Considerable intra-specific variation in functional strategies can occur within a single plant species. C-S-R theory was developed to classify functional strategies (competitive, stress tolerant, ruderal) in different plant species.
Using a range of Arabidopsis (Arabidopsis thaliana) accessions from different geographic origins, May et al. test whether competitor, stress-tolerator, ruderal (CSR) theory can be applied to characterise intra-specific variation. The study shows that functional strategies in Arabidopsis vary along the stress tolerant/ruderal axis: accessions originating from warm climates were classified as stress tolerant, whereas accessions from colder climates were classified as ruderal.