North American boreal and western temperate forest vegetation

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

Itinera Geobotanica 12:5-316 (1999)


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Description of Plant Communities: Tsugion mertensianae

6. Tsugion mertensianae alliancia nova hoc loco

[Vaccinion membranecei Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 254. 1970 (art. 29), Vaccinion alaskensis Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 261. 1970 (art. 9, 29), Oplopanacion horridi Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 271. 1970 (art. 29), Lysichition americani Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 273. 1970 (art. 29)]

Typus nominis: Abieti amabilis-Tsugetum mertensianae Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 263. 1970.

Oceanic Temperate (euoceanic and semicontinental) and barely subcontinental (Continental Temperate), and Oceanic Boreal (euoceanic and semicontinental) or barely subcontinental (Continental Boreal); orotemperate and supraboreal; perhumid and ultraperhumid; climactical coniferous micro-, meso- and macroforests, and also chionophilous or chionophobic permanent woodlands [affinity, -philous or aversion, -phobic, for stations with a long persistence or ephemeral presence of the winter snow and snow-packs], widespread throughout the Cascade and Boreal Pacific Provinces.

Bioclimatic diagnosis: Ic Ic 11-23, Io 9.0-30.0, Tp 380-650, Tps 270-400, Tmin < -3, m < -5. [Teoc, Teco, Booc, Boco-Ote, Mbo, Sbo-Hum, Hhu, Uhh].

In a short synthesized synoptical table (table 14) we assemble 46 relevés from Norht-Western Pacific Subregion territories belonging to Tsugion mertensianae alliance. The most important coniferous tree species which are involved in the forest canopies are: Abies lasiocarpa (subalpine fir), Abies procera (noble fir), Larix lyallii (subalpine larch), Picea engelmannii var. engelmannii (Engelmann spruce), Picea sitchensis (Sitka spruce), Tsuga heterophylla (western hemlock) and Tsuga mertensiana (mountain hemlock).

We distinguish within the Tsugion mertensianae alliance six different forest associations (figures 19 and 23): 6a. Abieti amabilis-Tsugetum mertensianae: Oceanic Temperate (euoceanic), orotemperate and hemiboreal, hyperhumid and ultrahyperhumid, spreading into Canadian Coastal Sector and Washingtonian Cascade Subsector territories, 6b. Abieti lasiocarpae-Tsugetum mertensianae: Oceanic Temperate (euoceanic and semicontinental) and barely subcontinental, upper orotemperate, upper humid and hyperhumid, spreading into Canadian Coastal Mountains and Cascade Ranges Sectors territories, 6c. Tsugo mertensianae-Abietetum procerae: Oceanic Temperate (euoceanic and semicontinental), orotemperate, humid and mainly hyperhumid spreading into Cascade Ranges Sector areas, in Oregonian Cascade Subsector, 6d. Tsugo mertensianae-Piceetum sitchensis: Oceanic Boreal (euoceanic and semicontinental) and barely subcontinental, upper mesoboreal and supraboreal, upper humid to ultrahyperhumid, spreading into Boreal Oceanic Alaskan Province territories, 6e. Abieti lasiocarpae-Pinetum albicaulis: Oceanic Temperate (euoceanic and semicontinental) and barely subcontinental, upper orotemperate, upper humid to hyperhumid, chionophobic, spreading into Cascade Ranges Sector territories, 6f. Phyllodoco glanduliflorae-Laricetum lyallii: Oceanic Temperate (semicontinental) and barely subcontinental, upper orotemperate, upper humid to lower subhumid, chionophilous in mountain snow-packs, spreading into Cascade Ranges and Columbia Mountains Sectors areas.

Characteristic species: Abies lasiocarpa, Abies lasiocarpa x amabilis, Abies procera, Abies procera x lasiocarpa, Aconitum delphiniifolium subsp. chamissonianum, Bromus sitchensis var. aleutensis, Chamaecyparis nootkatensis, Elliottia pyroliflorus, Erythronium montanum, Gaultheria humifusa, Larix lyallii, Ligusticum grayi, Luzula glabrata var. hitchcockii, Luzula piperi, Mertensia paniculata var. borealis, Mitella breweri, Picea xlutzii (Picea sitchensis x glauca), Pleuricospora fimbriolata, Pulsatilla occidentalis, Ranunculus suksdorfii, Rhododendron albiflorum, Ribes acerifolium, Rubus arcticus subsp. stellatus, Rubus lasiococcus, Rubus nivalis, Saussurea americana, Sorbus sitchensis var. grayi, Sorbus sitchensis var. sitchensis, Streptopus streptopoides var. brevipes, Tsuga mertensiana, Vaccinium membranaceum, Viola ocellata.

