Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Forest Planning  

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：THE JAPANESE FORESTRY SOCIETY  

<p>[in Japanese]</p>

DOI： 10.11519/jfsc.129.0_804

Publisher：Japan Society of Forest Planning  

<p>To assess potential increases in profitability of privately owned sugi (<i>Cryptomeria japonica</i>) plantations in Atsumi District, Tsuruoka City, Yamagata Prefecture, Japan, we simulated effects of two strategies. One was a traditional strategy involving use of a logging system with cable yarders to intend to produce high-price logs, and the other was an efficient strategy involving use of a logging system with high-performance forestry machines to mass-produce regular logs. We calculated forest rent per ha per year for each strategy by site class and cutting age, changing the maximal height where A-grade logs could be bucked and the ratio of numbers of crooked trees to total trees. The efficient strategy resulted in higher forest rents per year than the traditional strategy in almost all cases, showing that it was usually more profitable,despite standardizing the bucking to produce regular A-grade logs. The findings suggest that changing from a traditional management strategy to an efficient strategy with a high-density forest road network and highperformance forestry machines should increase the profitability of sugi plantations at hypothetical stand level.</p>

DOI： 10.20659/jjfp.51.2_69

Publisher：THE JAPANESE FORESTRY SOCIETY  

<p>[in Japanese]</p>

DOI： 10.11519/jfsc.129.0_68

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Rainwater Catchment Systems Association  

Publisher：Japan Rainwater Catchment Systems Association  

<p>  The Takakuma Experimental Forest at Kagoshima University experienced record rainfall in September 2016. Following this event, we investigated sediment yields related to various types of erosion and collapse along forest roads and slopes within this forest. In particular, we focused on a 6.8-km² study area. To evaluate the effect of rainfall intensity on erosion and collapse, we compared results from September 2016 (when maximum hourly rainfall was 154 mm.) with those from September 2005 (when maximum hourly rainfall was 55 mm). The numbers of forest roads and natural slopes damaged by erosion and collapse in September 2016 were greater than in September 2005. Moreover, when erosion and collapse were of the same type, sediment yields recorded in September 2016 were between 1.4 and 11.5 times greater than in September 2005. Thus, total sediment yield in September 2016 was about 3.1 times greater than in September 2005. Our results suggest that both frequency and magnitude of erosion and collapse are correlated with rainfall intensity in this area. </p>

DOI： 10.7132/jrcsa.23_1_59

Publisher：FOREST ECONOMIC RESEARCH INSTITUTE  

DOI： 10.19013/rinrin.70.8_13

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Forest Engineering Society  

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Forest Engineering Society  

<p>We observed changes in the productivity of log-loading work using a grapple loader and determined how an operator can gain proficiency in operating forest machines by evaluating the subsequent machine work of the operators who were inexperienced in forest machine operations. Consequently, we found that the work time tended to decrease with an increase in the work experience of the operator. This could be because of the improvement in machine operation techniques such as simultaneous operation of actuators or effective uses of machine abilities and the acquisition of work knowledge regarding log treatment or efficient trajectory of the work machine. This consistent decrease in work time and improvement in productivity can be expressed using a log-linear learning model, with a determination coefficient of >0.90 in regression analysis. This showed that an operator's long-term improvement in forest machine operation can be predicted by observing the early progress of the operator. In addition, we revealed that observation of the work should be performed at least five times to complete an exact model.</p>

DOI： 10.18945/jjfes.31.155

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：THE JAPANESE FORESTRY SOCIETY  

[in Japanese]

DOI： 10.11519/jfsc.127.0_670

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Forest Engineering Society  

Forest roads have been constructed on Amami Islands since 1960 by the Kagoshima prefectural government and they have been damaged because of heavy rains. The latest damage of the forest roads was caused by the record rainfall received in October 2010. We collected data on the serious damages of forest roads because of heavy rains on and after 1975 including the damages in October 2010 and analyzed their data. The results are as follows: 1) More than 80 % of the serious damages of forest roads are due to the collapse of cut slope. 2) The frequency of forest road damages in each route decreased the year when a route of forest road was established and is at a low level after around 1995. This may be because of the change in planning and designing in 1995. 3) Analyzation by a mathematical quantification theory class 1 showed that an amount of collapsed mass relates geological and geomorphological conditions of the road route such as catchment area, slope shape, and longitudinal gradient.

DOI： 10.18945/jjfes.KJ00010223635

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Rainwater Catchment Systems Association  

<p>  We conducted field investigations to study temporal changes in erosion and collapse types and sediment yields of yarding roads in an abandoned clear-cut plantation forest. The study site in Kumamoto Prefecture, Japan, is 0.89 km², and was clear-cut in September 2002. Moreover, to study sediment yields before replantation was abandoned in the study site, we interpreted aerial photographs taken in 1963, 1968, 1977, 1983, 1988, and 1995. Many of the shallow landslides that occurred on replanted slopes in the study site before replantation was abandoned were smaller than 400 m², and were on slopes with gradients greater than 30 degrees. Sediment yields from these landslides were greater when the tree age was 20 years or less than when the tree age was 20 years or more. The annual average sediment yield/km² between September 2002 and 2007 from yarding roads in the abandoned clear-cut forest was～17 times greater than the maximum annual sediment yield/km² from shallow landslides on replanted slopes prior to abandonment of replantation. The annual sediment yield/km² from September 2007 to 2008 from those yarding roads was～7 % of the annual average yield during that period from yarding roads. The decrease in annual sediment yield/km² from the yarding roads was due to washout of slope collapse material from filled slopes toward lower parts of the slopes and an increase in the rate of water infiltration caused by vegetation spread into cuttings in grass tracks for cutting and filling slopes. </p>

