The Relation of Growth Ring Widths in American Beech and White Oak to Variations in Climate

Abstract

An analysis is made of beech from Ohio and white oak from Illinois using a stepwise multiple regression technique to evaluate ring growth and climatic relationships. Ring widths for beech are directly related to the moisture supply during August and to temperatures for May-July of the preceding year. They are equally related to moisture during June-August of the current year and somewhat dependent upon the precipitation of the previous winter. The earlywood width of white oak is directly related to available moisture during the preceding September and to moisture during the current June, and inversely related in slight degree to the temperature of April. Latewood width of oak is primarily dependent upon the availability of moisture during the current June and July but is somewhat related to the moisture during May of the previous year. Serial correlation is prominent from growth layer to growth layer in both species. The physiological relationships which may produce these results are discussed. Some relationships involving considerable lag in the growth response are possible controls of bud formation and food accumulation, while others involving more immediate response are primarily the effect of moisture stress within the tree.