Table Of ContentContributions
A trial ofslash and burn management of
Coast Tea-tree Leptospermum laevigatum on Wonthaggi Heathland
MaryEllis1 and Terri Allen
'POBox67,FishCreek,Victoria3959.Email:[email protected]
Abstract
In2000, a trialprogramofmanagementoftheWonthaggi HeathlandNatureConservationReservewasim-
plemented. This used theslash andburn technique in smallpatchesofvegetation. Theaimswere: to assess
theinvasionofCoastTea-treeLeptospermumlaevigatum,todeterminetheeffectofeachtreatmentonspecies
richnessandtoobservetheresponseofweedsandorchids.Post-treatmentmonitoringwascarriedoutin2008,
2009and2012.TheresultsfromthistrialshowthatthesemanagementstrategiesreducetheinvasionofSand
andWet HeathlandEVCsbyCoastTea-treeandenhancespeciesdiversity.Itwouldbeappropriatetoextend
theareaofmanagementandcontinuetomonitortheresultsoverthelongterm. {TheVictorianNaturalist130(5)
2013,212-218).
KeyWords CoastTea-tree, slashandburnmanagement, SandandWetHeathland
Introduction
WonthaggiHeathlandNatureConservationRe- Primary Industries). It is important that man-
serve(WHNCR) covers811 haextendingfrom agementshouldnothaveanadverse impacton
the outskirts ofWonthaggi south to the coast thisspecies.
and east to Harmers Haven. The vegetation Coast Tea-tree develops as a small, single-
has been mapped as Sand and Wet Heathland stemmedtreereachingaheightof8-12m,with
(EVCs 6 and 8) and Coast Banksia Woodland alifespan of100-150years. Althoughthetrees
(EVC2),withCoastDuneScrub Mosaic (EVC arekilledbyfire, seeds arenot,astheyare pro-
1) alongthedunes (Davies etal 2002). In 1985 tected by the hard woodycapsules. These cap-
large sections ofthe reserve were burnt. Since sules drop from the plant and remain closed,
then there have been controlled burns over but open soon afterafire. Germination is pro-
small areas in different parts ofthe reserve in lific in the following winter (Burrell 1981). As
2000, 2007, 2008, 2009 and 2010. These burns manyas400 seedlingspersquaremetre (MEl-
were part of the fire prevention management lis pers. obs.) germinated post-fire at Wilsons
plan to reduce the fuel load in a reserve close Promontory National Park (WPNP) in 2006.
tothetownandasecologicalburnstoenhance Seed is usually viable for one year. Most seeds
biodiversity. germinateinthefirstyearafterafire.
Overthelastcoupleofdecadestheinvasionof Invasion of Coast Tea-tree into heathland
Coast Tea-tree Leptospermum laevigatum into showsavarietyofeffectscausedbyfire. Burrell
heathland vegetation has become a significant (1981) showed that three factors were neces-
concern for the Friends ofWonthaggi Heath- sary to produce extensive areas ofCoast Tea-
land,volunteerswhocarefortheheathlandand tree: disturbedtopsoil, atemporary increase in
workcloselywithParksVictoria.Theirconcern soil phosphorus level and release ofthe accu-
is that Coast Tea-tree does not belong in Sand mulated reservoir ofseed. Fire was suggested
and Wet Heathland (Davies et al. 2002) and asthefactorlikelytoproduce theseconditions;
that itsinvasion mayreducethebiodiversityof however, Bennett (1994) considered that fire
theseEVCs. was not a pre-requisite for Coast Tea-tree ex-
Inaddition,thisreserveisoneofthesitesused pansion on the Yanakie Isthmus at WPNP, but
in the study ofthe rare and threatened Eastern thatgrazingpressuremayhavebeenthecause,
Spider Orchid Caladenia orientalis by the De- due to the exposure of bare ground and the
partment of Sustainability and Environment restriction of the feeding range of cattle. Fire
(DSE) (now Department ofEnvironment and suppression wasapossiblecause ofinvasion of
212 TheVictorianNaturalist
'
Contributions
CoastTea-treeinto remnantsofHeathTea-tree years since this was last burnt. The treatments
Leptospermum myrsinoidesheathlandinsubur- for each quadrat were as follows: A. Dry Tea-
ban areas ofMelbourne (Browning2004). Itis, tree was burnt in 2002, slashed in mid 2007,
therefore,appropriatetotesttheeffectoffire in burnt in 2010; B. Dry Tea-tree was burnt in
situinorder todevelop amanagementstrategy 2000,slashedinmid2007andburntin2008;C.
fortheWHNCR. Dry, light cover ofTea-tree was burnt in 2000
and 2008; and E. MoistTea-tree, burnt in 2000
Methods
and2008.
