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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MATERIAL AND METHODS

Our field work in North America started in 1991. In over eight years of intensive geobotanic research in United States and Canada, we have made more than 3,000 phytosociological relevés in about four hundred days" field work and have driven a 150,000 km. In our studies we follow the Braun-Blanquet phytosociological approach (1932, 1964) integrating the recent Dynamic-Catenal landscape analysis methodology (Alcaraz 1996; Deil 1995, 1997; Géhu 1977, 1991; Géhu & Rivas-Martínez 1981; Rivas-Martínez 1976, 1978, 1987, 1994, 1996a, 1997; Schwabe 1997; Theurillat 1991, 1992). Following our previous publication for all the nearly described plant communities we include their bioclimatic and biogeographic diagnoses. With small modifications we follow the previous North American bioclimatic and biogeographic syntheses proposed by Rivas-Martínez (1996a, 1996b, 1997); our proposals are included in the monographic chapters, figures and maps (including an attached and newly-proposed biogeographic map of North America). For soil classification and typology nomenclature we use the publications of Fao-Unesco (1988), Duchaufour (1987) and Porta, López-Acevedo & Roquero (1994). Taxonomy and nomenclature of Spermatohyta agree with the following publications, in order of importance: Flora of North America [N.R. Morin (ed.), 1993-1997] and J.T. Kartesz's Checklist (1994). Anderson, Crum & Buck's list (1990) was used for the bryophytes and Anderson's checklist for the Sphagnum (1990). For the liverworts we used Vitt, Marsh & Bovey's published guide (1988), and finally for the lichenized fungi Esslinger & Egan's checklist (1995). When we do not agree with these publications the taxa authorities involved are indicated in the checklist following the compilation of Brummitt & Powell (1996). When the original determination of some taxa extracted from the bibliographic resources used does not agree with the catalogues mentioned we indicate the determination in inverted commas and, if affirmative, the appropriate name in square brackets. Translation from the bibliographic original scale relevés into Braun-Blanquet's scale was made when necessary for the nomenclatural type transcriptions. We strictly follow the current issue of the Code of Phytosociological Nomenclature (Barkman & al. 1986, thereafter CPN) for the syntaxonomic nomenclature. Concerning the bibliographic resources we have used all the reported publications, and the bibliographic compilations of Knapp (1981, 1982) and Major & Rejmánek (1988a, 1988b).

The phytosociological vegetation relevés include the precise geographic location with coordinates, plot exposure, plot inclination, sampled plot area in square meters, average vegetation height, thickness of older trees and plot surface studied. (S2) is refers to understory forest stratum and in the synthesized column of each table of relevés the average altitude and average number of species is also given. The relevé register number, unless otherwise indicated, belongs to Rivas-Martínez's phytosociological databank [Centro de Investigaciones Fitosociológicas (CIF) Phytosociological Research Center]. Nomenclatural types relevés (bibliographic or newly proposed) are included in the text with their origin, reference and the geographic data of the locality, as well as some bioclimatic, biogeographic and ecologic comments; if they are original we include the precise date and authors.

When the present document was submitted to the reviewing process, a paper was published on North American Boreal forests, by Peinado, Aguirre & de la Cruz: "A phytosociological survey of the boreal forest (Vaccinio-Piceetea) in North America" in Plant Ecology 137: 151-202. 1998. Peinado and his collaborators claim to have used 2,084 North American bibliographic relevés (taken from sixteen papers by different authors) in their multivariate analyses for syntaxonomical purposes. Their 101 published relevés from Western Canada and Alaska were made between 13-26 July 1994 by the Peinado & Alcaraz field work team, but unfortunately they only give precise geographical data for 15 relevés. However, we have tried to interpret and to use the Peinado, Aguirre & Cruz syntaxonomical proposals as much as possible, unless they have mistakenly used the current CPN or when we disagree with their concepts. Nevertheless, we indicate our previous unpublished names within the synonyma (nobis ined.) in case they have not prospered, in accordance with the principle IV of the current CPN (priority).