2019–20 SLATS Report
Key findings
Statewide overview
- At the start of the 2019–20 SLATS monitoring period, Queensland had 95,978,402 hectares (ha) of woody vegetation with more than 10% crown cover.
- Approximately 8 million ha of this woody vegetation is existing regrowth. The remainder is remnant or high-value regrowth woody vegetation.
- In 2019–20, 418,656ha of woody vegetation was affected by clearing activity. This is a 38% decrease in clearing activity from 2018–19 (680,688ha).
- Of the total clearing activity undertaken in 2019–20, 339,144ha (81% of all clearing activity) resulted in full removal of the woody vegetation (i.e. ‘full clearing’). This is a 39% decrease in full clearing from 2018–19 (559,844ha). The remaining 79,512ha of clearing activity in 2019–20 was partial clearing.
- In 2019–20, 42,575ha of new regrowth was mapped. This is the first monitoring period where new regrowth has been mapped and reported following changes to the SLATS methodology that commenced in 2018–19.
- With a starting balance of 95,978,402ha, and 339,144ha of full clearing (i.e. loss) and 42,575ha of new regrowth (i.e. gain), there was 95,681,833ha of woody vegetation in Queensland at the end of the 2019–20 SLATS monitoring period. This represents a net reduction of 296,569ha in the extent of the state’s woody vegetation.
Statewide breakdown—clearing activity
- About 21% (88,327ha) of the statewide clearing activity was in Category B (remnant) areas—a 53% decrease in clearing activity in Category B from 2018–19 (189,735ha). Of this total, 48% (42,577ha) resulted in full removal of the woody vegetation. The remainder of the clearing in Category B (remnant) areas was evenly distributed between areas that were partially cleared with a major level of disturbance (26% or 23,153ha) and areas cleared with a minor level of disturbance (26% or 22,597ha).
- About 2% (6,512ha) of the statewide clearing activity was in Category C (high-value regrowth vegetation), and less than 1% (2,447ha) 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 77% (320,952ha) of the total clearing activity in Queensland. Most of this resulted in full removal of the woody vegetation (290,496ha or 91% of all Category X clearing activity).
- About 18% (74,305ha) of the clearing activity was in areas that have least concern regional ecosystems present and a further 5% (21,748ha) was in areas that have of concern regional ecosystems. About 1% (4,866ha) of the clearing was in areas that have endangered regional ecosystems present.
- Of the state’s 13 bioregions, the Brigalow Belt (48% or 199,218ha) and Mulga Lands (26% or 110,161ha) accounted for nearly three-quarters (74%) of the state’s woody vegetation clearing activity. In each of these bioregions, about 80% of the clearing activity was mapped as full clearing.
- Clearing activity in the Great Barrier Reef catchment areas accounted for 44% (182,904ha) of the state’s total clearing. This was a 16% decrease in clearing activity in reef catchments from 2018–19 (217,419ha). More than three-quarters (79% or 143,645ha) of the clearing in reef catchments in 2019–20 resulted in the full removal of the woody vegetation.
- About 85% (357,604ha) of the clearing activity was attributed to the pasture landcover replacement class. Of this, about 87% was full clearing. A further 3% (12,671ha) of the clearing activity was attributed to forestry.
- About 84% (352,169ha) of the total clearing activity occurred in sparse or very sparse woody vegetation (i.e. vegetation with less than 50% crown cover). A further 15% (62,665ha) 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% (216,335ha) of the total clearing activity occurred in vegetation estimated to be greater than 15 years old (refer to note). About 34% (141,044ha) of the total clearing occurred in vegetation that was estimated to be less than 15 years old. The remainder (15% or 61,279ha) occurred in woody vegetation where a valid ‘age since disturbance’ estimate could not be determined.
Statewide breakdown—regrowth
- Combined, the Desert Uplands (38% or 16,015ha) and Brigalow Belt (25% or 10,852ha) bioregions accounted for almost two-thirds of the new regrowth mapped for the state.
- About 77% (32,606ha) of the new regrowth mapped was attributed as regrowth in pasture, and about 17% (7,118ha) was attributed to forestry.
- Of the new regrowth mapped in 2019–20, about 83% (35,341ha) was categorised as either sparse or very sparse woody vegetation, and 17% (7,179ha) as mid-dense woody vegetation.
- Of the new regrowth mapped in 2019–20, 74% (31,636ha) was estimated to be less than 15 years old. A further 20% (8,503ha) was estimated to be greater than 15 years old. For the remaining 6% (2,436ha), a valid ‘age since disturbance’ estimate could not be determined.
Note: Since the release of the 2018–19 SLATS Report, the methods for estimating the age since disturbance of woody vegetation have been refined. Estimates reported in the 2019–20 SLATS Report are based on revised and updated data relating to time since cleared derived from SLATS clearing histories, and time-series analysis of over 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 estimates are derived, refer to the SLATS methodology. As a result of refining the methods for estimating the age since disturbance, the 2018–19 data has also been revised. Note that the 2018–19 SLATS Report has not been revised using these new data. It is also 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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