r> GEORGIA FOREST RESEARCH PAPER 31 APRIL, 1982 TOTAL TREE AND MAJOR COMPONENT GREEN WEIGHT OF WHITE PINE AND HEMLOCK IN NORTH GEORGIA BY W. HENRY McNAB AND ALEXANDER CLARK III Received RESEARCH DIVISION MAY 3 1988 DOCUMENTS UGA LIBRARIES GEORGIA FORESTRY COMMISSION AUTHORS W. HENRY MCNAB is Silviculturist with the Southeastern Forest Experiment Station at Athens, Georgia. He has a B.S. degree in Forest Management and an M.S. in Silviculture, both from the University of Florida. He is currently a member of the Utilization of Southern Timber Research Work Unit, where he works mainly on problems related to the effects of silvicultural practices on biomass yields and utilization of forest residue. ALEXANDER CLARK, III, is a Wood Scientist with the Southeastern Forest Experiment Station at Athens, Georgia. He received a B.S. degree in Forestry and an M.S. degree in Wood Technology from West Virginia University. He is a member of the Utilization of Southern Timber Research Work Unit. ACKNOWLEDGMENT The authors gratefully acknowledge the support of the Georgia Forestry Commission for this research. A special note of thanks is extended to District Ranger Jack R. McCormick on the Brasstown Ranger District, Malcom L. Jowers on the Chestatee Ranger District, and their staffs, U. S. Forest Service, Chattahoochee National Forest, for their assistance in locating suitable areas and carrying out field work connected with this study. TOTAL TREE AND MAJOR COMPONENT GREEN WEIGHT OF WHITE PINE AND HEMLOCK IN NORTH GEORGIA BY W. HENRY McNAB AND ALEXANDER CLARK III INTRODUCTION Over 30,000 acres in north Georgia are classified in the White Pine-Hemlock forest cover type, where timber stands are predominantly eastern white pine Pinus ( strobus ) or eastern hemlock (Tsuga canadensis) (Knight 1973). This forest type is relatively small compared with other types in Georgia and is concentrated in Gilmer, Lumpkin, Rabun, and Union Counties (Figure 1). Over a wider area in north Georgia, these species occur as scattered trees in mountain hardwood stands. The combined timber resource for these two species is about 9.5 million trees, with a volume of 170 million cubic feet as estimated from the 1972 survey (Knight 1973). Installation of industrial wood com- bustion systems is causing increased de- mand for fuelwood in Georgia (Bulpitt and others 1980). Use of whole-tree chippers to convert unused portions of trees, such as crown wood, and unmerchantable species into fuelwood is a new means of increasing utilization of forest resources (Butts and Preston 1979). The purpose of this study was to develop biomass equations and tables for estimating green weight of the total tree and its components for hemlock and white pine. Biomass equations are available for esti- mating the weight of common hardwood growing in association with white pine and hemlock (Phillips and Saucier 1979). PROCEDURES AND RESULTS Field A stratified sample of 28 hemlocks and 36 white pines was selected from natural, mixed pine hardwood stands in Union and Lumpkin Counties, on the Chattahoochee National Forest (Figure 1). Three to four trees were selected in each 2-inch d.b.h. class from 6 to 18 inches for hemlock and 6 to 24 inches for white pine. The average Girard form class for both species was 79 (Table 1). Site index for white pine at age 50 was about 90.