Final Report: Temporal Variability of Macroinvertebrate Communities In

Supt'ꢀisꢁng Scientist Division

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rꢆꢇꢈI1
ꢂabꢃlꢄꢅ Field Station

LWRRDC Final Report:

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Australian streams.

Chris Humphrey August 1998

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Temporal variability of macroinveꢀebraꢁe communiꢁies in Australian sꢁreams:

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Implications for the prediction and detection of environmental change

by

Chris Humphrey (Principal Investigator)

Environmental Research Institute of the Supeꢀising Scientist,
Locked Bag 2, Jabiru, NT 0886.

FINAL REPORT TO
LAND AND WATER RESOURCES
RESEARCH AND DEVELOPMENT CORPORATION
(Reference No. ARR1)

December 1997

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LWꢉC Final Report
Project ꢊRꢋ

Project title: Temporal variability of macꢊoinꢇerꢄebrate communities in Austꢊalꢆan streams (Implications for ꢄhe prediction and detection ofenꢇironmental cꢂange)

Principal investigators: Dr Chꢊis Humpꢂrꢃy, eriss

Date ofsubmission: December 1997 Contents

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Final report

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ꢀꢁacꢂmꢃnꢄ 1

Humpꢂrey C, Sꢄorꢈy A & Doig L 1997b. Dꢃgreꢃ of ꢄemporal vaꢊꢆabꢆlꢆty of macroinverꢋebratꢈ communitiꢃs iꢅ ꢀustralian stꢊeams.

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ꢀꢁacꢂmꢃꢅꢄ 2

Humpꢂꢊey C & Doig L 1997. Bentꢂic macꢊoꢆnꢇꢈꢉꢈbꢊate communities in ꢊifﬂe substratꢈs of streams in tꢂe Noꢊꢋhꢈꢌ Tꢈꢊꢊitoꢊy, 1994-1995: tꢈmporal variability and implications fo r Mꢍꢎ model deꢇꢈlopmꢃnt.

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Abstract

Tꢐꢃ ꢜꢃgꢏꢃꢃ aꢅꢜ ꢃxꢄꢃnꢄ ofꢝꢃmꢑoꢊal ꢇarꢟabꢓꢡꢓꢄy of ꢕꢄꢊꢖam macꢊoiꢅꢇꢖrꢝꢖbꢊaꢄꢖ commꢚꢅiꢝꢟꢖs ꢐaꢇꢃ bꢖꢖꢅ ꢓꢅꢇꢖsꢝꢓgaꢄꢃꢜ across a bꢊoaꢜ cꢊoꢕꢕ-ꢕꢔcꢄioꢅ of climaꢝꢓclꢐyꢜrological ꢊꢔgimꢔs iꢅ ꢀꢚsꢝꢊalꢓa. Coꢅꢕꢄaꢅcy or ꢑꢃrsꢓsꢄꢃꢅcꢃ ofmacꢊoꢟꢅꢇꢔꢊtꢖbꢊaꢄꢔ commꢚꢅiꢝiꢖs was foꢚꢅꢜ ꢄo bꢃ signiﬁcanꢄly aꢅꢜ ꢑosꢟꢝꢓꢇꢃꢡy coꢏꢏꢃlaꢄꢃꢜ 'wiꢝꢐ ꢑꢖꢊmaꢅꢖꢅcꢖ of sꢝrꢖam ﬂow, anꢜ ꢅꢔgaꢝiꢇꢖly coꢊꢊꢔlaꢄꢖꢜ wiꢄꢐ inꢝꢃranꢅꢚal ꢇaꢊꢟabꢟliꢄy of aꢅꢅꢚal sꢝrꢖam discꢐaꢊgꢃ. Tꢐꢃrꢖ waꢕ a ꢄꢖꢅꢜꢖncy (oꢅꢡy) for macroiꢅꢇꢃrtꢃbꢊaꢝꢃ commꢚniꢄiꢔꢕ of ꢑꢔꢊmaꢅꢖꢅꢄ sꢝꢊꢖams ꢓn ꢝꢃmꢑꢖꢊaꢝꢔ ꢀꢚsꢄꢊalꢟa ꢄo bꢖ moꢊꢃ ꢑꢃrsꢓsꢄꢃnꢝ ꢝꢐaꢅ ꢄꢐosꢃ in ꢄꢊoꢑical rꢖgioꢅs. Tꢖmꢑoꢏal ꢇarꢟabiliꢝy ꢟꢕ bꢔlꢟꢖꢇꢖꢜ ꢄo ꢐaꢇꢃ mosꢄ ꢑoꢄꢖꢅꢝꢓaꢡ ꢄo ꢡimiꢄ AUSRIVꢀS ꢕꢔnꢕiꢄiꢇꢓty aꢅꢜ ꢄo ꢊꢖsꢚꢡꢝ in grꢃaꢄꢃꢊ moꢜꢔl oꢚꢄꢑꢚꢝ failꢚrꢖs fo r ꢕiꢄꢖs ꢓꢅ ꢅoꢏꢄꢐꢃꢌ ꢀuꢕꢄralꢟa (QLD inclꢚꢕꢟꢇꢖ) aꢅꢜ ꢑossibꢡy fo r siꢝꢖs iꢅ ꢜꢊoꢚgꢐꢝ-ꢑronꢖ ꢑoꢒꢓons of waꢊm-ꢄꢔmꢑꢖraꢄꢃ, ꢃasꢄꢃꢌ Aꢚꢕꢝꢊalia. Dꢊoꢚgꢐꢝ iꢅ ꢔaꢕꢄꢖꢗ ꢀꢚsꢝꢊalia aꢅꢜ major ꢜꢟꢕꢄꢚrbaꢅcꢃ aꢊꢟꢕiꢅg fꢊom cycloꢅꢔꢕ ꢟꢅ ꢅoꢘꢐꢃꢗ Aꢚꢕꢝralia aꢑꢑeaꢊ ꢄo bꢔ ꢝꢐꢖ majoꢊ coꢅꢝꢊꢟbꢚꢝoꢊs ꢝo ꢐigꢐ ꢄꢃmꢑoꢊal ꢇaꢊiabiliꢝy ofmacroiꢅꢇꢖrꢝꢃbꢊaꢝꢃ commꢚniꢄiꢖs.

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Wꢐilsꢄ a ꢑrꢃlimiꢅary ꢕꢝꢚꢜy was ꢚꢅꢜꢖꢊtakꢖꢅ ꢝo ꢜꢃꢝꢃrmiꢅe ꢝꢐꢔ coꢅꢕꢔqꢚꢔꢅcꢖꢕ ꢄo moꢜꢃl ꢜꢃꢇeloꢑmꢔꢅꢄ (clasꢕꢟficaꢄꢓoꢅ) of ꢄꢃmꢑoral ꢇaꢊiabiliꢝy, a morꢖ comꢑlꢃꢝꢃ sꢖꢅꢕꢟꢝꢟꢇiꢝy analyꢕiꢕ ꢓs rꢃqꢚirꢃꢜ in ꢙꢄꢚꢊꢔ Mꢛ R&D ꢄo dꢃꢄꢃꢏminꢃ ꢝꢐꢃ ꢙll imꢑlicaꢄꢓoꢅs of coꢡlꢃcꢝiꢇꢃ ꢃrꢊor anꢜ ꢇaꢊꢟabꢓꢡꢓꢝy (aꢄ ꢇarioꢚꢕ sꢑaꢝꢟal scalꢔꢕ) foꢊ modꢖꢡ sꢖꢅsꢓꢝiꢇity. Tꢐis analyꢕiꢕ woꢚlꢜ ꢓncꢡꢚdꢃ ꢝꢐꢃ ꢜꢃꢝꢃꢞꢟnaꢝioꢅ of ꢄꢐꢔ ꢕizꢖꢕ of ꢇarioꢚs ꢕoꢚrcꢃs of eꢊꢊor anꢜ ꢇariaꢄion aꢅꢜ ꢄꢐꢃꢟꢊ ꢃffꢃcꢝs on ꢝꢐꢖ ꢊaꢝꢖs of misclaꢕꢕꢟficaꢝꢟon ꢄo qꢚaliꢝy bands. Daꢄa on ꢝꢃmꢑoꢊal ꢇarꢓabꢓꢡiꢝy arising from ꢄꢐꢔ cꢚrreꢅꢝ sꢄꢚꢜy wꢓꢡꢡ ꢑroꢇꢓdꢃ aꢅ imꢑortaꢅꢄ ꢟnformaꢝioꢅ baꢕꢔ ꢚꢑoꢅ wꢐicꢐ sꢚcꢐ an assꢔꢕꢕmꢔnꢝ can ꢑꢊocꢖꢃd. Fꢚꢝꢚꢊꢃ R&D nꢃꢃꢜꢕ ꢝꢐaꢄ wꢓll aꢕsꢓsꢝ ꢓn ꢄꢐꢓs 'ꢕꢃnꢕiꢝiꢇꢟꢝy analysꢓs' ꢐaꢇꢃ bꢃꢃn ꢟꢜꢃnꢝꢟfiꢖꢜ in ꢝꢐe ꢊꢔꢑoꢊt anꢜ aꢝꢝacꢐmꢃꢅtꢕ.

Tꢐe sꢄꢚꢜy fo rmꢚlaꢄꢖd a nꢚmbꢃr ofaꢑꢑroacꢐꢃs ꢝo ꢑꢚꢊꢕꢚꢖ ꢓn rꢃlaꢝion ꢝo ꢝꢃmꢑoꢊal ꢇaꢊꢓabꢓlꢓꢝy and ꢑꢊꢔꢜꢓcꢄꢓꢇꢃ moꢜꢃlling. Tꢐꢓꢕ inclꢚꢜꢔꢜ aꢑꢑroacꢐꢃs for aꢕsꢃssing imꢑꢡꢓcaꢝꢓoꢅs fo r ꢑrꢃꢜꢟcꢄiꢇꢔ moꢜeꢡ sꢔnsiꢝꢓꢇꢓꢝy arꢓꢕꢓng from ꢄꢃmꢑoral ꢇaꢊꢟabilꢟꢝy, aꢕ wꢖll as aꢑꢑroacꢐes ꢄꢐaꢄ mꢟgꢐꢝ bꢔ ꢚsꢖd ꢝo accoꢚnꢝ for ꢕꢚcꢐ variabꢟꢡꢟꢝy, iꢔ: (ꢓ) conꢄꢖxꢝꢚal daꢝa fo r assꢔssing ꢄꢐꢔ ꢕꢔꢇꢔrꢓꢝy of ꢄꢖmꢑoral ꢇariabiliꢝy, (ꢟꢟ) moꢜꢔllꢓng ꢝꢃmꢑoral ꢇariabiliꢝy, (ꢟiꢟ) aꢜjꢚꢕꢄing and ꢚꢑꢜaꢝing moꢜꢃl oꢚꢝꢑꢚꢝ, (iꢇ) moꢜꢔꢡꢕ for dꢓffꢃrꢃꢅꢝ cꢡimaꢄic coꢅꢜꢟꢝionꢕ, anꢜ (ꢇ) combinꢃꢜ-ꢕꢃasons oꢊ -yꢔaꢊs moꢜꢔlꢕ.

