The relationships among structure variables of larch forests in China

Forest Ecosystems

Table 3 Parameters of the quantile regression (QR) and the ordinary least square regression (OLS) between average DBH and stem density for larch forests in China

Forest type	No. of plots	Exponent d (mean ± standard error)
Forest type	No. of plots	OLS	50% quantile	75% quantile	95% quantile
L. gmelinii	37	−0.51 ± 0.05^**	−0.50 ± 0.08^**	−0.56 ± 0.07^**	−0.49 ± 0.08^**
L. gmelinii var. principis - rupprechtii	51	−0.28 ± 0.10^**	−0.33 ± 0.09^**	−0.37 ± 0.08^**	−0.53 ± 0.23^*
L. olgensis ^a	1	–	–	–	–
L. sibirica	19	−0.38 ± 0.07^**	−0.40 ± 0.08^**	−0.48 ± 0.11^**	−0.60 ± 0.13^**
L. griffithii	4	−0.35 ± 0.68	−0.13 ± 1.16	−1.15 ± 1.74	−1.15 ± 2.04
L. himalaica	4	0.13 ± 0.74	0.42 ± 1.15	0.20 ± 1.17	0.20 ± 1.09
L. mastersiana	3	0.16 ± 0.36	−0.03 ± 4.73	−0.03 ± 4.82	−0.03 ± 5.11
L. potaninii	4	−0.38 ± 0.40	−0.33 ± 0.89	−0.40 ± 0.99	−0.40 ± 0.97
L. potaninii var. australis	11	−0.25 ± 0.36	−0.19 ± 0.59	−0.28 ± 0.60	−1.01 ± 0.87
L. potaninii var. chinensis	19	−0.25 ± 0.15	−0.13 ± 0.23	−0.49 ± 0.31	−0.30 ± 0.47
L. speciose ^a	2	–	–	–	–
Sect. Larix	108	−0.44 ± 0.05^**	−0.44 ± 0.06^**	−0.50 ± 0.06^**	−0.43 ± 0.12^**
Sect. Multiseriales	47	−0.05 ± 0.17	0.03 ± 0.17	−0.02 ± 0.19	−0.57 ± 0.40
Overall	155	−0.30 ± 0.05^**	−0.33 ± 0.07^**	−0.39 ± 0.06^**	−0.43 ± 0.12^**

The d is the parameter of Eq. 4. ^aindicates larch forest types with the number of plots less than 3. ^** and ^* indicate p < 0.01 and p < 0.05, respectively