Theoretical and experimental study of a mechanical model describing the trunk behaviour of mature beech trees (Fagus sylvatica L.) under the static loading of the crown

The effect of the self-weight increment, caused by annual growth, can be one of the principal processes affecting the development of growth stresses linked to the formation of reaction wood. This paper presents a preliminary study focusing on the relationship between the whole weight of the crown and the trunk displacement it creates. A mechanical beam model is proposed and tested theoretically, as well as experimentally, on three mature beech trees. Once the suitability of the model has been established, a simple sensitivity test in proposed that highlights the principal parameters involved in displacement.