De decimale schaal voor vegetatiekundige opnamen van permanente kwadraten

The decimal scale for vegetation analyses of permanent plots Formerly for vegetation analysis of permanent plots the author used the modified scale of Braun-Blanquet with smaller intervals than the original scale. For calculations on the basis of coverage (e.g. of difference- and change quotients) the symbols of this scale have to be transformed in values proportional to the real coverage percentages. A transformation in very simple values is not possible; so calculations are time-consuming. It has become clear that for an efficient and exact analysis of permanent plots a scale is needed that fulfills the following demands: 1. The scale should be fine enough to register small changes in vegetation. 2. The symbols (numbers) of the scale should be proportional to the real coverage. The coverage values are then equal to the coverage symbols and transformations are not necessary. 3. Coverage and abundance should be determined separately. It is unlogical to combine such uncomparable characteristics in one quantitative scale. 4. The symbols should be as simple as possible. The decimal scale fulfills all these demands and is applied among others by the Research Institute for Nature Management in the Netherlands. At the meeting of the Working Group for Succession Research on Permanent Plots of the International Society for Plant Geography and Ecology the decision has been made to take up the decimal scale in the research program. For the analysis of small divisions of a permanent plot the coarse scale is used. This scale is directly comparable with the finer decimal scale.