Table 3.

Parameters of the vectorial circular analysis of the centre of volume (COV) of the first- and second-order laterals and the centre of branching (COB) of the first-order at increasing radial distance (20–80 cm) from the root-stump centre. Rao's test was used to test the uniformity of the distribution. N, number of data; μ, mean vector; r, length of μ; U, Rao parameter with the significance level P. COV and COB are significantly clustered at P < 0·05

Centres	Radii reference hemisphere (cm)	Slope inclination	Number	Mean vector (μ)	Length of mean vector (r)	Circular standard deviation	Rao's spacing test (U)	Rao's spacing test (P)
COV 1st order	20	Steep	5	177·403°	0·914	24·344°	225·118	<0·01
		Shallow	5	249·51°	0·368	81·014°	89·889	>0·50
	40	Steep	5	178·949°	0·951	18·167°	240·768	<0·01
		Shallow	5	195·563°	0·612	56·783°	124·363	>0·10
	60	Steep	5	162·622°	0·932	21·506°	233·195	<0·01
		Shallow	5	176·007°	0·801	38·182°	168·881	>0·05
	80	Steep	5	160·376°	0·921	23·223°	224·468	<0·01
		Shallow	5	171·539°	0·948	18·68°	233·388	<0·01
COB 1st order	40	Steep	5	154·683°	0·56	61·736°	143·777	>0·10
		Shallow	5	311·98°	0·419	75·589°	158·268	>0·10
	60	Steep	5	163·562°	0·974	13·117°	252·3	<0·01
		Shallow	5	250·554°	0·387	78·924°	104·199	>0·50
	80	Steep	5	159·3°	0·91	24·922°	221·53	<0·01
		Shallow	5	207·692°	0·274	92·246°	69·022	>0·90
COV 2nd order	40	Steep	5	230·134°	0·545	63·084°	144·005	>0·50
		Shallow	5	219·772°	0·113	119·589°	55·239	>0·50
	60	Steep	5	226·502°	0·489	68·51°	125·584	>0·50
		Shallow	5	255·001°	0·223	99·234°	60·478	>0·50
	80	Steep	5	212·558°	0·467	70·687°	119·848	>0·50
		Shallow	5	254·283°	0·098	123·516°	88·087	>0·50