Many woodland plants rely on ants to disperse their seeds; such seed dispersal increases the plant population’s chance of survival. Robert Warren, assistant professor of biology, has recently demonstrated that ant-dispersed plants (myrmecochores) compete for ant dispersers by staggering seed release.
“Competition as a mechanism structuring mutualisms” by Warren and coauthors Itamar Giladi and Mark A. Bradford was published online on January 13 in the Journal of Ecology. The researchers hypothesized that the staggered timing of seed release by ant-dependent plants has been shaped by competition, through which plants with less desirable (smaller) seeds avoid competing with plants with more desirable (larger) seeds. Warren showed that ants will ignore small seeds altogether if they are placed close to large seeds.
“It is well known that plants compete for the light, water, and nutrients they need to thrive, ” said Warren. “However, we show that plants also compete for living resources such as ants to disperse seeds.” In other words, mutualist partners—members of different species whose mutual dependence benefits members of each species—are as fundamental a resource as sun and moisture. Via Plants compete for friendly ants.