Madake (Phyllostachys bambusoides) is produced around Kameoka City and it is supplied mainly to Kyoto City. Bamboo grove management in this area is performed not by bamboo grove owner but by bamboo culm production dealer. In order to clarify the bamboo culm production dealer's present situation, and the actual state of the bamboo grove management, interviews were carried out in Kameoka City. There were 11 bamboo culm production dealers at Kameoka City in 1993. But the bamboo culm production dealer had decreased to 7 because they grew old. It is thought that 4 or 5 of them are going to continue the bamboo culm production dealer. They are small-scale dealer of family labor, and are having forced severe management in bamboo culm demand reduction. It is thought that there are three methods of slipping out of the difficulty. Moreover, in the Madake grove near Kameoka, low-quality and abandonment of bamboo grove management are in progress. The main causes are the following three. "They are cutting the bamboo culms at convenient point near road", "They are cutting only good bamboo culms" and "The damage of wild boar are expanding."

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Nutrient contents (N, P, K, Ca, Mg) of beech leaf litter decomposed in vitro by 19 fungal isolates (6 of Basidiomycota, 7 of xylariaceous Ascomycota and 6 of other Ascomycota) were measured, and the mean values were compared among the taxonomical groups. The mean N concentration in the litter decomposed by Basidiomycota fungi (litter B) was not significantly different from that decomposed by the xylariaceous Ascomycota (litter XA) but was significantly higher than that decomposed by the other Ascomycota (litter OA). The mean P concentration of litter XA was significantly higher than that of litters B and OA. The mean Mg concentration of litter B was significantly lower than that of litters XA and OA. No significant differences were found in the mean K and Ca concentrations among the litters. These results were discussed in relation to the role of these fungi in nutrient dynamics during litter decomposition.

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Low thinning of 26-year-old stands of Sugi (Cryptomeria japonica) was performed to study the effect of the degree of thinning on canopy openness. Thinning in P-2, P-3, and P-4 was repeated twice, four times, and four times respectively, and the thinning ratios based on number of trees after the last thinning were 26%, 51%, and 70% respectively. Before and after thinning, hemispherical photographs were taken at six places in each plot and the Hemiphot method used to measure canopy openness. No differences in the relationship of canopy openness with thinning ratio based on number of trees and in the relationship of canopy openness with thinning ratio based on basal areas were found between the plots. The relationships of the enlargement of canopy openness with thinning ratios based on number of trees, with thinning ratios based on basal area, and with the decrease of the yield ratio were identical for each plot and each relationship could be expressed by a quadratic curve.

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Seasonal development of symptoms and production and dispersal of conidia of Lecanosticta acicola, the causal fungus of the brown spot needle blight, were examined in Pinus thunbergii in Shimane Prefecture, Japan. In February 1999, infected 5-yr-old seedlings, as an infection source, were transplanted to a nursery where sound 3-yr-old seedlings were being raised. Conidia were produced from late March through late September on the needles of the 5-yr-old seedlings, and were abundantly dispersed in late June as the primary infection source. Symptoms were first evident on current-year needles in early August and the infection severity rapidly increased in September and October. No progress in symptoms was observed in winter and the infection severity slightly increased in the next April through June. Conidia were produced on the 3-yr-old seedlings from mid-August through late December and were abundantly dispersed from late September through mid-October. The conidia dispersed only during rainfall, but a large number of conidia dispersed even during a slight rainfall.

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Spatial distributions of entry holes bored by Platypus quercworus on living trees were investigated every week at the area where the mass mortality of oak trees had been occurring. Results showed that attack to a certain tree was concentrated in a week and boring by the beetles occured near the entry holes already bored in a short distance.

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Number of galleries and progenies of Platypus quercworus released through the clear plastic soft drink bottles and reproducing in freshly cut Quercus serrata logs and autoclaved Quercus serrata logs were investigated by dissecting logs. The females began to deposit eggs 7 to 12 days after the copulation. There were a lot of eggs and larvae including 5th instar larvae at the terminal of galleries excavated by the adults one month after the release of females. It is suggested that the autoclaved logs are suitable for the rearing of this beetle, because both the survival rate of released adults and the rate of galleries with successful reproduction were higher in the autoclaved logs than that in the freshly cut logs.

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Net nitrification properties of forest soils were evaluated in watersheds of three natural forests (T6, T7, T8) and a conifer plantation (T9) at Ichmomata in Kochi, southern Japan. Soil nitrate pool was less than 2 mg N kg^<-1>. Nitrate production during the 90-day laboratory incubation was 152〜314 mg N kg^<-1>. In the soils from T6 and T8, nitrate was produced at a constant rate. In contrast, in the soils from T7 and T9, nitrate was not produced in 30 days, but was produced rapidly after 30 days. In these soils, low nitrate production and active nitrate consumption by soil heterotrophic microbes may keep soil nitrate concentrations very low at the initial period of incubation. In the later period, microbial consumption of nitrate may decrease due to the depletion of available carbon sources. Soil production of nitrate after 90-day incubation was positively correlated with stream nitrate concentration. This indicates that consumption of nitrate by soil microbes is an important factor for retaining nitrogen within forest ecosystems.

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[in Japanese]

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Male Platypus quercivorus were induced to bore into fresh logs of a Quercus serrata tree that had survived beetle attack in the previous year and from which an unidentified oak pathogenic fungus was isolated, and in fresh logs from an undamaged tree that was free from the fungus. As no surviving males were found in any log 20 days after initial boring it was clear that the presence of the fungus had no effect on the longevity of unmated males. There were also no differences in attractiveness of males that bored into logs from the attacked tree or undamaged tree.

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To clarify the effects of an unidentified fungus infecting oaks and of live and dead log tissue on boring of Platypus quercivorus, the numbers of male beetles landing and galleries produced were assessed for logs of Quercus crispula and Q. serrata either inoculated with the fungus or autoclaved. The number of male beetles collected by adhesive traps set on no-treated logs, fungus-inoculated logs, and autoclaved logs was not different from that collected by the traps set with no materials. The boring of the beetle occurred irrespective of the colonization of the fungus. The number of males collected on autoclaved logs was not different from that on non-autoclaved logs, but males did not bore into autoclaved logs. Thus, males may prefer to bore into logs with living tissue irrespective of the colonization of the fungus.

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Platypus quercivorus and scolytid beetles were collected on adhesive paper traps that were set on cages containing logs from a Quercus serrata tree that had survived attack, an unattacked tree, and logs from an unattacked tree that were freeze-treated. Only small numbers of males of P. quercivorus were collected on logs from the attacked, surviving tree and the freeze-treated logs (which were split into four parts after 13 days). It was therefore considered that to test the response of male beetles to host tree odor, a larger quantity of logs may be required as an attractant. Scolytid beetles in the tribe Xyleborini were collected most often on the freeze-treated logs.

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