Why trees are not common in the alpine zone

The fact is that alpine meadows lie at an altitude of up to 3 km. It is very cold there and the air is very thin. The flora is characterized by low-growing vegetation. The leaves of the plants growing there are small and tough, the roots are strong and deep, to make it easier to endure frost. Alpine meadows are dominated by evergreen and seasoned perennials. Due to strong winds, powerful insolation, significant illumination and sudden temperature changes, tall trees cannot take root there and remain at the level of the subalpine belt.