© G. D. Carr
Mertensia paniculata var. alaskana (Britt.) Williams [1,34], Alaska tall bluebells
Mertensia paniculata var. borealis (Macbr.) Williams [9,30,31,42], northern bluebells
Mertensia paniculata var. eastwoodae (Macbr.) Hultén , Eastwood's bluebells
Mertensia paniculata var. paniculata [30,34], tall bluebells (typical variety)
Distribution of varieties: Of the tall bluebells varieties, the typical variety is the most widespread. Its distribution is identical to that of the species. Alaska tall bluebells is limited to Alaska, Yukon, and Northwest Territory . Northern bluebells occurs in northwestern Montana, adjacent Idaho, and British Columbia south to Washington and Oregon [30,37]. Eastwood's bluebells is present in Alaska and Northwest Territory [1,37]. Plants Database provides a distributional map of tall bluebells and its varieties.ECOSYSTEMS :
balsam fir-cottonwood/prickly rose (Abies balsamea-Populus spp./Rosa acicularis)/tall bluebells phase of the white spruce-fir (Picea glauca-Abies spp.) community type
prickly rose-red currant/naked miterwort (Ribes triste/Mitella nuda)-tall bluebells phase of the black spruce (P. mariana) community type
|© G. D. Carr|
GENERAL BOTANICAL CHARACTERISTICS:
This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available [1,11,19,26,30,41,42,54,70].
Tall bluebells is a native, perennial forb. Aerial stems are erect, 1 to many, and are 8 to 59 inches (20-150 cm) tall. They arise from a fibrous caudex or stout rhizome. Each aerial stem produces 1 to several inflorescences with few to many pendulous, bell-shaped flowers. Basal leaves, when present, are 2 to 8 inches (5-20 cm) long, 1 to 4 inches (2.5-10 cm) wide, cordate to ovate, and borne on 6- to 12-inch- (15-30 cm) long petioles. They are distinctly veined. Numerous cauline leaves are alternate, lanceolate to cordate, 1.2 to 7 inches (3-18 cm) long, 0.4 to 3 inches (1-8 cm) wide, and short-petiolate. They are strigose above and coarsely strigose beneath. Each flower produces 0 to 4 single-seeded nutlets [1,11,26,31,50,52,54].
Descriptions and a key for identifying 3 of the tall bluebells varieties―Alaska tall bluebells, Eastwood's bluebells, and the typical variety―are available in . A general description for northern bluebells is available in [9,31].RAUNKIAER  LIFE FORM:
Pollination: Bumble bees are the only documented pollinator of tall bluebells [46,50].
Breeding system: No information is available on this topic.
Seed production: Each flower may produce up to 4 single-seeded nutlets .
Seed dispersal: No information is available on this topic.
Seed banking: Soil excavated from a tussock tundra site at Eagle Creek, Alaska, was tested in the laboratory for viable seeds. Tall bluebells was part of the aboveground tundra vegetation but did not germinate in the laboratory , suggesting either that it does not have a great capacity for seed banking or that its germination requirements were not met during testing.
Germination: No information is available on this topic.
Seedling establishment/growth: No information is available on this topic.
