Guidelines for salvage harvest, storage and processing of plantation-grown logs affected by fire

As consequence of the impact of the 2019/2020 fires in Australia this project was designed to the develop guidelines for fire salvage and burnt log storage and processing, for pine and eucalypt plantation-grown.

Fires regularly affect plantation forest areas in Australia and every year various locations need to deal with the aftermath. Salvage of usable log products from burnt forest will always be a prime objective for the forest grower. In the case of fires that have a significant impact on future resource availability, effective salvage will also be a strong objective for processors.

The full report, ‘Guidelines for salvage harvest, storage and processing of plantation-grown logs affected by fire’, brings together a large amount of relevant Australian and international information and knowledge contributed by a number of foresters and mill personnel associated with previous major fire activities. It includes an analysis of available data, identification of areas of future research requirements and recommendations for the development of an integrated fire management and response plan to inform both growers and processors.

The information has been collated, analysed and summarised into a single document to act as a set of guidelines for both growers and processors to reference when dealing with future significant fire events.

While the major focus in the report is on plantation timber, many of the findings are also applicable to management and salvage associated with native forests.

There are a number of priority issues that need to be assessed in regard to how the industry responds to fire events within current forest estates. These can be summarised into four key areas:

1. Industry impacts associated with scale and probability of future fires.

2. Salvage planning processes.

3. Salvage operational processes including storage/stockpiling efficacy.

4. Management of production processes associated with the variable fibre quality issues (physical and biological) relating to salvaged and stockpiled log products.

 Guidelines_for_fire_log_salvage_Exec_Summary.pdf

Guidelines_for_fire_log_salvage_Tech_Recommendations.pdf

Validated softwood stiffness predictions using IML-Resistograph and eCambium (VNB459-1718)

This project utilised the IML-RESI, a tool that works by using small-diameter drill technology, to quickly and cost effectively capture details of a tree’s wood variability and quality. The recorded data (also known as ‘traces’) get uploaded to a specially-developed online wood-quality assessment platform, where it’s processed and interpreted to estimate average density and stiffness across the stand. The FWPA-supported research was led by Dr Geoff Downes of Forest Quality. 

The technology also has advantages in aiding grower decision making around which sites and silvicultural practices will impact the stiffness and volume of their timber. This knowledge will allow growers to plan for improved wood quality in their stands, meaning increased value for processors.

To keep the channels of communication open between industry and the researchers, a regular Zoom meeting has been scheduled for IML-RESI users, who will be given opportunities to discuss any issues experienced during use and application, share ideas on operationalising the technology.

The online wood quality assessment platform can be accessed by clicking here.

For more details on this project, please email geoff.downes@forestquality.com

 Resi_Final_Report_VNB459-1718.pdf

Increasing the value of under-utilised forest resources through the development of advanced engineered wood products (PNB407-1516)

The aim of this project was to deliver and validate technologies to transform low-value forest resources and sub-optimum quality logs into high-value construction and appearance products suitable for Australian and international markets. The project was designed to achieve this objective through a methodology that focused on forest resource, new technologies, market and economic aspects. Critical to the project design was direct participation and guidance by forest industry stakeholders.

The project has provided a wealth of new knowledge for the Australian industry and identified many technical and economic opportunities for industry to consider that can utilize forest resources that are currently under-valued and underutilized, for the manufacture of high-performing value-added engineered wood products. 

Active participation of key industry stakeholders through the duration of the project and the commercial investigations that have occurred in parallel with the project demonstrates strong industry interest in the subject. Further collaborative effort is required to advance the definition of target markets, allowing further product development focus that optimizes species selection, lay-up strategies, manufacturing protocols and final product performance criteria. This effort would have the best chances of success, demonstrated by product commercialization, by close partnership with industries ready to adopt and develop the necessary practices required to produce the new product(s). 

Specialist marketing expertise would add significant value to further efforts to better enable genuine ‘new’ markets (markets not currently occupied by a wood product) to be identified and developed as well as ‘substitute’ markets (markets historically or currently occupied by wood products of some description) to be targeted. Continued economic assessment is also necessary to guide decision making.

 PNB407-1516_Advanced_EWP_Final_Report.pdf

Control and manage the moisture content of logs and biomass to maximise benefits along the wood supply chain (PNC400-1516)

This project aimed to provide forest managers with the tools to balance reduced transport costs through natural drying of roadside stocks of biofuel and of logs for chips and other wood products against quality specifications, and increased costs for storage time and processing machinery wear and tear. In order to extract the gains from infield drying, there are a number of changes that need to be made by the Australian forest industry to capitalise on the research. The key changes discussed are:

• Moving from payment on delivered green weight to payment on delivered volume or oven-dry weight.

