Due to the growth in the construction industry sand and gravel extraction scale is annually increasing. This trend is typical for many subjects of the Russian Federation. The disturbed lands in the Republic of Mari El are mainly quarries and cutover bogs located in the forests and restored through setting tree plantations. Therefore, the problem of sound and timely forest regeneration on the areas disturbed by the human industrial activity is quite urgent now.
The purpose of the work was testing seedlings of Scots Pine with root-balled tree system on the abandoned sand pits and finding the optimal arrangement system for them.
The objects of the research are 12-year-old cultivated growing stock of Scots Pine having been planted on the sand pit bottom using containerized seedlings with different patterns of arrangement in the row.
In the course of the research, the vegetation cover as a result of the processes to restore the soil fertility of the sandy soil has been studied. The agrochemical parameters of the upper root layer of soil were analyzed. An increase in the soil biological activity was observed after recultivation and planting Scots Pine in the pit. A slight increase in the organic substance (0.44 - 1.31%), nitrogen (4.2 - 4.67 mg/100 g) and mobile potassium (1.43 - 2.73 mg/100 g) was traced. In general, the agrochemical and biological properties of the soil can be considered to be quite suitable for Scots Pine growth but extremely unbalanced by the major nutrient concentration.
To provide higher growth rate of Scots Pine on the abandoned sand quarry, pine seedlings with root-balled tree system and plant spacing from 0.8 to 1.0 m, planting density from 3.3 to 4.2 thousand pcs./ha are recommended. Such plant spacing ensures a higher conservation (75 - 89%) and intensive high growth (4.5 - 4.7 m) of 12-year-old Scots Pine.
Forest plantation of Scots Pine in the quarry does not differ from the forest plantation grown on the cut-over areas which proves the resistance of the species to the limiting crop-producing power factors. High vital capacity proves the practicability of recultivation at the abandoned sand pits by creating forest plantation of Scots Pine using one-year old containerised seedlings.
Šumarska genetika, sjemenarstvo, rasadničarstvo i osnivanje šuma