Crop Tree Management

Transcription

1 Crop Tree Management Crop Tree Release is the selection and release of desirable trees by removing adjacent competing trees in immature stands Purpose --- increase growing space, increase growth rate, increase proportion of highlyvalued species in the stand Criteria --- based on purpose ---

2 References to Review for Exam ations/documents/pb1774.pdf Also located on FWF 312 Web Page

3 free growing space Increase free growing space crop tree initial growing space

4 Divide crown into 4 sides

5 Crown touching release

6 Crown touching release free growing space

7 1 side release 2 side release 4 side release 3 side release

8 Annual dbh growth (inches) Oak Response to Crown Touching Release Data from G. Miller, USFS-NE NRO CHO Number of sides released

9 Annual dbh growth (inches) Yellow-Poplar Response to Crown Touching Release Number of sides released YP Data from G. Miller, USFS-NE

10 Increase free growing space. crop tree Keep your focus on the crop tree!!!

11 Increase free growing space. crop tree

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13 Proper 3- and 4-side release

14 Crop Tree Management In application 1. Target crop trees per acre 2. Use crown touching technique, release on at least 2 and preferably 3 or 4 sides --- judge differences in cost of treatment 3. Remove only trees interfering with horizontal crown expansion

15 Crop Tree Management In application 4. Apply in overstocked, young stands where form or butt log has been established after crown closure 5. Competing trees may be mechanically cut or girdled, and/or chemically (herbicide) removed

16 Crop Tree Management Avoid Trees with Live crown ratios < 33% Intermediate & suppressed crown classes Flat-topped crowns Usually these indicate low-vigor, nonresponsive trees

17 Crop Tree Management Economics Growth rate is enhanced, rotation is shortened Better trees, improved form & grade Better sites Primary Factor ---- Adjusts species composition. Greater proportion of higher-valued species in the stand!

18 When Selecting Crop Trees Look for the Following 1. Valuable species and healthy trees those with potential for further development; 2. Trees with good form, relatively straight and with few forks; 3. Better-grade trees (those with few knots);

19 When Selecting Crop Trees Look for the Following 4. Those whose average age is between years old; and, 5. Those in the upper levels of the forest canopy

20 Wildlife Benefits from Crop Tree Release 1. Dead trees create snags. Snags provide food (decomposing insects), as well as sites for nesting, roosting, denning and perching. 2. Dead trees allow sunlight to reach the forest floor, increasing forage for deer and nesting cover for wild turkeys and song birds 3. Increased sunlight also allows the crowns of crop trees to expand, increasing mast production (acorns, etc.)

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23 Poor Form with multi -sprouts

24 Split, Poor Bole Form

25 LCR too Low

26 Economic Considerations of Crop Tree Release Wayne K. Clatterbuck The University of Tennessee Data Courtesy of Dr. Gary Miller USDA Forest Service Morgantown, West Virginia

27 Factors That Affect Tree Value Species Size Quality Markets Increase dbh growth Improve species composition Improve stand quality

28 Inches 10-Year DBH Growth G. Miller, USDA-FS 5 Control Release Red Oak Yellow-poplar Black Cherry Chestnut Oak

29 Faster Growth 1-inch increase in dbh per decade 5-10% increase in volume and value 3- to 5-year decrease in rotation Reduced risk of mortality

30 Percent Percent of Cost Recovered Due to Faster Growth G. Miller, USDA-FS Red Oak Black Cherry Yellow-poplar Chestnut Oak

31 MBF Stumpage Prices Black Cherry $680 / Mbf Red Oak $380 Sugar Maple $200 Yellow-Poplar $140 Red Maple $120 Chestnut Oak $180 Basswood $100 Birch $29

32 The increase in value of the stand is based the value and growth of species present. Costs are covered with the more highly-valued species, i.e., black cherry in this example $700 mbf, compared to $ mbf for lesser species such as chestnut oak, yellow-poplar, or red maple Thus increase proportion of stand in more highly valued species

33 Improve Species Composition Evaluate potential of the whole stand Limited by initial composition Impact determined by value difference among species Trade up favor high-value, better formed species. Increase the value of the stand by increasing proportion of more-valued species

34 No. Stems/Acre Reproduction* 12 Years After Even-Age Harvest (SI 70) Miller, USDA-FS SM SAS RM NRO YP LOC BC BIR Other Species * Stems 1.0 inch dbh and larger

35 Percent Percent of cost recovered due to species composition 500 G. Miller, USDA-FS Red Oak Black Cherry Yellow-poplar Chestnut Oak

36 Improve Quality Straight stems Clear stems Vigor Potential log height Potential grade

37 Percent Percent of cost recovered due to improved quality 120 G. Miller, USDA-FS Red Oak Black Cherry Yellow-poplar Chestnut Oak

38 Summary Benefits: growth, species, quality Consider whole stand Must trade up for more-valued species to be economical Invest in best trees available Consider risks

39 Risks for Crop Tree Release Epicormic Branching --- Factors include species, genetics, crown position, aspect, density, position on the bole Logging Damage --- size, season of year Condition of Tree --- vigor --- respond to release? Potential for Damage from Ice, Wind, etc. Mortality --- opportunity costs

40 Economics is Real World Increase in Value vs. Costs of Treatment and Potential Risk --- e.g., Rate of Return Practice on better sites Bigger Trees Better Trees More Value??? Faster