Knight measured the effects of early and late deer (Odocoileus virginianus) herbivory (actual and simulated), on Trillium grandiflorum. Early season herbivory reduced the potential of the plant to be reproductive the following growing season while late season herbivory did not, however, grazing in both the early and late season reduced relative growth of those plants that were reproductive the following year. Plant size was directly related to the number of ovules on the plants, smaller plants produced fewer ovules and therefore had less reproductive success than larger plants, therefore, the reduction in plant size due to grazing will reduce reproductive success even if plants remain reproductive after grazing. These results suggest that herbivory, in both early and late season, can reduce the reproductive success of Trillium grandiflorum but early season grazing has greater negative effects than late season grazing.
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