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Cedergreen N, Pedersen KE, Fredensborg BL. Quantifying synergistic interactions: a meta-analysis of joint effects of chemical and parasitic stressors. Sci Rep 2023; 13:13641. [PMID: 37608060 PMCID: PMC10444819 DOI: 10.1038/s41598-023-40847-6] [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: 03/01/2023] [Accepted: 08/17/2023] [Indexed: 08/24/2023] Open
Abstract
The global biodiversity crisis emphasizes our need to understand how different stressors (climatic, chemical, parasitic, etc.) interact and affect biological communities. We provide a comprehensive meta-analysis investigating joint effects of chemical and parasitic stressors for 1064 chemical-parasitic combinations using the Multiplicative model on mortality of arthropods. We tested both features of the experimental setup (control mortality, stressor effect level) and the chemical mode of action, host and parasite phylogeny, and parasite-host interaction traits as explanatory factors for deviations from the reference model. Synergistic interactions, defined as higher mortality than predicted, were significantly more frequent than no interactions or antagony. Experimental setup significantly affected the results, with studies reporting high (> 10%) control mortality or using low stressor effects (< 20%) being more synergistic. Chemical mode of action played a significant role for synergy, but there was no effects of host and parasite phylogeny, or parasite-host interaction traits. The finding that experimental design played a greater role in finding synergy than biological factors, emphasize the need to standardize the design of mixed stressor studies across scientific disciplines. In addition, combinations testing more biological traits e.g. avoidance, coping, and repair processes are needed to test biology-based hypotheses for synergistic interactions.
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Affiliation(s)
- Nina Cedergreen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Kathrine Eggers Pedersen
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark
| | - Brian Lund Fredensborg
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871, Frederiksberg, Denmark.
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Aguirrebengoa M, Müller C, Hambäck PA, González-Megías A. Density-Dependent Effects of Simultaneous Root and Floral Herbivory on Plant Fitness and Defense. PLANTS (BASEL, SWITZERLAND) 2023; 12:283. [PMID: 36678999 PMCID: PMC9867048 DOI: 10.3390/plants12020283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/23/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Plants are attacked by multiple herbivores, and depend on a precise regulation of responses to cope with a wide range of antagonists. Simultaneous herbivory can occur in different plant compartments, which may pose a serious threat to plant growth and reproduction. In particular, plants often face co-occurring root and floral herbivory, but few studies have focused on such interactions. Here, we investigated in the field the combined density-dependent effects of root-chewing cebrionid beetle larvae and flower-chewing pierid caterpillars on the fitness and defense of a semiarid Brassicaceae herb. We found that the fitness impact of both herbivore groups was independent and density-dependent. Increasing root herbivore density non-significantly reduced plant fitness, while the relationship between increasing floral herbivore density and the reduction they caused in both seed number and seedling emergence was non-linear. The plant defensive response was non-additive with regard to the different densities of root and floral herbivores; high floral herbivore density provoked compensatory investment in reproduction, and this tolerance response was combined with aboveground chemical defense induction when also root herbivore density was high. Plants may thus prioritize specific trait combinations in response to varying combined below- and aboveground herbivore densities to minimize negative impacts on fitness.
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Affiliation(s)
| | - Caroline Müller
- Department of Chemical Ecology, Bielefeld University, 33615 Bielefeld, Germany
| | - Peter A. Hambäck
- Department of Ecology, Environment and Plant Sciences, Stockholm University, 106 91 Stockholm, Sweden
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3
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Pathogens and predators: examining the separate and combined effects of natural enemies on assemblage structure. Oecologia 2022; 200:307-322. [PMID: 35969272 DOI: 10.1007/s00442-022-05228-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 07/20/2022] [Indexed: 10/15/2022]
Abstract
Natural enemy ecology strives to unify predator-prey and host-pathogen interactions under a common framework to gain insights into community- and ecosystem-level processes. To address this goal, ecologists need a greater emphasis on: (1) quantifying pathogen-mediated effects on community structure to enable comparisons with predator-mediated effects and (2) determining the interactive effects of combined natural enemies on communities. We conducted a mesocosm experiment to assess the individual and combined effects of predators (dragonfly larvae and adult water bugs) and a pathogen (ranavirus) on the abundance and composition of a larval amphibian assemblage. We found that our three natural enemies structured victim assemblages in unique ways, producing distinct assemblages. Additionally, we found that in combination treatments, predators mainly drove assemblage structure such that the assemblages most closely resembled their respective predator treatments. We also found that predators reduced infection prevalence in combination treatments, and that the magnitude of this effect was dependent on predator identity. Compared to virus-alone treatments, the presence of dragonflies and water bugs reduced infection prevalence by 79% and 63%, respectively. Additionally, the presence of dragonflies eliminated ranavirus infection in two species, which demonstrates the prominent role of predators in disease dynamics in this system. Overall, this work demonstrates the importance of considering natural enemies in community ecology, as each enemy can elicit a unique structural change. Additionally, this study provides a unique empirical test of the healthy herds hypothesis for multi-species assemblages and underscores the importance of advancing our understanding of multi-enemy interactions within communities.
