University of Minnesota Extension

BU-05900     1992

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Managing Oak in the Driftless Area

Table of Contents


Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
Appendix H
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Appendices

Appendix A. Summary of Research and Case Histories

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The key to regenerating oak has been the presence of large (greater than 4 feet tall) advance reproduction or trees capable of producing stump sprouts (Sander 1977, Loftis 1989). Unfortunately, stands meeting the recommended minimum requirements for advance reproduction (Sander et al. 1984) are rare and usually occur only on very dry sites. For example, Kenneth N. Anderson found no such stands in a recent inventory of 100 mature oak stands in southeastern Minnesota (personal communication). The shelterwood method had been proposed as a means for developing large advance reproduction in previous guidelines for the area (Sander 1977), but supportive research results and definitive prescriptions had not been available.

Recently, however, some encouraging results have been reported in the Driftless Area on the establishment of red and white oak on good sites by clearcutting without advance reproduction as well as by shelterwood. Johnson et al. (1981, 1989) reported that red oak had been successfully regenerated by both methods in southwestern Wisconsin. Similar successes following clearcutting without advance reproduction occurred in at least 10 widely scattered trials in eastern Iowa. (Data from two such stands are available from Robert McQuilkin, U.S. Forest Service, State and Private Forestry, Columbia, Missouri.) In addition, researchers in Wisconsin (Lorimer 1989) and the southern Appalachians (Loftis 1988) have developed techniques for stimulating growth of advance reproduction beneath shelterwood overstories. The shelterwood method is also being successfully applied by industrial foresters in Pennsylvania (Wolf 1988). Prescriptions based on these experiences appear applicable in the Driftless Area until local research provides more definitive information.

CLEARCUTTING WITHOUT ADVANCE REPRODUCTION

The Iowa and Wisconsin clearcutting trials produced mixed hardwood stands in which red oak was or could be a major component. In one of the two Iowa stands inventoried, red oak was the third most numerous of 17 species; in the other it was the sixth of 19 species. In the Wisconsin stand, at age 11 years, half of the trees were red oak. The few competing species that developed in the Wisconsin trials included aspen, white birch, black cherry, elm, and hickory. But in Iowa these species were accompanied by 10-15 other mesic species: sugar maple, ironwood, white ash, basswood, hackberry, etc. White oak was a minor component in stands where a seed source existed. Oak stocking is variable, but when the stands reach pole size, at least 25 percent of the basal area is expected to be red oak. Furthermore, red oak stocking can usually be increased by weeding and/or early thinning. In some stands and parts of all stands, red oak will dominate the overstory.

All of these clearcutting successes have several things in common:

  1. The stands were mature, usually with 80-90 percent of the basal area in red oak.
  2. All overstory trees 1.6 inches DBH and larger were harvested or killed.
  3. Harvesting coincided with a good acorn crop.
  4. Understory competition was controlled before or during overstory removal.
  5. The soil was disturbed by logging or site preparation, often when acorns were on the ground.
Although the relative importance of these factors is unknown, one thing is obvious: A good acorn crop is essential when advance reproduction is lacking. These case histories, as well as recent shelterwood trials (Loftis 1988, Lorimer 1989, Wolf 1988), also highlight another key element: understory competition control. Removing the overstory without controlling the understory only stimulates the competition. All the stands had dense layers of understory vegetation. In Wisconsin, the understory was mostly shrubs (gray dogwood and hazel) and ferns (lady and interrupted); in Iowa, it was mostly tolerant trees (especially ironwood and sugar maple). Control in Wisconsin was done with herbicides before the harvest. In Iowa the understory was mechanically uprooted before and during logging and, in some cases, the tree tops were dragged across part of the stands to disperse acorns and disturb the surface soil.

The value of soil disturbance other than to control understory competition is uncertain. However, the fact that more oaks become established on skid trails than in undisturbed areas indicates that soil disturbance can be important. Crow (1988) suggests that soil scarification is vital to protecting acorns from predators. It helps by burying the acorns, by removing cover essential to rodents, by destroying other wildlife habitat, and by reducing desiccation of the acorns. Galford et al. (1988) also recommended scarification to reduce insect damage to germinating acorns. The value of scarification may depend upon the size of the acorn crop: unnecessary for good crops but needed for fair to poor ones.

These case histories clearly show that red oak seedlings derived from acorns can grow through the dense herbaceous vegetation (including a seemingly impregnable layer of Rubus spp.) that immediately occupies clearcut sites. However, it is not clear whether weeding and cleaning are necessary to assure red oak survival later. Where intolerant species with rapid height growth (mainly aspen, white birch, and black cherry) become established, they quickly form the dominant height class. But red oaks seem able to survive as intermediates just beneath this canopy and may emerge and become dominant later, according to Oliver (1978). Local foresters generally weed and clean when the stands are about 10 years old to promote survival and faster growth of red oak.

In spite of all this, clearcutting without advance reproduction is not recommended for general application. The shelterwood method is preferred when possible because it minimizes the risk of regeneration failure by retaining a seed source, eliminating the need to coordinate with a seed crop, and allowing more competitive seedlings to develop before the stand is opened to vigorous competition. However, if the landowner demands an immediate return, clearcutting is a promising option. But, as mentioned before, to be successful you must:

  1. Control understory competition when necessary.
  2. Wait for a good acorn crop.
  3. Scarify the soil after the acorns have fallen.
  4. Remove or kill all overstory trees.
  5. Control rapidly growing competing trees as needed within 5-15 years after clearcutting.

SHELTERWOOD

Two versions of the shelterwood system have proved successful in Wisconsin (Johnson et al. 1989). A 2-cut application consisted of a seeding cut followed by overstory removal 8 years later, and a 3-cut version involved two seeding cuts 21 and 10 years before overstory removal. Both are now stocked with enough oak to eventually dominate the stands, but neither is stocked as well as the herbicide/clearcut treated stands on the same site. This minimal stocking will limit the selection of crop trees for growth and quality development. Understory competition, mainly shrubs, was not controlled in these trials; presumably, some control was effected by logging during the seeding cuts.

