Live crown ratio and crown class are descriptors of tree crown characteristics and indicators of tree vigor. One of the ways foresters use these terms is to communicate decisions about stand management. For example, let’s say a forester wants to improve stand vigor by doing the following:
- decreasing tree density to reduce competition for resources
- concentrating growth on the healthiest trees; and
- removing trees with evidence of disease.
These are general concepts and overall directions for the stand. But how does one decide which individual trees to cut or leave, and how does one communicate that information, especially to a crew of people marking the trees? Each acre of ground and each individual tree in the forest are unique. Until one actually walks through the entire stand, decisions about individual trees cannot be made. So a set of specific directions describing cut and leave trees must be written to more clearly explain a forester’s intentions.
Therefore, in writing a prescription for the stand management described above, a forester would use standard terms to describe the intended management outcomes. For example, the following directions might be part of the tree marking directions.
- Reduce tree density to 75 trees per acre. On average, space trees ≈ 24 feet apart.
- Leave primarily Dominant trees; second preference is for Codominant trees with LCR > 40%.
- Favor trees with intact crowns.
- Remove trees with evidence of disease or deformity.
- Remove primarily Intermediate and Suppressed trees.
- Remove primarily trees with LCR< 30%.
In this way, the person making the cut and leave decisions on the ground has a much clearer idea of how to achieve the overall objective to “improve stand vigor.”