Wildlife herbivory and rare plants: the effects of white-tailed deer, rodents, and insects on growth and survival of Turk's cap lily

Abstract

Current land-use changes in eastern deciduous forests, such as fragmentation, may affect population sizes of native wildlife that may exacerbate declines in rare and endangered wildflower populations in the eastern deciduous forests. In this study, we examined the influence of herbivory by rodents ( Peromyscus leucopus, Sciurus sp., and Tamias striatus) and white-tailed deer ( Odocoileus virginianus) on the growth and survival of Turk's cap lily ( Lilium superbum) planted in Virginia. Bulbs were planted in pairs and in patches. One plant per pair was protected from deer damage with a wire cage, and patches consisted of two, 10 and 25 bulbs planted within 0.04 ha. Rodents dug up and consumed 9% of all the bulbs planted, and fatal rodent damage was 3 times greater in successional than in upland hardwood and creek bottom habitats. White-tailed deer consumed the apical meristem of 28% of the unprotected lilies that emerged, reducing mean plant height and stopping growth and reproduction for that season. Deer and insects, but not rodents, damaged a greater proportion of plants emerging in small patches (1–2 plants/0.04 ha) than on larger patches (3–20 plants/0.04 ha). Therefore, when protecting remaining populations or restoring new populations of rare perennial wildflowers in the eastern deciduous forest, methods for protecting plants from herbivory by rodents and white-tailed deer should be considered.