FIRE EFFECTS GUIDE - National Wildfire Coordinating Group

- V -
vapor pressure: the contribution to total atmospheric pressure due to
the presence of water molecules in the air (Schroeder and Buck 1970).
variable: any changing characteristic; in statistics, a measurable
characteristic of an experimental unit.
variance: the sum of the squares of the deviates divided by one less
than the total number of deviates; a measure which indicates how far
away from the middle the statistics are; usually denoted by the lower
case s 2 . Variance is the standard deviation squared. In practice, it is
easier to compute the variance, then take the square root to obtain the
standard deviation. (See standard deviation.)
vegetative regeneration: development of new aboveground plants from
surviving plant parts, such as by sprouting from a root crown or
rhizomes. Even if plants form their own root system, they are still
genetically the same as the parent plant (Zasada 1989).
vegetative reproduction: establishment of a new plant from a seed that
is a genetically distinct individual (Zasada 1989).
vigor: a subjective assessment of the health of individual plants in
similar site and growing conditions; or a more specific measure based
upon a specific facet of growth, such as seed stalk or tiller production
per plant or per unit area.
- W -
weight: as used in vegetation inventory and monitoring, the total
biomass of living plants growing above the ground in a given area at a
given time.
wildfire: a free burning and unwanted wildland fire requiring a
suppression action.
This page was last modified 05/31/01