Abundance and Distribution of Arbuscular Mycorrhiza in the Ultramafic Soils of Mt. Kiamo in Bukidnon, Philippines

The present study was aimed to investigate the occurrence of mycorrhiza in an inland ultramafic mountain ecosystem to determine if the extreme soil conditions associated with high concentrations of toxic heavy metals could deter their presence across various elevation gradients. Twelve (12) sampling plots distributed across the major elevation gradient were used in this study. Soil samples were collected at a depth of 30cm and were analyzed to determine the heavy metal content. The standard protocol in the separation of spores was followed. Spore identification was based on existing literatures. Results revealed four genera of arbuscular mycorrhiza fungi (AMF) which includes Glomus, Acaulospora, Scutellospora and Entrophospora. Among the four genera, Glomus was the most abundant and widespread comprising of 40 species while Acaulospora sp. and Entrophospora sp. were the least observed. Further, no significant correlation was observed between mycorrhizal spore count to nickel and chromium implying that these heavy metals did not significantly affect the occurrence and distribution of mycorrhiza. However, a similar pattern of decreasing spore count with increasing elevation was also observed in comparison to tropical mountain forest ecosystems with normal soil conditions.