Effects of experimental fire regimes on the abundance and diversity of cursorial arachnids of Brazilian savannah (cerrado biome)

2011·6.5 MB·English

by  Geraldo De Brito Freire-Jr

—
2011.TheJournalofArachnology39:263-272
Effects ofexperimental fire regimes on the abundance and diversity ofcursorial arachnids ofBrazilian
savannah (cerrado biome)
GeraldodeBritoFreire-Jr. and PauloCesarMotta; DepartamentodeZoologia, Universidadede Brasilia-70910-900,
Brasilia/DF, Brazil. E-mail: [email protected]
Abstract. Weinvestigated theinfluenceofburningfrequencyandtimingon theabundanceanddiversityofcursorial
arachnidsinthecerrado(savannahofcentralBrazil).Fiveareasweresubjectedtodifferentburningregimes.Ineacharea,
40pitfalltrapswereinstalled.ThearachnidsweresampledforthreedayseachmonthfromApril2007toOctober2008.
Abundancewashigherinthecontrolareathaninareassubjectedtoanyfireregime. Speciesrichnesswassimilarinall
areas.Theevennesswaslowerinthecontrolarea. Theareassubjecttofireshadsignificantlyhigherdiversitythanthe
controlarea.Althoughitwasnotpossibletorankareasaccordingtotheirdiversity,areasburnedinthemiddleofthedry
seasontendedtohavehigherdiversitythanareasburnedatthebeginningorendofthisseason,indicatingthatthetimeat
whichfireoccursmaybemoreimportantthanthefrequencyofburningforthediversityofcursorialarachnidsin the
Braziliancerrado.
Keywords: Fireeffects,spiders,Arachnida,Araneae
Cerrado is savannah typical of central Brazil. It covers METHODS
around two million km^ and includes various types of Studysiteandsamplingdesign.—Thisstudywascarriedout
vegetation,amixofwoodyandherbaceousplants. Following in the Roncador Ecological Reserve (RECOR) (15°56'21"S,
theAmazonForest,itisthelargestBrazilianbiomeandhasa 47°53'07"W), Brasilia, Brazil, which covers ca 1,350 ha. We
well-definedclimatewithastrongdryseasonduringthewinter used pitfall traps installed in five experimental areas (each
(approximatelyMaytoSeptember). 200m X 500m)ofcerradosensustricto(excludingveryopen
Fireisthemostprevalentformofdisturbanceinthecerrado areas and gallery forests) subjected to different burning
bLiaobmoeu,riwahuic&h daFteersrazb-aVcikcetnotiantile1a9s9t4)3.2,0B0u0rnyienagrss(tSiamluglaadtoe-s prreegsiemrevsed(tfirmionmgfairnedfofrreaqtuleenacsyt)3:61y)r;th2e)ctohneteraorllyarbeiaenn(iCaTl)(wEaBs)
regrowth, seed germination, flowering and fruiting ofmany wasburnedevery2yrinearlydryseason(lateJune),similarto
species (Miranda et al. 2002). The rapid occupation ofthe theoccurrenceofnaturalfires(Ramos-Neto&Pivello2000);
cveerrsriatdyoinhamsaniyncrleoacsaetdionfsire(Kflrienqkue&ncyM,acthharedaote2n0i0n5g).the biodi- d3)rythseeamsoodnal(eabrileynnAiuaglu(stM)B,)awapesriboudrniendwihnicthheamnitdhdrloepoogfentihce
In the cerrado, as well as in other savannahs, burns are burningismorecommon(Coutinho 1982;Coutinho 1990);4)
superficial, and their effects are related to water content, thelatebiennial(LB)wasburnedattheendofSeptember, a
according to the shade ofthe herbaceous layer. Small areas periodthatfavorstherenewalofleavesandfloweringofmost
can be preserved from the fire, changing the landscape into woody plants (Oliveira & Gibbs 2000); 5) the modal
mosaics of different post-burn ages and different floristic quadrennial (QD) was burned every 4 yr in the middle of
structures,andthiskindofabioticdisturbancemayaffectthe the dry season (early August), a period that favors the
diversitypatterns(Coutinho1990;Pianka1992;Mirandaetal. recruitment ofwoody biomass and the replenishment oflost
1993; Kauffman et al. 1994; Castro & Kauffman 1998; nutrients (Pivello & Coutinho 1992; Kauffman et al. 1994).
