In 2012, ADAS were commissioned by Cambridge City Council to undertake a survey of trees in the city of Cambridge1. This study was designed to assess canopy cover within the city’s tree stock, determine cost-effective tree planting strategies in areas of low canopy cover and identify areas of unprotected trees with large canopies. Ultimately, ADAS aimed to inform the Council on the health and fitness of its stock with respect to risks from climate change.
An aerial tree survey of Cambridge had previously been undertaken by Bluesky International using ProximiTREETM, generating a digital tree map layer which detailed the spatial locations, height and canopy area of individual trees. This tree map was analysed by ADAS GIS consultants to quantify the density and canopy cover of trees within areas of different land-uses, wards and ownership categories. Detail on the height and canopy spread distributions was also provided. In addition, ADAS arboricultural consultants conducted a ground survey of twenty-four 4-hectare plots at random to ground-truth the aerial survey findings.
The ground-based tree surveys correlated with the canopy density data recorded in the aerial survey. In addition, tree species in the city were confirmed by ADAS tree surveyors, which provided a baseline for the assessment of future changes in the characteristics of the city’s tree population.
In comparison with a national survey undertaken in 20082, tree densities in Cambridge were seen to be lower than estimates for other British cities, while canopy densities were higher. This indicated that Cambridge had a more mature stock of fewer trees compared to other English towns and cities.
Subsequently, the number of trees that would need to be planted in Cambridge per year over five years in order to meet targets was calculated to be 3,000. In addition, the tree survey findings identified commercial and residential areas in Cambridge in need of additional canopy cover.
The tree survey undertaken by ADAS recommended a revision of managerial strategies and planting schemes, and identified tree protection and maintenance hotspots in the city of Cambridge. This ensured the local authorities adherence to their tree management objectives whilst improving their financial efficacy.
A recent report on the value of London’s urban forest published in 20153 has highlighted the potential scale and benefits of tree management strategies that can be performed. Our dedicated team of arboricultural consultants are trained to undertake all aspects of tree surveys from ground level building development surveys to large-scale aerial surveys for landowners, local authorities and utility providers.
To view the full article please follow this link: (PDF attachment)
For more information please contact Ian Braddock
1Enhancing the Climate Change Benefits of Urban Trees in Cambridge (ADAS Wilson et al, 2012)
2The Trees in Towns II Project (Britt & Johnston, 2008)
3 Valuing London’s Urban Forest: Results of the London i-Tree Eco Project (Treeconomics London, 2015)