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Lancaster J, Downes BJ, Kayll ZJ. Bigger is not necessarily better: empirical tests show that dispersal proxies misrepresent actual dispersal ability. Proc Biol Sci 2024; 291:20240172. [PMID: 38772418 DOI: 10.1098/rspb.2024.0172] [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: 01/21/2024] [Accepted: 04/05/2024] [Indexed: 05/23/2024] Open
Abstract
Tests for the role of species' relative dispersal abilities in ecological and biogeographical models rely heavily on dispersal proxies, which are seldom substantiated by empirical measures of actual dispersal. This is exemplified by tests of dispersal-range size relationships and by metacommunity research that often features invertebrates, particularly freshwater insects. Using rare and unique empirical data on dispersal abilities of caddisflies, we tested whether actual dispersal abilities were associated with commonly used dispersal proxies (metrics of wing size and shape; expert opinion). Across 59 species in 12 families, wing morphology was not associated with actual dispersal. Within some families, individual wing metrics captured some dispersal differences among species, although useful metrics varied among families and predictive power was typically low. Dispersal abilities assigned by experts were either no better than random or actually poorer than random. Our results cast considerable doubt on research underpinned by dispersal proxies and scrutiny of previous research results may be warranted. Greater progress may lie in employing innovative survey and experimental design to measure actual dispersal in the field.
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Affiliation(s)
- Jill Lancaster
- School of Geography, Earth and Atmospheric Sciences, The University of Melbourne , , Victoria, 3010, Australia
| | - Barbara J Downes
- School of Geography, Earth and Atmospheric Sciences, The University of Melbourne , , Victoria, 3010, Australia
| | - Zachary J Kayll
- School of Geography, Earth and Atmospheric Sciences, The University of Melbourne , , Victoria, 3010, Australia
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2
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Carey N, Chester ET, Robson BJ. Loss of functionally important and regionally endemic species from streams forced into intermittency by global warming. GLOBAL CHANGE BIOLOGY 2023; 29:3019-3038. [PMID: 36811356 DOI: 10.1111/gcb.16650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 01/04/2023] [Accepted: 01/27/2023] [Indexed: 05/03/2023]
Abstract
Climate change is altering hydrological cycles globally, and in Mediterranean (med-) climate regions it is causing the drying of river flow regimes, including the loss of perennial flows. Water regime exerts a strong influence over stream assemblages, which have developed over geological timeframes with the extant flow regime. Consequently, sudden drying in formerly perennial streams is expected to have large, negative impacts on stream fauna. We compared contemporary (2016/17) macroinvertebrate assemblages of formerly perennial streams that became intermittently flowing (since the early 2000s) to assemblages recorded in the same streams by a study conducted pre-drying (1981/82) in the med-climate region of southwestern Australia (the Wungong Brook catchment, SWA), using a multiple before-after, control-impact design. Assemblage composition in the stream reaches that remained perennial changed very little between the studies. In contrast, recent intermittency had a profound effect on species composition in streams impacted by drying, including the extirpation of nearly all Gondwanan relictual insect species. New species arriving at intermittent streams tended to be widespread, resilient species including desert-adapted taxa. Intermittent streams also had distinct species assemblages, due in part to differences in their hydroperiods, allowing the establishment of distinct winter and summer assemblages in streams with longer-lived pools. The remaining perennial stream is the only refuge for ancient Gondwanan relict species and the only place in the Wungong Brook catchment where many of these species still persist. The fauna of SWA upland streams is becoming homogenised with that of the wider Western Australian landscape, as drought-tolerant, widespread species replace local endemics. Flow regime drying caused large, in situ alterations to stream assemblage composition and demonstrates the threat posed to relictual stream faunas in regions where climates are drying.
