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Rouabah A, Lasserre-Joulin F, Plantureux S, Taugourdeau S, Amiaud B. Functional trait composition of carabid beetle communities predicts prey suppression through both mass ratio and niche complementarity mechanisms. INSECT SCIENCE 2024; 31:562-574. [PMID: 37596960 DOI: 10.1111/1744-7917.13261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 07/03/2023] [Accepted: 07/12/2023] [Indexed: 08/21/2023]
Abstract
Several components of predator functional diversity have been hypothesized to influence prey suppression through either niche complementarity or mass ratio effects. Nevertheless, most studies have used a functional group approach when assessing the role of these predators in ecosystem functioning. By adopting a trait-based approach, we evaluated the relative contributions of carabid diversity components in predicting prey suppression. Our results highlight the importance of both taxonomic and functional diversity components of carabids as key drivers of prey suppression. Prey suppression was best predicted by carabid densities, with the dominance of Poecilus cupreus potentially driving the positive effect of community total abundance through the mass ratio effect. Prey suppression increased with increasing the density of large carabids. In addition, carabid eye diameter and antennal length were key functional traits for predicting prey suppression. Furthermore, prey suppression increased with increasing carabid functional richness following the niche complementarity effect. In contrast to functional richness, functional evenness and functional divergence of carabid communities were weakly correlated with prey suppression. By identifying which diversity components of carabid communities contribute the most to increase prey suppression, our results can guide efforts aiming to predict the relationship between diversity of these predators and ecosystem functioning.
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Affiliation(s)
| | | | | | - Simon Taugourdeau
- UMR SELMET, CIRAD, INRAE, Institut Agro, Université de Montpellier, Montpellier, 34000, France
- CIRAD, UMR SELMET-PPZS, Dakar, Sénégal
| | - Bernard Amiaud
- UMR Silva, Université de Lorraine, AgroParisTech, INRAE, Vandoeuvre Les Nancy, 54506, France
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Borges I, Oliveira L, Durão A, Arruda P, Soares AO. Feeding preference and intraguild interactions between the parasitoid Trichogramma achaeae and the predator Macrolophus pygmaeus, two biological agents of Tuta absoluta. PEST MANAGEMENT SCIENCE 2023; 79:4376-4382. [PMID: 37384575 DOI: 10.1002/ps.7635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/01/2023]
Abstract
BACKGROUND Tuta absoluta is an exotic species and a major pest of tomato crops in Europe. Macrolophus pygmaeus and Trichogramma achaeae are two biocontrol agents widely used in integrated pest management programs of the South American tomato pinworm Tuta absoluta. In this study, we evaluated under laboratory conditions the (i) voracity of M. pygmaeus females fed on single diets of Tuta absoluta eggs parasitized or unparasitized by Trichogramma achaeae, (ii) voracity and feeding preference of M. pygmaeus females provided with mixed diets of Tuta absoluta eggs unparasitized and parasitized by Trichogramma achaeae and (iii) effect of competitive and intraguild interactions between M. pygmaeus and Trichogramma achaeae on the number of Tuta absoluta eggs consumed and/or parasitized. Lastly, we assessed under field conditions the effect of interspecific and intraspecific interactions between natural enemies on the number of Tuta absoluta eggs consumed and/or parasitized. RESULTS Macrolophus pygmaeus consumed more unparasitized than parasitized eggs of Tuta absoluta. Under mixed diet regimes, Manly indices revealed a feeding preference for unparasitized eggs, and a decrease in the total number of eggs consumed, as the proportion of available parasitized eggs increased, whereas the unparasitized eggs were consumed in direct proportion to their availability. Conspecific interactions between M. pygmaeus, in contrast to Trichogramma achaeae, revealed the possible occurrence of intraspecific competition. For intraguild heterospecific interactions, the number of Tuta absoluta eggs consumed by M. pygmaeus and parasitized by Trichogramma achaeae was lower than that predicted for additive and non-interactive scenarios. Under field conditions, a significant difference between the conspecific treatment and heterospecific treatments revealed a slightly higher success rate in controlling Tuta absoluta when both M. pygmaeus and Trichogramma achaeae were used simultaneously. CONCLUSION Macrolophus pygmaeus prefers unparasitized eggs of Tuta absoluta but inflicts intraguild predation on Trichogramma achaeae. In conspecific experiments, mutual interference between M. pygmaeus predators intensifies as the number of individuals increases, but for Trichogramma achaeae, it occurs in an unpredictable manner. Adding Trichogramma achaeae could significantly increase the level of control of Tuta absoluta compared to what could be achieved when only M. pygmaeus is present in glasshouse tomatoes. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Isabel Borges
- cE3c - ABG - Center for Ecology, Evolution and Environmental Changes and Azorean Biodiversity Group and CHANGE - Global Change and Sustainability Institute, Faculty of Science and Technology, Ponta Delgada, Portugal
| | - Luisa Oliveira
- CBA - Biotechnology Center of Azores, Faculty of Sciences and Technology, University of the Azores, Ponta Delgada, Portugal
| | - Ana Durão
- Serviço de Desenvolvimento Agrário de São Miguel, Quinta de São Gonçalo, Ponta Delgada, Portugal
| | - Patricia Arruda
- Faculty of Science and Technology, University of the Azores, Ponta Delgada, Portugal
| | - António O Soares
- cE3c - ABG - Center for Ecology, Evolution and Environmental Changes and Azorean Biodiversity Group and CHANGE - Global Change and Sustainability Institute, Faculty of Science and Technology, Ponta Delgada, Portugal
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Vagnon C, Pomeranz J, Loheac B, Vallat M, Guillard J, Raymond JC, Sentis A, Frossard V. Changes in vertical and horizontal diversities mediated by the size structure of introduced fish collectively shape food-web stability. Ecol Lett 2023; 26:1752-1764. [PMID: 37492003 DOI: 10.1111/ele.14290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 07/05/2023] [Accepted: 07/10/2023] [Indexed: 07/27/2023]
Abstract
Species introductions can alter local food-web structure by changing the vertical or horizontal diversity within communities, largely driven by their body size distributions. Increasing vertical and horizontal diversities is predicted to have opposing effects on stability. However, their interactive effects remain largely overlooked. We investigated the independent and collective effects of vertical and horizontal diversities on food-web stability in alpine lakes stocked with variable body size distributions of introduced fish species. Introduced predators destabilize food-webs by increasing vertical diversity through food chain lengthening. Alternatively, increasing horizontal diversity results in more stable food-web topologies. A non-linear interaction between vertical and horizontal diversities suggests that increasing vertical diversity is most destabilizing when horizontal diversity is low. Our findings suggest that the size structure of introduced predators drives their impacts on stability by modifying the structure of food-webs, and highlights the interactive effects of vertical and horizontal diversities on stability.
