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HomeMy WebLinkAboutDifferential Use of Willow Species by Moose in AK 1979ACKNO\JLEIJGEHE1YrS I would like to take this opportunity to express my appreciation to those who assisted me during the course of this study. Th~ guidance, interest t:~nd critical revie\ .. )f drafts of this manuscript by my major advisor, Dr. Samuel J. Harbo, is greatly appreci<:~ted. I would also like to thank my other committee members, Drs. David R. Klein and Jerry 0. Wolff, foe their words of encour~gement and critical revi~w of this m~nuscript. Sincere thanks are ex~cnded to the other graduate students who expr8ssed interest in this study and often offered words of encouragement. A special worJ of gratitude is extended to Drs. John L. Old.::meyer and Hayn2 R~gel in of the D.:n vee Nild life Reset:~ rch Center, Kenai Field Station, who.were most helpful in the design, logistics and data analysis segments of the study. \ Their experience in .moose habitat evaluation greatly improved the quality of this study. Thanks is extended to the U.S. Fish and Wildlife Service for providing needed employment and logistical support during the course of this study. The financial and logistical support of the Alaska Cooperative Wildlife Research Unit, University of Al~skn ~nd the Institute of Northern Forestry, Fairb~nks is greatly appreciated. Special t~anks is extended to Dr. L.A. Viereck iv TABLE OF CONTENTS Introductit.")n............................................. 1 Study Areas ...........•. 3 Slikok Lake Study Area. . . . . . . . . . . . . . . . . . . . . 3 Harathon Road Study Area ....•••.•....•••.•. 6 ' ) ~l!jicki~rshanl Study Areu .............•.................... 7 t'lethods and Data Analysis. 10 Locatin-g Study Sites ............. . 10 Browse Production and Utilization. 15 Evaluation of Within-species Preference .....•.•.•...... 20 ' ) Pellet Group Counts ............••.••••..•..•..•....•... 21 Tracking .•...•••....• . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 -Protein Conteht S~3mpl in::1.· ........................•..... 22 Snow Depth Sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Statistical Approach .............••............•...••.. 24 Discussion of Results .. 26 Bro~/Se Production and Utilization. 26 Browse Species Preference ...•....••...•....•.....•.•..• 32 Within-species Preference .............................. 35 Pellet Group Counts •..••••.••.••.•..••••••..••.•.•.•..• 46 'l'racking ..•....• . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 Protein Content ...........•••........•................. 51 Snow De p t h . . . . • • . • • • . . . • . . . . • . . • . • . . . • • • . . . . . . . . . . . . . . . 5 8 vi vii Concluding Discussion ...•........•..•.........••..•..•..• 60 BroivSe Production and Utilization ...........•••....••.. 6~J Protein Content ........................................ 67 Factors Influe~cing Betwe2n-species-Preference ..•....•• 69 F~ctors Influencing Within-species Preference •••••.•... 75 Management Implications ..•..•.............••...••........ 86 hf>pen:J.i:x I ••••••••••••••••••••••••••••••••••••••••••••••• !39 Appe11dix II ... ·'· ......................................... 91 Literature Cited ......................................... 92 LIST CF FIC:UF.E2 Fi;ura 1: Lnc~tinn of the ?likok La~~ stu1y area (L) ~n·3 tl1o t1t:rothnn F.nr:·.J stu:.~y area (G)................... 4 Figure 2: Location of the ~7 i·=!-:-:rshai""\ hur.n stu::'iy 2.rea (C) ••••••••••••••••••••••••••••••••••••••••••••••••••• ~ 2 Figure 3: Linear regres~ion relating the 1£76-77 winter browsing to availability for the portion of plant not browsed during the 1975-76 winter. Xl corresponds to the number of stems per plant not browsed during the 1975-76 winter and available during the 1976-77 winter. Yl corresponds to the nucb~r of steres per plant not brnws~d during the !~75-76 winter anj browsed during the 197~-77 wintar. The e~uatinn of the r.egr~ssinn line and the ~ctermin~tion coefficient (r ) are also shown. The dotted circle indicates that more th3n one sa~pling point occurs here .••••••• ~ •••••••••••••••• · 42 Figure 4: Linear regression relating the 1976-77 winter browsing to availability for the portinn of plant br.otr~sed :Juring the 1975-7(:: ~-iinter. X2 corresponds to the nu~ber of steT<s per plant browsed during the 1975-7~ winter an~ avail9ble during the 197~-77 winter. Y2 corresponds to the number of ste~s per plant browsed during the 1975-76 winter and browsed during the 1975-77 w~nter. The equation nf the r.egr~ssinn line and the determination coefficient (r2 ) ~re alsn shown. The dotted circle indicates that more than one sampling point occurs here......................... 4L~ viii TCJble lt:: 7rac:~ i.n-J .!a tA for shrubs brn•.·JS~.:-: over ::; r_::!erc·2~t .3t ti1~ ~~i~!-:·:=rsharn stu:~y :~!-::·=··················· 5:3 \ Table 15: ProtGin c~ntent fnr ~ach S)2Ci~s and sit~ at the ~2nai Peninsul~ stu~y ar23s •.•.•••••••.....•..•. Table 16: Protein content for eac~ s~ecies an6 site a t t h (~ ~ ·; i ~ h: r:? r sham s t u d y a r 2 a • • • • • • • • • . ••••••••••••••••• T~ble 17: Protein cnntent of the tagged plants at the t,.; i c k e r sham stu ·:1 y a r e a • • • • • • • • . • • . • . • • • • • • • • • • • • • • • • • • • . 5 7 Table 18: Snow depth measurements for each site at the Wickersham study area ..•.................•......... Table 19: Drowse cnnsum9tion an~ pellet grnu~ density as indices of. moose use at the ~~ick2rsh3::1 stu:iy area ••• Table 2~: Shrub height .:1ata for Sites l and 2 at the ~arathon Foad study area............................... 71 Table 21: Comparison of twig ~ro~uction during t~e 1976 gro~ing season for stems browsed ~uring the 1S75- 76 winter and those not browsed at the Kenai Peninsula study areas............................................ 79 \ Table 22: Comparison of twiJ 9roductinn during the 1975.growing season fnr stems browse1 during the 1~7~- 76 winter and those not bro~sed at the Wickersham stu ... :ly ~rea •....•.............•...........•..•..... ".... 81 Table 2~: Cbserve~ distribution of pellet grou?s fitted against the expected ran6om distribution for sites 11 and 13 .............................. 0 •••••• Cl • • e. 4 X ) ( ! 