Large oaks Quercus robur have increased at Tumhem's oak meadow

We have described a significant increase in the number of large oaks Quercus robur in the Tunhem oak meadow during 23 years. We define large oak as having a circumference at chest height larger than 250 centimeters. The number of large oaks have increased by 29 percent from our first survey in 1996 to our second survey in 2019. Most of the recruitment of larger oaks are in the smaller size-classes from 250 to 400 centimeters. Nineteen oaks have died during our study period. 

We have found that very large oaks have a similar continuous growth as smaller large oaks. They have increased in circumference from 0.5 to 4.5 centimeters. Oaks standing in open areas increase more in circumference (34.8 cm) compared to half-shaded (32.1 cm) and shaded large oaks (28.3 cm). 

Methods
Data on the number of large oaks Quercus robur in the Tunhem oak meadow collected in 1996 and in 2019. Circumference at chest height was measured.