> XXXIX-B8, 2012 
  
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
CROWN DELINEATION INFLUENCE ON STANDING VOLUME CALCULATIONS IN 
PROTECTED AREA 
K. Stereñczak*, S. Miscicki, 
Department of Forest Management, Geomatics and Economics, Faculty of Forestry, Warsaw University of Life 
Sciences - SGGW, 159 Nowoursynowska str., PL-02-776 Warszawa, Poland. 
Corresponding author e-mail: Krzysztof.Sterenczak@wl.sggw.pl 
Commission VIII, WG VIII/7 
KEY WORDS: Forestry, LIDAR, Inventory, Crown Delineation, Protected Area 
ABSTRACT: 
The aim of this study was to evaluate the automatically determined parameters of tree crowns, which are then used in two-phase 
inventory method of growing stock. Research was performed in forest stands of different age, located in the Stolowe Mountains 
National Park (south-western Poland) where the dominant species was Norway spruce (Picea abies L.). On the test area 
of approximately 500 hectares, 35 sample plots were measured. On LIDAR-based Crow Height Model (CHM), in the places 
corresponding to the position of 500 n circular ground samples, automatic segmentation was carried out. The extent of the crown 
was associated with the height of the tree. Two variants of the assigning separate crowns in the sample were used: (1) according to 
the centroid position, (2) according to the location of any fragment of the crown inside the sample plot boundary. In each of the 
variants five series of measurements with different relative height of the range 0.65-0.8 (with a gap of 0.05) were carried out. 
Relationship between the volume of living trees measured on the ground and LIDAR parameters (average height of trees and tree 
canopy projection area) automatically measured based on CHM was determined. Multiple correlation coefficient differed depending 
on the location to extract coverage crowns and ranged from 0.687 to 0.788. The variant of counting of all trees with crowns or pieces 
inside the sample appeared to perform better. The relationship between the above-indicated characteristics was stronger after 
elimination of dead trees (about 0.1 for each of cases). This means that for measurements of the growing stock in forests under 
protection, it is necessary to improve the process of automatic segmentation of the crown, by identification and elimination of dead 
trees — usually present at sample plot. 
1. INTRODUCTION surface and based on threshold, below which pixels are 
removed and not concerned as part of the crown. 
1.1 General Instructions 
  
Airborne Laser Scanner (ALS) have been used for environment 
study for almost 20 years now (Baltsavias, 1999a, 1999b). 
Lotof different applications and research was done so far. 
Number of publications about using of ALS passed in the 
thousands per year. It is even impossible to read them all. 
Main forest parameters received with LIDAR data are: tree 
height (Nilsson, 1996; St-onge et al, 2004; Sterefczak and 
Zasada, 2011), volume (Naesset, 2002; Maltamo, 2004; Hollaus 
et al., 2007), biomass (Lefsky et al., 1999; Popescu et al., 2011) 
and many others (Næsset et al., 2004). Analysis can be based on 
à sample plot level or single tree level (Yu et al., 2010). 
Single tree detection methods were studded from very 
beginning. There were a lot of methods described in the 
literature. Two test carried out to compare different methods 
(Kaartinen and Hyyppä, 2008; Vauhkonen et al., 2010) proved 
that single tree methods give the best results for stands for 
Which were developed. If we would like to receive the best 
results, algorithms have to be parameterized additionally 
regarding to specifying stands structure and species 
composition. 
  
  
Crown threshold = 0.7 x Hmax 
1.2 Tree Crown Delineation 
Ai : Tree segment based on threshold 
irborne Laser Scanner (ALS) was used for environment study 
but one from unsowed problem yet is properly crown definition. 
Many of them were already described (Kaartinen and Hyyppä, 
2008). Figure 1 presents difference between crowns segments 
defined based on methods concentrating on slope of the crown 
Tree segment based on crown 
slope definition 
| Vi 
  
  
  
Figure 1. Tree crown delineation philosophy and its influence 
on crown segment size