North American boreal and western temperate forest vegetation

Salvador Rivas-Martínez, Daniel Sánchez-Mata & Manuel Costa

Itinera Geobotanica 12:5-316 (1999)


Go to: Contents - Show Table - Previous Page - Next Page

Description of Plant Communities: Gaultherio procumbentis-Piceion glaucae

2. Gaultherio procumbentis-Piceion glaucae Peinado, Aguirre & Cruz 1998 em. hoc loco

[Piceo marianae-Laricion laricinae Looman in Phytocoenologia 15(3) 308. 1987 (art. 5, 8), Piceion glaucae Looman in Phytocoenologia 15(3) 313. 1987 (art. 5, 8), Piceion marianae Nakamura, Grandtner & Villeneuve in Miyawaki, Iwatsuki & Grandtner, Veg. East. North America: 147. 1994 (art. 5, 8), Abietion balsameae Nakamura, Grandtner & Villeneuve in Miyawaki, Iwatsuki & Grandtner, Veg. East. North America: 147. 1994 (art. 5, 8), Gaultherio procumbentis-Piceion glaucae Peinado, Aguirre & Cruz in Plant Ecology 137: 187. 1998, Viburno cassinoidis-Piceion marianae Peinado, Aguirre & Cruz 1998 in Plant Ecology 137: 189. 1998 (syntax. syn.) (art. 25) (holotype: Kalmio angustifoliae-Piceetum marianae Damman 1964 in For. Sci. Mon. 8: 10, tb. 1. 1964), Piceion marianae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 196. 1998 (art. 8) (holotype: Corno canadensis-Piceetum marianae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 196. 1998 (art. 16, 37), Gymnocarpio dryopteridis-Abietion lasiocarpae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 192. 1998 (art. 8, 9, 37, 38) (holotype: Gymnocarpio dryopteridis-Abietetum lasiocarpae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 192. 1998 (art. 8, 37), incl. Vaccinio vitis-idaeae-Abietetum balsameae x bifoliae Achuff & La Roi ex Peinado, Aguirre & Cruz in Plant Ecology 137: 195. 1998 (art. 8), Abietion balsameae Nakamura, Grandtner & Villeneuve ex nobis ined.]

Typus nominis: Abietetum balsameae Damman in For. Sci. Mon. 8: 18. 1964.

North American Continental Boreal (eucontinental and subcontinental); thermo-, meso- and supraboreal, hemiboreal and occasionally upper supratemperate; subhumid to hyperhumid; coniferous micro-, meso- or macroforests dominated by balsam fir (Abies balsamea), black and white spruce (Picea mariana, Picea glauca var. glauca) and tamarack (Larix laricina), growing on podzol, regosols and histosols with gleyic, dystric or gelic character, and with or without vadose soil horizon, throughout the Canadian Boreal Province and the hemiboreal or orotemperate Northern Prairies Sector areas (see remarks). The Gaultherio-Piceion glaucae associations constitute climactical forests and wooded permanent plant communities (climatic or edaphic climax: zonal, extrazonal and intrazonal vegetation).

Bioclimatic diagnosis: Ic 20-40, Io 2.5-14.0, Tp 380-1050, Tps 300-600, Tmin < -4º, m < -8º. [Boco, Bosc, Booc, Teco, Teoc-Tbo, Mbo, Sbo, Hbo, Ste, Ote-Dry, Shu, Hum, LHhu].

Locality Alt.m Ic Io Tp Climactical forest association Bioclimate
Gander (Newf.) 151 23.3 9.5 728 Abietetum balsameae Bosc-Utbo-Uhum
Val d'Or (Québec) 337 33.9 7.6 756 Abietetum balsameae Boco-Ltbo-Lhum
Sept-Isles (Québec) 55 28.3 9.7 622 Kalmio-Piceetum marianae Boco-Lmbo-Lhum
Natashquan (Québec) 5 28.9 8.8 583 Kalmio-Piceetum marianae Boco-Umbo-Lhum
Amstrong (Ontario) 322 37.8 7.1 639 Kalmio-Piceetum marianae Boco-Lmbo-Lhum
The Pass (Manitoba) 270 41.1 4.3 706 Mertensio-Abietetum balsameae Boco-Utbo-Lshu
Prince Albert (Sask.) 428 38.3 4.1 756 Mertensio-Abietetum balsameae Boco-Ltbo-Lshu
Edmonton (Alberta) 723 32.8 4.1 767 Mertensio-Abietetum balsameae Teco-Hbo-Lshu
Caribou (Maine) 190 30.0 7.7 807 Abieti-Piceetum rubentis Teco-Hbo-Lhum
Saint John (N.Brow.) 362 24.1 11 878 Abieti-Piceetum rubentis Teco-Hbo-Lhum

