Since ca. 70% of the national land in Japan is covered with forests, Japan has abundant potential energy from woody biomass. On the other hand, the energy use of woody biomass is not sufficiently advanced. The production cost of woody biomass in Japan is relatively high, and the supply and demand balances for the energy use is not established. In this study, we focused on a detailed bottom-up approach for the production cost structure of woody biomass; we evaluated the production cost of woody biomass from site preparation to tree trimming with a detailed bottom-up approach for production processes in planted forests in terms of areas, slope angles and forest machines. The quantitative evaluation made it clear that the stand volume of trees influenced the cost structure of the woody biomass production significantly. We also investigated the present cost structure in Sweden, and performed a sensitivity analysis of the production cost in Japan in terms of the slope angles of each area. Based on the analysis, we discussed the technical improvements to achieve a lower woody biomass production cost and proposed innovation pathways (i.e., a technological scenario) to realize the wide spread use of woody biomass. Based on the technological scenario with the relevant improvements, the production cost of woody biomass on a gentle slope can become ca. 4,000 JPY/m³, which is about one third of the present cost.

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.

This case study aimed to clarify people’s preferences regarding a rural Satoyama footpath landscape using the visitor-employed photography method, along with the KJ method, in Yurugi District, Hiratsuka City, Kanagawa Prefecture, Japan. The subjects were 17 adults who participated in a Satoyama walking tour and farming activities with children on September 12, 2014. The subjects took 437 photographs of impressive scenes related to Satoyama activities. We analyzed these photographs to categorize them into six clusters: “forest,” “farm,” “distant view,” “waterside,” “cultural asset,” and “others.” It was possible to divide each cluster into sub-clusters according to visual range and so forth. We can make the following observations using the results. First, it is confirmed that most people preferred beautiful scenery, such as outstanding distant views, water views, and cultural assets. Second, many people also appreciated ordinary scenes such as annex landscapes, which include wooded trails, extremely close views of nuts, and views of participants’ activities. Therefore, the results suggest that forest managers should consider not only the outstanding landscape but also ordinary scenes in their management of Satoyama forest.

Cerasus ｘ yedoensis ‘Somei-yoshino’ Fujino, one of the most popular flowering cherry cultivars in Japan, is considered a hybrid of Cerasus spachiana and Cerasus speciosa. In the present study, 27 microsatellite marker loci on the genetic linkage map of ‘Somei-yoshino’ were genotyped in the wild populations of C. spachiana and C. speciosa. Based on the allele frequencies in the wild population, two alleles of ‘Somei-yoshino’ were assigned to each of them. Of the 54 alleles analyzed, 44.4 and 33.3％ were assigned to C. spachiana and C. speciosa, respectively. The remaining 22.2％ were unidentified because of their equal frequencies or rare observations in both species. In addition, some chromosomes consisted of two regions derived from C. spachiana and C. speciosa, respectively. These results suggested that some ‘Somei-yoshino’ chromosomes were formed by the crossing-over of hybrid ancestors. Thus, we concluded that ‘Somei-yoshino’ may not have originated from a simple hybrid such as a first filial generation, but from a more complicated crossing between C. spachiana and C. speciosa.