Master Craftsman Forestry flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Shade tolerance

A species' capacity to survive and grow beneath a closed canopy. It determines which regeneration method works: tolerant species regenerate under shelterwood or selection, intolerant species need clearcut or seed-tree.

Shelterwood seed cut

An intermediate harvest retaining enough overstory to seed and shelter the new cohort, commonly leaving 30-60% of full stocking basal area for tolerant regeneration before the final removal cut.

Stand initiation stage

The first stand development stage after disturbance, when regeneration establishes and occupies the site. Competition among new seedlings is intense; early release and stocking checks happen here.

Site index

Height of dominant and codominant trees at a reference age, usually 50 or 100 years. It ranks site productivity within one species and region, not across species.

Basal area per tree

Cross-sectional area of a stem at breast height, computed in imperial units as 0.005454 times DBH squared. Summed per acre, it gives stand basal area.

Prism plot trees per acre

For each tallied tree on a variable-radius plot, trees per acre equals the basal area factor divided by 0.005454 times DBH squared. Larger trees represent fewer trees per acre.

Reineke stand density index

SDI equals trees per acre times quadratic mean diameter divided by 10, raised to about 1.605. Relative density is SDI divided by the species maximum SDI.

Girard form class

The ratio of inside-bark diameter at 17 feet to DBH, expressed as a percentage. It is used to select the correct tree volume table for a species and region.

Cable yarding limits

Skyline and cable systems handle slopes too steep for ground skidders, but payload is capped by the skyline safe working load, deflection, and required clearance over terrain.

Machine rate calculation

Cost per productive machine hour combines ownership costs (depreciation, interest, insurance) and operating costs (fuel, repairs, labor), then is divided by utilization to get cost per scheduled hour.

Skid trail coverage

On sensitive soils, restricting equipment to designated trails covering roughly 10-15% of the harvest area limits compaction and rutting while keeping skid distances economic.

Bark beetle aggregation pheromone

A chemical signal that coordinates mass attack, overcoming tree defenses. Managers counter it with anti-aggregants such as verbenone and with rapid salvage of infested trees.

Annosus root rot control

Heterobasidion spores colonize fresh stumps. Treating stumps with borax after thinning, and avoiding cutting during high-spore periods, reduces new infection centers.

Fire behavior triangle

Fuel, weather, and topography govern fire behavior. Wind, slope, and continuous fine fuels raise rate of spread; moisture and fuel arrangement affect intensity and crowning.

Prescribed fire burn plan

A written document specifying objectives, weather prescription, ignition pattern, holding resources, smoke management, and contingency actions. A test fire precedes ignition.

Faustmann rotation

The financially optimal harvest age where marginal value growth equals the alternative rate of return. It maximizes soil expectation value across infinite rotations, not just the current stand.

Mean annual increment

Total volume divided by stand age. Culmination of MAI, where periodic annual increment falls below it, marks the biological rotation age for maximum average yield.

Stumpage residual value

Stumpage price equals delivered product price minus harvest, haul, and processing costs minus a profit and risk allowance. Appraisals compute it separately by product class.

Soil expectation value

The present value of an infinite series of rotations, computed as net present value divided by one minus (1 plus interest rate) raised to the negative rotation length.

Stopping sight distance

The distance a driver needs to perceive a hazard and stop, equal to perception-reaction distance plus braking distance. Forest road design speeds are typically 15-25 mph.

Cross-drain spacing

The interval between drainage structures on a road, set by road grade and soil erodibility. Steeper grades and fine-textured soils require closer spacing to prevent erosion.

Culvert design storm

Forest road culverts are commonly sized for the 25-year peak flow plus debris, using inlet and outlet control hydraulics, with the invert at or below streambed elevation.

Road decommissioning steps

Remove culverts and stream crossings, recontour and outslope the prism, decompact and revegetate the surface, and prioritize unstable fills and crossings for treatment first.

Snag retention target

Retaining roughly 3-6 snags per acre across a range of diameters and decay classes supports cavity-nesting birds, bats, and invertebrates that depend on dead wood.

Riparian buffer function

Streamside vegetation shades and cools water, filters sediment, stabilizes banks, and supplies large woody debris. Buffers of 50-100 feet are common on fish-bearing streams.

Large woody debris

Key pieces at least 12 inches in diameter and 20 feet long create pools, sort gravel, and provide cover for salmonids. Recruitment from the riparian buffer sustains it.

Streamside management zone

A buffer along streams where heavy equipment is excluded and partial canopy is retained. It filters sediment, shades water, and protects bank stability during harvest.

Rational method peak flow

Q equals the runoff coefficient times rainfall intensity times drainage area. It estimates peak flow for small drainages; larger basins need regional regression or gage data.

Paired-watershed study

Two similar basins are monitored before and after treatment on one, isolating harvest effects from climate. It is the strongest design for detecting land-use impacts on streamflow.

Timber trespass damages

Unauthorized cutting of another's timber. Many states allow treble damages for willful trespass, so verify property lines and ownership before any felling or sale.

Endangered Species Act sections

Section 7 requires federal agencies to consult on actions affecting listed species; Section 9 prohibits take. Critical habitat is designated after listing and affects federal projects.

Chainsaw kickback control

Use a functioning chain brake, low-kickback chain, correct bar length, and a two-handed grip. Never cut above shoulder height, and keep the tip clear of contact.