Table 23
6a. Abieti amabilis-Tsugetum mertensianae

(Tsugion mertensianae, Tsugetalia mertensiano-heterophyllae)

Altitude (1=10m) 128 173 158 147 112 152 149 154 114 150 154 135 144
Number of species 16 17 17 18 19 20 21 22 22 22 25 28 21
Ordinal number 1 2 3 4 5 6 7 8 9 10 11 12 13
Trees:
Abies amabilis 4 4 3 4 3 3 4 4 2 4 3 2 V
Tsuga mertensiana 3 3 4 3 2 4 3 3 3 3 3 3 V
Chamaecyparis nootkatensis . . + 1 2 . 2 1 2 2 2 2 IV
Characteristic species:
Menziesia ferruginea 4 2 3 1 1 2 2 2 2 2 3 2 V
Vaccinium membranaceum 3 2 3 3 1 3 2 2 1 3 3 3 V
Rubus lasiococcus + 2 1 2 + 3 1 3 + 2 2 + V
Vaccinium ovalifolium 1 2 1 . 4 1 2 3 3 2 1 2 V
Rubus pedatus 3 2 2 . 2 . 1 2 3 2 3 3 V
Sorbus sitchensis 1 1 2 1 + 1 2 + 1 2 . . IV
Tiarella unifoliata + 1 1 1 . 2 + 3 . . 2 2 IV
Orthilia secunda 1 1 . 2 . + 1 2 . 3 1 1 IV
Luzula piperi . 2 . 1 + 2 1 + 1 1 1 . IV
Veratrum viride + + + . . + + . . . + + III
Gymnocarpium dryopteris . . 2 1 . 1 . + . . 1 1 III
Vaccinium scoparium . . . 1 . . 2 2 . . 1 1 III
Phyllodoce empetriformis . 1 . 1 . 1 3 . . . . . III
Rhododendron albiflorum . . . . 2 . 3 . 2 3 . . III
Arnica latifolia . . . 2 . . . 1 . 1 1 . III
Osmorhiza berteroi . . . . . 1 . . + . + + III
Cornus canadensis 3 . 1 . . . . . . . + . II
Rubus strigosus . . . . 2 . . . 3 . . 1 II
Listera caurina . . . . . . . 2 . . + 1 II
Maianthemum amplexicaule . . . . . . . 2 . . 1 2 II
Erythronium montanum . . . 2 . . . 3 . . 2 . II
Xerophyllum tenax . . . + . . . . . . 1 2 II
Companion species:
Rhytidiopsis robusta 2 2 3 . 3 2 2 3 2 . 2 3 IV
Blechnum spicant + . . + 1 . . . 1 . + + III

Other species. Trees: Abies lasiocarpa x amabilis 1 in 7. Characteristics species: Erythronium grandiflorum 1 in 2, 3 in 6. Valeriana sitchensis 1 in 2 and 10. Rubus spectabilis 2 in 3, + in 12. Osmorhiza purpurea 1 in 4 and 10. Sambucus pubens + in 5 and 7. Phyllodoce glanduliflora 3 in 5, 1 in 9. Elliottia pyroliflorus 2 in 5, 1 in 9. Luetkea pectinata 2 in 6, 1 in 9. Alnus sinuata + in 7 and 10. Viola glabella 1 in 8 and 11. Corallorhiza mertensiana + in 8 and 12. Linnaea americana 1 in 1. Mertensia borealis + in 2. Ribes bracteosum 1 in 3. Athyrium cyclosorum +, Gaultheria humifusa + in 5. Heuchera glabra 1, Vahlodea atropurpurea 1 in 6. Bromus sitchensis 1, Disporum smithii 1, Dryopteris expansa 1 in 9. Mitella breweri 2, Saxifraga odontoloma 1, Streptopus curvipes 1, Ribes lacustre + in 10. Clintonia uniflora 2, Achlys triphylla +, Chimaphila menziesii +, Gaultheria ovatifolia +, Trillium ovatum + in 12. Companion species: Claytonia lanceolata + in 1 and 6, 1 in 10. Alectoria sarmentosa 2 in 8 and 12, 3 in 11. Equisetum boreale + in 3. Spiraea diversifolia 2 in 7. Anaphalis margaritacea + in 9. Lupinus latifolius + in 10.