Vegetative regeneration: Tall bluebells regenerates vegetatively from rhizomes .SITE CHARACTERISTICS:
|State, Region, Province||Variety, if applicable||Site Characteristics|
|Alaska (and neighboring Provinces)||Alaska tall bluebells||woods and riverbanks|
|Eastwood's bluebell||woods and riverbanks|
|typical variety||woods, riverbanks, in McKinley Park to 5,600 feet (1,700 m) |
|Idaho||northern bluebells||streamsides and wet meadows |
|riverbanks, rocky slopes, wet meadows; 5,000-8,400 feet (1,500-2,600 m) |
|Michigan||...*||Coniferous swamps and woods, shaded edges of streams, rocky openings; rarely in deciduous woods |
|Montana (west-central)||...||moist woods and meadows [11,19]|
|Mt Rainier National Park||...||moist places; 4,000 to 6,000 feet (1,200-1,800 m) |
|Pacific Northwest||...||streambanks, wet meadows, damp thickets, and wet cliffs, open forests at all elevations [31,54]|
|Selway-Bitterroot Mountains, ID and MT||...||riverbanks to timberline |
|Canada||...||damp woods |
Tall bluebells is often present in early seral stages and increases in frequency and cover over time. Average percent cover of tall bluebells increased, though not significantly (P=0.516), within a regenerating quaking aspen (Populus tremuloides) stand in Alberta 3, 5, 9, and 20 years after clearcutting. Percent cover was 1%, 2%, 1%, and 4%, respectively . On 18- and 19-year-old black spruce plantations, tall bluebells had mean relative frequency of 3%. Twenty years later at the same site, mean relative frequency was 39% . Tall bluebells was not present in the pioneer stage (25 to 35 years) on gravel outwash from the Muldrow Glacier in Alaska. Cover and frequency increased throughout the meadow (100 years after glacial scour), early shrub (150-200 years), and late shrub (200-300 years) stages, with the greatest tall bluebells cover and frequency during the latter. There was no evidence of tall bluebells in climax tundra (5,000-9,000 years) . Tall bluebells percent frequency and cover increased through the 1st 3 stages of succession recorded for the Chena River floodplain near Fairbanks, Alaska, but tall bluebells was not present in later successional and climax communities. Percent frequency and cover for tall bluebells are provided below .
|Successional stage||Percent frequency||Percent cover|
|15-year-old Alaska willow (Salix alaxensis) stand||10||<1|
|50-year-old balsam poplar (Populus balsamifera) stand||20||1|
|120-year-old white spruce stand||40||2|
|220-year-old white spruce-black spruce stand||0||0|
|climax black spruce/sphagnum (Sphagnum spp.) stand||0||0|
|State or province||Anthesis period|
|Idaho||May to August |
|Ontario||June to September |
|Yukon||May to June |
Fire regimes: The white-black spruce boreal forest ecosystems where tall bluebells most commonly occurs are susceptible to frequent (35-200 years), stand-replacing fires because of the accumulation of large amounts of highly flammable organic matter. Tall bluebells is also common in quaking aspen-dominated boreal forest ecosystems that are characteristic of a mixed-severity fire regime .
The following table provides fire return intervals for plant communities and ecosystems where tall bluebells is important. For further information, see the FEIS review of the dominant species listed below.
|Community or Ecosystem||Dominant Species||Fire Return Interval Range (years)|
|grand fir||Abies grandis||35-200 |
|birch||Betula spp.||80-230 |
|tamarack||Larix laricina||35-200 |
|Great Lakes spruce-fir||Picea-Abies spp.||35 to >200 |
|Engelmann spruce-subalpine fir||Picea engelmannii-Abies lasiocarpa||35 to >200 |
|black spruce||P. mariana||35-200|
|conifer bog*||P. mariana-Larix laricina||35-200 |
|jack pine||Pinus banksiana||<35 to 200 [14,20]|
|Rocky Mountain lodgepole pine*||P. contorta var. latifolia||25-340 [6,7,66]|
|Sierra lodgepole pine*||P. contorta var. murrayana||35-200|
|western white pine*||P. monticola||50-200 |
|aspen-birch||Populus tremuloides-Betula||35-200 [20,71]|
|quaking aspen (west of the Great Plains)||P. tremuloides||7-120 [3,27,49]|
|Rocky Mountain Douglas-fir*||Pseudotsuga menziesii var. glauca||25-100 [3,4,5]|
|coastal Douglas-fir*||P. menziesii var. menziesii||40-240 [3,51,58]|
|western redcedar-western hemlock||Thuja plicata-Tsuga heterophylla||>200 |
FIRE REGIMES: Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes"
DISCUSSION AND QUALIFICATION OF FIRE EFFECT:
No additional information is available on this topic.
