A Snapshot of Seedling Growth Dynamics on Stanley Island

A SNAPSHOT OF SEEDLING GROWTH
DYNAMICS ON STANLEY ISLAND
JOSHUA COLE
DI PLOMA I N ENVI RONMENTAL MANAGEMENT 2011
BAY OF PLENTY POLYTECHNI C
(Cabbage Tree Creative Ltd, 2011)

A SNAPSHOTOFSEEDLING GROWTH DYNAMICSON STANLEY ISLAND 2
Joshua Cole
ABSTRACT
StanleyIslandisanimportantthreatenedandendangeredspeciessanctuarythatismaintainedby
the Departmentof Conservation’sWaikatoConservancy whichhasalack of seedlings. The aimof
the studyis to assessthe successional regenerationof StanleyIslandbymonitoringseedlingheights,
densityandabundance afterthe removal of rabbitsandkiore andthe burningof landby Maori
settlers orlighteningstrikesindroughttimes. These resultswill be comparedtopastpapersabout
native forestsuccession. Nineteenplotsdividedintofourseedlingsubplotswere laidacrossthe
tracks of StanleyIsland. Seedlingswere thenmeasured,countedandidentified. The datawas then
collatedandthe locationof the plotswere clumpedintofourlocationgroups,whichwerelabeledas
north,northwest,southwestandsouth to provide meaningful differencesbetweenthe sites.
It was foundthat Coprosma spp.(C.lucida andC. robusta) wasbyfar the most abundantseedlingon
StanleyIslandyetthisisthe firststudytofindthis. C. grandifolia wasalsoquite abundantandnot
includedinanyothervegetationlistsinpastpapers. The overrepresentationof Coprosma spp.
confirmsthe fact that StanleyIslandvegetationisstill recoveringfrompastfiresandbrowsing
mammals. Anotherthingconfirmingthisisthatthere were onlytwo climax speciesseedlings
countedoutof a total of tenspecies(Planchonella costata (11) and Dysoxylumspectibile(38)).
The biggestfactorin determiningseedlingdensity,numbersandheightwasdirectinterspecificand
intraspecificcompetitionbetweeneachotherforresourcessuchasspace,moisture andlight.
Canopycoverand litterdepthare onlyslightfactorsindeterminingseedlingheightinthatless
canopycover andmore litterdepthmeantallerseedlings.
Anotherfindingfromthisstudyisthatthe furthersouthareasare more speciesdiverse,more
abundantand more denselypopulated. ThiswouldsuggestthatMaori occupiedthe warmerareas
of the northwhere there isalsobetteraccessto the coastline. Indeedthere isevidenceof Maori
occupationinthe north evidencedbystone walls,shallowpitsandstone chips.
It was concludedthatmore research needstobe performedonStanleyIslandandmore plotsneed
to be laidinorder to clarifyseedlingabundanceandseedlingdensity. Itisassumedthatif more
plotswere laid,more seedlingsspecies wouldbe found. Thisstudydidnotdelve intoseabird
burrowsbecause of the restraintof time yetitmay have shownsome interestingresults.

Joshua Cole
ACKNOWLEDGEMENTS
The author wouldlike toacknowledge RobChappell of the Departmentof Conservationforfunding
much of the excursion andfortakingus out on theirboat. Also,EstaChappell andDebashisDuttaof
Bay of PlentyPolytechnicforguidingme throughthe gathering andinterpretation of dataand
JordanSandfordand LoganVickers,fellow studentswhoconductedstudiesondifferentaspectsof
the StanleyIslandecosystemandhelpedwiththe gatheringof data.

