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-Piceetalia

Va. Gaultherio-Piceetalia Br.-Bl., Sissingh & Vlieger ex Lavoie 1968

[Gaultherio-Piceetalia Br.-Bl., Sissingh & Vlieger in Prodr. Pflanzengesellschaften 6: 118. 1939 (art. 3b, 8), Piceo (rubentis)-Abietetalia fraseri Knapp in Geobot. Mitt. 4: 56. 1957 (art. 8), Pinetalia banksianae Knapp in Geobot. Mitt. 4: 56. 1957 (art. 8), Abieti (balsameae)-Piceetalia albae Knapp in Geobot. Mitt. 5: 55. 1957 (art. 8), Gaultherio-Piceetalia Br.-Bl., Sissingh & Vlieger ex Lavoie in Nat. Can. 95: 402. 1968 (holotype: Pinion divaricatae Lavoie in Nat. Can. 95: 402. 1968), Gaultherio procumbentis-Piceetalia glaucae Br.-Bl., Sissingh & Vlieger ex Lavoie 1968 (art. 10d), Piceetalia glauco-marianae Krajina in Ecol. Western North America 2: 51.1969 (art. 8), Piceetalia glauco-marianae Wali & Krajina in Vegetatio 26(4-6) 253. 1973 (art. 8, 10), Pino-Piceetalia Looman in Phytocoenologia 15(3) 297. 1987 (art. 5, 8), Abieti-Piceetalia marianae Nakamura, Grandtner & Villeneuve in Miyawaki, Iwatsuki & Grandtner, Veg. East. North America: 297. 1994 (art. 5, 8), Gaultherio procumbentis-Piceetalia glaucae Br.-Bl., Sissingh & Vlieger ex Peinado, Aguirre & Cruz in Plant Ecology 137: 187. 1998 (holotype: Gaultherio procumbentis-Piceion glaucae Peinado, Aguirre & Cruz in Plant Ecology 137: 187. 1998) (art. 22), Arctostaphylo rubrae-Piceetalia glaucae Peinado, Aguirre & Cruz in Plant Ecology 137: 164. 1998 (holotype: Shepherdio canadensis-Piceion glaucae Peinado, Aguirre & Cruz 1998 in Plant Ecology 137: 167. 1998) (syntax. syn.), Piceetalia glauco-marianae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 191. 1998 (art. 8, 9, 37, 38) (holotype: Gymnocarpio dryopteridis-Abietion lasiocarpae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 192. 1998 (art. 8, 9, 37, 38) and holotype: Gymnocarpio dryopteridis-Abietetum lasiocarpae Wali & Krajina ex Peinado, Aguirre & Cruz in Plant Ecology 137: 192. 1998 (art. 8, 37, 38)]

Typus nominis: Pinion divaricatae Lavoie in Nat. Can. 95: 402. 1968 [Pinion banksianae nom. mut. propos. (art. 45)].

Potential natural coniferous forests (both: climatophilous forests and edaphophilous forested permanent or secondary woodland communities) in the North American Boreal Region (subcontinental, continental and xeric; thermo-, meso- and supraboreal) and the North American Atlantic Region (orotemperate, upper supratemperate and hemiboreal), growing in Western Canadian Boreal, Canadian Prairies and Great Lakes to Appalachian Sectors. The most relevant coniferous trees are: Picea mariana, Picea glauca var. glauca, Picea rubens, Larix laricina y Pinus banksiana.

Bioclimatic diagnosis: Ic 20-46, Io 18-20.0, Tp 380-1050, Tps 300-600, Tmin < -4º, m< -8º. [Boco, Bosc, Booc, Teco, Teoc-Tbo, Mbo, Sbo, Ste, Hbo, Ote, USar, Dry, Shu, Hum, Hhu, Uhh].

Within the order Gaultherio-Piceetalia (Linnaeo-Piceetea marianae) we recognize four alliances with different optimal distribution: 1. Pinion banksianae (Canadian Boreal Province), 2. Gaultherio-Piceion glaucae (Canadian Boreal Province), 3. Piceion rubentis (Appalachian Province), 4. Ledo decumbentis-Piceion marianae (Yukonian-Alaskan Province). In a short synthesized table (table 2) we assemble fifty-two relevés from the North American Boreal Region and adjacent territories belonging to Gaultherio-Piceion glaucae, Piceion rubentis and Ledo-Piceion marianae alliances. A synopsis of the bioclimatic diagnoses of the alliances and associations which we accept or propose in the Gaultherio-Piceetalia order is also given in figure 9.

