What is the tree line elevation in Washington state, and does it vary with latitude?
First a word of explanation; the 'tree line' marks the beginning of the 'Alpine Zone', the area where the climate is too harsh to permit tree growth. It varies in Washington state, ranging between 5,000 and 6,000 feet. Factors affecting the 'tree line' include what's called the slope 'aspect' (the direction the slope faces which impacts how much sunlight falls on the slopes and vegetation), moisture and yes...latitude. To give an example of the importance of latitude, the average tree line in Alaska is just 2,000' but in Colorado, it averages between 10,000 and 11,000'.