Figure 14. Relationships between local climatic data, bioclimates and climatophilous or edaphophilous forest associations (climatic and edaphic climax) in the climactic territories (sigmion) of Gaultherio-Piceion glaucae and Piceion rubentis in Canada (Canadian Boreal and Appalachian Provinces).

We distinguish in the Gaultherio-Piceion glaucae alliance four different associations (figures 14 and 15): 2a. Abietetum balsameae (continental and subcontinental thermoboreal, humid and hyperhumid in the Newfoundlandian and Eastern Canadian Boreal Sectors), 2b. Kalmio angustifoliae-Piceetum marianae (continental and subcontinental, meso- and supraboreal, humid and hyperhumid in the Newfoundlandian and Eastern Canadian Boreal Sectors), 2c. Sphagno-Piceetum marianae (continental and subcontinental, thermo- and supraboreal, also Temperate hemiboreal, humid and hyperhumid growing in boggy soils and stagnic podzols in the Canadian Boreal Province and locally in the Appalachian and Great Lakes Sectors), 2d. Mertensio paniculatae-Abietetum marianae (eucontinental, thermo-, meso- and supraboreal, occasionally Temperate hemiboreal, upper dry and subhumid, growing in podzols without vadose horizon in the Western Canadian Boreal Sector (Western Canadian Boreal Subhumid Subsector) and locally in the Canadian Prairies Sector and Western Hemiboreal Great Lakes Subsector territories.

Characteristic species: Abies balsamea, Abies balsamea x bifolia, Chimaphila umbellata subsp. cisatlantica, Clintonia borealis, Coptis trifolia subsp. groenlandica, Cypripedium acaule, Epigaea repens, Gaultheria procumbens, Kalmia angustifolia, Maianthemum canadense, Oxalis montana, Picea mariana x rubens, Rhododendron canadense, Thuja occidentalis, Trientalis borealis subsp. borealis, Vaccinium angustifolium, Vaccinium myrtilloides.

2a. Abietetum balsameae Damman 1964

[Abietetum balsameae Damman in For. Sci. Mon. 8: 18. 1964, Betulo papyriferae-Abietetum balsameae Nakamura, Grandtner & Villeneuve, Veg. East. North America: 129, tb. 2. 1994 (art. 5)]

Continental Boreal (subcontinental and eucontinental); thermoboreal; humid-hyperhumid; oligo-mesotrophic balsam fir (Abies balsamea) with black and white spruce (Picea mariana, Picea glauca var. glauca) climactical mesoforests, growing on well-drained haplic, ferric or gleyic podzols without vadose zone in the Canadian Boreal Province territories (Newfoundlandian and Eastern Canadian Boreal Sectors).

Bioclimatic diagnosis: Ic 20-38, Io 6.0-14.0, Tp 700-800, Tps 420-500, Tmin < -4º, m < -8º. [Bosc, Boco-Tbo-hum, Lhhu].

Table 5 holds five relevés from Québec sampled throughout several humid thermoboreal areas included in the Eastern Canadian Boreal Sector (Boreal Laurentian and Hudson Bay Basin Subsectors). Actaea rubra, Clintonia borealis, Coptis groenlandica, Maianthemum canadense and Oxalis montana could be considered as differential species of Abietetum balsameae association in front to meso- and supraboreal Vaccinio-Piceetum marianae association. Because of repeated fires and wood cutting these Picea and Abies forests are replaced by secondary pine forests (Pinetum banksianae) and secondary deciduous Populus and Betula forests and woodlands (Populetum tremuloidis).

