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Report, 2003

Critical length sampling for estimating the volume of coarse woody debris

Ståhl, Göran


In this paper, critical length sampling for estimating the volume of downed coarse woody debris is presented. With critical length sampling, the volume of downed dead wood in a stand can be determined by summing the critical lengths of trees included in the sample. The critical length of a downed tree is the length of the &em section, which from a certain sample point is coarse enough to be counted when a relascope is used. In comparison to traditional relascope sampling, where the instrument is held vertically during the mea­ surements, the instrument is operated horizontally. By combining critical length sampling with critical height sampling-a method previously described for estimating the volume of standing trees -the total volume of dead wood can be estimated in a stand. It is proposed that the main area of use of the combined method would be in connection with rapid in-place inventories where a quick estimate of the volume of dead wood is needed. In this context, the combined critical height-critical length method provides a relatively simple means for obtaining such an estimate. In this report, the theoretical background is described and a short description of the use of the method in the field is presented. The report should be considered as a simple first description of the method, which will later on be complemented with a more compre­ hensive proof, efficiency comparisons with other methods, and experiences from field tests.


deadwood; sampling; statistical methods; forest inventories

Published in

Arbetsrapport / Sveriges lantbruksuniversitet, Institutionen för skoglig resurshushållning
Publisher: Institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet