More info for the terms: cover, fern, fire intensity, fire management, forbs, fuel, natural, prescribed fire, presence, reburn, shrub, shrubs, top-kill, wildfire
Evidently managers in western Montana have a large window of opportunity to
treat Saskatoon serviceberry with fire. All aboveground stems were killed by all
fire treatments, while rhizomes did not receive much heat treatment. This
indicates that even low-intensity fires are sufficient to top-kill Saskatoon
serviceberry, and that fires in natural fuels are unlikely to kill underground
buds and remove Saskatoon serviceberry from the site.
The weak relationship between sprouting response and phenological stage suggests
that the season in which Saskatoon serviceberry is burned is not critical to
postfire response of Saskatoon serviceberry in western Montana. Similar results
can be expected from spring, summer, or fall fire.
The size of the plant was positively related to sprouting response, while
proportion of dead stem in the plant was not a deterrent to sprouting. The
management implication is that even decadent plants may be successfully treated
with fire.
2nd
CASE STUDY:
FIRE CASE STUDY CITATION:
Fryer, Janet L., compiler. 1997.
Prescribed fire effects on Saskatoon serviceberry in a northern Idaho rangeland.
In: Amelanchier alnifolia. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).
Available: http://www.fs.fed.us/database/feis/ [
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REFERENCES :
Leege, Thomas A. 1978. Changes in browse intercept, production and seedlings after burning--Holly Creek.
Job Completion Report No. W-160-R. Elk ecology: Range rehabilitation by spring burning: July 1, 1965
to June 30, 1978. Boise, ID: Idaho Department of Fish and Game. 11 p. [62].
Leege, Thomas A. 1978. Changes in browse production after burning vs. slashing and burning on the four
cardinal aspects--Polar Ridge. Job Completion Report No. W-160-R. Elk ecology: Range rehabilitation
by spring burning: July 1, 1967 to June 30, 1978. Boise, ID: Idaho Department of Fish & Game. 20 p.
[63].
Leege, Thomas A. 1979. Effects of repeated prescribed burns on northern Idaho elk browse. Northwest Science.
53(2): 107-113. [64].
Leege, Thomas A.; Hickey, William O. 1966. Lochsa elk study. Big Game Surveys and Investigations: W 85-R-17,
Job No. 8. July 1, 1965 to June 30, 1966. Boise, ID: State of Idaho Fish and Game Department. 22 p.
[65].
SEASON/SEVERITY CLASSIFICATION:
Holly Creek: spring/severity not given
Polar Ridge: spring and fall/severity not given
Fish Creek: repeat spring/severity not given
STUDY LOCATION:
Three areas on Lochsa River watersheds of the Clearwater National Forest,
northern Idaho, were selected for study. The study areas were Holly Creek, Polar
Ridge, and Fish Creek [62,63,64].
Holly Creek flows into the Lochsa River from the north, about halfway between
the Lowell and Powell Ranger Stations along U.S. Highway 12. Study plots were
located about 1.5 miles (2.4 km) from the mouth of Holly Creek [62].
Polar Ridge is located between the Polar and Walde Creek drainages, which are
tributaries of Pete King Creek. Pete King Creek flows into the Lochsa River [63].
Fish Creek is a major tributary of the Lochsa River. The study site was on lower
slopes of the Fish Creek drainage [64].
PREFIRE VEGETATIVE COMMUNITY :
Due to wildfires, all three study sites were dominated by shrubs. The Holly
Creek site had some conifer regeneration on north slopes and along watercourses.
Habitat type of the Holly Creek site was not given. Scouler willow (Salix
scouleriana) and thimbleberry (Rubus parviflorus) were dominant. Other common
shrubs included Saskatoon serviceberry (Amelanchier alnifolia), oceanspray
(Holodiscus discolor), common snowberry (Symphoricarpos albus), and ninebark
(Physocarpus malvaceus) [62].
The Polar Ridge site was on a grand fir-pachistima (Abies grandis/Pachistima
myrsinites) habitat type. Thimbleberry, common snowberry, oceanspray, redstem
ceanothus (Ceanothus sanguineus), and Saskatoon serviceberry were dominant
shrubs; Saskatoon serviceberry dominated slopes with southerly aspects. Other
common shrubs included Rocky mountain maple (Acer glabrum), Scouler willow,
bitter cherry (Prunus emarginata), and white spiraea (Spiraea betufolia).
Bracken fern (Pteridium aquilinum) was common on the site [65].
