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Vegetatio

, Volume 117, Issue 2, pp 113–121 | Cite as

A Modified-Whittaker nested vegetation sampling method

  • T. J. Stohlgren
  • M. B. Falkner
  • L. D. Schell
Article

Abstract

A standardized sampling technique for measuring plant diversity is needed to assist in resource inventories and for monitoring long-term trends in vascular plant species richness. The widely used ‘Whittaker plot’ (Shmida 1984) collects species richness data at multiple spatial scales, using 1 m2, 10 m2, and 100 m2 subplots within a 20 m × 50 m (1000 m2) plot, but it has three distinct design flaws involving the shape and placement of subplots. We modified and tested a comparable sampling design (Modified-Whittaker plot) that minimizes the problems encountered in the original Whittaker design, while maintaining many of its attractive attributes. We overlaid the two sampling methods in forest and prairie vegetation types in Larimer County, Colorado, USA (n=13 sites) and Wind Cave National Park, South Dakota, USA (n=19 sites) and showed that the modified design often returned significantly higher (p<0.05) species richness values in the 1 m2, 10 m2, and 100 m2 subplots. For all plots, except seven ecotone plots, there was a significant difference (p<0.001) between the Whittaker plot and the Modified-Whittaker plot when estimating the total number of species in the 1000 m2 plots based on linear regressions of the subplot data: the Whittaker plot method, on average, underestimated plant species richness by 34%. Species-area relationships, using the Modified-Whittaker design, conformed better to published semilog relationships, explaining, on average, 92% of the variation. Using the original Whittaker design, the semilog species-area relationships were not as strong, explaining only 83% of the variation, on average. The Modified-Whittaker plot design may allow for better estimates of mean species cover, analysis of plant diversity patterns at multiple spatial scales, and trend analysis from monitoring a series of strategically-placed, long-term plots.

Key words

Nested sampling techniques Plant species richness Species-area curves Species diversity 

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References

  1. Baker W.L. 1990. Species richness of Colorado riparian vegetation. J. Veg. Sci. 1: 119–124.Google Scholar
  2. Barbour M.G., Burk J.H. & Pitts W.D. 1987. Terrestrial Plant Ecology. Second Edition Benjamin/Cummings Publishing Company, Menlo Park, California.Google Scholar
  3. Bormann F.H. 1953. The statistical efficiency of sample plot size and shape in forest ecology. Ecology 34: 474–487.Google Scholar
  4. Dallmeier F. 1992 (ed.) Long-term Monitoring of Biological Diversity in Tropical Forest Areas: Methods For Establishment and Inventory of Permanent Plots. MAB Digest 11. United Nations Educational, Scientific, and Cultural Organization (UNESCO), Paris, France.Google Scholar
  5. Fortin M., Drapeau P. & Legendre P. 1989. Spatial autocorrelation and sampling design in plant ecology. Vegetatio 83: 209–222.Google Scholar
  6. Heltshe J.F. & Forrester N.E. 1983. Estimating species richness using the jackknife procedure. Biometrics 39: 1–12.Google Scholar
  7. Magurran A.E. 1988. Ecological Diversity and Its Measurement. Princeton University Press, Princeton, New Jersey.Google Scholar
  8. Miller R.I. & Wiegert R.G. 1989. Documenting completeness, species-area relations, and the species-abundance distribution of a regional flora. Ecology 70: 16–22.Google Scholar
  9. Mueller-Dombois D. & Ellenberg H. 1974. Aims and Methods of Vegetation Ecology. John Wiley & Sons, New York.Google Scholar
  10. Nevah Z. & Whittaker R.H. 1979. Structural and floristic diversity of shrublands and woodlands in northern Israel and other Mediterranean areas. Vegetatio 41: 171–190.Google Scholar
  11. Palmer M.W. 1990. The estimation of species richness by extrapolation. Ecology 71: 1195–1198.Google Scholar
  12. Palmer M.W. 1991. Estimating species richness: the second-order jackknife reconsidered. Ecology 72: 1512–1513.Google Scholar
  13. Peters R.L. & Lovejoy T.E. 1992. Global Warming and Biological Diversity. Yale University Press, London.Google Scholar
  14. Pielou E.C. 1977. Mathematical Ecology. pp. 285–290. John Wiley & Sons, New York, NY.Google Scholar
  15. Podani J., Czárán T. & Bartha S. 1993. Pattern, area and diversity: the importance of spatial scale in species assemblages. Abstracta Botanica 17: 37–51.Google Scholar
  16. Rice B. & Westoby M. 1983. Plant species richness at the 0.1 hectare scale in Australian vegetation compared to other continents. Vegetatio 52: 129–140.Google Scholar
  17. Scott J.M., Davis F., Csuti R., Noss R., Butterfield B., Groves C., Anderson H., Caicco S., D'Erchia F., DewardsJr. T.C., Ulliman J. & Wright R.G. 1993. GAP Analysis: a geographic approach to protection of biological diversity. Wildlife Monographs 123: 1–41.Google Scholar
  18. Shafer C.L. 1990. Nature reserves: Island theory and conservation practice. Smithsonian Institute Press, Washington, DC. pp. 189.Google Scholar
  19. Shmida A. 1984. Whittaker's plant diversity sampling method. Israel Journal of Botany 33: 41–46.Google Scholar
  20. Stohlgren T.J. 1994. Planning long-term vegetation studies at landscape scales. pp. 209–241. In: Ecological Time Series. Powell T.M. & Steele J.H. (eds) Chapman & Hall, New York. (In Press).Google Scholar
  21. Stohlgren T.J. & Quinn J.F. 1992. An assessment of biotic inventories in western US national parks. Natural Areas Journal 12: 145–154.Google Scholar
  22. Stohlgren T.J., Quinn J.F., Ruggiero M. & Waggoner G. 1993. Status of biotic inventories in US National Parks. Biological Conservation 71: 97–106.Google Scholar
  23. Soulé M.E. & Kohm K.A. 1989. Research Priorities for Conservation Biology. Island Press. Washington, DC.Google Scholar
  24. Tilman D. & Downing J.A. 1994. Biodiversity and stability in grasslands. Nature 367: 363–365.Google Scholar
  25. Whittaker R.H. 1977. Evolution of species diversity on land communities. Evolutionary Biology 10: 1–67.Google Scholar
  26. Whittaker R.H., Niering W.A. & Crisp M.O. 1979. Structure, pattern, and diversity of a mallee community in New South Wales. Vegetatio 39: 65–76.Google Scholar
  27. Wilson E.O. 1988. Biodiversity. National Academy Press. Washington, DC.Google Scholar
  28. Zar J.H. 1974. Biostatistical analysis. Prentice-Hall. New Jersey.Google Scholar

Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • T. J. Stohlgren
    • 1
  • M. B. Falkner
    • 2
  • L. D. Schell
    • 2
  1. 1.National Biological Service, Natural Resource Ecology LaboratoryColorado State UniversityFort CollinsUSA
  2. 2.Natural Resource Ecology LaboratoryColorado State UniversityFort CollinsUSA

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