R2 = 0.87). Nonetheless, linear regression modeling discovered a very strong positive relation between mmIBI 08 and mmIBI 11 (R2 = 0.91), thereby implying previously used indices demonstrate better approximation. In significant contrast to both old indices, the newer index exhibited improved facility to better classify the study sites between the assortments of ‘excellent to very poor’ compared to old indices elucidated one-step lower, i.e., from ‘excellent to poor’. For instance, the newer index categorized 60 sites as ‘very poor’, requiring immediate attention owing to biological degradation. Additionally, the newer index endures grander ability to indicate sites requiring immediate management or restoration attention with a plausible site classification, especially in relation to the invasive alien species (IAS). The water chemistry was mainly influenced by rampant anthropogenic actions compounded by intensive monsoon precipitation that may relinquish highly suitable grounds for invasive alien fish species. This may eventually lead to severe biological degradation and successive deterioration of habitat by the IAS. In conclusion, the newer index endures ample capacity to indicate the fish community disturbances in rivers and streams. Further, correlation, linear regression, as well as principal component analysis (PCA) analyses on biotic indices and water chemistry showed higher approximations. Therefore, our newer index would be a valuable BHA tool to classify and elucidate the streams and rivers by indicating sites necessitating preferred attention and restoration measures.
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11
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Identification of unique species in the marine ecosystem based on the weighted trophic field overlap. MethodsX 2019; 6:469-476. [PMID: 30923684 PMCID: PMC6423988 DOI: 10.1016/j.mex.2019.02.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 02/19/2019] [Indexed: 11/23/2022] Open
Abstract
Based on the trophic field overlap of species in the food webs, we propose using the weighted trophic field overlap (WTO) to determine the uniqueness of species in a topological network by considering the food web structure and the proportions of prey in the diets of predators. This proposed method measures uniqueness structurally and mathematically and considers cannibalism and mutual predation between species to overcome the deficiencies of the traditional method (the sum of trophic field overlap, STO), which only relies on the topological structure of the food web. Species with the lowest WTO values have high interaction strengths with other species in the food web weighted by the proportion of prey and play important roles as prey in the initial ecosystem, which are not recognized by the traditional method. The proposed index is sensitive to changes in the diets of predators since slight fluctuations may cause the index to vary considerably. The proposed methodology could be extended to other marine ecosystems to identify unique species from a practical and dynamic perspective and will contribute to the protection of unique species that maintain the trophic diversity of food webs and ecosystem robustness. •A WTO index was proposed for identifying unique species in food webs.•This index considers both the topological network structure and proportion of prey.•Cannibalism and mutual predation between species are also accounted for.
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12
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Gauzens B, Barnes A, Giling DP, Hines J, Jochum M, Lefcheck JS, Rosenbaum B, Wang S, Brose U. fluxweb
: An
R
package to easily estimate energy fluxes in food webs. Methods Ecol Evol 2018. [DOI: 10.1111/2041-210x.13109] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benoit Gauzens
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Institute of BiodiversityUniversity of Jena Jena Germany
| | - Andrew Barnes
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- School of ScienceUniversity of Waikato Hamilton New Zealand
- Institute of Landscape EcologyUniversity of Münster Münster Germany
| | - Darren P. Giling
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Institute of BiologyLeipzig University Leipzig Germany
| | - Jes Hines
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Institute of BiologyLeipzig University Leipzig Germany
| | - Malte Jochum
- Institute of Plant SciencesUniversity of Bern Bern Switzerland
| | - Jonathan S. Lefcheck
- Tennenbaum Marine Observatories Network, MarineGEOSmithsonian Institution Edgewater Maryland
| | - Benjamin Rosenbaum
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Institute of BiodiversityUniversity of Jena Jena Germany
| | - Shaopeng Wang
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Institute of BiodiversityUniversity of Jena Jena Germany
- Institute of Ecology, College of Urban and Environmental SciencePeking UniversityBeijingChina
| | - Ulrich Brose
- EcoNetLab, German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Leipzig Germany
- Institute of BiodiversityUniversity of Jena Jena Germany
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13
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Guzman LM, Germain RM, Forbes C, Straus S, O'Connor MI, Gravel D, Srivastava DS, Thompson PL. Towards a multi-trophic extension of metacommunity ecology. Ecol Lett 2018; 22:19-33. [PMID: 30370702 DOI: 10.1111/ele.13162] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/10/2018] [Accepted: 08/27/2018] [Indexed: 12/24/2022]
Abstract
Metacommunity theory provides an understanding of how spatial processes determine the structure and function of communities at local and regional scales. Although metacommunity theory has considered trophic dynamics in the past, it has been performed idiosyncratically with a wide selection of possible dynamics. Trophic metacommunity theory needs a synthesis of a few influential axis to simplify future predictions and tests. We propose an extension of metacommunity ecology that addresses these shortcomings by incorporating variability among trophic levels in 'spatial use properties'. We define 'spatial use properties' as a set of traits (dispersal, migration, foraging and spatial information processing) that set the spatial and temporal scales of organismal movement, and thus scales of interspecific interactions. Progress towards a synthetic predictive framework can be made by (1) documenting patterns of spatial use properties in natural food webs and (2) using theory and experiments to test how trophic structure in spatial use properties affects metacommunity dynamics.
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Affiliation(s)
- Laura Melissa Guzman
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rachel M Germain
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Coreen Forbes
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Samantha Straus
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mary I O'Connor
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dominique Gravel
- Département de biologie, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - Diane S Srivastava
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Patrick L Thompson
- Department of Zoology & Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
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14
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García-Callejas D, Molowny-Horas R, Araújo MB. The effect of multiple biotic interaction types on species persistence. Ecology 2018; 99:2327-2337. [PMID: 30030927 DOI: 10.1002/ecy.2465] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/03/2018] [Accepted: 07/05/2018] [Indexed: 11/08/2022]
Abstract
No species can persist in isolation from other species, but how biotic interactions affect species persistence is still a matter of inquiry. Is persistence more likely in communities with higher proportion of competing species, or in communities with more positive interactions? How do different components of community structure mediate this relationship? We address these questions using a novel simulation framework that generates realistic communities with varying numbers of species and different proportions of biotic interaction types within and across trophic levels. We show that when communities have fewer species, persistence is more likely if positive interactions-such as mutualism and commensalism-are prevalent. In species-rich communities, the disproportionate effect of positive interactions on persistence is diluted and different combinations of biotic interaction types can coexist without affecting persistence significantly. We present the first theoretical examination of how multiple-interaction networks with varying architectures relate to local species persistence, and provide insight about the underlying causes of stability in communities.