Early results of research in Wisconsin (Lorimer 1989) and the southern Appalachians (Loftis 1988) show that controlling understory competition while retaining dense overstories promotes survival and growth of red oak reproduction. In these stands, the overstories were described as "70 percent crown cover" (Lorimer) and "80 square feet of basal area with no gaps in the canopy" (Loftis).

Other than the Wisconsin trials reported by Johnson et al. 1989, the only trials involving overstory removal are those reported by Wolf (1988) in south central Pennsylvania. His technique consists of:

  1. Marking trees to leave.
  2. Leaving 55-60 percent crown cover.
  3. Chemically treating individual undesirable understory stems up to 2 inches DBH and cutting larger understory trees.
  4. Removing the overstory when 70 percent of milacre plots contain at least one desirable seedling more than 2 feet tall – usually 5-10 years after the seeding cut.
Where this technique did not produce adequate advance reproduction, the failure was attributed to uncontrolled understory competition and browsing by deer.

This prescription seems appropriate for the Driftless Area – with some modification. For example, retaining more crown cover might be advisable to discourage understory competition. Keeping as much as 70 percent crown cover, as suggested by Lorimer (1989), would be appropriate, especially if acorns or small seedlings are lacking when the seeding cut is applied. Also, shrubs and ferns should be controlled as needed. Finally, mechanically controlling woody understory competition is desirable when there is a good acorn crop.

Appendix B. Site Index Curves

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Table 1. Site index curves for northern red oak (Carmean et al. 1989)
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  • Northern red oak
  • Southwestern Wisconsin
  • Number of plots and number of dominant and codominant trees not given
  • Total height and total age, anamorphic, equation not given
  • Add 4 years to DBH age to obtain total age (BH = 0.0)
    • b1 b2 b3 b4 b5 R2 SE Maximum difference
    H 1.5403 1.0006 -0.0216 1.0616 -0.0044 0.99 0.86 0.7
    SI 1.0000 0.9058 -0.0269 -0.5382 0.2108 0.98 1.19 3.4

    Table 2. Site index curves for upland oaks (Carmean et al. 1989) 5900t02.gif - 10.18 K

  • Upland oaks
  • Michigan south to Georgia, Missouri east to Pennsylvania and Maryland
  • 404 plots, combined data for white, black, scarlet, chestnut, and red oaks; number of dominant and codominant trees not given
  • Total height and total age, anamorphic, equation not given
  • Add 3 years to DBH age to obtain total age (BH = 0.0)

    b1 b2 b3 b4 b5 R2 SE Maximum difference
    H 2.1037 0.9140 -0.0275 3.7962 -0.2530 0.99 1.67 6.6
    SI 0.1890 1.2031 -0.0081 -2.1975 -0.2582 0.98 2.23 4.9

    Appendix C. Site Productivity by Soil and Topographic Features

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    Table 3. Soil and topographic features affecting site productivity of oak forests in the Lake States (Arend and Scholz 1969)
    Site Quality Site index and growth poptential at age 801 Soil featutes and corresponding topographic features2
    Site Index Number 16-foot logs Mean annual growth per tree periodic annual growth per acre Soil Topography
    Good 70+ 21/2+ 0.4-0.6
    (Cu. ft.)    		 200-300
    (Bd. ft).
    1. Deep, moderately and well-drained silts, loams, and clays where soil depth is 3 feet or more to parent rock; sands where water table is within 4 to 10 feet of the surface.
    1. On relatively flat topography, broad ridges, lower slopes, bottoms and valley coves; all north and east slopes where gradients are less than 20 percent; middle north and east slopes where gradients range from 20 to 35 percent.
    Medium 55-65 11/2-21/2 0.3-0.4 100-200
    1. Moderately deep (20 to 36 inches) silts, loams, and clays, or deep sands, with fine-textured bands in sub-soil 2 to 6 inches in thickness at depths less than 60 inches

    2. Deep sands.

    3. Deep silts and loams.
    1. On relatively flat land, upper and middle north and east slopes where gradients are less than 20 percent; middle north and east slopes where gradients range from 20 to 35 percent.

    2. On lower slopes in rolling topography.

    3. On upper and middle south and west slopes where gradients are less than 20 percent.
    Poor 40-55 1/2-11/2 0.1-0.2 less than 100
    1. All shallow soils less than 20 inches in depth and deep porous sands.

    2. All soils.

    3. All soils.
    1. On flat topography.

    2. On narrow ridges and upper slopes in hilly topography.

    3. On middle south and west slopes where gradients exceed 20 percent.
    1Measurements from dominant trees (red oak group) in unmanaged stands.
    2Does not apply to prairie soils and loessal deposits.

    Appendix D. Yield Tables for Upland Oaks

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    Table 4. Yields per acre for upland oak; no thinning (Gingrich 1971)

    Age Basal area Trees Average tree diameter1
    Yields
    Years Square feet No. Inches Cubic feet Cords Board feet
    SITE INDEX 55
    20 55 2,500 2.0 60 0.6 --
    30 75 1,260 3.3 583 5.3 --
    40 87 790 4.5 1,320 12.1 --
    50 97 480 6.1 2,150 19.7 400
    60 104 357 7.3 2,520 22.9 900
    70 108 295 8.2 2,730 24.4 2,800
    80 112 242 9.2 2,880 25.6 5,400
    SITE INDEX 65
    20 59 1,880 2.4 178 1.6 --
    30 81 930 4.0 1,200 10.6 --
    40 96 505 5.9 1,840 18.2 440
    50 105 342 7.5 2,800 26.9 2,150
    60 111 262 8.8 3,300 30.8 5,160
    70 115 215 9.9 3,700 33.3 7,200
    80 117 187 10.7 3,950 35.6 8,200
    SITE INDEX 75
    20 70 1,425 3.0 694 6.4 --
    30 89 680 4.9 1,670 16.7 --
    40 101 400 6.8 2,440 23.7 1,380
    50 110 279 8.5 3,315 30.1 4,100
    60 114 222 9.7 4,140 37.7 9,288
    70 117 187 10.7 4,760 43.0 11,200
    80 120 166 11.5 5,160 46.5 12,500
    1The diameter of the tree of average basal area.

    Table 5. yields per acre for upland oak; first thinning at age 10 (Gingrich 1971)

    Age
    Residual Stand
    Cut stand
    Cummulative total yields
    (cut stand plus redidual stand)
    Basal area Average tree diameter
    Yield
    		 Basal area
    Yield
    Years Square feet Inches Cubic feet Cords Board feet Square feet Cubic feet Cords Board feet Cubic feet Cords Board feet
    SITE INDEX 55
    10 20 1.9 – – – – – – – – – –
    20 48 4.1 515 5.0 – 7 25 – – 540 5.0 –
    30 58 5.9 1,190 9.9 240 20 345 4.2 – 1,560 14.1 240
    40 64 8.0 1,640 15.0 1,560 19 350 3.6 160 2,360 22.8 1,720
    50 71 10.6 1,990 18.3 3,800 16 415 4.4 590 3,125 30.5 4,550
    60 75 13.0 2,280 20.7 6,540 16 485 4.9 1,050 3,900 37.8 8,340
    SITE INDEX 65
    10 23 2.1 – – – – – – – – – –
    20 51 4.5 775 6.8 – 8 125 1.2 – 900 8.0 –
    30 59 6.4 1,445 13.1 540 25 370 3.8 – 1,940 18.1 540
    40 66 8.6 1,920 18.0 2,280 21 465 3.8 280 2,880 26.8 2,560
    50 72 11.0 2,340 21.8 5,250 19 575 5.2 970 3,875 35.8 6,500
    60 76 13.7 2,655 24.3 8,940 18 670 5.8 1,810 4,860 44.1 12,000
    SITE INDEX 75
    10 25 2.5 – – – – – – – – – –
    20 55 5.4 1,060 9.6 – 12 200 1.6 – 1,260 11.2 –
    30 62 7.4 1,920 17.5 1,380 30 520 5.2 60 2,640 24.3 1,440
    40 71 10.5 2,550 23.0 4,840 22 610 5.6 500 3,880 35.4 5,400
    50 75 13.2 3,025 26.8 10,300 22 745 6.8 1,540 5,100 46.0 12,400
    60 78 15.5 3,360 29.7 13,200 21 925 7.8 3,540 6,360 56.7 18,840

    Table 6. yields per acre for upland oak; first thinning at age 20 (Gingrich 1971)

    Age
    Residual Stand
    Cut stand
    Cummulative total yields
    (cut stand plus redidual stand)
    Basal area Average tree diameter
    Yield
    		 Basal area
    Yield
    Years Square feet Inches Cubic feet Cords Board feet Square feet Cubic feet Cords Board feet Cubic feet Cords Board feet
    SITE INDEX 55
    20 34 2.3 60 0.6 – – – – – 60 0.6 –
    30 49 4.2 600 5.1 – 15 – 0.9 – 600 6.0 –
    40 58 6.1 1,220 12.2 880 16 300 2.9 – 1,520 16.0 880
    50 66 8.6 1,750 16.0 2,350 15 300 3.2 150 2,350 23.0 2,500
    60 71 10.6 1,980 18.6 3,960 15 360 3.2 570 2,940 28.8 4,680
    70 74 12.1 2,170 20.0 5,810 14 370 3.8 820 3,500 34.0 7,350
    SITE INDEX 65
    20 37 2.8 160 1.6 – – 18 – – 178 1.6 –
    30 50 4.6 750 7.4 – 20 132 1.2 – 900 8.6 –
    40 63 7.7 1,760 16.0 1,320 15 290 3.2 – 2,200 20.4 1,320
    50 69 9.8 2,150 19.7 3,500 19 625 4.1 400 3,215 28.2 3,900
    60 73 12.0 2,460 22.5 6,120 18 515 4.4 1,160 4,040 35.4 7,680
    70 77 14.6 2,730 24.2 9,030 16 520 4.9 2,010 4,830 42.0 12,600
    SITE INDEX 75
    20 46 3.6 476 4.4 – – 218 2.0 – 694 6.4 –
    30 57 5.6 1,275 13.0 – 26 307 3.6 – 1,800 18.6 –
    40 66 8.4 2,140 19.8 2,160 21 535 4.8 240 3,200 30.2 2,400
    50 71 10.8 2,600 24.7 6,450 21 665 5.4 1,160 4,325 40.5 7,850
    60 76 13.4 3,060 28.5 10,680 19 615 4.9 2,020 5,400 49.2 14,100
    70 79 16.3 3,465 31.5 13,720 19 635 5.2 2,740 6,440 57.4 19,880

    Table 7. yields per acre for upland oak; first thinning at age 30 (Gingrich 1971)

    Age
    Residual Stand
    Cut stand
    Cummulative total yields
    (cut stand plus redidual stand)
    Basal area Average tree diameter
    Yield
    		 Basal area
    Yield
    Years Square feet Inches Cubic feet Cords Board feet Square feet Cubic feet Cords Board feet Cubic feet Cords Board feet
    SITE INDEX 55
    30 58 4.3 528 4.8 – 17 55 0.5 – 583 5.3 –
    40 55 5.7 1,120 9.4 200 27 265 3.1 – 1,440 13.0 200
    50 62 7.8 1,600 14.2 1,500 15 330 3.4 – 2,250 21.2 1,500
    60 67 10.2 1,950 17.4 3,000 15 310 3.2 360 2,910 27.6 3,360
    70 72 11.7 2,135 19.6 5,040 12 335 3.1 550 3,430 32.9 5,950
    80 75 13.0 2,280 20.6 8,000 12 345 3.7 1,010 3,920 37.6 9,920
    SITE INDEX 65
    30 62 4.9 1,120 9.6 – 20 80 1.0 – 1,200 10.6 –
    40 60 6.6 1,520 13.6 640 29 400 3.8 – 2,000 18.4 640
    50 67 9.0 2,000 18.5 2,450 18 470 4.2 – 2,950 27.5 2,450
    60 72 11.2 2,370 21.5 4,620 17 430 3.9 600 3,750 34.5 5,220
    70 76 13.7 2,660 23.8 8,320 16 440 3.9 1,510 4,480 40.6 10,430
    80 78 16.1 2,880 24.8 10,900 16 460 4.0 2,510 5,160 45.6 15,520
    SITE INDEX 75
    30 66 5.5 1,450 14.0 – 23 220 2.7 – 1,670 16.7 –
    40 62 7.1 1,840 17.0 1,400 34 600 5.5 – 2,660 25.2 1,400
    50 68 9.7 2,400 22.8 4,200 20 555 5.0 650 3,775 36.0 4,850
    60 73 12.4 2,880 26.7 7,980 19 515 4.8 1,450 4,770 44.7 10,080
    70 77 15.2 3,325 29.8 13,020 17 490 4.4 2,100 5,705 52.2 17,220
    80 80 17.7 3,760 31.6 15,440 16 500 4.8 3,400 6,640 58.8 23,040