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Affiliation(s)
- Chloé Vagnon
- Université Savoie Mont Blanc, INRAE, UMR CARRTEL, Thonon-les-Bains, France
- Pôle R&D Ecosystèmes Lacustres (ECLA), OFB-INRAE-USMB, Aix-en-Provence, France
| | | | - Bertrand Loheac
- Fédération de Savoie pour la Pêche et la Protection du Milieu Aquatique (FDPPMA 73), Saint-Alban-Leysse, France
| | - Manuel Vallat
- Fédération de Savoie pour la Pêche et la Protection du Milieu Aquatique (FDPPMA 73), Saint-Alban-Leysse, France
| | - Jean Guillard
- Université Savoie Mont Blanc, INRAE, UMR CARRTEL, Thonon-les-Bains, France
- Pôle R&D Ecosystèmes Lacustres (ECLA), OFB-INRAE-USMB, Aix-en-Provence, France
| | - Jean-Claude Raymond
- Pôle R&D Ecosystèmes Lacustres (ECLA), OFB-INRAE-USMB, Aix-en-Provence, France
- Office Française pour la Biodiversité, Unité Spécialisée Milieux Lacustres, Thonon-les-Bains, France
| | - Arnaud Sentis
- Pôle R&D Ecosystèmes Lacustres (ECLA), OFB-INRAE-USMB, Aix-en-Provence, France
- INRAE, Université Aix Marseille, UMR RECOVER, Aix-en-Provence, France
| | - Victor Frossard
- Université Savoie Mont Blanc, INRAE, UMR CARRTEL, Thonon-les-Bains, France
- Pôle R&D Ecosystèmes Lacustres (ECLA), OFB-INRAE-USMB, Aix-en-Provence, France
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4
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Chen S, Liu X, He Q, Zhou S. Higher-order interactions on disease transmission can reverse the dilution effect or weaken the amplification effect to unimodal pattern. Ecol Modell 2022. [DOI: 10.1016/j.ecolmodel.2022.110156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sentis A, Hemptinne J, Magro A, Outreman Y. Biological control needs evolutionary perspectives of ecological interactions. Evol Appl 2022; 15:1537-1554. [PMID: 36330295 PMCID: PMC9624075 DOI: 10.1111/eva.13457] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 07/20/2022] [Accepted: 07/26/2022] [Indexed: 05/30/2024] Open
Abstract
While ecological interactions have been identified as determinant for biological control efficiency, the role of evolution remains largely underestimated in biological control programs. With the restrictions on the use of both pesticides and exotic biological control agents (BCAs), the evolutionary optimization of local BCAs becomes central for improving the efficiency and the resilience of biological control. In particular, we need to better account for the natural processes of evolution to fully understand the interactions of pests and BCAs, including in biocontrol strategies integrating human manipulations of evolution (i.e., artificial selection and genetic engineering). In agroecosystems, the evolution of BCAs traits and performance depends on heritable phenotypic variation, trait genetic architecture, selection strength, stochastic processes, and other selective forces. Humans can manipulate these natural processes to increase the likelihood of evolutionary trait improvement, by artificially increasing heritable phenotypic variation, strengthening selection, controlling stochastic processes, or overpassing evolution through genetic engineering. We highlight these facets by reviewing recent studies addressing the importance of natural processes of evolution and human manipulations of these processes in biological control. We then discuss the interactions between the natural processes of evolution occurring in agroecosystems and affecting the artificially improved BCAs after their release. We emphasize that biological control cannot be summarized by interactions between species pairs because pests and biological control agents are entangled in diverse communities and are exposed to a multitude of deterministic and stochastic selective forces that can change rapidly in direction and intensity. We conclude that the combination of different evolutionary approaches can help optimize BCAs to remain efficient under changing environmental conditions and, ultimately, favor agroecosystem sustainability.
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Affiliation(s)
- Arnaud Sentis
- INRAEAix Marseille University, UMR RECOVERAix‐en‐ProvenceFrance
| | - Jean‐Louis Hemptinne
- Laboratoire Évolution et Diversité biologiqueUMR 5174 CNRS/UPS/IRDToulouseFrance
- Université Fédérale de Toulouse Midi‐Pyrénées – ENSFEACastanet‐TolosanFrance
| | - Alexandra Magro
- Laboratoire Évolution et Diversité biologiqueUMR 5174 CNRS/UPS/IRDToulouseFrance
- Université Fédérale de Toulouse Midi‐Pyrénées – ENSFEACastanet‐TolosanFrance
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Bai J, Zhang H, Zhou H, Li S, Gao B, Chen P, Ma L, Xu Z, Zhang Z, Xu C, Ruan L, Ge G. Winter coexistence in herbivorous waterbirds: Niche differentiation in a floodplain, Poyang Lake, China. Ecol Evol 2021; 11:16835-16848. [PMID: 34938476 PMCID: PMC8668764 DOI: 10.1002/ece3.8314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 10/15/2021] [Accepted: 10/22/2021] [Indexed: 11/13/2022] Open
Abstract
The classical niche theory supports the idea that stable coexistence requires ecological differences between closely related species. However, information on waterbirds coexistence in the entirely landlocked freshwater system of Poyang Lake is not well understood, especially when the available biomass of their food in the area decreases. In this study, we tested the ecological segregation mechanisms in the 2015/2016 and 2016/2017 wintering periods among eight herbivorous waterbirds (including the Siberian crane Grus leucogeranus, hooded crane Grus monacha, white-naped crane Grus vipio, common crane Grus grus, greater white-fronted goose Anser albifrons, bean goose Anser fabalis, swan goose Anser cygnoides, and tundra swan Cygnus columbianus) at Poyang Lake. Using field observations and species niche and foraging habitat selection models, we investigated the abundance, distribution, and food sources of these eight waterbird species to quantify and compare their habitat use and ecological niches. Our results showed that niche segregation among the waterbirds, with respect to food types, time, and spatial location, allow them to coexist and use similar resources. The water level gradually receded in the sub-lakes of the Poyang Lake, which could provide food sources and various habitats for wintering herbivorous waterbirds to coexist. We demonstrated that the differences in habitat use could mitigate interspecific competition, which may explain the mechanism whereby waterbirds of Poyang Lake coexist during the wintering period, despite considerable overlap in the dietary niches of herbivorous waterbirds.
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Affiliation(s)
- Junpeng Bai
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Huan Zhang
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Hongkang Zhou
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Shu Li
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Bin Gao
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Peng Chen
- Ministry of Ecology and Environment Nanjing Institute of Environmental Sciences Nanjing China
| | - Long Ma
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Zhifeng Xu
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Zhen Zhang
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Changxin Xu
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
| | - Luzhang Ruan
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
- Institute of Life Science and School of Life Sciences Jiangxi Province Key Laboratory of Watershed Ecosystem Change and Biodiversity Center for Watershed Ecology Nanchang University Nanchang China
| | - Gang Ge
- School of Life Sciences Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education Nanchang University Nanchang China
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Lu A, Gonthier DJ, Sciligo AR, Garcia K, Chiba T, Juárez G, Kremen C. Changes in arthropod communities mediate the effects of landscape composition and farm management on pest control ecosystem services in organically managed strawberry crops. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.14076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adrian Lu
- Department of Environmental Science, Policy, and Management University of California Berkeley CA USA
| | | | | | - Karina Garcia
- Department of Entomology University of Kentucky Lexington KY USA
| | - Taiki Chiba
- Department of Environmental Science, Policy, and Management University of California Berkeley CA USA
| | - Gila Juárez
- Department of Environmental Science, Policy, and Management University of California Berkeley CA USA
| | - Claire Kremen
- Department of Environmental Science, Policy, and Management University of California Berkeley CA USA
- Institute for Resources, Environment, and Sustainability Department of Zoology and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
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8
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Perez‐Alvarez R, Grab H, Polyakov A, Poveda K. Landscape composition mediates the relationship between predator body size and pest control. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02365. [PMID: 33938606 PMCID: PMC8459275 DOI: 10.1002/eap.2365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
Understanding the mechanisms contributing to positive relationships between predator diversity and natural pest control is fundamental to inform more effective management practices to support sustainable crop production. Predator body size can provide important insights to better understand and predict such predator-pest interactions. Yet, most studies exploring the link between predator body size and pest control have been conducted in species-poor communities under controlled environmental conditions, limiting our ability to generalize this relationship across heterogeneous landscapes. Using the community of naturally occurring ground beetles in cabbage fields, we examined how landscape composition (percent cropland) influences the size structure (mean, variance, and skewness of body size distribution) of predator communities and the subsequent effects on pest control. We found that predator communities shifted their size distribution toward larger body sizes in agriculturally dominated landscapes. This pattern arose from increasing numerical dominance of a few large-bodied species rather than an aggregated response across the community. Such landscape-driven changes in community size structure led to concomitant impacts on pest control, as the mean body size of predators was positively related to predation rates. Notably, the magnitude of pest control depended not only on the size of the dominant predators but was also strongly determined by the relative proportion of small vs. large-bodied species (i.e., skewness). Predation rates were higher in predator assemblages with even representation of small and large-bodied species relative to communities dominated by either large or small-bodied predators. Landscape composition may therefore modulate the relationship between predator body size and pest control by influencing the body size distribution of co-occurring species. Our study highlights the need to consider agricultural practices that not only boost effective predators, but also sustain a predator assemblage with a diverse set of traits to maximize overall pest control.
