Biomass and potential energy yield of perennial woody energy crops under reduced planting spacing

Woody biomass can be used for supplying energy as a strategy to mitigate climate change and increase energy security by reducing the dependency on fossil fuels. The aims of this study were: (i) to evaluate the biomass production for energy generation; and (ii) to determine the leaf area index, solar radiation interception and mean annual increment of three perennial woody crops Eucalyptus grandis, Mimosa scabrella and Ateleia glazioviana, grown under four planting spacings in Southern Brazil. A field experiment was conducted from September 2008 to September 2018 in Frederico Westphalen, Brazil. The above-belowground woody biomass was determined by the destructive method. Also, the solar radiation interception, leaf area index, potential energy yield, biomass yield and partitioning were evaluated. Findings have shown that the highest biomass yield and potential energy yield were obtained in the planting spacing (2.0 × 1.5 m) for the Eucalyptus grandis. Among the woody species studied, the Eucalyptus grandis was the one that presented the largest potential to produce biomass for energy, followed by Mimosa scabrella and Ateleia glazioviana. Therefore, reduced planting spacings should be recommended for woody energy crops plantations, changing the planting spacing pattern (3.0 × 1.5 m) used by the majority of the forest producers.