Future Brisbane Blueprint proposes an increase in “deep planting” areas on multi-unit residential sites from 10 to 15% of site area across Brisbane. What difference can 5% more site area for deep planting make to Inner City Brisbane tree cover on multiunit residential sites?
Answer = an estimated additional 20,000 m2 of tree canopy per year (by 2031), which
- adds summer cooling benefits to Brisbane’s most populated urban hot spot
- grows Inner Brisbane’s canopy area from 16.3% by an extra 0.1 % per year **
- sequesters extra 10 tonnes/yr of carbon dioxide, delivering the equivalent of almost 560,000 less kilometres of passenger car trips or 40 less passenger cars in greenhouse gas emission equivalents(GGE)
- intercepts extra 110 kg of air pollutants/yr, (mostly particulate matter PM10 and PM2.5)
- intercepts extra 800,000 litres of rainfall/yr
|INNER CITY BRISBANE||“other residential” (non house) building approvals*||Number of apartments completed#||Site area of approved or completed multiunit dwellings||10% site area of approved or completed multiunit dwellings||15% site area of approved or completed multiunit dwellings||Potential tree canopy area in 2031 for 10% deep planting##||Potential tree canopy area in 2031 for 15% deep planting##|
|2017-2018||3,338||4,275||100,000m2###||10,000 m2||15,000 m2||40,000 m2||60,000 m2|
*Australian Bureau Statistics 8731.0 Building Approval SA2 scale
# BIS Oxford Economics forecast for whole of Brisbane published in “The Urban Developer”, assuming 75% of completions in Inner City Brisbane
## Based on deep planting area(DPA) X assumed available 1m depth within DPA, converted to tree canopy area using Leake & Haege “Soil volume simulator” https://www.elkeh.com.au/soils/ in reverse.
### Based on estimate of 25 m2 site area per completed apartment 2017-2018
** Based on Inner Brisbane land area of 8,000 ha and 2014 tree cover of 16.3 % (or 1,304 ha) reported in Jacobs, B., Mikhailovich, N., and Delaney, C. (2014) Benchmarking Australia’s Urban Tree Canopy: An i-Tree Assessment, prepared for Horticulture Australia Limited by the Institute for Sustainable Futures, University of Technology Sydney.