As a result of the rapid growth of Internet, people have acquired new way to acquire information. WWW (World Wide Web) is a tool of multimedia information service, and expected to play a key role in world-wide communication network in the near future. This study examined what kind of information was currently provided about forest and forestry on WWW in Japan. The survey results showed a tendency that information contents were different between the information servers; public administrations, business, and individuals. It was also concluded that targeting of users makes the providing of information more effective. However, the contents and the effects of providing of information surveyed in this study only reflected how the information system of each server is organized at the time of survey; Sept. -Dec. 1996. Contents of information on WWW will keep changing and improving through the interactive action. Organization and individuals related to forest and forestry were expected to construct system of communication network and make more efforts to find out the needs of the general public for information concerned with forest and forestry.

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The purpose of this study is to analyze the quantitative effect of log quality on log price in the local market using Hayashi's quantification type-1 method. In this analysis, log price was set as the dependent variable and the 8 factors (length, diameter, crook, knot, color, age, cutting position and annual ring) were set as independent variables and these 8 factors were classified into 29 categories according to the external form of the logs in this quantification. The factors which had a significant effect on log price were in order of ranking: diameter, crook, age, length, knot, color, cutting position and annual ring. In this case, 72% of the deviation of the log price was statistically explained by these factors. This result can therefore furnish more effective information for forest management decision making and to develop a silvicultural technology.

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Mainly based on interviews and questionnaire, this paper firstly outlines the state of sawmill industry and distribution of regional timber in Osaka Prefecture, which is one of the metropolitan areas in Japan. The connection between sawmill industry and regional timber is then discussed. In Osaka Prefecture, there are no large sawmills that produce a large quantity of standard-size lumber and sell it to auction markets or wholesalers. Instead, small retail sawmills consume regional timber and directly sell their production to local builders or carpenters. They mostly produce nonstandard-size lumber such as pillars, lintels, boards, beams and so on, using Japanese cypress, Japanese cedar, Japanese pine, or Douglas fir. These kinds of lumber are used for expensive houses. Because demand for those houses is still high in the suburbs of Osaka, many retail sawmills have been able to maintain their business. The Osaka Fushinren Log Auction Market, run by Osaka Prefectural Federation of Forestry Cooperatives, deals with 70% of the timber produced in Osaka Prefecture, and plays an important role of connecting regional timber with sawmills in the metropolitan area.

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Since 1996, a governmental model project "Entrusted forest management system" has been started in Tokushima Pref. This project aims to define the forest boundaries in private forest. We investigated this project in Yamashiro town and Aioi town mainly based on interviews and questionnaire. In these towns, the project is proceeding smoothly, the boundaries in 180 ha of private forest were defined in 1996. We discussed the frame and details of this project, and following results were observed; ョ There were close cooperation between forest owner's cooperative and a public office. ゥ As forest owners knew the necessities of the project, they also cooperated actively in carrying it out. And as a problem in the future; (D Taking.account of the decrease in forest owners who know their boundaries well, it will have more difficulties to carry out this project.

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This paper examines the characteristics of attitudes toward forests among visitors to forest recreation area compared with attitudes of the public in general. The study used two sets of data. The one is results of a survey to the residents both in a upper stream village surrounded by forests and in a down stream fairly urbanized area in Osaka prefecture in December, 1996, and the other is results of a survey conducted in May and August, 1997 to the visitors to the Ashiu Kyoto University Forest which is a popular recreational site and to which many visitors come repeatedly. The comparison suggests the following; 1) Visitors to the Ashiu Forest have rather different attitudes toward forests compared with people living in the upper stream. 2) Visitors to the Ashiu Forest and people in the down stream are in common with respect to their positive agreement on wildlife's right to live. 3) Frequent visitors in particular are interested in information related to forests and tend to put higher values to various functions of forests.

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This study aims to understand forest function and establish an estimation method depending on regional character. The result of this study is that forest evaluated as high rank is TPF-sugi (cryptomeria japonica ) 37.9%, TPF-hinoki (chamaecyparis obtusa ) 73.6% and WCF 65.5%. This evaluated rank of forest function was depend on soil types and geology types.