Localities: 1. British Columbia: Lillooet Range, Lillooet Pass, southwestern side. 50º38'N-121º57'W. SW, 20%, 25 m, 60 cm, 400 m2 (reg. 1995c: 121). 2. Washington: Pierce Co. Mt. Rainier National Park. Chinook Pass, southern side. 46º52'N-121º31'W. S, 40%, 25 m, 120 cm, 200 m2 (reg. 1996b: 89). 3. Washington: Whatcom Co. Mount Baker-Snoqualmie National Forest. Mount Baker National Recreation Area. Mount Baker. 48º51'N-121º40'W. N, 40%, 25m, 120 cm, 200 m2 (reg. 1997: 42). 4. Washington: Pierce Co. Mount Rainier National Park, Cayuse Pass, between Owy High Lakes and Dewey Lake. 46º52'N-121º32'W. NE, 20%, 30 m, 130 cm, 2000 m2 (reg. 1997: 58). 5. British Columbia: Vancouver. Grouse Mountain. 49º21'N-123º07'W. N, 15%, 30 m, 140 cm, 400 m2 (reg. 1997: 11). 6. Washington: Pierce Co. Mt. Rainier National Park. Between Cayuse Pass and Dewey Lake.. 46º52'N-121º32'W. E, 25%, 30 m, 200 cm, 1000 m2 (reg. 1996b: 90). 7. Washington: Lewis Co. Louise Lake. 46º47'N-121º45'W. N, 30%, 30 m, 120 cm, 1000 m2 (reg. 1992e: 137). 8. Washington: Pierce Co. Mount Rainier National Park. Elisabeth Ridge under Mowich Lake. 46º57'N-121º52'W. W, 25%, 30 m, 140 cm, 1000 m2 (reg. 1997: 45). 9. British Columbia: Vancouver, Grouse Mountain. 49º20'N-123º07'W. SW, 20%, 25m, 120 cm, 400 m2 (reg. 1997: 10). 10. Washington: Pierce Co. Mount Rainier National Park, between Owy High Lakes and Sunrise Point. 46º54'N-121º36'W. S, 40%, 40 m, 130 cm, 1000 m2 (reg. 1997: 57). 11. Washington: Pierce Co. Mount Rainier National Park. Elisabeth Ridge under Mowich Lake. 46º57'N-121º52'W. S, 35%, 30 m, 140 cm, 1000 m2 (reg. 1997: 44). 12. Washington: Pierce Co. Mount Rainier National Park. Elisabeth Ridge under Mowich Lake. 46º57'N-121º53'W. W, 30%, 40 m, 120 cm, 2000 m2 (reg. 1997: 43). 13. Synthesized table.

6a. Abieti amabilis-Tsugetum mertensianae Brooke, Peterson & Krajina 1970 em. hoc loco

[Vaccinio membranacei-Tsugetum mertensianae Brooke, Peterson and Krajina in Ecol. Western North. Am. 2(2): 255. 1970 (art. 25), Cladothamno pyroliflori-Tsugetum mertensianae Brooke, Peterson and Krajina in Ecol. Western North. Am. 2(2) 257. 1970 (art. 25), Abieti amabilis-Tsugetum mertensianae Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 263. 1970, Streptopo rosei-Abietetum amabilis Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 267. 1970 (art. 25) em. hoc loco, Oplopanaco horridi-Thujetum plicatae abietetosum amabilis Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 272. 1970 (art. 25) (lectotype: loc. cit., tb. 11b, plot no. 91), Lysichito americani-Chamaecyparetum nootkatensis Brooke, Peterson & Krajina in Ecol. Western North. Am. 2(2) 273. 1970 (art. 25)]

Oceanic Temperate (euoceanic); mainly upper orotemperate, hemiboreal; hyperhumid and ultrahyperhumid; Pacific silver fir (Abies amabilis), Alaska cedar (Chamaecyparis nootkatensis) and mountain hemlock (Tsuga mertensiana) climactical coniferous macroforests, growing on dystric, ferric, gleyic or stagnic podzols, podzoluvisols or andosols throughout the Cascade Province territories, mostly windward in the Canadian Coastal Mountains Sector areas (excluded Queen Charlotte and Prince of Wales Islands Subsector) and in Washingtonian Cascade Subsector.