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Affiliation(s)
- David García-Callejas
- CREAF, Cerdanyola del Vallès, 08193, Spain.,Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), Calle José Gutiérrez Abascal 2, 28006, Madrid, Spain
| | | | - Miguel B Araújo
- Departamento de Biogeografía y Cambio Global, Museo Nacional de Ciencias Naturales, Consejo Superior de Investigaciones Científicas (CSIC), Calle José Gutiérrez Abascal 2, 28006, Madrid, Spain.,InBio/Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Universidade de Évora, Largo dos Colegiais, 7000, Évora, Portugal.,Center for Macroecology, Evolution and Climate (CMEC), Natural History Museum of Denmark, University of Copenhagen, 2100, Copenhagen, Denmark
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15
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Landi P, Minoarivelo HO, Brännström Å, Hui C, Dieckmann U. Complexity and stability of ecological networks: a review of the theory. POPUL ECOL 2018. [DOI: 10.1007/s10144-018-0628-3] [Citation(s) in RCA: 182] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Pietro Landi
- Department of Mathematical SciencesStellenbosch UniversityStellenboschSouth Africa
- Evolution and Ecology ProgramInternational Institute for Applied Systems AnalysisLaxenburgAustria
| | - Henintsoa O. Minoarivelo
- Department of Mathematical SciencesStellenbosch UniversityStellenboschSouth Africa
- Centre of Excellence in Mathematical and Statistical SciencesWits UniversityJohannesburgSouth Africa
| | - Åke Brännström
- Evolution and Ecology ProgramInternational Institute for Applied Systems AnalysisLaxenburgAustria
- Department of Mathematics and Mathematical StatisticsUmeå UniversityUmeåSweden
| | - Cang Hui
- Department of Mathematical SciencesStellenbosch UniversityStellenboschSouth Africa
- Mathematical and Physical BiosciencesAfrican Institute for Mathematical SciencesMuizenbergSouth Africa
| | - Ulf Dieckmann
- Evolution and Ecology ProgramInternational Institute for Applied Systems AnalysisLaxenburgAustria
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16
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Barbosa TAP, Rosa DCO, Soares BE, Costa CHA, Esposito MC, Montag LFA. Effect of flood pulses on the trophic ecology of four piscivorous fishes from the eastern Amazon. JOURNAL OF FISH BIOLOGY 2018; 93:30-39. [PMID: 29882352 DOI: 10.1111/jfb.13669] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 04/16/2018] [Indexed: 06/08/2023]
Abstract
This study investigated the effect of hydrological periods on the feeding activity and trophic interactions of four piscivorous fishes from the middle Xingu River, Brazil: pike-characid Boulengerella cuvieri, dogtooth characin Hydrolycus armatus, dogtooth characin Hydrolycus tatauaia and South American silver croaker Plagioscion squamosissimus. Repletion Index (IR %), Alimentary Index (IAi %) and food web properties were calculated for each species. A total of 825 specimens were collected. The IR showed changes in feeding intensity of B. cuvieri, H. armatus and H. tatauaia among hydrological periods. Flood pulse showed no influence on composition and importance of food items consumed. Trophic connections showed that connectivity ranged from 0.025 to 0.038. The highest number of trophic connections (75) occurred in the high-water period, when 51 food items were recorded and the lowest number of trophic connections (43) occurred in receding water, with 31 food items. In all food webs, over 45% of food items were consumed by only one species (ultra-peripheral items), which is common in piscivorous fishes.
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Affiliation(s)
- Thiago A P Barbosa
- Instituto de Estudos Costeiros (IECOS), Universidade Federal do Pará, Bragança, Brazil
| | - Daniela C O Rosa
- Laboratório de Ecologia de Peixes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bruno E Soares
- Laboratório de Ecologia de Peixes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Christophe H A Costa
- Instituto de Estudos Costeiros (IECOS), Universidade Federal do Pará, Bragança, Brazil
| | - Maria C Esposito
- Laboratório de Zoologia de Invertebrados, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Brazil
| | - Luciano F A Montag
- Instituto de Estudos Costeiros (IECOS), Universidade Federal do Pará, Bragança, Brazil
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17
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Deagle BE, Thomas AC, McInnes JC, Clarke LJ, Vesterinen EJ, Clare EL, Kartzinel TR, Eveson JP. Counting with DNA in metabarcoding studies: How should we convert sequence reads to dietary data? Mol Ecol 2018; 28:391-406. [PMID: 29858539 PMCID: PMC6905394 DOI: 10.1111/mec.14734] [Citation(s) in RCA: 279] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/28/2018] [Accepted: 05/30/2018] [Indexed: 02/06/2023]
Abstract
Advances in DNA sequencing technology have revolutionized the field of molecular analysis of trophic interactions, and it is now possible to recover counts of food DNA sequences from a wide range of dietary samples. But what do these counts mean? To obtain an accurate estimate of a consumer's diet should we work strictly with data sets summarizing frequency of occurrence of different food taxa, or is it possible to use relative number of sequences? Both approaches are applied to obtain semi-quantitative diet summaries, but occurrence data are often promoted as a more conservative and reliable option due to taxa-specific biases in recovery of sequences. We explore representative dietary metabarcoding data sets and point out that diet summaries based on occurrence data often overestimate the importance of food consumed in small quantities (potentially including low-level contaminants) and are sensitive to the count threshold used to define an occurrence. Our simulations indicate that using relative read abundance (RRA) information often provides a more accurate view of population-level diet even with moderate recovery biases incorporated; however, RRA summaries are sensitive to recovery biases impacting common diet taxa. Both approaches are more accurate when the mean number of food taxa in samples is small. The ideas presented here highlight the need to consider all sources of bias and to justify the methods used to interpret count data in dietary metabarcoding studies. We encourage researchers to continue addressing methodological challenges and acknowledge unanswered questions to help spur future investigations in this rapidly developing area of research.