The Fish Creek study area was on a grand fir-pachistima habitat type [64,65].
Redstem ceanothus and Scouler willow were dominant. Other common shrubs included
Saskatoon serviceberry, oceanspray, paper birch (Betula papyrifera), Rocky
Mountain maple, and bitter cherry. Common herbaceous species included false
lupine (Thermopsis montana), bracken fern, St. Johnswort (Hypericum perforatum),
western yarrow (Achillea millefolium), and woodland strawberry (Fragaria vesca)
[64].
TARGET SPECIES PHENOLOGICAL STATE :
Not given
SITE DESCRIPTION:
The Holly Creek drainage was completely burned by wildfire in 1919 and again in
1929. Slope on the study site averaged 55 percent. Soil was derived from
granitic parent material and was coarse on steep terrain but more loamy on
gentler terrain [62].
Polar Ridge was completely burned by wildfire in 1934. Study plots were selected
on each cardinal aspect and ranged from 3,000 to 3,200 feet (900-960 m)
elevation. Average slope was 60 to 80 percent [63].
The Fish Creek site area was completely burned by wildfire in 1934 and in 1954.
Slope on the study site ranged from 35 to 50 percent. Soil was derived from
granitic parent material [64].
FIRE DESCRIPTION:
Elk populations were declining on the Lochsa River watershed at the time of
these studies, possibly because most larger shrubs that had become dominant
after the wildland fires had grown above browseline. The burn objectives on all
three sites were to make more browse available to big game species by reducing
shrub heights, and to increase shrub productivity [62,63,64,65].
HOLLY CREEK: The study site was burned on May 2, 1966. Eight hundred and ten
acres were burned, mostly that afternoon. Ignition time was 13:00. Temperature
at that time was 84 degrees Fahrenheit (29 deg C); relative humidity was 18
percent. At 15:30, temperature and relative humidity were 85 degrees and 14
percent, respectively. Wind was negligible. Fuels were "dry and
abundant," except that fuels on northern exposures were moist enough to
retard lateral fire spread. Snowline was at 4,500 feet (1,350 m). Vegetation on
all plots was mostly consumed [65].
POLAR RIDGE: Four fires, one on each cardinal aspect, were set. It had rained 3
days prior to burning on the south aspect. Rain had not fallen for at least 4
days prior to burning on other aspects [63].
North aspect: North slope plots were fired on May 9, 1969. Maximumtemperature was 74 degrees Fahrenheit (23 deg C); minimum relativehumidity was 35 percent. The burn was not successful. This wasattributed to lack of enough flammable herbaceous material to carry afire and because microclimate on the north slope prevented
fuels from drying adequately. However, one area with a northeast exposure andadundant cover of dry bracken fern did burn despite the presence ofgreen forbs and grasses growing up among the bracken fern [a href="http://www.fs.fed.us/database/feis/plants/shrub/amealn/all.html#63>63].
It was decided to slash the vegetation and reburn the area in fall 1972. All
woody vegetation was cut to ground level during the summer and fall of 1971. The
area was again fired on October 4, 1972. Maximum temperature was 60 degrees
Fahrenheit (16 deg C) and minimum relative humidity was 50 percent. In the
previous winter, snow had compressed the slashed fuels to ground level and there
was an abundance of green vegetation, mostly Scouler willow sprouts, covering
the slash. The reburn was unsuccessful [63].
East aspect: The site was fired on May 6, 1969. Based upon measurements taken at
the Kooskia Ranger Station, maximum temperature was estimated at 74 degrees
Fahrenheit (23 deg C); relative humidity was estimated at 38 percent. The burn
was not successful: only 2 of 25 plots burned. Failure was attributed to lack of
flash fuels in the understory and a cool, damp microclimate [63].
The area was slashed in the summer and fall of 1971 and reburned on October 6,
1972. Maximum temperature was 67 degrees Fahrenheit (19 deg C); minimum relative
humidity was 50 percent. The burn was marginally successful: 10 of 25 plots
burned [63].
West aspect: Vegetation was not uniform over the entire area. Slope with a
southwesterly aspect had more herbaceous vegetation, particularly bracken fern.
Slopes with a northwesterly aspect had a dense overstory of young conifers. The
site was burned on May 6, 1969. Maximum temperature and minimum relative
humidity at Kooskia Ranger Station were 84 degrees Fahrenheit (29 deg C) and 28
percent, respectively. Fourteen of 25 plots burned. Portions of the study area
with minimum conifer overstory and abundant bracken fern burned best [63].