    Table 8. yields per acre for upland oak; first thinning at age 40 (Gingrich 1971)

    Age
    Residual Stand
    Cut stand
    Cummulative total yields
    (cut stand plus redidual stand)
    Basal area Average tree diameter
    Yield
    		 Basal area
    Yield
    Years Square feet Inches Cubic feet Cords Board feet Square feet Cubic feet Cords Board feet Cubic feet Cords Board feet
    SITE INDEX 55
    40 63 5.0 1,140 10.5 – 24 180 1.6 – 1,320 12.1 –
    50 62 7.4 1,538 13.0 900 23 282 3.4 – 2,000 18.0 900
    60 67 9.1 1,830 15.6 2,430 15 288 3.1 270 2,580 23.7 2,700
    70 72 11.0 2,065 18.6 4,445 12 300 2.7 465 3,115 29.4 5,180
    80 74 12.7 2,240 21.6 6,880 12 350 2.8 865 3,640 35.2 8,480
    90 76 13.8 2,430 24.8 9,180 9 355 3.0 1,100 4,185 41.4 11,880
    SITE INDEX 65
    40 69 6.5 1,600 15.9 440 27 240 2.3 – 1,840 18.2 440
    50 66 8.5 1,910 17.7 1,800 28 410 4.0 200 2,560 24.0 2,000
    60 70 10.4 2,200 20.7 4,200 18 400 3.6 280 3,270 30.6 4,680
    70 74 12.4 2,485 23.1 7,210 16 420 3.7 710 3,955 36.7 8,400
    80 77 14.5 2,720 24.8 8,960 15 410 4.0 1,050 4,600 42.4 11,200
    90 79 16.5 2,925 26.6 10,710 13 460 4.0 1,630 5,265 48.2 14,580
    SITE INDEX 75
    40 73 7.4 2,130 20.2 1,380 28 300 3.0 – 2,440 23.2 1,380
    50 68 9.6 2,390 21.8 3,450 31 635 6.2 300 3,325 31.0 3,750
    60 73 11.6 2,730 24.9 7,680 19 625 5.2 1,020 4,290 39.3 9,000
    70 76 13.8 3,115 28.0 11,200 19 610 4.8 1,620 5,285 47.2 14,140
    80 79 16.5 3,480 30.8 14,080 17 590 5.2 2,340 6,240 55.2 19,360
    90 81 18.7 3,735 33.7 15,810 15 660 5.3 3,000 7,155 63.4 24,120

    Table 9. yields per acre for upland oak; first thinning at age 50 (Gingrich 1971)

    Age
    Residual Stand
    Cut stand
    Cummulative total yields
    (cut stand plus redidual stand)
    Basal area Average tree diameter
    Yield
    		 Basal area
    Yield
    Years Square feet Inches Cubic feet Cords Board feet Square feet Cubic feet Cords Board feet Cubic feet Cords Board feet
    SITE INDEX 55
    50 69 6.5 1,627 14.9 400 28 523 4.8 – 2,150 19.7 400
    60 66 8.4 1,710 14.7 1,350 23 317 3.9 150 2,550 23.4 1,500
    70 68 9.3 1,855 15.4 3,585 15 280 3.2 165 2,975 27.3 3,900
    80 71 10.5 1,960 18.0 6,160 12 280 2.1 325 3,360 32.0 6,800
    90 73 11.5 2,115 20.0 8,240 10 220 2.2 620 3,735 36.2 9,500
    100 74 12.7 2,250 22.8 8,900 9 230 1.5 1,240 4,100 40.5 11,400
    SITE INDEX 65
    50 75 8.0 2,130 19.6 1,850 30 670 7.3 300 2,800 26.9 2,150
    60 68 9.6 2,130 19.5 4,090 29 470 4.4 210 3,270 31.2 4,600
    70 70 10.4 2,240 20.6 6,160 18 400 3.7 330 3,780 36.0 7,000
    80 74 12.2 2,480 22.8 8,240 14 300 2.6 520 4,320 40.8 9,600
    90 77 14.8 2,745 25.2 10,305 12 275 2.7 935 4,860 45.9 12,600
    100 79 17.0 3,000 28.5 10,700 10 235 1.8 1,905 5,350 51.0 14,900
    SITE INDEX 75
    50 78 9.0 2,590 24.4 3,650 32 725 5.7 450 3,315 30.1 4,100
    60 72 11.3 2,700 25.2 6,300 30 655 6.8 1,050 4,080 37.7 7,800
    70 75 12.8 2,965 26.8 9,200 19 475 5.2 1,100 4,820 44.5 11,800
    80 77 14.1 3,180 29.0 11,500 18 425 4.8 1,500 5,460 51.5 15,600
    90 79 16.5 3,620 31.4 13,000 16 420 4.6 1,900 6,320 58.5 19,000
    100 81 18.4 3,880 33.0 14,450 14 500 4.9 2,750 7,080 65.0 23,200

    Table 10. yields per acre for upland oak; first thinning at age 60 (Gingrich 1971)

