In fragmented and abandoned forests near urban areas, vegetation succession often follows a plagiosere, but the direction of succession may vary depending on the surrounding landscape. We investigated edge effects and five-year change in stand structure of an abandoned secondary deciduous forest located adjacent to agricultural fields and near lucidophyllous forest. In the secondary forest, the number and basal area of evergreen-species increased, while many small individuals of deciduous species died. Size, number, and basal area of evergreen species increased from forest edge to interior, while mortality of deciduous species increased during the five-year study period. Although newly established trees included many bird-dispersed species, more than half of these were lucidophyllous forest components, dispersal was not concentrated near the forest edge, and no ornamental or invasive species were observed. Thus, we inferred that the vegetation change in the secondary forest is not following a plagiosere.We predict that evergreen species will spread from the interior toward the forest edge, shade-tolerant evergreen species will increase in the lower canopy, and tree species composition of the secondary forest will become more similar to the nearby lucidophyllous forest. In a landscape where mature forests may function as seed sources, vegetation change in fragmented and abandoned forests may not divert to a plagiosere.

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At forests suffering intensive disturbances such as logging and fire, every regenerating woody species are expected to have a unique strategy to acquire light resource. Such interspecific variation will influence initial development of secondary forests. In this study, we investigated an among-species above-ground dry matter allocation patterns for woody sprouts at a deciduous coppice which had been just harvested, with relation to growth and survival of sprouting to structure and dynamics of the tree community. Based on allometric relationships between leaf mass and non-photosynthetic organ, species were categorized as follows: more biased allocation to leaves (Type-L: e.g., Quercus serrata), more bias to branches and a stem (Type-B: e.g., Prunus grayana) and intermediate of these (Type-M: e.g., Styrax japonica). Most dominant type in the study coppice was Type-B during the study period although Type-L had been dominant before harvesting. Comparing growthand survival of sprouts among the types, it was shown that mean size was greatest in the Type-B, that growth rate was greatest in the Type-L, and that survivorship was greatest in the Type-B. These results suggest that higher survival of Type-B species made them to become dominant. These allocation patterns are effective to understand the short-time community dynamics after clear-cutting of a coppice.

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Artificial coniferous forests in Japan are important food resources for Japanese black bears (Ursus thibetanus japonicus) because they can feed on nuts, berries and grasses existing in the artificial coniferous forests. In the present study, we surveyed biomass of plants that can be food for the bear in artificial coniferous forests in relation to characteristics of the forest such as degree of thinning, age and density of deer, to find factors affecting the amount of food for Japanese black bears. We measured diameter at breast height (DBH) and basal area of trees or degree of cover of food plants as an index of the amount of food resource, and analyzed the relationship between the amount of food resource and characteristics of the forests using generalized linear model. The results suggested that: (1) nuts are rich in the forests without thinning but berries are rich in the forests with thinning, (2) grasses are rich in the forests under high deer density, whereas berries are rich in theforests under low deer density, (3) nuts are rich in the old forests. Forest managements such as thinning can affect type of food and practical and effective management is expected considering deer density.

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The purpose of this paper was to calculate the unit cost of J-VER certification by summing up labors and monetary costs consumed in the removal by forest sinks accelerated thinning project in The University of Tokyo Chiba Forest. In addition, sales price of J-VER was discussed by considering the standard case of thinning project. In the case of Chiba forest, the unit cost of J-VER certification was 3,606 yen/t-CO2 for 1,614 t-CO2 credits summing up validation and verification fees, labor costs for J-VER related work and thinning fees altogether. Adjusting each cost of Chiba forest project compared with common cases of registered and certified thinning projects in terms of thinning areas, monetary costs, amounts of credit, etc., the unit cost of J-VER certification was estimated about 4,700 yen/t-CO2 at most in the standard case of 5 year credit period, thinning area of 100 ha and credits of 1,600 t-CO2. If all of the 1,600 t-CO2 credits were sold for the unit price of around 4,500yen/t-CO2, which was the recent indicative price of removal by forest sinks project by buyers, validation and verification fees, labor costs for J-VER related work and thinning fees for a couple of years were considered to be covered.

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To increase domestic timber supply, enlarging the stable supply capacity is indispensable. Consequently, it is important to determine how much timber forests can produce. In this study, the timber supply level from a forest was predicted using 0-1 integer programming considering stable profits. The study area comprised privately owned sugi (Cryptomeria japonica) plantations in the area of Sampoku, a town that has merged into the city of Murakami, Niigata Prefecture, Japan. Four scenarios were simulated that maximized the volumes of both total harvest timber and intermediate-sized logs, and considered the present range of rotation ages as well as rotation ages increased by 20 years. The simulations showed that increased production was possible, while keeping a high profit level. Increasing the rotation age increased the sustainable timber supply compared to the present age distribution. Maximizing the volume of intermediate-sized logs used in large sawmills did not necessarily lead tomaximum profits. Thus, the method proposed in this study would be effective to predict a sustainable timber supply level.

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We evaluated canopy opening, which was expected to be a critical factor affecting snow damage, using Voronoi polygon area to explain the occurrence of snow accretion damage in an old planted Cryptmeria japonica stand in December 2010. We performed a logistic regression analysis using slope gradient, height: diameter at breast height (DBH) ratio, tree form class, and Voronoi polygon area as explanatory variables. Trees on the slope site that had a larger Voronoi polygon area and a greater height: DBH ratio tended to be more damaged by snow. The odds ratio based on the difference in average height: DBH ratio between trees on the slope site with and without snow damage was 1.21, and the odds ratio based on the difference in the average Voronoi polygon area between trees on the slope site with and without snow damage was 1.40. In conclusion, canopy open-ing in dense plantations of old sugi does not prevent snow accretion damage; thus, height: DBH ratio and canopy opening are critical fac-torsaffecting snow damage.

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