Stand Table is a table showing the distribution of stems by diameter classes for each of the series of crop diameters.A stand table gives number of trees in each diameter class. Future stand tables can be predicted from current stand tables using a stand table projection method.

• Recognizes the structure of a stand and growth projections are made according to dbh classes.
• Best suited to uneven-aged, low-density and immature timber stands
• There are cases where the reverse information is needed, i.e. predicting the past instead of the future. Examples of these scenarios include estimating timber damages and retroactively establishing the tax basis of timber that was earlier inherited orpurchased (Quang, McCarty, Shanna 2006).

The procedure growth prediction

• A conventional inventory showing the number of trees in each dbh class.
• Past periodic growth, by dbh classes, is determined fromincrement borings or from re-measurements of permanent sample plots, when increment borings are used, growth values must be converted from an inside-bark basis to outside bark readings
• Past diameter growth rates are applied to the present standtable to derive a future stand table showing the predicted number of trees in each dbh class at the end of the growth period.
• Numbers of trees in each class must then be corrected for expected mortality and predicted ingrowth.
• Both present and future stand tables are converted to stock tables by use of an appropriate local volume table. Thus, for short growth periods, the expected changes in tree heightduring the growth period are inherently accommodated by diameter increases.
• Periodic stand growth is obtained as the difference betweenthe total volume of the present stand and that of the future stand.

An Example of Stand Projection

The upward movement of trees into larger dbh classes is proportional to the ratio of growth to the chosen diameter class interval

Growth-index ratio = g/i

Where g = diameter growth (in inches), i = diameter-class interval (in inches)

An example, using the 6-inch dbh class, Diameter growth = 2.2” and Interval = 2”

Here,

Growth-index ratio = 2.2”/2” = 1.10

The interpretation of a growth-index ratio of 1.10 is that 100% of trees move up one dbh class, and 0.10 or 10% of these advance two classes. It means 90% moves up to the 8” and 10% move all the way to 10” class. None will remain in the 6” class in this instance. If the growth-index ratio had been less than unity, for example, 0.80 or 80% of the trees would move up one class interval, and 20% would remain in the present dbh class.

To apply the method of stand table projection, the following data are required:

1. Diameter growth information
2. Present stand table
3. Local volume table
4. Information to calculate ingrowth
5. Estimates of mortality

Assumptions

• All trees in each diameter class are located at the class mid-point and that all trees will grow at the average rate.
• Trees in each diameter class are evenly distributed throughthe class and that each tree will grow at the average rate,
• Recognize the actual position of trees in each diameter classand apply the diameter growth for individual trees in the class.