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Mitchell RJ, Starvaggi D, Fitzgerald V, Karron JD. The timing of visits by large and small bees differentially affects pollination success in Mimulus ringens. AMERICAN JOURNAL OF BOTANY 2024; 111:e16375. [PMID: 39004802 DOI: 10.1002/ajb2.16375] [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: 11/13/2023] [Revised: 05/09/2024] [Accepted: 05/09/2024] [Indexed: 07/16/2024]
Abstract
PREMISE Cross-fertilization in most flowering plants is facilitated by mobile animals that transport pollen while foraging for floral rewards. The contributions of different visitors can vary widely, depending on the amount of pollen transferred during a single visit and on the frequency and timing of the visits of each pollinator taxon. METHODS We used three approaches to measure the pollination value of bees that visit Mimulus ringens: pollinator interviews, field population observations, and caging studies. RESULTS The single-visit effectiveness of small bees (primarily Halictidae) was only half that of larger bees (primarily Bombus) for pollen delivery and removal. In five field populations, we found substantial temporal and spatial variation in visitation and pollination. In most sites big bees were active before 08:00 hours, and by 10:00-11:00 hours, stigmas were usually fully pollinated and closed, and little pollen remained in anthers. Small bees seldom visited before 10:00 hours. Excluding big bees from plants confirmed that pollination is reduced and delayed in this ecological context. CONCLUSIONS Big bees are the primary pollinators of M. ringens, accounting for at least 75% of seed production. Not only are they more effective per visit, in most situations they also visit before small bees become active. Although small bees are not usually important pollinators of M. ringens, they have the potential to partially replace them as a "fail-safe" pollinator in contexts where big bees are not abundant. In a world where pollinator abundance is declining, such backup pollinators may be important for maintaining plant reproduction.
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Affiliation(s)
| | | | | | - Jeffrey D Karron
- Department of Biological Sciences, University of Wisconsin, Milwaukee, 53211, WI, USA
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Ellis EE, Edmondson JL, Maher KH, Hipperson H, Campbell SA. Negative effects of urbanisation on diurnal and nocturnal pollen-transport networks. Ecol Lett 2023; 26:1382-1393. [PMID: 37272470 PMCID: PMC10946945 DOI: 10.1111/ele.14261] [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: 10/17/2022] [Revised: 05/15/2023] [Accepted: 05/15/2023] [Indexed: 06/06/2023]
Abstract
Pollinating insects are declining due to habitat loss and climate change, and cities with limited habitat and floral resources may be particularly vulnerable. The effects of urban landscapes on pollination networks remain poorly understood, and comparative studies of taxa with divergent niches are lacking. Here, for the first time, we simultaneously compare nocturnal moth and diurnal bee pollen-transport networks using DNA metabarcoding and ask how pollination networks are affected by increasing urbanisation. Bees and moths exhibited substantial divergence in the communities of plants they interact with. Increasing urbanisation had comparable negative effects on pollen-transport networks of both taxa, with significant declines in pollen species richness. We show that moths are an important, but overlooked, component of urban pollen-transport networks for wild flowering plants, horticultural crops, and trees. Our findings highlight the need to include both bee and non-bee taxa when assessing the status of critical plant-insect interactions in urbanised landscapes.
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Affiliation(s)
- Emilie E. Ellis
- School of BiosciencesThe University of SheffieldSheffieldUK
- NERC Environmental Omics Facility, School of BiosciencesThe University of SheffieldSheffieldUK
| | | | - Kathryn H. Maher
- NERC Environmental Omics Facility, School of BiosciencesThe University of SheffieldSheffieldUK
| | - Helen Hipperson
- NERC Environmental Omics Facility, School of BiosciencesThe University of SheffieldSheffieldUK
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3
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Travis DJ, Kohn JR. Honeybees ( Apis mellifera) decrease the fitness of plants they pollinate. Proc Biol Sci 2023; 290:20230967. [PMID: 37357853 PMCID: PMC10291720 DOI: 10.1098/rspb.2023.0967] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/01/2023] [Indexed: 06/27/2023] Open
Abstract
Most flowering plants require animal pollination and are visited by multiple pollinator species. Historically, the effects of pollinators on plant fitness have been compared using the number of pollen grains they deposit, and the number of seeds or fruits produced following a visit to a virgin flower. While useful, these methods fail to consider differences in pollen quality and the fitness of zygotes resulting from pollination by different floral visitors. Here we show that, for three common native self-compatible plants in Southern California, super-abundant, non-native honeybees (Apis mellifera L.) visit more flowers on an individual before moving to the next plant compared with the suite of native insect visitors. This probably increases the transfer of self-pollen. Offspring produced after honeybee pollination have similar fitness to those resulting from hand self-pollination and both are far less fit than those produced after pollination by native insects or by cross-pollination. Because honeybees often forage methodically, visiting many flowers on each plant, low offspring fitness may commonly result from honeybee pollination of self-compatible plants. To our knowledge, this is the first study to directly compare the fitness of offspring resulting from honeybee pollination to that of other floral visitors.