Wꢐilꢕꢝ aꢄ ꢄꢐꢓꢕ sꢝagꢃ ꢄꢐe ꢃxꢝꢔnꢄ ꢄo wꢐꢓcꢐ ꢐꢓgꢐ ꢄꢃmꢑoraꢡ ꢇaꢊꢟabꢟliꢝy may comꢑꢊomꢓsꢃ ꢝꢐꢃ ꢕeꢅsꢟꢝiꢇꢓꢝy of ꢑrꢃꢜꢓctꢓvꢃ moꢜꢃls is ꢅoꢝ kꢅown, ꢄꢐꢖ abꢓꢡꢓty ꢄo ꢊꢃꢡꢟably ꢟꢜꢃnꢝiꢠ aꢅꢜ ꢑꢊꢖꢜꢓcꢝ ꢜꢓffꢖꢊꢖnꢄ gꢃograꢑꢐicaꢡ ꢊꢃgꢟonꢕ anꢜ ꢕꢝꢊꢖam tyꢑꢃs sꢚscꢃꢑꢄibꢡe ꢄo ꢐigꢐ ꢄꢔmꢑoꢊaꢡ ꢇaꢊꢓability arꢃ in ꢄꢐꢃmsꢃꢡves ꢟꢅformaꢄꢓꢇꢖ aꢅꢜ ꢇaꢡꢚabꢡe fo r maꢅagemꢃꢅꢝ. Tꢐꢔ magnꢓꢝꢚꢜꢃ of ꢑꢃrꢕisꢝeꢅce inꢜꢟcꢔꢕ calcꢚlaꢄꢖꢜ ꢓꢅ tꢐis ꢕꢄꢚꢜy aꢅꢜ moꢜꢔlꢡꢔꢜ accoꢊꢜꢓng to diffꢃ rꢃꢅꢝ ꢊꢔgꢟonꢕ anꢜ ꢕꢄꢊꢖam ꢝyꢑꢃꢕ, may ꢖꢇꢃꢅtꢚalꢡy be reꢡaꢄꢔꢜ ꢄo somꢃ mꢃasurꢃ of AUSRIVAS moꢜꢃꢡ 'ꢅoiꢕꢃ' aꢅꢜ variabiꢡꢟꢝy aꢅꢜ, coꢅseqꢚꢃnꢄly, ꢄo ꢑoor moꢜel ꢑreꢜꢟcꢝꢟonꢕ. Wꢟꢝꢐ qꢚaꢅꢄꢓﬁꢃꢜ ꢜꢃgꢊeꢃs of 'ꢊꢟꢕk' of moꢜꢖl fa iꢡꢚrꢃ, ꢊꢃꢕꢃarcꢐꢃrs anꢜ maꢅagꢖꢊꢕ migꢐꢝ ꢄꢐꢃꢅ bꢃ bꢃtter informꢔꢜ and ꢑlacꢃꢜ ꢝo accoꢚnꢝ fo ꢊ ꢕꢚcꢐ varꢟabilꢟꢝy, ꢕtꢓꢑꢚꢡatꢃ ꢃrror anꢜ ꢑꢊobabꢟꢡꢟꢝy ꢕꢄaꢄꢖmꢖnꢄs aroꢚnꢜ ꢑꢊꢃꢜicꢝionꢕ, oꢊ rꢖcommꢃnꢜ aꢡꢝꢃꢢaꢝꢟꢇꢖ monꢓtorꢓꢅg aꢑꢑroacꢐeꢕ.

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Temporal variability of macroinveꢀebrate communities in
Australian streams:

Im plications for the prediction and detection of environmental change

Final reꢁoꢂ to LWRRDC

1

Introduction

In 1993 tꢐꢃ Commonwꢃaltꢐ ofꢀꢚꢧtꢊalia ꢙnꢣꢔꢣ ꢝꢐꢩ 'National ꢥiꢇꢔꢊ Hꢃaltꢐ Proꢫꢊam' (ꢤꢥꢦ) to monitoꢊ ꢪnꢣ aꢧsꢔꢕꢕ tꢐꢔ ꢐꢃaltꢐ oftꢐꢩ natꢟon'ꢧ ꢊiꢇꢔꢊꢧ ꢪnꢣ ꢧꢨꢩꢪmꢧ (Sꢯꢐoﬁꢃlꢣ & Daꢇiꢔꢧ 1996). Part oftꢐiꢧ ꢑꢮoꢫram iꢕ tꢐꢩ ꢳMonitoꢊinꢫ ꢥiꢇꢩꢮ Hꢩaltꢐ Initiatiꢇꢩ' (ꢌ)ꢍ inꢇolꢇinꢫ ꢫoꢇꢔꢗmꢩnt aꢫꢔnꢯiꢔꢧ fꢊom all ꢀꢚꢧtꢊaliꢪn Statꢃꢧ anꢣ Tꢖꢮꢮitoꢊiꢃꢧ in a national ꢑꢊoꢫꢊam to ꢣꢃꢇꢩloꢑ a ꢧtanꢣꢪrꢣiꢧꢖꢣ anꢣ ꢯooꢮꢣinatꢃꢣ ꢊaꢑiꢣ bioaꢧꢧꢃꢧꢧmꢔnt aꢑpꢊoaꢯꢐ to bioloꢫiꢯal monitoꢊinꢫ of watꢩꢊ qꢚality in ꢀꢚꢧtꢊalian ꢕtꢊꢖamꢧ anꢣ ꢊiꢇꢔꢊꢧ.

Tꢐꢃ ꢥiꢇꢔꢊ InVꢃrtꢃbꢊatꢔ Pꢮꢃꢣiꢯtion ꢀnꢣ Claꢧꢧifiꢯation Syꢧtꢩm (ꢥIVPꢀCS; Wꢊꢟꢫꢐt 1995) waꢧ aꢣoꢑtꢩꢣ aꢧ a nationaꢡ framꢔwoꢮk foꢊ tꢐꢃ ꢀꢚꢧtꢮalian ꢑꢊoꢫꢮam. Moꢣꢃls wꢔꢮꢔ to bꢃ baꢕꢔꢣ on family-lꢔꢇꢖl iꢣꢃnꢺifiꢯationꢧ of maꢯꢮoinꢇꢃꢊtꢃbꢊatꢖꢧ ꢯoꢡlꢩꢯtꢩꢣ by ꢐabitaꢺ-ꢧꢑꢃꢯꢟfiꢯ kiꢯkꢹꢧwꢃꢔꢑ ꢕamꢑlinꢫ aꢺ an initial 1400 ꢮꢩfꢩꢊꢃnꢯꢃ ꢕꢟtꢔꢕ ꢧamꢑlꢃꢣ aꢯꢊoꢧꢧ ꢀꢚꢧtralia ꢟn ꢮꢖꢑꢮꢃꢧꢃntatiꢇꢔ ꢧꢖaꢧonꢧ (Sꢯꢐofielꢣ & Daꢇꢟꢖꢧ 1 996). ꢀ fꢷ ll ꢣꢃꢧꢯꢮiꢑtꢟon of tꢐꢩ ꢑꢮoꢫram aꢕ ꢣꢔꢇeloꢑꢃꢣ to 1997, ꢀUSꢥIVꢀS (ꢀUStꢊalian ꢥIVꢃꢊ ꢀꢕꢕꢔꢧꢕmꢖnt Sꢯꢐꢔmꢔ), ꢟꢧ pꢊoꢇiꢣꢔꢣ by Daꢇiꢃꢧ (In ꢣꢮaﬅ).

It waꢧ rꢩꢯoꢫniꢧꢃꢣ ꢃaꢊly in tꢐꢃ ꢣꢔꢇꢔloꢑmꢖnt of tꢐꢔ Mꢥꢬ tꢐat ꢕamꢑꢡꢩ ꢑroꢯꢃꢧꢧinꢫ ꢖꢮꢮoꢊ anꢣ tꢃmꢑoꢮal ꢇaꢊiability in ꢯommꢚnꢟty ꢯomꢑoꢧition anꢣ stꢮꢚꢯtꢚꢮꢃ in a ꢯoꢚntꢮy of ꢯlimatiꢯ ꢔxtꢮꢩmꢩꢧ ꢕꢚꢯꢐ aꢧ ꢀꢚꢕꢺꢮalia, woꢷlꢣ ꢑꢮobabꢡy ꢑoꢕꢔ tꢐe moꢧt ꢕꢔꢊioꢚꢧ ꢮiꢧkꢧ to ꢣꢃꢇꢔloꢑmꢃnt of ꢧꢃnꢧꢟtiꢇꢔ, ꢑrꢃꢣꢟꢯꢺiꢇꢔ moꢣꢃls fo ꢊ bioꢡoꢫꢟꢯal moniꢺorinꢫ. Tꢐe iꢧꢧꢚꢃ of ꢺꢔmꢑoꢊal ꢇaꢮꢟabiliꢺy of maꢯꢮoinꢇꢃꢭꢔbꢮatꢃ ꢯommꢷnitiꢃꢧ anꢣ ꢑoꢧꢧiblꢃ ꢟmꢑliꢯationꢧ to sꢚꢯꢯꢖꢧꢧfꢚꢡ moꢣꢃl ꢣꢔꢇꢖloꢑmꢃnt wꢃrꢩ tꢐꢖ ꢧubjꢃꢯꢺ ofꢺꢐiꢧ ꢧtꢷꢣy.

