To examine the applicability of non-woven fabric strips with Beauveria bassiana conidia (NFS) to the control of Monochamus alternatus adults in southern Kyushu, we piled 1 m³ of Pinus thunbergii logs infested with M. alternatus in each of two outdoor cages, and placed 2,500 cm² of NFS on one of these piles in May 2003. We covered each log pile with a blue vinyl sheet containing two triangular openings (the base: 50 cm, the height: 40 cm) on both cut end sides of the log piles. We captured adult beetles every day and reared them individually to determine the longevity and infection by B. bassiana. Infection by B. bassiana did not affect the average rate of food consumption. By applying NFS, the percentage of adults on which B. bassiana produced conidia increased from 2 to 34 % and the mortality rate of adults 15 days after emergence from 20 to 52 %. These mortality rates were similar to those obtained by the same application test to 0.2 m³ of logs in 2001, suggesting that the dose of NFS per log volume might determine the efficiency of B. bassiana. The mortality rate and infection rate in this study were lower than those reported in Kanto District. We discussed the problems to be solved for the improvement of the efficiency of NFS-application in southern Kyushu.

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To examine the effects of riparian deforestation on juvenile masu salmon (Oncorhynchus masou), I compared the salmon's habitat between an undisturbed watershed and a disturbed watershed where the riparian forest along the mainstem had been converted into meadow, in northern Japan. I investigated salmon abundance and habitat characteristics in the mainstems and the tributaries of the 2 watersheds, in 3 seasons: summer (Jul.∼Aug.), early winter (mid-Oct.∼mid-Dec.), and spring (mid-May∼early Jun.). As for the habitats of the 2 watersheds, it was noticeable that the maximum water temperature was higher and the cover of woody debris was less in the mainstem of the disturbed watershed, where salmon densities were generally lowest. According to multiple regression analyses, maximum temperature in summer and debris cover in early winter are the most important variables for masu salmon. Subyearling salmon densities tended to be higher in the narrower channels (tributaries and the upper reaches of the mainstem), probably because of the distribution of spawning redds. These results indicate that riparian forests are very important to masu salmon, and that small tributaries are important for spawning and as fry habitat.

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Dimensions of wood chips from logging residue stems and comminuted with a cutter-type chipper were measured to examine size distributions and analyze the relationship between tree species and shape of the logs. Size distributions of the chips (destined for burning in a wood chip boiler), i.e. length, width, and thickness were obtained through sieving and a stratified sampling method and expressed with log-normal distributions. Chip length and width of Chamaecyparis obtusa were significantly larger than those of Cryptomeria japonica which has a smaller specific gravity. The proportion of chips with greater width was significantly greater for larger diameter logs than for smaller diameter logs. There was no significant relationship between chip thickness and length-width ratio with the factor of tree species and log shape. Chips larger than a nominal sieve size often go through the sieve; however the results suggest that the actual length of sieved chips can be controlled by appropriate selection of sieve size as related to chip size distribution.

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Inoculation of an avirulent isolates of the pinewood nematode, Bursaphelenchus xylophilus, is known to induce resistance in Japanese red pine (Pinus densiflora) trees to pine wilt disease caused by virulent isolates of the same nematode species. Mature P. luchuensis trees were examined to determine whether the resistance would also be induced by inoculation of an avirulent isolate in this species or not. The pine trees were pre-inoculated with the avirulent nematode or distilled water, and then inoculated with the virulent nematode. Pre-inoculation with the avirulent nematode decreased the tree mortality after the inoculation with the virulent nematode compared with pre-inoculation with distilled water. The persistence of induced resistance was confirmed by inoculating the surviving sample trees with the virulent nematode again in the following year.

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We analyzed the relationships between the annual growth rate of the diameter at breast height (ΔDBH) and the sun-exposed crown size (sun-exposed crown diameter, length, and surface area) of trees in 38 to 210 year-old stands in the Yoshino Forestry area to propose quantitative criteria for sun-exposed crown management for the production of high-quality timber under long-rotation forestry. We obtained significant regressions of ΔDBH against the sun-exposed crown diameter and surface area. The reliability of the regression and convenience of field measurements suggest that sun-exposed crown diameter (Dsc) can be used as a useful criterion for sun-exposed crown management. The ΔDBH-Dsc relationship varied with stand age, indicating a decline in the efficiency of stem diameter growth per unit of sun-exposed crown diameter. This suggests that differences in the ΔDBH-Dsc relationship should be considered in long-term forest management, which includes a wide range of stand ages and tree sizes. We used the ΔDBH-Dsc relationship to estimate the Dsc ranges that corresponded to ΔDBH of 0.25∼0.54 cm/year (approximately 2-mm annual growth ring widths) for each stand age. The estimated Dsc ranges predicted annual ring widths within approximately 2 mm with 74∼88% accuracy. We conclude that this approach provides accurate quantitative criteria for a given stand age for the selection of which trees to leave for the production of high-quality timber with evenly spaced annual rings.

