Polytrichum juniperinum


Table of Contents


INTRODUCTORY


 

2006 Robert Svensson.

AUTHORSHIP AND CITATION:
Fryer, Janet L. 2008. Polytrichum juniperinum. 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/ [].

FEIS ABBREVIATION:
POLJUN

NRCS PLANT CODE [142]:
POJU70

COMMON NAMES:
juniper haircap moss
juniper polytrichum moss

TAXONOMY:
The scientific name of juniper haircap moss is Polytrichum juniperinum Hedw. (Polytrichaceae) [24,26,34,39,136].

Polytrichum juniperinum Hedw. var. affine (Funck) Brid., P. juniperinum var. alpestre (Hopp) Brid., and P. juniperinum Hedw. var. gracilius Wahlenb. are now classified as upright haircap moss (P. strictum) Brid. [66], so information on those taxa is not included in this review.

SYNONYMS:
None

LIFE FORM:
Bryophyte

FEDERAL LEGAL STATUS:
None

OTHER STATUS:
Information on state- and province-level protection status of juniper haircap moss in the United States and Canada is available at NatureServe.

DISTRIBUTION AND OCCURRENCE

SPECIES: Polytrichum juniperinum
GENERAL DISTRIBUTION:
Juniper haircap moss is a cosmopolitan moss [26,124], growing on every continent including Antarctica [26]. Its distribution is nearly transcontinental in North America [24,26]; juniper haircap moss is distributed from Alaska east to Greenland, south through all of the contiguous United States except Texas, Louisiana, Mississippi, and Florida, with its distribution extending into Mexico. It is rare in the high arctic and does not occur in Hawaii [34]. Flora of North America provides a distributional map of juniper haircap moss.

HABITAT TYPES AND PLANT COMMUNITIES:
Juniper haircap moss occupies a wide range of habitats [5,136], from alpine meadow [5,29] and tundra [63] plant communities to dry scrub oak (Quercus spp.) forests in the Northeast [5]. In a review, Peterson and others [111] list juniper haircap moss as occurring across a wide gradient of habitats in the Pacific Northwest, from low-elevation savannas through wet and dry coniferous forests to alpine communities. Juniper haircap moss is most commonly reported in forests that experience frequent disturbances (see Successional Status and Fire Ecology). Descriptions of juniper haircap moss in northern (boreal and subboreal), northeastern, and western plant communities follow.

Northern communities: Across North America, juniper haircap moss is reported most often in early-successional boreal and subboreal spruce (Picea spp.) taiga communities of Alaska and northern Canada (for example, [35,53,65,119,148]). In northern Quebec, juniper haircap moss, common haircap moss (P. commune), and globose haircap moss (P. piliferum) dominated the floor of a black spruce-jack pine (Picea mariana-Pinus banksiana) forest that had established after a wildfire 47 years previously [78]. The moss layer in boreal and subboreal communities is often diverse; a moss species with 1% to 2% cover or frequency can be common to dominant on some sites [50,57,109,117,122,134].

Juniper haircap moss frequently occurs in northern shrublands. It is an important component of dwarf birch (Betula nana), willow (Salix spp.), and heath tundra communities in Alaska and western Canada [10]. In central Alberta, juniper haircap moss was an associated species on a bog Labrador tea/red sphagnum (Sphagnum rubellum) peatland [81].

Northeastern communities: Juniper haircap moss is often noted as a component of northeastern coniferous forests. In a study in southeastern Manitoba, juniper haircap moss occurred in a tamarack/bog birch-sedge-yellow marsh marigold-purple marshlocks (Larix laricina/Betula glandulosa-Carex spp.-Caltha palustris-Comarum palustre) forest [94]. Juniper haircap moss is a common to dominant moss in fire-maintained pitch pine (Pinus rigida) barrens [44,86,100,131]. In the Adirondack Mountains of New York, juniper haircap moss was the most common moss on study plots in the pitch pine barrens [7]. In New Jersey, juniper haircap moss and reindeer lichens (Cladonia (Cladina) spp.) formed mats in fire-maintained canopy openings within pitch pine barrens [131]. Juniper haircap moss is an indicator species of unproductive conditions for Virginia pine (Pinus virginiana) stands in central Pennsylvania. Sites with "an unusual abundance" of juniper haircap moss are generally "poor" sites with open canopies on dry, high-elevation ridges [17].

Juniper haircap moss is occasionally reported in forests that rarely experience disturbance. For example, it grows in old-growth Atlantic white-cedar-red maple (Chamaecyparis thyoides-Acer rubrum) swamps in New Jersey [100].

Juniper haircap moss and common haircap moss were components of a catberry-highbush blueberry (Nemopanthus mucronata-Vaccinium corymbosum) heathland in central New York [79].

Western communities: In western North America, juniper haircap moss occurs in coniferous forest, grassland, alpine, and herbaceous subalpine communities. In British Columbia it occurs in subalpine fir-Engelmann spruce (Abies lasiocarpa-Picea engelmannii) forests [82]. Juniper haircap moss is "occasional to frequent" in white spruce (P. glauca) stands of central Alberta [92]. Juniper haircap moss occurs in the coast Douglas-fir (Pseudotsuga menziesii var. menziesii)- mountain grassland transition zone in western Washington [77] and in Rocky Mountain Douglas-fir/mountain big sagebrush (P. m. var. glauca/Artemisia tridentata subsp. vaseyana) communities of Hell's Canyon National Recreation Area and Medicine Lodge Peak, Idaho [46].

Juniper haircap moss may form cryptogamic soil cover on palouse prairies and mountain grasslands. Tveten and Fonda [141] found juniper haircap moss was a dominant moss on the Wier Prairie of Fort Lewis, Washington; juniper haircap moss and hairy rhacomitrium moss (Rhacomitrium canescens) had approximately 23% cover. Idaho fescue (Festuca idahoensis) dominated the palouse prairie site; 3- to 5-year-rotation prescribed fires and livestock exclusion are used to maintain historical palouse prairie vegetation [141]. Juniper haircap moss formed part of the cryptogamic soil crust in a bluebunch wheatgrass (Pseudoroegneria spicata)-Idaho fescue community of Hell's Canyon National Recreation Area, Oregon [15].

Juniper haircap moss occurs in alpine and subalpine herbaceous as well as coniferous forest communities in the Cascade Range. In British Columbia and Washington, juniper haircap moss was noted in woolly pussytoes (Antennaria lanata) alpine fellfield, sedge (Carex spp. and Kobresia myosuroides) meadow, timber oatgrass (Danthonia intermedia) meadow, heath, and willow (Salix nivalis and S. cascadensis) communities. It was most important in capitate sedge (C. capitata) meadows [29]. Juniper haircap moss was a component of an alpine fellfield community on Monument Peak in Oregon. Common woolly sunflower (Eriophyllum lanatum) and woolly rhacomitrium moss (Rhacomitrium languinosum) dominated the community [3].

Juniper haircap moss was the most abundant species on subalpine sites in Wyoming where snowfields remained through mid-July. The authors suggested that on sites covered with snow for most of the year, the short growing season limits establishment of vascular species. Rocky Mountain lodgepole pine (Pinus contorta var. latifolia) and subalpine fir-Engelmann spruce forests surround the snowfields [72].

Juniper haircap moss is occasional in cold western hardwood communities such as aspen (Populus spp.). In central Alberta, juniper haircap moss was more frequent in balsam poplar (Populus balsamifera ssp. balsamifera) stands (14%) than in balsam poplar-quaking aspen (P. tremuloides) (8%) and quaking aspen (3%) stands [92].

Juniper haircap moss is often associated with fireweed (Chamerion angustifolium) across broad geographic areas [42,65,118,135,145]. Juniper haircap moss also associates with other haircap mosses [42,57,68,78,130,135], fire moss [65], reindeer lichens (Cladonia spp.) [50,130], and the liverwort Marchantia polymorpha [130,151] on many sites across juniper haircap moss's distributional range. Common hair cap moss generally grows taller than juniper haircap moss and may successionally replace juniper haircap moss on mesic sites [42,57,68,68]. See Successional Status and Northern ecosystems for further information on the ecology of these associations.

Vegetation typings describing plant communities where juniper haircap moss is dominant are listed below.

California Wyoming British Columbia

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

SPECIES: Polytrichum juniperinum

 

Photo by Daniel Mosquin, courtesy of Creative Commons.
GENERAL BOTANICAL CHARACTERISTICS:
Juniper haircap moss has 2 phases to its life cycle that are morphologically distinct: the gametophyte (n) and sporophyte (2n) generations. The following description of juniper haircap moss provides characteristics that may be relevant to fire ecology and is not meant for identification. Keys for identification are available in these sources: [26,34].

Gametophyte: The gametophyte generation is the predominant and most conspicuous phase of juniper haircap moss's life cycle. Gametophytes consist of stems, leaves, and rhizoids [116]. Growth form of juniper haircap moss gametophyte clusters is variable. Gametophytes typically form thin, interwoven mats. Less commonly, they grow as closely associated individuals or colonies [39,124] that sometime form distinct, globular masses (review by [107]). Relatively thick juniper haircap moss mats may have live stem tissue 2 to 3 inches (6-8 cm) below the mat surface. Surface stems translocate photosynthate to stems below the mat surface [68]. Rhizoids extend down from stems, anchoring juniper haircap moss to its substrate [39,95,147]. When soil is the substrate, rhizoids may penetrate into mineral soil [68].

Juniper haircap moss stems are upright and unbranched in habit, growing from 0.4 to 4 inches (1-10 cm) tall [34,52]. The stems are a shiny bluish-green, resembling common juniper (Juniperus communis) leaves in color and shape [124]. Stems are usually densely packed [57,116]. Juniper haircap moss is heterothallic, with male and female stems on separate plants. Male and female plants may grow in separate clumps [107] or intermingle [116]. Male and female stems develop antheridia and archegonia, respectively, at their tips (see the Life cycle figure). Juniper haircap moss's leathery leaves are 4 to 8 mm long. They spread widely when moist, becoming narrower and more upright when dry. Leaf margins curve into the stem when dry, which probably reduces water loss [68,108,136] and enhances juniper haircap moss's ability to photosynthesize on xeric sites [136].

Sporophyte: Sporophytes grow out of archegonia. Juniper haircap moss sporophytes are large, generally about as tall as the female gametophytes to which they are attached [108,116]. The sporophyte consists of a foot that anchors the sporophyte to the archegonia, a stalk, and a 4-sided spore capsule. Juniper haircap moss's stalk is upright, wiry in texture, and unusually long compared to the stalks of most mosses; stalks range from 0.8 to 2 inches (2-6 cm) tall [34,108,124]. The spore capsule is 2.5 to 5 mm long. It is vertical when young, becoming horizontal with age. It has 64 blunt "teeth" at its top [34,124]. The spore capsule is capped with a hairy calyptra; the long hairs extend down the length of the entire capsule [34,124,136]. Spores are 6 to 12 m in diameter [34,136]: relatively large compared to the spores of most moss species [108].

Physiology: Juniper haircap moss gametophytes continue photosynthesis and respiration when dry, although at much reduced rates [108]. Faster rates of photosynthesis and respiration resume after gametophytes remoisten [68]. In an Alaskan field study, juniper haircap moss had significantly higher rates of photosynthesis and respiration compared to 4 commonly associated mosses (P<0.05). Maximum rate of photosynthesis occurred from 68 to 86 F (20-30 C) for juniper haircap moss [99].

Osmosis is apparently the primary method of water conduction in juniper haircap moss [140] but is not the sole method. Haircap mosses (Polytrichaceae) have a well-developed system of small tubes that carry water from rhizoids to leaves [124,136], which allows for taller stem growth than is usual for most mosses.

RAUNKIAER [113] LIFE FORM:
Not applicable

REGENERATION PROCESSES:
Juniper haircap moss regenerates sexually from spores and vegetatively by sprouting from stems and rhizoids [59,68,108].
Gametophyte dispersal and development: A spore is the first growth stage of a developing gametophyte [116,154]. The long hairs on the spore capsules help protect the developing gametophytes within from desiccation [34,124]. Spores within a single capsule usually mature synchronously [116]. The calyptra breaks off when the spore capsule is mature, exposing the encapsulated spores. Release of the exposed spores requires dry weather and is governed by a row of hygroscopic teeth that ring the capsule's top. The capsule teeth bend outward when air is dry, which permits the spores to fall [116,136,154]. Dry winds disperse moss spores by shaking the capsule. When air is moist, the teeth bend inward, holding the spores within the capsule [154]. Hausmann [52] and Reighard [116] describe archegonial and antheridial development and spore release at the cellular level. Wind dispersal of juniper haircap moss spores allows colonization on new sites [40,45,55,59,68,155]. Juniper haircap moss spores are very light in weight [40], and wind may carry the spores for long distances [45]. The spores require a moist substrate to germinate [116,154].

A germinated spore, or sporeling, develops into a protonema (a branched, threadlike structure) [116,154]. Nehlsen [95] describes protonema development at the cellular level. Rhizoids grow down from the protonema, often penetrating permeable substrates [116,154]. Protonema develop stem buds as they grow; stem buds sprout and develop into leafy gametophytes [116]. As stems grow, they develop their own rhizoids and become independent of the protonema. Mature male and female stems develop antheridia and archegonia, which produce sperm and eggs, respectively [116,154]. In Margo Frankel Woods State Park, juniper haircap moss protonema and sporelings growing under litter were more likely to desiccate and die than protonema and sporelings in the open [146].