Joshua Cole
TABLE OF CONTENTS
ABSTRACT....................................................................................................................................2
ACKNOWLEDGEMENTS ................................................................................................................. 2
INTRODUCTION............................................................................................................................ 5
METHODS ....................................................................................................................................6
RESULTS.......................................................................................................................................8
Seedling Abundance.................................................................................................................. 9
Seedling Density ..................................................................................................................... 11
Seedling Heights..................................................................................................................... 14
DISCUSSION ............................................................................................................................... 14
CONCLUSIONS............................................................................................................................ 18
REFERENCES............................................................................................................................... 19
APPENDICIES.............................................................................................................................. 20
Appendix One - Seedling Data Sheet........................................................................................ 20
Appendix Two – General Site Data Sheet.................................................................................. 21
LIST OF FIGURES
Figure 1: Plot Layout explain all aspects, e.g. circular subplots, X,etc............................................... 6
Figure 2: Aerial photoof StanleyIslandandthe groupingof plotsintogeographical areas
(Google.com, 2011) ...................................................................................................................... 8
Figure 3: Seedling counts (±SE)......................................................................................................9
Figure 4: Seedling species abundance in plot locations (±Se)........................................................... 9
Figure 5: Seedling size abundance in differentlocations(±SE) ....................................................... 10
Figure 6: Number of seedling versus seedling height..................................................................... 10
Figure 7: Comparison between seedling height and seedling density............................................. 11
Figure 8: Location seedling density (±SE)...................................................................................... 12
Figure 9: Degree of insignificantdifference(TTestprobabilityvalues)betweenthe seedlingdensities
of eachlocation (±SE) ................................................................................................................. 12
Figure 10: Seedling density(per m2
) under different light conditions ............................................. 13
Figure 11: The effect of litter depth on seedling density................................................................ 13
Figure 12: The impact of litter depth on seedling height................................................................ 14
Figure 13: The effect of canopy cover on seedling height.............................................................. 14

Joshua Cole
INTRODUCTION
StanleyIsland(KawhituorAtiu) isone of the islandsthatmake up the Mercury Group of islandsoff
the north westerncoastof the Coromandel Peninsula. Itisan importantthreatenedand
endangeredspeciessanctuarythatismaintainedbythe Departmentof Conservation’sWaikato
Conservancy Ref. Itbeganlife aspart of the greaterCoromandel volcanicareathat formedinthe
Pliocene tolowerPleistocene Epoch(5.3millionto120,000 yearsago) (Townsand Stephens,1997).
These volcanoesthenunderwentmassiveerosionperiodsandsealevel risesoverthe millionsof
yearssince to leave uswiththe presentdayMercuryIslandgroup. The principallybasaltbase of
StanleyIsland hasresultedinanislandthat looksfairly tabularfromthe sea(Towns&Stephens,
1997). Ithas a rollingsurface landscape andrisesto137 metres. It has sharpcliffs andcoastal caves
and rockyslopeswith nopermanentstreams. The islandhasa rich wildlife communitywithsea
birds,lizards,invertebratesandthe release of 24saddlebacksin1977 ledto a populationof ca.250
birdsin1997 (Towns& Stephens,1997). Recentfires litbysettlingMaori andthe impact of rabbits
and kiore have ledtoa greatlymodifiedfloradominatedbypohutukawa(Metrosiderosexcelsa)and
a subcanopyof mahoe (Melicytusramiflorus) withverylittlegroundvegetation (Towns&Stephens,
1997).
The lack of groundvegetationiswhere thisreportcomesin. Inlate June,2011, the islandwas
visitedaftergainingpermissionfromDoCandlocal iwi toperformdetailedanalysison seedling
success. The methodsas detailedinthe respectivesectionwere carriedoutandit is hopedthatthis
will be the firstreportof an annual seriesof analysis of seedlingsonStanleyIsland. Inthe past,
there have beenvegetationsurveysonStanleyIsland,whichwill be summarised anddrawnupon.
The aim of the studyisto assessthe successional regenerationof StanleyIslandbymonitoring
seedlingheights,densityandabundance afterthe removal of rabbitsand kiore andthe burningof
landby Maori settlers. These resultswillbe comparedtopastpapersaboutnative forestsuccession.

