Crown shyness, also known as canopy disengagement or canopy shyness, is an interesting phenomenon observed in certain tree species. Instead of touching each other, the crowns of these trees form gaps, creating a channel-like canopy. Crown shyness is most commonly seen among trees of the same species, but it can also occur between different species. The reasons for this behavior are still being studied, but one hypothesis suggests that it may help prevent the spread of leaf-eating insects. The physiological mechanisms behind crown shyness are not yet fully understood, but there are several theories that suggest wind abrasion and light sensing by adjacent plants play a role. Overall, crown shyness is a unique and intriguing aspect of tree behavior.
https://en.wikipedia.org/wiki/Crown_shyness