DISCUSSION AND RESULTS. DESCRIPTION OF PLANT COMMUNITIES

9g. Penstemono whippleani-Pinetum aristatae associatio nova hoc loco

Continental Temperate (subcontinental); orotemperate; dry and subhumid, often submediterranean; climactical (mainly in dry ombrotype territories) or permanent edapho-xerophilous (dolomitic or serpentine habitats) micro- and mesoforests. The main tree in this forest association is Pinus aristata (Colorado bristlecone pine) usually with Picea engelmannii var. engelmannii (Engelman spruce). These forest communities spreading into high altitude mountain areas in the Colorado Rockies Sector and growing on podzo-luvisols, andosols and leptosols such as serpentine ranker soils and magnesian rendzinas. In upper subhumid ombrotypes territories, Colorado bristlecone pine forests normally represent the edapho-xerophilous permanent forest communities and the regional climactical mesoforests belonging to the subalpine fir-Engelmann spruce forest community (Vaccinio scoparii-Abietetum bifoliae).

Bioclimatic diagnosis: Ic 23-28, Io 3.2-6.0, Tp 380-700, Tps 300-420, Tmin < -11, m < -18. [Teco, Texe-Ote-Udry, Lshu-Stp].

Table 46 shows three relevés from Colorado, in the Colorado Rockies Sector territories (Central-Eastern Rocky Mountain Province). Pinus aristata (Colorado bristlecone pine) is the most important tree in the forest community often with Picea engelmannii var. engelmannii (Engelmann spruce). Juniperus communis var. depressa, Penstemon whippleanus and Pulsatilla patens subsp. multifida are the commonest plants in the understory, and in the herbaceous layer we could remark some species such as Heuchera utahensis, Polemonium pulcherrimum subsp. delicatulum, Erigeron mancus, Mertensia lanceolata var. nivalis and Penstemon procerus.

Table 46
 9g. Penstemono whippleani-Pinetum aristatae
(Piceo-Abietion bifoliae, Pseudotsugo-Abietetalia bifoliae)

Other species. Trees: Populus tremuloides 1 in 1. Companion species: Achillea occidentalis 1 in 2, 2 in 3. Arenaria fendleri 1 in 2, 2 in 3. Artemisia arctica + in 2, 2 in 3. Fragaria platypetala + in 2, 2 in 3. Eriogonum aureum + in 2, 1 in 3. Carex rossii 1 in 2. Carex elynoides 1, Campanula rotundifolia +, Castilleja miniata +, Cystopteris fragilis + in 3.

Localities: 1. Colorado: Clear Creek Co. Arapaho National Forest. Idaho Springs, Echo Lake Park, between Echo Lake and Juniper Pass. 39º40'N-105º36'W. W, 20%, 20 m, 120 cm, 200 m2 (reg. 1995d: 27). 2. Colorado: Clear Creek Co. Idaho Springs, Mt. Evans Wilderness. 39º38'N-105º36'W. SE, 25%, 16 m, 120 cm, 200 m2, holotypus ass. (reg. 1995d: 25b). 3. Colorado: Clear Creek Co. Idaho Springs, Mt Evans Wilderness. 39º38'N-105º36'W. S, 20%, 14 m, 100 cm, 200 m2 (reg. 1995d: 25). 4. Synthesized table

Type relevé (holotypus): Table 46, relevé n. 2. Rivas-Martínez reg. 1995d: 25b. 27.08.95, made with Dr. Costa. Site: Colorado: Clear Creek Co. Mt. Evans Wilderness, Idaho Springs. 39º38'N-105º36'W. 3380 m, SE, 25%, 16 m, 120 cm, 200 m2. Physiognomy and habitat: Colorado bristlecone pine (Pinus aristata) open woodland with Engelmann spruce (Picea engelmannii var. engelmannii) growing on ultramafic outcrops. Estimated bioclimatic factors: Pluviseasonal Continental Mediterranean, subcontinental (Ic ~ 26), upper oromediterranean (Tp ~ 460), lower subhumid (Io ~ 4.0), Positive Summer Temperature Tps ~ 320. Biogeographic location: Rocky Mountain Region, Rocky Mountain Subregion, Central-Eastern Rocky Mountain Province, Colorado Rockies Sector, Colorado-Wyoming Rockies Subsector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 1 Picea engelmannii var. engelmannii, 4 Pinus aristata. Others: 2 Antennaria rosea. + Erigeron mancus, 2 Heuchera parvifolia var. utahensis, 1 Juniperus communis var. depressa, + Mertensia lanceolata var. nivalis, + Penstemon procerus, 2 Penstemon whippleanus, 1 Polemonium pulcherrimum subsp. delicatum, 3 Pulsatilla patens subsp. multifida. Companion species: 1 Achillea millefolium var. occidentalis, 2 Arabis lemmonii, 1 Arenaria fendleri, + Artemisia arctica, 1 Carex rossii, 1 Epilobium angustifolium, + Eriogonum corymbosum var. aureum, + Fragaria virginiana subsp. platypetala, 3 Poa fendleriana, + Sedum lanceolatum, + Senecio canus, 1 Trifolium dasyphyllum subsp. uintense.

