The first part of Mapping Green Dublin consisted of mapping the detailed tree cover of the Dublin City Council (DCC) area, which does not exist currently. This work was done to assess the environmental services provided by the trees in the city and to identify gaps in their geography.
In previous work, Geography at UCD in collaboration with the four Dublin local authorities and the Office of Public Works assessed tree canopy cover across Dublin county using a sampling method. By contrast, Mapping Green Dublin has mapped over 290,000 trees in DCC; each tree was digitised using a very detailed aerial image taken in summer 2018.
The distribution of trees across DCC is very uneven as can be seen in the figures. Leaving aside the large number of trees in Phoenix Park, most are located on private lands, especially in the low-density suburbs on the north and south side of the city. By comparison, apart from public parks, there are relatively few trees in the city centre.
To examine the ecosystem services we need to know about the size and species of trees, neither of which are available. The heights of trees have been estimated using data acquired using Light Detection and Ranging (LIDAR) for the same study area. The LIDAR data can be used to estimate the size of the tree canopy, which is a critical measure of the ability of the tree to perform environmental services. To obtain tree species, Mapping Green Dublin is working with DCC and Curio (https://www.curio.xyz/) to gather information on the trees in parks, streets and back gardens.