No matter how much space and light are available, radial growth distribution in Fagus sylvatica L. trees is under strong biomechanical control

Table 1 Means of growth ratios for beech poles submitted to different treatments (mean ± standard deviation; n = 9)

Growth ratios	Treatments				Differences between treatments (p value)
Growth ratios	TF	TG	uTF	uTG	TF/TG	uTF/uTG	TF/uTF	TG/uTG
Axial growth	0.93 (± 0.009)	0.88 (± 0.19)	0.83 (± 0.14)	0.86 (± 0.21)
Root radial growth	1.87 (± 0.38)	1.24 (± 0.29)	0.71 (± 0.11)	0.39 (± 0.08)	< 0.0001	< 0.0001	< 0.0001	< 0.0001
Volume increment	2.26 (± 0.45)	1.58 (± 0.24)	0.97 (± 0.11)	0.66 (± 0.10)	< 0.0001	< 0.0001	< 0.0001	< 0.0001

The ratio of axial growth is the axial growth 4 years after treatment related to the axial growth 4 years prior to treatment. The ratio of root ring width is the root ring width 4 years after treatment related to the root ring width 4 years prior to treatment. The ratio of volume increment is the volume increment in the stem below the guy-wiring point 4 years after treatment related to the volume increment in the stem below the guy-wiring point 4 years prior to treatment. Ratios are dimensionless; a ratio of 1 means growth was unchanged. TF Thinned trees free to sway, TG Thinned and guy-wired trees, uTF Unthinned trees free to sway, uTG Unthinned and guy-wired trees. P values refer to Tukey test results

ISSN: 1297-966X