How can altitude affect biomes?
Biomes are partially determined by altitude.
Biomes are partially determined by altitude. More specifically, biomes are determined primarily by temperature and precipitation and altitude is going to have effects on both temperature and precipitation.
As altitude increases, temperature decreases. This is going to change the structure and composition of our biome.
For example, in the image below, as we increase in elevation or altitude, we see that there is different vegetation and eventually less and less vegetation.
Precipitation and altitude is a bit more complex. Higher elevations typically receive snow instead of rain because the temperature is lower. Mountains can trap moisture on one side, leading to an increase in precipitation in this area but lower amounts of precipitation on the opposite of the mountain. See the image below for more explanation.
Thus, altitude is going to affect both temperature and precipitation which will affect the composition of biome. However, remember that temperature and precipitation are determined by multiple factors, such as air currents and position on the globe. Altitude is one of these factors.