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Buono CM, Lofaso J, Smisko W, Gerth C, Santare J, Prior KM. Historical forest disturbance results in variation in functional resilience of seed dispersal mutualisms. Ecology 2023; 104:e3978. [PMID: 36692005 DOI: 10.1002/ecy.3978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 12/05/2022] [Accepted: 12/13/2022] [Indexed: 01/25/2023]
Abstract
Mutualistic interactions provide essential ecosystem functions that contribute to promoting and maintaining diversity in ecosystems. Understanding if functionally important mutualisms are "resilient" (i.e., able to resist or recover) to anthropogenic disturbance is essential for revealing the capacity for diversity to recover. Animal-mediated seed dispersal supports plant population growth and influences community structure, and disturbance affecting seed dispersal can contribute to low resiliency of plant diversity. Ant-seed dispersal mutualisms are sensitive to anthropogenic disturbance, as they rely on one to a few high-quality dispersal partners. In North American eastern deciduous forests, ants in the genus Aphaenogaster are "keystone dispersers" of understory forbs adapted to dispersal by ants (myrmecochores), which make up more than one-third of the understory herbaceous community. The majority of forests within this region have regenerated from previous disturbance in the form of clearing for agriculture. Previous studies have revealed that myrmecochore diversity is not resilient to previous clearing. Here, we ask if seed dispersal mutualisms are resilient to historical forest disturbance and if decreases in mutualistic interactions with partners, Aphaenogaster sp., or increases in antagonistic interactions cause degradation of function. In a large-scale natural experiment (20 sites), we measured seed removal, the abundance of mutualistic partners and other invertebrates interacting with seeds, myrmecochore cover, and diversity, along with ant habitat and forest structure. We found lower and more variable seed removal in secondary forests compared with remnant forests. A path analysis of all forests revealed that the abundance of mutualists was the primary determinant of the variation in seed removal, and that seed damage by antagonists (invasive slugs) negatively affected dispersal and was higher in secondary forests. In a path analysis of remnant forests, the link between mutualist abundance and seed removal was absent, but present in the secondary forest path, suggesting that seed dispersal is more variable and dependent on the mutualist abundance in secondary forests and is stable and high in remnant forests. Our results suggest that functional resilience to disturbance is variable, where seed dispersal is low in some secondary forests and not others. This work provides key insights into the effects of disturbance on mutualistic interactions and how the resilience of critical ecosystem functions impacts the capacity for diversity resiliency.
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Affiliation(s)
- Carmela M Buono
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
| | - Jesse Lofaso
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
| | - Will Smisko
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
| | - Carly Gerth
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
| | - John Santare
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
| | - Kirsten M Prior
- Department of Biological Sciences, Binghamton University, Binghamton, New York, USA
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Johnson RA, Rutowski RL. Color, activity period, and eye structure in four lineages of ants: Pale, nocturnal species have evolved larger eyes and larger facets than their dark, diurnal congeners. PLoS One 2022; 17:e0257779. [PMID: 36137088 PMCID: PMC9499225 DOI: 10.1371/journal.pone.0257779] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 08/24/2022] [Indexed: 11/28/2022] Open
Abstract
The eyes of insects display an incredible diversity of adaptations to enhance vision across the gamut of light levels that they experience. One commonly studied contrast is the difference in eye structure between nocturnal and diurnal species, with nocturnal species typically having features that enhance eye sensitivity such as larger eyes, larger eye facets, and larger ocelli. In this study, we compared eye structure between workers of closely related nocturnal and diurnal above ground foraging ant species (Hymenoptera: Formicidae) in four genera (Myrmecocystus, Aphaenogaster, Temnothorax, Veromessor). In all four genera, nocturnal species tend to have little cuticular pigment (pale), while diurnal species are heavily pigmented (dark), hence we could use cuticle coloration as a surrogate for activity pattern. Across three genera (Myrmecocystus, Aphaenogaster, Temnothorax), pale species, as expected for nocturnally active animals, had larger eyes, larger facet diameters, and larger visual spans compared to their dark, more day active congeners. This same pattern occurred for one pale species of Veromessor, but not the other. There were no consistent differences between nocturnal and diurnal species in interommatidial angles and eye parameters both within and among genera. Hence, the evolution of eye features that enhance sensitivity in low light levels do not appear to have consistent correlated effects on features related to visual acuity. A survey across several additional ant genera found numerous other pale species with enlarged eyes, suggesting these traits evolved multiple times within and across genera. We also compared the size of the anterior ocellus in workers of pale versus dark species of Myrmecocystus. In species with larger workers, the anterior ocellus was smaller in pale than in dark species, but this difference mostly disappeared for species with smaller workers. Presence of the anterior ocellus also was size-dependent in the two largest pale species.