Bioclimatic diagnosis: Ic 11-16, Io 12-28, Tp 380-600, Tps 280-370, Tmin < -3, m < -5. [Teoc-Uote-Hum, Hhu, Uhh].

Table 23 holds 12 relevés sampled in British Columbia and Washington which belong to South Canadian Coastal Mountains and Washingtonian Cascade Subsectors. Abieti amabilis-Tsugetum mertensianae is mainly an upper orotemperate, euoceanic, and hyperhumid association, which most significant floristical characteristic species are Abies amabilis in the canopy and Elliottia pyroliflorus in the understory, both absent in the more continental geovicarious association Abieti lasiocarpae-Tsugetum mertensianae where Abies lasiocarpa usually become dominant and Picea engelmannii var. engelmannii are a common tree; Rhododendron albiflorum and Phyllodoce empetriformis are some common species in both associations. The secondary deciduous thickets and microforests belong to the Alno sinuatae-Populion trichocarpae alliance.

Map Figure 23. Distribution of the coniferous forest associations belonging to alliance 6. Tsugion mertensianae: 6a. Abieti amabilis-Tsugetum mertensianae: Temperate oceanic, orotemperate and hemiboreal, Canadian Coastal Mountains Sector and Washingtonian Cascade Subsector, 6b. Abieti lasiocarpae-Tsugetum mertensianae: Temperate oceanic, upper orotemperate, Canadian Coastal Mountains and Cascade Ranges Sectors, 6c. Tsugo mertensianae-Abietetum procerae: Temperate oceanic, orotemperate, Cascade Ranges Sector, 6d. Tsugo mertensianae-Piceetum sitchensis: Boreal oceanic, upper mesoboreal and supraboreal, Boreal Oceanic Alaskan Province, 6e. Abieti lasiocarpae-Pinetum albicaulis: Temperate oceanic, upper orotemperate, Cascade Ranges Sector, 6f. Phyllodoco glanduliflorae-Laricetum lyalli: Temperate oceanic, upper orotemperate, Cascade Ranges and Columbia Mountains Sectors.

Type relevé (lectotypus hoc loco): Brooke, Peterson & Krajina in Ecol. Western North Am. 2(2): 263, tb. 9b (335), plot n. 83. 1970 sub Abieti amabilis-Tsugetum mertensianae abieto-tsugosum mertensianae. Site: British Columbia. Garibaldi Park. 49º50'N-123º10'W. 0.2 acre, 4540 ft. Estimated bioclimatic factors: Oceanic Temperate, euoceanic (Ic ~ 14), lower orotemperate (Tp ~ 650), upper hyperhumid (Io ~ 20.0), Positive Summer Temperature Tps ~ 320. Biogeographic location: Rocky Mountain Region, North-Western Pacific Subregion, Cascade Province, Canadian Coastal Mountains Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 6 [2] Abies amabilis, 5 [2] Tsuga mertensiana. Others: 3 [+] Abies amabilis (S2), + Menziesia ferruginea, 1 [+] Rubus pedatus, 2 [+] Tsuga mertensiana (S2), 5 [2] Vaccinium alaskense [V. membranaceum], 5 [2] Vaccinium membranaceum, 1 [+] Vaccinium ovalifolium. Companion species (excl. species on rocks and decayed wood) 1 [+] Bazzania ambigua, 1 [+] Blepharostoma trichophyllum, 1 [+] Calypogeia neesiana, 1 [+] "Cephalozia media", 2 [+] Cladonia bellidiflora, 1 [+] Cladonia coniocraea, 5 [2] Dicranum fuscescens, 1 [+] Hypnum circinale, 4 [1] Orthocaulis floerkii [Barbilophozia floerkii], 3 [+] Rhytidiopsis robusta, 1 [+] "Roellia roellii", 1 [+] Scapania bolanderi.

