Timber cruise program
DNR timber cruising methods
The DNR implemented new cruising methods for timber sale preparation and contracting in 2020. A timber cruise is a forest survey conducted to locate and estimate the quantity of timber on a given area according to species, size, quality and other characteristics.
Training is available in the cruise methods. Training will be required for all DNR-certified timber sale preparation contractors and is suggested for procurement foresters purchasing DNR timber sale contracts.
Questions? Contact Brenda Haskill.
Field procedures and exam
A timber cruising products and standards exam and field test is required for those who wish to bid on contract work for timber sale preparation. Demonstration sites, training, an online training video and additional resources are available for review.
Software and hardware
Hardware and software changes are optional for those who are not DNR timber cruise contract holders.
The DNR has contracted with Mason, Bruce and Girard to provide timber cruising software including MobileMap configured to the CSS-M Michigan taper model.
The software functions on Android operating systems.
CSS-M volume model
To increase accuracy, the DNR has adopted use of a "taper model." A taper model is used to predict the diameter of a tree at any point along the stem and estimate the cubic volume of wood up to that point.
The DNR collected data on approximately 3,000 trees and tested the taper model, working to fine-tune it for local conditions. This resulted in the 2019 development of the Michigan variant of the Clark, Souter and Schlaegel (CSS) taper model, called the CSS-M, as modified by Dr. MacFarlane of Michigan State University. The Michigan Taper Model is available online to calculate cubic foot volume by species. There are roughly 79 cubic feet in a cord and 185 cubic feet in 1,000 board foot Scribner.
For further information regarding model development, please see: