The natural regeneration pattern and process of Korean pine population under natural Poplar-birch forest in Xiaoxing’an Mountains

According to a great deal of field investigation and detailed indoor analysis, the natural regeneration pattern and process of Korean pine population under natural Poplar-birch forest has been uncovered. The results show that the regeneration quantity and quality of Korean pine population under mountainous Poplar-birch forest and mountainous white birch forest are better than those under valley moss-grass White Birch forest and virgin broad-leaved Korean pine forest. Korean pine population shows aggregated distribution, the mass-occurrence period of Korean pine population is behind the mass-occurrence period of Poplar-birch population. Various aged Korean pines growth is affected by different stand structure factors. Man-made lighting tending can accelerate the regeneration process and increase the regeneration quality of Korean pine population. It is feasible to set up regeneration recombination of upper layer White Birch and lower layer Korean pines.