The Edaphic-Endemics in the Metal-Rich Soils of Mt. Kiamo in Malaybalay, Bukidnon, Philippines

Abstract

Serpentine soils also known as ultramafic soils comprise 5 percent of the total land area of the Philippines. Majority of the ultramafic soils occur at the edges of the mainland and small island groups. However, little information had been known regarding inland ultramafic forest ecosystems just like Mt. Kiamo, which form part of the northern Mindanao ultramafic soils. Nine sampling plots with 20x20m dimensions were established within the lower, middle and top elevations at 1,563 to 1,782 masl. All plants having ≥5cm dbh were identified and recorded. Soil characterization was done by digging a 1x1m hole at variable depths within sampling plots. Composite soil samples were collected on every horizon and analyzed. Result showed that Mt. Kiamo is composed of 151 species belonging to 114 families and 129 genera. The dominant species include Symplocos ophirensis, Myristica sp., Polyosma integrifolia Blume, Calophyllum soulattri, Phyllanthus everettii, Madhuca sp., Scaevola micrantha, Ardisia elliptica, Weinmannia urdanetensis, Morella javanica, and Omalanthus fastuosus. Soil analysis revealed an extremely high level of Ni, Cr, Mn and Fe. Canonical Correspondence Analysis showed that species' dominance, frequency, and diversity was influenced by Ni, soil moisture and thickness while plant density was influenced by Cr and bulk density.