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Affiliation(s)
- Ricardo Perez‐Alvarez
- Department of EntomologyCornell UniversityIthacaNew York14853USA
- Zoological BiodiversityInstitute of GeobotanyLeibniz University of HannoverHannover30167Germany
| | - Heather Grab
- Department of EntomologyCornell UniversityIthacaNew York14853USA
- School of Integrative Plant ScienceCornell UniversityIthacaNew York14853USA
| | - Anthony Polyakov
- Department of EntomologyCornell UniversityIthacaNew York14853USA
| | - Katja Poveda
- Department of EntomologyCornell UniversityIthacaNew York14853USA
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9
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Webster SC, Chamberlain MJ, Hinton JW, Beasley JC. Isotope analysis reveals dietary overlap among sympatric canids. J Mammal 2021. [DOI: 10.1093/jmammal/gyab077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
When colonizing new regions, invading species might compete strongly with phylogenetically related species native to the regions they are colonizing, eventually leading to coexistence or displacement. In the southeast of the United States, recently established coyotes (Canis latrans) compete with red fox (Vulpes vulpes) and gray fox (Urocyon cinereoargenteus), although it remains unclear if competition is leading to resource partitioning or displacement by species. Using nitrogen and carbon stable isotopes, we tested the hypothesis that coyotes compete with foxes for food resources, with canids partitioning those resources to mitigate competition. We compared diets of canids in the southeast to those in the Plains region of the United States, a region where all three species historically have coexisted. We analyzed 217 hair samples from both regions pre-1960, prior to coyote colonization of the southeast, and post-2000, after coyotes were ubiquitous there, to assess differences in diet among species for both regions (southeast versus Plains and time periods, pre- versus postcolonization by coyotes). Modeling revealed significant dietary overlap among historical and contemporary populations in the southeast. Historically, all species partitioned resources in the Plains. Contemporarily, red fox and coyotes co-occurring in the Plains overlapped in diet; however, gray fox diet did not overlap with those of red fox and coyotes. Absence of partitioning in diet among co-occurring canids in the southeast indicates that interspecific competition could be strong in the region. Competition among canid populations in the southeast could lead to further resource partitioning among species that promotes coexistence or competitive exclusion of smaller fox species where coyote populations are abundant.
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Affiliation(s)
- Sarah C Webster
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30601, USA
- Savannah River Ecology Lab, University of Georgia, Aiken, SC 29802, USA
| | - Michael J Chamberlain
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30601, USA
| | - Joseph W Hinton
- Department of Environmental and Forest Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, NY 13210, USA
| | - James C Beasley
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30601, USA
- Savannah River Ecology Lab, University of Georgia, Aiken, SC 29802, USA
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10
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Nessel MP, Konnovitch T, Romero GQ, González AL. Nitrogen and phosphorus enrichment cause declines in invertebrate populations: a global meta-analysis. Biol Rev Camb Philos Soc 2021; 96:2617-2637. [PMID: 34173704 DOI: 10.1111/brv.12771] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 06/15/2021] [Accepted: 06/17/2021] [Indexed: 01/17/2023]
Abstract
Human-driven changes in nitrogen (N) and phosphorus (P) inputs are modifying biogeochemical cycles and the trophic state of many habitats worldwide. These alterations are predicted to continue to increase, with the potential for a wide range of impacts on invertebrates, key players in ecosystem-level processes. Here, we present a meta-analysis of 1679 cases from 207 studies reporting the effects of N, P, and combined N + P enrichment on the abundance, biomass, and richness of aquatic and terrestrial invertebrates. Nitrogen and phosphorus additions decreased invertebrate abundance in terrestrial and aquatic ecosystems, with stronger impacts under combined N + P additions. Likewise, N and N + P additions had stronger negative impacts on the abundance of tropical than temperate invertebrates. Overall, the effects of nutrient enrichment did not differ significantly among major invertebrate taxonomic groups, suggesting that changes in biogeochemical cycles are a pervasive threat to invertebrate populations across ecosystems. The effects of N and P additions differed significantly among invertebrate trophic groups but N + P addition had a consistent negative effect on invertebrates. Nutrient additions had weaker or inconclusive impacts on invertebrate biomass and richness, possibly due to the low number of case studies for these community responses. Our findings suggest that N and P enrichment affect invertebrate community structure mainly by decreasing invertebrate abundance, and these effects are dependent on the habitat and trophic identity of the invertebrates. These results highlight the important effects of human-driven nutrient enrichment on ecological systems and suggest a potential driver for the global invertebrate decline documented in recent years.
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Affiliation(s)
- Mark P Nessel
- Center for Computational and Integrative Biology, Rutgers University, 201 S. Broadway, Camden, NJ, 08103, U.S.A
| | - Theresa Konnovitch
- Center for Computational and Integrative Biology, Rutgers University, 201 S. Broadway, Camden, NJ, 08103, U.S.A.,Biology Department, La Salle University, 1900 W Olney Ave, Philadelphia, PA, 19141, U.S.A
| | - Gustavo Q Romero
- Department of Animal Biology, Institute of Biology, University of Campinas (UNICAMP), CP 6109, Campinas, São Paulo, 13083-862, Brazil
| | - Angélica L González
- Center for Computational and Integrative Biology, Rutgers University, 201 S. Broadway, Camden, NJ, 08103, U.S.A.,Biology Department, Rutgers University, Science Building, 315 Penn Street, Camden, NJ, 08102, U.S.A
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11
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Qu Y, Ullah F, Luo C, Monticelli LS, Lavoir AV, Gao X, Song D, Desneux N. Sublethal effects of beta-cypermethrin modulate interspecific interactions between specialist and generalist aphid species on soybean. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 206:111302. [PMID: 33080437 DOI: 10.1016/j.ecoenv.2020.111302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 08/21/2020] [Accepted: 09/06/2020] [Indexed: 06/11/2023]
Abstract
In agroecosystems, plant-pest interactions are at the basis of complex food webs, which can be affected by both biotic and abiotic factors. In the present study, we evaluated the impact of the insecticide beta-cypermethrin on interspecific interactions between the specialist aphid Aphis glycines and the generalist aphid Aulacorthum solani on soybean. Aphis glycines showed higher fecundity than A. solani on soybean and the aphids caused unbalanced reduction in population growth on each other. A sublethal concentration of beta-cypermethrin (LC5 for A. glycines) stimulated the reproduction of A. glycines but it did not impact the fecundity of A. solani. However, the LC5 of beta-cypermethrin enhanced the interspecific inhibition of fecundity between the two aphid species. Moreover, the two species showed different spatial distribution on soybean seedlings. Aphis glycines mainly aggregated on the stem of soybean plant while A. solani colonized soybean leaves. The LC5 of beta-cypermethrin drove A. solani migrating from soybean leaves to stems independently of interspecific competition. Aphis glycines facilitated A. solani colonization on soybean plant through impacting host susceptibility, and vice versa. Nevertheless, such facilitated colonization-induced susceptibility could be modulated through exposure to the LC5 of beta-cypermethrin. These findings hinted that the pyrethroid insecticide beta-cypermethrin has the potential to mediate the interspecific competition between specialist and generalist aphids (at the sublethal concentration of LC5), and that it could influence aphid population growth and community structure in soybean crops. This knowledge could contribute to rationalize application of insecticides and to optimize Integrated Pest Management in soybean.
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Affiliation(s)
- Yanyan Qu
- Université Côte d'Azur, INRAE, CNRS, UMR ISA, 06000, Nice, France.
| | - Farman Ullah
- Department of Entomology, China Agricultural University, Beijing, 100193, China
| | - Chen Luo
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi Province, China
| | | | | | - Xiwu Gao
- Department of Entomology, China Agricultural University, Beijing, 100193, China
| | - Dunlun Song
- Department of Entomology, China Agricultural University, Beijing, 100193, China.
| | - Nicolas Desneux
- Université Côte d'Azur, INRAE, CNRS, UMR ISA, 06000, Nice, France
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12
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Ostertag R, Sebastián-González E, Peck R, Hall T, Kim J, DiManno N, Rayome D, Cordell S, Banko P, Uowolo A. Linking plant and animal functional diversity with an experimental community restoration in a Hawaiian lowland wet forest. FOOD WEBS 2020. [DOI: 10.1016/j.fooweb.2020.e00171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Culshaw‐Maurer M, Sih A, Rosenheim JA. Bugs scaring bugs: enemy-risk effects in biological control systems. Ecol Lett 2020; 23:1693-1714. [PMID: 32902103 PMCID: PMC7692946 DOI: 10.1111/ele.13601] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/30/2020] [Accepted: 08/13/2020] [Indexed: 01/09/2023]
Abstract
Enemy-risk effects, often referred to as non-consumptive effects (NCEs), are an important feature of predator-prey ecology, but their significance has had little impact on the conceptual underpinning or practice of biological control. We provide an overview of enemy-risk effects in predator-prey interactions, discuss ways in which risk effects may impact biocontrol programs and suggest avenues for further integration of natural enemy ecology and integrated pest management. Enemy-risk effects can have important influences on different stages of biological control programs, including natural enemy selection, efficacy testing and quantification of non-target impacts. Enemy-risk effects can also shape the interactions of biological control with other pest management practices. Biocontrol systems also provide community ecologists with some of the richest examples of behaviourally mediated trophic cascades and demonstrations of how enemy-risk effects play out among species with no shared evolutionary history, important topics for invasion biology and conservation. We conclude that the longstanding use of ecological theory by biocontrol practitioners should be expanded to incorporate enemy-risk effects, and that community ecologists will find many opportunities to study enemy-risk effects in biocontrol settings.