    Age
    Residual Stand
    Cut stand
    Cummulative total yields
    (cut stand plus redidual stand)
    Basal area Average tree diameter
    Yield
    		 Basal area
    Yield
    Years Square feet Inches Cubic feet Cords Board feet Square feet Cubic feet Cords Board feet Cubic feet Cords Board feet
    SITE INDEX 55
    60 76 8.2 1,860 17.1 780 28 660 5.8 120 2,520 22.9 900
    70 73 9.3 1,960 17.5 2,345 19 285 4.0 685 2,905 27.3 3,150
    80 70 10.3 2,000 18.4 4,320 16 335 3.0 555 3,280 31.2 5,680
    90 72 11.3 2,115 19.3 5,850 10 250 2.5 530 3,645 34.6 7,740
    100 74 12.3 2,200 20.8 7,300 8 270 1.9 510 4,000 38.0 9,700
    110 75 13.2 2,310 22.6 8,580 7 235 2.0 570 4,345 41.8 11,550
    SITE INDEX 65
    60 78 9.4 2,400 22.2 3,900 33 900 8.6 1,260 3,300 30.8 5,160
    70 75 10.2 2,450 22.1 4,550 23 360 3.6 770 3,710 34.3 6,580
    80 73 12.0 2,520 23.0 5,920 20 400 3.6 810 4,180 38.8 8,760
    90 77 14.1 2,610 23.8 7,785 13 365 3.6 895 4,635 43.2 11,520
    100 78 15.5 2,650 25.5 9,850 12 325 3.1 915 5,000 48.0 14,500
    110 80 17.2 2,750 26.6 11,770 9 345 3.1 960 5,445 52.2 17,380
    SITE INDEX 75
    60 82 10.2 3,060 27.0 7,848 32 1,080 10.7 1,440 4,140 37.7 9,288
    70 78 11.5 3,150 27.3 8,540 21 460 4.7 870 4,690 42.7 10,850
    80 76 13.5 3,320 28.4 9,760 21 420 4.2 1,290 5,280 48.0 13,360
    90 78 15.6 3,510 29.9 10,935 16 425 3.6 1,665 5,895 53.1 16,200
    100 80 17.2 3,725 31.5 12,200 13 415 3.3 1,835 6,525 58.0 19,300
    110 82 19.1 3,795 33.0 13,530 9 445 3.2 1,920 7,040 62.7 22,550

    Appendix E. Pest Management guidelines for oak1

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    HAZARD LOSS OR DAMAGE PREVENTION, MINIMIZING LOSSES, AND CONTROL ALTERNATIVES REFERENCES
    FOLIAGE PESTS
          Anthracnose Occasional spring defoliation which may be severe enough to cause loss of vigor and susceptibility to other organisms. No practical prevention or control practices. Fertilization may restore vigor. Monitor severely infected stands for signs of decline and consider harvest if necessary. Oak Pests: A Guide to Major Insects, Diseases, Air Pollution and Chemical Injury. 1980. J. D. Solomon et al. USDA Forest Service General Report SA-GR11.
    SPRING DEFOLIATORS
         Cankerworms
          Oak Leaf
          Roller, Oak
          Leaf Tier
          Forest Tent
          Caterpillar    		 Periodic outbreaks cause heavy defoliation in spring which invites attack by two-lined chestnut borer and shoe-string root rot. Outbreaks often occur where oaks are under stress due to droughty sites, overstocking, competition from shade tolerant species or over-maturity. ALTERNATIVES:
    1. Maintain proper stocking levels.
    2. Harvest when mature.
    3. Control competition.
    4. Protect foliage with insecticide.
    5. Accept defoliation and monitor for decline and harvest when necessary.    		 Oak Pests: A Guide to Major Insects, Diseases, Air Pollution and Chemical Injury. 1980. J. D. Solomon et al. USDA Forest Service General Report SA-GR11.
          Iron Deficiency
          Chlorosis    		 Interveinal yellowing of leaves of one branch or entire tree caused by inability of roots to take up iron because of high soil pH, soil disturbance, or root damage. Seriousness varies from year to year. Some growth loss is normal; branch and tree mortality occur in extreme cases. Older trees are more susceptible. Seldom serious enough to require action.
    ALTERNATIVES:
    1. Harvest mature oaks.
    2. In extreme cases, convert to a less susceptible type.    		 Oak and Other Trees Disorder: Iron Chlorosis. J. R. Love. 1975. University of Wisconsin Extension, Urban Phytonarian A2638.
          Gypsy Moth Summer defoliation (late June, early July) occurs in widespread outbreaks lasting 3 to 10 years. Two or more years of heavy defoliation may cause decline and mortality of oak, and attack by two-lined chestnut borer.

    HAZARD ZONE: South of Eau Claire, Wausau, and Marinette, Wisconsin.

    FAVORED FOOD: Oak, basswood, aspen, white birch, willow.

    HIGH-RISK SITES: Upland, droughty sites with favored food trees in low-vigor, open-grown stands.

    		 ALTERNATIVES:
    ON HIGH-RISK SITES:
    1. Reduce oak and favored component to 25% or less.
    2. Convert to unfavored type or non-timber type.
    3. Accept risk of defoliation.

    ON LOW-RISK SITES:
    1. Maintain proper stocking levels.
    2. Remove "wolf" trees.

    CURRENT OR IMPENDING OUTBREAKS:
    1. Monitor high-risk sites for rising population.
    2. Spray rising populations to prevent outbreak.
    3. Allow population to rise and spray to protect foliage.
    4 . Accept defoliation and monitor for decline.

    		 Gypsy Moth: Forest Influence. R. W. Campbell. 1979. USDA Forest Service Agr. Info. Bull. 423.

    Guides for Predicting Gypsy Moth Damage for Forest Landowners. USDA Forest Service. NAFB/P-25

    The Gypsy Moth: Research Toward Integrated Pest Management. C. C. Doane, ed. 1981. USDA Tech. Bull. 1584. 757 pp.
    LATE SUMMER DEFOLIATORS:
    Oak Skeletonizer
    Red Humped Oakworm
    Orange-Striped Oakworm
    Variable Oakleaf Caterpillar
    Walkingstick
    Oak Grass-hopper
    Actinopelte Leafspot

    Oak Decline

    		 Infrequent outbreaks of late summer defoliation seldom last more than one year. Normally of little concern. However, complete defoliation may initiate branch dieback and decline of low-vigor trees, especially on droughty sites.

