the relative importance of herbivory and abiotic conditions to the relative growth rate of two...

The$Rela(ve$Importance$of$Herbivory$and$Abio(c$Condi(ons$to$the$Rela(ve$Growth$

Rate$of$two$Na(ve$Cactus$Species$in$Florida$

Kristen$E.$Sauby1,$John$Kilmer2,$Mary$C.$Christman3,$Robert$D.$Holt1,$and$Travis$D.$Marsico2$

1Department*of*Biology,*University*of*Florida*2Department*of*Biological*Sciences,*Arkansas*State*University*

3MCC*Sta@s@cal*Consul@ng*LLC,*Courtesy*Associate*Professor,*Department*of*Biology*and*Department*of*Sta@s@cs,*University*of*Florida*

$Ecological$Society$of$America$Mee(ng$

Bal(more,$Maryland$August$13,$2015$

Plant$Responses$to$Herbivory$•  Response*can*range*from*

undercompensa@on*to*overcompensa@on*

•  The*strength*of*the*herbivore’s*impact*may*

be*mediated*by*abio@c*condi@ons*(Maron*and*

Crone*2006)*

–  affec@ng*•  the*rate*of*plant*development*rela@ve*to*insect*

development*

•  plant*phenology*rela@ve*to*insect*phenology*•  Their*interac@on*

Climate$Change$

Source:*hOp://

www.climatecentral.org/news/

acrossSusSheaviestSdownpoursSonS

theSriseS18989*

Source:*hOps://www.ipcc.ch/publica@ons_and_data/

ar4/wg1/en/figureSspmS6.html*

•  Abio@c*condi@ons*may*

be*more*important*

The$invasive$cactus$moth,$Cactoblas)s*cactorum,*

“blas(ng”$its$host$species,$Opun)a*stricta,*in$Florida*

Climate,$Plants,$and$Invasive$Herbivores$

Florida$Opun)a*and$Their$Specialist$Insect$Herbivores*Invasive$Cactus$Moth,$Cactoblas)s*cactorum*

Na(ve$Cactus$Moth,$Melitara*prodenialis*

Na(ve$Cactus$Bug,$Chelinidea*vi7ger*

Na(ve$Cactus$Scale,$Dactylopius$sp.$

O.*stricta* O.*pusilla* O.*humifusa*

Successful$Biological$Control$in$Australia$

Before…$ ASer.$

•  Quotes*from*Dodd*(1940)*

•  Photos*from*Osmond*et#al.#2008#(Journal*of*Experimental*Botany)*

“In*August*1930,*for*150*miles*[240*km]*

along*the*river*the*pest*[O.#stricta]*was*in*its*full*vigour,*its*con@nuity*almost*unbroken*

by*cleared*land;*the*pastoral*proper@es*had*

been*overrun*and*mainly*deserted.”*

“…in*August*1932,*90*percent*of*the*[prickly]*

pear*had*collapsed.*The*change*in*exactly*

two*years*was*extraordinary.”*

Source:*USDA*APHIS,*

hOp://www.aphis.usda.gov/plant_health/plant_pest_info/cactoblas@s/spread.shtml,********

accessed*21*March*2009*

Most*recent*

detec@ons:*Jefferson,*

Lafourche,*and*

Terrebonne*Parishes,*

Louisiana*(2009)*

Distribu(on$of$the$Invasive$Cactus$Moth$in$the$Southeastern$United$States$

South$Carolina,$2004$

Louisiana,$2009$

First$detec(on,$Florida$Keys,$1989$

2000$2003$ 2002$

•  Invasive*moth*

may*invade*the*

southwestern*

US*and*Mexico*

Mo(va(on$

Image*Source:*hOp://

geochange.er.usgs.gov/sw/impacts/

biology/veg_chg_model/*

Insect$–$Opun)a*Interac(ons$in$Florida$•  *Past*studies*have*examined*the*effect*of*the*