2 comm0nly found in random measurements of browse production anJ utilization. Milke (1969) suggested that the probability of utilization associated with a browse plant may be relQted to tlle speci~s composition of brmvse plants in th•: immediate vicinity. A browse plant of a species with low preference may show a higher than expected probability of being browsed if it is surrounded by plant species which are highly preferred. The prcsant study was designed to datermine whether moose show between-species and within-species preferences among willows in two areas of Alaska with. very different moos~ population densities. Protein content as a possible factor influencing preference was also investigated. Dat~ were collected in 1977 and 1978. Fig 1. L()cation ()f the Slil~ok Lakt? study ar~a (A) and the Marathon R()ad study area (B) • \ _, --------··~--~-·--... ·' 8 Fig. 2. Location of the i'iick•=rsham burn study ur.eu (C). ~~ble 1. Dcscri~tion of sites and sampling quadrats for the three study areas. Site Description Dominant BrO\'ISe Species BrovJSe Quadrats Replicate Number Size Pellet Group Quc.:dr<:~ts Repl ic<l te Number Size ------------------------------------------·--~---·------·--·----------------------------- 1 LOVJland; r-larathon R. ,, ~~!:.£!.~Y.!. 20 10 m2 30 lG m2 b. study are.:.; burned in •' arbusculoides ;) . 1969 .Jnd uncrushed; i? • trciiili rorcr;;-s--------------for.merly bli:ick spruce climax. 2 Lowland; <·1a r a thon R. s. £~££!.~Y.!. 20 10 m2 30 10 m2 stuay urea; burned in s. arbuscu.loides 1969 and uncrushed; P'. tremufoid'es-- formerly black --·---------- spruce climax. 3 Upland; Slikok Lake s. Barcloyi 20 10 m2 3" 10 m2 study area; burned in ,. se-s5Tnna u• 1926 and crushed in s. ITarcTa¥I early 196!:J's; formerly P'. tremufoid c s \oJh i te S!:)ruc~ climax. 8. P:~ei~If:££~- 4 'Upland; Slikok Luke s. scouleriana 20 10 m2 30 10 m2 study area; timbered IT. e~elEI£££~-a reo adjacent to Site 3 i white spruce/birch mixture. ---------------------------·--------------------·-------------------------------------- . ~'·')',l.'i' ~~ .• , •• ·-~ •. , :··. ·~ J Table 1. Description of sites and sampling quadrats for the three study ~re~s (continued). Site 5 G 7 8 D•=scr ipt ion Upl~nd; Slikok Lake study area; unburned and crushed in early l960 1 s; formerly white Sf>ruce c.lim~x. Uf>land; Slikok Lake study area; timbered area adjacent to Site 5; white spruce/aspen mixture. Lowland; Slikok Lake study area; unburned ctnd crushed; formerly black spruce climax. Lowland; Slikok Lake study are~; timbered area ~djacent to Site 7~ black spruce climax. Dominant l3rov/Se Species S. bebbiuna s. scouT2rTana s . a.3rcT5¥r--- p. tr8"muToia e s S. scouleriana s. n~r.~ra-y-r--­s. se-G"sra-n-.:1 s. e:~e~~I~~£.£ Browse Quadrats R2plicate Humber Size 20 20 20 20 10 nf Pellet Group Quadrats Ref)lic.Jte Number 30 30 30 30 Size 10 m2 10 rrf 10 m 2 ------------------------------------------------------------------------------------- 'l'.:.ble l. o~~scri;;tion of sites and samplin~J quadrats for the thrf:e study arcns (t.:ontinued). Site 10 11 12 D~scription Upland; Slikok Lake study are~; burned in 1926 and crusncd in the early 1960's; formerly ~hite spruce climax. Upland; Slikok Lake study area; timbered area adjacent to Site 9; white spruce climax. Upland; Wickersham study area; burned in 1971; formerly black Si.)ruce climax. Upland; crushed for fire break in 1971; forillerly bl~ck spruce cl i1nax. Domin.:lnt i3rowse Speci0s . S. scou.leriana s. sarcTayT ___ _ 8. oapyrifcru ~--------- Browse Quadrats Replicate Number Size 20 20 20 Pellet Group •.Juudrats Rcpl ica te Number 30 30 20 . 20 Size 250 r.? I-' w ) distally from the cut ~nd each twig was placed into a diameter class. Each diam~ter class was 0.5 rnm wide with classes ranging from 1.1 -1.5 to 4.6 -5.0 mm. The dpb sam?le of each species and site in question was also partitioned into diameter classes. A sample of twigs for / each species and site suitable for analysis of protein was collected possessing either an identical or proportionately similar diameter distribution as the dpb sample~ The samples were oven-dried, ground through a 40-mesh screen and an3lyzed for crude protein by the macrokjeldahl mathod (AOAC 1960). Four replicates per sample were analyzed. Since the twig quantity was not a problem at the Wickersham study area, the distribution of twig diameters was identical to the dpb sample. Three samples instead of one were usGd for each species and site to permit the cal~ulation of variance. The samples were analyzed for cruJe protein level as above except the number of replicates per sample WdS three. For all study areas, only current annual growth twigs were collected. The above methodology represents an attempt to assess the protein level of browse consumed by moose. For those spe~ies where second-year growth is eaten in addition to current annual growth, the results may be misleading. A similar probl~m was discussed earlier concerning the Shafer twig-count method. Since the second-year growth twigs prob~bly contain less protein per unit weight than the 23 ' ) ' ) current ~nnu~l growth (Cowan et al 1970), the results obtained may tend to overestimate protein levels of browse consumed by moose for applicable species. During 10-11 April 1978, twi3 samples were collected from the tagged plants ~t Sites 11 and 12 for protein analysis to determine whether protein level is related to browse history. Only plant pairs where one plant was browsed during both the 1976-77 and 1977-78 winters and the other plant was not browsed both winters were sampled. Thirty or mGre current annual growth t'.'ligs 3.0 mm in diameter clip!?ed from each plant constituted a sample. Replication was three per sample a~d the protein analysis followed the procedure outlined above. On 10 March 1978, snow depth was sampled at the four sites at the Wickersham study area. Fifty me~surements were taken at each site in a random s~mpling procedure. Since thaws were rare for the Interior for that winter and snowfall after 10 March was minimal, the snow depths taken were assumed to be the deepest moose would face during that All statistical proc~dures were according to Zar (1974) and Freese (1962). In situation~ where I suspected the ~ ) 25 assumptions of normality were not justified, nonparametric tests were preferred over their parametric counterparts. For goodness-of-fit tests, the chi-square statistic was used. If expected frequen~ies tended to be small ( < 5.0), the lo3-likelihood statistic (G) was used instead. _If any expected frequency fell below l.G, the test was not done. Significance level for all statistical tests were set at the 0.05 level. ) 'l'abl0 .., ,.) . Browse production and utilization for the Kenai. Peninsul.:t .study nreas (~ standard error). -------------------------------------------------------------------------------------- •.rotal 'I'w ig s 'l'o tal 'l'wig s Available Browsed Product ion Utilization Percent Chi-a: Site Species Year per ~ ocr .. m2 (kg/h~) (kg /ha) Bro•,.,scd squure ------------------------------------------------------~-------------------------------- 1 Bare. 1977 6.09 1. 