    Twig, branch and tree mortality brought on by various stresses especially defoliation.

    		 No practical prevention.
    Insecticide application seldom necessary.

    Maintain vigorous, well-stocked stands. Protect from defoliation. On especially droughty site, convert to alternate species.

    		 Oak Pests: A Guide to Major Insects, Diseases, Air Pollution and Chemical Injury. 1980. J. D. Solomon et al. USDA Forest Service General Report SA-GR11.

    Stress Triggered Tree Diseases, The Diebacks and Declines. D. R. Houston. 1981. USDA Forest Service NE-INF-41-81.
    MAIN STEM PESTS
    Oak Wilt Individual tree and group mortality in spreading pockets. Red oaks more susceptible than white oaks. Prevent wounding during growing season, especially April-July .
    PREVENT SPREAD VIA ROOT GRAFTS:
    1. Cut roots with trenching machine and remove all trees on diseased side of trench.
    2. Create root graft barrier with soil fumigant.
    3. Kill ring of trees outside growing oak wilt pocket with a frill or cut-stump herbicide application. (This method is not very effective. It only delays the spread of oak wilt.)
    4. Consider conversion to alternate species. If valuable species such as red or white pine are growing under oak, then the presence of oak wilt may act as a beneficial agent, releasing the pine.
    		 Oak (Quercus) Disorder: Oak Wilt 1986. G. Worf. 1978. Univ. of Wisconsin Extension Leaflet A1693.
         Two-lined Chestnut Borer Branch and individual tree mortality in pole to sawlog sized trees occurring as scattered individuals and in pockets. Attack usually due to stress:
    1. Trees stressed by drought, overstocking, disease or overmaturity die from the top down in two or thee years.
    2. Trees stressed by defoliation in spring may die in fall of same year.
    3. Trees stressed by droughty site.
    		 1. Maintain vigorous, well-stocked stands; harvest at or before maturity; remove individual low-vigor trees during thinnings.
    2. Harvest dead and partially dead trees before following spring. This will remove the overwintering borer population and reduce but not eliminate risk of further attack. Trees that die in August or September will suffer no wood stain or decay if utilized before following growing season.
    3. Consider conversion to alternate species:
        a. On sandy soil: red, jack or white pine.
        b. On heavier soil: white pine or alternate.
    		 Oak Disorder: Two-lined Chestnut Borer. D. Hall. 1977. UW Extension Urban Phytonarian A2902.
    WOOD BORERS
          White Oak Borer
          Red Oak Borer
          Carpenter worm    		 Tunneling in wood causes serious lumber degrade and decay entry. Attacked trees are often suppressed or diseased. Maintain vigorous, well-stocked stands.
    Remove suppressed and other unhealthy trees.
    Remove brood trees.
    Avoid wounding.
    On poor sandy sites, consider conversion to pine or mixed pine-oak type.    		 Bionomics and Control of the White Oak Borer. J. D. Solomon et al. USFS Res. Paper 50-198.

    Life History of the Red Oak Borer in White Oak. J. R Galford. 1983. Ent. News, 94: 7-10.

    ROOT PESTS
          Shoestring Root Rot
          (Armillaria mellea)    		 Root loss and mortality of pole to sawlog sized trees often following drought or defoliation. Maintain vigorous well-stocked stands.
    Harvest mature trees.    		 Oak Pests: A Guide to Major Insects, Diseases, Air Pollution and Chemical Injury. 1980. J. D. Solomon et al. USDA Forest Service General Report SA-GR11.
    1Source: Wisconsin Department of Natural Resources, Silviculture and Aesthetics Handbook.

    Appendix F. Determining Regeneration Potential

    Return to table of contents


    (Adapted from Sander et al., 1984)

    To determine the potential ability of a stand to reproduce itself, you will need to inventory the advance reproduction and the overstory oaks. If the advance reproduction does not meet the minimum stocking standards, the overstory inventory is used to determine whether there will be enough stump sprouts to make up the difference.

    The advance reproduction is evaluated in terms of the potential contribution of understory stems, after release, to stand stocking at age 20-25. The potential contribution of an individual stem is rated according to its height; this rating is called Stocking Value (SV). Ratings range from SV 1 for stems less than 1 foot tall to SV 30 for stems more than 4 feet tall:

    Height Stocking Value
    of each stem    		 Adequate Stocking
    (no. of stems)
    (class) (feet)
    A < 1.0 1 30
    B 1.1-2.0 5 6
    C 2.1-4.0 15 2
    D 4.1+ 30 1

    An aggregate Stocking Value of 30 for stems in any combination of height classes in a reproduction plot indicates adequate stocking for that plot. For example, 3 class B stems (3 stems x 5 SV = 15) plus 1 class C stem (1 stem x 15 SV = 15) total 30.

    An SV of 30 for all reproduction plots sampled indicates a potential minimum stocking of 220 4.5-inch DBH dominant or codominant oak stems per acre, or C-level stocking (see Appendix G), where the average tree diameter in the stand is 3.0 inches at age 20-25 years. However, a stocking of 154 dominant and codominant trees per acre (70 percent of reproduction plots stocked) is considered adequate. Although this is less than C-level stocking (30 percent stocked), if the trees maintain their crown position, either naturally or by thinning, there will be enough stems to reach B-level stocking when the average diameter reaches 9 inches and A-level when average diameter is 12 inches. Presumably, total stocking will include the projected stocking of dominant and codominant oaks as well as other species and additional oaks in the subordinate crown classes.

    The forester or landowner can set less or more restrictive minimum standards for oak reproduction depending on the management objective. For example, if other desirable species (walnut, white ash, basswood) are present and, in combination with oak advance reproduction, meet the suggested minimum standard, fewer oaks may be acceptable. Moreover, if competition remains under control after establishment of the seedlings, acceptable stocking value can be reduced by half to SV 15. This means that a reproduction plot can be considered stocked if it contains at least one oak 2 feet or more in height, at least three oaks 1 foot or more, or at least 15 oaks less than 1 foot tall.

