Survival, height and tree stability responses of Quercus petraea, two decades after the introduction of different tree shelter types

The long-term effects of 20 replicated tree shelter types (0.45-1.8m) were tested on sessile oak (Quercus petraea) saplings in mid Wales (1994-2014), against two control treatments. After 20 years shelters significantly (p<0.05) promoted survival in 17 of 20 treatments. Tree height was unaffected, but DBH was significantly (p<0.05) increased in 3 of the 20 types. Height:DBH, used as a tree stability proxy, revealed significantly (p<0.05) lower mean values in 12 shelter types compared to the open control. This study suggests shelters can enhance survival and result in morphological changes that may make trees more stable in the longer term.