Ectomycorrhizal Fungal Communities at Different Soil Depths in a Forest Dominated by Endangered Pseudotsuga japonica

• Published in: Journal of the Japanese Forest Society Vol. 99; no. 5; pp. 195 - 201
• Main Authors: Murata, Masao, Nara, Kazuhide
• Format: Journal Article
• Language: Japanese; English
• Published: THE JAPANESE FORESTRY SOCIETY 2017
• Subjects: ectomycorrhizal fungi; endangered tree; Pseudotsuga japonica; soil spore bank; vertical distribution
• ISSN: 1349-8509; 1882-398X
• DOI: 10.4005/jjfs.99.195

To explore whether ectomycorrhizal (ECM) fungal communities differ by soil depth, we studied soil spore banks and ECM fungi colonizing the roots of Pseudotsuga japonica in a forest dominated by P. japonica in Sannokogawa, Nara Prefecture, Japan. Soil samples were collected at 25 points in the forest. At each sampling point, we obtained two soil blocks from each of four different depths (0-5, 5-10, 10-15, and 15-20 cm) . ECM fungi associated with roots in one of the two soil blocks were subjected to molecular identification. ECM spores in the other soil block were grown on seedling roots for 1 year (a bioassay experiment) , and the ECM fungi were then identified as described above. Both the frequency and species richness of ECM fungi on resident trees decreased with soil depth, while the frequency of spore bank was highest in the deepest soil layer. The observed soil spore bank communities were generally species-poor, being composed exclusively of Rhizopogon species specific for Pseudotsuga or Pinus. Fungal colonization increased bioassay seedling growth significantly. Although soil spore banks are the principal source of ECM infection after forest disturbances, this is the first report on the vertical distribution pattern of soil spore banks of ECM fungi. The results indicate that soil spore banks of ECM fungi can be used to conserve endangered P. japonica, which is regarded as a disturbance-dependent species.