Spatial Pattern of Vascular Plant Diversity in North America North of Mexico and its Floristic Relationship with Eurasia

Abstract This paper reports: (1) patterns of taxonomic richness of vascular plants in North America (north of Mexico), an area accounting for 16.6% of the total world land, in relation to latitudinal and longitudinal gradients; (2) floristic relationships between different latitudinal zones, longitudinal zones, and geographic regions of North America; and (3) floristic relationships between North America and Eurasia at various geographic scales. North America was geographically divided into twelve regions, which were latitudinally grouped into four zones, each with three regions, and longitudinally grouped into three zones, each with four regions. The native vascular flora of North America consists of 162 orders, 280 families, 1904 genera and 15352 species. Along the latitudinal gradient, species richness shows a striking increase with decreasing latitude (e.g. the northernmost latitudinal zone has only 11.7% of the number of species in the southernmost latitudinal zone). However, about 63% of the species of the northernmost latitudinal zone are also present in the southernmost latitudinal zone of North America. Among the three longitudinal zones, the zone on the Pacific coast has 1.48 and 1.64-times as many species as the zones in the interior and on the Atlantic coast, respectively. About 36% of the species in the zone of the Atlantic coast also occur in the Pacific coast zone. However, each of over 40% of the species in North America occupies less than 10% of the total land area of North America. Some 48% of the genera and 6.5% of the species of North America are also native to Eurasia. In general, the number of genera common to North America and Eurasia increased from the north to the south and from the west to the east of North America, whereas the number of species common to the two continents decreased along the same two geographic gradients.

[1]  H. Qian.  Large‐scale biogeographic patterns of vascular plant richness in North America: an analysis at the generic level , 1998 .

[2]  A. Gentry,et al.  Neotropical Floristic Diversity: Phytogeographical Connections Between Central and South America, Pleistocene Climatic Fluctuations, or an Accident of the Andean Orogeny? , 1982 .

[3]  K. Emery,et al.  The Geology of the Atlantic Ocean , 1967 .

[4]  B. Tiffney.  Perspectives on the origin of the floristic similarity between Eastern Asia and Eastern North America , 1985 .

[5]  R. Brummitt,et al.  Vascular plant families and genera , 1992 .

[6]  G. C. Stevens.  The Latitudinal Gradient in Geographical Range: How so Many Species Coexist in the Tropics , 1989, The American Naturalist.

[7]  M. Mckenna.  Cenozoic Paleogeography of North Atlantic Land Bridges , 1983 .

[8]  D. M. Newbery,et al.  M. A. Huston, Biological Diversity: the coexistence of species on changing landscapes . Cambridge University Press. ISBN 0-521-36930-4 (pbk). 681 + xix. pages. £24.95. , 1995, Journal of Tropical Ecology.

[9]  E. Pianka.  Latitudinal Gradients in Species Diversity: A Review of Concepts , 1966, The American Naturalist.

[10]  B. Huntley.  Species-richness in north-temperate zone forests , 1993 .

[11]  The appearance and disappearance of major vegetational assemblages: Long-term vegetational dynamics in eastern North America , 1987 .

[12]  J. A. Wolfe.  Some Aspects of Plant Geography of the Northern Hemisphere During the Late Cretaceous and Tertiary , 1975 .

[13]  David J. Currie,et al.  Large-scale biogeographical patterns of species richness of trees , 1987, Nature.

[14]  L. Struwe,et al.  Vascular Plants of Russia and Adjacent States (The Former USSR). , 1996 .

[15]  D. Boufford,et al.  Eastern Asian-Eastern North American phytogeographical relationships. A history from the time of linnaeus to the Twentieth century , 1983 .

[16]  R. Macarthur.  Mathematical Ecology and Its Place among the Sciences. (Book Reviews: Geographical Ecology. Patterns in the Distribution of Species) , 1974 .

[17]  R. Ricklefs,et al.  Intercontinental Correlation of Geographical Ranges Suggests Stasis in Ecological Traits of Relict Genera of Temperate Perennial Herbs , 1992, The American Naturalist.

[18]  Hui-lin Li.  Floristic relationships between eastern Asia and eastern North America , 1952 .

[19]  H. Wright.  ASPECTS OF THE EARLY POSTGLACIAL FOREST SUCCESSION IN THE GREAT LAKES REGION , 1964 .

[20]  Arthur Cronquist,et al.  Floristic Regions of the World , 1978 .

[21]  A. Hallam.  An Outline Of Phanerozoic Biogeography , 1994 .

[22]  J. A. Wolfe.  Paleogene floras from the Gulf of Alaska region , 1977 .

[23]  R. Thorne.  Major Disjunctions in the Geographic Ranges of Seed Plants , 1972, The Quarterly Review of Biology.

[24]  E. M. Reid,et al.  The London clay flora , 1933 .

[25]  David H. Wright,et al.  Species-energy theory: an extension of species-area theory , 1983 .

[26]  B. Tiffney.  The Eocene North Atlantic land bridge: its importance in Tertiary and modern phytogeography of the northern hemisphere , 1985 .

[27]  A. Takhtajan,et al.  Flowering plants; origin and dispersal , 1970 .

[28]  M. B. Davis,et al.  Pleistocene biogeography of temperate deciduous forests , 1976 .

[29]  A. L. Takhtadzhi︠a︡n,et al.  Dictionary of generic names of seed plants , 1995 .