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Affiliation(s)
- Robert A. Johnson
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- * E-mail:
| | - Ronald L. Rutowski
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
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Miller CN, Papeş M, Schilling EE, Kwit C. Reproductive traits explain occupancy of predicted distributions in a genus of eastern North American understory herbs. DIVERS DISTRIB 2021. [DOI: 10.1111/ddi.13297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Chelsea N. Miller
- The Warnell School of Forestry and Natural Resources University of Georgia Athens GA USA
- Department of Ecology and Evolutionary Biology University of Tennessee Knoxville TN USA
| | - Monica Papeş
- Department of Ecology and Evolutionary Biology University of Tennessee Knoxville TN USA
| | - Edward E. Schilling
- Department of Ecology and Evolutionary Biology University of Tennessee Knoxville TN USA
| | - Charles Kwit
- Department of Ecology and Evolutionary Biology University of Tennessee Knoxville TN USA
- Department of Forestry, Wildlife and Fisheries University of Tennessee Knoxville TN USA
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Csősz S, Loss AC, Fisher BL. Taxonomic revision of the Malagasy Aphaenogaster swammerdami group (Hymenoptera: Formicidae). PeerJ 2021; 9:e10900. [PMID: 33717685 PMCID: PMC7934650 DOI: 10.7717/peerj.10900] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 01/13/2021] [Indexed: 11/20/2022] Open
Abstract
Background Madagascar is famous for its extremely rich biodiversity; the island harbors predominantly endemic and threatened communities meriting special attention from biodiversity scientists. Continuing ongoing efforts to inventory the Malagasy ant fauna, we revise the species currently placed in the myrmicine genus Aphaenogaster Mayr. One species described from Madagascar, Aphaenogaster friederichsi Forel, is synonymized with the Palearctic A. subterranea Latreille syn. nov. This species is considered neither native to Madagascar nor established in the region. This revision focuses on the balance of species in the A. swammerdami group which are all endemic to Madagascar. Methods The diversity of the Malagasy Aphaenogaster fauna was assessed via application of multiple lines of evidence involving quantitative morphometric, qualitative morphological, and DNA sequence data. (1) Morphometric investigation was based on hypothesis-free Nest Centroid clustering (NC-clustering) combined with PArtitioning based on Recursive Thresholding (PART) to estimate the number of morphological clusters and determine the most probable boundaries between them. This protocol provides a repeatable and testable approach to find patterns in continuous morphometric data. Species boundaries and the reliability of morphological clusters recognized by these exploratory analyses were tested via confirmatory Linear Discriminant Analysis (LDA). (2) Qualitative, external morphological characteristics (e.g., shape, coloration patterns, setae number) were subjectively evaluated in order to create a priori grouping hypotheses, and confirm and improve species delimitation. (3) Species delimitation analyses based on mitochondrial DNA sequences from cytochrome oxidase I (COI) gene fragments were carried out to test the putative species previously delimited by morphological and morphometric analyses. Results Five species can be inferred based on the integrated evaluation of multiple lines of evidence; of these, three are new to science: Aphaenogaster bresslerisp. n., A. gonacantha (Emery, 1899), A. makaysp. n., A. sahafinasp. n., and A. swammerdamiForel, 1886. In addition, three new synonymies were found for A. swammerdami Forel, 1886 (A. swammerdami clara Santschi, 1915 syn. n., A. swammerdami curta Forel, 1891 syn. n. and A. swammerdami spinipes Santschi, 1911 syn. n.). Descriptions and redefinitions for each taxon and an identification key for their worker castes using qualitative traits and morphometric data are given. Geographic maps depicting species distributions and biological information regarding nesting habits for the species are also provided.