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To clarify necessary conditions when forest owner's cooperative introduces and makes use of GIS, Y forest owner's cooperative was analyzed as case study. Because Y town finished survey ownership of land, especially forest land in 1984, the land register map is precise geometrically and in content. In Y town the register about forest, such as forest owner's register, forest history register and forest map have been compiled correctly. Now that these GIS data source are precise GIS output are precise. From this it is necessary that GIS source data are correctly compiled. For introduction and practical use of GIS, following actions were needed: reaching consensus on developing GIS in cooperative, getting budget, designing system, getting good developer, driving away bugs, instructing users in GIS, directing user organization, and existing bright users. As trial and error were needed now for practical use of GIS on daily work, it is necessary that usage of GIS on daily work was developed step by step. For maintenance and renewal of GIS data, it is necessary that GIS is used daily work.

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As the concern of global environmental problems grows, the monitoring to obtain the scientific fundamental data adds importance. In the field of forestry practice, the discussion about the management of elder forest stands and about the store of the resource information in River-basen planning unit is required with the introduction of long rotation age and the River-basen Management System. In order to design the database on the nation-wide field survey and the field studies in Shikoku, the total system of data management is discussed.

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Variation in systolic blood pressure was an effective parameter in the evaluation of geometrical design of forest roads from the viewpoint of driver's psychological and physiological response. The authors attempted to evaluate geometrical design of forest roads by variation in pulse pressure (difference between systolic blood pressure and diastolic blood pressure) for driver's psychological response on the basis of variation in systolic blood pressure. As a result, the variation coefficient of the pulse pressure increased with the increase in the speed of vehicles. This increasing tendency especially in case of small curve radius, became more significant because of muliplicative effect between the speed of vehicles and radius size. The variation coefficient of the pulse pressure when the vehicle drove around the right side of mountain was found to be higher than when the vehicle did on the left side of mountain. Furthermore, the variation coefficient of pulse pressure increased with the decrease in curve radius and the increase in the speed of vehicles. When the radius of curve was less than about 20m, an apparent variation in pulse pressure was observed, which resulted in a big psychological load on the driver. Pulse pressure reflected sensitively on psychological pressure. Thus the geometrical design of forest roads under the condition of greatly psychological load on a driver was accurately evaluated using the variation in pulse pressure as an additional measure, when variation in systolic blood pressure was used as the main parameter of an evaluation.

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Water chemistry was investigated in the main stream and the tributary of Yotsugo River in Siga town, Siga prefecture. Chemical analysis showed that most of inorganic ions were stable and the coefficient of variation of them was less than twenty percents, whereas NO_3^-, dissolved organic carbon (DOC), biochemical oxygen demands and chemical oxygen demands were more changeable. The annual variation of stream water temperature was smaller than that of atmospheric temperature, but the pattern was similar with that of atmospheric temperature. The water temperature was positively correlated with pH, K^+ and DOC concentrations and was negatively correlated with Cl^- concentrations. The discharge was positively correlated with NO_3^- and was negatively correlated with F^- concentrations.

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One hundred and ten Abies needle (Abies mariesii and Abies veitchii) litter bags and 110 Betula leaf (Betula ermanii and B. coryfolia) litter bags were placed in the forest floor on Sept. 1994. Ten litter bags of each litter type were collected at monthly interval during growing season from Sept. 1994 to Sept. 1996. Collected litter were dried and weighted. Concentration of C, N, K, Ca, Na, Mg for litters was determined. Mass loss of Abies needle litter and Betula leaf litter was about 41% and 56% respectively during two-year decomposition. Concentration of carbon approached about 50% for both litters during two-year decomposition. Mass loss of carbon was significantly correlated with mass loss of litter. Concentration of N increased with mass loss for both litters. Absolute amount of N did not change in early stage of decomposition, but decreased in later stage of study period. Behavior of Ca, P and Na was almost same during the decomposition process. Their absolute amounts increased first and then decreased in the later stage. K and Mg were much released for Betula leaf litter and Abies needle litter in early stage, but no much changes in the concentration and the absolute amount were found in the later stage. The initial concentration of nutrients in Betula leaf was higher than that in Abies needle, but after 22 months decomposition, the concentration of nutrients approached to almost same level.

