Tree terms: i
- IACA
- IC
- ICE
- ice age
- ice sheets
- ice storm
- ICF
- IEA
- IHBC
- impact moling
- imperial system
- impervious
- impulse hammer
- incipient decay
- inclinometer
- Inclosure Acts
- included bark
- increment borer
- increment core
- indicator species
- indurated layer
- industry code of practice
- infill development
- infiltration
- influencing distance
- infrastructure
- injunction
- Inns of court
- inorganic
- inosculate
- insect
- insecticide
- inspection chamber
- instant roadway
- Institute of Australian Consulting Arboriculturists (IACA)
- Institute of Chartered Foresters (ICF)
- Institute of Directors (IoD)
- Institute of Historic Building Conservation (IHBC)
- Institution of Civil Engineers (ICE)
- Institution of Occupational Safety and Health (IOSH)
- Institution of Structural Engineers (IStructE)
- insurance loading
- integrated pest management
- intention
- interception
- interceptor
- intergeneric hybrid
- interglacial
- interlocked grain
- International Dendrology Society
- International Energy Agency
- International Panel on Climate Change
- International Powered Access Federation
- International Society of Arboriculture
- International Tree Foundation
- International Union for the Conservation of Nature
- internode
- inter-row
- interspecific hybrid
- interstock (interstem)
- introgression
- invasive
- Investor in People
- IoD
- iodine test
- ion
- IOSH
- IPAF
- IPCC
- IPM
- iron pan
- ISA
- ISO 9001
- isoprene
- IStructE
- i-tree
- i-tree eco
- i-tree streets
- IUCN
- ivy