Index of Species Information

SPECIES:  Pinus banksiana

Introductory

SPECIES: Pinus banksiana
AUTHORSHIP AND CITATION : Carey, Jennifer H. 1993. Pinus banksiana. 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/ []. ABBREVIATION : PINBAN SYNONYMS : Pinus divaricata (Ait.) Sudw. SCS PLANT CODE : PIBA2 COMMON NAMES : jack pine scrub pine northern scrub pine gray pine black pine Banksian pine Hudson Bay pine Banks pine princess pine TAXONOMY : The currently accepted scientific name of jack pine is Pinus banksiana Lamb. [48]. A rarely described shrubby form, P. b. forma procumbens Rouseau, occurs in Quebec and Nova Scotia on rocky headlands [64]. Jack pine hybridizes with Rocky Mountain lodgepole pine (Pinus contorta var. latifolia) where their ranges overlap in central and northwestern Alberta and in scattered locations in Saskatchewan. The hybrid is P. X murraybanksiana Righter & Stockwell [48]. LIFE FORM : Tree FEDERAL LEGAL STATUS : No special status OTHER STATUS : NO-ENTRY


DISTRIBUTION AND OCCURRENCE

SPECIES: Pinus banksiana
GENERAL DISTRIBUTION : Jack pine occurs in Canada and in the north-central and northeastern United States.  The northern boundary of its range extends east from the Mackenzie River in the Northwest Territories to Cape Breton Island, Nova Scotia.  Its range extends southwest from Nova Scotia to Maine, New Hampshire, Vermont, northern New York, Michigan, extreme northwestern Indiana, and northeastern Illinois, and northwest through Wisconsin and Minnesota to Manitoba, Saskatchewan, central Alberta, and extreme northeastern British Colombia [48].  Jack pine has been planted outside its native range in the Central States and in Alaska. ECOSYSTEMS :    FRES10  White - red - jack pine    FRES11  Spruce - fir    FRES15  Oak - hickory    FRES19  Aspen - birch STATES :      IL  IN  ME  MI  MN  NH  NY  VT  WI  AB      BC  MB  NB  NT  NS  ON  PE  PQ  SK BLM PHYSIOGRAPHIC REGIONS : NO-ENTRY KUCHLER PLANT ASSOCIATIONS :    K093  Great Lakes spruce - fir forest    K095  Great Lakes pine forest    K100  Oak - hickory forest    K108  Northern hardwoods - spruce forest SAF COVER TYPES :      1  Jack pine     12  Black spruce     14  Northern pin oak     15  Red pine     16  Aspen     18  Paper birch SRM (RANGELAND) COVER TYPES : NO-ENTRY HABITAT TYPES AND PLANT COMMUNITIES : Jack pine is a dominant tree in the southern boreal forest region. Associates are almost always subdominant except for aspen (Populus spp.), paper birch (Betula papyrifera), and red pine (Pinus resinosa) which may be codominant [34]. The following published classifications list jack pine as dominant or codominant: The vegetation of Alberta [57] Field guide to forest ecosystems of west-central Alberta [28] Virgin plant communities of the Boundary Waters Canoe Area [59] Plant communities of Voyageurs National Park, Minnesota, U.S.A. [46] The principal plant associations of the Saint Lawrence Valley [32] The vegetation of Wisconsin [31] Classification and ordination of southern boreal forests from the    Hondo-Slave Lake area of central Alberta [47] Jack pine-lichen woodland on sandy soils in northern Saskatchewan and    northeastern Alberta [16]