39 0.56 0~17 72.4 22.6 G.7 2.5 9.2 1.9 14. 4 7b 1978 4.32 1.14 0.21:) 0.03 51.3 17.9 2.4 1.1 4.6 1.6 3ebb. 1977 0.35 lJ. 29 0. Hl :J.08 2.7 2.6 0.8 0.7 23.7 1.6 Arbu. 1977 2.19 1.32 0.65 0.38 50.2 38.8 14.9 11.2 29.7 4.5 123.34b 1978 4.44 1.18 0.26 0.16 102.2 3G.1 5.7 4.2 5.7 3.2 2 Burc. 1977 20.12 3.19 2.97 ~L 74 247.4 55.4 36.5 11. 4 14.7 3.1 1978 20.55 3.87 3.05 0.88 252.8 ()3.2 37.5 13.5 14.8 3. 1 Bebb. 1977 8.18 (:).18 ,, . 03 tJ. 03 1.4 1.6 0.2 r.J. 2 13.9 0.1 1978 ~i. 0 6 0.04 0 0 N.D. N.D. 0 c'\rbu. 1917 1. 51 0.61 0.62 (!). 29 22.2 12.0 9.U 5.4 40.7 7.6 1978 2.41 1.10 0.47 0.31 35.4 21. (J 6.8 5.5 19.3 6.2 3 Scou. 1977 8.91 1. 4~ 5.74 1. 03 204.9 59.1 132.0 39.9 64.4 2.5 Bare. 1977 0.23 0.14 O.OG 0.06 N.D. N.D. . 26. 1 12.4 a Chi-square was used to test for differences in percent utilization between years for a site und species. b Signific~nt at the .05 significance level. t:i.01 30.78b .I Table 3. Drowse production and utilization for the Kenai Peninsula study areas (:t standard error) (continued). Site Species Year Total Twigs Availab~c per m To t a 1 '1"11 i g s Browses per m Production (kg /ha) Utilization (kg./ha) Percent Brows~d Chi-a· square --------------------------------------------------------------------------------------- 3 I3ebb. 1977 0.90 0.35 0.51 0 .• 20 11. 3 5.5 6.4 3.2 56.7 4.6 4 Scou. 1977 0.32 0.12 9.10 0.08 9.6 5.6 3.1 2.9 31.7 17.2 5 Scou. 1977 0.17 0.10 0.05 ~~.114 N.D. lJ. D. 30.3 11.4 13. 56 1978 0.06 0.04 0.03 0.02 N.D. N.D. 45.4 9.6 Bare. 1977 IL 66 0.36 0.09 0.07 N.D. N.IJ. 13.6 6.1 e. 4 4b 197SJ ~.72 11.32 0.03 0.02 N.D. N.D. 3.5 1.8 3abb. 1977 2.51 0.49 0.54 1L14 36.3 11.9 7.8 3.1 21.5 3.9 15. 79b 1970 4.11 ll.6:?J 0.52 n.o9 52.5 12.5 6.6 1.7 12.5 2.3 ,.. Scou. 1977 0.14 0.07 0 N.D. N.D. 0 IJ 1978 0.05 ll. 0 3 !:J.Ol 0.01 N.D. H.D. 10.0 6.3 l3arc. 1977 0.58 0. 24 !L04 fJ. 02 N.D. N.D. 7.0 4.3 8. 59 b 1978 l. 24 0.70 0.02 I.J. (ll N.D. N.D. 1.2 ~L 9 Babb. 1977 0.23 0.09 0.01 J.Ol N.D. N.D. 2.2 1.9 1978 ~.69 !3. 21 0.01 0.01 9.1 3.5 N.D. 7.1 4.7 -------------------------------------------------------------------------------------- achi-square \'las used to test for differ-ences in percent utilization be t\veen years for a site und S?ecies. bsignificont <Jt the .05 significance level. . ,, ~ ~ ,, t·. r:· 1\) ()) TQble 3. Browse production and utilization for the Kenai Peninsula stujy areas (:_t Gtandard error) (continued). -------------------------------------------------------------------------------------- ·rotal •rvJ ig s Total '1'\-iig s Available Browsed Production Utilization Percent Chi-m Site Species Year per m2 per m2 (kg/ha) ( kg/ha) Drmvsed square -------------------------------------------------------------------------------------- 9 Oebb. 1977 2.87 8.65 1. 42 0 .• 42 27.8 8.4 13.8 5.2 49.6 6.3 1978 2.79 0.41 0.72 0.15 27.1 6. 4 7.0 2.1 25.9 2.9 Hl Scou. 197i ;).09 0.01 0.04 l1. 0 2 1.3 0. 3 0.6 0.4 47.1 20.6 1978 0.07 0.05 I} (3 ~.9 0.1 f1 0 0 0 Bare. 1977 0.24 l). 20 0.02 0.04 N.D. N.D. 6.3 1.8 a Chi-square was used to test for difference!3 in percant utilization between years for a site and species. b Signific~nt at the .05 significance level. 41.92 b w 0 'i'.:t bl e 4. Browse production and utilization for the Hi.ckersharn burn stuCly arecJ· {:t_ stund~rd error). -----------------------------------------------------------------------------·--------- 'l'o ta 1 'l'\v ig s 'l'o tit 1 T\·i ig s Av.::~ilable Browsed Production Utilization Percent Chi-a Jite Species Year per m2 per m2 ( l~g/hu) (kg/ha) Br ov1scd square ---------------·--------------------------------------------------------------------..... --- 11 Scou. 1977 8.89 1. 93 0.08 "~06 75.6 30.6 0.7 0.6 0.9 0.6 999.36b 1978 7.35 l. 59 1. 22 0.34 69.9 21.0 11.7 4.2 16.7 4.1 12 Scou. 1977 1. 76 0.95 0.28 0.17 14.9 Hl. 8 2.4 1.9 15.9 7.G 0.06 1978 0.13 !1.13 0.02 H.02 1.0 l.C !3. 2 0.2 16.0 0.3 Plan. 1977 6.40 1. 87 1. 71 0.56 67.2 27.3 17.9 8.0 26.6 3. 3 419~4Gb 1978 5.51 l. 56 0.43 0.20 47.6 10.:1 4. 1 2.1 8.6 3.0 13 Alux. 1977 27.10 5.37 10. 2~j 2.18 213.8 69.5 11a.2 32.7 37.7 4.3 13.88 b 1978 14.94 3.08 7.50 1. 91 111.9 34.1 56.4 19.8 50.2 S.G .f>lan. 1977 12.60 3.94 1. 55 0.68 99.3 36.2 11.2 5.8 12.3 3.2 6.12 1978 11. 37 3. Hl 2.93 0.72 81.3 29.3 21.2 7.1 26.3 G.9 iiust. 1977 8.80 2.67 IL 55 0.23 N.D. N.D. 6.J 2.1 0.01 1978 5.05 l. J9 g,J2 ~). 12 H.D. N.D. 6.2 1.6 14 Scou. 1977 1. 01 0.27 0 0 8.G 3.8 0 0 0 {] 20.5Gb 1978 1. 48 0.18 0.01 0.01 13.9 2.9 ILl 0.1 . ~j. 8 0.8 achi-square was used to test for differences in percent utilization between years for a site and species. bsignificant at the .35 significance level. = w ,.._ _ . ........_ ......... _______ _ J ) T~blc 7. Two by two contingency tables for within-speci2s preference at the Ken~i Peninsula study areas. Sit~ Species 1 2 3 4 5 7 9 s. Bare. , .. ., . arbu. s. Bare. s. arbu. s. scou. s. scou. s. Bare. s. bebb. s. scou. s. be5b. s. scou. Bro~;sea· History Status of St:ems 6 u u B u B u B u B u B u B u B u B u B u No. of Stems Brov1sed During 19 7 6 - 7 7 ~'Ji n t e r Obs. 31 16 125 122 34 lv 226 ., .) 4 1 6 2 41 3 11 0 3 ..• 'J 298 23 Exp. 12.2 48.8 21.7 25.3 58.5 lCD.S 2G.3 17.7 22G.2 8.8 2.9 2.1 3.0 5.0 39.8 4.2 7.1 3.9 1.7 1.3 284.1 37.0 No. of Stems Not Bro\·/3ed Durin:J 1976-77 ~Hnter Obs. 23 151 13 32 67 496 12 21 25 7 G 6 3 13 64 8 27 21 22 19 94 28 Exp. 34.8 139. 2 19.3 22.7 133.5 429.5 19.7 13. 3 30.8 1.2 7.1 4.9 6.0 10.0 65.2 6.8 38.9 17.1 23.3 17.7 108.0 14.1 G-b statistic 17.517 16. I} 4 !·i 133.879 13.378 19.259 1. 395 7.315 o.Gl2 7.424 2.447 19.384 a i3 = Brov1sed durin') the 1975-76 wintG:r. U = Not browsed during the 1975-76 winter. b Value of G at the .05 si~nificance level is 3.841 37 '1''-!ble 7. (continued). 'l'\vo by t\·Jo contingency tables for within-species preference at the Kenai Peninsul~ study areas. ----------------------·--:.--------------------------------------- Sit,~ Species 9 s. Bare. s. bebb. Browst::a History Status of Stems B u B u No. of Stems Browsed During 1976-77 ~Vinter Obs. Exp. 4 3.8 4 4.2 78 68.1 1 10.9 No. of Stems Not Bro'.·JSed During 1976-77 ~Hn ter: Obs. Ex!?. 8 8.2 9 8.8 22 31.9 15 5.1 G-b statistic 0.019 32.389 aG =Browsed durin~ the 1975-76 winter. U =Not browsed during the 1975-76 winter. bva1ue of Gat the .