Pinion banksianae alliance, which represents the obligatory nomenclatural type of Gaultherio-Piceetalia order (art. 6), is occasionally the climactical forest vegetation growing mainly throughout the Xeric Boreal bioclimate territories, and also permanent forest communities growing on deep dry, sandy soils, but more frequently represents the pyrogenic secondary coniferous forests. Their optimum range covers the eucontinental Canadian Boreal Province areas (Pinetum banksianae, Oryzopsio-Pinetum banksianae), and they are also frequent in the Great Lakes Sector territories (Pinetum banksiano-resinosae) and in the hemiboreal and supratemperate districts of the Appalachian Sector (Carici-Pinetum banksianae). Conversely, these forests are rare in the rest of the Appalachian and Canadian Prairies Sectors and they do not exist within the oceanic and suboceanic Newfoundlandian Sector territories.

In the short synthesized table syntaxa (table 2) we assemble fifty-two personal relevés, selected from our databank, belonging to Gaultherio-Piceion glaucae, Piceion rubentis and Ledo-Piceion marianae alliances. Figure 10 shows the relationships between the associations of Gaultherio-Piceetalia order and the boreal and hemiboreal territories North American biogeographic sectors.

Table 2
2. Gaultherio-Piceion glaucae, 2B. Piceion rubentis and 3. Ledo-Piceion marianae
(Short synthesized table syntaxa)

Number of species (average) 24 18 16 23 20 20 21 20 20
Number of relevés 5 2 5 5 7 10 5 13 52
Association number 2a 2b 2c 2d 3a 4a 4b 4c .
Ordinal number 1 2 3 4 5 6 7 8 9
Trees:
Larix laricina . . V . . I . . II
Betula commutata . . . IV . . . . I
Picea rubens . . . . V . . . I
Betula papyrifera IV 1 I . IV . . . II
Abies balsamea V 2 III V V . . . III
Populus balsamifera . . I   III . . I III
Populus tremuloides V 1 . III III . . IV III
Picea mariana IV 2 V III I V V . V
Picea glauca IV 1 . V III III IV V V
Characteristic species:
Vaccinium oxycoccos . 1 V . . III . . II
Chamaedaphne latifolia . . III . . . . . I
Rubus pubescens . . . III . . . . I
Viburnum lantanoides . . . . III . . . I
Pteridium pubescens . . . . V . . . I
Carex lugens . . . . . V . . I
Equisetum sylvaticum . . . . . . IV . I
Shepherdia canadensis . . . I . . . V II
Clintonia borealis II . . . IV . . . II
Gaultheria hispidula II 2 IV . . . . . II
Vaccinium angustifolium V 2 . . III . . . II
Kalmia angustifolia V 2 III . I . . . III
Trientalis borealis IV 2 I . IV . . . III
Coptis groenlandica V . III . I . . . III
Aralia nudicaulis III . . IV V . . . III
Maianthemum canadense V . I V V . . . III
Rubus chamaemorus . . . . . IV V . II
Salix arbusculoides . . . . . V II . II
Betula glandulosa . . . . . IV II . II
Geocaulon lividum . . . . . II II IV III
Empetrum hermaphroditum . . . . . IV I IV III
Arctagrostis arundinacea . . . . . IV II II III
Salix acutifolia . . . . . IV IV III III
Mertensia paniculata . . . IV . III II V III
Orthilia secunda . . . IV I II . IV III
Lycopodium annotinum V . . . II II II I IV
Ledum groenlandicum III 2 V I I V V III V
Linnaea americana V . I V III I V IV V
Cornus canadensis V 2 II V IV I V II V

Associations: 1. [2a] Abietetum balsameae (Gaultherio-Piceion glaucae). 2. [2b] Kalmio angustifoliae-Piceetum marianae (Gaultherio-Piceion glaucae). 3. [2c] Sphagno-Piceetum marianae (Gaultherio-Piceion glaucae). 4. [2d] Mertensio paniculatae-Abietetum balsameae (Gaultherio-Piceion glaucae). 5. [3a] Abieti balsameae-Piceetum rubentis (Piceion rubentis). 6. [4a] Rubo chamaemori-Piceetum marianae (Ledo-Piceion marianae). 7. [4b] Piceetum glauco-marianae (Ledo-Piceion marianae). 8. [4c] Hypno procerrimi-Piceetum glaucae (Ledo-Piceion marianae). 9. Synthesized table.

Characteristic species: Amerorchis rotundifolia, Arceuthobium pusillum, Betula pumila var. pumila, Cypripedium passerinum, Diervilla lonicera, Gaylussacia baccataGeocaulon lividum, Larix laricina, Ledum groenlandicum, Lycopodium lagopus, Picea glauca var. glauca, Picea glauca x mariana, Picea mariana, Ribes oxyacanthoides, Rubus chamaemorus, Rubus pubescens, Salix phyllicifolia subsp. planifolia, Viola renifolia.

Remarks: Lavoie [in Nat. Can. 95: 402. 1968] when described the valid name Pinion divaricatae [Pinion banksianae] and included it in the order Gaultherio-Piceetalia Br.-Bl., Sissingh & Vlieger 1939 (art. 3b, 8), he validated (art. 6) the previous North American Boreal order provisionally published by Braun-Blanquet & al. in the sixth fascicle of the "Prodromus der Pfanzengesellschaften" (1939: 3).

