Morphological types of arbuscular mycorrhizas in pioneer woody plants growing in an oil palm farm in Sumatra, Indonesia

Morphological types of arbuscular mycorrhizas (AM) in pioneer woody plants were examined in an oil palm farm 1 year after reclamation. In total, 18 plant species belonging to 15 genera in 9 families were examined, and the Arum type was found in 12 species belonging to 9 genera in 5 families. In contrast, the Paris type was found in 5 species belonging to 5 genera in 4 families. The number of plant species with Arum-type AM was always higher than that with Paris-type AM in all four sampling plots. All the examined species in Euphorbiaceae, most of which are fast-growing pioneer trees and were dominant in forming the canopy in secondary forests, were found to have Arum-type AM. These results suggest that Arum-type colonization is beneficial for fast-growing woody plant species.