When mature, the tips of juniper haircap moss antheridia swell with water, and fluid accumulates at antheridia bases. Osmotic pressure at the tip and base of the antheridia forces sperm out [52,103]. Splashing rain or dew carry juniper haircap moss sperm to archegonia on female plants [52,116]. The sperm swim down the archegonia neck to the egg [116]; water is required to enable the sperm to swim [146]. For information on development of juniper haircap moss sperm, see these sources: [2,104]. The sporophyte generation begins with the fertilized egg [116].

Spore banking: A soil-stored spore bank is possible for juniper haircap moss, but the spore bank may not be as important as newly-deposited, wind-blown spores. Based on research in pitch pinelands of New Jersey, Sedia and Ehrenfeld [131] suggest that freshly-dispersed spores are probably more important to juniper haircap moss establishment than soil-stored spores. In a greenhouse study, juniper haircap moss spores germinated in soil samples collected from a Norway spruce/downy birch (Picea abies/Betula pubescens) bog in Finland. Juniper haircap moss density on soil trays ranged from 16 to 48 sporelings/m [64].

Breeding system: Juniper haircap moss is dioecious [52,116,136]. Male and female plants sometimes form separate colonies [52].

Juniper haircap moss shows genetic differences between populations. In the laboratory, juniper haircap moss from alpine populations in New Hampshire and from populations in an oak-hickory (Quercus-Carya spp.) forest in Indiana showed differences in photosynthetic rates under varying light conditions, with forest populations photosynthesizing under lower light conditions than the alpine populations [5].

Sporophyte development: Eggs are fertilized within the archegonium [154]. After fertilization, the juniper haircap moss sporophyte embryo is partially parasitic on the gametophyte [116]. The embryo grows rapidly, differentiating into foot, stalk, and spore capsule tissue [154]. Gametophyte spores develop within the capsule [154].

Vegetative regeneration: Juniper haircap moss reproduces asexually from specialized gametophyte tissues and from plant breakage. Juniper haircap moss can sprout from rhizoids [65,147] and stem fragments [59,68,108]. Desiccated, whole or fragmented juniper haircap moss stems may regenerate from dormant stem buds after rehydration [108].

Growth: As of 2008, so few data were available on juniper haircap moss growth rates that conditions fostering or hindering growth were not apparent. Juniper haircap moss spores collected in Santa Cruz County, California, germinated 5 days after sowing in the laboratory. Protonema began developing 7 days after sowing, and rhizoids appeared after 7 to 14 days. Development was significantly slower at 64 F (18 C) than at 75 F (24 C) (P<0.05) [95]. A laboratory experiment using soils from an Australian mountain-ash forest in Tasmania suggests that moderately-burned soil encourages the most rapid germination of juniper haircap moss spores, but that juniper haircap moss spores can germinate under a range of burned soil conditions. Soils were collected from 1- to 3-year-old burns representing a continuum of fire severities, from "severely burned" to unburned [31]:

Mean laboratory hours required for 50% of total germination of juniper haircap moss spores [31]
Substrate  Hours (SE)
Severely burned soil 58.53 (5.08)
Burned forest soil 94.79 (3.65)
Charred humus 61.67 (0.50)
Unburned forest soil 59.73 (1.80)
Unburned forest litter 57.56 (2.48)
Agar (control) 69.37 (0.47)

Juniper haircap moss protonema had a mean radial growth rate of 1.65 mm/week in this laboratory study [31].

On the Edwin S. George Reserve, Michigan, juniper haircap moss stems spread horizontally 16 inches (40 cm) in one growing season, forming a mat. A network of stems extended 2 to 3 inches (6-8 cm) below the mat surface [68]. In the Margo Frankel Woods State Park, Iowa, changes in juniper haircap moss stem lengths over 1 year ranged from 104% increase to 1.5% decrease in stem length. Mean change in stem length was a gain of 24.4% [146].

SITE CHARACTERISTICS:
Juniper haircap moss is most common on dry, exposed sites [21,26,34,71,78,108,108]. It typically grows in open woods and forests and old fields [34,108]. It is rare in moist soils, although it is found occasionally on moist sites such as streambanks [108] and moist woods. In central Alberta, juniper haircap moss was more frequent in balsam poplar (Populus balsamifera ssp. balsamifera) stands (14%) than in balsam poplar-quaking aspen (8%) and quaking aspen (3%) stands, although balsam popular generally grew on the moistest sites and quaking aspen the driest sites [92].

Substrates: Juniper haircap moss is most common on mineral soil [33,53,91,101] but also grows over rock [34,87,98], in humus [108] and peat [79,81,111], and on logs [105] and stumps [26,34,108]. In a black spruce forest in Ontario, juniper haircap moss occurred on sites with a 4-foot (1.3 m)- thick peat layer overlying clay [6]. Juniper haircap moss is not an arboreal species [89]. A vegetation survey in the Cascade Range of Oregon, for example, found juniper haircap moss growing on the forest floor and on logs, but not in trees [105].

Juniper haircap moss typically grows in habitats with "excessively dry to very dry" soils [71] and on soils with extremely fluctuating moisture levels [108]. In white spruce forests of British Columbia, juniper haircap moss was most frequent growing on relatively dry sites over coarse morainal materials: microsite conditions where lodgepole pine tended to dominate [106]. Juniper haircap moss is an indicator species of moisture-deficient sites in British Columbia [70,71], and Rowe [121] described juniper haircap moss as an indicator species of xero-mesophytic, fresh spruce forests of Saskatchewan and Manitoba. Morphological characteristics of the leaves (see General Botanical Characteristics) probably allow juniper haircap moss to inhabit dry sites where other mosses cannot easily grow [136]. Juniper haircap moss is occasionally found on moist to wet sites. It was noted on very wet, mucky peat in a tamarack bog in southeastern Manitoba [94] and in marsh sod in New Jersey [100].

Juniper haircap moss usually grows on acidic soils [6,26,34] over a variety of parent materials. In a hybrid spruce (Picea glauca P. engelmannii) forest of central British Columbia, juniper haircap moss occurred on moderately- to well-drained sands of morainal and colluvial parent materials. Soil pH averaged 4.6 [30]. On black spruce sites in interior Alaska, juniper haircap moss occurred on soils ranging from 3.4 to 3.6 in pH and 3.6 to 5.6 inches (9.2-14.6 cm) in thickness of the 02 horizon. The soils overlay permafrost [32]. In pitch pine barrens of New York, juniper haircap moss occurred on strongly acidic, deep sands overlying glacial outwash deposits and on rock pavement with parent materials of gneiss and sandstone [7].

When growing on soil, juniper haircap moss occurs on a variety of soil textures [23,101]. It occurred on fine-textured, sandy and gravelly soils in thermal basins of Yellowstone National Park, Wyoming. Soil temperatures where juniper haircap moss grew ranged from 95 to 140 F (35-60 C) 4 inches (10 cm) below the soil surface [23]. Juniper haircap moss grows on sands in Indiana [5], shallow skeletal sands in the Sierra Nevada [123], and silts and coarse-textured soils in subalpine fir-Engelmann spruce forests of southeastern British Columbia [101].

Juniper haircap moss is characteristically found on disturbed substrates, especially burned soils [27,37,55,127]. It is well adapted to the large fluctuations summer temperature, high light levels, and low humidity levels that are typical of recently burned soils [99]. In the laboratory, juniper haircap moss cover was positively correlated with high light conditions and high evaporation rates (P<0.001) [68]. Heinselman [55] noted that on northern sites, juniper haircap moss is common on new burns where fire has consumed the organic soil layer. Juniper haircap moss colonized burned mineral soil after fires in northern Quebec [91], Kluane National Park, Yukon [53], and Yellowstone National Park, Wyoming [33]. In Alberta, juniper haircap moss was noted on burned wood and soil substrates in postfire year 1 [16]. It colonized burned peat on the Seward Peninsula of Alaska [111].

Juniper haircap moss is not commonly found on peat, but a few studies have noted juniper haircap moss in arctic and subarctic peatlands [6,74,111,139]. Macrofossil juniper haircap moss was a component of peat deposits on northern Ellesmere Island in the Northwest Territories [74]. Timoney [139] described juniper haircap moss as an indicator species of dry peat bogs in Wood Buffalo National Park, Alberta.

Nutrients: Nonvascular plants, including juniper haircap moss, are generally more common on sites with low soil fertility than on productive sites (review by Hart and Chen [51]). Juniper haircap moss is an indicator species of nutrient-poor to nutrient-medium sites in coastal British Columbia [70,71]. In northern British Columbia, juniper haircap moss was more common in low-productivity quaking aspen stands than in productive stands [51]. Analysis of vegetation patterns in a balsam fir-black spruce forests in Gros Morne National Park, New Brunswick, found juniper haircap moss was significantly associated with low calcium, low soil moisture, low pH levels, and moderate light levels (P=0.005) [120].

Juniper haircap moss and other mosses tend to enrich their substrates, allowing for establishment of later-successional species ( see Successional Status). In a study measuring nitrogen accumulation on a New Hampshire sandpit dominated by juniper haircap moss and globose haircap moss, Bowden [14] found the haircap mosses were "extremely efficient" at retaining nitrogen input, which came mostly from precipitation. Moss removal resulted in a rapid loss of soil nitrogen. The author found that nitrogen capture by haircap mosses facilitated growth of basidiomycete fungi and microbes in the soil. Accumulation of soil organic material was faster on sites with mosses, furthering the capacity of the site to retain nitrogen [14].

Elevation: Studies describing juniper haircap moss's elevational occurrences are too few to discern trends. Juniper haircap moss decreases with increasing elevation in coastal British Columbia [71]. On the Washington Creek Fire Ecology Experimental Area near Fairbanks, Alaska, juniper haircap moss had greatest coverage (13.7%) in closed black spruce/splendid feather moss (Hylocomium splendens) forests at 2,600 to 3,440 feet (800-1,050 m) elevation and did not occur above 9,190 feet (2,800 m) elevation, where black spruce coverage was sparse [32]. It was unclear from the study whether elevation or canopy cover was driving juniper haircap moss's relative abundance on the study sites. In a study on the western slope of the Cascade Range in central Oregon, juniper haircap moss was negatively correlated with high elevation; juniper haircap moss occurred from 1,700 to 2,200 feet (510-680 m) in a western hemlock-Douglas-fir forest [105].

Climate: Juniper haircap moss occurs in arctic, boreal, cool temperate, cool semiarid, and cool mesothermal climates. In British Columbia, juniper haircap moss occurrence increases with increasing continentality [71].

SUCCESSIONAL STATUS:
Juniper haircap moss is typically a pioneer species (for example, [37,87,123,130,133]), although it is occasionally reported in late succession [79,89]. It is frequent after fire, logging, and other disturbances [34,124].

Juniper haircap moss is most common on open sites with high light levels [14,108,116] but is moderately shade tolerant [71]. Juniper haircap moss colonized bare areas of an alpine meadow in New Zealand. It was significantly more common in interior sections of the bare areas than on edges of bare areas (P<0.01). The authors suggested that higher light levels in interior portions of bare areas may have favored juniper haircap moss [83]. In northern Ontario, juniper haircap moss frequency declined in jack pine and black spruce plantations with time since planting and canopy closure [61]. There may be differences in light tolerance between populations. In the laboratory, juniper haircap moss plants collected in Indiana from a closed-canopy oak-hickory forest showed greater tolerance of low-light conditions than plants collected from an alpine Bigelow sedge (Carex bigelowiii) meadow in New Hampshire [5].

Primary succession: Several studies have noted juniper haircap moss occurrence in primary succession. Juniper haircap moss pioneers on granite outcrops in the Sierra Nevada [123]. Windisch [155] found juniper haircap moss, swamp placynthiella lichen (Placynthiella uliginosa), and curly reindeer lichen (Cladonia cristatella) were primary successors on pitch pine plains in New Jersey, colonizing bare sand and gravel. Juniper haircap moss formed mats over rock depressions in a burnt-over western hemlock (Tsuga heterophylla)-Douglas-fir forest in coastal British Columbia [87], and formed tufts and mats over rock ledges in High Point State Park, New Jersey. Juniper haircap moss alone, or in combination with other mosses, often spread enough to eventually cover entire rock surfaces [98]. Juniper haircap moss occurred on pumice substrates 18 years after the 1980 eruption of Mount St Helens in Washington. It also occurred in secondary succession on refugia that escaped the pumice flow; it is likely that spore sources for juniper haircap moss on the pumice sites came from refugia [40].

By colonizing bare substrates, juniper haircap moss sometimes facilitates establishment of later-successional species, and sometimes other species aid juniper haircap moss establishment. Juniper haircap moss and globose haircap moss pioneered on a New Hampshire sand pit, facilitating succession of soil biota [14] (see Site Characteristics for further details). However, on rock outcrops of boreal Manitoba, juniper haircap moss formed a tertiary mat over existing vegetation mats. It successionally followed pioneering low-growing lichens, which formed the first mat layer, and the secondary colonizers grimmia dry rock moss (Grimmia spp.) and twisted moss (Tortula ruralis), which grew over the lichen mat [38].

Disturbance: Juniper haircap moss is characteristically found on disturbed sites [133], especially burned soils (see Substrates). Steele [137] reported that juniper haircap moss was "opportunistic" in disturbed Douglas-fir forests of central Idaho, rarely occurring on undisturbed sites. Juniper haircap moss has persisted and/or colonized after plowing, windstorms, oil and mining exploration, construction, fire, and logging.

