The Use of Terrestrial Laser Scanners for 3-Dimensional Modelling and Quantification of the effects of Competition and Phenology on Plant Structure with Fractal Analysis and Quantitative Structural Modelling Tools

  • Author / Creator
    Alencastro, Felipe
  • Terrestrial laser scanners (TLS) are active remote sensing sensors that use light to measure distances between the sensor and objects generating a three-dimensional dataset. This technology has been used in a diverse range of ecological studies measuring plant and vegetation properties. In the present dissertation, I used three-dimensional modelling algorithms on TLS derived point-clouds to assess plant structural parameters, plant competition, and the effects of plant phenological processes on tree structure.
    Chapter 2 uses the Quantitative structure Model (QSM) to assess lianas and host-trees structural metrics in three different lianas infestation scenarios. The findings reveal that liana infestation impacts hosting trees differently. Lifeform structural metrics showed that lianas wood elements can reach much longer lengths than the elements of the host trees indicating a better space distribution. Also, the total wood volume proportion presented by each lifeform varies with the tree size and the level of liana infestation. In the end, two QSM derived metrics were proposed to evaluate liana infestation on trees of different sizes and ecosystems.
    In chapter 3, fractal analysis was used to identify structural differences between trees living in forested and open-field environments. This study showed that the competition against neighboring plants in forested areas affects tree development and space occupancy. Trees living in open-field conditions occupy the space more efficiently and present more symmetric architecture than trees living in the forest, indicating less environmental stress.
    The presence of leaves has a great impact on plant three-dimensional modelling, space occupancy, and tree architecture. In chapter 4, fractal analysis was used to explore the effect of the change of leave coverage on temperate broad-leaf tree species during the winter and spring seasons on tree architecture. The findings showed that trees occupy the space more efficiently during the leafed season. Last, Chapter 5 presents the summary of this thesis findings and provides directions for future research on three-dimensional modelling of plants using TLS point-clouds.

  • Subjects / Keywords
  • Graduation date
    Spring 2024
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.