This project has been funded by Hort Innovation, using the nursery research and development levy and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

This project has been funded by Hort Innovation, using the nursery research and development levy and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Human perception of plant leaf and flower colour can influence species management. Colour and colour contrast may influence the detectability of invasive or rare species during surveys. Quantitative, repeatable measures of plant colour are required for comparison across studies and generalisation across species. We present a standard method for measuring plant leaf and flower colour traits using images taken with digital cameras. We demonstrate the method by quantifying the colour of and colour difference between the flowers of eleven grassland species near Falls Creek, Australia, as part of an invasive species detection experiment. The reliability of the method was tested by measuring the leaf colour of five residential garden shrub species in Ballarat, Australia using five different types of digital camera. Flowers and leaves had overlapping but distinct colour distributions. Calculated colour differences corresponded well with qualitative comparisons. Estimates of proportional cover of yellow flowers identified using colour measurements correlated well with estimates obtained by measuring and counting individual flowers. Digital SLR and mirrorless cameras were superior to phone cameras and point-and-shoot cameras for producing reliable measurements, particularly under variable lighting conditions. The analysis of digital images taken with digital cameras is a practicable method for quantifying plant flower and leaf colour in the field or lab. Quantitative, repeatable measurements allow for comparisons between species and generalisations across species and studies. This allows plant colour to be related to human perception and preferences and, ultimately, species management.

Presentation prepared for the 2nd Australian Industrial Hemp Conference in Fremantle, WA from 25 -28 February 2020. Abstract and slides.

To better understand the role of plant flammability in driving landscape-scale fire behaviour and fire regimes, field-scale flammability research needs to occur. Yet, experimental fires are costly to implement and research within wildfires is both logistically challenging and potentially dangerous. As an alternative, we propose that operational prescribed burns undertaken for land management purposes should be exploited for flammability research.. In some parts of the world, large areas are burnt annually, providing extensive opportunities for research. In this paper we describe three broad methods that can be used to measure different facets of flammability in prescribed burns. We compare the strengths and potential limitations of each method before finally providing ten principles for conducting effective flammability research in prescribed burns. We conclude that operational prescribed burns are a largely untapped resource that could be used to better understand links between plant flammability and landscape-scale fire behaviour.

Vegetation is a key determinant of wildfire behaviour at field scales as it functions as fuel. Past studies in the laboratory show that plant flammability, the ability of plants to ignite and maintain combustion, is a function of their traits. However, the way the traits of individual plants combine in a vegetation community to affect field flammability has received little attention. This study aims to bridge the gap between the laboratory and field by linking plant traits to metrics of field-scale flammability. Across three prescribed burns, in Eucalyptus-dominated damp and dry forest, we measured pre-burn plant species abundance and post-burn field flammability metrics (percentage area burnt, char and scorch height). For understory species with dominant cover-abundance, we measured nine traits that had been demonstrated to influence flammability in the laboratory. We used fourth-corner ordination to evaluate covariation between the plant traits, species abundance and flammability. We found that several traits covaried at the species level. In some instances, these traits (e.g. specific leaf area and bulk density) could have cumulative effects on the flammability of a species while in other instances (e.g. moisture and specific leaf area) they may have counteractive effects, assuming trait effects on flammability are akin to previous research. At field scales, species with similar traits tended to co-occur, suggesting that the effects of individual traits accumulate within a plant community. Fourth-corner analyses found the trait-field flammability relationship to be statistically significant. Traits significantly associated with increasing field flammability metrics were: bulk density (negatively associated) and hydrocarbon quantity, specific leaf area and surface area to volume ratio (all positively associated). Our study demonstrates that some traits known to influence flammability in the laboratory can be associated with field-scale flammability metrics. Further research is needed to isolate the contributions of individual traits to understand how species composition drives forest flammability.

Aerially suspended fuels play an important role in forest fire behaviour. They can act as a ladder to flames, increasing the potential for crownfire, and can ignite and act as firebrands. When large accumulations of these fuels are present, wildfires may spread more rapidly, be more difficult to suppress and be more likely to impact assets such as houses. However, as these fuels are suspended above the ground, their moisture status is predominantly a function of atmospheric humidity. As a result, bark and suspended fuels may become flammable at times when the remainder of the fuel bed is too wet to burn due to high soil moisture levels. This means that these fuels can be reduced by burning when conditions are unfavourable for prescribed burning using the practice candling. Candling is the deliberate ignition of bark and other dead fine ladder fuels under conditions where surface fires are unlikely to spread. We compared the number of days available for prescribed burning and candling for a locality in South Eastern Australia and found that in the period 2012 – 2016, candling could be undertaken for an average 124 days per year, 48 days more than the window available for prescribed burning (76 days). As each accumulation of aerial fuel must be individually lit during candling, the practice is labour intensive and inefficient over large areas relative to prescribed burning, so it is best used for targeted risk reduction such as near control lines or assets. However, it can be used to reduce risk with low chance of escape in locations where prescribed burning is difficult such as the Wildland Urban Interface. The practice is applied operationally in South Eastern Australia, however to date there has been limited research into its effects on wildfire spread and intensity. Given its suitability for strategic use near highly vulnerable assets, we believe further investigation into its utility is warranted.

