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Veresoglou SD, Xi J, Peñuelas J. Mechanisms of coexistence: Exploring species sorting and character displacement in woody plants to alleviate belowground competition. Ecol Lett 2024; 27:e14489. [PMID: 39075934 DOI: 10.1111/ele.14489] [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: 11/15/2023] [Revised: 06/29/2024] [Accepted: 07/02/2024] [Indexed: 07/31/2024]
Abstract
Rarely do we observe competitive exclusion within plant communities, even though plants compete for a limited pool of resources. Thus, our understanding of the mechanisms sustaining plant biodiversity might be limited. In this study, we explore two common ecological strategies, species sorting and character displacement, that promote coexistence by reducing competition. We assess the degree to which woody plants may implement these two strategies to lower belowground competition for nutrients which occurs via nutritional (mostly mycorrhizal) mutualisms. First, we compile data on plant traits and the mycorrhizal association state of woody angiosperms using a global inventory of indigenous flora. Our analysis reveals that species in locations with high mycorrhizal diversity exhibit distinct mean values in leaf area and wood density based on their mycorrhizal type, indicating species sorting. Second, we reanalyse a large dataset on leaf area to demonstrate that in areas with high mycorrhizal diversity, trees maintain divergent leaf area values, showcasing character displacement. Character displacement among plants is considered rare, making our observation significant. In summary, our study uncovers a rare occurrence of character displacement and identifies a common mechanism employed by plants to alleviate competition, shedding light on the complexities of plant coexistence in diverse ecosystems.
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Affiliation(s)
- Stavros D Veresoglou
- State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-Sen University, Shenzhen, China
| | - Jingjing Xi
- State Key Laboratory of Biocontrol, School of Ecology, Sun Yat-Sen University, Shenzhen, China
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Barcelona, Catalonia, Spain
- CREAF, Barcelona, Catalonia, Spain
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2
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Marcou T, Revilla TA, Křivan V. Evolutionary emergence of plant and pollinator polymorphisms in consumer-resource mutualisms. J Theor Biol 2024:111911. [PMID: 39069203 DOI: 10.1016/j.jtbi.2024.111911] [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: 03/26/2024] [Revised: 07/17/2024] [Accepted: 07/21/2024] [Indexed: 07/30/2024]
Abstract
Mutualism is considered a major driver of biodiversity, as it enables extensive codiversification in terrestrial communities. An important case is flowering plants and their pollinators, where convergent selection on plant and pollinator traits is combined with divergent selection to minimize niche overlap within each group. In this article, we study the emergence of polymorphisms in communities structured trophically: plants are the primary producers of resources required by the primary consumers, the servicing pollinators. We model natural selection on traits affecting mutualism between plants and pollinators and competition within these two trophic levels. We show that phenotypic diversification is favored by broad plant niches, suggesting that bottom-up trophic control leads to codiversification. Mutualistic generalism, i.e., tolerance to differences in plant and pollinator traits, promotes a cascade of evolutionary branching favored by bottom-up plant competition dependent on similarity and top-down mutualistic services that broaden plant niches. Our results predict a strong positive correlation between the diversity of plant and pollinator phenotypes, which previous work has partially attributed to the trophic dependence of pollinators on plants.
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Affiliation(s)
- Thomas Marcou
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic.
| | - Tomás A Revilla
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic; Institute of Entomology, Biology Center, Czech Academy of Science, Branišovská 31, 370 05 České Budějovice, Czech Republic
| | - Vlastimil Křivan
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic; Institute of Entomology, Biology Center, Czech Academy of Science, Branišovská 31, 370 05 České Budějovice, Czech Republic
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3
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Campbell C, Granath G, Rydin H. Variations in water economy traits in two Sphagnum species across their distribution boundaries. AMERICAN JOURNAL OF BOTANY 2024; 111:e16347. [PMID: 38760943 DOI: 10.1002/ajb2.16347] [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: 01/14/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 05/20/2024]
Abstract
PREMISE We assessed changes in traits associated with water economy across climatic gradients in the ecologically similar peat mosses Sphagnum cuspidatum and Sphagnum lindbergii. These species have parapatric distributions in Europe and have similar niches in bogs. Sphagnum species of bogs are closely related, with a large degree of microhabitat niche overlap between many species that can be functionally very similar. Despite this, ecologically similar species do have different distributional ranges along climatic gradients that partly overlap. These gradients may favor particular Sphagnum traits, especially in relation to water economy, which can be hypothesized to drive species divergence by character displacement. METHODS We investigated traits relevant for water economy of two parapatric bryophytes (Sphagnum cuspidatum and S. lindbergii) across the border of their distributional limits. We included both shoot traits and canopy traits, i.e., collective traits of the moss surface, quantified by photogrammetry. RESULTS The two species are ecologically similar and occur at similar positions along the hydrological gradient in bogs. The biggest differences between the species were expressed in the variations of their canopy surfaces, particularly surface roughness and in the responses of important traits such as capitulum mass to climate. We did not find support for character displacement, because traits were not more dissimilar in sympatric than in allopatric populations. CONCLUSIONS Our results suggest that parapatry within Sphagnum can be understood from just a few climatic variables and that climatic factors are stronger drivers than competition behind trait variation within these species of Sphagnum.
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Affiliation(s)
| | - Gustaf Granath
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden
| | - Håkan Rydin
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, SE-752 36, Uppsala, Sweden
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4
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Schmutz A, Schöb C. Coadaptation of coexisting plants enhances productivity in an agricultural system. Proc Natl Acad Sci U S A 2024; 121:e2305517121. [PMID: 38621135 PMCID: PMC11047107 DOI: 10.1073/pnas.2305517121] [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: 04/05/2023] [Accepted: 03/12/2024] [Indexed: 04/17/2024] Open
Abstract
Growing crops in more diverse crop systems (i.e., intercropping) is one way to produce food more sustainably. Even though intercropping, compared to average monocultures, is generally more productive, the full yield potential of intercropping might not yet have been achieved as modern crop cultivars are bred to be grown in monoculture. Breeding plants for more familiarity in mixtures, i.e., plants that are adapted to more diverse communities (i.e., adaptation) or even to coexist with each other (i.e., coadaptation) might have the potential to sustainably enhance productivity. In this study, the productivity benefits of familiarity through evolutionary adaptation and coevolutionary coadaptation were disentangled in a crop system through an extensive common garden experiment. Furthermore, evolutionary and coevolutionary effects on species-level and community-level productivity were linked to corresponding changes in functional traits. We found evidence for higher productivity and trait convergence with increasing familiarity with the plant communities. Furthermore, our results provide evidence for the coevolution of plants in mixtures leading to higher productivity of coadapted species. However, with the functional traits measured in our study, we could not fully explain the productivity benefits found upon coevolution. Our study investigated coevolution among randomly interacting plants and was able to demonstrate that coadaptation through coevolution of coexisting species in mixtures occurs and promotes ecosystem functioning (i.e., higher productivity). This result is particularly relevant for the diversification of agricultural and forest ecosystems, demonstrating the added value of artificially selecting plants for the communities they are familiar with.