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Affiliation(s)
- Michael Culshaw‐Maurer
- Department of Entomology and NematologyUniversity of CaliforniaDavisCA95616USA
- Department of Evolution and EcologyUniversity of CaliforniaDavisCA95616USA
| | - Andrew Sih
- Department of Environmental Science and PolicyUniversity of CaliforniaDavisCA95616USA
| | - Jay A. Rosenheim
- Department of Entomology and NematologyUniversity of CaliforniaDavisCA95616USA
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14
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Klapwijk MJ. The effect of multiple natural enemies on a shared herbivore prey. Ecol Evol 2019; 9:9052-9060. [PMID: 31463003 PMCID: PMC6706237 DOI: 10.1002/ece3.5451] [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: 02/06/2019] [Revised: 05/20/2019] [Accepted: 06/17/2019] [Indexed: 11/05/2022] Open
Abstract
Natural enemy diversity is thought to be important for effective suppression of herbivores in production systems. Studies investigating the importance of the diversity and composition of the natural enemy complex often use within-year empirical studies or experimental exclusion setups.However, within-year population suppression might not translate in long-term population regulation. Therefore, I used a combination of long-term data collection and an exclusion experiment to investigate mechanisms behind year-to-year population changes and potential effects of disturbance of the natural enemy complex.Using the holly leaf miner study system in Wytham Woods, I find that the dominant predator in the system does not necessarily contribute the most to the reduction in year-to-year changes in mine density or within-patch fluctuations. Using the exclusion experiment, it becomes clear that parasitism later in the prey life cycle can to a certain level compensate for disruption of mortality in the earlier life stage of the prey.Thus, for host suppression in perennial systems the mortality pressure over the whole life cycle is important and disturbance during one part of the life cycle might not necessarily be buffered by mortality in other parts of the life cycle, especially if the natural enemy complex consists of multiple predator guilds.
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Affiliation(s)
- Maartje J. Klapwijk
- Department of EcologySwedish University of Agricultural SciencesUppsalaSweden
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15
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Griffin JN, Silliman BR. Predator size-structure and species identity determine cascading effects in a coastal ecosystem. Ecol Evol 2018; 8:12435-12442. [PMID: 30619556 PMCID: PMC6308854 DOI: 10.1002/ece3.4571] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/22/2018] [Accepted: 08/30/2018] [Indexed: 11/24/2022] Open
Abstract
Cascading consequences of predator extinctions are well documented, but impacts of perturbations to predator size-structure and how these vary across species remain unclear. Body size is hypothesized to be a key trait governing individual predators' impact on ecosystems. Therefore, shifts in predator size-structure should trigger ecosystem ramifications which are consistent across functionally similar species. Using a US salt marsh as a model system, we tested this hypothesis by manipulating size class (small, medium, and large) and size diversity (combination of all three size classes) within two closely related and functionally similar predatory crab species over 4 months. Across treatments, predators suppressed densities of a dominant grazer and an ecosystem engineer, enhanced plant biomass, and altered sediment properties (redox potential and saturation). Over the metabolically equivalent experimental predator treatments, small size class predators had stronger average impacts on response variables, and size class interacted with predator species identity to drive engineer suppression. Within both predator species, size diversity increased cannibalism and slightly weakened the average impact. These results show that predator impacts in a salt marsh ecosystem are determined by both size class and size diversity; they also highlight that size class can have species-dependent and response-dependent effects, underlining the challenge of generalizing trait effects.
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Affiliation(s)
| | - Brian R. Silliman
- Division of Marine Science and Conservation, Nicholas School of the EnvironmentDuke UniversityBeaufortNorth Carolina
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16
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Laws AN, Prather CM, Branson DH, Pennings SC. Effects of grasshoppers on prairies: Herbivore composition matters more than richness in three grassland ecosystems. J Anim Ecol 2018; 87:1727-1737. [PMID: 30102785 DOI: 10.1111/1365-2656.12897] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 08/05/2018] [Indexed: 11/28/2022]
Abstract
Understanding how biodiversity affects ecosystem processes is a key question in ecology. Previous research has found that increasing plant diversity often enhances many ecosystem processes, but less is known about the role of consumer diversity to ecosystem processes, especially in terrestrial ecosystems. Furthermore, we do not know how general biodiversity responses are among ecosystem types. We examined the role of insect herbivore (Orthoptera) diversity on plant production using parallel field experiments in three grassland ecosystems (mixed grass prairie, tallgrass prairie and coastal tallgrass prairie) to determine whether the effects of grasshopper diversity were consistent among sites. Using mesocosms, we manipulated orthopteran species richness (0, 1, 2, 3 or 4 species), functional richness (number of functional feeding groups present; 0, 1 or 2 functional groups) and functional composition (composition of functional groups present; mixed-feeders only, grass-feeders only, both mixed-feeders and grass-feeders). Diversity treatments were maintained throughout the experiment by replacing dead individuals. Plant biomass was destructively sampled at the end of the experiment. We found no effect of species richness or functional richness on plant biomass. However, herbivore functional composition was important, and effects were qualitatively similar across sites: The presence of only grass-feeding species reduced plant biomass more than either mixed-feeding species alone or both groups together. Orthopterans had consistent effects across a range of abiotic conditions, as well as different plant community and orthopteran community compositions. Our results suggest that functional composition of insect herbivores affects plant communities in grasslands more than herbivore species richness or functional richness, and this pattern was robust among grassland types.
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Affiliation(s)
- Angela N Laws
- Division of Biology, Kansas State University, Manhattan, Kansas.,Department of Biology and Biochemistry, University of Houston, Houston, Texas
| | - Chelse M Prather
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
| | - David H Branson
- United States Department of Agriculture, Agricultural Research Service, Sidney, Montana
| | - Steven C Pennings
- Department of Biology and Biochemistry, University of Houston, Houston, Texas
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17
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Greenop A, Woodcock BA, Wilby A, Cook SM, Pywell RF. Functional diversity positively affects prey suppression by invertebrate predators: a meta-analysis. Ecology 2018; 99:1771-1782. [PMID: 29727489 PMCID: PMC6099248 DOI: 10.1002/ecy.2378] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 04/10/2018] [Accepted: 04/12/2018] [Indexed: 02/02/2023]
Abstract
The use of pesticides within agricultural ecosystems has led to wide concern regarding negative effects on the environment. One possible alternative is the use of predators of pest species that naturally occur within agricultural ecosystems. However, the mechanistic basis for how species can be manipulated in order to maximize pest control remains unclear. We carried out a meta‐analysis of 51 studies that manipulated predator species richness in reference to suppression of herbivore prey to determine which components of predator diversity affect pest control. Overall, functional diversity (FD) based on predator's habitat domain, diet breadth and hunting strategy was ranked as the most important variable. Our analysis showed that increases in FD in polycultures led to greater prey suppression compared to both the mean of the component predator species, and the most effective predator species, in monocultures. Further analysis of individual traits indicated these effects are likely to be driven by broad niche differentiation and greater resource exploitation in functionally diverse predator communities. A decoupled measure of phylogenetic diversity, whereby the overlap in variation with FD was removed, was not found to be an important driver of prey suppression. Our results suggest that increasing FD in predatory invertebrates will help maximize pest control ecosystem services in agricultural ecosystems, with the potential to increase suppression above that of the most effective predator species.
