24/06/2026
🌳Light Pollution vs. Tree Biomechanics: The Hidden Impact of ALAN💡
Urban tree stress is not limited to drought or soil compaction. Artificial Light at Night (ALAN) is increasingly recognized as an environmental factor capable of altering tree physiology and long-term structural performance.
Trees rely on photoperiod as a key environmental signal regulating seasonal growth cycles. Changes in day length trigger the transition from active growth to tissue maturation, dormancy preparation, and, in many species, leaf senescence. Artificial night-time lighting can disrupt these processes, altering the timing of both budburst and senescence.
🌸Why does this matter?
- Reduced tissue maturation – Prolonged growth activity may limit tissue development and lignification. Insufficiently lignified tissues exhibit lower stiffness and mechanical strength, making newly formed shoots more prone to deformation under wind loading and reducing overall structural stability.
- Increased environmental stress susceptibility – Incompletely matured tissues remain vulnerable to seasonal temperature extremes. Delayed lignification is associated with higher moisture content and lower tissue density, increasing the likelihood of frost injury and subsequent mechanical weakening.
- Greater pathogen vulnerability – Physiologically stressed or damaged tissues can provide entry points for opportunistic wood-decay fungi. Over time, fungal colonization may compromise critical load-bearing tissues and reduce the structural reliability of branch attachments.
These processes are often invisible during routine visual inspections but may contribute to the gradual development of structural defects and elevated failure risk.
At Adbian, we are interested in these hidden interactions because tree biomechanics begins long before visible symptoms appear.