ꢀn aꢕꢧꢚmꢑtion of ꢑrꢃꢣꢟꢯtiꢇꢖ moꢣꢃllinꢫ iꢕ tꢐat maꢯꢮoinꢇꢩꢰꢩbꢊaꢺꢔ ꢯommꢚnity ꢯomꢑoꢧitꢟon iꢕ ꢮꢖaꢧonably ꢯonsꢺant oꢇꢃr tꢟmꢖ. Sꢚꢏꢑꢊiꢕinꢫꢡy, tꢃmꢑoꢊal ꢇariabiliꢺy ꢐaꢧ ꢫainꢔꢣ liꢱꢡꢃ ꢯonꢕiꢣꢖꢮaꢺion ꢣꢷꢮinꢫ ꢣꢔꢇꢖloꢑmꢃnt of ꢥIVPꢀCS. Claꢊkꢃ ꢩt al (1996) ꢯonꢕiꢣꢃꢮꢖꢣ tꢃmꢑoꢮal ꢇarꢟabiliꢺy as a faꢯꢺoꢏ wꢐꢔn iꢣꢩntiꢲꢟnꢫ tꢐꢃ ꢧoꢷꢊꢯꢔꢕ of ꢷnꢯꢔrtainꢺy foꢮ ꢥIVPꢀCS, bꢷt only aꢧ a ꢑotꢩntꢟal ꢧoꢚrꢯꢃ of ꢖꢮꢮor fo ꢊ tꢐꢖ ꢳobꢕꢃꢴꢩꢣꢵ faꢚna anꢣ not tꢐꢩ 'ꢃxꢑꢔꢯtꢔꢣꢵ fauna. Tꢐiꢕ iꢕ ꢣꢃꢧꢑiꢺꢃ tꢐꢖ faꢯt tꢐat tꢐꢃ rꢃfꢃꢊꢔnꢯꢃ ꢧꢟtꢃ ꢣata baꢧꢃ foꢊ ꢥIVPꢀCS ꢐaꢕ aꢯꢯꢚmulaꢺꢔꢣ tꢐꢊoꢚꢫꢐ aꢣꢣiꢺion of ꢣatꢪ fo ꢮ ꢣiffe ꢊꢔnt ꢧiꢺꢃꢧ oꢇꢖꢮ timꢃ (1977- 1995) (Wꢮiꢫꢐt 1995). Tꢐꢃ ꢣꢃꢫrꢃꢃ of ꢑoꢧꢧiblꢃ ꢇaꢮiability aꢮiꢧinꢫ fꢊom natꢷꢊal ꢯꢐanꢫꢃꢧ in maꢯꢮoinꢇꢩꢮꢋꢔbꢮatꢖ ꢯommꢷniꢺy ꢯomꢑoꢕꢟꢺꢟon oꢇꢔꢊ tꢐiꢕ ꢑꢖꢊioꢣ anꢣ ꢺꢐꢃ ꢃffꢔꢯt of ꢺꢐꢟꢕ, if any, uꢑon moꢣꢃl ꢯonstꢮꢚꢯtion ꢐaꢧ noꢺ bꢔꢔn ꢮꢖꢑorꢺꢃꢣ. Wꢃaꢺꢐꢔꢮꢡꢃy anꢣ Oꢏmꢃroꢣ ( 1990) qꢷantꢟﬁꢖꢣ ꢺꢐꢔ ꢣꢔꢫꢮꢖꢃ of ꢺꢔmꢑoꢮaꢡ ꢇariabilꢟꢺy ꢃꢇꢟꢣꢃnꢺ in Wꢃlꢕꢐ ꢧtꢮꢖams oꢇꢃr a 5ꢹyꢃaꢊ ꢑꢖꢮioꢣ anꢣ ꢯonꢯꢡꢚꢣꢃꢣ tꢐat tꢐiꢧ woꢚlꢣ bꢔ too ꢧliꢫꢐꢺ to aꢣꢇꢃꢊꢕꢔly affꢃꢯt ꢣꢔꢇꢔloꢑmꢃnt of prꢃꢣiꢯtꢟꢇꢖ moꢣꢃꢡꢕ. Wrꢟꢫꢐꢺ ( 1 995), ꢐowꢃꢇꢃꢊ, ꢟmꢑliꢃꢣ ꢺꢐaꢺ ꢝꢃmꢑoꢊal ꢇaꢊiabilꢟꢺy of ꢧmall tꢃmꢑoꢊaꢊy ꢧtꢮꢔamꢕ ꢟn ꢺꢐꢔ UK miꢫꢐt bꢃ ꢧꢷfﬁꢯꢟꢃnꢺ to bꢃ of ꢯonꢯꢃꢢ ꢟn ꢺꢐiꢕ ꢮꢩꢧpꢃꢯt.

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Tꢐiꢧ rꢩꢑoꢶ anꢣ aꢺꢺaꢯꢐmꢃnꢺꢕ ꢣꢃꢧꢯribꢃ ꢊꢃꢧꢷltꢕ of a broaꢣ-ꢕꢯalꢃ ꢑroꢫꢊam ꢺꢐat waꢧ conꢣꢚꢯꢺꢃꢣ ꢺo qꢷantꢟꢸ tꢐꢃ ꢜeꢫꢊꢃꢃ ofꢺꢔmꢑoꢮal ꢇaꢊꢟabilꢟꢺy ꢃꢇiꢣꢃnt in lonꢫꢹꢺꢩꢻ ꢣata ꢧꢃꢺꢕ from ꢊꢃꢑrꢃꢕꢔnꢺaꢺꢟꢇꢃ ꢧtꢮꢃamꢕ aꢯrosꢧ ꢀuꢕꢺralia. Wꢐꢃꢊꢃ laꢯk of 'ꢑꢖꢮꢧꢟꢕꢺꢃnꢯꢔ' ꢓꢧ obꢧꢃꢊvꢃꢣ, a ꢡonꢫꢃr ꢺꢃꢊm aim, ꢑꢊꢃꢡiminaꢊy ꢧꢺeꢑꢕ of wꢐiꢯꢐ ꢐaꢇꢃ bꢃꢃn ꢺakꢃn fo r onꢃ ꢣaꢺa ꢧꢃꢺ, ꢟꢕ ꢺo ꢔxꢑꢡorꢃ ꢺꢐꢃ ꢟmꢑliꢯatꢟonꢕ of tꢐꢃ ꢮꢃꢧꢚlt fo r moꢣeꢡ ꢕꢃnꢧiꢺivꢟꢺy by aꢧꢧꢃꢧꢧinꢫ ꢺꢐꢃ ꢣꢃꢫrꢃꢃ of ﬁꢣꢃꢡity of lonꢫꢹꢺꢃrm ꢣata in ꢫroupꢧ

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ꢣeꢮꣁꢇeꢣ from ꢼꢚꢮꢮeꢅt AUSꢥIVAS ꢼlaꢽꢽiﬁꢼatꣁons. Some ꢑossꣁble ways to aꢼꢼoꢚꢅt fo r temꢑoꢮal ꢇaꢮꣁabꣁꢡꢟty are also ꢊaꣁseꢣ foꢊ ꢣꣁꢽꢼꢚssion. Fꢚll imꢑlꣁꢼations of temꢑoꢊal ꢇaꢊiabꣁlity for moꢣellꣁꢅꢾ wꢟll be tꢐe ꢽꢚbjeꢼt of moꢮe ꢣetaileꢣ ꢥ&D to be ꢼommissioneꢣ ꢚnꢣeꢮ ꢋhe seꢼonꢣ ꢑꢐase oftꢐe ꢑroꢾram.

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Tꢐe ꢑꢊojeꢼt objeꢼtꢟꢇes were to: I. aꢼꢼeꢽꢽ ꢡonꢾꢹteꢻ ꢣaꢺa sets fꢊom ꢽꢚꢓtable rꢿfeꢊenꢼe ꢽtꢊeams aꢼꢊoss Aꢚsꢺꢊalꣁa; foꢊ ꢽome of
ꢺꢐeꢽe ꢽꣁteꢽ, samꢑlꣁꢅꢾ or samꢑle ꢑꢊoꢼeꢽꢽꣁnꢾ was ꢋo be extenꢣeꢣ so tꢐat ꢣata setꢽ weꢊe sꢚﬃꢼꣁenꢋly ꢵloꢅꢾꢹtermꢳ ꢟn natꢚre;

2.

measꢚrꢿ 'ꢑeꢊꢽꣁꢽtenꢼe' of maꢼꢊoꣁꢅꢇerꢋebraꢺꢿ ꢼommꢚnꣁty struꢼtꢚre foꢊ ꢺꢐeꢽe ꢣaꢋa sets ꢚsinꢾ aꢑꢑꢮoꢑꢊꢟate sꢺatistiꢼal analyꢽeꢽ ofꢺꢐe ꢣata;

Where lack o/persistence was observed:

3. exꢑloꢮe tꢐe imꢑliꢼaꢺionꢽ of tꢐe ꢊeꢽꢚlt by assessinꢾ wꢐeꢋꢐeꢊ tꢐe anomaloꢚꢽ ꢣata ꢼlasꢽiꢸ neaꢊ oꢮ toꢾetꢐeꢊ wꢟtꢐ those fꢊom ꢊelateꢣ ꢣꣁꢽtꢚrbeꢣ siteꢽ;

4. ꢽeek enꢇironmeꢅtal ꢼoꢊꢊelateꢽ ꢄꢐat may aꢼꢼoꢚnꢺ foꢮ any yꢿar-to-yeaꢊ ꢇaꢊꣁaꢄꣁon iꢅ
ꢼommꢚnꣁty ꢽtꢮꢚꢼtꢚre anꢣ ꣁnꢑꢚt ꢺꢐese ꢇaꢊꣁableꢽ to tꢐe ꢀ ꢑꢊeꢣꣁꢼꢋꣁꢇe moꢣels; anꢣ

5. makꢿ aꢑꢑꢊoꢑꢮꣁate ꢮeꢼommꢿꢅꢣatioꢅs aꢼꢼoꢊꢣꣁnꢾ ꢺo ꢣꢟffeꢊent ꢼlꣁmatꣁꢼ/ꢐyꢣroloꢾiꢼal ꢊeꢾꣁonꢽ ofAꢚꢽtꢮaꢡꢟa.

2 Methods

Objectiꢇeꢽ I ꢹ 5 are reꢑortꢿꢣ ꣁn ꢺꢐe fo llowꣁꢅꢾ ꢽeꢼtioꢅs ꢚnꢣeꢊ ꢄꢐe broaꢣeꢊ ꢼollecꢄꣁꢇe aꣁmꢽ, aꢅꢣ ꣁn tꢐe ꢡoꢾical oꢊꢣeꢊ:

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aꢼꢼeꢽꢽ ꢡoꢅꢾꢹꢺꢿꢻ ꢣaꢺa ꢽetꢽ fꢊom ꢽꢚꣁtable rꢿfeꢊenꢼe ꢽtꢮeamꢽ anꢣ meaꢽꢚꢊe 'ꢑeꢮꢽꣁꢽteꢅꢼe' of maꢼroꣁnꢇeꢘeꣀꢮate ꢼommꢚꢅity ꢽtructꢚꢊe;

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wꢐerꢿ ꢡack of ꢑeꢊꢽꣁꢽtenꢼe is obsꢿꢮvꢿꢣ, exꢑloꢮe tꢐe ꢟmꢑlicatꣁonꢽ of ꢄꢐe ꢮesꢚlt by assꢿssinꢾ wꢐeꢄꢐeꢊ ꢺꢐe aꢅomaloꢚs ꢣata ꢼlaꢽꢽꣁꢸ ꢅear or toꢾetꢐeꢊ wꣁꢺꢐ thoꢽe fꢊom ꢊelateꢣ ꢣꣁꢽtꢚꢮꣀeꢣ ꢽꢓꢺeꢽ; aꢅꢣ

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ꢿꢇaꢡꢚate ꢑoꢕꢕibꢡꢿ ways ꢺo aꢼꢼoꢚnꢺ for temꢑoꢊal ꢇaꢊꢓabꣁlꣁty anꢣ make aꢑꢑꢊoꢑꢊꢓaꢄe ꢊeꢼommꢿꢅꢣatꢓonꢽ aꢼꢼoꢊꢣꣁnꢾ to ꢣifferꢿꢅꢺ ꢼ1ꣁmatꢓꢼ/ ꢐyꢣꢮoꢡogiꢼal ꢊeꢾꣁonꢽ ofAꢚꢽtꢮalꣁa.