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Affiliation(s)
- Arran Greenop
- NERC Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK.,Lancaster Environment Centre, Lancaster University, Library Avenue, Lancaster, LA1 4YQ, UK
| | - Ben A Woodcock
- NERC Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK
| | - Andy Wilby
- Lancaster Environment Centre, Lancaster University, Library Avenue, Lancaster, LA1 4YQ, UK
| | - Samantha M Cook
- Biointeractions and Crop Protection Department, Rothamsted Research, Harpenden, Herts, AL5 2JQ, UK
| | - Richard F Pywell
- NERC Centre for Ecology & Hydrology, Maclean Building, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB, UK
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18
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Olivares I, Karger DN, Kessler M. Assessing species saturation: conceptual and methodological challenges. Biol Rev Camb Philos Soc 2018; 93:1874-1890. [PMID: 29733121 DOI: 10.1111/brv.12424] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 04/04/2018] [Accepted: 04/10/2018] [Indexed: 11/29/2022]
Abstract
Is there a maximum number of species that can coexist? Intuitively, we assume an upper limit to the number of species in a given assemblage, or that a lineage can produce, but defining and testing this limit has proven problematic. Herein, we first outline seven general challenges of studies on species saturation, most of which are independent of the actual method used to assess saturation. Among these are the challenge of defining saturation conceptually and operationally, the importance of setting an appropriate referential system, and the need to discriminate among patterns, processes and mechanisms. Second, we list and discuss the methodological approaches that have been used to study species saturation. These approaches vary in time and spatial scales, and in the variables and assumptions needed to assess saturation. We argue that assessing species saturation is possible, but that many studies conducted to date have conceptual and methodological flaws that prevent us from currently attaining a good idea of the occurrence of species saturation.
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Affiliation(s)
- Ingrid Olivares
- Department of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
| | - Dirk N Karger
- Department of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland.,Swiss Federal Research Institute WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
| | - Michael Kessler
- Department of Systematic and Evolutionary Botany, University of Zurich, Zollikerstrasse 107, 8008 Zurich, Switzerland
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19
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Lichtenberg EM, Kennedy CM, Kremen C, Batáry P, Berendse F, Bommarco R, Bosque-Pérez NA, Carvalheiro LG, Snyder WE, Williams NM, Winfree R, Klatt BK, Åström S, Benjamin F, Brittain C, Chaplin-Kramer R, Clough Y, Danforth B, Diekötter T, Eigenbrode SD, Ekroos J, Elle E, Freitas BM, Fukuda Y, Gaines-Day HR, Grab H, Gratton C, Holzschuh A, Isaacs R, Isaia M, Jha S, Jonason D, Jones VP, Klein AM, Krauss J, Letourneau DK, Macfadyen S, Mallinger RE, Martin EA, Martinez E, Memmott J, Morandin L, Neame L, Otieno M, Park MG, Pfiffner L, Pocock MJO, Ponce C, Potts SG, Poveda K, Ramos M, Rosenheim JA, Rundlöf M, Sardiñas H, Saunders ME, Schon NL, Sciligo AR, Sidhu CS, Steffan-Dewenter I, Tscharntke T, Veselý M, Weisser WW, Wilson JK, Crowder DW. A global synthesis of the effects of diversified farming systems on arthropod diversity within fields and across agricultural landscapes. GLOBAL CHANGE BIOLOGY 2017; 23:4946-4957. [PMID: 28488295 DOI: 10.1111/gcb.13714] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 03/17/2017] [Indexed: 05/25/2023]
Abstract
Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in-field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in-field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes.
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Affiliation(s)
- Elinor M Lichtenberg
- Department of Entomology, Washington State University, Pullman, WA, USA
- Department of Ecology & Evolutionary Biology, The University of Arizona, Tucson, AZ, USA
| | | | - Claire Kremen
- Department of Environmental Sciences, Policy and Management, University of California, Berkeley, CA, USA
| | - Péter Batáry
- Agroecology, University of Goettingen, Göttingen, Germany
| | - Frank Berendse
- Nature Conservation and Plant Ecology Group, Wageningen University, Wageningen, the Netherlands
| | - Riccardo Bommarco
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Nilsa A Bosque-Pérez
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID, USA
| | - Luísa G Carvalheiro
- Departamento de Ecologia, Universidade de Brasília, Brasília, Brazil
- Center for Ecology, Evolution and Environmental Changes (CE3C), Faculdade de Ciencias, Universidade de Lisboa, Lisboa, Portugal
| | - William E Snyder
- Department of Entomology, Washington State University, Pullman, WA, USA
| | - Neal M Williams
- Department of Entomology and Nematology, University of California, Davis, CA, USA
| | - Rachael Winfree
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ, USA
| | - Björn K Klatt
- Agroecology, University of Goettingen, Göttingen, Germany
- Centre for Environmental and Climate Research, Lund University, Lund, Sweden
- Department of Biology, Lund University, Lund, Sweden
| | - Sandra Åström
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - Faye Benjamin
- Department of Ecology, Evolution and Natural Resources, Rutgers University, New Brunswick, NJ, USA
| | - Claire Brittain
- Department of Entomology and Nematology, University of California, Davis, CA, USA
| | | | - Yann Clough
- Centre for Environmental and Climate Research, Lund University, Lund, Sweden
| | - Bryan Danforth
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Tim Diekötter
- Department of Landscape Ecology, Kiel University, Kiel, Germany
| | - Sanford D Eigenbrode
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID, USA
| | - Johan Ekroos
- Centre for Environmental and Climate Research, Lund University, Lund, Sweden
| | - Elizabeth Elle
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Breno M Freitas
- Departamento de Zootecnia, Universidade Federal do Ceará, Fortaleza, CE, Brazil
| | - Yuki Fukuda
- Centres for the Study of Agriculture Food and Environment, University of Otago, Dunedin, New Zealand
| | | | - Heather Grab
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Claudio Gratton
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - Andrea Holzschuh
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Rufus Isaacs
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Marco Isaia
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Shalene Jha
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, USA
| | - Dennis Jonason
- Department of Physical Geography, Stockholm University, Stockholm, Sweden
| | - Vincent P Jones
- Department of Entomology, Tree Fruit Research and Extension Center, Washington State University, Wenatchee, WA, USA
| | - Alexandra-Maria Klein
- Nature Conservation and Landscape Ecology, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany
| | - Jochen Krauss
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Deborah K Letourneau
- Department of Environmental Studies, University of California, Santa Cruz, CA, USA
| | | | - Rachel E Mallinger
- Department of Entomology, University of Wisconsin-Madison, Madison, WI, USA
| | - Emily A Martin
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | | | - Jane Memmott
- School of Biological Sciences, University of Bristol, Bristol, UK
| | | | - Lisa Neame
- Alberta Environment and Parks, Regional Planning Branch, Edmonton, AB, Canada
| | - Mark Otieno
- Department of Agricultural Resource Management, Embu University College, Embu, Kenya
| | - Mia G Park
- Department of Entomology, Cornell University, Ithaca, NY, USA
- Department of Humanities & Integrated Studies, University of North Dakota, Grand Forks, ND, USA
| | - Lukas Pfiffner
- Department of Crop Science, Research Institute of Organic Agriculture, Frick, Switzerland
| | | | - Carlos Ponce
- Department of Evolutionary Ecology, Museo Nacional de Ciencias Naturales, CSIC, Madrid, Spain
| | - Simon G Potts
- Centre for Agri-Environmental Research, School of Agriculture, Policy and Development, University of Reading, Reading, UK
| | - Katja Poveda
- Department of Entomology, Cornell University, Ithaca, NY, USA
| | - Mariangie Ramos
- Department of Agricultural Technology, University of Puerto Rico at Utuado, Utuado, PR, USA
| | - Jay A Rosenheim
- Department of Entomology and Nematology, University of California, Davis, CA, USA
| | - Maj Rundlöf
- Department of Biology, Lund University, Lund, Sweden
| | - Hillary Sardiñas
- Department of Environmental Sciences, Policy and Management, University of California, Berkeley, CA, USA
| | - Manu E Saunders
- Institute for Land Water & Society, Charles Sturt University, Albury, NSW, Australia
| | - Nicole L Schon
- AgResearch, Lincoln Research Centre, Christchurch, New Zealand
| | - Amber R Sciligo
- Department of Environmental Sciences, Policy and Management, University of California, Berkeley, CA, USA
| | - C Sheena Sidhu
- University of California Cooperative Extension, San Mateo & San Francisco Counties, Half Moon Bay, CA, USA
| | - Ingolf Steffan-Dewenter
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | | | - Milan Veselý
- Department of Zoology, Faculty of Science, Palacký University, Olomouc, Czech Republic
| | - Wolfgang W Weisser
- Terrestrial Ecology Research Group, Department for Ecology and Ecosystem Management, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - Julianna K Wilson
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - David W Crowder
- Department of Entomology, Washington State University, Pullman, WA, USA
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20
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Meadows AJ, Crowder DW, Snyder WE. Are wolves just wasps with teeth? What invertebrates can teach us about mammal top predators. FOOD WEBS 2017. [DOI: 10.1016/j.fooweb.2016.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Clarke DA, York PH, Rasheed MA, Northfield TD. Does Biodiversity–Ecosystem Function Literature Neglect Tropical Ecosystems? Trends Ecol Evol 2017; 32:320-323. [DOI: 10.1016/j.tree.2017.02.012] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/13/2017] [Accepted: 02/13/2017] [Indexed: 11/16/2022]
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22
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Sánchez-Hernández J, Gabler HM, Amundsen PA. Prey diversity as a driver of resource partitioning between river-dwelling fish species. Ecol Evol 2017; 7:2058-2068. [PMID: 28405272 PMCID: PMC5383502 DOI: 10.1002/ece3.2793] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 12/28/2016] [Accepted: 01/14/2017] [Indexed: 11/11/2022] Open
Abstract
Although food resource partitioning among sympatric species has often been explored in riverine systems, the potential influence of prey diversity on resource partitioning is little known. Using empirical data, we modeled food resource partitioning (assessed as dietary overlap) of coexisting juvenile Atlantic salmon (Salmo salar) and alpine bullhead (Cottus poecilopus). Explanatory variables incorporated into the model were fish abundance, benthic prey diversity and abundance, and several dietary metrics to give a total of seventeen potential explanatory variables. First, a forward stepwise procedure based on the Akaike information criterion was used to select explanatory variables with significant effects on food resource partitioning. Then, linear mixed‐effect models were constructed using the selected explanatory variables and with sampling site as a random factor. Food resource partitioning between salmon and bullhead increased significantly with increasing prey diversity, and the variation in food resource partitioning was best described by the model that included prey diversity as the only explanatory variable. This study provides empirical support for the notion that prey diversity is a key driver of resource partitioning among competing species.
