A method for determining the altitudes of Tertiary floras

Authors

  • Daniel I. Axelrod University of California, Los Angeles 24, California

DOI:

https://doi.org/10.54991/jop.1965.727

Abstract

Effective temperature (ET) at lowland stations can be used to determine accurately the altitude of ET at stations in upland forests today. The ET of a Tertiary flora near sea level appears to provide a reliable basis for determining the altitude indicated by the ET of a contemporaneous upland flora because there was a more regular vertical distribution to ET zones in the Tertiary. This resulted from climates which were more broadly zoned and less diverse in type; from relief which was lower and which had less influence on the local distribution of temperature; and from temperateness (M) which was high over wide regions.

Since Tertiary climate was characterized by pronounced temperateness (M). the effective temperature (ET) of a Tertiary flora can be determined most accurately if inferences are drawn from analogous modern forests in areas of high temperateness (M 60 +), the regions where forests have persisted with least change since the Tertiary (i.e., Szechuan Yunnan, Puebla-Oaxaca, New Zealand, southern Chile, Canary Islands).

The method devised to determine altitudes of stations in modern upland forests is applied to Tertiary floras with the following results. (1) A late Eocene subalpine forest (Bull Run flora) in north-eastern Nevada probably lived near 4,300 feet, contemporaneously with road-leafed evergreen forest near sea level to the west (Montgomery Creek-Moonlight, Comstock floras). (2) Mixed deciduous hardwood forest, inferred by botanists to have occupied the ancestral Great Smoky Mountains during Eocene, probably had its lower margin near 2,500 feet, situated above the warm temperate broad-leafed evergreen forest that dominated the lowlands (Wilcox flora). (3) Middle Miocene floras of the Columbia Plateau and  adjacent region display a gradient from a marginal ecotone to warm temperate broad-leafed evergreen forest (Wishkaw, Grand Coulee, Latah, Whitebird floras) extending up to about 500 feet, to deciduous hardwood forest (Succor Creek, Horseshoe Bend, Upper Cedarville, Mascall floras) from 500-1.500 feet, to montane conifer-deciduous hardwood forest  (Blue Mountains, Trout Creek floras) ranging from 1,500-3,000 feet, to montane conifer forest (Trapper  Creek flora) above 3,000 feet. (4) Analysis of Eocene to early Oligocene floras along the Pacific Coast (Lat. 40-65°) reveals a vertical zonation of forests and climates, with the cooler zones rising to higher altitudes at lower latitudes.

The data support the principles that (1) altitudinal zonation of Tertiary climate exerted a primary control on the distribution and composition of forests much as it does today, that (2) a rise in altitude during the Tertiary corresponds to time transgression because floras of younger aspect lived in the cooler uplands, and that (3) owing to altitudinal zonation of climate, analysis of the secular trend of Tertiary climate should be based on sequences of floras in local areas at or close to sea level, and not on fossil floras in widely separated regions for they will display pseudoclimatic fluctuations since they occur in different climate zone.

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References

Axelrod DI 1950. The Anaverde flora of southern California. Publ. Carneg. Instn., 590: 119-158.

Axelrod DI 1957. Late Tertiary floras and the Sierra Nevadan uplift. Bull. geol. Soc. Amer., 68: 19-45.

Axelrod DI 1958. Evolution of the Madro-Tertiary Geoflora. Bot. Rev., 24: 433-509.

Axelrod DI 1960. The evolution of flowering plants, in Evolution after Darwin, 1: 227-305, Univ. Chicago Press.

Axelrod DI 1964. The Miocene Trapper Creek flora of southern Idaho. Univ. Calif. Publ. Geol. Sci., 51: 1-160.

Axelrod DI 1965. The Eocene Copper Basin flora of northeastern Nevada. Ibid., 59.

Bailey HP 1960. A method of determining the warmth and temperateness of climate. Geogr. Ann. Stock., 42: 1-16.

Bailey HP 1964. Toward a unified concept of the temperate climate. Geogr. Rev., 54: 516-545.

Berry EW 1924. The middle and upper Eocene floras of Southeastern North America. Proc. Pap. U.S. geol. Surv., 92: 1-206.

Berry EW 1930. Revision of the Lower Eocene Wilcox flora of the southeastern States. Ibid., 156: 1-196.

Berry EW 1934. Tertiary flora from the Rio Pichileufu, Argentina. Spec. Pap. Geol. Soc. Amer., 12: 1-149.

