| Abstract Detail
Ecology Southgate, Morgan [1]. Ecological dynamics of allopolyploidy in the Adiantum pedatum complex across micro- and macro- habitat scales. The fundamental forces underlying ecological niche evolution include interspecific competition and shifts in environmental conditions over time. As interspecific competition is predicted to lead to niche divergence, niche evolution has been most fully explored in the context of divergent speciation. What ecological patterns characterize the niche evolution of hybrid species? The purpose of the present work is to characterize the ecological outcome of allopolyploidy in the Adiantum pedatum complex, a clade of maidenhair ferns. In northeastern North America, the group comprises two diploid species, Adiantum aleuticum and A. pedatum, and their allotetraploid hybrid A. viridimontanum. As the Adiantum pedatum complex is a clade of spore-dispersed plants, abiotic factors are likely more important than biotic factors or mobility constraints in shaping their distribution because 1) they are capable of long-distance dispersal, and 2) they lack associations with pollinators or seed dispersers. Abiotic ecological factors vary across different scales, with microhabitat variables shaping distribution on a fine scale and macrohabitat variables shaping distribution on a coarse scale. In the present study, microhabitat characteristics were assessed by collecting data on light availability, topography, and soil chemistry across 100 survey plots in northeastern North America. To characterize macrohabitat variation, climatic and topographic variables from the ENVIREM raster data were extracted for a range-wide occurrence data-set for the three species derived from GBIF data and personal observations. Micro- and macro- habitat data were analyzed in parallel using PCA to characterize multivariate niche space, and the niche hypervolume occupied by each species and the niche overlap between species pairs were quantified using the hypervolume package in R. In macrohabitat niche space, the niche of the allopolyploid is intermediate between that of it's progenitors, and occupies a smaller portion of niche space. In microhabitat niche space, the niche of Adiantum viridimontanum occupies more space than either progenitor, and shows a strong pattern of niche intermediacy that manifests as niche novelty at a local scale. Consideration of coarse-resolution climatic variables suggests that the distribution of the hybrid species is bounded by the ecological limitations of it's progenitors, but at a microhabitat scale the larger niche hypervolume of Adiantum viridimontanum, and it's occupation of novel habitats, suggests that this hybrid species is more than the sum of its parts.
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Publication on microhabitat variation at a local scale
1 - University Of Vermont, Plant Biology, 63 Carrigan Dr., Burlington, VT, 05405, United States
Keywords:
niche evolution
edaphic niche
serpentine
Allopolyploidy.
Presentation Type: Oral Paper
Session: ECO9, Ecology: Species Ranges and Distributions
Location: /
Date: Friday, July 23rd, 2021
Time: 3:00 PM(EDT)
Number: ECO9001
Abstract ID:665
Candidate for Awards:Ecological Section Best Graduate Student Paper |