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Affiliation(s)
- Javier Sánchez-Hernández
- Department of Arctic and Marine Biology Faculty of Biosciences Fisheries and Economics UiT The Arctic University of Norway Tromsø Norway; Department of Zoology, Genetics and Physical Anthropology Faculty of Biology University of Santiago de Compostela Santiago de Compostela Spain
| | - Heidi-Marie Gabler
- Department of Arctic and Marine Biology Faculty of Biosciences Fisheries and Economics UiT The Arctic University of Norway Tromsø Norway
| | - Per-Arne Amundsen
- Department of Arctic and Marine Biology Faculty of Biosciences Fisheries and Economics UiT The Arctic University of Norway Tromsø Norway
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23
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Jonsson M, Kaartinen R, Straub CS. Relationships between natural enemy diversity and biological control. CURRENT OPINION IN INSECT SCIENCE 2017; 20:1-6. [PMID: 28602230 DOI: 10.1016/j.cois.2017.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/03/2017] [Indexed: 05/17/2023]
Abstract
Natural enemy diversity generally strengthens biological control, but individual studies have found everything from positive to negative effects. We discuss the factors that promote these different outcomes. We argue that a trait-based approach is helpful to improve our understanding of the relationship between enemy diversity and biological control, and suggest that enemy diversity is likely to be particularly important as an insurance against effects of climate change. Future research should increase the scale and ecological realism of enemy diversity studies, and consider both the strength and stability of biological control. Such research is likely to reveal even stronger evidence that conserving enemy biodiversity will improve biological pest control.
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Affiliation(s)
- Mattias Jonsson
- Swedish University of Agricultural Sciences, Department of Ecology, PO Box 7044, SE-750 07 Uppsala, Sweden.
| | - Riikka Kaartinen
- University of Edinburgh, Institute of Evolutionary Biology, Ashworth 11 Laboratories, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Cory S Straub
- Department of Biology, Ursinus College, Collegeville, PA 19426-1000, USA.
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24
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Weinstein BG, Graham CH. Persistent bill and corolla matching despite shifting temporal resources in tropical hummingbird-plant interactions. Ecol Lett 2017; 20:326-335. [PMID: 28150364 DOI: 10.1111/ele.12730] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/22/2016] [Accepted: 12/12/2016] [Indexed: 11/26/2022]
Abstract
By specialising on specific resources, species evolve advantageous morphologies to increase the efficiency of nutrient acquisition. However, many specialists face variation in resource availability and composition. Whether specialists respond to these changes depends on the composition of the resource pulses, the cost of foraging on poorly matched resources, and the strength of interspecific competition. We studied hummingbird bill and plant corolla matching during seasonal variation in flower availability and morphology. Using a hierarchical Bayesian model, we accounted for the detectability and spatial overlap of hummingbird-plant interactions. We found that despite seasonal pulses of flowers with short-corollas, hummingbirds consistently foraged on well-matched flowers, leading to low niche overlap. This behaviour suggests that the costs of searching for rare and more specialised resources are lower than the benefit of switching to super-abundant resources. Our results highlight the trade-off between foraging efficiency and interspecific competition, and underline niche partitioning in maintaining tropical diversity.
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Affiliation(s)
- Ben G Weinstein
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Catherine H Graham
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY, 11794, USA
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25
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Milosavljević I, Esser AD, Bosque-Pérez NA, Crowder DW. The identity of belowground herbivores, not herbivore diversity, mediates impacts on plant productivity. Sci Rep 2016; 6:39629. [PMID: 28004758 PMCID: PMC5177958 DOI: 10.1038/srep39629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 11/25/2016] [Indexed: 11/09/2022] Open
Abstract
Across many ecosystems, increases in species biodiversity generally results in greater resource acquisition by consumers. Few studies examining the impacts of consumer diversity on resource capture have focused on terrestrial herbivores, however, especially taxa that feed belowground. Here we conducted field mesocosm experiments to examine the effects of variation in species richness and composition within a community of wireworm herbivores on wheat plant productivity. Our experiments involved wireworm communities consisting of between one and three species, with all possible combinations of species represented. We found that the presence of wireworms reduced plant biomass and seed viability, but wireworm species richness did not impact these plant metrics. Species identity effects were strong, as two species, Limonius californicus and Selatosomus pruininus, had significantly stronger impacts on plants compared to L. infuscatus. Communities with either of the two most impactful species consistently had the greatest impact on wheat plants. The effects of wireworms were thus strongly dependent on the particular species present rather than the overall diversity of the wireworm community. More broadly, our study supports the general finding that the identity of particular consumer species within communities often has greater impacts on ecosystem functioning than species richness.
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Affiliation(s)
- Ivan Milosavljević
- Washington State University Entomology, 166 FSHN Bldg, Pullman, WA, 99164, USA
| | - Aaron D Esser
- Washington State University Extension, 205 W Main, Ritzville, WA, 99169, USA
| | - Nilsa A Bosque-Pérez
- Department of Plant, Soil and Entomological Sciences, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844-2339, USA
| | - David W Crowder
- Washington State University Entomology, 166 FSHN Bldg, Pullman, WA, 99164, USA
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Griffin JN, Toscano BJ, Griffen BD, Silliman BR. Does relative abundance modify multiple predator effects? Basic Appl Ecol 2015. [DOI: 10.1016/j.baae.2015.05.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Long EY, Finke DL. Predators indirectly reduce the prevalence of an insect-vectored plant pathogen independent of predator diversity. Oecologia 2015; 177:1067-74. [PMID: 25561170 DOI: 10.1007/s00442-014-3194-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/12/2014] [Indexed: 10/24/2022]
Abstract
A widely cited benefit of predator diversity is greater suppression of insect herbivores, with corresponding increases in plant biomass. In the context of a vector-borne pathogen system, predator species richness may also influence plant disease risk via the direct effects of predators on the abundance and behavior of herbivores that also act as pathogen vectors. Using an assemblage of generalist insect predators, we examined the relationship between predator species richness and the prevalence of the aphid-vectored cereal yellow dwarf virus in wheat. We found that increasing predator richness enhanced suppression of the vector population and that pathogen prevalence was reduced when predators were present, but the reduction in prevalence was independent of predator species richness. To determine the mechanism(s) by which predator species richness contributes to vector suppression, but not pathogen prevalence, we evaluated vector movement and host plant occupancy in response to predator treatments. We found that pathogen prevalence was unrelated to vector suppression because host plant occupancy by vectors did not vary as a function of vector abundance. However, the presence of predators reduced pathogen prevalence because predators stimulated greater plant-to-plant movement by vectors, which likely diminished vector feeding time and reduced the transmission efficiency of this persistent pathogen. We conclude that community structure (i.e., the presence of predators), but not predator diversity, is a potential factor influencing local plant infection by this insect-vectored pathogen.
