Vermont Forest Indicators Dashboard


What is condition?

Condition is the overall health and status of the trees in forests. While forest condition can vary from year to year due to weather or pests and pathogens, long-term trends often indicate a more persistent problem. The condition of the forest dictates provisioning of the important ecosystem services we rely on, like wood and maple syrup production, and carbon storage.

Why is forest condition important?

Condition provides insight into how the forest is reacting to its surrounding environment and whether or not the forest is susceptible to long-term damage. Tracking condition provides information on potential and current threats to the overall health of the forest.

How do we quantify condition?

To assess forest condition, the Forest Indicators Dashboard uses data on tree dieback, growth, damage and mortality, as well as landscape-level metrics like canopy density.

  • Crown dieback
    Crown dieback is assessed by visually inspecting the leaves and crown of trees When trees experience stress, they begin to move resources from the outermost leaves and fine branches, and these areas will die. While dieback can vary from year to year based on weather or insects, multi year trends are indicative of a more pervasive issue and decline in overall health. For a higher score, the overall dieback must decline.
  • Forest damage
    Forest damage is assessed through the US Forest Service Insect and Disease Surveys. Technicians assess forest damage via fixed-wing aircraft. Here we included all identified damages, except for mortality (see below). These damages could be caused by pests, weather, disease, fire, or a range of other causes. All damages of unknown cause are flagged for a ground survey. As the acreage of forest damage decreases score will increase.
  • Forest mortality
    Forest mortality is calculated by summing only those areas of newly visible tree mortality that were mapped through the IDS Program described above. In these surveys, old mortality is distinguished from current-year mortality. As forest mortality decreases, the score will increase.
  • Tree mortality
    Every year trees die for a variety of reasons, from wind storms and lightning strikes, to fungal or insect infestations. However, changes to the baseline tree mortality rate may signify that environmental conditions are changing and could pose problems to the lifespan of our trees. For a higher score, tree mortality should remain stable over time.
  • Tree growth
    Trees grow to different sizes and at various rates depending on species, age, and site characteristics. This distinction allows for various tree layers to form over time, resulting in structural diversity, as well as more timber resources from our forests. A higher score results when tree growth remains stable over time.
  • Damage and decay
    While damaged and decaying trees have a vital role in the forest ecosystem through providing habitat and food for a variety of organisms from fungi to insects, an increase in the proportion of our trees that are classified as damaged or decaying can impact the value of timber and non-timber resources and suggest that trees are being negatively impacted by stressors. A higher score results from stable amounts of damage and decay over time.
  • Canopy density
    Canopy density or greenness is estimated using data collected by the MODIS Satellite. Higher values are associated with a greener and more photosynthetically-active forest. As canopy density increases, the score will increase.