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Affiliation(s)
- Bruce E Deagle
- Australian Antarctic Division, Channel Highway, Kingston, TAS, Australia
| | | | - Julie C McInnes
- Australian Antarctic Division, Channel Highway, Kingston, TAS, Australia
| | - Laurence J Clarke
- Australian Antarctic Division, Channel Highway, Kingston, TAS, Australia.,Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, TAS, Australia
| | - Eero J Vesterinen
- Biodiversity Unit and Department of Biology, University of Turku, Turku, Finland.,Department of Agricultural Sciences, University of Helsinki, Helsinki, Finland
| | - Elizabeth L Clare
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Tyler R Kartzinel
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island
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18
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Dougoud M, Vinckenbosch L, Rohr RP, Bersier LF, Mazza C. The feasibility of equilibria in large ecosystems: A primary but neglected concept in the complexity-stability debate. PLoS Comput Biol 2018; 14:e1005988. [PMID: 29420532 PMCID: PMC5821382 DOI: 10.1371/journal.pcbi.1005988] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 02/21/2018] [Accepted: 01/19/2018] [Indexed: 11/18/2022] Open
Abstract
The consensus that complexity begets stability in ecosystems was challenged in the seventies, a result recently extended to ecologically-inspired networks. The approaches assume the existence of a feasible equilibrium, i.e. with positive abundances. However, this key assumption has not been tested. We provide analytical results complemented by simulations which show that equilibrium feasibility vanishes in species rich systems. This result leaves us in the uncomfortable situation in which the existence of a feasible equilibrium assumed in local stability criteria is far from granted. We extend our analyses by changing interaction structure and intensity, and find that feasibility and stability is warranted irrespective of species richness with weak interactions. Interestingly, we find that the dynamical behaviour of ecologically inspired architectures is very different and richer than that of unstructured systems. Our results suggest that a general understanding of ecosystem dynamics requires focusing on the interplay between interaction strength and network architecture.
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Affiliation(s)
- Michaël Dougoud
- Department of Mathematics, University of Fribourg, Fribourg, Switzerland
| | - Laura Vinckenbosch
- Department of Mathematics, University of Fribourg, Fribourg, Switzerland
- University of Applied Sciences Western Switzerland - HES-SO, Yverdon-les-Bains, Switzerland
| | - Rudolf P. Rohr
- Department of Biology, Unit of Ecology and Evolution, University of Fribourg, Fribourg, Switzerland
| | - Louis-Félix Bersier
- Department of Biology, Unit of Ecology and Evolution, University of Fribourg, Fribourg, Switzerland
| | - Christian Mazza
- Department of Mathematics, University of Fribourg, Fribourg, Switzerland
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19
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Barnes AD, Jochum M, Lefcheck JS, Eisenhauer N, Scherber C, O'Connor MI, de Ruiter P, Brose U. Energy Flux: The Link between Multitrophic Biodiversity and Ecosystem Functioning. Trends Ecol Evol 2018; 33:186-197. [PMID: 29325921 DOI: 10.1016/j.tree.2017.12.007] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 12/06/2017] [Accepted: 12/13/2017] [Indexed: 01/02/2023]
Abstract
Relating biodiversity to ecosystem functioning in natural communities has become a paramount challenge as links between trophic complexity and multiple ecosystem functions become increasingly apparent. Yet, there is still no generalised approach to address such complexity in biodiversity-ecosystem functioning (BEF) studies. Energy flux dynamics in ecological networks provide the theoretical underpinning of multitrophic BEF relationships. Accordingly, we propose the quantification of energy fluxes in food webs as a powerful, universal tool for understanding ecosystem functioning in multitrophic systems spanning different ecological scales. Although the concept of energy flux in food webs is not novel, its application to BEF research remains virtually untapped, providing a framework to foster new discoveries into the determinants of ecosystem functioning in complex systems.
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Affiliation(s)
- Andrew D Barnes
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany; Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103 Leipzig, Germany; Institute of Landscape Ecology, University of Münster, Heisenbergstrasse 2, 48149 Münster, Germany.
| | - Malte Jochum
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | | | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany; Institute of Biology, Leipzig University, Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Christoph Scherber
- Institute of Landscape Ecology, University of Münster, Heisenbergstrasse 2, 48149 Münster, Germany
| | - Mary I O'Connor
- Department of Zoology and Biodiversity Research Centre, Univ. of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Peter de Ruiter
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands; Biometris, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Ulrich Brose
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany; Institute of Ecology, Friedrich Schiller University Jena, Dornburger-Str. 159, 07743 Jena, Germany
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20
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Tylianakis JM, Morris RJ. Ecological Networks Across Environmental Gradients. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2017. [DOI: 10.1146/annurev-ecolsys-110316-022821] [Citation(s) in RCA: 258] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jason M. Tylianakis
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
- Department of Life Sciences, Imperial College London, Silwood Park, Ascot, Berkshire SL5 7PY, United Kingdom
| | - Rebecca J. Morris
- Biological Sciences, Faculty of Natural and Environmental Sciences, University of Southampton, Southampton SO17 1BJ, United Kingdom
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
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21
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Cirtwill AR, Lagrue C, Poulin R, Stouffer DB. Host taxonomy constrains the properties of trophic transmission routes for parasites in lake food webs. Ecology 2017; 98:2401-2412. [PMID: 28609566 DOI: 10.1002/ecy.1927] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 05/19/2017] [Accepted: 06/01/2017] [Indexed: 11/11/2022]
Abstract
Some parasites move from one host to another via trophic transmission, the consumption of the parasite (inside its current host) by its future host. Feeding links among free-living species can thus be understood as potential transmission routes for parasites. As these links have different dynamic and structural properties, they may also vary in their effectiveness as trophic transmission routes. That is, some links may be better than others in allowing parasites to complete their complex life cycles. However, not all links are accessible to parasites as most are restricted to a small number of host taxa. This restriction means that differences between links involving host and non-host taxa must be considered when assessing whether transmission routes for parasites have different food web properties than other links. Here we use four New Zealand lake food webs to test whether link properties (contribution of a link to the predator's diet, prey abundance, prey biomass, amount of biomass transferred, centrality, and asymmetry) affect trophic transmission of parasites. Critically, we do this using both models that neglect the taxonomy of free-living species and models that explicitly include information about which free-living species are members of suitable host taxa. Although the best-fit model excluding taxonomic information suggested that transmission routes have different properties than other feeding links, when including taxonomy, the best-fit model included only an intercept. This means that the taxonomy of free-living species is a key determinant of parasite transmission routes and that food-web properties of transmission routes are constrained by the properties of host taxa. In particular, many intermediate hosts (prey) attain high biomasses and are involved in highly central links while links connecting intermediate to definitive (predator) hosts tend to be dynamically weak.
