Summary Estimates of Forest Resources on Unreserved Lands of the Ketchikan Inventory Unit, Tongass National Forest, Southeast Alaska, 1998

Transcription

1 United Sttes Deprtment of Agriculture Forest Service Pcific Northwest Reserch Sttion Resource Bulletin PNW-RB-233 Jnury 2001 Summry Estimtes of Forest Resources on Unreserved Lnds of the Ketchikn Inventory Unit, Tongss Ntionl Forest, Southest Alsk, 1998 Willem W. S. vn Hees

2 Author Willem W.S. vn Hees is reserch forester, Forestry Sciences Lbortory, 3301 C. St., Suite 200, Anchorge, AK

3 Abstrct Summry Prefce Inventory Are vn Hees, Willem W.S Summry estimtes of forest resources on unreserved lnds of the Ketchikn inventory unit, Tongss Ntionl Forest, southest Alsk, Resour. Bull. PNW-RB-233. Portlnd, OR: U. S. Deprtment of Agriculture, Forest Service, Pcific Northwest Reserch Sttion. 8 p. Summry estimtes re presented of forest resource re, timber volume, nd growth nd mortlity of timber on unreserved ntionl forest lnd in the Ketchikn inventory unit of the Tongss Ntionl Forest. Pcific Northwest Reserch Sttion, Forest Inventory nd Anlysis, crews collected inventory dt from 1995 to Productive forest lnd re (timberlnd) ws estimted t 1,295 thousnd cres, cubic-foot volume on timberlnd t 7,448 million cubic feet, nd net nnul growth nd mortlity t 11,003 nd 50,426 thousnd cubic feet, respectively. Keywords: Forest surveys, timber resources, sttistics (forest), Alsk (southest), Ketchikn. The totl lnd nd wter re of the Ketchikn inventory unit of the Tongss Ntionl Forest is 5,164,000 cres. Unreserved lnds within the unit encompss 2,705,676 cres, 52 percent of the totl. Eighty-three percent (2,256,623 cres) of this unreserved re is forested nd slightly more thn hlf (57 percent) of the forest lnd is timberlnd (1,295,490 cres). Cubic-foot volume on timberlnd is estimted t bout 7.4 billion cubic feet. Nerly 75 percent of this volume is in western hemlock nd Sitk spruce trees. Net nnul growth of growing stock on timberlnd is estimted t 11.0 million cubic feet nd verge nnul mortlity is bout 50.4 million cubic feet. Forest Inventory nd Anlysis (FIA) is ntionwide project of the USDA Forest Service uthorized by the Forest nd Rngelnd Renewble Resources Reserch Act of Work units, locted t Forest Service reserch nd experiment sttions, conduct forest resource inventories throughout the 50 sttes. The FIA progrm of the Pcific Northwest Reserch Sttion is responsible for forest inventories in Alsk, Wshington, Oregon, Cliforni, Hwii, nd the Pcific Trust Islnds. The forest resources on unreserved, ntionl forest lnds within the Ketchikn inventory unit (fig. 1) were smpled with single phse, unstrtified, systemtic grid smple (grid spcing is 2.98 miles). No ground smpling occurred in wilderness res. Ground plots (2.47 cres) were estblished t ech grid intersection nd were subsmpled by cluster of four, 24-foot, fixed-rdius subplots. Three other subplots were sited, one ech t 120 feet north, southest, nd southwest from the first, centrlly locted subplot. Ech subplot ws mpped for lnd cover. Some plots were either entirely or prtilly physiclly inccessible owing to dngerous terrin. For these loctions, lnd cover ws estimted; detiled mesurements of trees nd other vegettion were not mde. These loctions contribute to estimtes of other forest lnd nd nonforest re. 1