Juniper haircap moss may tolerate severe soil disturbance such as plowing, and often grows on abandoned agricultural lands. In a white spruce forest on the Cariboo Forest Region, British Columbia, discing and glyphosate treatments had no effect on juniper haircap moss cover and height compared with glyphosate treatment alone [8]. Juniper haircap moss is common on old fields [34], growing, for example, on old fields in New Jersey [100].

Windstorms that expose soil may promote juniper haircap moss. One to 6 years after a tornado in an old-growth American beech-eastern hemlock (Fagus grandifolia-Tsuga canadensis) forest of northwestern Pennsylvania, juniper haircap moss was common on both windthrow plots and plots on the edge of undisturbed forest. Its mean cover was significantly (P<0.04) greater on windthrow (x=2.21%) than edge plots (x=0.54%) in 4 of 6 postdisturbance years [109].

Based on studies in the Northwest Territories, oil exploration and construction in northern zones may have less impact on juniper haircap moss than on many associated groundlayer species. A study of succession was conducted 48 years after construction of the CANOL Pipeline through bog birch-heath tundra. Juniper haircap moss was common in denuded vehicle track, borrow pit, and undisturbed areas [50,67]. It was also common on 5- to 22-year-old borrow pits that were used during construction of the Dempster Highway [67]. Juniper haircap moss was the only moss to grow on experimental oil spills 1 year after oil-dump treatments on arctic and subarctic sites in the Mackenzie Delta [62,152].

Juniper haircap moss colonized strongly acidic, 5- to 38-year-old coal mine spoils in southern Iowa [20].

Fire: Juniper haircap moss is typically among the first groundlayer species to establish after fire (for example, [37,126,130,134,135]). It is characteristically found on burned mineral soils and other charred substrates [27,37]. A chronosequence study of soil profiles of black spruce habitats in Labrador, for example, found juniper haircap moss typically colonized burned mineral soil after fire in black spruce woodlands. Analysis of the humus layer showed that reindeer lichens dominated successionally after juniper haircap moss. Reindeer lichens were replaced successionally by Schreber's moss (Pleurozium schreberi) and Girgensohn's sphagnum (Sphagnum girgensohnii). The author noted that juniper haircap moss and/or fire moss often formed dense patches in depressions and mineral hollows created by postfire windthrow of black spruce. On average, coverage of juniper haircap moss peaked at 25% in postfire year 18. Juniper haircap moss dominated the ground layer through postfire year 25, when spineless reindeer lichen (Cladonia mitis) became more abundant. A black spruce/lichen woodland formed, on average, by postfire year 100, with a closed-canopy black spruce forest developing around postfire year 112 [37]. Scotter [130] described similar postfire succession of groundlayer vegetation on black spruce sites that provide winter range for caribou in northern Saskatchewan:

In white spruce forests of Kluane National Park, Yukon, juniper haircap moss occurs in the woody plant seedling-herb stage of early postfire succession, which lasts from 1 to 15 years after fire. Stages that follow are: tall shrub/conifer sapling (postfire years 5-80), pole (postfire years 50-100), conifer woodland (postfire years 100-200), and mature white spruce forest (postfire years 150-400) [53].

Postfire colonization by juniper haircap moss and other mosses may increase the rate of succession over sites colonized by lichens. On the Lebanon State Forest of New Jersey, pitch pinelands subjected to either "hot" wildfires or sand mining were experimentally recolonized with either juniper haircap moss or reindeer lichen (Cladonia spp.) mats. Soils under juniper haircap moss accumulated more organic matter and had higher nitrogen levels than soils under reindeer lichens. The authors noted that vascular plants established more often on moss than on lichen mats; they attributed the more rapid rate of succession on juniper haircap moss mats to higher organic matter and nitrogen content [132]. On nearby, naturally recolonized sites, juniper haircap moss and reindeer lichens occurred on open sites, with juniper haircap moss tending to colonize sites with relatively thicker organic soil horizons and greater shrub cover compared to sites where reindeer lichens colonized. Reindeer lichens grew over pioneering juniper haircap moss on some sites; 47% of lichen-dominated plots had dead juniper haircap moss and other mosses beneath the lichens, whereas none of the moss mats covered dead lichens. Moss and lichen mats in open areas tended to persist for decades. Both thick moss and thick lichen mats trapped seeds easily; however, germination and mycorrhizal infection rates of vascular plants were lower on lichen than on moss mats (P<0.001) [131].

Sphagnum mosses usually replaces juniper haircap moss successionally on burned peatlands, but reindeer lichens may succeed juniper haircap moss on some, probably drier, sites. In northern Quebec, the ground layers of 47-year-old black spruce-jack pine burns were dominated by juniper haircap moss, common haircap moss, and globose haircap moss, while sphagnum mosses dominated the ground layers on nearby 67-year-old burns [78]. Reindeer lichens have replaced juniper haircap moss successionally in the Northwest Territories [9], Maine (review by [135]), New Jersey [131], and Jamaica [135].

See Plant Response to Fire for further information on postfire succession in ecosystems with juniper haircap moss.

Logging generally favors juniper haircap moss [117], probably by opening the canopy and reducing coverage of other groundlayer species. On sites representing a postlogging chronosequence in New Brunswick, juniper haircap moss occurred more often than expected (P<0.05) on clearcuts, heavily-thinned sites with small (<5 feet (1.5 m) tall) balsam firs, and in machinery tracks; but occurred less often than expected in relatively dense, mature spruce-balsam fir forest [20]. In logged black spruce peatland forests of northeastern Ontario and western Quebec, juniper haircap moss was described as a widespread species with peak abundance (mean frequency >45%) on all logging sites studied, including nutrient-rich, nutrient-poor, horse-logged, and skidder-logged plots [19]. In quaking aspen communities of northeastern British Columbia, juniper haircap moss was more common on 4-year-old logged sites than in 100-year-old forest; it grew on compacted and uncompacted soils on logged sites [47]. In quaking aspen, jack pine, and black spruce forests in northern Minnesota, juniper haircap moss had greater mean coverage after logging (65.4%) than after wildfire (51.7%). Data were pooled across 2 age classes (25-40 and 70-100 years) and the 3 forest types (n=80 stands) [115]. In logged subalpine fir-Engelmann spruce forests of southeastern British Columbia, juniper haircap moss had similar frequencies (52-56%) and cover (3.5-8.6%) on slash-burn sites, skid trails, and the downslope sides of skid trail banks. Its frequency (88%) and cover (27%) were much greater on the upslope, cutbank sides of skid trails compared to slash burns, skid trails, and downslope skid trail banks [101].

Studies on other continents demonstrate juniper haircap moss's widespread ability to colonize after logging. For example, juniper haircap moss dominated clearcuts in Finland. It was 2 to 8 times more abundant on 30-year-old clearcuts than in thinned, old-growth Scots pine (Pinus sylvestris) forests [97]. Juniper haircap moss pioneered after logging in an Australian mountain-ash (Eucalyptus regans) forest in Tasmania. Juniper haircap moss was the dominant groundlayer species 5 years after tree harvest; it was the only species to colonize the "bare, compacted, and deeply puddled" tracks left by logging tractors [25].

Only 1 study reporting negative effects of logging on juniper haircap moss abundance was found in this literature review. In the Northwest Territories, juniper haircap moss was strongly negatively correlated with clearcuts and mechanical site preparation (various shearing and soil mixing treatments) on mixed-hardwood-white spruce sites on the Muskeg River Forest Demonstration Area, Northwest Territories [13].

Juniper haircap moss typically tolerates combinations of logging, fire, and conifer restocking. Moss cover was "almost completely destroyed" after an 80-year-old jack pine-tamarack forest in central Saskatchewan was clearcut, slash burned, and restocked with jack pine. Juniper haircap moss was the dominant moss in early postdisturbance succession, attaining greatest coverage on the driest sites. Juniper haircap moss coverage in postfire year 4 ranged from 10% to 40% on fresh soils and from 5% to 10% on moderately moist to moist soils [21]. Also in central Saskatchewan, juniper haircap moss dominated the ground layer on jack pine sites that had been clearcut, slash burned, and restocked with jack pine and white spruce. Prior to treatments, Schreber's moss dominated the ground layer of the 80-year-old stands [22]. Juniper haircap moss was an important moss 10 years after clearcutting followed by a wildfire and replanting of balsam fir in northwestern Newfoundland. Bunchberry (Cornus canadensis) was the dominant groundlayer species [145].

Near Thunder Bay, Ontario, juniper haircap moss and feather mosses colonized a plantation of red (Picea rubens), black, and white spruce. The plantation had formerly been an old field [96].

Late succession: Juniper haircap moss is generally uncommon after early succession, but a few studies note its presence in later stages of succession. It was listed among the "most abundant" native species in climax Sitka spruce (Picea sitchensis)-western hemlock forests on Olympic National Forest, Washington [54]. In the Swan Valley of Montana, juniper haircap moss occurred in old-growth and second-growth mixed-conifer forests, although it was more frequent in second growth (5% vs. 2% frequency) [80]. In a late successional, mixed-conifer-hardwood forest of northwestern Alberta, juniper haircap moss occurred with low frequency (0.26%) on disturbed patches on the forest floor but not on undisturbed patches of the forest floor, on logs, or on stumps [89]. Juniper haircap moss was present on a 94-old-year catberry-highbush blueberry heathland that developed after a wildfire in central New York [79]. The fire consumed over 3 feet (1 m) of peat in some areas (Ketchledge 1963, unpublished report cited in [79]).

SEASONAL DEVELOPMENT:
Generally, juniper haircap moss's antheridia begin developing in late fall, when terminal leaves curl over and help protect the antheridia. Archegonia and antheridia mature in late spring, when terminal leaves spread and expose the antheridia [52,116]. Sporophytes are discernible on female plants in early winter [116]. Sperm are released from antheridia and fertilization occurs in late spring or early summer [52,116]. Sporophytes persist after fertilized eggs are released from archegonia [52]. The following table provides details of juniper haircap moss's phenological development in several locations:

Juniper haircap moss phenology in the United States

State Event
Santa Cruz County, California spores ripened in May [95]
Margo Frankel Woods State Park, Iowa gemetophyte growth began in mid-April with some fall regrowth on south slopes;
gametophytes under litter desiccated from September-November;
eggs fertilized during late September rains;
sporophytes emerged mostly in September and October but emerged in early April on one site [146]
Illinois and Indiana calyptra began splitting open in April;
spores dispersed in late May [116]
Edwin S. George Reserve, Michigan vegetative stem growth from March-June [68]
Tompkins County, New York immature antheridia present in late January;
antheridia matured after 2 weeks in greenhouse [103]
Marathon County, Wisconsin embryonic calyptra present 28 February;
calyptra mature 31 August-22 September;
capsules ripened or spores dispersed 29 September [36]

FIRE ECOLOGY

SPECIES: Polytrichum juniperinum
FIRE ECOLOGY OR ADAPTATIONS:
Fire adaptations: Juniper haircap moss is a fire-follower (for example, [65,126,134,135,151]). It may survive fire, and shows strong ability to colonize newly-burned sites. Juniper haircap moss's rhizoids sometimes penetrate into mineral soil. This adaptation allows juniper haircap moss to survive some surface fires: a rare ability in mosses [147]. Juniper haircap moss also establishes on burned sites by wind-dispersed spores [59,155]. Wind dispersal of spores is not an adaptation specific to fire; however, wind may transport juniper haircap moss spores for long distances, making colonization on new burns likely [45]. See Plant Response to Fire for further information.

Fire regimes: Juniper haircap moss occurs in ecosystems that experience frequent fire, such as pitch pine and jack pine, and in ecosystems which may experience fire-free intervals of 100 or more years, such as black spruce. Juniper haircap moss is generally common in ecosystems with short fire-return intervals. In plant communities with long fire-return intervals, it is generally frequent in early postfire succession and declines with canopy closure. Information on fire regimes in northern, northeastern, and western ecosystems where juniper haircap moss is common follow.

Northern ecosystems:
Spruce Boreal black spruce forests have fire-return intervals ranging from about 50 to 100 years and experience both combination crown and ground fires [60,84]. Fires in spruce taiga may last for months, burning thousands to millions of acres [84]. In Ontario, a black spruce-tamarack-northern white-cedar (Thuja occidentalis) forests burned at least once every 130 to 140 years [85]; fire-return intervals averaged 30 to 50 years for boreal forests in the area [73,85]. The area has relatively flat, uniform topography, and fires generally cover large areas. Juniper haircap moss was among the most common plant species on study plots that had burned 10 years previously [6]. Black spruce-jack pine taiga forests in northwestern Manitoba have a long history of fire. McMinn [87] stated that it "is difficult to locate an area of homogeneous cover of more than 10 acres (4 ha) in the taiga (caribou) winter range, partly because of the incidence of forest fires and partly due to variable drainage". Estimated percentage of land burned annually over a 12-year period (1955-1967) was 0.17%. Fire-return intervals were not measured, although conifer stands in the area ranged from less than 60 to over 120 years old [87]. A black spruce-jack pine forest in northern boreal Quebec experienced fire at intervals of 47 to 270 years. Juniper haircap moss, globose haircap moss, and common haircap moss dominated the forest floor on well-drained sites. Well-drained sites with haircap mosses tended to experience fires every 47 to 67 years: the short end of the fire-return interval range. The overstory was less dense on sites where haircap mosses dominated the ground layer than on sites dominated by sphagnum mosses; sphagnum-dominated sites were wetter and had longer fire-return intervals. Snag densities on one well-drained site that had burned 11 years previously ranged from 754 to 896 trees/ha [78].