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Affiliation(s)
- Nicole Carey
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - Edwin T Chester
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia, Australia
| | - Belinda J Robson
- Centre for Sustainable Aquatic Ecosystems, Harry Butler Institute, Murdoch University, Murdoch, Western Australia, Australia
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Fournier RJ, de Mendoza G, Sarremejane R, Ruhi A. Isolation controls reestablishment mechanisms and post-drying community structure in an intermittent stream. Ecology 2023; 104:e3911. [PMID: 36335551 PMCID: PMC10078480 DOI: 10.1002/ecy.3911] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/16/2022] [Indexed: 11/07/2022]
Abstract
Biota in disturbance-prone landscapes have evolved a variety of strategies to persist long term, either locally (resistance) or by regional recolonization (resilience). Habitat fragmentation and isolation can limit the availability of recolonization pathways, and thus the dynamics of post-disturbance community reestablishment. However, empirical studies on how isolation may control the mechanisms that enable community recovery remain scarce. Here, we studied a pristine intermittent stream (Chalone Creek, Pinnacles National Park, California) to understand how isolation (distance from a perennial pool) alters invertebrate community recolonization after drying. We monitored benthic invertebrate reestablishment during the rewetting phase along a ~2-km gradient of isolation, using mesh traps that selected for specific recolonization pathways (i.e., drift, flying, swimming/crawling, and vertical migration from the hyporheic). We collected daily emigration samples, surveyed the reestablished benthic community after 6 weeks, and compared assemblages across trap types and sites. We found that isolation mediated migration dynamics by delaying peak vertical migration from the hyporheic by ca. 1 day on average per 250 m of dry streambed. The relative importance of reestablishment mechanisms varied longitudinally-with more resistance strategists (up to 99.3% of encountered individuals) in the upstream reaches, and increased drift and aerial dispersers in the more fragmented habitats (up to 17.2% and 18%, respectively). Resistance strategists persisting in the hyporheic dominated overall (88.2% of individuals, ranging 52.9%-99.3% across sites), but notably most of these organisms subsequently outmigrated downstream (85.6% on average, ranging 52.1%-96% across sites). Thus, contrary to conventional wisdom, resistance strategists largely contributed to downstream resilience as well as to local community recovery. Finally, increased isolation was associated with a general decrease in benthic invertebrate diversity, and up to a 3-fold increase in the relative abundance of drought-resistant stoneflies. Our results advance the notion that understanding spatial context is key to predicting post-disturbance community dynamics. Considering the interaction between disturbance and fragmentation may help inform conservation in ecosystems that are subject to novel environmental regimes.
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Affiliation(s)
- Robert J Fournier
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA
| | - Guillermo de Mendoza
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA.,Faculty of Oceanography and Geography, Institute of Geography, University of Gdansk, Gdańsk, Poland
| | - Romain Sarremejane
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA.,INRAE, UR RiverLy, Centre de Lyon-Grenoble Auvergne-Rhône-Alpes, Villeurbanne Cedex, France
| | - Albert Ruhi
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, California, USA
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Martínez-Pérez S, Galante E, Micó E. Sex specificity of dispersal behaviour and flight morphology varies among tree hollow beetle species. MOVEMENT ECOLOGY 2022; 10:41. [PMID: 36153610 PMCID: PMC9508746 DOI: 10.1186/s40462-022-00340-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
BACKGROUND Flight performance and dispersal behaviour can differ between sexes, resulting in sex-biased dispersal. The primary sex ratio of populations may also explain dispersal bias between sexes, as this bias may evolve with the primary sex ratio to reduce intrasexual competition. Although dispersal bias between sexes is relevant to population dynamics, there are few studies on sex-biased dispersal in insects. We studied the flight performance and dispersal behaviour of seven saproxylic beetle species associated with tree hollows from a sex perspective. We also analysed the possible coevolution of flight performance with the primary sex ratio. METHODS Wing loading and wing aspect ratio were used as measures of the flight performance of species and sexes. Dispersal behaviour was explored by analysing the frequency of each sex in interception traps versus the primary sex ratio obtained by tree hollow emergence traps using contingency tables and posthoc standardized residuals. A more active flight behaviour was expected for the sex with higher capture frequency in the interception traps. To explore the causes of flight performance bias between sexes, we searched for possible correlations between wing loading or wing aspect ratio and primary sex ratio using Pearson's correlation coefficient. RESULTS Wing loading and wing aspect ratio differed between species and sexes, with flight performance being higher in males than in females for four of the seven species analysed. Dispersal behaviour and flight performance matched in the case of Elater ferrugineus; males showed higher flight performance and were the most collected sex in the interception traps (more active flyers). In contrast, the higher flight activity of Cetonia carthami aurataeformis females was not correlated with a higher flight performance than that of males. Moreover, we found that a bias in the primary sex ratio towards females is often correlated with a decrease in female flight performance. CONCLUSIONS We stress that flight performance and dispersal behaviour of sexes do not always go hand in hand. Moreover, the relationship between the sex ratio and flight performance bias between sexes is not driven by competition within the most abundant sex. The inclusion of a sex perspective in insect dispersal studies would be useful to detect dispersal bias between sexes and its causes and would allow for further analysis of its effects on population dynamics.
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Affiliation(s)
- Sandra Martínez-Pérez
- Instituto de Investigación CIBIO (Centro Iberoamericano de la Biodiversidad), Universidad de Alicante, 03690, San Vicente del Raspeig, Alicante, Spain.
| | - Eduardo Galante
- Instituto de Investigación CIBIO (Centro Iberoamericano de la Biodiversidad), Universidad de Alicante, 03690, San Vicente del Raspeig, Alicante, Spain
| | - Estefanía Micó
- Instituto de Investigación CIBIO (Centro Iberoamericano de la Biodiversidad), Universidad de Alicante, 03690, San Vicente del Raspeig, Alicante, Spain
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Outomuro D, Golab MJ, Johansson F, Sniegula S. Body and wing size, but not wing shape, vary along a large-scale latitudinal gradient in a damselfly. Sci Rep 2021; 11:18642. [PMID: 34545136 PMCID: PMC8452623 DOI: 10.1038/s41598-021-97829-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 08/24/2021] [Indexed: 11/09/2022] Open
Abstract
Large-scale latitudinal studies that include both north and south edge populations and address sex differences are needed to understand how selection has shaped trait variation. We quantified the variation of flight-related morphological traits (body size, wing size, ratio between wing size and body size, and wing shape) along the whole latitudinal distribution of the damselfly Lestes sponsa, spanning over 2700 km. We tested predictions of geographic variation in the flight-related traits as a signature of: (1) stronger natural selection to improve dispersal in males and females at edge populations; (2) stronger sexual selection to improve reproduction (fecundity in females and sexual behaviors in males) at edge populations. We found that body size and wing size showed a U-shaped latitudinal pattern, while wing ratio showed the inverse shape. However, wing shape varied very little along the latitudinal gradient. We also detected sex-differences in the latitudinal patterns of variation. We discuss how latitudinal differences in natural and sexual selection regimes can lead to the observed quadratic patterns of variation in body and wing morphology via direct or indirect selection. We also discuss the lack of latitudinal variation in wing shape, possibly due to aerodynamic constraints.
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Affiliation(s)
- David Outomuro
- Department of Biological Sciences, University of Cincinnati, Rieveschl Hall, Cincinnati, OH, 45221, USA. .,Section for Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 75236, Uppsala, Sweden.
| | - Maria J Golab
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
| | - Frank Johansson
- Section for Animal Ecology, Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 75236, Uppsala, Sweden
| | - Szymon Sniegula
- Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland.
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Sarremejane R, Cid N, Stubbington R, Datry T, Alp M, Cañedo-Argüelles M, Cordero-Rivera A, Csabai Z, Gutiérrez-Cánovas C, Heino J, Forcellini M, Millán A, Paillex A, Pařil P, Polášek M, Tierno de Figueroa JM, Usseglio-Polatera P, Zamora-Muñoz C, Bonada N. DISPERSE, a trait database to assess the dispersal potential of European aquatic macroinvertebrates. Sci Data 2020; 7:386. [PMID: 33177529 PMCID: PMC7658241 DOI: 10.1038/s41597-020-00732-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/21/2020] [Indexed: 11/09/2022] Open
Abstract
Dispersal is an essential process in population and community dynamics, but is difficult to measure in the field. In freshwater ecosystems, information on biological traits related to organisms' morphology, life history and behaviour provides useful dispersal proxies, but information remains scattered or unpublished for many taxa. We compiled information on multiple dispersal-related biological traits of European aquatic macroinvertebrates in a unique resource, the DISPERSE database. DISPERSE includes nine dispersal-related traits subdivided into 39 trait categories for 480 taxa, including Annelida, Mollusca, Platyhelminthes, and Arthropoda such as Crustacea and Insecta, generally at the genus level. Information within DISPERSE can be used to address fundamental research questions in metapopulation ecology, metacommunity ecology, macroecology and evolutionary ecology. Information on dispersal proxies can be applied to improve predictions of ecological responses to global change, and to inform improvements to biomonitoring, conservation and management strategies. The diverse sources used in DISPERSE complement existing trait databases by providing new information on dispersal traits, most of which would not otherwise be accessible to the scientific community.
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Affiliation(s)
- Romain Sarremejane
- School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK.
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA 94720, USA.
| | - Núria Cid
- INRAE, UR RiverLy, centre de Lyon-Villeurbanne, 5 rue de la Doua CS70077, 69626, Villeurbanne, Cedex, France
- Grup de Recerca Freshwater Ecology, Hydrology and Management (FEHM), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Rachel Stubbington
- School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK
| | - Thibault Datry
- INRAE, UR RiverLy, centre de Lyon-Villeurbanne, 5 rue de la Doua CS70077, 69626, Villeurbanne, Cedex, France
| | - Maria Alp
- INRAE, UR RiverLy, centre de Lyon-Villeurbanne, 5 rue de la Doua CS70077, 69626, Villeurbanne, Cedex, France
| | - Miguel Cañedo-Argüelles
- Grup de Recerca Freshwater Ecology, Hydrology and Management (FEHM), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Adolfo Cordero-Rivera
- ECOEVO Lab, E.E. Forestal, Univesidade de Vigo, Campus A Xunqueira, 36005, Pontevedra, Spain
| | - Zoltán Csabai
- Department of Hydrobiology, University of Pécs, Ifjúság útja 6, H7624, Pécs, Hungary
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic
| | - Cayetano Gutiérrez-Cánovas
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga, Portugal
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Braga, Portugal
| | - Jani Heino
- Finnish Environment Institute, Freshwater Centre, Paavo Havaksen Tie 3, FI-90570, Oulu, Finland
| | - Maxence Forcellini
- INRAE, UR RiverLy, centre de Lyon-Villeurbanne, 5 rue de la Doua CS70077, 69626, Villeurbanne, Cedex, France
| | - Andrés Millán
- Department of Ecology and Hydrology, Biology Faculty, Murcia University, Campus de Espinardo, 30100, Murcia, Spain
| | - Amael Paillex
- Department of Aquatic Ecology, Eawag, Swiss Federal Institute of Aquatic Sciences, Überlandstrasse 133, CH-8600, Dübendorf, Switzerland
- ECOTEC Environment SA, 1203, Geneva, Switzerland
| | - Petr Pařil
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic
| | - Marek Polášek
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 61137, Brno, Czech Republic
| | - José Manuel Tierno de Figueroa
- Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, Avenida Fuente Nueva, s/n, 18071, Granada, Spain
| | - Philippe Usseglio-Polatera
- Université de Lorraine, CNRS, UMR 7360, LIEC, Laboratoire Interdisciplinaire des Environnements Continentaux, F-57070, Metz, France
| | - Carmen Zamora-Muñoz
- Departamento de Zoología, Facultad de Ciencias, Universidad de Granada, Avenida Fuente Nueva, s/n, 18071, Granada, Spain
| | - Núria Bonada
- Grup de Recerca Freshwater Ecology, Hydrology and Management (FEHM), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona (UB), Diagonal 643, 08028, Barcelona, Catalonia, Spain
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Brooks AJ, Lancaster J, Downes BJ, Wolfenden B. Just add water: rapid assembly of new communities in previously dry riverbeds, and limited long-distance effects on existing communities. Oecologia 2020; 194:709-722. [DOI: 10.1007/s00442-020-04799-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 11/03/2020] [Indexed: 01/23/2023]
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Renault D. A Review of the Phenotypic Traits Associated with Insect Dispersal Polymorphism, and Experimental Designs for Sorting out Resident and Disperser Phenotypes. INSECTS 2020; 11:insects11040214. [PMID: 32235446 PMCID: PMC7240479 DOI: 10.3390/insects11040214] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 03/13/2020] [Accepted: 03/27/2020] [Indexed: 01/06/2023]
Abstract
Dispersal represents a key life-history trait with several implications for the fitness of organisms, population dynamics and resilience, local adaptation, meta-population dynamics, range shifting, and biological invasions. Plastic and evolutionary changes of dispersal traits have been intensively studied over the past decades in entomology, in particular in wing-dimorphic insects for which literature reviews are available. Importantly, dispersal polymorphism also exists in wing-monomorphic and wingless insects, and except for butterflies, fewer syntheses are available. In this perspective, by integrating the very latest research in the fast moving field of insect dispersal ecology, this review article provides an overview of our current knowledge of dispersal polymorphism in insects. In a first part, some of the most often used experimental methodologies for the separation of dispersers and residents in wing-monomorphic and wingless insects are presented. Then, the existing knowledge on the morphological and life-history trait differences between resident and disperser phenotypes is synthetized. In a last part, the effects of range expansion on dispersal traits and performance is examined, in particular for insects from range edges and invasion fronts. Finally, some research perspectives are proposed in the last part of the review.