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Affiliation(s)
- Dillon J. Travis
- Department of Ecology, Behavior, and Evolution, School of Biological Sciences, University of California San Diego, San Diego, CA 92093, USA
| | - Joshua R. Kohn
- Department of Ecology, Behavior, and Evolution, School of Biological Sciences, University of California San Diego, San Diego, CA 92093, USA
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4
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Lewis EM, Fant JB, Moore MJ, Skogen KA. Hawkmoth and bee pollinators impact pollen dispersal at the landscape but not local scales in two species of Oenothera. AMERICAN JOURNAL OF BOTANY 2023:e16156. [PMID: 36934437 DOI: 10.1002/ajb2.16156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 02/01/2023] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
PREMISE Animal pollinators play an important role in pollen dispersal. Here, we assessed differences in pollen and seed dispersal and the role of pollinator functional groups with different foraging behaviors in generating patterns of genetic diversity over similar geographic ranges for two closely related taxa. We focused on two members of Oenothera section Calylophus (Onagraceae) that co-occur on gypsum outcrops throughout the northern Chihuahuan Desert but differ in floral phenotype and primary pollinator: Oenothera gayleana (bee) and O. hartwegii subsp. filifolia (hawkmoth). METHODS We measured breeding system and floral traits and studied gene flow and population differentiation at the local (<13 km; four populations) and landscape (60-440 km; five populations) scales using 10-11 nuclear (pollen dispersal) and three plastid (seed dispersal) microsatellite markers. RESULTS Both taxa were self-incompatible and floral traits were consistent with expectations for different pollinators. Seed and pollen dispersal patterns were distinctly different for both species. We found no evidence of genetic structure at the local scale but did at the landscape scale; O. gayleana showed greater differentiation and significant isolation by distance than in O. hartwegii subsp. filifolia. The plastid data were consistent with gravity dispersal of seeds and suggest that pollen dispersal is the principal driver of genetic structure in both species. CONCLUSIONS We demonstrated that pollinator functional groups can impact genetic differentiation in different and predictable ways. Hawkmoths, with larger foraging distances, can maintain gene flow across greater spatial scales than bees.
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Affiliation(s)
- Emily M Lewis
- Northwestern University, Program in Plant Biology and Conservation, Evanston, IL, 60201, USA
| | - Jeremie B Fant
- Northwestern University, Program in Plant Biology and Conservation, Evanston, IL, 60201, USA
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, 60022, USA
| | - Michael J Moore
- Biology Department, Oberlin College, Oberlin, OH, 44074, USA
| | - Krissa A Skogen
- Northwestern University, Program in Plant Biology and Conservation, Evanston, IL, 60201, USA
- Negaunee Institute for Plant Conservation Science and Action, Chicago Botanic Garden, Glencoe, IL, 60022, USA
- Department of Biological Sciences, Clemson University, Clemson, SC, 29634, USA
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5
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Torres-Vanegas F, Hadley AS, Kormann UG, Jones FA, Betts MG, Wagner HH. Pollinator foraging tactics have divergent consequences for the mating system of a tropical plant. THE NEW PHYTOLOGIST 2023; 237:1050-1066. [PMID: 36285370 DOI: 10.1111/nph.18574] [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: 12/10/2021] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Resolving the consequences of pollinator foraging behaviour for plant mating systems is a fundamental challenge in evolutionary ecology. Pollinators may adopt particular foraging tactics: complete trapline foraging (repeated movements along a fixed route), sample-and-shift trapline foraging (a variable route that incorporates information from previous experiences) and territorial foraging (stochastic movements within a restricted area). Studies that integrate these pollinator foraging tactics with plant mating systems are generally lacking. We investigate the consequences of particular pollinator foraging tactics for Heliconia tortuosa. We combine parentage and sibship inference analysis with simulation modelling to: estimate mating system parameters; infer the foraging tactic adopted by the pollinators; and quantify the impact of pollinator foraging tactics on mating system parameters. We found high outcrossing rates, ubiquitous multiple paternity and a pronounced departure from near-neighbour mating. We also found that plants repeatedly receive pollen from a series of particular donors. We infer that the pollinators primarily adopt complete trapline foraging and occasionally engage in sample-and-shift trapline foraging. This enhances multiple paternity without a substantial increase in near-neighbour mating. The particular pollinator foraging tactics have divergent consequences for multiple paternity and near-neighbour mating. Thus, pollinator foraging behaviour is an important driver of the ecology and evolution of plant mating systems.
