Pine cultures growth and formation during reclamation of sewage sludge

Abstract

The results of studying the parameters of 12-year-old Scotch pine cultures, created by planting along the furrows on sewage sludge and on felling-slash areas, are considered. The cultures were established on plots in the pine forest type with a dark coniferous mossy-bilberry layer. It has been established that the survival rate of plants on drag dumps turned out to be almost 16 % less than in felling-slash for forest plantations on sewage sludge. There were no significant differences in significant differences between pine crops on sewage sludge and felling-slash areas in terms of average diameter and height of the trunk. There were no significant differences in significant differences between pine crops on sewage sludge and felling-slash areas in terms of average diameter and height of the trunk. There were no fundamental differences in the distribution of trees by growth classes between crops on sewage sludge and on felling-slash areas. It has been established that pine trees of I and II rank growth classes on sewage sludge are significantly larger in diameter than trees on felling-slash areas. There were no significant differences in the height of the tree trunk by growth classes between the trees on the sewage sludge and the felling-slash area. The relative height of the trees on the sewage sludge was significantly lower than that of the trees on the felling-slash area. This indicates that, with a significant loss of trees, the rows of crops on the sewage sludge turned out to be of a less density, which ensured the enhanced growth of trees of all growth classes along the thickness of the trunk. The natural renewal of tree species on the sewage sludge was 1,2, and in the felling-slash 1,1 thousand trees per 1 ha. As part of the natural renewal on the sewage sludge, only coniferous species are represented, on the felling-slash area — deciduous and coniferous species. The projective cover of the living ground cover on the sewage sludge was uneven and amounted to 40…50 %, and reached 100 % in the felling-slash. The results obtained indicate the need for preliminary reclamation to improve the physical and mechanical properties of the soil.