Table 5.

The results of variance partitioning between the effects of mopane (Colophospermum mopane) cover and the north–south (N–S) gradient in the Kruger National Park on plant species richness.

Response	Predictor	Marginal effect	Estimate	Effect	Explained variability (adjusted R-square)	Partial effect (N-S × mopane)	Estimate	Effect	Explained variability (adjusted R-square)	Partial effect (bedrock × habitat)	Estimate	Effect	Explained variability (adjusted R-square)
Species richness (total)	Mopane cover	0.0095	− 26.30	−	0.095	0.895	− 1.13	−	− 0.017	0.123	− 7.217	−	0.024
Species richness (total)	N–S gradient	< 0.001	16.77	+	0.313	0.0013	111.08	+	0.151	0.0767	3.072	+	0.037
Species richness (herbs)	Mopane cover	0.0219	− 19.83	−	0.071	0.951	− 0.47	−	− 0.018	0.0946	− 7.462	−	0.031
Species richness (herbs)	N–S gradient	< 0.001	12.85	+	0.253	0.0040	8.73	+	0.119	0.0494	3.246	+	0.049
Species richness (shrubs)	Mopane cover	0.0002	− 1.36	−	0.195	0.169	− 0.49	−	0.016	0.0585	− 0.37167	−	0.044
Species richness (shrubs)	N–S gradient	< 0.001	0.61	+	0.288	0.0106	0.33	+	0.092	0.115	0.11582	+	0.026

The marginal effects represent the coarse effects, without accounting for the confounded factors, while partial effects represent the net effects after accounting for the confounded factors. Significant effects are in bold, marginally significant in italics, the direction of the effect is indicated by the plus/minus symbol.