In August 1910, men trained in turpentine collecting arrived in Flagstaff at the behest of US Forest Service (USFS) engineer Harold S. Betts. The men were from the southeastern US which had been long considered America鈥檚 turpentine capitol. Betts wanted to test the ponderosa pines of northern Arizona for turpentine-producing capabilities and the Coconino National Forest managers hoped this endeavor might create local jobs. As the men adjusted to the high elevation and colder temperatures, they learned interesting comparisons between Florida and Arizona turpentine investigations.
They lived in tents at the two-year-old USFS Fort Valley Experimental Forest (FVEF), then called the Coconino Experiment Station, about 10 miles from Flagstaff. The rustic Station campus had few amenities, one being a raised water tower under which showers were taken. Infrequent trips to the village of Flagstaff were by wagons hitched to slow-moving mules via a one-lane-dirt Fort Valley Road. The lone permanent staff member was Station director G.A. Pearson whose assignment was to initiate experiments to understand how the ponderosa pine regenerates. Periodically, additional forestry scientists were onsite to learn silviculture (the study of trees) methods as FVEF was the first USFS forest research facility in the nation.
The newcomers tapped 90 mature ponderosa pines to collect the dripping resin. The outer tree bark was removed from one side near the base and an incision was made to hold an apron, a device that guides the dripping resin into a cup placed below the apron. New notches were made in the trees each week. Cold temperatures caused the trees鈥� gum resin to harden overnight, but after a few hours of morning sun, the resin would drip again. This phenomenon taught the workers to tap a tree on its south-facing side where the sun could reach it.
Numbers from the initial test showed that during a two-month period, the ponderosa pines produced an average of 23 barrels of resin, while the southeastern trees averaged 25 to 30 barrels; promising enough for Betts to plan more extensive tests for the following year, especially since production of turpentine in southeastern trees was declining and demand was increasing.
In the spring of 1911, Betts鈥檚 team returned to Fort Valley and examined four separate forest areas near FVEF. Cups were hung on 600 trees that spanned 28 acres. Both the older, larger yellow pines and younger, smaller blackjack pines were tapped. Every three weeks, resin was collected or 鈥渄ipped鈥� from the cups and poured into buckets; then weighed to determine how much dip was gathered. The results showed that the average flow of resin per cup per week was nearly the same between the Arizona and Florida trees. Local pine鈥檚 drip was comprised of 77.9% resin and 22.1% turpentine, both of which were considered satisfactory for commercial use.
Tests indicated that the ponderosa pine produces about 4/5 the quantity of southeastern U.S. trees when factors such as length of season are the same. The southeastern season can last for 35 weeks while the northern Arizona season can last, at best, 26 weeks because of the temperature changes. The quality of the resin was similar between the two regions and Betts believed the potential existed for a northern Arizona turpentine production program, but the idea was never pursued mostly due to the lack of local skilled workers.
A turpentine program never evolved, but the Fort Valley Experimental Forest has; it celebrates its 117th birthday this year. Pearson and fellow foresters established and conducted studies in all factors that affect a ponderosa pine: disease, lightning, fire, rodents, soil types, weather, wildlife and domestic stock, etc. Records from these valuable studies are housed at the USFS Rocky Mountain Research lab on the NAU campus. 365bet体育在线世界杯鈥檚 scientists may access this information to continue the research as most of the original study plots are still extant. A tree first measured in 1910 can be remeasured today to see its growth and other impacts on its life over the past century.
Having long-term data sets like these is valuable and greatly assists current foresters to understand the impacts of climate change on the forests.