Saltmarsh conservation through inventory, biogeographic analysis and predictions of change: Case of Tasmania, south‐eastern Australia

Abstract

1. Effective conservation of saltmarshes involves detailed and accurate mapping of their range, area of occupancy and plant community composition as part of region-wide inventories. There is also a need to identify the major mesoscale influences on the distributions of types of saltmarsh, obligate saltmarsh plants and salt pans, and evaluate possible responses to macroclimatic changes.2. Tidal saltmarshes of Tasmania and its offshore islands (coastline of 4,882 km, spanning latitudes 39°40′ to 43°40′S), off south-eastern Australia, were mapped at a high spatial resolution of 1 : 500-1 : 3,000. The distributions of types of saltmarsh, obligate plant taxa and salt pans were related to climatic, geomorphic and land-use variation. The future distribution of climatically controlled species and communities was determined for two climate change scenarios.3. There was 58.6 km 2 of tidal saltmarsh in Tasmania in 61 mesoscale complexes. The complexes were classified into three broad saltmarsh groups, which together offer a more ecologically relevant planning unit for saltmarsh conservation than macroscale bioregions. The small median patch size of 0.2 ha demonstrates the effectiveness of the manual interpretation and mapping with extensive field checking.Mapping of these smaller saltmarshes provides them recognition within the land use planning and approvals process. 4. Climatic, but not geomorphic and land-use, factors have strong effects on the distribution of saltmarsh plant communities, species and salt pans in Tasmania.Mean annual rainfall was most significant in predicting saltmarsh extent, range, plant community composition, salt pans and the three saltmarsh groups. Mean annual daily minimum temperature and saltmarsh area best predicted obligate plant distributions. 5. Projected wetter and drier climatic change by 2100 is not expected to substantially alter macroscale plant community patterns but may reduce the range of the rare herb Wilsonia humilis R.Br. However, stochastic disturbances may continue to play an important role at local scales.

Introduced Spartina anglica modifies fish habitat in southern temperate succulent saltmarshes

“…2). This region contains nearly 25% of the mapped saltmarsh in Tasmania (Prahalad & Kirkpatrick 2019). Saltmarshes occupy 1,326 ha of coastal embayments, estuaries and tidal islands between Temdudheker/Woolnorth Point and Stanley (Prahalad 2016).…”

“…Sampling sites in Duck Bay, near Smithton in far northwest Tasmania, southeastern Australia. Coastal saltmarsh mapping data sourced from Prahalad and Kirkpatrick (2019), Spartina anglica mapping sourced from Prahalad (2016). Base data from the LIST ( www.thelist.tas.gov.au, accessed 9 March 2022; State of Tasmania).…”

Public perceptions of wetlands and preferences for on-site visitor facilities and communication media: a case study from an Australian Ramsar wetland

“…There are ,1048 ha of saltmarshes fringing the Lagoon (Fig. 1), which is close to one-fifth of the Tasmanian extent (Prahalad and Kirkpatrick 2019). Tasmanian coastal saltmarshes, including those in Moulting Lagoon, are recognised as 'threatened ecological communities' under the Australian Federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act).…”

Vegetation communities and edaphic relationships along a typical coastal saltmarsh to woodland gradient in eastern Tasmania

“…Tasmania has about 58.6 km 2 of coastal saltmarshes, principally located on the east coast and Flinders Island, the north coast and the far northwest including King Island (Prahalad & Kirkpatrick 2019). Although only a small proportion of the Australian total, Tasmania features the highest diversity of saltmarsh vegetation communities (Saintilan 2009a(Saintilan , 2009b.…”

“…Gouldthorpe (2000) researched the impacts of drainage and grazing on Derwent River marshes and a recent study identified changes in the extent and community composition of southeast Tasmanian saltmarshes (Prahalad et al 2011). The real and projected impacts of climate change have also received recent attention (Mount et al 2010, Prahalad et al 2015, Prahalad & Kirkpatrick 2019. Nevertheless, there are no Tasmanian studies with detailed field measurements that focus on the interactions of saltmarsh soils and vegetation.…”