Joshua Cole
METHODS
Nineteenplotswere markedoutonStanleyIsland - fourteenonthe Ampitheatre Trackandfive on
the East Track. Theyare one hundredmetresapart (asillustratedbythe mapFigure 2) and
consistedof a mainfive metre square quadrat(25 m2
) comprisingfoursubplots(A-D). The plots
were laidstraightalongthe compasspointsnorthto southand eastto westand nopart of itwas laid
on the maintrack. A florescent yellow triangle (asmarkedbythe XinFigure 1) was nailedtoa tree
and wasusedas the corner of subplotA. Asin Figure 1, in the middle of the boundarybetween
subplots,a0.49 m radius(0.75 m2
) circle seedlingsubplot wasmeasured usingastringpulledtight
and attached to a peginsertedintothe ground. Seedlingswerethencountedandthe species
identified inarange of size classeswithinthe circularplot. The size classesincentimetersare 0 – 15,
16 – 45, 46 – 75, 76 – 105 and 106 – 135. The data sheetusedforthisisin AppendixOne.
The litterdepthwasalsomeasuredandthe canopy coverpercentage wasestimatedandrecorded
on the sheetsinAppendix Two. Thisdatasheetwasalsousedby otherfieldworkersstudying
differentaspectsof the StanleyIslandecosystem.
Excel 2007 wasusedto analyse the datathat is publishedbelowinthe resultssection. T-testswere
usedto compare significantdifferencesinseedlingdensitiesindifferentlocationsandregressions
and scattergraphs were usedtotestthe strengthof the relationshipsbetweenseedlingheightand
densitywithcanopycoverpercentagesandlitterdepths.
FI GURE 1: PLOT LAYOUT
A B
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Joshua Cole
SITE DESCRIPTION
The vegetationof StanleyIslandhasgone throughastage of destructionfromfiresandthe
introductionof kiore andrabbits. Thisisresultedinasparsenessof seedlingsdespite itsvolcanic
originsprovidingforfertile soils. The forestscomprisesmostlyof coastal forestwitha
Metrosiderousexcelsum andMelicytusramiflorus canopywithpatchesof Beilschmeidia tarairi and
Dysoxylumspectibileand the undergrowthismainly Coprosma lucida andC.robusta. There isa hut
providedbyDoCthat has a bunkbed,chillybin,rainwatertankanda gas stove.

Joshua Cole
RESULTS
The plot locationsandthe groupingof the plotsintolargerareasare shown inFigure 2. These
locationswere simplygroupedintoevenlysizedgroupsandlooselynamedNorth,NorthWest,South
Westand South. Coprosma robusta andCoprosma lucida are groupedtogetherunderCoprosma
spp.because itwas difficulttodistinguishbetweenthematseedlingstage. Itwaslaterlearnedby
readingPoole andAdams(1994) that the difference betweenthe twobeingthe raisedmidribin C.
lucida,whichwas sometimesreferredto,inthe raw data,as C. robusta,hence the move togroup
themall underC. spp. It isimportantto note that all the standarderror bars on the bar graphs in
thissectionwere generatedbyusingExcel 2007 andnot manuallyderived.
The total area surveyedwas 57 square metres,whichrepresents 0.006% of the total area of land on
StanleyIsland. There were atotal of 76 seedlingsubplotslaid andatotal of 176 seedlingscounted.
There were 10 differentspeciesof seedlingcounted andthe meannumberof seedlingsineach
seedlingplotisjustunder2. The mean seedlingdensityacrossall plotsis 28.3 seedlings persquare
metre witha standarddeviationof 34.4, indicatingthatthere are numerous outliersonthe upper
endof thatscale.
FI GURE 2: AERIAL PHOTO OF STANLEY ISLAND AND THE GROUPING OF PLOTS I NTO GEOGRAPHI CAL AREAS
(GOOGLE.COM, 2011)
North
NorthWest
SouthWest
South

