East Bearskin Lake
Grass Lake
Cut burned Cut unburned Cut burned Precut Postfire Precut Postcut Precut Postfire 1960 1961 1962 1963 1964 1960 1961 1963 1962 1963 1964 0 100 77 87 23 0 0 0 0 97 97Treatment
This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available [9,33,36,42,49,57,67,78,86,90,91,92].
Bicknell's cranesbill is a native, annual or biennial forb. It has erect to decumbent stems ascending 4 to 24 inches (10-60 cm) [33,43,59] from a slender taproot [91]. In some cases Bicknell's cranesbill attains heights greater than 39 inches (100 cm) [9,86]. The flowers are few and small [73]. Fruits are cylindrical capsules and have long stiff hairs or bristles. Bicknell's cranesbill seeds are dark, oblong and finely pitted [43,47,59].
Fire adaptations: Bicknell's cranesbill regenerates after fire from on-site seed stored in the soil seed bank [74,75,76,88,89].
FIRE REGIMES: Bicknell's cranesbill occurs in many fire-dependent ecosystems. FIRE REGIMES for plant communities with Bicknell's cranesbill vary from frequent understory fires in black oak, ponderosa pine, and larch and frequent stand-replacement fire in jack pine to infrequent, stand-replacement crown fires in white spruce. The northern boreal forests where Bicknell's cranesbill most often occurs are characterized by mixed-severity and stand-replacing FIRE REGIMES. Fire-return intervals in jack pine stands in eastern Canada and the Great Lakes were as low as 15 to 35 years. Fire-return intervals averaged between 50 and 150 years in white spruce stands [27].
The following table provides fire-return intervals for plant communities and ecosystems where Bicknell's cranesbill is important. 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".
Fire-return intervals for plant communities with Bicknell's cranesbill Community or Ecosystem Dominant Species Fire-Return Interval Range (years) sugar maple Acer saccharum >1,000 [87] tamarack Larix laricina 35-200 [63] western larch Larix occidentalis 25-350 [12,18,26] Great Lakes spruce-fir Picea-Abies spp. 35 to >200 northeastern spruce-fir Picea-Abies spp. 35-200 black spruce Picea mariana 35-200 conifer bog* Picea mariana-Larix laricina 35-200 [27] jack pine Pinus banksiana <35 to 200 [24,27] Rocky Mountain lodgepole pine* Pinus contorta var. latifolia 25-340 [17,18,80] Sierra lodgepole pine* Pinus contorta var. murrayana 35-200 Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [11] interior ponderosa pine* Pinus ponderosa var. scopulorum 2-30 [11,16,50] red pine (Great Lakes region) Pinus resinosa 3-18 (x=3-10) [23,30] red-white pine* (Great Lakes region) Pinus resinosa-P. strobus 3-200 [24,40,52] eastern white pine Pinus strobus 35-200 [87] aspen-birch Populus tremuloides-Betula papyrifera 35-200 [27,87] quaking aspen (west of the Great Plains) Populus tremuloides 7-120 [11,37,56] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [11,13,14] coastal Douglas-fir* Pseudotsuga menziesii var. menziesii 40-240 [11,58,66] black oak Quercus velutina <35 [87] western redcedar-western hemlock Thuja plicata-Tsuga heterophylla >200 [11] *fire-return interval varies widely; trends in variation are noted in the species reviewDeer preferred grazing Bicknell's cranesbill growing in young clearcut-and-burned sites in the Seeley-Swan area of northwestern Montana [54].
Palatability/nutritional value: No information is available on this topic.
Cover value: No information is available on this topic.
Bicknell's cranesbill regenerates from seed [5]. Information on pollination, breeding system, seed production, seed establishment, and growth are lacking for Bicknell's cranesbill. Research is needed on Bicknell's cranesbill regeneration.
