title: Selective forces exerted by vertebrate herbivores on plants.
abstract: The question of whether herbivory can benefit plants remains controversial. A series of papers on the effects of lesser snow geese grazing on grasses in northern Canada is throwing new light on this problem.
authors.affiliation: School of Biological Sciences, Macquarie University, NSW 2109, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Westoby