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SEEDLING ABUNDANCE
FI GURE 3: SEEDLI NG COUNTS (±SE)
Figure 3 above showsthat the mostabundantspeciesof seedlingwas Coprosma spp.,distantly
followedby Dysoxylumspectibile, althoughthe standarderrorbarsdo overlap,asdo the restof the
seedlingspecies.
FI GURE 4: SEEDLI NG SPECI ES ABUNDANCE I N PLOT LOCATI ONS (±SE)
Figure 4 showshowabundanteach speciesisineachlocation. Coprosma spp.isthe onlyspecies
that isabundantin everylocationwhile the southlocationshowsupinsevenoutof the tenspecies.
In the southlocation,itisclear that C. spp., D. spectibile and C. grandifolia are the mostdominant
speciesalthoughthe orderof dominance isnotclearconsideringthatone of the sub southplotshad
20 seedlingsof D.spectibilein it. Itis alsoclearthat considerablymore dataisneededtodetermine
the abundance of these species. The onlyclimax tree speciesare Planchonella costata (11seedlings)
and Beischmiedia tarairi (1 seedling). There were no Metrosidersousexcelsa seedlingsfounddespite
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it dominatingthe canopy. Dysoxylumspectibilewasthe onlysubcanopy tree witha decentamount
of seedlings(38) mainlydue toone subplotcontaining20 seedlings.
FI GURE 5: SEEDLI NG SI ZE ABUNDANCE I N DI FFERENT LOCATI ONS (±SE)
Figure 6 showsthat seedlingabundance inthe differentlocationsisproportionatelydifferentateach
heightclassandthat the southlocationisagaina lot more abundantthanany otherlocation.
FI GURE 6: NUMBER OF SEEDLI NG VERSUS SEEDLI NG HEI G HT
Figure 6 producesa regressionpvalue of 0.7798, whichshowsthat the variationinseedlingheight
explains77.98%of the variationinthe numberof seedlings,whichmeansthat whenaseedlingdies,
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77.98% of the time itis because of the increase of seedlingnumbers. The ‘y’interceptis88.6,which
representsthe maximumcapacitynumberof seedlingsinaplot(0.49m2
). Anexponentialcurve
wouldshow thatthere isnot zeroseedlingdensityatjustover120 cm seedlingheights.
SEEDLING DENSITY
FI GURE 7: COMPARI SON BETWEEN S EEDLI NG HEI GHT AND S EEDLI NG DENSI TY
Figure 7 is verysimilartoFigure 6 inproducinga regressionpvalue of 0.7485, whichindicates that
seedlingdensityiscontrolledby the heightof surroundingseedlings 74.85% of the time. That is that
whena seedlingdies,itisbecause of seedlingdensity74.85% of the time. Onaverage,there would
be around 1 seedlingevery71 centimeterswhentheygerminate assuggestedbythe ‘y’interceptof
71.092. The additionof an exponential curve wouldagainshow thatthere isnotzero seedling
densityatjustover120 cm height.
y = -0.5758x + 71.092
R² = 0.7485
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FI GURE 8: LOCATI ON SEEDLI NG DENSI TY (±SE)
Figure 8 showsthat seedlingdensityishighestin the southernplotsandlowestinthe northern
plots. See Figure 2for a map of locations.
FI GURE 9: DEGREE OF INSIGNIFICANT DIFFERENCE (T TEST PROBABILI TY VALUES) BETWEEN THE SEED LI NG
DENSI TI ES OF EACH LOCATI ON (±SE)
Figure 9 showsthe T Testresultswheneachlocationiscomparedtoeach other. The most
significantdifferenceinseedlingdensityisbetweenthe northandsouthlocationsandthe most
insignificantdifferenceisbetweenthe northwestandsouthwestlocations. Any comparisonthat
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Comparitive locations

