Influence of elevation and soil conditions on arbuscular mycorrhizal fungi colonization in the rhizosphere of <i>Cedrela montana</i>

Soil and fine root samples were collected from <italic>C. montana</italic> individuals at different elevations to study the abundance of AMF and their driving factors. AMF spore abundance was measured using the sieving and decantation method, while root analysis was performed using a staining technique. Soil chemical properties (pH, SOM, N, P, and K) were analyzed. Data analysis included independent linear regressions to assess the effect of elevation on spore abundance, intensity, and frequency of mycorrhization. Additional regressions were conducted to assess the effect of SOM, pH, P, and K concentrations on spore abundance. Finally, linear models were used to evaluate the influence of soil properties and elevation on AMF spore abundance. A significant positive correlation was found between AMF spore abundance and elevation. Positive correlations were observed between AMF spore abundance and pH, as well as between AMF spore abundance and K concentration. Conversely, the total frequency of mycorrhization showed a negative correlation with K concentration. Interactions indicated that spore abundance increases in the rhizosphere of trees at high elevations with pH values of 6−7. In conclusion, AMF spore abundance in <italic>C. montana</italic> roots is associated with elevation and soil physical-chemical conditions in the Andean montane forest. Key soil characteristics influencing spore abundance include pH and K concentration. The composition of soil nutrients regulates AMF-root associations, particularly with K concentration along the elevation gradient.