Wood densities of six hardwood tree species in Eastern Guangdong and Influencing factors

Objective This study aims to provide the theoretical and data supports for the breeding of wood density and carbon sink accounting by analyzing the effects of different impact factors on wood density.

Method Six tree species were selected through the analysis of communities in sample plots of Kanghe nature reserve, and their wood densities were measured. This study analyzed the effects of different species, different diameter grades and different slope aspects on wood density, and the correlation between tree traits and wood density using a variety of statistical softwares.

Result There were significant differences in wood density among different tree species. The highest averages of green densities (1.10 g·cm^-3), basic densities (0.53 g·cm^-3) and the moisture contents (122.84%) were found in Castanopsis carlesii, C. hystrix and C. carlesii respectively. There was no significant difference in wood density among different diameter grades for all species except C. fargesii. There was no significant difference in wood density among different slope aspects for all species. The nonparametric Spearman's rank correlation analysis showed that both diameter at breast height and tree height were significantly correlated with green density but not with basic density.

Conclusion C. hystrix produces high quality wood with low moisture content and high basic density. Wood density has a tendency to rise with the increase of diameter grade, but has no regular change with the change of slope aspect. The relationship between diameter at breast height, tree height and green density, and the relationship between diameter at breast height, tree height and basic density are different probably because green density is affected by the moisture content.