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Affiliation(s)
- Alyssa R Cirtwill
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand.,Department of Physics, Chemistry, and Biology (IFM), Linköping University, 58183, Linköping, Sweden.,Department of Zoology, University of Otago, 340 Great King Street, PO Box 56, Dunedin, 9054, New Zealand
| | - Clement Lagrue
- Department of Physics, Chemistry, and Biology (IFM), Linköping University, 58183, Linköping, Sweden
| | - Robert Poulin
- Department of Physics, Chemistry, and Biology (IFM), Linköping University, 58183, Linköping, Sweden
| | - Daniel B Stouffer
- Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, 8140, New Zealand
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22
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Abstract
A classic measure of ecological stability describes the tendency of a community to return to equilibrium after small perturbations. While many advances show how the network architecture of these communities severely constrains such tendencies, one of the most fundamental properties of network structure, i.e. degree heterogeneity-the variability of the number of links associated with each species, deserves further study. Here we show that the effects of degree heterogeneity on stability vary with different types of interspecific interactions. Degree heterogeneity consistently destabilizes ecological networks with both competitive and mutualistic interactions, while its effects on networks of predator-prey interactions such as food webs depend on prey contiguity, i.e. the extent to which the species consume an unbroken sequence of prey in community niche space. Increasing degree heterogeneity tends to stabilize food webs except those with the highest prey contiguity. These findings help explain why food webs are highly but not completely interval and, more broadly, deepen our understanding of the stability of complex ecological networks.
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Affiliation(s)
- Gang Yan
- School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China
| | - Neo D Martinez
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| | - Yang-Yu Liu
- Channing Division of Network Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA .,Center for Cancer Systems Biology, Dana Farber Cancer Institute, Boston, MA 02115, USA
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23
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Avalos DS, Mangeaud A, Valladares GR. Parasitism and Food Web Structure in Defoliating Lepidoptera - Parasitoid Communities on Soybean. NEOTROPICAL ENTOMOLOGY 2016; 45:712-717. [PMID: 27299866 DOI: 10.1007/s13744-016-0416-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 05/24/2016] [Indexed: 06/06/2023]
Abstract
Food webs are usually regarded as snapshots of community feeding interactions. Here, we describe the yearly and cumulative structure of parasitoid-caterpillar food webs on soybean in central Argentina, analyzing parasitism rates and their variability in relation to parasitoid diversity and food web vulnerability in the system. Lepidoptera larvae were collected along four seasons from soybean crops and reared in laboratory to obtain and identify adults and parasitoids. Eleven species of defoliating Lepidoptera and ten parasitoid species were recorded. Food web statistics showed rather low annual variability, with most variation coefficients in the order of 0.20 and generality showing the most stable values. Parasitism showed the highest variability, which was independent of parasitoid diversity and food web vulnerability, although parasitism rates were negatively related to parasitoid richness. Our study highlights the need to consider food web structure and variability in order to understand the functioning of ecological communities in general and in extensive agricultural ecosystems in particular.
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Affiliation(s)
- D S Avalos
- Facultad de Ciencias Agropecuarias, Univ Nacional de Córdoba, Av. Valparaíso S/N, Ciudad Universitaria, Córdoba, Argentina.
| | - A Mangeaud
- Facultad de Ciencias Exactas, Físicas y Naturales, UNC, Córdoba, Argentina
| | - G R Valladares
- Centro de Investigaciones Entomológicas de Córdoba, Instituto Multidisciplinario de Biología Vegetal (CONICET-UNC), Córdoba, Argentina
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24
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Neutel AM, Thorne MAS. Beyond connectedness: why pairwise metrics cannot capture community stability. Ecol Evol 2016; 6:7199-7206. [PMID: 28725392 PMCID: PMC5513267 DOI: 10.1002/ece3.2461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/29/2016] [Accepted: 08/04/2016] [Indexed: 11/17/2022] Open
Abstract
The connectedness of species in a trophic web has long been a key structural characteristic for both theoreticians and empiricists in their understanding of community stability. In the past decades, there has been a shift from focussing on determining the number of interactions to taking into account their relative strengths. The question is: How do the strengths of the interactions determine the stability of a community? Recently, a metric has been proposed which compares the stability of observed communities in terms of the strength of three‐ and two‐link feedback loops (cycles of interaction strengths). However, it has also been suggested that we do not need to go beyond the pairwise structure of interactions to capture stability. Here, we directly compare the performance of the feedback and pairwise metrics. Using observed food‐web structures, we show that the pairwise metric does not work as a comparator of stability and is many orders of magnitude away from the actual stability values. We argue that metrics based on pairwise‐strength information cannot capture the complex organization of strong and weak links in a community, which is essential for system stability.