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Growth of Hinoki (Chamaecyparis obtusa) in two-storied forests with deciduous broad-leaved trees and with Japanese red pine (Pinus densiflora) was examined from 1991 to 1995. The amount of undergrowth in the forest tended to decrease with decreasing relative light illuminance (RLI), but the growth of Hinoki in the forest was not decreased. In the forest with RLI lower than 7%, the growth of Hinoki was markedly inhibited, and in the forest with less than 15% RlI, the H/D ratio was increased markedly. The light saturation point for photosynthesis of Hinoki in the experimental forest was about 50% RLI. RLI in the Japanese red pine forest was stable at 30-60%, which was suitable for Hinoki growth, but not for the development of undergrowth. In broad-leaved forest, RLI was lower than the photosynthetic light saturation point, and accretion cutting was necessary to grow Hinoki there. The RLI in deciduous broad-leaved forest decreased year by year; the higher the RLI, the greater the yearly decreased. However,the RLI in deciduous broad-leaved forest was rarely lowered below 5%.

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We set a study plot with 20m×16m in size and measured the DBH and heights of all individuals with more than 1.3m high. We also measured the relative light intensity (RLI) before and after leaf fall. As results 860 individuals belonging to 44 species were observed. The basal area at 1.3m high (BA) was 35.2m^2/ha and density was 26,875ind./ha. The mean annual increment of BA was 1.09m^2/ha/yr (sugi) and 0.59 (broadleaved). RLI was 1.9-18% before leaf fall and 9-45% after it. According to RLI distribution, the crown of this stand was patchily occupied by hardwood. Since BA increment of hardwood species was not so small, it is worthwhile to make coniferous plantations under snowy condition like the Hikimi Forest change into mixed forests.

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Effects of stand density on the tree growth were investigated in four different planting plots (2,500, 4,500, 7,000 and 10,000 trees per hectare). The height and diameter growth of trees in high density plots (7,000 and 10,000) were greater than those in low density plots (2,500 and 4,500). These differences seem to be caused by the reduction of undergrowth which was dominated by Miscanthus sinensis in the low density plots. Clear bole lengths of trees in the high density plots were also greater than those in the low density plots, therefore the stem taper rate (DBH/DSB: DBH; Diameter at breast height, DSB; diameter at stem base) in the high density plots were greater than those in the low density plots. Furthermore,the rate of crooked trees in the low density plots were greater than those in the high density plots. These results suggest that optimum density for planting Zelkova serrata trees is more than 7,000 trees per hectare

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In the forest stand consisting of only 14-years-old Hinoki (Chamaecyparis obtusa (Sib. et Zucc.) Endl), rooting-up occurred in February 1996. Around the seven gaps caused by the rooting-up, residual trees were trimmed, and artificial gaps with different sizes and different cumulative amounts of relative solar radiation were made. The nursery stocks of Keyaki (Zelkova serrata (Thumb.) Makino) were planted in each gap, and the effect of the cumulative amount of relative solar radiation on their height growth was examined by comparing the growth in each gap. The height growth of Keyaki was markedly influenced by the cumulative amount of relative solar radiation that varied with the position of planting. That is, the higher the cumulative amount of relative solar radiation, the greater the height growth of Hinoki. In the gaps surrounded by partly opened canopy, the cumulative amount of relative solar radiation did not vary so much with the position of planting, and even the Keyaki trees near the edge of the forest stand grew well. This suggests that smallarea afforestation is possible even in the gaps, depending on the shape of the gap.

