This study aimed to delineate the seed transfer zone of Pinus densiflora. After generating transfer functions based on growth characteristic data from 10 pine test sites for 36 seed sources and six bioclimatic variables, the critical seed transfer distance for each climate variable was calculated. Based on our results, seed transfer zones were delineated by overlaying maps for all climate variables. In the pine provenance test, seeds from eastern Korea generally showed superior growth at each test site. Temperature-related variables accounted for a higher proportion of the selected bioclimatic variables than precipitation-related variables. Additionally, warm-to-cold seed transfer in eastern Korea and cold-to-warm seed transfer in central and southern Korea were overestimated, widening the seed-transfer zone. Examining the long-term growth of the trees, introducing additional variables, and applying a model with a higher level of rationality to the transfer function are necessary for delineating the optimal seed-transfer zone.

Studies on forest tree breeding (FTB) in South Korea started in the 1950s and have achieved remarkable outcomes through various techniques and methods such as selective breeding, cross breeding, introduction breeding, and biotechnology. Despite these outstanding achievements, no attempt has been made to
objective
ly and quantitatively evaluate the results of domestic FTB research. Here, we quantitatively analyzed past research trends using keywords of published journal papers and compared the current domestic research level of FTB with the international level. Using various keywords in this field, we searched for research articles published in the Journal of Korean Society of Forest Science, the Korean Journal of Breeding Science, and the journals listed on the Science Citation Index from 1962 to present. The analysis of these studies showed that the research on FTB has grown quantitatively in Korea, and has been conducted on various subjects. Research topics from Korea, in terms of purpose and species, are not significantly different from those of foreign countries. The genus Pinus has been the major subject of FTB studies both domestically and internationally. However, in foreign FTB research, the trees used for research have diversified each year, while they were not diverse in Korea. The FTB research capacity of Korean national institutions, such as the National Institute of Forest Science, continues to dramatically increase, while the research capacity of universities is relatively low. Based on the results of this analysis, it is necessary to establish a concrete and effective policy for future research and development of FTB.