Habitat specificity, seed germination and experimental translocation of the endangered herb Brachycome muelleri (Asteraceae) |
| |
| Authors: | Manfred Jusaitis Lesley Polomka |
| |
| Institution: | a Plant Biodiversity Centre, Department for Environment and Heritage, Hackney Road, Hackney, SA 5069, Australiab Science Division, WA Herbarium, Department of Conservation and Land Management, Locked Bag 104, Bentley Delivery Centre, WA 6983, Australiac Resource Management Division, Department for Water, Land and Biodiversity Conservation, GPO Box 2834, Adelaide, SA 5001, Australia |
| |
| Abstract: | Brachycome muelleri Sonder (Corunna daisy) is an endangered annual herb, endemic to the upper Eyre Peninsula of South Australia. It is restricted to a single population occupying an area of approximately 3 ha on steep, south-facing cliff-foot slopes of the Baxter Hills. Its unique habitat, within an otherwise generally arid region, optimises soil moisture retention through the provision of concentrated water catchment, shade, and low evaporation rates during the growing season. Weeds had the potential to significantly disrupt recruitment, growth and reproductive output, but grazing did not constitute a direct threat to the population. Fresh seeds were innately dormant, requiring a period of after-ripening before they would germinate. Dormancy was artificially broken by gibberellic acid (GA3) treatment. Germination was optimal at 20 °C, and it was proposed that temperature plays an important role in regulating germination in situ. B. muelleri seeds did not respond to smoked water treatment, and GA3 (1000 mg l−1) was recommended as a routine seed treatment to stimulate germination. Trial translocations using seed as founder propagules resulted in low establishment, growth and flowering rates. Established seedlings provided several advantages over seed as founder propagules, including higher success rates, more vigorous growth, and improved seed yields in the first season. Successful regeneration, proliferation and expansion of a new translocated population was observed and recorded over four consecutive years. We suggest that conservation management of this species should include the establishment of several new populations by translocation to suitable, isolated, weed-free sites. |
| |
| Keywords: | Endangered plants Conservation Compositae Brachyscome Ecology Weeds Herbivores Grazing Threats Dormancy Temperature Smoke |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
