Identifiering av konfliktbestånd med hjälp av laserskanning

Abstract: The interest in harvesting wood fuel in conflict stands has grown in recent years as a consequence of the increased demand for biofuel. Conflict stands are young forests that have not been cleaned and have a large number of stems ha-1with a great height and diameter distribution. This means that traditional field measurements in conflict stands are difficult and very time consuming. Therefore, the forestry sector is in need of new, more efficient inventory methods. In this study, the Lidar data from Lantmäteriet’s (the Swedish mapping, cadastral and land registration authorities) new national height model was used in combination with plots from the Swedish national forest inventory from 2009 to create functions for; height, volume, diameter and number of stems. The functions were used to create rasters corresponding to the estimated variables. The basis for the identification of the conflict stands in the rasters was the criteria for: height, volume and diameter. In the study 112 plots was used to estimate the basal area weighted mean height. In the estimation of diameter in breast height, volume and stem numbers 33 sample plots were used after the stratification based on the average height (<12 m). The results show that the function for basal area weighted mean height had an adjusted determination degree (R2-adj) of 92,0 % and a standard deviation (SD) of 1.4 m. Volume and diameter had anR2-adj of 88.2 % and 75,6 %, SD of 11.5 m3sk ha-1 and 15,3 mm. The high accuracy of the estimates indicates that conflict stands can be identified by means of laser scanning. The study also shows that it is difficult to estimate the stem numbers ha-1, the function had an R2-adj of 10.7 % and a SD of 7352 stems ha-1.