the population-level consequences of native and invasive herbivores for native cacti in florida

The$popula*on,level$consequences$of$na*ve$and$invasive$herbivores$for$na*ve$

cac*$in$Florida$Kristen(E.(Sauby,(Mary(C.(Christman(and(

Robert(D.(Holt(Department(of(Biology,((University(of(Florida(

Ecological(Society(of(America(Fort(Lauderdale,(Florida(

August(8,(2016(

IntroducKon(

•  What(is(the(impact(of(an(invasive(insect(to(its(naKve(host(plants?(– Host(plant(vital(rates(

– negaKve(effects(on(vital(rates(do(not(necessarily(translate(into(a(negaKve(effect(on(populaKon(size(or(trends(

–  thus(it(is(difficult(to(infer(the(consequences(of(species(interacKons(to(plant(populaKon(dynamics(

QuesKons(

•  What(is(the(impact(of(an(invasive(insect(to(naKve(host(plant(vital(rates?(

•  What(is(the(impact(of(an(invasive(insect(to(naKve(host(plant(populaKon(dynamics((i.e.,(asymptoKc(populaKon(growth(rate)?(

Florida$Opun%a'and$Their$Specialist$Insect$Herbivores'

The$invasive$cactus$moth,$Cactoblas%s'cactorum,'

“blas*ng”$its$host$species,$Opun%a'stricta,'in$Florida'

The$Path$to$the$North$American$Introduc*on$of$C.'cactorum$

1925(

Successful$Biological$Control$in$Australia$

Before…$ AFer.$

Photos(from(Osmond(et&al.&2008&(Journal(of(Experimental(Botany)(

1957(

Early(1930s(

1925(

The$Path$to$the$North$American$Introduc*on$of$C.'cactorum$

Source:(USDA(APHIS,(h_p://www.aphis.usda.gov/plant_health/plant_pest_info/cactoblasKs/spread.shtml,((((((((accessed(21(March(2009(

Most(recent(detecKons:(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$

Sampling(at(the(Guana(Tolomato(Matanzas(NaKonal(Estuarine(Research(Reserve((GTMNERR)(

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)

Plot(Surveys(Across(7(Habitat(Patches((•  447(1fmeter2(plots(

•  Each(plot(was(surveyed(twice(a(year(from(May(2013(–(August(2015(•  Measured(plant(size(and(reproducKve(output(Spring/Summer(•  Recorded(insect/presence(absence,(recruitment(in(Spring/Summer(and(Fall/Winter(•  Number(of(individuals(surveyed(at(start(:(886((Spring/Summer(2013)(•  Number(of(individuals(surveyed(in(total:(1369((483(recruits)(

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)

Hypotheses(

•  The(invasive(moth(will(negaKvely(affect(vital(rates(and(the(asymptoKc(populaKon(growth(rate,(λ,(of(Opun-a&stricta(

•  The(naKve(moth(will(have(no(effect(on(vital(rates(and(λ(

Objec*ves$

•  Examine(relaKonship(between(moth(presence(and(vital(rates(– Growth(– Sexual(ReproducKon(– Survival(

•  Construct(and(analyze(matrix(populaKon(model(to(determine(effect(of(moth(presence(on(asymptoKc(populaKon(growth(rate,(λ(– ElasKcity(analysis(

Rela*ve$Growth$Rate$

RGR = 365×(!"#$!!! − !"#$!)/(!×!"#$!)

d(=(days(between(survey(at(Kme&t&and(Kme(t+1&

Growth$

Linear(mixed(model(in(SAS/STAT(version(13.2((

0

10

20

30

0 1 2 3 4 5

ln(Sizet)

Annu

al R

elat

ive G

row

th R

ate

Invasive Moth Present During Study? Yes No

•  Overall,(negaKve(relaKonship(between(size(and(RGR(•  Significant((small)(posiKve(effect(of(the(invasive(moth(

0

10

20

30

0 1 2 3 4 5

ln(Sizet)