MANAGEMENT CONSIDERATIONS

SPECIES: Pinus banksiana
WOOD PRODUCTS VALUE : Jack pine is an important commercial timber species in the United States and Canada.  The moderately hard and heavy wood is used for pulpwood, lumber, telephone poles, fence posts, mine timbers, and railroad ties [17,41]. IMPORTANCE TO LIVESTOCK AND WILDLIFE : Jack pine provides food and cover for numerous wildlife species.  Jack pine seeds are eaten by rodents and birds.  The stomach contents of red squirrels, chipmunks, and white-footed mice showed that they had eaten on average 392 seeds, 31 seeds, and 19 seeds apiece, respectively. Red-backed voles also consume jack pine seeds [72].  White-tailed deer, caribou, and snowshoe hares browse jack pine [12,68,80].  Woodland and barren-ground caribou eat lichens growing on the ground and on tree bark in jack pine stands [3,68]. The federally endangered Kirtland's warbler is endemic to jack pine barrens.  Nests are located on the ground near or at the edge of fairly dense young jack pine stands.  For further information on this bird and its relationship to jack pine, see FEIS review of Kirtland's warbler. PALATABILITY : Jack pine browse is of intermediate preference to white-tailed deer [36] and highly preferred by snowshoe hares in the winter [12].  Moose do not prefer this browse, and it constitutes less than 1 percent of their diet [8,30].  Caribou only browse jack pine occasionally; it constituted 1.7 to 3.9 percent air-dry weight of barren-ground caribou rumens in one study [68]. NUTRITIONAL VALUE : Jack pine browse is on average, by wet weight, 3.8 percent crude protein, 4.2 percent fat, 15.1 percent crude fiber, and 22.2 percent nitrogen-free-extract.  It is more digestible than northern white-cedar (Thuja occidentalis) browse, although much less preferred [80]. COVER VALUE : Jack pine stands provide cover to mammals such as moose [8] and snowshoe hares [12].  Debris and seedlings in burned stands provide cover for smaller mammals such as red-backed voles [44]. VALUE FOR REHABILITATION OF DISTURBED SITES : Jack pine is adapted to acidic, dry, and sandy disturbed sites with a lower pH limit of 4.0 [82].  In Ohio, jack pine is recommended for planting on drier upper slopes, on moister and better drained lower slopes, on all sandy and loamy mine spoils, and on clay spoils that have a high proportion of coarse material [49].  This species has performed well on anthracite spoils in Pennsylvania, with 48 percent survival at age 10.  Survival was low (13 percent after 30 years), however, on coal mine spoils in Missouri and Kansas.  In mixed plantings with hardwoods in Illinois and Indiana, jack pine showed only 8 percent survival after 30 years [82]. Jack pine is recommended for planting on mined oil sands in northeastern Alberta [16,39].  A planting density of 182 jack pine stems per acre (450/ha) for tailing sands and 112 stems per acre (278/ha) for overburden sites is recommended to provide 61 surviving stems per acre (150/ha), a density considered sufficient for the natural perpetuation of either a fully stocked jack pine stand or a mixed pine/deciduous stand [39]. OTHER USES AND VALUES : Jack pine is planted for Christmas trees [17]. OTHER MANAGEMENT CONSIDERATIONS : Jack pine is intensively managed for lumber in the Lake States.  Stands are regenerated by planting, direct seeding, scattering cone-bearing slash on mechanically scarified ground, or using the seed tree silviculture method combined with prescribed fire.  Jack pine is also managed to provide habitat for the federally endangered Kirtland's Warbler. Root borers, root feeders, shoot and stem borers, leaf feeders, needle miners, and sucking insects affect the survival and growth of seedlings. Many other insects feed on jack pine cones [67].  Young stands of jack pine are susceptible to defoliation by the redheaded pine sawfly (Neodiprion lecontei) [84]. The jack pine budworm (Choristoneura pinus) defoliates mature jack pine. There is often a 20- to 30-year lag after major fire before the jack pine budworm invades.  The regenerated stand does not produce abundant cones on average for about 20 years and the jack pine budworm population thrives in years of abundant cone production.  A model has been developed to forecast the area to be infested with this pest [83]. In one study, all trees that died from jack pine budworm infestation had roots infected with Armillaria root rot (Armillaria ostoyae) [52]. Jack pine is susceptible to many diseases including rust fungi [67]. Pine gall rust (Endocronartium harknessii) accounted for more than 99 percent of all stem rusts in a survey of 71 young jack pine plantations in northwestern Ontario [43].

