LCF5771 - Tree Biomechanics

Credit hours

Instructor
José Nivaldo Garcia

Objective
Develop in-depth theoretical and practical studies of the reaction of trees and forests to internal and external forces and stimuli during individual and joint growth. Produce and analyze models of wind-tree and wind-forest interactions, as well as forest management, focusing on the impacts on survival, productivity, lumber yield and the quality of this wood for uses in the timber industry.

Content
1. Wind action on trees: Wind obstruction area (crown and trunk), concentrated and distributed wind forces, bending moment and stresses diagram along the trunk, crown's own weight at different temporary water contents on the surfaces of leaves and branches, crown and tree center of gravity, critical moment of uprooting/snapping;
2. Impacts of forest management: Competition factors, reorientation of the crown and stem, density and persistence of branches, natural and artificial factors of branch suppression, diameter distribution of trees, stem shape, root architecture and interaction with the soil for the aspect of nutrition and anchorage;
3. Isoproperties curves in the stem: Specific mass of wood, compressive strength, flexural strength, modulus of elasticity to flexure, total moisture content of wood, physiological moisture content, saturation moisture content, plasmolysis and turgidity;
4. Stability of the tree: Peripheral stresses and strains, distribution of stresses and strains along the radius and height of the tree, critical rupture point, elastic properties of the tree stem, critical displacements, maintenance and reversal factors of displacements unfavorable to the survival of the tree, defects in sawn timber resulting from growth stresses;
5. Techniques for determining peripheral stresses: Original in the standing tree, residual in the logs, residual in the sawn pieces, redistribution of stresses during breakdown;
6. Sawing techniques: Focus on maximum yield, focus on maximum quality oriented to use;
7. Field/laboratory experiments: Trunk under the action of wind and own weight, trunk deformation test.
8. Balance of energy, C and CO2 on the sustainable interaction of planted forests and wood industries;
9. Standing stock of sawn wood, large residues (slabs, side strands, ends), thin residues (chips, strands, sawdust) and bark in planted forests;
10. Uses of AI (Chat GPT, Gemini, Copilot, Claude, Bardeen, Deep Seek, Gamma, others,) on the preparation of projects, presentations (lectures, classes, speeches), technical reports, academic texts and scientific papers.

Bibliography
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