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4
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Barton M, Parry H, Ward S, Hoffmann AA, Umina PA, van Helden M, Macfadyen S. Forecasting impacts of biological control under future climates: mechanistic modelling of an aphid pest and a parasitic wasp. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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5
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Nordkvist M, Klapwijk MJ, Edenius LR, Björkman C. Interacting effects of insect and ungulate herbivory on Scots pine growth. Sci Rep 2020; 10:22341. [PMID: 33339887 PMCID: PMC7749124 DOI: 10.1038/s41598-020-79346-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 12/04/2020] [Indexed: 12/03/2022] Open
Abstract
Most plants are subjected to damage from multiple species of herbivores, and the combined impact on plant growth can be non-additive. Since plant response to herbivores tends to be species specific, and change with repeated damage, the outcome likely depend on the sequence and number of attacks. There is a high likelihood of non-additive effects on plant growth by damage from mammals and insects, as mammalian herbivory can alter insect herbivore damage levels, yet few studies have explored this. We report the growth response of young Scots pine trees to sequential mammal and insect herbivory, varying the sequence and number of damage events, using an ungulate-pine-sawfly system. Combined sawfly and ungulate herbivory had both additive and non-additive effects on pine growth—the growth response depended on the combination of ungulate browsing and sawfly defoliation (significant interaction effect). Repeated sawfly herbivory reduced growth (compared to single defoliation) on un-browsed trees. However, on browsed trees, depending on when sawfly defoliation was combined with browsing, trees exposed to repeated sawfly herbivory had both higher, lower and the same growth as trees exposed to a single defoliation event. We conclude that the sequence of attacks by multiple herbivores determine plant growth response.
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Affiliation(s)
- Michelle Nordkvist
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Maartje J Klapwijk
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - La Rs Edenius
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Christer Björkman
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
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6
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Lucero JE, Arab NM, Meyer ST, Pal RW, Fletcher RA, Nagy DU, Callaway RM, Weisser WW. Escape from natural enemies depends on the enemies, the invader, and competition. Ecol Evol 2020; 10:10818-10828. [PMID: 33072298 PMCID: PMC7548199 DOI: 10.1002/ece3.6737] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/05/2020] [Accepted: 06/29/2020] [Indexed: 11/19/2022] Open
Abstract
The enemy release hypothesis (ERH) attributes the success of some exotic plant species to reduced top‐down effects of natural enemies in the non‐native range relative to the native range. Many studies have tested this idea, but very few have considered the simultaneous effects of multiple kinds of enemies on more than one invasive species in both the native and non‐native ranges. Here, we examined the effects of two important groups of natural enemies–insect herbivores and soil biota–on the performance of Tanacetum vulgare (native to Europe but invasive in the USA) and Solidago canadensis (native to the USA but invasive in Europe) in their native and non‐native ranges, and in the presence and absence of competition. In the field, we replicated full‐factorial experiments that crossed insecticide, T. vulgare–S. canadensis competition, and biogeographic range (Europe vs. USA) treatments. In greenhouses, we replicated full‐factorial experiments that crossed soil sterilization, plant–soil feedback, and biogeographic range treatments. We evaluated the effects of experimental treatments on T. vulgare and S. canadensis biomass. The effects of natural enemies were idiosyncratic. In the non‐native range and relative to populations in the native range, T. vulgare escaped the negative effects of insect herbivores but not soil biota, depending upon the presence of S. canadensis; and S. canadensis escaped the negative effects of soil biota but not insect herbivores, regardless of competition. Thus, biogeographic escape from natural enemies depended upon the enemies, the invader, and competition.
