International Tree Foundation
- Plant and preserve trees. Information is given about the society, tree preservation orders, the ribbon campaign and events.
- http://www.internationaltreefoundation.org/

The Conifer Conservation Programme
- Based at the Royal Botanic Garden Edinburgh, aiming to establish a network of safe sites throughout the UK and abroad for the conservation of conifers and their associated species.
- http://193.62.154.29/rbge/web/science/research/biodiversity/iccp.jsp

Global Tree Campaign
- Tree Conservation Information Service. Includes The World List of Threatened Trees (survey of the conservation status of trees species worldwide) and Tree Conservation Database.
- http://www.unep-wcmc.org/trees/Background/intro2.htm