Integrated land management using small-scale harvesting operations for biomass utilization
This study – produced in the frame of IEA Bioenergy Task 43 (biomass supply) – reports research conducted to evaluate small-scale biomass harvesting as a silvicultural thinning treatment for forest management in the Private Native Forests (PNF) of Southeast Queensland, Australia. A ‘native forest’ in Australia is a forest consisting entirely of indigenous trees and plants.
In recent years there has been an increasing interest in 1) better management of Australian private native forests for increased productivity and higher long-term value and 2) the utilization of woody biomass for products ranging from pellets to boiler fuel to landscape material with feedstock sourced from both softwood plantations and private native hardwood estates. At present the vast majority of the private native forests are over-stocked and in a degraded state with limited forest management. Mechanised thinning is a promising alternative to chopper-rolling and traditional thinning which leave dead tree biomass as waste on the forest floor. Biomass thinning, as a saleable product, may help make silvicultural thinning treatments viable and allow effective forest management of the resource.
This study analysed integrated land management in the rural Australian context through a field study around small-scale operations. Four different plots and operational treatments were analysed to better understand the complexity of the resource and operational considerations to support integrated land management. An analysis of the resulting product yields and machine productivity were assessed and then coupled with hypothetical chipping assumptions to determine approximate costs of production and recovery. Furthermore, this document also outlines proposed further research and considerations resultant from this study.
Conclusions and Recommendations
This preliminary study highlights the biomass and operational considerations inherent in any biomass recovery harvest in the Australian native forest resource towards a goal of integrated land management practices. It provides a first look at some of the important considerations one must consider when using mechanisation for biomass in this setting, namely the importance of underlying stand conditions (stand density, DBH – diameter at Brest Height, etc.) and anticipated sawlog/pole recovery for biomass yields and operational efficiencies for every element the harvest sequence (felling, extraction, chipping, etc.).
Overall, a broader range of conditions and operational harvesting methods needs to be explored to more fully understand the issues and complexity of biomass recovery systems in private native stands. This study further illustrates the potential viability for integrated land management where silvicultural thinning may be an economical way to generate a co-product.
Source: Private Forestry Service Queensland (PFSQ)