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Pinus banksiana
GENERAL BOTANICAL CHARACTERISTICS : Jack pine is a small to medium-sized, native, coniferous, evergreen tree with 0.75- to 2.0-inch-long (2-5 cm) needles.  Mature jack pine are usually 55 to 65 feet (17-20 m) tall and 8 to 10 inches (20-25 cm) in d.b.h. but can attain a maximum height of 100 feet (30 m) and a diameter of 25 inches (64 cm) [67].  On extremely harsh, sandy sites, jack pine is small and bushy [31].  Although the canopy begins showing signs of decay by age 75, jack pine can live more than 200 years [17].  A 243-year-old jack pine was found in the Boundary Waters Canoe Area in Minnesota [40]. Jack pine develops a taproot as a seedling and maintains it to maturity. On deep, well-drained soils, roots of mature trees may penetrate 9 feet (2.7 m).  The abundant lateral roots are mostly confined to the upper 18 inches (46 cm) of soil [67]. Although the species is predominantly closed-coned, individual trees can have nonserotinous cones or a combination of serotinous and nonserotinous cones.  Mature stands with mostly open-coned trees are common in the southern Great Lakes region and sporadic in the East [29]. RAUNKIAER LIFE FORM :       Phanerophyte REGENERATION PROCESSES : The minimum seed-bearing age of open-grown jack pine is 5 to 10 years. Some seed is produced every year and serotinous cones accumulate in the crown.  A mature stand of jack pine may have as many as 2 million seeds per acre (5 million/ha) stored in unopened cones [35].  Because of abundant seed production, few mature trees are necessary to regenerate a stand.  Regeneration after fire in a balsam fir (Abies balsamea) forest with only 5 relic jack pine per acre (12/ha) averaged 400 jack pine seedlings per acre (1000/ha) in the first postfire year [74]. The serotinous cones, sealed shut by a resinous bond, require high temperatures to open.  This heat is usually provided by fire, but hot, dry weather (air temperatures of at least 80 degrees Fahrenheit [27 deg C]) also opens some cones [67].  Because temperatures required to open cones typically occur in the warmest part of the summer, survival of new germinants may be poor because of drought conditions or lack of time to become established before winter. The winged seeds are the smallest of the native North American pines [35] and are dispersed by gravity and wind.  The effective dispersal range is about 110 to 130 feet (34-40 m) or two tree heights [53]. Seeds usually germinate rapidly after release when the 10-day mean maximum air temperature is 65 degrees Fahrenheit (18 deg C) or higher [35].  Jack pine seeds occasionally exhibit partial dormancy which is probably broken naturally by heat from fire [4].  Seeds remain viable in closed cones for years, but viability decreases over time.  Eyre and LeBarron [35] found that 1- to 6-year-old cones had 78 to 89 percent seed viability and cones over 5 years old had 62 percent seed viability. Fifty percent of 20-year-old seeds may be viable [17]. Exposed mineral soil or thin residual humus of about 0.2 inch (0.5 cm) or less provide the best seedbeds.  The presence of deeper humus has an adverse effect on establishment; humus deeper than 1.5 inches (3.8 cm) is a low-quality seedbed [22].  Successful germination and establishment of jack pine usually occurs only after fire, but mechanical disturbance may also expose adequate mineral seedbeds [33].  In northeastern Minnesota, germination averaged 63 percent on mineral soil, 49 percent on burned duff, 47 percent on scarified duff, and 17 percent on undisturbed duff.  First-year survival of germinated seedlings was 84 percent on mineral soil, 70 percent on burned duff, 41 percent on scarified duff, and 41 percent on undisturbed duff [35]. Germination and initial survival sometimes improve with partial shade, but the positive effect of shade eventually becomes negative because seedlings soon require higher light levels [10].  Mortality of 2-year-old jack pine seedlings was high under 11 and 20 percent of full light, but minimal under 43 percent light and higher [69].  Seedling survival may be low if drought conditions follow germination.  However, in northeastern Minnesota, 3 consecutive days of 140 degree Fahrenheit (60 deg C) surface temperatures for 2 hours did not result in appreciable jack pine mortality [5]. During its first 20 years, jack pine is one of the fastest growing conifers in its native range [67].  