More info for the terms: constancy, cover, fern, fire use, forbs, frequency, fuel, hardwood, natural, prescribed burn, prescribed fire, succession, wildfire
Due to its broad distribution, accounts of spreading dogbane following fire are widespread
and vary throughout a range of ecosystems. Adverse postfire effects on spreading dogbane
appear to be temporary with reports of fluctuating population cover and frequency in the
years following fire. A large percentage of studies fail to report the significance of the
increase or decrease of populations, likely due to a lack of prefire data. Where spreading
dogbane occurs, it is commonly found on both burned and unburned sites [9] such as Pacific
ponderosa pine (Pinus ponderosa var. ponderosa) stands in Oregon [141], jack pine stands in northwestern Wisconsin [186],
chestnut oak (Quercus prinus) stands in south-central New York [171], and clearcuts in eastern Ontario [196].
California:
Spreading dogbane has been observed after fires in northern California [93,169]. Following
fire in the hardwood forests of northwestern California, it was reported to have 1.5% and
3.4% mean relative cover on 2 sites [169].
Idaho:
Spreading dogbane cover increased from 0.5% to 0.9% following a shelterwood cut at the
Priest River Experimental Forest in northern Idaho. Areas subsequently treated with a
"moist" burn (duff was moist and fire was conducted 1 day during the warmest,
driest period) had 1.0% cover prior to cutting and burning and 2.6% cover 1 year after
treatment. Areas treated with a "dry" burn (duff was dry and burn was conducted
over the course of 2 days throughout the evening, night, and morning) had 0.5% cover prior
to treatment and 1.4% cover 1 year following cutting and burning [154].
Cover and frequency of spreading dogbane on high intensity prescribed burns in Idaho were
significantly higher (P<0.01) than cover and frequency on control and low intensity burn
sites averaged across the 1st 3 years [10]. Following a large wildfire in a western larch
(Larix occidentalis)-Douglas-fir cover type in northern Idaho, spreading dogbane
constituted a maximum of 10% to 14% of cover within the 1st postfire decade due to vegetative
reproduction [164]. It was reported on 11 of 21 plots measuring 16 Ã 82 feet (5 Ã 25 m),
returning 2 to 15 years postfire on sites that had previously supported standing timber or
shrubfields. It was not reported on clearcut sites. Three plots reported flowering in the
1st year [165].
Logging and helicopter yarding were conducted in Rocky Mountain Douglas-fir habitat types of
central Idaho in September through November, 1976. Micro plots on each of the logged areas
were burned under prescription or by wildfire following harvest activities and vegetation
plots were measured 1, 2, 5, and 10 years postburn. A comparison of burned and unburned areas
in the years following fire resulted in the following cover [59]:
Prescribed burned (% cover)
Wildfire burned (% cover)
Year
Unburned
Burned
Unburned
Burned
Pre-disturbance
1
1
1
1
1
1
1
2
1
2
<1
1
1
1
5
1
2
2
3
10
1
2
1
2
Maine:
Five years after a wildfire on Peaks Island off the coast of Maine, spreading dogbane
was considered a characteristic "shrub" layer. The area had also experienced
fire 26 and 28 years prior to measurements [37]. On Mount Desert Island off the coast of
Maine, spreading dogbane returned through vegetative reproduction 1 year after the 1923
wildfire and was considered "abundant" [155].
Michigan: In Michigan spreading dogbane was found on mature jack pine stands, unburned
jack pine stands within a 3-year-old clear cut, and jack pine plots burned under prescription
1 and 2 years previously. The highest frequency of spreading dogbane was found on the 1-year-old
prescribed burn site [1]. In the gray birch-red maple (Betula populifolia-Acer
rubrum) habitat type of Painted Rocks National
Lakeshore, spreading dogbane had an average frequency of 13% and constancy of 9% in an area that
had previously experienced fire [102].
