Table Of ContentGreatBasinNatiinJist52(2),pp. 174-178
CHARACTERISTICS OF SITES OCCUPIED BY SUBSPECIES OFARTEMISIA
TRIDENTATA IN THE PICEANCE BASIN, COLORADO
Thomas R.Cottrell andChiules D. Bonham"
Kit/words: Artemisiatridentata. Colorado,sagehnisli,clirointifoij^raplu/,factoranalysis,sod.
Artemisia tridentata, big sagebiiish, is the annual temperature ranges from 7 C at 1800 m
dominantplantspeciesinthePiceance Basinof to -1 C at2700 m.
western Colorado and displays great morpho- The stronginfluence oftopographyon tem-
logical variabilitv between sites. The existence peratiu'e and precipitation results in acomplex
ofat least three subspecies is widely accepted ofhabitats inthebasin (TiedemanandTerwilli-
(McArthur et al. 1981, 1988). These are A. ger 1978). Generally, soildevelopmentiscorre-
tridentata spp. tridentata Beetle, A. tridentata lated to elevation. At higher elevations, except
spp. ivi/oming^ensi.s Beetle and Young, and A. ridge tops, soils are dark brown, shallow
tridentata spp. vaseyana Beetle. mollisols. At mid-elevations, aridisols are
Despite extensive research in the Piceance common on deep loess. The lowest elevations
Basin (RedenteandCook 1986),wehavefound are characterized by entisols developed on
only one study referringto intraspecific taxa of heavyclays anddeep, sandyalluvial soils.
sagebrush (Ward et al. 1985). This work
referred to subspecies tridentata but did not Methods
indicate where this taxon was found. Because
the taxa are known to respond differentiiilly to
Six sites dominated by sagebrush were
soilandclimatefactors(Hironoka 1978,Sturges
1978) their existence in the basin should be selected for this study (Table 1). These sites
spanned the environmental extremes of sage-
recognized. The present studywas designed to brush habitat in the Piceance Basin. Two sites
identify the subspecies o{Artetnisia tridentata
were selected from each ofthree broad topo-
present in the Piceance Basin and to describe
graphic regions. High mounttiin sites were
soil characteristics of sites occupied by sub-
about 2000 ni; upland terraces and valley
species.
bottom siteswere below2000 m.
Sagebrushsubspecieswereidentifiedbvthe
Study Site combined information ofthree techniques and
verified by A. H. Winward, regional ecologist
for Range andWatershed Management, USFS
The Piceance Basin comprises about 3()()() Intermountain Region, Ogden, Utah. The first
km" in Garfield and Rio Blanco counties of technique involved field identification using
northwest Colorado (Fig. 1). ThecUmateofthe moqihological characteristics based on keys by
Piceance Basin is semiarid and shows extreme A. H. Winward and Tisdale (1977). Leafsam-
variability in monthlv precipitation (Wymore ples were taken for the other two procedin-es.
1974). Consecutive months often receive little Two-dimensionalchromatography,asdescribed
precipitation. The mean annual precipitation by Hanks et al. (1973), was done on persistent
for eight weather stations in the region for the overwintering leaves from three plants at each
period 1951-70was 35.3cm,with a95% confi- siteexceptsite5,wherethemoqihologiciilvari-
dence intei-val of ±18.7 cm. About one-halfof abilit)'ofthe sagebnish plants was greaterthan
thetotalprecipitation fallsassnow.Theaverage at the other sites. At this site five plants were
^DepartmentofBiology,ColoradoStateUniversity,FortC^ollins.Colorado80523.
RangeScienceDepartment,(ColoradoStateUniversity,FortCollins,Colorado80.52,3.
174
1992] Notes
175
WYOMING
m. PICEANCE
BASIN
OLORADO
C
''830
NEW MEXICO
2130-
2430-
Meeker
e^^
P'il
40°N
/
PICEANCE BASIN
COLORADO SCALE IN MILES
SCALE IN KILOMETERS
CONTOUR INTERVAL 300m
Fig. 1. TheshulviireaofthedistribuHcMi,AAnemisia trklcutata subspeciesi„ northuestColorado.
tested by chromatography. Results were com- matelv ISotherplants inthestucK-sites Leaves
paredwith representative chromatograms. The were crushed In hand and placed in glass con-
hirdprocedurewas a leafextract in uater. This tainersforfourhours.Thesewereviewedunder
Ubiyttcerhrmoemtahtoodgrwaapshpyerafnodrmoendaontoatlallploafntaspptreosxtie-d dleosncgr-iwpatvioensulbtyraSvtioelveetnsliagnhdt MacnAdrtchoumrpa(r19e7d4)to
176 Great Basin Naturalist [Volume52
Tabi.K1.Location,elevation,;uidsagebnislisubspeciesofstutlysites.VAS—ssp.id.sci/ana:TRI —ssp.tridoitata:WTO
= ssp.wuoimngensis. Selectedsoilcharacteristicsarelistedfor()-L5cmand 16^30cm soilsamplesforeachsite.
