ObjectiveThis paper aims to study the medium and long term effects of structure-based forest management (SBFM) on forest quality of broadleaved Korean pine forests in Northeastern China and to explore the mechanism of forest management in forest quality improvement.

MethodSix sample plots with an area of 100 m × 100 m were set up in Jiaohe Forestry Experimental Area, Jilin Province of northeastern China. Among the six plots, there is 1 target sample plot, 4 managed sample plots and 1 control plot. The SBFM measures were applied in 4 managed plots for data collection. Quantitative and comparative analysis has been carried out using Excel Pivot Tables, R 3.4.3, Origin 2015, Winkelmass to study the effects of SBFM on forest productivity, density, structure and comprehensive status of the stand.

ResultThe results indicated that after applying SBFM, the average annual stand volume growth (mean) of managed stands was 17.28% more than those of control, and growth rate was 17.60% higher, meanwhile the average annual stand basal area growth (mean) and growth rate of it increased by 42.86% and 47.37%, respectively, and the rate of tree mortality decreased by 57.22%. In a word, the productivity was significantly improved. With main conifers maintaining a high level of species dominance, the horizontal distribution of managed stands was random pattern, i.e. the ideal natural forest pattern. The optimum micro-structures with high mixing and random distribution remained a high proportion throughout the study, while those with low mixing and non-random distribution accounted for a low proportion and showed a downward trend in managed stands. The comprehensive status of the managed stand had been optimized rapidly by SBFM, the state of stands was maintained stable, and the continuous and regular follow-up operation was required to maintain the management effect.

ConclusionStructure-based forest management improves the quality of broadleaved Korean pine forests in Northeastern China in a precise manner. SBFM has been proved to be an effective and reliable way to improve stand productivity and optimize stand spatial structure at the same time.