4 Smpling Error Estimtes presented in this report re bsed on smpling nd re subject to two types of error. The first is smpling error. This type of error cn be estimted mthemticlly. The second type of error comes from mesurement mistkes or equipment limittions; it cnnot be estimted mthemticlly but is minimized through proper trining, supervision, nd emphsis on creful work. Bootstrp estimtion ws used to estimte smpling error. The bootstrp process is n itertive resmpling, with replcement, of the smple list. For ech resmple, new estimte of the totl is constructed. The mens nd vrinces of the estimted totls provide the estimte of stndrd error. The estimted errors presented in tble 1 resulted from 300 itertions. Sixty-eight percent confidence bnds (one stndrd error) cn be clculted from these figures. Figure 1 Ketchikn inventory unit, southest Alsk, Tble 1 Bootstrp estimtes of the men nd stndrd error for selected forest resource estimtes, Ketchikn inventory unit, southest Alsk, 1998 Resource estimte Men Stndrd error Productive cres 1,302,322 54,996 Nonproductive cres 953,587 54,225 Nonforest cres 449,767 44,988 Net volume (ft 3 ) 7,419,075, ,799,942 Gross growth (ft 3 ) 61,414,744 3,325,562 2

5 Key Findings Eighty-three percent of the Ketchikn inventory unit s unreserved lnd bse of 2,706 thousnd cres ws clssified s forest lnd (2,257 thousnd cres), nd n estimted 57 percent of this forest lnd ws timberlnd (1,295 thousnd cres) Sitk spruce ws encountered rrely s pure type nd ws found on 4 percent of the timberlnd cres. 1 The dominnt forest types, by percentge of re, were western hemlock (40 percent), western redcedr/hemlock (22 percent), western hemlock/sitk spruce (16 percent), nd mixed conifer (12 percent). Although Sitk spruce seldom ws found in pure stnds, the species ccounted for lmost 23 percent of totl net cubic volume on timberlnd. Also, the Sitk spruce forest type produced the highest cubic volumes per cre (9,210 cubic feet). Gross nnul growth per cre ws highest for the western hemlock/sitk spruce forest type (60 cubic feet per cre) followed closely by tht for the pure Sitk spruce type (56 cubic feet per cre). Averge nnul gross growth exceeded verge nnul mortlity for ll forest types except western hemlock, resulting in n verge nnul net growth of 11.0 million cubic feet. Acknowledgments Completion of this inventory, from design through dt collection nd compiltion, resulted from the efforts of mny people. Thnks go to Ry Koleser, dt collection tem leder, nd the dt collection stff: DeAnn Brbri, Aron Bergdhl, Whitney Burgess, Brin Chrlton, In Dolemn, Json Downing, Json Edney, Jhn Hddelnd, Albert Helgenberg, Corey Henderson, Keith Knoti, Dn Kenney, Tristn Kelley, Brd Krieckhus, Teres Lysk, Mry Miller, Frnk Pendleton, Dvid Pierce, Brndy Reed, Julie Roller, Sdie Rosenthl, John Sddler, Chris Teutsch, Dvid Thompson, Fred Thorsteinson, nd August Wright. Thnks lso to Kevin Dobelbower, informtion mngement tem leder, for dtbse development nd field dt recorder nd compiltion progrmming, nd to Edwrd Ezzell for dtbse nd systems mintennce. Literture Cited Viereck, L. A.; Little, E. E., Jr Alsk trees nd shrubs. Agric. Hndb Wshington, DC: U.S. Deprtment of Agriculture. 265 p. Appendix Common nme Scientific nme Nmes of trees 2 Softwoods: Alsk-cedr Chmecypris nootktensis (D. Don) Spch Lodgepole pine Pinus contort (Dougl.) Mountin hemlock Tsug mertensin (Bong.) Crr. Pcific silver fir Abies mblis (Dougl.) Forbes Sitk spruce Pice sitchensis (Bong.) Crr. Western hemlock Tsug heterophyll (Rf.) Srg. Western redcedr Thuj plict (Donn) Hrdwoods: Oregon crb pple Mlus diversifoli (Bong.) Roem. Red lder Alnus rubr Bong. 2 Scientific nmes ccording to Viereck nd Little (1972). 1 Scientific nmes for ll trees re given in the ppendix. 3

6 Tble 2 Are by lnd clss, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Lnd clss Other forest Totl forest Nonforest All Timberlnd lnd lnd lnd lnd Thousnd cres 1, , ,706 (47.9%) (35.5%) (83.4%) (16.6%) (100%) Totls my be off due to rounding. Estimtes re subject to smpling error. Tble 3 Are of timberlnd by forest type, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Forest type Are Thousnd cres Percent Softwoods: Alsk-cedr/hemlock Lodgepole pine 4.3 Mixed conifer Mountin hemlock Sitk spruce Western hemlock/sitk spruce Western redcedr/hemlock Western hemlock Totl, softwoods 1, Hrdwoods: Red lder Totl, hrdwoods All types 1, = no dt were collected. Totls my be off due to rounding. Estimtes re subject to smpling error. 4

