Wood density and heartwood proportion in Eucalyptus trees from intensively-managed short-rotation plantations in Kerala, India

We analysed the impact of nitrogen fertilisation and weed management on wood density and heartwood proportion in Eucalyptus tereticornis and E. grandis trees from 6.5-year-old experimental plantations in Kerala, India. Wood samples taken from 0.20 m, breast height, 50, 75 and 100% of the merchantable bole length of trees were used in the analysis. Addition of nitrogen significantly improved productivity in E. tereticornis (15-28 m3 ha-1 year-1) and E. grandis (44-72 m3 ha-1 year-1) plantations. Likewise, weed management had significant effect on productivity of E. tereticornis plantation (8–19 m3 ha-1 year-1). In terms of heartwood proportion in trees, treatment effect was significant only in E. grandis plantation added with nitrogen. However, axial variation was significantly different for wood density and heartwood proportion of trees in nitrogen input plots in E. tereticornis plantation. Significant axial variation was found only in proportion of heartwood in weed management plots. In E. grandis, axial variation was significant only in heartwood proportion in both experimental plots. Density varied from pith to periphery in both species.