U. S. Long-Term Ecological Research Network

• Ecological Monitoring and Assessment Network
• Center for Tropical Forest Science of the Smithsonian Tropical Research Institute
• SEPASAL project of the Center for Economic Botany

Assistance in selecting tree species

• Queensland Tree Selector
  

Information on measurement procedures

• SI/MAB Protocol
• UFRO International Guidelines for Forest Monitoring
• Growth and Yield Standards and Procedures (Canada)
• Resources Inventory Standards and Procedures (Canada)
• ESA's Committee on the Future of Long-term Ecological Data (FLED)

Other resources

• USDA's Plants project
• World Conservation Monitoring Centre
• Geographic Information Retrieval (GIR) Network