Joshua Cole
includesthe southlocationbearsthe most significantdifferenceresults. The greyline indicatesa
95% significance,whichshouldbe takenasa real significantdifference. Nobarsgo below thisline
but a numberof standarderror bars do.
FI GURE 10: SEEDLI NG DENSI TY (PER M2) UNDER DI FFERENT LI GHT CONDI TI ONS
Figure 10 showsthatthe thicknessof the canopy doesnoteffectseedlingdensity. The linear
trendline accentuatesthisfurtherasdoesthe regressionpvalue of 0.0148
FI GURE 11: THE EFFECT OF LI TTER DEPTH ON SEEDLI NG DENSI TY
Figure 11 andthe regressionpvalue of 0.0566 showsthat litterdepth hasa veryminorbearingon
seedlingdensity.
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y = -6.1828x + 45.271
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SEEDLING HEIGHTS
FI GURE 12: THE I MPACT OF LI TTER DEPTH ON SEEDLI NG HEI GHT
Figure 12 shows thattallerseedlinggrow inthickerlitter. The regressionpvalue of 0.5581 means
that thisoccurs 55.81% percentof the time.
FI GURE 13: THE EFFECT OF CANOPY COVER ON SEEDLI NG HEI GHT
Figure 13 showsthatseedlingsgrowtallerinhighercanopycoverlevels. The regressionpvalue of
0.2981 meansthat thisoccurs 29.81% of the time.
DISCUSSION
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The onlyreal factor affectingseedlingdensity,sizeandabundance isincreasingcompetitionfrom
each otheras theygrowtallerandtake upmore space and resources. AsillustratedbyFigure 6,
77.98% of the heightinseedlingsisbecause of asmallernumberof seedlingsinaplot. Similarlyin
Figure 7, where around75% of the casesseedlingdensitydecreaseswithincreaseinheightof
seedlings –that is,self thinningoccurswhere,due tocompetition,weakerseedlingsdie andextant
seedlingsasa consequence gainfromreducedcompetitionand increase inspace and nutrientsto
grow.Figures6 and 7 showthat linearcurvescanbe innaccurate and theyneedtohave a curved
trendline toillustrate the obviousfactthatthere will notbe zeroseedlingdensityorzeroseedlings
ina plotover120 cm inheight. Indeedthere wereseedlingsmeasuredinthisstudythatwere over
120 cm. It isassumedthata curvedline wouldflattenoutandrunnearlyparallel withthe ‘x’axisas
the seedlingsgettaller.
Surprisingly,canopycoverandlitterdepth have onlyminorinfluences onseedlingdensity. Litter
depthis more influential thancanopycoverbecause moistureismore importantthanlightfor
germinatingseedlings(Baines,2010). It wasassumedthat litterdepthwouldinhibitthe germination
rate of seedlingsandthatcanopycoverwouldblocklight,makingitharderforseedlingstoproduce
itsown food,butithas beenfoundthatthisis notreallythe case. It is assumedthatdifferent
specieswiththeirdifferentenvironmental conditionpreferenceswouldshow betterresultsfor
canopycover percentage andlitterdepth inthe same wayas the studybyHoffman(1996). Seedling
densityandheightare influencedindifferentwaysbylitterdepthandcanopycover. Litterdepth
slightly influencesseedlingheightasillustratedbyFigure 12. Thisis by a factor of 55.8% whereas
canopycover influencesheightbyonly29.81% as illustratedbyFigure 13. Litterdepthand canopy
coverdoesnot influence seedlingdensityatall asillustratedbyFigures10and 11. Therefore litter
depthismore influential thancanopycover. The small regressionvaluesproducedbythe litter
depthandcanopy coverdata is the reasonwhyseedlingabundance wasnotcomparedwithcanopy
coverand litterdepth. Itmighthave beeninterestingtosee whateffectaspecthadonseedling
height,abundance anddensity,butitwasdifficulttoquantifythis.
By far the most abundantspeciesof seedlingonStanleyIslandasillustratedbyFigures3and 4 is
Coprosma spp. Accordingtothe data collected, Dysoxylumspectibilelooksasthoughitis very
abundant, as the raw data shows,itcan be seenthat there isan anomalywhere 20 seedlingswere
countedinjustone of the subplots,whichhappenedtobe underaparent tree. Notenoughdata
was collecteddue totime restraintsthatwouldhave ironedoutanddilutedthisanomalyalong with
manymore anomaliesthatwouldlikelytosurface. The lackof data alsopreventsthe abilityto
determine the nextmostabundantspeciesof seedlingafter Coprosmaspp.
The southernareasof StanleyIsland highlightedinFigure 2are more denselypopulated,abundant
and speciesrichthannorthernareas as shownbyFigures4, 5 and 8. This ispossiblydue to more
favourable livingconditionsinthe northwhere there the landformsallow accesstothe seafor
Maori. If Maori settledinthe north,they wouldhave burnedsome of the bushtoallow themspace
and to encourage bracken tospread(Atkinson,2004). Bracken wasnot seenwhile conductingthis
studybut there are recordsof itexistingin1997 by Taylorand Lovegrove (1997). Lighteningin
droughtperiodsisanotherpossiblecause of fires(Atkinson,2004). There isevidence of Maori
presence providedbystone walls,shallowpitsandstone chips onthe northernslopes where
kumara wouldhave beencultivatedonthese sunnierslopesof the island (Taylor&Lovegrove,
1997). AsillustratedbyFigure 6,seedlingabundance indifferentlocationsislargelyinproportion
witheachotherwiththe south plotshavingthe mostseedlingsandthe northplotshavingthe least.
The difference inseedlingdensitiesisbestillustratedbyFigure 9withthe mostsignificantdifference
beingbetweenthe northandsouthplots. ComparisonsinFigure 9that include the southplotsare
the comparisonsthathave the most significantdifferences. Althoughnone of these comparisonsfall

