The Upland Heath Swamps Plot Network Soil Properties data package for Royal National Park contains soil properties data obtained from samples taken within 10 cm of each of the floristics plots (see Upland Heath Swamps Plot Network: Vegetation Floristics, Royal National Park, Sydney Basin, NSW, Australia, 1990+). A synopsis of related data packages which have been collected as part of the Upland Heath Swamps Plot Network’s full program is provided at http://www.ltern.org.au/index.php/ltern-plot-networks/upland-health-swamps. **This data package is associated with the following publications: [1] Letten, A. D., Keith, D. A., Tozer, M. G., Hui, F. K.C. (2015), Fine-scale hydrological niche differentiation through the lens of multi-species co-occurrence models. Journal of Ecology. doi: 10.1111/1365-2745.12428 [2] Keith, D. A. and Bradstock, R. A. (1994). Fire and competition in Australian heath: a conceptual model and field investigations. Journal of Vegetation Science 5, 347-354. [3] Keith, D. A. (1995a). Mosaics in Sydney heathland vegetation: the roles of fire, competition and soils. CALMScience Supplement 4, 199-206. [4] Keith, D. A., Lindenmayer, D. B., Lowe, A.,Russell-Smith, J.,Barrett, S.,Enright N. J., Fox, B. J.,Guerin, G.,Paton, D. C., Tozer, M. G. and Yates, C. J. (2014). Heathlands. In: Biodiversity and Environmental Change: Monitoring, Challenges and Direction. Lindenmayer, D., Burns, E., Thurgate, N., and Lowe, A. Editors, pp215-285. CSIRO, Melbourne.

The Upland Heath Swamps Plot Network Soil Moisture data package for Royal National Park contains soil moisture data obtained from monitoring tubes for soil moisture probes installed within 10 cm of each of the floristics plots (see Upland Heath Swamps Plot Network: Vegetation Floristics, Royal National Park, Sydney Basin, NSW, Australia, 1990+). Soil moisture sampling commenced in early August 2013 and was repeated at monthly intervals until July 2014. A synopsis of related data packages which have been collected as part of the Upland Heath Swamps Plot Network’s full program is provided at http://www.ltern.org.au/index.php/ltern-plot-networks/upland-health-swamps. This data package is associated with the following publication: Letten, A. D., Keith, D. A., Tozer, M. G., Hui, F. K.C. (2015), Fine-scale hydrological niche differentiation through the lens of multi-species co-occurrence models. Journal of Ecology. doi: 10.1111/1365-2745.12428

The Upland Heath Swamps Plot Network Soil Properties Data Package contains detailed soil analysis from 60 established swamp monitoring sites in upland swamps scattered throughout the study area (Keith and Myerscough 1993). Each site is sampled in nine combinations of moisture-by-vegetation structure strata. The Upland Heath Swamps Plot Network research plots commenced in 1983 and have been revisited in 2004, 2009 and again in 2014. A synopsis of related data packages which have been collected as part of the Upland Heath Swamps Plot Network’s full program is provided at http://www.ltern.org.au/index.php/ltern-plot-networks/upland-heath-swamps.

The Upland Heath Swamps Plot Network Soil Properties Data Package contains detailed soil analysis from 60 established swamp monitoring sites in upland swamps scattered throughout the study area (Keith and Myerscough 1993). Each site is sampled in nine combinations of moisture-by-vegetation structure strata. The Upland Heath Swamps Plot Network research plots commenced in 1983 and have been revisited in 2004, 2009 and again in 2014. A synopsis of related data packages which have been collected as part of the Upland Heath Swamps Plot Network’s full program is provided at http://www.ltern.org.au/index.php/ltern-plot-networks/upland-heath-swamps.

The Upland Heath Swamps Plot Network Hydrological Climate data are monitored at automatic weather stations established by the University of NSW in 2013 within the study area. In addition, three soil probes placed along local soil moisture gradients in the vicinity of each station record soil moisture, conductivity and temperature at various depths below the surface at 30-minute intervals, which are averaged to produce daily mean estimates. The Upland Heath Swamps Plot Network research plots commenced in 1983 and have been revisited in 2004, 2009 and again in 2014. A synopsis of related data packages which have been collected as part of the Upland Heath Swamps Plot Network’s full program is provided at http://www.ltern.org.au/index.php/ltern-plot-networks/upland-heath-swamps.

