Selection Criteria for Plus Stands in Field-Protective Forest Belts in the North-Western Caucasus

Abstract

Field-Protective Forest Belts (FPFB) are one of the leading objects that ensure the preservation of soil fertility and increase the productivity of agricultural land. The appropriate breeding material is needed for their creation. The suitable forest-seeded objects are selected for this purpose, one of them are plus stands (PS). For the selection of PS, it is necessary to develop appropriate requirements taking into account their regional features. The purpose of this work was to set the PS selection criteria for protective afforestation in the North-Western Caucasus. In this regard, the following tasks have been performed: selection of highly productive forest belts from promising species, selection assessment, determining the ratio of individuals of various breeding categories, comparing the results obtained with data from other authors in various conditions. Fifteen sample plots (SP) have been laid in the field-protective forest belts consisting of pedunculate oak (Quércus róbur L.), pseudoacacia robinia (white acacia) (Robinia pseudoacacia L.), lanceolate ash (Fraxinus lanceolata B.), common ash (Fraxinus excelsior L.), three-pronged gleditschia (Gleditschia triacanthos L.). Thus, 144 – 572 trees were assessed on each sample plot according to the corresponding regional methodology. The processing of the obtained results was carried out using the licensed program Stadia 8.0/prof. The ratio of plus and normal trees to minus trees was calculated on the selected objects. The plantings with 29% or less of minus trees in the selection inventory are recommended to be selected as plus trees in the region. For a smaller sample size, it is necessary to clarify the proportion of negative trees.