Floristic analysis of the southwestern United States

Journal Article · Fri Jan 31 00:00:00 EST 1986 · Great Basin Nat.; (United States)

OSTI ID:7067068

McLaughlin, S P

A study was made of the distributions of native, terrestrial, vascular plants occurring in 50 local floras from throughout the Basin and Range and Colorado Plateau physiographic provinces of the southwestern US. The objectives of the study were to objectively define and describe the floristic elements - assemblages of species with roughly coincident geographic distribution - occurring in the southwestern US and to determine what such assemblages reveal about the floristic history of the region. Factor analysis was used to identify seven floristic elements for the region: Great Basin element, a Mojavean element, a Colorado Plateau element, a Chihuahuan element, an Apachian element, and a Mogollon element. This factor analysis solution was shown to satisfy criteria of interpretability and consistency. The Mojavean, Colorado Plateau, and Apachian elements are believed to be autochthonous. The other four elements show high overlap in species composition with one or more adjacent regions. Each floristic element is mapped to show its geographic form and distribution. Analysis of the maps shows how the existence of objectively defined floristic elements is not contradictory to either the individualistic view of the distribution of a species or local continuity of vegetation and flora. The rarity of the majority of species and the clear association of floristic elements with rather narrowly circumscribed Holocene environments suggest that many Southwestern species have migrated little and are of rather recent, probably post-glacial origin. Geographic principles derived from the distribution patterns of relatively few, widespread, dominant, usually woody species may not be applicable to entire, regional floras. 78 references, 11 figures, 7 tables.

• Research Organization: Univ. of Arizona, Tucson
• OSTI ID: 7067068
• Journal Information: Great Basin Nat.; (United States), Vol. 46:1
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
PLANTS
POPULATION DYNAMICS
SPECIES DIVERSITY
ARIZONA
CALIFORNIA
COLORADO
ENVIRONMENT
EXPERIMENTAL DATA
GREAT BASIN
NEVADA
NEW MEXICO
SPATIAL DISTRIBUTION
SURVEYS
UTAH
DATA
DISTRIBUTION
FEDERAL REGION IX
FEDERAL REGION VI
FEDERAL REGION VIII
INFORMATION
NORTH AMERICA
NUMERICAL DATA
USA
510100* - Environment
Terrestrial- Basic Studies- (-1989)