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25
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Bairey E, Kelsic ED, Kishony R. High-order species interactions shape ecosystem diversity. Nat Commun 2016; 7:12285. [PMID: 27481625 PMCID: PMC4974637 DOI: 10.1038/ncomms12285] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Accepted: 06/20/2016] [Indexed: 02/02/2023] Open
Abstract
Classical theory shows that large communities are destabilized by random interactions among species pairs, creating an upper bound on ecosystem diversity. However, species interactions often occur in high-order combinations, whereby the interaction between two species is modulated by one or more other species. Here, by simulating the dynamics of communities with random interactions, we find that the classical relationship between diversity and stability is inverted for high-order interactions. More specifically, while a community becomes more sensitive to pairwise interactions as its number of species increases, its sensitivity to three-way interactions remains unchanged, and its sensitivity to four-way interactions actually decreases. Therefore, while pairwise interactions lead to sensitivity to the addition of species, four-way interactions lead to sensitivity to species removal, and their combination creates both a lower and an upper bound on the number of species. These findings highlight the importance of high-order species interactions in determining the diversity of natural ecosystems.
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Affiliation(s)
- Eyal Bairey
- Department of Physics, Technion—Israel Institute of Technology, Haifa 3200003, Israel
| | - Eric D. Kelsic
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Roy Kishony
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Department of Biology and Department of Computer Science, Technion—Israel Institute of Technology, Haifa 3200003, Israel
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Iles AC, Novak M. Complexity Increases Predictability in Allometrically Constrained Food Webs. Am Nat 2016; 188:87-98. [DOI: 10.1086/686730] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Zhao L, Zhang H, O'Gorman EJ, Tian W, Ma A, Moore JC, Borrett SR, Woodward G. Weighting and indirect effects identify keystone species in food webs. Ecol Lett 2016; 19:1032-40. [PMID: 27346328 PMCID: PMC5008267 DOI: 10.1111/ele.12638] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/13/2016] [Accepted: 05/20/2016] [Indexed: 11/27/2022]
Abstract
Species extinctions are accelerating globally, yet the mechanisms that maintain local biodiversity remain poorly understood. The extinction of species that feed on or are fed on by many others (i.e. 'hubs') has traditionally been thought to cause the greatest threat of further biodiversity loss. Very little attention has been paid to the strength of those feeding links (i.e. link weight) and the prevalence of indirect interactions. Here, we used a dynamical model based on empirical energy budget data to assess changes in ecosystem stability after simulating the loss of species according to various extinction scenarios. Link weight and/or indirect effects had stronger effects on food-web stability than the simple removal of 'hubs', demonstrating that both quantitative fluxes and species dissipating their effects across many links should be of great concern in biodiversity conservation, and the potential for 'hubs' to act as keystone species may have been exaggerated to date.
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Affiliation(s)
- Lei Zhao
- Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing, 102206, China.,Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK
| | - Huayong Zhang
- Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing, 102206, China
| | - Eoin J O'Gorman
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK
| | - Wang Tian
- Research Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing, 102206, China
| | - Athen Ma
- School of Electronic Engineering and Computer Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - John C Moore
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, 80523, USA.,Natural Resource Ecology Laboratory, Colorado State University, Fort Collins, CO, 80523, USA
| | - Stuart R Borrett
- Department of Biology and Marine Biology, University of North Carolina Wilmington, Wilmington, NC, 28403, USA.,Duke Network Analysis Center, Duke University, Durham, NC, 27708, USA
| | - Guy Woodward
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Buckhurst Road, Ascot, Berkshire, SL5 7PY, UK
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Genetic specificity of a plant-insect food web: Implications for linking genetic variation to network complexity. Proc Natl Acad Sci U S A 2016; 113:2128-33. [PMID: 26858398 DOI: 10.1073/pnas.1513633113] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Theory predicts that intraspecific genetic variation can increase the complexity of an ecological network. To date, however, we are lacking empirical knowledge of the extent to which genetic variation determines the assembly of ecological networks, as well as how the gain or loss of genetic variation will affect network structure. To address this knowledge gap, we used a common garden experiment to quantify the extent to which heritable trait variation in a host plant determines the assembly of its associated insect food web (network of trophic interactions). We then used a resampling procedure to simulate the additive effects of genetic variation on overall food-web complexity. We found that trait variation among host-plant genotypes was associated with resistance to insect herbivores, which indirectly affected interactions between herbivores and their insect parasitoids. Direct and indirect genetic effects resulted in distinct compositions of trophic interactions associated with each host-plant genotype. Moreover, our simulations suggest that food-web complexity would increase by 20% over the range of genetic variation in the experimental population of host plants. Taken together, our results indicate that intraspecific genetic variation can play a key role in structuring ecological networks, which may in turn affect network persistence.
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Wirta HK, Vesterinen EJ, Hambäck PA, Weingartner E, Rasmussen C, Reneerkens J, Schmidt NM, Gilg O, Roslin T. Exposing the structure of an Arctic food web. Ecol Evol 2015; 5:3842-56. [PMID: 26380710 PMCID: PMC4567885 DOI: 10.1002/ece3.1647] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/16/2015] [Accepted: 07/09/2015] [Indexed: 02/06/2023] Open
Abstract
How food webs are structured has major implications for their stability and dynamics. While poorly studied to date, arctic food webs are commonly assumed to be simple in structure, with few links per species. If this is the case, then different parts of the web may be weakly connected to each other, with populations and species united by only a low number of links. We provide the first highly resolved description of trophic link structure for a large part of a high-arctic food web. For this purpose, we apply a combination of recent techniques to describing the links between three predator guilds (insectivorous birds, spiders, and lepidopteran parasitoids) and their two dominant prey orders (Diptera and Lepidoptera). The resultant web shows a dense link structure and no compartmentalization or modularity across the three predator guilds. Thus, both individual predators and predator guilds tap heavily into the prey community of each other, offering versatile scope for indirect interactions across different parts of the web. The current description of a first but single arctic web may serve as a benchmark toward which to gauge future webs resolved by similar techniques. Targeting an unusual breadth of predator guilds, and relying on techniques with a high resolution, it suggests that species in this web are closely connected. Thus, our findings call for similar explorations of link structure across multiple guilds in both arctic and other webs. From an applied perspective, our description of an arctic web suggests new avenues for understanding how arctic food webs are built and function and of how they respond to current climate change. It suggests that to comprehend the community-level consequences of rapid arctic warming, we should turn from analyses of populations, population pairs, and isolated predator-prey interactions to considering the full set of interacting species.
