Effects of climate variation on radial growth of Pinus densiflora in Okutama, Tokyo, Japan

The effects of climate variation on radial growth of Pinus densiflora and other four coniferous species in Okutama, Tokyo, were investigated by dendroclimatic analysis. Tree-ring indices of annual ring width and annual mean density were used as art index of radial growth. In P. densiflora, wood anatomical features of the number of tracheid cells, cell radial diameter, and cell-wall thickness were measured by image analysis. The relationships between tree-ring indices and wood anatomical features were analyzed. As a result, annual ring width was significantly correlated with the number of cells within annual ring, and also was significantly and positively correlated with mean temperature in March of the current year. Annual mean density was significantly correlated with mean cell radial diameter within annual ring and mean cell-wall thickness within annual ring, and also was significantly and positively correlated with mean temperature in July of the current year. Moreover, these relationships were maintained in recent 47 years.