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Affiliation(s)
- Sandor Csősz
- Evolutionary Ecology Research Group, Institute of Ecology and Botany, Centre for Ecological Research, Vácrátót, Hungary
| | - Ana C Loss
- National Institute of the Atlantic Forest, Santa Teresa, Brazil
| | - Brian L Fisher
- Entomology, California Academy of Sciences, San Francisco, CA, USA
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5
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Parker WJ, Buono CM, Prior KM. Antagonistic and mutualistic interactions alter seed dispersal of understory plants at forest edges. Ecosphere 2021. [DOI: 10.1002/ecs2.3397] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Wyatt J. Parker
- Department of Biological Sciences Binghamton UniversityState University of New York PO Box 6000 Binghamton New York13902USA
- Environmental Studies Program Binghamton UniversityState University of New York PO Box 6000 Binghamton New York13902USA
| | - Carmela M. Buono
- Department of Biological Sciences Binghamton UniversityState University of New York PO Box 6000 Binghamton New York13902USA
| | - Kirsten M. Prior
- Department of Biological Sciences Binghamton UniversityState University of New York PO Box 6000 Binghamton New York13902USA
- Environmental Studies Program Binghamton UniversityState University of New York PO Box 6000 Binghamton New York13902USA
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Prior KM, Meadley-Dunphy SA, Frederickson ME. Interactions between seed-dispersing ant species affect plant community composition in field mesocosms. J Anim Ecol 2020; 89:2485-2495. [PMID: 32745258 DOI: 10.1111/1365-2656.13310] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 07/06/2020] [Indexed: 11/29/2022]
Abstract
In generalized mutualisms, species vary in the quality of services they provide to their partners directly via traits that affect partner fitness and indirectly via traits that influence interactions among mutualist species that play similar functional roles. Myrmecochory, or seed dispersal by ants, is a generalized mutualism with ant species varying in the quality of dispersal services they provide to their plant partners. Variation in ant species identity can directly impact seed dispersal patterns and plant community composition; however, we know less about how interactions among seed-dispersing ant species indirectly influence plant partners. The invasive ant Myrmica rubra, is a high-quality seed-disperser in its native range that interacts with myrmecochores (ant-dispersed plants) and the high-quality seed disperser Aphaenogaster sp. in its invaded range. We use this system to examine how interactions between two functionally similar mutualist ant species influence the recruitment and community composition of ant-dispersed plants. We performed a field mesocosm experiment and a laboratory behavioural experiment to compare discovery and dominance behaviours between ant species, and seed dispersal and seedling recruitment of four myrmecochore species among intraspecific interaction treatments of each ant species and an interspecific interaction treatment. We found that M. rubra was better at discovering and dispersing seeds, but Aphaenogaster sp. was dominantly aggressive over M. rubra. Interspecific interactions dampened seed dispersal relative to dispersal by the better disperser. Despite this dampening, we found no effect of interspecific interactions on seedling recruitment. However, community composition of seedlings in the interspecific interaction treatment was more similar to composition in the aggressively dominant ant (Aphaenogaster sp.) treatment than in the better discoverer ant M. rubra treatment. We show that interspecific interactions between mutualist species in the same functional guild affect the outcome of mutualistic interactions with partner species. Despite the native ant dispersing fewer seeds, its dominance over the subordinate (invasive) ant has the potential to allow for some level of biotic resistance against the effects of M. rubra on plant communities when these species coexist.
