Table 2. Statistical table of samples in different forest types.

Type of forest	Sensor type	Number of samples	Sample proportion (%)	I2 (%)
Broadleaf forests	UAV lidar	22	11.52	98.2
	Ground lidar	14	7.33	42.1
	RGB	11	5.76	97.7
	Spectra	6	3.14	83.3
Coniferous forests	UAV lidar	20	10.47	85.8
	Ground lidar	12	6.28	42.1
	RGB	11	5.76	77.4
	Spectra	4	2.09	83.3
Mixed forests	UAV lidar	31	16.23	97.7
	Ground lidar	17	8.90	80.9
	RGB	6	3.14	0.0
	Spectra	3	1.57	99.6
Shrubs	UAV lidar	9	4.71	47.4
	Ground lidar	8	4.19	80.6
	RGB	12	6.28	88.8
	Spectra	5	2.62	86.0
Total		191	100