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Affiliation(s)
- Anja Schmutz
- Department of Environmental Systems Science, Institute of Agricultural Sciences, ETH Zürich, 8092Zurich, Switzerland
| | - Christian Schöb
- Department of Environmental Systems Science, Institute of Agricultural Sciences, ETH Zürich, 8092Zurich, Switzerland
- Área Biodiversidad y Conservación, Universidad Rey Juan Carlos, 28933Móstoles, Madrid, Spain
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5
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Pérez ÁJ, Tobar F, Burgess KS, Henning T. Contributions to Ecuadorian butterworts (Lentibulariaceae, Pinguicula): two new species and a re-evaluation of Pinguiculacalyptrata. PHYTOKEYS 2023; 222:153-171. [PMID: 37252644 PMCID: PMC10209607 DOI: 10.3897/phytokeys.222.98139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/27/2023] [Indexed: 05/31/2023]
Abstract
Comparatively few species of the insectivorous genus Pinguicula L. have been recognized in South America so far. In recent years, a number of narrowly endemic taxa from the Andes have been described that simultaneously refined the broad taxonomic concepts of the "historical" species. Here, we describe two striking new species from Southern Ecuador that further condense the circumscription of Pinguiculacalyptrata Kunth. Pinguiculajimburensissp. nov. and P.ombrophilasp. nov. are clearly beyond the taxonomic scope of the known species and consequently described as new to science. The deviating morphological features of the two new taxa are described and illustrated and the remaining morphological spectrum of P.calyptrata in Ecuador is outlined. The two new species add to the exceptional biodiversity in the Amotape-Huancabamba Zone and underline its importance as a biodiversity hotspot in urgent need of protection.
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Affiliation(s)
- Álvaro J. Pérez
- Herbario QCA, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Av. 12 de Octubre 1076 y Roca, Apartado 17-01-2184, Quito, EcuadorPontificia Universidad Católica del EcuadorQuitoEcuador
| | - Francisco Tobar
- Área de Investigación y Monitoreo de Avifauna, Aves y Conservación-BirdLife en Ecuador, Quito, EcuadorÁrea de Investigación y Monitoreo de AvifaunaQuitoEcuador
- Herbario Nacional del Ecuador, Instituto Nacional de Biodiversidad, Pasaje Rumipamba 341 y Av. de los Shyris, 170135, Quito, Pichincha, EcuadorHerbario Nacional del Ecuador, Instituto Nacional de BiodiversidadQuitoEcuador
| | - Kevin S. Burgess
- Department of Biology, College of Letters & Sciences, Columbus State University, University System of Georgia, 4225 University Ave, Columbus, GA 31907, USAColumbus State UniversityColumbusUnited States of America
| | - Tilo Henning
- Leibniz Centre for Agricultural Landscape Research (ZALF), Eberswalder Str. 84, 15374, Müncheberg, GermanyLeibniz Centre for Agricultural Landscape ResearchMünchebergGermany
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6
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Forey E, Lodhar SYF, Galvin SD, Lowry JH, Gopaul S, Hanson G, Carboni M, Chauvat M, Boehmer HJ. Alien palm invasion leads to selective biotic filtering of resident plant communities towards competitive functional traits. Biol Invasions 2023. [DOI: 10.1007/s10530-022-02991-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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7
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Du FK, Qi M, Zhang YY, Petit RJ. Asymmetric character displacement in mixed oak stands. THE NEW PHYTOLOGIST 2022; 236:1212-1224. [PMID: 35706383 DOI: 10.1111/nph.18311] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 05/28/2022] [Indexed: 06/15/2023]
Abstract
Ecological character displacement (ECD) refers to a pattern of increased divergence at sites where species ranges overlap caused by competition for resources. Although ECD is believed to be common, there are few in-depth studies that clearly establish its existence, especially in plants. Thus, we have compared leaf traits in allopatric and sympatric populations of two East Asian deciduous oaks: Quercus dentata and Quercus aliena. In contrast to previous studies, we define sympatry and allopatry at a local scale, thereby comparing populations that can or cannot directly interact. Using genetic markers, we found greater genetic divergence between the two oak species growing in mixed stands and inferred that long-term gene flow has predominantly occurred asymmetrically from the cold-tolerant species (Q. dentata) to the warm-demanding later colonizing species (Q. aliena). Analysis of leaf traits revealed greater divergence in mixed than in pure oak stands. This was mostly due to the later colonizing species being characterized by more resource-conservative traits in the presence of the other species. Controlling for relevant environmental differences did not alter these conclusions. These results suggest that asymmetric trait divergence can take place where species coexist, possibly due to the imbalance in demographic history of species resulting in asymmetric inter-specific selection pressures.
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Affiliation(s)
- Fang K Du
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, 100083, China
| | - Min Qi
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing, 100083, China
| | - Yuan-Ye Zhang
- Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, Fujian, 361102, China
| | - Rémy J Petit
- Université de Bordeaux, INRAE, BIOGECO, F-33610, Cestas, France
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8
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Joffard N, Olofsson C, Friberg M, Sletvold N. Extensive pollinator sharing does not promote character displacement in two orchid congeners. Evolution 2022; 76:749-764. [PMID: 35188979 DOI: 10.1111/evo.14446] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 01/07/2022] [Accepted: 01/18/2022] [Indexed: 01/22/2023]
Abstract
Pollinator sharing between close relatives can be costly and can promote pollination niche partitioning and floral divergence. This should be reflected by a higher species divergence in sympatry than in allopatry. We tested this hypothesis in two orchid congeners with overlapping distributions and flowering times. We characterized floral traits and pollination niches and quantified pollen limitation in 15 pure and mixed populations, and we measured phenotypic selection on floral traits and performed controlled crosses in one mixed site. Most floral traits differed between species, yet pollinator sharing was extensive. Only the timing of scent emission diverged more in mixed sites than in pure sites, and this was not mirrored by the timing of pollinator visitation. We did not detect divergent selection on floral traits. Seed production was pollen limited in most populations but not more severely in mixed sites than in pure sites. Interspecific crosses produced the same or a higher proportion of viable seeds than intraspecific crosses. The two orchid species attract the same pollinator species despite showing divergent floral traits. However, this does not promote character displacement, implying a low cost of pollinator sharing. Our results highlight the importance of characterizing both traits and ecological niches in character displacement studies.
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Affiliation(s)
- Nina Joffard
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden.,University of Lille, UMR 8198 - Evo-Eco-Paleo, Villeneuve d'Ascq, F-59655, France
| | - Caroliné Olofsson
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden
| | - Magne Friberg
- Department of Biology, Lund University, Lund, SE-223 62, Sweden
| | - Nina Sletvold
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, Uppsala, 752 36, Sweden
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9
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Reproductive character displacement allows two sexually deceptive orchids to coexist and attract the same specific pollinator. Evol Ecol 2022. [DOI: 10.1007/s10682-021-10149-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractAn increased divergence in characters between species in secondary contact can be shaped by selection against competition for a common resource (ecological character displacement, ECD) or against maladapted hybridization (reproductive character displacement, RCD). These selective pressures can act between incipient species (reinforcement) or well-separated species that already completed the speciation process, but that can still hybridize and produce maladapted hybrids. Here, we investigated two well-separated sexually deceptive orchid species that, unusually, share their specific pollinator. Sympatric individuals of these species are more divergent than allopatric ones in floral characters involved in a mechanical isolating barrier, a pattern suggestive of RCD. To experimentally test this scenario, we built an artificial sympatric population with allopatric individuals. We measured flower characters, genotyped the offspring in natural and artificial sympatry and estimated fertility of hybrids. Different from naturally sympatric individuals, allopatric individuals in artificial sympatry hybridized widely. Hybrids showed lower pollination success and seed viability than parentals. Character displacement did not affect plant pollination success. These findings suggest that RCD evolved between these species to avoid hybridization and that selection on reinforcement may be very strong even in plants with highly specialized pollination.
