P | Lexicon of Forestry

Paint gun: A low-pressure hand tool for squirting a distinctive mark of paint on trees and timber.

Palatability: The relative desirability of certain plants as forage for domestic and wild animals. Varies with composition of the plant cover or the season of grazing.

Paleo-ecology: Ecology of prehistoric times; the study of the interaction of prehistoric life forms and their environments

Paleomagnetism: The natural magnetic traces that reveal the intensity and direction of Earth’s magnetic field in the geologic past. Also, the study of these magnetic traces.

Paleoseismology: The study of ancient (prehistoric) earthquakes.

Panchayat forest: (See: Communal forest)

Parameter: A characteristic which describes the whole or part of a population in some way. The average height of trees in a forest is a parameter that partially describes the population. He area occupied by the forest is also a parameter of that forest.

Parapet: [Late 16th century. Via French < Italian parapetto < parare “protect” + petto “chest” (< Latin pectus)] A low protective wall built where there is a sudden dangerous drop, e.g. along the edge of a balcony, roof, or bridge. Some parapets are battlemented, especially on castles, and many are built as ornamental features. OR; a bank of soil, rubble, or sandbags piled up along the edge of a military trench for protection from enemy fire

Parasite: An organism which lives on or in another living organism and obtains part or all of its nutrients from that other living organism.

Parasitoid wasp: Many species of wasp prey on other insects. They deposit their eggs into the larvae or pupae of the host insect, and the wasp larvae then consume the host. These wasps are correctly termed parasitoid rather than parasitic since they kill their hosts. Parasites or parasitic animals live off a host without killing it, in a relationship that could be viewed as a type of symbiosis. Read more about specific parasitoid insect species.

Parent rock: It refers to the original rock from which something else was formed. It is mainly used in the context of soil formation where the parent rock will have a large influence on the nature of the resulting soil. The term is also used in the context of metamorphic rocks where again the parent rock refers to the original rock before metamorphism takes place. Parent Rocks can be sedimentary, igneous or metamorphic. (ex. – shale becomes slate, granite becomes gneiss etc.) In these cases, parent rock may be referred to as the protolith. Parent rock is the main source of soil. This type of soil is also called residual soil. Different parent rocks have different chemical compositions. The Parent Rock is also known as bedrock and is made mostly of solid rocks, there is no weathering occurred there because the roots of the plant cannot go that deep. It is the third layer and is underneath Topsoil and Subsoil. The parent rock has little organic matter.

Parthenogenesis: [Mid-19th century. < Greek parthenos “virgin”] reproduction without fertilization: a form of reproduction, especially in plants, insects, and arthropods, in which a female gamete develops into a new individual without fertilization by a male gamete

Partial cut: A Silvicultural cutting scheme that removes at any one time less than the total tree stand (selective cut, seed tree cut, shelterwood. cut).

Particle-board: A type of board made by compressing chips or particles of wood under heat and pressure, in the presence of glue or resin. Flakeboard is a new product made by a similar process.

Partial harvest: Any cutting in which only part of the stand is harvested

Partial seeding: Seeding confined to limited areas, e.g., drills, strips, patches, or nests, generally according to a regular spatial pattern.

Passel: A channel in Irrigated Layout. Its dimensions are: depth 15 ft and width 1 ft. Passel and khals (See Khals) are always parallel to each other. Passels and Trenches (See Trench) are always perpendicular to each other.

Patch burning: Burning felling debris, grass, etc. in patches for the purpose of preparing sites for group planting or sowing.

Patch cut: A clearcut on a small area.

Patch logging: A modification of the clearcutting system developed in the Pacific Coast region of North America, whereby patches of about 5 to 200 ha are logged as single units, 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 hazard of large continuous areas of slash, particularly with respect to fire. 

Patch planting: See spot planting

Patch scarifier: A mechanized implement used to expose patches of mineral soil in a systematic pattern.

Patch seeding: See seeding: spot

Path burning: 1. Controlled burning for the purpose of forming a barrier to subsequent fires. 2. Burning felling debris, grass, etc., in patches for the purpose of preparing sites for group-planting or sowing.

Pathogen: Any agent of the environment capable of inciting disease.

Pathology, forest: The science that pertains to diseases of forest trees or stands and to the deterioration of forest products by organisms.

Peat soil: An organic soil containing more than 50% organic matter. In such soil, the slightly decomposed or unrecompensed deposits of original plant parts can be recognized. (See Muck soil)

Peavey: A long-handled tool with a spike point and hinged arm; used to roll logs.

