Vegetation Monitoring

Native plants, particularly trees, provide food and shelter that supports the complex web of life in our forests.  

These foundational plants are at risk of being significantly harmed, and even completely eliminated from the landscape, when there are too many deer eating them too quickly.  

The Deer Management Program will employ two forms of vegetation monitoring to directly measure the impact that deer are having on native plants and their ability to grow and sustain our forests.  

When deer impacts are reduced and plant communities are showing healthy regeneration, that is a signal that the deer population may have been brought back to balance with its environment.  

The two vegetation monitoring methods used will be Herbivory Impact Assessment and Deer Exclosures. 

The Herbivory Impact Assessment is a field survey that will directly document injuries to plants from deer eating them at plots randomly scattered throughout parks in Arlington County.  

The County will also use a method called ‘Exclosures’ to measure the impact of Arlington’s deer population on forest health and regeneration. Exclosures are fenced-in areas that exclude deer, but not other herbivores from a particular patch of forest. By comparing plants within that protected area to plants just outside, the County can isolate and monitor the effect that deer are having on plants in the forest.  

County Natural Resources staff will measure both Herbivory Impact Assessment and Exclosure survey sites annually to provide continually updated data to evaluate and inform our deer management activities over time. 

You can read the results from prior herbivory impact assessments from 2022 here. The results begin in appendices ‘A’ and ‘B’ beginning on page 49.