Influence of selective logging on the productivity of pine trees in the conditions of Krasnoyarsk forest-steppe

Abstract

Research has been carried out to study the effect of the first thinning on the overall productivity of mature pine stands in the forest-steppe zone of the Krasnoyarsk Kray. The results of the influence of felling from low to very high volume intensity on the value of the current periodic growth in mature pine stands of different initial basal area are presented. In pine forests of forb-green moss and lingonberry-forb-green moss types, a comparative analysis of the average annual periodic increase in the stock for 5–10 years was carried out. It was found that the increase is due to both the intensity of felling and the initial density of stands and varies within wide limits (from 2.4 to 7.3 m3/ha per year). On control plot, this value was 2.6–4.9 m³/ha per year. A positive dependence of the average current annual increment per 1 m3 of stand volume after the first thinning with the felling intensity was revealed. Thinning intensity optimums were determined for stands of different initial density at the age of 100–120 years. For initial densities of 500, 600, 700 and 800 trees/ha, it will be equal to 100 (20 %), 200 (33 %), 300 (43 %) and 400 trees/ha (50 %), respectively, which can be used for practical recommendations for the renewal felling. At the same time, the main criterion for the intensity of thinning of forest stands is their purpose (protective forests) and their condition (natural regeneration and wind sustainability).

Keywords

• mature pine forests
• average current periodic increment
• radial increment
• wood stock
• partial cuts
• natural reforestation