Map

Figure 15. Mape A. Distribution of the forest plant communities belonging to alliance 2. Gaultherio procumbentis-Piceion glaucae: 2a. Abietetum balsameae (Newfoundlandian and Eastern Canadian Boreal Sectors: thermoboreal), 2b. Kalmio angustifoliae-Piceetum marianae (Newfoundlandin and Eastern Canadian Boreal Sectors: meso- and supraboreal), 2c. Sphagno-Piceetum marianae (Canadian Boreal Province, Appalachian and Great-Lakes Sectors: boggy soils), 2d. Mertensio paniculatae-Abietetum balsameae (Western Canadian Boreal Subhumid and Western Hemiboreal Great Lakes Subsectors). Mape B. Distribution of the forest plant communities belonging to alliance 3. Piceion rubentis: 3a. Abieti balsameae-Piceetum rubentis (Appalachian Sector), 3b. "Abietetum fraseri" (Smoky Mountains Subsector).

Table 5
2a. Abietetum balsameae
(Gaultherio-Piceion glaucae, Gaultherio-Piceetalia)

Altitude (1=10m) 45 30 36 46 28 37
Number of species 22 23 23 26 27 24
Ordinal number 1 2 3 4 5 6
Trees:
Abies balsamea 2 4 3 4 2 V
Populus tremuloides 1 1 1 1 1 V
Betula papyrifera + + 1 . 2 IV
Picea mariana 4 1 . 3 3 IV
Picea glauca . 1 3 + 1 IV
Acer spicatum . + 2 1 + IV
Characteristic species:
Kalmia angustifolia 4 + 1 1 1 V
Linnaea americana 3 2 2 2 2 V
Vaccinium angustifolium 3 2 1 3 2 V
Maianthemum canadense 2 2 3 3 2 V
Coptis groenlandica 1 2 3 2 2 V
Cornus canadensis 2 3 2 3 + V
Lycopodium annotinum + 3 + + 2 V
Sorbus americana 1 + + 1 . IV
Trientalis borealis + 1 2 . 1 IV
Amelanchier sanguinea 1 1 . 1 . III
Ledum groenlandicum 2 . . 1 3 III
Aralia nudicaulis . 1 2 2 . III
Lycopodium obscurum . 2 . 2 1 III
Companion species:
Pleurozium schreberi 4 2 2 3 3 V
Ptilium crista-castrensis 2 1 1 2 . IV

Other species. Trees: Pinus banksiana 1 in 1. Characteristic species: Gaultheria hispidula 2 in 1 and 5. Viola renifolia + in 1, 2 in 5. Sambucus pubens 1 in 2, + in 3. Gymnocarpium dryopteris 1 in 2, 2 in 5. Clintonia borealis 3 in 3, 2 in 4. Prunus pensylvanica 1 in 3, + in 4. Ribes glandulosum + in 4 and 5. Moneses uniflora 1 in 2. Epigaea repens 1, Oxalis montana 1 in 3. Carex trisperma 2, Actaea rubra 1, Corallorhiza trifida 1, Galium trifidum 1 in 5. Companion species: Cladina sp. 2 in 1, 3 in 4. Dicranum scoparium 2 in 1, 2 in 4. Dryopteris carthusiana 1 in 3 and 5. Polytrichum commune 1, Pteridium latiusculum 1 in 4. Sphagnum sp. 2 in 5.

Localities: 1. Québec: Reserve faunique Ashuapmshuuan, Lac Aigremont. 48º48'N-72º52'W. SW, 15 %, 20 m, 50 cm, 500 m2, basalt (reg. 1995a: 45). 2. Québec: 10 Km N from Lebel-sur-Quevillon, rivière Bell. 49º05'N-76º52'W. E, 5%, 25 m, 60 cm, 500 m2 (reg. 1995a: 40). 3. Québec: Reserve faunique la Vérendrye. 47º21'N-77º00'W. E, 20 %, 20 m, 40 cm, 500 m2 (reg. 1995a: 26). 4. Québec: Between Alma and Mont Apica, Reserve faunique des Laurentides, Lac de la Belle Rivière. 48º14'N-71º46'W. NE, 10 %, 20 m, 40 cm, 1000 m2, granit (reg. 1995a: 48). 5. Québec: Lebel-sur-Quevillon, rivière Bell. 49º02'N-76º58'W. N, 10%, 30 m, 70 cm, 500 m2, gleyic podzol (reg. 1995a: 38). 6. Synthesized table.

