Comparative Analysis of Growth and Wood Properties of Cunninghamia lanceolata 3^rd Generation and Red Heartwood Varieties

This study aims to provide a basis for the selection of improved Cunninghamia lanceolata varieties for targeted afforestation by comparing the growth and basic wood properties of the 3^rd generation variety with the red heartwood variety. A comparative experiment was conducted on a 7-year-old stand. Results indicate that the 3^rd generation variety demonstrates superior growth traits,with a height of 7. 95 m,a breast height diameter(DBH) of 11. 4 cm,and a volume of 0. 0483 m₃,representing increases of 17. 26%, 4. 59% and 34. 92% over the red heartwood variety,respectively. Conversely,the red heartwood variety exhibits a higher red heartwood rate,at 34. 94%,surpassing the 3^rd generation variety by 10. 7% and the 2^nd generation variety by 9. 49%. Additionally,the consistency of red heartwood rate in the red heartwood variety was significantly higher compared to the 3^rd generation variety,while its growth matches the level of the 2^nd generation variety. Both varieties have similar basic wood densities,with the 3^rd generation variety at 0. 3549 g·cm^-3 and the red heartwood variety at 0. 3607 g·cm^-3,showing no significant difference. Utilizing the 3^rd generation variety could improve tree height growth by 16.55%,while selecting red heartwood varieties could enhance the red heartwood rate by 20.08%.