2020–21 SLATS Report
Statewide breakdown
Key findings—clearing activity
- About 15% (54,136ha) of the statewide clearing activity was in Category B (remnant) areas—a 39% decrease from 2019–20 (88,327ha). Just over two-thirds of this Category B clearing activity (70% or 37,888ha) resulted in full removal of the woody vegetation.
- About 1% (4,701ha) of the statewide clearing activity was in Category C (high-value regrowth vegetation), and less than 1% (2,321ha) was in Category R (regrowth watercourse area).
- Clearing activity in Category X areas (i.e. those areas not generally regulated by the Vegetation Management Act 1999) accounted for 82% (288,165ha) of the total clearing activity in Queensland. Most of this resulted in full removal of the woody vegetation (278,884ha or 97% of all Category X clearing activity).
- Less than 1% (2,714ha) of the statewide clearing activity was in areas that have endangered regional ecosystems present and about 3% (10,546ha) was in areas that have of concern regional ecosystems. About 14% (49,850ha) of the clearing activity was in areas that have least concern regional ecosystems present.
- Of the state’s 13 bioregions, the Brigalow Belt (52% or 180,283ha) and Mulga Lands (21% or 72,238ha) accounted for nearly three-quarters (72%) of the state’s woody vegetation clearing activity. In each of these bioregions, over 90% of the clearing activity was mapped as full clearing.
- Clearing activity in the Great Barrier Reef catchment areas accounted for 47% (164,766ha) of the state’s total clearing. This was a 10% decrease in clearing activity from 2019–20 (182,904ha). About 90% (148,507ha) of the clearing in reef catchments resulted in the full removal of the woody vegetation.
- About 89% (310,339ha) of the statewide clearing activity was attributed to the pasture landcover replacement class. Of this, about 96% was full clearing. A further 4% (12,905ha) of the clearing activity was attributed to forestry. The crop (5,156ha) and mine (4,736ha) landcover replacement classes each contributed about 1% of the total clearing activity.
- About 91% (317,866ha) 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% (29,851ha) of the clearing activity occurred in mid-dense vegetation (i.e. 50-80% crown cover).
- Based on estimates of woody vegetation ‘age since disturbance’, about 52% (182,913ha) of the total clearing activity occurred in vegetation estimated to be greater than 15 years old (refer to note). About 36% (125,765ha) of the total clearing occurred in vegetation that was estimated to be less than 15 years old. The remainder (12% or 40,721ha) occurred in woody vegetation where a valid ‘age since disturbance’ estimate could not be determined.
Key findings—regrowth
- Of the state’s 13 bioregions, the Brigalow Belt bioregion had the greatest area of new regrowth mapped, contributing 39% (23,454ha) to the state’s total. The Southeast Queensland bioregion had the next greatest area of new regrowth mapped, contributing about 20% (12,229ha) to the state’s total.
- About 67% (39,837ha) of the new regrowth mapped was attributed to the pasture landcover class, and about 24% (14,531) attributed to forestry. A further 7% (4,041ha) 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 80% (47,933ha) was categorised as either sparse or very sparse woody vegetation, and 20% (11,686ha) as mid-dense woody vegetation.
- Of the new regrowth mapped, 70% (41,484ha) was estimated to be less than 15 years old.
Regulated vegetation management map categories
In 2020–21, about 15% (54,136ha) of the statewide clearing activity was in Category B (regulated remnant) areas. This represents a 39% decrease in clearing activity from 2019–20 (88,327ha). The Brigalow Belt (41% or 22,288ha), Mulga Lands (17% or 9,105ha) and Mitchell Grass Downs (15% or 7,901ha) bioregions had the highest areas of Category B clearing activity, similar to 2019–20. However, each of these bioregions also recorded significant decreases in Category B clearing activity (36%, 65% and 20%, respectively) from 2019–20.
Of the Category B clearing activity, 70% (37,888ha) resulted in full removal of the woody vegetation, with the remainder of the Category B clearing activity distributed between areas that were partially cleared with a major level of disturbance (11% or 6,207ha) or partially cleared with a minor level of disturbance (19% or 10,041ha). About 1% (4,701ha) of the statewide clearing activity was in Category C (high-value regrowth vegetation)—a 28% decrease from 2019–20 (6,512ha). Less than 1% (2,321ha) of the clearing activity was in areas that intersect with Category R (regrowth watercourse area)—a 5% decrease from 2019–20 (2,447ha).