White spruce forests of Kluane National Park, Yukon, have 150- to 400-year fire-return intervals. Juniper haircap moss occurs in the woody plant seedling-herb stage, which lasts from 1 to 15 years after fire. Mean fire-return interval increases with increasing latitude, from 133 years in the southern end of the Park, to 164 years in the middle of the Park, and 234 years in the northern end of the Park [53]. Driscoll and others [30] reported a return interval of 140+ years for fires in hybrid spruce forests of central British Columbia.

Postfire succession proceeds slowly in black spruce forests near the northern treeline in the Northwest Territories. Juniper haircap moss was most common as a pioneer and early-successional species in open-canopy black spruce forests near treeline. Dominance of juniper haircap moss and other early-seral mosses declined about 120 years after fire, when reindeer lichens gained dominance [9].

In boreal ecosystems, fire-return intervals are generally longer in northeastern North America than further west. In southeastern Labrador, the fire-return interval for a black spruce-balsam fir/bog-laurel/Schreber's moss ((Kalmia polifolia/Pleurozium schreberi) forest was approximately 100 years, with an approximate 500-year fire rotation interval [37]. The fire rotation was 3 to 10 times longer than fire rotations in the Great Lakes area [55]. One black spruce stand on the site in southeastern Labrador had not burned in 230 years. Foster [37] attributed the long fire rotation in Labrador to abundant precipitation and extensive mires that serve as fuelbreaks.

Northeastern ecosystems: Pitch pine barrens have historically had short fire-return intervals, ranging from around 5 years on pitch pine plains to 80 years in mixed pitch pine-oak (Quercus spp.) forests [155]. Juniper haircap moss cover and frequency tend to increase as fire-return intervals shorten (see Plant Response to Fire).

Western ecosystems: As of 2008, studies on juniper haircap moss's postfire occurrence in coniferous forests in western North America were lacking, so it is difficult to project what role fire plays in juniper haircap moss abundance in those forests. Juniper haircap moss is often noted in fir-spruce forests (see Habitat Types and Plant Communities), which have relatively long fire-free intervals compared to pine ecosystems. Arno [4] estimated fire-return intervals for subalpine fir-Engelmann spruce forests of the northern Rocky Mountains at 150+ years. Western hemlock forests of the west coast burn at intervals of 150 to 400 years (review by [102]). Research is needed on the relative importance of juniper haircap moss and other mosses after fire in conifer ecosystems of the western United States.

The following table provides fire regime information that may be relevant to juniper haircap moss.

Fire regime information on vegetation communities in which juniper haircap moss may occur. For each community, fire regime characteristics are taken from the LANDFIRE Rapid Assessment Vegetation Models [76]. These vegetation models were developed by local experts using available literature, local data, and/or expert opinion as documented in the PDF file linked from the name of each Potential Natural Vegetation Group listed below. Cells are blank where information is not available in the Rapid Assessment Vegetation Model.
Pacific Northwest California Southwest Great Basin Northern and Central Rockies
Northern Great Plains Great Lakes Northeast South-central US Southern Appalachians
Southeast        
Pacific Northwest
Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics
Percent of fires Mean interval
(years)
Minimum interval
(years)
Maximum interval
(years)
Northwest Grassland
Bluebunch wheatgrass Replacement 47% 18 5 20
Mixed 53% 16 5 20
Idaho fescue grasslands Replacement 76% 40    
Mixed 24% 125    
Alpine and subalpine meadows and grasslands Replacement 68% 350 200 500
Mixed 32% 750 500 >1,000
Northwest Forested
Sitka spruce-western hemlock Replacement 100% 700 300 >1,000
Douglas-fir-western hemlock (dry mesic) Replacement 25% 300 250 500
Mixed 75% 100 50 150
Douglas-fir-western hemlock (wet mesic) Replacement 71% 400    
Mixed 29% >1,000    
Mixed conifer (southwestern Oregon) Replacement 4% 400    
Mixed 29% 50    
Surface or low 67% 22    
California mixed evergreen (northern California) Replacement 6% 150 100 200
Mixed 29% 33 15 50
Surface or low 64% 15 5 30
Lodgepole pine (pumice soils) Replacement 78% 125 65 200
Mixed 22% 450 45 85
Pacific silver fir (low elevation) Replacement 46% 350 100 800
Mixed 54% 300 100 400
Subalpine fir Replacement 81% 185 150 300
Mixed 19% 800 500 >1,000
Spruce-fir Replacement 84% 135 80 270
Mixed 16% 700 285 >1,000
California
Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics
Percent of fires Mean interval
(years)
Minimum interval
(years)
Maximum interval
(years)
California Grassland
Alpine meadows and barrens Replacement 100% 200 200 400
California Forested
California mixed evergreen Replacement 10% 140 65 700
Mixed 58% 25 10 33
Surface or low 32% 45 7  
Mixed conifer (North Slopes) Replacement 5% 250    
Mixed 7% 200    
Surface or low 88% 15 10 40
Mixed conifer (South Slopes) Replacement 4% 200    
Mixed 16% 50    
Surface or low 80% 10    
Jeffrey pine Replacement 9% 250    
Mixed 17% 130    
Surface or low 74% 30    
Sierra Nevada lodgepole pine (dry subalpine) Replacement 11% 250 31 500
Mixed 45% 60 31 350
Surface or low 45% 60 9 350
Northern and Central Rockies
Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics
Percent of fires Mean interval
(years)
Minimum interval
(years)
Maximum interval
(years)
Northern and Central Rockies Grassland
Mountain grassland Replacement 60% 20 10  
Mixed 40% 30    
Northern and Central Rockies Forested
Douglas-fir (xeric interior) Replacement 12% 165 100 300
Mixed 19% 100 30 100
Surface or low 69% 28 15 40
Douglas-fir (warm mesic interior) Replacement 28% 170 80 400
Mixed 72% 65 50 250
Persistent lodgepole pine Replacement 89% 450 300 600
Mixed 11% >1,000    
Lower subalpine lodgepole pine Replacement 73% 170 50 200
Mixed 27% 450 40 500
Lower subalpine (Wyoming and Central Rockies) Replacement 100% 175 30 300
Great Lakes
Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics
Percent of fires Mean interval
(years)
Minimum interval
(years)
Maximum interval
(years)
Great Lakes Woodland
Great Lakes pine barrens Replacement 8% 41 10 80
Mixed 9% 36 10 80
Surface or low 83% 4 1 20
Jack pine-open lands (frequent fire-return interval) Replacement 83% 26 10 100
Mixed 17% 125 10 100
Northern oak savanna Replacement 4% 110 50 500
Mixed 9% 50 15 150
Surface or low 87% 5 1 20
Great Lakes Forested
Conifer lowland (embedded in fire-prone system) Replacement 45% 120 90 220
Mixed 55% 100    
Great Lakes spruce-fir Replacement 100% 85 50 200
Minnesota spruce-fir (adjacent to Lake Superior and Drift and Lake Plain) Replacement 21% 300    
Surface or low 79% 80    
Great Lakes pine forest, jack pine Replacement 67% 50    
Mixed 23% 143    
Surface or low 10% 333
Oak-hickory Replacement 13% 66 1  
Mixed 11% 77 5  
Surface or low 76% 11 2 25
Pine-oak Replacement 19% 357    
Surface or low 81% 85    
Red pine-eastern white pine (frequent fire) Replacement 38% 56    
Mixed 36% 60    
Surface or low 26% 84    
Great Lakes pine forest, eastern white pine-eastern hemlock (frequent fire) Replacement 52% 260    
Mixed 12% >1,000    
Surface or low 35% 385    
Northeast
Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics
Percent of fires Mean interval
(years)
Minimum interval
(years)
Maximum interval
(years)
Northeast Woodland
Rocky outcrop pine (Northeast) Replacement 16% 128    
Mixed 32% 65    
Surface or low 52% 40    
Pine barrens Replacement 10% 78    
Mixed 25% 32    
Surface or low 65% 12    
Oak-pine (eastern dry-xeric) Replacement 4% 185    
Mixed 7% 110    
Surface or low 90% 8    
Northeast Forested
Appalachian oak forest (dry-mesic) Replacement 2% 625 500 >1,000
Mixed 6% 250 200 500
Surface or low 92% 15 7 26
Northeast spruce-fir forest Replacement 100% 265 150 300
Southern Appalachians
Vegetation Community (Potential Natural Vegetation Group) Fire severity* Fire regime characteristics
Percent of fires Mean interval
(years)
Minimum interval
(years)
Maximum interval
(years)
Southern Appalachians Woodland
Table Mountain-pitch pine Replacement 5% 100    
Mixed 3% 160    
Surface or low 92% 5    
Appalachian Virginia pine Replacement 20% 110 25 125
Mixed 15% 145    
Surface or low 64% 35 10 40
*Fire Severities
Replacement: Any fire that causes greater than 75% top removal of a vegetation-fuel type, resulting in general replacement of existing vegetation; may or may not cause a lethal effect on the plants.
Mixed: Any fire burning more than 5% of an area that does not qualify as a replacement, surface, or low-severity fire; includes mosaic and other fires that are intermediate in effects.
Surface or low: Any fire that causes less than 25% upper layer replacement and/or removal in a vegetation-fuel class but burns 5% or more of the area [49,75].

Fuels: Low precipitation, long hours of daylight in summer, ground covers of dry mosses and lichens, and resinous conifers can make taiga forests highly flammable [84]. Studies on the relative flammability of juniper haircap moss were not found for this literature review; however, ground layers of taiga forests dominated by juniper haircap moss may be less flammable than those dominated by lichen and most other moss species. Juniper haircap moss is highly resistant to desiccation [57] and may not dry out as rapidly as reindeer lichens and most other moss species. It tends to form thinner mat layers [39,124] than most moss species [84], so it provides fewer fuels than peat-forming mosses such as sphagnum. Studies are needed on the ability of juniper haircap moss mats to carry fire under varying levels of relative humidity and mat moisture content.

Density and biomass measurements of juniper haircap moss may provide baselines for juniper haircap moss fuel loads and/or rates of postdisturbance biomass accumulation on similar sites. On the Edwin S. George Reserve, Michigan, juniper haircap moss had a mean density of 127.84 stems/cm/39 cm plot and mean cover of 83.46 cm/39 cm plot [68]. Biomass in 4 unburned sheathed cottonsedge (Eriophorum vaginatum) tundra communities of Alaska and the Northwest Territories averaged 516 g/m; total moss cover averaged 22%. Juniper haircap moss was the dominant moss on burned sites in postfire year 1, averaging 2% cover across sites [153]. Seven years after construction of a powerline in northern Manitoba, aerial biomass of vegetation on disturbed sites was less than 40% of aerial biomass on undisturbed sites. Dark sphagnum moss (Sphagnum fuscum) and juniper haircap moss dominated both disturbed and undisturbed plots; juniper haircap moss frequency was 46% on undisturbed plots and 30% on disturbed plots [133].

Aboveground biomass of vegetation on undisturbed and disturbed plots 7 years after powerline construction in northern Manitoba [133]
Species Undisturbed Powerlines
Biomass (kg/ha)
Black spruce 2,280 ND
Dwarf shrubs 3,948 1,747
Herbs 345 197
Graminoids 104 138
Ground lichens 780 1
Bryophytes 482 15
     juniper haircap moss 4 5

Total

7,939 2,098

POSTFIRE REGENERATION STRATEGY (adapted from [138]):
Vegetative propagules on soil surface
Ground residual colonizer (on-site spores, initial community)
Secondary colonizer (on- or off-site spore sources)


FIRE EFFECTS

SPECIES: Polytrichum juniperinum
IMMEDIATE FIRE EFFECT ON PLANT:
Information on direct fire effects on juniper haircap moss were not found for this literature review; however, shallow peat fires, other ground fires, and severe surface fires probably kill juniper haircap moss [149]. Juniper haircap moss rhizoids sometimes grow in mineral soil [33,53,91,101] where they are insulated from heat, so light- to moderate-severity surface fire that does not heat mineral soil to lethal temperatures may only top-kill juniper haircap moss [147]. Juniper haircap moss rhizoids or stem fragments in or below unburned peat or other organic soil layers may survive surface peat fires [65,87].

DISCUSSION AND QUALIFICATION OF FIRE EFFECT:
No additional information is available on this topic.

PLANT RESPONSE TO FIRE:
Juniper haircap moss can establish on burns from off-site, wind-blown spores [59] and by sprouting from unburned rhizoids and/or stem fragments [59,84,147,149,156], including stem fragments in lower-layer, unburned portions of peat or other organic soil [65]. Viereck and Schandelmeier [147,149] report that juniper haircap moss and horsetails (Equisetum spp.) are often the only survivors after fires that remove most of the organic soil layer.

Juniper haircap moss is frequently included in a small group of groundlayer species that obtain high frequencies in early postfire communities (for example, [134,135]). In a review, Wein [151] identified juniper haircap moss and Marchantia polymorpha as "the first cryptogams to emerge" after tundra fires in Alaska and Canada. In spruce forests of the Northwest Territories, juniper haircap moss, common haircap moss, and fire moss were called "the most efficient" at vegetative reproduction in early postfire succession among 9 bryophytes studied [65]. Juniper haircap moss and common haircap moss were described as "covering the soil" (80% cover) 4 years after experimental fires in a Scots pine-Norway spruce forest in Sweden [126].

