Ecological trade-offs between growth, reproduction and both condensed tannins and cyanogenic glycosides were examined in Lotus corniculatus by correlating shoot (leaves and stem) size and reproductive output with chemical concentrations. We found that cyanide concentration was not related to shoot size, but that condensed tannin concentrations were positively correlated with shoot size; larger plants contained higher tannin concentrations. Both tannin and cyanide concentrations were depressed when plants produced fruits. Defense costs change as plants mature and begin to reproduce. These trade-offs indicate that cost of defense chemical production cannot be predicted merely on the basis of molecular size, composition or concentration.
Keywords: Allocation; Chemical defenses; Growth; Lotus corniculatus; Trade-offs.