Evaluating Habitat Manipulations and Rodenticides to Protect Seedlings from Rodent Damage at Restored Landfills in New York

Solid waste landfills have become rather commonplace in urbanized and industrialized regions of the world. If designed, managed, and restored properly, they can be converted to useful land uses. However, restoration of woody vegetation can be difficult when animal damage occurs. Numerous species of voles occur throughout the northern hemisphere and several may become serious pests of restoration plantings at high population density, increasing the expense and difficulty of establishing targeted plant communities. We anticipated that meadow voles (Microtus pennsylvanicus) were responsible for causing the majority of damage to seedlings planted on restored landfill sites in Brooklyn, New York. We evaluated the ability of two habitat manipulations (e.g. mowing, pea gravel barrier) and rodenticides to protect seedlings. We documented substantial damage and deaths of seedlings caused by rodents in the study plots with losses (damaged or dead seedlings combined) ranging from 40 to 73%. These losses occurred regardless of seedling species. Because of the preponderance of voles (71% of all first-time captures), we suspect that voles are the main species causing seedling damage. Substantial losses of seedlings occurred across treatments, although there were fewest losses with a pea gravel barrier treatment. While the pea gravel treatment reduced seedling losses about 55% compared to control plots, it is clear that additional research is needed to identify more efficient ways to reduce seedling losses to rodents in restoration plantings.