^ The sample trees were felled, measured for diameter, total height, and height to various merchantability limits, and cut into three major tree components: sawtimber, pulpwood, and crown. Saw logs measured to a 7-inch diameter outside bark (d.o.b.) top diameter were cut from trees more than 9 inches d.b.h. Pulpwood only was cut from trees less than 9 inches d.b.h. and from larger trees above the sawtimber top to a 4-inch d.o.b. limit. Crown wood included stem wood less than 4 inches d.o.b. and all the branches. Foliage weight was estimated from sample branches for each tree. Dead limbs were not weighed because most of these would have been broken off of the trees during logging operations. Each component was weighed separately in the field. Data Analysis SAMPLE LOCATION NATURAL RANGE STAND-SIZE AREAS Figure 1. -Natural range of eastern white pine and eastern hemlock in Georgia. Stand-size areas of timber in the White Pine-Hemlock forest cover type are found primarily at higher elevations in the Blue Ridge Mountains. Standard regression analysis was used to develop prediction equations for estimating green weight of the total tree without foliage and green weight of the stem to a 4-inch d.o.b. top. Independent variables were tree d.b.h. in combination with stem height to a 4-inch or 7-inch top. The green weight of sawtimber in trees more than 9 inches d.b.h. was estimated by applying a factor to the predicted stem weight to a 4-inch top. These factors were derived for each species and d.b.h. class by computing the stem green weight to a 7-inch top as a percentage of the weight to a 4-inch d.o.b. top (Figure 2). Both species had about the same percentfactor relationship, probably due to their similar form classes. The distribution of green total tree weight among the major components of sawtimber, pulpwood, and crown is shown in Figure 3. Weight of tree crowns without foliage and topwood can be estimated by subtracting stem weight to a 4-inch top from total tree weight. Estimated foliage weights averaged about 3 percent of the total green weight of wood and bark for white pine and about 5 percent for hem- lock. Yield Tables Yield tables based on d.b.h. and height to 4-inch d.o.b. top and on d.b.h. and saw-log merchantable height to a 7-inch d.o.b. top were produced to estimate the green weight of the total tree and its components for the two species. Tables 2-7 give the estimated green weight of wood and bark for the total tree, stem weight to a 4-inch top, and saw-log weight to a 7inch top for white pine and hemlock. The appropriate prediction equations are included with each table. Yield tables based on other cruise measurements, such as d.b.h. alone or in combination with total height, are available from the authors. Table 1. --Mean dimensions of sample white pine and hemlock, by d.b.h. class D.b.h. class (inches) Sample trees D.b.h. mean Number Inches 6 3 8 5 10 4 12 4 14 6 16 3 18 4 20 3 22 2 24 2 Mean 36 6.1 7.8 10.2 12.0 14.2 15.9 17.6 19.9 22.1 23.6 13.9 Total Height 7-inch top (d.o.b.) WHITE PINE 42 _ 56 -- 73 14 86 34 86 42 92 50 106 67 103 68 104 69 120 95 84 50 4-inch top (d.o.b.) 24 40 56 69 71 77 90 87 90 108 68 Age Form class Years 25 -- 34 - 41 76 52 81 50 77 57 82 60 79 49 80 54 