Peeler core: A piece of round wood that is a byproduct of the veneer-peeling process; usually 8 feet long and about 4 inches in diameter.

Pelleting: Incorporating seed in a matrix of fungicide, insecticide, repellent, coloring material or inert carrier, or any combination of these, so as to form a small ball termed a seed pellet.

Percent grade: 1. The vertical rise of land in 100 horizontal ft. A 16% grade means that in 100 ft horizontal, the elevation has changed 16 ft. Measured with an abney level or clinometer. 2. Amount of forest volume found to be in a given log grade.

Perithecium: A sexual fruiting structure of the Ascomycetes with an opening called the ostiole at or near its top.

Percolation: The downward movement of water through the soil, primarily because of gravity.

Perennial: Plants that live or grow for more than one year. Some re-sprout from a root system or reseed themselves every year.

Perennial Wildlife Mixture: A mixture of all or some of the following: shrub lespedeza, partridge pea, cowpea, annual lespedeza, reseeding soybeans, and other perennial plants that are beneficial to wildlife.

Period: The time between two successive wave crests.

Periodic block: The part(s) of a forest allocated for regeneration or other treatment during a specified period. It is a sub-division of a Felling series. Depending upon the degree of flexibility PBs are of the following types. a)         Permanent PBs: “The PBs which is permanently demarcated on the ground and is not subjected to alterations is called permanent PBs.” These PBs are compact and equiproductive eg a felling series in Chir forest with rotation of 100 yrs and regeneration period of 25 yrs, have the following PBs:

No of PBs                               Age Class (Yrs)

PB I                                             76 – 100

PB II                                             51 – 75

PB III                                           26 – 50

PB IV                                            1 – 25

If a forest is changed into this form, its mgt is greatly simplified because different types of Silvicultural operations would be confined to separate PBs. But natural regeneration comes up where and when it is wanted and even in plantation, though the establishment of the young crop can be assured; but there is no guarantee that it will reach maturity. b)            Revocable PBs: To increase the flexibility of the PB system, revocable PBs have been introduced which are neither permanent nor compact but are equiproductive. All each revision of the working plan, compartments and sub-compartments are allotted to the various PBs according to the size of their growing stock. This also enables the use of a no of rotation age for different spp or for the same spp growing on several different site qualities because the crops on better sites attain exploitable size sooner than the planned rotation and those of inferior sites later. Revocable PBs also take up areas which need regeneration due to special factors eg insect attack, first, etc. c)       Sing PB or Floating PB: This is further stage in the effort to make PBs more flexible. Since there are only two based categories of Silvicultural operation ie regeneration operations in PB I and tending operations in the rest of the area (II, III, IV) so the compartment and sub-compartment needing regeneration during the plan period are allotted to PB I and the rest of the compartment are un allotted. This PB I is called single periodic block. Sometimes a PB II is also distinguished to accommodate compartment which will be regenerated in the next working plan period. Since a fresh allotment of area is made to PB I at each revision of the working plan so the reg block ‘means’ or ‘floats’ around the felling series and it is thus also called “Floating Period Blocks.”

Periodic yield: (See annual yield)

Pest: Any organism that is out of place or causes stress to a desired organism. 

Pesticides: A general term for chemicals used to kill any of the pests of a desired crop.

pH: (from French pouvoir hydrogène, “hydrogen power”) pH =  –  log10[H+]; the negative logarithm of the concentration of H+ ions. A measure of acidity or alkalinity in which the pH of pure water is 7, with lower numbers indicating acidity and higher numbers indicating alkalinity

Pharmaceutical: [Mid-17th century. < late Latin pharmaceuticus < Greek pharmakeutēs “somebody who prepares drugs” < pharmakon “drug”] relating to drugs: involved in or related to the manufacture, preparation, dispensing, or sale of drugs used in medicine

Phase: The onset of a displacement or oscillation on a seismogram indicating the arrival of a different type of seismic wave.

Pheasant: Pheasants belong to the cock family. These are beautifully colored and magnificently designed. The female pheasants are colorless usu of soil color. Pheasants have 52 types throughout the world out of which 51 are found in Asia. In Pakistan 6 species of pheasant are found namely blue pheasant, kaleej pheasant, koklass pheasant, cheer pheasant, western tragopan pheasant, and monal pheasant.