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Affiliation(s)
- Felipe Torres-Vanegas
- Department of Ecology and Evolutionary Biology, University of Toronto, Mississauga, ON, L5L 1C6, Canada
| | - Adam S Hadley
- Department of Ecology and Evolutionary Biology, University of Toronto, Mississauga, ON, L5L 1C6, Canada
- Forest Biodiversity Research Network, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331-5704, USA
- Biodiversity Section, Department of Natural Resources and Energy Development, Fredericton, NB, E3C 2G6, Canada
| | - Urs G Kormann
- Swiss Ornithological Institute, Sempach, CH-6204, Switzerland
| | - Frank Andrew Jones
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, 97331, USA
- Smithsonian Tropical Research Institute, Panama City, 0843-03092, Panama
| | - Matthew G Betts
- Forest Biodiversity Research Network, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, 97331-5704, USA
| | - Helene H Wagner
- Department of Ecology and Evolutionary Biology, University of Toronto, Mississauga, ON, L5L 1C6, Canada
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6
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Spatial isolation impacts pollinator visitation and reproductive success of a threatened self-incompatible Mediterranean tree. ACTA OECOLOGICA 2022. [DOI: 10.1016/j.actao.2022.103866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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7
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Gómez JM, Schupp EW, Jordano P. The ecological and evolutionary significance of effectiveness landscapes in mutualistic interactions. Ecol Lett 2021; 25:264-277. [PMID: 34971487 DOI: 10.1111/ele.13939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/08/2021] [Accepted: 11/17/2021] [Indexed: 11/30/2022]
Abstract
Mutualism effectiveness, the contribution of an interacting organism to its partner's fitness, is defined as the number of immediate outcomes of the interactions (quantity component) multiplied by the probability that an immediate outcome results in a new individual (quality component). These components form a two-dimensional effectiveness landscape with each species' location determined by its values of quantity (x-axis) and quality (y-axis). We propose that the evolutionary history of mutualistic interactions leaves a footprint that can be identified by three properties of the spatial structure of effectiveness values: dispersion of effectiveness values, relative contribution of each component to the effectiveness values and correlation between effectiveness components. We illustrate this approach using a large dataset on synzoochory, seed dispersal by seed-caching animals. The synzoochory landscape was clumped, with effectiveness determined primarily by the quality component, and with quantity and quality positively correlated. We suggest this type of landscape structure is common in generalised coevolved mutualisms, where multiple functionally equivalent, high-quality partners exert similarly strong selection. Presumably, only those organisms located in high-quality regions will impact the evolution of their partner. Exploring properties of effectiveness landscapes in other mutualisms will provide new insight into the evolutionary and ecological consequences of mutualisms.