    FIELD PROCEDURES

    1. Inventory all oaks 1.6 inches DBH and larger on 10 or more 1/20-acre plots (26.3-foot radius). Record these data by species and size class on the "plot tally" lines of the Oak Overstory Tree Inventory form (table 13a, p. 28). This information may be used later to determine stump sprouting potential. Also record the ages to the nearest 20 years of both the overstory (dominant and codominant crown classes) and the understory (intermediate and suppressed) oaks, and enter the oak site index from Appendix B.
    2. Count the advance reproduction on 1/735-acre plots (4.3-foot radius) distributed uniformly throughout the stand and record by height on the Advance Reproduction Inventory form (table 14a, p. 30). The number of reproduction plots to sample depends on the area of the stand:
      Stand area (acres) No. of 1/735-acre plots
      <10 25
      10-30 40
      30-50 60

    3. For each reproduction plot, determine the aggregate SV for oaks. If it is 30 or more, check column E on the Advance Reproduction Inventory form (table 14a). To simplify the procedure, begin with the tallest stems (column D). If at least one stem of this size is present (SV 30; see SV at the head of columns A-D), record as stocked in column E and look no further (see example). If no column D (4.1-foot+) stems are present, go to column C; two stems this size indicate a stocked reproduction plot. And so on. Check column E when SV totals 30 or more. Also record the number of stems by height class, which together provided the SV 30 sum. This information will be used later in selecting the preferred regeneration method. If the SV for oak is less than 30 and other species are acceptable to the owner, repeat the above process for the other desirable species. When SV is 30 or more for the combination of species, including oak, check column F. If undesirable vegetation is preventing the establishment of desirable reproduction or hindering its growth, enter F in column G for ferns, S for shrubs and trees less than 6 feet tall, and T for taller shrubs and trees. Use judgment in evaluating potential competition – look for an understory "canopy layer" or the potential for one developing after the stand is opened up. Base your decision on density, height, and vigor of interfering vegetation.

    Example (based on the sample data in table 14b, p. 31)

    Assume that your inventory has resulted in the entries shown in table 14b. We see that reproduction plot 1 has one tree taller than 4 feet. This immediately gives that plot an SV of 30, so we check column E and go on. Plot 2 has one tree in the 2.1-4.0-foot class with an SV of 15. It also has more than three trees (3+) in the 1.1-2.0-foot class. Three times the SV for that class (5) is 15. The total for plot 2 is thus at least 30, so we check column E again and continue in a similar manner throughout the form.

    CALCULATIONS

    1. Determine the potential stocking from advance reproduction by adding the entries in columns E (and F, if used) and dividing by the number of reproduction plots sampled. If 70 percent or more of the plots are stocked, advance reproduction is adequate and no further calculations are needed. See Strategy for Adequate Regeneration Potential, p. 6.
    2. If fewer than 70 percent of the reproduction plots are stocked, stump sprouts are needed to supplement the advance reproduction. Calculate the projected stocking from advance reproduction by multiplying the percent of reproduction plots stocked by 220 (100 percent stocking). Subtract the result from 154 to find the number of stump sprouts needed to bring projected stocking up to minimum. Referring back to our example (page 31), divide the total number of entries in column E (12) by the number of reproduction plots (20) giving us a stocking percent of 60. Multiply 60 percent by 220 and we get 132 projected stems per acre, 22 less than the 154 needed for minimum stocking. Thus, the stand will be inadequately stocked with advance reproduction and at least 22 stump sprouts will be needed to bring stocking up to minimum.
    3. The number of sprouts that will be available to supplement advance reproduction is calculated from the "plot tally" data on the Oak Overstory Tree Inventory form (table 13a). For each species and DBH class convert the plot tally to number of trees per acre by dividing the plot tally sum by the area sampled. Then determine the number of potential sprouts by applying the appropriate percentages from table 12 to the stems-per-acre figures. Finally, add all the resulting numbers to get the number of sprouts per acre.
    4. Add the projected number of stump sprouts to the projected stocking from advance reproduction. If the sum is more than 154, see Strategy for Adequate Regeneration Potential, p. 6; if less than 154, see Strategy for Inadequate Regeneration Potential, p. 6.

    Example (based on the sample data in table 13a, p. 29):

    1. Assume 10 1/20-acre plots, site index 60, understory age 20, and overstory age 90.
    2. Divide the red oak plot tally for 2-5-inch DBH trees (14) by the area sampled (1/2-acre) to get 28 stems per acre.
    3. Multiply this number by the appropriate percentage for trees less than 60 years old from table 12 (86) to find the number of stumps expected to produce dominant or codominant trees at age 20, i.e., 28 x 86% = 24 (rounded to the nearest whole number). Record this number in the appropriate cell in table 13b.
    4. Compute the corresponding numbers for the other species and diameter classes (age greater than 60 years).
    5. Add the numbers across for each species and then add the sums for a grand total of 29 expected stump sprouts per acre.
    6. To determine whether the number of stump sprouts is adequate to bring stocking up to minimum, add this number to the projected stocking (132) based on the advance reproduction survey (table 14b). The result is 161, more than 154, so stocking is adequate. See Strategy for Adequate Regeneration Potential, p. 6.

