WATER SOURCE DETERMINATION IN COTTONWOOD/WILLOW AND MESQUITE FORESTS ON THE SAN PEDRO RIVER IN ARIZONA K. A. Snyder, v. G. Williams, and v. L. Gempko, University ~f Arizona, Tucson 1. ABSTRACT &.\..1\d-SIl'.'. ~ .0 ~"' .. f' - . 1 - ~ - T his research investigated physiological and environmental controls on plant water-use and transpiration loss at the species-level. We identified water sources (precipitation, stream, soil moisture and/or groundwater) utilized by cottonwood (Populus fremontil), willow (Salix gooddingii) and mesquite (Prosopis velutina) in relation to patterns of seasonalmoisture stress, and consequencesof plant water sources for stomatal regulation of transpiration. Results indicate that cottonwood, along perennial and intermittent stream reaches in Arizona did not utilize soil moisture derived from monsoon precipitation and were primarily dependent on ground- water, however, at an ephemeral site cottonwood utilized monsoon derived Cant. page 3...SALSA Inside This Issue ..2 ..2 ..7 ..8 ..9 .II .13 {Editors' Note: The San Pedro River ecosystemis one of the country's most significant riparian areas. Of particular interest in Arizona is the San Pedro National Riparian Conservation Area (SPNRCA). An internationallong-term research program termed Semi-Arid Land-Surface- Atmosphere (SALSA), was launched to understand, model, and predict the consequences of natural and human changes on the basin-wide water balance and ecological di\'ersity at event to decadal time scales. The current research isfocused on the San Pedro River basin, both in Mexico and the United States. Primary priorities of the research ~ - efforts during 1997 included basin- - wide mesoscalemeteorological modeling. upland estimation of variations in the surface energy and I "'ater balance and estimation of e\'apotransporation, and surface water and groundwater interactions in the riparian system. The following article is 1 of 31 presented at a Special Symposium on Hydrology, Session on Integrated Observations of Semi-Arid Land-Surface-Atmosphere Interactions during the American Meteorological Society (AMS) Meeting held in Phoenix, Arizona, January 11-16, 1998. A SALSA web site has been established to provide additional information on research efforts by SALSA team members. The address is: http: Ilwww. tucson. ars.ag.govlsalsalsalsahome. html Please treat this article as proyisional and use it only as a research aid. The AMS published preprints, available in January 1998, will be considered thefinal versions of thesedocuments. The article here isfrom the webpage and should be used as research information only.] President's Message. Volunteer Comer AWPFWebSite Fall Campout Spring Meeting Species Profile Legal Issues
Transcript
WATER SOURCE DETERMINATION IN COTTONWOOD/WILLOW
AND MESQUITE FORESTS ON THE SAN PEDRO RIVER IN ARIZONAK. A. Snyder, v. G. Williams, and v. L. Gempko, University ~f Arizona, Tucson
1. ABSTRACT
&.\..1\d-SIl'.'.~ .0~"' ..f' -
. 1-~ -
T his research investigatedphysiological andenvironmental controls on plantwater-use and transpiration loss
at the species-level. We identified watersources (precipitation, stream, soilmoisture and/or groundwater) utilized bycottonwood (Populus fremontil), willow(Salix gooddingii) and mesquite(Prosopis velutina) in relation to patternsof seasonal moisture stress, andconsequences of plant water sources forstomatal regulation of transpiration.Results indicate that cottonwood, alongperennial and intermittent stream reachesin Arizona did not utilize soil moisturederived from monsoon precipitation andwere primarily dependent on ground-water, however, at an ephemeral sitecottonwood utilized monsoon derived
Cant. page 3...SALSA
Inside This Issue..2..2..7..8..9.II.13
{Editors' Note: The San Pedro River ecosystem is one ofthe country's most significant riparian areas. Of particularinterest in Arizona is the San Pedro National RiparianConservation Area (SPNRCA). An internationallong-termresearch program termed Semi-Arid Land-Surface-Atmosphere (SALSA), was launched to understand, model,and predict the consequences of natural and humanchanges on the basin-wide water balance and ecologicaldi\'ersity at event to decadal time scales. The currentresearch is focused on the San Pedro River basin, both inMexico and the United States.Primary priorities of the research ~ -
efforts during 1997 included basin- -
wide mesoscale meteorologicalmodeling. upland estimation ofvariations in the surface energy and I"'ater balance and estimation ofe\'apotransporation, and surfacewater and groundwater interactionsin the riparian system.
The following article is 1 of 31 presented at a SpecialSymposium on Hydrology, Session on IntegratedObservations of Semi-Arid Land-Surface-AtmosphereInteractions during the American Meteorological Society(AMS) Meeting held in Phoenix, Arizona, January 11-16,1998. A SALSA web site has been established to provideadditional information on research efforts by SALSA teammembers. The address is:http: Ilwww. tucson. ars.ag.govlsalsalsalsahome. htmlPlease treat this article as proyisional and use it only as aresearch aid. The AMS published preprints, available inJanuary 1998, will be considered the final versions ofthese documents. The article here is from the web pageand should be used as research information only.]
President's Message. Volunteer Comer AWPFWebSite Fall Campout Spring Meeting Species Profile Legal Issues
The Arizona Riparian Council 2 1998 Vol. 11, No.1
PRESIDENT'S MESSAGE
DESERT PRESERVATION PARTNERSHIP
o n January 15, 1998,I represented theArizona RiparianCouncil at a meeting
at City Hall in Phoenix. Themeeting was held by MayorSkip Rimsza and his staff todiscuss plans for acquisition ofpreserve lands in far northPhoenix. The area is referredto as the Sonoran PreserveInitiative and will include theacquisition of 15,000 acres ofState Trust Lands. Accordingto the Mayor, lands will beacquired using city revenues.No new taxes will be imposed.
The proposed preserveincludes about 14 differentareas north of Pinnacle PeakRoad between 67th Avenueand Tatum Boulevard. Itincludes a broad corridoralong Cave Creek, south ofCarefree Highway. Biologicalvalues of the Cave Creek areawere evaluated by a team ofecologists and biologists fromthe School of Planning andLandscape Architecture and
these lands. Then, the city willhave to bid on the lands atauction. If successful, this willbe the fIrst preserve to bepurchased under the DesertInitiative Act.
After reviewing the resultsof the preservation boundarystudy, I believe the ArizonaRiparian Council shouldendorse and support this effortto protect this important desertwash. I have reservationsabout the future impacts ofadjacent development in thearea. But it appears they intendto purchase substantial bufferlands adjacent to the wash.
For more informationregarding this proposal,contact Eric Gorsegner ,Assistant to the Mayor, City ofPhoenix, at (602) 262-7111, orJames P. Burke, DeputyDirector, City of PhoenixParks and RecreationDepartment at (602) 534-1870.Maps of the proposed area areavailable.
the Life Sciences Departmentat Arizona State University ,Northern Arizona University ,Desert Botanical Gardens , andArizona Game and FishDepartment. A document,titled Cave Creek Wash:Preservation Boundary Study ,contains their evaluation ofand recommendations for thearea.
Mayor Rimsza is in theprocess of building support forthis project before asking theCity Council to endorse theplan. He believes that if thearea is not acquired now, theopportunity will be lostforever. Development isoccurring rapidly at thenorthern boundaries of thecity .The City Council will beasked to adopt the plan at anopen meeting held at 2:30p.m. on Wednesday, February17. If adopted, the city willfile an Arizona PreserveInitiative application asking theState Land Department for aconservation designation on
VOLUNTEER CORNER-
Inwood, Nominations Chair ,to be put on a list ofcandidates for the office. Youmust be a current member ofthe Council. Duties includemaintaining the Council'sfunds, arranging meetingfacilities with vendors, etc.Elections take place at thespring meeting. The term ofoffice for Treasurer is three
years and there are two yearsremaining in the current term.
Ruth Valencia needsvolunteers to help her seekdonations for the springmeeting. Ruth may be reachedat (602) 417-2400 X7012.
For further information,contact Cindy (602) 965-2490or Jeff (602) 263-9522.
T he Arizona Riparian
Council always needs
people who will helpat environmental
education fairs with our booth.This can sometimes be withshort notice and is often onweekends.
Our Treasurer has resigned.If anyone is interested in thisposition, please contact Jeff
The Arizona Riparian Council 3 1998 Vol. 11) No.1
(Cont. from page 1 SALSA)soil moisture. Mesquite shiftedbetween groundwater and soilmoisture in response tochanging climatic andhydrologic conditions .Mesquite likewise had agreater ability to withstandincreasingly negative middaywater potentials. In contrast,cottonwood and willowappeared to regulate middaywater potentials to -1.5 MPa,indicating that reliance on deepgroundwater may be indicativeof highly regulated stomatalcontrol on transpiration.
2. INTRODUCTION
the critical xylem pressuresthat induce cavitation (Tyreeand Sperry 1988). Previousresearch demonstrates thatcavitation occurs incottonwood and willow shootsat less negative xylempressures (pockman et al.1995) than in mesquite(pockman 1996) .Plantsadapted to using soil moisturewill necessarily experiencelow soil water potentialsfavoring cavitation.Consequently, vulnerability tocavitation may correlate withwater source acquisitionstrategies and stomatalbehavior for these species.
In this research we relatedpatterns of water sourceutilization with patterns ofstomatal regulation, both ofwhich may be operating toavoid cavitation. To examinethese patterns we contrastedthe obligate phreatophytescottonwood (Populusfremontil) and willow (Salixgooddingil), with mesquite(Prosopis velutina) which isable to exist in both riparianand upland environments.Three principal researchquestions were posed. First,we asked if variations ingroundwater or stream wateravailability influence theamount of rainfall derived soilmoisture used by thesespecies. We hypothesized thatspecies with access to astablewater source, in this casegroundwater or perennialstreamwater, would be lesslikely to expend carbon togrow lateral surface roots toacquire sporadic precipitation.T o examine this hypothesis ,we studied stomatal and wateracquisition behavior at sites
Of great concern is howhuman alterations ofhydrology and climateinfluence terrestrialvegetation. One such exampleis the alteration of riparianecosystems by groundwaterpumping and surface waterdiversions. In semiarid andarid regions of the world,these impacts have produceddramatic structural and speciescomposition changes inriparian systems (Strombergand Patten 1990). Obligateriparian species, such ascottonwood 'and willow, willregulate water-use in amarkedly different mannerthan the more droughtresistant mesquite, whichaffects water-use efficiencyand carbon acquisition,ultimately influencingcompetitive advantage andplant distribution. Thisresearch attempts to elucidatehow different tree speciesfound within riparian systemsand adjacent uplands utilizeavailable water and how these
patterns of water-use affectspecies distribution andproductivity .
Recent studies in aridenvironments have shown thatplants may not be using waterfrom all potential sources(Dawson and Ehleririger1991), Lin et al. 1996). Depthof water extraction has beenfound to vary among species(Ehleringer and Dawson 1992,Flanagan et al. 1992) as wellas within a species (Donovanand Ehleringer 1994, Williamsand Ehleringer in review). Weinvestigated seasonal patternsof water source utilization ofsemi-arid riparian tree speciesbecause it is likely thatspecies-specific ability toutilize water from one or morehydrologic compartments hasimplications for plant andstand-level transpiration(Schaeffer and Williams, thisvolume) and plant hydraulicarchitecture .
