Wood density and wood chemical traits are strong predictors of tree performance, carbon stock, and wood decomposition, which play important roles in ecosystem processes and carbon and nutrient cycling in forests. However, it remains unknown how root wood traits are related to stem wood traits. We examined the relationships of wood density and wood chemical traits (lignin and nitrogen concentrations, carbon-to-nitrogen ratio) between the stems and coarse roots of 90 individuals representing 53 tropical tree species in Malaysian Borneo. We developed regression equations of each wood trait using the standardized major axis method. Each root wood trait was highly correlated with the corresponding stem wood trait, and most regression equations fitted well (R2 > 0.5). The lignin concentration of roots was significantly greater than that of stems. We conclude that root wood traits can be estimated from the corresponding stem wood traits in South-East Asian tropical trees. Further analysis of coarse root decomposability will provide more accurate estimates of carbon and nutrient fluxes in tropical forest ecosystems.

We have studied effects of H atom source on deposition profiles of carbon films, deposited by H assisted anisotropic plasma CVD method. Deposition rate normalized by that for the aspect ratio of 1 at sidewall and bottom decreases with increasing discharge power of H atom source from 0 W to 500 W, because the incident H atom flux per surface area in a trench increases and H atoms etch carbon films.

Conducting thin films were prepared by entrapping water-suspended polyaniline into a silica matrix by a sol-gel route. Without metal oxide, the conductivity of the film decreased after heat treatment. However, in the presence of metal oxides such as TiO2 and Al2O3, the conductivity increased after heat treatment at 85 °C and reached 17 Scm−1 The conductivity of the film depended on the kinds and amounts of metal oxides and the temperature of heat treatment.