In 2000, a trial program ofmanagementofthe VegetationmonitoringwascarriedoutinOc-
reservewas implemented usingslash and burn
tober 2008, September 2009 and October-No-
in small areas ofvegetation, with the aims: to vember 2012. Quadrats (1 x 1 m) in the centre
assess the invasion ofCoast Tea-tree, to deter- m
and in each corner ofthe 20 x 20 quadrats
mine the effect of each treatment on species
were examined, recording all species present
richness and to observe the response of indi- and all Coast Tea-tree seedlings. We also re-
vidual species ofweeds and orchids where ap-
corded any additional species present in the
propriate. Plant species were named according 20 x20 m quadrat. Exactcountsofspecies and
toWalshandStajsic (2007).
Anareaofapproximately6hawasselectedfor seedlingswerepossibleinallthetreatments. In
the control D, only a rough calculation ofthe
tnuwheepenritetnr2eit0ashltexa(b2lFli0oigns.mhge-1d)qu..unaWbAdiurtrcahontnitstnra(rotAelh,ai.qsBu,IaatrCdemraaaa,nytfdo(bEuDer)o3pnw0eamtrsoampsa4e)-0t tb1oetxaml1amndue,bmybbe4yr00moufalstmitaphtleuyrqinuegaCdtorhaaetstmweaTsaeanv-itrnrteuuemaslblceyoriumli-dn
Chisholms Road Car Park
To Cutler’s Beach
rw-
^
•
r r
A
/s B
/
e V.
\ c /
%
¥
\ / D
\5. *v E,
/
V. \
N
J
S
T
Scale A-B=200m
Fig. 1. Locationofquadratsintrialarea.Shadedareawasslashedin2007.
Vol 130 (5) 2013 213
Contributions
Fig.3.EasternSpiderOrchidCaladeniaorientalis.
heath. Thisisborneoutinthedataforthecon-
D
trol (Table 1). IntreatmentA,therewascon-
siderablerecruitmentinthefirsttwoyearsafter
slashing,butitwasreducedtothecontrollevel
within two years ofthe 2010 burn. The lowest
recruitment occurred in treatment B with two
Fig.2. RedbeaksPyrorchisnigricans. burns and slashing oneyear before the second
burn. IntreatmentsCandEthereweresimilar
penetrable,mwith access on hands and knees to results except for one anomalyin treatment C,
each 1 x 1 quadrat. 69 seedlings in the north east corner, possibly
We have preslenxteldmthe results as tables of fromoneparentplant,aftertheburn in2008.
means per five quadrats and the total
numberofspeciesin20x20mquadratsforthe Theeffectofeachtreatmentonspeciesrichness
threefielddays. Theonlyquadratwith matureCoastTea-treeis
In October 2008, following fire the previ- thecontrol(D)wherethelowestnumberofun-
ous autumn, there were numerous Redbeaks derstoreyspecieswasfound (Table 2).
Pyrorchis nigricans (Fig. 2) flowering on the In the first year after the fire, species diver-
heathland. Using four ofour lxlm quadrats sity as determined by counting the number of
m
we counted the total number ofRedbeaks per species present in 20 x20 quadratswasvery
square metre and the number flowering. We similar in all treatments as well as the control
also countedEasternSpiderOrchidsCaladenia (Table 3). Bythe secondyear there weregreat-
orientalis(Fig. 3) inthesamearea. er numbers. The numbers all dropped by the
fourthyearafterthelastfire.
Results The regrowth ofvegetation afterthe fire pro-
Invasion ofCoastTea-tree duced a dense heath in all treatmentswith less
There is almost no recruitment of Coast Tea- than20%baregroundandaheightoflessthan
tree under mature closed-canopy tea-tree 1 m in the first year and up to 1.25 m by the
214 TheVictorianNaturalist
Contributions
Fig.4.ThedenseheathinquadratB,November2012.
fourthyear (Fig. 4). In the control quadrat, the total numberoforchidspeciesknowntooccur
m
mature Coast Tea-tree reached 4 in height, intheReserve(Table5).Overalifetimeofvisit-
baregroundwas20%andlitter70%. Therewas ingthe Reserve, 74 specieshave been recorded
nolitterinthetreatmentareas. (TAllenpers. obs.).