A brꢟꢿfꢣeꢕꢼrꢟꢑꢺꢟoꢅ of mꢿtꢐoꢣꢽ ꢚꢕeꢣ foꢊ ꢄꢐe ꢕꢺꢚꢣy ꢼomꢑonenꢺꢽ fo llowꢽ.

2.1 Measurꢂ 'pꢂꢀsistꢂnce' of macꢀoꢁnvꢂꢃꢂbꢀatꢂ communꢁty structuꢀꢂ fꢀom long-tꢂrm data sꢂts

Daꢄa fꢮom a ꢅꢚmbeꢊ of ꢮeꢽearꢼꢐers aꢼꢊoꢽꢽ ꢀꢚꢕtꢊaꢡꢓa were ꢼomꢑileꢣ ꢄo qꢚaꢅꢺꢟꢸ ꢺꢐe ꢣꢿꢾꢊee of ꢺꢿmꢑoꢊaꢡ ꢇaꢮꢓabꢟlity of stꢊeam maꢼꢊoꢓnꢇerꢋebrate ꢼommꢚnꢓꢺꢟeꢽ (Hꢚmꢑꢐꢊey et al. 1997b). Teꢅ ꢾeoꢾraꢑꢐꢟꢼal ꢮeꢾioꢅs, 1 5 caꢺcꢐmenꢄꢕ aꢅꢣ 38 ꣁꢅꢣꣁꢇiꢣꢚal ꢽiꢄes weꢮe reꢑresenteꢣ. Tꢐe aꢇeꢊaꢾe ꢣꢚꢮaꢋꢟoꢅ of ꢺꢐe ꢣaꢺa ꢕeꢺs was aꢑꢑꢊoxꣁmaꢄeꢡy 6 years, wiꢺꢐ ꢕome ꢣata ꢽeꢺꢽ extꢿꢅꢣꣁnꢾ ꢺo 10 yꢿarꢕ. Sꢓꢺes wꢿrꢿ ꢡoꢼateꢣ ꢓn ꢕꢺꢮeamꢕ ofꢑꢿrmaneꢅꢺ aꢅꢣ ꢕeaꢽoꢅaꢡ ﬂow aꢅꢣ fo ꢊ alꢡ bꢚt one ꢣaꢋa ꢕeꢺ, samꢑꢡꢿꢕ weꢮe ꢼoꢡꢡecꢺeꢣ from rꢟfﬂe ꢐaꣀꣁꢄaꢺ oꢅꢡy.

Temꢑoraꢡ ꢇaꢊꢓaꣀiꢡity waꢽ ꢿxꢑreꢽseꢣ ꢓn terms of aꢅ iꢅꢣꢿx of 'Inꢼonꢽtaꢅꢼy', ꢣetermꢟneꢣ foꢊ eaꢼꢐ ꢽꢟtꢿ aꢅꢣ ꢕeaꢕoꢅ aꢕ tꢐe ꢑꢊoꢑoꢮꢺꣁon of iꢅꢺꢿraꢅꢅꢚaꢡ ꢼomꢑarꢟꢽoꢅꢽ of ꢼommꢚnꢟty comꢑositioꢅ (ꢑꢮeꢕeꢅcꢿ/aꣀꢕeꢅce) aꢅꢣ ꢕꢺrꢚꢼꢺꢚꢊe (ꢊaꢅk abuꢅꢣaꢅcꢿ) fo ꢊ wꢐiꢼꢐ BrayꢹCꢚꢮtis ꢣꣁssꢓmꢟꢡaꢮꢓty meaꢕꢚres (famꢟly ꢡeꢇeꢡ ꢟꢣeꢅꢺꢟﬁcatioꢅꢕ) exꢼeeꢣeꢣ ꢑre-ꢣeꢺermꣁneꢣ ꢄꢐꢊesꢐoꢡꢣs. Aꢽ ꢣꣁꢕꢕꣁmꣁꢡaꢊꣁty meaꢕureꢽ are ꢺꢐe ꣀaꢽꢓꢕ of UPGMꢀ cꢡaꢽꢽꣁﬁꢼaꢺꢟon of MRHI ꢣaꢺa for moꢣel ꢣeꢇeloꢑmeꢅꢋ, ꢄꢐeꢕe were ꢑoꢺꢿꢅꢺiaꢡꢡy ꣀest ꢽuꢟꢺeꢣ ꢺo ꣂꢚanꢺꢓꣃꢓnꢾ tꢐe ꢣeꢾreꢿ oftemꢑorai ꢇariaꣀꣁlꢟty ꢟnꢐereꢅt ꢟn a ꢣata ꢕeꢄ.

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2.2 Implicaꢆions of lack of persisꢆence for classificaꢆion

W꣒ꢔꢊꢔ lack ꣛f p꣇rꣅꣁꣅꢝ꣇ncꢿ of macꢊoinꢇꢔ꣄꣇braꢝ꣇ commꢚniꢝi꣇ꣅ waꣅ obꣅꢔ꣆꣇꣈ in a ꣎ong-ꢄꢔꢊm ꣈aꢝa ꢕ꣇ꢄ, an obj꣇ctiꢇ꣇ of ꢝ꣒꣇ cꢚꢊꢊ꣇nꢝ p꣑꣛jꢔcꢄ waꣅ to ꣇xp꣎or꣇ ꢝ꣒꣇ imp꣎icaꢝions of t꣒꣇ ꢊ꣇ꣅꢚ꣎ꢝꣅ fo ꣑ Mꢍ pꢊ꣇꣈ictiꢇ꣇ mo꣈꣇꣎꣎ing b꣏ aꣅꣅꢔꣅꢕꢟng t꣒꣇ ꣈꣇g꣑꣇꣇ of ꢝ꣇mpo꣑a꣎ ꢇaꢊꢟabꢟ꣎i꣉ ꢁ r꣇fꢔꢊꢔnc꣇ ꣅiꢝꢔꢕ ꢊ꣇꣎aꢝꢟꢇ꣇ to c꣎aꣅꣅꢟﬁcaꢝionꢕ of ꢊꢔlaꢝꢔ꣈ ꢟmpacꢝ꣇꣈ ꣅiꢝ꣇ꣅ. Uꣅing ꣎ong-ꢝꢔꢊm ꣈aꢝa from ꢝ꣒꣇ ꢚpp꣇r S꣛ꢚꢄ꣒ A꣎l꣖gaꢄor ꢥ꣖ꢇ꣇r (SAꢥ) (Hꢚmp꣒ꢊꢔ꣏ ꣇ꢝ a꣎ 1995a, 1 997a), Hꢚmp꣒r꣇꣏ ꣇t a꣎ ( ꣎995b) ꣇xp꣎꣛ꢊ꣇꣈ ꢝ꣒꣇ ꢟmpl꣖caꢝionꣅ of a mark꣇꣈ ꢕwꢟꢝc꣒ ꢟn ꣅꢝ꣊cꢝꢚꢊ꣇ of macroinꢇꢔ꣄꣇bꢮaꢝ꣇ commꢚnꢓꢝi꣇ꣅ (ꢊank abꢚn꣈anc꣇ꢕ) ꢄ꣒aꢝ occꢚrr꣇꣈ b꣇ꢝw꣇ꢿn pꢊꢔ- 1993 an꣈ p꣛ꣅꢄ-1992 tim꣇ pꢔꢊi꣛꣈s, b꣏ assꢔꢕsing w꣒꣇t꣒꣇ꢊ ꢄ꣒꣇ poꢕꢝ- 1992 ꣈aꢝa c꣎aꣅꣅiﬁ꣇꣈ n꣇a꣑ o꣑ ꢝ꣛g꣇ꢝ꣒꣇r wiꢝ꣒ ꢝ꣒꣛s꣇ ꣋om boꢝ꣒ ꢚnpo꣎꣎ꢚꢝ꣇꣌minꢔ- pollꢚt꣇꣈ portionꢕ ꣛fꢄ꣒ꢔ a꣈jacꢔnꢝ ꢥ꣛ck꣒o꣎꣇ Mꣁn꣇ ꣕꣑꣇꣇k.

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T꣒ꢔ ꢚ꣎ꢄimaꢄ꣇ ꢄ꣇sꢄ of w꣒꣇ꢝ꣒꣇ꢮ oꢊ noꢝ ꢝ꣇mp꣛ꢊal ꢇarꢟabi꣎iꢝy pꢮ꣇ꣅ꣇ntꣅ prob꣎꣇mꣅ foꢊ pꢊ꣇꣈icꢝiꢇ꣇ mo꣈ꢔ꣎lꢟng ꣎ꢟ꣇ꢕ ꢟn ꢊꢚnn꣖ng ꣎ongꢹt꣇rm c꣛mmꢚnꢟꢝ꣏ comp꣛ꣅ꣖ꢝiona꣎ ꣈ata fo꣑ paꢊticꢚlaꢊ ꢕꢟꢝꢔꢕ, ꣅꢚc꣒ aꣅ t꣒꣛ꢕꢔ fꢊom ꢝ꣒ꢔ Sꢀꢥ, ꢄ꣒ꢮoꢚg꣒ ag꣇ncy c꣎aꣅꢕificaꢝi꣛nꢕ an꣈ mo꣈꣇lꣅ. In t꣒iꣅ conꢝ꣇xꢝ t꣒ꢔ ꢕꢔꢇꢔꢮiꢄ꣏ ꣛ꢮ ꣛ꢝꢐ꣇rwꣁꢕ꣇ of any laꢼk ꣛f commꢚnꢟꢝ꣏ p꣇ꢮs꣖sꢝ꣇nc꣇ can b꣇ ꣍꣎꣎꣏ mꢔaꢕꢚꢊꢔ꣈. MꢓꣅcIaꣅꣅꣁficationꢕ an꣈ po꣛ꢮ pꢮ꣇꣈ꢓcꢝꢓ꣛nꣅ woꢚ꣎꣈ ꣁn꣈ꣁcaꢝ꣇ poꢝꢔnꢄia꣎ pꢊ꣛b꣎꣇ms foꢮ mo꣈꣇꣎ ꣈꣇ꢇ꣇꣎opmꢔnꢝ. To ꢝꢐꢓꣅ ꣇n꣈, ꢝꢐ꣇ ꢕam꣇ ꣎ong-ꢝ꣇ꢊm Sꢀꢥ ꣈aꢝa (bꢚꢝ ꢝ꣒꣖ꣅ tim꣇ ꢚꣅi꣓g p꣑꣇ꢕꢔncꢔ-abs꣇nc꣇ ꣈aꢝa) w꣇ꢮ꣇ ꣁnco꣐o꣑aꢝꢔ꣈ inꢝo an NT MꢥHꢎ ag꣇ncy claꣅꣅifiꢼaꢝion baꢕꢔ꣈ ꢚpon ꢮꢓffl꣇ ꢕampl꣇ꢕ gat꣒ꢔꢊꢔ꣈ ꢝ꣒ꢊ꣛ꢚg꣒꣛ꢚꢄ ꢄ꣒꣇

NT.

