Why is vegetation sparse near the summit of Mount Fuji?

Vegetation is sparse near the summit of Mount Fuji primarily due to the harsh alpine environmental conditions found at high elevations. Above the forest line, the terrain is largely barren, consisting of volcanic rock and ash.1

The summit experiences a cold, alpine climate with average temperatures that remain low even during the summer months, and the area is typically covered with snow for much of the year. These factors create a challenging environment that limits the growth of plant life.1