On the distribution, ecology and conservation status of three rare plant taxa Zygophyllum compressum, Elachanthus glaber and Eremophila crassifolia in southwestern New South Wales

The arid and semi-arid southwest of New South Wales has received disproportionately less attention from botanists than other similar-sized geographic regions of the state. Recent work has extended our knowledge of three extremely rare plant taxa from this part of the state. Zygophyllum compressum (Zygophyllaceae) and Elachanthus glaber (Asteraceae) are restricted to gypseous rises within active saline groundwater discharge complexes with limited distribution in southwest New South Wales and occur within the plant community “Gypseous shrubland on rises and semi-arid plains” (ID253) which is listed as threatened (vulnerable) within the state. Eremophila crassifolia (Myoporaceae) is restricted to a few plants on a roadside and adjacent mallee vegetation approximately 35 km east of Wentworth. Based on IUCN criteria it is suggested that Eremophila crassifolia is critically endangered and Zygophyllum compressum and Elachanthus glaber endangered in New South Wales and all should be listed under the NSW Threatened Species Conservation Act 1995

On the ecology, distribution and conservation status of Vittadinia blackii (Asteraceae) in Australia

Distribution records of Vittadinia blackii (family Asteraceae) across southern Australia show the species has a strong and moderately common presence across a broad range of climate zones and sites in South Australia, but a much more restricted occurrence in other mainland state’s. Using the IUCN criteria, adopted by the separate state regulatory authorities vested with listing threatened species, Vittadinia blackii is considered to be not threatened in South Australia, but endangered in Western Australia, Victoria and New South Wales

Soil reconstruction after mining fails to restore soil function in an Australian arid woodland

The biogeochemical properties of soils drive ecosystem function and vegetation dynamics, and hence soil restoration after mining should aim to reinstate the soil properties and hydrological dynamics of remnant ecosystems. The aim of this study is to assess soil structure in two vegetation types in an arid ecosystem, and to understand how these soil properties compare to a reconstructed soil profile after mining. In an arid ecosystem in southeast Australia, soil samples were collected at five depths (to 105 cm) from remnant woodland and shrubland sites, and sites either disturbed or totally reconstructed after mining. We assessed soil physico-chemical properties and microbial activity. Soils in the remnant arid ecosystem had coarse-textured topsoils that overlay clay horizons, which allows water to infiltrate and avoid evaporation, but also slows drainage to deeper horizons. Conversely, reconstructed soils had high sand content at subsoil horizons and high bulk density and compaction at surface layers (0–20 cm). Reconstructed soils had topsoils with higher pH and electrical conductivity. The reconstructed soils did not show increased microbial activity with time since restoration. Overall, the reconstructed soil horizons were not organized in a way that allowed rainfall infiltration and water storage, as is imperative to arid-zone ecosystem function. Future restoration efforts in arid ecosystems should focus on increasing sand content of soils near the surface, to reduce evaporative water loss and improve soil quality and plant health. © 2020 Society for Ecological Restoratio

Biocrust amendments to topsoils facilitate biocrust restoration in a post-mining arid environment

Soil cryptogamic biocrusts provide many ecological functions in arid zone ecosystems, though their natural reestablishment in disturbed areas is slow. Accelerating reestablishment of biocrusts may facilitate the establishment of vascular plant communities within the timeframes of restoration targets (typically 5–15 years). One technique is to inoculate the soil surface using slurries of biocrust material harvested from another site. However, this is destructive to donor sites, and hence the potential to dilute slurries will govern the feasibility of this practice at large spatial scales. We conducted a replicated experiment on a disturbed mine site to test the individual and combined effects of two strategies for accelerating soil cryptogamic biocrust reestablishment: (1) slurry inoculation using biocrust material harvested from native vegetation; and (2) the use of psyllium husk powder as a source of mucilage to bind the soil surface, and to potentially provide a more cohesive substrate for biocrust development. The experiment comprised 90 experimental plots across six treatments, including different dilutions of the biocrust slurries and treatments with and without psyllium. Over 20 months, the reestablishing crust was dominated by cyanobacteria (including Tolypothrix distorta and Oculatella atacamensis), and these established more rapidly in the inoculated treatments than in the control treatments. The inoculated treatments also maintained this cover of cyanobacteria better through prolonged adverse conditions. The dilute biocrust slurry, at 1:100 of the biocrust in the remnant vegetation, performed as well as the 1:10 slurry, suggesting that strong dilution of biocrust slurry may improve the feasibility of using this technique at larger spatial scales. Psyllium husk powder did not improve biocrust development but helped to maintain a soil physical crust through hot, dry, and windy conditions, and so the potential longer-term advantages of psyllium need to be tested. Copyright © 2022 Schultz, Sluiter, Allen, Machado-de-Lima and Muñoz-Rojas

