Crown of forest shrub is a physical factor that affect amenity of the visitors. In this study, interception of the visual field by individual crown of shrub was quantitatively measured through newly defined crown outline, which is based on visual perception theory, followed by discussion about the factors affecting the size of crown side projection area. The visual perception based crown outline was defined as follow, 1) the circles which have fixed diameter (Fixed Diameter Circle, FDC) are circumscribed to the crown projection on the image, 2) the group of the inner arcs is defined as the outline, named AVO (Approximated Visual Outline). The image of the crowns was taken with white cloth behind them. The crown of 28 individuals of Eurya japonica Thunberg were examined with using FDC which have diameter of 30cm. The actual sizes of crown were well estimated from the images. The AVO area was about twice as large as the Profile Projection Outline (PPO) area and about half as Elliptic Outline (EO) area. Each of three crown type show allometric relationship with stem size. The crown depth was increased as the light intensity was increased. The PPO area, which is an index of the amount of mass in a crown, per crown basal area showed positive relationship with light intensity, although PPO area per crown volume have no relationship with light intensity. The fact that the inner structure of the crown of the species do not change along light intensity shows that not structure but size is a primary determinant of the impression of the crown.

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The chemical properties of leachates percolating through A_0 and surface soil (A horizon) using by micro-lysimeter method were analyzed in a Cryptomeria japonica stand and a deciduous broadleaved forest (dominated by Quercus serrata) at Sanbe Forest of Shimane University. The pH of water through A_0 layer was lower than that of through-fall in the Quercus forest. The Ca and NO_3 concentrations of water through A horizon in the Cryptomeria forest, and NO_3 concentration of water through A_0 layer in the Quercus forest, are lower than those of through-fall. Al concentrations of both forests increased from autumn to winter, but are extremely low compared with the spraying experiment of artificial acid rain. Amounts of ions leaching from surface soil are greater in Cryptomeria forest than in Quercus forest. The rates from A_0 layer to total amount of ions leaching were 23〜50% for Ca, 39〜43% for Mg, 18〜36% for K, 21〜62% for Cl, 3〜222% for NO_3, 8〜60% for SO_4, and 41〜56% for Al, respectively. These rates were high in the Quercus forest, except for Mg, Na, NH_4.

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The spatial and vertical differences in soil nitrogen (N) availability were evaluated in-situ by ion exchange resin (IER) along a slope in a Cryptomeria japonica plantation to clarify the relationship between laboratory rates of N transformations and in-situ N availability. The NC_3^--N dominated IER inorganic N at all positions on the slope, in contrast to the extreme spatial difference of laboratory nitrification to N mineralization ratio. The IER total inorganic N at a depth of 5 cm in the mineral soil was 15.9-57.5 kg-N ha^<-1> year^<-1> and showed a weak negative correlation with the distance from the bottom of the slope (r_s=-0.32, P<0.10), although laboratory N mineralization did not changed with positions on the slope. This may be because of higher nitrification at a lower position on the slope and the greater mobility of NO_3^--N. The IER total inorganic N at a depth of 10 cm or deeper was 9.8-15.6 kg-N ha^<-1> year^<-1> and showed a minor spatial difference at selected four points on the slope. Two-way ANOVA including the result at a depth of 5 cm suggested spatially different vertical change of IER total inorganic N. The IER total inorganic N decreased with soil depth at a lower position on the slope, while it showed less or no decrease with soil depth at an upper position. These results and the vertical distributions of fine roots suggested lower utilization of inorganic N by plants at an upper position on the slope.