RSMA measures change in the relative contributions of photosynthetic vegetation (PV, or GV green vegetation), non-photosynthetic vegetation (NPV) and soil reflectance compared to a baseline date. These spectral changes correspond to changes in fractional cover relative to the baseline date. Full details on the RSMA method are presented in Okin (2007). One of the key advantages of the RSMA, its insensitivity to changes in soil spectra, is a result of the fact that it does not require us to know the soil reflectance profile for a region. This strength is also the cause of a major weakness in RSMA. Since the measure is relative to a baseline date, and the absolute cover levels for every pixel are unknown at the baseline, the RSMA does not convey the absolute cover levels at any other point in time. However, if the absolute cover levels are known at any point in time, it is theoretically possible to convert the RSMA to absolute relative spectral mixture analysis (ARSMA).<br> As with all products derived from passive remote sensing imagery, this product represents the world as seen from above. Therefore, the cover recorded by this product represent what would be observed from a bird's-eye-view. Therefore, dense canopy may prevent observation of significant soil exposure.

Vadose zone soil moisture was collected at the Avon River Critical Zone Observatory (CZO). The measurements were taken at four different depths: 0.6, 1.2, 1.8, 2.4 metres.

The soil in terrestrial and blue carbon ecosystems (BCE; mangroves, tidal marshes, seagrasses) is a significant carbon (C) sink. National assessments of C inventories are needed to protect them and aid nature-based strategies to sequester atmospheric carbon dioxide. We harmonised measurements from Australia's terrestrial and BCE and, using consistent multi-scale spatial machine learning, unravelled the drivers of soil organic carbon (SOC) variation and digitally mapped their stocks. The modelling shows that climate and vegetation are continentally the primary drivers of SOC variation. But the underlying regional drivers are ecosystem type, terrain, clay content, mineralogy, and nutrients. The digital soil maps indicate that in the 0-30&nbsp;cm soil layer, terrestrial ecosystems hold 27.6&nbsp;Gt (19.6-39.0&nbsp;Gt), and BCE 0.35&nbsp;Gt (0.20-0.62&nbsp;Gt). Tall open eucalypt and mangrove forests have the largest mean SOC per unit area. Eucalypt woodlands and hummock grassland, which occupy vast areas, store the largest total SOC stock. These ecosystems constitute important regions for conservation, emissions avoidance, and preservation because they also provide additional co-benefits.

The Upland Heath Swamps Plot Network Hydrological Climate data are monitored at automatic weather stations established by the University of NSW in 2013 within the study area. In addition, three soil probes placed along local soil moisture gradients in the vicinity of each station record soil moisture, conductivity and temperature at various depths below the surface at 30-minute intervals, which are averaged to produce daily mean estimates. The Upland Heath Swamps Plot Network research plots commenced in 1983 and have been revisited in 2004, 2009 and again in 2014. A synopsis of related data packages which have been collected as part of the Upland Heath Swamps Plot Network’s full program is provided at http://www.ltern.org.au/index.php/ltern-plot-networks/upland-heath-swamps.

<p>Soil is a huge carbon (C) reservoir, but where and how much extra C can be stored is unknown. Here, using 5089 observations, we estimated that the uppermost 30&nbsp;cm of Australian soil holds 13&nbsp;Gt (10–18&nbsp;Gt) of mineral-associated organic carbon (MAOC). Using a frontier line analyses, described in Viscarra Rossel et al. (2023), we estimated the maximum amounts of MAOC that Australian soils could store in their current environments, and calculated the MAOC deficit, or C sequestration potential. We propagated the uncertainties from the frontier fitting and mapped the estimates of these values over Australia using machine learning and kriging with external drift (KED). The maps show regions where the soil is more in MAOC deficit and has greater sequestration potential. The modelling shows that the variation over the whole continent is determined mainly by climate, linked to vegetation, and soil mineralogy. We find that the MAOC deficit in Australian soil is 40&nbsp;Gt (25–60&nbsp;Gt). The deficit in the vast rangelands is 20.84&nbsp;Gt (13.97–29.70&nbsp;Gt) and the deficit in cropping soil is 1.63&nbsp;Gt (1.12–2.32&nbsp;Gt). Our findings suggest that the C sequestration potential of Australian soil is limited by climate.