Juniper haircap moss generally colonizes soon after fire, declining within 5 to 15 postfire years in most North American ecosystems [1,30,42,53,57,68,129]. Juniper haircap moss's appearance in early postfire succession has been documented across its distribution. In a review, Ryoma and Laaka-Lindberg [125] note that juniper haircap moss is most common from postfire years 1 through 4 in diverse locations and plant communities including coastal heath dunelands of Denmark, heathlands of Scotland and France, coniferous forests of Europe and North America, tropical mountain associations in Jamaica, and eucalyptus forests of Australia. Worldwide, juniper haircap moss occurrence generally declines after 10 to 20 postfire years [125]. The following sections provide information on juniper haircap moss postfire establishment across juniper haircap moss's North American distribution. The sections are arranged geographically from north to south and west to east, followed by studies of postfire juniper haircap moss establishment outside North America.

Northern ecosystems: Juniper haircap moss and other haircap mosses colonized burned areas at low to high densities after tundra wildfires on the Seward Peninsula of Alaska. Haircap mosses had 0% to 1% total prefire coverage on permanent study plots in tussock sedge (Carex spp. and sheathed cottonsedge)-heath-dwarf birch and heath-dwarf birch communities a year before wildfires in 1977. Prefire density was not measured. In postfire year 1, haircap mosses grew on charred peat surfaces at densities ranging from less than 1 to 81 stems/m. Juniper haircap moss was the dominant moss on 2 nearby tussock sedge-mixed shrub sites that had burned 7 years previously, with total haircap moss density averaging 135 stems/m on the 7-year-old burns [111,112].

Juniper haircap moss and other haircap mosses often dominate early postfire succession in spruce taiga forests of interior Alaska and northern Canada, first appearing approximately 3 months to 3 years after fire. The moss-herb stage of postfire succession, which often includes juniper haircap moss, lasts about 10 years [35]. In the Mackenzie Delta in the Northwest Territories, juniper haircap moss was the only groundlayer species that "regrew" 1 and 2 years after wildfires. The study sites were in black spruce-tundra ecotone and marsh Labrador tea (Ledum palustre ssp. decumbens)/sheathed cottonsedge tundra communities [11].

Juniper haircap moss and other early-seral groundlayer species typically form postfire assemblages across moisture and other gradients; postfire successional trajectories of these assemblages may be difficult to predict. Reindeer lichens [37,91], Marchantia polymorpha, fireweed [65], fire moss, and other haircap mosses are common juniper haircap moss associates on burned spruce taiga [156]. Because juniper haircap moss is taller in stature and more drought tolerant, it successionally replaces fire moss on many burned sites [25]. In a review, Lutz [84] described juniper haircap moss as rare to abundant in early-successional, burned black spruce, paper birch, and quaking aspen forests in southwestern and central interior Alaska. Juniper haircap moss often replaced pioneering fire moss and Pohlia spp. mosses, with juniper haircap moss cover peaking about 10 to 20 years after fire. In turn, juniper haircap moss was often replaced by reindeer lichens and Schreber's moss [84]. However, in a chronosequence study of burned black spruce stands in interior Alaska, fire moss gained dominance over juniper haircap moss in early postfire succession. Juniper haircap moss grew in young (3-, 7-, and 10-year-old) stands but never attained over 4% cover, while fire moss showed 35% to 59% cover in young stands. Neither moss was found in older stands [99].

Juniper haircap moss was the dominant moss in black spruce and quaking aspen communities 3 years after the Wickersham Dome Fire near Fairbanks. It was more frequent in black spruce than quaking aspen communities [148]:

Juniper haircap moss density and frequency on severely burned sites following the Wickersham Dome Fire near Fairbanks, Alaska, in summer 1971 [148]
  Density (stems/ha) Frequency (%)
Black spruce forest
Fall 1971 0 0
1972 (postfire year 1) 0.40 40
1973 (postfire year 2) 0.65 65
1974 (postfire year 3) 5.10 45
Adjacent unburned control 1.70 65
Quaking aspen forest
1972 (postfire year 1) 0.05 5
1973 (postfire year 2) 0.05 5
1974 (postfire year 3) 1.40 65
Adjacent unburned control 0.20 10

Hawkes [53] observed juniper haircap moss soon after fire in white spruce forests of Kluane National Park, Yukon; juniper haircap moss colonized mineral soil in postfire years 1 to 15 [53]. It was among the most common mosses of early postfire succession in the 1st and 2nd growing season after a wildfire in a black spruce muskeg in northeastern Alberta. Juniper haircap moss was more common on unlogged, burned soils than on other substrates in postfire year 1, but juniper haircap moss frequencies were similar on unlogged and salvage-logged burned soils by postfire year 2 [16].

Frequency (%) of juniper haircap moss on burned wood or scorched soil the 1st and 2nd growing seasons after a wildfire in Alberta [16]

Substrate

Frequency (%)
Postfire year 1
(2003)
Postfire year 2
(2004)

Burned wood

  burned only 25.8 40.0
  burned and salvage logged 20.8 29.2

Soil (includes mineral and organic soils)

  burned only 58.3 65.0
  burned and salvage logged 38.9 66.7

In a chronosequence study of burned hybrid spruce/devil's club (Oplopanax horridus)/moss sites in central British Columbia, juniper haircap moss was the dominant moss in early postfire succession (<14 years after fire), with average cover of 35% [30].

Analyses of 141 black spruce-jack pine stands in the Slave Lake area of the Northwest Territories found juniper haircap moss was associated with stands that had burned 10 or fewer years previously. Juniper haircap moss, fire moss, and fireweed formed an "eclectic group which seems to reflect survival and regeneration from the prefire vegetation" [65]. Juniper haircap moss cover was similar among burns of different ages in the Northwest Territories [122]:

Juniper haircap moss abundance on different-aged burns on black spruce/bog birch peat plateaus of Chick Lake Basin, Northwest Territories [122]
Postfire year Cover (%) Frequency (%)
4 3 7
53 1 no data
92 2 22

In the Mackenzie Valley, Northwest Territories, juniper haircap moss dominated the moss layer of a white spruce/splendid feather moss habitat type that burned 30 years prior to plant surveys. Quaking aspen, meadow horsetail (Equisetum pratense), and juniper haircap moss had 2% cover each; no other plant and no lichen species had gained more than 2% cover by postfire year 30. Juniper haircap moss was also a dominant moss on a dwarf heathland/herb community in Mackenzie Valley that burned in 1911 and reburned in 1968, showing 1% cover 5 years after the 1968 fire [122].

A chronosequence study of black spruce/reindeer lichen woodlands in northern Quebec found juniper haircap moss and other early-successional mosses colonized mineral soil, with a black spruce woodland forming about 65 years after fire. Postfire succession proceeded as follows [91]:

Postfire chronosequence development of black spruce forests in northern Quebec [91]
Postfire year Dominant species
4 juniper haircap moss-globose haircap moss-fire moss
14 granular trapeliopsis lichen (Trapeliopsis granulosa)
23 reindeer lichens
38 spineless reindeer lichen
42 star reindeer lichen (Cladonia alpestris)
65 star reindeer lichen-immature black spruce
129 black spruce/star reindeer lichen woodland
250 black spruce/Schreber's moss-hairy ptilidium liverwort (Ptilidium ciliare) forest

Analyses of soil profiles from burned black spruce woodlands in Labrador showed juniper haircap moss was the first moss to establish after surface, shallow, and deep peat fires. On sites with deep peat fire, juniper haircap moss grew over a layer of mineral soil and charcoal. On sites where fire consumed only the upper peat layer, juniper haircap moss grew over a layer of reindeer lichens (Cladonia spp.). On some of these sites, the reindeer lichens had in turn grown over a layer of juniper haircap moss in the lower peat profile. Juniper haircap moss in the lower layer overlaid charcoal and mineral soil [37].

In a 38-year chronosequence study, postfire coverage of juniper haircap moss peaked in postfire year 4 but fluctuated across study years. Study sites were located in black spruce/sheep-laurel (Kalmia angustifolia) habitats in Newfoundland [12].

Mean juniper haircap moss coverage after fires in Terra Nova National Park, Newfoundland [12]
Postfire year Cover (%)
1 0
4 10
9 1
13 6
17 0
20 8
23 8
38 0

Northeastern ecosystems: Juniper haircap moss may colonize relatively dry sites in areas where other haircap mosses cooccur. Four years after a wildfire in a mixed-hardwood stand on Mt Desert Island, Maine, juniper haircap moss and globose haircap moss formed discontinuous swards in valleys and on hilltops. Globose haircap moss tended to grow in wet depressions, while juniper haircap moss grew on drier microsites [135].

Juniper haircap moss attains generally high cover in the frequent fire-return intervals typical of pitch pinelands. On pitch pine plains in New Jersey, fire-return intervals range from 5 to 60 years. The fire regime in pitch pine communities is mixed, with surface fires occurring in the low end of the range and stand-replacement crown fires in stands where fire has not occurred for many decades. Old, closed-canopy pitch pine stands with a shrub understory are most likely to experience crown fire. Juniper haircap moss is common on such severely burned sites, apparently establishing from wind-dispersed spores [155]. Frequent, prescribed surface fires also favored juniper haircap moss on a New Jersey pitch pine barrens site. Postfire inventories on sites burned under prescription showed juniper haircap moss, fire moss, and broom dicranum moss (Dicranum scoparium) comprised 98% of total moss cover on 3-year or annual-burn rotations. Overall moss cover at postfire year 3 was 29% and lichen cover was 19%. Annual burning reduced the moss and lichen ground layer compared to 3-year fire-return intervals, with 9% total moss cover and 8% total lichen cover on annually-burned plots [93]. Fourteen years after a "hot" wildfire on the Lebanon State Forest in New Jersey, juniper haircap moss and reindeer lichens dominated open areas within young pitch pine-oak stands [131].

Western ecosystems: Juniper haircap moss was more abundant on 29-year-old burns than on unburned sites in subalpine fir-mountain hemlock/pink mountainheath-Cascade bilberry (Tsuga mertensiana/ Phyllodoce empetriformis-Vaccinium deliciosum) krummholz and pink mountainheath-Cascade bilberry-heather (Cassiope mertensiana) alpine heath communities of the North Cascade Range, Washington. Juniper haircap moss and Tolmie's penstemon (Penstemon procerus var. tolmiei) had highest postfire coverage (8% each) compared to other plant species in the krummholz community [28].

Mean percent cover and frequency of juniper haircap moss on burned and unburned alpine plant communities of the North Cascade Range, Washington [28]
  Krummholz Alpine heath
Cover (%) Frequency (%) Cover (%) Frequency (%)
Burned 8 61 2 17
Unburned trace 4 0 0

A study in a bluebunch wheatgrass-Idaho fescue community in Hell's Canyon National Recreation Area, Oregon, found wildfire had no significant effect on cover of moss and lichen cryptogamic soil crusts. Juniper haircap moss was not present on unburned plots but had 0.3% cover on wildfire-burned plots in postfire month 11 [15]. Fire may have favored formation of cryptogamic soil crusts in Yellowstone National Park. Thirteen years after the 1988 fires, juniper haircap moss and globose haircap moss had formed mats over dry mineral soil. The study sites had been lodgepole pine forest before the stand-replacement fires [33].

Outside North America: After reaching peak cover in early postfire decades, juniper haircap moss declined with time since fire in Finland studies. Juniper haircap moss generally colonized in postfire year 3 on Norway spruce (Picea abies) and Scots pine (Pinus sylvestris) sites burned under prescription. Time since fire ranged from 1 month to 50 years in the study area. In Norway spruce stands, juniper haircap moss first occurred in postfire year 3, following common dandelion (Taraxacum officinale) and fireweed. Juniper haircap moss dominated the moss strata of 3-year-old burns in both forest communities, with juniper haircap moss and other haircap mosses comprising nearly 100% of total moss cover. Haircap mosses reached maximum frequency in postfire years 4 to 9. On 30-year-old plots, juniper haircap moss and other haircap mosses comprised 40% of total moss cover. On 50-year-old burns, haircap moss comprised 4% of total moss cover. Haircap mosses had 1% cover on unburned sites [150].

Juniper haircap moss dominated the groundlayer vegetation 21 years following prescribed burning in a Norway spruce peatland forest in northern Sweden. Splendid feather moss and Schreber's moss dominated before the fire. The fire removed an average thickness of 0.5 inch (1.3 cm) of peat [143,144].

Some Scottish heathlands have been burned for centuries for rangeland management. There are anecdotal reports of juniper haircap moss dominating on heath rangelands where prescribed fire "got entirely out of control" and burned into the peat layer, smoldering for "days or weeks". Areas denuded by such peat fires are typically colonized by juniper haircap moss, other mosses, and lichens [41]. On a heather (Calluna vulgaris) heathland on the Muir of Dinnet National Nature Preserve, Scotland, juniper haircap moss was not present on study plots prior to a prescribed fire but had 8% frequency in postfire year 1 [58].

On heathlands in France, juniper haircap moss typically establishes soon after fire but grows "slowly" compared to associated groundlayer species [42,43].