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A simulation model of forest dynamics was made based on the ZELIG model, and was used to simulate a broad-leaved secondary forest in Mt. Ginkakuzi National Forest, where a permanent plot was settled and surveyed. Though some uncertain data made it difficult to evaluate the results quantitatively, it was predicted qualitatively that Quercus glauca would dominate in the stand. Four factors were assumed to be required for dominance in this simulation : abundant recruitment, high shade tolerance, long life span and large individual size. There were only two tree species, Q. glauca and Cleyera japonica, which satisfied the necessary conditions in the species simulated. However, C. japonica lacks medium and large trees in the forest and was predicted to take a long time to increase its presence. Therefore, Q. glauca was predicted to be the most dominant species. It was supposed that Q. glauca should be noticed when the forest managers wanted to suppress the succession to evergreen stands.

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This paper is to study on the influence of its growth and biomass under saline irrigation and differency of nutrition in sandy soil by making 4 treatments for Populus alba L.(saline irrigation has or not, nutrition has much or few). The tree height, diameter and biomass in non-saline irrigation and much nutrition plots were larger than those in saline irrigation and few nutrition plots in 1999 and 2000. The roots in saline irrigation plots were distributed more shallow in depth of soil and shorter in the width than those in non-saline irrigation plots. It was shown the decrease of the photosynthetic, transpiration efficiency and water potential of leaves in saline irrigation plots. The leaf areas also decreased with increase of ages in saline irrigation plots. The growth of Populus alba L. was mainly influenced by nutrition in first year after planted and by nutrition and saline irrigation in second year.

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Line density effect on the yield of Leucaena leucocephala (Ll) and Gliricidia sepium (Gs) as cattle feed and green manure material in the Alley-cropping system was examined at Khon Kaen, Northeast Thailand. Seedlings were transplanted in June on the 5m interval ridge with line spacing of 0.25m, 0.5m, 1.0m and 2.0m, and monitored the growth monthly until January. A pattern common to both species was growth in rainy season and following cessation in dry season. Survival after severe desiccation differed by species i.e. Gs with shallow root died notably while Ll with deep root survived. Averaged mass of Ll was the highest at 1m spacing and lowest at 2m, and the difference grown larger while difference was not clear in Gs over whole period. The denser the interval, the higher the yield per length became. Above ground yield converted into biomass ranged between 0.73 to 0.06 in Ll and 2.14 to 0.27 ton/ha in Gs. The spacing-dependent difference was apparent from the initial stage in Ll. Leaf yield after rainy season ranged 800 to 80 g/10m-ridge in case of Ll, and harvest of 0.25m or denser spacing by October was recommended since giving the highest leaf yield on the assumption that 2cm in stem diameter was the handling criteria.

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Cryopreservation was examined as a way of preserving rare cherry trees. The shoot apex was removed from mature winter buds and treated with cryoprotectant mix solution. Then, the apex was placed into a cryotube and preserved in liquid nitrogen. When thawed, the shoot apex survived and the leaf opened when the apex was transferred to regenerate agar medium after treatment in high concentration sucrose liquid medium. The survival percentage was high when program freezer was used. Adventitious shoots appeared healthy and the clones grew normally. In previous studies using short pre-treatments, the survival percentage was lower, and regen- eration was not ensured. Subsequently, a difference in leaf morphological changes was noted on cloned plants.

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The tree height and breast height diameter (DBH) were measured in a 17-year-old stand to detect the hereditary characteristics of the growth of Cryptomeria japonica (CJ) and Chamaecyparis obtusa (CO). The tree height was measured from the 3rd to 17th year after planting. The mean annual height increment (MH) from the 3rd to 5th year was less than 0.2 m for both trees. Due to the error at the time of planting, the repeatability of clones (RC) fluctuated with the year (35-46% for CJ and 41-56% for CO). From the 6th to 10th year, the MH was 0.4m for both trees, and the variance of replication increased in CJ, but, the RC tended to be stabilized in both trees (37-41%, 53-58%). From the 11th to 17th year, the MH was 0.9m for CJ and 0.8m for CO. Accordingly, the variance of replication decreased in CJ and the RC increased year by year in both trees, being 53-58% for CJ and 56-68% for CO. The DBH was measured from the 9th to 17th year. The mean annual DBH increment was 1.3cm for both trees. At the 9th to 10th year, there was an effect of individual size especially in CO, and the variance of replication in CJ, the RC was low (26-32%, 32-33%). However, at the 11th to 17th year, the variance of replication decreased in CJ. The RC increased markedly for both trees being 42-61% for CJ and 37-78% for CO. Thus, the time lag until the appearance of the hereditary characteristics, especially tree height was greatly affected by the mean annual increment. In CJ, the tree height and DBH were affected by the variation of replication, while in CO, the DBH in the first few years of the survey was affected by the individual size .