Seed dispersal: The capsules of Bicknell's cranesbill open explosively, splitting lengthwise from the bottom and flinging seeds away from the parent plant [47]. The large seeds are not adapted for broad wind dispersal [31] but can be transferred by small mammals [5].
Seed banking: Bicknell's cranesbill stores long-lived propagules in the soil [10,74,75,76,77]. It germinates and flowers in the first 1 to 3 years after fire and stores seeds for long periods between brief postfire flowerings [41,60,68].
Bicknell's cranesbill seeds have been found in soils of stands 200+ years old; however, the viability of these seeds is unknown. A study conducted in the Boundary Waters Canoe Area, Minnesota, recovered seeds from soil samples taken from plots in which the time since last disturbance ranged from 3 to 200+ years. The plots occurred in stands of jack pine, red pine, eastern white pine, quaking aspen, balsam fir, paper birch, and white spruce. The viability of the seeds from the old growth was not revealed since seeds from all plots were combined to undergo germination tests. Thirty percent of the combined seeds germinated [7]. Fyles [31] reveals finding Bicknell's cranesbill seed in soil samples taken from mature jack pine and white spruce stands in central Alberta where parent plants did not occur. He suggests that the seed was deposited by plants growing in the stand in the past and that the population was maintained as a result of extended seed longevity [31].
Germination: The seeds of Bicknell's cranesbill, in most cases, are stimulated to germinate by fire-induced high temperatures [1,2,22,35,68,85,93]. Bicknell's cranesbill seeds present in both burned (Little Sioux wildfire) and unburned soils taken from 270-year-old red pine stands in the Boundary Waters Canoe Wilderness Area underwent greenhouse germination tests. Bicknell's cranesbill only germinated from soil taken from the burned land 3 years after fire, suggesting that heat is required to break dormancy [8]. A greenhouse study by Granstrom and Schimmel [35] revealed that dormancy was released after exposure to high temperatures (moist heat, water bath). There was progressively higher germination at temperatures above 100 to 110 °F (40-45 °C), with 90% germination after 10 minutes exposure at 150 to 210 °F (65-100 °C). Lethal temperatures for seeds were in the range of 200 to 230 °F (95-110 °C). Virtually no germination occurred in nonheated seeds [35].
Germination can also be triggered by the warming of the soil [47], such as when the canopy cover is removed. Bicknell's cranesbill was present on clearcuts on boreal mixed-wood (white spruce, black spruce, balsam fir, jack pine, quaking aspen, paper birch, balsam poplar) forests in Ontario, but was significantly (P<0.05) more abundant on wildfire sites dominated mainly by quaking aspen [38]. Bicknell's cranesbill was observed growing 3 and 5 years after clearcutting stands dominated by quaking aspen in Alberta. The harvested forest was of fire origin, but no further information on the fire was given [79].
Bicknell's cranesbill may germinate in the absence of heat treatments as well. Soil samples from partially cut or clearcut boreal stands in the Black Sturgeon Forest northeast of Thunder Bay, Ontario, underwent 3 months of cold storage to mimic stratification. Subsequent greenhouse germination tests were used to identify seed banking species. Bicknell's cranesbill did germinate from these soils; however, there was no mention of heat treatment applied to samples or recent fire on sampled sites. Bicknell's cranesbill was not found in the aboveground vegetation at the study site [64].
Vegetative regeneration: Information on vegetative regeneration in Bicknell's cranesbill is lacking. Bicknell's cranesbill may sprout from the root crown after top-kill; however, reproduction from seed is Bicknell's cranesbill's primary method of regeneration.
Bicknell's cranesbill is a shade intolerant, ephemeral, pioneer species that occurs after fire from soil stored seed [10,28,46,68,74] already present at the time of disturbance.