Clearing activity in Category X areas accounted for 82% (288,165ha) of the total clearing activity—a 10% decrease from 2019–20 (320,952ha). Almost all this clearing activity (97% or 278,884ha) resulted in full removal of the woody vegetation. About half of the Category X clearing activity was in the Brigalow Belt bioregion (53% or 154,092ha) with a further 22% (62,861ha) occurring in the Mulga Lands bioregion. Category X areas are those that are not generally regulated by the Vegetation Management Act 1999, as identified in the Regulated vegetation management map.
Clearing activity—regulated vegetation management map category 2020–21
Regulated vegetation management maps show the different vegetation categories that are present on a parcel of land. This information helps land managers determine the type of approval needed for vegetation clearing. The categories are as follows:
- Category A—vegetation that is subject to compliance notices, offsets and voluntary declarations
- Category B—remnant vegetation shown on a regional ecosystem or remnant map as an endangered regional ecosystem, an of concern regional ecosystem or a least concern regional ecosystem
- Category C—high-value regrowth vegetation
- Category R—regrowth watercourse area
- Category X—vegetation that is not generally regulated by the vegetation management laws.
For further information refer to General guide to the vegetation clearing codes (PDF).
Vegetation management class
In 2020–21, about 14% (49,850ha) of the clearing activity was in areas that contained least concern regional ecosystems—a decrease of 33% from 2019–20 (74,305ha). About 3% (10,546ha) of the clearing was in areas identified as having of concern regional ecosystems—a decrease of about 52% from 2019–20 (21,748ha). Less than 1% (2,714ha) of the clearing was in areas which have endangered regional ecosystems present—44% decrease from 2019-20 (4,866ha). About 70% (1,891ha) of the clearing in areas which have endangered regional ecosystems present was in the Brigalow Belt bioregion and three-quarters (1,427ha) of this was full clearing. The remaining 82% (286,288ha) was in areas with no vegetation management class.
SLATS reporting applies the precautionary principle, with the highest vegetation management class used, regardless of the proportion present in regional ecosystem mapping. For example, where a mapped regional ecosystem contains least concern regional ecosystems as the dominant ecosystems, and an endangered regional ecosystem as subdominant, this will be reported as clearing in areas containing endangered regional ecosystems.
Clearing activity—vegetation management class 2020–21
The vegetation management class refers to the current regulated extent of a regional ecosystem. The categories are endangered, of concern and least concern. No VM class refers to areas with no vegetation management class due to no regulated vegetation being present.
For further information refer to Biodiversity status and vegetation management class.
Bioregions
Of the state’s 13 bioregions, the Brigalow Belt (52% or 180,283ha) and Mulga Lands (21% or 72,238ha) accounted for nearly three-quarters (72%) of the state’s woody vegetation clearing activity. Both bioregions recorded decreases in clearing activity (10% and 34%, respectively) from 2019–20. There has been a continued significant decline in clearing activity in the Mulga Lands between 2018–19 (284,648ha) and 2020–21.
In each of these bioregions, over 90% of the clearing activity was mapped as full clearing. Most of the clearing activity in these two bioregions was in Category X areas, accounting for 85% (154,092ha) of the clearing in the Brigalow Belt and 87% (62,861ha) in the Mulga Lands. The bioregions with the next highest levels of clearing activity were Mitchell Grass Downs (8% of statewide total or 26,671ha), Desert Uplands (8% or 26,353ha) and Southeast Queensland (7% or 24,720ha). These bioregions all recorded decreases in clearing activity (1%, 21% and 18%, respectively) from 2019–20.
Clearing activity—bioregion 2020–21
Area of clearing activity in bioregions in 2020–21.
The Brigalow Belt bioregion had the greatest area of new regrowth mapped, contributing 39% (23,454ha) to the state’s total of 59,564ha. The Southeast Queensland bioregion had the next greatest area of new regrowth mapped, contributing about 20% (12,229ha) to the state’s total.
Regrowth—bioregion 2020–21
Area of new regrowth in bioregions in 2020–21.
- Regrowth includes new woody vegetation areas which have regrown sufficiently to be reliably added to the SLATS woody extent.
For further detailed breakdowns for each of the bioregions see further breakdowns by bioregion.
Great Barrier Reef catchments
Clearing activity in the Great Barrier Reef catchment areas accounted for 47% (164,766ha) of the state’s total clearing—a 10% decrease in clearing activity from 2019–20 (182,904ha). About 90% (148,507ha) of the clearing in reef catchments in 2020–21 resulted in the full removal of the woody vegetation.
Clearing activity in Great Barrier Reef catchments 2018–19 to 2020–21
Area of clearing activity in Great Barrier Reef catchments from 2018–19 to 2020–21.
In 2020–21, about 61% (36,432ha) of the new regrowth mapped in the state was in Great Barrier Reef catchments.