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Affiliation(s)
- Helena K Wirta
- Department of Agricultural Sciences, University of Helsinki Latokartanonkaari 5, FI-00014, Helsinki, Finland
| | - Eero J Vesterinen
- Department of Biology, University of Turku Vesilinnantie 5, FI-20014, Turku, Finland
| | - Peter A Hambäck
- Department of Ecology, Environment and Plant Sciences, Stockholm University SE-106 91, Stockholm, Sweden
| | - Elisabeth Weingartner
- Department of Ecology, Environment and Plant Sciences, Stockholm University SE-106 91, Stockholm, Sweden
| | - Claus Rasmussen
- Department of Bioscience, Aarhus University Ny Munkegade 114, DK-8000, Aarhus, Denmark
| | - Jeroen Reneerkens
- Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen P.O. Box 11103, 9700 CC, Groningen, The Netherlands ; Arctic Research Centre, Department of Bioscience, Aarhus University Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Niels M Schmidt
- Arctic Research Centre, Department of Bioscience, Aarhus University Frederiksborgvej 399, DK-4000, Roskilde, Denmark
| | - Olivier Gilg
- Laboratoire Biogéosciences, UMR CNRS 6282, Université de Bourgogne 6 Boulevard Gabriel, 21000, Dijon, France ; Groupe de Recherche en Ecologie Arctique 16 rue de Vernot, 21440, Francheville, France
| | - Tomas Roslin
- Department of Agricultural Sciences, University of Helsinki Latokartanonkaari 5, FI-00014, Helsinki, Finland
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Fründ J, McCann KS, Williams NM. Sampling bias is a challenge for quantifying specialization and network structure: lessons from a quantitative niche model. OIKOS 2015. [DOI: 10.1111/oik.02256] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jochen Fründ
- Integrative Biology, Univ. of Guelph; Guelph ON Canada
- Entomology and Nematology, Univ. of California; Davis CA USA
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Mukherjee J, Scharler UM, Fath BD, Ray S. Measuring sensitivity of robustness and network indices for an estuarine food web model under perturbations. Ecol Modell 2015. [DOI: 10.1016/j.ecolmodel.2014.10.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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33
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Inherent directionality explains the lack of feedback loops in empirical networks. Sci Rep 2014; 4:7497. [PMID: 25531727 PMCID: PMC4273603 DOI: 10.1038/srep07497] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 11/24/2014] [Indexed: 11/08/2022] Open
Abstract
We explore the hypothesis that the relative abundance of feedback loops in many empirical complex networks is severely reduced owing to the presence of an inherent global directionality. Aimed at quantifying this idea, we propose a simple probabilistic model in which a free parameter γ controls the degree of inherent directionality. Upon strengthening such directionality, the model predicts a drastic reduction in the fraction of loops which are also feedback loops. To test this prediction, we extensively enumerated loops and feedback loops in many empirical biological, ecological and socio-technological directed networks. We show that, in almost all cases, empirical networks have a much smaller fraction of feedback loops than network randomizations. Quite remarkably, this empirical finding is quantitatively reproduced, for all loop lengths, by our model by fitting its only parameter γ. Moreover, the fitted value of γ correlates quite well with another direct measurement of network directionality, performed by means of a novel algorithm. We conclude that the existence of an inherent network directionality provides a parsimonious quantitative explanation for the observed lack of feedback loops in empirical networks.
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34
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Dynamics in microbial communities: unraveling mechanisms to identify principles. ISME JOURNAL 2014; 9:1488-95. [PMID: 25526370 DOI: 10.1038/ismej.2014.251] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 10/20/2014] [Accepted: 11/16/2014] [Indexed: 01/16/2023]
Abstract
Diversity begets higher-order properties such as functional stability and robustness in microbial communities, but principles that inform conceptual (and eventually predictive) models of community dynamics are lacking. Recent work has shown that selection as well as dispersal and drift shape communities, but the mechanistic bases for assembly of communities and the forces that maintain their function in the face of environmental perturbation are not well understood. Conceptually, some interactions among community members could generate endogenous dynamics in composition, even in the absence of environmental changes. These endogenous dynamics are further perturbed by exogenous forcing factors to produce a richer network of community interactions and it is this 'system' that is the basis for higher-order community properties. Elucidation of principles that follow from this conceptual model requires identifying the mechanisms that (a) optimize diversity within a community and (b) impart community stability. The network of interactions between organisms can be an important element by providing a buffer against disturbance beyond the effect of functional redundancy, as alternative pathways with different combinations of microbes can be recruited to fulfill specific functions.
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35
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Johnson S, Domínguez-García V, Donetti L, Muñoz MA. Trophic coherence determines food-web stability. Proc Natl Acad Sci U S A 2014; 111:17923-8. [PMID: 25468963 PMCID: PMC4273378 DOI: 10.1073/pnas.1409077111] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Why are large, complex ecosystems stable? Both theory and simulations of current models predict the onset of instability with growing size and complexity, so for decades it has been conjectured that ecosystems must have some unidentified structural property exempting them from this outcome. We show that trophic coherence--a hitherto ignored feature of food webs that current structural models fail to reproduce--is a better statistical predictor of linear stability than size or complexity. Furthermore, we prove that a maximally coherent network with constant interaction strengths will always be linearly stable. We also propose a simple model that, by correctly capturing the trophic coherence of food webs, accurately reproduces their stability and other basic structural features. Most remarkably, our model shows that stability can increase with size and complexity. This suggests a key to May's paradox, and a range of opportunities and concerns for biodiversity conservation.
