Dendroclimatic analysis of Acer saccharum, Fagus grandifolia, and Tsuga canadensis from an old-growth forest, southwestern Quebec

Radial growth of three tree species (eastern hemlock, Tsuga canadensis (L.) Carriere; sugar maple, Acer saccharum Marsh.; and American beech, Fagus grandifolia Ehrh.) from an old-growth forest, in southwestern Quebec was compared using a dendroclimatic approach. The beech and maple tree-ring chronologies were significantly correlated, whereas the hemlock chronology was correlated only to that of beech. Radial growth of all three species was positively correlated with precipitation and negatively correlated with temperatures during the early summer months of the year the annual ring was formed. This suggests early summer water balance limits the growth of these species on this site. Radial growth of the three species was also negatively correlated with temperatures during the late summer months of the year prior to ring formation. Only hemlock and sugar maple showed a positive correlation with precipitation during the year prior to ring formation. Of the three species, hemlock was most influenced by temperature and showed a positive correlation with winter temperatures. Our results also showed that, since the mid-19th century, certain climatic variables temporarily dominated the growth-climate association of the species. Hemlock showed the most stable growth-climate association, whereas in sugar maple, negative correlations with late winter temperature showed up during the second half of the 20th century.