Raunkiær’s oaks: mortality and growth among old oaks in a Danish deer park

Abstract

ABSTRACT We evaluate the growth and mortality of veteran oaks studied by C. Raunkiær in a game park in Denmark in 1933. Raunkiær mapped 664 oaks, of which 329 healthy looking oaks had their girth measured (average girth of 318 cm). Mortality decreased with increasing circumference and was estimated to be 0.426% per year. The healthy-looking trees in 1933 had even lower mortality (0.211% per year). There was no difference in mortality between naturally recruited oaks and those planted in the 1830s. These mortality estimates were lower than in previous reports of oaks, veteran trees and large tropical trees, presumably because these oaks were in a non-crowded, non-forested situation. When girth was measured after 50 growing seasons, they had grown an average of 1.33 cm per year. However, the growth rate of these initially healthy trees was highly variable and could be partially explained by the initial tree size. Taking this into account, statistical models suggest that a 300 cm circumference oak in 1933, measured at breast height (130 cm), would have grown 1.28 cm per year in circumference, corresponding to radial growth of 0.20 cm per year and basal area increment of 71.0 cm2 per year.