South aspect: The site was burned on April 16, 1969. Onsite maximum temperature
was 70 degrees Fahrenheit (21 deg C) and minimum relative humidity was 35
percent. A continuous cover of surface fuels, primarily bracken fern, was
present. All 25 plots burned [63].
FISH CREEK: Three spring prescribed fires were set on the same site at 5-year
intervals. Each fire achieved 100 percent top-kill of shrubs on all plots. The
first prescribed fire was set on March 31, 1965. Maximum temperature at the
Kooskia Ranger Station was 77 degrees Fahrenheit (25 deg C); minimum relative
humidity was 35 percent. There was a westerly wind at 8 km/hr. Shrubs were
dormant [64].
The area was reburned on May 3, 1970. Maximum temperature was 80 degrees
Fahrenheit (27 deg C); minimum relative humidity was 16 percent. Wind was
negligible. Small leaves had emerged on some shrubs [64].
The third burn was conducted on May 14, 1975. Weather readings at the Kooskia
Ranger Station were: maximum temperature 88 degrees Fahrenheit (31 deg C) and
minimum relative humidity 27 percent. Wind was negligible. Leaves had expanded
on shrubs and herbaceous vegetation was greening up. Green vegetation appeared
to retard fire spread [64].
FIRE EFFECTS ON TARGET SPECIES :
Holly Creek: Saskatoon serviceberry was lower in average height after fire, but
productivity did not increase. Production of Saskatoon serviceberry stayed at
approximate prefire levels for the first 2 postfire years, but the third
postfire growing season was the beginning of a decline that stabilized at about
15 percent of prefire production at postfire years 9 through 12. Leege [62]
speculated that the decline was due to elk and mule deer use of Saskatoon
serviceberry during active summer growth. Saskatoon serviceberry production was
[62]: Twigs/ha Avg. twig weight (g) Kg/ha*
________ ____________________ _____
1966 (prefire) 672 0.26 16.6
1966 (postfire) 137 1.19 15.5
1967 215 0.72 14.7
1968 312 0.26 7.8
1969 229 0.10 2.1
1970 458 0.11 4.8
1971 387 0.20 7.4
1972 645 0.11 6.9
1973 387 0.15 5.4
1974 312 0.07 2.0
1975 270 0.07 1.9
1976 219 0.11 2.2
1977 195 0.13 2.5
_______________
*new growth
Polar Ridge: The fires on the west and south slopes lowered average height of
Saskatoon serviceberry but had little effect on productivity. On the south
slope, where a good prescription burn was obtained, average height was reduced
from prefire levels for at least 10 postfire years. Production did not change
greatly until 1977, when average twig length and kilograms of new growth
produced per hectare were reduced on south slopes. However, 1977 was a poor
growth year for all shrub species measured. Production of Saskatoon serviceberry
on west and south slopes follows [63].
(East slope data were not stated and the north slope did not burn.)
Twigs/ha Twig length (cm) Kg/ha
____________ ________________ ____________
west south west south west south
prefire (1967) 257 413 2.5 10.4 0.8 6.8
1969 42 73 50.8 32.5 10.9 4.2
1970 185 226 17.8 15.2 13.4 9.3
1971 255 177 7.6 11.7 7.0 5.6
1972 179 326 5.1 10.2 2.7 6.8
1977 171 248 7.6 6.4 4.2 2.1
Fish Creek: Saskatoon serviceberry was top-killed by and sprouted after each
prescribed fire, but average sprout height and maximum crown diameter were
significantly lower (p = 0.05) after each successive burn. Changes in Saskatoon
serviceberry follow [64].
Height (cm) Crown diameter (cm)
___________ ___________________
prefire 378 125
postfire yr 2
1966 fire 183 140
1970 fire 162 134
1975 fire 134 128
Sprouts/plant Sprout height (cm)
_____________ __________________
postfire yr 1
1965 fire > 50 94
1970 fire 149.4 67
1975 fire 112.2 55
FIRE MANAGEMENT IMPLICATIONS:
HOLLY CREEK - Elk use of the area increased after burning. Overall, the burning
objectives were met: height of most palatable browse species was lowered and
remained below browseline until at least postfire year 11. Browse productivity
also increased for most shrub species. It increased greatly from prefire levels
at postfire year 1, returned to prefire levels at postfire year 2, then
gradually rose. At postfire year 11, browse productivity was about two times
prefire levels [62].
