Montane ecology is the branch of ecology that studies life systems on mountains or other high elevation regions on the Earth. The ecosystems on mountains is strongly affected by climate, which gets colder as elevation increases. Because of this, mountain ecosystems form life zones, which are stratified according to elevation. Dense forests are common at moderate elevations. However, as the elevation increases, the climate becomes harsher, and the plant community transitions to grasslands or tundra.

As elevation increases, the climate becomes cooler and wetter, due to the lower air pressure. Due to the harsher climate, the dominant lifeforms on mountains is different from that of surrounding lowlands. The characteristic flora and fauna in the mountains tend to strongly depend on elevation. This dependency causes life zones to form: bands of similar ecosystems at similar altitude.

One of the typical life zones on mountains is the montane forest: at moderate elevations, the rainfall and temperate climate encourages dense forests to grow. Holdridge defines the climate of montane forest as having a biotemperature of between 6 and 12 °C (43 and 54 °F), where biotemperature is the mean temperature considering temperatures below 0 °C (32 °F) to be 0 °C (32 °F). Above the elevation of the montane forest, the trees thin out in the subalpine zone, become twisted krummholz, and eventually fail to grow. The elevation where trees fail to grow is called the treeline. The biotemperature of the subalpine zone is between 3 and 6 °C (37 and 43 °F).