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Affiliation(s)
- José María Gómez
- Departamento de Ecología Funcional y Evolutiva, Estación Experimental de Zonas Áridas (EEZA- CSIC), Almería, Spain
| | - Eugene W Schupp
- Department of Wildland Resources and Ecology Center, S. J. and Jesse E. Quinney College of Natural Resources, Utah State University, Logan, Utah, USA.,Integrative Ecology Group, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain
| | - Pedro Jordano
- Integrative Ecology Group, Estación Biológica de Doñana (EBD-CSIC), Sevilla, Spain.,Departamento de Biología Vegetal y Ecología, Universidad de Sevilla, Sevilla, Spain
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8
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Page ML, Nicholson CC, Brennan RM, Britzman AT, Greer J, Hemberger J, Kahl H, Müller U, Peng Y, Rosenberger NM, Stuligross C, Wang L, Yang LH, Williams NM. A meta-analysis of single visit pollination effectiveness comparing honeybees and other floral visitors. AMERICAN JOURNAL OF BOTANY 2021; 108:2196-2207. [PMID: 34622948 DOI: 10.1002/ajb2.1764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 08/23/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
PREMISE Many animals provide ecosystem services in the form of pollination including honeybees, which have become globally dominant floral visitors. A rich literature documents considerable variation in single visit pollination effectiveness, but this literature has yet to be extensively synthesized to address whether honeybees are effective pollinators. METHODS We conducted a hierarchical meta-analysis of 168 studies and extracted 1564 single visit effectiveness (SVE) measures for 240 plant species. We paired SVE data with visitation frequency data for 69 of these studies. We used these data to ask three questions: (1) Do honeybees (Apis mellifera) and other floral visitors differ in their SVE? (2) To what extent do plant and pollinator attributes predict differences in SVE between honeybees and other visitors? (3) Is there a correlation between visitation frequency and SVE? RESULTS Honeybees were significantly less effective than the most effective non-honeybee pollinators but were as effective as the average pollinator. The type of pollinator moderated these effects. Honeybees were less effective compared to the most effective and average bird and bee pollinators but were as effective as other taxa. Visitation frequency and SVE were positively correlated, but this trend was largely driven by data from communities where honeybees were absent. CONCLUSIONS Although high visitation frequencies make honeybees important pollinators, they were less effective than the average bee and rarely the most effective pollinator of the plants they visit. As such, honeybees may be imperfect substitutes for the loss of wild pollinators, and safeguarding pollination will benefit from conservation of non-honeybee taxa.
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Affiliation(s)
- Maureen L Page
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Charlie C Nicholson
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Ross M Brennan
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
| | - Anna T Britzman
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Jessica Greer
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
- Department of Fish, Wildlife, and Conservation Biology, University of California, Davis, Davis, California, 95616, USA
| | - Jeremy Hemberger
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Hanna Kahl
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Uta Müller
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Youhong Peng
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, 610041, China
| | - Nick M Rosenberger
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
| | - Clara Stuligross
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
- Graduate Group in Ecology, University of California, Davis, Davis, California, 95616, USA
| | - Li Wang
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Louie H Yang
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
| | - Neal M Williams
- Department of Entomology and Nematology, University of California, Davis, Davis, California, 95616, USA
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Wessinger CA. From pollen dispersal to plant diversification: genetic consequences of pollination mode. THE NEW PHYTOLOGIST 2021; 229:3125-3132. [PMID: 33159813 DOI: 10.1111/nph.17073] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 11/02/2020] [Indexed: 06/11/2023]
Abstract
Pollinators influence patterns of plant speciation, and one intuitive hypothesis is that pollinators affect rates of plant diversification through their effects on pollen dispersal. By specifying mating events and pollen flow across the landscape, distinct types of pollinators may cause different opportunities for allopatric speciation. This pollen dispersal-dependent speciation hypothesis predicts that pollination mode has effects on the spatial context of mating events that scale up to impact population structure and rates of species formation. Here I consider recent comparative studies, including genetic analyses of plant mating events, population structure and comparative phylogenetic analyses, to examine evidence for this model. These studies suggest that highly mobile pollinators conduct greater gene flow within and among populations, compared to less mobile pollinators. These differences influence patterns of population structure across the landscape. However, the effects of pollination mode on speciation rates is less predictable. In some contexts, the predicted effects of pollen dispersal are outweighed by other factors that govern speciation rates. A multiscale approach to examine effects of pollination mode on plant mating system, population structure and rates of diversification is key to determining the role of pollen dispersal on plant speciation for model clades.