Regrowth in Great Barrier Reef catchments 2019–20 and 2020–21
Area of new regrowth in Great Barrier Reef catchments in 2019–20 and 2020–21.
- Regrowth includes new woody vegetation areas which have regrown sufficiently to be reliably added to the SLATS woody extent. Regrowth was not reported in 2018–19.
Landcover replacement class
In 2020–21, 89% (310,339ha) of the clearing activity was attributed to the pasture landcover replacement class—a 13% decrease from 2019–20 (357,604ha). Of this, about 96% was full clearing. A further 4% (12,905ha) was attributed to forestry, with crop (5,156ha) and mine (4,736ha) each accounting for about 1% of the total clearing activity.
Clearing activity—landcover replacement class 2020–21
The landcover replacement class is determined as part of the SLATS mapping process. It provides an indication of the purpose for which the vegetation was cleared. Read more about this in SLATS methodology.
- Pasture is clearing activity associated with grazing and other general agricultural land management practices—this class includes clearing for pasture, internal property tracks, fence lines or fire breaks.
- Crop is clearing activity for cropping or horticulture.
- Forestry is clearing activity for timber harvesting in state or privately owned native or exotic (e.g. pine) forests or plantations (where it can be reliably attributed using authoritative data or other ancillary data sources).
- Mine is clearing activity for mining activities (including coal seam gas infrastructure).
- Infrastructure is clearing activity for utilities such as roads, railways, water storage, pipelines and powerlines.
- Settlement is clearing activity for urban development.
- Other refers to partial (minor) clearing activity that is not able to be reliably attributed to a landcover replacement class due to the low level of modification associated with these clearing events.
About 67% (39,837ha) of the new regrowth mapped was attributed to the pasture landcover class, and about 24% (14,531) was attributed to forestry. A further 7% (4,041ha) was mapped as crop, mainly due to new tree-crop orchards in parts of Southeast Queensland (Burnett-Mary) and Wet Tropics (around Atherton) bioregions. Due to the difficulty of differentiating between native and non-native woody vegetation using satellite imagery, non-native woody vegetation change is also included in SLATS. This may include exotic pine plantations, orchards or invasive exotic woody weeds.
Regrowth—landcover class 2020–21
The landcover class is determined bas part of the SLATS mapping process. It provides an indication of the purpose for which the land is used where the regrowth occurs. Read more about SLATS methodology.
- Pasture is new regrowth in areas associated with grazing and related land management practices.
- Crop is new regrowth in woody crops and horticulture, including fodder crops and tree fruits and nuts.
- Forestry is new regrowth in state or privately owned native or exotic (e.g. pine) forests or plantations (where it can be reliably attributed using authoritative data or other ancillary data sources).
- Mine is new regrowth in mining areas (e.g. rehabilitation areas).
- Infrastructure is new regrowth associated with utilities such as roads, railways, water storage, pipelines and powerlines.
- Settlement is new regrowth in urban areas and can include gardens and parklands.
Density and age since disturbance
In 2020–21, about 91% (317,866ha) of the total clearing activity occurred in sparse and very sparse woody vegetation (i.e. vegetation with less than 50% crown cover). This is reflective of a large proportion of the state’s clearing activity occurring in rangeland ecosystems including the Brigalow Belt, Mulga Lands, Desert Uplands and Mitchell Grass Downs bioregions, which are characterised by scattered trees and shrubs, open woodlands and shrublands. A further 9% (29,851ha) of the clearing activity occurred in mid-dense woody vegetation (i.e. 50–80% crown cover). Less than 1% of the total clearing occurred in dense woody vegetation (1,669ha).
Clearing activity—density 2020–21
Area of clearing activity for density classes of woody vegetation.
Density classes are as follows:
- Dense vegetation has a Foliage Projective Cover (FPC) of 70–100% (>80% crown cover)
- Mid-dense vegetation has a FPC of 30–70% (50–80% crown cover)
- Sparse vegetation has a FPC of 10–30% (20–50% crown cover)
- Very sparse/isolated vegetation has a FPC of <10% (0.25–20% crown cover)
- NDC (i.e. no density class) refers to small areas that have not been assigned a density class due to cloud or other contamination in the satellite imagery.
Based on estimates of woody vegetation age since disturbance (refer to note), about 52% (182,913ha) of the total clearing activity in 2020–21 occurred in vegetation greater than 15 years old, and about 86% (157,676ha) of this occurred in sparse or very sparse woody vegetation.
