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Determining Ground Check Priorities


Figure 6- High priority spot in plantation
Figure 6- High priority spot in plantation
(North Carolina Forest Service).

Figure 7- Low priority spot in sparse
Figure 7- Low priority spot in sparse
pine stand.

If spots are numerous, assign a priority for ground checking to each SPB spot reported. List at the time of observation both the estimate of spot size and the ground check priority next to each spot location on your map or photo. Ground crews will then know which spots to check immediately and which ones they may visit as time permits. For your own reference or to aid new observers, prepare a priority table for your survey area. On it, list conditions to look for in evaluating spots from the air. Table 1 is an example of a priority table for aerial observers.

Experience has shown that SPB infestations in mature sawtimber stands (see fig. 1) or dense pine plantations (fig. 6) are most apt to spread unless controlled. You should assign these spots a higher ground check priority than SPB spots in sparse pine stands (fig. 7) or in areas containing more hardwoods than pines.

Many forest managers prefer commercial salvage of infested pines for beetle control. But the spot must be accessible and have enough timber volume to justify salvage efforts. A logger can afford to build roads when a large volume of timber is involved; a small volume may be worth salvaging only if it is near an existing road. If salvage is the only means of control used in your area, you should give a low ground check priority to small, inaccessible spots.

The land use objective may also influence the priority you assign a spot. A SPB spot in a residential or recreational area (see fig. 3), for example, may require immediate action. But a spot in a wilderness area or in a remote, noncommercial forest may well be given a low ground check priority.

Upon completion of each detection flight, give ground crews a fist of the spots requiring ground checking. For each spot, include plotted position, estimate of spot size, and ground check priority. Ground crews then have all the information they need to systematically handle large numbers of spots.



Table 1. - Example of a table for setting ground check priorities from the air, May through October. Choose the spot classification which best describes the spot.
Priority for ground check Spot classification

Priority 1 (high)

More yellow than red-crowned trees

In dense natural pine stand or in area with past history of SPB outbreaks

Easy access or high salvageable volume

In plantation or other high value area

Threat to cross property lines and affect high value stands

Priority 2 (breakout)

Yellow-crowned trees in spot previously reported controlled or inactive

Priority 3 (medium)

More red-crowned than yellow-crowned trees

Poor access or moderate salvageable volume

Priority 4 (low)

Few yellow-crowned trees

Infested pines surrounded by hardwoods or open land

Difficult to locate on ground because of small size or inaccessibility

In unmerchantable timber or with low salvageable volume

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