The vegetation-type units easily recognized within the North American Boreal potential natural coniferous forests are related with the topographic, hydric and edaphic variations. However, after a detailed phytosociological analysis including all the climatophilous and edapho-hygrophilous associations (which are vegetation series mature phases) recognized by us in the North American Boreal Region, we can to identify within the order Gaultherio-Piceetalia not any characteristic species closely related with the mentioned edaphic conditions including precise, exclusive and territorial relationships. Therefore, it does not seems coherent with the Braun-Blanquet phytosociological methodology to joint the wooded geo-vicariant associations with the same edaphic requirements in biogeographically different alliances using the differential species mainly belonging to others vegetation classes (vg.: "-Piceion glaucae" climatophilous forests, "-Piceion marianae" edapho-hygrophilous or boggy forests). Moreover, is suitable to remind that if it was necessary to publish new syntaxa (alliances and orders) to designate some broadly distributed plant communities, as occurs within the North American Boreal and Temperate forests, it must be avoided the unnecessary increase of the higher syntaxa, and especially to describe high syntaxa mainly using differential species.

Syntaxa Ic Io Itc Tp Ts Tmin m Mb, Var
Va. Gaulterio-Piceetalia 20-46 1.8-20.0 - 380-1050 300-600 < -4 < -14 Bo, Te
1. Pinion banksianae 23-46 2.4-12.0 - 500-1000 400-550 < -4 < -10 Bo, Te
1a. Pinetum banksianae 28-38 6.0-12.0 - 500-800 400-500 < -14 < -20 Bo
1b. Carici-Pinetum banksianae 23-32 6.0-10.0 - 800-1000 450-550 < -4 < -10 Te
1c. Oryzopsio-Pinetum banksianae 28-46 2.4-5.8 - 500-850 400-500 < -13 < -20 Bo, Te
2. Gaultherio-Piceion glaucae 20-40 2.5-14.0 - 380-1050 300-600 < -4 < -8 Bo, Te
2a. Abietetum balsameae 20-38 6.0-14.0 - 700-800 420-500 < -4 < -8 Bo
2b. Kalmio-Piceetum marianae 23-38 6.0-12.0 - 380-700 300-450 < -14 < -20 Bo
2c. Sphagno-Piceetum marianae 20-40 2.5-14.0 - 380-1050 300-600 < -4 < -8 Bo, Te
2d. Mertensio-Abietetum balsameae 28-40 2.5-5.9 - 400-900 300-500 < -14 < -20 Bo, Te
3. Piceion rubentis 21-32 6.0-20.0 - 380-950 300-550 < -4 < -9 Te
3a. Abieti bals.-Piceetum rubentis 21-32 6.0-20.0 - 380-950 300-550 < -4 < -9 Te
4. Ledo-Piceion marianae 22-46 1.8-10.0 - 380-650 300-450 < -9 < -14 Bo, Te
4a. Rubo-Piceetum marianae 23-46 1.8-10.0 - 380-630 300-450 < -9 < -14 Bo, Te
4b. Piceetum glauco-marianae 22-46 3.6-10.0 - 380-640 300-420 < -10 < -15 Bo
4c. Hypno-Piceetum glaucae 28-46 1.8-4.5 - 380-600 300-450 < -15 < -19 Bo, Stp
4d. Pulsatillo-Pinetum latifoliae 28-38 2.0-3.6 - 450-600 350-450 < -15 < -19 Bo, Stp

Figure 11. Synopsis of the bioclimatic diagnoses of syntaxa belonging to Gaultherio Piceetalia. Relationships between the potential natural vegetation forests and the thresholds of the bioclimatic indexes and climatic parameter values [1. Pinion banksianae (1a. Pinetum banksianae, 1b. Carici-Pinetum banksianae, 1c. Oryzopsio-Pinetum banksianae), 2. Gaultherio-Piceion glaucae (2a. Abietetum balsameae, 2b. Kalmio-Piceetum marianae, 2c. Sphagno-Piceetum marianae, 2d. Mertensio-Abietetum balsameae), 3. Piceion rubentis (3a. Abieti balsameae-Piceetum rubentis), 4. Ledo-Piceion marianae (4a. Rubo-Piceetum marianae, 4b. Piceetum glauco-marianae, 4c. Hypno-Piceetum glaucae, 4d. Pulsatillo-Pinetum latifoliae)]. Ic: Continentality Index, Io: Ombrothermic Index, Itc: Compensated Thermicity Index, Tp: Yearly Positive Temperature Index, Tps: Positive Summer Temperature, Tmin: Average temperature value of the coldest month of the year, m: Average minimum temperature of the coldest month of the year (Tmin and m in degrees Celsius), Mb: Macrobioclimate (Bo: Boreal, Te: Temperate), Var: Bioclimatic variants (Stp: Steppic).