Estimating tree size distributions and timber assortment recoveries for wood procurement planning using airborne laser scanning
Peuhkurinen J. (2011). Estimating tree size distributions and timber assortment recoveries for wood procurement planning using airborne laser scanning. https://doi.org/10.14214/df.126
Abstract
ALS-based inventory methods are replacing traditional field inventories in the production of stand-level data for operative and management purposes. Despite the advances made in the species-specific inventories of mean stand variables, ALS has not succeeded in providing accurate growing stock descriptions for operative wood procurement planning, for example, containing information on tree quality, tree size distribution and the distribution of the logs in timber assortment classes. The aim of this thesis is to evaluate and develop ALS-based methods of predicting tree size distributions and timber assortment recoveries. The experimental work was carried out in two inventory areas both located in Eastern Finland: Matalansalo, representing a typical managed boreal forest, and Koli, located in the Koli National Park. The remote sensing material for Matalansalo consisted of low and high pulse density ALS data and digital aerial images, and the material for the Koli area of high density ALS data only. The investigated estimation methods were individual tree delineation (ITD) and areabased statistical approach (ABSA), which were also compared within the same test areas. The performance of ITD in estimating tree size distributions and theoretical timber assortment classes was found to be better than that of the compared methods (ABSA and field assessments) in cases where individual trees could be discerned from the ALS data. In the aggregate, the different ALS methods were comparable when estimating volume and basal area, but ITD tended to produce a bias in saw log volumes and tree size distributions because of the errors in tree delineation. It was stated that the errors in both of the methods,ITD and ABSA, were in correlation with the tree size distribution and the spatial distribution of tree locations. The estimation of theoretical and actual saw log recoveries was investigated using two area-based methods. The results of the linear regression indicated that it is possible to obtain accurate saw log recoveries using an area-based ALS method. The second method employed k-nearest neighbour imputation and harvester-collected stem data bank. The method produced species-specific saw log recoveries although the estimation accuracies were not as good as expected. The method could be improved by using a more representative stem data bank and additional search variables. The harvester data from final cuttings was found to be suitable material for validating the diameter distributions and theoretical saw log recoveries estimated from ALS data, although there were challenges considering the delineation of the stand, tree positioning accuracy and different bucking preferences. The use of stem data bank as an auxiliary data source was more challenging because the stem data bank did not include reliable information on stand delineation and bucking parameters.
Keywords
forest inventory;
remote sensing;
nearest neighbor;
linear regression
Published 15 August 2011
Views 4034
Available at https://doi.org/10.14214/df.126 | Download PDF
Original articles
Peuhkurinen, J., Maltamo, M., Malinen, M. Pitkänen, J. & Packalén. P. 2007. Preharvest measurement of marked stands using airborne laser scanning. Forest Science. 53(6): 653–661.
http://www.ingentaconnect.com/content/saf/fs/2007/00000053/00000006/art00005
Korhonen, L., Peuhkurinen, J., Malinen, J., Suvanto, A., Maltamo, M., Packalén. P. & Kangas, J. 2008. The use of airborne laser scanning to estimate sawlog volumes. Forestry81(4): 499-510.
https://doi.org/10.1093/forestry/cpn018
Peuhkurinen, J., Maltamo, M. & Malinen, J. 2008. Estimating species-specific diameter distributions and saw log recoveries of boreal forests from airborne laser scanning data and aerial photographs: a distribution-based approach. Silva Fennica 42(4): 625–641.
https://doi.org/10.14214/sf.237
Peuhkurinen, J., Mehtätalo, L. & Maltamo, M. 2011. Comparing individual tree detection and the area-based statistical approach for the retrieval of forest standcharacteristics using airborne laser scanning in Scots pine stands. Canadian Journal of
Forest Research 41(3): 583-598.