invasive*moth*on*growth*rate*and*survival*

•  What*is*the*importance*of*herbivory*rela@ve*

to*abio@c*factors?*

•  What*are*the*popula@onSlevel*impacts*of*the*

invasive*and*na@ve*insect*herbivores?*–*

Coming$soon!$

Insect$–$Opun)a*Interac(ons$in$Florida$•  *Past*studies*have*examined*the*effect*of*the*

invasive*moth*on*growth*rate*and*survival*

•  What*is*the*importance*of*herbivory*rela@ve*

to*abio@c*factors?*

*

•  What*are*the*popula@onSlevel*impacts*of*the*

invasive*and*na@ve*insect*herbivores?*–*

Coming$soon!$

Objec(ves$

•  Vital*Rates*– Recruitment*

– Growth*– Fecundity*– Survival*

•  Quan@fy*the*rela@ve*importance*of*herbivory*

and*abio@c*factors*to*Opun/a#vital*rates*

Hypotheses$

•  Invasive*moth*has*greater,*nega@ve*impact*rela@ve*

to*na@ve*insects*

•  Effect*of*insects*on*cac@*varies*with*precipita@on*and/or*temperature*

•  Plants*should*be*more*nega@vely*impacted*by*insects*

during*drier*condi@ons*with*high*temperatures*

Sampling$Sites$–  15S20*plants*sampled*along*transects*for*5*years*

•  4*@mes*in*January**2009*(January*–*October);*every*spring/

summer*and*fall/winter*from*2010*–*January*2014*

–  Recorded*insect*presence,*plant*size*(number*of*segments),*

number*of*fruit,*and*survival*

*

0km 25km 50km

N

Big Lagoon State Park

Nokuse Plantation Torreya State Park

Henderson Beach State Park

Mexico Beach

St. Andrew's State Park

Henderson Beach State Park

St. Andrew's State Park

29.5°N

30°N

30.5°N

31°N

88°W 87.5°W 87°W 86.5°W 86°W 85.5°W 85°W 84.5°WLongitude

Latit

ude

�*O.#humifusa#!**O.#stricta#

Abio(c$Data$Summary Statistic Variable

Mean daily precipitationStandard deviation daily precipitation

Mean consecutive days with rainfallMaximum consecutive days with rainfall

Standard deviation consecutive days with rainfallMean consecutive days without rainfall

Maximum consecutive days without rainfallStandard deviation consecutive days without rainfall

Percentage of days with rainfall

Summary Statistic VariableMean maximum temperature

Standard deviation maximum temperatureMean consecutive days with freeze

Maximum consecutive days with freezeStandard deviation consecutive days with freeze

Mean Degree DayPercentage of days with freeze

Precipitation

Temperature

•  Daily*climate*data*

from*NOAA*

Na@onal*Climate*

Data*Center*

•  For*each*sampling*

loca@on,*used*

closest*available*

weather*sta@on****

(2*–*17*miles)*

●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●

●●●●●●●●●

●●●●●●●●●●●●●●●●●

Daily Precip, meanDaily Precip, SDPerc. Days w/Rain

Consec. Days

w/Rain, Mean

Consec. Days w/Rain, Max

Consec. Days

w/Rain, SD Consec. Days w/o Rain, Mean

Consec. Days w/o Rain, Max

Consec. Days w/o Rain, SDPC Var.: 55.9 + 27.6 = 83.5%EV: 5.04, 2.48

−10

−5

0

−10 −5 0 5 10Principal Component 1

Prin

cipa

l Com

pone

nt 2

Amount*of*rainfall*

warm

er*

●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●

●●●●●●●●●●

●●●●●●●●●●

●●●●●●●●●

●●●●●●●●●

●●●●●●●●●

●●●●●●●●

Max Temp, MeanMax Temp, SD Mean Degree Day

Perc. Freezing DaysConsec. Freezing Days, Mean

Consec. Freezing Days, Max

Consec. Freezing Days, SD

PC Var.: 75.6 + 10.9 = 86.5%EV: 5.29, 0.77

−6

−4

−2

0

2

−10 −5 0 5Principal Component 1

Prin

cipa

l Com

pone

nt 2

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● ●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