Juniper haircap moss was 1 of 3 early-seral mosses occurring after fire in an Australian mountain-ash forest in Tasmania [18,25]. Cord moss (Funaria hygrometrica), fire moss, and Marchantia polymorpha dominated the burn in postfire years 1 and 2, with scattered colonization by juniper haircap moss. Juniper haircap moss grew more slowly than the initial groundlayer dominants, but became dominant on sites where taller, herbaceous species were not present by postfire year 3.5. It remained dominant, with approximately 50% cover, on open sites through at least postfire year 6.5 [25]. On another Australian mountain-ash forest in Tasmania, juniper haircap moss first occurred on study plots in postfire year 2. By postfire year 4, juniper haircap moss had successionally replaced fire moss and cord moss [31].

Fire and logging: Several studies show that juniper haircap moss is tolerant of fire and logging. See Logging and Discussion and Qualification of Plant Response for further information on this topic.

DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
Juniper haircap moss had greater coverage and frequency on burned mineral soil compared to the unburned forest floor after multiple silvicultural treatments in east-central British Columbia. The site was a hybrid spruce/devil's club community that was logged, slashburned, and replanted with conifers prior to plant and lichen inventories in postfire year 4. Coverage of juniper haircap moss at postfire year 4 was 18% on burned plots and 13% on unburned plots; its frequency was 63% on burned and 59% on unburned plots. Postfire coverage of over 100 vascular plants, mosses, liverworts, and lichens was measured in this study; prefire coverage was also measured for vascular plants. For details on the fire prescription and plant and lichen species' responses to fire, see the Research Paper by Hamilton [48].

For information on prescribed fire and postfire response of many plant species, including juniper haircap moss, see these Research Project Summaries:

FIRE MANAGEMENT CONSIDERATIONS:
Lack of data on moss fuels make it impossible to recommend moss- and peat-layer moisture levels that will sustain but help contain a prescribed fire in ecosystems with juniper haircap moss. Further experimental studies such as the FrostFire prescribed burn near Fairbanks, Alaska, are needed in order to provide guidelines for fire suppression and wildland fires for resource benefit in northern and other ecosystems with juniper haircap moss.

Juniper haircap moss's rapid colonization after fire may reduce erosion on burned sites [128]. In a study of fire effects on soils in northern Saskatchewan, Scotter [127] concluded that "erosion following forest fires on the study area did not appear serious", mainly due to rapid postfire colonization of burned soils by juniper haircap moss, globose haircap moss, and Marchantia polymorpha; the typically low intensity of summer rainstorms in the area; and because the soil is frozen for 7 months of the year. Study sites were 5- to 22-year-old burns in black spruce-jack pine communities [127].

MANAGEMENT CONSIDERATIONS

SPECIES: Polytrichum juniperinum
IMPORTANCE TO WILDLIFE AND LIVESTOCK:
Wildlife generally avoid grazing mosses when other forage is available. Caribou may graze juniper haircap moss from late fall to spring if more palatable forage is unavailable. On black spruce-jack pine taiga of northeastern Saskatchewan, mean frequency of barren ground caribou use of juniper haircap moss was 53% in November, 50% in January, and 57% in April, based on rumen samples. It was unclear if caribou consumed juniper haircap moss as emergency food or accidentally while grazing more palatable forage such as reindeer lichens [87]. In a study of lemming forage preferences during a population peak on a Norway tundra site, frequency of juniper haircap moss in spring was higher in exclosures (8.2%) than open plots (4.0%). Overall cover of mosses was significantly higher on plots in exclosures than plots on open tundra (P≥0.05), suggesting that the lemmings grazed juniper haircap moss and other mosses on open sites [90].

Waterfowl may avoid sites where juniper haircap moss is dominant because those areas are relatively dry [139].

Palatability/nutritional value: Mosses in general are low in nutritional value compared to associated groundlayer species. Even compared to other mosses, juniper haircap moss was low in nitrogen and other nutrients on a burned Australian mountain-ash forest in Tasmania. Brasell and Mattay [18] provide a nutritional analysis of juniper haircap moss on that site.

Cover value: Wildlife seeking hiding or thermal cover probably avoid open areas dominated by juniper haircap moss or other low vegetation.

Woodland caribou in the Mackenzie and Selwyn Mountains of Yukon and the Northwest Territories use snowfields within arctic dryad-red fruit bearberry (Dryas integrifolia-Arctostaphylos rubra) tundra cushion plant communities as relief habitat to escape insect harassment. Juniper haircap moss is a common moss in that habitat [63].

VALUE FOR REHABILITATION OF DISTURBED SITES:
Juniper haircap moss has potential for use on restoration sites. Juniper haircap moss mats help stabilize sandy soils on slopes [124]. Experimental oil spills on upland tundra sites in Canada suggest that juniper haircap moss could be used for revegetation soon after oil spills. Juniper haircap moss was the only moss present on spill sites 1 year after the oil treatments [62,152].

OTHER USES:
No information is available on this topic.

OTHER MANAGEMENT CONSIDERATIONS:
No information is available on this topic.

REFERENCES:


