I thought that these tree-distribution patterns might be related to precipitation and so I went to the weather station records and recorded long-term precipitation data for a number of locations in the central Wasatch Mountains (recorded below). You see, I thought that precipitation amount might possibly be related to elevation. I even found a few climate diagrams for key cities at the base of the mountains as well within the Wasatch Mountain Range. It took me a while, but now I realize that there are clear distinct precipitation patterns with elevation. Hmm, I'll bet that these data even explain why the snow is generally deeper at the Alta Ski Resort (front side) than at the Park City Ski Resort (back side).
East or west side of central Wasatch Mountains
Mean annual precipitation (mm)
Salt Lake City
Park City Summit
Red Butte #2
Red Butte #4
Red Bute #6
Given this, I went back to my lecture notes and found a possible explanation for plant distributions based on potential evapotranspiration. Wow, who would ever have thought that there was a relationship between these water and plant distribution parameters. This approach even seems to explain why the tree canopy has its lowest leaf areas at the lower distribution limit. Interesting, very interesting. In fact, this is almost as exciting as going out this weekend to pick elderberries in order to make my Thanksgiving elderberry pie.