Hydraulic architecture ofdominant plants may have animportant role in detenniningthe structure and sustainabilityof plant communities andecosystem processes. Xylemcavitation, the vaporization ofwater under negative pressure
during drought, interruptsplant water transport.Cavitation occurs when xylemsap, which is under tension(pockman et al. 1995), reachescritically low pressures and airbubbles are pulled into xylemconduits (Tyree and Sperry1988). Xylem pressure is aresult of transpiration, whichis regulated by stomata, andsoil water potential. Cavitationis injurious to plants, sostomata may operate to controltransportation at a level below
(Ehleringer and Dawson 1992,BruneI et al. 1995). Duringeach sample period, soils forisotopic analysis werecollected at each site from 5,10, 25, 50 and 100-cm depths.At each sampling period and atall sites, streamwater wascollected and groundwater wassampled containing a layer ofmineral oil to minimizeevaporation. Precipitation wascollected monthly throughout1997 and more frequentlyduring the monsoon season .
(July-September). Using apressure chamber, water stresswas quantified withmeasurements of predawn leafwater potential ('P pd) andmidday leaf water potential('P md) .
characterized by differentstreamflow and groundwatercharacteristics. Although otherstudies have found thatobligate phreatophytes did notutilize soil moisture (Busch etal. 1992), we speculated that,as conditions become lessfavorable for species existenceand cavitation becomes moreexcessive, a species will utilizeother water sources.
Second, we hypothesizedthat the water acquisitionstrategy and vulnerability tocavitation of a species wouldtranslate into definablepatterns of stomatal regulationof transpiration. If this is thecase, trees primarilydependent on groundwatershould be relatively insensitiveto seasonal soil moisturedrought. Third, it ishypothesized that differencesin these integrated patterns ofwater-use will explaindifferences in the speciesdistribution of cottonwood,willow, and mesquite.
4. RESULTS AND DiSCUSSiON
and Escapule Wash (EW),respectively. Sites along theSan Pedro were selected inclose proximity to encompassvarying hydrologic regimesand with the target species(cottonwood, willow andmesquite) present. Theephemeral site appears to bethe extreme hydrologicboundary of willow andcottonwood. At EW the standof cottonwood and willow wassparse and graded into amesquite communityupstream.
At each site 7-10individuals of each specieswere randomly selected asstudy plants. Each individualwas repeatedly sampled at keytimes (spring, summerdrought, and monsoon season)throughout the growing seasonto determine seasonal patternsof water source use. Stableisotopes of oxygen in xylemsap extracted from twigsamples were used as a naturaltracer for measuring plantfractional uptake fromgroundwater, soil moisture,streamwater and precipitation
3. METHODS
Figure 1. Variations in the mean tJI80 value
of xylem sap in cottonwood and mesquite
during drought conditions in June and
following a monsoon rain in August.
A pilot study wasconducted in 1996 alongan intermittent reach ofRincon Creek. In 1997 amore extensive study wasconducted along the SanPedro River in south-eastern Arizona. ThreeSan Pedro sites wereselected to represent agradient in surface wateravailability and depth togroundwater. Thehydrologic regime variedfrom perennial tointermittent to ephemeralat Lewis Springs (LS),Boquillas Ranch (BQ)
Monsoon rains had 0180values ranging from 0.8 to 2.0(%0), and groundwater hadstable values throughout theyear, averaging -8.6 (%0). Wefound little variation in the0180 values of cottonwoodxylem sap sampled at LS-during the June drought
and in August after asignificant input ofmonsoon precipitation(26.7 mrn) .This indicatesthat cottonwood did notutilize surface soil moistureat the perennial site (LS),and relied primarily ongroundwater (Fig. 1), evenafter significant monsoonrain. However, at theephemeral site 0180 ofcottonwood showedenrichment in Augustrelative to xylem sapsampled in June, indicatinga fraction of xylem sap was
The Arizona Riparian Council 5 1998 Vol. 11, No.1
rrtrI$!)0'1 ranall
6 1 80 (%0 )
.grourxt.o.tater
derived not from more plausible.groundwater, but from Results at Rinconsoil moisture. This Creek indicate thatcontrasts with previous willow experiencedresearch (Busch et al. monsoon moisture1992) which found (5180=6.8) (Fig. 2).cottonwood to utilize Willow samples wereonly deep groundwater collected after a rainfallat the Colorado River event in July of 1996.and the Bill Williams This is in contrast toRiver in Arizona. previous research (BuschCottonwood trees at et al. 1992) that foundEW experienced willow to utilize onlygreater water stress deep groundwater .With mean 'Pmd Further analysis ofdeclining to -2.5 MPa samples will need to beduring the summer Figure 2. Variations in the mean l5JBO signature completed before specificdrought, while of xylem sap for dominant woody plants at conclusions can becottonwoods at LS Rincon Creek, an intermittent stream in reached about willowmaintained mean 'Pmd southeastern Arizona. Plant species are netleaf growing along the Sanof -1.5 MPa. Whether hackberry (Celtis laevigata), velvet ash Pedro.cottonwood switches to (Fraxinus velutina), mesquite, Goodding willow, Stoma~1 regulationwater uptake by lateral Fremont cottonwood and seepwillow (Baccharis patterns dIffered betweensurface roots is not glutinosa). ' the obligate phreatophytes
known as the isotopic and mesquite. Thevalue may not relationship between 'P pdrepresent a shift in the activity and 'Pmd at LS (Fig. 3)of roots used to take up water. indicates that regardless ofHowever, the 5180 value of 'P pd' 'Pmd are maintained atthe groundwater remained a -1.5 MPa for both willow andconsistent -8.7 (%0) cottonwood. In contrast,throughout the summer, mesquite exhibitedsuggesting that roots higher in considerable variation in 'P md .the sol profile were being used 'P pd are a measure of soilto uptake water. Regardless of moisture conditions with morethe functional rooting depth negative values reflectingfor water uptake, these results decreased soil moistureindicate that summer rainfall is availability .The negligiblean imponant contribution to slope of the relationship forcottonwood water supply at a cottonwood and willowsite marginal for the existence indicates that these speciesof this species. maintain a critical level of 'Pmd
