Some neighbours are better than others: Variation in associational effects among plants in an old field community

Consumer-resource interactions are often influenced by other species in the community, such as when neighbouring plants increase or reduce herbivory to a focal plant (known associational effects). The many studies on effects between and some neighbour have shown that these can vary greatly strength direction. But because almost all of measure from only one two species, we know little about actual range might encounter natural setting. This makes it difficult determine how important neighbours real field settings, interact with competition processes influence community composition. In this study, used experiment Solanum carolinense, 11 common investigate among co-occurring test whether factors apparency, phylogenetic proximity defence traits help explain interspecific variation effect strength. We found affected S. carolinense damage attack specialist herbivores, but most were weak. Associational increased herbivore average earlier season (associational susceptibility) reduced later resistance) relative monoculture. evidence neighbour's was related its biomass species. While differed their physical leaf (trichome density, specific area, toughness), did not appear mediate herbivory. Synthesis. Our results suggest distribution strengths communities similar those observed for interaction types, multiple mechanisms likely acting simultaneously shape different