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For making lacquer wares Castanea logs more than 16cm in diameter were usually used. We found that from trees having DBH more than 25-30cm the logs of 6 meters in length for lacquer ware making could be obtained. Previous studies on the growth of Castanea trees in natural or artificial forests, 40-50 years were sufficient for the fulfilment of this requirement if the sites were suitable for this species. Logs having malformation or abundant knots were not suitable for this purpose, therefore, the prevention of them by thinning or uplifting of snow-bended trees were necessary. Also thinning would be important to promote growth for shortening the period until harvest.

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The seed dispersal and seedling dynamics of the three main species, Chamaecyparis obtusa, Tsuga sieboldii and Abies firma, were studied from autumn in 1994 to spring in 1997, in a matured natural stand. In case of C. obtusa and T. sieboldii, 1995 was assumed to be the mast year so that a lot of rectuitment was observed in the following spring. In case of A. firma, seeds were shed in 1994 and 1995, and some rectuitment was taken place. Since very few seeds were produced in all three conifer species, in 1996, no recruitment was observed in 1997. Large portion of the current year seedlings were disappeared by autumn, however, the seedlings survived over that critical season remained until next spring. Among three species, A. firma showed the highest survival rate one year after the germination and C. obtusa was the lowest. Although a lot of seeds were produced, all recruited seedlingsC. obtusaand T. sieboldii disappeared at the steep slope. Seedlings of C. obtusa could survive only within the canopy gap. Few seedlings of T. sieboldii could survive even on the atand floor, however, survival rate was much higher at the gap site. Some A. firma seedlings were observed surviving even on the steep slope. The specific differences of ecological characteristics in seedlings stage was placed emphasis as one of the key agents which form different stand structures by topographies.

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In order to examine the effect of so-called "tube method", in which planted trees are protected by treeshelters against browsing damage of deer, a survey has been carried out to make a comparison between the "shelter plot" using "Hexatube" made by Phytoculture Control Co. Ltd., and the "control plot" without treeshelters,in number of deer damages, dead trees and height increment. The comparison has resulted in followings. 1) Rate of damage by deer amounted to 80% with Sugi trees (Cryptomeria japonica) planted trees and 100% with Hinoki trees (Chamaecyparis obtusa) planted trees in the control plot, whereas 0% and 7% respectively in the shelter plot. Thus the high effectiveness of the tube method against deer damage has been confirmed. 2) Rate of dead trees amounted to 8% with Sugi in the shelter plot as against 27% in the control plot, while no significant difference between the two plots was observed with Hinoki trees (about 10%). 3) Mean height increment of Sugi trees in the shelter plot amounted to be more than twice, and mean height of Hinoki trees was more than three times that of the same species in the each control plot. However, in the shelter plot, bending tree was observed, which occurred more frequently with Hinoki trees (48%). Consequently, the tube method may be counted on as an effective means for coexistence of forestry with wild mammals such as deer.

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Shoot production rates, shoot abortion rates, and pattern of abortion were observed in crown tops of oak (Quercus mongolica Blume var. grosseserrata Rehd. et. Wils.: QM) canopy trees from 1992 to 1994. Among three years, shoot production rates (number of produced shoots per 1-yr.-old branch) were ranged 1.7-1.9. A year was divided into leafing and leaf less season, then shoot abortion rate was determined for each season. Shoot abortion rate was about 20% per season (ranged 14-23%), except extraordinary value as 44% of Tree 1 at leafing season in 1993. Almost half of the shoots were aborted annually. Aborted shoots were classified into three morphological types. Single shoot abortion (type 1) shared considerable proportion of abortion. Most of type 1 abortion was occurred on lateral shoots. Another abortion type, abortion of live monopodial branches attached to current shoots (type 2), was abundant in 1-yr.-old branch, and secondly frequent in 2-yr.-old branch. High turnover rate of shoots in crown tops of QM canopy trees was suggested.

