Predicting current and future suitable habitat and productivity for Atlantic populations of maritime pine (Pinus pinaster Aiton) in Spain

Table 7 Variables included in the productivity model, including their type and variable importance

Type	Variable	Normalized importance	Relative importance	Summarized values for suitable habitat
Type	Variable	Normalized importance	Relative importance	Mean	Max	Min	SD
Lithostratigraphy	LIT_dlo¹	51.24	100.00	–	–	–	–
Geology	Geo_es¹	24.13	43.16	–	–	–	–
Soil	R	6.31	5.80	16.02	43.00	1.00	5.48
Climate	BIO03	6.17	5.52	3.94	4.40	3.60	0.14
Soil	CEC	4.71	2.45	25.04	66.00	15.00	2.82
Soil	WRB-LEV1¹	3.89	0.72	–	–	–	–
Climate	BIO08	3.54	0.00	8.59	12.50	2.60	1.64

To ensure values of variable importance were expressed on a comparable scale for each of the response variable, the scores of all the predictors selected were normalized so that they added up to a unitary value (normalized importance) or were expressed as relative values. Relative importance = (VIM−VIM_min)/(VIM_max−VIM_min)
¹Qualitative variables

ISSN: 1297-966X