Biology and Ecology of Tamarix

Joe DiTomaso University of California, Davis Riparian Areas of the West

„ <1%<1% ofof allall publicpublic landslands inin 1111 WesternWestern StatesStates

„ AmongAmong thethe mostmost biologicallybiologically diversediverse andand importantimportant fishfish andand wildlifewildlife habitatshabitats

„ 80%80% ofof vertebratevertebrate wildlifewildlife useuse riparianriparian habitathabitat atat somesome pointpoint inin theirtheir lifetimelifetime Distribution of Tamarix species

Species Range

T. aphylla Texas, Utah, Arizona, Nevada, and California, to 660 ft.

T. chinensis Oregon, Montana, Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, and California, to 650 ft. T. gallica New Mexico and California, to 980 ft.

T. parviflora All western states, except Wyoming, to 2625 ft. Many southern and eastern states. T. ramosissima Utah, Colorado, New Mexico, Arizona, Nevada, central Washington, and California, to 2625 ft. Central U.S., some southern states. Mexico (Baja California). Smallflower tamarisk

Tamarix parviflora

Saltcedar Tamarix ramosissima French tamarisk Tamarix gallica Stems of athel tamarisk (left) and saltcedar (right)

Athel tamarisk Tamarix aphylla Impacts on plant diversity, flooding and erosion, and fire frequency „ StandsStands cancan reachreach 7070--80%80% cover,cover, reducingreducing nativenative vegetationvegetation „ StabilizeStabilize streamstream sides,sides, restrictsrestricts channelchannel widthwidth byby increasingincreasing sedimentationsedimentation ‹ BrazosBrazos RiverRiver inin TexasTexas  MeanMean riverriver widthwidth wentwent fromfrom 155155 mm inin 19411941 (pre(pre--invasion)invasion) toto 6666 mm inin 19791979 (post(post--invasion)invasion)  IncreasedIncreased incidenceincidence ofof floodingflooding „ FireFire adaptedadapted ‹ ReducesReduces firefire intervalsintervals  35%35% ofof ColoradoColorado RiverRiver infestedinfested withwith TamarixTamarix burningburning fromfrom 19811981--19921992 comparedcompared toto 2%2% inin mesquitemesquite dominateddominated areaarea

Impacts of wildlife - Insects

„ TwoTwo insectsinsects thrivethrive inin TamarixTamarix,, honeyhoney beesbees andand cicadascicadas „ FewFew insectsinsects useuse TamarixTamarix asas aa covercover oror forageforage „ DecompositionDecomposition ofof TamarixTamarix litterlitter causedcaused aa 22-- foldfold decreasedecrease inin aquaticaquatic insectinsect richnessrichness andand 44--foldfold reductionreduction inin overalloverall abundanceabundance Impacts on wildlife – Birds

„ Sticky exudate can damage the plumage „ Birds that roost in Tamarix often forage elsewhere „ Many species with reduced use in Tamarix communities ‹ Bell’s vireo, summer tanagers, yellow-billed cuckoos, various doves, Gambel’s quail ‹ Granivores (seed feeders), frugivores (fruit feeders) and insectivores „ Some species utilize Tamarix ‹ White-winged and mourning dove ‹ Willow flycatcher Impacts on wildlife – Birds

„ BiodiversityBiodiversity highesthighest inin cottonwoodcottonwood--willowwillow communitiescommunities alongalong ColoradoColorado RiverRiver ‹ NativeNative riparianriparian areaarea –– 154154 birds/40birds/40 haha ‹ TamarixTamarix dominateddominated areaarea –– 44 birds/40birds/40 haha „ AlongAlong PecosPecos RiverRiver inin NewNew MexicoMexico ‹ MoreMore birdsbirds observedobserved inin 3939 haha ofof cottonwood,cottonwood, willowwillow andand mesquitemesquite thanthan 19,60019,600 haha ofof TamarixTamarix Impacts on wildlife – Mammals

„ NoNo nativenative mammalsmammals knownknown toto feedfeed onon maturemature TamarixTamarix „ PorcupinePorcupine andand beaverbeaver havehave highhigh affinityaffinity forfor willow/cottonwoodwillow/cottonwood communities,communities, butbut dodo poorlypoorly inin TamarixTamarix dominateddominated communitiescommunities „ DiversityDiversity ofof nativenative rodentsrodents increasedincreased significantlysignificantly whenwhen TamarixTamarix infestedinfested sitesite werewere restoredrestored toto nativenative vegetationvegetation

Tamarix Biology

„„ ShootShoot growthgrowth „„ RootRoot growthgrowth „„ ReproductionReproduction „„ GerminationGermination „„ SeedlingSeedling establishmentestablishment Shoot growth

„ CanCan growgrow 33 toto 44 mm perper seasonseason „ TolerantTolerant toto aa varietyvariety ofof stressstress conditionsconditions