9h. Vaccinio scoparii-Pinetum latifoliae La Roi & Hnatiuk associatio nova hoc loco

[Pinus contorta community type La Roi & Hnatiuk in Ecol. Monogr. 50 (1): 16. 1980]

Permanent edapho-xerophilous vegetation, generally succesional pyrogenic meso- and macroforests spreading into Continental Temperate (subcontinental and barely eucontinental) bioclimate territories; orotemperate; upper dry, subhumid and lower humid; often submediterranean. Lodgepole pine (Pinus contorta var. latifolia) is the most important and dynamic tree in the forest community. These pine forests are distributed throughout the Rocky Mountain Subregion areas (Northern Rocky Mountain and Central-Eastern Rocky Mountain Provinces) and grow on podzols, cambisols and podzo-luvisols. Some climactical coniferous trees grow in the forest understory as small trees (S2) by dynamic succesion. According to precise biogeographic and ecological circumstances other trees such as Picea engelmannii var. engelmannii, Picea glauca var. albertiana, Picea glauca var. glauca, Abies bifolia or Pseudotsuga menziesii var. glauca appear, and by time become preponderant trees giving way to the stable regional climax (Vaccinio-Abietetum bifoliae, Piceetum engelmanio-albertianae, Menziesio-Abietetum bifoliae). La Roi & Hnatiuk (Ecol. Monogr. 50(1): 1-29. 1980) give an exelent table and description of the association and its ecoclinal variations of Banf and Jasper National Parks.

Bioclimatic diagnosis: Ic 23-30, Io 3.2-9.0, Tp 400-700, Tps 300-420, Tmin < -8, m < -14. [Teco, Texe-Ote-Udry, Shu, Lhum-Sbm, Stp].

Table 47 gives twelve relevés from Alberta, British Columbia, Idaho, Montana and Wyoming, in the Northern Rocky Mountain and Central-Eastern Rocky Mountain Provinces. Pinus contorta var. latifolia (lodgepole pine) is the only preponderant tree in the forest association, and the climactical trees such as firs, spruces or Colorado Douglas firs usually only occur as small trees in the undercanopy, or as clumps of big trees barely spreading in the forests, as the rests of the former climax forests. Several shrubs grow in the understory such as Juniperus communis var. depressa, Arctostaphylos uva-ursi (mainly var. adenotricha), Vaccinium scoparium and Shepherdia canadensis; conversely, the herbaceous and mycorrhizal forest species usually growing in shady places such as Orthilia secunda, Pyrola asarifolia, Pyrola minor, Mitella nuda, Cornus canadensis, etc. are clearly less common that they are in their succesional climactical forest communities.

Table 47
9h. Vaccinio scoparii-Pinetum latifoliae
(Piceo-Abietion bifoliae, Pseudotsugo-Abietetalia bifoliae)

Other species. Characteristic species: Thalictrum sparsiflorum + in 4, 1 in 8. Arctostaphylos uva-ursi 4 in 5, 2 in 6. Aster conspicuus 1 in 5, 2 in 6. Salix prolixa + in 5, 1 in 6. Antennaria racemosa 2 in 9, 1 in 11. Aster ciliolatus 2 in 10, 1 in 11. Senecio streptanthifolius 1 in 2. Antennaria umbrinella 1in 4. Solidago missourensis 1, Zigadenus elegans + in 5. Xerophyllum tenax 3, Gaultheria ovatifolia 1, Rhododendron albiflorum 1, Viola renifolia 1, Chimaphila occidentalis + in 7. Lonicera utahensis 2, Paxistima myrsinites 2, Symphoricarpos utahensis 2, Geranium viscosissimum 1 in 8. Anemone lithophila 1, Maianthemum stellatum 1 in 9. Galium boreale 2, Viola adunca 1, Disporum trachycarpum + in 11. Empetrum hermaphroditum 1, Ledum glandulosum 1, Mitella nuda 1, Senecio eremophyllus 1 in 12. Companion species: Pleurozium schreberi 3 in 3 and 12, 2 in 11. Campanula rotundifolia + in 8 and 11. Pedicularis surrecta 1 in 9, + in 12. Ptilium crista-castrensis 2 in 11 and 12. Penstemon rydbergii + in 2. Allium brevistylum 2, Artemisia spiciformis 1 in 4. Achillea occidentalis +, Dryas drummondii + in 5. Hylocomium splendens 2 in 6. Solidago neomexicana 2, Oxytropis lambertii 1, Poa tracyi 1, Ribes aureum +, Sedum lanceolatum + in 10. Ceanothus velutinus 1 in 11.

