Canopy – The highest horizontal layer of vegetation in a forest made up of tree crowns.
Certification – Forest certification is a voluntary process by an authorized forester that verifies whether your forest management, including harvesting timber or other products, is environmentally appropriate, socially beneficial, and economically viable.
Chain – A distance of 66 feet.
Cleaning – See release cutting.
Clearcut – A harvesting method that removes all the trees on an area in one operation. Regeneration occurs from seed or seedlings present before cutting, from dormant seed on the ground, from seed that disperses from adjoining stands, or from artificial planting or seeding. Clearcutting is used most often with species that require full sunlight to reproduce and grow well. Produces an even-aged forest stand.
Clone – A group of plants derived from a single individual through asexual (vegetative) reproduction.
Codominant – See crown classification.
Commercial cut – A timber harvest for which the value of cut timber exceeds the cost of cutting.
Conifer – A tree belonging to the order Coniferales that usually is evergreen, cone-bearing, and has leaves that are needle-, awl- or scale-like, such as pine, spruce, fir, and cedar; often referred to as softwood.
Conservation – The protection, improvement, and wise use of natural resources to assure the attainment of their highest economic and social values over a long time period.
Cord – A stack of logs containing 128 cubic feet of wood, bark and air space. Normal dimensions of a standard cord are 4 feet x 4 feet x 8 feet. In the Lake States, pulpwood cords usually are 4 feet x 4 feet x 100 inches.
Crop tree – A tree that will be grown to economic or physical maturity. Usually selected on the basis of its species, location with respect to other trees, and quality.
Crown – The leaves and branches of a tree.
Crown classification – Ranking of individual trees in a stand according to the size and height of their crowns. In descending order of crown height and size, the classes commonly used are dominant, codominant, intermediate, and suppressed.
Crown ratio – Percentage of total tree height that is occupied by living branches.
Cruise – Process of collecting stand inventory information such as tree volumes.
Cubic foot – A wood volume measurement containing 1,728 cubic inches, such as a piece of wood measuring 12 inches on a side. A cubic foot of wood contains approximately 6 to 10 usable board feet of wood.
Cull – A tree or log of merchantable size but no market value because of serious wood quality defects.
Cutting – A segment of a tree stem, usually about 12 inches long, that can be planted to grow a new tree. The practice of severing a tree stem to fell it.
Cutting cycle – The planned time interval between major harvesting operations in a stand. The term usually is applied to uneven-aged stands. For example, a cutting cycle of 10 years means that a harvest would be carried out once every 10 years in a stand.