The Influence of Spacing on Survival, Growth, and Biomass Accumulation of Eucalyptus globulus (Labill.) in Wogera District, Northwestern Ethiopia

Eucalyptus is the most planted genus in Ethiopia, and it was introduced during the regime of Emperor Menelek II in 1895. Plantation forest establishment with optimum plant density is a major challenge under the current situation of land constraint in the highland areas of Amhara region, Ethiopia. Moreover, the effect of spacing on survival, growth performance, total aboveground biomass, and carbon stock of Eucalyptus globulus is unknown in the study area. Hence, this study was conducted to fill a knowledge gap in the effect of spacing on survival, growth performance, total aboveground biomass, and carbon stock of E. globulus in Wogera District. The field trial was carried out in Wogera District, Central Gonder Zone of Amhara region, northwestern Ethiopia. Four different spacings (1.5 × 1.5 m, 2 × 2 m, 2.5 × 2.5 m, and 3 × 3 m) were laid out in randomized complete block design (RCBD) with three replications. Tree height and root collar diameter (RCD) were not influenced by spacing in all ages months after planting. Diameter at breast height (DBH), biomass accumulation, carbon stock, and economic returns were significantly ( p < 0.05) influenced by spacing. Likewise, survival rate varied significantly ( p < 0.05) in all growth ages except at 4 and 18 months after planting. Larger DBH was obtained at broader spacing (3 × 3 m) at 63 and 76 months after planting. Moreover, higher biomass accumulation, carbon stock, and economic returns were obtained at 1.5 × 1.5 m spacing at all months after planting. Overall, our finding confirmed that broader spacing had a significant effect on survival and DBH growth of Eucalyptus globulus . Conversely, narrow spacing had significant effect on total aboveground biomass, carbon stock, and economic return. Therefore, we recommend that the planting of the Eucalyptus globulus species in narrow spacing is good for getting higher economic return, total aboveground biomass, and carbon stock accumulation.