As a residual, colonizing species following fire [74], Bicknell's cranesbill most often occurs in early postfire communities; however, there is evidence that it can occur in later seral communities. Maycock [55] reports the presence of Bicknell's cranesbill in 75- to 85-year-old white spruce and balsam fir stands on the Keweenaw Peninsula, northern Michigan, that were free from "unnatural disturbance". The presence of charcoal in the soil indicated that the stand was of fire origin. Bicknell's cranesbill's presence was also recorded in a 130-year-old mixed stand dominated by sugar maple (Acer saccharinum) along with balsam fir, white spruce, and red pine [55]. There was no mention of previous fire in this stand. Taylor [81] reports the presence of Bicknell's cranesbill on open stream banks and meadows found within climax forests (mainly western hemlock-Sitka spruce (Picea sitchensis)) of southeastern Alaska.
Geranium bicknellii is a species of geranium known by the common names Bicknell's cranesbill and northern cranesbill. It is native to much of the northern half of North America, where it can be found in a number of forest and woodland habitats. This is an annual or biennial herb which grows hairy stems up to about half a meter long. It may be erect or lie near the ground. Each leaf is several centimeters long and wide and is divided into several lobes, each of which may have smaller lobes or teeth. Flowers grow singly or in pairs and have pointed sepals and small lavender petals, each with a notch in the tip. The fruit has a rounded body with a long, straight style about 2 centimeters in length and tipped with a small beak.
Geranium bicknellii is a fire-adapted species, occurring most abundantly in recently burned forests. The seeds remain dormant while buried in the forest floor, sometimes for centuries, until a fire removes the organic litter and exposes the seeds to sunlight. The geraniums will germinate, bloom, and set seed profusely for several years after the fire, until other plants grow large enough to shade them out. The new seeds will then lie dormant in the soil, waiting for the next fire.[1]
The leaves of this species and some related species are somewhat difficult to distinguish from those of some plants in the family Ranunculaceae, particularly members of the genera Aconitum and Delphinium. They have also been confused with members of the genus Ranunculus, which is also part of that family, such as the meadow buttercup, Ranunculus acris. As the species from this family with a similar leaf shape are toxic to ingest or sometimes even touch, especially in the case of Aconitum species, it is possible that this is an example of mimicry designed to reduce herbivory. However, it may simply be accidental, due to adaption to conditions. As the family Ranunculaceae is especially ancient, other families have had quite a lot of time to mimic their characteristics via selection by herbivory.[2][3]
Geranium bicknellii is a species of geranium known by the common names Bicknell's cranesbill and northern cranesbill. It is native to much of the northern half of North America, where it can be found in a number of forest and woodland habitats. This is an annual or biennial herb which grows hairy stems up to about half a meter long. It may be erect or lie near the ground. Each leaf is several centimeters long and wide and is divided into several lobes, each of which may have smaller lobes or teeth. Flowers grow singly or in pairs and have pointed sepals and small lavender petals, each with a notch in the tip. The fruit has a rounded body with a long, straight style about 2 centimeters in length and tipped with a small beak.
Geranium bicknellii is a fire-adapted species, occurring most abundantly in recently burned forests. The seeds remain dormant while buried in the forest floor, sometimes for centuries, until a fire removes the organic litter and exposes the seeds to sunlight. The geraniums will germinate, bloom, and set seed profusely for several years after the fire, until other plants grow large enough to shade them out. The new seeds will then lie dormant in the soil, waiting for the next fire.
The leaves of this species and some related species are somewhat difficult to distinguish from those of some plants in the family Ranunculaceae, particularly members of the genera Aconitum and Delphinium. They have also been confused with members of the genus Ranunculus, which is also part of that family, such as the meadow buttercup, Ranunculus acris. As the species from this family with a similar leaf shape are toxic to ingest or sometimes even touch, especially in the case of Aconitum species, it is possible that this is an example of mimicry designed to reduce herbivory. However, it may simply be accidental, due to adaption to conditions. As the family Ranunculaceae is especially ancient, other families have had quite a lot of time to mimic their characteristics via selection by herbivory.