77 72 80 48 79 HEMLOCK 6 4 6.3 46 25 8 7 7.7 48 -- 31 10 3 10.2 67 17 49 12 6 12.0 68 26 52 14 4 14.3 81 43 64 16 3 16.0 89 47 69 18 4 18.2 92 58 76 Mean 31 11.6 68 39 50 57 -- 57 - 56 75 62 77 85 82 97 82 79 79 68 79 100 ^ 95 K | 90 -- ^ 85 -- | 80 is ' u 10 12 14 16 18 20 D. B.H. CLASS (INCHES) Figure 2. --Relationship between tree d.b.h. and sawtimber content for white pine and hemlock. The values are given as the percentage of total stem weight of wood and bark to a 4- inch d.o.b. top. WHITE PINE HEMLOCK 20 30 40 50 60 70 80 PERCENT Figure 3. --Distribution of green total tree weight (without foliage) among major tree components for 14-inch d.b.h. white pine and hemlock. Table 2. --Predicted green weight of above-stump total wood a nd bark without foliage for white pine atid hemlock in north Georgia based on tree d.b.h. and height to a 4-inch d.o.b. top- D.b.h. (Inches) 20 30 40 5 158 221 280 6 214 298 378 7 275 384 487 8 343 479 607 9 416 581 736 10 495 691 876 11 579 808 1024 12 668 933 1182 13 762 1064 1348 14 861 1202 1523 15 965 1346 1706 16 1497 1897 17 1654 2096 18 2302 19 2516 20 21 22 23 24 5 183 6 248 7 320 8 400 9 486 10 579 11 678 12 784 13 895 14 1013 15 1136 16 17 18 19 20 21 22 23 24 256 347 448 560 681 811 950 1098 1254 1419 1591 1771 1959 325 441 569 711 865 1030 1207 1395 1593 1802 2021 2249 2488 2736 2993 --'Blocked-in area indicates range of data. -- Includes 1-foot stump allowance. -3/Y=0.95548(D 2 H4)^^ ^/Y=1.04832(D 2 H4) - 83096 Height to 4-inch d.o.b. 2/ (feet)-- ! 50 60 70 80 336 454 585 729 885 1052 1230 1420 1620 1829 2049 2279 2518 2766 3023 3284 3564 Pounds WHITE PINE-3/ 391 444 528 599 680 772 847 961 1028 1167 1222 1387 1430 1623 1649 1872 1882 2136 2125 2413 2381 2703 2647 3005 2925 3320 3213 3648 3512 3987 3821 4336 4140 4700 4470 5074 4809 5459 5854 495 668 861 1073 1302 1548 1811 2090 2384 2693 3016 3354 3706 4071 4449 4841 5248 5663 6092 6534 90 949 1182 1434 1706 1995 2302 2626 2967 3323 3695 4082 4485 4902 5333 5779 6239 6712 7198 100 1564 1860 2176 2511 2864 3235 3624 4029 4452 4891 5346 5816 I 6302 6803 1 7319 7850 392 530 685 856 1041 1240 1453 1679 1917 2169 2432 2708 2995 3293 3603 3923 4255 HEMLC)CK-' 456 518 617 702 797 906 996 1132 1211 1376 1443 1640 1690 1921 1953 2220 2231 2536 2524 2868 2830 3217 3151 3581 3485 3961 3832 4355 4192 4765 4565 5189 4951 5627 5349 6079 5759 6546 7025 579 784 1013 1265 1538 1832 2147 2481 2834 3205 3594 4001 4426 4867 5324 5798 6288 6793 7314 7850 1117 1395 1696 2021 2367 2736 3125 3535 3964 4413 4881 5367 5871 6394 6934 7491 8066 8657 1851 2205 2584 2986 3411 3858 4327 4817 5327 5858 6409 6979 7568 8177 8804 9449 110 2353 2715 3097 3499 3919 4358 4815 5290 5781 6290 6816 7358 7916 8490 2797 3232 3692 4176 4683 5214 5766 6341 6937 7554 8192 8851 9529 10228 Table 3. -Predicted green weight of stem wood and bark to a 4-inch top for white pine and hemlock in north Georgia based on tree d.b.h. and height to a 4-inch d.o.b. top-- . D.b.h. (inches) 20 30 40 5 103 148 192 6 143 206 267 7 189 272 352 8 240 345 447 9 296 427 553 10 358 516 668 11 425 612 793 12 497 716 927 13 574 827 1071 14 656 945 1224 15 743 1070 1385 16 834 1201 1556 17 1340 1735 18 1923 19 2119 20 21 22 23 24 5 118 169 218 6 163 234 301 7 214 307 395 8 271 388 500 9 334 478 616 10 402 576 742 11 476 681 