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10
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Park DS, Breckheimer IK, Ellison AM, Lyra GM, Davis CC. Phenological displacement is uncommon among sympatric angiosperms. THE NEW PHYTOLOGIST 2022; 233:1466-1478. [PMID: 34626123 DOI: 10.1111/nph.17784] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Interactions between species can influence successful reproduction, resulting in reproductive character displacement, where the similarity of reproductive traits - such as flowering time - among close relatives growing together differ from when growing apart. Evidence for the overall prevalence and direction of this phenomenon, and its stability under environmental change, remains untested across large scales. Using the power of crowdsourcing, we gathered phenological information from over 40 000 herbarium specimens, and investigated displacement in flowering time across 110 animal-pollinated species in the eastern USA. Overall, flowering time displacement is not common across large scales. However, displacement is generally greater among species pairs that flower close in time, regardless of direction. Furthermore, with climate change, the flowering times of closely related species are predicted, on average, to shift further apart by the mid-21st century. We demonstrate that the degree and direction of phenological displacement among co-occurring closely related species pairs varies tremendously. However, future climate change may alter the differences in reproductive timing among many of these species pairs, which may have significant consequences for species interactions and gene flow. Our study provides one promising path towards understanding how the phenological landscape is structured and may respond to future environmental change.
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Affiliation(s)
- Daniel S Park
- Department of Biological Sciences, Purdue University, West Lafayette, IN, 47906, USA
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN, 47906, USA
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Harvard University, Cambridge, MA, 02138, USA
| | | | - Aaron M Ellison
- Harvard Forest, Harvard University, Petersham, MA, 01366, USA
- Sound Solutions for Sustainable Science, Boston, MA, 02135, USA
| | - Goia M Lyra
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Harvard University, Cambridge, MA, 02138, USA
- Programa de Pós Graduação em Biodiversidade e Evolução, Instituto de Biologia, Universidade Federal da Bahia, Salvador, Bahia, 40000-000, Brasil
| | - Charles C Davis
- Department of Organismic and Evolutionary Biology, Harvard University Herbaria, Harvard University, Cambridge, MA, 02138, USA
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11
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Schrader J, Wright IJ, Kreft H, Westoby M. A roadmap to plant functional island biogeography. Biol Rev Camb Philos Soc 2021; 96:2851-2870. [PMID: 34423523 DOI: 10.1111/brv.12782] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 01/05/2023]
Abstract
Island biogeography is the study of the spatio-temporal distribution of species, communities, assemblages or ecosystems on islands and other isolated habitats. Island diversity is structured by five classes of process: dispersal, establishment, biotic interactions, extinction and evolution. Classical approaches in island biogeography focused on species richness as the deterministic outcome of these processes. This has proved fruitful, but species traits can potentially offer new biological insights into the processes by which island life assembles and why some species perform better at colonising and persisting on islands. Functional traits refer to morphological and phenological characteristics of an organism or species that can be linked to its ecological strategy and that scale up from individual plants to properties of communities and ecosystems. A baseline hypothesis is for traits and ecological strategies of island species to show similar patterns as a matched mainland environment. However, strong dispersal, environmental and biotic-interaction filters as well as stochasticity associated with insularity modify this baseline. Clades that do colonise often embark on distinct ecological and evolutionary pathways, some because of distinctive evolutionary forces on islands, and some because of the opportunities offered by freedom from competitors or herbivores or the absence of mutualists. Functional traits are expected to be shaped by these processes. Here, we review and discuss the potential for integrating functional traits into island biogeography. While we focus on plants, the general considerations and concepts may be extended to other groups of organisms. We evaluate how functional traits on islands relate to core principles of species dispersal, establishment, extinction, reproduction, biotic interactions, evolution and conservation. We formulate existing knowledge as 33 working hypotheses. Some of these are grounded on firm empirical evidence, others provide opportunities for future research. We organise our hypotheses under five overarching sections. Section A focuses on plant functional traits enabling species dispersal to islands. Section B discusses how traits help to predict species establishment, successional trajectories and natural extinctions on islands. Section C reviews how traits indicate species biotic interactions and reproduction strategies and which traits promote intra-island dispersal. Section D discusses how evolution on islands leads to predictable changes in trait values and which traits are most susceptible to change. Section E debates how functional ecology can be used to study multiple drivers of global change on islands and to formulate effective conservation measures. Islands have a justified reputation as research models. They illuminate the forces operating within mainland communities by showing what happens when those forces are released or changed. We believe that the lens of functional ecology can shed more light on these forces than research approaches that do not consider functional differences among species.
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Affiliation(s)
- Julian Schrader
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia.,Department of Biodiversity, Macroecology and Biogeography, University of Goettingen, Büsgenweg 1, 37077, Goettingen, Germany
| | - Ian J Wright
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Holger Kreft
- Department of Biodiversity, Macroecology and Biogeography, University of Goettingen, Büsgenweg 1, 37077, Goettingen, Germany.,Centre of Biodiversity and Sustainable Land Use (CBL), University of Goettingen, Büsgenweg 1, 37077, Goettingen, Germany
| | - Mark Westoby
- Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia
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12
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Eisen KE, Geber MA, Raguso RA. Emission rates of species-specific volatiles vary across communities of Clarkia species: Evidence for multi-modal character displacement. Am Nat 2021; 199:824-840. [DOI: 10.1086/715501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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13
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Colom SM, Baucom RS. Below-ground competition favors character convergence but not character displacement in root traits. THE NEW PHYTOLOGIST 2021; 229:3195-3207. [PMID: 33220075 DOI: 10.1111/nph.17100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 11/17/2020] [Indexed: 06/11/2023]
Abstract
Character displacement can play a major role in species ecology and evolution; however, research testing whether character displacement can influence the evolution of root traits in plant systems remains scarce in the literature. Here we investigated the potential that character displacement may influence the evolution of root traits using two closely related morning glory species, Ipomoea purpurea and Ipomoea hederacea. We performed a field experiment where we grew the common morning glory, I. purpurea, in the presence and absence of competition from I. hederacea and examined the potential that the process of character displacement could influence the evolution of root traits. We found maternal line variation in root phenotypes and evidence that below-ground competition acts as an agent of selection on these traits. Our test of character displacement, however, showed evidence of character convergence on our measure of root architecture rather than displacement. These results suggest that plants may be constrained by their local environments to express a phenotype that enhances fitness. Therefore, the conditions of the competitive environment experienced by a plant may influence the potential for character convergence or displacement to influence the evolution of root traits.
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Affiliation(s)
- Sara M Colom
- University of Michigan, 4034 Biological Sciences Building, Ann Arbor, MI, 48109, USA
| | - Regina S Baucom
- University of Michigan, 4034 Biological Sciences Building, Ann Arbor, MI, 48109, USA
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14
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Toll K, LoPresti EF, Lowry DB. Inbreeding depression contributes to the maintenance of habitat segregation between closely related monkeyflower species. Evolution 2021; 75:832-846. [PMID: 33590496 DOI: 10.1111/evo.14192] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 01/28/2021] [Accepted: 02/07/2021] [Indexed: 11/30/2022]
Abstract
Incompletely reproductively isolated species often segregate into different microhabitats, even when they are able to survive and reproduce in both habitats. Longer term evolutionary factors may contribute to this lack of cross-habitat persistence. When reproductive interference reduces immigrant fitness, assortative mating, including self-fertilization, increases immigrants' fitness in a single generation, but longer term, inbreeding depression may reduce the chance of population persistence. Two California monkeyflower species repeatedly segregate into drier and wetter areas in their zone of sympatry. To test whether inbreeding depression may contribute to the maintenance of this segregation pattern, we transplanted outbred and successively inbred Mimulus guttatus and Mimulus nudatus into their native habitats and heterospecific habitats. We measured germination, survival, and seed set and found that recurrent selfing reduced all aspects of fitness in both species, most strongly in foreign habitats. A simulation model, parameterized from the transplant experiment, found that inbreeding reduced fitness to such an extent that sequentially inbred populations of either species would be unable to persist in heterospecific-occupied habitats in the absence of continued gene flow. These results demonstrate that individual immigrants are unlikely to form persistent populations and thus, inbreeding depression contributes to the absence of fine-scale coexistence in this species pair.