Max Temp, MeanMax Temp, SD Mean Degree Day

Perc. Freezing Days

Consec. Freezing Days, Mean

Consec. Freezing Days, MaxConsec. Freezing Days, SD

PC Var.: 75 + 11.4 = 86.4%EV: 5.25, 0.79

−6

−4

−2

0

2

−10 −5 0 5Principal Component 1

Prin

cipa

l Com

pone

nt 2

warmer*

warm

er*

●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●● ●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● ●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●●●●●

●●●●●●●●●●●●●●Daily Precip, mean

Daily Precip, SD

Perc. Days w/Rain

Consec. Days w/Rain, Mean

Consec. Days w/Rain, Max

Consec. Days w/Rain, SD Consec. Days w

/o Rain, Mean

Cons

ec. D

ays w

/o R

ain, M

ax

Cons

ec. D

ays w

/o Ra

in, S

D

PC Var.: 49.4 + 25.9 = 75.3%EV: 4.44, 2.33−5

0

5

10

15

−15 −10 −5 0 5 10 15Principal Component 1

Prin

cipa

l Com

pone

nt 2

Amount*of*rainfall*Temporal*varia@on*in*rainfall*

O.#humifusa#Principal*Components*Analysis*

O.#stricta#Principal*Components*Analysis* **(done*in*R*3.1.4)*Precip.$

Precip.$

Temp.$

Temp.$

warmer*Temporal*varia@on*in*rainfall*

Model$Selec(on$of$Linear$Mixed$Models$

•  Performed*in*SAS*9.4*

•  Model*selec@on*using*condi@onal*AIC*(cAIC;*Müller*et*al.*2013)*$Response$Variable$•  Rela@ve*Growth*Rate*

–  based*on*the*number*of*segments*(“S”)*

–  n*=*number*of*days*between*surveys*

–  Formula*from*(Paine*et#al.*2011)$$$$Fixed$Effects$•  Insect*Presence/Absence*[tS1]*

•  ln(Plant*Size[tS1])*

•  First*two*PCA*Axes*for*Temperature*and*Precipita@on*

•  Interac@ons*–  Invasive*and*Na@ve*Insects*

–  Temperature*and*Precipita@on*

–  Insect*and*Temperature/Precipita@on*

Random$Effects$•  Loca@on*within*Year*(observa@ons*at*a*loca@on*tend*to*be*correlated*within*a*

year)**

Model*Selec@on*for*Best*Model*

Among*Those*Tested*–*O.#stricta#

Only*best*five*models*of*29*shown*


Among*Those*Tested*–*O.#stricta#


Mod

el

Stan

dard

ized

Ln(

Size

[t-1

])

Inva

sive

Mot

h [t-

1]

Nat

ive

Bug

[t-1

]

Nat

ive

Inse

cts

[t-1]

Prec

ipita

tion

Tem

pera

ture

Inva

sive

Mot

h [t-

1] x

Nat

ive

Bug

[t-1

]

Inva

sive

Mot

h [t-

1] x

Nat

ive

Inse

cts

[t-1]

Inva

sive

Mot

h [t-

1] x

Pre

cipi

tatio

n

Inva

sive

Mot

h [t-

1] x

Tem

pera

ture

Nat

ive

Bug

[t-1

] x P

reci

pita

tion

Nat

ive

Bug

[t-1

] x T

empe

ratu

re

Tem

pera

ture

x P

reci

pita

tion

Num

ber o

f Par

amet

ers

cAIC

delta

cA

IC

Mod

el L

ik

Prob

(Mod

el)

