Risk model of tree stand damage by winds and its evaluation based on damage caused by cyclone "Xaver"

Aim of study: To develop and evaluate the forest's wind-risk model, dedicated for stand damage level. Area of study: Model was tested in the northeastern Poland. Material and methods: A risk model referring to the damage of forest stands by wind specifies, for every stand in a selected forest district, the risk factor within the range of 0 to 3. The higher value of the factor, the greater risk of damage, if wind occurs. The model was based on 11 features: average size of a tree stand, mean diameter breast high in the specified features' ratio, species composition, degree of stand density, age of stand, forest site type, amount of damage caused by wind in the last 10-year period, location of forest district in the region of Poland, and three features for mountains: stand's altitude above sea level, direction, and slope. The model used information from the State Forests' Information System database (SILP), and since it was developed in JAVA computer language, the processing of data for one forest district lasted less than one minute. Main results: The model can create a forest district digital map, in which stands characterized by specific risk values are presented with high prediction accuracy. Research highlights: The risk model of tree stand damage by winds uses data provided by the SILP and what was proven in below study, can be used as an effective tool in a forestry practice.