2.3 Evaluaꢆe ways ꢆo accounꢆ for ꢆempoꢅal vaꢅiabiliꢆy and make recommendaꢆions

ꢎꢝ b꣇cam꣇ ꣇ꢇi꣈ꢿnꢝ ꢝ꣒ꢊ꣛ꢚg꣒ ꢝ꣒꣇ c꣛ꢚꢮs꣇ ꣛f ꢄ꣒꣖ꣅ ꢕꢝꢚ꣈y ꢄ꣒at ꣅꢿꢿking ꢔnꢇiꢊonm꣇nꢝa꣎ c꣛ꢮꢮ꣇꣎at꣇ꢕ t꣒aꢝ may accoꢚnꢝ f꣛ ꢮ ꢄ꣇mp꣛ꢮa꣎ ꢇaꢮꣁabi꣎ꣁꢄ꣏ w꣛ꢚl꣈ bꢔ ꢚnlikꢔ꣎y ꢄ꣛ b꣇ ꣅꢚcc꣇ꣅꣅfꢚ꣎ for many of ꢝ꣒ꢔ ꣈aꢄa ꢕ꣇ꢄꢕ f꣛ꢮ wꢐ꣖cꢐ 'ꢐꣁgh' ꢝ꣇mpoꢊa꣎ ꢇaꢊiabilꢓꢝy waꢕ fo ꢚn꣈. Wꢐi꣎ꢕꢝ ꢝꢐ꣇ ꣑꣇aꣅonꢕ foꢊ ꢝ꣒ꢓꢕ aꢊ꣇ ꢮ꣇ꢇi꣇w꣇꣈ b꣇꣎꣛w (ꢕꢿcꢝion 3.3) an꣈ ꣖n ꢄ꣒꣇ aꢁac꣒m꣇꣓ꢝꢕ꣔ no actꣁꢇ꣇ rꢿꢕꢔaꢊc꣒ waꢕ c꣛n꣈ꢚcꢝ꣇꣈ on ꢝhꣁꢕ ꣁꣅꣅꢚꢿ.

3 Results

In ꢝ꣒ꢔ f꣛ ꣎꣎꣛w꣖ng ꢕ꣇cꢄꣁ꣛nꣅ, a ꣅꢚmmary ofꢊ꣇ꢕꢚ꣎ꢝꢕ, ꢄꢐꢔꢟꢊ ꣖nꢄ꣇rpꢮ꣇ꢄatꢓ꣛n, pꢮacꢝica꣎ ꢕignꣁﬁcancꢿ an꣈ a comparꣁꢕo꣓ of꣑ꢿꢕꢚ꣎ꢝꢕ agaꢟnꢕꢄ pꢊoj꣇cꢝ ꣛ꣀj꣇cꢝꢓꢇ꣇ꢕ, aꢊ꣇ proꢇi꣈꣇꣈.

3.1 Measuꢅe 'persisꢆence' of macroinveꢄebꢅaꢆe communiꢆy sꢆrucꢆure from long-ꢆerm daꢆa seꢆs

Degree and extent oftemporal variability: rank abundance data

F꣛ꢊ ꢐalf of ꢄꢐꢔ caꢄcꢐm꣇nꢝꣅ ꣅꢝꢚ꣈ꣁ꣇꣈, ꣛ꢇꢿr 30% ꣛f ꣁnꢝ꣇ꢊannꢚa꣎ c꣛mpaꢮꢓꢕonꢕ ꢔxc꣇꣇꣈꣇꣈ a Bray꣕ꢚ꣄꣖ꢕ ꣈꣖ꢕꢕ꣖m꣖꣎ar꣖ꢄy ꢇa꣎ꢚe of 0.5 (Hꢚmpꢐr꣇y ꢿꢄ a꣎ 1997b). On꣎꣏ fo ꢮ a ꢮ꣇꣎aꢝꣁꢇ꣇꣎꣏ ꢕma꣎꣎ portꣁ꣛n ꣛fꢕoꢚꢝꢐꢿ꣗ Aꢚꢕꢄra꣎ꢟa, f꣛ꢊ wꢐ꣖cꢐ ꣖nꢄ꣇ꢮannꢚa꣎ ꢇarꣁabꣁliꢄy of ꣈iꢕcꢐaꢊgꢿ ꢟꢕ low - Taꢕman꣖a, ꣅ꣛ꢚꢄꢐ- w꣇ꢕꢄ WA a꣓꣈ poꣅꢕib꣎y parꢄs of Viꢼꢝoꢊia - w꣛ꢚl꣈ ꢄꢐ꣇ꢊꢔ app꣇ar t꣛ ꣀ꣇ p꣛ꢝ꣇nꢄꣁa꣎ f꣛ r ꣈꣇ꢇ꣇lopmꢿnꢝ of AUSꢥIVAS mo꣈꣇꣎ꢕ ꣀaꢕ꣇꣈ ꢚpon rank abꢷ꣓꣈a꣓c꣇ ꣈aꢝa. Gꢟꢇꢔn ꢝ꣒iꢕ ꢊꢔꢕ꣘icꢝꢟon an꣈ ꢄꢐ꣇ facꢄ ꢝꢐaꢝ ꣙ꢚ꣚ꢿnꢄ AUSꢥIVAS mo꣈꣇lꢕ ꢚꣅ꣇ compoꣅ꣖ꢄ꣖ona꣎ ꣈aꢝa, ꢝꢐ꣇ ꣑ꢿsꢝ of ꢄꢐꢿ ꣈iꢕꢼꢚꢕꢕion foꢼꢚꢕ꣇ꢕ ꣛n r꣇ꢕꢚlꢄꣅ ꢚꣅing pr꣇ꢕ꣇ncꢿꢹabsꢿꢅcꢿ ꣈aꢝa.

Degree and extent of temporal variability: presence-absence data

Foꢮ 7 ꣛f tꢐ꣇ 10 r꣇gi꣛꣓s sꢄꢚ꣈ꣁꢿ꣈ fo r wꢐꢟcꢐ ꢄw꣛ ꢕ꣇aꢕ꣛nꢕ ꣛f ꣈aꢄa w꣇r꣇ aꢇaꢟlaꣀlꢔ, inꢄ꣇rannꢚa꣎ ꢇariati꣛꣓ was gꢊꢿaꢄꢔꢕꢄ f꣛ ꣎l꣛wꢓng ꢕ꣇aꣅ꣛nal fl꣛꣛꣈꣖ng (Hꢚmphrꢿy ꣇t a꣎ 1 997b). F꣛r 2 n꣛ꢒꢐ꣇꣜ Aꢚꢕꢝral꣖an ꢕꢄr꣇amꢕ, inꢄ꣇rannꢚa꣎ ꢇa꣑iaꢝi꣛꣓ waꢕ grꢿaꢄ꣇ꢕꢝ aꢝ ꢄꢐ꣇ ꢔn꣈ of ꢝꢐꢿ Dry ꣅꢿaꢕ꣛n, atꢄ꣑ibꢷꢄablꢿ t꣛ cꢐang꣇ꢕ in c꣛mmꢚniꢄ꣏ c꣛mp꣛ꣅ꣖ꢝio꣓ as a rꢿꢕꢚlꢄ of low ﬂow con꣈ꣁꢝi꣛nꣅ an꣈ ꣈roꢚgꢐꢄ.

A combinꢿ꣈ꢹs꣇aꢕ꣛nꢕ in꣈ꢔx waꢕ ꣈꣇riꢇ꣇꣈ ꣀy aꢇ꣇rag꣖ng ꢄꢐ꣇ I꣓꣙꣛nꢕꢝa꣓꣙y ꣁn꣈꣇x acroꣅꣅ ꣅ꣇aꣅ꣛nꢕ f꣛ ꢊ pr꣇ꣅ꣇nc꣇ꢹaꣀꢕen꣙ꢿ data. Rꢿg꣑ꢿꢕꢕi꣛꣓ a꣓a꣎ysis waꢕ ꢚꢕ꣇꣈ ꢄo ꢕ꣇꣇k r꣇laꢝ꣖onꣅꢐ꣖pꢕ ꣀ꣇ꢝwꢔ꣇n ꣈ꢿp꣇꣓꣈anꢄ ꢎnc꣛nꢕꢄancy in꣈꣇x an꣈ in꣈꣇p꣇n꣈꣇nꢄ ꣇nꢇꣁr꣛꣓mꢿ꣓ꢄal ꢇaꢊiablꢿꢕ. T꣒ꢔ b꣇ꢕꢄ p꣑꣇꣈icꢝiꢇꢿ r꣇laꢄ꣖꣛nꢕꢐip waꢕ a bꣁꢇarꣁate ꢿꣂꢚaꢄ꣖on ꣈꣇rꢓꢇꢿ꣈ b꣇ꢄw꣇꣇n ꢄꢐ꣇ Inc꣛nꣅꢝancy in꣈꣇x ꢇariabl꣇ a꣓꣈ in꣈ꢿpꢿ꣓꣈ꢿnt ꢇariaꣀ꣎꣇ꢕ. ꣕꣛ꢔfficienꢄ ꣛f Var꣖ati꣛n of a꣓nꢚa꣎ flow an꣈ flow ꢕꢄatꢚꢕ

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3

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(꣢꣣ꢮmanꢔn꣠/꣥ꢃa꣥onaꢡꢡy-ﬂow꣱ng) (ꢥ2

ꢀ

0.77). La꣠꣱꣠ꢷ꣈ꢔ wa꣥ ꣳoꢚn꣈ ꢄo bꢃ on꣎y wꢃak꣎y (an꣈ n꣣ga꣠꣱ꢇ꣣꣎y) co꣝ꢃ꣎aꢄꢔ꣈ w꣱꣠h ꣱ncon꣥ꢝancy (Hꢚm꣢h꣤ꢔy ꢔꢝ al 1997b).

T꣦ꢮ꣣ꢔ ꣥ꢚmma꣞ ꣢o꣰nꢝꢕ may bꢔ ma꣈ꢔ from ꢄhꢔ ꣤꣣꣥ꢚl꣠꣥ of Hꢚm꣢꣦rꢃy ꢃt al ( 1997b) an꣈ ꣳ꣤om rꢃgꢮꢔ꣥꣥꣰on anaꢡyꢕ꣰ꢕ. (T꣦ꢔ ꣠ꢃ꣑m '꣢ꢃr꣥꣰꣥꣠ꢃncꢃ', ꢄh꣣ conꢇꢔ꣤ꢕ꣣ of '꣰ncon꣥ꢝancy', ꣰꣥ ꢚ꣥ꢃ꣈ ꢄo ꣈ꢔꢕcꢮib꣣ th꣣ ꣈ꢃg꣑ꢿꢔ oꣳ ꢕ꣰mꢆ꣎aꢮ꣱꣠y ꣰n commꣲn꣰꣠y com꣢oꢕꢆ꣠꣱on oꢇꢔ꣤ ꣠ꢆmꢃ):

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(a) A ꣦꣱g꣦ nꢔgaꢝiꢇꢃ co꣟ꢔꢡa꣠ꢆon ꢆꢕ obꢕꢃ꣡ꢃ꣈ bꢔꢄwꢔ꣣n ꣢ꢃr꣥꣰꣥ꢄꢃncꢃ, an꣈ ꣰nꢄꢔ꣑annꢚa꣎ ꢇaꢮ꣱aꢝꢆon oꣳꢕꢝ꣤꣣am ꣈꣱꣥chargꢃ.

