Cultivating Siberian Stone Pine Plantations under Wild Animal Damage Conditions

Abstract

The research of 26-year-old mixed plantations of Siberian spruce and Siberian stone pine cultivated by biogroups of about 300 pcs/ha (2–5 stone pine seedlings alternating 4–9 spruce seedlings in a row) has shown that the damage rate by moose to them is much lower than to pure stone pine plantations or the mixed ones of Siberian stone pines and Scots pines we have studied before. The share of biogroups containing damaged stone pine trees is 18 %. A third of this number is plantations with damage to all the trees. This is most pronounced in biogroups of 4 to 5 stone pines as well as in case of frequent alternation of biogroups in a row. 76 % living stone pines have been preserved (89.3 % of them without damage to the stem). About two thirds of them (about 500 pcs/ha) grow in the crown of spruce trees adjacent to stone pine biogroups. Prolonged exposure to growing in a spruce tree crown negatively affects the growth of a stone pine’s central shoot and crown. We are the first in the Middle Urals to propose a scheme for cultivating sustained productive mixed plantations of Siberian stone pines and Siberian spruce trees (or Norway spruce trees). Stone pines are planted in biogroups of 2–3 seedlings, beginning the planting strictly on one side of the site. The first biogroup in odd-numbered rows (1, 2, 3, 5, etc.) is planted after 3 spruce seedlings from the beginning of the row, the second and subsequent biogroups in these rows – after 9 spruce seedlings. The first biogroup in even-numbered rows (2, 4, 6, 8, etc.) is planted after 9 spruce seedlings from the beginning of the row, maintaining this sequence until the end of the row. Every row in mixed plantations is concluded with planting no less than 3 spruce seedlings. During silvicultural treatment procedures natural regeneration is completely removed: softwoods – by mechanical means, and hard woods – by ringing or injection of environmentally friendly water-based chemicals. These measures reduce or eliminate the appearance of coppice and, accordingly, food reserve for wild animals. Spruce trees adjacent to stone pine biogroups are cut down while lightening and thinning, which creates the possibility for the growth of stone pines. The proposed method for cultivating plantations of Siberian stone pines and Siberian spruce trees has been patented. It can be introduced into silvicultural practice in the taiga zone where stone pines are grown.