**5. Future perspectives on forest biomass in Japan**

*Biotechnological Applications of Biomass*

*Unutilized thinnings that were once abandoned in planted forests.*

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**Figure 16.**

**Figure 15.**

*Changes in the utilized amount of forest biomass.*

The self-sufficiency rate of wood in 2017 as shown in **Figure 4** was 36.2%, but it

It is unclear whether unutilized thinnings can continue to be utilized as energy in the future. Planted forests are going to mature so that the value of the thinning material will increase and the amount available for energy use will decrease. On the other hand, "true" logging residues such as tree tops and limbs are not currently

goes down to 31.6% when the use of wood as fuelwood is excluded.

The use of the whole-tree logging system has increased through the spread of mechanization, such as the use of processors and harvesters. This situation makes logging residues easier to collect. So an efficient and low-cost harvesting, transporting, and chipping system for logging residues must be established. The author's

**Figure 17.** *Experimenting with a forwarder hauling of slashes.*

**Figure 18.** *Comminution of logging residues with a tub grinder.*

**Figure 19.** *Chipper-forwarder.*

research group experimented with the collection of logging residues by a forwarder (**Figure 17**) [11]. Comminution of logging residues was also investigated (**Figure 18**) [12], and the harvesting (collecting and comminuting) cost of logging residues was calculated as 76.0 USD/dry-t [13]. As compared to Sweden and Finland, where the energy utilization of forest biomass is making steady progress (see **Figure 10**), the calculated cost is relatively expensive, so that the development of dedicated machines such as the chipper-forwarder (**Figure 19**) [14] and bundler (**Figure 20**) [15] may be necessary [16].

The use of small-sized trees is also promising. The area covered by planted forests that have undergone final cutting and subsequent reforestation is now gradually increasing. Thus, a cleaning operation in young planted forests will be necessary 15–20 years from now, when the FIT will expire. So the development of

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**Figure 22.**

**Figure 21.**

*Multi-tree feller-buncher.*

calculated as 99.4 USD/dry-t.

*Current Situation and Future Outlook of Forest Biomass Production and Its Utilization in Japan*

efficient harvesting technology for small-sized trees will be necessary. An accumulative felling machine (**Figure 21**) may be effective [17, 18]. Harvesting small-sized trees with a truck-mounted multi-tree felling head was attempted (**Figure 22**), and the harvesting (felling, collecting, and comminuting) cost of small-sized trees was

*Harvesting small-sized trees with a truck-mounted multi-tree felling head.*

*DOI: http://dx.doi.org/10.5772/intechopen.93433*

*Current Situation and Future Outlook of Forest Biomass Production and Its Utilization in Japan DOI: http://dx.doi.org/10.5772/intechopen.93433*

**Figure 21.** *Multi-tree feller-buncher.*

*Biotechnological Applications of Biomass*

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**Figure 20.** *Bundler.*

**Figure 19.** *Chipper-forwarder.*

[15] may be necessary [16].

research group experimented with the collection of logging residues by a forwarder (**Figure 17**) [11]. Comminution of logging residues was also investigated (**Figure 18**) [12], and the harvesting (collecting and comminuting) cost of logging residues was calculated as 76.0 USD/dry-t [13]. As compared to Sweden and Finland, where the energy utilization of forest biomass is making steady progress (see **Figure 10**), the calculated cost is relatively expensive, so that the development of dedicated machines such as the chipper-forwarder (**Figure 19**) [14] and bundler (**Figure 20**)

The use of small-sized trees is also promising. The area covered by planted forests that have undergone final cutting and subsequent reforestation is now gradually increasing. Thus, a cleaning operation in young planted forests will be necessary 15–20 years from now, when the FIT will expire. So the development of

**Figure 22.** *Harvesting small-sized trees with a truck-mounted multi-tree felling head.*

efficient harvesting technology for small-sized trees will be necessary. An accumulative felling machine (**Figure 21**) may be effective [17, 18]. Harvesting small-sized trees with a truck-mounted multi-tree felling head was attempted (**Figure 22**), and the harvesting (felling, collecting, and comminuting) cost of small-sized trees was calculated as 99.4 USD/dry-t.

**Figure 23.** *Experiment of harvesting willow trees using a sugarcane harvester.*

Short rotation woody coppices (SRWC) have a huge potential. Before and during World War II, an average of 50 million m3 /y of naturally regenerated forest was felled and harvested for energy use in the form of charcoal and firewood in Japan. The annual available amount of naturally regenerated broad-leaved trees used as SRWC is estimated to be 9 million dry-t/y [7]. The energy utilization of SRWC has already begun within the framework of the FIT. Moreover, the development of short rotation forestry in abandoned farmlands may be worth considering. Commercial willow plantations have been cultivated for bioenergy purposes in Sweden since the 1980s, and around 16,000 ha of short rotation willow plantations were established domestically from 1986 to 2000 [19]. In 2006, about 8,000 ha of the first commercial willow biomass crops in North America were started in upstate New York [20]. Growing and harvesting willow trees aimed at short rotation forestry was experimented with in northern Japan. A sugarcane harvester that was used in southern Japan was applied for harvesting willows during its agricultural off-season (**Figure 23**) [21]. The harvesting (growing, cutting, collecting, and comminuting) cost of SRWC was calculated as 136 USD/dry-t [22].
