To obtain the pine trees with high resistance to the pine wilt from susceptible species, the criteria for selective breeding should be made based on the inhibition factors of symptom development. Migration and population growth of the pine wood nematode (Bursaphelenchus xylophilus), and symptom development were compared among eight resistant families of Pinus thunbergii. In the 16-month-old seedlings inoculated with the pathogen on the lower stem, symptom development and nematode propagation were rapid except for one family, Namikata-(t)-73. In the case of 28-month-old seedlings that were inoculated on the shoot, the nematode population was kept low in the lower stems and roots of many specimens. Resistance level was obviously improved especially in the family Misaki-(t)-90 compared to that in the juvenile stage about 30 cm in height. The resistance by the host cells might lag behind the PWN migration in the short seedlings. The age (size) of the seedlings suitable for the selection of resistant trees and for the inoculation test should be reassessed because the level of the resistance changes as the seedlings grow.

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The author analyzed crop damage using agriculture and forestry census data to explain why crops are damaged by wild boars. The relationships between incidence (%) of crop damage in each community and nine factors extracted from census data were analyzed using a generalized linear model. The number of analyzed paddy fields was 57,361. The results showed that the forested land area ratio, elevation, the decreasing ratio of farmers, and the ratio of abandoned cultivated land were positively related to crop damage. Average paddy-field area, number of meetings, and community management level were negatively related to crop damage. No relationship was found between crop damage and the ratio of over-65-year-old farmers or the ratio of subsistence farmers. In conclusion, not only geographical factors but also human factors (i.e., the decreasing ratio of farmers, number of meetings, and community management level) are important as indicators of crop damage.

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Budburst phenology was observed in 29 broad-leaved tree species for 10 years at the Kamiatago Field of Shizuoka University, Japan, located in the warm temperate zone. Prediction methods for budburst days were developed using CT (Cumulative Temperature) and DTS (the number of Days Transformed to Standard temperature) models. In both models, the frequency distribution of starting days of accumulation minimizing the prediction error indicated the lowest value in the case of 45 days from January 1. In the CT model, the threshold temperature values minimizing the standard error were approximately from −7.5 to −2.5°C, while in the DTS model, the Ea values (temperature characteristic) minimizing the error were approximately between 10 and 15. Thus, these parameter sets consisted of starting days and threshold temperatures (or DTS) minimizing the prediction errors which enable the realization of adequate methods to predict budburst days. In discussion, applicability and problems in the two models were mainly discussed.

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In 2004 and 2005, we applied non-woven fabric strips inoculated with Beauveria bassiana conidia (NFS) to infested logs, then covered them in various ways, and compared the mortality of Monochamus alternatus adults emerging from the logs. Covering of the logs with a woven polyethylene sheet (blue sheet, #1500) without openings resulted in a high mortality of adults emerging from the logs. The mortality within 15 days after capture was 86% in Kagoshima and 80% in Sakurajima. Application of NFS increased the adult mortality to 100% and 96% in Kagoshima and 91% in Sakurajima. B. bassiana conidia appeared on 37∼100% of captured adults. However, covering of NFS-applied logs with a blue sheet with openings on both cut end sides or at the center of the upper side of log piles reduced the adult mortality to 92% and 86%, respectively. The adult mortality was also high, 96%, when NFS-applied logs were covered with a biodegradable organic sheet. However, the percentage of adults with B. bassiana conidia was low, 21%, suggesting that the high adult mortality might not be mainly caused by infection with B. bassiana. These results indicate that M. alternatus adults can be controlled efficiently by applying NFS to infested logs and covering them with a blue sheet anywhere in Japan.

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In order to practice effective forest management to prevent floods and landslides, we evaluated the awareness of inhabitants of the Tokoro and Abashiri River basins following a typhoon, using a questionnaire survey administered by a committee of the subprefectural office. Overall, the inhabitants of both basins had a negative impression of the state of the forest. Recognition of the state of the forest and the risk of flooding was classified into six categories using a quantification method III. City residents in the downstream area of the Abashiri River have few concerns about their homes in daily life, and they have a negative impression of the state of the forest. Farmers and foresters living in the middle reach of the Tokoro River are more concerned about their homes, have a positive impression about the state of the forest, and are interested in floods. Many inhabitants are very interested in forest volunteer work as part of flooding and landslide prevention programs, although they had different amounts of experience in terms of such volunteer work and of suffering during floods. The forest management prevention programs must be accountable to the victims of typhoons and there must be a scientific basis for forest planning in terms of regional characteristics (e.g., the state of forests and the causes of flooding). Moreover, it is very important that those affected understand the concepts of forest management and the goals of the prevention programs.

