1. Tools for individual tree analysis
by Andrew Plowright
March 9th, 2016
Photo: Jeremy Koreski

2. Outline Tools for individual tree analysis
Introduction to individual tree analysis
Development of open-source tools
Demonstration of a typical analysis
Where to get it

3. Individual tree detection
Tools for individual tree analysis
Two approaches to LiDAR
Area-based analysis
Individual tree detection

4. Advantages of individual tree analysis
Tools for individual tree analysis
Advantages of individual tree analysis
Measuring trees directly instead of making inferences
Directly measurable metrics:
Tree height
Crown width
Crown volume
Individual tree point clouds

5. Applications for FLNRO
Tools for individual tree analysis
Applications for FLNRO
BC inventory moving away from one size fits all
Individual tree data can be upscaled
Audit existing inventory
Keep up with remote sensing research

6. Creation of the ForestTools library
Tools for individual tree analysis
Creation of the ForestTools library
Open-source library in R
Main functions:
Treetop detection
Crown delineation
Spatial statistics
Examples and documentation

7. Treetop detection Tools for individual tree analysis
Many existing algorithms
Recognize the shape of a
distinct tree
Errors:
Commission
Omission

8. Variable window filter
Tools for individual tree analysis
Variable window filter
Moving window looks for
peaks in the canopy
Dynamic window size adapts
to height of the canopy
Computationally fast
Requires few parameters
Only detects dominant trees

9. Analysis workflow Tools for individual tree analysis
Canopy height model
Dominant treetops

10. Outlining tree crowns Tools for individual tree analysis
Watershed segmentation algorithm
Originally developed to outline drainage basin
Canopy height model
Inverted canopy
height model
Valleys are “filled” until
boundaries are identified

11. Outlining tree crowns Tools for individual tree analysis
Potential issue:
oversegmentation
Controlled using markers
(i.e.: location of treetops)

12. Analysis workflow Tools for individual tree analysis
Canopy height model
Dominant treetops
Tree crowns

13. Spatial statistics Tools for individual tree analysis
Get tree counts (density maps)
Summarize statistics (tree height,
crown diameter, etc.)
Within polygons (i.e.: management units)
Within a grid

14. Tools for individual tree analysis
Dominant treetops
Tree crowns
Tree count
Mean crown diameter

15. How to access ForestTools
Tools for individual tree analysis
How to access ForestTools
Install directly from R:
install.packages(“ForestTools”)
Online manual
Guided analysis
Source code is on Github
Alternatives:
Spatial Analyst extension for ArcGIS
Image processing toolbox in MATLAB
FUSION tools for LiDAR

16. Thank you!
Andrew Plowright, M.Sc.
Contact
information
Photo: Jeremy Koreski