Billings WD 1949. The shadscale vegetation zone of Nevada and eastern California in relation to climate and soils. Amer. Midl. nat., 42: 87-109.

Brown RW 1937. Additions to some fossil floras of the western United States. Prof. Pap. U.S. geol. Surv., 186J: 163-186.

Brown RW 1940. New species and changes of name in some American fossil floras. J. Wash. Acad. Sci., 30: 344-356.

Brown RW 1944. Temperate species in the Eocene flora of the southeastern United States. Ibid., 34: 349-351.

Brown RW 1946. Alterations in some fossil and living floras. Ibid., 36: 344-355.

Brown RW 1960. Corkwood in the Eocene flora of the Southeastern United States. J. Paleont., 34: 429-432.

Cain SA 1943. The Tertiary character of the cove hardwood forests of the Great Smoky Mountains National Park. Bull. Torrey bot. Cl., 70: 213-235.

Chaney RW 1936. The succession and distribution of Cenozoic floras around the northern Pacific basin. in Essays in Geobotany in honor of William A. Setchell. 1936: 55-85. T. H. Goodspeed, ed. Univ. Calif. Press.

Chaney RW 1940. Tertiary forests and continental history. Bull. geol. Soc. Amer., 51: 469-488.

Chaney RW 1959. Miocene floras of the Columbia Plateau. I. Compsition and Interpretation. Publ. Carneg. Instn., 617: 1-134.

Chaney RW & Hu HH 1940. A Miocene flora from Shantung Province, China. II. Physical conditions and correlation. Ibid., 507: 85-147.

Cheng WC 1939. Le forets du Se-tchouan et du Si-kang Oriental. Trav. Lab. For. Toulouse., 5, 1 (2): 1-220.

Chu Kwei-ling & Cooper WS 1950. An ecological reconnaissance in the native home of Metasequoia glyptostroboides. Ecology, 31: 260-278.

Clausen J 1963. Tree lines and germ plasm – a study in evolutionary limitations. Proc. nat. Acad. Sci. Wash., 50: 860-868.

Depape G 1928. Les mondes des plantes a l’apparition de l’Homme en Europe occidentale. Ann. Soc. Sci. Brux., Ser. B. 48 (2): 39-101.

Fernald ML 1931. Specific segregations and identities in some floras of eastern North America and the Old World. Rhodora, 33: 25-63.

Gray J 1960. Temperate pollen genera in the Eocene (Claiborne) flora, Alabama, Science, 132: 808-810.

Hare Fredrick K 1961. The restless atmosphere. Hutchinson Univ. Library. London.

Hibbard CW 1960. An interpretation of Pliocene and Pleistocene climate in North America. Mich. Acad. Sci., 62nd Ann. Rept.: 5-30.

Hopkins DM 1959. Some characteristics of the climate in forest and taiga regions in Alaska. Arctic, 12: 215-220.

Jones EL 1961. Environmental significance of palynomorphs from lower Eocene sediments of Arkansas. Science, 134: 1366.

Leopold AS 1950. Vegetation zones of Mexico. Ecology, 31: 507-518.

MacGinitie HD 1941. A middle Eocene flora from the central Sierra Nevada. Publ. Carneg. Instn., 534: 1-178.

MacGinitie HD 1953. Fossil Plants of the Florissant beds, Colorado. Ibid., 559: 1-188.

MacGinitie HD 1962. The Kilgore flora: a late Miocene flora from northern Nebraska. Univ. Calif. Publ. Geol. Sci., 35: 67-158.

Miranda F & Sharp AJ 1950. Characteristics of the vegetation in certain temperate regions of eastern Mexico. Ecology, 31: 313-333.

Nichol AA 1937. The natural vegetation of Arizona. Univ. Ariz. Tech. Bull., 68: 181-222.

Sharp AJ 1951. The relation between the Eocene Wilcox flora to some modern floras. Evolution, 5: 1-5.

Shreve F 1942. The desert vegetation of North America. Bot. Rev., 8: 195-246.

Takeda H 1913. Vegetation of Japan. New Phytol., 12: 37-59, 1913.

Wang Chi-Wu 1961. The forests of China with a survey of grassland and desert vegetation. Maria Moors Cabot Fdn. Publ. 5: Harvard Univ. Bot. Mus.

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Published

1965-12-31

How to Cite

Axelrod, D. I. (1965). A method for determining the altitudes of Tertiary floras. Journal of Palaeosciences, 14((1-3), 144–171. https://doi.org/10.54991/jop.1965.727

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Research Articles