What is it?

• A tree inventory is a listing and description of trees and planting sites.
• It can be sample, partial or complete, depending on its purpose.  
• It can be handwritten, typed, or computerized. Any inventory is better than none, but computerized inventories are best in the long run.

• Inventories permit better hazard reduction, budgeting, and work planning.
• A tree inventory is a powerful management tool because it:

• provides an overview of the ages, types, and condition of trees
• allows you to make a maintenance schedule on a solid basis
• makes it easy to set priorities for pruning and removal work
• is an excellent tool for budget planning and negotiation
• aids greatly in dealing with homeowners
• supplies guidelines for new tree selection

What is it like?

• Every inventory includes at least address, species, size, condition, hazard potential, and necessary maintenance work.
• A professional inventory is made by trained and experienced professionals, now routinely using a computer program capable of advanced data storage, analysis and reporting. 
• A serviceable amateur inventory can be made by trained non-professionals using a general spreadsheet such as Excel® or a database such as Access®.  Free downloadable inventories of this type exist on the web.  The information is commonly less detailed and less accurate, hazardous trees must still be examined by a qualified inspector, and many features of professional inventories will be missing.
• Field data can be collected on an inexpensive PDA, greatly speeding up the process and making the data more consistent.
  
• All inventories need to be updated periodically through ground inspection in order to stay current.

• Cost depends upon who does the inventory, and how many trees there are.
• The cost of a professional inventory will include the price of the software, the number of trees, and the amount of data being collected on each tree.
• The cost of an amateur inventory lies principally in the collection of ground inspection data, since data entry can either be carried out by existing staff or eliminated altogether through the use of PDAs..