The Seasonal Trends in Moisture Content, Ether Extractives, and Energy of Ponderosa Pine and Douglas-fir Needles
For. Serv. Res. Pap. INT-RP-102
USDA Forest Service
The moisture, ether extractive, and energy content of ponderosa pine and Douglas-fir foliage were measured during two fire seasons. The moisture content was highest in the fir foliage at the end of summer when fire severity is generally thought to be highest. Pine foliage extractive content was high throughout the sample period. The energy content of the extracted leaves and extractives varied through the summer. There may be a relationship between the extractives and crown fire potential in these species.
Philpot, Charles W.; Mutch, Robert W. 1971. The seasonal trends in moisture content, ether extractives, and energy of ponderosa pine and Douglas-fir needles. Research Paper INT-RP-102. Ogden, UT: USDA Forest Service, Intermountain Forest and Range Experiment Station. 21 p.