Synthesis: By explicitly testing the ERH in terms of more than one kind of enemy, more than one invader, and more than one continent, this study enhances our nuanced perspective of how natural enemies can influence the performance of invasive species in their native and non‐native ranges.
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Affiliation(s)
| | - Nafiseh Mahdavi Arab
- Terrestrial Ecology Research Group Department of Ecology and Ecosystem Management School of Life Sciences Weihenstephan Technical University of Munich Freising Germany
| | - Sebastian T Meyer
- Terrestrial Ecology Research Group Department of Ecology and Ecosystem Management School of Life Sciences Weihenstephan Technical University of Munich Freising Germany
| | - Robert W Pal
- Department of Biological Sciences Montana Technological University Butte MT USA.,Institute of Biology Faculty of Sciences University of Pecs Pecs Hungary
| | - Rebecca A Fletcher
- School of Plant and Environmental Sciences Virginia Tech Blacksburg VA USA
| | - David U Nagy
- Institute of Biology Faculty of Sciences University of Pecs Pecs Hungary
| | - Ragan M Callaway
- Divison of Biological Sciences and the Institute on Ecosystems University of Montana Missoula MT USA
| | - Wolfgang W Weisser
- Terrestrial Ecology Research Group Department of Ecology and Ecosystem Management School of Life Sciences Weihenstephan Technical University of Munich Freising Germany
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7
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Interactions between Magnaporthiopsis maydis and Macrophomina phaseolina, the Causes of Wilt Diseases in Maize and Cotton. Microorganisms 2020; 8:microorganisms8020249. [PMID: 32069974 PMCID: PMC7074752 DOI: 10.3390/microorganisms8020249] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/22/2020] [Accepted: 02/10/2020] [Indexed: 11/16/2022] Open
Abstract
Fungal pathogens are a significant threat to crops worldwide. The soil fungus, Magnaporthiopsis maydis, severely affects sensitive maize hybrids by causing the rapid wilting of plants at the maturity stage. Similarly, the soil fungus, Macrophomina phaseolina, develops in a variety of host plants, which leads to rot and plant mortality. The presence of both pathogens together in diseased cotton plants in Israel suggests possible interactions between them. Here, these relationships were tested in a series of experiments accompanied by real-time PCR tracking in maize and cotton. Despite the fact that neither of the pathogens was superior in a growth plate confrontation assay, their co-inoculum had a significant influence under field conditions. In maize sprouts and fully matured plants, infection by both pathogens (compared to inoculation with each of them alone) led to lesser amounts of M. maydis DNA but to increased amounts of M. phaseolina DNA levels. These results were obtained under a restricted water regime, while optimal water irrigation led to less pronounced differences. In water-stressed cotton sprouts, infection with both pathogens led to an increase in DNA amounts of each of the pathogens. Whereas the M. maydis DNA levels in the double infection remain high at the end of the season, a reduction in the amount of M. phaseolina DNA was observed. The double infection caused an increase in growth parameters in maize and cotton and decreased levels of dehydration in maize plants accompanied by an increase in yield production. Dehydration symptoms were minor in cotton under an optimal water supply. However, under a restricted water regime, the double infection abolished the harmful effect of M. phaseolina on the plants' development and yield. These findings are the first report of interactions between these two pathogens in maize and cotton, and they encourage expanding the study to additional plant hosts and examining the potential involvement of other pathogens.
