Growth performance and yield of eucalypt species grown at Wino Forest Plantation, Ruvuma region, Tanzania

Abstract

Plantation forestry in Tanzania is expanding to meet the growing demand for timber for construction, transmission poles and other wood products. However, limited site-specific information constrains the selection of suitable eucalypt species for different environments. This study assessed the growth performance and yield of 40 eucalypt entries, comprising 38 pure species/provenances and two hybrid clones (Eucalyptus grandis × E. camaldulensis from Green Resources Ltd; GRL) as a control group, 8 years after planting at Wino Forest Plantation in the Ruvuma region, southern Tanzania. Measurements included survival rate, diameter at breast height (DBH) and total height, from which basal area and volume were derived. Significant variation was observed among entries. The hybrid GC15_GRL achieved the highest survival (98%), while E. urophylla (South African Pulp and Paper Industries; SAPPI) exhibited the largest mean DBH (23.2 cm) and the highest standing volume (539.9 m³ha^-1). The hybrid GC584_GRL attained the greatest height (28.0 m). An integrated performance ranking identified GC584_GRL, E. urophylla (SAPPI), GC15_GRL, E. grandis (Merensky) and E. saligna (Republic of South Africa) as the most productive and reliable entries. These results provide critical, locally validated evidence to guide species selection for sustainable plantation forestry in the southern Highlands of Tanzania and similar subtropical highland environments.