From the U.S. Forest Service Jellico Vegetation Management project documentation:
CLEARCUT
This harvest method consists of cutting essentially all trees and regenerating the stand. Only immediate roost trees (IRTs), as defined in the Forest Plan (page A-16), and snags (dead trees) are retained. At least 15 basal area per acre (BA) is retained in any scoured ephemeral stream zones (DB-VEG-28, Forest Plan 2-27). [Scoured ephemeral stream zone: The area within 25 feet on either side of a definable channel of water flow in which surface waterways converge with enough energy to remove soil, organic matter, and leaf litter on an annual basis (Forest Plan A-32)]. The result is an even aged stand with scattered IRTs and snags (when present) and at least 15 BA retained in any scoured ephemeral stream zones.
TWO AGED SHELTERWOOD
This harvest method calls for retention of 10-20 BA of dominant or codominant trees. All IRTs are retained. Within any scoured ephemeral stream zones, a minimum of 15 BA is retained. Desired leave tree species in order of priority are: 1) white oak or chestnut oak, 2) hickory, 3) other hardwoods, except red maple. Leave trees selected for retention are generally long-lived species that are dominant, vigorous, exhibit healthy crowns, and ideally have a DBH of 14 inches or greater. Where no such tree is present, or no desired leave tree species is available, the healthiest tree of the most desired species with the largest DBH is selected. Some overlap between IRTs and desired leave trees may occur (i.e., an IRT can be a desired leave tree, such as shagbark hickory). All live IRTs are counted towards the minimum BA requirement. The result is an even aged stand with the residual 10-20 BA of shelterwood trees designed to provide structure and mast for wildlife.
DEFERMENT HARVEST
This harvest method calls for the initial retention of 20-40 BA of dominant or codominant trees. All IRTs are retained. Within any scoured ephemeral stream zones, a minimum of 15 BA is retained. Desired leave tree species in order of priority are: 1) white oak or chestnut oak, 2) hickory, 3) other hardwoods, except red maple. Leave trees selected for retention are generally dominant, vigorous, exhibit healthy crowns, and ideally have a DBH of 14 inches or greater. Where no such tree is present, or no desired leave tree species is available, the healthiest tree of the most desired species with the largest DBH is selected. Some overlap between IRTs and desired leave trees may occur (i.e., an IRT can be a desired leave tree, such as shagbark hickory). All live IRTs are counted towards the minimum BA requirement. Approximately 10 to 15 years after the initial harvest, a harvest of residuals is conducted in which the originally retained 20-40 BA is removed (except for IRTs) in a second harvest. The result is a 10-15 year old, even aged stand with at least 15 BA retained in any scoured ephemeral stream zones.
THINNING
This harvest method consists of cutting suppressed, intermediate, and a few co-dominant trees while retaining 50-70 BA of dominant and co-dominant, vigorous, healthy, trees. Leave tree species in order of retention priority are: 1) white oak or chestnut oak, 2) hickory, 3) yellow poplar, 4) other hardwoods, except red maple. The result is a two aged stand with 50-70 BA of overstory trees and a regenerating understory.
SALVAGE
This harvest consists of the removal of all damaged, dying, and dead trees within an area after a disturbance. Salvage harvests range from removal of several trees in a small area (a few acres) to salvage of large areas (100s or 1,000s of acres) following widespread disturbance. Common disturbances in this area that create a need for salvage harvests include damage from wildfire, wind, snow, ice, and forest pests. The need for this harvest type is disturbance driven. Results vary depending on the severity of the disturbance.