Since 2004, the Register of Old and Valuable Trees has recorded nearly 500 trees on unleased Government land within built-up areas and tourist attraction spots in village areas. These trees are distinguished in the following categories:

* Trees of large size
* Trees of precious or rare species
* Trees of particularly old age (e.g. aged 100 or above)
* Trees of cultural, historical or memorable significance; and
* Trees of outstanding form

Additional requirements for assessment include the health and physical condition of an individual selected tree, its life expectancy and its location.