|
Wildlife, Animals, and Plants
|
|
CASE STUDIES
SPECIES : Amelanchier alnifolia | Saskatoon Serviceberry
REFERENCE :
Noste, N. V.; Reinhardt, E. D.; Wilson, R. A., Jr. 1989 [80]
SEASON/SEVERITY CLASSIFICATION :
spring, summer, and fall (simulated)/light to severe
STUDY LOCATION :
The study site was near the Ninemile Ranger Station on the Lolo National
Forest in western Montana.
PREFIRE VEGETATIVE COMMUNITY :
The study site was in a Douglas-fir/common snowberry (Pseudotsuga
menziesii/Symphoricarpos albus) habitat type.
TARGET SPECIES PHENOLOGICAL STATE :
Individual Saskatoon serviceberry (Amelanchier alnifolia) plants were
treated with fire during four different phenological stages. Selected
plants were mature, growing in an open stand condition on relatively
level ground, and not heavily browsed. The four phenological stages
were:
1. Before leaf bud burst
2. After leaves were fully expanded
3. After initial change in fruit color
4. After first leaf coloring in fall
SITE DESCRIPTION :
Not stated
FIRE DESCRIPTION :
Saskatoon serviceberry plants were burned in 1984 and 1985, using artificial fuelbeds to produce high-, moderate- and low-intensity, long-
and short-duration fires by manipulating loading and fuel particle size.
Heat pulses to stems and soil were measured to characterize treatments
from fuels. Five treatments used fire; the sixth was mechanical removal
of aboveground stems:
Surface/
Treatment Fuel load volume Diameter
____________________________________________________________
Severity-
duration kg/m2 (T/ac) 1/cm (inch)
1. moderate-moderate 1 (5) 6 (1/8-1/4)
2. light-moderate 0.4 (2) 6 (1/8-1/4)
3. heavy-moderate 2 (10) 6 (1/8-1/4)
4. moderate-fast 1 (5) 81 excelsior
5. moderate-slow 1 (5) 3 (1/2)
6. clipped -- -- -- --
Plants were measured before treatment to determine their size and
condition. All stems within 0.5 m of the plant center were tallied by
diameter class, height, and status (live or dead). Ratio of live to
dead plant material was used as an indicator of plant vigor.
Fuels were conditioned to 6 percent moisture content by storing them
indoors. Litter and dead stems were removed from a 2 X 2-meter area
around each shrub before building the fuelbed. Fires were ignited along
the downslope-downwind edge of the fuelbed. Mean fire behavior characteristics of the five fire treatments follow.
Rate of Flame Flame Residence Total heat
spread depth length time release
Treatment (m/min) (cm) (cm) (min) (mJ/m2)
______________________________________________________________
1 0.47 36 51 1.6 52.0
2 0.16 23 21 4.1 20.0
3 0.37 49 99 1.4 105.0
4 4.05 48 142 0.6 41.0
5 0.12 30 28 4.5 44.0
FIRE EFFECTS ON TARGET SPECIES :
All fire treatments top-killed all plants. Little heat increase was
observed below 1 cm depth in soil. All plants sprouted vigorously
after fire. No significant differences were found between the five fire
treatments and the clipping treatment. Number of postfire sprouts was
significantly related to prefire size of shrub; however, sprouting
response was not significantly correlated to ratio of live:dead stems.
The relationship between sprouting and phenological stage was not
significant (p = 0.12). Saskatoon serviceberry response by treatment
was as follows:
Phenological stage Sprouts/plant (mean)
_________________________ _____________
before leaf bud burst 89
after leaf expansion 59
initial fruit color change 70
1st leaf color in fall 90
Treatment Sprouts/plant (mean)
____________________ _____________
1 moderate-moderate 88
2 light-moderate 72
3 heavy-moderate 75
4 moderate-fast 81
5 moderate-slow 81
6 clipping 73
_________________ __
mean 78
FIRE MANAGEMENT IMPLICATIONS :
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:
CASE NAME :
Range prescribed burning/northern Idaho
REFERENCES :
Leege, L. A. 1978 [62]
Leege, L. A. 1978 [63]
Leege, L. A. 1979 [64]
Leege, L. A.; Hickey, W. O. 1966 [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].
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 [2].
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 [1] 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:
CASE NAME :
Range prescribed burning/British Columbia
REFERENCES :
Thomson, S. 1988 [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.
References Index
Related categories for SPECIES : Amelanchier alnifolia
| Saskatoon Serviceberry
|
 |