Mirandaetal. 2002). The last time a quadrennial plot was burned was in August
The basic premise of the Intermediate Disturbance Hy- 2007,whilethebiennialplotswerelastburnedinJuly,August
pothesis is that the highest diversity is maintained at orSeptember2008.
intermediate levels of disturbance on various scales of In each plot, ten sets of traps were installed, each set
frequencyandintensitybypreventingcompetitivelydominant consisting offour containers (35 cm diam X 45 cm depth)
speciesfromexcludingothers(Connell 1978).Althoughthere buried with their rim at ground level. Each container
isvariation in the response ofinvertebrate fauna to fire, the connectedwithothersbydriftfences(6mlong X 0.4mhigh)
trend for most groups is high resilience to disturbance, the in a “Y” shape. The arachnids were sampled for three days
frequencybeingmoreimportantthantheintensityofthefire each month from April 2007 to October 2008. This
(Andersen«feMuller2000). experimental design followed a standardized protocol origi-
In 1989, a long-term experiment (the “Fire Project”) was nallydesignedforherpetologicalresearch.
initiated in a cerrado area ofcentral Brazil, with the overall All individuals were collected alive and then conserved in
objective of determining the effects of different regimes of 80% ethanol. The arachnids were identified to species level
prescribedburningonthestructureandfunctionofthisbiome when possible. Voucher specimens ofeach spider species are
(Nardoto et al. 2006). Using these experimental areas, this deposited at the arachnid collection ofthe Zoology Depart-
study aimed to investigate the influence of frequency and mentoftheUniversidadede Brasilia.
timingofburningonabundanceandthediversityofcursorial Data analysis. Only adults were used in the statistical
arachnidsofthecerrado. analysis. We used repeated ANOVA measures to investigate
263
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264 THEJOURNALOFARACHNOLOGY
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Table 1. Specieslistandnumberofindividualsofcursorialarachnids(Araneae,OpilionesandScorpiones)collectedinthefiveexperimental
treatmentsofcerradosensustrictoincentralBrazil.
Treatment
Species CT EB MB LB QD Total
Anyphaenidae
Ayshasp. 0 0 0 1 0 1
Barychelidae
Neodipbthelesp. 1 0 1 7 1 5 14
Neodiplothelesp.2 2 4 10 10 9 35
Sasoninaesp. 1 0 0 0 0 1
Caponiidae
Caponinanotahilis(Mello-Leitao 1939) 0 0 0 1 0 1
Nopssp. 3 2 0 1 2 8
Corinnidae
AhapebarioclaroBonaldo2000 2 10 12 2 12 38
Castkmeirasp. 8 3 0 0 0 11
Carinacapita(Lucas 1856) 1 12 10 1 10 34
Corinnidaesp. 1 5 6 5 1 2 19
Corinnidaesp.2 16 3 0 3 2 24
Falcaninagracilis(Keyserling 1891) 1 2 2 5 1 11
Mazaxsp. 2 0 0 0 0 2
Paradiestusgiganteus(Karsch 1880) 0 3 1 4 2 10
XerapigacamilaeDeSouza&Bonaldo2007 3 3 3 0 3 12
Xerapigatridentiger(O. Pickard-Cambridge 1869) 17 2 5 4 8 36
Ctenidae
Calocteninaesp. 0 0 1 0 0 1
Isoctermscaxalis(F.O.Pickard-Cambridge 1902) 1 5 2 2 0 10
Isactenussp. 19 1 0 0 0 20
Parabatmgabrevipes(Keyserling 1891) 93 30 31 24 34 212
PhoneutriaeickstedtaeMartins&Bertani2007 0 1 1 1 1 4
Deinopidae
Deinapissp. 1 0 0 0 0 1
Dipluridae
Diplurasp. 1 2 4 6 11 6 29
Diplurasp.2 1 22 9 4 6 42
IsclinatheleammlataTullgren 1905 5 0 3 0 0 8
Gnaphosidae
Apapylliissilvestrii(Simon 1905) 26 74 68 24 30 222
Apapyliltssp. 1 2 2 0 0 1 5
Camillinasp. 23 3 7 1 1 35
EilicamodestaKeyserling 189 10 7 11 9 13 50
Eilicarujithorax(Simon 1893) 0 0 1 2 3 6
Lycosidae
Aglaoctenuslagotis(Holmberg 1876) 6 1 1 0 '0 8
Alopecosamoestci(Holmberg 1876) 1 5 9 2 17 34
Alapecasasp. 1 0 4 6 4 4 18
Alopecosasp.2 431 0 0 0 0 431
Alopecosasp.3 5 7 10 8 3 33
Arctosasp. 1 22 18 5 12 6 63
Arctosasp.2 71 6 12 5 11 105
Hognagumia(Petrunkevitch 1911) 66 63 50 19 48 246
Hognasternalis(Bertkau 1880) 6 11 7 2 10 36
Lycosaanroguttata(Keyserling 1891) 1 3 8 6 4 22
LycosaerytlirognathaLucas 1836 21 6 4 22 8 61
LycosainornataBlackwall 1862 1 1 2 6 9 19
Lycosathorelli(Keyserling 1877) 1 5 11 11 11 39
Lycosinaesp. 1 26 16 25 12 12 91
Lycosinaesp.2 0 19 10 33 30 92
Pavocosasp. 0 6 1 2 4 13
FREIRE-JR.&MOTTA—EFFECTSOFFIREONCURSORIALARACHNIDS 265
—
Table 1. Continued.
