Michael R. Starr

Erään monimuuttujamenetelmän käyttämisestä suotyyppien välisten suhteiden tutkimisessa

Starr M. R. Erään monimuuttujamenetelmän käyttämisestä suotyyppien välisten suhteiden tutkimisessa.

Tiivistelmä

Non-metric multidimensional scaling (MDS) is used to produce a two-dimensional sample ordination of a set of peatland site type community data. The MDS ordination is assessed by comparing it to Heikurainen's and Pakarinen's informal two-dimensional ordination of peatland site types. The MDS ordination produces clusters of quadrats which correspond to the five site types sampled. The result with species presence-absence data is similar to that with species percentage cover data although the clusters are more distinctive with presence-absence data. The relationship of the five sampled site types to trophy and wetness gradients as indicated by Heikurainen and Pakarinen could only be approached by fitting curved, overlapping gradients in the MDS ordination. The reason for the curvature of the environmental gratients is considered to be largely the result of the bias towards nutrient poor and dry conditions represented by the site types sampled. The effect of drainage upon ecological conditions in two of the site types sample is briefly discussed.

Vastaanotettu 31.10.2017 Julkaistu 1.1.1984

Katselukerrat 1113

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