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Affiliation(s)
- Kirsten M Prior
- Department of Biological Sciences, Binghamton University, State University of New York, Binghamton, NY, USA.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - Shannon A Meadley-Dunphy
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, Canada.,Department of Biology, McGill University, Montreal, QC, Canada
| | - Megan E Frederickson
- Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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Effects of prescribed fire and social insects on saproxylic beetles in a subtropical forest. Sci Rep 2020; 10:9630. [PMID: 32541903 PMCID: PMC7295812 DOI: 10.1038/s41598-020-66752-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/27/2020] [Indexed: 11/08/2022] Open
Abstract
We tested the immediate and delayed effects of a low-intensity prescribed fire on beetles, ants and termites inhabiting log sections cut from moderately decomposed pine trees in the southeastern United States. We also explored co-occurrence patterns among these insects. Half the logs were placed at a site scheduled for a prescribed fire while the rest were assigned to a neighboring site not scheduled to be burned. We then collected insects emerging from sets of logs collected immediately after the fire as well as after 2, 6, 26 and 52 weeks. The fire had little effect on the number of beetles and ants collected although beetle richness was significantly higher in burned logs two weeks after the fire. Both beetle and ant communities differed between treatments, however, with some species preferring either burned or unburned logs. We found no evidence that subterranean termites (Reticulitermes) were influenced by the fire. Based on co-occurrence analysis, positive associations among insect species were over two times more common than negative associations. This difference was significant overall as well for ant × beetle and beetle × beetle associations. Relatively few significant positive or negative associations were detected between termites and the other insect taxa, however.
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Miller CN, Whitehead SR, Kwit C. Effects of seed morphology and elaiosome chemical composition on attractiveness of five Trillium species to seed-dispersing ants. Ecol Evol 2020; 10:2860-2873. [PMID: 32211161 PMCID: PMC7083703 DOI: 10.1002/ece3.6101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 01/18/2020] [Accepted: 01/27/2020] [Indexed: 12/23/2022] Open
Abstract
Morphological and chemical attributes of diaspores in myrmecochorous plants have been shown to affect seed dispersal by ants, but the relative importance of these attributes in determining seed attractiveness and dispersal success is poorly understood. We explored whether differences in diaspore morphology, elaiosome fatty acids, or elaiosome phytochemical profiles explain the differential attractiveness of five species in the genus Trillium to eastern North American forest ants. Species were ranked from least to most attractive based on empirically-derived seed dispersal probabilities in our study system, and we compared diaspore traits to test our hypotheses that more attractive species will have larger diaspores, greater concentrations of elaiosome fatty acids, and distinct elaiosome phytochemistry compared to the less attractive species. Diaspore length, width, mass, and elaiosome length were significantly greater in the more attractive species. Using gas chromatography-mass spectrometry, we found significantly higher concentrations of oleic, linoleic, hexadecenoic, stearic, palmitoleic, and total fatty acids in elaiosomes of the more attractive species. Multivariate assessments revealed that elaiosome phytochemical profiles, identified through liquid chromatography-mass spectrometry, were more homogeneous for the more attractive species. Random forest classification models (RFCM) identified several elaiosome phytochemicals that differed significantly among species. Random forest regression models revealed that some of the compounds identified by RFCM, including methylhistidine (α-amino acid) and d-glucarate (carbohydrate), were positively related to seed dispersal probabilities, while others, including salicylate (salicylic acid) and citrulline (L-α-amino acid), were negatively related. These results supported our hypotheses that the more attractive species of Trillium-which are geographically widespread compared to their less attractive, endemic congeners-are characterized by larger diaspores, greater concentrations of fatty acids, and distinct elaiosome phytochemistry. Further advances in our understanding of seed dispersal effectiveness in myrmecochorous systems will benefit from a portrayal of dispersal unit chemical and physical traits, and their combined responses to selection pressures.
