Importance and Issues
Forests are the main vegetation of national parks in the National Capital Region Network (NCRN), making up about two-thirds of park land. These forests are part of the Eastern Deciduous Forest, which stretches from Florida to southern Canada, and extends as far west as Louisiana and Minnesota. Broad-leafed deciduous trees dominate these forests, but conifers (such as pines and hemlocks) are common in some areas too.
The Eastern Deciduous Forest was once about a million square miles, most of which has been logged or cultivated by humans. Remaining lands are often fragmented and have had some historic disturbance (forests regrown on farmed lands), or ongoing disturbance (periodic logging). In NCRN, forests are often surrounded by urban or suburban development or agricultural areas.
Jump to how we monitor forest vegetation.
Monitoring Questions and Approach
- What tree and shrub species make up park forests and how are they distributed?
- Are any tree or shrub species booming or rapidly declining?
- Are enough tree seedlings and small saplings surviving to ensure future forest regeneration?
- What understory plants are growing on the forest floor?
- How much dead wood is present on the forest floor (to provide habitat for animals and microbes)?
- How is forest vegetation affected by physical and chemical properties of soil?
- We also monitor targeted invasive plants and forest pests.
Detailed monitoring objectives from our protocol document are found here.
How We Monitor
In 2006, the National Capital Region Network began forest vegetation monitoring. More than 400 sites are spread across all NCRN parks. Field crews sample more than 100 forest plots each year from approximately May through September. The cycle repeats every four years.
At each plot, field crews take the following measures:
- Identify species of trees, shrubs, vines, and specific herbaceous plants
- Tag and record individual trees and shrubs
- Assess trees for canopy class and diameter
- Note any evidence of deer browse on trees or shrubs
- Count seedlings and record cover of herbaceous plants in 12 small quadrats
- Record any presence of targeted invasive plants and targeted insect pests and pathogens
- Measure coarse woody debris along three transects
Last updated: October 18, 2022