Page 10 - Wood Plenty, Grass Good, Water None

the grasslands and understory vegetation within the woodlands?
probably were not characteristic of the drier uplands. Certainly none of the presettlement photographs of the Plains and Great Basin Grasslands lend credence to such growth, and early diaries suggest that conditions wereaustereatbest.Differencesinobservationsmay reflect annual or seasonal variations in precipitation, h e n c e t e m p o r a r y v e g e t a t i o n c o n d i t i o n s s e e n b y d i f f e r e n t
The use of diaries and old photographs to view
historic habitats provides one method of approaching thesequestions(HastingsandTurner1965;Bahre1991).
Such sourcesgiveglimpsesofthelandscapesthatexisted
im m e d i a t e l y p r i o r t o ,d u r i n g ,a n d s i n c e ,s e t t l e m e n t .T h e i r usealsoleavemanyquestionsunanswered.Theyshow travelersatdifferenttimes. usonlythebeginningandthepresentbutlittleofwhat happenedinbetween.Theytelluslittleaboutearly conditionsregardingherbaceousorephemeralplants.
Grazing by domestic livestock has been blamed for woodland encroachment on grasslands more than any otherfactor.Thatthesuddenarrivaloflargenumbers of ungulates could create change seems reasonable, especially ifthe area had previously been free of graz ers. Grazing is a persistent, visible land use, hence easy to indict. But the intensity and time of grazing itself must be considered. Moderate, well managed grazing maycreatelittleifanychange.Conversely,aneventof extremely heavy grazing over a relatively short period, perhaps a decade or less, can permanently change a landscape, regardless of subsequent treatment. Other activities, such as the cutting of fuel w o o d for railroads andminesattheendofthelastcentury,happenquickly andareeasilyforgotten.Theytoo,maysetecological processes into motion that continue indefinitely. A problemexistsinseparatingchangesthatwouldhave happened regardless of human impacts and those that were truly caused by postsettlement activities.
Fire isan important factorthatfallswithin thissecond category.Firefrequencymayhavechangeddrastically duetoreducedfuelsonheavilygrazedlandsandofdirect fire p r e v e n t i o n e f f o r t s b y l a n d m a n a g e m e n t a g e n c i e s . T h e changes in fire frequency have been well-documented for forested areas at higher elevations in the Southwest (SwetnamandBaisan1996).Theyarelessunderstood forwoodlands,especiallypurejuniperwoodlands.This isinpartbecauseagingjuniperswithdendrochronologi- calmethodsismoredifficultthanagingpinespecies. It is also partly because juniper does not sustain fire scarswelland,infact,oftendieswhensubjectedto fire.Evidencetodatesuggeststhatlargefirefrequency andreplacementperiodsaremuchlongerinwoodlands than in forests (Floyd and others 2000).
Uncertainty exists regarding northern Arizona's pre-grazingconditions.Someearlywriterssuggestthat the grasslands were originally more lush than they are today.One often-quotedstatement,attributedtoCharles G e n u n g ,an early settler of Skull Valley, proclaimed that grassesweretallenoughtohideahorse(Hall1934). While such stands might have existed in wetlands, they
Earlydifferencesindescriptionsofthelandscape mayalsoreflectthebackgrounds,attitudes,andexpecta tionsoftheobservers.Manyoftheearlydiaristsgrew up in the forests of the eastern United States. While they might find the open stands of mature ponderosa pineforestsontheMogollonRimimposing,they were probably not impressed with our southwestern oaks and "cedars," compared with oak or red cedar forests of the East. Similarly, the short, sparse stands of grama grass in the Southwest were not particularly noteworthy compared with eastern savannas or tall grass prairie.
Study Area
IfocusedmainlyontheupperVerdeRiverwatershed, roughlyfromBillWilliamsMountaintotheeast,the headofPartridgeCreektothenorth,AztecPasstothe west,andWalnutCreekwhereitentersBigChinoValley tothesouth.TheupperVerdeRiverwatershedwasone of the last areas in the continental United States to be settled by Europeans when the 1850s military expedi tions set the stage for settlement in the area.
Thestudyarea(fig.1)encompassestheroutesex ploredanddescribedbyArmyTopographicalEngineers Sitgreaves, Whipple, Ives, and Beale during the 1850s. Iusedtheroutesdescribedbythevariousexpeditions as historic vegetation "transects." I emphasized that portionoftheWhippleexpeditionbetweenNewYear SpringnortheastofBillWilliamsMountainandAztec PassattheheadofWalnutCreekbecauseofthegreater amountofinformationrecordedbythemembersofthe Whipple party. This route crosses much of the "dry" upperpartoftheVerdeRiverwatershed,includingBig ChinoWash anditsmajortributaries,PartridgeCreek andWalnutCreek.
In order to employ photographs by Timothy O' Sullivan and diaries by Sitgreaves, Ives, Edward Beale,andEdgarMearns,Ialsoincludedportionsof the Cataract Creek and Truxton Wash watersheds, all within the elevational and latitudinal ranges of the ju niper/grasslands ecotone. For the most part,Ideal with recordsandphotographsintheUtahjuniperandgrama grass habitats along a belt paralleling present Interstate
2
USDAForestServiceRMRS-GTR-177. 2006.