José Delgadillo

Phytosociological, bioclimatic and biogeographical classification of woody climax communities of western North America

. In this study, combining the Braun-Blanquet phytosociological approach with numerical methods (cluster analysis and principal coordinate ordination), woody climax associations of western North America are described, ranging from NW Baja California (Mexico) to Alaska (USA), and including some interior zones of Idaho and Montana (USA), Alberta, British Columbia and the Yukon Territory (Canada). 95 floristic associations are identified, and each is characterized by floristic combination, biogeographical range, and bioclimatic conditions.

A phytosociological and phytogeographical survey of the coastal vegetation of western North America. Part I: plant communities of Baja California, Mexico

Through tabular and average linkage cluster analyses, 737 phytosociological relevés were classified. Based on these relevés, we described and typified the associations, alliances, orders, and classes grouping the coastal plant communities of the Baja California peninsula. Diagnostic tables, classification by average linkage clustering, and climatic, edaphic, and biogeographical data were used to establish floristic affinities among these syntaxa and to interpret their distributions. Syntaxa were characterized by their floristic composition, physiognomy, and biogeographical distribution, along with their positions in halophilous and psammophilous gradients. Thirty-three associations were identified, of which 22 are here described for the first time. Our syntaxonomical proposal includes descriptions of nine new alliances, seven new orders and four new classes: Allenrolfeetea occidentalis, Atriplici julaceae–Frankenietea palmeri, Euphorbio leucophyllae–Sporoboletea virginici and Achyronichio cooperi–Abronietea villosae.

Zonobiomes, zonoecotones and azonal vegetation along the Pacific coast of North America

In this study of the Pacific coast of North America, from Baja California to Alaska, we evaluated the hypothesis that the floristic composition of azonal vegetation determines areas and distribution limits similar to those of the corresponding zonobiomes (ZB), and does so in response to the same macroclimatic changes occurring on the continental scale. To this end, 686 vascular plants of the different habitats found in 279 sites along this coastal strip were recorded. Using an objective classification system (Average Linkage Clustering) and factorial analysis, floristic data acquired in fieldwork were classified into groups, which were in turn related to regional macroclimates. Our main finding was that the azonal coastal vegetation follows a distribution model that is closely linked to the corresponding macroclimate. The four ZB of the northern Pacific coast show a flora and azonal vegetation characteristic to each zonobiome; the latitudinal limits of the azonal vegetation practically coinciding with those already established for the zonal vegetation. The Boreal and Temperate ZB show high percentages of broadly distributed elements. The floristically richest zonobiome in terms of endemic taxa is the Mediterranean zonobiome, whereas the flora of Baja California is characterized by a high number of taxa related to Neotropical flora, especially to those showing links with South America. Data on the geographical distribution and habitats of the 247 most significant coastal species are also provided.

Major plant communities of North America's most arid region: The San Felipe Desert, Baja California, México

Abstract This vegetation study describes the landscape of the San Felipe Desert (Baja California, México) based on the phytosociological analysis of its major plant associations, as determined by the Braun-Blanquet method and supported by cluster analysis. Four geomorphological or phytotopographical units were identified in the landscape of the San Felipe Desert (salt marshes, playas or sandy flats, bajadas or alluvial fans, and malpaíses or badlands), each characterized by its own plant communities. Two communities and eleven associations were identified, four of which are described and typified for the first time: Atriplici linearis-Frankenietum palmeri, Parkinsonio microphyllae-Olneyetum tesotae, Errazurizio megacarpae-Ephedretum trifurcae and Pachycereo schottii-Prosopidetum torreyanae. Ecological, phytogeographical, bioclimatic, syntaxonomical and floristic data are provided for each of these new associations.

Bioclimates and vegetation along the Pacific basin of Northwestern Mexico

We describe relationships between the bioclimates and vegetation of the northwest of Mexico, including the Baja California peninsula and the stretch of the Pacific basin between the states of Sonora and Colima, a transition zone from the most arid deserts of North America to tropical rainforests. Links were inferred from temperature and rainfall data obtained from 453 weather stations that were used to construct climatograms, calculate several climate indices and describe main latitudinal and longitudinal trends, and from sampling the vegetation around these stations. Across this extensive area, spanning some 14° of both latitude and longitude as well as three zonobiomes and two zonoecotones, two macrobioclimates were identified, Mediterranean and Tropical, within which we were able to distinguish six bioclimates. For each of these bioclimates, we find different types of zonal and azonal vegetation, whose floristic composition and physiognomy are described here.

PLANT ASSOCIATIONS OF EL VIZCAÍNO BIOSPHERE RESERVE, BAJA CALIFORNIA SUR, MEXICO

Abstract This vegetation study describes the plant associations of El Vizcaíno Biosphere Reserve (Baja California, Mexico) as determined by the Braun-Blanquet method and supported by cluster analysis. Twenty-two associations were identified, 7 of which are described for the first time (Camissonio crassifoliae-Encelietum ventori, Encelio phenocodontae-Atriplicetum polycarpae, Lycietum brevipedis, Errazurizio benthamii-Pachycormetum veatchianae, Merremio aureae-Lysilometum candidae, Opuntio taponae-Burseretum microphyllae, and Suaedo taxifoliae-Allenrolfeetum occidentalis). Ecological, biogeographical, bioclimatic, and floristic data are provided for each of these new associations.

The coastal salt marshes of California and Baja California

A comparative study of the North American salt marshes between Magdalena Plain (Baja California, 24° N)_and the north of San Francisco (California 38° N) is made in order to establish relationships between floristic and zonal gradients. The sigmatistic-phytosociological method along with Average Linkage Clustering are used to describe the zonation of these salt marshes and to define the optimum zone of several halophilous plants and communities.

A phytosociological survey of the dune forests of the Pacific Northwest

Abstract We report on phytosociological survey of the forests dominated by Pinus contorta var. contorta and/or Picea sitchensis that thrive on the Pacific Northwest, between the Strait of Juan de Fuca in Washington and Cape Mendocino in northwestern California. Through tabular and average linkage cluster analyses, 198 relevés taken at 69 sites were classified. Diagnostic tables, climatic, edaphic, and biogeographical data were used to establish floristic affinities among the seven identified associations and to interpret their distributions in psammophilous and zonal gradients, as well as their syntaxonomic position in the Temperate North American class Tsugetea mertensiano-heterophyllae. Four associations are described here for the first time: Arctostaphylo uva-ursi-Pinetum contortae, Carici obnuptae-Pinetum contortae, Morello californicae-Piceetum sitchensis, and Pseudotsugo menziesii-Pinetum contortae.

A Phytosociological Survey of the Chionophilous Communities of Western North America. Part I: Temperate and Mediterranean Associations

Through tabular and average linkage cluster analyses, 872 phytosociological relevés, including 491 obtained from the literature and 381 of our own relevés obtained in the field, were ordered and classified. Based on these relevés, we then described and typified the associations, alliances, orders, subclasses, and classes defining the chionophilous communities of the boreal, temperate and Mediterranean climates of western North America. Diagnostic tables, ordination, clustering, and climatic, edaphic, and biogeographical data were used to establish floristic affinities among these syntaxa and interpret their distributions. Syntaxa were characterized by their floristic composition, physiognomy and biogeographical distribution, along with their position on the snow gradient. Finally, we ascribed the communities growing in temperate and Mediterranean climates to the new class Hieracio gracilis-Juncetea drummondii, including 3 subclasses, 6 orders, 12 alliances and 34 associations.

A Phytogeographical Classification of the North American Pacific Coast Based on Climate, Vegetation and a Floristic Analysis of Vascular Plants

This study was designed to explore floristic variation along the Pacific coast from Cook Inlet, Alaska, to the southern tip of Baja California, Mexico. Data corresponding to 965 phytosociological releves (including 686 vascular plants) obtained by sampling 279 coastal sites were examined. Using an objective classification system (Average Linkage Clustering), floristic data acquired in fieldwork were related to the macroclimates of the study area. The registered taxa were grouped into phytogeographical elements, giving rise to a phytogeographical classification in which eight floristic provinces were distinguished. Floristic differences among provinces were correlated with palaeoclimatic and palaeogeographical events. The boreal and temperate provinces show high percentages of broadly distributed elements, whose origins can be found in the Boreotropical or Arcto-Tertiary geoflora that dominated the Northern Hemisphere during the Tertiary. The floristically richest provinces are the three that occupy the Mediterranean zone, since these provinces harbour elements of Arcto-Tertiary and Madro-Tertiary geofloras. The flora of tropical Baja California is characterised by a high number of taxa related to Neotropical flora, especially to those showing links with South America.