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Affiliation(s)
- Samuel Johnson
- Warwick Mathematics Institute, and Centre for Complexity Science, University of Warwick, Coventry CV4 7AL, United Kingdom;
| | - Virginia Domínguez-García
- Departamento de Electromagnetismo y Física de la Materia, and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, 18071 Granada, Spain; and
| | - Luca Donetti
- Departamento de Electrónica y Tecnología de Computadores and Centro de Investigación en Tecnologías de la Información y de las Comunicaciones, Universidad de Granada, 18071 Granada, Spain
| | - Miguel A Muñoz
- Departamento de Electromagnetismo y Física de la Materia, and Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, 18071 Granada, Spain; and
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36
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37
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Food-web topology of Ukrainian mountain grasslands: Comparative properties and relations to ecosystem parameters. Ecol Modell 2014. [DOI: 10.1016/j.ecolmodel.2014.05.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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38
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Boit A, Gaedke U. Benchmarking successional progress in a quantitative food web. PLoS One 2014; 9:e90404. [PMID: 24587353 PMCID: PMC3937422 DOI: 10.1371/journal.pone.0090404] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 02/02/2014] [Indexed: 11/19/2022] Open
Abstract
Central to ecology and ecosystem management, succession theory aims to mechanistically explain and predict the assembly and development of ecological communities. Yet processes at lower hierarchical levels, e.g. at the species and functional group level, are rarely mechanistically linked to the under-investigated system-level processes which drive changes in ecosystem properties and functioning and are comparable across ecosystems. As a model system for secondary succession, seasonal plankton succession during the growing season is readily observable and largely driven autogenically. We used a long-term dataset from large, deep Lake Constance comprising biomasses, auto- and heterotrophic production, food quality, functional diversity, and mass-balanced food webs of the energy and nutrient flows between functional guilds of plankton and partly fish. Extracting population- and system-level indices from this dataset, we tested current hypotheses about the directionality of successional progress which are rooted in ecosystem theory, the metabolic theory of ecology, quantitative food web theory, thermodynamics, and information theory. Our results indicate that successional progress in Lake Constance is quantifiable, passing through predictable stages. Mean body mass, functional diversity, predator-prey weight ratios, trophic positions, system residence times of carbon and nutrients, and the complexity of the energy flow patterns increased during succession. In contrast, both the mass-specific metabolic activity and the system export decreased, while the succession rate exhibited a bimodal pattern. The weighted connectance introduced here represents a suitable index for assessing the evenness and interconnectedness of energy flows during succession. Diverging from earlier predictions, ascendency and eco-exergy did not increase during succession. Linking aspects of functional diversity to metabolic theory and food web complexity, we reconcile previously disjoint bodies of ecological theory to form a complete picture of successional progress within a pelagic food web. This comprehensive synthesis may be used as a benchmark for quantifying successional progress in other ecosystems.
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Affiliation(s)
- Alice Boit
- University of Potsdam, Institute of Biochemistry and Biology, Department of Ecology & Ecosystem Modelling, Potsdam, Germany
- Potsdam Institute for Climate Impact Research, Earth System Analysis, Potsdam, Germany
| | - Ursula Gaedke
- University of Potsdam, Institute of Biochemistry and Biology, Department of Ecology & Ecosystem Modelling, Potsdam, Germany
- Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany
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39
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Fabian Y, Sandau N, Bruggisser OT, Aebi A, Kehrli P, Rohr RP, Naisbit RE, Bersier LF. Plant diversity in a nutshell: testing for small-scale effects on trap nesting wild bees and wasps. Ecosphere 2014. [DOI: 10.1890/es13-00375.1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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40
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Morris RJ, Gripenberg S, Lewis OT, Roslin T. Antagonistic interaction networks are structured independently of latitude and host guild. Ecol Lett 2013; 17:340-9. [PMID: 24354432 PMCID: PMC4262010 DOI: 10.1111/ele.12235] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 10/07/2013] [Accepted: 11/19/2013] [Indexed: 11/30/2022]
Abstract
An increase in species richness with decreasing latitude is a prominent pattern in nature. However, it remains unclear whether there are corresponding latitudinal gradients in the properties of ecological interaction networks. We investigated the structure of 216 quantitative antagonistic networks comprising insect hosts and their parasitoids, drawn from 28 studies from the High Arctic to the tropics. Key metrics of network structure were strongly affected by the size of the interaction matrix (i.e. the total number of interactions documented between individuals) and by the taxonomic diversity of the host taxa involved. After controlling for these sampling effects, quantitative networks showed no consistent structural patterns across latitude and host guilds, suggesting that there may be basic rules for how sets of antagonists interact with resource species. Furthermore, the strong association between network size and structure implies that many apparent spatial and temporal variations in network structure may prove to be artefacts.
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Affiliation(s)
- Rebecca J Morris
- Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK
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41
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Rodríguez RA, Delgado JD, Herrera AM, Riera R, Navarro RM, Melián C, Dieguez L, Quirós Á. Effects of two traits of the ecological state equation on our understanding of species coexistence and ecosystem services. Ecol Modell 2013. [DOI: 10.1016/j.ecolmodel.2013.06.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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42
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Fabian Y, Sandau N, Bruggisser OT, Aebi A, Kehrli P, Rohr RP, Naisbit RE, Bersier LF. The importance of landscape and spatial structure for hymenopteran-based food webs in an agro-ecosystem. J Anim Ecol 2013; 82:1203-14. [PMID: 23863136 DOI: 10.1111/1365-2656.12103] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2012] [Accepted: 05/12/2013] [Indexed: 11/26/2022]
Abstract
1. Understanding the environmental factors that structure biodiversity and food webs among communities is central to assess and mitigate the impact of landscape changes. 2. Wildflower strips are ecological compensation areas established in farmland to increase pollination services and biological control of crop pests and to conserve insect diversity. They are arranged in networks in order to favour high species richness and abundance of the fauna. 3. We describe results from experimental wildflower strips in a fragmented agricultural landscape, comparing the importance of landscape, of spatial arrangement and of vegetation on the diversity and abundance of trap-nesting bees, wasps and their enemies, and the structure of their food webs. 4. The proportion of forest cover close to the wildflower strips and the landscape heterogeneity stood out as the most influential landscape elements, resulting in a more complex trap-nest community with higher abundance and richness of hosts, and with more links between species in the food webs and a higher diversity of interactions. We disentangled the underlying mechanisms for variation in these quantitative food web metrics. 5. We conclude that in order to increase the diversity and abundance of pollinators and biological control agents and to favour a potentially stable community of cavity-nesting hymenoptera in wildflower strips, more investment is needed in the conservation and establishment of forest habitats within agro-ecosystems, as a reservoir of beneficial insect populations.
