Quality of Genetically-Improved Acacia auriculiformis For Renewable Short-Rotation Wood-Energy

R L Hendrati,S H Nurrohmah

doi:10.7226/jtfm.24.3.136

Abstract

To be viable, fast-growing energy plantations must be large in volume, harvested at early age, and maximized calorific value which linked to heartwood proportion. This study examines 38 families in the second generation (F2) progeny trial of Acacia auriculiformis for energy. Heartwood proportion, calorific value and lignin content were assessed at ages 22, 30, 35, and 40 months. Wood samples from around 300 selected individuals of observed ages from all families were examined. Quality was based on heartwood and sapwood development until reaching the commercial requirement of >33% for lignin content and >4,500 cal g-1 for calorific value. When required quality has been obtained at particular age, assessment of biomass was carried out from all final individuals in the progeny test. Heartwood proportion varies among families. Heartwood possesses higher values than sapwood in lignin content and calorific value. Individuals with higher heartwood proportion are preferred. Both wood types only reached the required quality for solid wood energy after 3.5 years, however lignin content at much early age are appropriate for wood pellet and briquette. Selection improves heartwood proportion and quality from the first generation (F1) into F2 with an increase of 52% at three years. Mean annual increments at 3.5 years is 43 m3ha-1yr-1.

Highlights

To be economically viable, energy plantations must be fast-growing so that large volumes of wood could be harvested at an early age and meet the standard quality (Apiolaza 2009; Krzyzaniak et al 2014)
At 3.5 years, both wood types are high in lignin content and caloric values, making it a proper rotation age for harvesting solid wood for energy such as fuelwood, chips, and charcoal
Earlier rotation age will be appropriate for wood pellet and briquette in which the quality of compacting process will determine the quality

Summary

Introduction

Energy plantations must be fast-growing so that large volumes of wood could be harvested at an early age and meet the standard quality (Apiolaza 2009; Krzyzaniak et al 2014). With a genetic improvement that has been carried out for this species, it is important to find the proper rotation age for energy-wood This might be influenced by several factors, including the source of genetic materials, environment, spacing, and maintenance. This study (undertaken by using genetically improved individuals) is expected to select the best genotypes for deployment and for developing mass scale production The success of this action provide a carbon-neutral renewable-energy source and help the community to fulfill their fuelwood needs, without destroying surrounding woodlands and forests. This fast-growing species capture more abundant carbon from the atmosphere for climate change mitigation, than the slower one. Having abilities to coppice for branch harvest while securing cut back the main stem and grow well in marginal sites, this species help maximizing land cover with vegetation, useful for maintaining the ecosystem

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Results

Conclusion