Fractal analysis for root growth of plant seedlings under doubled CO2 concentration

Fractal geometry was applied and box dimension was used as an indicator to analyze the effects of doubled CO2 concentration on the root growth of plan t seedlings. Results showed that doubled CO2 concentration displayed differ ent effects on root branching characteristics of C-3 and C-4 plants. There was an obvious increase of root branches in spring wheat while there were n o significant effects on roots of sweet sorghum, In different soil layers, root branching of spring wheat was stimulated and this promotion was most s ignificant in the second layer (10-20 cm), which denoted that elevated CO2 altered the root branching pattern. That means higher CO2 concentration inf luences not only root growth but also its differentiation and development.