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The New South Wales Seedbank (at Mount Annan Botanic Garden) stores seeds of both common and threatened species for conservation, research and restoration or revegetation projects. The value of the collections depends on our ability to germinate seeds once they have been retrieved from storage. The collection includes 129 collections representing 93 taxa in the family Rutaceae, but seed viability in Rutaceae is variable, germination cues are poorly-understood and problems are likely to arise in trying to grow plants from seed. In this study we quantified seed fill and/or viability and germination for 112 species in the Rutaceae family. For many of the species, this is the first time that these seed characteristics have been recorded. We found that seed fill (0–100%) and seed viability (0–97%), were highly variable, with 80% of collections having low viability (<75%). There was also a trend for threatened species to have lower seed fill than common species, while viability and germination were similar. This review reaffirms the need for further study of seed characteristics in Rutaceae.
The flowers of Waratahs, Telopea speciosissima (family Proteaceae) are regularly harvested illegally from natural bushland, particularly close to urban areas such as the New South Wales Central Coast. The removal of Waratah blooms from the wild may have implications for the long-term survival of local populations because of the interaction between wildfire events, subsequent flowering and limited seedling recruitment opportunities. To reduce the incidence of theft, blue acrylic paint was applied to blooms to reduce their commercial value. The painting of blooms in 2004 did not significantly reduce the incidence of wildflower theft when compared to unpainted blooms, but overall losses were lower (27%) than in 2003 (33%). However, painting of blooms had a deleterious affect on fruit production on plants with multiple heads with painted blooms having significantly reduced fruit set compared to unpainted blooms. Painting of blooms had no significant effect on seed quality (seed production per fruit, seed germination or seedling vigour) when compared to unpainted blooms. The painting of Waratah blooms to reduce theft was relatively ineffective and decreased fruit production. Alternative strategies should be considered to reduce wildflower theft in the area.
Seed production varies from year-to-year in most species. Factors influencing this variation can include pollination and dispersal mechanisms, seed predation and resource availability. Here we examine a long-term (12– year) photographic record of seed cone production for the Australian endemic conifer Wollemia nobilis (Araucariaceae). Coefficient of variation (a commonly used measure of variation in seed production) was low for the two trees analysed, compared with published values for other polycarpic plants. Nevertheless, cone production decreased with increasing spring minimum temperatures (during pollination) and increased with summer total rainfall (during cone initiation). Hence, Wollemia nobilis cone production was correlated with weather, in line with the resource-matching hypothesis. Impacts of variation in cone production on the Wollemia nobilis population are likely to be buffered by the shade-tolerant, slow-growing juvenile life stage of Wollemia nobilis.
Persoonia (family Proteaceae) is a diverse genus of 99 species, mainly of woody shrubs and small trees, that are endemic to Australia. The fleshy fruits that characterise these plants are an important resource in otherwise resource-depauperate ecological communities. However, this genus is highly under-represented in restoration and conservation programs, as its species are notoriously difficult to propagate and transplant in the wild. Understanding the mechanisms that control seed production, viability, dormancy and germination will hasten progress on Persoonia propagation. Here we review Persoonia studies to reveal the nature of, and variability within, the genus. We identify key factors that need to be addressed; specifically, those affecting fruit set, endocarp degradation and subsequent propagation of Persoonia. This synthesis of current knowledge provides important material to inform management of this taxon in the landscape, and outlines several important priorities for future seed biology research on the genus. We outline several important priorities for future seed biology research on the genus.