Localities: 1. Wyoming: Albany Co. Medicine Bow National Forest. Between Centennial and Snowy Range.. 41º20'N-106º10'W. N, 10%, 25 m, 30 cm, 400 m2 (reg. 1995d: 190). 2. Wyoming: Johnson Co. Bighorn National Forest. Between Buffalo and Tenslep, Bighorn Mountains. 44º12'N-107º12'W. S, 30%, 20 m, 30 cm, 400 m2 (reg. 1994b: 39). 3. Alberta: Jasper National Park, Jasper. 52º46'N-118º01'N. E, 15%, 20 m, 30 cm, 400 m2, holotypus ass. (reg. 1995d: 138). 4. Montana: Big Horn Co. Big horn Mountains near Bighorn Canyon National Recreation Area. 45º17'N-107º55'W. N, 10%, 20 m, 40 cm, 400 m2 (reg. 1996b: 59). 5. Alberta: Jasper, Sumwapta Falls, Sumwapta River. 52º32'N-117º38'W. N, 25m, 40 cm, 20%, 400 m2 (reg. 1992e: 55). 6. Alberta: Banff National Park, Lake Louise. 51º25'N-116º13'W. SW, 20%, 20 m, 40 cm, 200 m2 (reg. 1992e: 42). 7. Idaho: Idaho Co. Between Lolo Hot Springs and Lochsa River. 46º38'N-114º35'W. S, 15%, 25 m, 50 cm, 400 m2. Secondary forest after fire (reg. 1994b: 75). 8. Wyoming: Teton Co. Grand Teton National Park, Signal Mountain Road, Signal Mountain. 43º51'N-109º52'W. SW, 15 m, 20 cm, 400 m2 (reg. 1996b: 47). 9. Montana: Powell Co. Between Helena and Avon, Frontier Town, McDonald Pass. 46º33'N-112º19'W. NW, 30%, 20 m, 40 cm, 400 m2, glacier alluvial deposits (reg. 1994b: 70). 10. Wyoming: Albany Co. Medicine Bow National Forest, Medicine Bow Mountains, Snowy Range Pass. 41º21'N-106º19'W. SW, 15%, 15 m, 30 cm, 400 m2 (reg. 1995d: 193). 11. Alberta: Medicine Hat, Cypress Hill. 49º49'N-110º21'W. W, 15%, 20 m, 30 cm, 400 m2 (reg. 1995d: 159). 12. British Columbia: Banff National Park, between Storm Mountain Lodge and Vermillion Pass. 51º15'N-116º03'W. E, 15%, 15 m, 30 cm, 500 m2(reg. 1998b: 116). 13. Synthesized table.

Type relevé (holotypus): Table 47, relevé n. 3. Rivas-Martínez reg. 1995d: 138. 05.09.95, made with Dr. Costa. Site: Alberta: Jasper National Park, Jasper. 52º46'N-118º01'N. 1080 m, E, 15%, 20 m, 30 cm, 400 m2. Physiognomy and habitat: Lodgepole pine (Pinus contorta var. latifolia) open mesoforest. Estimated bioclimatic factors: Continental Temperate, subcontinental (Ic ~ 24), upper orotemperate (Tp ~ 420), lower humid (Io ~ 6.5), Positive Summer Temperature (Ts ~ 350), submediterranean (Ios2 ~ 2.0). Biogeographic location: Rocky Mountain Region, Rocky Mountain Subregion, Northern Rocky Mountain Province, Canadian Rockies Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 1 Picea engelmannii var. engelmannii (S2), 5 Pinus contorta var. latifolia. Others: 1 Arctostaphylos uva-ursi var. adenotricha, 2 Calamagrostis purpurascens, 2 Cornus canadensis, 1 Juniperus communis var. depressa, + Ledum groenlandicum, 3 Linnaea americana, + Pyrola asarifolia, 2 Rosa woodsii var. ultramontana, 3 Shepherdia canadensis, 1 Spiraea betulifolia var. lucida, 1 Vaccinium caespitosum, 1 Vaccinium scoparium. Companion species: 2 Epilobium angustifolium, 1 Fragaria vesca var. americana, 3 Pleurozium schereberi.