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8
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Garcia LC, Eubanks MD. Overcompensation for insect herbivory: a review and meta‐analysis of the evidence. Ecology 2019; 100:e02585. [DOI: 10.1002/ecy.2585] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/02/2018] [Accepted: 11/13/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Loriann C. Garcia
- Department of Entomology Texas A&M University 2475 TAMU College Station Texas 77840 USA
| | - Micky D. Eubanks
- Department of Entomology Texas A&M University 2475 TAMU College Station Texas 77840 USA
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Troth EEG, Johnston JA, Dyer AT. Competition Between Fusarium pseudograminearum and Cochliobolus sativus Observed in Field and Greenhouse Studies. PHYTOPATHOLOGY 2018; 108:215-222. [PMID: 28956711 DOI: 10.1094/phyto-03-17-0110-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Among root pathogens, one of the most documented antagonisms is the suppression of Cochliobolus sativus by Fusarium (roseum) species. Unfortunately, previous studies involved single isolates of each pathogen and thus, provided no indication of the spectrum of responses that occur across the respective species. To investigate the variability in interactions between Cochliobolus sativus and Fusarium pseudograminearum, field and greenhouse trials were conducted that included monitoring of spring wheat plant health and monitoring of pathogen populations via quantitative real-time polymerase chain reaction. The interactions between two isolates of C. sativus and four isolates of F. pseudograminearum were explored in three geographically distinct wheat fields. To complement field trials and to limit potentially confounding environmental variables that are often associated with field studies, greenhouse trials were performed that investigated the interactions among and between three isolates of C. sativus and four isolates of F. pseudograminearum. Across field locations, C. sativus isolate Cs2344 consistently and significantly reduced Fusarium populations by an average of 20.1%. Similarly, F. pseudograminearum isolate Fp2228 consistently and significantly reduced C. sativus field populations by an average of 30.9%. No interaction was detected in the field between pathogen species with regards to disease or crop losses. Greenhouse results confirmed a powerful (>99%), broadly effective suppression of Fusarium populations by isolate Cs2344. Among greenhouse trials, additional isolate-isolate interactions were observed affecting Fusarium populations. Due to lower C. sativus population sizes in greenhouse trials, significant Fusarium suppression of C. sativus was only detected in one isolate-isolate interaction. This study is the first to demonstrate suppression of Fusarium spp. by C. sativus in field and greenhouse settings. These findings also reveal a complex competitive interaction between these two pathogen species that was previously unknown.
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Affiliation(s)
- Erin E Gunnink Troth
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman 59717-3150
| | - Jeffrey A Johnston
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman 59717-3150
| | - Alan T Dyer
- Department of Plant Sciences and Plant Pathology, Montana State University, Bozeman 59717-3150
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10
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Muneret L, Thiéry D, Joubard B, Rusch A. Deployment of organic farming at a landscape scale maintains low pest infestation and high crop productivity levels in vineyards. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.13034] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lucile Muneret
- INRA UMR 1065 Santé et Agroécologie du Vignoble; ISVV; Université de Bordeaux; Bordeaux-Sciences-Agro; Villenave d'Ornon Cedex France
| | - Denis Thiéry
- INRA UMR 1065 Santé et Agroécologie du Vignoble; ISVV; Université de Bordeaux; Bordeaux-Sciences-Agro; Villenave d'Ornon Cedex France
| | - Benjamin Joubard
- INRA UMR 1065 Santé et Agroécologie du Vignoble; ISVV; Université de Bordeaux; Bordeaux-Sciences-Agro; Villenave d'Ornon Cedex France
| | - Adrien Rusch
- INRA UMR 1065 Santé et Agroécologie du Vignoble; ISVV; Université de Bordeaux; Bordeaux-Sciences-Agro; Villenave d'Ornon Cedex France
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11
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Saleem M, Meckes N, Pervaiz ZH, Traw MB. Microbial Interactions in the Phyllosphere Increase Plant Performance under Herbivore Biotic Stress. Front Microbiol 2017; 8:41. [PMID: 28163703 PMCID: PMC5247453 DOI: 10.3389/fmicb.2017.00041] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 01/06/2017] [Indexed: 11/30/2022] Open
Abstract
The phyllosphere supports a tremendous diversity of microbes and other organisms. However, little is known about the colonization and survival of pathogenic and beneficial bacteria alone or together in the phyllosphere across the whole plant life-cycle under herbivory, which hinders our ability to understand the role of phyllosphere bacteria on plant performance. We addressed these questions in experiments using four genetically and biogeographically diverse accessions of Arabidopsis thaliana, three ecologically important bacterial strains (Pseudomonas syringae DC3000, Xanthomonas campestris, both pathogens, and Bacillus cereus, plant beneficial) under common garden conditions that included fungus gnats (Bradysia spp.). Plants supported greater abundance of B. cereus over either pathogenic strain in the phyllosphere under such greenhouse conditions. However, the Arabidopsis accessions performed