Arbuscular mycorrhizal colonization of tree species grown in peat swamp forests of Central Kalimantan, Indonesia

Arbuscular mycorrhizas improve the growth and nutrient uptake of plants and are formed in 80% of all land plants. Little information is available on the status of arbuscular mycorrhizas in tropical soils. The objective of this study was to clarify mycorrhizal colonization of tree species grown in tropical peat soils. Seedlings of 22 tree species in 14 families grown in a peat swamp forest of Central Kalimantan, Indonesia were collected in 2000 and 2001. Roots were stained with 0.05% aniline blue and arbuscules, vesicles and internal hyphae were observed under a compound microscope. Seventeen of 22 species showed arbuscular mycorrhizal colonization. Arbuscular mycorrhizal colonization was observed for the first time in roots of Shorea teysmanniana, Shorea balangeran, Shorea uliginosa (Dipterocarpaceae), Calophyllum sclerophyllum, Calophyllum soulattri (Guttiferae), Cratoxylum arborescens (Guttiferae), Tetramerista glabra (Tetrameristaceae), Palaquium gutta (Sapotaceae), Melastoma melabathricum (Melastomataceae), Gonystylus bancanus (Thymelaeaceae), Hevea brasiliensis (Euphorbiaceae) and Campnosperma auriculatum (Anacardiaceae). C. soulattri, C. arborescens, G., bancanus, Acacia mangium, M. melabathricum and H. brasiliensis showed a percentage mycorrhizal colonization of 50% or higher. No arbuscular mycorrhizal colonization was found in Hopea mengarawan (Dipterocarpaceae), Koompassia malacensis (Caesalpiniaceae), Tristaniopsis whiteana (Myrtaceae), Combretocapus rotundatus (Rhizophoraceae) and Dyera costulata (Apocynaceae). It is suggested that inoculation of arbuscular mycorrhizal fungi can improve the early growth of some tree species grown in peat swamp forests and this will be expected as a key technology to rehabilitate disturbed peatlands. (C) 2003 Elsevier Science B.V. All rights reserved.