Effect of climate warming to the dormancy and dehardening of pedunculate oak (Quercus robur L.) seedlings in assumed climate conditions of the year 2030 and 2100

Abstract

The climate warming effect on the development of the pedunculate oak (Quercus robur L.) during the dormancy state and dehardening development was studied by the simulation of different growth conditions. The seed material used was obtained from 9 different origins from Poland to South Finland, to ascertain the most appropriate origin to grow in South Finland. In greenhouses they were simulated two future climatic conditions belonging to the years 2030 and 2100, using the scenario A1B, as well as two conditions of humidity. To find out the state of dormancy and the dehardening ability, we used a freezing test to simulate the injuries caused by the frosts. In dormancy experiment, the seedlings of the year 2030 presented null injuries and a high rate of survival. On the contrary, by the year 2100 the injuries were 50%. In the dehardening experiment, it was observed that the late frost was a huge threat to the survival, since the mortality increased by 30 % in two weeks. Among all the origins, the one that presents better adaptability was the one from Ruissalo. The results of this thesis supports the theory that climate warming will increase the risk of frost damage of the one year old seedlings of pedunculate oak in South Finland.