Mesquite xylem water, as water availability declines.sampled in August, showed Maintenance of stable 'Pmd5180 enrichment at both sites under conditions of decreasedcompared to xylem water water availability may besampled in June, indicating accomplished either by 1)that mesquite utilized monsoon dynamic regulation ofmoisture at both the ephemeral transpirational water loss byand perennial sites (Fig .1) .stomatal regulation, 2)August mesquite xylem water increased soil-to-leaf hydraulic
was enriched relative to Junexylem water by 3.9%0 at theephemeral site and by 1.4%0at the perennial site. Mesquiteappeared to respond moredramatically to rainfall eventsat the ephemeral site comparedto mesquite populations at theperennial site. Two processesmay be responsible for theapparent difference in themagnitude of response ofmesquite: 1) sites with lessgroundwater and surface waterpromote greater utilization ofsoil moisture, or 2) themagnitude of response isactually the same at both sites,but the clayey soil texture atLS has a dampening effect onthe isotopic value of rainfallby mixing with older soilwater. Construction of theisotopic profile of the soil willelucidate which explanation is
conductance, or 3) decreasedleaf area. In contrast, mesquitetolerates a wide range of 'Y md'indicating greater tolerance tolow water potentials, and lessstomatal regulation of
transpiration.Previous research found
that cottonwood and willowstems may reach completecavitation by xylem pressureof -2 to -3 MPa (pockman etal. 1995). This indicates that
type relationships tocharacterize processescontrolling transpiration atecosystem or basin scales. Onecritical parameter may be theregulation of stomata to nearcritical cavitation levels .
Cottonwood and willowappear to rely on groundwateruntil irreversible cavitationlevels are reached. Theirtolerance of low waterpotentials is substantially lessthan that of mesquite, and theymust maintain a high degree oftranspiration regulation. Thesedata provide further evidencethat declining water tables willhave a disproportionate effecton the sustainability ofobligate riparian trees, such ascottonwood and willow, whichare critically tied togroundwater levels .
6. ACKNOWLEDGMENTS
Financial support from theUSDA-ARS Global ChangeResearch Program, NASAgrant W-18,997 and USDANational Research InitiativeGrant Program is gratefullyacknow ledged .
architecture of riparian treeroot systems; not all sourcesof available water are usedequally. Water usage dependson the species present and thehydrologic conditions. Stableisotopic analysis identifiesplant water uptake fromvarious hydrologiccompartments. The complexand highly plastic behavior ofmesquite must be consideredin relation to water
availability .~ Similarly, even
obligatephreatophytes mayexhibit flexibility inwater sources atecotones where theconditions for theirsurvival aremarginal. Our dataindicate thatobligatephreatophytesregulate criticalwater potentials in adifferent manner
Figure 3. Relationship between predawn than the more(IJI ~ vs. midday (IJI nJ water potential drought tolerantthroughout the entire growing season of mesquite. Patternscottonwood, willow, and mesquite sampled of stomatalat a perennial reach (Lewis Springs) of the regulation coupledSan Pedro River. with water source
investigations couldprove to be useful
for determining plantfunctional types (Williams etal. , this issue). Reliance on asingle water source, whileother sources of water areavailable may be indicative ofplants that are extremelyvulnerable to cavitation andexhibit more stomatalregulation of transpiration. Ifthese water-use relationshipsare determined for a variety offunctional types then it may bepossible to scale up functional
7. REFERENCES
cottonwood and willow at LSmay be regulating 'P md toavoid cavitation. At theephemeral site cottonwoodutilized precipitation derivedsoil moisture, perhaps a resultof the decrease in 'Pmd to -2.5MPa, a level which is likelycausing significant cavitation.
5. CONCLUSIONS
Site hydrology has aninfluence on the functional
BruneI, J. P., G. R. Walkerand A. K. Kennett-Smith,1995: Field validation ofisotopic procedures fordetermining source waterused by plants in a semi-arid environment. Journalof Hydrology, 167, 351-268.
Busch, D. E., N. L. Ingiahamand S. D. Smith, 1992:Water uptake in woodyriparian phreatophytes ofthe southwestern United
The Arizona Riparian Council 7 1998 Vol. 11, No.1
Management, 14, 185-194.Tyree, M. T. and J. S.
Sperry , 1988: Do woodyplants operate near thepoint of catastrophic xylemdysfunction caused bydynamic water stress? PlantPhysiology, 88, 574-580.
Williams D. G. and J. R.Ehleringer, (submitted):Summer precipitation useby three semi-arid treespecies along a summer
precipitation gradient.
7.1 REFERENCES
IN THIS ISSUE[SALSA's issue, not ARC]
Schaeffer, S. and D. Williams,Transpiration of desertriparian forest canopiesestimated from sap flux.
Williams, D. CJ., J. 1>. J3runel,S. M. Schaeffer and K. S.Snyder, J3iotic controlsover the functioning ofdesert riparian ecosystems.
juniper woodland. Plant,Cell, and Environment, 15,831-836.
Lin, G. S. L. phillips and I.R. Ehleringer, 1996:Monsoonal precipitationresponses of shrubs in acold desert community onthe Colorado Plateau.Oecologia, 106,8-17.
Pockman, W. T., I. S. Sperryand I. W. O'Leary, 1995:Sustained and significantnegative water pressure inxylem. Nature, 378, 715-716.
Pockman, W. T., 1996:Xylem cavitation and thedistribution of SonoranDesert vegetation. Ph.D.Dissertation, University ofUtah.
