Which vertebrate is known for damaging the bark and roots of ornamentals?

The prairie vole is known for causing damage to the bark and roots of ornamental plants. These small rodents are herbivorous and tend to feed on the lower parts of plants, including the bark and roots, particularly during the colder months when other food sources may be scarce. Their feeding habits can lead to girdling of trunks and destruction of root systems, which can severely weaken or kill ornamental plants.

In contrast, the white-tailed deer primarily browse on leaves and stems, rather than specifically targeting bark and roots like the prairie vole does. The eastern gray squirrel, while it may feed on the seeds and fruits of plants, does not typically damage the bark and roots to the same extent as the prairie vole. The common mullein, on the other hand, is not a vertebrate but rather a plant itself, and therefore cannot damage the bark and roots of ornamentals. The prairie vole's specific behavior makes it the best choice for this question.