Project SW2: Baselines, trends and drivers for soil stability and health in forest catchments

The Forest Monitoring Steering Committee commissioned a consortium between the NSW Department of Planning, Industry and Environment and the University of Sydney to deliver baselines, drivers and trends for soil stability and health in forest catchments across the NSW Regional Forest Agreement areas.

The researchers have now delivered a final report.

The findings

In summary:

• Modelling reveals soil organic carbon has declined slightly over the last three decades. However, significant fluctuations occurred in this period likely driven by climatic conditions.
• Climate change is predicted to contribute to a decline in soil organic carbon condition over most of the area covered by the NSW Regional Forest Agreements, particularly the southern alps.
• Areas subject to increased ground disturbance from land use activity (particularly in forests in which grazing is permitted) have lower concentrations of soil organic carbon than less disturbed areas.
• Wildfires have a major influence on soil organic carbon concentrations and more frequent wildfires may result in continuous decline of soil health.

The researchers reported critical data gaps relating to soil health due to a lack of sustained monitoring. They recommended that a long-term soil health monitoring program is needed to support management of forest soils. In addition, the researchers suggested forest managers should implement appropriate soil carbon-enhancing strategies to at least maintain current levels, if not increase them, to assist in meeting net carbon emission targets and mitigate climate change.

The full findings and analysis are available in the final report.

The approach

The researchers:

• Designed a conceptual framework to evaluate soil health and stability.
• Collated and evaluated existing soil data from NSW forests in relation to presence, age, geographical coverage, parameters measured, repetition, and accuracy.
• Estimate the current status of soil indicators for which there is sufficient data for analysis.
• Identified potential drivers of change and threats to soil health.
• Determined trends for soil health and stability (including by spatial analysis).
• Proposed a soil monitoring program to address data gaps, inform soil and land management and maintain or improve the condition of forest soils.

Papers and reports

• Soil baselines - Literature review - Soil health and stability monitoring in forests (NSW DPIE, February 2021)
• Soil baselines - Final report - Determining baselines, drivers and trends of soil health and stability in NSW forests – RFA regions (DPIE and University of Sydney, October 2021)

Data

The report, methods and project data can be found on the NSW SEED. Data also can be visualised and interacted with through the Spatial Collaboration Portal.