Type relevé (neolectotypus hoc loco): Damman in For. Sci. Mon. 8: 17, tb 2, n. 736. 1964 (excl. lectotype: Peinado, Aguirre & Cruz 1998: 187, tb. 2 ex Damman 1964: 17, n. 710) sub Abietum rubetosum. Site: Central Newfoundland. Exploits Dam. 48°50'N-55°35'W. 45 feet (height of tree layer). Estimated bioclimatic factors: Subcontinental Boreal (Ic ~ 25), upper thermoboreal (Tp ~ 710), upper hyperhumid (Io ~ 11.0), Positive Summer Temperature Tps ~ 420. Biogeographic location: North American Boreal Region, Canadian Boreal Province, Newfoundlandian Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 5 Abies balsamea, 1 Abies balsamea (S2), 1 Betula papyrifera, + Picea mariana, + Sorbus americana. Others: 1 Coptis groenlandica, + Cornus canadensis, + Gaultheria hispidula, + Linnaea borealis [L. americana], + Lycopodium annotinum, + Mitella nuda, 1 Pyrola secunda [Orthilia secunda], + Trientalis borealis, + Rubus pubescens. Companion species: + Brachythecium salebrosum, + Carex vaginata,+ Dicranum scoparium, + Dicranum undulatum, + Dryopteris spinulosa [D. carthusiana], + Hypnum crista-castrensis [Ptilium crista-castrensis], 2 Pleurozium schreberi, + Viola incognita [V. blanda var. palustriformis].

Remarks: Peinado, Aguirre & Cruz (1998: 187) mistakenly selected as lectotype of the association Abietetum balsameae (typicum) the relevé number 710 (table 2) which lacks some species as Linnaea americana, Trientalis borealis, Clintonia borealis and Maianthemum canadense proposed as differentials by Damman, opposite to its more oligotrophic association Kalmio-Piceetum marianae. If we use the lectotype designated by the Spanish authors the relevé could belongs to Kalmio-Piceetum marianae and, in consequence, both associations should be considered as synonyms. Therefore, it is necessary to exclude the mentioned typification (art. 19A) to propose now a new lectotype (relevé number 736).

2b. Kalmio angustifoliae-Piceetum marianae Damman 1964 em. hoc loco

[Kalmio angustifoliae-Piceetum marianae Damman in For. Sci. Mon. 8: 13. 1964, Piceetum marianae Damman in For. Sci. Mon. 8: 24, tb. 3, n. 701. 1994 (art. 25), Abieti balsameae-Piceetum marianae Grandtner, Camiré, Ansseau, Lamontagne & Villeneuve, Guide de l'excursion en Écologie Forestière: 84. 1991, Pleurozio schreberi-Piceetum marianae Nakamura, Grandtner & Villeneuve in Miyawaki, Iwatsuki & Grandtner, Veg. East. North America: 133, tb. 2. 1994 (art. 5), Cladino-Piceetum marianae Nakamura, Grandtner & Villeneuve in Miyawaki, Iwatsuki & Grandtner, Veg. East. North America: 129. 1994 (art. 5), Kalmio polifoliae-Piceetum marianae Sirois ex Peinado, Aguirre & Cruz in Plant Ecology 137: 189. 1998].

Continental Boreal (subcontinental, eucontinental); meso- and supraboreal; humid-hyperhumid; oligotrophic black spruce mesoforests (Picea mariana), growing on dry or wet soils usually coarse textured, and with ferric, gleyic or gelic podzol soils, sometimes with vadose zone, throughout the Eastern Canadian Boreal and Newfoundlandian territories.

Bioclimatic diagnosis: Ic 23-38, Io 6.0-12.0, Tp 380-700, Tps 300-450, Tmin < -14º, m < -20º. [Bosc, Boco-Mbo, Sbo-Hum].

Described by Damman from Central Newfoundland near Lake Ambrose the association Kalmio angustifoliae-Piceetum marianae can be accept as the general meso- and supraboreal, humid and hyperhumid, climactical coniferous forest community from Ontario to Newfoundland. Almost all the thermic species growing in the Abietetum balsameae association are missing. Table 6 shows two relevés from the Reserve faunique des Laurentides in Québec giving us a typical aspect and species combination of this association.