6b. Abieti lasiocarpae-Tsugetum mertensianae associatio nova hoc loco

Oceanic Temperate (euoceanic and semicontinental) and barely subcontinental (Continental Temperate); upper orotemperate, upper humid and hyperhumid; meso- and oligotrophic subalpine fir (Abies-lasiocarpa), mountain hemlock (Tsuga mertensiana), Engelmann spruce (Picea engelmannii var. engelmannii) and rare Alaska cedar (Chamaecyparis nootkatensis) climactical coniferous meso- and macroforests, growing on dystric, ferric, gleyic or stagnic podzols throughout the Columbia Mountains and Cascade Ranges Sectors territories. Also it is possible to recognize this association in leeward expositions and more continental eastern slopes in the South Canadian Coastal Mountains Subsector territories.

Bioclimatic diagnosis: Ic 16-23, Io 9.0-18.0, Tp 380-600, Tps 280-380, Tmin < -4, m < -7. [Teoc, Teco-Ote-Uhmu, Lhhu].

Table 24 holds 15 relevés from British Columbia and Washington territories which biogeographically belong to Columbia Mountains and Washingtonian Cascade Subsectors. The most significant high altitude understory characteristic species in this semicontinental upper orotemperate forest association are: Anemone lyallii, Cassiope tetragona var. saximontana, Erythronium montanum, Ligusticum grayi, Luetkea pectinata, Luzula hitchcockii, Mertensia paniculata var. borealis, Mitella breweri, Phyllodoce empetriformis, Rhododendron albiflorum, Sorbus sitchensis var. sitchensis and Valeriana sitchensis.

Type relevé (holotypus): Table 24, relevé n. 9. Rivas-Martínez reg. 1998b: 106. 29.08.98, made with Dr. Sánchez-Mata. Site: British Columbia: Mount Revelstoke National Park. Balsam Lake, Summit. 51º04'N-118º04'W. 1650 m, NW, 15%, 20 m, 70 cm, 500 m2. Physiognomy and habitat: Mature subalpine fir (Abies lasiocarpa) and mountain hemlock (Tsuga mertensiana) mesoforest. Estimated bioclimatic factors: Oceanic Temperate , semicontinental (Ic ~ 19), upper orotemperate (Tp ~ 430), lower hyperhumid (Io ~ 15), Positive Summer Temperature Tps ~ 320. Biogeographic location: Rocky Mountain Region, North-Western Pacific Subregion, Cascade Province, Columbia Mountains Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 4 Abies lasiocarpa, + Picea engelmannii, 2 Tsuga mertensiana. Others: 1 Arnica cordifolia, + Calamagrostis rubescens, 1 Cassiope tetragona var. saximontana, 2 Gaultheria humifusa, 3 Luetkea pectinata, 1 Luzula glabrata var. hitchcockii, 2 Mitella breweri, + Orthilia secunda, 1 Pedicularis alba var. racemosa, 2 Phyllodoce empetriformis, 4 Rhododendron albiflorum, + Senecio triangularis, 1 Sorbus sitchensis var. sitchensis, 2 Streptopus streptopoides var. brevipes, 2 Tiarella trifoliata var. unifoliata, 3 Vaccinium membranaceum, 1 Vaccinium scoparium, 2 Valeriana sitchensis, + Viola orbiculata. Companion species: 4 Rhytidiopsis robusta.

Table 24
6b. Abieti lasiocarpae-Tsugetum mertensianae

(Tsugion mertensianae, Tsugetalia mertensiano-heterophyllae)

