The effect of soil chemical properties on the diversity and colonization of arbuscular mycorrhiza (AM) varies among ecosystems. This study was conducted to assess and compare the abundance of AM in a rehabilitated forest and a logged-over forest soil using the most probable number and spore number methods. | Research Article Turk J Agric For 36 (2012) 451-458 © TÜBİTAK doi: Influence of soil chemical properties on relative abundance of arbuscular mycorrhiza in forested soils in Malaysia Kian Huat ONG*, John Keen CHUBO, Jie Hung KING, Chia Shing LEE, Dennis Shan An SU, Philip SIPEN Faculty of Agricultural and Food Sciences, Universiti Putra Malaysia Bintulu Sarawak Campus, P. O. Box 396, 97008 Bintulu, Sarawak - MALAYSIA Received: ● Accepted: Abstract: The effect of soil chemical properties on the diversity and colonization of arbuscular mycorrhiza (AM) varies among ecosystems. This study was conducted to assess and compare the abundance of AM in a rehabilitated forest and a logged-over forest soil using the most probable number and spore number methods. Glomus () and Acaulospora () were found to be abundant in both sites, while Gigaspora was found only in the loggedover forest. The abundance of AM in the rehabilitated forest based on the spore count was significantly higher than in the logged-over forest by a 6-fold difference. Furthermore, root colonization in the rehabilitated forest was found to be almost 9-fold higher than in the logged-over forest. Such differences are linked to the soil chemical properties. The addition of organic matter during forest rehabilitation activity had created favorable conditions for AM sporulation. Soil P in both forests was positively related to the spore count (r > , P < ) while the most probable number (MPN) was negatively influenced by soil K (r = –, P < ). In conclusion, this study showed that soil chemical properties have a direct effect on the abundance of AM. Key words: Arbuscular mycorrhiza, logged-over forest, rehabilitated forest, soil nutrient Introduction Deforestation is widespread in the tropics. It was estimated that in the 1980s Malaysia lost approximately 250,000 ha of forest annually (McMorrow and Talip 2001). Between 1990 and
