We analyzed differences in the relationship between the intermate distance and the cumulative mating frequency, the allelic richness of the pollen pool, and effective number of pollen parents among neighboring trees of Faugs crenata. Six mother trees we studied were located relatively close together but under slightly different microenvironments. We determined genotypes of 823 seedlings derived from the mother trees at seven microsatellite loci. We assigned seedling paternity and estimated the three parameters of pollen dispersal. Patterns of increases in the cumulative mating frequency with the increasing intermate distance varied among the mother trees although short-distance matings were frequently observed. The pollen immigration rates from outside the 4-ha study plot varied from 15.7 to 33.8%. Among the mother trees, the allelic richness of pollen pools was very similar, with values ranging from 8.524 to 12.803, and the effective number of pollen parents (N_ep) varied from 2.941 to 16.340. In addition, the rate of unsound seeds production was high in mother trees with low N_ep value. In conclusion, patterns of pollen dispersal and seed soundness were similar among neighboring mother trees but varied in accordance with their microenvironments.

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Clone identification was carried out with the combined method of ISSR (Inter Simple Sequence Repeat) analysis (31 markers with 9 primers) and AFLP (Amplified Fragment Length Polymorphism) analysis (26 markers with 2 primer pairs) concerning the superior candidate individuals of Rhus succedanea L. selected by Kyushu Regional Breeding Office, Forest Tree Breeding Center, Forestry and Forest Products Research Institute and Fukuoka Prefectural Government. As the result of the clone identification, 77 individuals are classified into 45 clones, included local cultivars, 9 of Showafuku, 24 of Ikichi and 2 of Oh. In process of identification analysis, although 2 individuals showed identical band pattern but were different from known local cultivars in the ISSR analysis, these 2 individuals showed different fragment patterns in the AFLP analysis were judged as separate genotypes. Cluster analysis and principal component analysis based on the information of the total 204 markers of ISSR, AFLP, and RAPD was also carried out. However there were two genetic groups with low bootstrap probabilities, it was obscureness the relationship between the similarities and geographical distances among selection area of clones. It was considered that artificial transfer of R. succedanea cultivars or mating among cultivated individuals have occurred. The knowledge from this study will help carrying forward R. succedanea breeding program.

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Lightning damage was studied on predominant trees growing at two experimental forests whose area were 3 ha of level land and 1 ha of a gentle slope. Though external lightning scars of cracks and black colored on bark were noted on 114 trees of the two forests, the damaged trees did not die but continued to grow. In the forest situated on flat land, 18% of 593 surveyed trees had external lightning scars, and the tree species with the highest percentage of external scars was Pinus densiflora (52%). In the forest situated on a gentle slope, 33 trees were cut and a cross section of each was examined. Internal lightning scars of rings damaged were counted on 62% of surveyed trees of P. densiflora, as well as on 10% of surveyed trees of Quercus serrata and on 0% of surveyed trees of Chamaecyparis obtusa. Internal and external lightning scars parallel with inner bark fibers were formed, and most of these scars were observed at stems under tree crowns. Thirteen external scars remained on bark just above internal ones, but one scar disappeared due to covering over with callus tissue. Average and range of thirteen internal scars in P. densiflora were 2.2 (1∼4.5) m in length and 8 (4∼18) cm in maximum width, while the callus width on sites above internal scars was from 0.1 cm to 1.3 cm/year. Rot was formed around scars in one Q. serrata tree.

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To clarify the variations among clones for several characteristics of the clone-complex cultivar of Cryptomeria japonica, Shakain, we investigated the clone composition and the stem form characteristics (stem circularity, tapering grade, and stem crookedness) and wood quality characteristics (stress wave velocity of standing trees) of each clone. CAPS (cleaved amplified polymorphic sequences) makers revealed that there were 19 DNA types in 220 individuals of the Shakain cultivar collected from eight stands in Kumamoto Prefecture. The age of the eight stands ranged from 22 to 82 years old. The three major DNA types accounted for 87.7% of the sampling individuals of the cultivar. ANOVA for each characteristic among the three major DNA types in the four stands that were around 40 years old indicated that there were statistically significant differences in the stem-form coefficient, height at maximum stem-crookedness, and stress wave velocity of standing trees, respectively. However, the magnitude of the difference was small enough from the viewpoint of wood use. Thus we concluded that the three major DNA types could be treated the same for wood use. To improve the uniformity of Shakain woods, we should remove all of minor clones from scion sources and lead to the clone complex which consists of the three major clones.

