Influence of precipitation and temperature on ring, annual branch increment, and needle growth of white fir [Abies concolor] and Douglas-fir [Pseudotsuga menziesii] in central Utah

• Published in: The Great Basin naturalist Vol. 39; no. 3; pp. 219 - 225
• Main Authors: Shane, J.D, Harper, K.T
• Format: Journal Article
• Language: English
• Published: Brigham Young University 30-09-1979
• Subjects: Branches; Conifers; Correlation coefficients; Dendroclimatology; Growth rings; Plant growth; Precipitation; Sea level; Topographical elevation; Tree growth
• ISSN: 0017-3614

The study evaluates growth variations in mixed stands of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and White Fir (Abies concolor Hoopes) from the Bighorn Ranch in northern Sanpete County, Utah. The study area lies 26 km southwest of Thistle, Utah. Tree-ring width, annual branch growth and needle length for the period 1970-1976 were obtained from Douglas-Fir and White Fir individuals distributed along an altitidinal and moisture gradient. Elevation ranged from 2257 m to 2500 m above sea level. Temperature and precipitation are shown to exert a significant influence on needle and annual branch growth and width of the annual rings. It was found that multiple correlation coefficients were always larger than the simple correlation coefficients. This suggests that the trees are responding to both temperature and precipitation. Annual branch growth is shown to be positively correlated with ring width and needle length. The influence of precipitation on growth is synchronized with 1 October-1 June precipitation. Best growth occurs in cool, moist years and at lower elevations.