7 Tble 4 Net volume of growing stock on timberlnd by species, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Species Volume Thousnd ft 3 Percent Softwoods: Alsk-cedr 715, Lodgepole pine 21, Mountin hemlock 322, Pcific silver fir 596 t Sitk spruce 1,698, Western redcedr 911, Western hemlock 3,761, Totl, softwoods 7,430, Hrdwoods: Oregon crb pple 31 t Red lder 17,611.2 Totl, hrdwoods 17,642.2 All types 7,448, t = trce. Totls my be off due to rounding. Estimtes re subject to smpling error. Tble 5 Net volume of growing stock on timberlnd by forest type, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Forest type Volume Thousnd ft 3 Percent Ft 3 / cre Softwoods: Alsk-cedr/hemlock 227, ,263 Lodgepole pine 8, ,055 Mixed conifer 613, ,110 Mountin hemlock 140, ,508 Sitk spruce 455, ,210 Western hemlock/sitk spruce 1,530, ,488 Western redcedr/hemlock 1,473, ,110 Western hemlock 3,000, ,819 Totl, softwoods 7,448, ,749 Hrdwoods: Red lder Totl, hrdwoods All types 7,448, ,749 = no dt were collected. Totls my be off due to rounding. Estimtes re subject to smpling error. 5

8 Tble 6 Gross nnul growth of growing stock on timberlnd by forest type, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Forest type Growth Cubic feet Ft 3 / cre Softwoods: Alsk-cedr/hemlock 2,186, Lodgepole pine 221, Mixed conifer 6,680, Mountin hemlock 1,102, Sitk spruce 2,763, Western hemlock/sitk spruce 12,178, Western redcedr/hemlock 14,658, Western hemlock 21,637, Totl, softwoods 61,429, Hrdwoods: Red lder Totl, hrdwoods All types 61,429, = no dt were collected. Totls my be off due to rounding. Estimtes re subject to smpling error. Tble 7 Net nnul growth of growing stock on timberlnd by forest type, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Forest type Growth Cubic feet Ft 3 / cre Softwoods: Alsk-cedr/hemlock 278,518 5 Lodgepole pine 208, Mixed conifer 2,330, Mountin hemlock 855, Sitk spruce 1,270, Western hemlock/sitk spruce 7,361, Western redcedr/hemlock 2,974, Western hemlock -4,277,575-8 Totl, softwoods 11,003,135 8 Hrdwoods: Red lder Totl, hrdwoods All types 11,003,135 8 = no dt were collected. Totls my be off due to rounding. Estimtes re subject to smpling error. 6

9 Tble 8 Averge nnul mortlity of growing stock on timberlnd by forest type, unreserved ntionl forest lnd, Ketchikn inventory unit, southest Alsk, 1998 Forest type Mortlity Cubic feet Ft 3 / cre Softwoods: Alsk-cedr/hemlock 1,907, Lodgepole pine 12,628 3 Mixed conifer 4,349, Mountin hemlock 247,355 8 Sitk spruce 1,492, Western hemlock/sitk spruce 4,816, Western redcedr/hemlock 11,683, Western hemlock 25,915, Totl, softwoods 50,426, Hrdwoods: Red lder Totl, hrdwoods All types 50,426, = no dt were collected. Totls my be off due to rounding. Estimtes re subject to smpling error. Glossry Forest lnd Lnd t lest 16.7 percent stocked by live trees of ny size, or lnd formerly hving such tree cover nd not currently developed for nonforest use. The minimum re for clssifiction s forest lnd or subclsses of forest lnd is 1 cre. Rodside, stremside, nd shelterbelt strips of timber must be t lest 120 feet wide to be clssified s forest lnd. Unimproved rods nd trils, strems, nd clerings in forest res must be less thn 120 feet wide to be clssified s forest lnd. (See lso timberlnd, other forest lnd, reserved forest lnd, nd nonforest lnd.) Forest type A clssifiction of forest lnd bsed on the species forming plurlity of stocking on the re currently occupied by tree cover. Growing stock volume Net volume in cubic feet of live swtimber nd poletimber growing stock trees from stump to minimum 4.0-inch top (of centrl stem) outside the brk. Net volume equls gross volume less deductions for rot nd missing bole sections. Lnd clss A clssifiction of lnd by mjor use, such s timberlnd, other forest, or nonforest. The minimum size re for clssifiction is 1 cre. Men nnul increment (m..i.) A mesure of the productivity of forest lnd in terms of the verge increse in cubic-foot volume per cre per yer. The minimum stndrd for timberlnd is the bility to produce 20 cubic feet per cre per yer t culmintion of m..i. Mortlity, verge nnul, of growing stock The volume of sound wood in live swtimber nd poletimber trees dying nnully from nturl cuses during the 5 yers prior to mesurement. 7

