What is a timberline?

Some mountains have trees growing clear to their tops, but on many high mountains there is a line above which trees stop growing.

The place where trees stop growing is called the “timberline”.  Trees don’t grow above it because they cannot survive the freezing temperatures there.

Above the timberline the mountainside is likely to be a cold desert with only patches of lichens, moss and stunted vegetation twisted by the strong winds of the mountain tops.

Here, the bitter cold keeps the water in the ground frozen for much of the year, and bigger plants cannot get enough water.

Just  below the timberline the tall pine forests stand alone.  There tough, needle-shaped leaves can withstand the icy winds and harsh living conditions on the cold mountainside better than the broad-leaf trees can.

The timberline is much higher on some mountains than on others.  It depends on the climate, and latitude.