1 X X X . X X . . . . . . Full 14 1313.4 0 1 0.6

2 X X X . X X . . . . . . . 11 1314.33 0.93 0.63 0.38 3 X X . . X X . . . . . . . 8 1321.99 8.59 0.01 0.01 4 X X X . X X . . . . . . . 10 1323.81 10.41 0.01 0 5 X X X . X X . . . . . . T2 x P1 11 1325.65 12.25 0 0

1


Among*Those*Tested*–*O.#humifusa# M

odel

Stan

dard

ized

Ln(

Size

[t-1

])

Nat

ive

Bug

[t-1

]

Nat

ive

Scal

e [t-

1]

Nat

ive

Mot

h [t-

1]

Nat

ive

Inse

cts

[t-1]

Pre

cipi

tatio

n

Tem

pera

ture

Nat

ive

Bug

[t-1

] x P

reci

pita

tion

Nat

ive

Bug

[t-1

] x T

empe

ratu

re

Nat

ive

Scal

e [t-

1] x

Pre

cipi

tatio

n

Nat

ive

Scal

e [t-

1] x

Tem

pera

ture

Nat

ive

Mot

h [t-

1] x

Pre

cipi

tatio

n

Nat

ive

Mot

h [t-

1] x

Tem

pera

ture

Tem

pera

ture

x P

reci

pita

tion

Num

ber o

f Par

amet

ers

cA

IC

del

ta c

AIC

Mod

el L

ik

Pro

b(M

odel

)

1 X . . X . X X . . . . . . . 8 2736.68 0 1 0.44 2 X . . . . X X . . . . . . . 6 2737.1 0.42 0.81 0.36 3 X X . . . X X . . . . . . . 8 2739.8 3.12 0.21 0.09 4 X . X . . X X . . . . . . . 8 2741 4.32 0.12 0.05 5 X X X X . X X . . . . . . T1 x P1 13 2743.4 6.72 0.03 0.02


Parameter*Es@mates*for*the*Best*RGR*

Models*

$$ Intercept$Invasive$Moth$

Na(ve$Bug$

Na(ve$Moth$ ln(Size)$ T1$ T2$ P1$ P2$

O.#stricta# 0.5541* S0.393* S0.174* S* S*0.60* +*0.13* S*0.15* +*0.12* S*0.05*

O.#humifusa# 1.01* S* S* 0.76* S2.09* *S0.03* +*0.34* +*0.09* +*0.01*

O.#stricta#RGR*increases**with:*

Absence*of*invasive*moth*

and*na@ve*bug*

Smaller*plant*size*

T1*–*warmer*weather*

T2*–warmer*weather*

P1*–*less*rainfall*

P2*–*days*without*rain*

warm

er*

warmer*colder*•  Nega@ve*impact*of*invasive*about*2x*greater*than*that*of*na@ve*

•  RGR*posi@vely*related*to:*

•  T1*and*T2:*warmer*weather*

•  P1:*less*rainfall*

•  P2:*greater*temporal*varia@on*in*rainfall*

Parameter*Es@mates*for*the*Best*RGR*

Models*

•  Posi@ve*rela@onship*with*presence*of*na@ve*moth*

•  RGR*posi@vely*related*to:*

•  T1*and*T2:*colder*weather*

•  P1:*less*rainfall*

•  P2:*greater*temporal*varia@on*in*rainfall*

$$ Intercept$Invasive$Moth$

Na(ve$Bug$

Na(ve$Moth$ ln(Size)$ T1$ T2$ P1$ P2$

O.#stricta# 0.5541* S0.393* S0.174* S* S*0.60* +*0.13* S*0.15* +*0.12* S*0.05*

O.#humifusa# 1.01* S* S* 0.76* S2.09* *S0.03* +*0.34* +*0.09* +*0.01*

Conclusions$

•  Invasive*moth*has*greater,*nega@ve*impact*rela@ve*to*na@ve*insects*✓*–  True*only*for*O.#stricta*