Biocrust Amendments to Topsoils Facilitate Biocrust Restoration in a Post-mining Arid Environment

Soil cryptogamic biocrusts provide many ecological functions in arid zone ecosystems, though their natural reestablishment in disturbed areas is slow. Accelerating reestablishment of biocrusts may facilitate the establishment of vascular plant communities within the timeframes of restoration targets (typically 5–15 years). One technique is to inoculate the soil surface using slurries of biocrust material harvested from another site. However, this is destructive to donor sites, and hence the potential to dilute slurries will govern the feasibility of this practice at large spatial scales. We conducted a replicated experiment on a disturbed mine site to test the individual and combined effects of two strategies for accelerating soil cryptogamic biocrust reestablishment: (1) slurry inoculation using biocrust material harvested from native vegetation; and (2) the use of psyllium husk powder as a source of mucilage to bind the soil surface, and to potentially provide a more cohesive substrate for biocrust development. The experiment comprised 90 experimental plots across six treatments, including different dilutions of the biocrust slurries and treatments with and without psyllium. Over 20 months, the reestablishing crust was dominated by cyanobacteria (including Tolypothrix distorta and Oculatella atacamensis), and these established more rapidly in the inoculated treatments than in the control treatments. The inoculated treatments also maintained this cover of cyanobacteria better through prolonged adverse conditions. The dilute biocrust slurry, at 1:100 of the biocrust in the remnant vegetation, performed as well as the 1:10 slurry, suggesting that strong dilution of biocrust slurry may improve the feasibility of using this technique at larger spatial scales. Psyllium husk powder did not improve biocrust development but helped to maintain a soil physical crust through hot, dry, and windy conditions, and so the potential longer-term advantages of psyllium need to be tested

Dry matter losses and quality changes during short rotation coppice willow storage in chip or rod form

This study compares dry matter losses and quality changes during the storage of SRC willow as chips and as rods. A wood chip stack consisting of approximately 74 tonnes of fresh biomass, or 31 tonnes dry matter (DM) was built after harvesting in the spring. Three weeks later, four smaller stacks of rods with an average weight of 0.8 tonnes, or 0.4 tonnes DM were built. During the course of the experiment temperature recorders placed in the stacks found that the wood chip pile reached 60 °C within 10 days of construction, but the piles of rods remained mostly at ambient temperatures. Dry matter losses were calculated by using pre-weighed independent samples within the stacks and by weighing the whole stack before and after storage. After 6 months the wood chip stack showed a DM loss of between 19.8 and 22.6%, and mean losses of 23.1% were measured from the 17 independent samples. In comparison, the rod stacks showed an average stack DM loss of between 0 and 9%, and between 1.4% and 10.6% loss from the independent samples. Analysis of the stored material suggests that storing willow in small piles of rods produces a higher quality fuel in terms of lower moisture and ash content; however, it has a higher fine content compared to storage in chip form. Therefore, according to the two storage methods tested here, there may be a compromise between maximising the net dry matter yield from SRC willow and the final fine content of the fuel

On the distribution, ecology and conservation status of three rare plant taxa Zygophyllum compressum, elachanthus glaber and Eremophilia crassifolia in southwestern New South Wales

