Change in the radiation regime and composition of the herbal layer of pine crops at the closing of the crown of the tree

Kulyasova Oksana Alekseevna, Kastornova Marina Gennadievna

In the conditions of the northern forest-steppe of the Tyumen region, changes in the radiation regime of Scotch pine crops and the transformation of the species composition of the herbaceous layer in the process of closing the crowns of a pine stand have been studied. It is shown that in unclosed pine forests of 13 years of age, the total solar radiation is on average 48.7% of the radiation of the open area. In cultures of 23 years of age with a crown density of 80%, the share of the total incoming radiation decreases to 17.2%. After the pine crowns close, the species diversity of the herbaceous layer decreases; the proportion of light-loving species of herbage is decreasing; the representation of species of meadow and forest-steppe ecological-cenotic groups decreases, the proportion of birch and boron species of grasses increases.

Keywords:radiation regime; grass layer; species composition; Scots pine culture; northern forest-steppe.