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below0.05, whichisseenas a real significantdifference(95%),andmore data istherefore needed
to make these comparisonsclearer.
If more time wasallowedformore datacollection,certainspeciesmayhave shownupmore in
differentlocations. Thisisnotthe case inthis study withthe amountof data that was collectedthis
time round,althoughFigure 4doeshave the southplots showingupwiththe most Coprosma spp.,
Dysoxylumspectibile(evenwhen subtracting20 from the one subplotanomaly) and C. grandifolia.
Hedycarya arborea andPlanchonella costata are alsomostabundantinthe south plotsandare the
onlyotherspeciestohave itsstandarderror bars notoverlap withthe othersouthplotspecies.
There are nospeciesthatare more abundantthanothersin anyotherlocation – thatis there are no
otherspeciesthathave overlappingstandarderrorbars – exceptCoprosma spp.ineverylocation.
The overrepresentationof Coprosma spp. andthe large presenceof otherpioneerspecies
(Coprosma grandifolia, Melicytusramiflorus andMyrsineaustralis) indicate thatthe islandis very
much still undergoingsecondarysuccessioninanattemptto recoverfromthe firesandbrowsing
mammalsthat have recentlybeenremoved. Itisinterestingtonote thatin a reportby Taylorand
Lovegrove (1997),whichhas an expansive listof vegetationthatwaspresentonStanleyIslandin
1997 that there were no C. lucida or C.robusta. Thiswouldsuggestthatseedshave since arrivedby
birdsfromneighbouringislandsandthere hasbeenasubsequentpopulationboom. Atkinson(2004)
confirmsthisinsayingthatwindand birddispersedspeciestypicallymigrate fromislandtoisland.
Anotherindicationof the degreeof regenerationof the islandisthe abundance of abnormallylarge
specimensof Melicytusramiflorus formingmuchof the subcanopy comparedto onshore forests
(personal ovbservation). There were notmanyclimax speciesseedlings found except11
Planchonella costata andone Beilschmiedia tarairi. Despite the majorcanopyof Metrosiderous
excelsa,there were noseedlingsfoundandthe subcanopyof Melicytusramiflorus,(one seedling
found). Dysoxylumspectibilewasthe onlysubcanopytree witha decentamountof seedlings(38)
mainlydue toone subplotcontaining20 seedlings. A factor contributingtothiswouldbe thatthe
plotsare nexttowalkingtracksthat are easiertotraverse,whichisonlyone type of ecosystem
whereasthere islikelytobe more species foundthatwere notinthisstudy onthe inaccessible parts
of the island where the environmentalconditionsare different. The 1997 vegetationlistprovidedby
Taylorand Lovegrove (1997) includes climax speciesof whichnoseedlings werefoundinthisstudy.
They include Myoporumlaetum,Melicopeternata andVitex lucens. Taylor andLovegrove (1997)
alsoidentifiedeightforesttypesonthe islandof whichthe plotsinthisstudywere inonlythree of
them,namelythe pohutukawa/mahoeforest,the pohutukawa/mapouforest andone of the twoof
the taraire forests.
The lack of available seedisthoughttobe the maincause for the extendedamountof time for
StanleyIslandtobe regenerating. Birdandwinddispersedseedfromnearbyislandsare the only
seedsourcesandtherefore itisunlikelythatthere willbe muchmore speciesdiversityinthe future.
It ismore likelythatthe presentspecieswillbecome more numerousandfill intheirniches onthe
islandandinthe future,there willbe ahigherdensityof trees. Seedlingdensityislikelytoremain
the same if notless. Atkinson(2004) outlineshow successional processesdeveloponfire induced
islands. Typically, Metrosiderousexcelsa usuallywithPteridiumesculentum,Leptospermum
scoparium andPhormiumtenax are the firstspeciestoestablishwith M.excelsa eventuallyforming
the canopy. If the seedisavailable, D.spectibileusuallycomesnextwithiteventuallysharingthe
canopywith M. excelsa.B. tarairi and B. tawa come nexttoshare the canopy,but onStanleyIsland,
only B. tarairi has founditsway there. Afterthatcomessomethingthathasonlyhappenedinparts
on StanleyIsland,that B.tarairi (andB. tawa on islandswithavailable seed) dominatesthe canopy
as all the other speciesgetdwarfed,shadedoutanddie. Nearthe coast of these islands,
Corynocarpuslaevigatus usuallyarrivesandsharesthe canopywith M.excelsa. There were some C.