Stromberg, I. C. and D. T.Fatten, 1990: Riparianvegetation instream flowrequirements: a case studyfrom a diverted stream inthe eastern Sierra Nevada,California. Environmental
States: a stable isotope study.
Ecological Applications, 2,450-459.Dawson, T. E. and J. R.
Ehleringer, 1991 :Streamside trees that do notuse stream water. Nature ,350, 335-337.
Donovan, L. A. and J. R.Ehleringer, 1994: Waterstress and use of summerprecipitation in a GreatBasin shrub community .Functional Ecology , 8, 289-297.
Ehleringer, J. R. and T. E.Dawson, 1992: Wateruptake by plants :perspectives from stable
Flanagan, L. B., J. R.Ehleringer and J. D .Marshall, 1992:Differential uptake ofsummer precipitationamong co-occurring treesand shrubs in a pinyon
Arizona Water Protection Fund Launches Web Site!!!
T he Arizona Water
Protection Fund
(A WPF) is in the finalstages of constructing its
Web site with the assistance ofthe Water Resources ResearchCenter staff in Tucson. TheWeb site is designed to be asource of information for pastand perspective grant appli-cants, other agencies, legis-lators, and the general public.
Established by theLegislature in 1994, thepurpose of the A WPF is toprovide monies "for the
development and irnplementa-tion of measures to protectwater of sufficient quality andquantity to maintain, enhanceand restore rivers and streamsand associated riparianresources. II The Legislature
also created the A WPFCommission to administer thefund and is composed of 15voting members and 4 non-voting ex-officio members.
The Web site will provideinterested parties theopportunity to access thefollowing information:
.common questions andanswers (with links to the
enabling legislation) ;.past Commission meeting
minutes;.past A WPF newsletters;.staff contacts ;.commissioner information;
and.a multi-media searchable
database.
The searchable databaseallows viewers to accessinformation on current andprevious A WPF projects
The Arizona Riparian Council 8 1998 Vol. 11, No.1
any further questions, pleasecontact Lisa Jackson at(602) 417-2448.
~
including: dollar amountawarded, project summary andcontact person, map of projectarea, photos and status .
Interested parties will alsobe able to e-mail theCommission directly throughthe Web site to receive furtherinformation, or makecomments.
This spring, the 1998application forms will beavailable on the Web Site foruse by potential applicants.For those interested, theAWPF address will be:
www .awpf.state.az.usand the Web site should beaccessible to the public aroundJanuary 1, 1998. If you have
FALL CAMPOUT AND GET TOGETHER
meal was produced byBuckaroo BBQ and it wasenjoyed by all.
After dinner, Tim Snow,Bill Burger, and MarikayRamsey from Arizona Gameand Fish Department set upmist nets to catch bats overthe stream. They had anecholocation device whichcould detect the bats andvisually display their callson a laptop computer screen.It was really quitefascinating and interesting .As the evening progressedthey monitored bat activityfor some time while somepeople gathered around the
campfire and visited.Finally, around 9 PMthey caught a juvenilefemale hoary bat, whichTim said was a rarefind!
Saturday morning wesplit into two groups and
enjoyed fields trips led byJanet Johnson and LynnMason to an exclosure alongCamp Creek and by ScottWoods to the Sears Kayruins.
T he weekend campoutfor the ArizonaRiparian Council thispast October 18-19,
1997 was well attended andenjoyed by all. We campedat the Tonto National Forest,Cave Creek Ranger -District, AshdaleAdministrative Site.
IDr. Robert Smithand Jon Hokstra,graduate student,University of Arizona,gave us a presentationabout crayfish and theirdistribution in the state. Ifanyone has information onlocations of crayfishthroughout the state pleasecontact him atbobsmith@ag .arizona. edu .The boys from the WebelosScouts who attended thecampout had a great timecatching specimens forthem! After that informativetalk, everyone wentstreamside to Cave Creek tosee how riparian streamassessments were conducted.Janet Johnson and LynnMason from the TontoNational Forest sho~ed howthey assessed streams using
the Tonto National ForestRiparian Area and StreamChannel Inventory andAssessment Methods whichinclude Rosgen'sClassification, PfankuchStreambank Stability Rating,
pebble counts, and theBureau of LandManagement's ProperFunctioning ConditionAssessment. Theirassessment of CaveCreek was "impaired"or "functioning at risk. "
Dr. Robert Ohmart, ArizonaState University , also talkedto the group streamside andgenerally agreed with theassessment of thestream made byJanet and Lynn. Healso told us aboutthe RapidAssessment ofRiparian Systems(RARS) that isbeing worked on at ASU forthe Arizona Game and Fish
Department.The rest of the afternoon
was spent relaxing, birdwatching, hiking, andoverall just enjoying thesurroundings. An excellent
The Arizona Riparian Council 10 1998 Vol. 11, No.1
year and shall be eligible forre-election.
Vice President. The VicePresident shall assist the Pres-ident in duties where needed.In the absence of the President,or in the event of the inabilityof the President to act, thePresident's duties shall beassumed by the Vice President.The Vice President shall servein office for one year and shallbe eligible for re-election.
Treasurer. The Treasurershall serve as general businessmanager. The Treasurer shallbe responsible for coordinatingwith the Secretary upon receiptof funds and shall disburse allfunds of the Council. A reportconcerning all activities of thepreceding year, and an auditingof accounts for that year shallbe made by the Treasurer to the
If you are a current memberand are interested in any ofthese offices, please contactJeff Inwood at (602) 263-9522.
Howard Kopp was electedTreasurer last year, butresigned last fall due to othercommitments. The Treasureracts as the business managerfor this organization. Wedesperately need to fill thisvacancy with someone who iswilling to oversee our finances.Another importantresponsibility of the position isarranging facilities, with theSecretary , for the spring andfall meetings. You do not needto be an accountant and it doesnot take a large commitment oftime. It just takes a willingnessto work with the group.