much better (i.e., early flowering, biomass, siliques, and seeds per plant) in the presence of pathogenic bacteria rather than in the presence of the plant beneficial B. cereus. As a group, the plants inoculated with any of the three bacteria (Pst DC3000, Xanthomonas, or Bacillus) all had a higher fitness than uninoculated controls under these conditions. These results suggest that the plants grown under the pressure of different natural enemies, such as pathogens and an herbivore together perform relatively better, probably because natural enemies induce host defense against each other. However, in general, a positive impact of Bacillus on plant performance under herbivory may be due to its plant-beneficial properties. In contrast, bacterial species in the mixture (all three together) performed poorer than as monocultures in their total abundance and host plant growth promotion, possibly due to negative interspecific interactions among the bacteria. However, bacterial species richness linearly promoted seed production in the host plants under these conditions, suggesting that natural enemies diversity may be beneficial from the host perspective. Collectively, these results highlight the importance of bacterial community composition on plant performance and bacterial abundance in the phyllosphere.
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Affiliation(s)
- Muhammad Saleem
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh PA, USA
| | - Nicole Meckes
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh PA, USA
| | - Zahida H Pervaiz
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh PA, USA
| | - Milton B Traw
- Department of Biological Sciences, University of Pittsburgh, PittsburghPA, USA; Department of Biology, Berea College, BereaKY, USA
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12
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Côté IM, Darling ES, Brown CJ. Interactions among ecosystem stressors and their importance in conservation. Proc Biol Sci 2017; 283:rspb.2015.2592. [PMID: 26865306 DOI: 10.1098/rspb.2015.2592] [Citation(s) in RCA: 313] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Interactions between multiple ecosystem stressors are expected to jeopardize biological processes, functions and biodiversity. The scientific community has declared stressor interactions-notably synergies-a key issue for conservation and management. Here, we review ecological literature over the past four decades to evaluate trends in the reporting of ecological interactions (synergies, antagonisms and additive effects) and highlight the implications and importance to conservation. Despite increasing popularity, and ever-finer terminologies, we find that synergies are (still) not the most prevalent type of interaction, and that conservation practitioners need to appreciate and manage for all interaction outcomes, including antagonistic and additive effects. However, it will not be possible to identify the effect of every interaction on every organism's physiology and every ecosystem function because the number of stressors, and their potential interactions, are growing rapidly. Predicting the type of interactions may be possible in the near-future, using meta-analyses, conservation-oriented experiments and adaptive monitoring. Pending a general framework for predicting interactions, conservation management should enact interventions that are robust to uncertainty in interaction type and that continue to bolster biological resilience in a stressful world.
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Affiliation(s)
- Isabelle M Côté
- Earth to Ocean Group, Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6
| | - Emily S Darling
- Wildlife Conservation Society, Toronto, Ontario, Canada M5S 3A7
| | - Christopher J Brown
- Australian Rivers Institute, Griffith University, Nathan, Queensland 4111, Australia
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13
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Adam N, Erler T, Kallenbach M, Kaltenpoth M, Kunert G, Baldwin IT, Schuman MC. Sex ratio of mirid populations shifts in response to hostplant co-infestation or altered cytokinin signaling . JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2017; 59:44-59. [PMID: 27862998 PMCID: PMC5234700 DOI: 10.1111/jipb.12507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Accepted: 11/08/2016] [Indexed: 05/11/2023]
Abstract
Herbivore species sharing a host plant often compete. In this study, we show that host plant-mediated interaction between two insect herbivores - a generalist and a specialist - results in a sex ratio shift of the specialist's offspring. We studied demographic parameters of the specialist Tupiocoris notatus (Hemiptera: Miridae) when co-infesting the host plant Nicotiana attenuata (Solanaceae) with the generalist leafhopper Empoasca sp. (Hemiptera: Cicadellidae). We show that the usually female-biased sex ratio of T. notatus shifts toward a higher male proportion in the offspring on plants co-infested by Empoasca sp. This sex ratio change did not occur after oviposition, nor is it due differential mortality of female and male nymphs. Based on pyrosequencing and PCR of bacterial 16S rRNA amplicons, we concluded that sex ratio shifts were unlikely to be due to infection with Wolbachia or other known sex ratio-distorting endosymbionts. Finally, we used transgenic lines of N. attenuata to evaluate if the sex ratio shift could be mediated by changes in general or specialized host plant metabolites. We found that the sex ratio shift occurred on plants deficient in two cytokinin receptors (irCHK2/3). Thus, cytokinin-regulated traits can alter the offspring sex ratio of the specialist T. notatus.
