Summary of Griffith University LiDAR analyses .
and retain resources and provide a habitat for plant growth , were calculated from Landscape Function Analysis data :
1 . Stability index , for the surface soil against erosion . 2 . Infiltration index , for potential rainfall infiltration rate . 3 . Nutrient cycling index , to show how tightly available nutrients are retained .
• Overall the indices were stable during the monitoring period for Tabletop and Mt . Pleasant . Strathalbyn had a trend for small increases in all three indices .
• The report concluded the monitoring and the photographic evidence suggested neither the UHD ( at Tabletop and Strathalbyn Stations ) nor HRM ( at Mt . Pleasant and Tabletop Stations ) treatments changed pasture yield or land condition when compared to the ungrazed . It appears that seasonal conditions were an overriding factor regardless of whether the plots were treated with UHD , HRM , or were ungrazed .
• The study is consistent with other current studies (* Jones et al . 2016 ) and shows that long time frames will be needed to improve pasture composition and land condition . A key element to the lack of change is most likely the lack of a viable seed bank of 3P grasses and the competitive advantage of the dominant B . pertusa .
* Jones P , Silcock R , Scanlan J , Moravek T ( 2016 ) Spelling strategies for recovery of pasture condition . Project B . NBP . 0555 final report . Meat and Livestock Australia , Sydney .
Summary of Griffith University LiDAR analyses .
For the Glenalpine project area :
• Headcut retreat rates differed between each gully head , but were consistent across all paddocks and generally between 0.6 – 3.0 m across the project period .
• Overall , there was not a significant difference in the observed net erosion in the control ( livestock exclusion ) compared to the treatment paddocks , within the limitations of the available data . Greater variability occurred between treatment paddocks than between the control and treatments .
• As there was no historical erosion trend data for the site , the data cannot determine whether any reductions or increases in erosion trajectory have occurred in response to the different treatments .
• While there was some variability between paddocks , the paddock-scale analysis demonstrates relatively low rates of detectable erosion at approximately 0.11 – 0.38t / ha .
• Variation of erosion rates between the paddocks is likely a function of other environmental factors . As such , no conclusion can be drawn as to whether there is a significant difference between treatment effectiveness .
• Ongoing erosion in the control paddock indicates cattle exclusion in isolation of other remediation activities is ineffective at completely preventing further gully erosion . Note that whether any reduction did occur is unresolvable from this dataset .
For the Strathalbyn alluvial gully project sites :
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• In all years , the gully remediation site ( including the trial of biological carpeting ) achieved more than 99 per cent effectiveness . Aerial imagery suggests there was an 86 per cent reduction in the extent of bare ground within the biological carpeting paddock from May 2018 to May 2022 .