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Affiliation(s)
- Katherine Toll
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824
| | - Eric F LoPresti
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824
| | - David B Lowry
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, 48824.,Program in Ecology, Evolutionary Biology, and Behavior, Michigan State University, East Lansing, Michigan, 48824
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15
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Orsucci M, Sicard A. Flower evolution in the presence of heterospecific gene flow and its contribution to lineage divergence. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:971-989. [PMID: 33537708 DOI: 10.1093/jxb/eraa549] [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: 08/10/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
The success of species depends on their ability to exploit ecological resources in order to optimize their reproduction. However, species are not usually found within single-species ecosystems but in complex communities. Because of their genetic relatedness, closely related lineages tend to cluster within the same ecosystem, rely on the same resources, and be phenotypically similar. In sympatry, they will therefore compete for the same resources and, in the case of flowering plants, exchange their genes through heterospecific pollen transfer. These interactions, nevertheless, pose significant challenges to species co-existence because they can lead to resource limitation and reproductive interference. In such cases, divergent selective pressures on floral traits will favour genotypes that isolate or desynchronize the reproduction of sympatric lineages. The resulting displacement of reproductive characters will, in turn, lead to pre-mating isolation and promote intraspecific divergence, thus initiating or reinforcing the speciation process. In this review, we discuss the current theoretical and empirical knowledge on the influence of heterospecific pollen transfer on flower evolution, highlighting its potential to uncover the ecological and genomic constraints shaping the speciation process.
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Affiliation(s)
- Marion Orsucci
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
| | - Adrien Sicard
- Department of Plant Biology, Swedish University of Agricultural, Sciences and Linnean Center for Plant Biology, Uppsala, Sweden
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16
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Kyogoku D, Wheatcroft D. Heterospecific mating interactions as an interface between ecology and evolution. J Evol Biol 2020; 33:1330-1344. [PMID: 32762053 DOI: 10.1111/jeb.13687] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 07/21/2020] [Indexed: 12/25/2022]
Abstract
Reproductive interference (costly interspecific sexual interactions) is well-understood to promote divergence in mating-relevant traits (i.e. reproductive character displacement: RCD), but it can also reduce population growth, eventually leading to local extinction of one of the species. The ecological and evolutionary processes driven by reproductive interference can interact with each other. These interactions are likely to influence whether the outcome is coexistence or extinction, but remain little studied. In this paper, we first develop an eco-evolutionary perspective on reproductive interference by integrating ecological and evolutionary processes in a common framework. We also present a simple model to demonstrate the eco-evolutionary dynamics of reproductive interference. We then identify a number of factors that are likely to influence the relative likelihoods of extinction or RCD. We discuss particularly relevant factors by classifying them into four categories: the nature of the traits responding to selection, the mechanisms determining the expression of these traits, mechanisms of reproductive interference and the ecological background. We highlight previously underappreciated ways in which these factors may influence the relative likelihoods of RCD and local extinction. By doing so, we also identify questions and future directions that will increase our holistic understanding of the outcomes of reproductive interference.
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17
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Moreira-Hernández JI, Muchhala N. Importance of Pollinator-Mediated Interspecific Pollen Transfer for Angiosperm Evolution. ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS 2019. [DOI: 10.1146/annurev-ecolsys-110218-024804] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Understanding how pollen moves between species is critical to understanding speciation, diversification, and evolution of flowering plants. For co-flowering species that share pollinators, competition through interspecific pollen transfer (IPT) can profoundly impact floral evolution, decreasing female fitness via heterospecific pollen deposition on stigmas and male fitness via pollen misplacement during visits to heterospecific flowers. The pollination literature demonstrates that such reproductive interference frequently selects for reproductive character displacement in floral traits linked to pollinator attraction, pollen placement, and mating systems and has also revealed that IPT between given pairs of species is typically asymmetric. More recent work is starting to elucidate its importance to the speciation process, clarifying the link between IPT and current and historical patterns of hybridization, the evolution of phenotypic novelty through adaptive introgression, and the rise of reproductive isolation. Our review aims to stimulate further research on IPT as a ubiquitous mechanism that plays a central role in angiosperm diversification.
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Affiliation(s)
- Juan Isaac Moreira-Hernández
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri–St. Louis, St. Louis, Missouri 63121, USA;,
| | - Nathan Muchhala
- Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri–St. Louis, St. Louis, Missouri 63121, USA;,
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18
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Lagomarsino LP, Muchhala N. A gradient of pollination specialization in three species of Bolivian Centropogon. AMERICAN JOURNAL OF BOTANY 2019; 106:633-642. [PMID: 31021395 DOI: 10.1002/ajb2.1276] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 02/27/2019] [Indexed: 06/09/2023]
Abstract
PREMISE Closely related plant species with overlapping ranges often experience competition for pollination services. Such competition can select for divergence in floral traits that attract pollinators or determine pollen placement. While most species in Centropogon (Campanulaceae: Lobelioideae) have flowers that suggest adaptation to bat or hummingbird pollination, actual pollinators are rarely documented, and a few species have a mix of traits from both pollination syndromes. We studied the pollination biology of a "mixed-syndrome" species and its co-occurring congeners to examine the relationship between floral traits and visitation patterns for Centropogon. METHODS Fieldwork at two sites in Bolivian cloud forests involved filming floral visitors, quantifying pollen transfer, and measuring floral traits. Stamen exsertion, which determines pollen placement, was measured from herbarium specimens across the geographic range of these species to test for character displacement. RESULTS Results show a generalization gradient, from primarily bat pollination in white-flowered Centropogon incanus, to bat pollination with secondary hummingbird pollination in the cream-flowered C. brittonianus, to equal reliance on both pollinators in the red-flowered, mixed-syndrome C. mandonis. Pollen transfer between these species is further reduced by differences in stamen exsertion that are accentuated in zones of sympatry, a pattern consistent with character displacement. CONCLUSIONS Our results demonstrate that key differences in floral color and shape mediate a gradient of specialization in Bolivian Centropogon. Interspecific pollen transfer is further reduced by potential character displacement of a key trait. Broadly, our results have implications for understanding the hyper-diversity of Andean cloud forests, in which multiple species of the same genus frequently co-occur.
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Affiliation(s)
- Laura P Lagomarsino
- Department of Biology, University of Missouri-St. Louis, Research Building, One University Boulevard, St. Louis, Missouri, 63121, USA
- Shirley C. Tucker Herbarium, Department of Biological Sciences, Louisiana State University, Baton Rouge, Louisiana, 70803, USA
| | - Nathan Muchhala
- Department of Biology, University of Missouri-St. Louis, Research Building, One University Boulevard, St. Louis, Missouri, 63121, USA
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19
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Abstract
Increasing evidence for rapid evolution suggests that the maintenance of species diversity in ecological communities may be influenced by more than purely ecological processes. Classic theory shows that interspecific competition may select for traits that increase niche differentiation, weakening competition and thus promoting species coexistence. While empirical work has demonstrated trait evolution in response to competition, if and how evolution affects the dynamics of the competing species-the key step for completing the required eco-evolutionary feedback-has been difficult to resolve. Here, we show that evolution in response to interspecific competition feeds back to change the course of competitive population dynamics of aquatic plant species over 10-15 generations in the field. By manipulating selection imposed by heterospecific competitors in experimental ponds, we demonstrate that (i) interspecific competition drives rapid genotypic change, and (ii) this evolutionary change in one competitor, while not changing the coexistence outcome, causes the population trajectories of the two competing species to converge. In contrast to the common expectation that interspecific competition should drive the evolution of niche differentiation, our results suggest that genotypic evolution resulted in phenotypic changes that altered population dynamics by affecting the competitive hierarchy. This result is consistent with theory suggesting that competition for essential resources can limit opportunities for the evolution of niche differentiation. Our finding that rapid evolution regulates the dynamics of competing species suggests that ecosystems may rely on continuous feedbacks between ecology and evolution to maintain species diversity.
