A picture of growth rings of a tree can be obtained on paper by placing it over a disc of a trunk or stump and rubbing it with a pencil. The ‘shadows’, while not yielding the complex data obtainable from the actual wood, do show the proportion of the growth rings composed of spring wood and the denser summer wood. It is possible to collect large amount of data by using an unexperienced staff cheaply and quickly, and the samples may be mailed at little expense. The method may be used to study the previous cuttings of a stand from stumps. The shadowing of tree rings is possible to do even from rather decayed stumps.
The article includes a Finnish abstract.
Especially in experimantal ecological research it is used small sample plots that are inventoried consequently. The paper describes a method for establishing small sample plots, developed by the writer in 1956. In the method, the central point of the sample plot is marked with an iron skewer, and the marking of the area to be inventoried was accomplished with a circular frame that is movable. The frame was fitted to the skewer with an aperture that indicated the central point. The area of the frame was relatively small, 0,25 m2. The sample plots were arbitarily placed at intervals from one another.
The PDF includes a summary in Finnish.