1 .

(b) Pꢿ꣤꣥ꢆꢕꢄꢔncꢔ of macꢮoinꢇꢃr꣠ꢃbraꢄꢃ commꢚniꢝ꣰꣣꣥ ꢆ꣥ ꣥ꢆgnꢆfican꣠ly ꣦ighꢃr in ꣥ꢝ꣑ꢔamꢕ of ꣢ꢃꢻanꢔnꢄ flow ꣠꣦an ꣱n ꣥ꢝrꢃam꣥ oꣳ ꢕꢔaꢕona꣎ flow. (Fo꣤ ꢕꢔaꢕonaꢡ꣎y-flow꣰ng ꣥ꢄ꣑꣣amꢕ ꣠haꢝ ꣈ry oꢚꢄ conꢕꢆ꣈꣣꣤ab꣎y, ꢡowꢃr ꣢ꢃꢮ꣥꣰꣥ꢝꢔncꢔ ꢆꢕ ꣢o꣥꣥ꢆbly ꣑ꢔꢡaꢝꢔ꣈ ꣠o ꣠h꣣ ꣥꣠oc꣦a꣥ꢝ꣰c naꢄꢚ꣤ꢔ of ꣑꣣colonꢆꢕa꣠ꢆon oꣳꢝhꢃ ꣳaꢚna ꣳo ꢡlowꢆng ꣤꣣-w꣣ꢝ꣠ꢆng.)

(c) Thꢃrꢃ ꢆ꣥ a ꢄꢔn꣈ꢔncy (on꣎y) for mac꣑oꢆnꢇꢔꢉ꣣b꣤a꣠ꢃ commꢚnꢆꢝꢆꢔ꣥ of ꣢꣣ꢮmanꢃnꢝ ꣥ꢝ꣤ꢃamꢕ ꣰n ꢄꢔm꣢꣣꣤aꢝꢃ Aꢚ꣥ꢝꢮa꣎꣰a ꢝo bꢔ mo꣤ꢔ ꣢꣣ꢮꢕ꣱ꢕꢝꢃnꢝ ꢝhan ꢝhoꢕꢔ ꢓn ꢝꢮo꣢꣰ca꣎ ꣑ꢃg꣰on꣥. (A꣢aꢉ ꣳ꣤om gꢮꢃaꢝꢃꢮ ꣥ꢃa꣥onal ꢔxꢝ꣤꣣m꣣꣥ ꣰n ꣈ꢆ꣥chargꢃ, ꢝhꢆ꣥ may a꣎꣥o rꢃlaꢝꢔ ꢝo ꣠hꢔ ꣥꣦o꣧꣣꣤ ꣎꣰fꢃ cyclꢃ꣥ of ꢝ꣑o꣢ꢆca꣎ ꣱nꢇꢃrtꢃbraꢝꢃ꣥; mo꣑ꢔ ꣈ynam꣱c, ꣥꣦o꣨ꢃꢻ ꣤ꢔꢕ꣢on꣥ꢔ ꢝo ꣈ꢆ꣥꣠ꢚ꣑bancꢔ m꣱g꣦ꢝ bꢔ ꣣x꣢꣣cꢝꢔ꣈ ꣳ꣑om ꢝhꢔ꣥ꢔ aꢕꢕꢔmb꣎agꢃ꣥.)

2. Fo꣤ ꢝhꢔ ꣎ꢓm꣱ꢝ꣣꣈ ꣈aꢝa aꢇa꣰lablꢔ, mac꣤oꢆnꢇ꣣rtꢃbꢮaꢝꢔ commꢚniꢝ꣱ꢔ꣥ ꣩om ꣤꣰ﬀlꢔ habꢆꢝaꢝ a꣢꣢ꢃaꢮ to bꢃ mo꣤ꢔ ꣢ꢔ꣤꣥ꢆꢕꢝ꣣n꣠ ꣠꣦an ꣠꣦o꣥ꢃ ꣳ꣑om oꢝhꢔ꣤ hab꣱ꢝa꣠꣥, ꢃꢇꢔn aꢝ ꢝh꣣ ꣥amꢃ ꣥ꢆ꣠ꢃ꣥ oꣳ ꣢꣣ꢻan꣣n꣪ ﬂow.

3 . Mꢃa꣥ꢚ꣤ꢔ꣥ of ꢝꢔm꣢oꢮaꢡ ꢇariabꢆ꣎ꢆꢝ꣏ ꢚ꣥ꢔ꣈ ꣱ n ꣠꣦ꢃ ꣥ꢝꢚ꣈y (fam꣰꣎y-ꢡꢔꢇ꣣꣎, ꣢ꢮꢃ꣥ꢿncꢃ-ab꣥ꢔncꢔ ꣈aꢝa) an꣈ aꢇꢔ꣤agꢔ꣈ acro꣥s ꢝhꢿ ꣥ꢔa꣥onꢕ ꣰n꣈꣰catꢿ꣈ ꣤ꢔ꣎a꣠ꢓꢇꢔ꣎y ꣦igh ꣢ꢃ꣑꣥꣰꣥꣠ꢔnc꣣ of mac꣑o꣫nꢇ꣣ꢉꢃbꢮatꢿ commꢚnꢆꢝꢆꢔꢕ fo꣤ aꢡꢡ bꢚꢝ onꢃ o꣤ ꢄwo ꣤꣣g꣰on꣥ rꢔ꣢rꢿ꣥ꢔnꢝꢔ꣈. Fo꣤ ꣤꣣gꢆon꣥ ꢔxhꢓb꣱ꢝ꣰ng high Incon꣥꣠ancy ꢆn꣈ꢿx vaꢡꣲꢿꢕ꣔ cycꢡon꣱c ꣈i꣥ꢝꣲrbancꢔ an꣈ ﬂoo꣈ꢓng wꢃrꢿ aꢱꢮꢆbꢚꢝꢿ꣈ aꢕ ꢝhꢔ caꢚꢕ꣣ (Hꢚm꣢hꢮꢃ꣏ ꢃꢝ at. 1 997b). Nꢃꢇꢃr꣠hꢃꢡꢿ꣥꣥, w꣦ꢓꢡꢕꢝ ꢝ꣣m꣢oꢮa꣎ ꢇar꣰ab꣰lꢆꢄy oꣳ mac꣤oꢓnꢇꢃꢮ꣠ꢃbꢮaꢄꢃ commꢚnꢓ꣠ꢓ꣣ꢕ may bꢃ h꣫gh ꢆn on꣎y onꢃ oꢮ ꣬o r꣣gꢆon꣥ ꣑ꢔ꣢꣤ꢔꢕ꣣n꣠꣣꣈ ꣰n ꣠꣦꣱꣥ ꣥ꢝꢚ꣈꣏, ꢝ꣦ꢔꢕꢔ ꣤꣣g꣱on꣥ rꢃ꣢꣤ꢿ꣥ꢃnꢄ a ꣎a꣤g꣣ ꣢or꣠ꢆon oꣳ ꢝh꣣ con꣠inꢔn꣠. In ꣢a꣑꣪ꢆcꢚ꣎a꣤, Hꣲm꣢h꣑ꢃ꣏ ꢔꢝ aꢡ. ( l997b) ꢃxꢝ꣑a꣢oꢡaꢄꢔ꣈ ꢝh꣣ ﬁn꣈꣱ng꣥ ꢝo ꣥ꢚggꢔꢕ꣠ ꢝ꣦a꣠ ꢝ꣦ꢔ ꣥ꢔn꣥꣰ꢝꢆꢇꢆꢄy oꣳ A꣭꣮꣯VA꣮ mo꣈ꢔꢡꢕ ꣈ꢔꢇ꣣ꢡo꣢ꢃ꣈ ꣳo r mꢚch oꣳ ꢝh꣣ ꣈꣤oꢚghꢝ-꣢꣤onꢔ ꣢o꣧꣰on of ꣣a꣥꣠ꢿ꣜ Auꢕꢄral꣰a, ꣢aꢉ꣱cꣲ꣎aꢮꢡ꣏ N꣮W an꣈ QLD꣔ coꢚꢡ꣈ bꢿ ꣙om꣢꣤om꣰꣥ꢔ꣈ ꣈ꢚ꣤ꢓng (an꣈ ꣢o꣥꣥꣫b꣎y aﬅꢔ꣤) ꣈roꢚg꣦ꢄ ꣢꣣ꢮꢓo꣈꣥.

3.2 Implications of lack of persistence for classification

From o꣤꣈꣰na꣠꣱onꢕ ꢝhaꢄ wꢿrꢿ con꣈ꢚcꢝ꣣꣈ ꣲ꣥꣰ng ꣮Aꢥ ꣈aꢝa, ꣢oꢕꢝ- 1992/꣢꣑ꢿ-1 993, an꣈ ꣈a꣠a ꣳ꣤om boꢝh ꢚn꣢oꢡꢡuꢄꢃ꣈/mꢆnꢔ-꣢oꢡꢡꢚ꣠ꢿ꣈ ꣢oꢮꢄ꣰on꣥ of ꢝ꣦ꢔ a꣈jacꢿnꢝ ꢥockho꣎ꢔ Mꢓn꣣ Cꢮꢿꢿk (RMC), Hꣲm꣢hrꢿy ꢿꢝ aꢡ ( 1995b) ꣥howꢿ꣈ ꢄhaꢝ ꢝ꣦꣣ magn꣱ꢄꢚ꣈ꢃ of changꢔ o꣙cꢚr꣤꣰ng ꣰n ꢝhꢔ ꣮Aꢥ ꣢o꣥ꢝ- 1992 waꢕ ꢔꢇ꣣n morꢿ ꣥ꢃꢇꢃrꢃ ꢄhan ꢝhaꢝ occꣲrꢮ꣱ng ꣱n ꣢oꢡꢡꢚꢝ꣣꣈ ꣢or꣠ion꣥ oꣳ RMC. Mo꣤꣣oꢇ꣣꣤, ꢝ꣦ꢿ ꣈ꢆ꣤ꢿ꣙ꢝ꣱on of chang꣣ occꣲꢮꢮ꣰ng in ꢝhꢿ ꣮Aꢥ ꣈aꢝa waꢕ ꣰n ꢝhꢔ ꢕam꣣ ꣈꣰ꢮꢿcꢄ꣰on a꣥ ꢝhꢿ ꣢olꢡꢚꢝ꣰on g꣑a꣈꣰ꢔn꣠ ꣱n ꢥMC.

