Cambridge City Council’s tree officers collect data on its trees using Ezytreev™ tree management software as part of our routine inspections.

As a Council we are working toward making our data more open. The tree data on this page contains data that is commonly sought as part of Freedom of Information (FOI) requests and other data that puts the city’s tree cover into a wider context.

Number of trees in Cambridge

It is difficult to know exactly how many trees there are in Cambridge at any one time and estimates vary depending on the techniques used to gather the information.

Source: Analysis and interpretation of tree audit data for Cambridge City Council (ADAS, 2013) [PDF, 6.5MB].

10 most common types of tree in Cambridge

The data below is derived from our own tree inventory and randomised sample plot across the city as a whole, regardless of ownership.

Source: Analysis and interpretation of tree audit data for Cambridge City Council (ADAS, 2013) [PDF, 6.5MB].

Council parks and street trees

• Cherry (Prunus): 14%
• Maple (Acer): 12%
• Lime (Tilia): 8%
• Birch (Betula): 8%
• Sorbus (Sorbus): 8%
• Ash (Fraxinus): 6%
• Apple (Malus): 4%
• Thorn (Crateagus)
• Willow (Salix): 3%
• Horse chestnut (Aesculus): 2%

Cambridge city as a whole

• Ash (Fraxinus): 22%
• Cherry (Prunus): 15%
• Lime (Tilia): 8%
• Apple (Malus): 6%
• Cupressus (Cupressus): 6%
• Sorbus (Sorbus): 5%
• Maple (Acer): 5%
• Birch (Betula): 5%
• Yew (Taxus): 4%
• Poplar (Populus): 3%

Tree canopy cover

Tree canopy cover is the metric used to indicate the benefits provided by the urban forest, and is measured as a tree canopy cover percentage of the total area under review.

In 2008 tree canopy cover was measured at 17.1% by analysing Proximitree™ data. Ward measurements were:

• Abbey: 12.9%
• Arbury: 17.2%
• Castle: 20.7%
• Cherry Hinton: 12.8%
• Coleridge: 14.4%
• East Chesterton: 16.6%
• King’s Hedges: 16.5%
• Market: 14.8%
• Newnham: 22.6%
• Petersfield: 16.5%
• Queen Edith’s: 17.9%
• Romsey: 14.8%
• Trumpington: 17.8%
• West Chesterton: 17.7%

Source: Analysis and interpretation of tree audit data for Cambridge City Council (ADAS, 2013) [PDF, 6.5MB].

In 2016 the Forestry Commission measured the city’s tree canopy at around 19%, plus or minus 1.75% standard error, using i-Tree Canopy.

Source: The Canopy Cover of England’s Towns and Cities: Baselining and setting targets to improve human health and well-being (K Doick et al., 2017).

The increase in tree canopy cover may be due to the differing methodologies used, or to the substantial urbanisation of the green belt in the south and west of the city since 2008.

A new Proximitree™ dataset for 2018 is currently being analysed as part of the Nature Smart Cities 2 Seas project and the canopy cover results are planned to be released by the end of the year.

Cambridge’s tree canopy cover compared with other districts

The amount of tree canopy cover depends on a number of different factors including population and built density, land use type, and age of primary development.

We have selected a list of four towns and cities of similar size, populations and land uses. Cambridge fairs pretty well in these comparisons.

Sources:

• Population: List of English districts by population – last accessed 21 May 2019
• Population density: List of English districts by population density – last accessed 21 May 2019
• Land use: How much is your area built on (BBC) – last accessed 21 May 2019
• Tree cover: Doick, K., et al., (2017) The Canopy Cover of England’s Towns and Cities: baselining and setting targets to improve human health and well-being

Ownership of tree cover in Cambridge

The bulk of tree canopy cover in Cambridge is in private ownership. Most of this is in residential gardens which make up the largest single land use (around 39%):

Source: Analysis and interpretation of tree audit data for Cambridge City Council (ADAS, 2013) [PDF, 6.5MB].

Number of trees felled each year

The figures below relate to individual street and parks trees only. Figures are for the last 10 years. The data is recorded by our tree officers using Ezytreev™ tree management software. It should be treated as indicative as it does not show for example trees in groups or recently planted trees that have been removed within the first year of planting:

• Find out more about how we manage trees in Cambridge

Number of trees planted each year in streets and parks

The figures below relate to planting ‘standard’ trees that are between 2.5 & 3.5m tall at planting, and planted in our streets and parks trees only.

The data is recorded by our tree officers using Ezytreev™ tree management software. In 2016 we approved a ring-fenced budget for tree planting that meant we can ensure no-net-loss to the Council’s tree population.

• Request a tree to be planted in a street or park

The Free Tree for Babies scheme

This has been running for over 30 years to incentivise tree planting in the city. In 2017 we approved a ring-fenced budget for the scheme of £5000. In 2018 we changed the way we delivered the scheme enabling us to nearly double the amount of trees could give away under the scheme.

• Find out more about our Free Tree for Babies Scheme

Ash decline in Cambridge

Ash trees have been estimated to make up around 22% of the total number of trees in Cambridge.

They are currently under threat from Ash Dieback Disease which is predicted to kill around 95% of all ash trees in the UK. Ash Dieback has been officially recorded as being present in the Cambridge area since 2014.

We have over 1400 individual ash recorded on our tree management database (excluding groups & woodlands). The following ash species where present in May 2018:

• Fraxinus americana: 1.2%
• Fraxinus angustifolia: 0.4%
• Fraxinus excelsior: 77.4%
• Fraxinus excelsior ‘Diversifolia’: 1.7%
• Fraxinus excelsior ‘Jaspidea’: 1.1%
• Fraxinus excelsior ‘Pendula’: 0.6%
• Fraxinus excelsior cultivar: 0.1%
• Fraxinus ornus: 6.5%
• Fraxinus oxycarpa: 0.1%
• Fraxinus oxycarpa ‘Raywood’: 6.7%
• Fraxinus pennsylvanica: 0.2%
• Fraxinus (not identified to species level): 4.0%

A randomised sample of 99 trees from this population was taken in 2017 and surveyed in September of that year. The aim is not aimed to identify ash die back disease but to monitor ash condition as indicative of the spread and impact of the disease.

A follow-up survey was undertaken in September 2018. A new survey is planned for this year. The survey measured the amount of defoliation, deadwood and regrowth present in each tree and the results are presented below.

The degree of defoliation from the norm is indicative of the degree of stress a tree is currently under.

The amount of regrowth is both indicative of stress and the ability of a tree to respond to that stress:

The size of the deadwood is indicative of the overall impact that stress is causing the tree:

• Download the survey methodology [PDF, 0.4MB]

Number of TPOs served each year

The Council has served over 800 TPOs since 1955. The table below shows the numbers served over the last 10 years:

Number of tree work applications assessed each year

Applications and notifications of works to tree protected by TPO or that grow in conservation areas have to be submitted to the Council for assessment:

• Find out more about protected trees

Number of High Hedges complaints received each year

Under the Anti-Social Behaviour Act 2003 local authorities must deal with disputes between neighbours regarding high hedges, where a complaint has been made under the Act.

• How to make a High Hedges complaint