Average height of Saskatoon serviceberry was reduced by fire, and Saskatoon
serviceberry remained below browseline for at least 11 years after fire [62,65].
Productivity, however, declined after fire and had not reached prefire levels by
postfire year 11 [63].
Although common on the study site, Saskatoon serviceberry was not dominant.
Browsing pressure on Saskatoon serviceberry may have increased after fire to the
point that little new growth was achieved.
POLAR RIDGE - Where prescribed burning was successful, the effect of fire was to
increase availability of palatable browse species including Saskatoon
serviceberry. Productivity of Saskatoon serviceberry and other browse increased
until postfire year 4, then stabilized at approximate prefire levels. At
postfire year 4, Scouler willow, the dominant shrub, was greatly reduced by an
outbreak of a willow borer insect [63],
and browsing pressure on Saskatoon serviceberry probably increased. Had the
Scouler willow die-back not occurred, Saskatoon serviceberry productivity after
postfire year 4 might have been greater.
Based upon his experiences at Polar Ridge, Leege [63]
gave recommendations for prescribed burning northern Idaho brushfields on north,
east, and west aspects. Those recommendations follow.
North slopes: On north slopes with a high percentage of overstory, burning is
difficult in either spring or fall because of a lack of flash fuels to carry
fire. Fuel flammability can be improved by cutting woody vegetation to ground
level and then burning; however, burning should be done the first fall after
slashing, before snow compacts the fuels and new spring growth appears.
Recommended treatment is to slash during July and August and burn during warm
October days after the first killing frost [63].
East slopes: The east aspect was difficult to treat with fire due to sparse
understory fuels and unfavorable microclimate. Such sites would be difficult to
burn in spring even with good burning conditions. Slashing and fall burning
produced a marginal burn. Leege [63]
speculated that the burn would have been more successful if slash had been
burned the first fall after cutting, instead of the second year, and burning had
been done with a warmer temperature and especially a lower relative humidity.
West slopes: Prescribed burning was successful where bracken fern and other
herbaceous fuels were present. Dense conifer regeneration on northwest slopes
eliminated the understory and prevented the fire from carrying. Leege [63]
recommended cutting down at least 50 percent of the conifers in early summer to
create continuous surface fuels.
FISH CREEK - There were indications that Saskatoon serviceberry declined in
vigor with repeat prescribed burning at 5-year intervals. Sprout numbers and
height were less in 1975 than in 1970 despite twice the precipitation in 1975.
However, the data are inconclusive because sample size was small (n = 5) and
because Saskatoon serviceberry had put on more spring growth (and therefore may
have been more harmed) before the 1975 fire than before the 1970 fire. Leege [64]
speculated that on northern Idaho brushfields, prescribed fire at 5-year
intervals will favor Scouler willow and redstem ceanothus. Burning at 10- to
15-year intervals would better maintain prefire shrub species composition,
including Saskatoon serviceberry, while lowering shrub height and providing
browse for big game species.
3rd
CASE STUDY:
FIRE CASE STUDY CITATION:
Fryer, Janet L., compiler. 1997.
Prescribed fire effects on Saskatoon serviceberry in a British Columbia rangeland.
In: Amelanchier alnifolia. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer).
Available: http://www.fs.fed.us/database/feis/ [
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REFERENCES :
Thomson, Sandra. 1988. The effects on vegetation of prescribed burning for wildlife habitat and range improvement in southeastern British Columbia. In: Feller, M. C.; Thomson, S. M.,
eds. Wildlife and range prescribed burning workshop proceedings; 1987
October 27-28; Richmond, BC. Vancouver, BC: The University of British
Columbia, Faculty of Forestry: 120-133. [97].
SEASON/SEVERITY CLASSIFICATION:
Operational burns: spring/severity not given
Experimental burns: fall/moderate severity
STUDY LOCATION:
The study areas were located in the Purcell Mountains near Cranbrook, British
Columbia, within four different range units. The range units were Pickering
Hills, Luckhurst, Power Plant, and Newgate.