L()cation
1992] Notes 177
3s
LJ
< 1.5
Ld
u
O
<
0.5 -
Q
<
- -0.5
cOt:
uI— -1 -
<
-1.5
-1.5
178 Great Basin Naturalist [Volume 52
consequently, different life history'strategies in HiRONAKA. M. 1978. Basic svnecological relationships of
the subspecies (Bonham et al. 1991). TthheeCsoalguembbniisahReicvoesrysstaegme:brausshytmyppoes.iuPma.gesUt2a7h-.3St2atine
Soils at sites with ssp. vaseyana are distin- University, LogiUi.
guished from the other sites by factor 2 ofthe McARTHUR, E.D.,C. L. Pope,andD.C.Freeman 1981.
factoranalysis. Thisaxis represents bothan ele- ChromosomalstudiesofsubgenusTridentataeofArte-
vational and soil pH gradient (Table 1, Fig. 2). moifsBiao:taenvyid6e8:nc5e89f-o6r0a5u.topoKploidv. AmericanJournal
Siteswith ssp. vaseyana were at ahighereleva- McArthur, E. D., B. L. Welch, andS. C. Sanderson.
tion, and soils were lower in pH and CaCO^ 1988. Naturdandartificialhybridizationbetweenbig
values. Thetextures atthese sites didnot differ sagebnish{Artemisiatridentata)subspecies.Journalof
substantiiillvfrom theothersites. Heredit)'79:268-276.
Noprevious studyin the areahas identified Redefnutnect,ioEn.alF.,cahnadngCe.sW.inCoeaorkl,yesducsce1s9s8i6o.naSltrsutcatguersaloafnda
these taxa or characterized their habitats. The semiaridecosystem. Progress Reportto U.S. Depju't-
great differences in habitat preference among mentofEnergy. DepiutmentofRangeScience,Colo-
these subspecies suggest this is a major over- Shumraard,oSMt.atLe.,UaninvdersiEt.y,AFnodretrCsololnins.196876.ppG.radientanal-
J.
sight. ysisofvegetationdominatedbytwosubspeciesofbig
sagebnish. Journal of Range Miuiagement 39: 156-
159.
Acknowledgments Stevens, R., iuid E. D. McArthur 1974. A simple field
technique for identification ofsome sagebnish taxa.
JournalofRange Management27:.325-.326.
The research was supported jointly by the
Sturc:es. D. L. 1978. Hydrologic relations ofsagebrush
U.S. DepartmentofEnergy, Contract No. DE- lands. Pages 86-100 in The sagebnish ecosystem: a
AS02-76EV04018toColoradoStateUniversit)- symposium. UtahState Universitv',Logan.251pp.
andthe Agricultural E.xjoeriment Station, Colo- TiEDEMAN. J. A., and C. Terwilliger. Jr 1978. A phy-
toedaphic classification ofthe Piceance Basin. Colo-
rado State University, Project 660(4242). radoState University, Department ofRange Science,
ScienceSWeries31.265pp.
Literature Cited Ward. R. T, L. Slauson, and C. W. Weldon 1985.
Responseofshnibecotvpes to miningwaste material
in soil profiles and competitive interactionsofwoodv'
Affifi. a. a.,andClark. V. 1984. Computer-aidedmulti- species under experimental and naturiJ conditions.
variate analy.sis. Lifetime Learning Publications, Bel- Pages87-94in E. ¥.Redente,C.W.Cook,J. M. Stark,
mont,California.458pp. andC.L.Simmons,eds.,Semiaridecosvstemde\eIop-
Bakkeenrc,esJ.bRe.,twaenednCb,asMi.n MancdKWeylolmi1n9g83.bigHasbaigteabtrduisfbferi-n tmieonn.tParsogarfeusnsctRieopnorotfrtoesUo.uSr.ceDeprpoacretsmseinngtaonfdEnaelrlgo\c-a.-
contiguous populations. Journal of Range Manage- ColoradoState University, DepartmentofRange Sci-
ment36:450-454. ence,FortCollins.
BoNiiAM. C. D., T. R. CoTTHELL. and E. Mitchell. Winward, A. H., and E. W. Tisdale 1977. Titxonomvof
1991.InferencesforlifehistorystratJe.giesofArtemisia theArtemisiatridentata complexin Idiilio. Uni\ersit\'
tridentatasubspecies.JournalofVegetationScience2: ofIdiilio, Forest,WildlifeandRangeExperimentSta-
339-;344. tion Bulletin No. 19. 15pp.
GooDRiCM, S., E. D. McArthur, and A. H, Winward WvMORE, I. F. 1974. Estimated average annualwaterbal-
1985.AnewcombinationandanewvarietyoiArtemi- anceforPiceanceandYellowCreekwatersheds.En\a-
siatridentata. Great Basin Naturalist45: 99-104. ronmentiJ Resources Center, Colorado State
Hanks, D. L., E. D. McArthuk. R. Steven.s, and A. R University, Fort Collins. Technical Report Series No.
PiAJMMER. 1973.Chromatographiccharacteri.sticsand 2. 60pp.
phylogeiietic relationships of Artemisia section
Tridentatae. USDA Forest Service Research Paper Received20November1991
INT-141.24pp. Accepted4May 1992