    Table 12. Percentage of stumps that will produce at least one codominant or larger stem at age 20-25 years (Sander et al. 1984)

    Species Site Index Age Class (years)
    DBH (inches)
    2-5 6-11 12-16 17+
    Percent
    Red oak all < 60 86 86 86 86
    > 60 49 46 38 24
    Black oak 50 all 30 10 3 2
    60 all 45 15 5 2
    70 all 60 20 7 2
    White oak 50 40 47 18 6 0
    60 25 10 4 2
    80 12 6 3 1
    100 5 3 2 1
    60 40 63 26 9 0
    60 38 16 7 3
    80 19 9 5 2
    100 8 5 3 2
    70 40 81 36 15 0
    60 55 25 11 5
    80 31 16 8 4
    100 15 9 6 4

    Table 13a. Oak Overstory Tree Inventory
    (trees 1.6+ inches dbh)

    1/20 Acre plots (26.3 foot radius) Age: Understory oaks ________________________
    Overstory oaks ________________________
    Number of plots ___________ Site index: Oaks ________________________

    DBH Class-inches
    2-5 6-11 12-16 17+ Total
    Red Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    White Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    Black Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    Other Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    Other Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    All Oaks
        Sprouts/acre          

    Table 13b. Oak Overstory Tree Inventory: Example
    (trees 1.6+ inches dbh)

    1/20 Acre plots (26.3 foot radius) Age: Understory oaks _________20_____________
    Overstory oaks _________90_____________
    Number of plots __10_______ Site index: Oaks _________60_____________

    DBH Class-inches
    2-5 6-11 12-16 17+ Total
    Red Oak
        Plot tally 14 3 3 1 21
        Stems/acre 28 6 6 2  
        Sprouting% 86 46 38 24  
        Sprouts/acre 24 3 2 0 29
    White Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    Black Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    Other Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    Other Oak
        Plot tally          
        Stems/acre          
        Sprouting%          
        Sprouts/acre          
    All Oaks
        Sprouts/acre 24 3 2 0 29

    Table 14a. Advance Reproduction Inventory

    1/735 Acre Plot (4.3-foot radius)

    Column
    A
    B
    C
    D
    E
    F
    G
    Plot Number
    Height Class-Feet
    Plot Stocking
    < 1.0
    1.1–2.0
    2.1–4.0
    4.1 +
    Stocking Values (SV)
    Oak
    Desirable Species
    Understory Competition
    1 5 15 30
    Number of stems
    1             
    2             
    3             
    4             
    5             
    6             
    7             
    8             
    9             
    10             
    11             
    12             
    13             
    14             
    15             
    16             
    17             
    18             
    19             
    20             
    21             
    22             
    23             
    24             
    25             

    Calculations
    1. Plots stocked: __________ ÷ total no. of plots: __________ x 100 = Percent of plots stocked: __________.
    2a. If more than 70% of plots are stocked, no further calculations are needed; see Strategy for Adequate Regeneration Potential, p. 6.
    2b. If fewer than 70% of plots are stocked, continue calculations.
    3. Projected stocking from advance reproduction: 220 x percent stocking
    Projected no. of stump sprouts from Oak Overstory Tree Inventory =
    Total projected stocking =
    4a. If total is greater than 154, see Strategy for Adequate Regeneration Potential, p. 6.
    4b. If total is less than 154, see Strategy for Inadequate Regeneration Potential, p. 6.

    Table 14a. Advance Reproduction Inventory: Example

    1/735 Acre Plot (4.3-foot radius)

    Column
    A
    B
    C
    D
    E
    F
    G
    Plot Number
    Height Class-Feet
    Plot Stocking
    < 1.0
    1.1–2.0
    2.1–4.0
    4.1 +
    Stocking Values (SV)
    Oak
    Desirable Species
    Understory Competition
    1 5 15 30
    Number of stems
    1      1 yes    
    2  3+ 1   yes    
    3        no    
    4     2+  yes    
    5  6+     yes    
    6        no    
    7        no    
    8 15+ 3    yes    
    9     2+  yes    
    10   3+ 1  yes    
    11        no    
    12 15+   1  yes    
    13        no    
    14       1     
    15        no    
    16   3+ 1  yes    
    17   3+ 1  yes    
    18        no    
    19   6+    yes    
    20        no    
    21             
    22             
    23             
    24             
    25             

    Calculations
    1. Plots stocked: ___12_____ ÷ total no. of plots: ____20____ x 100 = Percent of plots stocked: ___60_____.
    2a. If more than 70% of plots are stocked, no further calculations are needed; see Strategy for Adequate Regeneration Potential, p. 6.
    2b. If fewer than 70% of plots are stocked, continue calculations. YES
    3. Projected stocking from advance reproduction: 220 x percent stocking ___60___=____132____.
    Projected no. of stump sprouts from Oak Overstory Tree Inventory =___29___
    Total projected stocking =_____161____
    4a. If total is greater than 154, see Strategy for Adequate Regeneration Potential, p. 6. YES
    4b. If total is less than 154, see Strategy for Inadequate Regeneration Potential, p. 6.

    Appendix G. Upland Central Hardwood Stocking Charts

    Return to table of contents

    Table 15. Relation of basal area, number of trees, and average tree diameter to stocking percent for upland central hardwoods (Gingrich 1971)

    5900t15a.gif - 11.17 K 5900t15b.gif - 9.55 K

    For average tree diameters 7 to 15, use the chart at left; for diameters 3 to 7, use the chart at right. (Average tree diameter is the diameter of the tree of average basal area.) On both charts the area between curves A and B indicates the range of stocking where trees can fully utilize the site. Curve C shows the lower limit of stocking necessary to reach the B level in 10 years on average sites.

    Appendix H. Internal Rates of Return for Selected Management Options

    Return to table of contents

    Assumptions:

    • Rotation: 80 years
    • Thinnings: Ages 30, 40, 50, 60, 70 years
    • Regeneration and noncommercial thinning cost: $60 per acre
    • Market available only for sawtimber

    Table 16. Internal rates of return from oak forests by selected management options, costs, selling prices, and sites (from Utz and Sims 1981*)

    Selling price
    ($/MBF)
    Site Index
    55 65 75 85
    Internal rates of return (percent)
    STANDS WITH $0 REGENERATION COST
    100 7.6 9.6 12.1 14.4
    200 9.4 11.4 14.0 16.8
    300 10.4 12.4 15.2 18.3
    STANDS WITH $60/AC REGENERATION COST
    100 5.5 6.7 7.5 8.7
    200 6.6 7.7 8.5 9.8
    300 7.2 8.3 9.2 10.5
    * Presents internal rates of return and present net worth for 55 management regimes based on differences in site quality, treatment costs, initial treatment age, rotation age, and product value.

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