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A paired watershed experiment was conducted in the Fukuroyamasawa Experimental Watershed (35°12′ N, 140°06′ E) in University Forest in Chiba, The University of Tokyo. The watershed is located in a Tertiary formation area and is covered by a mixed plantation of Sugi (Cryptomeria japonica) and Hinoki (Chamaecyparis obtusa). The annual precipitation and annual mean temperature are 2,170 mm and 14.2°C, respectively. Watershed-A (WS-A, 0.802 ha) was the control watershed and Watershed-B (WS-B, 1.087 ha) was the treatment watershed. WS-B was clear-cut in the spring of 1999 and the same species were planted in 2000. The monthly water yield in WS-B increased in the 3 years after cutting; the increase ranged from 3.6 to 54.7 mm/month, and averaged 26.1 mm/month. There was a positive correlation between the increase in the monthly water yield and the monthly precipitation. There was a seasonal variation in the relationship between the increase in the monthly water yield and the monthly precipitation; the increase in the monthly water yield was relatively greater in winter than in summer. The positive correlation between the increase in monthly water yield and monthly precipitation appeared to result from canopy interception; the remaining seasonal variation was caused by transpiration and soil surface evaporation. The change in evapotranspiraion after cutting was estimated; the change in canopy interception was greater than the change in transpiration and soil surface evaporation. Therefore, the seasonal variation in the change in evapotranspiration after cutting depends primarily on the seasonal variation in the canopy interception.

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Monthly weights of the sand blown into different depths of a coastal pine forest (with a maximum forest depth of 800 m) were measured for one year at the Muramatsu sea coast, Ibaraki. The maximum weights of blown sand appear at approximately 20 m into forest. But the weights decrease sharply from 20 m to 60 m into the forest. The sand weights are very slight at over 110 m into the forest. There are two grades in the semi-logarithmic graph that express the process of the decrease in the amount of wind-blown sand with distance into the forest. The first grade is the area from 0 m to approximately 60 m into the forest and the second is from over approximately 110 m. In the Grade 1 area, the reduction rate of the wind-blown sand is much larger than in the Grade 2 zone. Especially in the grade 1 zone, reduction of the forest leads to an exponential decrease in the forest's ability to prevent sand penetration. The character of the sand weight decrease process does not change, even with the addition of the sand weights that are acquired by the pine forest's leaves and branches.

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In this study, annual weight growth of Thujopsis dolabrata var. hondai Makino was calculated by tree-ring width and wood density by soft X-ray densitometry. Correlation coefficients were calculated from this tree-ring information and climate data on monthly average temperature and monthly total precipitation. It was recognized that three kinds of tree-ring information are influenced by average temperature during the enlargement period. In particular, the correlation coefficient value of annual weight growth and June temperature was larger than tree-ring width. It was suggested that annual weight growth data can be used in climatic analysis on similar occasions of tree ring width and wood density.

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We describe the “Funkago method”, a field method to estimate the decomposition rate of deer feces that includes fragmentation of feces but not direct transportation into soil by dung beetles. We compared the loss rate of feces measured using three methods: the Funkago method, the “pellet counting method”, which does not interfere with the activity of dung beetles, and the “Fun-bag method”, which prevents all dung beetle activity. The loss rate of feces estimated by the Funkago method was intermediate; the rate estimated by the Fun-bag method may be lower because there is no ingestion by dung beetles, while the rate estimated by the pellet counting method might be higher because dung beetles bury some feces. The nitrogen concentration and carbon concentration of feces did not differ significantly between the Funkago and Fun-bag methods, suggesting that dung beetles may have little effect on microbial decomposition. Thus, by using these three methods, it is possible to quantitatively evaluate the three loss processes, i.e., transportation and decomposition by dung beetles, and decomposition by microbes.

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