Phenology: The study of timing of periodic phenomena, such as flowering, growth initiation, growth cessation, etc., especially as related to seasonal changes in temperature, photoperiod, etc.

Phenotype: An organism as observed, i.e., as judged by its visually perceptible characters resulting from the interaction of its genotype with the environment. Identical phenotypes do not necessarily breed alike.

Phloem: An outer layer of tree tissue that conducts food from the leaves to the stem and roots.

Phosphate: A chemical compound that aids root growth and is essential in energy transfer. It is commonly incorporated into beds as triple super phosphate (TSP) at time of planting. 

Photosynthesis: Carbohydrate production using light and chlorophyll: a process by which green plants and other organisms turn carbon dioxide and water into carbohydrates and oxygen, using light energy trapped by chlorophyll

Phylum: In biology, a phylum (plural: phyla) is a taxonomic rank below Kingdom and above Class. “Phylum” is equivalent to the botanical term division. Informally, phyla can be thought of as grouping animals based on general body plan, as well as developmental or internal organizations. The best known animal phyla are the Mollusca, Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Arthropoda, Echinodermata, and Chordata, the phylum to which humans belong. Although there are approximately 35 phyla, these nine include over 96% of animal species.

Physical rotation: The rotation that coincides with the natural lease of life of a spp on a given site.

Pier: Vertical structural support: a pillar, especially a rectangular one supporting the end of an arch, lintel, or vault

Pile and burn: A controlled burn where the material to be disposed of is concentrated, usually with machinery, before burning.

Piling: Round timbers driven into the ground to support other structures.

Piling and burning: Piling slash after lopping, and subsequently burning the individual piles.

Pillar: An isolated vertical load bearing member of considerable height used for support ornament or as a memorial. It is usu square or rectangular in plan and may be constructed of any material.

Pioneer species: A species adapted to early stages of natural forest succession or growth on newly available sites.

Pistol butt: Applied to trees with bases curving away from the slope and then upwards. This may indicate unstable or moving soil.

Pit:

Pitch: A term applied to the resin occurring in the wood of certain conifers.

Pitch pocket: A well defined, lens-shaped opening between or within annual growth rings of coniferous wood, containing pitch and possibly bark.

Pit planting: Setting out young trees in small depressions, natural or excavated, with a view to collecting and conserving moisture.

Planer: A machine used to put a smooth surface or shape on lumber.

Plant: 1. To place young trees or cuttings in the soil on forest land; to establish a forest crop. Sometimes used loosely to include direct seeding. Trees may be placed as bare-root stock, or with roots within a ball of earth, or in earth within a container. 2. A processing facility for wood products.

Plant Cell: Plant cells contain a variety of membrane-bound structures called organelles. These include a nucleus that carries genetic material; mitochondria that generate energy; ribosomes that manufacture proteins; smooth endoplasmic reticulum that manufactures lipids used for making membranes and storing energy; and a thin lipid membrane that surrounds the cell. Plant cells also contain chloroplasts that capture energy from sunlight and a single fluid-filled vacuole that stores compounds and helps in plant growth. Plant cells are surrounded by a rigid cell wall that protects the cell and maintains its shape.

Plant Or Habitat Diversity: A variety of food or cover for wildlife. Variation may occur at one point in time or over a period of time such as during the course of a season. Seasonal diversity of food and cover is often critical to the survival of a species.

Plantation: An artificially reforested area established by planting or by direct seeding, typically in an ordered configuration such as equally spaced rows.

Plantation forest: See planting

Plantation forestry: Application of forestry principles to an artificial crop or stand.

Planting: Establishing a forest by setting out seedlings, transplants or cuttings in an area.

Planting auger: A motorized auger used to create planting holes.

Planting bar: A long-handled, tapered spade used to make narrow, deep holes for young plants of tap-rooted tree species.

Planting gun: Special devices of varying complexity which make holes by compression and either set or shoot a containerized seedling into the soil.

Planting machine: Specially designed machine that cuts a narrow trench through the soil in which seedling roots are inserted and then held in place by closing of the trench. 

Planting out: See planting

Planting spot: The exact spot where a young tree has been set out.

Planting stock: Seedlings, transplants, cuttings, and occasionally wildlings, for use in planting.

Plant lifter: See plant lifting machine

Plant lifting machine: A specially designed machine that loosens and removes plants from the ground.

Plant percentage: The percentage by number of seeds in a given sample that develop into seedlings at the end of a given period, generally the end of the first growing season.

