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Ecological applications

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    The seasonal dynamic reference cover method images are created using a modified version of the dynamic reference cover method developed by <a href="https://doi.org/10.1016/j.rse.2012.02.021">Bastin et al (2012) </a>. This approach calculates a minimum ground cover image over all years to identify locations of most persistent ground cover in years with the lowest rainfall, then uses a moving window approach to calculate the difference between the window's central pixel and its surrounding reference pixels. The output is a difference image between the cover amount of a pixel's reference pixels and the actual cover at that pixel for the season being analysed. Negative values indicate pixels which have less cover than the reference pixels. The main differences between this method and the original method are that this method uses seasonal fractional ground cover rather than the preceding ground cover index (GCI) and this method excludes cleared areas and certain landforms (undulating slopes), which are considered unsuitable for use as reference pixels. This product is based upon the JRSRP Fractional Cover 3.0 algorithm.

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    The Sentinel-2 seasonal fractional ground cover product shows the proportion of bare ground, green and non-green ground cover and is derived directly from the Sentinel-2 seasonal fractional cover product, also produced by Queensland's Remote Sensing Centre. The seasonal fractional cover product is a spatially explicit raster product, which predicts vegetation cover at medium resolution (10&nbsp;m per-pixel) for each 3-month calendar season. However, the seasonal fractional cover product does not distinguish tree and mid-level woody foliage and branch cover from green and dry ground cover. As a result, in areas with even minimal tree cover (>15%), estimates of ground cover become uncertain. With the development of the fractional cover time-series, it has become possible to derive an estimate of ‘persistent green’ based on time-series analysis. The persistent green vegetation product provides an estimate of the vertically-projected green-vegetation fraction where vegetation is deemed to persist over time. These areas are nominally woody vegetation. This separation of the 'persistent green' from the fractional cover product, allows for the adjustment of the underlying spectral signature of the fractional cover image and the creation of a resulting 'true' ground cover estimate for each season. The estimates of cover are restricted to areas of <60% woody vegetation. Currently, the persistent green product has only been produced at 30&nbsp;m pixel resolution based on Landsat imagery, resulting in this Sentinel-2 seasonal ground cover product having a medium 30&nbsp;m pixel resolution also. This is an experimental product which has not been fully validated. This product is similar to the <a href="https://portal.tern.org.au/metadata/23884 ">Seasonal ground cover - Landsat, JRSRP algorithm Version 3.0, Australia Coverage</a> which is based on a different satellite sensor.

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    Terrestrial laser scans were acquired in native Eucalypt Open Forest (dry sclerophyll Box-Ironbark forest) in Victoria, Australia. Two plots (RUSH06 and RUSH07) with a 40 m radius were established in Rushworth forest and partially harvested in May 2012 to acquire accurate estimates of above-ground biomass. The main tree species in these plots were Eucalyptus leucoxylon, Eucalyptus microcarpa and Eucalyptus tricarpa. Single trees were extracted from the TLS data and quantitative structure models were used to estimate the tree volume directly from the point cloud data. Above-ground biomass (AGB) was inferred from the derived volumes and basic wood density information, and compared with estimates of above-ground biomass derived from allometric equations and destructive sampling. See <a href="https://doi.org/10.1111/2041-210X.12301">Calders et al. (2014)</a> and <a href="http://www.vcccar.org.au/publication/final-report/comprehensive-carbon-assessment-program">Murphy et al. (2014)</a> for further information.

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    We established a common garden experiment within a 238 ha restoration site owned and managed by the South Australian Water Corporation (SA Water), near the township of Clarendon (-35.0882°S, 138.6236°E). We grew ca. 1500 seedlings sourced from one local and two non-local provenances of <i>Eucalyptus leucoxylon</i> to test whether local provenancing was appropriate. The three provenances spanned an aridity gradient, with the local provenance sourced from the most mesic area and the distant from the most arid. We explored the effect of provenance on four fitness proxies after 15 months, including survival, above-ground height, susceptibility to insect herbivory, and pathogen related stress.

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    The monthly blended ground cover product is a spatially explicit raster product that shows the proportion of bare ground, green and non-green ground cover at medium resolution (30&nbsp;m per-pixel) for each calendar month. It is derived directly from both the Landsat-based fractional cover product and the Sentinel-2-based fractional cover product by Queensland's Remote Sensing Centre. A 3 band (byte) image is produced: band 1 - bare ground fraction (in percent), band 2 - green vegetation fraction (in percent), band 3 - non-green vegetation fraction (in percent). The no data value is 255. This product is derived from the <a href="https://portal.tern.org.au/metadata/TERN/8d3c8b36-b4f1-420f-a3f4-824ab70fb367 ">Monthly blended fractional cover - Landsat and Sentinel-2, JRSRP algorithm Version 3.0, Queensland coverage</a>

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    The project is focused on the topic, 'enhanced heat tolerance of virus-infected aphids lead to niche expansion and reduced interspecific competition. The two aphid species studied are <i>Rhopalosiphum padi</i> and <i>Rhopalosiphum maidis</i>. The project had some of the following objectives: [1] Spatial distribution of two aphid species on the host plants [2] Upper thermal limits of two aphid species. [3] Effects of the viral infection on the host plant thermal profile. [4] Levels of expression of heat shock protein genes of virus-free and viruliferous aphids. [5] Locomotor capacity of aphids, effects of viruses on the locomotor capacity. [6] Effects of viral infection, temperature, and competition on the lifespan and fecundity of <i>R. padi</i> [7] Effects of viral infection, temperature, and competition on the lifespan and fecundity of <i>R. maidis</i> [8] Temperature of acrylic tubes used on aphid experiments. [9] Thermal lethal dose 50 of virus-free and viruliferous aphids [10] Thermal preference of virus-free and viruliferous aphids. This information can be very useful for ecologist working on insect population dynamics as well as physiologist and eco-physiologists doing meta-analyses of expression of heat shock protein genes induced by symbionts.

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    Wood block decomposition assessment at the Litchfield Savanna site is part of a global program looking at the influence of microbes and invertebrates on wood decay. A common protocol was developed exposing small (~400 cm3) pieces of a wood-substrate (untreated Pinus radiata) to the environment excluding and not-excluding macroinvertebrates (e.g. termites) by the use of a plastic mesh.

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    Wood block decomposition assessment at the Alice Mulga site is part of a global program looking at the influence of microbes and invertebrates on wood decay. A common protocol was developed exposing small (~400 cm3) pieces of a wood-substrate (untreated Pinus radiata) to the environment excluding and not-excluding macroinvertebrates (e.g. termites) by the use of a plastic mesh.

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    Wood block decomposition assessment at the Gingin Banksia Woodland site is part of a global program looking at the influence of microbes and invertebrates on wood decay. A common protocol was developed exposing small (~400 cm3) pieces of a wood-substrate (untreated Pinus radiata) to the environment excluding and not-excluding macroinvertebrates (e.g. termites) by the use of a plastic mesh.

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    Wood block decomposition assessment at the Warra Tall Eucalypt site is part of a global program looking at the influence of microbes and invertebrates on wood decay. A common protocol was developed exposing small (~400 cm3) pieces of a wood-substrate (untreated Pinus radiata) to the environment excluding and not-excluding macroinvertebrates (e.g. termites) by the use of a plastic mesh.