Summary: Relatedness predicts phenotypic plasticity in
plants better than weediness
Susan C. Cook-Patton and Anurag A. Agrawal
Department of Ecology and Evolutionary Biology, Cornell University,
Ithaca, New York, USA
Background: Weedy non-native species have long been predicted to be more phenotypically
plastic than native species.
Question: Are weedy non-native species more plastic than natives?
Organisms: Fourteen perennial plant species: Acer platanoides, Acer saccharum, Bromus
inermis, Bromus latiglumis, Celastrus orbiculatus, Celastrus scandens, Elymus repens, Elymus
trachycaulus, Plantago major, Plantago rugelii, Rosa multiflora, Rosa palustris, Solanum
dulcamara, and Solanum carolinense.
Field site: Mesic old-field in Dryden, NY (42 27 49N, 76 26 40W).
Methods: We grew seven pairs of native and non-native plant congeners in the field and tested
their responses to reduced competition and the addition of fertilizer. We measured the plasticity
of six traits related to growth and leaf palatability (total length, leaf dry mass, maximum
relative growth rate, leaf toughness, trichome density, and specific leaf area).
Conclusions: Weedy non-native species did not differ consistently from natives in their
phenotypic plasticity. Instead, relatedness was a better predictor of plasticity.