Plant tray: A flat, box-type container in which plants are raised.

Plate: One of the huge sections which make up the Earth’s crust. The plates are continuously moving.

Plate boundary: The place where two or more plates in the Earth’s crust meet.

Plate tectonics: The theory that the Earth’s crust and upper mantle (the lithosphere) is broken into a number of more or less rigid, but constantly moving, segments or plates.

Plinth: [Late 16th century. Directly or via French < Latin plinthus < Greek plinthos “tile, squared building stone”] the portion of the structure b/w the surface of the surrounding ground and the surface of the floor immediately above the ground.

Ploughing: Operation designed to loosen compacted soils and/or to pull the roots of unwanted plants out of the ground by means of single- or double-moldboard ploughs or special shaping devices pulled by a tractor, bulldozer, or similar equipment.

Plot: A carefully measured area laid out for experimentation or of mensuration; may be permanent or temporary. (Syn. study plot.)

Plugs: Young seedlings grown in roughly one-inch-across and four-inch-deep tubular holes, generally grown in a “plug pack” with six such holes or a “plug tray” with three or four dozen. Growers can sell the entire plug pack or plug tray, or they can transfer the seedlings to larger individual pots.

Plug transplant: A small container seedling which is to be planted and raised as a bare-root seedling.

Plus stand: A stand containing a preponderance of good phenotypes, but not necessarily plus trees.

Plus tree: A phenotype judged (but not proved by testing) to be unusually superior in some quality or qualities, e.g., exceptional growth rate relative to site, desirable growth habit, high wood quality, exceptional apparent resistance to disease and insect attack or to other adverse local factors.

Plug seedling: A seedling grown in a small container, under carefully controlled environmental conditions. Seedlings are removed from containers for planting.

Plywood: A wood product constructed of three or more layers of veneer joined with glue and (usually) laid with the grain of adjoining plies at right angles to one another.

Pneumatophore: A root in swamp plants such as the mangrove or bald cypress that grows upward from the roots and carries out respiration

Pointing: Final treatment with cement or lime mortar made to the joints of a masonry neat appearance.

Poison girdling: See girdling

Pole: 1. A young tree between 5 and 12 in d.b.h.; It is the third stage in tree development when natural pruning starts in the tree (See sapling.) 2. A log cut for the manufacture of power or telephone poles (involves trees larger than 12 in d.b.h.).

Pole stage: See stand development

Pole timber: Trees 4 to 10 inches dbh.

Policy: [14th century. Via Old French policie “government, civil organization”] course of action: a program of actions adopted by a person, group, or government, or the set of principles on which they are based

Pollarding: Cutting back, in more or less systematic fashion, the crown of a tree to produce a close head of shoots (a pollard) beyond the reach of browsing animals, either for commercial purposes (e.g., fuel, withes for willow and poplar basketwork) or for amenity.

Pollard system: The systematic harvest cutting of pollard shoots, with due provision for replacing exhausted or defective pollards.

Pollution: Pollution is contamination of Earth’s environment with materials that interfere with human health, the quality of life, or the natural functioning of ecosystems (living organisms and their physical surroundings).

Polyculture: The simultaneous cultivation of a number of crops as opposed to stands composed of a single species.

Polygamy: System of animal mating in which an individual mates with more than one animal during any single breeding season, is known as polygamy.

Polyphagia: 1. Diet of many foods. 2. The habit on the part of some animals of feeding on many different types of food

Population: An aggregate of items, each with a common characteristic or set of characteristics that are of interest. In a statistical sense, a population is an assembly of all possible individuals (units, measurements, observations, etc.) that meet a specified and well-defined objective. All the trees in a farm woodlot could be one population. Alternatively, if there were two species in the woodlot, the population could be defined as all the trees of one species only – the other species could be treated as a different population. The clear definition of the population is important to avoid inappropriate extrapolation of results from measurements. 

Porcupine: [14th century. < Old French porc espin “spiny pig”] rodent with protective quills: a large rodent whose body is covered with long protective quills that it can erect in defense against predators. Families: Hystricidae, Erethi zontidae

Poria: It is a genus of fungi in the family Polyporaceae

Portable mill: A small sawmill that can be readily moved from one place to another. The usual daily capacity ranges from 3,000 to 10,000 board ft.

