OzSET – Australian Surface Elevation Tables and Marker Horizon Data Collection 

The Australian Surface Elevation Table (OzSET) dataset provides long-term measurements of surface elevation dynamics in Australia's coastal wetlands, including mangroves, saltmarshes and tidal forests. The dataset comprises repeated measurements collected using Rod Surface Elevation Tables (RSETs) and Marker Horizons (MHs) at permanent monitoring sites distributed across continental Australia.
RSETs quantify net vertical surface elevation change relative to a deep, stable benchmark, while Marker Horizons independently measure surface sediment accretion. Together, these complementary measurements enable estimation of shallow subsurface processes, such as subsidence and root-zone expansion, providing critical information on the capacity of coastal wetlands to maintain their elevation relative to sea-level rise.
This parent dataset describes the OzSET monitoring network and links to individual site datasets containing the curated RSET and Marker Horizon observations collected through ongoing national monitoring

 

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. This data was collected historically by the authors. This work was partly funded by the Terrestrial Ecosystem Research Network (TERN), an Australian Government NCRIS-enabled project. 

The OzSET network was established to provide nationally consistent, long-term observations of coastal wetland elevation dynamics across Australia. The dataset supports research, environmental monitoring and management by quantifying the capacity of mangroves, saltmarshes and other tidal wetlands to respond to sea-level rise and environmental change. The data contribute to understanding ecosystem resilience, blue carbon processes, habitat condition, climate adaptation and national environmental reporting.
 

Rod Surface Elevation Table: The RSET measures total surface elevation change relative to a fixed deep benchmark. A stainless steel rod is driven into the ground until it hits resistant substrate (often several metres deep), and a horizontal arm is attached to the top of that rod. From each arm, 9 measuring pins are lowered vertically until they just touch the sediment surface, and their heights above the arm are recorded in millimetres. Because the benchmark rod is anchored deep below any surface processes, changes in the pin readings over time reflect the net vertical movement of the surface; including compaction, swelling, root growth, subsidence, and sediment deposition or erosion. In this dataset, each SET has 4 arms at fixed compass bearings, and 5 direction codes (2, 4, 5, 6, 8); arm numbers are discrete positions on the instrument collar, each locked to a specific bearing (45 °, 315 °, 90 °, 270 °, depending on the plot). Marker Horizon The marker horizon measures sediment accretion only; the amount of new material deposited on top of the surface since a known reference time. A thin layer of white feldspar clay powder is spread on the sediment surface to create a bright, dateable horizon. On each subsequent visit, a small core or plug is extracted, and the thickness of new sediment above the white layer is measured in millimetres.In this dataset there are 12 MH stakes per SET plot (recorded in the separate "marker" sheets), each with its own MH_ID. Not all stakes survive every visit; roots, bioturbation, and erosion can destroy or obscure the feldspar layer, which is why the MH sheets have many null readings