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To establish an effective cutting-based system for the propagation of Pinus thunbergii clones that are highly resistant to pine wilt disease, the productivity of rooted cuttings obtained using a closed system (in a plastic greenhouse or an open field) was compared to that of cuttings obtained using a mist system. Consequently, the rooting rate increased more rapidly in the closed system than in the mist system. Moreover, the root system of the cuttings developed faster in the closed system than in the mist system. Therefore, the survival rate of the transplanted cuttings obtained using the closed system was higher than that of the cuttings obtained using the mist system in rainy season. The rooted cuttings transplanted in the rainy season grew to a bigger size than those transplanted in the following spring. Therefore, the growth period could be shortened. However, the rooting rate of the cuttings obtained using the closed system in the open field did not increase after the 16th week of insertion. These cuttings seemed to have incurred injury owing to high temperature. Using the closed cutting system in the plastic greenhouse, the production cost of resistant plants could be reduced by approximately 10% in comparison to seedlings-based system requiring nematode artificial inoculation.

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We investigated the effects of small-scale clearcutting management on species composition and stratification of understory vegetation of a conifer plantation comprising stands of uneven age. Seven understory types were detected, which corresponded to the stand age of plantation patches. These understory types were characterized by degree of stratification and differences in composition of species characteristic habitats and life forms. There were few understory types in which all layers were fully developed in terms of tree abundance, indicating that the upper (sub-tree) layer limited the development of the lower (shrub and herb) layers. Similarly, no understory type had a high species diversity in all layers. Therefore, we suggest that managing stands of different age by the appropriate spatio-temporal arrangement of patches supports the various understory types, and thus maintains the complex structures and dynamics of the whole stand.

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The amount of evapotranspiration in the Minamitani, which experienced a period of forest decline and Kitatani that had no forest decline, was calculated by the short-time period water-budget method of calculating critical discharge based on the discharge duration curve in the Tatsunokuchi-yama Experimental Watershed from 1960 to 1965. As for the results calculated by the proposed method, daily evapotranspiration were estimated throughout a consultation period in both watersheds. Using the different average discharge duration curves of 1∼22 water years to establish the average discharge duration curve, the difference between the annual evapotranspiration based on the proposed method and the annual loss by the water budget was from 1.5 to 3.2%. It was possible for the proposed method to accurately estimate daily evapotranspiration in the Tatsunokuchi-yama Experimental Watershed, which experienced a period of forest decline.

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The physical characteristics of selected male sterile trees in Niigata Prefecture, tree height, diameter at breast height (DBH), basal bending, modulus of elasticity of tree trunk and types of snow damage, were compared with those of male fertile trees from eleven stands. The sampled stands were regarded as being typical of an unsuccessful plantation and exhibited potentially fatal examples of snow damage, including stem breakage, stem splitting and uprooting. Moreover, the stands sampled also had a lower average tree height, smaller DBH, and remarkably lower stand density than other C. japonica stands in the region. Interestingly, no marked differences were observed in any of the characters examined or in the extent of snow damage between male sterile and fertile trees. The results imply that the abnormalities exhibited by male sterile trees are restricted to pollen formation, and not to other characteristics such as growth, which is normal.

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We collected seeds of Pterostyrax hispida from a 12 year-old autogenous mother tree in the Okutama university forest of Tokyo University of Agriculture. We cleaned and examined the seeds to research the characteristics and germination. The maturation rate was 59.0% by sifting the seeds and removing impurities. The wind selection was not effective to raise maturation rate, however it was useful to remove empty seeds. We also attempted some gravity selection, but most of the seeds did not sink. Germination rate was 17% immediately after the collection. Germination rate after 5 months in cold stratification was approximately same rate. However, the seeds after cold and dry storage did not germinate and kept dormant condition.

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We designed a method of estimating the internal volume of a tree hollow based upon its depth that was obtained from the CCD camera image. We made four cylindrical models with different bore diameter hollows. While changing the internal depth, we took internal pictures of the models with a CCD camera. A regression formula to estimate the depth of tree hollows was obtained from the ratio between the area of the bottom in the images to the area of the bottom of actual cylindrical models and their inside diameters. To verify the depth estimated from the regression model, we measured the inside diameter at the entrance and the depth of tree hollows in natural forests. We found that the measured depth in 16 of 19 samples was deeper than the estimate. The internal volume of tree hollows calculated from the estimated depth was also undervaluing, but this method may be useful for estimating the scale of tree hollows.

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