Table 6
2b. Kalmio angustifoliae-Piceetum marianae

(Gaultherio-Piceion glaucae, Gaultherio-Piceetalia)

Altitude (1=10m) 85 75 80
Number of species 17 19 18
Ordinal number 1 2 3
Trees:
Picea mariana 4 4 2
Abies balsamea 3 2 2
Betula papyrifera + . 1
Picea glauca . 1 1
Populus tremuloides . 1 1
Characteristic species:
Gaultheria hispidula 3 2 2
Cornus canadensis 2 2 2
Vaccinium angustifolium + 2 2
Ribes glandulosum 1 2 2
Amelanchier sanguinea + 1 2
Kalmia angustifolia + 1 2
Trientalis borealis + 1 2
Ledum groenlandicum + + 2
Prunus pensylvanica . 2 1
Lycopodium obscurum . 1 1
Companion species:
Ptilium crista-castrensis 3 1 2
Pleurozium schreberi 2 1 2
Lycopodium clavatum 1 + 2

Other species. Companion species: Dryopteris carthusiana 1 in 1. Dicranum scoparium 2, Sphagnum sp. 2 in 2. Cladina sp. pl. 3, Hylocomium splendens 3 in 1.

Localities: 1. Québec: Reserve faunique des Laurentides, Lac Beloeil, L'Etape. 47º51'N-71º17'W. N, 20 %, 22 m, 60 cm, 500 m2 (reg. 1995a: 50). 2. Québec: Mont Apica, Reserve faunique des Laurentides. 47º59'N-71º25'W. E, 15 %, 15 m, 40 cm, 500 m2 (reg. 1995a: 49). 3. Synthesized table.

Type relevé (neolectotypus hoc loco): Damman in For. Sci. Mon. 8: 10, tb 1 n. 716. 1964 (excl. lectotype: Peinado, Aguirre & Cruz 1998: 189 ex Damman 1964: 13, tb. 1 n. 739). Site: Central Newfoundland. Lake Ambrose. 49°20'N-55°50'W. S-SW, 8%, 34 feet (height of tree layer). Estimated bioclimatic factors: Continental Boreal, subcontinental (Ic ~ 25.0), lower mesoboreal (Tp ~ 660), upper humid (Io ~ 10.0), Positive Summer Temperature Tps ~ 420. Biogeographic location: North American Boreal Region, Canadian Boreal Province, Newfoundlandian Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 1 Abies balsamea, 5 Picea mariana. Others: + Abies balsamea (S2), 2 Gaultheria hispidula, + Kalmia angustifolia, 2 Picea mariana (S2). Companion species: + Bazzania trilobata, 1 Cladonia gracilis, 1 Cladonia rangiferina [Cladina rangiferina], 2 Dicranum undulatum, 1 Dicranum scoparium, 2 Hylocomium splendens, + Hypnum crista-castrensis [Ptilium crista-castrensis], 2 Peltigera aphthosa, 3 Pleurozium schreberi, 2 "Sphagnum capillaceum", 2 Vaccinium vitis-idaea.

Remarks: The lectotype selected by Peinado, Aguirre & Cruz (Damman 1964: 13, tb. 1, no. 739) lacks some species considered by the original author as differential species (Rhododendron canadense, Cladina mitis, etc.). Conversely the relevé includes other species suggested by Damman as antithetical species: Maianthemum canadense, Clintonia borealis, etc. Therefore, it is necessary to propose a new lectotype to respect the original concept of the Damman"s association and to avoid the situation of "nomen ambiguum" for this association following the current CPN (art. 36).

2c. Sphagno-Piceetum marianae Grandtner 1960

[Sphagno-Piceetum marianae Grandtner in Fonds Rech. For. Univ. Laval 7: 29, tb. 20. 1960, Alno rugosae-Piceetum marianae Damman in For. Sci. Mon. 8: 29. 1964 (syntax. syn.) (art. 22)]

Continental Boreal (eucontinental and subcontinental); thermo-, meso- and supra- boreal and Temperate hemiboreal; dry to hyperhumid; black spruce (Picea mariana) micro- and mesoforests, growing on bog-peaty acid soils and gleyic or gelic podzols with histic horizon in the Canadian Boreal Province and locally in the Appalachian Province, as well as in the Great Lakes and Canadian Prairies Sectors. Their secondary deciduous shrubby or dense thickets in most of their central and eastern distribution area are the swamp alder (Alnus rugosa) communities: Carici-Alnetum rugosae and Alnetum rugosae.