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Affiliation(s)
- Carolyn A Wessinger
- Department of Biological Sciences, University of South Carolina, Columbia, SC, 27708, USA
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10
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Kirmse S, Chaboo CS. Flowers are essential to maintain high beetle diversity (Coleoptera) in a Neotropical rainforest canopy. J NAT HIST 2020. [DOI: 10.1080/00222933.2020.1811414] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Susan Kirmse
- Florida State Collection of Arthropods, Museum of Entomology, Gainesville, FL, USA
| | - Caroline S Chaboo
- Systematics Research Collections, University of Nebraska State Museum, University of Nebraska, Lincoln, NE, USA
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11
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Murúa M. Different Pollinators' Functional Traits Can Explain Pollen Load in Two Solitary Oil-Collecting Bees. INSECTS 2020; 11:insects11100685. [PMID: 33050547 PMCID: PMC7599834 DOI: 10.3390/insects11100685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
Functional traits have been shown to be a good predictor of pollen load for some pollinator bee species, but little is known about solitary bees. In this study, I used two solitary oil-collecting bees to explore the impact of functional traits on the pollen load of two oil-secreting Calceolaria species. I therefore measured the visitation frequency, the time spent manipulating the flower, pollinator body size and pollen load for each bee species. The results reveal that each pollinator visits different Calceolaria species (C. cavanillesii and C. filicaulis) for pollen and/or oil and at least another four herb species for pollen in different proportions. In addition, each bee species presents different functional traits that affect Calceolaria pollen load. For C. chilensis, it was only its body size that affected the Calceolaria pollen load, while in C. subcaeruleus, both body size and handling time together account for its pollen load. Overall, these results highlight the role of pollinators' functional traits in different stages of the pollination process, and even more in specialized plant-pollination systems.
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Affiliation(s)
- Maureen Murúa
- Centro GEMA: Genómica, Ecología y Medio Ambiente, Facultad de Estudios Interdisciplinarios, Universidad Mayor, Camino La Pirámide 5750, Santiago 8580745, Chile
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12
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Fuster F, Kaiser-Bunbury CN, Traveset A. Pollination effectiveness of specialist and opportunistic nectar feeders influenced by invasive alien ants in the Seychelles. AMERICAN JOURNAL OF BOTANY 2020; 107:957-969. [PMID: 32592166 DOI: 10.1002/ajb2.1499] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Opportunistic nectar-feeders may act as effective pollinators; nonetheless, we still lack information on whether these opportunistic species differ in their pollination effectiveness from specialized nectarivorous vertebrates and insects. Many nectar specialists have coevolved with the plants on which they feed; therefore, we would expect higher pollination effectiveness in specialists than in opportunistic feeders. Here, we assessed quantity and quality components of pollination effectiveness in specialist and opportunistic vertebrate nectarivores and insects, focusing on three plants from the Seychelles: Thespesia populnea, Polyscias crassa, and Syzygium wrightii. METHODS We determined the quantity component (QNC) of pollination effectiveness with pollinator observations, and the quality component (QLC) by measuring fruit and seed set resulting from single visits by each pollinator. To detect potential negative effects of invasive ants on native plant-pollinator interactions, we classified pollinator visits (quantity component) as disturbed (>6 ants/30 min) vs. undisturbed. RESULTS All focal plants were visited by insects, and vertebrate specialist and opportunist nectarivores, yet their pollination effectiveness differed. Flying insects were the most effective pollinators of T. populnea. The other two plants were most effectively pollinated by vertebrates; i.e., sunbirds (nectar specialists) in S. wrightii and Phelsuma geckos (nectar opportunists) in P. crassa, despite marked variation in QNC and QLC. Ant presence was associated with lower pollinator visitation rate in P. crassa and S. wrightii. CONCLUSIONS Our study highlights the importance of all pollinator guilds, including opportunist nectarivorous vertebrates as pollinators of island plants, and the vulnerability of such interactions to disruption by nonnative species.
