More info for the terms:
habitat type,
herbaceous,
root crown,
shrubsLewis' mock orange sprouts vigorously from the root crown following fire
[
10,
23,
24]. After an April fire on a south-facing slope in
north-central Idaho, Lewis' mock orange increased to prefire densities by
the third postfire growing season [
22].
The following two studies have investigated the sprouting response of
Lewis' mock orange to fire.
Seral brushfields within the grand fir (Abies grandis)/pachistima
(Pachistima myrsinites) habitat type in northern Idaho were burned in
either spring (late March - early April) or fall (October).
Temperatures during the fires ranged from 67 to 78 degrees Fahrenheit
(19-26 deg C), and relative humidities ranged from 25 to 48 percent.
Lewis' mock orange on sites burned in October did not sprout until the
following April. Lewis' mock orange on the spring-burned sites sprouted
4 to 8 weeks after the fire. Twenty completely top-killed Lewis'
mock orange (eleven on the fall burned sites and nine on the spring
burned sites) were measured at the end of the first postfire growing
season [
24]:
Fall Fires Spring Fires
Average crown diameter (ft)
prefire 4.7 (143 cm) 4.7 (143 cm)
postfire 2.4 (73 cm) 2.2 (67 cm)
Average crown height (ft)
prefire 8.8 (268 cm) 9.6 (293 cm)
postfire 4.1 (125 cm) 3.7 (113 cm)
No. basal sprouts per plant
prefire 1.5 0.6
postfire 38.0 28.9
Average postfire sprout height (ft) 2.4 (73 cm) 2.1 (64 cm)
A multiple regression equation is presented which relates the number of
postfire basal sprouts to prefire crown height, crown diameter, and
crown volume [
24].
In another study in north-central Idaho, a brushfield was burned three
times at 5-year intervals (31 March 1965, 3 May 1970, and 14 May 1975).
Maximum air temperatures during the fires were 77, 81, and 88 degrees
Fahrenheit (25, 27, and 31 deg C), and relative humidities at 4:00 pm
were 35, 16, and 27 percent, respectively. Leaves on shrubs and
succulent herbaceous growth depressed the fire in 1975. A single Lewis'
mock orange was followed during the study. The plant was dormant during
the first fire, but leaves were beginning to emerge at the time of the
second fire and were completely emerged at the time of the third fire.
With each successive fire, average sprout height decreased. Reduced
growth following the second and third fires may have resulted from the
advanced phenological stage at the time of those fires. Sprout height
and number were measured the first growing season following each fire.
Crown height and diameter were measured during the second postfire
growing season [
23].
No. basal sprouts Average sprout height (ft)
1965 14 2.0 (61 cm)
1970 19 1.5 (46 cm)
1975 16 1.0 (30 cm)
Crown height (ft) Crown diameter (ft)
prefire 7.0 (213 cm) 1.5 (46 cm)
1966 4.0 (122 cm) 2.0 (61 cm)
1971 2.5 (76 cm) 2.0 (61 cm)
1976 2.5 (76 cm) 1.5 (46 cm)