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Affiliation(s)
- Chelsea N. Miller
- Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleTNUSA
| | - Susan R. Whitehead
- Department of Biological SciencesVirginia Tech UniversityBlacksburgVAUSA
| | - Charles Kwit
- Department of Ecology and Evolutionary BiologyUniversity of TennesseeKnoxvilleTNUSA
- Department of Forestry, Wildlife and FisheriesUniversity of TennesseeKnoxvilleTNUSA
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Invasive ants disperse seeds farther than native ants, affecting the spatial pattern of seedling recruitment and survival. Oecologia 2019; 192:119-132. [PMID: 31720779 DOI: 10.1007/s00442-019-04553-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022]
Abstract
Mutualists can vary in the quantity and quality of service which they provide to their partners. Variation in seed disperser quality depends on seed-processing traits, dispersal distance, and deposition location, all of which ultimately affect plant fitness. Here, we compared these aspects of seed dispersal quality between a native and an invasive ant species, and examined how they affect competition and plant performance. Using experimental mesocosm communities, we examined how these two ant species affect the spatial pattern of recruitment and establishment for four myrmecochorous plant species, including one invasive species. We measured the locations of dispersed seedlings relative to ant nests, adult plants, and other dispersed seedlings, as well as measured the effects of location on plant performance. The invasive ant, Myrmica rubra, secondarily dispersed seeds farther from its nests, creating a less clumped pattern of seedling recruitment compared to the native ant, Aphaenogaster rudis. Plant species responded differently to dispersal. Invasive seedlings recruited farther from adult plants than native seedlings, and had higher survival the farther they were from conspecifics. In contrast, native plants had higher survival and grew taller when dispersed farther from invasive plants. We show that seed-dispersing ant partners differ in mutualist quality creating differences in dispersal distance and deposition location that affects a plant's competitive environment. Our results reveal the potential for long-term consequences on plant community structure with changing ant partner identity. We emphasize the need to examine dispersal quality in addition to quantity to uncover the importance of partner identity in structuring communities.
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Nguyen AD, Brown M, Zitnay J, Cahan SH, Gotelli NJ, Arnett A, Ellison AM. Trade-Offs in Cold Resistance at the Northern Range Edge of the Common Woodland Ant Aphaenogaster picea (Formicidae). Am Nat 2019; 194:E151-E163. [PMID: 31738107 DOI: 10.1086/705939] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Geographic variation in low temperatures at poleward range margins of terrestrial species often mirrors population variation in cold resistance, suggesting that range boundaries may be set by evolutionary constraints on cold physiology. The northeastern woodland ant Aphaenogaster picea occurs up to approximately 45°N in central Maine. We combined presence/absence surveys with classification tree analysis to characterize its northern range limit and assayed two measures of cold resistance operating on different timescales to determine whether and how marginal populations adapt to environmental extremes. The range boundary of A. picea was predicted primarily by temperature, but low winter temperatures did not emerge as the primary correlate of species occurrence. Low summer temperatures and high seasonal variability predicted absence above the boundary, whereas high mean annual temperature (MAT) predicted presence in southern Maine. In contrast, assays of cold resistance across multiple sites were consistent with the hypothesis of local cold adaptation at the range edge: among populations, there was a 4-min reduction in chill coma recovery time across a 2° reduction in MAT. Baseline resistance and capacity for additional plastic cold hardening shifted in opposite directions, with hardening capacity approaching zero at the coldest sites. This trade-off between baseline resistance and cold-hardening capacity suggests that populations at range edges may adapt to colder temperatures through genetic assimilation of plastic responses, potentially constraining further adaptation and range expansion.