•  Effect*of*insects*on*cac@*varies*with*precipita@on*and/or*temperature*

•  Plants*should*be*more*nega@vely*impacted*by*insects*during*drier*condi@ons*with*high*temperatures*–  *maybe*

Future*Work*

•  Model*other*vital*rates*

– Fruit*Produc@on*•  Hurdle*model*

–  Including*Plant*Size*as*a*predictor*–  Does*a*very*good*job*of*explaining*probability*of*fruit*presence*but*NOT*fruit*abundance*

Future*Work*

Torreya SP

Mexico Beach

Big Lagoon SP

St. Andrew's SP

Nokuse Plantation

Henderson Beach SP

MARINELAND

SAINT AUGUSTINE

0 400 800 1,200 1,600200Kilometers

0 5 10 15 202.5Kilometers

400 0 400200 Meters

660 0 660330 Meters 0.6 0 0.60.3 Kilometers

ST. JOHNSCOUNTY

FLAGLERCOUNTY

0 0.3 0.6 0.9 1.20.15Kilometers

0 0.5 10.25 Kilometers

0 350 700175 Meters

(a)

(b)

(1)$

(2)$

Torreya SP

Mexico Beach

Big Lagoon SP

St. Andrew's SP

Nokuse Plantation

Henderson Beach SP

MARINELAND

SAINT AUGUSTINE

0 400 800 1,200 1,600200Kilometers


400 0 400200 Meters


ST. JOHNSCOUNTY

FLAGLERCOUNTY

0 0.3 0.6 0.9 1.20.15Kilometers


0 350 700175 Meters

(a)

(b)

•  Build*popula@on*model*for*cac@*at*7*sites*in*

northeastern*Florida*

•  ~1000*O.#stricta#and#~1000*O.#pusilla#monitored*since*Jan.*2013*

Future*Work*

Torreya SP

Mexico Beach

Big Lagoon SP

St. Andrew's SP

Nokuse Plantation

Henderson Beach SP

MARINELAND

SAINT AUGUSTINE

0 400 800 1,200 1,600200Kilometers


400 0 400200 Meters


ST. JOHNSCOUNTY

FLAGLERCOUNTY

0 0.3 0.6 0.9 1.20.15Kilometers


0 350 700175 Meters

(a)

(b)

(1)$

(2)$

Torreya SP

Mexico Beach

Big Lagoon SP

St. Andrew's SP

Nokuse Plantation

Henderson Beach SP

MARINELAND

SAINT AUGUSTINE

0 400 800 1,200 1,600200Kilometers


400 0 400200 Meters


ST. JOHNSCOUNTY

FLAGLERCOUNTY

0 0.3 0.6 0.9 1.20.15Kilometers


0 350 700175 Meters

(a)

(b)

•  How*do*these*associa@ons*between*herbivory,*precipita@on,*and*demographic*

rates*scale*up*to*affect*plant*popula@on*

dynamics?*

Acknowledgments$•  Gary*N.*Ervin,*Mississippi*

State*University*

•  Anastasia*Cooper,*Kansas*State*University*

Arkansas$State$University$•  Meghan*Foard*

•  Emily*Mizell*

University$of$Florida$•  Doria*Gordon*•  Robert*Fletcher*•  Jose*Miguel*Poncianco*

•  Mike*Barfield*

•  Florida*State*Parks*

•  Nokuse*Planta@on*

Feel*free*to*contact*me*

at*[email protected]$$$$$$$$$$$$@KristenSauby$

Funding$•  USGS*grants*04HQAG0135*and*

08HQAG0139*(to*G.N.*Ervin)*

•  USDA*grant*2007S55320*S17847*

(to*G.N.*Ervin)*

•  Arkansas*State*University*

Molecular*BioSciences*Program*

(to*A.*Cooper)*