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Affiliation(s)
- Nora Adam
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Deutscher Platz 5e, 04103 Leipzig, Germany
| | - Theresa Erler
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Mario Kallenbach
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Martin Kaltenpoth
- Max Planck Research Group Insect Symbiosis, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Grit Kunert
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Ian T. Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
| | - Meredith C. Schuman
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv), Deutscher Platz 5e, 04103 Leipzig, Germany
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14
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Endress BA, Naylor BJ, Pekin BK, Wisdom MJ. Aboveground and belowground mammalian herbivores regulate the demography of deciduous woody species in conifer forests. Ecosphere 2016. [DOI: 10.1002/ecs2.1530] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Bryan A. Endress
- Eastern Oregon Agriculture and Natural Resource Program Department of Animal and Rangeland Sciences Oregon State University La Grande Oregon 98750 USA
| | - Bridgett J. Naylor
- USDA Forest Service Pacific Northwest Research Station La Grande Oregon 98750 USA
| | - Burak K. Pekin
- Eurasia Institute of Earth Sciences Istanbul Technical University Istanbul 34469 Turkey
| | - Michael J. Wisdom
- USDA Forest Service Pacific Northwest Research Station La Grande Oregon 98750 USA
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15
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Carrillo J, Siemann E. A native plant competitor mediates the impact of above- and belowground damage on an invasive tree. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:2060-2071. [PMID: 27755734 DOI: 10.1002/eap.1359] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 04/05/2016] [Indexed: 06/06/2023]
Abstract
Plant competition may mediate the impacts of herbivory on invasive plant species through effects on plant growth and defense. This may predictably depend on whether herbivory occurs above or below ground and on relative plant competitive ability. We simulated the potential impact of above- or belowground damage by biocontrol agents on the growth of a woody invader (Chinese tallow tree, Triadica sebifera) through artificial herbivory, with or without competition with a native grass, little bluestem (Schizachyrium scoparium). We measured two defense responses of Triadica through quantifying constitutive and induced extrafloral nectar production and tolerance of above- and belowground damage (root and shoot biomass regrowth). We examined genetic variation in plant growth and defense across native (China) and invasive (United States) Triadica populations. Without competition, aboveground damage had a greater impact than belowground damage on Triadica performance, whereas with competition and above- and belowground damage impacted Triadica similarly. Whole plant tolerance to damage below ground was negatively associated with tolerance to grass competitors indicating tradeoffs in the ability to tolerate herbivory vs. compete. Competition reduced investment in defensive extrafloral nectar (EFN) production. Aboveground damage inhibited rather than induced EFN production while belowground plant damage did not impact aboveground nectar production. We found some support for the evolution of increased competitive ability hypothesis for invasive plants as United States plants were larger than native China plants and were more plastic in their response to biotic stressors than China plants (they altered their root to shoot ratios dependent on herbivory and competition treatments). Our results indicate that habitat type and the presence of competitors may be a larger determinant of herbivory impact than feeding mode and suggest that integrated pest management strategies including competitive dynamics of recipient communities should be incorporated into biological control agent evaluation at earlier stages.