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Affiliation(s)
- David Renault
- Université de Rennes 1, CNRS, ECOBIO (Ecosystèmes, Biodiversité, Évolution) UMR 6553, F-35000 Rennes, France; ; Tel.: +33-(0)2-2323-6627
- Institut Universitaire de France, 1 Rue Descartes, 75231 Paris CEDEX 05, France
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9
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Lancaster J, Downes BJ. Aquatic versus Terrestrial Insects: Real or Presumed Differences in Population Dynamics? INSECTS 2018; 9:insects9040157. [PMID: 30388810 PMCID: PMC6315690 DOI: 10.3390/insects9040157] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 10/29/2018] [Accepted: 10/30/2018] [Indexed: 01/28/2023]
Abstract
The study of insect populations is dominated by research on terrestrial insects. Are aquatic insect populations different or are they just presumed to be different? We explore the evidence across several topics. (1) Populations of terrestrial herbivorous insects are constrained most often by enemies, whereas aquatic herbivorous insects are constrained more by food supplies, a real difference related to the different plants that dominate in each ecosystem. (2) Population outbreaks are presumed not to occur in aquatic insects. We report three examples of cyclical patterns; there may be more. (3) Aquatic insects, like terrestrial insects, show strong oviposition site selection even though they oviposit on surfaces that are not necessarily food for their larvae. A novel outcome is that density of oviposition habitat can determine larval densities. (4) Aquatic habitats are often largely 1-dimensional shapes and this is presumed to influence dispersal. In rivers, drift by insects is presumed to create downstream dispersal that has to be countered by upstream flight by adults. This idea has persisted for decades but supporting evidence is scarce. Few researchers are currently working on the dynamics of aquatic insect populations; there is scope for many more studies and potentially enlightening contrasts with terrestrial insects.
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Affiliation(s)
- Jill Lancaster
- School of Geography, University of Melbourne, Melbourne, VIC 3010, Australia.
| | - Barbara J Downes
- School of Geography, University of Melbourne, Melbourne, VIC 3010, Australia.
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10
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Tonkin JD, Death RG, Muotka T, Astorga A, Lytle DA. Do latitudinal gradients exist in New Zealand stream invertebrate metacommunities? PeerJ 2018; 6:e4898. [PMID: 29844999 PMCID: PMC5971837 DOI: 10.7717/peerj.4898] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/14/2018] [Indexed: 12/18/2022] Open
Abstract
That biodiversity declines with latitude is well known, but whether a metacommunity process is behind this gradient has received limited attention. We tested the hypothesis that dispersal limitation is progressively replaced by mass effects with increasing latitude, along with a series of related hypotheses. We explored these hypotheses by examining metacommunity structure in stream invertebrate metacommunities spanning the length of New Zealand’s two largest islands (∼1,300 km), further disentangling the role of dispersal by deconstructing assemblages into strong and weak dispersers. Given the highly dynamic nature of New Zealand streams, our alternative hypothesis was that these systems are so unpredictable (at different stages of post-flood succession) that metacommunity structure is highly context dependent from region to region. We rejected our primary hypotheses, pinning this lack of fit on the strong unpredictability of New Zealand’s dynamic stream ecosystems and fauna that has evolved to cope with these conditions. While local community structure turned over along this latitudinal gradient, metacommunity structure was highly context dependent and dispersal traits did not elucidate patterns. Moreover, the emergent metacommunity types exhibited no trends, nor did the important environmental variables. These results provide a cautionary tale for examining singular metacommunities. The considerable level of unexplained contingency suggests that any inferences drawn from one-off snapshot sampling may be misleading and further points to the need for more studies on temporal dynamics of metacommunity processes.
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Affiliation(s)
- Jonathan D Tonkin
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
| | - Russell G Death
- Institute of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Timo Muotka
- Department of Ecology, University of Oulu, Oulu, Finland.,Natural Environment Centre, Finnish Environment Institute, Oulu, Finland
| | - Anna Astorga
- Institute of Ecology and Biodiversity, P. Universidad Catolica de Chile & Centro de Investigación de Ecosistemas de la Patagonia, Coyhaique, Chile
| | - David A Lytle
- Department of Integrative Biology, Oregon State University, Corvallis, OR, USA
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11
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Mims MC, Hartfield Kirk EE, Lytle DA, Olden JD. Traits-based approaches support the conservation relevance of landscape genetics. CONSERV GENET 2017. [DOI: 10.1007/s10592-017-1028-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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