Advertisement

Theoretical and Applied Genetics

, Volume 47, Issue 1, pp 27–34 | Cite as

Variation and selection in western montane species II. Variation within and between populations of white firon an elevational transect

  • J. L. Hamrick
Article

Summary

Four populations of Abies concolor, white fir, were sampled along an elevational transect in the central Sierra Nevada mountains of California. This paper is based on data taken during the first two years' growth in a nearby nursery at Placerville, California. Ten of the thirteen growth, size, and needle morphological characteristics had significant differences between population samples, while eleven characteristics had significant differences between open-pollinated families within the population samples. High-elevation population samples were smaller in size and needle measurements, had fewer adaxial stomatal rows, blunter needle tips, and a shorter growing season. Most characteristic values were distributed ecotypically between the two lower- and the two higher-elevation population samples. Analyses of the patterns of variation demonstrated that characteristics of size and growth showed greater differentiation between population samples than did characteristics of needle morphology. It was concluded that the differences between characteristic patterns were caused by the more intense selection pressures acting upon the characteristics of size and growth. No consistent differences were discovered between these population samples in terms of total amounts of within-population genetic variation. The failure to find differences in intra-population variation may be due to the high rates of migration that probably exist within such a transect, and the fact that none of the populations included in this study are truly marginal. There were large differences between characteristics for total within-population variation; a positive but non-significant correlation was found between high coefficients of variation and those characteristics with much differentiation between populations. It is postulated that the maintenance of this intra-population variation was caused by microhabitat adaptations and gene flow. Evidence for increased genetic variation within open-pollinated families due to pollen immigration is presented, and its implications discussed.

Keywords

Population Sample Sierra Nevada Mountain Blunt Needle Elevational Transect Firon 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature

  1. Allard, R.W.; Babbel, G.R.; Clegg, M.T.; Kahler, A.L.: Evidence for coadaptation in Avena barbata. Proc. Nat. Acad. Sci. 69, 3043–3048 (1972)Google Scholar
  2. Barber, H.N.; Jackson, W.D.: Natural selection in action in Eucalyptus. Nature 179, 1267–1269 (1957)Google Scholar
  3. Carson, H.L.: The genetic characteristics of marginal populations of Drosophila. Cold Spring Harbor Symp. Quant. Biol. 20, 276–287 (1955)Google Scholar
  4. Carson, H.L.: Genetic conditions that promote or retard the formation of species. Cold Spring Harbor Symp. Quant. Biol. 24, 87–103 (1959)Google Scholar
  5. Clausen, J.; Keck, D.D.; Hiesey, W.M.: Experimental studies on the nature of species. III. Environmental responses of climatic races of Achillea. Carnegie Institution of Washington Publication 581, 129 p. (1948)Google Scholar
  6. Conkle, M.T.; Libby, W.J.; Hamrick, J.L.: Winter injury among white fir seedlings. Pacific Southwest Research Note 138, 6 p. (1966)Google Scholar
  7. Critchfield, W.B.; Allenbaugh, G.L.: The distribution of Pinaceae in and near northern Nevada. Madrõno 20, 12–25 (1969)Google Scholar
  8. Ehrlich, P.R.; Raven, P.H.: Differentiation of populations. Science 165, 1228–1232 (1969)Google Scholar
  9. Fowells, H.A.: Silvics of forest trees of the United States. Agriculture Handbook No. 271. U.S. Department of Agriculture, Forest Service, 762 p. (1965)Google Scholar
  10. Griffin, J.R.; Critchfield, W.B.: The distribution of forest trees in California. ISDA Forest Service Research Paper PSW 82, 114 p. (1972)Google Scholar
  11. Hamrick, J.L.: Geographic variation in white fir. M.S. Thesis, University of California, Berkeley, 143 p. (1966)Google Scholar
  12. Hamrick, J.L.; Allard, R.W.: Microgeographical variation in allozyme frequencies in Avena barbata. Proc. Nat. Acad. Sci. 69, 2100–2104 (1972)Google Scholar
  13. Hamrick, J.L.; Libby, W.J.: Variation and selection in western montane species. I. White fir. Silvae Genetica 21, 29–35 (1972)Google Scholar
  14. Koski, V.: A study of pollen dispersal as a mechanism of gene flow in conifers. Commun. Inst. Forest. Fenn. 70(4), 78 p. (1970)Google Scholar
  15. Silen, R.R.: Pollen dispersal considerations for Douglas fir. J. Forestry 60, 790–795 (1962)Google Scholar
  16. Soulé, M.: The epistasis cycle: A theory of marginal populations. Annual Rev. Ecology a. Systematics 4, 165–187 (1973)Google Scholar
  17. Tigerstedt, P.M.A.: Studies on isozyme variation in marginal and central populations of Picea abies. Hereditas 75, 47–60 (1973)Google Scholar

Copyright information

© Springer Verlag 1976

Authors and Affiliations

  • J. L. Hamrick
    • 1
  1. 1.Department of BotanyUniversity of KansasLawrenceUSA

Personalised recommendations