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Affiliation(s)
- Simon P Hart
- Institute of Integrative Biology, ETH Zürich, 8092 Zürich, Switzerland;
| | - Martin M Turcotte
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260
| | - Jonathan M Levine
- Institute of Integrative Biology, ETH Zürich, 8092 Zürich, Switzerland
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20
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Li Q, Grossenbacher DL, Angert AL. The effect of range overlap on ecological niche divergence depends on spatial scale in monkeyflowers. Evolution 2018; 72:2100-2113. [PMID: 30094835 DOI: 10.1111/evo.13567] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 07/20/2018] [Indexed: 12/24/2022]
Abstract
Patterns of niche divergence and geographical range overlap of closely related species provide insights into the evolutionary dynamics of ecological niches. When ranges overlap, shared selective pressures may preserve niche similarity along coarse-scale macrohabitat axes (e.g., bioclimates). Alternatively, competitive interactions may drive greater divergence along local-scale microhabitat axes (e.g., micro-topographical features). We tested these hypotheses in 16 species pairs of western North American monkeyflowers (Erythranthe and Diplacus, formerly Mimulus) with estimations of species' niches, geographic ranges, and a robust phylogeny. We found that macrohabitat niche divergence decreased with increasing range overlap, consistent with convergent selection operating at a coarse scale. No significant relationship was detected for microhabitat niches. Additionally, niche divergence was greater for recently diverged pairs along all macrohabitat niche axes, but greater for distantly diverged pairs along one microhabitat axis related to vegetation cover. For species pairs with partially overlapping ranges, greater microhabitat divergence was detected in sympatry than in allopatry for at least one niche axis for three of four pairs, consistent with character displacement in sympatry. Thus, coarse- and local-scale niche divergence show dissimilar patterns in relation to range overlap and divergence time, perhaps because the relative importance of convergent versus divergent selection depends on spatial scale.
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Affiliation(s)
- Qin Li
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada.,Integrative Research Center, The Field Museum, Chicago, Illinois, USA
| | - Dena L Grossenbacher
- Department of Biology, California Polytechnic State University, San Luis Obispo, California, USA
| | - Amy L Angert
- Department of Botany and Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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21
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Eisen KE, Geber MA. Ecological sorting and character displacement contribute to the structure of communities of Clarkia species. J Evol Biol 2018; 31:1440-1458. [PMID: 30099807 DOI: 10.1111/jeb.13365] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/10/2018] [Accepted: 08/06/2018] [Indexed: 01/27/2023]
Abstract
Despite long-standing interest in the evolutionary ecology of plants that share pollinators, few studies have explored how these interactions may affect communities during both community assembly (ecological sorting) and through ongoing, in situ evolution (character displacement), and how the effects of these interactions may change with community context. To determine if communities display patterns consistent with ecological sorting, we assessed the frequency of co-occurrence of four species of Clarkia in the southern Sierra foothills (Kern County, CA, USA). To investigate potential character displacement, we measured pollination-related traits on plants grown in a greenhouse common garden from seed collected in communities with one, two or four Clarkia species. Among the four species of Clarkia in this region, the two species that are often found in multi-species communities also co-occur with one another more frequently than expected under a null model. This pattern is consistent with ecological sorting, although further investigation is needed to determine the role of pollinators in shaping community assembly. Patterns of trait variation in a common garden suggest that these two species have diverged in floral traits and converged in flowering time where they co-occur, which is consistent with character displacement. Trait variation across community types also suggests that the process and outcome of character displacement may vary with community context. Because community context appears to affect both the direction and magnitude of character displacement, change in more species-rich communities may not be predictable from patterns of change in simpler communities.
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Affiliation(s)
- Katherine E Eisen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - Monica A Geber
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
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22
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Li HD, Ren ZX, Zhou W, Bernhardt P, Zhao YH, Wu ZK, Li DZ, Wang H. Comparative intra- and interspecific sexual organ reciprocity in four distylous Primula species in the Himalaya-Hengduan Mountains. PLANT BIOLOGY (STUTTGART, GERMANY) 2018; 20:643-653. [PMID: 29683559 DOI: 10.1111/plb.12834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 04/17/2018] [Indexed: 06/08/2023]
Abstract
Distyly is a mechanism promoting cross-pollination within a balanced polymorphism. Numerous studies show that the degree of inter-morph sexual organ reciprocity (SOR) within species relates to its pollen-mediated gene flow. Similarly, a lower interspecific SOR should promote interspecific isolation when congeners are sympatric, co-blooming and share pollinators. In this comparative study, we address the significance of SOR at both intra- and interspecific levels. Seventeen allopatric and eight sympatric populations representing four Primula species (P. anisodora, P. beesiana, P. bulleyana and P. poissonii) native to the Himalaya-Hengduan Mountains were measured for eight floral traits in both long- and short-styled morphs. GLMM and spatial overlap methods were used to compare intra- and interspecific SOR. While floral morphology differed among four Primula species, SOR within species was generally higher than between species, but in species pairs P. poissonii/P. anisodora and P. beesiana/P. bulleyana, the SOR was high at both intra- and interspecific levels. We did not detect a significant variation in intraspecific SOR or interspecific SOR when comparing allopatric versus sympatric populations for all species studied. As intraspecific SOR increased, disassortative mating may be promoted. As interspecific SOR decreased, interspecific isolation between co-flowering species pairs also may increase. Hybridisation between congeners occurred when interspecific SOR increased in sympatric populations, as confirmed in two species pairs, P. poissonii/P. anisodora and P. beesiana/P. bulleyana.
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Affiliation(s)
- H-D Li
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Z-X Ren
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - W Zhou
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - P Bernhardt
- Department of Biology, Saint Louis University, St. Louis, USA
| | - Y-H Zhao
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Z-K Wu
- Lijiang Forest Ecosystem Research Station, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - D-Z Li
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - H Wang
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China
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23
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Karunarathne P, Schedler M, Martínez EJ, Honfi AI, Novichkova A, Hojsgaard D. Intraspecific ecological niche divergence and reproductive shifts foster cytotype displacement and provide ecological opportunity to polyploids. ANNALS OF BOTANY 2018; 121:1183-1196. [PMID: 29415153 PMCID: PMC5946955 DOI: 10.1093/aob/mcy004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 01/15/2018] [Indexed: 05/20/2023]
Abstract
Background and Aims Niche divergence between polyploids and their lower ploidy progenitors is one of the primary mechanisms fostering polyploid establishment and adaptive divergence. However, within-species chromosomal and reproductive variability have usually been neglected in community ecology and biodiversity analyses even though they have been recognized to play a role in the adaptive diversification of lineages. Methods We used Paspalum intermedium, a grass species with diverging genetic systems (diploidy vs. autopolyploidy, allogamy vs. autogamy and sexuality vs. apomixis), to recognize the causality of biogeographic patterns, adaptation and ecological flexibility of cytotypes. Chromosome counts and flow cytometry were used to characterize within-species genetic systems diversity. Environmental niche modelling was used to evaluate intraspecific ecological attributes associated with environmental and climatic factors and to assess correlations among ploidy, reproductive modes and ecological conditions ruling species' population dynamics, range expansion, adaptation and evolutionary history. Key Results Two dominant cytotypes non-randomly distributed along local and regional geographical scales displayed niche differentiation, a directional shift in niche optima and signs of disruptive selection on ploidy-related ecological aptitudes for the exploitation of environmental resources. Ecologically specialized allogamous sexual diploids were found in northern areas associated with higher temperature, humidity and productivity, while generalist autogamous apomictic tetraploids occurred in southern areas, occupying colder and less productive environments. Four localities with a documented shift in ploidy and four mixed populations in a zone of ecological transition revealed an uneven replacement between cytotypes. Conclusions Polyploidy and contrasting reproductive traits between cytotypes have promoted shifts in niche optima, and increased ecological tolerance and niche divergence. Ecologically specialized diploids maintain cytotype stability in core areas by displacing tetraploids, while broader ecological preferences and a shift from sexuality to apomixis favoured polyploid colonization in peripheral areas where diploids are displaced, and fostered the ecological opportunity for autotetraploids supporting range expansion to open southern habitats.
