Treeconomics, Torbay and council trees: Sequel planned on important urban forestry study

A DECADE ago, a groundbreaking report assessing the urban forest effects and values of Torbay was published by Treeconomics. The foreward of the report, written by Sir Harry Studholme, concluded: “With better information (including economic understanding), we can make better long-term decisions to maintain and improve the urban environment for the benefit and future populations of Torbay. Leading by example, Torbay’s experience shows a way forward for other towns and cities in the country.”

Once again, Torbay is taking a lead. Working again with Treeconomics, the authority is in the process of preparing its second report on the effects and value of its urban forest.

Back in 2011, the initiative was groundbreaking in that it was the first report prepared in the UK using i-tree Eco. Since then, many local authorities in the UK, working with Treeconomics and others, have used the model to gain valuable information about their urban forest to inform strategic management plans and decisions. This second study and the subsequent report will again be the first of its kind in the UK.

Reassessment allows the success of planting practices to be evaluated and reviewed.

The first report identified that the urban forest of Torbay contained approximately 818,000 trees with a structural value of over £280 million. It stated that Torbay’s urban forest removed 50 tonnes of pollution each year, stored 98,000 metric tonnes of carbon and sequestered 3,320 metric tonnes of carbon each year with a tree cover of 11.8 per cent.

Many interesting facts emerged from the 2011 study. It identified the most common species in the tree population were Leyland cypress (118,306 trees, 14.5 per cent), ash (94,776 trees, 11.6 per cent) and sycamore (81,000 trees, 10 per cent) and that these three species accounted for 36.1 per cent of the total tree population. It also recorded that 71 per cent of the total tree population is on private land and 29 per cent on public land.

In the conclusions outlined at the end of the report, it was said that Torbay’s urban forest provided at least £1.5 million of ecosystem services each year and that Torbay had more trees per hectare than many US and European cities but that, in general, Torbay’s trees are smaller in stature supporting less canopy cover than other comparable cities. It was also identified that tree diversity within Torbay was good but that the size and health of trees within the population contribute directly to the provision of ecosystem services.

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The report presented urban forest information and detail in a way not replicated in any other UK city at the time. More cities and towns have followed the route pioneered by Torbay and Treeconomics. At the time of the report being issued, ash dieback was rearing its ugly head and the mainstream press was clamouring for numbers to estimate the potential impact of the disease. While floundering for accurate UK numbers, it was possible to provide detail of ash in Torbay and reflect the species represented 11.6 per cent of the population, was comprised of over 94,000 trees and had a replacement value of over £37 million.

Reassessment allows canopy cover and canopy effectiveness in delivering ecosystem services to be evaluated.

As a result of the 2011 study, many policy decisions were taken within Torbay.

For many reasons, the new study is significant both locally and nationally with regard to urban forest management. It is the first study to be re-visited and the first which enables a review to be carried out assessing the impact of policy and other actions carried out by Torbay Council. 

Has the replacement value of Torbay’s urban forest increased or decreased in the 10-year period since the first report? Have the small trees identified in the first report developed and grown to provide desired canopy cover increases? What has been the impact of ash dieback and how effective have strategies to contain the disease been? Is the population larger or smaller than it was in 2011? These are just a few of the many questions that may be answered, but it is the opportunity to assess the effectiveness of decisions made and actions taken which is really important and the answers will be really informative and hopefully illuminating, not only for Torbay but for others who may follow their example.

During the period between 2011 and now, much has been learned about the use of i-tree in the UK and how the information can facilitate long-term strategic urban forest management. As previously indicated, Torbay was the first and there are now many more aspects of the urban forest which can be included in Treeconomics-managed reports. The new study will replicate the original, but other new aspects will be included.

Discussions are ongoing as to whether the foreshore and the vegetation contained there form part of the urban forest and whether this should be included in the new report. Questions about tree species selection and procurement are being re-visited as are the linkages between trees, other vegetation, and wider biodiversity within the urban environment.

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Torbay’s original report was a pathfinder. It stimulated Kenton Rogers and a team from Torbay to undertake a study tour in the USA to understand i-tree and how to fully exploit the potential of the tool. It prompted myself and Barcham Trees to bring representatives from the USA to explain i-tree and how to use it. It consolidated the position of Treeconomics as a viable and expert service provider, brought Kenton Rogers and myself together at Treeconomics, set out the benchmark for how urban forest data can be gathered and assessed, provided the most detailed urban forest assessment carried out in the UK at the time, reinforced and demonstrated as practical the methodology outlined in the last UK government-commissioned urban forest assessment, Trees in Towns II published in 2008, and perhaps most importantly, provided a route map for others to follow.

It is intended that the new study and report will be equally groundbreaking, demonstrating the value of such studies to others who have yet to embark on a truly evidenced-based assessment of their urban forest and encourage them to do so.

Because of the vision of Torbay, the next time there is the need for a national picture of the urban forest in the UK, the information may be available in a constant and comparable form.