Responseofweeds Discussion
There areveryfewweeds on theheathland and The primary value ofthe trial is that detailed
only two species were recorded in the quad- observationsweremadesothatwehaveameas-
rats. Dandelion Taraxacum officinale occurred ure ofthe effect ofthe treatments on the inva-
lxlm
in three quadrats in 2008 and Cat’s- sion ofCoast Tea-tree, on species richness, on
ear Hypochoeris radicata was found in seven weeds andon twoorchid species, oneofwhich
lxlm quadrats in 2009 and in onequadrat in isaknownfireresponsespeciesandonewhich
2012. In every instance the percentage cover israre.Thiswasasmalltrialinarestrictedarea,
wasjustatrace. but accumulation ofresults from similar work
elsewhere can elucidate appropriate manage-
Responseoforchids
mentstrategiesandareworth reporting.
In October 2008, there were numerous Red-
Mature Coast Tea-tree does not burn easily
beaks leaves per square metre, a quarter of
them with flowers. OfEastern Spider Orchids because there is so little fuel underneath the
in the same area, halfofthem were in flower canopy; slashing prepares a fuel load that will
burn readily. Given that Coast Tea-tree cap-
(TIanblteh4e).trial quadrats the number of orchid sules don’t open until dropped, that seeds are
species found wasverylowcomparedwith the onlyviable for one year and that it is a fire re-
sponsive species, slashing ayearpriorto burn-
Vol 130 (5) 2013 215
Contributions
Table 1.MeanNumberofseedlingCoastTea-treeinfive lxlmquadrats.
Quadrat EVC Treatment Date Mean
A SandHeathland Burnt2002,slashed2007,burnt2010 6/10/08 14.8
24/9/09 30
25/10/12 2.6
B SandHeathland Burnt2000,slashed2007,burnt2008 6/10/08 2.4
24/9/09 1.4
C SandHeathland Burnt2000,2008 61/91/01/10/812 131.8
24/9/09 0.6
D SandHeathland Controlunburnt30-40years 62/51/01/00/812 50.2
24/9/09 0
25/10/12 2.6
E WetHeathland Burnt2000,2008 6/10/08 6.4
24/9/09 5.4
25/10/12 0.2
Table2.Meannumberofunderstorey(U)andtotalnumberofcanopy(C)speciesinifive lxl mquadrats.
Quadrat EVC Treatment Date MeanU MeanC
A SandHeathland Burnt2002,slashed2007,burnt2010 6/10/08 13.2 0
24/9/09 13 0
25/10/12 19.6 0
B SandHeathland Burnt2000,slashed2007,burnt2008 6/10/08 10.4 0
24/9/09 15.4 0
19/11/12 8.6 0
C SandHeathland Burnt2000,2008 6/10/08 12.2 0
24/9/09 17.8 0
25/10/12 15.6 0
D SandHeathland Controlunburnt30-40years 6/10/08 7 8
24/9/09 6 5
25/10/12 6.4 6
E WetHeathland Burnt2000,2008 6/10/08 18.2 0
24/9/09 21.6 0
25/10/12 10.2 0
Table3.Totalnumberofspeciesin20x20mquadratsoneachfieldday.
Quadrat EVC Treatment 2008 2009 2012
A SandHeathland Burnt2002,slashed2007,burnt2010 36 44 55
B SandHeathland Burnt2000,slashed2007,burnt2008 31 60 41
C SandHeathland Burnt2000,2008 38 59 40
D SandHeathland Controlunburnt30-40years 33 35 22
E WetHeathland Burnt2000,2008 31 40 32
Table4.Meannumberoforchidspresentandpercentage(%)flowering.
Orchidspp. Scientificname Total Flowering %flowering
Redbeaks Pyrorchisnigricans 186 47 25
EasternSpiderOrchids Caladeniaorientalis 50 25 50
216 TheVictorianNaturalist
Contributions
Table5.Numberoforchidspeciesfoundin 1 x 1 mquadrats.