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Affiliation(s)
- Piyal Karunarathne
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Untere Karspuele, Goettingen, Germany
| | - Mara Schedler
- Instituto de Botánica del Nordeste (IBONE), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (FCA-UNNE), Corrientes, Argentina
| | - Eric J Martínez
- Instituto de Botánica del Nordeste (IBONE), Facultad de Ciencias Agrarias, Universidad Nacional del Nordeste (FCA-UNNE), Corrientes, Argentina
| | - Ana I Honfi
- Programa de Estudios Florísticos y Genética Vegetal, Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Instituto de Biología Subtropical (CONICET-UNaM), Rivadavia, Posadas, Misiones, Argentina
| | - Anastasiia Novichkova
- Department of Botany, Institute of Biology, Taras Shevchenko National University of Kyiv, Ukraine
| | - Diego Hojsgaard
- Department of Systematics, Biodiversity and Evolution of Plants, Albrecht-von-Haller Institute for Plant Sciences, University of Goettingen, Untere Karspuele, Goettingen, Germany
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24
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Kay KM, Woolhouse S, Smith BA, Pope NS, Rajakaruna N. Sympatric serpentine endemic
Monardella
(Lamiaceae) species maintain habitat differences despite hybridization. Mol Ecol 2018; 27:2302-2316. [DOI: 10.1111/mec.14582] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 02/09/2018] [Accepted: 02/20/2018] [Indexed: 01/09/2023]
Affiliation(s)
- Kathleen M. Kay
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California
| | - Suzie Woolhouse
- Department of Biological Sciences San José State University San José California
| | - Brett A. Smith
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California
| | - Nathaniel S. Pope
- Department of Integrative Biology The University of Texas at Austin Austin Texas
| | - Nishanta Rajakaruna
- Biological Sciences Department California Polytechnic State University San Luis Obispo California
- Unit for Environmental Sciences and Management North‐West University Potchefstroom South Africa
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25
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Espeland EK. Disarming the Red Queen: plant invasions, novel weapons, species coexistence, and microevolution. THE NEW PHYTOLOGIST 2018; 218:12-14. [PMID: 29488281 DOI: 10.1111/nph.15060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Affiliation(s)
- Erin K Espeland
- USDA-ARS Pest Management Research Unit, 1500 N Central Ave, Sidney, MT, 59270, USA
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26
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Neri J, Wendt T, Palma-Silva C. Natural hybridization and genetic and morphological variation between two epiphytic bromeliads. AOB PLANTS 2018; 10:plx061. [PMID: 29308124 PMCID: PMC5751037 DOI: 10.1093/aobpla/plx061] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 11/22/2017] [Indexed: 05/18/2023]
Abstract
Reproductive isolation is of fundamental importance for maintaining species boundaries in sympatry. Here, we examine the genetic and morphological differences between two closely related bromeliad species: Vriesea simplex and Vriesea scalaris. Furthermore, we examined the occurrence of natural hybridization and discuss the action of reproductive isolation barriers. Nuclear genomic admixture suggests hybridization in sympatric populations, although interspecific gene flow is low among species in all sympatric zones (Nem < 0.5). Thus, morphological and genetic divergence (10.99 %) between species can be maintained despite ongoing natural hybridization. Cross-evaluation of our genetic and morphological data suggests that species integrity is maintained by the simultaneous action of multiple barriers, such as divergent reproductive systems among species, differences in floral traits and low hybrid seed viability.
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Affiliation(s)
- Jordana Neri
- Programa de Pós Graduação em Botânica, Departamento de Botânica, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, Rio de Janeiro, RJ, Brazil
| | - Tânia Wendt
- Departamento de Botânica, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Clarisse Palma-Silva
- Programa de Pós Graduação em Ecologia, Departamento de Ecologia – Universidade Estadual Paulista Julio Mesquita Filho, Rio Claro, SP, Brazil
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27
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Kooyers NJ, James B, Blackman BK. Competition drives trait evolution and character displacement between Mimulus species along an environmental gradient. Evolution 2017; 71:1205-1221. [PMID: 28186619 DOI: 10.1111/evo.13200] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/24/2017] [Accepted: 01/27/2017] [Indexed: 01/31/2023]
Abstract
Closely related species may evolve to coexist stably in sympatry through niche differentiation driven by in situ competition, a process termed character displacement. Alternatively, past evolution in allopatry may have already sufficiently reduced niche overlap to permit establishment in sympatry, a process called ecological sorting. The relative importance of each process to niche differentiation is contentious even though they are not mutually exclusive and are both mediated via multivariate trait evolution. We explore how competition has impacted niche differentiation in two monkeyflowers, Mimulus alsinoides and M. guttatus, which often co-occur. Through field observations, common gardens, and competition experiments, we demonstrate that M. alsinoides is restricted to marginal habitats in sympatry and that the impacts of character displacement on niche differentiation are complex. Competition with M. guttatus alters selection gradients and has favored taller M. alsinoides with earlier seasonal flowering at low elevation and floral shape divergence at high elevation. However, no trait exhibits the pattern typically associated with character displacement, higher divergence between species in sympatry than allopatry. Thus, although character displacement was unlikely the process driving initial divergence along niche axes necessary for coexistence, we conclude that competition in sympatry has likely driven trait evolution along additional niche axes.
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Affiliation(s)
- Nicholas J Kooyers
- Department of Biology, University of Virginia, Charlottesville, Virginia, 22904.,Department of Plant and Microbial Biology, University of California, Berkeley, California, 94720.,Department of Integrative Biology, University of South Florida, Tampa, Florida, 33620
| | - Brooke James
- Department of Biology, University of Virginia, Charlottesville, Virginia, 22904
| | - Benjamin K Blackman
- Department of Biology, University of Virginia, Charlottesville, Virginia, 22904.,Department of Plant and Microbial Biology, University of California, Berkeley, California, 94720
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28
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Armbruster WS. The specialization continuum in pollination systems: diversity of concepts and implications for ecology, evolution and conservation. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12783] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- William Scott Armbruster
- School of Biological Sciences University of Portsmouth PortsmouthPO1 2DY UK
- Institute of Arctic Biology University of Alaska Fairbanks Fairbanks AK99775‐7000 USA
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29
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Koski MH, Ashman TL. Reproductive character displacement and environmental filtering shape floral variation between sympatric sister taxa. Evolution 2016; 70:2616-2622. [PMID: 27566693 DOI: 10.1111/evo.13042] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 08/06/2016] [Accepted: 08/18/2016] [Indexed: 01/24/2023]
Abstract
Divergence in reproductive traits between closely related species that co-occur contributes to speciation by reducing interspecific gene flow. In flowering plants, greater floral divergence in sympatry than allopatry may reflect reproductive character displacement (RCD) by means of divergent pollinator-mediated selection or mating system evolution. However, environmental filtering (EF) would prevail for floral traits under stronger selection by abiotic factors than pollination, and lead to sympatric taxa being more phenotypically similar. We determine whether floral UV pigmentation and size show signatures of RCD or EF using a biogeographically informed sister taxa comparison. We determine whether 35 sister pairs in the Potentilleae tribe (Rosaceae) are allopatric or sympatric and confirm that sympatric sisters experience more similar bioclimatic conditions, an assumption of the EF hypothesis. We test whether interspecific differences are greater in allopatry or sympatry while accounting for divergence time. For UV pigmentation, sympatric sisters are more phenotypically similar than allopatric ones. For flower size, sympatric sisters show increased divergence with time since speciation but allopatric ones do not. We conclude that floral UV pigmentation shows a signature of EF, whereas flower size shows a signature of RCD. Discordant results between the traits suggest that the dominant selective agent differs between them.
