The mega-tsunami resulting from the Tohoku earthquake destroyed most of the forests along the eastern Pacific coastline of Japan. Seawater inundation of costal forest soils carried a large influx of sea salt, leading to excessive adsorption of salt in buried 2A horizons under sea sand deposits. Forest soils that were inundated by seawater in turn caused severe damage, including needle discoloration, debilitation, droop, and finally death, to broad areas of the eastern Pacific coastal forests. Rehabilitation of tsunami-created saline soils in these forested lands generally requires the removal of sea salt, which is particularly difficult because most Japanese forests have poor irrigation facilities. Efficient removal of sea salt from the soils must therefore rely on high-precipitation events, such as typhoons and precipitation events in the rainy season. In this study, we monitored the progress of improvement in seawater-inundated forest soils in Hachinohe, Aomori Prefecture, and Watari-cho, Miyagi Prefecture, over time to evaluate the role of natural precipitation in desalinizing seawater-inundated forest soils. Measures of soil chemistry in tsunami-hit forests, such as exchangeable calcium and potassium content, initially showed decreasing tendencies, reached a state of equilibrium with time, then showed alteration in soil conditions. The results indicate that continuous and frequent rainfall events caused gradual removal of sea salt from seawater-inundated forest soils with time, and lead to a general recovery from the chemical condition caused by salination damage.

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In this study, we investigated the relationships among damage by Anaglyptus subfasciatus Pic, site condition, and growth of Cryptomeria japonica and Chamaecyparis obtusa in poorly managed forests in Odai Town, Mie Prefecture. Damage by A. subfasciatus was evaluated on the basis of log-sawing ability by using disks obtained for stem analysis from the field survey. Stem analysis was used to determine the growth potential of the site by calculating tree height and diameter at breast height at a stand age of 40 years. In the C. japonica forest, concave sites with colluvial deposits tended to show slight damage by A. subfasciatus and promoted faster growth, and thus, were considered suitable for C. japonica . In C. obtusa stands, less damage was observed if the soil-particle size was that of clay. Stands with colluvial deposits tended to be vulnerable to damage. Hence, sites with residual deposits and clay were considered suitable for C. obtusa . The sites appropriate for C. japonica and C. obtusa were their natural habitats and were historically considered as suitable. Thus, our results indicate that the damage by A. subfasciatus might decrease if appropriate trees are planted on suitable sites.

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To estimate the volumes of forest road runoff, we measured the infil-tration capacity of forest road surface using in-situ rainfall simulator (1 × 1 m) and monitored forest road runoff including overland flow (OF) and road intercepted flow (RIF) in forest road plots (5 × 15 m). Three plots with different topographic conditions such as plainer, concave, and convex were installed for measurement OF and RIF separately. The results by a rainfall simulator showed that the mean infiltration capacity of forest road surfaces was 33.3 mm/h (SD = 8.8 mm/h) with no relationship between vegetation ground cover and soil physical properties. Runoff coefficients of OF from forest road plots were from 14 to 21％ with 85 to 89％ of contribution to total runoff. The estimated infiltration capacities based on OF values of forest road plots were less than 5.0 mm/h and smaller than values estimated from the in-situ rainfall simulation. This results suggested that continuity of overland flow pathways due to the track length on forest road plots induced greater amount of OF. Contribution of RIF to total road runoff was less than 10％. Antecedent precipitation index was a controlling factor for RIF only in the plot with small areas of bedrock outcrop. Conditions of forest road (track length) and cut-bank (location of bedrock outcrop and fault) can be important factors for controlling the amount of forest road runoff and its pathways．

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In this study, we aimed to investigate the diversity of microlepidopteran species in the pre-dispersal nuts of two beech species, Fagus crenata (FC) and Fagus japonica (FJ). We used morphological characteristics and mitochondrial DNA barcoding for identifying microlepidopteran larvae in beech forests near the Pacific Ocean (Mt. Takahara) and the Sea of Japan (Minakami). We also examined species-specific feeding scars made by the microlepidopteran larvae on nuts. The pre-dispersal nuts of the two beech species were sampled directly from tree crowns, and larvae that emerged from the nuts were classified into morphotypes on the basis of their morphological characteristics. Nucleotide sequences of the COI gene were determined for the larvae of each morphotype, and species identification was conducted based on the sequences. Consequently, nine microlepidopteran species were identified from the nuts of FC or FJ in Mt. Takahara, and Pseudopammene fagivora was found to be the most dominant. In contrast, the number of species in Minakami was only two, suggesting different microlepidopteran assemblages in each type of beech forest. Examination of feeding scars on the nuts revealed a lack of species-specific scars for the nine species, implying that species identification based on the feeding scars was difficult. Seven of the nine emerged from nuts of both the beech species, implying that the presence of the seven species could lead to a higher proportion of infested nuts of FC in beech forests near the Pacific Ocean than in those near the Sea of Japan.