About 36% (125,765ha) of the total clearing activity occurred in vegetation with an age since disturbance of less than 15 years, and most of this (96% or 121,267ha) occurred in sparse or very sparse woody vegetation. About 12% (40,721ha) of the clearing activity occurred in woody vegetation where a valid age since disturbance estimate could not be determined. Most of this clearing activity occurred in sparse or very sparse woody vegetation (96% or 38,923ha).
Clearing activity—age since disturbance 2020–21
Area of clearing activity for age since disturbance classes (refer to note).
An age since disturbance of NASD (i.e. no age since disturbance) refers to those areas where a valid age since disturbance estimate could not be determined from SLATS clearing histories and/or time-series analysis of historical satellite imagery.
Clearing activity—age since disturbance and density 2020–21
Area of clearing activity by density and age since disturbance classes.
An age since disturbance of NASD (i.e. no age since disturbance) refers to those areas where a valid age since disturbance estimate could not be determined from SLATS clearing histories and/or time-series analysis of historical satellite imagery.
Density classes are as follows:
- Dense vegetation has a Foliage Projective Cover (FPC) of 70–100% (>80% crown cover)
- Mid-dense vegetation has a FPC of 30–70% (50–80% crown cover)
- Sparse vegetation has a FPC of 10–30% (20–50% crown cover)
- Very sparse/isolated vegetation has a FPC of <10% (0.25–20% crown cover)
- NDC (i.e. no density class) refers to small areas that have not been assigned a density class due to cloud or other contamination in the satellite imagery.
About 80% (47,933ha) of the regrowth mapped was categorised as sparse or very sparse woody vegetation. A further 20% (11,686ha) of the regrowth mapped was categorised as mid-dense woody vegetation and less than 1% (36ha) was in dense woody vegetation.
Of the 59,654ha of new regrowth mapped, 70% (41,484ha) was estimated to be less than 15 years old. A further 23% (13,651ha) of the new regrowth mapped was estimated to be greater than 15 years old, while the remaining 8% (4,520ha) was in areas where a valid ‘age since disturbance’ estimate could not be determined.
Most of the new regrowth (i.e. 90% or 12,318ha) is estimated to be greater than 15 years old was categorised as sparse or very sparse woody vegetation. These areas are likely to have been previously excluded from the 2018 woody extent baseline as they may not have been readily detectable in the satellite imagery used at the time and are now able to be reliably detected and mapped due to additional data in the time series or availability of other new imagery.
Regrowth—density 2020–21
Area of new regrowth for density classes of woody vegetation.
Density classes are as follows:
- Dense vegetation has a Foliage Projective Cover (FPC) of 70–100% (>80% crown cover)
- Mid-dense vegetation has a FPC of 30–70% (50–80% crown cover)
- Sparse vegetation has a FPC of 10–30% (20–50% crown cover)
- Very sparse/isolated vegetation has a FPC of <10% (0.25–20% crown cover)
- NDC (i.e. no density class) refers to small areas that have not been assigned a density class due to cloud or other contamination in the satellite imagery.
Regrowth—age since disturbance 2020–21
Area of new regrowth for age since disturbance classes (refer to note).
An age since disturbance of NASD (i.e. no age since disturbance) refers to those areas where a valid age since disturbance estimate could not be determined from SLATS clearing histories and/or time-series analysis of historical satellite imagery.
Regrowth—age since disturbance and density 2020–21
Area of new regrowth by density and age since disturbance classes.
An age since disturbance of NASD (i.e. no age since disturbance) refers to those areas where a valid age since disturbance estimate could not be determined from SLATS clearing histories and/or time-series analysis of historical satellite imagery.
Density classes are as follows:
- Dense vegetation has a Foliage Projective Cover (FPC) of 70–100% (>80% crown cover)
- Mid-dense vegetation has a FPC of 30–70% (50–80% crown cover)
- Sparse vegetation has a FPC of 10–30% (20–50% crown cover)
- Very sparse/isolated vegetation has a FPC of <10% (0.25–20% crown cover)
- NDC (i.e. no density class) refers to small areas that have not been assigned a density class due to cloud or other contamination in the satellite imagery.
Note: Since the release of 2018–19 SLATS report, the methods for estimating the age since disturbance of woody vegetation have been refined and data updated. The 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. These updates have resulted in the following for SLATS reporting and published data:
- the 2018–19 SLATS reporting has not been revised and remains as reported
- the updated age since disturbance estimates have been used in the 2019–20 SLATS reporting and this 2020–21 SLATS report
- the age since disturbance spatial data available in QSpatial includes the updated estimates
- the updated age estimates for all monitoring periods have been used in all relevant data files that can be accessed from this 2020–21 SLATS report.
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 by the Queensland Herbarium as part of the regional ecosystem mapping framework.
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