‹ heatheat

‹ coldcold

‹ droughtdrought

‹ floodingflooding

‹ saltsalt

Root growth „ PhreatophytesPhreatophytes (deep(deep--rootedrooted toto reachreach waterwater table)table) ‹ facultativefacultative ratherrather thanthan obligateobligate „ ExtensiveExtensive rootroot systemsystem ‹ primaryprimary rootroot >3>3 mm deepdeep ‹ secondarysecondary rootsroots developdevelop laterlater „ AdventitiousAdventitious rootsroots developdevelop fromfrom submergedsubmerged oror buriedburied stemsstems Tamarix parviflora shoot from broken fragment of stem washed downstream Reproduction

„ FlowersFlowers ‹ insect pollinated ‹ produced after a single year of growth „ FruitFruit ‹ produced over long time period to provide continuous supply „ SeedsSeeds ‹ small and light (0.1 mg); 500,000 a year per plant ‹ tuft of hairs at one end to aid in wind dispersal ‹ also carried in water and deposited along sandbars and riverbanks

Germination

„ OccursOccurs withinwithin 2424 hh onon saturatedsaturated soilssoils oror whilewhile afloatafloat „ ShortShort viability,viability, probablyprobably <7<7 weeksweeks „ VeryVery susceptiblesusceptible toto drought,drought, scouring,scouring, oror submergencesubmergence

Seedling establishment

„ CanCan occuroccur inin seasonallyseasonally saturatedsaturated soilssoils „ RootRoot growthgrowth slowslow inin firstfirst 22--44 weeksweeks „ SusceptibleSusceptible toto droughtdrought Tamarix Ecology

„„ SalinitySalinity „„ AllelopathyAllelopathy „„ WaterWater acquisitionacquisition Salinity

„ TypicallyTypically occursoccurs inin areasareas withwith 6,0006,000 ppmppm saltssalts „ CanCan survivesurvive atat levelslevels asas highhigh asas 15,00015,000 ppmppm Allelopathy

„ ExudesExudes saltsalt fromfrom scalescale--likelike leavesleaves (41,000(41,000 ppmppm fromfrom guttationguttation sap)sap) „ CanCan alsoalso secretesecrete boronboron andand otherother ionsions „ DepositedDeposited onon soilsoil surfacesurface „ UnderstoryUnderstory oftenoften dominateddominated byby saltsalt toleranttolerant species,species, suchsuch asas saltgrasssaltgrass ((DistichlisDistichlis spicataspicata)) oror perennialperennial pepperweedpepperweed ((LepidiumLepidium latifoliumlatifolium))

Water Acquisition

„ CanCan extractextract soilsoil moisturemoisture fromfrom lessless saturatedsaturated soilssoils inin areasareas withwith deeperdeeper waterwater tablestables „ HasHas aa widerwider cavitationcavitation safetysafety marginmargin andand lessless tighttight regulationregulation ofof waterwater lossloss „ MoreMore droughtdrought toleranttolerant thanthan mostmost nativesnatives „ InfestationsInfestations increaseincrease compositioncomposition ofof xericxeric speciesspecies „ CanCan bebe aa lowlow oror highhigh waterwater user,user, dependingdepending onon waterwater availabilityavailability „ HasHas higherhigher waterwater useuse efficiencyefficiency atat higherhigher salinitysalinity levelslevels

Saltcedar Transpiration Rates

„ WaterWater transpirationtranspiration higherhigher forfor willowswillows onon aa perper leafleaf basis,basis, butbut TamarixTamarix formsforms densedense standsstands andand hashas higherhigher leafleaf areaarea

„ MidsummerMidsummer ratesrates comparablecomparable toto irrigatedirrigated alfalfaalfalfa

„ Max:Max: 1111 mmmm dd-1 inin midmid JuneJune

„ 0.40.4 –– 4.04.0 mm3 // yearyear (data(data fromfrom aa rangerange ofof studystudy sitessites acrossacross thethe southwest)southwest)

„ TamarixTamarix waterwater useuse acrossacross thethe southwestsouthwest hashas beenbeen estimatedestimated toto bebe 2x2x thethe majormajor citiescities ofof SouthernSouthern California!California! „ TNC Coachella Valley Preserve

‹ Removal of 25 acres (80% saltcedar cover) over a five year period „ Rapid recovery of springs within cleared oases „ Vegetation restoration was rapid with increased water flow Additional Examples

„ EagleEagle BoraxBorax SpringSpring inin DeathDeath ValleyValley NationalNational MonumentMonument ‹ 19401940’’s:s: TamarixTamarix invasioninvasion ‹ 19601960’’s:s: surfacesurface waterwater ofof marshmarsh gonegone ‹ 19721972--82:82: TamarixTamarix removalremoval ‹ 1983:1983: rapidrapid recoveryrecovery withwith returnreturn ofof surfacesurface waterwater „ SpringSpring Lake,Lake, Artesia,Artesia, NewNew MexicoMexico ‹ WaterWater tabletable roserose fromfrom 66 mm toto << 11 mm followingfollowing saltcedarsaltcedar controlcontrol Artesia, New Mexico