Positive Economics: The branch of economics that describes the behavior of the economy and the reasons for it, but does not prescribe any economic policy to modify this behavior. (See also normative economics)

Post-abkalani: This operation is done after the flood in riverine forests. Such operations involve restocking, protection of new crop etc. (See Abkalani and Pre-abkalani)

Posterior: Hind or hindmost; opposite of anterior.

Potential evapotranspiration (PET): The rate of evaporation of water if water is not limiting. Or; It represents the maximum rate of evaporation possible from the land area, when the available supply of moisture is equal to or greater than the demand.

Pot planting: Setting out young trees in pot-shaped receptacles having a closed or only perforated end and made of various materials, in which they have been raised from seed or to which they have been transferred from the seed bed; a type of container planting.

Poultry: Domestic fowl in general, e.g. chickens, turkeys, ducks, or geese, raised for meat or eggs (takes a singular or plural verb)

Pre-abkalani: Areas which are prepared for growing in riverine forests. All such operations are included. Such operations include like cleaning, leveling, land preparations, etc. (See Abkalani, Post-abkalani)

Prebunch: In logging, to collect logs or other material at intermediate staging areas, in preparation for the main yarding operation.

Prechilling: See stratification

Precipitation: Deposits of atmospheric moisture in liquid or solid form, including rain, sleet, snow, hail, dew, or mist (also refers to quantity of water deposited).

Precision: The fineness of a single measurement. This relates to the resolving power of the measurement device. For example, a scanning electron microscope can be used to take more precise or fine measurements than a hand magnifying glass.

Definitions 2, 3 and 4 indicate that precision is freedom from variation.

Precommercial operations: Cutting in forest stands to remove wood too small to be marketed. Precommercial operations improve species composition and increase the quality, growth, and vigor of remaining trees.

Precommercial thinning: Removal of some of the trees in a young stand to reduce competition for water and nutrients, and to accelerate commercial growth on remaining trees. Trees thinned from these stands have no commercial value.

Precommercial treatments: Forestry operations that require landowner investment, such as cleaning or weeding stands to remove trees that have little or no cash value. See commercial treatments.

Predator: [Early 20th century. < Latin praedator < praedari “seize as plunder”] carnivorous animal or destructive organism: a carnivorous animal that hunts, kills, and eats other animals in order to survive, or any other organism that behaves in a similar manner.

Predator Guard: A physical barrier used to keep one animal from eating another. Usually refers to protection devices on nest boxes.

Predisposition: The weakening of an organism by some factor(s) of either the physical or biotic environment so as to render the organism more susceptible to a pathogen.

Predominant: A tree whose crown has grown above the general level of the upper canopy.

Pregermination: The germination of seed, generally to the stage when the radicle is just emerging, before sowing in the field or nursery.

Preparatory cutting: Removing trees near the end of a rotation so as to permanently open the canopy and enlarge the crowns of seed bearers, with a view to improving conditions for seed production and natural regeneration, as typically in shelterwood systems.

Prescribed burning:   The application of fire to land under conditions of weather, soil moisture, and time of day that will accomplish specific Silvicultural, wildlife, grazing, or fire-hazard-reduction purposes (SAF)

Present Use Valuation: Property tax relief classification based on the land’s productivity for agriculture, horticulture, or forestry production, rather than for market value. Can result in substantial tax savings in areas where land values are high. Some restrictions and penalties apply, including a 3-year roll back provision with interest. Consult your county tax supervisor for details.

Preservation: 1. To maintain in a natural state; human impact on the biological system is minimized. Commonly refers to wilderness area management. 2. Wood preservation involves the protection of timber and wood products against the action of destructive living organisms, especially fungi, insects, and marine borers.

Preservative: A substance that, when properly applied to wood, makes it resistant to attack by fungi, insects, or marine borers.

Pricking out: Transplanting seedlings that are too small to be handled by conventional lining-out methods, individually into boxes, flats, containers, etc., or into nursery beds.

Primitive area: An area of forest land that is left unaffected by human activities. These areas are in essence wilderness, but they are created by administrative regulation rather than by act of Congress.

Principal crop: See main crop

Principal species: The species to which the silviculture of a mixed forest is primarily directed, either for its (or their) economic or protective value.

Prism: A wedge-shaped Piece of clear or amber-colored glass that is used to select trees for timber sampling.

Production nursery: See nursery

Proctodeum: [Late 19th century. < modern Latin < Greek prōktos “anus” + hodaios “on the way” < hodos “way”] part of embryo: the exterior section of an embryo that develops into part of the anal canal

Productive capacity: See site capability

Productivity: The rate of production of wood of given specifications, by volume or weight, for a given area. 

