This Case Study comes from our Japanese distributor, Gigasolar, which is responsible for the distribution and service of MDB products in Japan. In this study, we examine how Sumitomo Forestry Group used Green Climber machines to prepare forest soil for replanting saplings.
Sumitomo Forestry approached Gigasolar with an interesting challenge. What is the best way to manage land preparation and maintenance for new sapling growth? Sumitomo Forestry had to deal with several conditions, such as operator safety, steep slopes, dense vegetation, and hidden stumps.
The previous method was to plant trees around the stumps of old trees where there was available space. The challenge of this method is the possible space constraints, the non-uniformity of the tree rows, and the irregular corridors between the trees to allow the machine to pass through to clear the vegetation.
The ideal solution would be to completely clear and reclaim the land, then plant the trees in straight rows with even spacing. This would create a corridor for undergrowth removal between rows so that saplings are not smothered by weeds. See Image 1: Ideal and actual planting scenarios for a visual representation of the conditions Sumitomo Forestry was in.
The customer concluded that the use of manual chainsaws and mowers required a lot of resources, was not effective, and was not time efficient. To achieve its goals, Sumitomo Forestry was looking for a machine strong enough to remove fibrous materials and at the same time powerful enough to shred stumps. After some initial trials, the radio-controlled machine Green Climber LV 800 was chosen as the most suitable one to do the job.
Image 1: Ideal and actual replanting scenarios
Operator safety
Forestry work can be dangerous if proper safety precautions are not taken. Operators can be subject to sunstroke, the risk of bees and snakes, working on steep slopes, and machine vibration. Many of these hazards are reduced by radio-controlled machines Green Climber, which move the operator away from the machine and allow them to operate at a safe distance. This has been an important factor for Sumitomo Forestry in creating a safer environment for its workers.
Efficiency and cost-effectiveness
One of the challenges for the entire forestry industry in Japan is to attract sufficient human capital to meet the demands of the forestry market. The gradual aging of the workforce, coupled with competition from other industries for candidates, poses unique resource constraints. To address this challenge, the solution has been to look to technology that can help fill the labor gap and make operations more efficient and effective.
By using the Green Climber LV 800 with the TF 150 forestry head, the customer was able to increase efficiency due to the speed of stump grinding. See Table 1 for field measurements.
Table 1: Strain removal data for 7 strains measured
| Tree type | D1 (cm) | D2 (cm) | H (cm) | Volume (m3) | Time (s) |
| Larch | 61 | 56 | 35 | 0.094 | 156 |
| Larch | 32 | 35 | 30 | 0.026 | 77 |
| Larch | 58 | 52 | 57 | 0.135 | 94 |
| Japanese oak | 26 | 28 | 37 | 0.021 | 103 |
| Larch | 35 | 34 | 33 | 0.031 | 110 |
| Larch | 35 | 32 | 36 | 0.032 | 99 |
| Larch | 27 | 35 | 25 | 0.019 | 84 |
| Media | 39 | 39 | 36 | 0.051 | 103 |
The results of these trials were extremely positive. In the time it took an operator equipped with an LV 800 forestry head and TF 150 to clear 0.25ha of all fibrous materials and more than 20 stumps, an operator equipped with a hand mower was only able to clear 0.125ha and still had stumps to grind.
In addition, by planting saplings in straight rows and at regular spacing, the same machines Green Climber can be used to perform maintenance between tree rows during the growing years.
In conclusion, Sumitomo Forestry, under the guidance of Gigasolar, has revamped its philosophy and strategy of clearing land to prepare it for sapling planting so as to increase employee satisfaction and make work much more efficient and effective.
The Sumitomo Forestry Group was founded by Masatomo Sumitomo in 1691 with the philosophy of placing the utmost importance on the integrity and safety of management. Their first work was to fortify the Besshi Cooper mines with timber from the nearby forest, and later they devised a reforestation plan to replenish the surrounding land. Today Sumitomo is the third largest forestry company in Japan, with 48,000 hectares of property.
There are interesting and comprehensive articles on reforestation projects in Japan, showing in great detail what the path looks like and how the best results are achieved.