Treatment
Species CT EB MB LB QD Total
Trochosasp. 58 47 28 13 37 183
Nemesiidae
Pvcnothelesp. 1 2 9 6 5 13 35
Pvcnothelesp.2 2 8 4 11 6 31
Pvcnothelesp.3 1 9 7 5 7 29
Oxyopidae
Peiicetiasp. 1 11 0 0 0 0 11
Pencetiasp.2 0 1 1 0 0 2
Oxyopessp. 0 1 0 0 0 1
Hamataliwasp. 1 0 0 0 0 1
Palpimanidae
Palpimanidaesp. 1 1 3 6 0 0 10
Palpimanidaesp.2 0 1 2 0 1 4
Palpimanidaesp.3 0 1 1 0 0 2
Philodromidae
Philodromidaesp. 1 10 1 0 2 0 13
Philodromidaesp.2 5 0 0 1 0 6
Philodromidaesp.3 0 0 2 0 0 2
Philodromidaesp.4 0 0 2 0 0 2
Scytodidae
ScytodesitapeviBrescovit&Rheims2000 0 0 1 0 0 1
Sparassidae
Polybetessp. 0 0 2 0 1 3
QQuueemmeeddiicceepeinriagcmuartuiccausRhMeelilmos-,LeLiatbaaorq1u9e42&Ramirez 5 0 0 1 2 8
2008 0 1 0 0 0 1
Sparassidaesp. 0 0 1 0 1 2
Nephilidae
Nephilaclavipes(Linnaeus 1767) 1 0 0 0 0 1
Theraphosidae
Acanthoscurriaaff.gomesiana 8 5 6 5 9 33
Hapalopussp. 3 5 12 9 8 37
SOilcikgiouxsysltornegibboullibiviSaomairmes(V&olC2a0m01a)rgo 1948 03 111 220 62 83 479
Theraphosinaesp. 1 0 4 1 5 3 13
Theraphosinaesp.2 1 0 2 0 2 5
Theridiidae
Argyrodessp. 0 0 1 1 I 3
Euryopissp. 1 0 3 2 1 0 6
Euryopissp.2 0 2 0 0 0 2
LatrodectusgeometricusC.L.Koch 1841 1 2 1 0 1 5
Steatodaancorata(Holmberg 1876) 2 0 0 4 0 6
SteatodadiamantinaLevi 1962 25 3 2 4 2 36
Theridiidaesp. 1 0 1 0 0 0 1
Theridionsp. 1 0 7 0 0 0 7
Theridionsp.2 0 0 0 0 10 10
Thomisidae
Strophiussp. 3 1 0 2 0 6
Tmarussp. 1 0 0 0 1 0 1
Tmarussp.2 1 0 0 0 0 1
Tmarussp.3 0 0 0 1 1 2
Tmarussp.4 1 0 0 0 0 1
Titanoecidae
Goeldiasp. 0 0 0 1 0 1
266 THEJOURNALOFARACHNOLOGY
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Table 1. Continued.