Progeny: The offspring of a particular tree or a combination of one female and one male tree.

Progeny test: A test in which the genetic constitution of an individual is evaluated from the performance of its progeny produced by some specific mating system.

Progeny trial: See progeny test

Progressive clear-strip system: A shelterwood system with clearcutting in strips that are generally not wider than the height of the adjoining trees and are generally laid out against the prevailing wind; regeneration is mainly natural, though sometimes supplemented artificially; the crop is young, even-aged. 

Proleg: Any process or appendage that serves the purpose of a leg; specifically, the fleshy, unjointed, ventral abdominal projections of caterpillars and certain sawfly larvae.

Prospectus: A document that describes the location of a property, indicates trees marked for cutting, and states that the timber will be sold in accordance with a suitable contact. A prospectus includes the number of trees marked, their diameter classes, and a volume estimate for each species.

Protected area: 1. An area of land or sea especially dedicated to the protection and maintenance of biological diversity, and of natural and associated cultural resources, and managed through legal or other effective measures. – IUCN 2. A geographically defined area which is designated or regulated or managed to achieve specific conservative objectives. – CBD 

Protein: [Mid-19th century. < French < Greek prōteios “primary” < prōtos “first”; from its importance to the proper functioning of the body] complex natural compound: a complex natural substance that has a globular or fibrous structure composed of linked amino acids.

Proteins are essential to the structure and function of all living cells and viruses.

Protozoa: [Mid-19th century. < modern Latin Protozoa “first animals” < Greek zōia, plural of zōion “animal”]. A single-celled organism that can move and feeds on organic compounds of nitrogen and carbon, e.g. an amoeba. Kingdom: Protoctista

Provenance: 1. The geographical area and environment to which the parent trees, etc., are native and within which their genetic constitution has been developed through natural selection. 2. The geographical source, i.e., place of origin, of a given lot of seed, propagules, or pollen.

Provenance test: An experiment, usually replicated, comparing trees grown from seed or cuttings collected from many parts of a species, natural range. 

Pruning: 1. The removal of live or dead branches from standing trees, whether done artificially or naturally. Natural pruning results from such causes as deficiency of light, decay, snow, ice, etc. (Syn. self-pruning). 2. Removal of live or dead branches from ground level to as high as a person’s reach (2.0-2.5 m) in a young stand, known as brashing; above a person’s reach (e.g., with a ladder), high pruning. If only crop trees are high pruned, the operation is selective high pruning. Pruning or lopping that increases the clearance under a tree is sometimes termed lifting the canopy.

Pruning saw: A saw specially designed to prune standing trees. 

Pulp, wood: Mechanically ground or chemically digested wood fibers used in the manufacture of paper and allied products. Bleached and purified wood pulp is also widely used in the manufacture of rayon and other chemicals.

Pulpwood: Woodcut or prepared primarily for manufacture into wood pulp, for later manufacture into paper, fiberboard, or other products (the products depend largely on the species and the pulping process).

Pulaski: Firefighters use this tool, which combines a single-bitted axe blade for chopping with a narrow blade for trenching, to clear vegetation when constructing a fireline.

Pulpwood: Wood suitable for use in paper manufacturing.

PUM yarding: Acronym for “pile unmerchantable material,” referring to a U.S. Forest Service contract regulation that requires loggers to concentrate all tops, chunks, and other unmerchantable material generated by harvesting. (See YUM).

Punky: A soft, weak, often spongy condition in wood; caused by decay.

Pupa: The resting, inactive, nonfeeding instar in all holometabolous insects; the stage intermediate between the larva and the adult.

Pure live seed: See germinative capacity

Pure stand: A timber stand in which at least 75-80 percent of the trees in the main crown canopy are of a single species.

P wave: Primary, longitudinal, irrotational, push, pressure, dilatational, compressional, or push-pull wave. P waves are the fastest body waves and arrive at stations before the S waves, or secondary waves. The waves carry energy through the Earth as longitudinal waves, moving particles in the same line as the direction of the wave. P waves can travel through all layers of the Earth. P waves are generally felt by humans as a bang or thump.

Pycnial stage (pycnium): A flaskshaped spore stage of the rust fungi; oozes out spores in a sticky matrix.

Pycnidium: An open-pored, flaskshaped fruiting structure in which asexual spores called conidia are produced.

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Regards
Naeem Javid Muhammad Hassani