~5 significance level is 3.841 r ' constructed for each species and site (Table 8). The categories used are: BB = Numb~r of stems browsed during the 1974-75 and 1975-7G winters; UU = Number of stems unbrowsed during the 1974-75 and 1975-76 winters; ua = Number of stems unbrowsed durin3 the 1974-75 winter and browsed durin3 the 1975-76 winter and; BU = Number of stems browsed during the 1974-75 winter and unbrowsed during the 1975-76 winter. The G statistic was again used due to an occassional low expected frequency value. In 4 of 5 species/site combinations, G is significant. In 3 of the 4 significant combinations, category BB stems were browsed more than expected during the 1976-77 winter. Also, in 3 of the 4 combinations, category UU stems were browsed less than expected during the 1976-77 winter. In 1 of the 4 combinations, category U3 stems were browsed less than exp2cted, and in 1 of the 4 combinations, category BU stems were browsed more thQn expected. The pattern suggests a decided preference by moose for stems browsed yearly. To ascertain whether selection is occurring within plant, between plant or both within and between requires a ~~ble B. Avail~bility-utilization chi-syuare tables for evfiluuting within-s~e:cir.:s fJl'·::ferr:nce ,:_ti: trw ~hcl~~!rsh:>m study .:H.::.::;. Exp•.:ct0d fruqu~nci.::s and proportions ware b~sad upon the r~lative quantities of stems avai1~ble from 0u~h cdtegory. Cdtegory b I.;>efA~cted r· .. o .c of of Stems S i tc Species Stem Drowsea Cbscrv-:d No.c Exp~cted of Stems Proportion Browsed Browsed CJbserveaa J? r o ~or t ion Bro·wsed + 95!6 c.r: G- statistic -----------------------------·-·-------·-·---·---------------------·----------·---- 11 Scou. BB 2.~ 5 0. 11 0. 28 ~j. 27 9. 6 c;d uu 9.8 4 U.54 ~:). 2 2 U.25 uo 3. 1 .., 0. 17 ~). l 7 0.22 ..J DU 3.2 6 0. ] 0 .u 0.33 ,;. '),... u • .c.O 12 :.Jcou. co 8. 1 19 0.1;1 !;i. J 3 0.15 17. 60d uu 3•L 6 29 u.GfJ iL 50 O.lG UB 11. 1 7 \1.19 0.12 0.11 BU 4. 2 J 0.0/ ~1 • [) 5 !.1.07 Pl.:!n. BC 2J • 2 42 0.07 0.13 0.05 7 7. 4 3d 0U 21J.G 142 :.}.67 u. 44 0.G7 UB 9. 9 9 n.o3 !L ljJ I;;. 02 BU 4 .. 'J i:J r, C:: 0.41 U.l.:l7 • L. ..; I • ~,".) aGbs2rved prc)portion bro~vsed .::!: 95 percent confidence intcrvul. b DB = Stems browse.j during the 1S74-75 an:l 1975-76 vJinters. UU = Stems not brovi5t.?CJ Juring ti:ic 1974-·;s and 1975-76 winters. UB =Sterns not browsed during the 1974-15 winter and bro~sed during the 1975-7G wincer. BU =Stems browsed Jurin·3 tile 1974-75 ;,dnter <111cl not brO\'iS.2d during the~ 1975-7u ·.vinter. C.lJt:ctuins to stG:m3 br<HJsed during the l'.J./G-77 ~<linter. dsignificant ~t the .05 significance level. l r l 1 ~. I ! • l t i. t i I ~able 8. n~ailability-utilization chi-squ~re t~bles for ~valuating within-species preference at the Wickersham sludy area. Expcctuj froqu.::ncL:s and proportions \•!cr.:! b;)Sf~d UiJOn tn~ relativ·2 yu~ntities of ste1.1S avi~il.:lblc troi11 c<.1cb Ci)t0-3ory (continued). -----·------·---------------·----------------------·-----------/--·-----·---------·--·------ Ci!teyory b B;<pected No.0 Ob3ervcd No.c ~xpected of of Stems o£ Stems Proportion Site Species Stem Browsed Browsed 13 Alax. 813 6 (1. 3 U7 0.37 uu 40.2 25 0.25 08 48.4 33 ~j. 3 ~J 80 15.1 1 g 0.09 Plan. EB C:J (j iJ uu 41.7 35 0.65 UB 5.4 Hi 0. 11 BU 1.9 4 fj • (J 4 a Observed proportion browsed ± 95 percent confidence interval. Observcda Proi.Jortion Gro1·1Sed + 95!2. c.r-:- 0.53 0.10 0. 15 O.fl7 u. 20 IJ. OS 0.) 2 ~). G 6 0 0.71 0.28 !} • (:j 8 G- statistic d 23.46 7.29 b BB :::Stems brows2d during the 1974-75 and 1975-76 wint-=rs. Ull =Stems tlOt browsed during the 1974-75 ~nd 1975-76 winters. UD = Sterns not brows2d during the 1974-75 ~~inter and brov;sed dur inq the 1975-76 winter. BU = Stems· browsed durin3 the 1974-75 winter and not browsed during the 1975-76 winter. c Partains to stems browsed during the 1976-77 winter. d Significant at the .05 significance lev~l. F i.']. 4. Lin2ar regression rel~ting the 197C-77 winter :.:JJ:o\·;sing to a·.;:..ilability for thE:: portion of plaut browsed ~'-lrin; tlle 1975-76 winter. X2 corr~sr:.onds to tile: nu;nb::::r of ~·:J.:lilable: durii1~ t~1<2 1976-77 •.vin'.:cr. Y2 corr~sponds to ~he: . l. f2::Jr':!:3GlOn. lnL: and the jet~rmin~tion cocfficianl ( l-2 ) are ~!so sho~n. ~he jotted circle inJicates that more than one I ;::.a.TttJlln:J point occurs her:.!. instead of stems. The chi-square statistic is significant (p < .001). An inspection of observ2J and expected fr0qu·2ncies reveals that plants bro\·Jsed durin9 the: 1975-7G winter sustained proportionately more browsing the following winter than those unbro0sed. The results from plants tagged at Sites 11 and 12 showed a similar trend although the results were not significant at the .OS significan~e level (T.:ble 10). 46 Mean pellet group counts varied from 0 to 600 groups per ha for the Kenai study areas (Table 11). For the 1976-77 winter, Site 3 ranked highest, Site 9 was next and the: remQining 8 sit~s ranked together as the last group (Kruskis-~vc.l1is, p < .05). For the 1977-78 winter, Si':es 2,9. and 10 ranked higher than Sites 1,5 and 5 {p < .05). Between year comparisons showed that, for all sites, the pellet group density did not change fro~ year to year (.09 < p < • 7 3) • For tl1::~ \H;;kersnam study area, the counts were 1mver than those from the Kenai Peninsula study areas ranging from 2 to 52 groups per ha {Table 12). Site 13 ranked highest; Site 12 was next and Sites 11 and 14 ranked last for the 1976-77 winter (p < .05). For the 1977-78 winter, Site 13 again ranked highest; Site 11 was next and Sites 12 and 14 ranked last (p < .OS). Between year comparisons showed that ~cibl~ 11. Pellet grou~ counts for the Kenai Peninsula study aceas. Sit·~ Yeur 1 1977 1978 2 1977 1973 1977 4 1977 5 1977 1Y7.8 G 1977 1978 7 1971 1977 1977 1978 1977 1978 t·lci.ll1 Nu:i1b0r of P-;.::11"-.:t Groups por h~ <t St~nd~rd error) 5 ... v (50) , :.J 100 ( 7 ~j) 1 .... -> .) _} ( 6 3) GJ ~j ( 16 3) 1 ~j~j (5G) -. ..., (33) J .) {~ f.-i " f1 33 (33) " u 333 ;: 3 3) 1G7 ( (3 4) 33 (56) 100 (56) --------------------·--------------------------------------- 49 \ f t l I I. ~0blu 12. Pel1ec group counts for th~ Wickersham study ~re2. Site Ye.:::.r 11 1977 1970 12 1977 1978 13 1977 1978 14 1977 1973 ~e~n Number of P2llet Groups per h~ (~ StDnd~rd Error) G { 6) 42 ( 7) 2 ~J {9) 14 { 5) S:J (10) 52 ( 10}. 0 6 { 4) 5o '1\")t;::l No. of f'li::lnt.s Gbse:rved l\o. of Plants Cbscrv,~d ho. o£ !'l a11 ts SrovJSC::i E:xpect-<::!::3 Proportion Br0~s2~-1 Observ-:.::ja i'rOf·Or tio:-~ Bro·,·iseJ + 95~ C.j,. 137.G 144 .U. 5S G.62 52 liD 131 41.6 52.9 83 5 0.18 G.23 {1.36 0.02 (.08) (.