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Affiliation(s)
- Elizabeth Y Long
- Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA,
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Soomdat NN, Griffin JN, McCoy M, Hensel MJS, Buhler S, Chejanovski Z, Silliman BR. Independent and combined effects of multiple predators across ontogeny of a dominant grazer. OIKOS 2014. [DOI: 10.1111/oik.01579] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nicole N. Soomdat
- Dept of Biology; Univ. of Florida; PO Box 118525, Gainesville FL 32611 USA
| | - John N. Griffin
- Dept of Biology; Univ. of Florida; PO Box 118525, Gainesville FL 32611 USA
- College of Science, Swansea Univ.; Swansea SA2 8PP UK
| | - Michael McCoy
- Dept of Biology; Univ. of Florida; PO Box 118525, Gainesville FL 32611 USA
- Dept of Biology; East Carolina Univ.; Greenville NC 27858 USA
| | - Marc J. S. Hensel
- Dept of Biology; Univ. of Florida; PO Box 118525, Gainesville FL 32611 USA
| | - Stephanie Buhler
- Dept of Biology; Univ. of Florida; PO Box 118525, Gainesville FL 32611 USA
| | | | - Brian R. Silliman
- Dept of Biology; Univ. of Florida; PO Box 118525, Gainesville FL 32611 USA
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Griffin JN, Byrnes JEK, Cardinale BJ. Effects of predator richness on prey suppression: a meta-analysis. Ecology 2014; 94:2180-7. [PMID: 24358704 DOI: 10.1890/13-0179.1] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
It is well established that species richness of primary producers and primary consumers can enhance efficiency of resource uptake and biomass production of respective trophic levels. At the level of secondary consumers (predators), however, conclusions about the functional role of biodiversity have been mixed. We take advantage of a recent surge of published experiments (totaling 46 since 2005) to both evaluate general effects of predator richness on aggregate prey suppression (top-down control) and explore sources of variability among experiments. Our results show that, across experiments, predator richness enhances prey suppression relative to the average single predator species (mean richness effect), but not the best-performing species. Mean richness effects in predator experiments were stronger than those for primary producers and detritivores, suggesting that relationships between richness and function may increase with trophic height in food webs. The strength of mean predator richness effects increased with the spatial and temporal scale of experiments, and the taxonomic distinctness (TD, used as a proxy of phylogenetic diversity) of species present. This latter result suggests that TD captures important aspects of functional differentiation among predators and that measures of biodiversity that go beyond species richness may help to better predict the effects of predator species loss.
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Affiliation(s)
- John N Griffin
- Department of Biosciences, Wallace Building, Swansea University, Singleton Park, Swansea SA28PP United Kingdom.
| | - Jarrett E K Byrnes
- Department of Biology, University of Massachusetts, 100 Morrissey Boulevard, Boston, Massachusetts 02125, USA
| | - Bradley J Cardinale
- School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan 48109, USA
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Cardinale BJ, Gross K, Fritschie K, Flombaum P, Fox JW, Rixen C, van Ruijven J, Reich PB, Scherer-Lorenzen M, Wilsey BJ. Biodiversity simultaneously enhances the production and stability of community biomass, but the effects are independent. Ecology 2013; 94:1697-707. [PMID: 24015514 DOI: 10.1890/12-1334.1] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To predict the ecological consequences of biodiversity loss, researchers have spent much time and effort quantifying how biological variation affects the magnitude and stability of ecological processes that underlie the functioning of ecosystems. Here we add to this work by looking at how biodiversity jointly impacts two aspects of ecosystem functioning at once: (1) the production of biomass at any single point in time (biomass/area or biomass/ volume), and (2) the stability of biomass production through time (the CV of changes in total community biomass through time). While it is often assumed that biodiversity simultaneously enhances both of these aspects of ecosystem functioning, the joint distribution of data describing how species richness regulates productivity and stability has yet to be quantified. Furthermore, analyses have yet to examine how diversity effects on production covary with diversity effects on stability. To overcome these two gaps, we reanalyzed the data from 34 experiments that have manipulated the richness of terrestrial plants or aquatic algae and measured how this aspect of biodiversity affects community biomass at multiple time points. Our reanalysis confirms that biodiversity does indeed simultaneously enhance both the production and stability of biomass in experimental systems, and this is broadly true for terrestrial and aquatic primary producers. However, the strength of diversity effects on biomass production is independent of diversity effects on temporal stability. The independence of effect sizes leads to two important conclusions. First, while it may be generally true that biodiversity enhances both productivity and stability, it is also true that the highest levels of productivity in a diverse community are not associated with the highest levels of stability. Thus, on average, diversity does not maximize the various aspects of ecosystem functioning we might wish to achieve in conservation and management. Second, knowing how biodiversity affects productivity gives no information about how diversity affects stability (or vice versa). Therefore, to predict the ecological changes that occur in ecosystems after extinction, we will need to develop separate mechanistic models for each independent aspect of ecosystem functioning.
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Affiliation(s)
- Bradley J Cardinale
- School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan 48109, USA.
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Interactions among resource partitioning, sampling effect, and facilitation on the biodiversity effect: a modeling approach. Oecologia 2013; 174:559-66. [DOI: 10.1007/s00442-013-2775-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 09/05/2013] [Indexed: 10/26/2022]
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Herbivore species richness, composition and community structure mediate predator richness effects and top-down control of herbivore biomass. Oecologia 2013; 172:1167-77. [PMID: 23292455 DOI: 10.1007/s00442-012-2573-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 12/17/2012] [Indexed: 10/27/2022]
Abstract
Changes in predator species richness can have important consequences for ecosystem functioning at multiple trophic levels, but these effects are variable and depend on the ecological context in addition to the properties of predators themselves. Here, we report an experimental study to test how species identity, community attributes, and community structure at the herbivore level moderate the effects of predator richness on ecosystem functioning. Using mesocosms containing predatory insects and aphid prey, we independently manipulated species richness at both predator and herbivore trophic levels. Community structure was also manipulated by changing the distribution of herbivore species across two plant species. Predator species richness and herbivore species richness were found to negatively interact to influence predator biomass accumulation, an effect which is hypothesised to be due to the breakdown of functional complementarity among predators in species-rich herbivore assemblages. The strength of predator suppression of herbivore biomass decreased as herbivore species richness and distribution across host plants increased, and positive predator richness effects on herbivore biomass suppression were only observed in herbivore assemblages of relatively low productivity. In summary, the study shows that the species richness, productivity and host plant distribution of prey communities can all moderate the general influence of predators and the emergence of predator species richness effects on ecosystem functioning.
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33
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Turnbull LA, Levine JM, Loreau M, Hector A. Coexistence, niches and biodiversity effects on ecosystem functioning. Ecol Lett 2012; 16 Suppl 1:116-27. [PMID: 23279851 DOI: 10.1111/ele.12056] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 10/25/2012] [Accepted: 11/20/2012] [Indexed: 12/01/2022]
Abstract
General principles from coexistence theory are often invoked to explain how and why mixtures of species outperform monocultures. However, the complementarity and selection effects commonly measured in biodiversity experiments do not precisely quantify the niche and relative fitness differences that govern species coexistence. Given this lack of direct correspondence, how can we know whether species-rich mixtures are stable and that the benefits of diversity will therefore persist? We develop a resource-based included-niche model in which plant species have asymmetric access to a nested set of belowground resource pools. We use the model to show that positive complementarity effects arise from stabilising niche differences, but do not necessarily lead to stable coexistence and hence can be transient. In addition, these transient complementarity effects occur in the model when there is no complementary resource use among species. Including a trade-off between uptake rates and the size of the resource pool stabilised interactions and led to persistent complementarity coupled with weak or negative selection effects, consistent with results from the longest-running field biodiversity experiments. We suggest that future progress requires a greater mechanistic understanding of the links between ecosystem functions and their underlying biological processes.
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Affiliation(s)
- Lindsay Ann Turnbull
- Institute of Evolutionary Biology and Environmental Studies, University of Zurich, 8057, Zurich, Switzerland.
