"The Devil's Own"—Tamarisk

Home , Kanab Creek, Virgin River

Item Type text; Article

Authors Hughes, Lee E.

Citation Hughes, L. E. (1993). " The Devil's own"—tamarisk. Rangelands, 15(4), 151-155.

Publisher Society for Range Management

Journal Rangelands

Download date 30/09/2021 12:16:14

Item License http://rightsstatements.org/vocab/InC/1.0/

Version Final published version

Link to Item http://hdl.handle.net/10150/638953 RANGELANDS15(4), August 1993 151

"The Devil's Own"—Tamarisk

Lee E. Hughes

I. Statement of the Problem commodate wide variation in its "When I was a boy in the 30's and Tamarisk, also known assaltcedar, environment, has led to its being 40's the Virgin River was open, no tamarack, tamarix, and many less classified as a troublesome weed. brush on its banks. Then in the late mentionable names by those who Tamarisk has replaced willows and 40's and in the 1950's the tamarisk have hiked through this occupantof cottonwoodson the riversides of the just seemed to roll down the river," stream banks, is considered an ag- Virgin River and Kanab Creek, both claimed a resident of Mesquite, gressive alien plant. The plant is a of which crossthe ArizonaStrip Dis- Nev. "I don't think there is anything phreatophyte,awaterglutton. Edward trict of the Bureau of Land Man- that can competewith that tamarisk. Abbey(1977) stated: "Like that other agement (BLM). When willows and Cottonwoods just die when typical desert plant the tumbleweed, cottonwoodslost their dominance,if they are near," commented a lifelong tamarisk is not native tothe American they indeed were dominant or co- resident of Littlefield, Ariz., a small west. It comes from North Africa,and dominate, on the Virgin River, is riverside hamlet on the Virgin. as is the way with other exotics, has unknown. In reviewing thechallenges of man- spread like a plague....clogging the Old photographs, from the early agingtamarisk, thereappear to be no desertwater courses and drivingout 1900's, show a very open and broad universal solutions. Each infested the willow river (Photo1 and 2), but also a river areahas unique problems(Brother- Tamarisk's abilityto colonize ripar- with whatappears to be cottonwoods son and Field 1987). In addition to ian areas rapidly, as well as ac- and willows on the river banks. But being a formidable problem on the most photosare too blurry to ascer- Virgin River and Kanab Creek, tama- Editor'sNote: risk is also a on lesser water- The author is employed bythe USDI-BLM,St. tain plant species accurately. problem George, Utah 84770.

SCALE I 500000 20. 8 0 MILE 20.8 II I.' -i P 20.8 0 20.8 KILOMETER

RI VER 152 RANGELANDS15(4), August 1993

Bunkerviflo Bridge near Mesquite, Nev.,—1921. Very open and no salt cedar. What Bulrush Wash-1940. Thestreambanksare appearsto be young cottonwood and willow are on the streambankin the foreground. free of any woody growth.

1992. The samelocation as above. Tamariskdominates in a big way.

ways of the Arizona Strip (Photos 3 and 4). Ii. Past Failures to Reestablish poleswere irrigated, no grazing was Cottonwood allowed. In less than 5 years the Bulrush Wash-1991. Tamarisk has plug- tamarisk exercised with a"slam ged the channel. Demonstrateswhat was What can be done with habitat grace, said about the Riverof how tamarisk dunk" redomination. The cottonwood Virgin dominated by saltcedar? Many claim plugged waterways. all died. as to 'ittle can bedone to replace tamarisk poles Many guesses from the level was, why the died were advanced— thinking ground with native woody or herbaceous poles and is, that to reduce tamarisk would soil too salty, thewater table dropped plants. in one case on the Arizona require intense repeated chem- Strip District in the early 1980's, 2-3 belowthe root zone andthe tamarisk chokedthem out. With these results, ical/mechanical/firemethods which acres of tamarisk near Beaver Dam would cost far beyond the benefits Creek on the River were bull- theeffort diedto repopulate theripar- Virgin gained by reducingtamarisk stands. dozed, burnedand then the area was ian zone with cottbnwoods. Dealing planted to cottonwood poles. The with tamariskseemed hopeless. The RANGELANDS15(4), August 1993 153

