Growth of Mongolian pine in Zhanggutai of Liaoning Province.

The aim is to summarize the growth process for first generation Mongolian pine (Pinus sylvestris var.mongolica) on sandy land, where its life cycle ends after about 60 years, and to provide a theoretical basis for promotion, regeneration, and management of a Mongolian pine plantation. 11 trees were selected for analysis, chosen from standard plots of 11 Mongolian pine plantation stands (> 30 a) with different site conditions in Zhanggutai of Liaoning Province. Then parameters for Richards model were solved and the goodness-of-fit was tested. To reveal the growth process of Mongolian pine, eigenvalues of Mongolian pine trees were used in Richards Equation. Results of height, diameter at breast height (DBH), and volume of Mongolian pine were simulated by Richards model with the parameter estimated values of 14.179, 0.084, and 2.803 for height; 19.379, 0.075, and 1.712 for DBH; and 0.296, 0.062, and 5.926 for volume. For tree height growth of first generation Mongolian pine introduced to Zhanggutai, the relative growth rate reached its maximum of 0.54 m·a-1 at year 12.3, and the average growth rate achieved its peak at year 21.4 with 0.39 m·a-1. Growth of DBH for trees started at year 6.6 with the relative growth rate reaching its maximum of 0.77 cm·a-1 at year 14.0 and the average growth rate achieving its peak at year 26.0 with 0.47 cm·a-1. Volume growth was very slow before age 12.0 with the relative growth rate reaching its maximum of 0.007 4 m3·a-1 at 29.0 years, the average growth rate achieving its peak at year 47.0 with 0.004 5 m3·a-1. The quantitative maturity age, when the maximum of average growth rate of volume appears, was 47.0 years of Mongolian pine in Zhanggutai. We drew a conclusion that the maximum of relative growth rate of height, DBH and volume of Mongolian pine appear at the age of 12.3 a, 14.0 a and 29.0 a, respectively. The maximum of average growth rate of height, DBH and volume appear at the age of 21.4, 26.0 and 47.0 years, respectively. The quantitative maturity appears in the 47th year after planting.