The arid and semi-arid southwest of New South Wales has received disproportionately less attention from botanists than other similar-sized geographic regions of the state. Recent work has extended our knowledge of three extremely rare plant taxa from this part of the state. Zygophyllum compressum (Zygophyllaceae) and Elachanthus glaber (Asteraceae) are restricted to gypseous rises within active saline groundwater discharge complexes with limited distribution in southwest New South Wales and occur within the plant community “Gypseous shrubland on rises and semi-arid plains” (ID253) which is listed as threatened (vulnerable) within the state. Eremophila crassifolia (Myoporaceae) is restricted to a few plants on a roadside and adjacent mallee vegetation approximately 35 km east of Wentworth. Based on IUCN criteria it is suggested that Eremophila crassifolia is critically endangered and Zygophyllum compressum and Elachanthus glaber endangered in New South Wales and all should be listed under the NSW Threatened Species Conservation Act 1995.C

WALNUT ROOTSTOCK SELECTION FOR CALCAREOUS SOILS IN SOUTHEASTERN AUSTRALIA AND THE POTENTIAL FOR EXPANDING THE WALNUT INDUSTRY IN THE REGION

Persian walnuts are grown over relatively small area within irrigated settlements of the Murray Lowlands Province of Southeastern Australia compared with traditional crops such as grapes and citrus or emerging crops such as almonds. Poor walnut tree health usually associated with wrong rootstock selection, or growth in areas with inadequate topsoil depth, have inculcated a strong traditional resistance amongst growers and horticultural developers to walnuts as a viable alternative crop for the region. Recent trials comparing Juglans hindsii, a traditional rootstock for the area, with a new selection of Paradox rootstock, have shown the Paradox 'entity' significantly outperforms J. hindsii in terms of scion growth in the first year. The Paradox hybrid has also been shown to grow vigorously in soils with shallow topsoil depth above calcareous B horizon subsoils. This suitability of the Paradox hybrid to calcareous soils provides the potential to expand the walnut industry into parts of the Murray Lowland Province characterized by Calcarosol soils with as little as 30 cm topsoil

Eocene-Oligocene coals of the Gippsland and Australo-Antarctic basins – Paleoclimatic and paleogeographic context and implications for the earliest Cenozoic glaciations

Australia's Gippsland Basin contains a semi-continuous Eocene-Oligocene (41.5–28.4 Ma) near-coastal coal record that formed adjacent to Pacific Ocean. Traralgon and Morwell Formation brown coals include 4 main seams (T2, T1, T0, M2). Coal seam palynology records show late Middle Eocene (T2) coals formed under megathermic conditions characterized by high-gymnosperm contents, Late Eocene (T1) coals formed under mesothermic conditions characterized by reduced-gymnosperm contents and earliest indications of palaeoclimate cooling. Earliest Oligocene T0 coal record (33.9–31.5 Ma) contains high-gymnosperm palynology profile, very similar to the T2 coals. The earliest indication of cooler climes only begins after this coal formed as indicated by low-gymnosperm high-Nothofagus (southern beech) pollen proportions. We suggest in Gippsland the earliest evidence for major glacial cooling (by inference the Oi1 event) be placed immediately above the T0 coal seam where Early to Late Oligocene Morwell Formation sands, clays and coals contain low counts of gymnosperms (< 10%) but high average proportions of Nothofagus (50%). This is the main definitive indicator that palaeoclimates had cooled between the Eocene and Oligocene. This agrees with the current ocean drilling position of the earliest (Oi1) glacial event shortly above the Eocene-Oligocene boundary. A number of contemporaneous Middle to Late Eocene brown coals occurred in near-coastal settings across 1200 km of southern Australia. Palaeogeographically, all these coal basins faced the Australo-Antarctic Gulf and have a much lower gymnosperm proportion (< 10%), low Nothofagus proportion (< 10%), but very high (non-Nothofagus) angiosperms proportion. This suggests a different climatic regime separated a cooler and wetter Gippsland Basin flora that responded to the cooler Proto-Ross Sea Gyre rotating around a wide Pacific Ocean, and a warm-wet climate associated with a warm proto-Leeuwin current of the Australo-Antarctic Gulf. © 2017 Elsevier B.V