- Bark beetle
- An insect that bores through the bark of forest trees to eat the inner bark and lay its eggs. Bark beetles are important pathogens in the natural process of forest ecosystems.
- Basal area
- The area of the cross section of a tree trunk near its base, usually 4 and 1/2 feet above the ground. Basal area is a way to measure how much of a site is occupied by trees. The term basal area is often used to describe the collective basal area of trees per acre.
- Biological control
- The use of natural means to control unwanted pests. Examples include introduced or naturally occurring predators such as wasps, or hormones that inhibit the reproduction of pests. Biological controls are alternatives to mechanical means or chemical pesticides.
- Biological diversity
- The number and abundance of species found within a common environment. This includes the variety of genes, species, ecosystems, and the ecological processes that connect everything in a common environment.
- The total weight of all living organisms in a biological community.
- BMP (Best Management Practices)
- Methods, measures, or practices designed to prevent or reduce water pollution.
- Board foot
- A measurement term for lumber or timber. It is the amount of wood contained in an unfinished board 1 inch thick, 12 inches long, and 12 inches wide. Roughly, about four million board feet (5 mmbf) can be extracted out of about 100 acres of old-growth forests in the Umpqua Basin. (see mmbf.)
- Broadcast burn
- A prescribed fire that burns a designated area. This is usually used after a clear-cut deforestation project to remove debris. Sometimes it is called "slash and burn."
- A land area that is designated to block or absorb unwanted impacts to the area beyond the buffer. For instance, deforested areas are usually buffered from roads used by tourists. (See Visual Resource or Riparian Area.)
- Bureau of Land Management (BLM)
- In the Department of the Interior, the BLM manages our public lands - usually range lands in the West. However, in western Oregon and Washington, the BLM also manages forested lands. This is because the O&C railroads were given lands back in the 1800's to build a railroad, and when they failed, the land reverted back to the federal government. These are called O&C lands, now managed by the BLM. They were a superb temperate rain forest because of their proximity to the Pacific Ocean. They supported huge trees and a vast array of wildlife. In general, they are located at lower elevations than Forest Service lands, west of Forest Service lands down to the Pacific Ocean. Much of O&C lands is spotted owl and marbled murrelet country. Because the O&C railroad company was given every other section in the area, BLM now manages a checkerboard configuration of public lands. Private timber industry holdings are usually the interspersed section. These lands have been harvested much more heavily than Forest Service managed lands, and are riddled with clear cuts.