Epsilon Archive for Student Projects

Abstract

Modern forest owners are very familiar with forest management and forest economics. Therefore they have high demands for quality in forest operations. Guarantee of quality in the shape of self-checking activities is an important tool to guarantee a well managed forestry operation. To meet the forest owners’ demands on guarantee of quality and the entrepreneurs wish of an easy method for self-checking, the forest owners association, Södra skogsägarna, has developed a new method for thinning inventory.
The purpose of this study is to evaluate the method that is used for self-checking and to find ways to develop and improve of the method.
The data has been collected by inventory in a number of stands with circle-area survey and with strip survey, which is method that is used for self-checking.
The results show that the strip survey does not diverge more than ±10 % in measuring values of basal area, number of stems, roads share, thinning quotient, outtake of basal area and total volume compared to circle-area survey. In volumes per tree-species the difference is significant. Single stands measuring values can vary a lot. In general the method has got a tendency to overrate high measuring values and to underrate low measuring values.
One of the problems with the strip survey is that it cannot capture the natural variations in a stand. This has got its origin in the limited area that is inventoried and that the inventory is made with just one sample plot. The variations are difficult to capture in a whole stand since they are geographically spread out. Inside the inventoried area it is possible to capture the stem distribution and by that get a value that will describe the stand distribution.
The recommended improvements are that just the total volume gets presented in the account and that the inventory of damages is removed from the method. It is also recommended that the strip survey direction should be dependent of the stands area.
It recommended that the entrepreneurs and forest managers get continuous education and constant follow-up so that the method feels comfortable.
It is very important that the results of the self-checkings get a distinct use and that the entrepreneurs and forest managers take part of the result of their daily quality work.