Council at its Annual Meeting,and at any time requested bythe President. In the eventneither the President, the VicePresident, nor the Secretary canserve in their capacity , theTreasurer will serve pro-tempore. The Treasurer shallserve in office for three yearsand shall be eligible for re-election. (The individualelected for this position willcomplete Howard's term ofoffice with two years left.)
Member-at-Large. At-largemembers of the Council shallbe elected to the Board ofDirectors by the majority voteof members at the Council'sAnnual Meeting. The at-largemembers shall assist theofficers with their duties whennecessary (completion of Pat'sterm of one remaining year).
ARIZONA WATER PROTECTION FUND
APPROVED GRANT APPLICATIONS .1997 FUNDING CYCLE
:~~
Pima County Flood Control District $83,179.00Bingham Cienega Riparian Restoration Project
$126,315.00Watershed Improvement to Restore Riparian and Aquatic
Habitat on the Muleshoe RanchThe Nature Conservancy
$154,580.00Atturbury Wash Project City of Tucson Water Dept.
$88,730.00Altar Valley Conservation Alliance
& Pima NRCDAltar Valley Watershed Resource Assessment
$228,800.00Ahakhav Tribal Preserve -Deer Island Revegetation Colorado River Indian Tribes
$69,100.00Walnut Creek Center for Education and Research-
Biological InventoryYavapai Community College
$91,110.00Demonstration Enhancement of Riparian Zone and StreamChannel along a Stretch of Pueblo Colorado Wash atHubbell Trading Post National Historic Site
National Park Service
APWF Table Cont. page 14
I
The Arizona Riparian Council 11 1998 Vol. 11, No.1
SPECIES PROFILE
THE USE OF XERORIPARIAN SYSTEMS BY DESERT MULE DEERbv Paul R. Krausmanc The Unfv~Hi!Y--.Qf Arizona
D esert mule deer( Odocoileushemionus crooki)inhabit the Sonoran
and Chihuahuan deserts ofNorth American; their rangeextends from southwestTexas to western Arizonaand south into centralMexico. These desert muledeer are an important gameanimal with increasingpopularity in Mexico.Although they are one of thedominant large mammals insouthwestern deserts, theyhave not received muchattention from the scientificcommunity. Behavior ,general ecology, diet,movements, and habitat havebeen examined in isolated
Fig. 1. Mule deer distribution inArizona (Arizona Game andFish Department Website,January 1998.http://www.gfstate. az. us/frames/fishwi ldlidx ~ame. htm)
association and the type ofwash. In general, washsystems in lower plantdensity associations arewider than those with highplant density associations.The largest washes used bydesert mule deer are over350 m wide.
At the eastern edge oftheir range the vegetationwithin wash systems is notsimilar to perennial speciescomposition of adjacentareas and species overlapbetween the two areas isminimal. However, plantspecies diversity is greater inwashes than in adjacentareas. Deer using plantassociations with low plantdensities probably fmd moreforage in washes than inadjacent areas.
On the western edge oftheir range there is a markeddifference betweenvegetation in washes andvegetation in areas adjacentto or between washes. Thereare less than two plants per100 m2 and these areasprovide very little forage fordeer and no shaded bedsites .Also, most preferred foragespecies are uncommon ornot found outside of thewashes.
These vegetationcharacteristics are importantto deer. Where washvegetation is more abundant(e.g. , eastern part of range)
areas and habitat studieshave been general. Fewstudies have examinedhabitat of desert mule deeracross their range and littleis known of theirdependence on riparianareas. However, biologiststhat have examined desertdeer report that riparianareas are an important partof desert mule deer habitat.
Across their range fromBig Bend National Park,Texas, in the east throughAvra Valley near Tucson,Arizona, to the northwesternedge of their range in KingValley , Arizona, desert muledeer use riparian areas. Inthe King Valley most plantlife is restricted toxeroriparian drainages. Theareas between drainages areusually covered with wind-eroded desert pavement andhave no vegetation or verysparse stands of creosotebush (Larrea tridentata),brittlebush (Enceliafarinosa), and white burs age(Ambrosia dumosa).Dominant overstory speciesin the washes include plantsthat serve as forage andthermal cover, an importanthabitat component,especially during hot wetand hot dry seasons .Theaverage width of washes inmule deer habitat rangesfrom 3.8 to 25.0 m,depending on the plant
The Arizona Riparian Council; 12 1998 Vol. 11,0
Service GeneralTechnical ReportRM-120.
Kucera, T. w. 1978. Socialbehavior and breedingsystem of the desert muledeer. Journal ofMammalogy 59:463-476.
Ordway, L. L., and P. R.Krausman. 1986. Habitatuse by desert mule deer .Journal of WildlifeManagement. 50:677-683.
Rautenstrauch, K. R. , andP. K. Krausman. 1989.
.Influence of wateravailability and rainfallon movements on desertmule deer. Journal ofMammalogy 70:197-201.
desert mule deer are thelargest (native).Conservation efforts have toensure these importanthabitat components are notmodified so they are nolonger available to wildlife.
REFERENCES
Krausman, P. R., A. I.Kuenzi, R. C.Etchberger, L. L.Ordway, K. R.Rautenstrach, and I. I.Hervert. 1997. Diet ofdesert mule deer in theUnited States. Journal ofRange Management50:513-522.
