NBFRAC - WILDLIFE TECHNICAL COMMITTEE
DWAMU HARVEST AND SILVICULTURE GUIDE WORKING GROUP
SPECIALIZED HARVESTING: As defined by Fraser Inc. refers to harvesting in a fashion other than clearcutting for the purpose of extracting wood products and leaving a standing residual voulume to gain some silvicultural advantage in a stand.
STAND DENSITY: A quantitative measurement of a stand in terms of Basal Area (BA in m2/ha), number of trees, or volume per hectare. (Husch, et al, see stocking)
STAND MATURITY: Related to FDS descriptions of stand development stage.
SITE QUALITY: Relates to the (1) development of the existing stand condition (ie. growth, vigour, longevity, etc.) and (2) the potential for coniferous regeneration and the establishment of other types competition. In the Spruce/Fir Guide, it pertains to the stand as a primary (pure) or secondary (mixed) softwood site.
SPECIES COMPOSITION: Is the relative distribution of the amount (#'s, BA, vol., etc.) of the various species present. Used as an indicator of the stands suitability as deer winter habitat or various silvicultural techniques.
STOCKING: Stocking is a relative term used to describe the distribution of the density of trees per unit area. Stocking is also related to the utilization of a given stand density in meeting a management objective. Thus a stand with a density of 18 m2/ha of BA, may be classified as overstocked or understocked depending on what density is considered desirable. (Husch, et al)
CHARTS: Stocking charts are graphical representations
of the degree or stocking percent, relative to the mean stand diameter (tree
size), the number of trees/hectare, and the basal area (BA) within the stand.
VARIABLE RETENTION Variable retention presciptions remove almost all mechantable stems of all species in a single teatment. This prescription is generally applied to even-aged mature or over-mature stands, leading to an even aged regeneration through natural processes or tree planting. In some variable situations, a "Seed Tree" harvest presciption will be utilized (typically used in white pine conditions). Within the harvested area attention is paid to maintain sufficient vertical structure and biodiversity by leaving residual trees, clumps or islands of uncut trees and advanced natural regeneration. This variable retention is imporatant for wildlife and to maintain natural disturbance and biodiversity patterns. We have assumed that approximately 3% of the pretreatment volume will remain as residual stand component following this presciption (source: JD Irving)
WINDTHROW HAZARD: The susceptibility of trees being blown over by normal winds. Determined by stand and species characteristics such as spacing, rooting habit and soil, tree size and vigour, and landscape position. (DNR Field Guides)
Questions, remarks, requests: mail to mailto:email@example.com
Last Updated 08/01/2004