10 Net nnul growth The increse in net volume of wood for growing stock trees during specified yer. Components of net nnul growth re () the increment in net volume of trees live t the beginning of the specified yer, plus (b) the net volume of trees reching swtimber or poletimber size during the yer, minus (c) the net volume of trees tht died during the yer. Net volume The gross volume of tree less deductions for rot, sweep, or other defect ffecting product use. Nonforest lnd Lnd tht does not qulify s forest lnd. Includes lnd tht hs never supported forests nd lnds formerly forested where forest use is precluded by development for nonforest uses. Included re lnds used for griculturl crops, improved psture, residentil res, city prks, improved rods, operting rilrods nd their right-of-wy clerings, nd pipeline clerings. If intermingled in forest res, unimproved rods, strems, cnls, nd nonforest strips must be more thn 120 feet wide, nd clerings or other res must be 1 cre or lrger to qulify s nonforest lnd. Other forest lnd Forest lnd not cpble of producing 20 cubic feet per cre per yer or more of wood t culmintion of men nnul increment (m..i.) nd not withdrwn from timber use by dministrtive sttute. Productive forest lnd Forest lnd producing or cpble of producing 20 cubic feet per cre per yer or more of wood t culmintion of men nnul increment (m..i.). Poletimber trees Growing stock trees greter thn 5.0 inches in dimeter t brest height nd less thn swtimber sized. Reserved forest lnd Forest lnd withdrwn from timber utiliztion through sttute or dministrtive regultion. Swtimber trees Growing stock trees t lest 11.0 inches in dimeter t brest height for hrdwoods nd 9.0 inches for softwoods. Timberlnd Forest lnd producing or cpble of producing 20 cubic feet per cre per yer or more of wood t culmintion of men nnul increment (m..i.) nd not withdrwn from timber use by dministrtive sttute. 8

11 The Forest Service of the U.S. Deprtment of Agriculture is dedicted to the principle of multiple use mngement of the Ntion s forest resources for sustined yields of wood, wter, forge, wildlife, nd recretion. Through forestry reserch, co-opertion with the Sttes nd privte forest owners, nd mn-gement of the Ntionl Forests nd Ntionl Grsslnds, it strives s directed by Congress to provide incresingly greter service to growing Ntion. The U.S. Deprtment of Agriculture (USDA) prohibits discrimintion in ll its progrms nd ctivities on the bsis of rce, color, ntionl origin, gender, religion, ge, disbility, politicl beliefs, sexul orienttion, or mritl or fmily sttus. (Not ll prohibited bses pply to ll progrms.) Persons with disbilities who require lterntive mens for communiction of progrm informtion (Brille, lrge print, udiotpe, etc.) should contct USDA s TARGET Center t (202) (voice nd TDD). To file complint of discrimintion, write USDA, Director,Office of Civil Rights, Room 326-W, Whitten Building, 14th nd Independence Avenue, SW, Wshington, DC or cll (202) (voice nd TDD). USDA is n equl opportunity provider nd employer. Pcific Northwest Reserch Sttion, 333 S.W. First Avenue P.O. Box 3890, Portlnd, OR

12 U.S. Deprtment of Agriculture Pcific Northwest Reserch Sttion 333 S.W. First Avenue P.O. Box 3890 Portlnd, Oregon Officil Business Penlty for Privte use, $300