A study of crown development mechanisms using a shoot-based tree model and segmented terrestrial laser scanning data.

Area of Science:

• Plant modeling
• Forestry
• Ecology

Background:

• Functional-structural plant models (FSPMs) simulate tree crown development at the organ scale.
• Validating FSPMs typically uses aggregated data (whole-crown/tree), limiting detailed assessment.
• Terrestrial laser scanning (TLS) offers high-resolution data for detailed FSPM validation.

Purpose of the Study:

• To test different crown development formulations within the LIGNUM FSPM.
• To validate FSPM predictions using segmented TLS data at the internode level.
• To identify optimal model components for simulating Scots pine crown architecture.

Main Methods:

• TLS measurements of Scots pine trees from sapling to mature stages.
• Segmentation of TLS data into internodes, noting needle presence.
• Optimization of LIGNUM model parameters using genetic algorithms and a combined fitness function.

Main Results:

• The Extended Borchert-Honda model demonstrated superior performance for shoot elongation in LIGNUM.
• Local crown density significantly influenced shoot elongation across all tested formulations.
• Modulating lateral bud number based on local crown density proved most effective for density control.

Conclusions:

• Segmented TLS data effectively validate shoot-based FSPMs at a detailed level.
• The study successfully selected and refined model components for Scots pine crown development.
• This approach enhances the accuracy of FSPMs for simulating tree architecture.