PREFIRE VEGETATIVE COMMUNITY :
Study sites were located in a Douglas-fir/bitterbrush (Pseudotsuga
menziesii/Purshia tridentata) habitat type. The overstory was a sparse canopy of
ponderosa pine (Pinus ponderosa); there were a few Douglas-fir in the
understory. Shrub cover varied between 5 and 60 percent. Common shrub species
included Saskatoon serviceberry (Amelanchier alnifolia), western snowberry
(Symphoricarpos albus), and snowbrush ceanothus (Ceanothus velutinus). Bluebunch
wheatgrass (Pseudoroegneria spicata) and Junegrass (Koeleria macrantha) were the
dominant herbs. Rough fescue (Festuca scabrella) and Kentucky bluegrass (Poa
pratensis) were also present.
TARGET SPECIES PHENOLOGICAL STATE :
Not stated
SITE DESCRIPTION:
All study sites but one were located on thick glacial moraine; one was on
fluvial glacial deposits. Soils were Orthic Eutric Brunisols, varying in coarse
fragment and sand content. Slopes were gentle to flat. The area is a key winter
range for elk, white-tailed deer, and mule deer, and is used as summer range for
cattle.
FIRE DESCRIPTION:
Operational burns: Six sites were prescription burned to thin conifers and
increase availability of browse and grasses for elk, deer, and cattle. Each of
the six sites was burned once, in April. Burning years were 1976, 1978, 1983,
1985, and 1986 (2 sites were burned in 1986). Fuels and fire behavior data were
not collected for the operational burns [98].
Experimental burns: Two sites were prescription burned, one in October 1986 and
one in October 1987. Fire-related data for the site burned in 1987 were not
given. Weather conditions during the 1986 fire were less than ideal. Temperature
was low and relative humidity high, making fire intensity less than desired.
Relatively low rates of spread and flame heights were obtained. Weather
conditions and fire behavior data for the 1986 fire follow [98].
Date of burn Oct. 8, 1986
Relative humidity 70%
Temperature 12.6 deg C
Wind speed 7.5 m/s
Rate of fire spread 0.1-0.9 m/min
flame height 0.15-1.50 m
The live fuel component (shrubs and grasses) was highly variable, but reduction
was significant. The forest floor was not reduced at time of postfire
measurement, but this could have been due to partially burned vegetation
dropping to the ground and becoming part of the postfire forest floor. Fuels
data follow.
Fuel component Prefire biomass % consumption
______________ _______________ _____________
coarse fuels 0.39 kg/sq m 66
forest floor 0.06 kg/sq m 0
shrubs 0.61 kg/sq m 39
grasses 0.02 kg/sq m 90
____________ __
total 1.08 kg/sq m 52
FIRE EFFECTS ON TARGET SPECIES :
Operational spring fires: Saskatoon serviceberry was not greatly affected by
spring prescribed burning. Percent cover of Saskatoon serviceberry on burned and
unburned control plots follows. (Data from the 6 operational burns were pooled.)
Percent cover
_______________________________________
postfire year 1 postfire year 2
_______________ _______________
unburned 5.0 4.5
burned 6.5* 8.2
_______________________________________________________
*significantly different at P = 0.05
Experimental fall 1986 fire: Saskatoon serviceberry was not greatly affected by
fall prescribed burning either. In postfire year 1, the only year for which data
are available, percent cover increased slightly but not significantly on burned
plots compared to unburned plots, and current annual growth decreased slightly
but not significantly:
unburned burned
________ ______
percent cover 2.5 5.0
current annual growth (g/m) 3.8 2.5
FIRE MANAGEMENT IMPLICATIONS:
Neither spring nor fall prescribed burning had much short-term effect on
Saskatoon serviceberry cover or production in this study. This is consistent
with other short-term studies in southeastern British Columbia. Davidson [25]
found a slight decrease in Saskatoon serviceberry 2 years after prescribed
burning. Demarchi and Lofts [27]
found production of current-annual twigs was greater, but leaf production less,
the first 2 years after prescribed burning.
This is not to say that the prescribed fires were unsuccessful. Shrubs were
reduced an average of 39 percent by spring prescribed burning, making Saskatoon
serviceberry and other browse more accessible to ungulates. Comparing percent
cover in short-term studies can be deceiving because unburned areas may contain
a few tall, inaccessible shrubs while burned areas contain a number of small
shoots. Data from the long term may show that the number of sprouts on burned
areas exceeds sprouts on unburned areas.
Thomson [97]
suggested that total grass biomass prior to burning is important in determining
success of burning on sparsely-treed Douglas-fir habitat types in the extreme
northern Rocky Mountains. Moisture content of grass and other herbaceous fuels
was not reported in this study, but is also an important factor in success of
burning.
