An overview of Monitoring and Evaluation for the LDC project

Mt Pleasant grazier Jamie Gordon explains the concept of The Hub at the first open day in 2019.

Data and results part of learning hub

THE Mount Pleasant Learning Hub, featuring Mulloon Institute landscape rehydration techniques, has been designed to reinstate the hydrological function of the landscape.

Works include five strategically-placed v-notch log and rock sills in the gully, and a “leaky” earth bank to divert water to where it used to flow. 

Results

Treatment works were completed on this site in 2019 and only one wet season of monitoring data has been obtained.

The key improvement at this site has been found in the vegetation, on the hillslope and the gully of the treatment site.

Few changes were measured between the treatment and control sites in other water quality indicators, and it is expected that this is because the property and site were in relatively good condition prior to the rehabilitation works taking place – the baseline conditions were already quite high.

The total suspended sediment concentrations at both the Mt Pleasant treatment and control sites, were found to be the lowest concentrations of any of the gully sites measured.

This site will continue to be monitored in the next wet season to see if these results remain consistent. If they do, this site is a good demonstration of what can be achieved in water quality on a stable gully system that is no longer active.

BIODIVERSITY SURVEYS

James Cook University researcher Rishab Pillai with a planigale, pulled from a pitfall bucket trap.

JCU conducting biodiversity surveys

JAMES Cook University is conducting biodiversity surveys to determine if the on-ground works  improve water quality and increase biodiversity values at the project site.

This information will also help decide how best to manage biodiversity in a grazing system.

More than 736 animals from 72 species were monitored across all sites. 

“The sheer amount of planigales, small carnivorous marsupials, found on Mt Pleasant was impressive. It’s rare to find this many in one location. It’s really good to know they are around”.
— JCU researcher Eric Nordberg

Species abundance was similar at the treatment and control sites.

There was a higher abundance of amphibians at the gully treatment sites, and the control sites supported a higher abundance of reptiles.

Mammal and bird abundance were similar between treatment and control sites. 

Amphibian abundance was greater in the post-wet survey undertaken in May 2020, compared to the pre-wet survey undertaken in November 2019.

This indicates that the addition of rain and increased pooling from the dam structures has increased these forms of wildlife, especially frogs.

These surveys detail the species found for each of birds, mammals, reptiles and amphibians and are a valuable pre and post treatment baseline to contrast longer term biodiversity changes attributable to the rehydration works in years to come. 

Longer time frames are generally required to better understand how these systems adapt to the water bodies created in the paddocks. 

MONITORING REHYDRATION

The Mt Pleasant Learning Hub is a scientific and practical demonstration of how regenerative agriculture practices can restore landscape function in a production (grazing) landscape. 

In conjunction with Agrotek, soil moisture monitoring equipment has been installed to collect site specific data to determine how the landscape in both the treatment and control sites are responding to water entering and leaving the sites.

Findings from the soil moisture probes show the rehydration treatment area is holding water longer, which is an intended outcome from this project. 

The data is being collected by four capacitance probes with 32 sensors at a depth of 80cm. 

Data is logged every 30 minutes to indicate the volume of water in the soil and how this changes over time. 

One of the probes will capture below the surface effects of pondage and reduced runoff. 

Sheridan Callcott (on the hurdy gurdy) and Sheyanne Frisby (driving in the star picket) install 80cm Agrotek soil moisture probes at the Mt Pleasant Learning Hub and (below) some of the probes in place.

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KEQ #1

Figure 1. Total fine sediment reduction by project type and erosion source. Inset shows the proportion of the total project area for each project type.

These estimates have been calculated using two methods: 

1) The pollutant reduction component of the Alluvium/Great Barrier Reef Foundation (GBRF) investment tool for hillslope and streambank erosion management projects; 

2) The Reef Trust Gully Toolbox method for gully erosion management projects. The LDC Water Quality Report 2020 (Waterhouse et al., 2020) highlights that a number of assumptions underlay these calculations, therefore these figures should be treated as the best available estimate of sediment reductions to date.

Preventing sediment from reaching the Great Barrier Reef

Each wet season sediment is washed into local waterways and out to the Great Barrier Reef (GBR). 

Most sediment is very fine, and can stay suspended for a long time and can travel great distances. Valuable topsoil is lost from production, and increased concentrations on the reef can be harmful to seagrasses and corals. 

Landholders in the BBB have completed 69 on-ground water quality practice changes, and it is estimated that these have contributed a fine sediment reduction of 6,154 tonnes per year from reaching the GBR. 

Of this, approximately half of the sediment savings are attributable to grazing land management changes on hillslopes and streambanks, and the other half as a result of gully remediation treatments across a broad range of scales, as shown in the graphs above. 

The table below also highlights the relatively small area of intervention in the gully management projects compared to the large sediment savings that these can achieve - 60 per cent of the sediment savings over only 4 per cent of the project area.

Table 1. Estimated sediment reductions (tonnes) from projects completed in the LDC Project to date.

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*GLMWW = Grazing Land Management Wire and Water

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*The Exploring New Incentives activity area has provided an opportunity for graziers to adopt improved land management practices through a range of activities. For some of these properties, it was the first time they signed contracts for on-ground works.

KEQ #4

The LDC project monitors four gully sites (represented in this table) with gold standard equipment and analysis, carried out by CSIRO.

Results have been compiled in a preliminary report from Bartley et al (2020), with the final report expected to be released by the end of 2020. The preliminary report shows all four sites have indicators of improvements, notably the Strathbogie and Mt Wickham sites.

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Reef regulations - grazing, standard conditions

  1. For land in good or fair condition (more than 50 per cent ground cover at 30 September), continue using measures to maintain land condition.
  2. For land in poor condition (less than 50 per cent ground cover at 30 September), steps must be taken to improve land condition.
  3. For land in degraded condition (less than 20 per cent ground cover at 30 September), steps must be taken to improve land condition OR prevent areas from further degrading or expanding.
  4. Keep records of measures taken and also of agricultural chemicals, fertiliser and mill mud or mill ash applied to land.
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