Effect of tree shelters on the survival and growth of deciduous tree species 6 years after afforestation

The effect of tree shelters on the survival and growth in height and diameter of three tree species: common beech (Fagus sylvatica L.), sycamore (Acer pseudoplatanus L.) and sessile oak (Quercus petraea Matt. (Liebl.)), was studied. The study was conducted in two experimental plantations established in the spring of 2018 at the Training and Experimental Forest Range Petrohan ((North-Western Bulgaria). Four experimental variants with tree shelters – Tubex Ventex Classic, Tubex Ventex Clear, Layflat Shelterguard, Layflat Treeguard and a control one (without tree shelters) were used. Twenty to twenty-seven seedlings in three replications of each variant and tree species were planted. The experimental plantation 1 was established on an east-facing flat terrain at an altitude of 600 m. The soil is Grey Luvisol mixture of sandy and clay, slightly stony, and very deep. The site class is medium rich to rich. The experimental plantation 2 is located in a high-density game area. The area is a meadow, facing north, with an 8o slope and altitude of 850 m. The soil is Dystric-Eutric Cambisol, a mixture of sandy and clay, slightly stony and deep. The site class is medium rich to rich. In the autumn of the 6-th year after the establishment of the plantations, survival was assessed and the height and root collar diameter of all seedlings from each variant and replication were measured. Survival is relatively high in the tree shelter variants, while it is significantly lower in the control variant. Height growth is better in the tree shelter variants, especially in the variants with ventilated tree shelters A and B, in which the highest percentage of seedlings with a height greater than that of the tree shelters was also found. The tree shelter variants have a larger root collar diameter, but in some cases the difference with the control (without tree shelters) is not statistically significant. For future afforestation, the ventilated tree shelters Tubex Ventex Classic and Tubex Ventex Clear could be recommended.