Data from: Reconstructing changes in the genotype, phenotype, and climatic niche of an introduced species
Atwater, Daniel Z. et al. (2015), Data from: Reconstructing changes in the genotype, phenotype, and climatic niche of an introduced species, Dryad, Dataset, https://doi.org/10.5061/dryad.mk649
An introduced species must contend with enormous environmental variation in its introduced range. In this study, we use niche models and ordination analyses to reconstruct changes in genotype, phenotype, and climatic niche of Johnsongrass (Sorghum halepense), which is regarded as one of the world's most threatening invasive plants. In the United States, Johnsongrass has rapidly evolved within- and among-population genetic diversity; our results show that genetic differentiation in expanding Johnsongrass populations has resulted in phenotypic variation that is consistent with habitat and climatic variation encountered during its expansion. Moreover, Johnsongrass expanded from agricultural to non-agricultural habitat, and now, despite occupying overlapping ranges, extant agricultural and non-agricultural populations are genetically and phenotypically distinct and manifest different plastic responses when encountering environmental variation. Non-agricultural accessions are broadly distributed in climatic and geographic space and their fitness traits demonstrate plastic responses to common garden conditions that are consistent with local specialization. In contrast, agricultural accessions demonstrate “general purpose” plastic responses and have more restricted climatic niches and geographic distributions. They also grow much larger than non-agricultural accessions. If these differences are adaptive, our results suggest that adaptation to local habitat variation plays a crucial role in the ecology of this invader. Further, its success relates to its ability to succeed on dual fronts, by responding simultaneously to habitat and climate variability and by capitalizing on differential responses to these factors during its range expansion.
United States of America