Maximum growth occurs under 43 percent light and higher [69]. Jack pine does not reproduce vegetatively. SITE CHARACTERISTICS : Jack pine occurs on level to gently rolling sand plains of glacial outwash, fluvial, or lacustrine origin.  It also occurs on eskers, sand dunes, rock outcrops, bald rock ridges, and lake shores.  In the Lake States, it commonly occurs between 1,000 and 1,500 feet (300-460 m) in elevation with a maximum elevation of about 2,000 feet (610 m).  In the East, jack pine grows near sea level to about 2,000 feet (610 m), with a population in New Hampshire occurring at around 2,500 feet (760 m) [34,67]. Jack pine usually grows in dry, acidic sandy soils of the Spodosol or Entisol Order, but it also grows in loamy soil, thin soil over bedrock, peat, and soil over permafrost.  Although jack pine does not usually grow in moderately alkaline soil, it can grow in calcareous soils up to pH 8.2 if normal mycorrhizal fungi associates are present [67]. Common tree associates of jack pine not mentioned in Distribution and Occurrence are bur oak (Quercus macrocarpa), northern red oak (Q. rubra), red maple (Acer rubrum), balsam fir, white spruce (Picea glauca), tamarack (Larix laricina), balsam poplar (Populus balsamifera), bigtooth aspen (P. grandidentata), and quaking aspen (P. tremuloides) [34]. Common shrub associates include prickly rose (Rosa acicularis), bunchberry (Cornus canadensis), velvetleaf blueberry (Vaccinium myrtilloides), mountain cranberry (V. vitis-idaea), bearberry (Arctostaphylos uva-ursi), American green alder (Alnus crispa), Labrador tea (Ledum groenlandicum), wintergreen (Pyrola spp.), and beaked hazel (Corylus cornuta) [28,34,46,47,57]. Groundcover commonly consists of reindeer lichen (Cladonia spp.) on drier sites and feather mosses, especially mountain fern-moss (Hylocomium splendens) and Schreber's moss (Pleurozium schreberi), on moister sites [16,34,57]. SUCCESSIONAL STATUS : Obligate Initial Community Species Jack pine invades areas where mineral soil has been exposed by major disturbance such as fire [17].  It also rapidly invades newly formed dunes after stabilization by grasses [60].  It is one of the most shade-intolerant trees in its native range; only aspens, paper birch, and tamarack are less tolerant [67]. Jack pine begins to show signs of decadence by age 75 [17], decreases in frequency by 150 years, and may disappear completely after 200 years [13], although some relic jack pine survive nearly 250 years [40].  In the absence of fire, jack pine is succeeded by longer lived species such as red pine (P. resinosa) or white pine, or by more shade-tolerant species such as balsam fir and black spruce (Picea mariana).  Black spruce, which often seeds in at the same time as jack pine, grows slower but lives longer, becoming codominant after 90 years and eventually succeeding jack pine [16,40,42].  On the driest, harshest sites, jack pine may persist and form an edaphic climax [67]. Although generally occurring in even-aged stands that regenerated after fire [34], some jack pine stands are uneven-aged.  Recruitment of jack pine may occur fairly long after a fire if the stand is only partially stocked.  In 65 percent of mature stands studied in northern lower Michigan, the largest individuals differed in age by 10 to 23 years. Two stands contained 40- to 45-year-old jack pines that had survived a wildfire 10 years previously, a dominant intermediate class of 22- to 35-year-old pine regenerated after the fire, and numerous smaller individuals from 4 to 20 years of age [1].  Zoladeski and Maycock [85] suggest that recruitment of jack pine stops completely 50 years after stand initiation, and that ultimate success is limited to the earliest generation of jack pine. Clearcutting alone or clearcutting followed by burning converts sites previously dominated by mature jack pine to meadows dominated by Carex spp. or early successional hardwoods, respectively [67]]. SEASONAL DEVELOPMENT : Jack pine staminate and ovulate cone primordia are initiated in late summer and then go dormant until spring.  Pollen shedding usually occurs in late spring or early summer but is highly dependent on the weather. Fertilization occurs 13 months after pollination.  Cones mature in late summer or early fall, 2 years after initiation [67].