Annu

al R

elat

ive G

row

th R

ate

Native Moth Present During Study? Yes No

Growth$

Linear(mixed(model(in(SAS/STAT(version(13.2((

•  Significant((small)(posiKve(effect(of(the(naKve(moth(

Sexual$Reproduc*on$

•  No(effect(on(fruit(presence(•  PosiKvely(associated(with(higher(fruit(count(

(•  Found(on(only(one(plant(with(fruit(

0

1

2

3

4

No Yes

Invasive Moth PresentDuring Study?

ln(N

umbe

r of F

low

ers

and

Frui

t)

Invasive$Moth$

Na*ve$Moth$

Zerofinflated(Poisson(model((SAS/STAT(version(13.2)((

Survival$

Study(length(=(1000(days((2012f12f02(to(2015f08f29)(Cox(proporKonal(hazards(regression((SAS/STAT(version(13.2)((

Follow Up Time (Days)0 100 200 300 400 500 600 700 800 900 1000

Surv

ival P

roba

bilit

y0.

00.

20.

40.

60.

81.

0

Invasive Moth Absent

InvasiveMothPresent

Higher(for(plants(infested(by(the(invasive(moth(during(the(study(

Posi*ve$Rela*onship$Between$Survival$and$Invasive$Moth$Presence$During$the$Study$

Due(to(the(invasive(moth’s(a_racKon(to(larger(plants?(

0

1

2

3

4

5

No Yes

Invasive Moth Presentat Time t?

ln(Size t)

Posi*ve$Rela*onship$Between$Survival$and$Invasive$Moth$Presence$During$the$Study$

Due(to(the(invasive(moth’s(a_racKon(to(larger(plants?(

0

1

2

3

4

5

Island 1 Island 2 Island 3 Island 4 Island 5 CoastalGrassland

BeachDunes

Habitat Patch

ln(S

izet)

Invasive Moth Present at Time t? No Yes

0

1

2

3

4

5

No Yes

Invasive Moth Presentat Time t?

ln(Size t)

Follow Up Time (Days)0 100 200 300 400 500 600 700 800 900 1000

Surv

ival P

roba

bilit

y0.

00.

20.

40.

60.

81.

0

Native Moth Absent

NativeMothPresent

Survival$

Study(length(=(1000(days((2012f12f02(to(2015f08f29)(Cox(proporKonal(hazards(regression((SAS/STAT(version(13.2)((

No(effect(of(naKve(moth(presence(during(the(study(

What(are(the(consequences(of(invasive(moth(infestaKon(for(the(asymptoKc(

populaKon(growth(rate,(λ?(

•  Construct(Matrix(PopulaKon(Models(

•  Determine(which(vital(rates(are(most(important(to(the(populaKon(growth(rate(– With(elasKcity(analyses(

Juvenile((1(segment)(

Life$Cycle$Diagram$for$Opun%a'stricta'

1(segment(

2(segments(

4(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Recruitment$Seed(Seedling(

Stasis$

Note:(•  TransiKons(are(based(on(data(except(•  seed$recruitment$rate:(based(on(previous(studies(•  Number$of$seeds$produced$per$plant:((

•  Average(#(of(seeds(per(fruit((observed(from(40(fruit)(x(observed(number(of(fruit(

•  Time(step(is(1(year(•  Data(represents(transiKons(from(2013(to(2014(

Seed(


1(segment(

2(segments(

4(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Growth$(1$year)$

Seedling(Juvenile((1(segment)(

Seedling( Seed(


1(segment(

2(segments(

4(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Juvenile((1(segment)(

Stasis$

Seedling( Seed(Juvenile(

(1(segment)(


2(segments(

4(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Sexual$Reproduc*on$

Growth$

Growth$

1(segment(

Stasis$

Stage(7((10+(

segments)(


(1(segment)(


1(segment(

4(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Clonal$Reproduc*on$+$$Retrogression$

Growth$Stasis$

Growth$

2(segments(


(1(segment)(


1(segment(

2(segments(

4(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(


Growth$

Growth$

Stasis$


3(segments(


(1(segment)(


1(segment(

2(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Stasis$

Growth$



Retrogression$

4(segments(


(1(segment)(


1(segment(

2(segments(

4(segments(

3(segments(

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Retrogression$

Stasis$

Growth$Clonal$Reproduc*on$+$$

Retrogression$

Retrogression$

5(segments(


(1(segment)(


1(segment(

2(segments(

4(segments(

3(segments(

5(segments(

Stage(7((10+(

segments)(

Stasis$

Growth$Clonal$Reproduc*on$+$$Retrogression$

Retrogression$

Sexual$Reproduc*on$

Stage(6((6f9(

segments)(


(1(segment)(


1(segment(

2(segments(

4(segments(

3(segments(

5(segments(

Stage(6((6f9(

segments)(

Stasis$

Clonal$Reproduc*o

n$

Clonal$Reproduc*on$

Retrogression$

Retrogression$

Sexual$Reproduc*on$

Stage(7((10+(

segments)(


(1(segment)(

Important$Transi*ons$According$to$Elas*city$Analysis'

1(segment(

2(segments(

4(segments(

3(segments(

5(segments(

0.14$

Note:(•  All(2013f2014(transiKon(data(•  StarKng(values(•  1000(seeds(•  100(individuals(all(other(stages(

0.15$

0.06$

Stage(7((10+(

segments)(

Stage(6((6f9(

segments)(

Popula*on$Dynamics$Based$on$2013,2014$Transi*on$Data$

Model$ λ$ Number$of$Unique$Individuals$

EnKre(Dataset( 0.988( 778(

Divide(dataset(based(on(invasive(moth(presence(

With(Invasive(Moth( 0.982( 664(

Without(Invasive(Moth( 1.45( 114(


With(NaKve(Moth( 1.098( 397(

Without(NaKve(Moth( 1.001( 381(

•  For(dataset(without(invasive(moth(•  no(seedling(recruitment(observed;(set(to(0.001(•  Seedling(to(juvenile(set(to(1(

Plots(with(cacK(sampled(in(clusters(

Yellow:(CacK(absent$Green:(CacK(present(

Popula*on$Dynamics$Based$on$2013,2014$Transi*on$Data$

Model$ λ$ Number$of$Unique$Individuals$

EnKre(Dataset( 0.988( 778(


With(Invasive(Moth( 0.982( 664(

Without(Invasive(Moth( 1.45( 114(


With(NaKve(Moth( 1.098( 397(

Without(NaKve(Moth( 1.001( 381(

•  For(dataset(without(invasive(moth(•  no(seedling(recruitment(observed;(set(to(0.001(•  Seedling(to(juvenile(set(to(1(

Conclusions$

•  Impact(of(invasive(but(not(naKve(moth(to(cactus(vital(rates(

•  PopulaKon(models(suggest(that(the(invasive(may(negaKvely(impact(the(populaKon(growth(rate(– Also(suggests(no(effect(of(naKve(moth(

Future(Work(

•  Run(simulaKons(with(2013f2014(and(2014f2015(transiKon(data(to(incorporate(– Demographic(stochasKcity(

– SpaKal(variaKon((among(the(7(habitat(patches)(

•  Sufficient(data(for(Life(Table(Response(Experiments?(

•  Increase(sample(size(of(large(plants?(

Acknowledgments$• University$of$Florida$

• James(Nifong(• Polly(Harding(

• GTMNERR$• KaKe(Petrinec(• Ma_(Welsh(

(

Funding$•  Carrie(Lynn(Yoder(Scholarship(for(Plant(Ecology(and(

ConservaKon(Research(in(Florida(•  Florida(NaKve(Plant(Society(•  Botanical(Society(of(America(•  QuanKtaKve(SpaKal(Ecology,(EvoluKon,(and(Environment(

(QSE3)(IGERT(•  Garden(Club(of(America(and(Center(for(Plant(ConservaKon(•  Cactus(and(Succulent(Society(of(America(•  Graduate(Student(Council,(University(of(Florida(•  Department(of(Biology,(University(of(Florida(

the population-level consequences of native and invasive herbivores for native cacti in florida

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