More info for the terms:
cover,
fire severity,
forest,
frequency,
severity,
wildfirePostfire response of pipsissewa is variable and is probably most
dependent on fire severity and the uniformity of the burn. Some studies
have reported pipsissewa surviving fire. In mixed western
hemlock-Douglas-fir-western redcedar (Thuja plicata) stands in North
Cascades National Park, Washington, pipsissewa was considered a
residual species following a July wildfire. Its frequency in postfire
years 1, 2, and 3 was 65.3, 52.1, and 52.1 percent, respectively [
54].
Pipsissewa appeared to survive on moderately burned sites following
the Waterfalls Canyon Fire in Grand Teton National Park in July, 1974,
but was eliminated from severely burned sites. The prefire vegetation
was spruce-fir with lodgepole pine (Pinus contorta) and whitebark pine
(P. albicaulis). Pipsissewa had the following percent frequency and
cover as measured in 1975 [
10]:
Frequency Cover
______________________________________________
Unburned sites 52 5
Sites burned in 1932 2 trace
Moderately burned sites 17 1
Severely burned sites 0 0
In the northern Rocky Mountains, slow recovery after fire has been
reported. Pipsissewa was eliminated from initial postfire
communities by a severe wildfire in western larch (Larix
occidentalis)-Douglas-fir stands on the Flathead National Forest,
Montana [
75]. In western larch-fir (Abies grandis and A. lasiocarpa)
stands on the Flathead and Lolo National Forests, Montana, pipsissewa
had not recovered by postfire year 9 following logging and broadcast
burning [
74]. Pipsissewa was also absent 10 months after a
late-summer wildfire in lodgepole pine stands in the Chamberlain Basin,
Idaho. It was found on adjacent unburned sites and was present on
burned sites 5 years after the fire, but had less biomass production
than on unburned sites [
61].
Variable responses to fire have been reported for pipsissewa in
Minnesota. It survived the Little Sioux Wildfire in May, 1971, in mixed
conifer-hardwood stands in northeastern Minnesota. Number of
individuals (on seventy 0.605 sq m plots) and aboveground average dry
weight per individual pipsissewa were measured at the end of each
growing season for the first 5 postfire years [
58]:
1971 1972 1973 1974 1975
________________________________________________________________
No. of individuals 15 no data 57 30 7
Ave. dry wt. (g) .07 no data .33 .29 .46
Pipsissewa responded more slowly after wildfires in second-growth
mixed conifer-hardwood forests in northeastern Minnesota. It was not
present in postfire years 3, 5, or 14 after the April Heartlake Fire.
It was not present on the Kelley Creek Burn, resulting from a July fire,
at postfire year 2 but had a frequency of 3 percent in postfire years 5
and 11 [
48].