Effects of planting density on the growth and stand volume of young Anthocephalus chinensis plantation

Objective To explore the effects of planting density on the growth of Anthocephalus chinensis plantation, namely, on tree height, canopy width, height under branch, diameter at breast height (DBH), individual tree volume and stand volume.

Method Planting densities of 625, 667, 833, 1 667 and 2 500 trees·hm^-2 were established in a complete randomized block design. Based on the method of tally, the major growth indicators of nine experimental trees in each block were measured. Differences among different planting densities were analyzed using one-way ANOVA and Duncan's Multiple Range Test. Relationship among different traits and planting density were explored using correlation analysis.

Result Planting density had significant effects on tree height, canopy width, height under branch, and stand volume (P < 0.01). Tree height(y) and planting density(x) were significantly positively correlated, and the regression equation was y =-4.000 0×10^-7x² + 0.001 6x + 8.270 3. Stand volume(y) and planting density(x) were significantly positively correlated, and the regression equation was y =-1.000 0×10^-5x² + 0.112 7x-12.664 0. Canopy width(y) and planting density(x) were significantly negatively correlated, and the regression equation was y =15.942 5^{-4.000 0×10-5x}. Canopy width(y) and DBH(x) were significantly positively correlated, and the regression equation was y =9.661 3x²-103.950 0x + 293.870 0.

Conclusion For young A.chinensis plantation, the planting density of 2 500 trees·hm^-2 leads to the optimum results with the highest stand volume and tree height.