DOI: 10.5061/dryad.1c59zw473
title: Habitat-scale ecological data for the <em>Adiantum pedatum</em> complex in northeastern North America

description: Species arising from hybridization are shaped by a different set of
 evolutionary mechanisms than species arising from divergence, providing a
 valuable opportunity to broaden our understanding of ecological niche
 evolution and conservatism. We focused on the ecology of hybridization
 within the North American members of the Adiantum pedatum complex
 (Pteridaceae), a clade of maidenhair ferns; in the northeast portion of
 its range, the clade includes the diploid species A. pedatum
 and A. aleuticum as well as their allotetraploid
 hybrid A. viridimontanum. Adiantum pedatum commonly occurs in
 rich woods across eastern North America, whereas A. viridimontanum and A.
 aleuticum (only in the eastern North American portion of its range) are
 restricted in distribution to the northern portion of a narrow belt of
 ultramafic and serpentinite bedrock scattered along the Appalachian
 mountains. As the fine-scale component of a broader effort to characterize
 the realized ecological niche of A. viridimontanum relative to
 its progenitors across spatial scales, we established 105 survey plots at
 41 sites across northeastern North America at sites of occurrence for one
 or more members of the Adiantum pedatum complex. At each survey
 plot, we collected a set of ecological attributes including percent canopy
 cover, topography, and soil layer depth. A soil sample collected from each
 plot was submitted to the University of Vermont Agricultural and
 Experimental Testing Laboratory for detailed analysis of chemical
 composition. These data were analyzed using Principal Component Analysis
 to characterize the realized niche of each species in environmental space.
 We found that the ecological niche of A. viridimontanum is intermediate
 between that of its progenitors. However, this pattern is spatially
 variable; in the core section of range, where all three species co-occur,
 the niche of the allotetraploid also exhibits a subtle pattern of
 expansion, corresponding in geographic space to novel habitats that are
 unoccupied by either progenitor. Our results highlight the importance of
 looking across spatial scales when studying complex ecological patterns.
 Re-use potentials for this dataset include 1) edaphic contrasts between
 serpentine and rich woods habitats, and 2) analysis of fine-scale
 differences in soil chemistry within each habitat type.
description: # Habitat-scale ecological data for the *Adiantum pedatum* complex in
 northeastern North America Dataset DOI:
 [10.5061/dryad.1c59zw473](10.5061/dryad.1c59zw473) ## Description of the
 data and file structure These data were collected to characterize the
 habitat-scale ecological niche of the allopolyploid maidenhair fern
 *Adiantum viridimontanum* relative to its progenitors. ### Files and
 variables #### File: AdiantumData_FL2023_Dryad.ods **Description:** 105
 observations of 42 (mostly quantitative and abiotic) ecological variables
 collected from survey plots established at occurrences of *Adiantum* in
 northeastern North America. Columns 1–10 = identifying information;
 Columns 10–29 = ecological data collected *in situ*; Columns 29–52 =
 edaphic variables measured from analysis by the University of Vermont
 Agricultural and Experimental Testing Laboratory. Coordinate locations for
 the serpentine maidenhair ferns *A. viridimontanum* and *A. aleuticum*
 have been omitted due to the rarity and sensitivity of these taxa. Blank
 cells are denoted with NA. * SurveyPlot = unique identifying number for
 plot * SurveyDate = date on which survey was completed * SiteNumber =
 unique identifying number for site * SiteType = type of site; NS =
 nonserpentine, S = serpentine * State = state in which data were collected
 * SpeciesFinal = species identity (A = *A. aleuticum*, V = *A.
 viridimontanum*, P = *A. pedatum*). * Habitat = natural community
 determination or ecotone between natural communities * Latitude, Longitude
 - in decimal degrees, WGS84 * Elevation - in meters * PatchSize(ft) - area
 of survey plot in feet squred * PatchSize(m)- area of survey plot in
 meters squared * RamNum = number of ramets * RamDens = ramet density
 (RamNum/PatchSize(ft)) * PCC = percent canopy cover * MicSlope = slope on
 scale of patch * MicAspect = aspect on scale of patch * final_MicAspect =
 MicAspect converted to qualitative direction * MicHs = hillslope form on
 scale of patch * MacSlope = slope on scale of landscape * MacAspect =
 aspect on scale of landscape * final_MacAspect = MacAspect converted to
 qualitative direction * MacHs = hillslope form on scale of landscape *
 HsPos = hillslope position (landscape scale only) * DepLit = depth of leaf
 litter (cm) * DepO = depth of O soil layer (cm) * DepA = depth of A soil
 layer (cm) * TexComp = soil textural class (following Brady & Weil,
 2008) * pH = soil pH * PctOM = soil percent organic matter * P = soil
 Phosphorus concentration (parts per million, ppm) * K = soil Potassium
 concentration (ppm) * Ca = soil Calcium concentration (ppm) * Mg = soil
 Magnesium concentration (ppm) * Zn = soil Zinc concentration (ppm) * B =
 soil Boron concentration (ppm) * Mn = soil Manganese concentration (ppm) *
 Cu = soil Copper concentration (ppm) * Fe = soil Iron concentration (ppm)
 * Al = soil Aluminum concentration (ppm) * Na = soil Sodium concentration
 (ppm) * S = soil Sulfur concentration (ppm) * ExchAcid = soil Exchangeable
 Acidity (meq/100g) * ECEC = Effective Cation Exchange Capacity (meq/100g)
 * Ca_BS = Calcium base saturation (%) * Mg_BS = Magnesium base saturation
 (%) * K_BS = Potassium base saturation (%) * Pb = soil Lead concentration
 (ppm) * Ni = soil Nickel concentration (ppm) * Cd = soil Cadmium
 concentration (ppm) * Cr = soil Chromium concentration (ppm)