Treatment
Species CT EB MB LB QD Total
Trechaleidae
SyntreclialeabrasiliaCarico2008 0 0 1 0 1 2
Zodariidae
CybaeockmmsmeridionalisLise,Ott&Rodrigues2010 3 2 7 0 1 13
Cybaeodamussp. 0 12 1 0 0 13
LeprolochusbirabeniMello-Leitao 1942 54 62 35 29 46 226
Opiliones
Eiisarcusadiinciis(Mello-Leitao 1942) 0 2 1 1 0 4
Grynecoccineloides(Mello-Leitao 1935) 5 8 1 6 3 23
Stygniismidtispinosus(Piza 1938) 2 12 7 5 1 27
Scorpiones
AmiiUerisbcdzaniiThorell 1891 10 9 6 5 1 31
BothriurusaragiiayaeVellard 1934 12 47 32 2 12 105
TityiisfasciolatusPessoa 1935 0 9 3 1 3 16
Total 1135 671 574 387 524 3291
the effects oftreatments (main factor) and month (repeated weight to abundant species (extensively sampled) in the
measures)ontheabundance, richness,diversityandevenness separationofgroups(Magurran2004).TheRenyiandPielou
(all response variables). Later, we applied a Bonferroni indices, cluster analysis and the hypothesis tests were
multiplecomparisontest(a<0.005)fortherequirednumber performed using the statistical program R-2.10.0 (R Devel-
ofcomparisons(n = 10). Weidentifiedandremovedoutliers opmentCoreTeam 2009)andtheBiodiversityRpackage.
fromtheanalysis,andappliedtransformations(logorsquare RESULTS
arosostu)mpttoitohnedoifstrhiobmuotgioenneoiftdyatoafinvaorridaenrcetso cwohmepnlynewcietshsatrhye Samplingeffort.—Wecollected4,132individuals, including
(Tabachnick & Fidel 2006; Crawley 2007). These analyses 2,699males(65%),592females(15%)and849juveniles(20%),
were used because they take into account the temporal representing 98 species (Table 1). The rarefactions based on
autocorrelations, since the experimental units were sampled MaoTau and Jacknife 1 values indicated that our sampling
repeatedlyovertime(Quinn& Keough2002). effortwassuitabletocollectmostofarachnidspeciesineach
We used rarefaction based on Mao Tauvaluesand bythe area(Fig. 1).ThemostabundantspecieswereAlopecosasp.2,
nonparametric estimator Jacknife 1, using 1000 randomiza- Hogna gumia and Leprolochus birabeni. Twenty-nine species
tionswithout replacementsby Estimates(Colwell2005). The (30%) were represented by fewer than five individuals
Jacknife estimators, in general, have been found to perform (Table 1).
quite well in extrapolation ofspecies richness with less bias, The fire regimes explained most (52%) ofthe variation in
less dependence on sample size and greater precision than abundancevalues. Inthecontrolarea,thereweresignificantly
otherestimators(Broseetal.2003).WeusedtheRenyiprofile morespiderscapturedthaninLBandQD(F4,i8-69= 6.2,P<
to measure the diversity ofthe arachnid community. While 0.001,Fig. 2).Therewasnosignificantdifferenceinabundance
traditional diversity indices supply point descriptions of between CTand EB {P = 0.71) or MB area(P = 0.35). The
communitystructure, accordingto the Renyi Equation there areashadsimilarrichness(^418-69=2.0,P=0.08,Figs. la,3).
is a continuum of possible diversity measures that equally The control area had the lowest equitability (Pielou),
consider both rare and abundant species (Tothmeresz 1995; differingsignificantly from all otherareas underfire regimes
SRiicmoptstoan20f0o3r)m.ulaAsd.ditTihoensaellyi,ndiwceesurseefldectShdainffneorne-ntWiaesnpeerctsanodf i('n^d4i,1v8i-d6u9al=s3w.e0r,ePmo=re0.e0v2,enFliyg.di4s)t.riTbhuetedaraemasonsgusbtjecthteedspteocifeisr.e
diversity: Shannon’s is sensitive to rare species, whereas Based on the Renyi indexvalues, thecontrol areahad the
Simpson’s is more sensitive to changes in abundance of lowestdiversityinrelationtoexperimentalfireareas(Fig. 5),
common species (Magurran 2004). Furthermore, both these althoughthedifferencesareonlymarginallysignificantwhen
indices are widely used in ecological studies and will enable alphavaluesareequalto4(i/4:9.34,P=0.053).Intersections
comparisonswith othersimilarstudies. ofprofiles(Fig. 5)indicatethattheareascannotbeseparated
We used MANOVA and Linear Discriminant Analysis based on the community as a whole (dominant and rare
(LDA) to separate the groups based on speciescomposition, speciestakensimultaneously).