1. Ahlgren, C. E. 1974. Effects of fires on temperate forests: north central United States. In: Kozlowski, T. T.; Ahlgren, C. E., eds. Fire and ecosystems. New York: Academic Press: 195-223. [7198]
2. Allen, Charles E. 1917. The spermatogenesis of Polytrichum juniperinum. Annals of Botany. 31(122): 269-291. [69443]
3. Aller, Alvin R. 1956. A taxonomic and ecological study of the flora of Monument Peak, Oregon. The American Midland Naturalist. 56(2): 454-472. [6385]
4. Arno, Stephen F. 1980. Forest fire history in the Northern Rockies. Journal of Forestry. 78(8): 460-465. [11990]
5. Bazzaz, F. A.; Paolillo, Dominick J., Jr.; Jagels, R. H. 1970. Photosynthesis and respiration of forest and alpine populations of Polytrichum juniperinum. The Bryologist. 73(3): 579-585. [70308]
6. Beasleigh, W. J.; Yarranton, G. A. 1974. Ecological strategy and tactics of Equisetum sylvaticum during a postfire succession. Canadian Journal of Botany. 52: 2299-2318. [9965]
7. Bernard, John M.; Seischab, Franz K. 1995. Pitch pine (Pinus rigida Mill.) communities in northeastern New York State. The American Midland Naturalist. 134(2): 294-306. [25966]
8. Biring, B. S.; Hays-Byl, W. J.; Hoyles, S. E. 1999. Twelve-year conifer and vegetation responses to discing and glyphosate treatments on a BWBSmw backlog site. Working Paper 43. Victoria, BC: British Columbia Ministry of Forests, Research Branch. 34 p. [41236]
9. Black, R. Alan; Bliss, L. C. 1980. Reproductive ecology of Picea mariana (Mill.) BSP., at tree line near Inuvik, Northwest Territories, Canada. Ecological Monographs. 50(3): 331-354. [8413]
10. Bliss, L. C. 1988. Arctic tundra and polar desert biome. In: Barbour, Michael G.; Billings, William Dwight, eds. North American terrestrial vegetation. New York: Cambridge University Press: 1-32. [13877]
11. Bliss, L. C.; Wein, R. W. 1972. Plant community responses to disturbances in the western Canadian Arctic. Canadian Journal of Botany. 50: 1097-1109. [14877]
12. Bloom, Robin G.; Mallik, Azim U. 2006. Relationships between ericaceous vegetation and soil nutrient status in a post-fire Kalmia angustifolia-black spruce chronosequence. Plant and Soil. 289(1/2): 211-226. [66677]
13. Bock, Michael D.; Van Rees, Ken C. J. 2002. Mechanical site preparation impacts on soil properties and vegetation communities in the Northwest Territories. Canadian Journal of Forest Research. 32: 1381-1392. [42578]
14. Bowden, Richard D. 1991. Inputs, outputs, and accumulation of nitrogen in an early successional moss (Polytrichum) ecosystem. Ecological Monographs. 6(12): 207-223. [15033]
15. Bowker, Matthew A.; Belnap, Jayne; Rosentreter, Roger; Graham, Bernadette. 2004. Wildfire-resistant biological soil crusts and fire-induced loss of soil stability in Palouse prairies, USA. Applied Soil Ecology. 26(1): 41-52. [50222]
16. Bradbury, S. M. 2006. Response of the post-fire bryophyte community to salvage logging in boreal mixedwood forests of northeastern Alberta, Canada. Forest Ecology and Management. 234(1-3): 313-322. [64988]
17. Bramble, William C. 1947. Indicator types for Virginia pine stands in central Pennsylvania. Research Paper No. 8. University Park, PA: The Pennsylvania State Forestry School. 8 p. [61118]
18. Brasell, H. M.; Mattay, J. P. 1984. Colonization by bryophytes of burned Eucalyptus forest in Tasmania, Australia: changes in biomass and element content. Bryologist. 87(4): 302-307. [20236]
19. Brumelis, G.; Carleton, T. J. 1989. The vegetation of post-logged black spruce lowlands in central Canada. II. Understory vegetation. Journal of Applied Ecology. 26(1): 321-339. [7864]
20. Carvey, Kathryn; Farrar, Donald R.; Glenn-Lewin, David C. 1977. Bryophytes and revegetation of coal spoils in southern Iowa. The Bryologist. 80(4): 630-637. [69949]
21. Chrosciewicz, Z. 1983. Jack pine regeneration following postcut burning and seeding in central Saskatchewan. Information Report NOR-X-253. Edmonton, AB: Environment Canada, Canadian Forestry Service, Northern Forest Research Centre. 11 p. [16916]
22. Chrosciewicz, Z. 1988. Forest regeneration on burned, planted, and seeded clear-cuts in central Saskatchewan. Information Report NOR-X-293. Edmonton, AB: Canadian Forestry Service, Northern Forestry Centre. 16 p. [16697]
23. Collins, Ellen I. 1984. Preliminary classification of Wyoming plant communities. Cheyenne, WY: Wyoming Natural Heritage Program; The Nature Conservancy. 42 p. [661]
24. Conard, Henry S. 1956. How to know the mosses and liverworts. Dubuque, IA: Wm. C. Brown Company Publishers. 226 p. [9927]
25. Cremer, K. W.; Mount, A. B. 1965. Early stages of plant succession following the complete felling and burning of Eucalyptus regnans forest in the Florentine Valley, Tasmania. Australian Journal of Botany. 13: 303-322. [70318]
26. Crum, Howard A.; Anderson, Lewis E. 1981. Mosses of eastern North America. Vol. 2. New York: Columbia University Press. 664-1328. [28341]
27. Crum, Howard. 1976. Mosses of the Great Lakes forest. Revised edition. Ann Arbor, MI: University of Michigan, University of Michigan Herbarium. 404 p. [70430]
28. Douglas, George W.; Ballard, T. M. 1971. Effects of fire on alpine plant communities in the North Cascades, Washington. Ecology. 52(6): 1058-1064. [6738]
29. Douglas, George W.; Bliss, L. C. 1977. Alpine and high subalpine plant communities of the North Cascades Range, Washington and British Columbia. Ecological Monographs. 47: 113-150. [9487]
30. Driscoll, K. G.; Arocena, J. M.; Massicotte, H. B. 1999. Post-fire soil nitrogen content and vegetation composition in sub-boreal spruce forests of British Columbia's central interior, Canada. Forest Ecology and Management. 121: 227-237. [30330]
31. Duncan, Diana; Dalton, P. J. 1982. Recolonization by bryophytes following fire. Journal of Bryology. 12: 53-63. [19774]
32. Dyrness, C. T.; Grigal, D. F. 1979. Vegetation-soil relationships along a spruce forest transect in interior Alaska. Canadian Journal of Botany. 57: 2644-2656. [12488]
33. Eversman, Sharon; Horton, Diana. 2004. Recolonization of burned substrates by lichens and mosses in Yellowstone National Park. Northwest Science. 78(2): 85-92. [50342]
34. Flora of North America Editorial Committee, eds. 2013. Flora of North America north of Mexico, [Online]. Flora of North America Association (Producer). Available: http://www.efloras.org/flora_page.aspx?flora_id=1. [36990]
35. Foote, M. Joan. 1983. Classification, description, and dynamics of plant communities after fire in the taiga of interior Alaska. Res. Pap. PNW-307. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 108 p. [7080]
36. Forman, Richard T. T. 1965. A system for studying moss phenology. The Bryologist. 68(3): 289-300. [70207]
37. Foster, David R. 1985. Vegetation development following fire in Picea mariana (black spruce)-Pleurozium forests of south-eastern Labrador, Canada. Journal of Ecology. 73(2): 517-534. [7222]
38. Frego, Katherine A.; Staniforth, Richard J. 1986. Vegetation sequence on three boreal Manitoban rock outcrops and seral position of Opuntia fragilis. Canadian Journal of Botany. 64(1): 77-84. [55073]
39. Frye, T. C. 1937. Moss flora of North America north of Mexico. Part 1: Polytrichaceae. In: Grout, A. J., ed. New York: Newfane: 99-128. [70309]
40. Fuller, R. N.; del Moral, R. 2003. The role of refugia and dispersal in primary succession on Mount St. Helens, Washington. Journal of Vegetation Science. 14(5): 637-644. [50307]
41. Gimingham, C. H. 1971. British heathland ecosystems: the outcome of many years of management by fire. In: Proceedings, annual Tall Timbers fire ecology conference; 1970 August 20-21; Fredericton, NB. No. 10. Tallahassee, FL: Tall Timbers Research Station: 293-321. [18943]
42. Gloaguen, J. C. 1993. Spatio-temporal patterns in post-burn succession on Brittany heathlands. Journal of Vegetation Science. 4(4): 561-566. [60969]
43. Gloaguen, J. C.; Gautier, N. 1981. Pattern development of the vegetation during colonization of a burnt heathland in Brittany (France). Vegetatio. 46: 167-176. [18477]
44. Good, Ralph E.; Good, Norma F.; Andresen, John W. 1998. The Pine Barren Plains. In: Forman, Richard T. T., ed. Pine Barrens: ecosystem and landscape. New Brunswick, NJ: Rutgers University Press: 283-295. [50780]
45. Gregory, P. H. 1973. The microbiology of the atmosphere. 2nd ed. Plymouth, United Kingdom: Leonard Hill Books. 377 p. [70317]
46. Grove, Adam J. 1998. Effects of Douglas fir establishment in southwestern Montana mountain big sagebrush communities. Bozeman, MT: Montana State University, Department of Animal and Range Science. 150 p. Thesis. [46897]
47. Haeussler, Sybille; Kabzems, Richard. 2005. Aspen plant community response to organic matter removal and soil compaction. Canadian Journal of Forest Research. 35: 2030-2044. [61573]
48. Hamilton, E. 2006. Vegetation development and fire effects at the Walker Creek site: comparison of forest floor and mineral soil plots. Technical Report No. 026. Victoria, BC: British Columbia Ministry of Forests and Range, Forest Science Program. 28 p. [64621]
49. Hann, Wendel; Havlina, Doug; Shlisky, Ayn; [and others]. 2005. Interagency fire regime condition class guidebook. Version 1.2, [Online]. In: Interagency fire regime condition class website. U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior; The Nature Conservancy; Systems for Environmental Management (Producer). Variously paginated [+ appendices]. Available: http://www.frcc.gov/docs/1.2.2.2/Complete_Guidebook_V1.2.pdf [2007, May 23]. [66734]
50. Harper, Karen A.; Kershaw, G. Peter. 1996. Natural revegetation on borrow pits and vehicle tracks in shrub tundra, 48 years following construction of the CANOL No. 1 Pipeline, N.W.T., Canada. Arctic and Alpine Research. 28(2): 163-171. [62701]
51. Hart, Stephen A.; Chen, Han Y. H. 2006. Understory vegetation dynamics of North American boreal forests. Critical Reviews in Plant Sciences. 25(4): 381-397. [66680]
52. Hausmann, Mary Kay. 1977. Development and ultrastructure of antheridia in Polytrichum juniperinum hedw. Ithaca, NY: Cornell University. 85 p. Thesis. [69454]
53. Hawkes, Brad C. 1983. Fire history and ecology of forest ecosystems in Kluane National Park. In: Wein, Ross Wallace; Riewe, Roderick R.; Methven, Ian R., eds. Resources and dynamics of the boreal zone: Proceedings of a conference; 1982 August; Thunder Bay, ON. Ottawa, ON: Association of Canadian Universities for Northern Studies: 266-280. [7444]
54. Heckman, Charles W. 1999. The encroachment of exotic herbaceous plants into the Olympic National Forest. Northwest Science. 73(4): 264-276. [36188]
55. Heinselman, Miron L. 1981. Fire and succession in the conifer forests of northern North America. In: West, Darrell C.; Shugart, Herman H.; Botkin, Daniel B., eds. Forest succession: concepts and applications. New York: Springer-Verlag: 374-405. [29237]
56. Heinselman, Miron L. 1981. Fire intensity and frequency as factors in the distribution and structure of northern ecosystems. In: Mooney, H. A.; Bonnicksen, T. M.; Christensen, N. L.; Lotan, J. E.; Reiners, W. A., technical coordinators. Fire regimes and ecosystem properties: Proceedings of the conference; 1978 December 11-15; Honolulu, HI. Gen. Tech. Rep. WO-26. Washington, DC: U.S. Department of Agriculture, Forest Service: 7-57. [4390]
57. Herbst, Lesley Ann. 1975. Comparative ecology of Polytrichum commune Hedw. and Polytrichum juniperinum Hedw. Madison, WI: University of Wisconsin. 70 p. Thesis. [69450]
58. Hobbs, R. J.; Gimingham, C. H. 1984. Studies on fire in Scottish heathland communities. II. Post-fire vegetation development. Journal of Ecology. 72: 585-610. [19767]
59. Hobbs, R. J.; Mallik, A. U.; Gimingham, C. H. 1984. Studies on fire in Scottish heathland communities. III. Vital attributes of the species. Journal of Ecology. 72: 963-976. [1173]
60. Hungerford, Roger D.; Frandsen, William H.; Ryan, Kevin C. 1995. Ignition and burning characteristics of organic soils. In: Cerulean, Susan I.; Engstrom, R. Todd, eds. Fire in wetlands: a management perspective: Proceedings, 19th Tall Timbers fire ecology conference; 1993 November 3-6; Tallahassee, FL. No. 19. Tallahassee, FL: Tall Timbers Research Station: 78-91. [25776]
61. Hunt, Shelley L.; Gordon, Andrew M.; Morris, Dave M.; Marek, George T. 2003. Understory vegetation in northern Ontario jack pine and black spruce plantations: 20-year successional changes. Canadian Journal of Forest Research. 33(9): 1791-1803. [65102]
62. Hutchinson, T. C.; Freedman, W. 1975. The impact of crude oil spills on arctic and sub-arctic vegetation. In: National Research Council, ed. Proceedings of the circumpolar conference on northern ecology. 1975 September; Ottawa, ON: 175-182. [29661]
63. Ion, Peter G.; Kershaw, G. Peter. 1989. The selection of snowpatches as relief habitat by woodland caribou (Rangifer tarandus caribou), Macmillan Pass, Selwyn/Makenzie Mountains, N.W.T., Canada. Arctic and Alpine Research. 21(2): 203-211. [62709]
64. Jauhiainen, Sinikka. 1998. Seed and spore banks of two boreal mires. Annales Botanici Fennici. 35(3): 197-201. [62956]
65. Johnson, E. A. 1981. Vegetation organization and dynamics of lichen woodland communities in the Northwest Territories, Canada. Ecology. 62(1): 200-215. [19244]
66. Kartesz, John T. 1999. A synonymized checklist and atlas with biological attributes for the vascular flora of the United States, Canada, and Greenland. 1st ed. In: Kartesz, John T.; Meacham, Christopher A. Synthesis of the North American flora (Windows Version 1.0), [CD-ROM]. Chapel Hill, NC: North Carolina Botanical Garden (Producer). In cooperation with: The Nature Conservancy; U.S. Department of Agriculture, Natural Resources Conservation Service; U.S. Department of the Interior, Fish and Wildlife Service. [36715]
67. Kershaw, G. Peter; Kershaw, Linda J. 1987. Successful plant colonizers on disturbances in tundra areas of northwestern Canada. Arctic and Alpine Research. 19(4): 451-460. [6115]
68. Kirkpatrick, Helen Elizabeth. 1990. Resource competition between two co-occurring species of Polytrichum. Ann Arbor, MI: The University of Michigan. 153 p. Dissertation. [69447]
69. Klinka, K.; Carter, R. E.; Feller, M. C.; Wang, Q. 1989. Relations between site index, salal, plant communities, and sites in coastal Douglas-fir ecosystems. Northwest Science. 63(1): 19-28. [6276]
70. Klinka, K.; Green, R. N.; Courtin, P. J.; Nuszdorfer, F. C. 1984. Site diagnosis, tree species selection, and slashburning guidelines for the Vancouver Forest Region, British Columbia. Land Management Report No. 25. Victoria, BC: Ministry of Forests, Information Services Branch. 180 p. [15448]
71. Klinka, K.; Krajina, V. J.; Ceska, A.; Scagel, A. M. 1989. Indicator plants of coastal British Columbia. Vancouver, BC: University of British Columbia Press. 288 p. [10703]
72. Knight, Dennis H.; Rogers, Brant S.; Kyte, Clayton R. 1977. Understory plant growth in relation to snow duration in Wyoming subalpine forest. Bulletin of the Torrey Botanical Club. 104(4): 314-319. [63270]
73. Kourtz, P. 1967. Lightning behaviour and lightning fires in Canadian forests. Departmental Publication No. 1179. Ottawa: Canadian Department of Forestry and Rural Development, Forestry Branch. 29 p. [21229]
74. LaFarge-England, Catherine; Vitt, Dale H.; England, John. 1991. Holocene soligenous fens on a high arctic fault block, northern Ellesmere Island (82N), N.W.T., Canada. Arctic and Alpine Research. 23(1): 80-98. [14469]
75. LANDFIRE Rapid Assessment. 2005. Reference condition modeling manual (Version 2.1), [Online]. In: LANDFIRE. Cooperative Agreement 04-CA-11132543-189. Boulder, CO: The Nature Conservancy; U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior (Producers). 72 p. Available: http://www.landfire.gov/downloadfile.php?file=RA_Modeling_Manual_v2_1.pdf [2007, May 24]. [66741]
76. LANDFIRE Rapid Assessment. 2007. Rapid assessment reference condition models, [Online]. In: LANDFIRE. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Lab; U.S. Geological Survey; The Nature Conservancy (Producers). Available: http://www.landfire.gov/models_EW.php [2008, April 18] [66533]
