Individual tree-based management in natural forests becomes more important in managing old growth Japanese cedar (Cryptomeria japonica) stands because of the decline of timber resources from natural forests. We set a 1-ha study plot in Nibuna-Mizusawa Forest Reserve, Akita, northern Japan, which mainly consisted of about 300-year-old Japanese cedars. The individual growth of tree diameter at breast height (DBH) was calculated using censuses in 2006 and 2010. The effects of soil depth (summed value of A and AB layers) , soil moisture, light conditions of the tree crown (relative concavity and convexity levels against the surrounding) , and neighborhood competition (indicated by sum of basal area of neighboring trees around each tree) were examined by generalized linear models. The mean DBH growth rate was 0.18±0.21 cm/year. The DBH growth rate decreased with increasing soil moisture within most values for soil moisture we observed. The tendency in our results suggested that some cedars grew worse in damp soils, although other unknown soil factors associated with soil moisture (e.g. nutrients) should also been examined. The effect of the neighboring trees was marginally negative, suggesting competition for soil nutrient and/or light. The processes leading to the presented patterns were discussed.

The number of Hokkaido Sika deer （Cervus nippon yesoensis） in Japan has been increasing, resulting in conflicts with human society. For dealing with the problem, a new idea is to use them as a hunting resource by establishing a hunting zone, for the purpose of population control, local economic development and safe hunting. This study using the case of Shimukappu hunting zone established in 2014 aimed to analyze the social impacts of recreational hunting and establishment of the hunting zone on the local community with field work, mainly based on interviews. The results showed that local residents, such as farmers, hunters and tourism operators, have both anxiety and anticipation concerning the hunting zone and recreational hunting in the village. Some residents expect hunters to obey the hunting rules for safe, but some are deeply concerned about the top-down approach tourism development and inadequate measures against cropraiding. Therefore, to utilize a hunting zone and recreational hunting as a means to Hokkaido Sika deer management and local revitalization, it is important to consider the livelihood and the history of local community, based on a sufficient explanation by the government and community-based activities.

Using 4,562 cross section data collected from 630 trees of widely various diameter at breast height （DBH） classes （9-56 cm） and height classes （10-34 m）, we ascertained the relative stem taper curve and estimated the stem volume of Japanese larch （Larix kaempferi） trees in Hokkaido, Japan. We applied a cubic function and power function for relative stem taper curves, hypothesizing that the coefficients are affected by tree height and DBH. We used all data or data measured for the upper 1.3 m to exclude the influence of butt swell. The cubic function obtained using data measured for the upper 1.3 m was selected as the best model, having the least root mean square error of the expected diameter for almost all relative height classes except for the top and bottom of the stem. The effects of height and DBH were excluded from the coefficient of the third-order term, but they remained for the coefficients of first-order and second-order terms of the best model. Stem volume estimated using the best model had higher accuracy than that estimated using the Nakajima stem volume table and the theoretical volume equation of Inoue and Kurokawa.

The pinewood nematode, Bursaphelenchus xylophilus, is thought to invade dead pine trees via oviposition wounds made by Monochamus alternatus, but the phenomenon has not been confirmed in the field. In the present study, we investigated to determine whether the nematode invasion into Pinus densiflora trees killed by some factor other than pine wilt disease through the oviposition wounds occurs in the field. Not only many oviposition wounds but also many entrance holes and pupal chambers made by the beetle were found in the dead pine trees. The nematode positive reaction was detected in wood under an oviposition wound, without either an oviposition wound or larval frass, and in pupal chamber walls using the Bursaphelenchus xylophilus detection kit. This is the first report of the nematode invasion into dead pine trees via oviposition wounds by M. alternatus in the field.

After the accident at the Fukushima Daiichi Nuclear Power Plant in March 2011, radiocesium concentration in the fruiting body of Pholiota microspora showed a higher trend than those in the fruiting body of other mushroom species in the open bed-log cultivation. Therefore, we started a bed-log cultivation experiment with Pholiota microspora using Chamaecyparis obtusa wood at the beginning of April 2013 in Tokigawa Town, Saitama Prefecture. In each of the 5 different forest sites, we established 3 plots: 1） non-processed plot （control）, 2） topsoil （0-5 cm） removal plot, and 3） bed-log covered with cheesecloth plot. The fruiting bodies were harvested in October and November 2014. In a fresh fruiting body harvested from one bed-log in the non-processed plot, ^134+137Cs concentration was 45 Bq/kg, but the mean value of the non-processed plot was 13 Bq/kg. Therefore, fruiting bodies harvested there were safe to be consumed as food. ^134+137Cs concentration in the fresh fruiting bodies grown in the topsoil removal plot was significantly different from that in fruiting bodies grown in the other plots; it was 36% lower than that in the non-processed plot. The ¹³⁴Cs/¹³⁷Cs ratio in the fruiting body was similar to that of the radiocesium derived from the accident and that in the litter layer, but was different from that in the soil and the log.