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Lau MK, Ellison AM, Nguyen A, Penick C, DeMarco B, Gotelli NJ, Sanders NJ, Dunn RR, Helms Cahan S. Draft Aphaenogaster genomes expand our view of ant genome size variation across climate gradients. PeerJ 2019; 7:e6447. [PMID: 30881761 PMCID: PMC6417409 DOI: 10.7717/peerj.6447] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 01/10/2019] [Indexed: 11/30/2022] Open
Abstract
Given the abundance, broad distribution, and diversity of roles that ants play in many ecosystems, they are an ideal group to serve as ecosystem indicators of climatic change. At present, only a few whole-genome sequences of ants are available (19 of >16,000 species), mostly from tropical and sub-tropical species. To address this limited sampling, we sequenced genomes of temperate-latitude species from the genus Aphaenogaster, a genus with important seed dispersers. In total, we sampled seven colonies of six species: Aphaenogaster ashmeadi, Aphaenogaster floridana, Aphaenogaster fulva, Aphaenogaster miamiana, Aphaenogaster picea, and Aphaenogaster rudis. The geographic ranges of these species collectively span eastern North America from southern Florida to southern Canada, which encompasses a latitudinal gradient in which many climatic variables are changing rapidly. For the six genomes, we assembled an average of 271,039 contigs into 47,337 scaffolds. The Aphaenogaster genomes displayed high levels of completeness with 96.1% to 97.6% of Hymenoptera BUSCOs completely represented, relative to currently sequenced ant genomes which ranged from 88.2% to 98.5%. Additionally, the mean genome size was 370.5 Mb, ranging from 310.3 to 429.7, which is comparable to that of other sequenced ant genomes (212.8-396.0 Mb) and flow cytometry estimates (210.7-690.4 Mb). In an analysis of currently sequenced ant genomes and the new Aphaenogaster sequences, we found that after controlling for both spatial autocorrelation and phylogenetics ant genome size was marginally correlated with sample site climate similarity. Of all examined climate variables, minimum temperature, and annual precipitation had the strongest correlations with genome size, with ants from locations with colder minimum temperatures and higher levels of precipitation having larger genomes. These results suggest that climate extremes could be a selective force acting on ant genomes and point to the need for more extensive sequencing of ant genomes.
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Affiliation(s)
| | | | - Andrew Nguyen
- Department of Entomology and Nematology, University of Florida, Gainesville, FL, USA
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Clint Penick
- The Biomimicry Center, Arizona State University, Tempe, AZ, USA
| | | | | | - Nathan J. Sanders
- Environmental Program, Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington, VT, USA
| | - Robert R. Dunn
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, USA
| | - Sara Helms Cahan
- Department of Biology, University of Vermont, Burlington, VT, USA
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12
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Gordon SCC, Meadley-Dunphy SA, Prior KM, Frederickson ME. Asynchrony between ant seed dispersal activity and fruit dehiscence of myrmecochorous plants. AMERICAN JOURNAL OF BOTANY 2019; 106:71-80. [PMID: 30644530 DOI: 10.1002/ajb2.1214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 10/25/2018] [Indexed: 06/09/2023]
Abstract
PREMISE OF THE STUDY Phenological mismatch has received attention in plant-pollinator interactions, but less so in seed dispersal mutualisms. We investigated whether the seasonal availability of myrmecochorous seeds is well matched to the seasonal activity patterns of seed-dispersing ants. METHODS We compared seasonal timing of seed removal by a keystone seed-dispersing ant, Aphaenogaster rudis, and fruit dehiscence of several species of plants whose seeds it disperses in a deciduous forest in southern Ontario, Canada. We examined the timing of elaiosome "robbing" by the nonnative slug Arion subfuscus and tested whether seed removal by ants declines in response to supplementation with additional elaiosome-bearing seeds (ant "satiation"). KEY RESULTS Seed removal from experimental depots peaked early in the season for all plant species and correlated with temperature. In contrast, elaiosome robbing by slugs increased late in the season and thus may disproportionately affect plants with late-dehiscing fruits. Ant colonies removed seeds at similar rates regardless of seed supplementation, indicating that satiation likely does not impact seasonal patterns of seed dispersal in this system. Fruits of the five myrmecochorous plant species in our study dehisced at discrete intervals throughout the season, with minimal overlap among species. Peak dehiscence did not overlap with peak seed removal for any plant species. CONCLUSIONS Fruit dehiscence of myrmecochorous plants and peak ant seed dispersal activity occur asynchronously. Whether future climate warming will shift ant and plant phenologies in ways that have consequences for seed dispersal remains an open question.