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In order to evaluate the role of Apodemus mice in invasion of Pasania edulis Makino into a plantation of Japanese cedar, Cryptomeria japonica D. Don, we studied the primary dispersal of acorns from parent trees, secondary dispersal of acorns by mice, and seedling establishment in the plantation and adjacent evergreen broad-leaved forest at the Kagoshima University Forest from April 2003 to January 2005. By primary dispersal, acorns were dispersed on average 2.4 m from the crown edge of the parent trees, and the maximum distance of invasion into the plantation by primary dispersal was 4.4 m from the border of the forests of two types. Of the 200 magnet-attached acorns we placed in the broad-leaved forest in autumn of 2003 and 2004, mice transported 66 and 58 acorns, respectively, into the plantation. The maximum distance from the border to cache site in the plantation was 34.5 m in 2003 and 18.5 m in 2004. Six acorns cached in 2003 remained intact until the next spring. In the plantation, the density of seedlings decreased with the distance from the border, but within 10 m of the border, the density did not differ significantly from that in the broad-leaved forest. From these results, we concluded that wood mice contribute to the invasion of P. edulis into the plantation as an important seed disperser.

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In 17C, Genroku period in the Edo Era, Mr. Bunzaemon Kinokuniya, who was a citizen of Edo, cooperated with Mr. Genzou Matukiya, who was a citizen of Suruga. The two were jointly contracted to log for the use of the Shogunate. That felling area was about 3,600 ha, and the gathered logs about 20,000 m³; it was used for only 9 years. The place of large-scale felling was at the upper reach of Ohi River, in northern Shizuoka Prefecture, Japan. The logs were carried to Suruga Bay by floating them in the Ohi River. Then the logs were carried by ship from Suruga Bay to Edo Bay. The floating damaged many logs. The wages of loggers were very low. Loggers cut many pole timbers, to supplement their income. Consequently the felling area was clear cut. The felling area was surrounded by high mountains of the 3,000 m class, and belonged to the heavy rainfall region in Shizuoka Prefecture.

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Fencing is often used to prevent crop damage by wild animals. Commonly used fences are classifiable into two categories: simple-temporary and durable-fixed. Although durable fences are believed to be more effective than simple fences, they are frequently reported to be less effective than expected. The author used path analysis to determine which of a series of factors influenced effectiveness. Analyses showed that effects of fencing were influenced by incomplete maintenance and installation. These inadequacies can be alleviated through expert advice and group activity. These results suggest that more attention should be given to these human factors to increase the effectiveness of fences in reducing crop damage by wild animals.

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Impact bending work was measured for 101 green samples extracted from branches of a Hinoki (Chamaecyparis obtusa) tree with the pendulum type impact tester. The measured work was proportional to the 3rd power of a sample diameter. Seventy-two samples among the lot were broken completely, and the measured work for them was proportional to each cross-sectional area. The result suggested that it was hard for a small branch to be broken in a stand. It was not denied that Hinoki branches would be broken by a strong wind.

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An olfactometer was developed to analyze the olfactory response of the Japanese horntail, Urocerus japonicus, adult to volatile constituents of trees. The olfactometer consists of T-shaped branched tubes made from polymethyl methacrylate and polyvinyl chloride, and of chambers to place samples. To the evaluate a suitability of the olfactometer, α-pinene was used as a standard attractant, because it was known to attract female horntails in the field. Females were significantly attracted to α-pinene in the olfactometer significantly, supporting that the olfactometer satisfied requirements to analyze an olfactory response of the horntails to volatiles. The assay revealed that volatile constituents from a fresh bolt of Japanese cedar Cryptomeria japonica, which is a host plant of the Japanese horntail, also attracted females. However, males were not attracted to either α-pinene or volatile constituents from the fresh cedar, indicating that olfactory responses to volatiles are different between males and females. These results suggest that the olfactometer developed here is useful for investigating olfactory responses of the horntails to tree volatiles.

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To test the utility of scarification to promote sustainable management of Betula maximowicziana resources in a second-growth forest established after a forest fire, an area of 0.27 ha was clear-cut and then scarified using a hydraulic excavator in October 2001. In this procedure, the soil of the A and A₀ layer was partly kept after scarification. The density of B. maximowicziana seedlings remained relatively low, at approximately 20∼30 m⁻¹ from 2002 to 2004, but it increased to 120 m⁻¹ in 2005. Vegetation cover of Sasa senanensis was low after the scarification, and was still only 8% in 2005. Thus, it was not responsible for preventing seedling emergence of B. maximowicziana. The results indicate that scarification with hydraulic excavator is effective against seedling emergence and establishment of B. maximowicziana.

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In order to evaluate the dendroclimatological potential of Fokienia hodginsii growing in montane forests of the Indochina Peninsula, increment core tree-ring samples were collected from 40 individual trees of F. hodginsii from northern Vietnam. Subsequent dendrochronological analysis revealed that ring-width growth was very uneven depending on radial direction with frequent wedging and missing rings. These difficult features hindered the cross-dating of some of the rings in 29 sample trees. However, the remaining 11 trees were not only precisely cross-dated but also revealed significant correlations in ring width among them. The established site chronology based on those 11 trees dates back to AD 1444, resulting in the longest ever made in Southeast Asia. Response analysis of tree-ring width with climate records revealed that hot weather and/or insufficient precipitation during the previous monsoon and current pre-monsoon seasons suppressed radial growth. With isolated but possibly wide natural distribution of Fokienia throughout the northern part of the Indochina Peninsula, Laos, southern China and possibly Myanmar, continued effort toward the development of tree-ring network would lead us to reconstruction of the regional climate.

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