Variation in Survival, Growth Performance and Yield of Corymbia and Eucalyptus Species at North Ruvu Forest Plantation, Kibaha District, Tanzania

This study compared survival, growth and yield of selected Corymbia and Eucalyptus pure species established in 2017 at North Ruvu Forest Plantation in Kibaha district, Pwani region, Tanzania. The trial was established using a randomised complete block design (RCBD) with trees planted at a spacing of 3m x 3m in 4 × 4 plots. Five Corymbia and five Eucalyptus entries were reassessed at 8 years (October 2024) for survival, diameter at breast height (DBH), total height, basal area (BA), volume, and mean annual increment (MAI). Survival was computed as live trees over trees planted per plot and arcsine-transformed. BA and volume were derived from DBH and height. Plot means were analysed by ANOVA (fixed effects: Species, Block). When significant, means were separated by Duncan’s Multiple Range Test (5%) and diagnostic statistics (MSE, RMSE, CV, F, p) were reported. Results showed that in Corymbia, survival did not differ significantly (p > 0.05), ranging 54.3–77.1%; DBH ranged 13.0–18.0 cm; height 18.9–22.8 m; BA 11.93–29.15 m² ha⁻¹; volume 112.9–321.9 m³ ha⁻¹; MAI 14.1–40.2 m³ ha⁻¹ yr⁻¹. C. variegata (CSIRO) had the largest DBH, BA, volume and MAI, whereas C. citriodora (ZFC) had the lowest for productivity traits. In Eucalyptus, survival differed significantly (p < 0.05), ranging from 76.0–97.9%; DBH ranged from 14.0–16.8 cm; height 20.6–23.6 m; BA 12.9–21.3 m² ha⁻¹; volume 125.5–247.7 m³ ha⁻¹, and MAI 15.69–30.96 m³ ha⁻¹ yr⁻¹. E. urophylla (SAPPI) recorded the highest BA, volume, and MAI at 8 years, while E. pellita (SAPPI) was lowest for these traits. Both genera exhibited substantial interspecific variation under coastal lowland conditions. The consistently high productivity of C. variegata (CSIRO) and E. urophylla (SAPPI) indicates strong potential for targeted deployment on similar coastal sites, whereas C. citriodora (ZFC) and E. pellita (SAPPI) were less productive at this site.