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Vegetatio

, Volume 29, Issue 3, pp 169–178 | Cite as

Vegetation — Site relationships in the Harvard forest

  • B. H. Walker
Article

Summary

Forty-four sites in the Harvard Forest were assessed with respect to overall physiognomy of the vegetation, coverabundance estimates of the woody species and several environmental variables. The data were subjected to cluster analysis and ordination. In the latter, principal component analysis produced more acceptable and clear-cut results than a Bray-Curtis ordination. The major gradient of vegetational variation is due to disturbance, followed by a moisture gradient and what appears to be a soil texture and soil depth gradient. The high proportion of variance which is not associated with common trends in the vegetation suggests that random variation is an important factor in the composition of the forest. The data obtained from the rapid estimates of physiognomy and species composition, and the methods used for analysing them, are considered to be satisfactory. The success of the approach lies in how well the number of sites used represents the study area as a whole.

Keywords

Floristic and physiognomic data Forest ecology Multivariate analysis Ranking methods 

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References

  1. Austin, M. P. & P. Greig-Smith. 1968. The application of quantitative methods to vegetation survey. I. Some methodological problems from rain forest. J. Ecol. 56: 827–844.Google Scholar
  2. Austin, M. P. & I. Noy-Meir. 1971. The problem of non-linearity in ordination: experiments with two-gradient models. J. Ecol. 59: 763–773.Google Scholar
  3. Gauch, H. G. & R. H. Whittaker. 1972. Comparison of ordination techniques. Ecology 53: 568–575.Google Scholar
  4. Maarel, E. van der 1969. On the use of ordination models in phytosociology. Vegetatio 19: 21–46.Google Scholar
  5. Moore, J. J., S. J. P. Fitzsimons, E. Lambe & J. White. 1970. A comparison and evaluation of some phytosociological techniques. Vegetatio 20: 1–20.Google Scholar
  6. Raup, H. M. 1964. Some problems in ecological theory and their relation to conservation. J. Ecol. 52 (Suppl.): 19–28.Google Scholar
  7. Stout, B. B. 1952. Species distribution and soils in the Harvard Forest. Harvard Forest Bulletin No. 24.Google Scholar
  8. Swan, J. M. A. 1970. An examination of some ordination problems by use of simulated vegetational data. Ecology 51: 89–102.Google Scholar
  9. Whittaker, R. H. & H. G. Gauch. 1973. Evaluation of ordination techniques. p. 289–321. In: Whittaker, R. H. (ed.) Handbook of vegetation science, Part V. Ordination and classification of communities. Dr. W. Junk, Publ., The Hague.Google Scholar
  10. Swan, J. M. A., R. L. Dix & C. F. Wehrhahn. 1969. An ordination technique based on the best possible stand-defined axes and its application to vegetational analysis. Ecology 50: 206–212.Google Scholar
  11. Walker, B. H. & C. F. Wehrhahn. 1971. Relationships between derived vegetation gradients and measured environmental variables in Saskatchewan wetlands. Ecology 52: 85–95.Google Scholar
  12. Walker, B. H. 1974. Some problems arising from the preliminary manipulation of plant ecological data for subsequent numerical analysis. J. S. Afr. Bot. 40: 1–13.Google Scholar

Copyright information

© Dr. W. Junk b.v. - Publishers 1975

Authors and Affiliations

  • B. H. Walker
    • 1
  1. 1.Division of Biological SciencesUniversity of RhodesiaSalisburyRhodesia

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