Look to the forest
Elevation is key to defining a tree’s neighborhood
Many factors contribute to the relative suitability of a growing range for each species of tree. While soil composition, moisture, slope direction, inter-species competition, microclimate, and history of fire each play a role, elevation is the most important factor in defining a tree’s “neighborhood.” As elevation increases, temperatures decrease and moisture levels rise. Trees that require more water and can withstand colder temperatures tend to be found higher on the slopes. Other species that can withstand higher temperatures and drier soils grow at lower elevations.
The graphic below illustrates at which elevation certain trees thrive in Idaho.
(Click here for full image and here for high-res PDF)
Pinyon-Juniper Woodland of Southeastern Idaho