Elevational Patterns of Plant Richness in the Taibai Mountain, China

Table 3

Series of second-order polynomial regressions for species richness and predictor variables.

Plant groups	Variable	Order	df
Overall plants	Ln(area)	2	27	0.63***	478.98	−219.83	27.15
	MDE	2	27	0.49***	12.55	1.74	−0.001
	MAT	2	27	0.71***	−210.59	244.83	−15.94
	MAP	2	27	0.65***	729.66	−5.79	0.007
Seed plants	Ln(area)	2	27	0.53***	374.60	−170.74	20.889
	MDE	2	27	0.41**	−2.71	1.95	−0.002
	MAT	2	27	0.63***	−173.81	185.07	−11.78
	MAP	2	27	0.55***	113.53	−3.31	0.004
Bryophyte	Ln(area)	2	27	0.95***	77.27	−37.26	4.71
	MDE	2	27	0.95***	9.038	0.85	0.001
	MAT	2	27	0.96***	−17.40	44.31	−3.31
	MAP	2	27	0.94***	1274.03	−3.88	0.003
Fern	Ln(area)	2	27	0.42**	27.11	−11.84	1.56
	MDE	2	27	0.24*	9.24	1.37	−0.014
	MAT	2	27	0.82***	−19.38	15.46	−0.84
	MAP	2	27	0.49***	−657.91	1.39	−0.0007

Equation for second-order polynomials following equation term = + variable + variable²; df = degrees of freedom; *, **, and ***.