FIRE ECOLOGY

SPECIES: Pinus banksiana
FIRE ECOLOGY OR ADAPTATIONS : Of all boreal forest conifers, jack pine is best adapted to fire [66]. With medium thick bark [15], mature individuals have only a moderate tolerance of fire, but populations survive because of delayed seed release from serotinous cones, early reproductive maturity, fast growth rates in full sun, and preference for mineral soil seedbeds [54,66]. In a model that integrates plant population dynamics and disturbance, jack pine is used to illustrate a species that maximizes the probability of being reproductively mature at the time of the next recruitment opportunity.  Fire provides the regeneration opportunity which usually results in mortality of the mature forest [27]. Cone serotiny:  The resin of serotinous cones melts when heated, usually at temperatures in excess of 140 degrees Fahrenheit (60 deg C).  In one study, cones opened in 80 seconds at 200 degrees Fahrenheit (93 deg C) and within 20 seconds at temperatures above 400 degrees Fahrenheit (204 deg C).  Seed viability is not markedly affected by heating, unless the cone ignites, which results in complete loss of seed viability.  For cones at 8 percent moisture content, the interval between cone opening and cone ignition lies between about 200 and 1,300 degrees Fahrenheit (93-705 deg C), depending on the time of exposure.  Cones exposed to temperatures of 800 degrees (427 deg C) or less did not ignite during a 5-minute test.  Cones ignited in 60 seconds when exposed to temperatures of 900 degrees (482 deg C) Fahrenheit and in 2 seconds when exposed to temperatures of 1,300 degrees Fahrenheit (705 deg C).  Heating cones at 900 degrees Fahrenheit (482 deg C) for 30 seconds had no adverse effect on germination.  Jack pine seeds unprotected by cones remain viable when exposed to high temperatures until the wings ash and the seed coats crack [9].  Crown torching does not ignite cones because the high temperatures are unlikely to last more than 3 minutes [9]. Regeneration:  Seeds are dispersed from cones after fire and germinate on burned duff or mineral soil exposed by fire.  Regeneration failures are associated with low-severity surface fires that result in little crown involvement [76] or in little duff removal [11].    Fire regime:  Estimates of fire intervals in jack pine forests are generally less than 50 years [40].  Based on jack pine fire scars, the shortest and longest times between major fires in jack pine forests of northern Ontario were 5 and 30 years, respectively [50].  The mean fire return interval for jack pine forests in the Athabasca Plains in northern Saskatchewan and northeastern Alberta is 38 years [16].  Large upland ridges and ridge complexes, far from natural fire breaks, burn most frequently.  Jack pine forests that burn more frequently than every 5 to 10 years become pine barrens [31].  Major stand-replacing fires in the Boundary Waters Canoe Area occurred in years with summer droughts [40]. The accumulation of litter and debris on the forest floor over time increase the likelihood of moderate- or high-severity fire [40].  A lichen mat, a highly flammable and continuous fuel source at ground level, develops within 40 years and is important in supporting fires in jack pine forests [16]. Mature and immature jack pine forests have very different stand and fuel characteristics and, therefore, exhibit different fire behavior.  