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Affiliation(s)
- Francisco Fuster
- Global Change Research Group, Institut Mediterrani d'Estudis Avançats (CSIC-UIB), Miquel Marqués 21, 07190, Esporles, Mallorca, Balearic Islands, Spain
| | - Christopher N Kaiser-Bunbury
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Cornwall Campus, Penryn, TR10 9FE, UK
| | - Anna Traveset
- Global Change Research Group, Institut Mediterrani d'Estudis Avançats (CSIC-UIB), Miquel Marqués 21, 07190, Esporles, Mallorca, Balearic Islands, Spain
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13
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Hernández‐Castellano C, Rodrigo A, Gómez JM, Stefanescu C, Calleja JA, Reverté S, Bosch J. A new native plant in the neighborhood: effects on plant–pollinator networks, pollination, and plant reproductive success. Ecology 2020; 101:e03046. [DOI: 10.1002/ecy.3046] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/18/2020] [Accepted: 02/24/2020] [Indexed: 11/12/2022]
Affiliation(s)
| | - Anselm Rodrigo
- CREAF E08193 Bellaterra Catalonia Spain
- Universitat Autònoma de Barcelona E08193 Bellaterra Catalonia Spain
| | - José María Gómez
- Departamento de Ecología Funcional y Evolutiva Estación Experimental de Zonas Áridas (EEZA‐CSIC) ES‐04120 Almería Spain
| | - Constantí Stefanescu
- CREAF E08193 Bellaterra Catalonia Spain
- Museu de Ciències Naturals de Granollers E08400 Granollers Catalonia Spain
| | - Juan Antonio Calleja
- CREAF E08193 Bellaterra Catalonia Spain
- Departamento de Biología (Unidad de Botánica) Centro de Investigación en Biodiversidad y Cambio Global (CIBC‐UAM) Universidad Autónoma de Madrid E28049 Madrid Spain
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14
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Baranzelli MC, Benitez-Vieyra S, Glinos E, Trenchi A, Córdoba S, Camina J, Ashworth L, Sérsic AN, Cocucci AA, Fornoni J. Daily fluctuations in pollination effectiveness explain higher efficiency of native over exotic bees in Lepechinia floribunda (Lamiaceae). ANNALS OF BOTANY 2020; 125:509-520. [PMID: 31745546 PMCID: PMC7061175 DOI: 10.1093/aob/mcz187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Despite Stebbins' principle of the most efficient pollinator being proposed decades ago, the most important pollinators are still mainly identified using the frequency of visits to flowers. This shortcoming results in a gap between the characterization of the flower visitors of a plant species and a reliable estimation of the plant fitness consequences of the mutualistic interaction. The performance of a mutualistic visitor depends on its abundance, behaviour, effectiveness (pollen removal and deposition per unit time) and efficiency (seed set per unit time) conditioned by the temporal matching between pollinator activity and temporal patterns of maturation of the sexual functions of flowers. Although there have been recent attempts to provide a conceptual and methodological framework to characterize pollinators' performance, few have combined all key elements of visitors and plants to provide an accurate estimation of pollinators' performance under natural conditions. METHODS We complement information on the flower biology and mating system of the sub-shrub Lepechinia floribunda (Lamiaceae) to provide a daily quantitative estimation of performance (effectiveness and efficiency) of the more abundant pollinators, i.e. native bumble-bees (Bombus spp.) and leafcutter bees (Megachile sp.), and the exotic honey-bee (Apis mellifera). KEY RESULTS Unlike honey-bees or leafcutter bees, native bumble-bees matched the daily pattern of nectar production and stigma receptivity, and showed higher effectiveness and efficiency. Despite the overabundance of honey-bees, visits occurred mainly when stigmas were not receptive, thus reducing the honey-bees' overall performance. CONCLUSIONS Bumble-bees appear to be the most important pollinators and potential historical mediators of reproductive trait evolution in L. floribunda. Because the production of seeds by bumble-bees involved fewer pollen grains for plants and less investment in floral display than honey-bees, contemporary and expected changes in pollinator abundance may affect future L. floribunda floral evolution. If bumble-bees were to be further displaced by anthropogenic disturbance or by competition with honey-bees, their lower efficiency will select for a larger floral display increasing reproductive costs. This scenario may also impose selection to reduce dichogamy to match honey-bee foraging activity.
