Sonication as an aid for handling geraldton wax (Chamelaucium uncinatum) pollen

Pollen in Chamelaucium species is exuded from the anthers in an oily substance and deposited onto the pollen presenter. Pollen in oil was sonicated in 20% sucrose at 20 watts, then spun down at 8,000 rpm for 60 s. Pollen germination was reduced by sonication (from 50% to 30%), and pollen tube length was reduced by about one third in 2 of the 3 lines tested. When sonicated pollen was used on the stigma, good germination was observed; by 48 h there were as many pollen tubes at the base of the style as when using unsonicated pollen. Overall 11.5% seed set was observed using sonicated pollen in intraspecific crosses of C. uncinatum, and 7% in C. uncinatum x megalopetalum crosses

A double-flowered geraldton wax (Chamelaucium uncinatum Schauer) with an anomalous flower in the ovary

A naturally occurring mutant of Chamelaucium uncinatum Schauer (Geraldton wax) is described. It has double flowers with the staminodes transformed into petals. Pollen is exuded from the anthers but is not deposited on the pollen presenter in a lipid droplet, which is normal for the species. An anomalous secondary flower with petals, stamens, and gynoecium is present in the ovary

First Nations’ interactions with underground storage organs in southwestern Australia, a Mediterranean climate Global Biodiversity Hotspot

Abstract Aims and background Underground storage organs (USOs) have long featured prominently in human diets. They are reliable year-round resources, especially valuable in seasonal climates. We review a significant but scattered literature and oral recounts of USOs utilised by Noongar people of the Southwest Australian Floristic Region (SWAFR). USOs are important to First Nations cultures in other geophyte-rich regions with Mediterranean climate, with specialist knowledge employed, and productive parts of the landscape targeted for harvest, with likely ecological interactions and consequences. Methods We have gathered Noongar knowledge of USOs in the SWAFR to better understand the ecological role of Noongar-USO relationships that have existed for millennia. Results We estimate that 418 USO taxa across 25 families have Noongar names and/or uses. Additionally, three USO taxa in the SWAFR weed flora are consumed by Noongar people. We found parallels in employment of specific knowledge and targeted ecological disturbance with First Nations’ practice in other geophyte-rich floristic regions. We found that only in 20% of cases could we identify the original source of recorded USO knowledge to an acknowledged Noongar person. Conclusion This review identified that traditional Noongar access to USOs is taxonomically and geographically extensive, employing specific knowledge and technology to target and maintain resource rich locations. However, we also found a general practice of ‘extractive’ documentation of Noongar plant knowledge. We identify negative implications of such practice for Noongar people and SWAFR conservation outcomes and assert ways to avoid this going forward, reviving Noongar agency to care for traditional Country. </jats:sec

Effectiveness and economic viability of native seed pelleting in large-scale seedling production for revegetation

Revegetation efforts in the context of ecological restoration require large numbers of nursery grown seedlings across a wide range of native species. Automated seeding production lines in nurseries struggle to handle low quality small-seeded species, often resulting in under or over-seeding which increases production costs by requiring manual sorting or thinning. A combination of seed processing and testing can improve seed quality, while seed pelleting can increase and standardise seed size, shape and weight, allowing for more homogenous seed delivery. In this study, we tested the effect of seed pelleting on seeding consistency and seed-to-seedling conversion rates for ten small-seeded Australian native species belonging to the Myrtaceae family. A break-even model was developed using seed and seedling production parameters and costs to explore the economic viability and benefits of seed pelleting for large-scale nursery seedling production. More than one million seedlings were produced for this study in a commercial native plant nursery and used in Eucalyptus woodland revegetation projects in the Wheatbelt region of Western Australia. Our results showed that seed delivery consistency was significantly improved in nine out of ten species, and seed-to-seedling conversion rates increased in eight species. The break-even analysis indicated that, on average, seed pelleting becomes economically viable for production targets above 38,287 seedlings. Given the average seedling production target of 100,985 seedlings per species, this could yield an average saving of $1459 per species. The enhanced efficiency in large-scale seedling production allows for more cost-effective revegetation and can help redirect resources to include a wider range of challenging native species that so far have been underutilised in restoration due to logistical constraints

Platysace (Apiaceae) of south-western Australia: silent story tellers of an ancient human landscape

AbstractHigh gene flow and a population structure corresponding to human rather than geographical drivers are likely to be genetic patterns of human-dispersed plant taxa. We examined variation in geographical structure and gene flow estimates based on three non-coding regions of plastid DNA in three south-west Australian members of the Platysace genus to identify whether a human influence on dispersion of utilized taxa was detectable. Edible tubers of Platysace deflexa and Platysace trachymenioides have been harvested historically by Noongar traditional owners, whereas Platysace effusa has no known cultural significance. We found differences between utilized and non-utilized taxa, particularly when considered against the generally complex phylogeographical patterning in south-west Australian plant taxa. Platysace effusa showed a pattern of high population divergence, low gene flow and multiple refugia, consistent with a long evolutionary history, past climatic oscillations and persistence in a highly fragmented landscape. In contrast, higher gene flow estimates, less divergence between populations and common haplotypes in P. deflexa and in P. trachymenioides over the south-eastern part of its range are consistent with anthropogenic influences. This study contributes to the understanding of human influences on south-west Australian plant taxa that have been present since the late Pleistocene, but to date have received little scientific attention.</jats:p

The Noongar of south-western Australia: a case study of long-term biodiversity conservation in a matrix of old and young landscapes

Abstract Occurring across all southern hemisphere continents except Antarctica, old, climatically buffered, infertile landscapes (OCBILs) are centres of biological richness, often in biodiversity hotspots. Among a matrix of young, often disturbed, fertile landscapes (YODFELs), OCBILs are centres of endemism and diversity in the exceptionally rich flora of the south-west Australian global biodiversity hotspot, home to Noongar peoples for ≥ 48 000 years. We analysed contemporary traditional Noongar knowledge of adjacent OCBILs (e.g. granite outcrops) and YODFELs (e.g. creekline fringes) both at a single site and in two larger areas to test whether patterns of disturbance dictated by Noongar custom align with OCBIL theory. We found that Noongar traditional knowledge reflects a regime of concentrated YODFEL rather than OCBIL disturbance—a pattern which aligns with maximal biodiversity preservation. SIMPER testing found traditional Noongar OCBIL and YODFEL activities are 64–75% dissimilar, whereas Pearson’s chi-square tests revealed camping, burning, travelling through country and hunting as primarily YODFEL rather than OCBIL activities. We found that Noongar activities usually avoid OCBIL disturbance. This combined with high floristic diversity following enduring First Peoples’ presence, suggests that traditional Noongar knowledge is valuable and necessary for south-west Australian biodiversity conservation. Similar cultural investigations in other OCBIL-dominated global biodiversity hotspots may prove profitable.</jats:p