In northern lower Michigan, spreading dogbane populations were assessed at 5 sites supporting
eastern white pine (P. strobus), red pine (P. resinosa) , northern red oak
(Q. rubra), and red maple that had previously experienced natural
and/or prescribed burns. Based on 100 1Ã1 m² quadrats at each site, spreading dogbane was absent
from 4 sites and found with 1% frequency on 1 site 27 years following fire [143]. Out of 53
recorded years, it showed the greatest frequency 16, 38, 45, and 50 years following fire [144].
Spreading dogbane in mature red pine-eastern white pine stands on the southwestern lower peninsula of Michigan had highest cover (0.96%) on a site that
had experienced 3 biennial burns and was not found on sites that had been burned once or were
unburned. Frequencies obtained from 1 m² plots following various burn treatments are as follows
[117]:
Biennial
Burned once
Unburned
Spreading dogbane frequency
1994 (2 burns)
1995 (3 burns)
1994
1995
1994
1995
0.3
1.9
0.1
0
0
0
Minnesota:
In a study related to burn succession in coniferous forests of Minnesota, spreading
dogbane was found on 7 of 10 burns. It was abundant in the herbaceous stage after a
pine burn [63]. In the boreal forests of northern Minnesota, plots were examined in
order to determine the effects of fire, logging, and forest type on biodiversity.
Spreading dogbane was found on 54.3% of postfire stands and 45.7% of post-logging
stands. Prefire occurrence was not recorded [130].
In northeastern Minnesota, a single spreading dogbane plant was recorded
immediately after fire and 4 plants were recorded the following year in a forest
supporting coniferous and hardwood species. Over the next 3 years, spreading
dogbane was absent from all sample sites [118]. Intact red pine soil blocks extracted from an unburned
site and a site burned 3 years previous were exposed to moist greenhouse conditions for 3
months. No seed or seedlings were detected in the unburned soil. The equivalent of 109,000
spreading dogbane seedlings per hectare sprouted in greenhouse samples obtained from the
burned area. No seed was found in sieved samples of burned soil, suggesting that seed had
blown in from adjacent plots postfire. Spreading dogbane frequency as measured at the burn
site was 0%, indicating poor establishment despite seed availability [4].
Montana:
Spreading dogbane was found in Rocky Mountain lodgepole pine (P. contorta
var. latifolia), Rocky Mountain Douglas-fir,
spruce (Picea spp.), and subalpine fir (Abies lasiocarpa) stands 34 years following fire in Glacier National
Park [68]. It was also detected following 2 wildfires and 1 broadcast burn in the northern Rocky
Mountains [166]. It was reported following a shelterwood cut in interior ponderosa pine-Rocky
Mountain Douglas fir forest types in Montana, on plots treated with a low-consumption burn,
high-consumption burn, or no burn. Spreading dogbane responded to increased intensity of fire
with increasing coverage [11]:
Preburn % cover
Postburn (3 years) % cover
No burn
1.62.0-3.5
Low consumption burn (between 0% and 80%
woody fuel consumption)
1.32.6-4.3
High consumption burn (~80% consumption
of woody fuels)
2.33.6-7.4
In a study that monitored the effects of "light" (<360ºF (180 ºC)),
"medium" (360 to 570 ºF (180-300 ºC)), and "hot" (>570 ºF
(300 ºC)) burn conditions in western larch-Douglas-fir habitat types, intermediate
dogbane averaged 1.63% cover on light burns and 0.20% cover on hot burns 3 years
following treatments [157].
New York:
In south-central New York, spreading dogbane was found to be an overall increaser in 8
chestnut oak stands, 3 of which had experienced 1 fire, 3 that had experienced 2 fires,
and 2 that had experienced 3 fires. Average frequency on burned sites was 39.3% while on
unburned sites it was 14.3%. In a similar study conducted in 2 aspen groves, spreading
dogbane had an average frequency of 47.5% on burned sites and 0% on unburned sites [171].