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Number and height of regenerated trees were investigated on three different covers (1％, low cover site (LC) ; 30％, middle cover site（MC）; 80％, high cover site (HC) ) of floor vegetation inside and outside of three deer-proof fences in an old-growth cedar and cypress plantation diminished by sika deer for 12 years after selection logging. Under-story relative Photosynthetic Photon Flux Density increased with selection logging on three sites inside the fences. Floor vegetation cover also increased with selection logging, and LC needed 4 years to increase as well as HC. Both species richness and number of individuals following selection logging were most on LC. The number of regenerated trees over 1 m in height was 11, 873 saplings /ha on LC, 7,499 saplings /ha on MC, and 2,083 saplings /ha on HC at 12 years after selection logging. These results indicated that many regener-ated trees invaded, established and grew on LC. In contrast, outside the fence 12 years after selection logging, there was no difference among sites for species richness or number of individuals, and both were less than inside the fence. Therefore I conclude that control of both floor vegetation and sika deer in addition to overstory tree density control was needed to regenerate trees on the overbrowsed old-growth plantation.

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An investigation was undertaken into the generation of overland flow and vegetation recovery on a spur road constructed at the time of thinning at the Nagasaka Experiment in Akita Prefecture, Japan. The vegetation coverage and the number of species were low, both on the cut slope and in wheel tracks on the upslope side of the road. Frost heave, snowmelt, and raindrop splash on the cut slope were considered factors that affected vegetation recovery, which contributed to the continuous overland flow in the wheel tracks on the upslope side. The intercepted subsurface flow from the cut slope, in addition to the inflow to the spur road from a stream channel, was observed as a source of overland flow. This overland flow occurred over 21.2％ of the entire length of the spur road within the watershed, and field observations suggested that this fragmented overland flow was caused primarily by intercepted subsurface flow. Moreover, overland flow was generated on the road during the snow season in the same locations as in the non-snow season. This study establishes that when constructing spur roads in watersheds, it is important to determine both the source of the subsurface flow and the locations of stream channels.

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We investigated the cumulative thermal constant and threshold temperature for the development of male flowers in Metasequoia glyptostroboides. The threshold temperature for the development of male flowers was approximately 0°C and the cumulative thermal constant was approximately 175°C/day. The male flowers of M. glyptostroboides bloomed earlier than those of Cryptomeria japonica (Tateyama-sugi and Boka-sugi) at 10°C in controlled environment rooms. From these results, it is inferred that the patients with Japanese cedar pollinosis are affected by the pollen of M. glyptostroboides earlier than that of C. japonica if there are trees of M. glyptostroboides in the neighborhood.

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Recently, moso-bamboo（Phyllostachys pubescens ) forests have been expanding in Japan. Some studies have pointed out their expansion could decrease ecosystem services. This paper summarized expansion rates in areas in the last ca. 70 years and biomass of moso-bamboo forests. We verified whether the expansions could increase risks in flood, water shortage, shallow landslide, and soil erosion. Many papers have reported increases in areas of moso-bamboo forests, and the average expansion rate was 1.03 ha/ha year. The rate in the surrounding open spaces tends to be larger than that in the surrounding closed spaces. Aboveground biomass in moso-bamboo forests was between 62.6 and 224.3 t/ha. The maximum aboveground biomass in moso-bamboo forests would be smaller than those in Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) forests. However, only a few studies examined belowground biomass in moso-bamboo forests. As well, based on results in previous studies, we concluded that risks in flood, water shortage, shallow landslide, and soil erosion in moso-bamboo forests would not be higher than those in other types of forests. This conclusion is different from the speculation. On the other hand, this conclusion was based on only a few studies. Therefore, further studies are required to clarify various processes related to flood, water shortage, shallow landslide, and soil erosion in moso-bamboo forests with various canopy structures under various meteorological conditions.

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