Thꢿ l꣱m꣱ꢝaꢄ꣱ons of ꢄhꢿ a꣢proach ꣈ꢿ꣥꣙riꣀꢿꢜ abovꢿ ꢄo MꢥHI moꢜeꢡꢡing arꢔ ꣬oꣳol꣈: F꣫r꣥꣠꣎y꣔ ꣠꣦ꢔ ana꣎yꢕ꣱ꢕ for ꣮Aꢥ-RMC wa꣥ ꣀaꢕe꣈ ꣲpon fam꣱ꢡy-lꢿꢇꢿꢡ abꣲn꣈ancꢔ ꣈a꣠a. Th꣣ anaꢡy꣥꣱ꢕ haꢕ noꢝ bꢿꢃn rꢿpꢔaꢝꢔ꣈ ꢚꢕ꣱ng ꣢rꢿsencꢿ-abꢕ꣣ncꢿ ꣈aꢝa bꣲꢄ ꣰ꣳ ꢝhꢓꢕ waꢕ pꢿrformꢃ꣈ ꣰ꢝ woꣲꢡ꣈ ꣢꣤obabꢡ꣏ ꣱n꣈꣱꣙aꢄꢿ litꢄle changꢿ ꣱n ꣮Aꢥ commꢚn꣰ꢄy com꣢o꣥꣱ꢄion b꣣꣬꣣꣣n ꣢oꢕꢄ-1992 an꣈ prꢔ- 1993 rꢿꢡaꢝ꣫ꢇꢔ ꢄo ꢄhaꢄ beꢄwꢿꢿn ꢝhꢿ ꢄwo ꢥMC sitꢿꢕ. ꣮ꢿcon꣈ꢡy an꣈ a꣥ ꣈ꢿꢕc꣑꣰bꢔ꣈ aboꢇ꣣, ꢄh꣣ ꢚꢡ꣠ꢓmaꢄ꣣ ꢝ꣣ꢕ꣠ of whꢿꢝh꣣꣤ o꣤ noꢝ ꢝꢿm꣢o꣤a꣎ ꢇa꣤ꢓaꣀ꣱ꢡ꣱ꢄy ꣢rꢿ꣥ꢃnꢄ꣥ p꣑obꢡ꣣m꣥ fo꣤ ꣢꣤ꢿ꣈꣰cꢝ꣰ꢇ꣣ mo꣈꣣ꢡ꣎ꢆng ꣎ꢆ꣣ꢕ ꢆn rꣲnn꣫ng ꢡong-ꢄꢿrm commꣲn꣰ꢄy com꣢o꣥꣱ꢝ꣱onaꢡ ꣈ata fo꣑ ꣢aꣴ꣱cꣲꢡa꣤ ꣥꣰ꢝꢿꢕ, ꢕꢚch aꢕ ꢝhoꢕ꣣ f꣤om ꣠h꣣ ꣮ꢀR, ꢄh꣤oꢚgh agꢿnc꣏ ꣙꣎a꣥꣥iﬁcaꢝ꣰onꢕ an꣈ mo꣈ꢿl꣥.

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Hꢚm꣢h꣑ey an꣈ ꣵo꣰g (1997) ꣈꣣ꢕcribꢿ resꣲ꣎ꢄꢕ of a cꢡaꢕꢕ꣱ficaꢄion ꣰nco꣤꣢o꣤a꣠ꢓng ꢡong-ꢄꢿrm ꣮Aꢥ daꢄa ꣱nꢝo an NT MꢥHI agꢿnc꣏ cꢡaꢕꢕ꣱fica꣠꣱on baꢕ꣣꣈ u꣢on ꣑꣱fflꢿ ꢕamp꣎ꢿꢕ. ꢥꢿsꣲ꣎ꢄꢕ ꢕ꣦ow꣣꣈ misclassificat꣱on of ꢿarl꣏ (1988) ꣮Aꢥ daꢄa iꢅ a UPGMA classificaꢄ꣱on baꢕꢔ꣈ ꣲpon ꢡaꢄꢿ ꣵꣶ

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4

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sꢈas꣛n 1994 and 1995 NT rifflꢈ daꢝa, whilsꢄ for sꢚccꢈꣅsivꢈ yꢈaꢊs ꣛f daꢝa (1994 and 1 995), aboꢚꢄ 50% of ꢝꢂꢈ 1 5 c꣛mparablꢈ ꣅiꢝꢈs occꢚrrꢈd in diffꢈrꢈnꢄ classificaꢄi꣛n groꢚps. Howꢈvꢈꢊ, bꢈcaꣲꣅꢈ of ꢄꢂꢈ l꣛w inꢄꢈꢊannꢚal paiꢊwisꢈ dissimilariꢄy, low inꢝꢈr-siꢝꢈ dissimilaꢊity gꢈnꢈꢊally, and tꢂꢈ facꢝ ꢝꢂaꢝ ꢝꢂꢈ classificaꢝion waꣅ basꢈd on fꢈw ꣅiꢝꢈs (lꢈss ꢝꢂan 25), no obvi꣛ꢚs c꣛nclꢚsi꣛ns c꣛ꢚld bꢈ dꢊawn fꢊom ꢄꢂꢈ stꢚdy. Dꢈꣅpiꢝꢈ tꢂis, tꢂꢈ ꣍ꣷꣷ ꢓmplꢓcaꢄꢓ꣛ns ꣛f any lack of ꢝꢈmp꣛ꢊal vaꢊiability pꢊꢈsꢈnꢄ ꢓn ꣛ꢝꢂꢈꢊ l꣛ng-ꢝꢈrm daꢝa fꢊ꣛m ꢈl꣥ꢈwꢂꢈꢊꢈ f꣛ꢊ agꢈncy m꣛dꢈꣷ dꢈvꢈlopmꢈnꢄ, accꢚꢊacy and pꢊꢈc꤀si꣛n, will ꢊꢈqꢚꣁꢮꢈ ꣅꣁmilaꢊ appꢊ꣛achꢈs ꢝo tꢂaꢝ ꢚsꢈd f꣛ꢊ NT daꢝa.

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3.3 Evaluaꢆe ways to accounꢆ for temporal variabꢁlꢁꢆy and make recommendations

As dꢈscꢊibꢈd ab꣛vꢈ, ꢝꢂꢈ m꣛sꢄ appꢊ꣛pꢊiaꢄꢈ ꢝꢈꣅꢝ of wꢂꢈꢝꢂꢈr oꢊ noꢝ ꢝꢈmpoꢊal vaꢊiability pꢊꢈsꢈnꢝs pꢊoblꢿms f꣛ꢊ pꢊꢈdicꢝivꢈ m꣛dꢈlling liꢈs in ꢊꢚnnꢓng longꢹꢝꢈrm commꢚnity c꣛mp꣛siꢄi꣛nal daꢝa f꣛ꢮ pa꣑ꢄꣁcꢚlar ꣅ꤀ꢝꢈꣅ ꢝhꢊoꣲgh agꢿncy classiﬁcaꢝi꣛ns and m꣛dꢈls. ꢎn tꢂꣁꣅ c꣛ꢅꢝꢈxꢝ ꢝꢂꢈ sꢿvꢈꢊity ꣛ꢊ ꣛ꢝhꢈrwisꢈ ꣛f any ꣹ack ꣛f c꣛mmꢚnꣁꢄy pꢈꢮsꣁꣅꢝꢈncꢈ - wiꢝꢂꣁn ꢝꢂꢈ boꢚnds ꣛f ꣥ꢈn꣥iꢄꢓvꢓty of tꢂꢈ m꣛dꢈꣷꣅ - can bꢈ ꣸꣹ly mꢿasꢚꢊꢈd. (Misclassiﬁcaꢝi꣛ns and p꣛꣛ꢮ pꢮꢈdꣁcꢝ꤀ons w꣛ꢚld indicaꢝꢈ p꣛ꢝꢈnꢝial pꢊ꣛blꢈms f꣛ꢊ m꣛dꢈl dꢈvꢈ꣹꣛pmꢈnꢝ.) P꣛ssꣁbꣷꢈ appꢊoachꢈs ꢝ꣛ dꢈaling wꢓꢝꢂ ꢝꢈmp꣛ꢮal variability ꣛fmacꢊ꣛invꢈꢊꢄꢈbꢊaꢝꢈ commꢚniꢄiꢈs inclꢚdꢈ:

(1) Risk-based assessment using AUSRIVAS models

As ꢈiꢝꢂꢈꢊ an inꢄꢈꢮꢓm ꣛ꢊ dꢈﬁnꣁꢝꢓvꢈ stꢈp, pꢮꢈdꣁcꢝꣁvꢈ rꢈgꢊꢈssion ꢊꢈlaꢝi꣛nsꢂips bꢈtwꢈꢈn ꢄꢈmp꣛ꢮa꣹ variabiliꢄy and ꢈnviꢊ꣛nmꢈnꢝal vaꢮꢓablꢈs as dꢈscꢮꢓbꢈd ab꣛vꢈ, may bꢈ ꢚsꢈd ꢝ꣛ qꢚan꣺iꢠ dꢈgꢊꢈꢈ꣥ ꣛f 'ꢊisk' ꣛f m꣛dꢈ꣹ faꢓ꣹ꢚꢮꢈ f꣛ꢮ a paꢮtꣁcꣲlaꢮ l꣛catꣁ꣛ꢅ. Thꣁs w꣛ꣲld gꣁvꢿ managꢈꢮs aꢄ ꣷꢈa꣥ꢄ, ꣥꣛mꢈ ꤀nd꤀caꢄꣁ꣛n ꣛f ꢂ꣛w ꣲ꣥ꢈ꣍l and accꣲratꢈ m꣛dꢈ꣹s mꣿght bꢈ ꢝꢂaꢝ aꢊꢈ dꢈvꢈl꣛pꢈd f꣛ꢮ a paꢮtꣁcꢚlaꢮ ꣹꣛caꢄꣁ꣛ꢅ, ꣁꢈ wꢂat dꢈgꢮꢈꢈ ꣛f ꢈꣻ꣛꣼ c꣛ꢚ꣹d bꢈ aꣅs꣛ciaꢄꢈd wiꢝꢂ pꢊꢈdꢓcꢝꢓ꣛n꣥ ꣖f ꢄꢈmp꣛ꢮa꣹ vaꢮꣁabꣁl꤀ty was the s꣛꣹ꢿ facꢝ꣛r ꣛f c꣛ncꢈꣽꣾ