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Three edible mushrooms, Lentinula edodes, Pholiota nameko and Naematoloma sublateritium were inoculated to Quercus crispula logs killed by the infestation of Platypus quercivorus. The fruitbody yield of the mushrooms and the number of beetles emerged from the logs were observed. Since all mushrooms yielded fruitbodies on the logs, it was suggested that dead Q. crispula logs can be used for mushroom cultivation. The number of emerged beetles was smallest from the logs inoculated with L. edodes. Subsequently, four edible mushrooms, L. edodes, P. nameko, N. sublateritium and Flammulina uelutipes were inoculated to dead standing trees of Q. crispula, and the number of beetles emerged from the trees were observed. Again, the number of emerged beetles was smallest with the trees inoculated L. edodes. These results suggest that the beetles can be controlled by the inoculation of L. edodes.

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A filamentous fungus has been isolated from wood killed by mass mortality of Quercus trees. Effects of four edible mushrooms, Lentinula edodes, Pholiota nameko, Naematoloma sublateritium, and Flammulina velutipes on mycelial growth of this unidentified oak pathogenic fungus were estimated on dual culture in petri dish. The results showed that only L. edodes inhibited the mycelial growth of the pathogenic fungus. Subsequently, we selected an excellent strain by carrying out dual culture between the pathogenic fungus and 73 strains of L. edodes. This strain is expected to be useful to control mass mortality.

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Boring of Platypus quercivorus in Quercus crispula, Q. serrata, and Castanea crenata trees and mortality of the bored trees were investigated at a newly damaged forest by the beetle in Kyoto Prefecture. Rate of trees bored by the beetle was high on the larger trees of both Q. crispula and Q. serrata, and the density of the entry holes was also high on these trees. However, the mortality of the bored trees was higher on Q. crispula than Q. serrata. The bored trees were concentrated at the area where thinning had been done. At the thinning area, the range between the highest and the lowest daily temperature was large, and the air humidity was low.

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Boring of Platypus querciuorus and mortality of the bored trees were investigated in two newly damaged forests by the beetle in Kyoto Prefecture. Rate of trees bored by the beetle was high on both Quercus crispula and Q. serrata, and the density of the entry holes was also high on these trees. The density of entry holes increased with the diameter of trunk for these two tree species, and was not different between the two. However, the mortality of the bored trees was higher on Q. crispula than Q. serrata. From these results, it is cleared that the beetle prefer to bore into the larger trees of both Q. crispula and Q. serrata, and Q. crispula is likely to be killed by the infestation of the beetle rather than Q. serrata. At one of the two study sites, the damage spread out from the area where both thinning forest and girdling of oak trunks to kill them had been done. At another study site, the damage spread out from the area where thinning forest had been done. These suggested that tree felling with remaining the large Q. crispula trees raises the mass mortality of oak trees.

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Ambrosia beetles were collected on adhesive paper traps that were set on cages containing logs of Quercus serrata and Q.crispula treated in various ways. Except for a few males of P.quercivorus that were collected at logs that were split into four parts 20 days after being cut, this beetle was not attracted to any logs, including logs inoculated with an unidentified oak-infecting fungus that is associated with this beetle. Many other ambrosia beetles were collected at autoclaved logs. This result suggested that the response of P.quercivorus to the odor of host trees was different from that of other ambrosia beetles.

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