~·32) acbs~rv~d proportion browsed + 95 percent confidence interv~l. 54 not been adequately accounte::l for. Conclusions should b~ ~valuated in this light. The results of protein analysis at the Wickersham study area are shcrwn in Table 16. The range of values is much narrower than those found at the Kenai study areas. The nighest value was 6.9 percent and the lowest was 5.3 perc~nt. Since three samples instead of one were submitted for orotein d~terillination for each species and site category, l was able to calculate an estimate of variability as8ociated with the mean. Each percent value was transformed by the arcsin transformation to allow the use of parametric H:~th,">ds of statistics (Zar 1974). ~-lean protein levels ~-;ere not significantly different between species and site categories (Nested one-way ANOVA, .20 < p .50). Results of protein evaluation from the tagged plant ex 9f! r imen t are shown in Table 17. Six pairs of S; olanifolia --L----~----- s:H ubs and five p.a irs of ~. ~£~~!:~~!:_~!]_~ shrubs \ve r e S.:lffi!?l ed. For s. E!:.£!2..!:.f~ll:_~, mean values rang2d from 4.9 to 5.9 ' p~rc~nt for plants browsed both the 1976-77 and 1977-78 winters and from 4.8 to 7.2 percent for plants browsed neither wint-:r. Values for ~-~£~~l~E.!:.~~~ ranged from 6.0 to 5.7 percent for plants browsed both winters and from 5.6 to 5.7 percent for plants browsed neither winter. All percent data were transformed by the arcsin transformation. For both species, protein content was not significantly different between th0 browse categories (paired t-test, ~ablG lG. Protein content for each species and site at th2 Wickersham study area. Prot~in Content (percent t Standard Error) .sit·~ .S. scoul-eriana S. alax~nsis 1 5.6 y). 2 N. D.a N.D. 2 5.3 0.2 5.4 0.4 N.D. "") N.D. N.D. 6.0 0.1 ,J t. 5. 4 ll.l N.D. N.D. a D..:t t.:·, not a v .::t i L.iblc:. .56 CONCLUGING DISCUSSION Crowse Production and Utiliz~tion Lrowss production is within the r2nge of that observed by other workers in Alaskd. Milke (1~69) founj willow projuction available as browse for ffiOose to ~~erage 2J3.S kg/ha at his Interior floodplain study area. Wolff (1975) found for his rip~rian, floodplain study area that willow production aversgej 31.45 kg/ha for ~n C-year-old st~nd and 99.35 kt;J/11<.:. for. a 15-year-oJJ stand. I found for my rip.Jrian sit•~ (S1 te 13) thz.t productioii av,:ragGd 325.7 .:.n.J 1S3. 2 kg/ha respectively for the two yedr period. Results of ~11 t I three studies show that S. olaxensis dominateJ the p r o c1 u c: t i c) n a t I n t e r i o r r i r-<': r i .:o. n s i t e s i n b~ r m s o f b i o :n a 3 s • Pro::Juction of 5. scoulerian~ ~t l)ld Interior burned regrowth and 75-ye~r old mature spruce site w~s found to av2rage 52.5 anj 21.1 kg/ha respectively (Wolff 1978). These values co~p&re f~vorably with those I obt~ineJ for a similar burned rGgrowth site (Site 11) and for a timb~red sitG (Site 14) at the ~-;ic}~e:rshaill study area ('I'able 4). The upland regrowth ranges ~t the Slikok L3kc study v.rea app03r to b·~ more productive than th~ir cou,~terp .. .Jrts at ~i~kcrsham. 1h2 hig~est level of production observed at the tvickersh::.rn .study C~rea w2s 75.G kg/ha for.§_. ~-~ule.!:~.§..~~:=_ (Table 4). The highest lev2l of production of S. scoulc:riana ~t a compar~ble site at th~ Slikok Lake study area was 2~4.9 62 thc.;t <.t r<::mov.:;l of SC percent mz,y be: optiri1;il for a m.::xiwum sust~in~d yield of hard~Jod browse (Spencer and Chatelain lS53, Krofting ~tal l9GG, ~olff lS7G). Moose appear to browse the upl~nds ranges more intensively at the Glik~k Lake study area than at \·;ickc:rs!vnn. 'l'he highe:st utiliz2.tion percent<1g.:.: for the Slikok L~ke study area was 64.4 p~rcent and the highest rc~cordec for comp.::rable: uplan::: sit12s ;.lt tlK \dckcrsl1<lm study dr2~ was 26.5 per~ent. Crete and Au~y (1974) hypothesized th~t high browsing in~ensiti~s arc rel~ted to high mean dpb and 11 possess nearly id~ntical densities of ~-!£~~!~!!~~~ twigs (Tables 3 ~nJ 4) but tb2 percent utiliz~tion and rn~an dpb's ar2 different (Appen~ix I). Percent utilization (or Sitt:! 3 is (j4.4, for Site 9, 53.4 .:.nd 43.4 ,:;n:J for Site 11, G.S• :.nd 1G.7. 'HH? mean :Jpb for Sitr::: 3 is 3.6 mm .:;nj the mean dpb's lumped over th~ two seasons at Sites 9 and 11 are 3.3 an:.~ 3. J. m.-n respectively; trH~ three mee1ns arc significantly different from c~ch oth0r (ANOV~ ~nd Neum~n-Kuels, p < .05}. ~he diff~renc~s in ms~n dpb ~re r~flected in v~stly differe:nt estiin.::tt•2S of biom.:,ss pro<'lu(;•.::c1 and utilized. Site 9 shows ct utilization level 1[ to 2C percentage points lower th~n Site 3 but the utilization level in terms of biom~ss Eo r S i t c 9 is c: bn u t one-h c:t l f t h.:. r for S i t e J • 'l'h e d i f f <~ r E: n c e bctwe~n Site 3 ~nj 11 is ev~n more pronounc~d. In spite of similar numb~rs of twigs dV~il~blc, 2v~il~bil ity in t~rms ) th~n normal, snow depth p~tterns did not depart subst~ntially fro~ that st~ted above. Kelsall (1969) cl~ims that spatially concentrated browse offsets the high energetic cost of moving through snow. In a winter range of high snow accumulation, moose would tend to concentrate in tnose areas where browse is abundant and snow depth is low. Site 13, a lowland riparian site, had by far the lowest snow accumulation (T~ble 18), a density of willow twiqs two to three times higher th~n the upland sites ~nd the highest utilization levels recorded for the Wickersham study area. lt is interestin3 to note that Site 13 compares favorably with the upland Sites 3 an_d 9 in terms of bio;nass utilized, availability and percentage utilizad. Lower snow accumulation may give the studied uplan~ ranges at Slikok Lake greater value as winter range than the studied upland ran;es at Wickersham. Possible reasons for th2 lower utilization percent le~els observed durin3 the 1977-78 winter at the Kenai study areas are not clear. Setting 0.2 mas the minimum browsing height may·be one cau3e. That criterion was used during both winters and w~s based upon measurements from all sites taken only for the 1976-77 winter. Snowfall accumulation on the K~nai Peninsula was much greater durin3 the 1977-78 winter than it was during the 1976-77 winter. (Oldemeycr, personal cn~munication). Although moose were observed pawing through snow for browse at the Kenai Peninsula study areas, such 'l'::.d::le 19. ErovJS2 consumptinn und p(!llct group density as indices of moose us8 at the ~ickccsham stu-Jy z:tro::a. fti. D. /haa (5roNse Consumption . Da t.:t) t':. D. /ha (Pallet Group Data) ·---------·----------------------------------~---·----·-·--- ll 12 1 .... -·..) 14 1977 1 s~ 7 s 1977 197B 1~77 1978 1S77 1978" a Monse-d~ys per hectare. 0.14 0.46 ? ,, .... _, ~ 3.23 4.0G 1.54 ~i. 86 1. 08 2 A ""l r~ -. • L(. 3.85 15.52 4.00 0 0 1;.~2 ~~. 