Rapid increase in sensitive indicator plants concurrent with deer management in an oak forest landscape

Abstract

Wildlife managers are implementing programs to reduce abundant populations of large herbivores, such as white-tailed deer (Odocoileus virginianus) in eastern North America, with renewed research interest in understanding these programs' ecological effects. To examine plant community change following culling of white-tailed deer in oak (Quercus spp.) forests in Ohio, USA, we measured browse severity on tree seedlings and cover of 43 deer-sensitive, native indicator plant species across 20 years spanning pre- (2002–2015) and post- (2016–2021) deer culling periods. After culling halved deer abundance from 16.7 deer/km2 to 8.6 deer/km2, browse patterns on tree seedlings reversed from most seedlings exhibiting browse damage to most being undamaged. Cover of deer-sensitive indicator plants increased 7-fold in the 6 years after deer culling. Five of 6 indicator plant groups (e.g., Liliaceae) and 32 of 43 indicator species (74%) increased in cover after deer culling. Rhizomatous, clonally reproducing and early flowering (May–Jun) species were generally most responsive. The rapid increase in deer-sensitive plants after deer culling in our study is among the fastest and largest reported among eastern North American studies. The plant community resilience observed in this study could partly relate to the relatively short duration (~10 yr) that deer populations were elevated before culling began, allowing persistence of local plant regeneration potential. Deer culling enabled a moderate deer population to coexist with a rising sensitive plant population.