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laevigatus saplingsthatwere noticedon the flat,easytotraverse areasof the island(personal
observation),soitisassumed thatthisis happeningonStanleyIsland. Itisinterestingtonote thatin
the reportby Taylorand Lovegrove (1997) that there were only tenindividualsfoundonthe island,
yeton personal observationof the flat,easytotraverse areasof the island;there isalot more than
tenthere nowand it isassumedthatthe densityof thisspeciesisalothigheron the coastal areas of
the islandsince itisa coastal species.
The study didnotcollate seabirdburrow data eventhoughthe data wasavailable because of time
restraints. More time was neededtoderive datafromseabirdburrowsandcompare it withthe
seedlingdataandsee what influencestheyhadoneachother. It isassumedthatit wouldnothave
effectedseedlinggrowthsince moistureandcompetitionseem tobe the onlyfactorsinseedling
densityandnumbers. Itisalsoassumedthat soil fertilityisinfluencedbyseabirdburrowswiththe
depositionof feathers,deadbirds,unhatchedeggsandfaecesinthe burrows.

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CONCLUSIONS
The seedlingsof StanleyIslandare notvery abundant,diverseordenselypopulated. There were
only10 differentspeciescountedinatotal of 57 square metres. The more southernareasof the
islandare more diverse,abundantandmore denselypopulatedbyseedlings. Coprosma spp.isby
far the most abundantanddenselypopulatedspeciesof seedlingonStanleyIslandindicatingthat
the islandis still verymuchregeneratingafterthe removal of browsingmammalsandfireslitby
Maori and possible lighteningstrikesintimesof drought. Thisisespeciallydue tothe lackof climax
speciesseedlingsinthe studywiththe notable exceptionof Planchonella costata.
It was a surprise tofindthatthe onlymajorfactor indeterminingseedlingdensityandnumbersis
directcompetitionwitheachother. Asseedlingsgetbigger,aroundthree quartersof themgetout
competedanddie thougha lackof accessto resourcessuchas space,moisture andlight. Litter
depthandcanopy coverwere foundtobe onlyveryminor,if atall,factors contributingtoseedling
densityandnumbers. The biggestfactorthatcanopycover has onseedlingsistheirheights. The
lesscanopycover,the higherseedlingsgrew.
Those are the onlyconclusionsthatare able to be drawnon because of the lack of data. In future
studies,more dataneedstobe collectedandtherefore more timespentonthe island. Itwasnot
possible todetermine the nextmostabundantspeciesof seedlingafter Coprosmaspp.

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REFERENCES
Atkinson,I.A.E.(2004). Successional processesinducedbyfiresonthe northernoffshore islandsof
NewZealand.NewZealand Journalof Ecology,28(2),181 – 193.
Baines,A.E.(2010). Germination in its Electical Aspect. London,UnitedKingdom: BiblioBazaar.
Cabbage Tree Creative Ltd.(2011). Hedgehog HouseNew Zealand,166796 Pacificgecko,Mercury
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Joshua Cole
APPENDICIES
APPENDIX ONE - SEEDLING DATA SHEET
STANLEY ISLAND VEGETATION MONITORING
BOP POLYTECHNIC – ENVIRONMENTAL MANAGEMENT
PlotCode: Measuredby:
Track: Recordedby:
Date:
Seedling
plot No.
Species <15 () 16 – 45 46 – 75 76 – 105 106 – 135

Joshua Cole
APPENDIX TWO – GENERAL SITE DATA SHEET
STANLEY ISLAND VEGETATION MONITORING
BOP POLYTECHNIC – ENVIRONMENTAL MANAGEMENT
Plot Code: Measuredby:
Track: Recordedby:
GPSReference:Easting:
(NZTM) Northing: Date:
Site Description
Altitude: Rock on surface: Yes / No
Physiography: Ridge Face Gully
Terrace
Bedrock on surface: Yes/ No
Aspect (5 - 360°): Bedrock %:
Slope (°): Broken rock %:
Drainage: Good Moderate Poor Soil %:
Mean top height(m): Size of loose rock: <30cm >30cm
Canopy %
GroundCover % Veg: Moss: Litter: Bare ground:
Rock:
Plot Layout
A – B B – C C – D D - A
Bearing (°)
Tape Distance (m)
Slope (°)
Notes

Joshua Cole

A Snapshot of Seedling Growth Dynamics on Stanley Island

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