Glossary - H

Habitat: Situation in which a particular plant or animal lives.
Hardwood: Descriptive term used for the wood of broad-leaved trees. Also old-fashioned term for the broad-leaved trees.
Hardwood: The wood of broadleaved trees, a term sometimes used for the broadleaved trees themselves.
Harvester: A machine that severs the tree from its roots, de-branches it, and converts it to pre-determined lengths. See Processor.
Heartwood: Dead wood consisting of several annual rings at centre of tree trunk or branch, no longer water-conducting tissue but providing structural support.
Heavy thinning: Removal of a large volume per unit area.
Hectare: Unit of land area equal to 10 000 square metres. There are 100 hectares in a square kilometre.
High forest: Trees capable of growing to be suitable for timber production (compare with coppice).
Highlead: A type of cable crane set up where there are no fixed overhead line wires. See also Skyline.
Hoppus measure: A form of imperial measure confined to round timber (now largely replaced by metric measure) in which a theoretical allowance was automatically made for wastage in conversion.
Hybrid: A natural or artificial cross between two species, or occasionally between two genera, when it is an 'inter-specific hybrid'.
Hypsometer: An instrument used from ground level for measuring the heights of trees.