4 6 66 67 {Neff 1968, Wolff 1976), moose use v~ried from a to 4.0 N.D./ha. Results calcul~ted by the two methods do not correspond well, particularly at Site 13. The lack of correspondence may be due to errors in the above values used for consumption and defecation rates. Mean consumption rates vary 0reatly in the literature. LeResche and Davis (1971) docuraen ted val Jes as lo~v as l. 3 kg /ha dry \·l2igh t for the K2n~i Peninsula while Palm~r (1944) found consumption rates to b2 as high as 16 kg/h~ air dry weight. Likewise, reported defecation rates vary greatly d2pendent both on the sex and a~e structure of the population as well as the forage eaten ) (Neff 1968). Franzmann et al (1976) documented a daily defecation rate for Kenai Peninsula moose of 14.5 for females and 19.6 for males. Unless the mean daily consumption ~nd/or defecation rates for moose in a given are~ are known, comput~tion of moosd days of use by either method is inconclusiv~. Protein Content The ran~2 of valu~s for crud~ protein levels of willows that I obtained (Tables 15, 15 and 17) were slightly lower tn3n other reported values for Alaska. Old~meycr et al (1977) reported a meun value of 6.4 percent for willow on the Kenai Peninsula. Milke (1969) reported values rangin3 from 5.2 porcent to 7.0 percent for four species of Interior Alaska willows. His reported value of 7.0 percent for s. 68 ~!_~~~Q_~!_~ is higher th:Jn my value of 6.0 percent althou9h both top their respective lists. Tha differences may be related to variability in clipping methodology and dates of sample colle~tion (Bailey 1967}. The observed percent protein of a twig Jepen~s a great deal upon ho~ fzr from the terminal bud it was cli~ped. Cowan et al (1979) found that twigs clipped close to the ter~inal buds had a higher percent protein than those including a larger portion of the stem. ~volff (1977} obs2rv2d a similor rel.:ttionship to occur l,vith twigs of ~· scoult:riana. The protein content of a twig also varies seasonally and is related to phenology (Bissell and Strong 1955, Tew 1978). Noteworthy are the significantly higher protein lev.::ls observed "for th.= tagJed plants of ~· ~£C::~!.~E.~~Q.~ than those of S. E!.~l2..~f<::!..~~ ('l'able 17}. Th·2 site-specific sumt.Jles for the two species were not significantly different in prot~in content. Protein in S. ~£~~!.££~~~~ tended to be hig~er in the tagged plants than.in the site-specific samples. A possible explanation of this apparent anomaly concerns the difference in Jates of sampla collection and relates to ph2nology. The sitc-s~~cific samples were collected in early March und the t~gged plants were sampled in April. Viereck and Little (1972) describe ~· scouleriana as one of the earliest willows to flower, often forming catkins prior to snow melt-off. Althoug~ catkins were not observed on the tagged plant sumples, the timing of the 72 Other ~tudi~s in Alaska h~ve su~y~sted that preference may b!2 related to height. t1ilk<= (19G9) found thut those willow species most utilized tenJad to be the tallest availabl~. Mould (1977) found that seven of eight browse sp2cies in a riparian habitat in arctic Alaska showed ~ significant positive correlation b2tween the height of plant and brousing intensity .. Sp2cics which tended to be the t~llest were browsed the heaviest. Snow depth and the need for cover were suggested as possible causes for preference. Although guantitativ2 data on height-use relations are lacking except for Sites 1 snd 2, l found the above conclusions on a subjective basis to be true for certain Sites 3 an1 9, ~· scouleriuna tended to be the ta.llcst i:lnd ?referred. At Site 13, f· alax~nsi5 tended to be much taller than S. olanifloia and ----------=----------- s. ~~~!:_~~~ and wCts the most [.>referred. l\t Site 12, hm.;evcr, s. scoulcriana tended to be taller but more preferred. At Sites 1 and 2, the same relationship ~as Other causes of between-specie3 preference may be related to nutrition, specifically, protein content. Cow~n ct al (1970) considered protein content to be an important indicator of forag2 ~alue. Some studies have documented a positiva correl~tion between the protein content of a sp~cies and preference by cattle and sheep {Hobbs et al 1945, H.:1rdison et al 1954, Cook 1959, He.:.dy 19G•i), deQr 74 correl~ted \iith preference (Lon':)hurst et al 19G8, Oh et al 1963). Some workers maintain that mixing of species in th~ diet is an important aspect of between-species preference {Longhurst et al 19G3, Cowan et al 1970, Mould 1977). Moose on h~avily utilized range in the Kenai Peni~sula and south~entral Alaska was attributed to a need for variety in the diet (LeHesche u.nd Davis 1973). Oldemey,.?r et al (1977} postulated that the observ2d decline in diversity of brows0 species on northwestern K2n~i Paninsula winter range over the past 20 years is at least pu.rtially responsible for the observed decline in moose popul~tions in recent years. Proper mixing of species would mu.ximize proportions of d~sirable nutrients and minimize proportions of undesirable digestive-inilibitory compounds and to:dns. In addition, digestive -inhibitory and toxic coumpounds of a species may ) be buffered by substances found in plants of other species. Mould (1977) found for the .Colville River ar~a of arctic Alaska that moose browsed willow and unusu~lly high amounts ' ) of alder {~!_!:!_~ ££.!.~12.£). Pu.p2r birch, asp.=n and cotton;,·mod were not ~vailable. Alder poss~sses higher levels of protein than willow while digestibility follows the reverse pattern (Oldcmeyer et al 1977). Proper mixing of the two species may possibly optimize the nutrition and digestibility levels in tne diet. At the Wickersham study area, usa of alder w~s . ~ -~--. ..__ ___ -~. ---~----· .... --........ ;.. ------· 17.6 percent protein while clippad forage fro~ the same area containin9 the same pro;?ortion of Sp•::cies had only 6.9 percent protein. The clippin3 procedure attemptad to duplic~te the browsing of each shrub by deer so as to minimize the effects of.pl~nt part selection. Bissell found 76 in additional experiments involving captive deer th~t rumen content protein level differed little from feeJ protein lev~l. If crude protein lev0ls fall bela~ the 6 to 7 percent maintain~nce lev8l, rumen functions are thought to be Lnl?u.ireJ (Dietz l9G5). Preferential browsin9 vmuld permit moose utilizing my s~uJy area to maintain a diet of 7 percent or hi·:Jher even thoug~ the mean protein levels of t:tll ffi·2asured spec.i·2S \vere bela·..; 7 p·~rcent (·rable 15 and lG). t·ly results suggest. that within-species preference is rel~ted to fa.::tors ott1•2r than i:)rotein level (Table 17). Ho•ti2VC!r, r2s~lts may h2v2 been jifEsrent if utiliz~tion was corr~lated with variability of protein content b~twecn stems rathar than between plctnts. Small sam9le sizes ~ake thQ results inconclusive. Other investig~tors h~vc documented that other chemical components, particularly vol~tile com~ounds, of forage plants may be important in determining within-species prcf€:rence. Junif)er utilization by mule de..?r <2.':!'2.