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We investigated the maintenance characteristics of the genet for Lindera unbellata under the deciduous trees in Hiruzen Experiment Forest of Tottori University. This study was focused on relationship between the material budget of undergrowth species and growth of the genet. Annual volume growth of the genet rapidly increased with growth of the genet in the initial growing stage, but gradually decreased and the net production of the genet also decreased. The stems within a genet of low productivity grew with interactions in each other, and the growth rate of stems markedly decreased with age. These results show the existence of translocation among stems within a genet, and especially current year sprouts might depend on the translocation from the genet. The annual height growth of current year sprouts varied among genets, and the maximum values of the growth increased in proportion to the size of the genet. Stems composed the shrub layer showed large annual height growth when just after they sprouted. These results suggested that stems showed larger height growth in a sprouted year within a genet play a role as the succeeding trees to keep the genet, and stems showed smaller height growth replace the succeedings when the former died.

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The effect of support (1.5m-height above ground) on the growth of an annual climber, kidney bean (Phaseolus vulgaris L.), was studied. The differences in growth performance between climbing and non-climbing (vineless) varieties of kidney beans were also examined. Changing patterns of the relative growth rate (RGR) and the net assimilation rate (NAR) were not affected by the absence of the support. In the case of vineless variety, RGR was larger than that of the climbing variety in the initial stage of growth while NAR was smaller. Average dry weight of individuals at 70th day after sowing was 60g in supported group and 43g in non-supported group. It is assumed that the growth of non-supported group was restricted by the dark condition under the canopy due to densely attached leaves. The relative allocations to leaf were similar among three treatments, while the allocations to stem were small in climbing variety. In vineless variety, basal diameter and relative allocation to the root were larger than that of climbing variety. It is considered that a vineless kidney bean might adapt to the self-supporting life.

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We investigated the seed productivity and the resistance of open pollinated resistant families (ORF) which comprise the clonal seed orchard in Okayama (established in 1985, 1.0ha). Seed productivity in seed orchard had increased from 1991 to 1995 and it amounted to about 4.5kg in 1995. However it decreased to about 0.5kg in 1996. The seed production of these showed clones annual correlation between each year. As in this seed orchard the seed production by a few clones was very large, about 50% of all production, therefore, was produced by the clones ranked from top to the fifth. Artifical inoculation test of the pine wood nematode had been conducted with ORF, in the nursery and greenhouse. As a result the extent of damage changed year by year depending on the year and testing condition. The average of survival rate of all families was from 20 to 95%. Moreover there was a difference between the ORF. By comparison of ORF with the seedlings from unselected trees, it was found that there was a clear difference in the degree of resistance between them when the inoculation test was carried out under the condition that the disease did not easily proceed. Under the easy-to-suffer condition, however, many seedlings of both groups died and no distinct difference was observed. From these results rankings of seed productivity of the mother stocks and degree of resistance of their families were given, respectivity.

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During the three years from 1994 to 1996, the formation of reproductive organs on the current shoots and boughs of a native Aesculus turbinata BLUME growing at Mikata-cho, Mikata-gun, Hyogo Prefecture, Japan, was examined. Then, yearly fluctuations in the number of reproductive organs on the current shoots and boughs were analyzed. The current shoots developed from the terminal buds of flowering shoots did not flower, and none of the current shoots flowered during the first two years. Some of the boughs consisting of the clusters of current shoots flowered vigorously, but the other boughs flowered scarcely. Flowers (reproductive organs) seem to be formed or not formed depending on each shoot and each bough, even in the same tree.

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Cultivation of Lyophyllum shimeji in forest was tested by inoculating artificially cultured myceliae. An inoculation method using "benomil", a fungicide, to prevent contamination of the inoculum by soil microbes was developed, and by this method the mycorrhiza of L. shimeji was successfully formed. Similar inoculation test was performed at 34 plots in the seven stands, and the development of mature fruit-body was observed at five plots in three stands after three years.