878 12 555 794 1024 13 640 915 1179 14 729 1042 1344 15 823 1177 1518 16 1320 1701 17 1469 1893 18 2094 19 2304 20 21 22 23 24 H Block ed-in area indicates range of data. --II Includes 1-foot stump, illowance. -/ Y=0.38556(DtH4r- '918 ^Y=0.491 37(D 2 H4) 088255 Height to a 4-inch d.o.b. 2/ (feet) 50 60 70 80 90 235 326 430 547 676 817 969 1134 1309 1496 1693 1902 2121 2350 2590 2841 3101 266 367 481 609 750 904 1069 1247 1436 1636 184 3 2071 2305 2550 2805 3071 3347 Pounds WHITE PINE-3/ 277 318 384 441 507 582 644 740 796 914 962 1105 1142 1312 1336 1534 1542 1772 1762 2024 1995 2291 2240 2573 2498 2870 2769 3181 3052 3505 3347 3844 3653 4197 3972 4563 4303 4943 5336 4/ HEMLOCK- 312 358 431 494 565 648 716 820 881 1010 1061 1216 1256 1439 1464 1677 1686 1932 1922 2202 2171 2487 2433 2787 2708 3102 2995 3431 3295 3775 3607 4133 3932 4505 4268 4890 4616 5289 5702 358 497 656 834 1031 1246 1479 1730 1998 2282 2584 2902 3236 3586 3953 4335 4732 5145 5573 6016 402 555 729 923 1136 1368 1619 1887 2174 2477 2798 3136 3490 3861 4247 4650 5068 5502 5951 6415 729 927 1146 1385 1644 1923 2221 2537 2872 3226 3598 3987 4394 4819 5261 5720 6196 6689 809 1024 1260 1518 1796 2094 2412 2749 3105 3480 3872 4284 4713 5159 5623 6104 6603 7118 100 110 1260 1523 1808 2114 2441 2789 3158 3547 3955 4383 4831 5298 5783 6288 6811 7353 1970 2303 2660 3039 3440 3864 4309 4775 5263 5772 6301 6851 7421 8011 1383 1666 1971 2298 2647 3017 3407 3819 4250 4701 5172 5662 6171 6699 7246 7811 2144 2500 2879 3281 3706 4154 4623 5114 5626 6159 6713 7287 7882 8497 Table 4. --Predicted green weight of stem wood and bark to a 7-inch merchantable saw-log top for white pine and hemlock in north Georgia based on tree d.b.h. and height to a 4-inch d.o.b. top-- . Height to 4-inch d.o.b. (feet)?/ D.b.h. (inches) 20 30 40 50 60 7C 80 90 100 110 9 191 10 275 11 358 12 442 13 528 14 617 15 710 16 17 18 19 20 21 22 23 24 9 215 10 309 11 401 12 494 13 588 14 686 15 787 16 17 18 19 20 21 22 23 24 275 396 516 637 761 889 1022 1160 1304 356 513 668 825 986 1152 1324 1503 1689 1882 2083 307 442 574 706 842 981 1125 1274 1429 396 570 740 901 1085 1264 1450 1643 1842 2050 2265 435 627 817 1008 1205 1407 1618 1836 2064 2300 2546 2801 3066 483 694 901 1109 1321 1540 1766 2000 2243 2496 2757 3029 3309 WHITE pine!/ 512 588 1 739 848 962 1105 1188 1364 1419 1630 1658 1905 1906 2189 2164 2485 2432 2793 2710 3113 3000 3446 3300 3791 3612 3935 4269 4149 4520 4904 5301 HEML 0CK-4/ 567 649 815 1058 933 1212 1302 1492 1552 1778 1809 2072 2074 2376 2349 2692 2635 3019 2931 3359 3239 3711 3557 3887 4228 4076 4454 4844 4580 5248 5664 663 957 1246 1539 1838 2148 2469 2802 3149 3510 3885 4275 4678 5097 5530 5977 731 1050 1364 1679 2000 2331 2674 3029 3397 3779 4175 4586 5011 5450 5904 6373 -- Blocked-in area indicates range of data. ,, -{includes 1-foot 3/Y=0.38556, 20.0 2372 2692 3030 3387 3761 4145 4564 4991 5436 5898 6377 698 816 846 990 1006 1178 1180 1381 1366 I 1598 1564 1 1830 1774 2076 1996 2336 2229 2609 2475 2897 2732 3197 3511 3839 HEMLOCK4-/ 929 1036 1126 1256 1340 1495 1571 1752 1818 2028 2082 2322 2362 2634 2657 2964 2968 3311 3295 3675 3637 4057 3995 4456 4367 4871 4754 5303 5157 5752 6217 1139 1381 1643 1926 2230 2553 2896 3258 3640 4041 4460 4898 5355 5830 6323 6834 -- ,Blocked-in area indicates range