Fig. 2
From: Regulation of priming effect by soil organic matter stability over a broad geographic scale
Partial correlations between the priming effect and the plant, soil and microbial properties after controlling soil organic matter stability. The x-axis shows the zero-order (without controlling any factors) and the factors being controlled. The y-axis shows the factors (a plant, b soil, c microbial properties) of which the correlations with the priming effect are examined. The size and colour of the circles indicate the strength and sign of the correlation. Differences in circle size and colour between the zero-order and controlled factors indicate the level of dependency of the correlation between the priming effect and the examined factor on the controlled variable (no change in circle size and colour between the controlled factor and zero-order = no dependency; a decrease/increase in circle size and colour intensity = loss /gain of correlation). ANPP, aboveground net primary productivity; EVI, enhanced vegetation index; CInp, C input amount; Gra, relative coverage of grass; Sed, relative coverage of sedge; Forb, relative coverage of forb; SOC, soil organic carbon content; BD, bulk density; PLFA: total PLFAs; Fun, fungal PLFAs; Bat, bacterial PLFAs; F/B, fungi/bacteria ratio; Cenz, C-acquiring enzyme activity; Nenz, N-acquiring enzyme activity; Penz, P-acquiring enzyme activity; CNenz, C:N ratio of enzyme activity; NPenz, N:P ratio of enzyme activity; CPenz, C:P ratio of enzyme activity; LPI, labile pool I; LPII, labile pool II; RP, recalcitrant pool; Carb, carbohydrate; Cut, cutin-derived compound; Sub, suberin-derived compound; FeAld, molar ratio of free Fe/Al oxides to SOC; FeAlo, molar ratio of amorphous Fe/Al oxides to SOC; Ca, ratio of exchangeable Ca to SOC; Mac, proportion of C occluded in macroaggregates; Mic, proportion of C protected by microaggregates; C + S, proportion of C associated with clay + silt fractions. *p < 0.05; **p < 0.01