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Affiliation(s)
- Juli Carrillo
- Department of Entomology, Purdue University, West Lafayette, Indiana, 47907, USA.
| | - Evan Siemann
- Department of Biosciences, Rice University, Houston, Texas, 77005, USA
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16
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Gagic V, Riggi LG, Ekbom B, Malsher G, Rusch A, Bommarco R. Interactive effects of pests increase seed yield. Ecol Evol 2016; 6:2149-57. [PMID: 27099712 PMCID: PMC4831447 DOI: 10.1002/ece3.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Revised: 01/18/2016] [Accepted: 01/23/2016] [Indexed: 11/22/2022] Open
Abstract
Loss in seed yield and therefore decrease in plant fitness due to simultaneous attacks by multiple herbivores is not necessarily additive, as demonstrated in evolutionary studies on wild plants. However, it is not clear how this transfers to crop plants that grow in very different conditions compared to wild plants. Nevertheless, loss in crop seed yield caused by any single pest is most often studied in isolation although crop plants are attacked by many pests that can cause substantial yield losses. This is especially important for crops able to compensate and even overcompensate for the damage. We investigated the interactive impacts on crop yield of four insect pests attacking different plant parts at different times during the cropping season. In 15 oilseed rape fields in Sweden, we estimated the damage caused by seed and stem weevils, pollen beetles, and pod midges. Pest pressure varied drastically among fields with very low correlation among pests, allowing us to explore interactive impacts on yield from attacks by multiple species. The plant damage caused by each pest species individually had, as expected, either no, or a negative impact on seed yield and the strongest negative effect was caused by pollen beetles. However, seed yield increased when plant damage caused by both seed and stem weevils was high, presumably due to the joint plant compensatory reaction to insect attack leading to overcompensation. Hence, attacks by several pests can change the impact on yield of individual pest species. Economic thresholds based on single species, on which pest management decisions currently rely, may therefore result in economically suboptimal choices being made and unnecessary excessive use of insecticides.
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Affiliation(s)
- Vesna Gagic
- Department of Ecology Swedish University of Agricultural Sciences SE-75007 Uppsala Sweden
| | - Laura Ga Riggi
- Department of Ecology Swedish University of Agricultural Sciences SE-75007 Uppsala Sweden
| | - Barbara Ekbom
- Department of Ecology Swedish University of Agricultural Sciences SE-75007 Uppsala Sweden
| | - Gerard Malsher
- Department of Ecology Swedish University of Agricultural Sciences SE-75007 Uppsala Sweden
| | - Adrien Rusch
- INRA ISVV UMR1065 Santé et Agroécologie du Vignoble F-33883 Villenave d'Ornon France
| | - Riccardo Bommarco
- Department of Ecology Swedish University of Agricultural Sciences SE-75007 Uppsala Sweden
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17
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Seastedt TR. Biological control of invasive plant species: a reassessment for the Anthropocene. THE NEW PHYTOLOGIST 2015; 205:490-502. [PMID: 25303317 DOI: 10.1111/nph.13065] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/17/2014] [Indexed: 05/12/2023]
Abstract
The science of finding, testing and releasing herbivores and pathogens to control invasive plant species has achieved a level of maturity and success that argues for continued and expanded use of this program. The practice, however, remains unpopular with some conservationists, invasion biologists, and stakeholders. The ecological and economic benefits of controlling densities of problematic plant species using biological control agents can be quantified, but the risks and net benefits of biological control programs are often derived from social or cultural rather than scientific criteria. Management of invasive plants is a 'wicked problem', and local outcomes to wicked problems have both positive and negative consequences differentially affecting various groups of stakeholders. The program has inherent uncertainties; inserting species into communities that are experiencing directional or even transformational changes can produce multiple outcomes due to context-specific factors that are further confounded by environmental change drivers. Despite these uncertainties, biological control could play a larger role in mitigation and adaptation strategies used to maintain biological diversity as well as contribute to human well-being by protecting food and fiber resources.
