Abstract: |
Tecticornia flabelliformis (known as Bead Samphire; Bead Glasswort or Fan Samphire) is a nationally (Australian) and state (South Australia) listed threatened-species, growing on coastal salt pan environments (sabkhas) along the eastern shore of Gulf St Vincent; South Australia. Previous surveys in 2009 and 2010 included all sabkhas between Port Gawler to Port Prime (south). This project mapped populations of the species at other sabkhas; located between Parham to Port Prime as well as at St Kilda. This study aimed to determine taxonomy; distribution, abundance and population structure of the T. flabelliformis population, which is the first specific recovery objective in the 2010 draft Recovery Plan. The extent and abundance of patches of the species were recorded using a GPS.
RESULTS: The area covered during the 2011 survey was around 5630 hectares and the total population estimated from previous and current surveys was 3,500,000. The low-lying sabkhas in the northern extent of the survey areas (Webb and Thompsons Beach) extended several kilometres inland and appeared to be too dry to support large homogenous stands of T. flabelliformis. In these sabkhas the species is restricted to narrow ribbons along the edge of the pans; where runoff from surface water and seepage from near-surface groundwater may provide sufficient water. In other sabkhas that were inundated at the time of survey and appeared to be either deeper or had a different soil type there was no evidence of T. flabelliformis growing even along the fringes of the saltpan. Some parts of the sabkha complex do not support the Fan Samphire. Where the plant does not appear to occur naturally; its absence is likely to be related to soil type and hydrology (water table levels as well as frequency; depth and duration of inundation). T. flabelliformis tolerates a wide range of soil moistures and very high salinities; but prefers higher pH than many other samphires. There were specific areas of high density seedling recruitment at Webb Beach and some notable densities of seedlings at Thompsons Beach. Off-road vehicle disturbance and fencing were important factors and there is much fragmentation of populations into separate smaller populations. The report includes management recommendations.
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