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The tissue culuture of Alaria cordata was carried out to get clone plants for line test and to secure breeding materials. When using the leaf segment of Alaria cordata, MS agar medium contained 2,4-D 0.5mg/1. was most suitable to callus formation. There were no conspicuous differences in the term of culture. The embryoid occured when the formed callus was moved to 1/2MS medium(hormone free), and the young clone plants were regenerated. However, many variants were seen in embryoids stage, therefore the normal individual must be selected while culturing. In 13 strains collected at Okayama prefecture, the regenerative percentages of young clone plants varied in strains greatly. Acclimation of regenerated young plants under controlled humidity was very difficult.

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When monitoring insects by traps, it is important to have advance knowledge of most efficient height to capture the objective insect by the trap. Traps using α-pinene and ethanol as attractants were fastened at 1, 4, 7 and 10m heights to edge trees of five pine forests at Fushimi, Kyoto, Japan. Of the 12 species of which more than 20 individuals were captured, catches of Elater sieboldi, Hylobitelus haroldi, Niphades variegatus, Shirahoshizo insidiosus and Sipalinus gigas were concentrated at the 1m height, while catches of Trogossita japonica were concentrated at the 4 and 7m heights. Melanotus legatus was caught at every height. Arhopalus correanus and Spondylis buprestoides were commonly captured at the 1m height in all forests, and also at 4 and 7m heights in forests taller than 20m. Monochamus alternatus tended to be caught more often in traps at higher than those at lower. Platystomos sellatus was caught abundantly in traps higher than 4m. Most Shirahoshizo rufescens were caught at all heights in forests under 10m in height. Total catch of beetles was greatest at 1m in all forests, and also at 4m in forests taller than 20m, but much lower numbers were caught near treetops.

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Adults of Trogossita japonica, a predator of Monochamus alternatus, and other beetles were captured with traps using several different attractants, namely, α-pinene, β-pinene, -β-pinene, ethanol and distilled water. T. japonica was strongly attracted to a-pinene and -β-pinene. Only few beetles were captured with traps using β-pinene and ethanol and no beetles were attracted to distilled water. Some females collected on 7-14 May already had many mature eggs in their ovarioles. Of other beetle species trapped, two species of Anthribidae, Platystomos sellatus and Phloeobius stenus, were attracted only to ethanol. In the Curculionidae, Shirahoshizo rufescens was strongly attracted to β-pinene and -β-pinene and Stenoscelis gracilitarsis to β-pinene. In the Scolytidae, Cryphalus fulvus was attracted to β-pinene and ethanol, Cyrtogenius brevior was lured by α-pinene and ambrosia beetles were strongly attracted by ethanol.

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We investigated the decline of oak trees in Tottori Prefecture from 1994 to 1996. In 1994, the mass mortalities occurred in four towns and villages of the eastern part of Tottori Prefecture, and in 1996 also in Koge town, the south side of the area of decline in 1994. The dead trees were mass-attacked invariabley by Platypus quercivorus. In one of our experimental plot, the mortality rate of Quercus mongolica was higher than that of Q. serrata, and the enlargement growth was larger in dead trees rather than live trees in Q. mongolica. There was large variation in water content among Quercus trees. This variation persisted for experimental period. The water content of a dead tree had been always within the range of those of 10 live trees. So, it was suggested that water content would not be an indicater of the wilting.

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Recentry, mass mortalities of oak trees have been revealed in Tottori Prefecture. The infected trees were attacked by Platypus quercivorus and P. calamus in mass. We investigated the attack density and seasonal prevalence of these platipodid beetles on the stem of oak trees, Querucus serrata and Q. mongorica var. grosseserrata under live, dead trees or bolts. The attack densities were different among live trees, dead trees and bolts. It was lower in live trees than the other. This difference was more conspicuous in P. calamus than P. quercivorus. For adult emergence from trees, many adults of both Platypodid beetles emerged from dead trees, but no adult emerged from live trees in spite of existence of thier attack holes. From the bolts cut healthy tree, many adults of P. quercivorus emerged in the cutting year, but no adult of P. calamus emerged. From the bolts cut decline tree, many adults of both Platypodid beetles emerged in the cutting year and the next year. Our results showed that both Platypodid beetles attacked live oak trees, but they could not breed in them. They could breed only in dead trees or decline ones. From dead trees, the adults of P. quercivorus and P. calamus emerged from June to November.