Krausman, P. R., K. R.Rautenstrauch, and B. D.Leopold. 1985.Xeroriparian systemsused by desert mule deerin Texas and Arizona.Pages 144-149 in R. R.Iohnson, C. D. Ziebell,D. R. Patton, P. F.Ffolliot, and R. H.Hamre, tech. coords. ,Riparian ecosystems andtheir management:reconciling conflictinguses. USDA Forest
Paul R. Krausman inProfessor, Wildlife andFisheries Sciences, TheUniversity of Arizona. Hecan be reached at (520) 621-3845 or emailed atkrausman@ag. arizona. edu
More information canalso be found about the muledeer at the Arizona Gameand Fish Department's Website athttp : / /www .gf. state. az. us
deer use washes or areimmediately adjacent towashes (i.e., within 30 m)9% of the time. Astemperatures increase andrainfall decreases movingwestward, vegetationrecedes to washes followedby desert deer. In centralArizona deer use washes42% of the time in winter ,increasing to 83 % in thesummer. In the arid and hotKing Valley , desert muledeer used washes 99% of thetime! I)eer in these areas areusing washes as they provideforage, cover, travel lanes,and birth sites;
Xeroriparian systems arean important part of desertmule deer habitat; in aridranges that cannot beoverlooked. Unfortunately,competition for deserts bymining companies, livestockoperators, offroad vehicles,housing developers, andnumerous other humanactivities often look at desertmule deer habitat as"unproductive " because
animal abundance is notevident. Xeroripariansystems provide habitat foran array of wildlife of which
I 'I,~
Service GeneralTechnical ReportRM-120.
Kucera, T. w. 1978. Socialbehavior and breedingsystem of the desert muledeer. Journal ofMammalogy 59:463-476.
Ordway, L. L., and P. R.Krausman. 1986. Habitatuse by desert mule deer .Journal of WildlifeManagement. 50:677-683.
Rautenstrauch, K. R. , andP. K. Krausman. 1989.
.Influence of wateravailability and rainfallon movements on desertmule deer. JournalofMammalogy 70:197-201.
desert mule deer are thelargest (native).Conservation efforts have toensure these importanthabitat components are notmodified so they are nolonger available to wildlife.
REFERENCES
Krausman, P. R., A. I.Kuenzi, R. C.Etchberger, L. L.Ordway, K. R.Rautenstrach, and I. I.Hervert. 1997. Diet ofdesert mule deer in theUnited States. Journal ofRange Management50:513-522.
Krausman, P. R., K. R.Rautenstrauch, and B. D.Leopold. 1985.Xeroriparian systemsused by desert mule deerin Texas and Arizona.Pages 144-149 in R. R.Iohnson, C. D. Ziebell,D. R. Patton, P. F.Ffolliot, and R. H .Hamre, tech. coords. ,Riparian ecosystems andtheir management:reconciling conflictinguses. USDA Forest
Paul R. Krausman inProfessor, Wildlife andFisheries Sciences, TheUniversity of Arizona. Hecan be reached at (520) 621-3845 or emailed atkrausman@ag. arizona. edu
More information canalso be found about the muledeer at the Arizona Gameand Fish Department's Website athttp : / /www .gf. state. az. us
deer use washes or areimmediately adjacent towashes (i.e., within 30 m)9% of the time. Astemperatures increase andrainfall decreases movingwestward, vegetationrecedes to washes followedby desert deer. In centralArizona deer use washes42% of the time in winter ,increasing to 83 % in thesummer. In the arid and hotKing Valley , desert muledeer used washes 99% of thetime! Deer in these areas areusing washes as they provideforage, cover, travel lanes,and birth sites;
Xeroriparian systems arean important part of desertmule deer habitat; in aridranges that cannot beoverlooked. Unfortunately,competition for deserts bymining companies, livestockoperators, offroad vehicles,housing developers, andnumerous other humanactivities often look at desertmule deer habitat as"unproductive" becauseanimal abundance is notevident. Xeroripariansystems provide habitat foran array of wildlife of which
The Arizona Riparian Council 13 1998 Vol. 11, No.1
LEGAL ISSUES OF CONCERN
Kimberly MacEachern, Law Offices of Kane Jorden von OppenfeldBischoff & Biskind, P.L.C.
FLEXING THE MUSCLE OF CLEAN WATER ACT §401
Any applicant for aFederal license or permitto conduct any activity ...,which may result in anydischarge into thenavigable waters, shallprovide. ..a certificationfrom the State. ..that anysuch discharge willcomply with applicablesections of [effluentlimitations, water quality
standards, performancestandards and
pretreatment standards].
T he Clean Water Act(CW A) is 25 years old,but some of its musclehas not been flexed. pro-
grams for controlling pointsource pollution are maturing,but water pollution is not yet athing of the past. Naturally,attention is turning to nonpointsources of pollution. Much likea circuit weight trainee movesfrom machine to machine todevelop muscle mass, regula-tors and environmentalists arecombing the Clean Water Actlooking for ways to bulk up themeasures that could reducenonpoint pollution. The musclemass of one provision,commonly known as §401,which requires states to certifythat a permitted discharge willmeet the surface water qualitystandards, is being flexed innew ways that may directlyeffect riparian areas .
Traditionally, states haveissued certifications underCWA §401 for NPDES permitsissued by EP A and Dredge andFill (§404) permits issued bythe U .5. Army Corps of Engi-neers. 33 U.S.C.A. §1341,1342, 1344. The certificationreflects the state's conclusionthat the terms of the Federalpermit, or any conditions thestate attaches to the permit, willprotect the quality of the waterimpacted by the permitteddischarge. Through this author-ity the state can delay or evenblock the issuance of a permituntil conditions are added tomeet the state's concerns:
to act at all will trigger thewaiver. Id. at F.