Ill. influence of Grazing on Estab- since 1970 and 1988, respectively. willow, arrowweed, reed grass and lishmentof Tamarisk These3 segments afford an oppor- coyote willow are native riparian The Virgin River and Kanab Creek tunity to assess the impact of a few plants. Rabbitfootgrass, cockleburr, have both long been grazed by live- years of restfrom grazing on riparian barnyard grass, dali isgrass, bermuda stock. The Virgin River was used by vegetation in a particular locale. grass, clover, andtamarisk are exotic invaders. Of the the Mexican livestock, as the Spanish Inventory exotics, majority Trail followed the river. is tamariskand rabbitfoot (1829-1850) River and grass. Later settlers moved onto in 1991—2, the Virgin European Creek were inventoried for the river. It is the riverbanks Kanab Wet Zone possible and wild- have been without cottonwood and soils,vegetation, geomorphic, The Virgin River wetzone (Table 1) life resources two four aredomin- willow dominancefor a century.The present. Riparian segments through vegetation was inventoried by ated by exotics such as rabbitfoot total lack of cottonwoods for long of distances 5-15 miles,seems, but does measuring dryweight plantspecies grass with small amountsof natives not that thestreambanks have occurring in a 9.6 squarefoot hoop suchas sedges andcattails. Segment prove, transects. been without the cottonwood for a which was placed along one'swet zone composition has twice time. Transects were done in 3 different the natives as in segments two long zonesin accordance to closeness to four. one is under Kanab Creek has had since through Segment grazing the stream's edge. The 3 sites run rotation the the 1860's. now occursfrom grazing during grazing Grazing parallel to the waterway. One, the season. Segment five's wet zone is OctobertoJuneonboth Kanab Creek wet zone, is that narrow band of mostly rock. Segmentsix is dominated and the River. There are 3 Virgin sedges and rushes at the water's by nativeswith small amount of rabbit- segments on the Virgin River that The next zone is wider and is foot and otherexotics. Livestock have been without A edge. grass grazing. seg- called regeneration. This zone has have not grazed this segmentsince ment is defined as a length of river the The about 1970. seven is dom- divided out or young woody vegetaton. Segment by geomorphology by next zone is thefloodplain. This zone inated by natives, mostly cattail. It fence in a different lines, resulting has a mix of riparian and upland receives livestock use livestock One every spring. management (Table1). vegetation and is where adult trees Some years it has been rested during segmenton theVirgin River, number or shrubs occur. the wet zone the when the is not due to Only spring pasture 6, geomorphology, has not and zone will used because of or other been beaver and regeneration vegetation drought grazed, except by be discussed. stressful periods. Segment eight's since about 1970. bighorn sheep, Thevegetation data shown in Table natives dominantby a large margin. The other 2 numbers 8 segments, 1 are from the plant composition Livestock has been and 9A, have had excluded grazing largely grazing data. Sedges, rushes, cattails, seep absent since the early 1970's. Seg-

Table. 1 FollowIng Is a list of the species composition of each segment'splant community.The numbers include all the native riparian vegetation (sedge,willow, re.dgrass, arrowweed),and exotic vegetation (rabbitfoot grass, daiiisgrass,tamarisk, etc.).

PLANT SPECIES COMPOSITION VIRGIN RIVER

f SEGMENTS ZONE SPECIES 2 4 5 6 7 8 9 -- j lJ 3 [ NATIVE 15% 0% 82% 82% 83% 25% 99% WET 31%]. ....lli.. EXOTICS 69%1 85% 86% 89% 0% 18%* 18% 17%* 75% REGENERATION NATIVE 7% 7% 0% 1% 10% 48% 12% 25% 28% 86% EXOTICS 93% 93% 100% 99% 90% 52%* 88% 75%* 72% 14% SEGMENT LENGTH (MILES) 2.5 3.25 1.0 5.0 3.0 2.75 2.25 3.0 9.25 2.5