Quadrat EVC Treatment 2008 2009 2012
A SandHeathland Burnt2002,slashed2007,burnt2010 0 1 3
CB SSaannddHHeeaatthhllaanndd BBuurrnntt22000000,,2sl0a0s8hed2007,burnt2008 41 45 03
D SandHeathland Controlunburnt30-40years 0 0 0
E WetHeathland Burnt2000,2008 1 0 1
ing may remove viable seeds, so that the burn tion communities on sandysoils are not prone
does not stimulate germination. At WPNP, af- topost-fireweed invasion (Tolsmaetal. 2011).
terthe 2005 fire, the mean number ofstems of Slashing and fire had no detrimental effect
m
Coast Tea-tree in 1 x 1 quadrats was more on the orchid species. Redbeaks seldom flow-
than 200 in thefirstyear, decreasingslightlyin ers without fire, butlarge numbers appear in a
thesecond yearand down to 150 bythefourth colony following fires (Foster and MacDonald
yearpost fire (Tolsma and Cheal 2012). This is 1999). The Eastern Spider Orchid population
10 times the number ofstems recorded in the on WHNCR is monitored regularly as part of
Wonthaggitrial.Theyalsonotedaverylowlev- the study by DSE and does not appear to be
el ofrecruitment ofCoast Tea-tree in unburnt detrimentally affected by the slash and burn
sites atWPNP. management.
Aftergermination ittakes onlyfouryearsbe-
Conclusion
fore Coast Tea-tree plants flower and set seed
(MEllispers.obs.).Theinterval betweenburns Theresultsfromthistrial showthattheseman-
inthistrialwaseightyears,whereastheinterval agementstrategiesreducetheinvasionbyCoast
between slashing and burning was three years Tea-tree ofSandandWetHeathlandEVCsand
winerterematomreentseAedalnidng1syreeacroirndetdreiantmternetaBt.meTnhterAe eicnahnatnacnedswpoecuiledsndoivterbseitay.maWneaegdesmweenrtepirnosbiglneimf.-
in the two years after slashing than in any of Theslashandburntechniquehadnodetrimen-
the other treatments. In the last assessment in taleffecton thetwoorchidspecies. Itwouldbe
2012, numbers of seedlings were back to the appropriate to extend the area ofmanagement
samelevel as in the control. Heathland reaches and continue to monitor the results over the
maturityat8yearsandwanesafter33years;the long term. We would recommend that the in-
recommended fire interval for management tervalbetween burns beextended to atleast 12
is 12 to 45 years (Cheal 2010). It is reasonable years and that an area be set aside for slashing
to conclude that the slash and burn technique only to determine the effect on Coast Tea-tree
doesreduce theinvasion ofCoast Tea-tree, but recruitment.
theinformationthatismissingfrom thistrialis Acknowledgements
theeffectofslashingalone. We would like to thank Danny Drummond, previ-
After aburn there is a demonstrable increase ously Parks Victoria Ranger at WHNCR, for setting
in species richness in all treatments in the first uunptetehrestwrihaol mcaanmaegfermoemntF.riWenedsaocfkWnoonwtlheadggegithHeeavtohl--
two years. By the fourth year species richness, land, South Gippsland Conservation Society and La
although reduced, remains greater than in the Trobe Valley Field Naturalists Club. We thank Jim
control. This maybeattributed tothe retreat of Whelan,SusanTaylor, PeterHoman andRalphLaby
short-lived ephemerals to a soil seed store, as fortheirconstructivecommentsonthemanuscript.
suggested by Tolsma and Cheal (2012) for the References
post-firemonitoringatWPNP. BennettLT(1994)TheexpansionofLeptospermum laeviga-
Weedsdonotpenetratedenseheathandeven tumontheYanakie Isthmus,Wilsons Promontory,under
changes in the burning and grazing regimes. Australian
the bare ground immediately following the fire JournalofBotany42,555-564.
was not invaded by pest plants. This compares Browning T (2004) The effect of long-term invasion of
with searches at WPNP after the 2009 fire, hLeeapttholsanpde.rm(uUmnpluabelviisghaetdumMoSncLTehepstioss,pUenrimvuemrsimtyyrsoifnoMiedle-s
whichfoundfewweeds,suggestingthatvegeta- bourne)
BookReviews
BurrellJP(1981) InvasionofCoastalHeathsofVictoriaby InstituteforEnvironmentalResearch,DepartmentofSus-
JLoeuprtnoaslpoefrBmoutmanlyae2v9i,g7a4t7u-m7(6J4..Gaertn.)F.Muell.Australian TotlasinmaabiAl,itSyuattnedrEGnvainrdoCnomaetnets,FMe(l2b0o1u1r)nRee.coveryofVictori-
Cheal D (2010) Growth stages and tolerable fire intervals anrareorthreatenedplantspeciesafterthe2009bushfires.
