Evidence for fine-scale habitat specialization in an invasive weed
Atwater, Fletcher, Dickinson, Paterson, Barney (pdf)
In previous studies, we found evidence for striking genetic and phenotypic differentiation in Johnsongrass (Sorghum halepense) populations collected throughout the United States. Here, we report that Johnsongrass may be adapting to local habitat variation.
Johnsongrass from non-agricultural populations competed better in a field community than Johnsongrass from agricultural populations. Agricultural and non-agricultural populations were separated by less than a kilometer, suggesting that this species may be adapting to habitat variation at extremely fine spatial scales.
These results contribute to a growing list of studies revealing the importance of fine-scale habitat specialization in invasive species, with possible ecological and management implications.