Fleurieu Peninsula wetlands collated plant survey data Version.2 

This is a collated plant survey data from the Fleurieu Peninsula wetlands (version.2). There is a biological and a spatial component to the dataset. [1] Biological data: This was collated from several sources, collected over the period 2000-2009 and used in the analyses for the paper Diversity patterns of seasonal wetland plant communities mainly driven by rare terrestrial species (Deane et al - Biodiversity and Conservation, DOI: 10.1007/s10531-016-1139-1). Biological data were pre-processed to remove sampling bias (the method is described in the paper). Data are presence-absence of 215 native plant species (i.e., exotic species removed) from 76 seasonal wetlands (size range 0.5 - 35 ha) located on the Fleurieu Peninsula, South Australia (centred on latitude 35.5 °S). [2] Spatial data: For each of the 76 wetlands a small amount of spatial data is also provided. Area, centroids, elevation and catchment. The data could be of interest for any typical community data analysis (e.g. beta diversity, similarity, assembly), provided only native wetland plant species were of interest. Data were used to model extinction risk, species-area relationships, occupancy distributions and so on. 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging. There are two data custodians for component datasets used in this analysis. 1). South Australian Department of Environment, Water and Natural Resources; 2). The Conservation Council of South Australia. 

Wetlands are among the most threatened habitats on Earth. They are essential components of functional landscapes, providing habitat for native flora and fauna as well as supporting critical ecosystem services. Loss of wetland biodiversity threatens these values. There is an urgent need to understand patterns of wetland biodiversity, the processes creating these and the risk of species loss to plan effective intervention. Species-area relationships have a successful, although controversial, history of quantifying the risk of extinction in terrestrial biomes, and can provide rapid estimates of extinction risk at a range of scales without the need for extensive datasets. Prior to my research, applications of species-area relationships in extinction risk were limited to island archipelagos and formerly continuous terrestrial habitats that had become fragmented. Naturally occurring, discrete habitat types such as wetlands have been ignored. I address this gap, demonstrating that area-based methods can, be successfully applied to predict extinction risk in wetland communities. Before considering extinction risk I analysed patterns of wetland plant diversity and occupancy and how competing community-assembly processes produce more or less unique combinations of species among wetlands. I showed that much of the plant community diversity in seasonal wetlands in South Australia is driven by rare terrestrial species of wetland fringes, which assemble from a much larger available species pool. The distribution of these rare species was not strongly related to wetland size, suggesting that changes in the number or total area of wetlands could result in different extinction dynamics, depending on how they affected endemic species. I therefore compared risks associated with loss of complete wetlands (patch loss), with loss of the equivalent wetland area while maintaining the total number of wetlands. I found that a higher extinction risk was associated with the loss of complete wetlands than the equivalent area loss shared among all wetlands. Moreover, for a given area loss, small wetlands had a much higher risk of species loss due to the distribution of endemic species. 

Data Collection Summary: A range of probabilistic (area-controlled e.g., quadrats), systematic searches and simple species lists were used to collect the data in the sources collated. Data are collated from a number of different surveys, each using different methods to collect the data (described in source materials listed in the metadata). To control for sampling effort bias among the wetlands, an extensive data validation process was applied, that was based on the scaling of species richness with wetland area. This method and all data pre-processing is described in detail in the manuscript 'Diversity patterns of seasonal wetland plant communities mainly driven by rare terrestrial species' (Deane et al - Biodiversity and Conservation, DOI: 10.1007/s10531-016-1139-1) and in the supporting information available online. Users should note these data represent comparable and reproducible near-complete samples of wetland plant communities, but they are constrained statistically to those wetlands following the observed scaling relationship (species-area curve). As a result, sites of unusually high or low diversity are likely precluded from the dataset.