South Dakota:
Spreading dogbane was detected after fire in the Black Hills of South Dakota. Vegetation
surveys took place in July or August, 2 years following a fire that consumed all organic
matter and killed all of the trees [119].
Washington:
In the ponderosa pine-Douglas-fir forest types of the Entiat Experimental Forest in the
Cascade mountains of Washington, 4 watersheds were "severely and uniformly burned"
in 1970 and received seed, seed and fertilizer, or no treatment. Spreading dogbane was most
abundant where fertilizer was applied. Refer to Tiedemann and Klock [175] for seed mix and
fertilizer types used. Average cover and frequency 1 year following treatments are shown below.
The average cover of spreading dogbane on all 4 watersheds 1, 2, 3, and 4
years after the fire was 0.9%, 1.4%, 1.1%, and 1.5%, respectively [176].
1 Year postburn
Cover (%)
Frequency (%)
Seed
0.5846
Seed and fertilizer
1.41731.0682
No treatment
0.4726
On a prairie site in western Washington that is burned annually as a result of military training
exercises, spreading dogbane is 1 of 16 species that retains at least 0.01% cover. Mean cover and
frequency are 0.2% and 16%, respectively [178,179]. In north-central Washington burns covered with
dense snowbrush (Ceanothus velutinus) 20 years after fire, spreading dogbane was reported to
have a "scattered" distribution [103].
Wisconsin:
Spreading dogbane is considered a prevalent species on burned jack pine stands in northwestern
Wisconsin with a frequency of 11.8% and is not considered prevalent in unburned stands. Nine control
sites and 28 burned sites averaging 3.5 burns per stand were examined. Twenty burned stands were
sampled the summer following the last spring burn while the other 8 were sampled 1 year postburn.
Spreading dogbane frequency was 6.8% greater on burned sites [186].
In the bracken fern (Pteridium aquilinum) grasslands of northeastern Wisconsin, spreading
dogbane is considered a "neutral" species, averaging 20.8% frequency on undisturbed sites
and 17.3% frequency following burning. Thirteen sites were burned once, 2 sites were burned 3 times
and 1 stand experienced 2 wildfires. Burning was done in March or April and sampling was completed
in July or August of the same year or the following year. A study utilizing 6 pairs of burned and
unburned stands of jack pine-northern pin oak (Q. ellipsoidalis) in north-central
Wisconsin reported a 1% reduction of spreading dogbane frequency on burned sites [186].
Canada: Spreading dogbane occurred on a logged, burned site in a forest
that dominated before treatment by eastern white pine and paper birch (B. papyrifera). Within
1 year of logging and 1 month of burning, spreading dogbane frequency was 5%, and aboveground biomass
totaled 0.40 g in sample plots covering a total area of 5 m2 [152]. Average ground cover
of spreading dogbane was less than 1% [153]. In another burn conducted with a gasoline-powered flamethrower
held 4 to 12 inches (10-30 cm) above the ground surface, there was no recorded effect on spreading
dogbane. Temperatures reached approximately 1700 ºF (925 ºC) [156].
Spreading dogbane in eastern Ontario was detected with 12% frequency 37 years after harvesting and
burning of a site that previously supported white spruce (Picea glauca), quaking aspen, and eastern white pine [28].
Spreading dogbane has also been reported 1 year after a prescribed burn in jack pine habitat where it
did not previously occur [109].
In the Engelmann spruce (P. engelmannii)-subalpine fir habitat type of the Selkirk Range in western Canada, spreading
dogbane was identified soon after reforestation of a burn site [148]. Following a severe fire in spruce
habitat (Picea spp.) of northern British Columbia where < 0.4 inch (1 cm) of ash and organic
matter were left behind, spreading dogbane was considered one of the most common forbs. The population
peaked after the 3rd year and had declined by year 5 [120].
The following Research Project Summary provides information on prescribed fire use and postfire response of many
plant species, including spreading dogbane:
Understory recovery after low- and high-intensity fires in northern Idaho
ponderosa pine forests
