| A unit of Lasting Forests
evolving since March 30, 1999 |
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A Total Forest Management Plan
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The deer browse resource is the collective weight of the metabolizable portions of the leaves and twigs of woody plants of the ownership. The resource is estimated in the field in terms of the browse that is available for use and in terms of the actual use, then metabolism of the browse. All leaves and twigs are not equally good for deer; some are not eaten; others, even if eaten, cost much energy to get them consumed; others have chemicals that block their use by the deer even after they are ingested.
The conditions on the area are cost effectively analyzed by making observations about availability and use. Conditions in each stand are grossly recorded as:
Availability:
Utilization (observed twigs having portions removed) is measured similarly and classed as follows:
Since utilization may be difficult to estimate and since it may be a temporary condition (not useful for assessing longterm potentials and management strategies for an area, it may be omitted. (This is a policy decision and entered don Form 1. Once the decsion is made, the computer analyzes either :
but not both. Field workers do not collect utilization data if only availability will be used.
The relative goodness of each condition for deer is judged by a pannel of experts and entered on Form 3. The weights assigned represent group concensus on the value of a stand of any reasonable size being in a particular average browse availability-utilization class, where 100 represents the most desirable condition.
A comparative index of browse status for the ownership is prepared by multiplying the proportion of the area in a particular class by the weight for that class. These figures are summed for all 9 classes (3 availability classes x 3 utilization classes) possible to give a relative approximate assessment of the of the browse conditions of the ownership as a whole. The equation shows the process for the browse status Index (BSI):
BSI = 
BiPi
where Bi is the experts' weights for the desirability of a stand being in a particular browse availability-utilization class. A weight of 100 represents the most desirable conditions for a growing or sdtable deer herd while a weight of 0 represents the least desirable condition.
and Pi is the proportion of the land in each ith stand.
A stand summary lists the stand numbers and the browse condition within it. The table enables the manager to determine quickly where conditions are satisfactory and where trouble spots may exist and where action may have greastest returns.
| Experts' weights for the desirability of different browse avaialability-utilization classes. A weight of 100 is the best condition. | |||
| Utilization | Availability | ||
| Little to None*1 - 0 | Some*2 - 1 | Abundant*3 - 2 | |
| Little to None*4 - 0 | 30 | 70 | 50 |
| Moderate*5 - 1 | 10 | 90 | 80 |
| Heavy*6 - 2 | 0 | 40 | 100 |
Additional conditions and specifications may be made such as:
- *1 Sparce understory with few browse plants available
- *2 Sparce to moderate understory but sprout growth common
- *3 Moderste to dense understory of preferred sprout growth
- *4 Little to no browsing evident
- *5 Up to 1/3rd of current annual growth browsed
- *6 More than 1/3rd of current annual growth browsed.
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This Web site is maintained by R. H.
Giles, Jr.
Last revision July 20, 2001.