Glossary of Forestry Terms - P - Q

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Partial cutting a general term referring to silvicultural systems other than clearcutting, in which only selected trees are harvested. Partial cutting systems include seed tree, shelterwood, selection, and clearcutting with reserves.
Pass in timber harvesting, one of a planned sequence of harvesting operations designed to harvest a management unit over an extended period of time in discrete phases, so that the size of individual cutblocks and the total area harvested in any one pass does not exceed prescribed limits.
Patch n landscape ecology, a particular unit with identifiable boundaries which differs from its surroundings in one or more ways. These can be a function of vegetative composition, structure, age or some combination of the three.
Patch cutting a silvicultural system that creates openings less than 1 hectare in size and is designed to manage each opening as a distinct even-aged opening.
Patch logging a modification of the clearcutting system whereby patches of from about 5 to 200 hectares are logged as single settings and separated for as long as practicable (preferably until the regeneration is adequately shading the forest floor) by living forest. This secures the optimum dispersal of seed and avoids the high fire hazard represented by large continuous areas of slash.
Pathological rotation age the maximum rotation age through which a stand of trees may be grown without significant volume loss from disease. The stand age at which annual volume loss from disease equals annual volume increment.
Performance-based logging means approval of future logging activities contingent upon a company's current practices. Until a company is in compliance with the Forest Practices Code the Government may refuse to enter into a new or replacement agreements, approve new logging plans, and issue new cutting permits.
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Periodic harvest (periodic cut) the removal of several years' accumulated AAC in one year or other period.
Permanent access structure a structure, including a road, bridge, landing, gravel pit or other similar structure, that provides access for timber harvesting, and is shown expressly or by necessary implication on a forest development plan, access management plan, logging plan, road permit or silviculture prescription as remaining operational after timber harvesting activities on the area are complete.
Permanent bridge a bridge having all its major components constructed of steel, concrete, or pressure-treated timber.
Pest any forest health agent designated as detrimental to effective resource management.
Pest incidence a measurement of the presence and magnitude of pests within a given area.
Pesticide any substance or mixture of substances (other than a device) intended for killing, controlling, or managing insects, rodents, fungi, weeds, and other forms of plant or animal life that are considered to be pests.
Pesticide buffer zone a strip of land between the pesticide-free zone and the pesticide treatment area for preventing entry of pesticides or pesticide residues by drift, runoff, or leachate into the pesticide-free zone.
Phenotype an organism as observed by its visible characteristics, resulting from the interaction of its genotype with the environment.
Phloem a layer of tree tissue just inside the bark that conducts food from the leaves to the stem and roots. See Cambium.
Pioneer plants a succession term for plants capable of invading bare sites, such as a newly exposed soil surface, and persisting there, i.e., 'colonizing' until supplanted by invader or other succession species.
Pitch tubes a tubular mass of resin that forms on the surface of bark at bark-beetle entrance holes.
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Planned grazing system a system approved by the regional manager or district manager respecting the use of land for grazing and the dispersal of livestock over land.
Planning the determination of the goals and objectives of an enterprise and the selection, through a systematic consideration of alternatives, of the policies, programs and procedures for achieving them.An activity devoted to clearly identifying, defining, and determining courses of action, before their initiation, necessary to achieve predetermined goals and objectives.
Planning horizon he time period which will be considered in the planning process.
Planning term the term of the actual plan before it must be updated.
Plant community an assemblage of plants occurring together at any point in time, thus designating no particular ecological status.
Plant harvesting the collection of plant life including, but not limited to, bark, berries, boughs, branches, burls, cones, conks, ferns, flowers, grasses, herbs, fungi, lichens, mosses, mushrooms, roots, sedges, shrubs, sprays and twigs.
Planting establishing a forest by setting out seedlings, transplants or cuttings in an area.
Plot a carefully measured area laid out for experimentation or measurement.
Plug a seedling grown in a small container under carefully controlled (nursery) conditions. When seedlings are removed from containers for planting, the nursery soil remains bound up in their roots. See Bareroot seedling.
Plus tree a phenotype judged (but not proven by test) to be unusually superior in some quality or qualities such as an exceptional growth rate relative to the site, desirable growth habit, high wood quality, exceptional apparent resistance to disease and insect attack or to other adverse locality factors.
Point sampling a method of selecting trees for measurements and of estimating stand basal area at a sample location or point sample. Also called plotless cruising, angle count method, Bitterlich method. A 360 degree sweep is made with an angle gauge about a fixed point and the stems with breast height diameters appearing larger than the fixed angle subtended by the angle gauge are included in the sample.
