Data Analysis
The FoBP used the new tree inventory information
to inform the replacement tree planting. We sought
"underused species"—i.e., tree species that make up less
than 2% of the current inventory. The proposed trees
would not necessarily be native species but would be
trees that were not already represented in the inventory,
in order to increase the biodiversity of the park. The Park
was originally granted its Green Flag status partially due
to the number of rare trees it contains, and the group was
keen to improve on this. The preliminary findings were:
• Number of Trees: 405
• Tree Cover: 1.017 hectares (2.5 acres)
• Most Common Species of Trees: Sycamore
maple (Acer pseudoplatanus), Common lime
(Tilia × europaea), and other maple species.
• Percentage of Trees Less than 6 inches (15.2
cm) Diameter at Breast Height: 9.9%
• Pollution Removal: 66.87 kilograms/year (£461/year)
• Carbon Storage: 357.4 metric tons (£21.4 thousand)
• Carbon Sequestration: 7.387 metric
tons/year (£443/year)
• Oxygen Production: 19.7 metric tons/year
• Structural values: £973 thousand
We were able to clearly make a case that the amount
spent on the trees was paid back tenfold in service values.
However, asset value (CAVAT) was not calculated—some-
thing to be considered for the next round of inspections.
Sourcing New Trees
Many nurseries could not provide the trees selected
at the sizes needed for the site. In Brunswick Park,
trees at a minimum caliper of 10 to 12 cm (4 to 4.75
inches) are required to avoid some of the issues
around management and vandalism, so this precluded
many specialist tree nurseries. However, persever-
ance paid off for the 2019 UK National Tree Week
planting, when another 10 taxa were added including
DED-resistant elms (Ulmus 'New Horizon'), a straw-
berry tree (Arbutus unedo), a few sweetgum cultivars
(Liquidambar spp.), and a tupelo (Nyssa sylvatica).
The evergreen (in the UK) strawberry tree (Arbutus
unedo) in Brunswick Park. It's also known as the
Irish, or Killarney, strawberry tree, as it is native to
regions within Ireland. The tree was donated by the
FoBP in honor of their secretary's 60th birthday.
A young black walnut (Juglans nigra) in the Brunswick
Park Arboretum. Native to eastern North America, black
walnut was introduced to Europe in the early 1600s.
40 CityTREES
