DOI: 10.5061/dryad.ch8d7
title: Data from: Breakdown of a geographic cline explains high performance of introduced populations of a weedy invader

description: 1. What drives the evolution of increased growth and fecundity in plants
 introduced to a novel range is not well understood. 2. We investigate
 between-range differences in performance for Verbascum thapsus, a weedy
 invader known to grow larger in its introduced than native range.
 Specifically, we question whether adaptation to herbivory or climate best
 explains increased performance of introduced populations. 3. We grew 14
 native and 22 introduced populations of V. thapsus in two common garden
 locations: near Prague, Czech Republic (native range) and in Colorado, USA
 (introduced range). By removing herbivores from half of the plants within
 each garden we tested the prediction of the Evolution of Increased
 Competitive Ability (EICA) hypothesis: increased performance is driven by
 an evolutionary shift of resources away from defence against herbivory
 towards growth and reproduction. We then investigated whether genetically
 based clines in performance are expressed along climate gradients within
 both the native and introduced ranges. 4. On average, seeds produce larger
 rosettes when collected from the introduced versus native range. While
 this evolution of increased growth in introduced populations in part
 matches the prediction of EICA, climate, not herbivory, best explains this
 between-range difference. Specifically, seeds collected from the native
 range produce smaller rosettes as the climate of origin becomes cooler and
 drier, while there is no cline in performance in rosettes grown from seed
 collected from the introduced range, which are large regardless of climate
 of origin. Thus, a climate-based cline within the native range best
 explains lower average performance of native compared to introduced
 populations. SYNTHESIS: The breakdown in a potentially adaptive cline
 emphasizes the need to more closely investigate the evolutionary processes
 that shape geographic structuring (or its absence) within the introduced
 range. In addition, EICA is not universally applicable to all invasion
 scenarios, and our findings underscore the importance of testing
 underlying assumptions alongside the predictions of this hypothesis.
description: Common Garden
 Performance DataIncludes data related to
 the performance of Verbascum thapsus rosettes grown in a common garden.
 Columns include: 'Plant' (unique ID associated with each
 rosette; numbers are not consecutive due to attrition before planting and
 plants that were excluded due to faulty irrigation),
 'Population' (unique ID associated with each population; numbers
 are also not consecutive due to attrition before planting and plants that
 were excluded due to faulty irrigation), 'Origin' (continental
 range of seed collection; North American or European), 'Block'
 (1 or 2; a spatial block that coincides with maternal line),
 'Treatment' (Ambient or Reduced Herbivory), 'PC1'
 (Principle Component associated mainly with temperature), 'PC2'
 (Principle Component associated mainly with precipitation during warm or
 wet periods), 'PC3' (Principle Component associated mainly with
 precipitation during warm and dry periods), 'Rosette.Area'
 (cm^2), 'Alive' (indicates where the rosette survived [1] or
 died [0] before September of the first growing season),
 'Survival.to.Beginning.of.the.Second.Growing.Season' (0=no,
 1=yes), 'Young.Leaf.Chewing.Damage' (estimate of average percent
 leaf tissue removed on young leaves by insect herbivores),
 'Binomial.Young.Leaf.Chewing.Damage' (0=no visible damage,
 1=visible damage on young leaves),
 'Old.Leaf.Average.Chewing.Damage' (estimate of average percent
 leaf tissue removed on old leaves by insect herbivores),
 Binomial.Old.Leaf.Chewing.Damage (0=no visible damage, 1=visible damage on
 young leaves), 'Garden' (Garden Location; either U.S. or Czech
 Republic).Performance
 Data.csvResistance to Herbivory
 DataIncludes data related to
 resistance against herbivory of native and introduced populations of
 Verbascum thapsus. Columns include: 'Garden' (Garden Location;
 either U.S. or Czech Republic), 'Block' (1 or 2; a spatial block
 that also coincides with maternal line), 'Population' (unique ID
 associated with each population; numbers are also not consecutive due to
 attrition before planting and plants that were excluded due to faulty
 irrigation), 'Origin' (continental range of seed collection;
 North American or European), 'Latitude' (of seed source),
 'Longitude' (of seed source), 'PC1' (Principle
 Component associated mainly with temperature), 'PC2' (Principle
 Component associated mainly with precipitation during warm or wet
 periods), 'PC3' (Principle Component associated mainly with
 precipitation during warm and dry periods),
 'Average.Rosette.Area.under.Reduced.Herbivory' (cm^2; rosette
 area for plants sprayed with systemic insecticide),
 'Average.Ambient.Old.Leaf.Damage' (estimate of average percent
 leaf tissue removed on old leaves by insect herbivores when plants were
 sprayed with a water control).Resistance
 Data.csvTolerance to Herbivory
 DataIncludes data related to
 tolerance to herbivory of native and introduced populations of Verbascum
 thapsus. Columns include: 'Garden' (Garden Location; either U.S.
 or Czech Republic), 'Block' (1 or 2; a spatial block that also
 coincides with maternal line), 'Population' (unique ID
 associated with each population; numbers are also not consecutive due to
 attrition before planting and plants that were excluded due to faulty
 irrigation), 'Origin' (continental range of seed collection;
 North American or European), 'Latitude' (of seed source),
 'Longitude' (of seed source), 'PC1' (Principle
 Component associated mainly with temperature), 'PC2' (Principle
 Component associated mainly with precipitation during warm or wet
 periods), 'PC3' (Principle Component associated mainly with
 precipitation during warm and dry periods),
 'Coefficient.of.Tolerance.Slope' (the slope of the line of
 log-transformed rosette area plotted against percent herbivore damage
 experienced by each plant),
 'Variance.of.Tolerance.Slope'.Tolerance
 Data.csv