Altitud (1=10m) 198 151 152 181 166 150 155 172 165 135 164 155 128 147 133 157
Number of species 19 21 21 21 21 22 22 23 23 25 25 26 27 28 36 24
Ordinal number 1 2 3 4 5 6 7 8 9* 10 11 12 13 14 15 16
Trees:
Abies lasiocarpa 4 3 4 5 4 5 5 4 4 3 3 3 4 4 3 V
Tsuga mertensiana 2 3 3 1 1 + 2 3 2 3 2 4 2 3 1 V
Picea engelmannii . . 1 + 2 1 . . + 1 2 . 1 1 3 IV
Tsuga xjeffreyi . . . . . . + . . 1 . . + 1 + II
Chamaecyparis nootkatensis . 2 . . . . . . . 2 . . . . . I
Abies procera x lasiocarpa . . . . . . . . . . + . + . . I
Characteristic species:
Vaccinium membranaceum 3 3 2 4 4 4 4 3 3 4 2 2 2 3 2 V
Rhododendron albiflorum 3 3 1 2 4 2 4 2 4 2 3 2 3 2 1 V
Sorbus sitchensis 1 2 1 2 1 1 2 2 1 . 1 2 1 1 1 V
Veratrum viride 2 + 2 + 1 1 1 1 . + + 1 1 + 1 V
Luzula hitchcockii 4 1 2 3 2 1 2 2 1 . 1 2 . 1 1 V
Valeriana sitchensis 2 . 3 1 1 1 2 1 2 + 1 2 . 2 2 V
Orthilia secunda + . . 1 1 1 . + + 2 + . 1 1 1 IV
Mitella breweri 2 . 2 1 . 2 1 1 2 . 2 1 . . 2 IV
Rubus lasiococcus 2 1 2 . . . 3 1 . 1 3 3 2 . . IV
Arnica cordifolia . 1 . 1 . 2 + . 1 2 2 . . 1 . IV
Viola orbiculata . . + 1 . 1 + 1 + . . 1 2 1 . IV
Tiarella unifoliata . . . 2 1 2 . 1 2 1 + . . 3 2 IV
Phyllodoce empetriformis 1 3 . 2 1 . 2 3 2 . 2 . . . . IV
Vaccinium ovalifolium . 3 . . . 2 . 3 . 1 . . + 2 2 III
Cassiope saximontana 1 2 . + + . . 2 1 . . . . . . III
Vaccinium scoparium 2 . 2 + . . . . 1 . 1 . . 1 . III
Rubus pedatus . 3 . . . . . 2 . . 2 . 1 3 3 III
Luetkea pectinata . . . 2 2 . 1 1 3 . . 2 . . . III
Polemonium pulcherrimum 2 . 3 . . . 1 1 . . . 1 . . . II
Pedicularis racemosa . . . + + + . . 1 . . 1 . . . II
Clintonia uniflora . . . . 2 3 . . . . . . 1 2 2 II
Arnica latifolia 2 1 1 . 2 . . . . . . . . . . II
Erythronium montanum . 2 + . . . 3 . . . . 2 . . . II
Streptopus streptopoides . . . . . 3 . . 2 . . . . 2 2 II
Companion species:
Rhytidiopsis robusta . 1 . 1 3 2 . . 4 3 . . . . 2 III

Other species. Trees: Abies lasiocarpa x amabilis 1 in 10. Pinus monticola 1, Pinus latifolia + in 13. Characteristics species: Xerophyllum tenax 1 in 2 and 10, 1 in 13. Calamagrostis rubescens 1 in 4, + in 9 and 11. Goodyera oblongifolia 1 in 6 and 10, + in 14. Anemone lyallii + in 7, 1 in 8 and 12. Senecio triangularis + in 8, 9 and 11. Gymnocarpium dryopteris 2 in 10 and 14, 3 in 15. Ligusticum grayi 1 in 1, 2 in 3. Mertensia borealis 1 in 1 and 3. Hieracium albiflorum 1 in 3, + in 15. Lupinus arcticus 2 in 5 and 8. Vaccinium caespitosum 1 in 5 and 3 in 12. Lonicera utahensis 2 in 6, + in 14. Ranunculus suksdorfii 1 in 7, 2 in 12. Erythronium grandiflorum + in 7 and 12. Gaultheria humifusa 2 in 9 and 13. Rubus parviflorus + in 10 and 14. Galium trifidum + in 10 and 15. Osmorhiza purpurea + in 11, 1 in 15. Menziesia ferruginea + in 13, 1 in 15. Athyrium cyclosorum 1 in 14 and 15. Dryopteris expansa 1 in 14 and 15. Ribes montigenum + in 14, 1 in 15. Viola glabella 1 in 3. Melampyrum lineare + in 5. Achlys triphylla 2, Ribes lacustre 1, Viola renifolia 1 in 10. Hieracium aurantiacum 1, Ribes laxiflorum 1, Rubus pubescens 1, Pyrola chlorantha + in 12. Disporum smithii 1, Paxistima myrsinites + in 11. Lycopodium integrifolium 3, Fragaria bracteata 2, Diphasiastrum complanatum 1, Linnaea americana 1, Spiraea densiflora 1, Alnus sinuata + in 13. Oplopanax horridus 1 in 14. Cornus canadensis 1, Lonicera involucrata 1, Lycopodium annotinum 1, Sambucus arborescens +, Streptopus roseus + in 15. Companion species: Epilobium angustifolium 1 in 8, + in 13 and 15. Lupinus latifolius + in 1, 1 in 3. Polygonum bistortioides 1 in 2 and 12. Claytonia lanceolata + in 7 and 12. Pedicularis surrecta + in 7 and 12. Rhytidiadelphus rugosus 3 in 6, 2 in 14. Alectoria sarmentosa 3, Dicranum scoparium 2 in 2. Dicranum fuscescens 1 in 10. Equisetum boreale +, Parnassia fimbriata + in 11. Pleurozium schreberi 3, Polytrichum commune 2, Equisetum braunii 1, Bromus vulgaris + in 15.