9i. Vaccinio scoparii-Pinetum albicaulis associatio nova hoc loco

Permanent edapho-xerophilous micro- and mesoforests, climactic in dry ombrotype territories, spreading into Continental Temperate (subcontinental) bioclimate areas; upper orotemperate; upper dry; subhumid and lower humid; occasionally submediterranean. Whitebark pine (Pinus albicaulis) is the main tree in the forest community with Picea engelmannii var. engelmannii and occasionally, with Abies bifolia. These pine forests spreading into Northern Rocky Mountain Province territories and in the High Missouri-Yellowstone Sector territories and grow on leptosols, dystric cambisols, andosols and haplic, ferric or cambic podzols. The whitebark Rocky Mountain forest association is contiguous in Northern Rocky Mountain Province with the climactical orotemperate subalpine fir-Engelmann spruce association Menziesio ferrugineae-Abietetum bifoliae or toward southern areas, in the High Missouri-Yellowstone Sector, with Vaccinio scoparii-Abietetum bifoliae.

Bioclimatic diagnosis: Ic 24-28, Io 3.6-9.0, Tp 380-600, Tps 300-380, Tmin < -12, m < -17. [Teco-Uote-Shu, Lhum, Sbm].

Table 48 gives three relevés from Montana and Wyoming, in the High Missouri-Yellowstone Sector territories (Central-Eastern Rocky Mountain Province). Pinus albicaulis (whitebark pine) is the most important tree in the forest community with Picea engelmannii var. engelmannii (Engelmann spruce) and Abies bifolia (Rocky Mountain subalpine fir). In the understory are frequent plants such as Orthilia secunda, Arnica cordifolia, Pedicularis racemosa subsp. alba, Ribes montigenum, Aster conspicuus and Vaccinium scoparium.

 Table 48
9i. Vaccinio scoparii-Pinetum albicaulis
(Piceo-Abietion bifoliae, Pseudotsugo-Abietetalia bifoliae)

Other species. Characteristic species: Juniperus depressa 2, Poa stenantha 1, Valeriana sitchensis + in 1. Senecio sphaerocephalus 2, Ligusticum filicinum 1, Antennaria umbrinella + in 2. Vaccinium cespitosum 3, Sambucus microbotrys 2, Sorbus scopulina 2, Hieracium gracile 1 in 3. Companion species: Penstemon rydbergii 1 in 1.

Localities: 1. Montana: Carbon Co. Custer National Forest, Beartooth Pass to Red Lodge. 45º01'N-109º24'W. N, 40%, 15 m, 100 cm, 400 m2, holotypus ass. (reg. 1994b: 55). 2. Wyoming: Teton Co. Bridger-Teton National Forest, Togwotee Pass, between Moran Junction and Dubois. 43º46'N-110º04'W. S, 30%, 15 m, 80 cm, 200 m2 (reg. 1994b: 29). 3. Wyoming: Teton Co. Targhee National Forest, Teton Range, Teton Pass to Jackson. 43º30'N-110º58'W. N, 30%, 20 m, 80 cm, 200 m2 (reg. 1994b: 21). 4. Synthesized table.

Revealing relevé: Table 48, relevé n. 1. Rivas-Martínez reg. 1994b: 55. 04.09.94, made with Dr. Costa. Site: Montana: Carbon Co. Custer National Forest. Beartooth Pass to Red Lodge. 45º01'N-109º24'N. 2800 m, N, 40%, 15 m, 100 cm, 400 m2. Physiognomy and habitat: Whitebark pine (Pinus albicaulis) open mesoforest with Engelmann spruce (Picea engelmannii var. engelmannii). Estimated bioclimatic factors: Continental Temperate, subcontinental (Ic ~ 26), upper orotemperate (Tp ~ 550), lower humid (Io ~ 7), Positive Summer Temperature Tps ~ 350, submediterranean (Ios2 ~ 2.0). Biogeographic location: Rocky Mountain Region, Rocky Mountain Subregion, Central-Eastern Rocky Mountain Province, High Missouri-Yellowstone Sector. Floristic combination: Linnaeo-Piceetea characteristic species, trees: 1 Picea engelmannii var. engelmannii, 5 Pinus albicaulis. Others: + Aquilegia jonesii, + Antennaria rosea, 1 Arnica cordifolia, 1 Aster conspicuus, 2 Juniperus communis var. depressa, 1 Lonicera utahensis, 2 Orthilia secunda, + Osmorhiza purpurea, + Paxistima myrsinites, 1 Pedicularis racemosa subsp. alba, 1 Poa stenantha, 1 Ribes montigenum, 1 Rosa woodsii var. ultramontana, 2 Senecio sphaerocephalus, 1 Vaccinium scoparium, + Valeriana sitchensis. Companion species: 1 Epilobium angustifolium, 1 Penstemon rydbergii.