Figure 4

Principal component (PC) analysis of the PLFAs in the rhizosphere and bulk soil in the treatments. R, rhizospheric soil; B, bulk soil; AN0, ambient CO₂ and no N added; AN1 ambient CO₂ and N supply at a rate of 2.5 g N m⁻² y⁻¹; AN2, ambient CO₂ and N supply at a rate of 5 g N m⁻² y⁻¹; EN0, elevated CO₂ and no N added; EN1, elevated CO₂ and N supply at a rate of 2.5 g N m⁻² y⁻¹; EN2, elevated CO₂ and N supply at a rate of 5 g N m⁻² y⁻¹.