The influence of stand density on the resin duct morphological structure and terpene components of Pinus massoniana were studied. The resin duct morphological characteristics and the relative content of the terpene components were investigated by microscopy and gas chromatography-mass spectroscopy, respectively. The experimental results revealed that there was a specific correlation between the stand density and resin duct area, resin duct diameter, and the relative contents of main terpene components in the turpentine extracts. Additionally, the relative contents of β-pinene and (+)-camphene were positively correlated with stand density, with correlation coefficients of 0.8208 and 0.5539, respectively. In contrast, the relative contents of (+)-longifolene and (+)-longicyclene were negatively correlated with stand density, with correlation coefficients of -0.5750 and -0.7726, respectively, and α-pinene, β-caryophyllene, and (+)-α-longipinene had no correlation with stand density. The relative content of (+)-α-pinene was negatively correlated with the relative contents of both (+)-longifolene and (+)-longicyclene, with correlation coefficients of -0.8770 and -0.8914, respectively. There were positive correlations between the relative contents of (+)-longifolene and (+)-longicyclene with correlation coefficient of 0.9718, (+)-longifolene and (+)-α-longipinene with correlation coefficient of 0.8399, β-caryophyllene and (+)-α-longipinene with correlation coefficient of 0.9360, and (+)-longicyclene and (+)-α-longipinene with correlation coefficient of 0.8626.
Based on the principle of tree chronology, this paper measures tracheid morphological characteristics, ring width, and latewood rate of harvested wood from Cupressus funebris plantation in Deyang, Sichuan Province. Using meteorological data of average temperature, precipitation, relative humidity, sunshine percentage, and average ground temperature from 1983 to 2015, correlation analyses were conducted. The results of the analysis showed that the correlation between tracheid morphological characteristics, ring width, and latewood rate was not consistent with a single climatic factor. Moreover, the correlation between tracheid morphological characteristics and climatic factors, and the correlation between ring width, latewood rate, and climatic factors were significantly different. Temperature was the main limiting factor for ring width and latewood rate. In addition, relative humidity was positively correlated with ring width and negatively correlated with most indicators of tracheid morphological characteristics. Fewer indicators were affected by sunshine percentage. Meanwhile, precipitation was not significantly correlated with ring width and latewood rate. In conclusion, the correlation between various indicators and climate factors was from high to low in order of temperature, relative humidity, sunshine percentage, and precipitation.