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Affiliation(s)
- Matthew H Koski
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260. .,Current Address: Department of Biology, University of Virginia, Charlottesville, Virginia, 22904.
| | - Tia-Lynn Ashman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, 15260
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30
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Gaume L, Bazile V, Huguin M, Bonhomme V. Different pitcher shapes and trapping syndromes explain resource partitioning in Nepenthes species. Ecol Evol 2016; 6:1378-92. [PMID: 26865951 PMCID: PMC4739188 DOI: 10.1002/ece3.1920] [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: 09/24/2015] [Revised: 11/30/2015] [Accepted: 12/01/2015] [Indexed: 11/09/2022] Open
Abstract
Nepenthes pitcher plants display interspecific diversity in pitcher form and diets. This species-rich genus might be a conspicuous candidate for an adaptive radiation. However, the pitcher traits of different species have never been quantified in a comparative study, nor have their possible adaptations to the resources they exploit been tested. In this study, we compare the pitcher features and prey composition of the seven Nepenthes taxa that grow in the heath forest of Brunei (Borneo) and investigate whether these species display different trapping syndromes that target different prey. The Nepenthes species are shown to display species-specific combinations of pitcher shapes, volumes, rewards, attraction and capture traits, and different degrees of ontogenetic pitcher dimorphism. The prey spectra also differ among plant species and between ontogenetic morphotypes in their combinations of ants, flying insects, termites, and noninsect guilds. According to a discriminant analysis, the Nepenthes species collected at the same site differ significantly in prey abundance and composition at the level of order, showing niche segregation but with varying degrees of niche overlap according to pairwise species comparisons. Weakly carnivorous species are first characterized by an absence of attractive traits. Generalist carnivorous species have a sweet odor, a wide pitcher aperture, and an acidic pitcher fluid. Guild specializations are explained by different combinations of morpho-functional traits. Ant captures increase with extrafloral nectar, fluid acidity, and slippery waxy walls. Termite captures increase with narrowness of pitchers, presence of a rim of edible trichomes, and symbiotic association with ants. The abundance of flying insects is primarily correlated with pitcher conicity, pitcher aperture diameter, and odor presence. Such species-specific syndromes favoring resource partitioning may result from local character displacement by competition and/or previous adaptations to geographically distinct environments.
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Affiliation(s)
- Laurence Gaume
- Université de MontpellierUMR AMAP: botAnique et Modélisation de l'Architecture des Plantes et des végétationsCIRAD – TA A51/PS2Boulevard de la LirondeF‐34398MontpellierFrance
- CNRSUMR AMAP: botAnique et Modélisation de l'Architecture des Plantes et des végétationsCIRAD – TA A51/PS2Boulevard de la LirondeF‐34398MontpellierFrance
| | - Vincent Bazile
- Université de MontpellierUMR AMAP: botAnique et Modélisation de l'Architecture des Plantes et des végétationsCIRAD – TA A51/PS2Boulevard de la LirondeF‐34398MontpellierFrance
| | - Maïlis Huguin
- CNRSUMR AMAP: botAnique et Modélisation de l'Architecture des Plantes et des végétationsCIRAD – TA A51/PS2Boulevard de la LirondeF‐34398MontpellierFrance
- Université François Rabelais60 rue du Plat D'EtainF‐37020ToursFrance
| | - Vincent Bonhomme
- Université de MontpellierUMR AMAP: botAnique et Modélisation de l'Architecture des Plantes et des végétationsCIRAD – TA A51/PS2Boulevard de la LirondeF‐34398MontpellierFrance
- Université de MontpellierUMR 5554 Institut des Sciences de l'EvolutionPlace Eugène BataillonF‐34095MontpellierFrance
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Sonnleitner M, Hülber K, Flatscher R, Escobar García P, Winkler M, Suda J, Schönswetter P, Schneeweiss GM. Ecological differentiation of diploid and polyploid cytotypes of Senecio carniolicus sensu lato (Asteraceae) is stronger in areas of sympatry. ANNALS OF BOTANY 2016; 117:269-76. [PMID: 26658487 PMCID: PMC4724049 DOI: 10.1093/aob/mcv176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/07/2015] [Accepted: 10/06/2015] [Indexed: 05/10/2023]
Abstract
BACKGROUND AND AIMS Ecological differentiation is recognized as an important factor for polyploid speciation, but little is known regarding whether the ecological niches of cytotypes differ between areas of sympatry and areas where single cytotypes occur (i.e. niche displacement). METHODS Ecological niches of four groups of Senecio carniolicus sensu lato (s.l.) (western and eastern diploid lineages, tetraploids and hexaploids) were characterized via Landolt indicator values of the accompanying vascular plant species and tested using multivariate and univariate statistics. KEY RESULTS The four groups of S. carniolicus s.l. were ecologically differentiated mainly with respect to temperature, light and soil (humus content, nutrients, moisture variability). Niche breadths did not differ significantly. In areas of sympatry hexaploids shifted towards sites with higher temperature, less light and higher soil humus content as compared with homoploid sites, whereas diploids and tetraploids shifted in the opposite direction. In heteroploid sites of tetraploids and the western diploid lineage the latter shifted towards sites with lower humus content but higher aeration. CONCLUSIONS Niche displacement can facilitate the formation of stable contact zones upon secondary contact of polyploids and their lower-ploid ancestors and/or lead to convergence of the cytotypes' niches after they have attained non-overlapping ranges. Niche displacement is essential for understanding ecological consequences of polyploidy.
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Affiliation(s)
- Michaela Sonnleitner
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
| | - Karl Hülber
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria, Vienna Institute for Nature Conservation & Analyses, Giessergasse 6/7, A-1090 Vienna, Austria,
| | - Ruth Flatscher
- Institute of Botany, University of Innsbruck, Sternwartestrasse 15, A-6020 Innsbruck, Austria
| | - Pedro Escobar García
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
| | - Manuela Winkler
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria, GLORIA co-ordination, University of Natural Resources and Life Sciences Vienna (BOKU), Center for Global Change and Sustainability & Austrian Academy of Sciences, Institute for Interdisciplinary Mountain Research, Silbergasse 30/3, A-1190 Vienna, Austria
| | - Jan Suda
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, CZ-128 01, Czech Republic and Institute of Botany, The Czech Academy of Sciences, Průhonice 1, CZ-252 43, Czech Republic
| | - Peter Schönswetter
- Institute of Botany, University of Innsbruck, Sternwartestrasse 15, A-6020 Innsbruck, Austria
| | - Gerald M Schneeweiss
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
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Narwani A, Matthews B, Fox J, Venail P. Using phylogenetics in community assembly and ecosystem functioning research. Funct Ecol 2015. [DOI: 10.1111/1365-2435.12431] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Anita Narwani
- Eawag, Aquatic Ecology Department Überlandstrasse 1338600 Dübendorf Switzerland
| | - Blake Matthews
- Eawag, Aquatic Ecology Department Seestrasse 79 6047 Kastanienbaum Switzerland
| | - Jeremy Fox
- Department of Biological Sciences University of Calgary 2500 University Dr. NW CalgaryAB T2N 1N4Canada
| | - Patrick Venail
- Institut F.‐A. Forel University of Geneva 10, route de Suisse CP 4161290 Versoix, Geneva Switzerland
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Norton NA, Fernando MTR, Herlihy CR, Busch JW. Reproductive character displacement shapes a spatially structured petal color polymorphism in Leavenworthia stylosa. Evolution 2015; 69:1191-207. [PMID: 25873258 DOI: 10.1111/evo.12659] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 03/30/2015] [Indexed: 11/28/2022]
Abstract
Character displacement is a potentially important process driving trait evolution and species diversification. Floral traits may experience character displacement in response to pollinator-mediated competition (ecological character displacement) or the risk of forming hybrids with reduced fitness (reproductive character displacement). We test these and alternative hypotheses to explain a yellow-white petal color polymorphism in Leavenworthia stylosa, where yellow morphs are spatially associated with a white-petaled congener (Leavenworthia exigua) that produces hybrids with complete pollen sterility. A reciprocal transplant experiment found limited evidence of local adaptation of yellow color morphs via increased survival and seed set. Pollinator observations revealed that Leavenworthia attract various pollinators that generally favor white petals and exhibit color constancy. Pollen limitation experiments showed that yellow petals do not alleviate competition for pollination. Interspecific pollinator movements were infrequent and low hybridization rates (∼0.40-0.85%) were found in each morph, with natural rates likely being lower. Regardless, hybridization rates were significantly higher in white morphs of L. stylosa, yielding a small selection coefficient of s = 0.0042 against this phenotype in sympatry with L. exigua. These results provide support for RCD as a mechanism contributing to the pattern of petal color polymorphism in L. stylosa.
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Affiliation(s)
- Nicholas A Norton
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, Washington, 99164
| | - M Thilina R Fernando
- Department of Biology, Evolution and Ecology Group, Middle Tennessee State University, PO Box 60, Murfreesboro,Tennessee, 37132
| | - Christopher R Herlihy
- Department of Biology, Evolution and Ecology Group, Middle Tennessee State University, PO Box 60, Murfreesboro,Tennessee, 37132
| | - Jeremiah W Busch
- School of Biological Sciences, Washington State University, PO Box 644236, Pullman, Washington, 99164.
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Beans CM, Roach DA. An invasive plant alters phenotypic selection on the vegetative growth of a native congener. AMERICAN JOURNAL OF BOTANY 2015; 102:217-224. [PMID: 25667074 DOI: 10.3732/ajb.1400355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
PREMISE OF THE STUDY The ecological consequences of plant competition have frequently been tested, but the evolutionary outcomes of these interactions have gone largely unexplored. The study of species invasions can make an important contribution to this field of research by allowing us to watch ecological and evolutionary processes unfold as a novel species is integrated into a plant community. We explored the ecological and evolutionary impact of an invasive jewelweed, Impatiens glandulifera, on a closely related native congener, I. capensis and asked: (1) Does the presence of the invasive jewelweed alter the fitness of native jewelweed populations? (2) Does the invasive jewelweed affect the vegetative growth of the native congener? and (3) Does the invasive jewelweed alter phenotypic selection on the vegetative traits of the native congener? METHODS We used a greenhouse competition experiment, an invasive species removal field experiment, and a survey of natural populations. KEY RESULTS We show that when the invasive jewelweed is present, phenotypic selection favors native jewelweed individuals investing less in rapid upward growth and more in branching and fruiting potential through the production of nodes. CONCLUSIONS This research demonstrates that invasive plants have the potential to greatly alter natural selection on native competitors. Studies investigating altered selection in invaded communities can reveal the potential evolutionary impact of invasive competitors, while deepening our understanding of the more general role of competition in driving plant evolution and permitting species coexistence.
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Affiliation(s)
- Carolyn M Beans
- Department of Biology, Gilmer Hall, University of Virginia, Charlottesville, Virginia 22904-4328 USA
| | - Deborah A Roach
- Department of Biology, Gilmer Hall, University of Virginia, Charlottesville, Virginia 22904-4328 USA
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Beans CM, Roach DA. An invasive plant alters pollinator-mediated phenotypic selection on a native congener. AMERICAN JOURNAL OF BOTANY 2015; 102:50-57. [PMID: 25587147 DOI: 10.3732/ajb.1400385] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
UNLABELLED • PREMISE OF STUDY Recent studies suggest that invasive plants compete reproductively with native plants by reducing the quantity or quality of pollinator visits. Although these studies have revealed ecological consequences of pollinator-mediated competition between invasive and native plants, the evolutionary outcomes of these interactions remain largely unexplored.• METHODS We studied the ecological and evolutionary impact of pollinator-mediated competition with an invasive jewelweed, Impatiens glandulifera, on a co-occurring native congener, I. capensis. Using a pollinator choice experiment, a hand pollination experiment, and a selection analysis, we addressed the following questions: (1) Do native pollinators show preference for the invasive or native jewelweed, and do they move between the two species? (2) Does invasive jewelweed pollen inhibit seed production in the native plant? (3) Does the invasive jewelweed alter phenotypic selection on the native plant's floral traits?• KEY RESULTS The pollinator choice experiment showed that pollinators strongly preferred the invasive jewelweed. The hand pollination experiment demonstrated that invasive pollen inhibited seed production in the native plant. The selection analysis showed that the presence of the invasive jewelweed altered phenotypic selection on corolla height in the native plant.• CONCLUSIONS Invasive plants have the potential to alter phenotypic selection on floral traits in native plant populations. If native plants can evolve in response to this altered selection pressure, the evolution of floral traits may play an important role in permitting long-term coexistence of native and invasive plants.
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Affiliation(s)
- Carolyn M Beans
- Department of Biology, University of Virginia, P.O. Box 400328, Charlottesville, Virginia 22904-4328, USA
| | - Deborah A Roach
- Department of Biology, University of Virginia, P.O. Box 400328, Charlottesville, Virginia 22904-4328, USA
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Grossenbacher DL, Stanton ML. Pollinator-mediated competition influences selection for flower-color displacement in sympatric monkeyflowers. AMERICAN JOURNAL OF BOTANY 2014; 101:1915-24. [PMID: 25366857 DOI: 10.3732/ajb.1400204] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
PREMISE OF STUDY When coflowering plant species share pollinators, pollinator-mediated competition may favor divergent floral characters associated with pollinator attraction. One potential outcome of this process is that sympatric populations will display increased divergence in floral traits compared with allopatric populations. We developed a new system to study the pattern and process of character displacement. In the central Sierra Nevada of California, USA, Mimulus bicolor is a spring wildflower with two flower-color morphs, one of which resembles coflowering M. guttatus. METHODS We documented a fine-scale geographic pattern of character displacement in sympatric and allopatric patches and, using experimental arrays, measured seed set in M. bicolor color morphs in the presence versus absence of M. guttatus. KEY RESULTS In sympatric arrays yellow, guttatus-like M. bicolor morphs had lower relative fitness (0.35 ± 0.05) and reduced conspecific pollen deposition compared with the distinct alternative morph, whereas in allopatric arrays yellow, guttatus-like morphs were occasionally strongly favored. CONCLUSIONS Pollinator-mediated competition with M. guttatus is consistent with ecological character displacement in M. bicolor and likely contributes to a geographic pattern of character displacement.
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Affiliation(s)
- Dena L Grossenbacher
- Department of Plant Biology, University of Minnesota, St. Paul, Minnesota 55108 USA
| | - Maureen L Stanton
- Department of Evolution and Ecology, Center for Population Biology, University of California, Davis, California 95616 USA
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