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Affiliation(s)
- Yvonne Fabian
- Unit of Ecology & Evolution, University of Fribourg, Chemin du Musée 10, 1700, Fribourg, Switzerland
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43
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Rodríguez RA, Herrera AM, Delgado JD, Otto R, Quirós Á, Santander J, Miranda JV, Fernández MJ, Jiménez-Rodríguez A, Riera R, Navarro RM, Perdomo ME, Fernández-Palacios JM, Escudero CG, Arévalo JR, Diéguez L. Biomass-dispersal trade-off and the functional meaning of species diversity. Ecol Modell 2013. [DOI: 10.1016/j.ecolmodel.2013.03.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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44
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Eklöf A, Tang S, Allesina S. Secondary extinctions in food webs: a Bayesian network approach. Methods Ecol Evol 2013. [DOI: 10.1111/2041-210x.12062] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Anna Eklöf
- Department of Ecology & Evolution; University of Chicago; Chicago; IL; USA
| | - Si Tang
- Department of Ecology & Evolution; University of Chicago; Chicago; IL; USA
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45
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Bellingeri M, Vincenzi S. Robustness of empirical food webs with varying consumer's sensitivities to loss of resources. J Theor Biol 2013; 333:18-26. [PMID: 23685067 DOI: 10.1016/j.jtbi.2013.04.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 04/18/2013] [Accepted: 04/25/2013] [Indexed: 11/17/2022]
Abstract
Food web responses to species loss have been mostly studied in binary food webs, thus without accounting for the amount of energy transferred in consumer-resource interactions. We introduce an energetic criterion, called extinction threshold, for which a species goes secondarily extinct when a certain fraction of its incoming energy is lost. We study the robustness to random node loss of 10 food webs based on empirically-derived weightings. We use different extinction scenarios (random removal and from most- to least-connected species), and we simulate 10(5) replicates for each extinction threshold to account for stochasticity of extinction dynamics. We quantified robustness on the basis of how many additional species (i.e. secondary extinctions) were lost after the direct removal of species (i.e. primary extinctions). For all food webs, the expected robustness linearly decreases with extinction threshold, although a large variance in robustness is observed. The sensitivity of robustness to variations in extinction threshold increases with food web species richness and quantitative unweighted link density, while we observed a nonlinear relationship when the predictor is food web connectance and no relationship with the proportion of autotrophs.
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Affiliation(s)
- Michele Bellingeri
- Department of Physics, University of Parma, Viale Usberti 7/A, I-43124 Parma, Italy
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46
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An KG, Choi JW, Lee YJ. Modifications of ecological trophic structures on chemical gradients in lotic ecosystems and their relations to stream ecosystem health. Anim Cells Syst (Seoul) 2013. [DOI: 10.1080/19768354.2013.768295] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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47
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Burkle LA, Knight TM. Shifts in pollinator composition and behavior cause slow interaction accumulation with area in plant-pollinator networks. Ecology 2013; 93:2329-35. [PMID: 23236904 DOI: 10.1890/12-0367.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Although ecologists have a solid understanding of the positive species-area relationship, little is known about how and why variation in habitat area influences the richness, structure, and function of species interaction networks. To address this, we investigated plant-pollinator interaction networks of the herbaceous rocky outcrop communities in Ozark glades (Missouri, USA) of different areas. We quantified the degree to which the increase in the number of species interactions with area differed from a null model based on sampling, where numbers of individuals increase with area. Although plant-pollinator interactions were expected to increase more steeply with area than species richness as a result of sampling, the observed rate of increase was considerably lower than expected. Two mechanisms could lead to this pattern: a higher proportion of specialist species in larger glades or generalist pollinators becoming more selective in their diets in larger glades. We found support for the former hypothesis, and those changes in species composition were strong enough to outweigh behavioral changes in the opposite direction; generalist pollinators were more selective in smaller glades. If these results are general, larger habitats may be needed to conserve interactions than would be thought based on species accumulation curves.
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Affiliation(s)
- Laura A Burkle
- Department of Biology, Washington University, St. Louis, Missouri 63130 USA.
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48
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Ceneviva-Bastos M, Casatti L, Uieda V. Can seasonal differences influence food web structure on preserved habitats? Responses from two Brazilian streams. COMMUNITY ECOL 2012. [DOI: 10.1556/comec.13.2012.2.15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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49
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Passmore HA, Bruna EM, Heredia SM, Vasconcelos HL. Resilient networks of ant-plant mutualists in Amazonian forest fragments. PLoS One 2012; 7:e40803. [PMID: 22912666 PMCID: PMC3415396 DOI: 10.1371/journal.pone.0040803] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 06/13/2012] [Indexed: 11/18/2022] Open
Abstract
Background The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions. Methodology/Principal Findings We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments. Conclusions/Significance We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide.
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Affiliation(s)
- Heather A. Passmore
- Department of Wildlife Ecology & Conservation, University of Florida, Gainesville, Florida, United States of America
| | - Emilio M. Bruna
- Department of Wildlife Ecology & Conservation, University of Florida, Gainesville, Florida, United States of America
- Center for Latin American Studies, University of Florida, Gainesville, Florida, United States of America
- Biological Dynamics of Forest Fragments Project, Instituto Nacional de Pesquisas da Amazônia & Smithsonian Tropical Research Institute, Manaus, Amazonas, Brazil
- * E-mail:
| | - Sylvia M. Heredia
- Department of Botany and Plant Sciences, University of California Riverside, Riverside, California, United States of America
- Biological Dynamics of Forest Fragments Project, Instituto Nacional de Pesquisas da Amazônia & Smithsonian Tropical Research Institute, Manaus, Amazonas, Brazil
| | - Heraldo L. Vasconcelos
- Instituto de Biologia, Universidade Federal de Uberlândia, C.P. 593, Uberlândia, Minas Gerais, Brazil
- Biological Dynamics of Forest Fragments Project, Instituto Nacional de Pesquisas da Amazônia & Smithsonian Tropical Research Institute, Manaus, Amazonas, Brazil
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