£~!!.£.~~ ~~~!~~~~) in Utah ;,-:~s found to be negatively correlated \vith the cs3onti~l oil content of individual shrubs (Smith 1950, 1959). S~gcbrush occurrin3 in the same area was thou~ht to 78 shrubs arc similar in composition to shrubs in an earlier growth stage; the parcentag~s of phosphorus, protein and carotene are high and the percentages of lignin and crude fiber are low. However, Klein (1977) suggested that regrowth twigs may be less desirable as forage if increased levels of digestiv2-inhibitory compounds are present. Tables 21 and illustrate the mean number of twigs available per stem ~uring the 1976-77 winter for two cateanrics of sterns {brO\·ISi?d and not browsed durinj the 1975-76 winter). Th·:! ~~nn-Whitnay non-parametric test was used to test for Jifferences in production between categories. In all cases (e~cept Site 14) where the difference is significant, stems bro·,;St:!d th'= ?r-<~vious winter tend::=~ to outproducr~ those stems which were unbrc-H·i5·.:d. Although these! rcsul ts on not establish cause and effect, stimulDtion of growth by browsin~ is a possibility. If the probability of a pl~nt or stem bein3 browsed is related to the number of twigs it possesses, stimulated regrowth may give the browsed plants a higher probability of bcinq brn\·;sed tile folln>..Jirlg . .. :.v 1 n .. e r • Th2 high~r nutritional value of regrowth twigs mdy serve to increase the prnb3bility still further if preference is related to nutrition rather th<:!n to dig·::!Stive-inhibitnry compounds. The indivi~uul height of a shrub may influence it's ~hanccs of b~ ing brmvsed. The relationship of plant h.=: igh t ) and between-species preference has alrcajy been discussed. Bo 'i':~b.12 21. Corn:.x.1rison of t\tig produ.:tion during the 197G growing se~son s2ason for sterns browsed during Lh2 1~75-76 winter and those not browse~ at the Kanai Peninsul~ study ~r2~s (continued). Sit0 6 7 (' :J lu i+:~ .:m t..;o • Br 0'.-iS.: a: of 'l\; ig 5 Sp0cies Cutegory· p2r Stern Bare. B 2.8B u 3.95 S_;ou. B 2.76 u 3.33 I3ebb. B 3. 6~J u 3.20 SC,)i.i. L 2. <i ·.:i u 1. 67 Bare. c ") •' ""\ ...... ~""' u ~.~G Deb!:... D il . c ~1 u 2.8G .:JC()U. D 4. 2l u 1. 94 Bare. L 3.42 u 3.15 D·.=bb. .8 S.lS u 3.31 Bdrc. c '~. 17 u 2.29 Standard Error ,, l.lo 52 ~L 4';j 0.26 1).51 U.3lr n.3e 0.26 0.14 l. GO ti . 19 1. 22 U.37 !).15 J.lS ~L 51 0.50 i). 29 0.51 0.75 1.17 Hann-b Sample \~h.i.tr1ey Size Statistic 0 11.0 u 22 38 {u.SGl) 21 25 226.0 19 38 19.0 16 2 16.5 16 5 15.5 5 ") c '• .j..,,{. (7.G3l)c 51 12 7~j. 5 13 1 ~1·3 ( 'l .:.. 60 5 )c 16 r 1~.5 0 7 a e = Stems bro\;~~.5 durin~) th .. : 1975-76 ~;inter. U = Ste;n.:; not bro:.-;s.:::J .Juring the 1975-7G \-linter. b 'i~i1:.~n s~•;upl<.: sizes ;:J.re gr·-=atr=r than 2-U for tile smaller categori.::s or gr::ater than 4·J for th2 lurgcr, th.:; norm.J] approxit~hltion was 1.W2.:i (~ar 1974). v~.lu•2S in pur.;ntll•:?sis repres2nt th0 normal z su~t.istic. Valu2s withnut p;;renth.::!sis r2pr<:S1.?nt th·:' stan-:larci t•i.:.nn-·,Jbit.Iv.::y statistic (U}. c SiJnifi-.;.::nt .Jt th8 .05 3ignific.::~nc,.? lev2l. A similar p~ttern m2y be o~crative conc~rntng within-sp0ci~s selection. Klein (1977) foull·~= th<:~t snO\·:sho.:: har·~s pr12f(~rrt::::1 t\iigs from the tops of tre:cs and t.Jll shrubs \·;hich norm,=..lly .::... r 2 o u t o f r e a c h o v c r t •·i i ·;; s f r o in r o o t s u c kt.: r s ;;1 n d 1 o •.-; s h r u b s of the Sfirr.<:.: species. It w;:;.s sugg!:?St\.:!j th~t the presence of ~igestiv2-inhibitory compounds in the root suck~rs and low shrubs w~s responsibl~ for ~heir low utilization. In ~r~~s such as Interior Alss~a wh2rc the influenc~ of hares upon v2getation is great, such ~n a~ti-herbivorc strdtcgy S8ems nccc:ssary. If digestive-inhibitory coml?ounds d·2velofH~-::J to prot2ct shubs fro~ excessive hare browsing affect rnoos2 in a s i ;n i l c. r v; ~ y , t h t: t a ll :: r s h r u b s o [ .:1 s p e: c.: i 2 s s h o u 1. d b ~-~ j?ref.::rr"'=d by moos'~ o;_>er short·.::r shcubs. During thE· 1977-7f; wint~r at the Wick2rsh~rn stu~y are~, tall paper birch shrubs (ov<=r 3m tall) thct hc:,Ci br:~n broi~en c.:Jo\-:n by rn:mse norii12il.ly h~d only their tops brnws~d. Twigs ~~ailDbl~ at a lower, raort= conveniE·nt l·..:'Vl.=l \..;er~ ofto:=n unbro.~·sec1. Such, ho;..;-2\'(!f, ;,.·as not co:11monly obseri.r2r} for viillo~;. nos t brn~,s ing of willa~ seemed to occur ~t a l~vel conv~nient for rnoos0. Uir~h and willow ffidY 20Ss0ss diffcrant anti-herbivore str~teyies ~nd, consequently, th~ r~ctors influcn~ing prefcr~nce for each species muy be different. Site factors extrinsic to the pl'-lnt may c.;lso be important in clt:termining -viithin-sp<~cies bro•:sing prcfervnce. Snow depth w~s observed to Dffect betw2en-speci~s browsing preft::rcnc•2 ond it mz,y ,"ilso L(~ i.mport,;.nt in d(~termiilin'J 82 ·1·aol.;;: 23. Cbserv.;d distr ibutinn of 9~ll..:t 0COUi_iS fitt.::d ~9~inst th2 exp2ct~d r~nso~ distribution for 5 i t 0 s ll c: ;1(; 1 3 . Frequ2ncy (grouvs ~it2 Ye~r P0r plo~) 0bs:::rvcd Disr.ribution E;{L)·~C t0d 1{<) nd oa1 Distribution Chi- ll 1578 " 6 Ll 7.0 0.474 1 ") £. 13 } 977 ,, Ll 1 2 ., J 4 1 J •• .J 1978 ,. "' 1 2 j 4 7 7 G 7 4 2 1 5 ,... 0 4 2 1 7.4 5.7 5.7 7. 1 4.5 2. Ga 5.5 7.1 4 • c. -) na "-. ~ 0.120 a fr.:::;quen.::y ,:>J te9or L.:s .3 unJ 4 lUillped togeth2r du2 to low obs..:rvad ~nj 0xp~cted values. l'ioose in Al.:1ska are prr.~scntly one of thE..· most important species hunted for both sport and subsistence. Nonconsumptive use of moose by sightse8rs and photogr~phers will continue to gain in pro~inence. Nainten~oce of he~lthy, st~ble populations is desirable for most are~s. Intensive mc)n,Jg2ment of habitut for a high sustained yi,=dd of moost: may eventu~lly b~ necess~ry to offset th0 loss of hunting opportunity caused by l~nj ~i~hdr~w~ls of one form or ~nother. Increased efficicn~y in th0 control of wildfire is currently reducing future ser~l habitat favor2ble for moose. Sound hQbit~t mana0emcnt practices nc2d to bQ developed for the futurt::. Th·= most com!r:<">II [on.ts of habitat reh~bilit:"tion for moose as currently practic2d in Alasko are controlled burning anj mechanical crushing. The Kenai ~ational Noose H.:mge 2nd the ChugcJCh Nation<il Forest, both located in southcentral Alaska, are currently the only areas in the state where habitat rehabilitation is pr~cticcd on ct regular b~sis. Controlled logging as a man~gement tool will gain in ~rominenc•.