Figure caption
Figure 1. Ruellia nudiflora individuals in a) Rural Sites (RS), b) Open Urban Sites (OUS), and c) Deep Urban Sites (DUS) in Mérida City and nearby rural areas. To see the distribution of sampled sites see Fig. S1.
Figure 2. Contrast between urban and rural concentration of a) N, b) P, and c) K, the more relevant macronutrients driving plant-AMF interaction (Heikham et al. , 2009; Salvioli di Fossalunga & Novero, 2019). d) AMF-colonization rates (± SE) of Ruellia nudiflora by AMF, e) spore density in 100g, and f) diversity Shannon index in R. nudiflora rhizospheric soil collected in rural (RS), open urban (OUS), and deep urban (DUS) environments. n.s. indicate no significance, and different letters indicate significant difference (P < 0.05).
Figure 3. Biplots of the first two principal components summarizing variation in a) soil properties and b) plant root morphological attributes, for RS (green), OUS (blue), and DUS (orange) environments. Soil PCA (PCsoil) (a) used recorded information at site level (nsite = 60), while root PCA (PCroot) (b) depicted included information at plant level (nplant= 201).
Figure 4. Association between AMF-colonization rate in R. nudilfora roots and the Z-scores for the first principal component (PC1soil) from the soil principal component analysis (PCA) in RS (green), OUS (blue), and DUS (orange) environments. Independent linear models were performed for each environment.
Figure 5. Sequential Equation Modeling for soil properties and AMF-colonization rates of Ruellia nudiflora . Solid and dashed lines indicate the positive and negative standardized paths, respectively. Path coefficients for RS (green arrows), OUS (blue arrows), and DUS (orange arrows) environments were reported together when detected significantly different by a multigroup test (see methods). Asterisks (*) denote path coefficients that are significantly different from 0. Different letters indicate significant differences between path coefficients. The SEM showed a good overall fit (χ22 = 2.661, P =0.264; CFI = 0.99; RMSEA = 0.074; SRMR = 0.053), as well as a good fit for RS (χ22 = 0.883, P =0.643; CFI = 1.0; RMSEA = 0; SRMR = 0.046), DUS (χ22 = 1.211, P = 0.546; CFI = 1.0; RMSEA = 0; SRMR = 0.046), and OUS (χ22 = 3.287, P =0.193; CFI = 0.00; RMSEA = 0.179; SRMR = 0.092).