Abstract: By using quadratic orthogonal rotation combinatorial design, and taking aluminum (Al), selenium (Se), silicon (Si), and phosphorus (P) as test factors, the regression models of test factors and the survival rate (SR), shoot mass per hundred plants (SMHP), root mass per one hundred plant seedlings (RMHP), and proline contents (PC) of rice seedlings were established, with the individual and interactive effects of the factors analyzed. The individual effects of test factors on the SR, SMHP, RMHP, and PC of rice seedlings decreased in the order of Al>P>Se>Si. Al showed negative effect, while Se, Si, and P showed positive effect. There were no significant interactive effects between the factors, except between Al and Si. Simulated optimization test showed that rice seedlings could grow better in an Al-containing solution when the Al was within the range of 0587〖KG-*2〗-〖KG-*7〗0913 mmol·L-1, Se was of 0478〖KG-*2〗-〖KG-*7〗0564 mg·L-1, Si was of 0613〖KG-*2〗-〖KG-*7〗1069 mmol·L-1, and P was of 2252 〖KG-*2〗-〖KG-*7〗2657 mmol·L-1.

Key words: landscape spatial differentiation, land use, vegetation, climate, Inner Mongolia Autonomous Region.