The mature jack pine fuel type in Ontario is characterized by 635 jack pine per acre (1,569/ha) averaging 58 feet (17.7 m) in height, and 5.8 inches (14.7 cm) in d.b.h. with an understory of black spruce [76].  The base of live crown in mature jack pine forests is typically 33 feet (10 m) above the ground surface [42]. After observing 12 experimental fires under different weather conditions, Stocks [75] grouped fire behavior in the mature jack pine fuel type into three categories:  (1) surface fires with slow to moderate rates of spread, low to medium flame heights (0.3 to 3.3 feet [0.1-1.0 m]), and a fire intensity less than 140 btu/s/ft (<500 kW/m); (2) vigorous surface fires with various degrees of torching or intermittent crowning, flame heights about 6.6 feet (2 m), and fire intensities of 140 to 870 btu/s/ft (500-3,000 kW/m); and (3) extremely vigorous surface behavior with high rates of spread (33 feet per minute [10 m/min]) that result in active crown fires with intensities over 1160 btu/s/ft (4,000 kW/m).  Because of the gap between the crown base and the surface fuels, sustained crown fires in this fuel type are rare, even with windspeeds above 16 miles per hour (25 km/h) at 33 feet (10 m) above the ground surface [76]. The immature jack pine fuel type is characterized by 3,489 live jack pine stems per acre (8,614/ha) averaging 26.9 feet (8.2 m) in height and 2.1 inches (5.3 cm) in d.b.h. with an understory of 3,953 dead, suppressed jack pine stems per acre (9,760/ha) ranging from 7 to 20 feet (2-6 m) in height [76].  The extremely dense nature of the stand and the vertical fuel continuity make it difficult for fires to spread at even moderate rate without crown fuels becoming involved [74].  Active crown fires occur at intensities of 1,450 btu/s/ft (5,000 kW/m) [76].  This fuel type crowns at a lower rate of spread than any other boreal forest fuel type [42].  Of 12 experimental fires in immature jack pine stands, the only two fires that did not crown had very low spread rates of 2.3 and 6.9 feet per minute (0.7 and 2.1 m/min), representing minimum conditions for continuous fire spread in this fuel type.  The rate of spread for the other 10 fires that crowned ranged from 26 to 162 feet per minute (7.9-49.4 m/min) [74].  Short-term spread rates and intensities as high as 223 feet per minute (68 m/min) and 17,350 btu/s/ft (60,000 kW/m) have been documented [76]. Temperatures during 18 surface fires in an open jack pine barren in northern Ontario were recorded.  The ground vegetation consisted of sweet-fern (Comptonia peregrina), blueberries (Vaccinium spp.), and abundant lichen and moss.  Temperatures recorded at 2 to 4 inches (5-10 cm) above the ground ranged from 248 to 1013 degrees Fahrenheit (120-545 deg C).  Fires with temperatures greater than 662 degrees Fahrenheit (350 deg C) occurred in dense vegetation with more than 0.7 ounce per square foot (235 g/sq m) fuel dry weight.  High wind speeds appeared to have a cooling effect on the fire temperatures [73]. POSTFIRE REGENERATION STRATEGY :    Tree without adventitious-bud root crown    Crown residual colonizer (on-site, initial community)    Initial-offsite colonizer (off-site, initial community)