• Increasing the use of high volumetric capacity trucks, particularly for the transport of dried and infield chipped forest biofuel

• Using the drying models and tools developed in the study to guide planning the storage of logs and forest biofuel, in particular as part of operational planning processes.

 Final_Report_PNC400-1516.pdf

Developing high-mass laminated flooring products from fibre-managed plantation hardwood

This project aimed to develop commodity-based high-mass laminated timber building components using fibre-managed plantation hardwood, aiming to diversify plantation hardwood product range through developing new products for the construction sector.

The study explored the structural performance of nail laminated (NLT) and glue laminated (GLT) commodity-based high mass timber floor products assembled from pulp-managed plantation Eucalyptus nitens and E. globulus. The target market for these products is the upper floors in residential housing and small to medium scale commercial projects. The hardwood resources used in this project were 15 years old E. nitens and 26 years old E. globulus.

The seasoned timber boards were nail or glue laminated to form floor panels. Bending tests were conducted to determine the MOE and MOR of the single boards and the laminated panels. Test results revealed that although the wood has a F7 performance if used in a scantling product limited by MOR, the overall structural performance of the species was improved when the wood was used as laminated panels through nail or glue lamination method. The E. nitens and E. globulus panels could be classified as F8 and F11 respectively. The structural performance of the wood was further enhanced by forming timber-concrete composite panels. The composite panels showed structural properties equivalent to timber boards with a F14 performance.

The results proved that the current eucalypt plantations targeted at pulpwood production can be used as laminated floor panels to provide additional options in the building sector.

Findings report:

Final_Report__High-mass_laminated_flooring_products_PNB387-1516.pdf

“Boxed-Heart” Posts From Small-Diameter Durable-Eucalypt Plantation Thinnings PRB357-1415

This project assessed the suitability of young (9-16 year-old) hardwood logs for the production of boxed-heart posts from four species being Eucalyptus botryoides (southern mahogany), E. cladocalyx (sugar gum), E. muelleriana (yellow stringybark) and Corymbia maculata (spotted gum) – all durability class 1 and 2 above ground. The primary potential benefit being to increase income from thinning operations, which would otherwise only be suitable for low-grade pulpwood or firewood markets.

This project sought to identify key log attributes, silviculture treatments, harvesting techniques and drying methods to improve post quality.

Logs were sourced from commercially managed plantations that were age 9.5 and 11.5 years at the time of thinning. Records of Dbh, competition index (CI) and pruning were taken for each tree prior to harvesting. A target of approximately 80 posts was sought from each species. 

Four drying treatments were employed across each of the four species. These included three Green-sawn treatments and one Dried Round (under water) treatment. Two of the green sawn treatments were air dried and one received a combination of air and kiln drying. Gang plates and End-wax sealer treatment was used in combination with the air dried treatments.

Posts were assessed after approximately 12 months of drying for both moisture content and checking (splits) of post surfaces and ends. The widest split on the ends and faces of each post was recorded. Splits in excess of 5 mm on any face or end rendered posts unacceptable. 

The results suggest the potential for producing viable numbers of posts from small-diameter eucalypt-plantation thinnings, in particular from spotted gum and yellow stringybark. The best outcome across all of the treatments and species was found to be a 50% recovery of acceptable posts from spotted gum when green sawn, End Waxed and Plated (EWP).  

The largest impact on post acceptability was checking in excess of 5mm on at least one face. Anecdotally this was most common on the face exposing the largest amount of inner heartwood. 

Findings Report:
Final_Report_Box-heart_posts_PRB357-1415.pdf

The potential to recover veneer based product from low grade native forest logs (PNB386-1516)

The project aimed to improve the value recovered by peeling low-grade native forest hardwood. It also aimed to define recoveries, characteristics and value from key eastern Victorian eucalypt species currently not peeled commercially, namely: Eucalyptus sieberi (Silvertop Ash), E. cypellocarpa (Mountain Grey Gum) and E. obliqua (Messmate or Brown Top), which are also found in southern New South Wales. The project examined the value and recovery from Tasmanian oak species Eucalyptus obliqua, logs currently graded for the pulpwood market will be peeled to assess their potential to produce veneer.