consideringonlythespecieswithmorethan 10individuals.To AccordingtotheShannon-Wienerindex,theareascouldbe
vuesreidfyhtiheerasricmhiilcaarlitycliunstsepreciaensalcyosmipsoswiittihonthbeetwseinegnlearelaisn,kawgee cseopmaproasteeddinotfotMhBreeagnrdoupQsD,(F4h,ia8d-69th=e1h8,igPhe<st0.d0i1v)e:rstihtye;firtshte,
clustering method and Bray-Curtis distance. This method is second(EBand LB),hadintermediatediversity;andCThad
commonly used in community studies, since it gives more the lowest diversity. The Simpson index (p4,i8-69 = 13, P <
.
FREIRE-JR.&MOTTA—EFFECTSOFFIREONCURSORIALARACHNIDS 267
a
1 11 21 31 41 51
Samples
—
Figure 1. Rarefactionvaluesgeneratedfrom1000randomizationswithoutrepositionandwitha95%confidenceinterval,performedinfive
experimentaltreatmentsoftheFireProject,a. MaoTau;b.Jacknife 1.
0.01)indicatedthatQDhadthehighestdiversity,followedby found an increase in the abundance ofspiders because ofa
MB and LB, while the treatments EB and CT presented the higherfrequencyofburningintheSwissAlps. Severalfactors
lowestdiversityofarachnids(Table2). — may explain the variation in abundance patterns presented,
Speciescompositionandsimilaritybetweentreatments. The among which are the types of vegetation, spider guild or
treatmentsdifferedinspeciescomposition(Wilk’sLambda = groupsofspecies. Besidethedifferencesinburningregimethe
0.034, df = 4.9, P < 0.01, Fig. 6). The control area was differences in abundance were probably due to structural
characterized by higher abundance of Alopecosa sp. 2 and changesintheenvironmentandnottothedirecteffectsoffire
Philodromidae sp. 2.; the QD plot featured Theridion sp. 2, (mortality).AccordingtoMirandaetal.(1993),savannahfires
and the treatments with biennial fire (EB, MB and LB) had are of short duration and do not promote a significant
moreIsoctenuscoxalisandPalpimanidaesp. 1 increase in soil temperature at depths greater than five
Thehierarchicalclusteranalysissplitthecompositionofthe centimeters. Thus, individuals that are sheltered at the time
soil arachnids into two groups (Mantel r = 0.97, P < 0.01), ofburning are protected from lethal temperatures promoted
onecontainingthecontrolarea(CT),andtheotherincluding byfire(Ghioneetal.2007). Itisnoteworthythattheonsetof
all areas subjected to different burning regimes. Within the the rainy season marks the reproductive period of most
secondgroup, LBareawasseparatedfromtheothers, which species, and fire at that time may eventually promote
wereverysimilartoeachotherinspeciescomposition(Fig. 7). reductions in population, since individuals are more active
DISCUSSION andthereforemore—exposedtotheadverseeffectsoffire.
— Species richness. Given the similarity in the values of
Abundance. Slightly lowerabundance in the late burning richness,thereisnosupportfortheIntermediateDisturbance
regimes (LB and QD) is consistent with the studies by HypothesisofConnell, wherehigh richnesswould havebeen
Andersenetal.(2005)ontheresponsesofcursorialAustralian expectedintheintermediatestageofdisturbanceinfrequency
spiders to savannah burning and Ferrenberg et al. (2006) in (QD) or season (MB). These results agree with the pattern
American coniferous forest. Moreover, Moretti et al. (2002) proposed by Mackey and Currie (2000), that richness shows
268 THEJOURNALOFARACHNOLOGY
60 -
40 -
20
0 -
"T” “T“
CT EB LB MB QD
Treatments
—
Figure 2. Boxplotofabundanceofcursorialarachnidscollectedinthefiveexperimentaltreatments. Differentlettersindicatesignificant
difference(P<0.05)betweentheabundanceoftreatments.
20
15 ~
I
a.
03
5 -
0 “
“T“ “T~
CT EB LB MB QD
Treatments
—
Figure 3. Boxplotofrichnessofcursorialarachnidscollectedinthefiveexperimentaltreatments.