Bioclimatic diagnosis: Ic 20-40, Io 2.5-14.0, Tp 380-1050, Tps 300-600, Tmin < -4º, m < -8º. [Booc, Bosc, Boco, Teco-Tbo, Mbo, Sbo, Hbo, Ste, Ote-Dry, Shum, Hum, LHhu].

The black spruce (Picea mariana) and tamarak (Larix laricina) microforests (4-14 m), growing in wet depressions and lakeshores on histosols and histic gleyic podzol soils, belong to Sphagno-Piceetum marianae association were described by Grandtner (1960) from la "Fôret du Beauséjour" in Québec. Inside this association could be recognized diverse variants and subassociations in all the Boreal territory of the Canadian Boreal Province and adjacent areas of the Great Lakes and Central Lowlands Province. As territorial characteristicand diagnostic species of this bog-wooded association could be mentioned: Alnus rugosa, Betula pumila, Chamaedaphne calyculata var. latifolia, Eriophorum brachyantherum, Vaccinium oxycoccos and many bryophytes, particularly those belonging to genus Sphagnum. As geographic diagnostic species (typic Eastern Canadian Boreal Sector species) could be mentioned: Alnus rugosa, Carex trisperma, Coptis groenlandica, Kalmia angustifolia, Nemopanthus mucronatus, Trientalis borealis, etc. The five relevés published in table 7 are from Québec official province, biogeographically belonging to the Eastern Canadian Boreal Sector (Hudson Bay Basin and Boreal Laurentian Subsectors) and the Appalachian Sector (Temperate Laurentian Subsector) and mostly sampled throughout several thermoboreal and hemiboreal areas.

Type relevé (lectotypus): Grandtner in Fonds Rech. For. Univ. Laval 7: 29, tb. 20. 1960, lectotypus: Ansseau & Grandtner in Documents Phytosociol. 11: 37. 1988. Site: Québec. Comté de Lévis, Fôret de Beauséjour. 46°40N-71°15'W. 100 m2. Estimated bioclimatic factors: Continental Boreal, eucontinental (Ic ~ 32.0), hemiboreal (Tp ~ 860), lower humid (Io ~ 7.0), Positive Summer Temperature Tps ~ 540. Biogeographic location: North American Atlantic Region, Eastern North American Province, Laurentian Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: + Abies balsamea, 1 Larix laricina, 2 Picea mariana. Others: + Chamaedaphne calyculata [C. calyculata var. calyculata], 1 Chiogenes hispidula [Gaultheria hispidula], 3 Kalmia angustifolia, + Kalmia polifolia, 3 Ledum groenlandicum, + Nemopanthus mucronatus, + Picea mariana (S2), 1 Vaccinium myrtilloides, 1 Vaccinium oxycoccos, 1 Viburnum cassinoides. Companion species: 1 Aronia melanocarpa, + Aulacomnium palustre, 3 Cladonia sp. pl., 2 Polytrichum juniperinum var. alpestre [P. juniperinum], + Sarracenia purpurea, 1 Sphagnum magellanicum, 1 Sphagnum fuscum.

Table 7
2c. Sphagno-Piceetum marianae

(Gaultherio-Piceion glaucae, Gaultherio-Piceetalia)

Altitude (1=10m) 33 38 42 85 20 44
Number of species 12 14 15 16 22 16
Ordinal number 1 2 3 4 5 6
Trees:
Picea mariana 3 5 4 3 3 V
Larix laricina 2 1 3 3 2 V
Abies balsamea . + . + 1 III
Populus balsamifera . . . . 2 I
Betula papyrifera . . . . 1 I
Characteristic species:
Vaccinium oxycoccos 3 2 2 1 2 V
Ledum groenlandicum 1 4 2 1 2 V
Gaultheria hispidula 2 3 1 3 . IV
Carex trisperma 1 2 1 . 3 IV
Kalmia polifolia 3 1 3 . . III
Kalmia angustifolia 2 1 . + . III
Coptis groenlandica 2 1 . . 2 III
Chamaedaphne latifolia . 1 4 2 . III
Betula pumila 2 . 3 . . II
Rubus acaulis . . 1 . 2 II
Alnus rugosa . . . 2 2 II
Cornus canadensis . . . 1 1 II
Companion species:
Sphagnum sp. pl. 5 5 5 5 4 V
Eriophorum brachyantherum 1 + 2 . . III
Cladina sp. pl. . 3 2 . . II

Other species. Trees: Betula alleghaniensis + in 5. Characteristic species: Equisetum sylvaticum 1 in 3. Epigaea repens 2, Vaccinium minus +, Ribes glandulosum 2, Spiraea latifolia 2 in 4. Linnaea americana 2, Oxalis montana 2, Trientalis borealis 2, Maianthemum canadense 1, Nemopanthus mucronatus 1, Sorbus americana 1, Vaccinium myrtilloides 1 in 5. Companion species: Salix sp. 1 in 3. Polytrichum commune 3 in 4. Dryopteris carthusiana 2 in 5.