FIRE EFFECTS

SPECIES: Pinus banksiana
IMMEDIATE FIRE EFFECT ON PLANT : Mature individuals survive low-severity fires [65].  Jack pine is typically killed by crown fires or by moderate-severity surface fires [37].  Alexander [7] found that double fire scars were fairly common in jack pine, but triple fire scars were rare, suggesting that an individual tree may survive only one or two surface fires in a lifetime. DISCUSSION AND QUALIFICATION OF FIRE EFFECT : NO-ENTRY PLANT RESPONSE TO FIRE : Serotinous cones opened by the heat of fire release jack pine seeds onto seedbeds exposed by fire.  Jack pine establishment is limited primarily by the depth of organic matter and, therefore, progressively increases with greater fire severity [22,77].  The dead boles of the former stand provide partial shade during the first few years of establishment [18]. Regeneration is typically better after summer fires than spring fires. In the Boundary Waters Canoe Area in Minnesota, a spring fire (The Little Sioux Fire) occurred while the forest floor was still cool and moist from snowmelt, and only the top few centimeters of duff were removed.  In the first postfire growing season, jack pine seedling density on three sites ranged from 0.86 to 1.58 seedlings per square foot (9.3-17.0/sq m).  A summer fire (The Prayer Lake Fire) exposed mineral soil almost everywhere and also destroyed many competing plant seeds and reproductive structures.  Seedling densities on two sites after the summer fire was 3.04 and 6.29 seedlings per square foot (32.7 and 67.6/sq m), considerably higher than the spring fire regeneration [58].  On a Little Sioux Fire site, seedling density decreased from 0.91 seedlings/sq ft (9.8/sq m) in the first postfire year to 0.61 seedlings/sq ft (6.6/sq m) in postfire year 2 because of competition [14]. In a 3-year study of postfire emergence of jack pine seed sown on two recently burned seedbed sites, jack pine seeds germinated in the first 2 years after being sown, but not the third year.  On the wetter site, 37 percent of viable seed sown emerged the first year and 18 percent the second year.  On the drier site, 14 percent emerged the first year and 8 percent emerged the second year.  The seedbed may be more favorable in postfire year 2 because of shade provided by regenerating understory species.  The authors conclude that a 1-year delayed emergence from soil-stored seed is an important strategy for postfire jack pine regeneration [78]. Conflicting reports in the literature of the effect ash has on jack pine germination may result from differences in type of ash and degree of leaching.  Ash from burned surface organic matter is chemically neither detrimental nor advantageous to the establishment of jack pine.  Wood ash is detrimental because of its extreme alkalinity, and hardwood ash is a poorer substrate than softwood ash.  Leaching of the ash improves germination rates [79]. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE : NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS : Dense, young stands are extremely susceptible to crowning wildfire which is hard to control.  A prescribed fire for the purpose of creating Kirtland's Warbler habitat escaped control in 1980 at Mack Lake, Michigan.  The fire crowned in a sapling stand, at times spread as fast as 175 feet per minute (53 m/min), and did not slow down until it ran out of jack pines and into hardwoods [70]. Prescribed fire is used in the jack pine type to prepare seedbeds, reduce fire hazard, remove slash for easier planting, and/or open serotinous cones in jack pine seed trees [55].  Slash has also been burned in order to release seeds from cones in the slash.  This method is ineffective, however, because if the fire is hot enough to prepare an adequate seedbed, it destroys the cones [10,19].  Reproduction after slash fires is often no better than on unburned clearcuts [23]. The seed tree silviculture method in conjunction with prescribed fire is the most promising method for regenerating jack pine.  A prescribed early summer fire serves to burn the slash, prepare a seedbed, and open the serotinous cones in the seed trees [55]. While headfires may be more likely to open serotinous cones high in the crowns of trees, backfires are generally recommended for use in seed-tree systems because they move slower, may burn more humus, and are safer [5,11].  However, in a series of prescribed fires in central Ontario, backfires removed no more duff than headfires.  Drought conditions were the the most important criteria in whether or not the fire resulted in an adequate removal of humus [20]. Because of drier conditions, summer fires prepare better seedbeds than spring fires [19,20,21].  If managers are relying on a natural seed source, the prescribed fire should be timed early enough in the season so that seedlings become well-established before winter [11], or late enough so that seeds overwinter before germinating [5].  See Fire Case Study for more information on prescribed fires in seed-tree systems. Full-tree harvesting, in which a tree is delimbed at a landing, is becoming a common practice.  This method leaves little slash to use as fuel for seedbed-preparation prescribed fire.  However, if feather mosses such as Schreber's moss are present, they will carry fire.  Spread rates up to 164 feet per minute (50 m/min) over short distances were observed in this fuel type, and prescribed fires have resulted in statistically significant reductions in duff depth [56]. Dwarf-mistletoe (Arceuthobium americanum), which parasitizes jack pine in the western part of its range, persists on dry ridges with sparse undergrowth where fires are less severe and do not kill every tree. Dwarf-mistletoe is eliminated if fire kills all of the trees. Prescribed burning of logging slash and residual trees sanitizes an area [6].  Seeds of dwarf-mistletoe are explosively discharged up to 60 feet (18 m) from the canopy margin, so a minimum buffer of 66 feet (20 m) is recommended between infected trees and new pine regeneration [61]. Equations were developed to predict the forest-floor moisture content under jack pine canopies and in stand openings from the Duff Moisture Code (DMC) and the Fine Fuel Moisture Code (FFMC) [26].  DMC and FFMC are weather-based codes of the Canadian Forest Fire Weather Index System [42].  The DMC and FFMC have also been calibrated to predict the forest-floor moisture content of clearcut jack pine sites in relation to slash distribution and by forest floor strata [25]. In one test, the Canadian Forest Fire Weather Index overestimated jack pine wood slash moisture by a factor of 3.5 and variability by 50 percent, but was only 25 percent low on foliage moisture and 6 percent low for its variability.  The U.S. National Fire-Danger Rating System underestimated the wood and foliage moisture by 50 percent and underestimated their variability by 30 percent [71]. Based on 12 experimental fires, Stocks [75] developed regression equations for predicting the fire behavior in the mature jack pine fuel type from the Canadian Forest Fire Weather Index System.  Frontal fire intensity was strongly correlated with the Fire Weather Index (FWI).

