2021–22 SLATS Report
Key findings
Statewide overview
- At the start of the 2021–22 SLATS monitoring period, Queensland had 95,383,184 hectares (ha) of woody vegetation with greater than 10% crown cover.
- In 2021–22, 323,676ha of woody vegetation was affected by clearing activity. This is a 7% decrease in clearing activity from 2020–21 (349,399ha) and continues a trend of decreasing clearing activity in Queensland in the past few years, albeit the downward trend is slowing.
- Of the total clearing activity, 269,432ha (83% of all clearing activity) resulted in full removal of the woody vegetation (i.e. ‘full clearing’). This is a 16% decrease in full clearing from 2020–21. The remaining 54,244ha of clearing activity in 2021–22 was partial clearing.
- In 2021–22, 31,097ha of new regrowth was mapped. It is important to note that most of the state’s existing regrowth is already included in the SLATS woody extent. New regrowth is only mapped if it can be reliably detected using SLATS methods.
- At the end of the 2021–22 SLATS monitoring period, Queensland had 95,144,850ha of woody vegetation: from a starting balance of 95,383,184ha, 269,432ha was subtracted for full clearing and 31,097ha was added for new regrowth. This represents a net reduction of 238,334ha in the extent of the state’s woody vegetation during the 2021–22 SLATS monitoring period.
Statewide breakdown—clearing activity
- About 20% (65,776ha) of the statewide clearing activity was in Category B (remnant) areas—a 22% increase from 2020–21 (54,136ha). Almost two-thirds of this Category B clearing activity (62% or 40,577ha) resulted in full removal of the woody vegetation.
- About 1% (3,624ha) of the statewide clearing activity was in Category C (high-value regrowth vegetation), and less than 1% (1,607ha) was in Category R (regrowth watercourse area). Both were decreases from 2020–21.
- Clearing activity in Category X areas (i.e. those areas not generally regulated by the Vegetation Management Act 1999) accounted for 78% (252,538ha) of the total clearing activity in Queensland. Most of this resulted in full removal of the woody vegetation (224,749ha or 89% of all Category X clearing activity).
- Less than 1% (2,508ha) of the statewide clearing activity was in areas that have endangered regional ecosystems present and about 3% (9,924ha) was in areas that have of concern regional ecosystems. About 18% (57,678ha) of the clearing activity was in areas that have least concern regional ecosystems present. These findings are similar to the 2020–21 SLATS report findings.
- Of the state’s 13 bioregions, the Brigalow Belt (54% or 173,294ha) and Mulga Lands (17% or 53,345ha) together accounted for nearly three-quarters (70%) of the state’s woody vegetation clearing activity.
- Clearing activity in the Great Barrier Reef catchment areas accounted for 44% (143,683ha) of the state’s total clearing. This was a 13% decrease in clearing activity from 2020–21 (164,766ha). About 79% (113,765ha) of the clearing in reef catchments resulted in the full removal of the woody vegetation.
- About 88% (286,108ha) of the statewide clearing activity was attributed to the pasture landcover replacement class. Of this, about 88% was full clearing. A further 5% (17,310ha) of the clearing activity was attributed to forestry. Mine activity resulted in around 2% (5,885ha) of the state’s clearing activity, and the infrastructure (2,207ha), crop (1,680ha) and settlement (1,341ha) landcover replacement classes each contributed about 1% of the total clearing activity.
- About 91% (294,841ha) of the total clearing activity occurred in sparse or very sparse woody vegetation (i.e. vegetation with less than 50% crown cover). A further 9% (27,622ha) of the clearing activity occurred in mid-dense vegetation (i.e. 50–80% crown cover). These proportions are similar to 2020–21.
- Based on estimates of woody vegetation ‘age since disturbance’, about 58% (187,762ha) of the total clearing activity occurred in vegetation estimated to be greater than 15 years old (refer to note). About 30% (97,090ha) of the total clearing occurred in vegetation that was estimated to be less than 15 years old. The remainder (12% or 38,823ha) occurred in woody vegetation where a valid ‘age since disturbance’ estimate could not be determined.
Statewide breakdown—regrowth
- Of the state’s 13 bioregions, the Southeast Queensland bioregion had the greatest area of new regrowth mapped, contributing 31% (9,741ha) to the state’s total. The Brigalow Belt bioregion had the next greatest area of new regrowth mapped, contributing about 26% (8,085ha) to the state’s total.
- About 69% (21,369ha) of the new regrowth mapped was attributed to the pasture landcover class, and about 25% (7,747ha) attributed to forestry. A further 5% (1,484ha) was mapped as crop, largely due to new tree-crop orchards in parts of Southeast Queensland (Burnett-Mary) and Wet Tropics (around Atherton) bioregions.
- Of the new regrowth mapped, about 88% (27,610ha) was categorised as either sparse or very sparse woody vegetation, and 11% (3,467ha) as mid-dense woody vegetation.
- Of the new regrowth mapped, 72% (22,484ha) was estimated to be less than 15 years old and around 15% (4,578ha) was estimated to be older than 15 years.
Note: Since the release of 2018–19 SLATS report, the methods for estimating the age since disturbance of woody vegetation have been revised and the spatial data has been updated for all years from 2018 onwards. It is important to note that the 2018 SLATS woody vegetation extent baseline report and the 2018–19 SLATS report remain as published at the time; age since disturbance figures in those reports are based on an earlier version of the age since disturbance data.
The SLATS age since disturbance estimates are based on time-since-cleared data derived from SLATS clearing histories, and time-series analysis of more than 30 years of Landsat satellite imagery aimed at detecting woody vegetation disturbance and regrowth. The age since disturbance estimates use the time-series information where sufficient evidence is available to assign a valid estimate of how long the woody vegetation has been regrowing following a disturbance event.
For more information on how the age since disturbance estimates are derived, refer to the SLATS methodology. It is important to note that woody vegetation that is greater than 15 years is not always considered to be remnant or high-value regrowth, as additional criteria such as species composition and vegetation height are used to determine remnant or high-value regrowth status. This is determined as part of the regional ecosystem mapping framework.
In this guide: