Productivity and profitability of Larix principis-rupprechtii and Pinus tabuliformis plantation forests in Northeast China

This study analyzes the productivity and profitability of Larix principis-rupprechtii and Pinus tabuliformis plantation forests in Northeast China. Three management regimes with different thinning intensities (heavy thinning, light thinning, and control) were considered. It is found that high initial planting densities without thinning cause high mortality and slow growth rates, leading to an unprofitable outcome. Thinning operations increase both diameter and height growth of the retained trees, boosting the merchantable volume of large-diameter trees and thus the profitability and productivity. The optimal rotation ages with heavy thinning of Larix principis-rupprechtii and Pinus tabuliformis plantations are 48 and 49 years, 7-8 years longer than what the current management regulation recommends. But the productivity per ha per year of Larix principis-rupprechtii in the heavy thinning regime doubled to 8.21 m(3). For Pinus tabuliformis, the thinning treatments cause the productivity gains to increase from 5.1 to 7.9%. The constraints of government regulation without allowance for thinning to the near-mature stands and increasing the intensity could severely reduce the profitability and productivity.