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Larix kaempferi is the main plantation species in the low-snow, cool-temperate zone of Japan. I studied L. kaempferi plantations of various stand ages in central Japan to examine and compare the effect of stand age on the abundance, size, and species composition of snags (standing dead trees) compared to those in secondary broadleaf forests. Plantations that were older than the standard rotation age had more and larger snags than young plantations, and the species diversity of snags was positively correlated with stand age. Because the density of living planted L. kaempferi showed little correlation with snag variables, whereas that of naturally regenerated tree species was positively correlated with snag variables, the density dependence of snag occurrence was stronger in naturally regenerated trees than in planted L. kaempferi. Snag species that were positively correlated with stand age were the main species in secondary broadleaf forests in this area. Basal area, density, and number of species of snags in standard-rotation plantations were significantly lower than in long-rotation plantations and secondary broadleaf forests. Long-rotation plantations are useful for retaining snags compared to standard-rotation plantations.

The intensity of grazing on palatable species can vary depending on the neighboring plants in plant communities. We aimed to search for species whose biomass can have a positive effect on palatable plants near them in a grassland under grazing pressure by sika deer. We selected Iris sanguinea Hornem. as an indicator species of ease of being grazed because it is a palatable and past dominant species before the increase in deer density. We estimated the effects of the biomass of neighboring plant species, soil water content, and distance from the forest edge on the height of I. sanguinea. The height was remarkably and positively affected by the biomass of four graminoid species with larger biomass and slightly positively affected by the biomass of a toxic species. This study suggests that the biomass of less‐palatable species may have an important influence on the size of palatable species under grazing pressure by deer. [ABSTRACT FROM AUTHOR]

The management of deer impacts on forested lands requires quantification of the negative factors (e.g., bark stripping) on tree survival in relation to other ecological variables (e.g., competition from neighboring trees). This study measured the effects of bark stripping by sika deer, Cervus nippon, and competition among trees on the survival of Abies veitchii in a subalpine coniferous forest in central Japan over 12 years. Most of the trees subjected to bark stripping by deer were small (< 10 cm in diameter at breast height); however, some trees were stripped repeatedly. Although light bark stripping did not strongly influence tree survival after 12 years, heavily stripped stems (i.e., > 65% of the stem circumference stripped) were severely affected. The effect on longevity for each tree after bark stripping was explained by maximum bark stripping intensity during the study period, rather than initial bark stripping intensity. When > 85% of the stem circumference had been stripped, survival rates decreased. Bark stripping influenced survival rates much more than competition from neighboring trees. Because bark stripping occurred repeatedly, frequent measurements are important to grasp the full effects caused by this action. Heavy bark stripping of a stem enhances tree mortality. Thus, management of bark stripping is an essential element of stand maintenance and species composition in subalpine coniferous forests in Japan. [ABSTRACT FROM AUTHOR]