Degraded riparian habitat at Charters Towers and its potential to decrease local diversity and/ or cause extinctions

1 Pages·1995·0.1 MB·

by  Alex Kutt

446 MEMOIRS OFTHE QUEENSLAND MUSEUM
DEGRADED RIPARIAN HABITAT AT CHAKTKRK Of atocni (e.g. ncanthljelds, tylvtids, mtt*c»can»ds. cuculids.
TOWERS AND ITS POTENTIAL TO DECREASE maruridsi. Medium to large rnacropods (6 spp.) and feral
LOCAL DIVERSITY AND/ OR CAUSE EXTINC- species (4spp.1were thedominantelementoftheterrestrial
TIONS. Memoirs ofthe QueenslandMuseum 38(2} 44b. EaUDJ No small ground-dwelling mammals were recorded
!995-The importance of'rifunan Tones as natural wildlife either by- live trapping or by secondary sources. This is a
corridors, as refuges during dry season* and as centres of typical pastern throughout arid and semi-and Queensland
increased species diversity and abundance has been well (Van Dyck, 1991>,thoughconfirmationofthe totalabsence
documented Red/bid & de Fbnesca, I«S6; Bennett, 1990; ofsmall terrestrial fauna in the study area requires further
|
Williams. 1994) In northern Australia, nparian zone*, form survey. Bothobservedpatternsarcareflectionofextremely
narrowcorridorsofmesic strcamsidehabitat fWrrthHiginto poorconditionandqualityofthegroundandshrubflora,and
drier inlandwoodlands {Williams. 1994). and allow species overall vegetation community structure BMtic weed inva-
otherwiseunahlctosurviveinandAndsemi-aridhabitat(e.g. sions, excessive grazing, unrestricted bank access by cattle
aquatic, semi-aquatic, coastal and weffier (ores! specie*, mi- andriverbankerosionhaveailcombinedtocreateariparian
gratoryspecies)toexpandintothese areas(LandConserva- habitatthatisdegradedandunlikelytoactasarefugeforfauna
tion Council. 1987). Features of noanan vegetation thai orasacentreofincreasedhioticdivenatyandabundance.Two
contribute to the observed high diversity and abundance of largevertebratespeciesrecordedhavethepotentialtobecome
fauna include it* flon--.iu and simcuiraldiversity andhence, CAtinccmthestudyareawithinihenearfuture.Anestingpair
thehigheravailabilityofresources(Bennett, 1990;William*. ofVVbitr-bcllicdSca-CAglcsandaGreaterGliderPetauroides
1994).Riparianhabitatsarethereforeimportantsitesforlocal votans were recorded in the Queensland Blue Gum E, trr-
and regional speciesconservation If ripanan babital 1$dc >. woodland. As outlined above, this community is
gradedoraltered,thereisapotentialforadecreaseinspecies heavilyinfestedwithRubberVine,andhasalreadyregressed
diversityandabundance,andpossiblyforshortandlongterm froma closed woodland toan open woodland as a resultor
speciesextinctions. the loss of mature iocs Loffl of the dominant overstorey
Ashortterrestrialfloraandfaunasurveyofriparianhabitat would result in the loss of nesting, denning and breeding
wasconductedinJune 1994on theBimJckin Rim nearthe resources forthese two species Therefore theconservation
ChartersTowersWeirby the AustralianCentreforTropical statusofthesetwospeciesinthelocalareaisCimsideredh»be
Freshwater Resenrch, James Cook University of North 'endangered'-speciesatseriousriskofdisappearingfromthe
Queensland Thestsnlyareaewnpnxedthenvi-rimpoundment wild state within 10-20 years ifpresent land use and other
and riparian zone to the high Icvre bank, toa point Skm cvK*1factorscontinuerooperate(Ingrain&Raven. 1991).
upstreamnfthe current weir.Vertebrate faunawassurveyed Anumberoflimitationsmayhaveinfluencedmanyofthe
