Arbuscular mycorrhizal fungal inoculation improves Albizia saman and Paraserianthes falcataria growth in post-opencast coal mine field in East Kalimantan, Indonesia

Opencast mining carried out in the natural forests of Indonesia has resulted in difficulty of reforestation due to soil removal. Arbuscular mycorrhizal (AM) fungi can increase growth of tree species in disturbed fields. The objective of this study was to investigate the effect of inoculating three native AM fungi on the growth of Albizia saman and Paraserianthes falcataria in a nursery and a post-opencast coal mine field. Seeds of A. saman and P. falcataria were inoculated with three native AM fungi, Rhizophagus clarus, Gigaspora decipiens, and Scutellospora sp., and sown in sterilized compost under nursery conditions for six months. Non-inoculated seeds were used as control. Inoculated seedlings were transplanted in a post-opencast coal mine field and grown for seven months. AM colonization, shoot nitrogen. (N) and phosphorus (P) concentration, stem diameter, and shoot dry weight were measured both in the nursery and in the field. AM colonization was 3-82% under nursery conditions and increased shoot P content and dry weight. Stem diameter, shoot N content, shoot P content, shoot dry weight, and survival rate under field conditions were higher in inoculated seedlings than in control seven months after transplanting. The results suggest that inoculating tree species with AM fungi promotes reforestation of post-opencast coal mine field. (C) 2016 The Authors. Published by Elsevier B.V.