Edges are ecologically important environmental features and have been well researched in agricultural and urban landscapes. However, little work has been conducted in flammable ecosystems where spatially and temporally dynamic fire edges are expected to influence important processes such as recolonization of burnt areas and landscape connectivity. We review the literature on fire, fauna, and edge effects to summarize current knowledge of faunal responses to fire edges and identify knowledge gaps. We then develop a conceptual model to predict faunal responses to fire edges and present an agenda for future research. Faunal abundance at fire edges changes over time, but patterns depend on species traits and resource availability. Responses are also influenced by edge architecture (e.g., size and shape), site and landscape context, and spatial scale. However, data are limited and the influence of fire edges on both local abundance and regional distributions of fauna is largely unknown. In our conceptual model, biophysical properties interact with the fire regime (e.g., patchiness, frequency) to influence edge architecture. Edge architecture and species traits influence edge permeability, which is linked to important processes such as movement, resource selection, and species interactions. Predicting the effect of fire edges on fauna is challenging, but important for biodiversity conservation in flammable landscapes. Our conceptual model combines several drivers of faunal fire responses (biophysical properties, regime attributes, species traits) and will therefore lead to improved predictions. Future research is needed to understand fire as an agent of edge creation; the spatio-temporal flux of fire edges across landscapes; and the effect of fire edges on faunal movement, resource selection, and biotic interactions. To aid the incorporation of new data into our predictive framework, our model has been designed as a Bayesian Network, a statistical tool capable of analyzing complex environmental relationships, dealing with data gaps, and generating testable hypotheses.

A comprehensive testing program has been developed to assess different physical and mechanical properties of 26 commercial and lesser-known PNG species from secondary and plantation forests. The impact of log position in a tree on the mechanical properties has also been assessed to optimize the utilization of timbers along the value chain. The results showed that stiffness and bending strength tend to decrease or remain unchanged along the stem. Shear strength and Janka hardness displayed a similar trend to a lesser extent where the position in the tree had a limited impact on compression strength properties. Thus, segregating based on log position can be of interest where desired mechanical properties and costs associated with segregating justify optimum mechanical properties for the intended end use. The properties of selected species from plantations and regrowth forests were generally lower than those found in the literature for timbers from old-growth forests. The size of specimens tested, the amount and provenance of tested material, and some adaptive traits for tropical tree species are some factors potentially explaining observed differences. However, a comparison with recent studies tends to confirm the overall reduction of physical and mechanical properties when compared with old-growth forests timbers.

This study tour was undertaken as a component of VALTIP 3 Activity 3.2 of Objective 3 (Develop and conduct formal and informal training programs for industry) in the ACIAR co-funded aid project FST/2016/151 Advancing enhanced wood manufacturing industries in Laos and Australia. The aim of this Study tour was to expose the new project partner PML Easbeam Company to engineered wood product manufacturing, potential markets and industries operating in Australia. The PML Easbeam company is a subsidiary of the PML company and was established in July 2019. The PML Company was successful in tendering for the construction of an add-on facility at the National University of Laos to contain equipment for veneer-based product production research. Subsequently, as an established construction company, the company saw the potential and were interested in engineered wood products made from wood veneer, in particular laminated veneer lumber (LVL) structural beams. At the point of writing this report, PML Easbeam is in the process of setting up an LVL plant in Vientiane to manufacture LVL beams using certified, plantation eucalyptus material for domestic and international markets. The PML Easbeam Company financed the study tour themselves. The expected mid to long-term outcome of this exposure is to facilitate the uptake of veneer-based processing and product development in Laos PDR. Previous research conducted during ACIAR co-funded aid project: FST/2008/039 Enhancement of veneer products from acacia and eucalypt plantations in Vietnam and Australia, identified spindleless-lathes as the most likely evolutionary technology to improve the productivity of processing small plantation-logs in Lao PDR. The veneer processing sector in Vietnam is well established and involves 4,200 wood processing and trading enterprises and in the order of thousands of household businesses employing over 300,000 labourers operating in over 300 traditional wood-processing villages (To and Quang, 2012). During surveys of small rural areas of Northern Vietnam, Ozarska et al. (2015) identified that exporters of peeled veneer to China and India cannot meet the demand of these countries. Therefore, this undersupply could provide potential export markets of processed veneer from small plantation-logs currently growing in Lao PDR.

The cacti are important plant genetic resources of the Brazilian semiarid region, with potential for the extraction of bioactive compounds such as flavonoids and alkaloids. The objective of this research was to characterize and quantify the chemical constituents of Pilosocereus catingicola (Gürke) Byles & Rowley subsp. salvadorensis (Werderm.) Zappi occurring in caatinga in the Westland of Paraíba, Brazil. We collected roots, stems and fruit of plants growing in populations at Arara, Areial and Boa Vista. Chemical characterization of the different plant tissues showed that roots and stems of P. catingicola contained steroids, flavonoids and saponins whereas fruit was dominated by high levels of betalainic chromoalkaloids (betalains). Tests performed to optimize extraction of betalains from P. catingicola fruit showed highest yields were from freeze-dried nuts extracted for 95 min, with the crude extract stored at -20°C for a maximum of 48 h. The betalains of all fruit samples were dominated by betacyanins with much lower amounts of betaxanthins observed in each population. Numerous betacyanin constituents were detected in fruit extracts, with the key constituents identified as betanin and phyllocactin. The Arara population yielded relatively more betaxanthins compared to plants from the Areial and Boa Vista regions.