FIRE CASE STUDIES

SPECIES: Pinus banksiana
FIRE CASE STUDY CITATION : Carey, Jennifer H., compiler. 1993. Jack pine regeneration after prescribed fire in a seed-tree system in central Saskatchewan. In: Pinus banksiana. 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/ []. REFERENCE : Chrosciewicz, Z. 1988. Jack pine regeneration following postcut burning under seed trees in central Saskatchewan. Forestry Chronicle. 64(4): 315-319. [24]. SEASON/SEVERITY CLASSIFICATION : Summer backfire/moderate-severity STUDY LOCATION : The study was conducted on an upland till site at latitude 53 deg 52 min N.  and longitude 105 deg 4 min W., about 15 miles (24 km) by road northeast of Candle Lake in central Saskatchewan. PREFIRE VEGETATIVE COMMUNITY : The original stand of 82-year-old jack pine with a small amount of black spruce (Picea mariana) and trembling aspen (Populus tremuloides) was logged to leave eight jack pine seed trees per acre (20/ha).  The seed trees had well-developed crowns, ranged in height from 60 to 70 feet (18-21 m), and were 8 or more inches (20 cm) in d.b.h.  About 95 percent of the forest floor was covered by Schrebers moss (Pleurozium schreberi).  Also present was bristly club-moss (Lycopodium annotinum), twinflower (Linnaea borealis var. americana), and bunchberry (Cornus canadensis).  American green alder (Alnus crispa) growing up to 6.6 feet (2 m) tall was present in the understory.  The slash averaged 1 foot (0.3 m) in depth and provided 71 percent intermittent ground cover. TARGET SPECIES PHENOLOGICAL STATE : NO-ENTRY SITE DESCRIPTION : The terrain was nearly flat with a slight south-southwest aspect.  The glacial till soil varied downward from sandy loam to sandy clay loam. The soil moisture regime was fresh to moderately moist, and the humus (including surface moss and litter) averaged 2.8 inches (7.1 cm) in depth. FIRE DESCRIPTION : Weather:  At the time of the fire, the air temperature ranged from 70 to 82 degrees Fahrenheit (21-28 deg C), relative humidity 43 to 61 percent, and wind speed 2 to 6 miles per hour (3-10 km/h) at 4 feet (1.2 m) above the ground and 3 to 10 miles per hour (5-16 km/h) at 33 feet (10 m) above the ground out of the southwest. Fuel moisture:  Preburn moisture content of the forest floor duff averaged 95 percent in exposed locations and 200 percent in locations shaded by slash.  The Duff Moisture Code (DMC) was 37 and the Fine Fuel Moisture Code (FFMC) was 80.  Preburn moisture content of the cured pine needles averaged 11 percent and the cured pine branches less than 0.8 inch (2 cm) in diameter averaged 15 percent. Fire and burn characteristics:  During the most active period of burning, flame heights averaged 3 feet (1 m) above the ground.  The fire crowned in a few seed trees.  All aerial parts of minor vegetation were completely burned.  Only stumps, logs, and some branch wood remained in a surface-charred state. The forest floor humus depth was reduced to 1.7 inches (4.2 cm).  After the fire, the forest floor was 9 percent exposed mineral soil, 88 percent partially burned humus, and 3 percent undisturbed original humus. FIRE EFFECTS ON TARGET SPECIES : More than 70 percent of the jack pine seed trees showed varying degrees of crown scorch immediately after the fire, and eventually most seed trees died.  Some cones on seed trees opened within 1 or 2 days of the fire, while others opened more slowly.  Overall seed shedding was expected to last up to 3 years. Jack pine regeneration was inventoried four growing seasons after the fire.  Stocking averaged 4,939 seedlings per acre (12,195/ha).  Twenty percent of the seedlings grew on exposed mineral soil and 80 percent on partially burned humus.  The dominant seedlings averaged 1.5 feet (0.47 m) in height.  The tallest seedlings (2.3 feet [0.71 m]) more than doubled in height in the next two growing seasons, averaging over 1 foot (0.3 m) height growth per year.  Most of the jack pine seedlings successfully competed with American green alder, aspen (Populus spp.), and Bebb willow (Salix bebbiana).  In a few locations, dense canopies of aspen sprouts overtopped the jack pine and retarded its height growth. FIRE MANAGEMENT IMPLICATIONS : The study demonstrates that prescribed burning in conjunction with a seed-tree system can successfully regenerate jack pine.  Enough heat was generated from burning logging slash and the other fuel present to open serotinous cones in the seed trees.  Jack pine regenerated successfully on partially burned humus because of adequate precipitation during the postfire growing seasons.  Had the fire been followed by a drought, seedlings may have only survived on mineral seedbeds.

REFERENCES


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