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Affiliation(s)
- Matias Cristian Baranzelli
- Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Santiago Benitez-Vieyra
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Evangelina Glinos
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Alejandra Trenchi
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Silvina Córdoba
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Julia Camina
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Lorena Ashworth
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Alicia Noemi Sérsic
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Andrea Aristides Cocucci
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
| | - Juan Fornoni
- Instituto de Ecología, Universidad Nacional Autónoma de México, Ciudad de México, México
- Instituto Multidisciplinario de Biología Vegetal, Universidad Nacional de Córdoba, CONICET, FCEFyN, Córdoba, Argentina
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15
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Torres-Vanegas F, Hadley AS, Kormann UG, Jones FA, Betts MG, Wagner HH. The Landscape Genetic Signature of Pollination by Trapliners: Evidence From the Tropical Herb, Heliconia tortuosa. Front Genet 2019; 10:1206. [PMID: 31867039 PMCID: PMC6906188 DOI: 10.3389/fgene.2019.01206] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/31/2019] [Indexed: 12/19/2022] Open
Abstract
Animal-mediated pollination is essential for the maintenance of plant reproduction, especially in tropical ecosystems, where pollination networks have been thought to have highly generalized structures. However, accumulating evidence suggests that not all floral visitors provide equally effective pollination services, potentially reducing the number of realized pollinators and increasing the cryptic specialization of pollination networks. Thus, there is a need to understand how different functional groups of pollinators influence pollination success. Here, we examined whether patterns of contemporary pollen-mediated gene flow in Heliconia tortuosa are consistent with the foraging strategy of its territorial or traplining hummingbird pollinators. Territorial hummingbirds defend clumps of flowers and are expected to transfer pollen locally. In contrast, traplining hummingbirds forage across longer distances, thereby increasing pollen flow among forest fragments, and are thought to repeatedly visit particular plants. If trapliners indeed visit the same plants repeatedly along their regular routes, this could lead to a situation where neighboring plants sample genetically distinct pollen pools. To test this hypothesis, we genotyped 720 seeds and 71 mother plants from 18 forest fragments at 11 microsatellite loci. We performed TwoGener analysis to test pollen pool differentiation within sites (among neighboring plants within the same forest fragment: ΦSC) and between sites (among forest fragments: ΦCT). We found strong, statistically significant pollen pool differentiation among neighboring mother plants (ΦSC = 0.0506), and weaker, statistically significant differentiation among sites (ΦCT = 0.0285). We interpret this pattern of hierarchical pollen pool differentiation as the landscape genetic signature of the foraging strategy of traplining hummingbirds, where repeatable, long-distance, and high-fidelity routes transfer pollen among particular plants. Although H. tortuosa is also visited by territorial hummingbirds, our results suggest that these pollinators do not contribute substantially to successful pollination, highlighting differences in realized pollination efficiency. This cryptic reduction in the number of realized pollinators potentially increases the vulnerability of pollination success to the decline of populations of traplining hummingbirds, which have been shown to be sensitive to forest fragmentation. We conclude that maintaining habitat connectivity to sustain the foraging routes of trapliners may be essential for the maintenance of pollen-mediated gene flow in human-modified landscapes.
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Affiliation(s)
- Felipe Torres-Vanegas
- Department of Ecology and Evolutionary Biology, University of Toronto, Mississauga, ON, Canada
| | - Adam S Hadley
- Department of Ecology and Evolutionary Biology, University of Toronto, Mississauga, ON, Canada.,Forest Biodiversity Research Network, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, United States
| | - Urs G Kormann
- Swiss Ornithological Institute, Sempach, Switzerland
| | - Frank Andrew Jones
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR, United States.,Smithsonian Tropical Research Institute, Panama, Panama
| | - Matthew G Betts
- Forest Biodiversity Research Network, Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, United States
| | - Helene H Wagner
- Department of Ecology and Evolutionary Biology, University of Toronto, Mississauga, ON, Canada
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16
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Page ML, Ison JL, Bewley AL, Holsinger KM, Kaul AD, Koch KE, Kolis KM, Wagenius S. Pollinator effectiveness in a composite: a specialist bee pollinates more florets but does not move pollen farther than other visitors. AMERICAN JOURNAL OF BOTANY 2019; 106:1487-1498. [PMID: 31713237 DOI: 10.1002/ajb2.1383] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 09/23/2019] [Indexed: 06/10/2023]
Abstract
PREMISE Variation in pollinator effectiveness may contribute to pollen limitation in fragmented plant populations. In plants with multiovulate ovaries, the number of conspecific pollen grains per stigma often predicts seed set and is used to quantify pollinator effectiveness. In the Asteraceae, however, florets are uniovulate, which suggests that the total amount of pollen deposited per floret may not measure pollinator effectiveness. We examined two aspects of pollinator effectiveness-effective pollen deposition and effective pollen movement-for insects visiting Echinacea angustifolia, a composite that is pollen limited in small, isolated populations. METHODS We filmed insect visits to Echinacea in two prairie restorations and used these videos to quantify behavior that might predict effectiveness. To quantify effective pollen deposition, we used the number of styles shriveled per visit. To quantify effective pollen movement, we conducted paternity analysis on a subset of offspring and measured the pollen movement distance between mates. RESULTS Effective pollen deposition varied among taxa. Andrena helianthiformis, a Heliantheae oligolege, was the most effective taxon, shriveling more than twice the proportion of styles as all other visitors. Differences in visitor behavior on a flowering head did not explain variation in effective pollen deposition, nor did flowering phenology. On average, visitors moved pollen 16 m between plants, and this distance did not vary among taxa. CONCLUSIONS Andrena helianthiformis is an important pollinator of Echinacea. Variation in reproductive fitness of Echinacea in fragmented habitat may result, in part, from the abundance of this species.