Localities: 1. Québec: 15 Km N from Senneterre. 48º23'N-77º20'W. 8 m, 20 cm, 400 m2 (reg. 1995b: 28). 2. Québec: Between Miquelon and Desmaraisville. Lac Waswanipi. 49º30'N-76º21'W. 14 m, 25 cm, 200 m2 (reg. 1995b: 42). 3. Québec: Reserve faunique Ashuapmshuuan, Lac Aigremont. 48º47'N-72º52'W. 8 m, 20 cm, 400 m2 (reg. 1995b: 44). 4. Québec: Reserve faunique des Laurentides. L'Etape. 47º52'N-71º17'W. 12 m, 30 cm, 200 m2 (reg. 1995b: 50). 5. Québec: L'Annonciation. 46º23'N-74º52'W. 12 m, 30 cm, 200 m2 (reg. 1995b: 23). 6. Synthesized table.

2d. Mertensio paniculatae-Abietetum balsameae associatio nova hoc loco

Continental Boreal (eucontinental); thermo-, meso- and supraboreal and Temperate hemiboreal; subhumid; balsam fir (Abies balsamea) with white and black spruce (Picea glauca var. glauca, Picea mariana) climactical mesoforests in the Western Canadian Boreal Subhumid Subsector and the Canadian Prairies Sector.

Bioclimatic diagnosis: Ic 28-40, Io 2.5-5.9, Tp 400-900, Tps 300-500, Tmin < -14º, m < -20º. [Boco, Teco-Tbo, Mbo, Sbo, Hbo, Ste, Ote-Dry, Shu].

Table 8 shows five relevés from Alberta and Manitoba which allow us to recognize this broad and peculiar association, mainly distributed in the Western Canadian Boreal Subhumid Subsector territories. From a floristic point of view, this association is transitional between the alliances Gaultherio-Piceion glaucae (with a eastern optimum in the Canadian Boral Province) y Ledo-Piceion marianae (with a western optimum in the Yukonian-Alaskan Province). However, the presence of Abies balsamea and Pinus banksiana pyrogenic forests within the climactical area of Ledo-Piceion marianae, and therefore absent in the Yukonian-Alaskan Province force the inclusion of the Mertensio-Abietetum balsameae association inside the Gaultherio-Piceion glaucae alliance. This intermediate position could be appreciate within the understory species, lacking in these areas some characteristic alliance species such as Kalmia angustifolia and Vaccinium angustifolium and become frequent other species such as Arctagrostis latifolia subsp. arundinacea, Mertensia paniculata var. paniculata, Mertensia paniculata var. eastwoodiae, Salix arbusculoides and Senecio lugens which have their optimum in the Alaskan-Yukonian Ledo-Piceion marianae alliance.

Throughout the meso- and supraboreal areas in the Western Canadian Boreal Xeric Subsector territories with dry ombroclimate, should be necessary in the future to recognize other climactical association within the open mesoforests of Picea and Pinus banksiana, characterized by the absence of Abies balsamea and within the secondary deciduous forests by the presence of Betula neoalaskana and its related hybrids with Betula papyrifera (Betula xwinteri).