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Policies statements on how the authority is to achieve its goals and objectives with regard to a specific subject area or class of subject areas, e.g., a policy for development on floodplains.
Polygon a closed geometric entity used to graphically represent area features with associated attributes.
Potentially unstable soil area any area where there is a moderate to very high likelihood of slope failure following conventional road construction or timber harvesting.
Precommercial thinning See Juvenile spacing.
Pre-harvest silviculture assessment (or survey) the survey carried out on a stand prior to logging to collect specific information on the silvicultural conditions such as planting survival, free-growing status, stocking, etc. See Silviculture survey.
Pre-Harvest Silviculture Prescription (PHSP) a document that applies site-specific field data and develops forest management prescriptions for areas in advance of logging.
Prescribed burning the knowledgeable application of fire to a specific unit of land to meet predetermined resource management objectives.
Prescription a course of management action prescribed for a particular area after specific assessments and evaluations have been made.
Preservation the action of reserving, protecting or safeguarding a portion of the natural environment from unnatural disturbance. It does not imply preserving an area in its present state, for natural events and natural ecological processes are expected to continue. Preservation is part of, and not opposed to, conservation.
Prime mover heavy equipment used to tow other machines such as disc trenchers for site preparation.
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Prism an optical instrument used as an angle gauge, consisting of a thin wedge of glass which establishes a fixed (critical) angle of projection in a point sample.
Problem forest type non-merchantable forest types, including: stands of unfavourable stocking (i.e., dense small trees), low productivity sites and decadent stands with high waste and breakage.
Procedure a particular way of accomplishing an objective; generally refers to the method rather than the result. Procedures are usually developed to describe the methods for implementing policy.
Proclamation date the date on which a statute has legal effect.
Production forest the forest used for production of various commodities; timber, for example.
Productive forest land forest land that is capable of producing a merchantable stand within a defined period of time.
Professional engineer, professional geoscientist a member in good standing of the Association of Professional Engineers and Geoscientists.
Professional forester See Registered professional forester.
Protected areas areas such as provincial parks, federal parks, wilderness areas, ecological reserves, and recreation areas that have protected designations according to federal and provincial statutes. Protected areas are land and freshwater or marine areas set aside to protect the province's diverse natural and cultural heritage.
Protection forest forest maintained on steep, unstable slopes to prevent accelerated erosion.
Protocol agreements an agreement between two or more ministries or two or more areas of the same ministry stating the role of each party in relation to the other or others with respect to an issue, or issues over which the parties have concurrent jurisdiction.
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Provenance the geographical area and environment to which the parent trees and other vegetation are native, and within which their genetic constitution has been developed through natural selection.
Provincial forest The Lieutenant Governor in Council may designate any forest land as a provincial forest. The uses of provincial forests include timber production, forage production, forest recreation, and water, fisheries and wildlife resource purposes.
Provincial forest inventory a description of the quantity and quality of forest trees, non-wood values, and many of the characteristics of the land base compiled from statistical data for the forest lands of the province.
Pruning the manual removal, close to or flush with the stem, of side branches, live or dead, and of multiple leaders from standing, generally plantation-grown trees. Pruning is carried out to improve the market value of the final wood product by producing knot-free wood for the improvement of the tree or its timber.
Public the entire population of a province, including all organizations, companies, and groups.
Public hearing a hearing formally advertised and convened to afford any person who deems their interest in property to be affected by a proposal an opportunity to be heard.
Public highway a highway for which public money has been spent and which is dedicated to public use by a plan deposited in the Land Titles Office for the district in which the road is situated.
Public involvement the procedures for obtaining and considering the views of the general public in planning and decision-making processes.
Public Sustained Yield Unit (PSYU) a portion of a TSA. An area of Crown land, usually a natural topographic unit determined by drainage areas, managed for sustained yield by the Crown. It includes all Crown lands within the currently established boundaries of the unit and excludes federal lands, provincial parks, experimental forest reserves, gazetted watersheds and tree farm licences.
Pulpwood agreement a pulpwood agreement allows the holder of a woodfibre processing facility to harvest Crown pulp timber, if sufficient quantities of raw material are not available to the holder from other sources. An agreement covers a set term which may be replaceable, and applies to a large area in one or more timber supply areas. Harvesting authority is provided through a timber sale licence where the licensee is responsible for all operational planning, development, basic silviculture and forest protection.
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Quasi-judicial a decision made by a government official or tribunal which involves the application of policy to a particular set of facts requiring the exercise of discretion and the application of the principles of natural justice.
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