of data. --2/ Includes 1-foot stump allowance. ^Y=2.78530(D 2 )-91 74>h)0.45512 i/Y=1.013118(D2)0-91343 (MH) 0.71519 4.5 1112 1349 1607 1385 2183 2502 2839 3196 3572 3967 4381 4813 5264 5733 6220 6725 1238 1501 1787 2094 2424 2776 3149 3543 3957 4393 4849 5325 5822 6338 6875 7430 5.0 1685 1977 2290 2624 2978 3352 3746 4161 4595 5048 5521 6013 6524 7054 1926 2257 2613 2991 3393 3818 4265 4735 5226 5739 6275 6831 7409 8008 5.5 2391 2739 3109 3500 3911 4344 4797 5270 5764 6278 6811 7364 2796 3201 3631 4086 4564 5067 5593 6142 6715 7310 7929 8570 12 Table i'. --Predictec 1 green weight of stem sawtimber wood and bark fo white pine and heml ock in north Georgia based on tree d.b.h. and merchantable height to a 7-inch d.o.b. top--'. D.b.h. (inches) 1.0 9 365 10 528 11 690 12 855 13 1024 14 1200 15 1383 16 17 18 19 20 21 22 23 24 9 276 10 400 11 522 12 646 13 774 14 906 15 1043 16 17 18 19 20 21 22 23 24 1.5 437 632 826 1023 1226 1436 1655 1884 2122 367 530 693 857 1027 1202 1384 1574 1772 Merchantable tree he ight (logs)2--/ 1 2.0 2.5 3.0 3.5 4.0 - - Pounds 496 719 940 1164 1394 1634 1883 2142 2413 2695 2989 449 649 848 1049 1257 1471 1695 1927 2170 2422 2685 549 795 1039 1286 1541 1806 2081 2368 2667 2979 3304 3641 3993 525 760 992 1228 1471 1722 1983 2256 2539 2835 3143 3463 3795 WHITE PINE 3/ 596 639 863 925 1127 1209 1396 1497 1673 1794 1960 2101 2259 2422 2570 2755 2895 3103 3234 3466 3586 3844 3953 4237 4334 4646 4730 5070 5139 5509 5964 HEMLOCK 4/ 597 666 864 964 1129 1259 1397 1559 1673 1866 1959 2185 2256 2517 2566 2862 2889 3222 3225 3597 3575 3988 3939 4394 4318 4816 4710 5253 5116 5707 6176 678 982 1284 1590 1905 2232 2572 2927 3296 3682 4083 4501 4935 5385 5852 6335 733 1060 1384 1713 2052 2402 2767 3147 3543 3955 4384 4831 5294 5775 6274 6789 j 4.5 i 715 1036 1354 1677 2009 2354 2713 3087 3476 3885 4306 4747 5204 5679 6172 6681 797 1152 1505 1863 2231 2612 3003 3421 3852 4300 4767 5252 5756 6279 6821 7382 5.0 1 1420 1759 2107 2469 2845 3237 3646 4072 4516 4978 5458 5956 6473 7007 1622 2008 2404 2815 3242 3687 4151 4634 5137 5660 6204 6767 7351 7955 5.5 2200 2578 2970 3380 3807 4252 4715 5198 5699 6219 6758 7316 2573 3012 3469 3946 4442 4959 5497 6057 6638 7242 7867 8513 --1/ Blocked-in area indicates range of data. -- Includes 1-fooj sjump allowance. nL )n^^< |'y=2.78530< PY=1.03118( D D o2 ) )- 911 3;4^3((MMHH) 1 .0-1.26920((7.0)3- 9 4580/(DBH) 4.07207 - 71515 (1.0-1.26920((7.0) 3 - 94580 /(DBH) 407207 ) )) 13 LITERATURE CITED Bulpitt, William S.; Aton, Carol L; Allen, J. Fred. Industrial wood combustion system. Ga. For. Res. Pap.13, Macon, GA: Georgia Forestry Commission; 1980, 15 p. Butts, Paul M.; Preston, Druid N. Whole tree A chipping... forest management tool. Ga. For. Res. Pap. 4. Macon, GA: Georgia Forestry Commission; 1979. 8 p. Knight, Herbert A. Forest statistics for north Georgia. Resour. Bull. SE-25. Asheville, NC: U.S. Department of Agricul- ture, Forest Service, Southeastern Forest Experiment Station; 1973. 34 p. Phillips, Douglas R.; Saucier, Joseph R. A test of prediction equations for estimating hardwood understory and total stand biomass. Ga. For. Res. Pap. 7. Macon, GA: Georgia Forestry Commission; 1979. 8 p. 14 1:11 3 ElOfl DMSSM ESfl^ 15 GEORGIA FORESTRY A. Ray Shirley, Director John W. Mixon, Chief of Forest Research