Ash Reduction Model 2" Diameter Class

Version 1.4, Tara L. Eberhart, Andrew J. Storer, Linda M. Nagel

Copyright Michigan Technological University

Version 1.4 Input Requirements

10/3/2008

ASH Trees Only

Trees per Acre

Ash Species may be used, but if not known use Any Ash Species column

Open Grown Trees

Use Open Grown Model if most trees are receiving 4 or 5 sides of direct sunlight

2" Size Class Increments

Use Forest Model if working in a forest setting or most trees receiving sunlight on 3 sides or less

No. Trees Per Acre

DBH Class "

Any Ash Species

Green Ash and/or White Ash

Black Ash

% Surface Area

2

4

6

8

10

Retaining Small Trees

12

Target Percentages

14

Diameter Limit Cut

16

99%

18

95%

20

90%

22

75%

Total

*Cutting all ash down to this size limit

Retaining Large Trees

Target Percentages

Diameter Limit Cut

99%

95%

90%

75%

* Cutting all ash up to this size limit

Summary

This version of the model serves to show what diameter limit cut would be needed in order to reduce the total surface area of ash trees in a stand by a desired amount.

The bottom table of Retaining Large Trees is calculated from the same graph as the top table, with the percent axis reversed.

This model can be used with Fraxinus nigra, or F. pennsylvanica and F. americana combined, or if species is only partially known, or not known at all, any ash species may be entered.

Separate equations are used for individual species but the total ash reduction is combined for all the ash in the stand.

Light Exposure and crown class have been accounted for in this model. The open grown version is appropriate if the majority of trees in the target area

are open grown trees, or are receiving full sunlight on 4 or 5 sides including the top of the tree.

The Forest version of the model is appropriate if the target reduction area is a forest setting and the majority of trees are receiving sunlight on 3 sides or less.

Over 500 ash trees have had their specific morphology recorded to estimate total surface area which is a good indicator of total phloem available to emerald ash borer.

This model only works with the ash component of a stand regardless of total stand size, other tree species presence, or how much ash there is present.

Depending on management goals, this model can be used to determine a lower diameter limit cut to retain small trees,

and an upper diameter limit cut to retain large trees. Surface area can be used as an estimate of phloem, a critical resource, available to

emerald ash borer in a stand. Use of this model in management decisions will reduce the ash resource available to emerald ash borer

by a target percentage and help maintain ash as a component in our forests and its genetic diversity

Note: surface area reduction will reduce the amount of breeding substrate (phloem) in the stand by a target level,

thereby reducing the population potential of eab, not ensuring remaining ash to be uninfested