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Affiliation(s)
- Maureen L Page
- Department of Entomology and Nematology, University of California-Davis, One Shields Avenue, Davis, California, 95616, USA
- Biology Department, Scripps College, 1030 Columbia Avenue, Claremont, California, 91711, USA
| | - Jennifer L Ison
- Biology Department, College of Wooster, 1189 Beall Avenue, Wooster, Ohio, 44691, USA
| | - Alison L Bewley
- Biology Department, Wittenberg University, 200 W. Ward Street, Springfield, Ohio, 45504, USA
| | - Keaton M Holsinger
- Biology Department, Wabash College, 301 West Wabash Avenue, Crawfordsville, Indiana, 47933, USA
| | - Andrew D Kaul
- Biology Department, St. Olaf College, 1520 St. Olaf Avenue, Northfield, Minnesota, 55057, USA
| | - Katie E Koch
- Biology Department, Lakeland University, W3718 South Drive, Plymouth, Wisconsin, 53073, USA
| | - Kory M Kolis
- Biology Department, Gustavus Adolphus College, 800 West College Avenue, Saint Peter, Minnesota, 56082, USA
| | - Stuart Wagenius
- Division of Plant Biology and Conservation, Chicago Botanic Garden, 1000 Lake Cook Road, Glencoe, Illinois, 60022, USA
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17
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Christopher DA, Mitchell RJ, Trapnell DW, Smallwood PA, Semski WR, Karron JD. Hermaphroditism promotes mate diversity in flowering plants. AMERICAN JOURNAL OF BOTANY 2019; 106:1131-1136. [PMID: 31403705 PMCID: PMC6852098 DOI: 10.1002/ajb2.1336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 06/04/2019] [Indexed: 05/12/2023]
Abstract
PREMISE Genetically diverse sibships are thought to increase parental fitness through a reduction in the intensity of sib competition, and through increased opportunities for seedling establishment in spatially or temporally heterogeneous environments. Nearly all research on mate diversity in flowering plants has focused on the number of fathers siring seeds within a fruit or on a maternal plant. Yet as hermaphrodites, plants can also accrue mate diversity by siring offspring on several pollen recipients in a population. Here we explore whether mate composition overlaps between the dual sex functions, and discuss the implications for plant reproductive success. METHODS We established an experimental population of 49 Mimulus ringens (monkeyflower) plants, each trimmed to a single flower. Following pollination by wild bees, we quantified mate composition for each flower through both paternal and maternal function. Parentage was successfully assigned to 240 progeny, 98% of the sampled seeds. RESULTS Comparison of mate composition between male and female function revealed high mate diversity, with almost no outcross mates shared between the two sexual functions of the same flower. CONCLUSIONS Dual sex roles contribute to a near doubling of mate diversity in our experimental population of Mimulus ringens. This finding may help explain the maintenance of hermaphroditism under conditions that would otherwise favor the evolution of separate sexes.
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Affiliation(s)
- Dorothy A. Christopher
- Department of Biological SciencesUniversity of Wisconsin – Milwaukee3209 N. Maryland AveMilwaukeeWisconsin53211USA
| | | | - Dorset W. Trapnell
- Department of Plant BiologyUniversity of Georgia120 Carlton StAthensGeorgia30602USA
| | - Patrick A. Smallwood
- Department of Plant BiologyUniversity of Georgia120 Carlton StAthensGeorgia30602USA
| | - Wendy R. Semski
- Department of Biological SciencesUniversity of Wisconsin – Milwaukee3209 N. Maryland AveMilwaukeeWisconsin53211USA
| | - Jeffrey D. Karron
- Department of Biological SciencesUniversity of Wisconsin – Milwaukee3209 N. Maryland AveMilwaukeeWisconsin53211USA
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