Localities: 1. Washington: Pierce Co. Mount Rainier National Park. 46º55'N-121º37'W. S, 20%, 15m, 70 cm, 500 m2 (reg. 1997: 52). 2. Washington: Pierce Co. Mount Rainier National Park. Elisabeth Ridge under Mowich Lake,. 46º57'N-121º52'W. W, 20%, 15 m, 60 cm, 500 m2 (reg. 1997: 46). 3. Washington: Pierce Co. Mount Rainier National Park. 46º54'N-121º35'W. SW, 10%, 20 m, 70 cm, 500 m2 (reg. 1997: 56). 4. British Columbia: Revelstoke, Mount Revelstoke National Park, Balsam Lake, Summit. 51º05'N-118º06'W. S, 10%, 10 m, 40 cm, 500 m2 (reg. 1998b: 104). 5. British Columbia: Mount Revelstoke National Park, Balsam Lake, Summit. 51º04'N-118º03'W. SW, 15%, 25 m, 80 cm, 400 m2 (reg. 1992e: 103). 6. British Columbia: Mount Revelstoke National Park, Balsam Lake, Summit. 51º06'N-118º03'W. SE, 20%, 20 m, 60 cm, 1000 m2 (reg. 1998b: 108). 7. Washington: Clallam Co. Olympic National Park. Hurricane Ridge.. 47º58'N-123º20'W. NW, 20%, 20m, 50 cm, 400 m2 (reg. 1998a: 62). 7. Washington: Pierce Co. Mount Rainier National Park, Paradise Park. 46º50'N-121º49'W. SE, 20%, 20m, 80 cm, 400 m2 (reg. 1992e: 133). 9. British Columbia: Mount Revelstoke National Park, Balsam Lake, Summit. 51º04'N-118º04'W. NW, 15%, 20 m, 70 cm, 500 m2, holotypus ass. (reg. 1998b: 106). 10. Washington: Yakima Co. White Pass, Cascade Trail. 46º39'N-121º24'W. N, 15%, 25 m, 150 cm, 2000 m2 (reg. 1998b: 82). 11. Washington: Chelan Co. Between Rainy Lake and Blue Lake Trail, southern side of Rainy Pass. 48º30'N-121º00'W. NW, 5%, 20 m, 50 cm, 2000 m2 (reg. 1998b: 91). 12. Washington: Clallam Co. Olympic National Park. Hurricane Ridge. 47º58'N-123º20'W. N, 20%, 20 m, 70 cm, 400 m2 (reg. 1998a: 65). 13. Washington: Skamania Co., between Taklakh and Blue Lake Creek. East Canyon Creek. 46º18'N-121º45'W. W, 5%, 20 m, 50 cm, 1000 m2 (reg. 1998b: 77). 14. British Columbia: Mount Revelstoke National Park, Balsam Lake, Summit. 51º06'N-118º03'W. S, 20%, 25m, 70 cm, 1000 m2 (reg. 1998b: 109). 15. British Columbia: Glacier National Park. Roger Pass,. 51º19'N-117º31'W. E, 15%, 20 m, 60 cm, 1000 m2 (reg. 1998b: 112). 16. Synthesized table.