usingacombinationofElliottandcagetrapping,spoitighi*ng. patternsobservedincludingarelativelyshortsurvey*, season
activesearchingandbirdcensus Vegetationw*4surveyedby amiprevailingdroughtconditions.Riparianareasareimport-
foot traverse Secondary sourcesforfloraandfaunarecords ant sitesforlocal andregional Speciesdiversity andconser-
were also examined. A total ofXfc bird, 12 nfumnul <four vation,especiallyinsub-optimalconditions,anddegradation
introducedt,sevenreptileamioneintroducedamphibianspe- v.i bin such /ones creates the potential for a reduction in
cies were recorded during the present survey. Additional biodiversity andlocalspeciesextinctions. Degradedriparian
Mituvrv(QOtcttfilajodMuM-uftirecofifs,Whrte,unpobt data) hartaaiaitdvegct.it-in luchasthisisprevalentthroughoutthe
lastafunlierfournative mammals,six reptilesand fourbird Burdrkin Houghtoncatchment and the careful management
species. Atotalof99vascularplantswererecorded, .15%of and rehabilitation of these /.ones should be a priority for
whichwereexotic.Threemajorvegetationcomtminitieswere conservationwithinthisregion.
M
Identified Mei.vViiiw rVucwrntffU *f\ AfJtfAItf »*d
vimrnalisriverbedandbankcommunity,tall(up25m)closed I.itera1iire Cind
toopes Eucalyptustereticorniswoodlandon the first levee Bennei^A.F. 19W.Habrtatcorridors. Theirrolein tvtlttflfe
bank, rolltomediumopen mixedspecies woodlandi£. us- managementandconservation. ArthurRylahInstitute
vriiatii. E rr\>hro>>HUfiQt £ prtjpuuna. £ dvftVAwwrpa, £ rorEnvirunrnentalResearch.DepartmentofConserva-
drepanophyila)onthehighestleveehank. tionandEnvironment.Victoria.
i\prE*xostuircvesypeedc.lOetfdpoamritnicautleadrcthoencuenrdncrissa*onrfe<y-<ItnaailmlnvnegeRtuabtbieonr IngramQ,ueOe.nJs.l,anAd'sRafvreong,s,RreJp.til(eesd,srbu1d9s91a.ndAnwnatmlwasuKof
Vk»eCrypu>Tt€fiaxrandif\cra,whichthreatenstheJong-term (QueenslandMuseum:Brisbane
ovibasbeirlivteydoinftthhee£.tiweomjwoioudmluarncdomcmoumnmiutrya-liicssa.naOrpteefnactcoafnothpiys LandCroenvsieerwv.aLtiCoCn,CMoeunlcbiolu.rn1e9,87V.icRieopno>ar.tontheMalicearea
eRxeoctniicicsmpeecniteosfrteraecehsiinngtthheemciadnaonpyduanndderksillloirnegymwaatsureevktlreenels.. Redforidn,tKhe&zodoegeFoongcrsacpah,yGofd19iSeoC.eTn»r»aedoro'lsenoofn£-*vHoclranytAmam
nor these were also being smothered Extensive gracing of matsfauna Bioiropica, 18:126-135.
icadtitiloenailnotnhgetrhieparriivaenrzboannek.hAassaalressouldte,ggrraoduenddthceovneartihvaesvbeegee-n VanDylciki,grSa.m,.M.G1]991A.ThReavsteant.usoRfJma(memdas)l,s.A3n49-a3t5U3v.Iunt,
substantiallyreduced(insomecases15-20%),exoticinvasion Queensland's frogs, reptiles, birds and mammals.
enhanced, sml erosion increased rind recruitment of naii\e (QueenslandMuseum Brisbane)
speciesdecreased. Williams, S. 1994. The importance of riparian habitats to
Thougb'hebirdcommunity wasdiverseandspeciesrich. vertebrate assemblages in North Queensland tMOOd-
2thAe%imofpothuensdemweenrte.wEaxtcelrubidridnsg,wparteesrebnitridns,hi4g7h%nuomfbaelrlsspdeoceietso. AUlKulatntdAs.SMteevmeoSikrulsl.ofAtuhsetrQauleieannsCleanntdrMefuosreTurmu,pi3c5r(i1F>:re24s8h.
recorded were 'uncommon* (<5 unservedi. A number of ^aterResfGTtk,JamesGwkUniversity,Ttmmsvitte,Queens*
typicalnnorianandwoodlandspeciesthatforagelisiHe~thruh tend,4ftn AfeaftrtU; <uJune tMS.
£iuSgroundlayers»e?cobscivedtobeofreduceda*undaiK*