The ARP A legislation was areaction to what it perceived asunnecessary delays andinefficiencies in the ADEQprocess. But it was also in parta reaction to the fIrst case thatreally tested the breadth of the§401 power. In 1994, theUnited States Supreme Courtupheld the a state conditionrequiring minimum instreamflows in a Federal EnergyRegulatory Commission(FERC) license for ahydroelectric power plant nearOlympic National Park inWashington. PUD No.1 ofJefferson County v. WashingtonDepartment of Ecology, 511U.S. 700, 114 S. Ct. 1900, 128L.Ed.2d 716 (1994). AlthoughFERC argued that the CW A didnot regulate water quantity , theCourt held that minimuminstream flows were required tomeet " antidegradation "
requirements which are afundamental facet of waterquality standards. Failing tomaintain a viable salmon habitatin the Dosewallips River, thecourt ruled, would constitute adegradation of the waterquality .Id. , citing FWPCA§303, 33 U.S.C.A.§1313(d)(4)(B) and 40 C.F.R.§131.12 (1992).
The second expansion of§401 also came out of thePacific Northwest. Oregonenvironmental groups broughtsuit against the U .S. ForestService for a declaratory
Federal Water Pollution ControlAct §401, 33 U.S.C.A. §1341.
As state §401 certificationprocesses have becorne rnoresophisticated over the years, sotoo have the controversies. Forexarnple, here in Arizona theArizona Rock ProductsAssociation CARP A) lobbied the1996 Legislature to limit therole of the Arizona Departmentof Environmental QualityCADEQ), the issuing agency for§ 401. The new law defines theprocedure for reviewingcertification requests, sets stricttirne frarnes that rnust befollowed until January 1, 1999for processing the requests, andlimits the state's authority toreviewing only those activitiesconducted within the navigablewater. A.R.S.§ 49-202.ADEQ's failure to meet thetime frame constitutes anautomatic waiver of the state'sright to issue the certification.A.R.S. §49-202.E. and F.After January 1, 1999, failure
The Arizona Rip~rian Council 14 1998 Vol. 11, No.1
within 180 days of receivingthem. Further, §401certification for federallypermitted grazing activities thatmeet the EMF's must be builtright into the rule. A.R.S.§§49-202.01 and .02. In themeanwhile, ADEQ must grant§401 certification
for a grazing activity ...conducted in accordancewith any currentvoluntary state bestmanagement practices orany applicable best
management practicesestablished by the federalland management agencyhaving jurisdiction overthe land upon which theactivity is occurring .
A.R.S. §49-202.01.F.
judgment that issuing a grazingpermit without a §401certification was a CW Aviolation. The U .S. DistrictCourt in Oregon agreed andheld that the definition of"discharge" was not limited topoint sources, but could take innonpoint sources as well.Oregon Natural DesertAssociation v. Thomas 940 F .Supp. 1534 (1996).
News travels fast and inArizona the reaction to theOregon decision was swift. The1997 legislature added two newsections to the water qualitystatute which create an advisorycommittee charged withdeveloping best managementpractices (EMF's) for grazing.ADEQ must adopt thecommittee' s recommendationsas a general permit in rule
Somewhat like a personaltrainer, the legislature iskeeping a close eye on localexercise of these national §401developments .The strength ofArizona's role in federalgrazing permits could be akin toeither a 180 pound weakling ora world record weightlifter ,depending upon how theadvisory committeerecommendations come out.The evolution of the §401certification program isdefinitely a program worthwatching for those withconcerns about the impact ofgrazing and other federallypermitted activities on riparianareas.
~
A WPF Table Cont. from page 10
$55,476.33Lyle Canyon Allotment Riparian Area Restoration Project Steve Lindsey
The Arizona Riparian Council (ARC)was formed in 1986 as a result of theincreasing concern over the alarming rateof loss of Arizona's riparian areas. It is es-timated that < 10% of Arizona's originalriparian acreage remains in its naturalform. These habitats are consideredArizona's most rare natural communities .
The purpose of the Council is toprovide for the exchange of information onthe status protection, and management ofriparian systems in Arizona. The term"riparian" is intended to includevegetation, habitats, or ecosystems that areassociated with bodies of water (streams orlakes) or are dependent on the existence ofperennial or ephemeral surface orsubsurface water drainage. Any person ororganization interested in the management,protection, or scientific study of ripariansystems, or some related phase of riparianconservation is eligible for membership.Annual dues (January-December) are $15.Additional contributions are gratefullyaccepted.
This newsletter is published three timesa year to communicate current events,issues, problems, and progress involvingriparian systems, to inform members aboutCouncil business, and to provide a forumfor you to express your views or newsabout riparian topics. The next issue willbe mailed in May with the deadline forsubmittal of articles April 15, 1998.Please call or write with suggestions,publications for review, announcements,articles, and/ or illustrations.
The Arizona Riparian Council 16 :,; 1998 Vol. 11, N
CALENDARSharing Our Precious Resources: Assuring an Adequate Supply of CleanWater for the Next 100 Years Through Conservation, Protection, & UsePlanning, Environmental Concerns Coalition, on March 28, 1998 in at theMesa Community and Conference Center, Mesa, Arizona. Contact the Leagueof Women Voters at 520-282-4935 for more information.
Changes Around the Bend: The Lower Colorado River, Arizona RiparianCouncil Fall12th Annual Meeting, April 17-18, 1998, Shilo Inn, Yurna, AZ.For further information, Contact Cindy Zisner at (602) 965-2490 or email
Challenge '98: A Working Symposium on Reducing the Impacts ofUrbanization on Southwestern Wetland and Riparian Resources, NewMexico Riparian Council, April 16-18, 1998, University of New Mexico,Continuing Education Center. Contact Jane11e Harden, SymposiumCoordinator, 505-256-7607 or [email protected].
Invasive Exotic Species in Sonoran Desert Ecosystems, Arizona-SonoraDesert Museum, May 2-3,1998 at the Museum in Tucson, Arizona. Forinfomlation contact Barbara Yates at (520) 883-3220.
BT5 1005Center for Environmental StudiesArizona Riparian CouncilArizona State UniversityPO Box 873211Tempe, AZ 85287-3211
