Durango Report   (33) Bob Leverett
July 3, 2009


Attached is an Excel spreadsheet representing my first crack at assembling the significant tree data gathered on this initial Durango visit. At this point, the spreadsheet includes only minimal information. It doesn't include observations about optimal growing conditions and site potential for the species measured - a primary objective of my visit. My thoughts are still coming together on optimal growing conditions, overall site potential, and individual species potential.

As a general observation, this trip has been successful beyond my wildest expectations as a search for tall trees. Record heights were set for the Rocky Mountain ponderosa pine (162 feet) and Colorado blue spruce (156.5) using sine top-sine bottom mathematics. Height records may also have been set for the Rocky Mountain chain for maximum tree height for any species at the altitude of 10,560 feet (2 miles) or higher and for the altitude of 11,000 feet or higher. The Englemann spruce in the San Juans reaches impressive heights. The 137.0-footer measured at 10,560+ feet in La Plata Canyon could well be a hard record to break, but there is so much territory, that I suspect there are at least a few dozen spruces in the 130 to 140-foot height class growing between 9,800 and maybe 10,800 feet in the San Juans. 

Farther north in the Wyoming, Montana, and Idaho Rockies, altitudes in the 10,500-foot range usually represent above timberline conditions. In northern Wyoming, timberline is right at 10,000 feet and in some exposures as low as 9,500 feet. Trees hug the ground when you have them at all. So, the idea of a 130+ foot tree at those latitudes at two miles above sea level is fanciful to say the least. 


I will put the data into the ENTS official format when I get back to Massachusetts, but I for now, I just want to get the ball rolling.



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