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Affiliation(s)
- Susan C C Gordon
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
| | - Shannon A Meadley-Dunphy
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
| | - Kirsten M Prior
- Department of Biological Sciences, Binghamton University, State University of New York, P.O. Box 6000, Binghamton, New York, 13902, USA
| | - Megan E Frederickson
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada
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Centorame M, Moschella F, Russini V, Fanfani A. DNA-barcoding of the Italian members of the Aphaenogaster testaceopilosa-group (Hymenoptera: Formicidae): hybridization and biogeographic hypothesis. ZOOL ANZ 2018. [DOI: 10.1016/j.jcz.2018.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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14
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Helms Cahan S, Nguyen AD, Stanton-Geddes J, Penick CA, Hernáiz-Hernández Y, DeMarco BB, Gotelli NJ. Modulation of the heat shock response is associated with acclimation to novel temperatures but not adaptation to climatic variation in the ants Aphaenogaster picea and A. rudis. Comp Biochem Physiol A Mol Integr Physiol 2017; 204:113-120. [DOI: 10.1016/j.cbpa.2016.11.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 02/04/2023]
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Stanton-Geddes J, Nguyen A, Chick L, Vincent J, Vangala M, Dunn RR, Ellison AM, Sanders NJ, Gotelli NJ, Cahan SH. Thermal reactionomes reveal divergent responses to thermal extremes in warm and cool-climate ant species. BMC Genomics 2016; 17:171. [PMID: 26934985 PMCID: PMC4776372 DOI: 10.1186/s12864-016-2466-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/12/2016] [Indexed: 12/03/2022] Open
Abstract
Background The distributions of species and their responses to climate change are in part determined by their thermal tolerances. However, little is known about how thermal tolerance evolves. To test whether evolutionary extension of thermal limits is accomplished through enhanced cellular stress response (enhanced response), constitutively elevated expression of protective genes (genetic assimilation) or a shift from damage resistance to passive mechanisms of thermal stability (tolerance), we conducted an analysis of the reactionome: the reaction norm for all genes in an organism’s transcriptome measured across an experimental gradient. We characterized thermal reactionomes of two common ant species in the eastern U.S, the northern cool-climate Aphaenogaster picea and the southern warm-climate Aphaenogaster carolinensis, across 12 temperatures that spanned their entire thermal breadth. Results We found that at least 2 % of all genes changed expression with temperature. The majority of upregulation was specific to exposure to low temperatures. The cool-adapted A. picea induced expression of more genes in response to extreme temperatures than did A. carolinensis, consistent with the enhanced response hypothesis. In contrast, under high temperatures the warm-adapted A. carolinensis downregulated many of the genes upregulated in A. picea, and required more extreme temperatures to induce down-regulation in gene expression, consistent with the tolerance hypothesis. We found no evidence for a trade-off between constitutive and inducible gene expression as predicted by the genetic assimilation hypothesis. Conclusions These results suggest that increases in upper thermal limits may require an evolutionary shift in response mechanism away from damage repair toward tolerance and prevention. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2466-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- John Stanton-Geddes
- Department of Biology, University of Vermont, Burlington, VT, 05405, USA. .,Data Scientist, Dealer.com, 1 Howard St, Burlington, VT, 05401, USA.
| | - Andrew Nguyen
- Department of Biology, University of Vermont, Burlington, VT, 05405, USA
| | - Lacy Chick
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - James Vincent
- Vermont Genetics Network, University of Vermont, Burlington, VT, 05405, USA
| | - Mahesh Vangala
- Vermont Genetics Network, University of Vermont, Burlington, VT, 05405, USA
| | - Robert R Dunn
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
| | - Aaron M Ellison
- Harvard Forest, Harvard University, Petersham, MA, 01336, USA
| | - Nathan J Sanders
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA.,Center for Macroecology, Evolution and Climate, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
| | - Nicholas J Gotelli
- Department of Biology, University of Vermont, Burlington, VT, 05405, USA
| | - Sara Helms Cahan
- Department of Biology, University of Vermont, Burlington, VT, 05405, USA
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