Treść książki

Przejdź do opcji czytnikaPrzejdź do nawigacjiPrzejdź do informacjiPrzejdź do stopki
23
(AdamsandPetersen1999:32)butoftenalsodependsonlevelofwatertableandrunoff
afterstorms("runofffarming”includesalso"akchin”farmsonfans).However,thedis-
tributionofgoodsoilsdiffersevenwithinsmallareassuchastheSandCanyonlocality
andoftenvariedwithphysiography(AdamsandBowyer2002:123–124;Lipeand
Varien2003:3).Also,thedistributionofproductivelandswouldhavechangedthrough
timeasclimaticconditionsvaried.ManypartsofthecentralMesaVerderegioninclud-
ingLowerSandCanyoniscoveredbydeepdepositsofeolian-derivedsiltyloamsoils
(MesaVerdeLoess)thatoftencoversuplandsandmesatopsandsometimesoccursin
lowerportionsofthecanyonsforexampleonrelativelylevelbenches;alsofarmingwas
atleastoccasionallypossibleincanyonsbottom(LipeandVarien2003:3).
ThepotentialforagricultureintheMesaVerderegionisassociatedwiththeamount
ofprecipitationandthenumberoffrost-freedays.Theannualprecipitationrangesfrom
18to48cmacrossthearea,withthegreatestlevelsinhigherelevations,forexamplein
MesaVerdeProper(MesaVerdeNationalPark),anditseemsthatatelevationshigher
than1800–1830m(ca.6000ft.)therewasadequaterainfallformaizeagriculturein
termsofdry-farming(AdamsandPetersen1999:23,33).Precipitationinthecentral
MesaVerderegioncorrelatesstronglywithelevation,aspect,topography,anddistance
fromthemountains(VanWestandDean2000:21).
Mostvarietiesofmaizerequireaminimumof120frost-freedaystoreachmaturity;
thisrequirementisusuallymetatelevationsbelow2195m(ca.7200ft.).Abovethis
elevationtherewerealsomanylocationswheremaizecouldhavebeengrown,givena
favorableaspect(Adams,Petersen1999:26–28).
BesidestheSanJuanRiver,theonlymajorpermanentwatersourcesintheareawere
theMancosRiver(atributaryoftheSanJuanRiver)attheeasternedgeofthecentral
MesaVerderegionandtheDoloresRiver(atributaryoftheColoradoRiver)inthenorth-
ernpartoftheregion.Therearealsoseasonalcreeksandmanyseepsandsprings.
Numerouscliffalcovescontainseepsaswell,seepsorspringsoccuralsoatthebaseof
thealcovewalls.ThereisevidenceofwatermanagementbytheancientPuebloans,for
instance,theconstructionofcheck-dams,reservoirs,andfarmingterraces(Erdmanetal.
1969:57–58;Rohn1963b;Wilshusenetal.1997).
TheoraofthecentralMesaVerderegion(AdamsandPetersen1999:14–21,29–30;
Erdmanetal.1969;Smith2002:31–32)variesbyelevationbutincludesmainlypiñon
pine(Pinusedulis)andUtahjuniper(Juniperusosteosperma)woodlandslocatedpar-
ticularlyonmesasanduplands,andsagebrush(Artemisiatridentata)andavarietyof
othershrubsonmorelevelareasofthelandscape.Othertrees,lesscommonandusually
foundathigherelevations,includeDouglasfir(Pseudotsugamenziesii),Ponderosapine
(Pinusponderosa),aspen(Populustremuloides),RockyMountainjuniper(Juniperus
scopulorum),andspruce(Picea).InnumerouspartsofthecentralMesaVerderegion
therearemanyshrubsbesidessagebrushincluding,forexample,serviceberry
(Amelanchierutahensis),mountainmahogany(Cercocarpusmontanus),broad-leafyuc-
ca(Yuccabaccata),pricklypearcactus(Opuntiasp.)andbitterbrush(Purshiatridenta-
ta).Loweranddrierelevationshostgrasslands.
Piñon-juniperwoodlands,grasslands,andsagebrush-saltbushareasweregoodplaces
forforagingforjuniperberries,piñonnuts,cacti,yucca,andavarietyofgrasses,aswell
asforhuntingmuledeerandcottontailrabbits.