FREIRE-JR.&MOTTA—EFFECTSOFFIREONCURSORIALARACHNIDS 269
Treatments
—
Figure 4. Boxplot ofevennessvalues(Pielou’s J) forthespeciescollected in thefiveexperimental treatments. Different letters indicate
significantdifference(P<0.05)betweentheevennessoftreatments.
Figure 5.—Renyidiversityprofiles(a=0, ...oo)forthefiveexperimentaltreatments.
270 THEJOURNALOFARACHNOLOGY
—
Table 2. Diversity valuescalculated from Shannon-Wienerand areassubjectedtofire.Furthermore,incontemplatingawider
Simpsonindicesforthefiveexperimentaltreatments.Differentletters disturbancegradient, forexample, thelongtimelagbetween
indicate significant difference {P < 0.001) between the treatments, the area burned every4yr (QD) and the areapreserved for
usingapair-wisecomparison.
36yr,itisimpossibletopredictthediversityinareasburning
Shannon-Wiener Simpson oftenwithinthattimeframe.TheseresultsagreewithMackey
Treatment mean ± SD mean ± SD anontdrCeuarcrhieed(i2n00a1)m,owdheroatsuegsgteasgtetohfatdiwshteunrbtahneceditvheirssiist,yipnemaoksits
CT 2.38 ± 0.12 a 6.12 ±0.2 a cases, due to the paucity of studies on broader levels of
EB 3.08 ±0.16 b 14.8 ± 1.2 b disturbance. This lack ofmethodological amplitude causes a
MB 3.22 ± 0.17 c 18.3 ± 2.1 c weak correlation between diversity and moderate perturba-
QLBD 33..1215 ±± 00..2211 bc 2117..19±± 22..54 dc tisiotnhs.eAinnfoltuheenrceiomfpodritfafnertenatspseucctcetshsaitonhaalsnstoatgebseeonfcvoengseitdaetrieodn
onthecommunityofcursorialarachnidsinthecerrado,being
littlevariationinresponsetoenvironmentaldisturbancesand animportant—issuetobeinvestigatedinfurtherstudies.
tothelackofawidegradientofdisturbance. — Similarity. The groups formed by the cluster analysis
Species composition, diversity, and evenness. Little is suggesttwo areaswith different burningfrequencies, butthe
knownaboutthespecifichabitatofarachnidsinthecerrado; sameperiod(MBandQD),areverysimilarincompositionof
however,thefactthatAlopecosasp.2wasrestrictedtotheCT arachnids.
area indicates that this species exhibits a preference for Thelackofrain,whilepromotingthelossoffuelmoisture
environments preserved from fire and with high densities of available to burn during the dry season, influences the
woodyplants.Inaddition,Theridionsp.2wasmoreabundant behavior of fire through the dry season (Miranda et al.
iinnatrheeasQwDitahreaa,biaennndiaIlsobcutrenniunsgcorxeagliimsea(nEdB,PaMlBpimaanndiLdBa)e.sTp.he1 2t0h0e2)c.erTrhaudso,wiitllismeoxdpiefcytetdhethvaetgbetuartniionngainndthleitstearmiensaeassiominlairn
results indicate that the fire did not affect the number of way, therefore promoting the coexistence of spider species
species, but reduced the population size and increased the withsimilarenvironmentalrequirements.
evenness, thereby promoting a greaterdiversity ofspecies of Concluding, theareassubjectedto firespresentedahigher
cursorialarachnids. Mackey&Currie(2000)pointedoutthat diversitythanunburnedareas,andburnedareasinthemiddle
evenness can be strongly influenced by fires, which was ofthe dry season tended to have higherdiversitythan areas
confirmedbythisstudy. burnedatthebeginningorendofthisseason,indicatingthat
However,itisnotpossibletocorroboratetheIntermediate thetimingoffiremaybemoreimportantthanthefrequency
Disturbance Hypothesis based on the results presented here, ofburnsonthediversityofcursorialarachnidsintheBrazilian
duetotheimpossibilityofclearlyorderingdiversityamongthe savannah(cerrado).
LDA1
—
Figure 6. Canonical variablesobtained from thediscriminantfunctiongenerated bythedistribution ofcursorial spiderspresentinfive
experimentaltreatments.
FREIRE-JR.&MOTTA—EFFECTSOFFIREONCURSORIALARACHNIDS 271
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