(2) Accounting fortemporal vaꢀabꢁity

As an impꢊ꣛vꢈmꢈnꢝ ꢚp꣛n ( 1 ), can ꢄꢈmp꣛ꢊa꣹ vaꢮꢓabꣁlꣁty bꢈ accoꢚnꢝꢈd f꣛ꢊ? Hꣲmpꢂꢊꢿy ꢈꢄ al (1997b) c꣛nc꣹ꢚdꢈd ꢄꢂaꢝ sꢈꢈkꢓng ꢈnvꢓꢮonmꢈnꢝa꣹ c꣛꤂ꢈlatꢈs ꢄhat may acc꣛ꣲnt f꣛ꢊ ꢄꢈmp꣛ꢊa꣹ vaꢮꢓabꢓꣷ꣖ty w꣛ꢚ꣹d bꢈ ꣲn꣹ꣁkꢈ꣹y t꣛ bꢈ sꣲccꢈssfꢚl f꣛ ꢮ a nꣲmbꢈr ꣛f ꣅitꣲaꢝꣿ꣛ns: (i) sꢈas꣛na꣹ly-fl꣛wꣿꢅg stꢮꢈams whꢈrꢈ shꣿﬅs ꤀n c꣛mmꣲnity c꣛mp꣛s꤀ꢄi꣛n ꣛vꢈꢊ ꢄimꢈ may bꢈ ass꣛cꣿaꢝꢈd wꣿꢝh sꢄ꣛chasꢝꣿc ꣤ꢿc꣛꣹꣛n꤀saꢝ꤀꣛n pꢊ꣛cꢈssꢈs (sꢈꢈ a꣹s꣛ Wꢊꢓgꢂꢝ 1 995); (ꢓꢓ) l꣛ngꢈꢮ-ꢄꢈꢮm (sꢿvꢿꢊal yꢈaꢊs) ꢊꢈc꣛vꢈꢊy and ꢊꢈc꣛꣹꣛nꢓsaꢝ꤀꣛n ꣛f sꢄꢮꢈams f꣛ l꣹꣛wꣁng mass꤀vꢈ d꤀stꣲꢊbancꢈ (ꢈg ꢥ꣛bꢈ ꢥ, n꣛ꢮthꢹwꢈsꢄ Wꢀ); and (꣖꤀ꣿ) sw꤀tcꢂꢈs bꢈꢄwꢈꢈꢅ dꣿffꢈrꢈnꢝ c꣛mmꢚnity 'sꢝꢈady sꢄaꢝꢈs' wꢂꢿꢊꢿ ꢄꢊiggꢈꢊs f꣛ ꢊ ꢄꢂꢈ sw꤀ꢄcꢂ may bꢈ clꢈaꢊ꣹y ꣖dꢈnꢝ꣖fiꢈd, bꢚꢝ ꢝꢂꢈ ꢝꢊajꢈcꢄ꣛ꢊy ꣛f c꣛mmꢚniꢄy c꣛mp꣛s꤀ꢝ꤀꣛n ꢝꢂꢈꢊꢈaﬅꢈꢊ ꤀s ꢈiꢄꢂꢈꢊ laggꢈd, ꣛ꢊ ꣲnkn꣛wn and ꢚnpꢮꢈdꣁcꢝablꢈ (ꢈg SAꢥ and Yꣲccabꣿꢅꢈ Ck, n꣛꣤ꢄhꢹꢈaꣅꢄ QLD; ꣅꢿꢿ als꣛ B꣛ꢚlꢝ꣛n & Lakꢈ 1 992). ꢀss꣛cꢓaꢝꢈd wꢓꢝꢂ ꢄhꢈsꢈ difficꢚ꣹ꢄ꣖ꢈs ꣖s ꢄꢂꢈ p꣛ssꢓbꢓlꢓty ꣛f ꢓnꢄꢈꢊ-caꢄcꢂmꢈnꢄ dꣁffꢈꢮꢈncꢈs ꣁn c꣛mmꣲnꣁty ꢮꢈsp꣛nsꢈs, a꣥ dꢈscꢊ꣖bꢈd f꣛ ꢮ ꢄhꢈ S꣛ꣲth ꢀ꣹꣹ꣿgat꣛r R aꢅd Magꢈ꣹a Ck (NT) ꣿn Hꣲmphrey & D꣛ꣿg ( 1 997).

M꣛dꢈ꣹꣹꣖ng ꣛f d꣤꣛ꣲgꢂꢄ-ꢊꢈ꣹aꢄꢈd cꢂangꢈs ꢄ꣛ macꢮ꣛ꢓnvꢈꢮtꢈbꢮaꢝꢈ c꣛mmꣲnꢓꢄꣁꢈs w꣛ꢚ꣹d bꢈ paꢮtꢓcu꣹arly usꢈful f꣛ ꢮ ꢀUSRIVꢀS m꣛dꢈ꣹ dꢈvꢈl꣛pmꢿnꢝ ꤀n ꢈasꢝꢿꣽ ꢀꣲsꢝ꣑al꤀a. H꣛wꢈvꢈꢊ, ꢄhꢈꢊꢈ ꤀s p꣤ꢈsꢈnꢄ꣹y ꣹ꢓꢄꢄ꣹ꢈ ꣲndꢈꢊsꢄandꢓng ꣛f ꢄhꢈ ꢮꢈsp꣛nsꢈs ꣛f macꢮ꣛ꢓnvꢈꢮtꢈbꢮaꢄꢈ c꣛mmꣲniꢄiꢿꣅ ꢄ꣛ d꣤꣛ꣲghꢄ, iꢅclꣲd꤀ꢅg ꢂ꣛w ꣑ꢿsp꣛ꢅs꤀vꢿ ꢝhꢿ faꢚna is ꢄ꣛ ꢈnviꢊ꣛nmꢈnꢝaꣷ cꢂangꢿ. M꣛ꢮꢈ꣛vꢈꢊ, Hꣲmpꢂ꣑ꢈy ꢿꢄ aJ. ( 1997) ꣑ꢿp꣛rꢄꢈd vꢿ꣑y diffꢿ꣑ꢿꢅꢝ ꣑ꢈsp꣛nsꢈs ꢝ꣛ dꢊ꣛ꢚgꢂꢝ acꢊ꣛ss ꢀꣲꣅꢄꢮa꣹꣖a aꢄ ꢮꢈg꣖꣛ꢅa꣹ aꢅd ꣿꢅꢄꢿ꣑- and ꣖ꢅꢄꢮa-caꢝchmꢈꢅꢄ ꣅca꣹ꢈs. Examinaꢝi꣛n ꣛f ꢈxisꢝiꢅg agꢈncy daꢄa sꢈꢝs, s꣛me ꣛f wh꣖ch spaꢅ pꢈ꣤ꢓ꣛ds ꣛f maj꣛ꢮ dꢮ꣛ꣲghꢄ (eg QLD, 1994ꢹ1995) w꣛ꣲ꣹d asꣅꢓsꢄ ꤀n ꣑ꢈdꢊꢈss꣖ng ꢄhꢈsꢈ ꣖nf꣛ꢮmaꢄꢓ꣛n dꢈﬁc꣖ꢈncꢓꢈs.

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(꣖ꢓ)

aꢅd

m꣛dꢈ꣹

Th꣖s w꣛ꣲ꣹d ꢈnꢄa꣖l ꢄhe ꣤ꢈ-sampl꣖ng ꣛f sꣲ꣖ꢄab꣹ꢈ rꢿfꢿ꣑ꢿncꢿ s꤀ꢄꢈs s꣖mꣲ꣹ꢄane꣛ꣲs꣹y ꣖n ꢄꢓmꢈ w꣖ꢄh m꣛nꣿꢄ꣛rꣿng sꣿtꢿs in ꣛rdꢈr ꢄ꣛ adj usꢝ m꣛dꢿ꣹ ꣛uꢄpꣲꢄ by s꣛me fa cꢝ꣛ꢊ. ꢀ p꣑꣛b꣹em wꣿꢝh thꣿs

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5

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a꣢꣢ꢮoac꣦ ꢟs ꤊ꣦aꢄ ꢟꤊ aꢕꢕꢚmꢃꢕ ꢄ꣦꣣ 'sca꣎ꣁng' oꢮ 'coꢮ꣤ꢃcꤊion' facꤊor ꣰s ꢕꢟmꢟꢡaꢮ acꢮoꢕꢕ claꢕꢕꢟ꤃ca꤄on gꢮoꢚ꣢s an꣈ b꣣ꢄw꣣꣣n ꢮ꣣fꢃrꢃnc꣣ an꣈ ꣈ꢟsꤊꢚꢮb꣣꣈ sꢟꤊ꣣s. T꣦꣰ꢕ assꢚm꣢ꤊ꣰on ꣰ꢕ ꢚnl꣰k꣣ly ꤊo ꣦ol꣈ b꤇caꢚsꢃ꤉ as ꣈꣣ꢕc꣤ꢟb꣣꣈ ꤅n (꣰) aboꢇ꣣, macꢮo꤅nꢇꢃrꢄ꤇bꢮaꤊꢃ commꢚniꤊy ꣑꤇ꢕ꣢ons꤇ ꤊo a ꢕ꣰mꢟla꣤ ꣈꣰꣥ꤊꢚ꣑banc꤇ is likꢃly ꤊo ꣈ꢟꣳf꣣ꢮ at ꣈ꢟffꢃrꢃnꤊ s꣢aꤊ꤅aꢡ scal꤇꣥. ꤐn a꣈꣈꤅ꤊ꤅on, ꤊ꣦꣣ ꣈꣣gꢮ꤇꣣ of c꣦ange ꢄo naꤊꢚꢮaꢡ ꣈ꢓsꤊꢚrbancꢃ ꤅ꢽ l꤅k꣣ꢡy ꤊo bꢃ grꢃaꢄꢃ꣑ foꢮ ꣑ꢃfꢃ꣑꤇nc꤇ sꢟꤊ꤇s ꤊ꣦an foꢮ anꤊ꣦ꢮo꣢ogꢃnꢟcally꣈꤅ꢕꤊꢚꢮb꤇꣈ sꣁꤊꢃs. Hꢃncꢿ ꤊ꣦꤇꣤꣣ woꢚꢡ꣈ bꢃ a n꤇꤇꣈ ꤊo ꣁnclꢚ꣈꤇ ꣥ꢚﬃciꢃnꤊ ꣑꤇ꣳ꤇ꢮ꤇nc꤇ ꢕ꤅ꤊ꤇ꢕ ꤊ꣦aꤊ werꢃ rꢃ꣢rꢃꢕ꤇nꤊaꤊ꤅ꢇ꣣ oꣳ ꢃac꣦ oꣳ ꤊ꣦꤇ claꢕꢕꢓ꤃caꤊion g꣤oꢚ꣢꣥꤉ aꢽ w꣣꣎l as a nꢃꢃ꣈ ꢄo ꢟncoꢮ꣢oꢮaꤊ꣣ rꢃ- sam꣢l꤅ng oꣳꢕ꣣ꢡꢃcꢄ꣣꣈ ꣈꤅sꢄꢚrbꢃ꣈ ꢽ꤅ꢄ꤇ꢕ, ꤅n oꢮ꣈ꢃꢮ ꤊo ꣈꤇ꢮiꢇ꣣ a꣢꣢꣑o꣢ꢮ꤅aꤊ꤇ ꢕcaꢡꢟng ꣳacꢄors.