forVictoriasnativevegetationdatasets.Fireandadaptive Arthur Rylah Institute for Environmental Research, De-
amnadnaEgnevmireonntmernetp,orMtelnob.ou8r4n.eD.epartmentofSustainability WaplasrhtmNenGtaofndSusSttaaijsniacbiVlit(y2a0n0d7)EnAviCreonnsmuesnto,fMtehleboVuasrcnuel.ar
DaviesJB, OatesAMandTrumbull-Ward AV (2002) Eco- Plants ofVictoria. 8edn. (Royal BotanicGardensofVic-
logicalVegetationClassMappingat1:25,000inGippsland. toria:Melbourne)
FinalReport.DepartmentofNaturalResourcesandEnvi-
ronment,Melbourne.
FosterEandMacDonaldM (1999) OrchidsoftheAnglesea
District:AFieldGuide.(InvertedLogic:Brunswick)
TolsmaAandChealD(2012)Ananalysisofpost-firemoni- Received24January2013;accepted27June2013
toring-WilsonsPromontoryNationalPark.ArthurRylah
Curious minds: the discoveries ofAustralian naturalists
byPeterMacinnes
Publisher:NationalLibraryofAustralia, Canberra. 2012, 213pages,paperback,
colouredillustrations, ISBN9780642277541. RRP$39.99
Curious minds: the discoveries of Australian rolesofJosephBanks,SydneyParkinson,James
naturalists is the most recent in aline ofbeau- Cook, Charles Darwin, Ferdinand Bauer, Rob-
tifully presented books from the National Li- ert Brown, Matthew Flinders, Amelie Dietrich
brary ofAustralia (NLA) on historical aspects and Georgiana Molloy. Three essays under the
ofAustralian natural history The objective is heading ‘Australia expanded’ focus on George
to publish books as part ofthe process ofin- Bennett,JohnWhite,ThomasWatling,Thomas
terpretingandhighlightingtheNLAcollection. Huxley, and John Macgillivray. The five essays
This much is partofthecharter ofthe Library, comprising ‘Makers oftheir own fates’ draws
and this book is a fine example ofthe produc- attention to Allan Cunningham, Richard Cun-
tion standard that hasbeen achieved in fulfill- ningham, Ludwig Leichhardt, John Gilbert,
ingthatrole. Thomas Mitchell, William Blandowski, and
The text consists of26 short biographical es- Gerard Krefft. Undertheheadingof‘True-blue
says. The subjects ofthese pieces are individu- naturalists’, the author has included Ferdinand
als,39innumber,whoarejudgedtohavemade Mueller, Louisa Meredith, Harriet and Helena
contributions to an understanding ofAustral- Scott, Louisa Atkinson, Ellis Rowan and Wil-
ian naturalhistory,ina200-year-periodbegin- liam Macleay. The final section is titled ‘Aus-
ning in the 1680s. These biographical sketches tralia live’ and looks at John Lewin, John and
aregroupedinsixsections,underheadingsthat Elizabeth Gould, George Angus and William
aremeanttoindicatesomethingofthecircum- Caldwell.
stances ortype ofactivity in which the contri- Thebookconcludeswithafewparagraphson
butionwas made. Thesesections are presented ‘The value ofa curious mind’. Although short,
in more-or-less chronological order, following itexpressesanumberofdisparatethoughts;af-
abriefIntroduction. ter a couple ofreadings ofthe piece, it is still
Inthe first section, Australian nature discov- unclear to this reviewer what value is being
ered’, the focus ofattention in fouressaysis on promoted.
WilliamDampier,WillemdeVlamingh,Jacques Given the large number of ‘curious minds’
LaBillardiere,ClaudeRiche,Charles-Alexandre who might have been included in this book, it
Lesueur and Francois Peron. ‘Putting Austral- is reasonable to assume that those individuals
iannatureonthemap’(fouressays)looksatthe whoarefeaturedhavebeenchosenespeciallyby
TheVictorianNaturalist
218
