Glossary of Forestry Terms - G - H

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Genetic diversity variation among and within species that is attributable to differences in hereditary material.
Genotype the entire genetic constitution, or the sum total of genes of an organism, in contrast to the phenotype.
Geographic information system (GIS) a computer system designed to allow users to collect, manage and analyze large volumes of spatially referenced information and associated attribute data.
Girdling to kill a tree by severing or damaging the cambium layer and interrupting the flow of food between the leaves and the rest of the tree. A method of 'brushing' carried out using a hatchet or special tool to cut through the bark and cambium of the tree.
Grading classifying timber, lumber or logs according to quality or end-use.
Grapple yarder a machine used in harvesting to bring logs into a landing. The grapple closes like teeth around the log and is controlled by the machine operator.
Green tree retention the reservation of live trees of a specific species and size from harvesting, to achieve a site-specific objective.
Greenbelt an extensive area of largely undeveloped or sparsely occupied land associated with a community set aside to contain development, preserve the character of the countryside and community and provide open space.
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Greened-up a cutblock that supports a stand of trees that has attained the green-up height specified in a higher level plan for the area, or in the absence of a higher level plan for the area, has attained a height that is 3 m or greater, and if under a silvicultural prescription, meets the stocking requirements of that prescription, or if not under a silviculture prescription, meets the stocking specifications for that biogeoclimatic ecosystem classification specified by the regional manager.
Gross total volume volume of the main stem of the tree including stump and top. Volume of the stand including all trees.
Ground-based systems ogging systems that employ ground-based equipment such as feller-bunchers, hoe chuckers, skidders, and forwarders.
Ground truthing the use of a ground survey to confirm the findings of an aerial survey or to calibrate quantitative aerial observations.
Groundwater water below the level of the water table in the ground; water occupying the sub-surface saturated zone.
Group selection See Selection silvicultural system.
Growing stock the sum of all trees in a forest or specified part of it.
Grubbing and retention removal of stumps, roots, embedded logs, organics, and unsuitable soils before or concurrently with subgrade construction.
Guideline an optional practice or new practice not currently legislated. Although guidelines are generally voluntary, the implication is that practitioners will use these concepts and principles in meeting their resource objectives.
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Habitat the place where an organism lives and/or the conditions of that environment including the soil, vegetation, water, and food.
Habitat enhancement any manipulation of habitat that improves its value and ability to meet specified requirements of one or more species.
Habitat management management of the forest to create environments which provide habitats (food, shelter) to meet the needs of particular organisms.
Hardwoods trees which are generally deciduous, broad leafed species such as oak, birch, alder or maple.
Harvest cut the felling of the mature crop of trees either as a single clearcut or a series of regeneration cuttings.
Harvest forecast the flow of potential timber harvests over time. A harvest forecast is usually a measure of the maximum timber supply that can be realized, over time, for a specified land base and set of management assumptions.
Harvest pattern the spatial distribution of cutblocks and reserve areas across the forested landscape.
Harvest rate the rate at which timber is harvested, commonly expressed as an (AAC).
Harvest schedule a document listing the stands to be harvested year or period, usually showing types and intensities of harvests for each stand, as well as a timetable for regenerating currently non-productive areas.
Harvesting the practice of felling and removing trees or the removal of dead or damaged trees from an area.
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Harvesting method the mix of felling, bucking, and yarding (skidding) systems used in logging a stand of timber.
Harvesting prescription detailed plan on how, when, and where timber will be harvested from an area.
Harvesting system the mix of felling, bucking and yarding systems used in logging a stand of timber.
Hauling a general term for the transportation of logs from one point to another, usually from a landing to the mill or shipping point.
Hazard a state that may result in an undesired event, the cause of risk. Hazard can apply to the probability of tree mortality or damage by an insect or disease and also represents material or fuel that will ignite and burn.
Hazardous or danger tree a tree or any component of a tree that has sufficient structural infirmity to be identified as having a high risk of falling and causing personal or property damage.
Healthy ecosystem an ecosystem in which structure and functions allow the maintenance of biodiversity, biotic integrity and ecological processes over time.
Heartwood the inner core of a woody stem composed of nonliving cells and usually differentiated from the outer wood layer (sapwood) by its darker colour. See Cambium.
Height class any interval into which the range of tree heights is divided for classification and use, commonly 3 m, 5 m, or 10 m classes.
Height/diameter curve a graphic representation of the relationship between individual tree heights and diameters used to determine tree volumes in localized areas.
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Helitack initial attack on wildfires involving the use of helicopters and trained crews, deployed as a complete unit.
Helitanker a helicopter equipped with a helitank - a specially designed tank used for transporting and dropping suppressants or retardants.
Helitorch a specialized drip torch, using a gelled fuel, slung and activated from a helicopter.
Herbicide chemical substances or living organisms (called bioherbicides) used to kill or control vegetation such as brush, weeds, and competing or undesirable trees.
Heritage areas sites of historical, architectural, archaeological, paleontological, or scenic significance to the province.
Heritage trail a trail having cultural significance by reason of established aboriginal use or use by early immigrants.
Highgrading the removal of only the best trees from a stand, often resulting in a residual stand of poor quality trees.
High hazard (forest health) physical characteristics (including tree species, composition, age, and size) and biogeoclimatic factors that make a forest highly susceptible to attack by damaging agents.
High sensitivity area area having special concerns, issues, or the potential for negative impacts on resource values, including any soils with high hazard or very high hazard for compaction, erosion, mass wasting, or displacement.
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High value stream a high value fish-bearing stream and a stream in a community watershed.
Higher level plan strategic or operational plans that provide direction to any lower level of plans, prescriptions or forest practices.
Hip chain a device used to measure distance by means of an anchored filament wrapped around a wheel that revolves as you walk (handy for measuring distances on your own).
Historical variation the range of the spatial, structural, compositional and temporal characteristics of ecosystem elements during a period specified to represent "natural" conditions.
Human dimension an integral component of ecosystem management that recognizes people are part of ecosystems, that people's pursuits of past, present, and future desires, needs and values (including perceptions, beliefs, attitudes and behaviours) have and will continue to influence ecosystems and that ecosystem management must include consideration of the physical, emotional, mental, spiritual, social, cultural and economic well-being of people and communities.
Human impact or influence a disturbance or change in ecosystem composition, structure or function caused by humans.
Humus a general term for the more or less decomposed plant and animal residues in the lower organic soil layer.
Hydrology the science that describes and analyzes the occurrence of water in nature, and its circulation near the surface of the earth.
Hydroseeding the application of seed in a water slurry that contains fertilizer, a soil binder and/or mulch.
Hypsometer a simple instrument, often a stick or other straight edge, used to measure the heights of trees on the basis of similar angles.
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