Modelling variation in Pinus radiata stem volume and outerwood stress-wave velocity from LiDAR metrics

New Zealand Journal of Forestry Science

Table 1 Mean and range for variables used in analyses

	Stem volume				Outerwood stress-wave velocity
	Mean	Range	R	P-value	Mean	Range	R	P- value
Stand dimensions
Stand density (stems ha^-1)	248	114-433	0.66	<0.0001	242	114-433	0.50	0.0032
Slenderness (m m^-1)	72.1	48.8-99.4	0.04	0.58	74.5	48.8-99.4	0.64	<0.0001
Mean top height (m)	36.3	27.1-41.4	0.30	<0.0001	36.9	28.1-41.4	0.50	0.0033
Diameter (cm)	50.8	39.2-67.1	0.16	0.036	50.7	39.2-64.0	−0.68	<0.0001
Basal area (m² ha^-1)	49.3	23.7-75.8	0.94	<0.0001	47.1	23.7-70.0	−0.03	0.88
Topographical variables
Slope (^o)	28.9	9.0-45.0	0.03	0.75	29.6	14.0-45.0	0.37	0.036
Aspect (^o)	175	0-356	0.0007	0.99	173	30-356	−0.22	0.22
Selected LiDAR metrics
H₉₅ (m)	34.1	24.9-39.3	0.30	<0.0001	34.7	25.8-39.3	0.50	0.0033
H₃₀ (m)	16.9	5.7-25.5	0.77	<0.0001	16.7	8.3-24.1	0.002	0.99
PC_veg (%)	98.8	80.3-100.0	0.14	0.086	98.6	89.8-100.0	−0.20	0.27
H_sd (m)	9.9	6.9-12.9	0.04	0.65	10.1	6.9-12.9	0.55	0.0010

Also shown are summary statistics describing the strength and significance of the relationship of each variable with stem volume and outerwood stress-wave velocity. Shown are the correlation coefficient (R) and P-value for simple linear correlations. Abbreviations for LiDAR metrics are as follows: H₉₅ and H₃₀ – 95^th and 30^th LiDAR height percentiles, PC_veg –percentage of first returns from the vegetation (above the cutoff of 0.5 m), H_sd –standard deviation of LiDAR height.