PLANT RESPONSE TO FIRE:
Tall bluebells sprouts from the caudex, rhizomes, and roots after fire. It is known to establish on burned soils, likely from an off-site seed source [2,47,72].
|Tall bluebells after a wildfire in Yukon-Charley Rivers National Park. Photo courtesy of USDI, National Park Service.|
DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
Underground vegetative parts allow for tall bluebells regeneration after fire. Mann and Plug  excavated 5 tall bluebells individuals and found plants were spreading laterally by adventitious roots, some as deep as 2 inches (5 cm) below the mineral soil surface. On this basis they inferred that tall bluebells can reproduce after fires by sprouting. Vegetative regeneration of tall bluebells following the 1999 Black River wildfire on quaking aspen boreal forests in southeastern Manitoba was recorded for each fire severity class. During the 1st 4 years after fire, tall bluebells was least abundant on severely burned plots [72,73].
|Mean percent cover||Mean percent frequency|
|Scorched (litter not burned or partially burned)||1.1||11|
|Lightly burned (litter burned but without or with very limited duff consumption)||2.9||23|
|Severely burned (forest floor completely consumed)||<0.1||1|
Tall bluebells responds favorably after fire. It established on mesic sites in the 2nd growing season following a prescribed fire on a jack pine clearcut in Saskatchewan . Tall bluebells was present on 6 of 21 burned stands 12 to 15 years following fire on boreal forests in southeastern Manitoba. Mean percent tall bluebells cover was 0.9% . Frequency and cover of tall bluebells were not significantly affected by a prescribed burn on Lutz spruce (Picea × lutzii) stands in Alaska. Tall bluebells cover before and 7 years after fire was 8% to 6%, respectively, and frequency ranged from 12% before to 18% seven years after fire. Tall bluebells cover and frequency on unburned transects increased in the same years. Cover went from 2% before fire to 8% after fire, and frequency from 15% to 31% . Whether regeneration came from off-site seed or vegetative sprouting was not indicated in either article.
Studies on tall bluebells regeneration from seed after fire are few and inconclusive. Soil block samples collected a week after wildfire on a quaking aspen boreal forest in Alberta were observed under greenhouse conditions to determine the effects of burn severity on seed banks, vegetative banks, and emergent understory species 2 years following fire. Tall bluebells did not germinate in soil samples and had a very low vegetative bank index (proportion of rhizomes present among all blocks; n=30) of 0.03 on blocks taken from "intensely" (complete consumption of aboveground vegetation) burned and unburned sites. Mean percent cover for tall bluebells as an emergent understory species 2 years following fire was: 5.65% on intensely burned sites, 4.28% on "lightly" (characterized by death of aboveground plant parts) burned sites, and 1.19% on unburned sites . In 1972, a study site on quaking aspen stands in central Alberta was burned under prescription. The site was reburned in 1978. Tall bluebells was not observed on either control or burned plots after the 1972 fire. It was, however, found on reburned plots in 1978 . It is possible that in these studies, tall bluebells emerged on the burned areas from an off-site seed source. See the Research Project Summary Understory recovery after burning and reburning quaking aspen stands in central Alberta for an extended report on the Quintilio and others  study.FIRE MANAGEMENT CONSIDERATIONS:
Palatability/nutritional value: No information is available on this topic.
Cover value: No information is available on this topic.VALUE FOR REHABILITATION OF DISTURBED SITES:
Tall bluebells increased or maintained pretreatment levels after white spruce harvesting on Willow Island near Fairbanks, Alaska. The percent frequency of tall bluebells surpassed pretreatment levels within 1 year, and percent cover was surpassed within 2 years of clearcutting. One year after a shelterwood treatment, tall bluebells cover value remained the same, and frequency decreased slightly . Harvesting in quaking aspen stands in British Columbia significantly (P≤0.05) increased the cover of tall bluebells on both grazed and ungrazed study areas, more so in the latter. Greater light transmission and reduced plant competition for water and nutrients after harvesting may increase tall bluebells cover. The percent cover of tall bluebells after treatments is detailed below .
|Ungrazed treatment||Grazed treatment|
Conversely, there is evidence that tall bluebells is intolerant to logging disturbance. In northeastern British Columbia tall bluebells is strongly associated with unlogged plant communities. It showed a reduction in frequency after clearcutting .Herbicides: On boreal quaking aspen stands in Alberta, tall bluebells percent cover was reduced after applications of the herbicide hexazinone. The herbicide was applied in a 3-year-old regenerating quaking aspen clearcut to determine the effects of spraying on the compositional and structural development of vegetation .
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