DOI： 10.7132/jrcsa.20_2_67

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Forest Engineering Society  

In this research, we attempted to clarify the effective machine control technique and working method of an expert worker by analyzing the motion of a grapple loader used in log loading work. In particularly, we focused on the locus of the grapple attachment, and thus installed sensors on each actuator of the knuckle boom for calculating the three-dimensional coordinates of the attachment. The average positioning error was 34.5 mm and the maximum error was 80.2 mm, both of which were considered adequately precise values for our analysis. We then investigated the task of loading 3.49 m^3 of logs on a forwarder carrier, as performed by two operators with different skill levels. As a result, we found that the productivity of work done by the expert was about two times higher than that by the beginner. A close examination of the operations clarified the expert's characteristic technique that contributed to high productivity as follows: 1) the work space was compact, and there was no unnecessary movement; 2) multiple actuators were operated simultaneously, and the attachment was maintained along the most efficient path; 3) the logs were handled stably by being gripped at their center of gravity; and 4) the machine's power was used effectively and continuously during the work. An apparent difference in the operating skills between the beginner and expert has been suggested, and that difference could cause the difference in productivity.

DOI： 10.18945/jjfes.KJ00009844652

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Forest Planning  

<p>The objective of this study was to examine the competition between Japanese cedar (<i>Cryptomeria japonica</i>) and broad-leaved trees at different slope positions in a 5-year-old non-weeded cedar stand in Kagoshima University Forest, Southern Kyushu. We investigated the height growth of planted cedar and broad-leaved trees without weeding treatment stand, and analyzed the species composition and size of broad-leaved trees at different slope positions to compare 5 m strips. We examined the degree of height growth inhibition to compare the affects non-weeding treatment with complete yearly weeding treatment in adjoining even-aged stands. On the upper slope, the height of cedars in the stand without weeding was four-fifths that of cedars in the stand with weeding but was higher than that of broad-leaved trees. In contrast, on the lower slope, broad-leaved trees suppressed cedar height growth in the stand without weeding to 35% of that in the stand with weeding. On the basis of these results, we suggest that weeding in cedar stands can be reduced on upper slopes but is necessary on lower slopes.</p>

DOI： 10.20659/jjfp.49.1_43

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Rainwater Catchment Systems Association  

<p>  This paper addresses the effect of revegetation on forest soil development and water infiltration rates in the shallow landslide scars of slopes covered by volcanic ash and pumice fall. The number of trees and tree species peaked approximately 10 years after the occurrence of the shallow landslides, and then declined with time. Approximately 40 years after the occurrence of the landslides, an apparent steady state was achieved. Based on the temporal variation of the Fisher-Williams' index of diversity, the forest located in the shallow landslide scars reached a climax approximately 40 years after the occurrence of the landslides. Revegetation developed on the forest soil and had grown to a thickness of approximately 40 cm by the time the forest reached a climax approximately 40 years after the landslides. After 58 years, the water infiltration rates and forest soil thickness in the shallow landslide scars were approximately 70 and 65 %, respectively, compared with those measured in the headwater forest of broad-leaf trees.</p>

DOI： 10.7132/jrcsa.20_1_63

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Rainwater Catchment Systems Association  

<p>  From 2000 until 2004, Japanese black pine growing on Sakurajima Volcano has been devastated by pine wilt disease. Most of the pines on the Taisho and Showa lava flows suffered high mortality rates after being invaded by pine wilt disease starting in 2004. We investigated a relationship between the growth of Japanese black pine forest, and the surrounding environment and water infiltration rates into soil of Japanese black pine forest after this invasion and the associated morality. We installed vegetation survey plots in the areas covered by the Taisho and Showa lava flows, which erupted from Sakurajima Volcano in 1914 and 1946, respectively, and conducted field surveys in 2013. In the study plots, for trees with the same diameter at breast height, pines on the Taisho lava flow grew taller than pines on the Showa lava flow; also, the pines on the Taisho lava flow grew faster and with a larger amount of diameter growth than pines on the Showa lava flow. In the study plots, the development of forest soil on the Taisho lava flow was better than that on the Showa lava flow because the Taisho lava flow has a better growth environment for pine, and therefore the water infiltration rate on the Taisho lava flow was larger than that on the Showa lava flow.</p>

DOI： 10.7132/jrcsa.20_1_57

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Forest Engineering Society  

DOI： 10.18945/jjfes.KJ00007331806

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：THE JAPANESE FORESTRY SOCIETY  

DOI： 10.11519/jfsc.123.0.E12.0

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：THE JAPANESE FORESTRY SOCIETY  

DOI： 10.11519/jfsc.123.0.E14.0

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese   Publishing type：Research paper (scientific journal)  

Language：Japanese Book type：Scholarly book

Total pages：7   Language：Japanese Book type：Scholarly book

Total pages：7   Language：Japanese Book type：Scholarly book

Language：Japanese Book type：Scholarly book

Language：Japanese Book type：Scholarly book

Language：Japanese Book type：Scholarly book

Event date： 2011.11

Language：Japanese  

Venue：京都  

国内学会

Event date： 2011.3

Language：Japanese  

Venue：静岡  

国内学会

Event date： 2011.3

Language：Japanese  

Venue：静岡  

国内学会

Event date： 2011.3

Language：Japanese  

Venue：静岡  

国内学会

Event date： 2011.3

Language：Japanese  

Venue：静岡  

国内学会

Event date： 2011.3

Language：Japanese  

Venue：静岡  

国内学会