Deer Exclosures

Forests in Maryland are rapidly degrading. This was once caused primarily by land clearing and logging. Today forests are changing because old senescent trees are not being replaced by young trees. Tree seedlings that would grow to mature trees are being eaten by deer. Jug Bay Wetlands Sanctuary’s woods have been suffering for many years from over-browsing by white-tailed deer. The seedlings and saplings of hardwood tree species such as oak, hickory and red maple are scarce. Wildflowers such as spring beauties, orchids, bloodroot and other species have also become rare. A browse line is evident in many areas of the Sanctuary.

Hundreds of acres of forest at Jug Bay are seriously damaged by deer. Dense deer populations are negatively impacting forest regeneration, natural succession, and biological diversity. Exotic invasive plants are also spreading in the Sanctuary as a result of the deer. No effort to reduce these impacts can succeed without managing the deer population within the park and other public lands. As a result, the Anne Arundel County Department of Recreation and Parks started in 2009 the implementation of managed hunts in some of its public parks, including Jug Bay.

In an effort to monitor the impact of deer management on the recovery of the forest understory, a total of ten exclosures of 10m2 were established in 2010 within the Sanctuary proper. Paired control sites (open plots) were established in 2014 for comparison purposes. These exclosures are sampled annually to record species presence, including numbers of seedlings and saplings.

The main goals of this monitoring project are to:

  1. Estimate the impact of deer management on the recovery of Jug Bay’s forest understory.
  2. Inform the need of implementing additional forest restoration practices at Jug Bay.
  3. Promote the use of monitoring data for education and stewardship purposes.