The project represents Australia’s first large-scale peeling trial of low grade native forest logs of species from different States and has the following objectives:

• Examine the potential to manufacture plywood panel products from the low grade logs from eucalypt species selected in this trial.
• Determine if the low grade logs under study have the desired structural properties for processing of veneer that can be utilised in high stress grade plywood panel products. 
• Examine the potential for log, billet, and veneer segregation and batching for optimal processing efficiencies.
• Determine the effectiveness of log and veneer batching strategies to assess the potential gains that can be made in plywood production.

Trial logs were supplied to Ta Ann’s Veneer Mill at Smithton and graded to a low-grade peeler log specification developed for this project by the company. The logs were rotary peeled for structural veneer. Vveneer stiffness assessment and segregation systems were used to sub-batch the veneer produced and the veneer was then visually assessed and selected for the production of plywood panels whose mechanical properties were tested to Australian/New Zealand Standard AS/NZS 2269.0:2012 Plywood-Structural Part 0: Specifications.

Findings Report:
Amended_Final_Report_Low_Grade_Logs_PNB386-1516.pdf

The extent and causes of decline in productivity from first to second rotation blue gum plantations

This project quantified changes in productivity of blue gum plantations between the first and second rotation, particularly in Western Australia. The research showed that well established forestry management principles, such as soil and nutrition management, can sustain production through multiple rotations.

The research developed predictive modelling that fits easily into existing company inventory systems. Empirical growth curves were constructed that calculated second rotation site index, basal area and volume as a function of a standardised precipitation evaporation index and, where first rotation site index is known, to develop growth for the second rotation. 

The research also modelled the processes driving the decline in production observed in the small sample set of plots. Some of the observed decline was due to variation in rainfall and soil water between rotations. For each millimetre of soil water lost in the 2nd rotation, there is a corresponding loss in wood production of approximately 0.015 cubic metres per hectare. In the worst case this will result in a 8–10% decrease in production

On sites where 1R site fertility was low, soil nutrition is likely to limit productivity in 2nd (and subsequent) rotations. 

Reference number:
PNC288-1112

Findings Report:
Battaglia_FWPA_report_2R_20150407_reviewed.pdf

Establishing the comparative durability of African mahogany (Khaya senegalensis) in weather exposed above-ground applications

This research reports the results from the first year of ongoing research into the natural above-ground durability of plantation grown African mahogany  (Khaya senegalensis). The study is through the Queensland Government’s Department of Agriculture, Fisheries and Forestry

Samples of timber from 10- and 20-year old trees are being tested in two test sites, one a fungal cellar laboratory and the other a field site in north Queensland in a region known to present a very high decay hazard. 

The African mahogany samples are also being compared with control samples from spotted gum (Corymbia citriodora) durability class 1, jarrah (Eucalyptus marginate) durability class 2, messmate (Eucalyptus oblique) durability class 3 and slash pine (Pinus elliottii) durability class 4.

After one year the African mahogany samples are showing minimal decay, and it is not yet possible to determine if they are is consistent with durability class 3 or durability class 2 timbers above ground. In addition, no termite attack was observed; however, more time is required before reliable conclusions can be drawn.

Future results from the trial will provide valuable data about African mahogany durability, and potentially lead to the development of new processes and products that will grow the market for the timber.

Reference Number:
PRB287-1112

Findings Report:
Final_report_African_Mahogany_Durability_DAFF.pdf

Carbon Storage in Engineered Wood Products in Landfills

Each year approximately two million tonnes of wood and engineered wood products (EWPs) are disposed of in Australian landfills.

This project determined the long-term storage of carbon in particleboard, medium-density fibreboard (MDF) and high-pressure laminate (HPL) in landfill and also in optimal laboratory decay conditions. The particleboard and MDF reactors produced gas (predominantly methane) for two months and then stopped, while high-pressure laminate did not produce any gas. The results show carbon loss was very low: particleboard stored 98.25% of its initial carbon, MDF stored 99.35% and high-pressure laminate stored 100%.

These findings show that virtually all of the carbon in EWPs disposed of in Australian landfills can be considered to be stored indefinitely, that EWPs have a real beneficial impact on greenhouse gas mitigation efforts and factors used to determine greenhouse gas emissions from wood and EWPs in landfills should be drastically reduced to reflect the findings of this study.

Reference Number:

PRB180-0910

Findings Report:
PRB180-0910_composite_products_in_landfills.pdf