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Affiliation(s)
- Timothy R Seastedt
- Department of Ecology and Evolutionary Biology, Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO, 80309-0450, USA
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18
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Hoddle MS, Warner K, Steggall J, Jetter KM. Classical Biological Control of Invasive Legacy Crop Pests: New Technologies Offer Opportunities to Revisit Old Pest Problems in Perennial Tree Crops. INSECTS 2014; 6:13-37. [PMID: 26463063 PMCID: PMC4553525 DOI: 10.3390/insects6010013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 12/13/2014] [Indexed: 11/24/2022]
Abstract
Advances in scientific disciplines that support classical biological control have provided "new tools" that could have important applications for biocontrol programs for some long-established invasive arthropod pests. We suggest that these previously unavailable tools should be used in biological control programs targeting "legacy pests", even if they have been targets of previously unsuccessful biocontrol projects. Examples of "new tools" include molecular analyses to verify species identities and likely geographic area of origin, climate matching and ecological niche modeling, preservation of natural enemy genetic diversity in quarantine, the use of theory from invasion biology to maximize establishment likelihoods for natural enemies, and improved understanding of the interactions between natural enemy and target pest microbiomes. This review suggests that opportunities exist for revisiting old pest problems and funding research programs using "new tools" for developing biological control programs for "legacy pests" could provide permanent suppression of some seemingly intractable pest problems. As a case study, we use citricola scale, Coccus pseudomagnoliarum, an invasive legacy pest of California citrus, to demonstrate the potential of new tools to support a new classical biological control program targeting this insect.
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Affiliation(s)
- Mark S Hoddle
- Department of Entomology, University of California, Riverside, CA 92521, USA.
| | - Keith Warner
- Center for Science, Technology, and Society, Santa Clara University, CA 95053, USA.
| | - John Steggall
- California Department of Food and Agriculture, Sacramento, CA 95814, USA.
| | - Karen M Jetter
- UC Agricultural Issues Center, University of California, Davis, CA 95616, USA.
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19
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Stephens AEA, Westoby M. Effects of insect attack to stems on plant survival, growth, reproduction and photosynthesis. OIKOS 2014. [DOI: 10.1111/oik.01809] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
| | - Mark Westoby
- Dept of Biological Sciences; Macquarie Univ.; New South Wales 2109 Australia
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20
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Yang Q, Li B, Siemann E. Positive and negative biotic interactions and invasiveTriadica sebiferatolerance to salinity: a cross-continent comparative study. OIKOS 2014. [DOI: 10.1111/oik.01552] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qiang Yang
- Coastal Ecosystems Research Station of Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan Univ.; 220 Handan Road CN-200433 Shanghai PR China
| | - Bo Li
- Coastal Ecosystems Research Station of Yangtze River Estuary, Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, Institute of Biodiversity Science, Fudan Univ.; 220 Handan Road CN-200433 Shanghai PR China
| | - Evan Siemann
- Dept of Ecology and Evolutionary Biology; Rice Univ.; Houston TX 77005 USA
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21
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Scherm H, Thomas CS, Garrett KA, Olsen JM. Meta-analysis and other approaches for synthesizing structured and unstructured data in plant pathology. ANNUAL REVIEW OF PHYTOPATHOLOGY 2014; 52:453-76. [PMID: 25001455 DOI: 10.1146/annurev-phyto-102313-050214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The term data deluge is used widely to describe the rapidly accelerating growth of information in the technical literature, in scientific databases, and in informal sources such as the Internet and social media. The massive volume and increased complexity of information challenge traditional methods of data analysis but at the same time provide unprecedented opportunities to test hypotheses or uncover new relationships via mining of existing databases and literature. In this review, we discuss analytical approaches that are beginning to be applied to help synthesize the vast amount of information generated by the data deluge and thus accelerate the pace of discovery in plant pathology. We begin with a review of meta-analysis as an established approach for summarizing standardized (structured) data across the literature. We then turn to examples of synthesizing more complex, unstructured data sets through a range of data-mining approaches, including the incorporation of 'omics data in epidemiological analyses. We conclude with a discussion of methodologies for leveraging information contained in novel, open-source data sets through web crawling, text mining, and social media analytics, primarily in the context of digital disease surveillance. Rapidly evolving computational resources provide platforms for integrating large and complex data sets, motivating research that will draw on new types and scales of information to address big questions.
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Affiliation(s)
- H Scherm
- Department of Plant Pathology, University of Georgia, Athens, Georgia 30602;
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22
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Maines A, Knochel D, Seastedt T. Biological control and precipitation effects on spotted knapweed (Centaurea stoebe): empirical and modeling results. Ecosphere 2013. [DOI: 10.1890/es13-00094.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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