= uS th'? ti111b•~r resourc~s of Southcentral cJnc1 Interior Alaska are devalop~d. The maintenance of cJ high c.mount of ecotone in proportion to the OV(:-raJ 1 acreage r~habilitcJted is or great importance for all these ~reas (Eustm.:.n 1974). 86 t~kcn. The observ2d nonran1o~ use pattetn indicates this is not necessarily so. It is import~nt that plant characteristics such as nutritional or digestibility factors \vhich may lead to this. type of use pattern be establishr::a. It is possible that habitat management practices which favor some of these ch~racteristics may consequently be develop2d and· evaludted. 88 AfJ::Ji.:r~Ji~: I. (-::ontinu.;:j) DJ?b an(i m2:.2n t;,vig ·1·t·2ight J:.t.:; Sitt..:: 13 14 f!)r the ti1r2e .:;tuJy .Jr·.=~:;s (_:!: SL::;1J-.:~rj Errt)f) Dp b ( r.1;n )a l\lC.lX. 1977 ., G 0. 1 -' . 1978 3. 1 fi • 1 f'l::!n. 1977 ' 1 ;:-\ 2 J. ,, . 1978 ") " I' 1 ,_ . J iJ • Scou. 1977 J. ,, u 0. ] 1978 ' 1 (l • 1 -' . He::!n tvli:J ~·i·2 i 9 h t. ( <.J) 1. 88 (\ Cl8 tJ • 0.73 0. () 7 J.. 05 (; . 12 0. 7'u r, x.; • G7 •'\ !·".J • 84 :J. 16 . ~ 73 C.C7 ..:1 • 90 LITERA~OR8 C[~ED Allen, R.S. and A.R. Porter. 1954. Effect of add2d 9roun(] corn on th~ consumption and palatability of stacked silage. J. Dairy Sci. 37:658. AOAC. 19GO. OfficiDl methods of analysis of the American Organization of Agricultural Chemists. Ninth Ed., wash., D.C. 832 p. Bailey, J.A. 19G7. Sam~ling deer browse for crude protein. J. Wildl. Manuge. 31:437-142. Baker, T.C., C. Anderson and ~.I. Crump. 1953. Food habits studies of game animals. Wyo. Wild Lif~ 17(11) :24-31. B~rret, J.D. and w.~. Guthrie. 19G3. in estimating browse. J. Wildl. Optimum plot sampl in·g Manage. 33:399-403. Berg, U.E. anu R.L. Philips. 1974. Habitat use by moos~ in northwestern Hinnesota with reference to other heavily willo;..J•::d areas. Can. Nat. 101:101-116. BishofJ, R.iJ. and F~.A. Rau.sch. 1974. Hoose population fluctuations in Alaska from 1950 to 1972. Can. Nat. 101:559-593. Bisse.ll, H.D. and H. Stron:J. 1955. 'l'he crude protein variations in the browse diet of California deer. California Fish and Game 41{2) :145-155. Bissell, H.D. 1959. California Fish Interpreting chemical analyses of browse. and Game 45:57-58. Blaser, R.E., R.C. Hames, II.'l'. Fontenot and R.H. Engel. grazing on animal output. Congress 8:601-606. Oryant, N.A. Hardison, J.P. 1960. The effect of Selective Proc. ath Internl. Grassl. Bo·,,d.;n, D.C., A.E. Anderson and D.E. H-:-din. 1969. Fn~quency distributions of mule deer fecal group counts. J. \lildl. H.Jnag.;. 33:895-905. Bro;.m, E.R. and J.H. Hand-.=ry. 1962. Planting and fertilization as a possible means of controlling di.stributions of big game animals. J. For. 60:33-35. Cnatelain, E.F. 1951. ~inter range problems of moose in the Susitna Valley. Proc. 2nd Ann. Alaska Sci. Conf. p. 343-347. 92 Gas2way, W.C. and J.W. Coady. 1974. Review of energy r~~uirements and rumen fermentation in moose a~d other ruminants. Nat. Can. 101:227-262. Hardison, W.A., J.T. Reit, C.M. Martin and P.G. Woolfolk. 1954. D2gree of herbage selection by grazing cattle. J. Dairy Sci. 37:89-102. Harry, G.B. 19 57. Hole, ~vyom ing. Winter food habits of moose in Jackson J. 'i'lildl. rlanage. 21:53-·57. Heady, U.F. 1964. Palatability of herbage and animal preference. J. Range Manage. 17:76-82. Hobbs, C.S., \LD. Gullup .~n·:J 3.R. 'I'aylor. 1945. The composition and apparent digestibility of bluestem 94 grass in the growing stage and in the dry and hay stages when supplem0nt~d with cottonseed cake. J. Animal Sci . 4: 3 9 5-4 ,j 2. J~nsen, C.Il., A.D. Smitb un:1 G.i·l. Scotter. 1972. Guidelines for grazing sheep on rangel~nds used by big game in winter. J. Range Manag~. 25:345-352. Johnson, P.R. and Hartm~n, C.W. 1969. Enviremcntal atlas of Al~ska. Institute of Arctic Envirementa1 Engineering, F'~irbanks,. i\l<1ska. 111 !?· Kelsa~1, J.P. 1969. deer for snow. Structural adaptations of moose and J. Mamilla!. 50:302-310. Klein, D.R. 1977. Winter food preferences of snowshoe hare (Lepus americ~nus) in Interior Alaska. Xliith Intl. con9ress-of"-G'~iae-Biolo':1 is ts. p. 2GG-27 5. Knowlton, F.F. 1960. Food habits, movements and populations of moose in the Grav.:lly t·1ountains, r:Iontana. J. ~Vildl. Manage. 24:162-170. K r e E t in~ , L • ~·J • , N • H • S t r en 1 u n d an J R • K • S 2 em.~ l • 1 9 G G • 1:: f f e c t of simulated and natural deer browsing on mountain maple. J. Wildl. M~nage. 30:431-438. Laycock, ri.A. and D.A. Price. 197~. Factors influuhcing forage quality. USDA Misc. Publ. No. 1147. p. 37-47. Leigh, J.H. 19Gl. The relative palatability of various varieties of weeping love grass (Eragrostis £~~~~~~). J. Br. Grassl. Soc. 16:135-140. ---------- P.:; ltuer, I .. J. l94A. f'()o6 rcqu i rer.1en ts of some Alaskan g ;:uue .:.n imal s. J. f·lc.Hniil.:i l. 2 5: -19-5 4. Pdck, J.M. 1971. A review of moos~ food hdbits studies in North America. Nat. Can. 101:195-215. Pirnlott, D.f:i. 1~61. North A;nerica. Th~ ecology and management of moose in L~ Terre Et Lu Vie No. 2-3:246-265. . Plice, M.J. 1952. b 1 1 i v '..! .s to c k . Sugar vcrs~s intuitive choice of foods J. R<.<n,.J..:: Hanagc. 5:G9-75. h:,i::J,;;;.·n, t·LA. 1972. Diff~rt:nc-=s b~L·.i.?en Dougl..:.~s fir g~noty~es in r~l~tion to browuin~ pref~r~nce by black-tail deer. Can. J. r .. or. Res. 2:25J-255. Radwan, M.A. 1975. Res e .:1 r c h B u 11 • , ~hat makes deer choosy eaters? U.SD.i\, Feb. 1975. p. 8-lH. For•.:?si:ry R8g0lin, W.L., J.G. ~a~y and O.C. snowdrifts on mountain shrub Congress of Gama Biolo9ists. ~~a 11m o . 1 9 7 7 • communities. Eff2cts of XTIIth Intl. !?· 114-419 •. Reyno 1~1 s, n. G. .:~nJ i\. rL Sampson. sprouts as browse for Jeer. 122. 1943. Cnapc:.rrt:~1 crovm J. ~ildl. Manag~. 7:119- Sil.:.-fcr, r::.L. hardwood 1963. The twig-count method for meusurinJ deer brows~. J. Wild!. Manage. 27:428-437. Sigm.:.:n, r-1. 1975. ·rhe impoJ~t.:.ncQ of ov2rwinter mnnse calf survival. Alaska, Fairbanks. 185 p • the cow-c~lf bond to M.S. Thesis, Univ. .S;nith, ! •. D. 1950. In·~3uirL~s into differential consum()tion of junipr2r. Utah F.i.sh and Gum.:: Gull. 9:4 Smit~, A.D. 1959. Adcq~~cy of SOille im~ortant browse species in ov~rwintcrin3 of mule jeer. J. Range Man~ge. 12:8-13. 3pcncer, D.H. and E.F. Chatelain. l s 53. man<:.19..:;,;·.=nt of \"li 1 d 1 . Con f . moose of southcentral 18:539-552. Pro<Jrcss in th·~ Ali.:ska. Tr. N. l\;n • Spencer, D.L. and J.B. ilakala. 19G4. Moose and fire on th2 Ken~i. Pro~. of the 3rd Ann. Tall Timbers Firu Ecology Conf. 3:11-33.