Tree terms: u
- UHI
- UK Forestry Standard
- UK tree care
- UK Woodland Assurance Standard
- ukplanning
- UKTC
- UKWAS
- ultra vires
- ultrasound
- unadopted road
- unbalanced crown
- unburnable carbon
- under cut
- undercutting
- underground cellular system
- underpinning
- underplanting
- undersailing
- underscrub
- undershrub
- understorey
- underwood
- uniform shelterwood system
- unilateral undertaking
- unitary authority
- United Kingdom tree care
- unity
- upland
- Upper tribunal
- upstand
- urban common
- urban forest
- urban forestry
- urban greenery
- urban heat island
- urban heat island (amelioration)
- urban sprawl
- urban tree
- urban woodland
- Ustulina deusta
- utilities
- utility arboriculture
- U-value