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Individual study: A review of the effects of prescribed burning on sagebrush-grasslands in British Columbia, Canada

Published source details

Wikeem B.M. & Strang R.M. (1983) Prescribed burning on B.C. rangelands: the state of the art as a management tool in British Columbia, Canada. Journal of Range Management, 36, 3-8

Summary

This paper reviews the state of knowledge regarding use and effects of prescribed burning in different range types (Artemisia sagebrush-grasslands, Ponderosa pine Pinus ponderosa and Douglas fir Pseudotsuga menziesii) in British Columbia, western Canada.

Current knowledge regarding prescribed burning management of the three range types was collated, drawing together information from relevant published papers and books. (No details of the extent of the search are given). Information regarding sagebrush-grasslands is summarised here.

Little published information was found regarding effects of prescribed fire on British Columbia grasslands, more research has been conducted in northwest USA (c. 25 published studies in total). Few studies have carefully monitored pre- and post-fire vegetation community response; only three provided quantitative descriptions. Available evidence on species effects are sometimes conflicting and inconclusive.
 
For example, five studies included information concerning bluebunch wheatgrass Pseudoroegneria spicata (an important native forage species): one reports increased productivity (24% compared to controls) following fire; one suggests a minor increase; one suggest a reduction in basal area; three report reductions in productivity in the first post-burn season (reductions up to 50% observed in one), with recovery time varying from 3 to 12 years. One study found that by the third year, productivity on burned sites was higher than on unburned sites; greatest increases were found on lightly burned areas, indicating that fire intensity may be important.
 
Regarding (non-native and invasive) cheatgrass Bromus tectorum, three studies concluded that it increases following fire. Conversely, two showed that annual Bromus species(including cheatgrass) declined after burning.
 
Consistent results (7 studies) are reported for Idaho fescue Festuca idahoensisand big sagebrush Artemisia tridentata, both being adversely affected by burning (declining in all study localities).

The British Columbia Fish and Wildlife Branch initiated a cool spring burning program in the mid 1970’s on several grassland ranges. Objectives were usually to improve forage (and reduce ‘undesirable plants’, notably big sagebrush) for bighorn sheep Ovis canadensis, elk Cervus canadensis, mule deer Odocoileus hemionus, and white-tailed deer O.virginianus. Few quantitative data were collected from this burning program but some general observations were recorded. A favourable change in spring distribution of bighorn resulted from spring burns, i.e. they spent more grazing time on the burned patches on lower slopes and less on heavily grazed ridges. Improvements in forage quality and production are claimed at one site, but no details are presented. The effect of burning on forage quality post-burn is reportedly short-lived. The British Columbia Forest Service also initiated a burning program but likewise, no detailed monitoring was undertaken to assess effects.

 
Note: If using or referring to this published study, please read and quote the original paper, this can be viewed at: https://www.uair.arizona.edu/holdings/journal/issue?r=http://jrm.library.arizona.edu/Volume36/Number1/