Production and profitability of low density Norway spruce (Picea abies (L.) Karst.) plantation at 50 years of age: case study from eastern Latvia
Latvian State Forest Research Institute ‘Silava’, Rigas str. 111, LV–2169, Salaspils, Latvia
Norway spruce (Picea abies (L.) Karst.) is one of the most important commercial tree species, for which wider spacing are being advocated to reduce management costs and improve radial growth. Nevertheless, little is known about tree and stand parameters at the larger age in stands of extremely low density. The aim of our study was to assess growth and economic profitability of 50 years old low density Norway spruce plantation in Latvia. Allometric parameters for all trees of Norway spruce clonal plantation planted in 1964 with two spacings (1×3 m and 5×5 m) were measured and profitability were estimated. Norway spruce plantation with wider (5×5 m) spacing ensured significantly larger tree diameter and height (35 cm and 25 m, respectively) than trees from higher density trial. However, mean net present value (3% interest rates) was non–significantly (P = 0.12) different between 5×5 m and 1×3 m spacings, 2,571.9 ± 355.6 and 3,085.8 ± 452.9 € ha-1, respectively. Values observed in low density (5×5 m) plantation fitted well in the observation of impact of density and stand parameters drawn based on National inventory data, showing a considerable potential to use plantations with low density in practice.