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Fourth instar larvae of the Japanese pine sawyer, which emerges once a year and diapauses in its last instar in Japan, had been collected on 20 Nov. 1996 and were kept at constant temperature in glass bottles under different photoperiods. At 25℃, LD16:8, the proportions of pupation within five months for whitish larvae collected from pupal chambers, yellowed larvae collected from pupal chambers and yellowed larvae collected under bark, were 90, 100 and 100%, respectively. Mean times to emergence following the start of the warming period were 86.8, 76.2 and 75.0 days, respectively. All whitish larvae which had been collected under bark died within five months. For 25℃, LD0:24 and 25℃, LD10:14 conditions, only the yellowed larvae collected from pupal chambers were examined. The proportions of these live larvae pupated within five months were 86.7 and 28.6%, respectively, and mean times to emergence 105.8 and 111.4 days, respectively. Individual larvae still remaining alive after five months at 25℃, LD10:14 were transferred to 25℃, LD16:8 conditions. The proportion of these which pupated within three months was 60.9%, and the mean time to emergence after the transfer was 49.0 days. These results indicated that photoperiod should be taken into account when we do warming M. alternatus larvae in or after winter in order to investigate whether they had already terminated their diapause or not.

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In order to examine development of the infection with Amylostereum sp. and of the fungus in the wood, inoculations with the fungus were conducuted onto stems of living and felled tree of Cryptmeria japonica and Chmaecyparis obtusa. Wood stain which was similar to that on naturally Amylostereum infected trees developed around all the inoculated points of living stems. The average extent of the stain expanded vertically, 50 to 60cm and 70cm on woods of Cr. japonica and Ch. obtusa, respectively, three months after inoculation and the infection with the fungus was evaluated to develop largely in a short period. No wood stain expanded on most logs of felled trees except on some logs at three months after inoculation. Reisolation frequencies of the inoculated fungus were high in most stained woods of living stems and in some no-stained woods of felled trees. Trichoderma sp. and Marasmiellus chamaecyparidis were isolated with high frequency from some logs in which reisolation frequency of the inoculated fungus was low and fungal flora in the log was assessed to success.

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The relationships among the degree of feeding damage on stem bark, density of pellets of sika deer and undergrowth of the plantation were investigated at seven young Cryptmeria japonica stands in South Tajima area, Hyogo Prefecture. Study sites were classified into 3 ranks of damage level as follows, 1: no damage stand (damage rate 0.0%), 2; slight damage stands (damage rate 3.5〜8.4%) and 3; intense damage stands (damage rate 60.0〜76.2%). The more serious the damage of trees in a study site was, the higher the density of pellets of sika deer was. The damage occurred mainly in April. At this season, in intense damage stands, many feeding marks of sika deer were observed at leaves of an undergrowth, Sasa. Undergrowth biomass in intense damage stand tended to be less than that in slight damage stand.

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To promote reasonable sabo works which consider not only disaster prevention but also environment preservation, it is necessary to estimate the structure of the river environment that should be preserved. In this study, it was tried to grasp the structure of the river environment systematically from the review of former literature, and the data of former sabo works was analyzed so as to make the actual state and issue of works clear. As a result, the river environment could be classified into six environment elements of disaster prevention, ecosystem, affinity with water, recreational function and area promotion. The river environment was recognized as the combination of them according to the condition of the location. The analysis of former sabo works showed certain relation between the frequency that each environment element was chosen as the purpose and the conditions of the location. However, the environment element and the devices adopted for the preservation have a tendency of uniformity. This fact seems to mean the issue that the estimation of the environment is not enough to achieve reasonable preservation.