77. Lang, Frank Alexander. 1961. A study of vegetation change on the gravelly prairies of Pierce and Thurston Counties, western Washington. Seattle, WA: University of Washington. 109 p. Thesis. [53740]
78. Le Goff, Heloise; Sirois, Luc. 2004. Black spruce and jack pine dynamics simulated under varying fire cycles in the northern boreal forest of Quebec, Canada. Canadian Journal of Forest Research. 34(12): 2399-2409. [55447]
79. LeBlanc, Cheryl M.; Leopold, Donald J. 1992. Demography and age structure of a central New York shrub-carr 94 years after fire. Bulletin of the Torrey Botanical Club. 119(1): 50-64. [18208]
80. Lesica, Peter; McCune, Bruce; Cooper, Stephen V.; Hong, Won Shic. 1991. Differences in lichen and bryophyte communities between old-growth and managed second-growth forests in the Swan Valley, Montana. Canadian Journal of Botany. 69: 1745-1755. [16295]
81. Lewis, Francis J.; Dowding, E. S. 1926. The vegetation and retrogressive changes of peat areas ("muskegs") in central Alberta. Journal of Ecology. 14: 317-341. [12740]
82. Lloyd, D.; Angove, K.; Hope, G.; Thompson, C. 1990. A guide to site identification and interpretation for the Kamloops Forest Region: Part 2. Land Management Handbook Number 23. Victoria, BC: British Columbia Ministry of Forests, Research Branch. 193-399. [37026]
83. Lloyd, Kelvin M.; Lee, William G.; Fenner, Michael; Loughnan, Abi E. 2003. Vegetation change after artificial disturbance in an alpine Chionochloa pallens grassland in New Zealand. New Zealand Journal of Ecology. 27(1): 31-36. [70336]
84. Lutz, H. J. 1956. Ecological effects of forest fires in the interior of Alaska. Tech. Bull. No. 1133. Washington, DC: U.S. Department of Agriculture, Forest Service. 121 p. [7653]
85. MacLean, D. W.; Bedell, G. H. D. 1955. Northern Clay Belt growth and yield survey. Technical Note No. 20. Ottawa, ON: Department of Northern Affairs and National Resources, Forest Research Division. 31 p. [70474]
86. McCormick, Jack; Buell, Murray F. 1968. The Plains: pigmy forests of the New Jersey Pine Barrens, a review and annotated bibliography. New Jersey Academy of Sciences Bulletin. 13: 20-34. [11611]
87. McMinn, Robert G. 1951. The vegetation of a burn near Blaney Lake, British Columbia. Ecology. 32(1): 135-140. [16498]
88. Miller, Donald R. 1976. Biology of the Kaminuriak population of barren-ground caribou. Part 3. Taiga winter range relationships and diet. Canadian Wildlife Service Rep. Series No. 36. Ottawa, ON: Environment Canada, Wildlife Service. 42 p. [13007]
89. Mills, Suzanne E.; Macdonald, S. Ellen. 2005. Factors influencing bryophyte assemblage at different scales in the western Canadian boreal forest. The Bryologist. 108(1): 86-100. [69756]
90. Moen, Jon; Lundberg, Peter A.; Oksanen, Lauri. 1993. Lemming grazing on snowbed vegetation during a population peak, northern Norway. Arctic and Alpine Research. 25(2): 130-135. [21667]
91. Morneau, Claude; Payette, Serge. 1989. Postfire lichen-spruce woodland recovery at the limit of the boreal forest in northern Quebec. Canadian Journal of Botany. 67(9): 2770-2782. [9270]
92. Moss, E. H. 1932. The vegetation of Alberta: IV. The poplar association and related vegetation of central Alberta. The Journal of Ecology. 20(2): 380-415. [63588]
93. Moul, Edwin T.; Buell, Murray F. 1955. Moss cover and rainfall interception in frequently burned sites in the New Jersey pine barrens. Bulletin of the Torrey Botanical Club. 82(3): 155-162. [14550]
94. Mueller-Dombois, D. 1964. The forest habitat types of southeastern Manitoba and their application to forest management. Canadian Journal of Botany. 42: 1417-1444. [70118]
95. Nehlsen, Willa. 1977. Control of gametophore bud initiation in Polytrichum juniperinum. Santa Cruz, CA: University of California. 142 p. Dissertation. [69440]
96. Newmaster, Steven G.; Bell, F. Wayne; Roosenboom, Christopher R.; Cole, Heather A.; Towill, William D. 2006. Restoration of floral diversity through plantations on abandoned agricultural land. Canadian Journal of Forest Research. 36: 1218-1235. [64263]
97. Nieppola, Jari. 1992. Long-term vegetation changes in stands of Pinus sylvestris in southern Finland. Journal of Vegetation Science. 3: 475-484. [21845]
98. Niering, William A. 1953. The past and present vegetation of High Point State Park, New Jersey. Ecological Monographs. 23(2): 127-148. [64426]
99. O'Neill, Katherine P.; Richter, Daniel D.; Kasischke, Eric S. 2006. Succession-driven changes in soil respiration following fire in black spruce stands of interior Alaska. Biogeochemistry. 80(1): 1-20. [65863]
100. Olsson, Hans. 1998. Vegetation of the New Jersey Pine Barrens: a phytosociological classification. In: Forman, Richard T. T., ed. Pine Barrens: ecosystem and landscape. New Brunswick, NJ: Rutgers University Press: 245-263. [50775]
101. Oswald, E. T.; Brown, B. N. 1993. Vegetation development on skid trails and burned sites in southeastern British Columbia. Forestry Chronicle. 69(1): 75-80. [20566]
102. Packee, E. C. 1990. Tsuga heterophylla (Raf.) Sarg. western hemlock. In: Burns, Russell M.; Honkala, Barbara H., technical coordinators. Silvics of North America. Volume 1. Conifers. Agric. Handb. 654. Washington, DC: U.S. Department of Agriculture, Forest Service: 613-622. [13422]
103. Paolillo, D. J., Jr. 1975. The release of sperms from the antheridia of Polytrichum juniperinum Hedw. The New Phytologist. 74(2): 287-293. [70304]
104. Paolillo, D. J., Jr.; Cukierski, M. 1976. Wall developments and coordinated cytoplasmic changes in spermatogenous cells of Polytrichum (Musci). The Bryologist. 79(4): 466-479. [70413]
105. Peck, JeriLynn E.; Acker, Steven A.; McKee, W. Arthur. 1995. Autecology of mosses in coniferous forests in the central western Cascades of Oregon. Northwest Science. 69(3): 184-190. [26793]
106. Peck, V. Ross; Peek, James M. 1991. Elk, Cervus elaphus, habitat use related to prescribed fire, Tuchodi River, British Columbia. The Canadian Field-Naturalist. 105(3): 354-362. [18204]
107. Perez, Francisco L. 1991. Ecology and morphology of globular mosses of Grimmia longirostris in the Paramo de Piedras Blancas, Venezuelan Andes. Arctic and Alpine Research. 23(2): 133-148. [14958]
108. Perez, Zhanita Nikolee. 2001. Effects of desiccation on sucrose-metabolizing enzymes in gametophytic tissue of Polytrichum juniperinum. Kingsville, TX: Texas A&M University. 116 p. Thesis. [69439]
109. Peterson, Chris J.; Pickett, Steward T. A. 1995. Forest reorganization: a case study in an old-growth forest catastrophic blowdown. Ecology. 76(3): 763-774. [26657]
110. Peterson, Janice; Schmoldt, Daniel; Peterson, David; Eilers, Joseph; Fisher, Richard; Bachman, Robert. 1992. Guidelines for evaluating air pollution impacts on class I wilderness areas in the Pacific Northwest. Gen. Tech. Rep. PNW-GTR-299. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 83 p. [20633]
111. Racine, Charles H. 1979. The 1977 tundra fires in the Seward Peninsula, Alaska: effects and initial revegetation. BLM-Alaska Technical Report 4. Anchorage, AK: U.S. Department of the Interior, Bureau of Land Management, Alaska State Office. 51 p. [8330]
112. Racine, Charles H. 1981. Tundra fire effects on soils and three plant communities along a hill-slope gradient in the Seward Peninsula, Alaska. Arctic. 34(1): 71-84. [7233]
113. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
114. Rees, Daniel C.; Juday, Glenn Patrick. 2002. Plant species diversity on logged versus burned sites in central Alaska. Forest Ecology and Management. 155(1-3): 291-302. [40745]
115. Reich, Peter B.; Bakken, Peter; Carlson, Daren; Frelich, Lee E.; Friedman, Steve K.; Grigal, David F. 2001. Influence of logging, fire, and forest type on biodiversity and productivity in southern boreal forests. Ecology. 82(10): 2731-2748. [45136]
116. Reighard, Jundith Ann. 1967. Light and electron microscopic studies on spore germination and bud apical meristems in Polytrichum juniperum Hedw. and P. ohioense Ren. & Card. Urbana, IL: University of Illinois at Urbana-Champaign. 125 p. Dissertation. [69441]
117. Rencz, Andrew N.; Auclair, Allan N. D. 1978. Biomass distribution in a subarctic Picea mariana--Cladonia alpestris woodland. Canadian Journal of Forestry. 8: 168-176. [15867]
118. Ringius, Gordon S.; Sims, Richard A. 1997. Indicator plant species in Canadian forests. Ottawa, ON: Natural Resources Canada, Canadian Forest Service. 218 p. [35563]
119. Ritchie, J. C. 1960. The vegetation of northern Manitoba. Canadian Journal of Botany. 38(5): 769-788. [55687]
120. Roberts, Mark R.; Wuest, Lawrence J. 1999. Plant communities of New Brunswick in relation to environmental variation. Journal of Vegetation Science. 10(3): 321-334. [62806]
121. Rowe, J. S. 1956. Uses of undergrowth plant species in forestry. Ecology. 37(3): 461-473. [8862]
122. Rowe, J. S.; Bergsteinsson, J. L.; Padbury, G. A.; Hermesh, R. 1974. Fire studies in the Mackenzie Valley. ALUR 73-74-61. Ottawa, ON: Canadian Department of Indian and Northern Development. 123 p. [50174]
123. Rundel, Philip W.; Parsons, David J.; Gordon, Donald T. 1977. Montane and subalpine vegetation of the Sierra Nevada and Cascade Ranges. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley & Sons: 559-599. [4235]
124. Runesson, Ulf T. 2007. Polytrichum commune/Polytrichum juniperinum--Hair cap mosses, [Online]. Thunder Bay, ON: Lakehead University, Faculty of Forestry and the Forest Environment (Producer). Available: http://www.borealforest.org/lichens/lichen10.htm [2008, May 16]. [70310]
125. Ryoma, Riitta; Laaka-Lindberg, Sanna. 2005. Bryophyte recolonization on burnt soil and logs. Scandinavian Journal of Forest Research. 20(6): 5-16. [61028]
126. Schimmel, Johnny; Granstrom, Anders. 1996. Fire severity and vegetation response in the boreal Swedish forest. Ecology. 77(5): 1436-1450. [27371]
127. Scotter, George W. 1963. Effects of forest fires on soil properties in northern Saskatchewan. Forestry Chronicle. 39(4): 412-421. [13605]
128. Scotter, George W. 1971. Fire, vegetation, soil, and barren-ground caribou relations in northern Canada. In: Slaughter, C. W.; Barney, Richard J.; Hansen, G. M., eds. Fire in the northern environment--a symposium: Proceedings; 1971 April 13-14; Fairbanks, AK. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Range and Experiment Station: 209-230. [15730]
129. Scotter, George W. 1972. Fire as an ecological factor in boreal forest ecosystems of Canada. In: Fire in the environment: Symposium proceedings; 1972 May 1-5; Denver, CO. FS-276. [Washington, DC]: U.S. Department of Agriculture, Forest Service: 15-24. [13404]
130. Scotter, George Wilby. 1964. Effects of forest fires on the winter range of barren-ground caribou in northern Saskatchewan. Wildlife Management Bulletin. Series 1. No. 18. Ottawa, ON: Canadian Wildlife Service, National Parks Branch, Department of Northern Affairs and National Resources. 111 p. [28989]
131. Sedia, Ekaterina G.; Ehrenfeld, Joan G. 2003. Lichens and mosses promote alternate stable plant communities in the New Jersey pinelands. Oikos. 100(3): 447-458. [47208]
132. Sedia, Ekaterina G.; Ehrenfeld, Joan G. 2005. Differential effects of lichens, mosses and grasses on respiration and nitrogen mineralization in soils of the New Jersey Pinelands. Oecologia. 144(1): 137-147. [69504]
133. Sims, R. A.; Stewart, J. M. 1981. Aerial biomass distribution in an undisturbed and disturbed subarctic bog. Canadian Journal of Botany. 59: 782-786. [8414]
134. Sirois, Luc. 1995. Initial phase of postfire forest regeneration in two lichen woodlands of northern Quebec. Ecoscience. 2(2): 177-183. [27068]
135. Skutch, Alexander F. 1929. Early stages of plant succession following forest fires. Ecology. 10(2): 177-190. [21349]
136. Smith, Gary L. 1971. A conspectus of the genera of Polytrichaceae. Memoirs of the New York Botanical Garden. 21(3): 1-83. [70331]
137. Steele, Alma. 1978. Bryophyte communities of central Idaho forests. Northwest Science. 52(4): 310-322. [21546]
138. Stickney, Peter F. 1989. Seral origin of species comprising secondary plant succession in northern Rocky Mountain forests. FEIS workshop: Postfire regeneration. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, MT. 10 p. [20090]
139. Timoney, Kevin. 1999. The habitat of nesting whooping cranes. Biological Conservation. 89: 189-197. [53513]
140. Trachtenberg, S.; Zamski, E. 1979. The apoplastic conduction of water in Polytrichum juniperinum Willd. gametophytes. The New Phytologist. 83: 49-52. [70337]
141. Tveten, R. K.; Fonda, R. W. 1999. Fire effects on prairies and oak woodlands on Fort Lewis, Washington. Northwest Science. 73(3): 145-158. [31289]
142. U.S. Department of Agriculture, Natural Resources Conservation Service. 2013. PLANTS Database, [Online]. Available: http://plants.usda.gov/. [34262]
143. Uggla, Evald. 1967. En studie over branningseffekten pa ett tunt rahumustacke. Effects of the fire on a thin layer of raw humus. In: Research Notes. No. 9. Stockholm, Sweden: Skogshogskolan, Institutionen for skogsforyngring. [Royal College of Forestry, Department of Reforestation]: 155-170. [70339]
144. Uggla, Evald. 1974. Fire ecology in Swedish forests. In: Proceedings, annual Tall Timbers fire ecology conference; 1973 March 22-23; Tallahassee, FL. No. 13. Tallahassee, FL: 171-190. [18974]
145. Van Nostrand, R. S. 1965. Results of experimental seeding of balsam fir on a recent burn. Department of Forestry Publication No. 1103. Ottawa, ON: Canadian Department of Forestry, Research Branch. 10 p. [41914]
146. Vanderwater, Orell R. 1964. The differential effects of north and south slope exposure on Polytrichum juniperinum. Des Moines, IA: Drake University. 38 p. Thesis. [69452]
147. Viereck, L. A. 1983. The effects of fire in black spruce ecosystems of Alaska and northern Canada. In: Wein, Ross W.; MacLean, David A., eds. The role of fire in northern circumpolar ecosystems. New York: John Wiley and Sons: 201-220. [7078]
148. Viereck, L. A.; Dyrness, C. T., tech. eds. 1979. Ecological effects of the Wickersham Dome fire near Fairbanks, Alaska. Gen. Tech. Rep. PNW-90. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 71 p. [6392]
149. Viereck, Leslie A.; Schandelmeier, Linda A. 1980. Effects of fire in Alaska and adjacent Canada--a literature review. BLM-Alaska Tech. Rep. 6; BLM/AK/TR-80/06. Anchorage, AK: U.S. Department of the Interior, Bureau of Land Management, Alaska State Office. 124 p. [28862]
150. Viro, P. J. 1969. Prescribed burning in forestry. Metsan tutkimuslaitoksen Julkaisuja. 67: 1-49. [22493]
151. Wein, R. W. 1974. Recovery of vegetation in arctic regions after burning. Rep. 74-6. Ottawa: Canadian Task Force on Northern Oil Development. 41 p. [13001]
152. Wein, Ross W.; Bliss, L. C. 1973. Biological considerations for construction in the Canadian permafrost region. Session VII: Principles of construction in permafrost regions. In: North American contribution: Permafrost, 2nd international conference; 1973 July 13-28;Yakutsk, Siberia. Washington, DC: National Academy of Sciences: 767-772. [70306]
153. Wein, Ross W.; Bliss, L. C. 1973. Changes in arctic Eriophorum tussock communities following fire. Ecology. 54(4): 845-852. [9827]
154. Wilson, C. L.; Loomis, W. E.; Steeves, T. A. 1971. Botany. New York: Holt, Rinehart and Winston. 752 p. [21163]
155. Windisch, Andrew G. 1999. Fire ecology of the New Jersey pine plains and vicinity. New Brunswick, NJ: Rutgers, The State University of New Jersey. 327 p. Dissertation. [53348]
156. Zoltai, S. C.; Pettapiece, W. W. 1973. Studies of vegetation, landform and permafrost in the Mackenzie Valley: Terrain, vegetation and permafrost relationships in the northern part of the Mackenzie Valley. Report No. 73-4. Task Force on Northern Oil Development, Environmental-Social Committee, Northern Pipelines. 105 p. [7227]

FEIS Home Page