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Fenoglio MS, Srivastava D, Valladares G, Cagnolo L, Salvo A. Forest fragmentation reduces parasitism via species loss at multiple trophic levels. Ecology 2012; 93:2407-20. [DOI: 10.1890/11-2043.1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Gable JT, Crowder DW, Northfield TD, Steffan SA, Snyder WE. Niche engineering reveals complementary resource use. Ecology 2012; 93:1994-2000. [DOI: 10.1890/12-0188.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Northfield TD, Snyder WE, Snyder GB, Eigenbrode SD. A simple plant mutation abets a predator-diversity cascade. Ecology 2012; 93:411-20. [PMID: 22624322 DOI: 10.1890/11-0399.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Resource consumption often increases with greater consumer biodiversity. This could result either from complementarity among consumers or the inclusion of particular key species, and it is often difficult to differentiate between these two mechanisms. We exploited a simple plant mutation (reduced production of surface waxes) to alter foraging within a community of aphid predators, and thus perhaps shift the nature of resulting predator diversity effects. We found that greater predator species richness dramatically increased prey suppression and plant biomass only on mutant, reduced-wax pea plants (Pisum sativum). On pea plants from a sister line with wild type, waxier plant surfaces, predator species richness did not influence predators' impacts on herbivores or plants. Thus, a change in plant surface structure acted to turn on, or off, the cascading effects of predator diversity. Greater predator richness encouraged higher densities of true predators but did not lead to greater reproduction by a parasitoid, Aphidius ervi; fecundity of each natural enemy species was similar for the two plant types. Behavioral observations indicated that although A. ervi was less likely to forage within species-rich predator communities, low-wax plants mitigated this interference by encouraging generally greater A. ervi foraging and thus high rates of aphid dislodgement (aphids dropped from plants to escape A. ervi, but not the other predators). Thus, only species-rich, low-wax plants simultaneously encouraged strong species-specific effects of A. ervi, and strong complementarity among the other predator species. In summary, our study provides evidence that diversity effects in predator assemblages are sensitive to habitat characteristics. Further, we show that a simple plant morphological trait, controlled by a single gene mutation, can dramatically alter the cascading effects of predator species richness on herbivores and plants.
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Affiliation(s)
- Tobin D Northfield
- Department of Entomology, Washington State University, Pullman, Washington 99164. USA
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Cardinale BJ, Matulich KL, Hooper DU, Byrnes JE, Duffy E, Gamfeldt L, Balvanera P, O'Connor MI, Gonzalez A. The functional role of producer diversity in ecosystems. AMERICAN JOURNAL OF BOTANY 2011; 98:572-92. [PMID: 21613148 DOI: 10.3732/ajb.1000364] [Citation(s) in RCA: 554] [Impact Index Per Article: 42.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Over the past several decades, a rapidly expanding field of research known as biodiversity and ecosystem functioning has begun to quantify how the world's biological diversity can, as an independent variable, control ecological processes that are both essential for, and fundamental to, the functioning of ecosystems. Research in this area has often been justified on grounds that (1) loss of biological diversity ranks among the most pronounced changes to the global environment and that (2) reductions in diversity, and corresponding changes in species composition, could alter important services that ecosystems provide to humanity (e.g., food production, pest/disease control, water purification). Here we review over two decades of experiments that have examined how species richness of primary producers influences the suite of ecological processes that are controlled by plants and algae in terrestrial, marine, and freshwater ecosystems. Using formal meta-analyses, we assess the balance of evidence for eight fundamental questions and corresponding hypotheses about the functional role of producer diversity in ecosystems. These include questions about how primary producer diversity influences the efficiency of resource use and biomass production in ecosystems, how primary producer diversity influences the transfer and recycling of biomass to other trophic groups in a food web, and the number of species and spatial /temporal scales at which diversity effects are most apparent. After summarizing the balance of evidence and stating our own confidence in the conclusions, we outline several new questions that must now be addressed if this field is going to evolve into a predictive science that can help conserve and manage ecological processes in ecosystems.
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Affiliation(s)
- Bradley J Cardinale
- School of Natural Resources and Environment, University of Michigan, 440 Church Street, Ann Arbor, Michigan 48109, USA.
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Griffin JN, Silliman BR. Predator diversity stabilizes and strengthens trophic control of a keystone grazer. Biol Lett 2011; 7:79-82. [PMID: 20739314 DOI: 10.1098/rsbl.2010.0626] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Despite the global vulnerability of predators to extinction, and the critical functional role they play in many ecosystems, there have been few realistic tests of the consequences of predator species deletion (conversely, predator diversity) in natural ecosystems. We performed a four-month field experiment in a southeastern United States salt marsh to test the role of predatory crab diversity in regulating populations of a keystone grazer that can decimate marsh vegetation at high densities. Our results revealed that a combination of this system's two resident predator species, in comparison to individual species, both stabilize and strengthen predation rates on the potent grazer. Monthly monitoring of predation rates from intense, hot summer months into the cooler autumn indicate this diversity benefit arises from predators responding differentially to changing environmental conditions across seasons. This study provides some of the first experimental field support for the insurance hypothesis from marine ecosystems, suggests that predator temporal complementarity may be more common than currently perceived, and argues for conservation of predator diversity to ensure reliable and effective control of potentially habitat-destroying grazers.
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Affiliation(s)
- John N Griffin
- Department of Biology, University of Florida, Gainesville, FL, USA.
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Takizawa T, Snyder WE. Cannibalism and intraguild predation of eggs within a diverse predator assemblage. ENVIRONMENTAL ENTOMOLOGY 2011; 40:8-14. [PMID: 22182605 DOI: 10.1603/en10047] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Greater biodiversity among aphid predators sometimes leads to greater predator reproductive success. This could occur if cannibalism of predator eggs is consistently stronger than intraguild predation, such that diversity dilutes cannibalism risk when total predator densities remain constant across diversity levels. We compared the frequency of cannibalism versus intraguild predation by adult predators of four species [the lady beetles Coccinella septempunctata L. and Hippodamia convergens Guerin-Meneville, and the predatory bugs Geocoris bullatus (Say) and Nabis alternatus Parshley] on the eggs of three predator species (all of these predators but Nabis). For both coccinellid species, egg predation averaged across all intraguild predators was less frequent than cannibalism. In contrast, Geocoris eggs were generally more likely to be consumed by intraguild predators than by conspecifics. Closer inspection of the data revealed that Geocoris consistently consumed fewer eggs than the other species, regardless of egg species. Indeed, for lady beetle eggs it was relatively infrequent egg predation by Geocoris that brought down the average across all heterospecific predators, masking the fact that adults of the two lady beetles were no more likely to act as egg cannibals than as intraguild predators. Nabis ate eggs of the two beetles at approximately equal rates, but rarely ate Geocoris eggs. Female predators generally consumed more eggs than did males, but this did not alter any of the patterns described above. Altogether, our results suggest that species-specific differences in egg predation rates determined the relative intensity of egg intraguild-predation versus cannibalism, rather than any more general trend for egg cannibalism to always exceed intraguild predation.
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Affiliation(s)
- Tadashi Takizawa
- Department of Entomology, Washington State University, Pullman, WA 99164, USA.
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Takizawa T, Snyder WE. Predator biodiversity increases the survivorship of juvenile predators. Oecologia 2011; 166:723-30. [PMID: 21203775 DOI: 10.1007/s00442-010-1891-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 12/15/2010] [Indexed: 11/29/2022]
Abstract
When predator biodiversity strengthens herbivore suppression, the pattern generally is attributed to interspecific complementarity. However, the relaxation of intraspecific interference within diverse communities has received less attention as an underlying factor, and most experiments to date span much less than one predator generation. Here, working with a community of aphid predators, we compared the survivorship of juvenile predators embedded within diverse versus single-species communities of adult predators. We found that greater predator diversity improved juvenile survivorship for three of four predator taxa (the lady beetles Hippodamia convergens and Coccinella septempunctata, and the bug Nabis alternatus; but not the small bug Geocoris bullatus), whereas survivorship was relatively low when juveniles foraged among only conspecific adults. When aphid densities differed they were lowest for the diverse treatment, and so resource availability could not explain differences in juvenile survivorship. Instead, feeding trials indicated that cannibalism generally posed a greater risk to juveniles than did intraguild predation (with Geocoris again the exception). Our results suggest that the dilution of intraspecific interference may play an important, and perhaps underappreciated, role in shaping predator diversity effects. Furthermore, relatively strong cannibalism but weak intraguild predation has the potential to project diversity effects forward into subsequent generations.
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Affiliation(s)
- Tadashi Takizawa
- Department of Entomology, Washington State University, Pullman, WA 99164-6382, USA.
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Affiliation(s)
- Shawn A Steffan
- Department of Entomology, Washington State University, Pullman, Washington 99164, USA.
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