Type relevé (holotypus): Table 8, relevé n. 4. Rivas-Martínez reg. 1995d: 153. 07.09.1995, made with Dr. M. Costa. Site: Alberta. Slave Lake. Lesser Slave Lake Provincial Park, Steep Hill. 55º26'N-114º48'W. 600 m, W, 15%, 25 m, 50 cm, 400 m2. Physiognomy and habitat: Mature white spruce (Picea glauca var. glauca) and balsam fir (Abies balsamea) mesoforest with a dense and shady herbaceous understory. Estimated bioclimatic factors: Continental Boreal, eucontinental (Ic ~ 32), upper thermoboreal (Tp ~ 710), lower subhumid (Io ~ 3.8), Positive Summer Temperature Tps ~ 450. Biogeographic location: North American Boreal Region, Canadian Boreal Province, Western Canadian Boreal Sector, Western Canadian Boreal subhumid Subsector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 2 Abies balsamea, 1 Betula payrifera var. commutata, 4 Picea glauca var. glauca, 1 Populus tremuloides, 2 Aralia nudicaulis, 2 Calamagrostis purpurascens, 2 Cornus canadensis, 2 Cornus sericea subsp. sericea, 2 Fragaria vesca subsp. bracteata, 2 Galium triflorum, 3 Linnaea americana, 1 Maianthemum canadense, + Mertensia paniculata, 1 Orthilia secunda, + Pyrola asarifolia, 3 Rosa acicularis subsp. sayi, 2 Viburnum edule. Companion species: + Aster ciliolatus, 1 Epilobium angustifolium, 2 Pleurozium schreberi, 2 Ptilium crista-castrensis.

Table 8
2d. Mertensio paniculatae-Abietetum balsameae

(Gaultherio-Piceion glaucae, Gaultherio-Piceetalia)

Altitude (1=10m) 105 59 60 60 68 70
Number of species 19 20 23 24 27 23
Ordinal number 1 2 3 4* 5 6
Trees:
Picea glauca 3 4 3 4 4 V
Abies balsamea 1 2 3 2 2 V
Betula commutata . 1 + 1 2 IV
Picea mariana 2 . 1 . 1 III
Populus tremuloides + . . 1 + III
Populus balsamifera 2 . . . 1 II
Characteristic species:
Linnaea americana 2 2 3 3 1 V
Cornus canadensis 1 3 2 2 1 V
Maianthemum canadense 1 1 + 1 3 V
Rosa sayi 1 + 1 3 2 V
Galium triflorum + 1 1 2 + V
Calamagrostis purpurascens 1 1 + 2 + V
Orthilia secunda 1 1 1 1 . IV
Viburnum edule 1 + 1 2 . IV
Aralia nudicaulis . 2 2 2 2 IV
Mertensia paniculata . 1 2 + 2 IV
Cornus sericea . + 1 2 . III
Rubus pubescens . 2 2 . 2 III
Pyrola asarifolia . + 1 + . III
Aster ciliolatus . . . + 1 II
Disporum hookeri . . . 1 . I
Companion species:
Epilobium angustifolium 2 1 + 1 1 V
Pleurozium schreberi 1 2 1 2 2 V
Fragaria glauca . 1 1 2 + IV

Other species. Characteristic species: Salix bebbiana 2, Ledum groenlandicum 2, Abies balsamea x bifolia +, Shepherdia canadensis + in 1. Lonicera cauriana 1, Lycopodium annotinum 1 in 4. Corylus cornuta 2, Prunus pensylvanica 2, Rubus strigosus 2, Alnus crispa 1, Thalictrum occidentale 1, Viola glabella 1 in 5. Companion species: Hylocomium splendens 3 in 2, 4 in 3. Peltigera aphthosa 1, Saxifraga mertensiana 1 in 3. Ptilium crista-castrensis 2 in 4. Bromus inermis 2, Geranium richardsonii 2 in 5.

Localities: 1. Alberta: Between Hinton and Edson, Obed Lake, Athabasca River. 53º28'N-117º29ºW. N, 10%, 20 m, 50 cm, 400 m2 (reg. 1992e: 61). 2. Alberta: Lesser Slave Lake Provincial Park. 55º27'N-114º48'W. S, 10%, 25 m, 60 cm, 400 m2 (reg. 1995d: 154b). 3. Alberta: Slave Lake, Lesser Slave Lake Provincial Park. 55º26'N-114º46'W. W, 5%, 25 m, 50 cm, 400 m2 (reg. 1995d: 155). 4. Alberta: Slave Lake, Lesser Slave Lake Provincial Park, Steep Hill. 55º26'N-114º48'W. W, 5%, 25 m, 50 cm, 400 m2, holotypus ass. (reg. 1995d: 153). 5. Manitoba: Riding Mountain, Riding Mountain National Pak. 50º48'N-100º07'W. 5%, 25 m, 100 cm, 400 m2 (reg. 1995d: 165). 6. Synthesized table.