Jim, Tom, Bob, Leslie, et al.

After learning that I had arrived a day late for the Forest Reserve meeting, I consoled myself with a trip back via MTSF and there I reached a measuring milestone! I was successful in measuring the prior year's growth of the Jake Swamp tree using the Macroscope 25. I've been talking about measuring annual candle growth for a long time, but had no way of accurately doing it. That has changed. The Macroscope 25 works marvelously well - even better than I had expected. I had absolutely no problem measuring 8 growth candles atop the Jake Swamp tree's broad crown. 

The distance to the candle targets varied from 66.5 to 69 meters. At the angle I was measuring (about 27 degrees), these linear distances represented a horizontal displacement in the line of sight of about 7.3 feet. It would be even more across the field of view, maybe 9 feet. For the 8 tops, the Macroscope reticle (scale) values varied from 0.3 to 0.5 millimeters. Converting the 8 measurements first to candle length in meters, via a formula, and then converting the resulting metric lengths to English units yielded some interesting results. The two highest candles atop the Jake tree have markedly differing lengths: 10.6" and 17.7". They are very close to one another. They're tips both convert to a full height of 167.3 feet for the Jake Swamp tree. The complete list of candle measurements follows: 

10.6', 17.7', 11.2', 16.9', 17.6', 10.4', 15.5', 10.9'. 

The average is 13.8 inches. However, the average of the two tallest candles is 14.15 inches. Barring crown damage, there is little doubt that the Jake Swamp pine will reach a height of 168 feet this year and continue its billing as New England's tallest tree, unchallenged. With luck, Jake will make 170 feet by the end of 2008, or 2009 at the latest. 

After measuring Jake's prior year candle growth, I then measured 3 candles on the Massasoit tree, a 146.1-foot tall tree climbed this past Oct by Will Blozan and measured via tape drop. The results were 13.8, 11.5, and 9.2 inches. Finally, I measured a weevil-damaged white pine in front of the MTSF Nature Center. The measurements were 14.8 and 14.9 inches for its two very conspicuous tops. 

So, for last year's growth, we have the Jake Swamp pine at an average of 13.8', 11.5' for Massasoit, and 14.8' for the Nature Center tree. The respective ages are Jake Swamp approximately 145 years, Massasoit, 110 years, and the Nature Center tree is about 70 years old. 

Yesterday's results confirm that the reticle-based measurements are ideally suited for determining annual candle growth on white pines. FMTSF and ENTS can now accurately track annual candle growth for the sample of white pines that we will be closely monitoring. And we will be assured of accuracies to the nearest half-inch! We will still take selective photographs, to document what we are measuring, but the Macroscope will be used for the actual measuring. 

Bob Leverett