*No Grazing

KANAB CREEK

1 SEGMENT 2 SEGMENT 3 SEGMENT 4 SEGMENT S ZONE SPECIES SEGMENT [ REGENERATION NATIVES 67% 67% 97% 55% 50% EXOTICS 33% 33% 3% 45% 50% SEGMENT LENGTH 2 MILES 4 MILES 8 MILES 2 MILES 7 /4ILES 154 RANGELANDS15(4), August 1993

Kanab Creek— 1991. Willowdominating on VirginRiver-Beaver Dam Arizona—1966. Thena more open river. Vegetationis a mix of one bank andsaltcedar on the other. willows, cottonwoods, andsaltcedar. ment nine has only asmall amountof natives with the exotics dominating this segment. Livestock graze this segment in the winter and spring. Segment9A's wet zone is dominated by nativesedge/rushes. This has not had livestockgrazing since 1988. Regeneration Zone Theregeneration zone on theVirgin River (Table1) is, with the exception of segments six and 9A, dominated by tamarisk. Both those segments have been without grazing since 1970 and 1988. However, Segment six is co-dominated by canary reed grass and tamarisk. Segment 9A is dominated by willow. Segment eight'sregeneration zone hasbeen without grazing since1970, and shows more natives in its com- 1992. Vegetationis thicker with all species. Willow, saltcedar,some cottonwoods, and arrowweed. This is in Segment8, which has not hadgrazing since 1970's. But bigcotton- position than segments one through woods on the floodplain terranceare gone. five and about the same as segment the willow has more IV. Conclusion nine, which has Phenologically grazing. time after the livestock are What is observed from the data The zone native growth regeneration woody moved out, as the livestock are in and picturesare: species compositionof Kanab Creek Kanab Creek the same time periods 1. Thatthe Virgin Riverwas, in the is morediverse (Table 1). In segments and five there is a dom- as in the Virgin. The heat and dry early decades of this century,a wide three, four, weather on the causethe bottomed river with ri- inance or measurable of Virgin woody sandy some presence to in natives, willow vegetation slow or stop growing parian brush along its steambanks. mostly (Photo 5). and 2. No tamarisk had invaded the reason the willow is June, July, August. yet Perhaps, The summer months, however, onto its banks; more recent making a healthier stand against (1966) tamarisk in Kanab Creek along Kanab Creekprovide time and pictures (Photos 6 and 7) show the compared environment for domination of to the River is that Kanab good regrowth. the steambank by Virgin tamarisk but willow and cottonwood Creek is about 2,000 feet higher. are evidentalso. RANGELANDS15(4), August 1993 155

3. Where grazing has been more restrictedor stream bankshave been rested from grazing, the wet zone native riparian vegetation hasrespon- ded with redominance. 4. The regeneration zone's woody nativevegetation in the Virgin River in all segments appears to have been slower to respond to rest, both short and long term, and remainsdominated by tam arisk.Segment six has shown improvement, however. But it's not woody plants but reed grass. 5. Kanab Creek's regeneration zone has shown that woody natives, willows,can competeeffectively with tamarisk and in some areasdominate with seasonal grazing. The best management solution to thetamarisk, is towork with the riparian areasby providingrest fromgraz- ing, especiallyduring the spring and summer periods. This would allow a slow return of such nativeriparian plants as willows, cottonwoods, sedges, rushes, and cattails into the areas now occupied by exotics as tamarisk and rabbitfootgrass (Photos and 8 and 9). In this scenario, tamarisk, however, would remain a dominate,into the future, on the Vir- gin River and Kanab Creek but, with time, would give way and become a co-dominate in the riparian zone on these two river/creeksystems. Literature Cited Abbey, Edward. 1977. The journey home, First Edition. E.P. Dutton, N.Y. Brotherson, Jack D., and Dean Field. 1987. Tamarix: Impacts of a Successful Weed. Rangelands. 9:110-112.

Cottonwoodsovertopping tamarisk on the Virgin River nearSt. George, Utah. This area has not had grazing for an unknown number of years—probablysince the early 1980s.