Interactions between Invertebrate Herbivores and Plant Competition

The combined effects of different types of invertebrate herbivory and competition on plant performance were studied with a manipulative field experiment involving chemical exclusion and hand weeding, using four species of annual crucifer. Two of the species, Raphanus raphanistrum and Capsella bursa-pastoris were locally abundant at the study site, whereas the other species, Sinapis arvensis and Sisymbrium officinalis, were uncommon. Plant masses were log-normally distributed at harvest. There was a non-linear relationship between plant mass and siliqua production in all four species (...)