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To protect acorns of oaks from dehydration and keep their germiability at a greening site, the acorns of Quercus serrata, Q. phylliraeoides, and Q. myrisnaefolia were put in a paper cylinder of 30cm in length and 38mm in diameter with a soil and humus mixture as a germination medium. They were applied on a site after a large-scale forest fire in August 1994 at Mt.Ouji in Tamano, southern part of Okayama Prefecture, from May 1994 to May 1996. Results obtained during two growing periods ware as follows; Germination rates of Q. serrata, Q. phylliraeoides, and Q. myrisnaefolia were 66.7%, 70.0%, and 77.8% respectively, and these rates were higher than those on the stick devices covered with oiled paper and fed no manure. Survival rates of them after two growth periods were more than 90%. Their height after two growth periods was twice or three times larger than the height after the first growth period. These results suggested that our stick type greening device could be successfully applicable to a site after a large-scale forest fire.

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The plate type greening devices originally developed by Okayama Prefecture Forest Experiment Station were tested on a road side slope. Four different devices (A, B, C, and D), which contained different combinations of the acorns of oaks, shrubs, and grass species were used. Only in the device D vermiculite was used as a material for a germination bed while in other three devices a mixture of mountain soils, humus, and straw segments were used. Results were as follows; (1) Germination rates of Quercus serrata, Q. phylliraeoides and Q. myrsinaefolia were more than 50% on each device except on the device C. (2) Mortality of Q. serrata was smaller than those of Q. phylliraeoides and Q. myrsinaefolia after two growing periods. (3) Height growth of these oak species on the device D which included no grass species seeds was the largest comparing to those on the other three devices, which included grass species seeds. (4) It was suggested that even on the steep slope of road side, for example, on a slope having more than slant of 51° and soil hardiness of 29mm, greening could be successfully performed by these plate type greening devices.

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The point of this study is to make it clear whether plants are able to cultivated by minimum water and nutriment in porous ceramic boards. The characteristics of the ceramics,such as speed of water absorption, quantity of water leak, water content etc. were examined to find suitable ones for cultivating plants. There were difference depending on kind of potters clay and on temperature of kiln. As the results, it was found that the ceramics made under 1,200℃ above fired condition are most suitable for cultivating plants. Glass fiber was used as the medium for supplying water to plants, because it can send a lot of water through capillary, is hard to deteriorate, contains no harmful materials, and so on. The rate of water absorbtion of glassfibers was proved to be different depending on the strength of twist. As for the water supplying system, upsidedown tank method was adopted, and the horizontally combinated pipe system was devised for keeping constant water level. Based on the results, now plants of about 50 species are cultivated, and they are growing well.

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In order to examine possibility in cultivating plants by various kinds of porous ceramic boards.without loam or humus soil, about 50 species of plants were cultivated by means of contacting root system on the surface of ceramics. As a result, it was recognized that many plants grow well with a very little amount of water and nutriment. On the other hand, the cultivation of plants for greenization by ceramic boards buried in various materials, such as gravel, sand and mountain soil was tested in greenhouses using the constant water level method. The plants used for the experiment were Camellia sasanqua, Photinia glabra, Abelia grandiflora Rehd, Querucus myrsinaefolia and other trees, and Artemisia princeps, Rumex acetosa, Brassica juncea and other herbs. The plants have grown well in both cases. Of all the cases, the plants in the gravel plot are growing noteworthily well. The above results have proved it highly possible to culture plants on the severe environment for growing, including artificial foundations or arid region.

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The log price has been cheaper recently and immature thinning stands have been increasing, so it is important to do yield cruise in national forest management. A method of each tree mesurement, sample tree method and sample plot method are used in the Kouchi Regional Forest Office, but the Bitterlich method used widely in Germany and Austria isn't used. The characteristic of this method is that it can exclude subjectivity of surveyer and evaluate cruise by taking measurement points systematically. The Kouchi Regional Forest Office has more than 20ha of thinning stand per plot. So it is very difficult to choose a standard plot. This method can be applied to design of real stands efficiently and easily without being troubled by finding stadard plot. Therefore it is an effective method in the case of increasing immature thinning stands.

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[in Japanese]

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