Spatio-temporal patterns in plant populations in small landscape elements Patrick Endels Laboratory...

Spatio-temporal patterns in plant populations

in small landscape elements

Patrick EndelsLaboratory for Forest, Nature and Landscape Research, KULeuvenVital Decosterstraat 102B-3000 Leuven, BelgiumTel +32(0)16.32.97.69 Fax +32(0)16.32.97.60

outlineoutline

1. research questions1. research questions

2. data recording2. data recording

3. data management3. data management

4. analysis of temporal changes4. analysis of temporal changes

5. analysis of spatial patterns5. analysis of spatial patterns

6. further analyses6. further analyses

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Impact of different ‘management’ regimes on demographic Impact of different ‘management’ regimes on demographic parameters of populations in small landscape elements?parameters of populations in small landscape elements?

barochory ((Primula verisPrimula veris) vs. ) vs. myrmecochory ((Primula Primula vulgarisvulgaris))-> population dynamics & max. dispersal distance?-> population dynamics & max. dispersal distance?

Impact of ‘management’ regimes on shape & tail of the Impact of ‘management’ regimes on shape & tail of the dipsersal curve?dipsersal curve?

Relationship between dispersal distance & subsequent Relationship between dispersal distance & subsequent seedling/juvenile survivalseedling/juvenile survival

general research questionsgeneral research questions11

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data recordingdata recording11

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66Primula vulgaris Primula veris


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Primula vulgarisPrimula vulgaris

•13 populations13 populations

• forest edges (n=3) forest edges (n=3) vs. vs. grazed parcel margins (n=4) grazed parcel margins (n=4) vs. vs. [1999-2002][1999-2002] clearing of ditches & mowing (n=2)clearing of ditches & mowing (n=2)

• restoration of mowing regime (n=1)restoration of mowing regime (n=1) [1999-[1999-2003]2003]

• changes in adjacent land use (n=1)changes in adjacent land use (n=1) [1999-[1999-2002]2002]


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Primula verisPrimula veris

•16 populations16 populations

• graft (Voeren) (n=4) graft (Voeren) (n=4) vs. vs. grazed parcel margins (n=4) grazed parcel margins (n=4) vs. vs. [2000-2002] [2000-2002] clearing of ditches & mowing (n=4)clearing of ditches & mowing (n=4)

• restoration of calcareous grassland (n=2)restoration of calcareous grassland (n=2) [1999-[1999-2001]2001] (Voeren)(Voeren)

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0 10 20 30 40 50 60 70 80 Centimeters

2000

1999

2001

data managementdata management11

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Life Life stage stage 19991999

rosetterosettes 1999s 1999

Life Life stage stage 20002000

rosettes rosettes 20002000

……

Plant Plant 11

fl. adultfl. adult 55 n-fl. n-fl. adultadult

1010

Plant Plant 22

seedlinseedlingg

11 juvenilejuvenile 11

Plant Plant 33

juvenilejuvenile 11

Plant Plant 44

n-fl. n-fl. adultadult

11 fl. adultfl. adult 22

Plant Plant 55

seedlingseedling 11

……

analysis of temporal changesanalysis of temporal changes11

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Stage classification = a combination of both reproductive and size criteria

Seedlings: individuals developed directly after the germination of seeds, with cotyledons still present and often also one ‘normal’ leaf-pair.

Juveniles: immature plants without cotyledons and with only one rosette of leaves. Juveniles can only be distinguished from vegetative adults with one rosette by means of their size: an individual is considered as an adult when its leaf size is comparable to flowering plants in the same population; if leaf size is significantly smaller then the individual is assigned to the juvenile category.

Vegetative adults: non-flowering individuals without cotyledons, with one or more rosettes, often showing signs of overwintering leaves. Leaf size is comparable to generative adults which are growing under similar conditions.

Reproductive adults: plants baring one ore more flowering stalks, having one or more rosettes and often showing signs of older, overwintering leaves. These flowering adults were divided into three size categories according to the number of rosettes.


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S J NFA

RA1 RA2

RA3

-> Moloney (1986) vs. empirical approach

YEAR YEAR t+1t+1

LL6666GG6262GG6464GG63630000ReprReprAdult 3Adult 3

LL5656LL5555GG5454GG5353GG5252GG5151ReprReprAdult 2Adult 2

LL4646LL4545LL4444GG4343GG4242GG4141ReprReprAdult 1Adult 1

LL3636LL3535LL3434LL3333GG3232GG3131NFNFAdult Adult

FF66FF55FF4400LL2222GG2121juvenilejuvenile

FF33FF22FF11000000seedlingseedling

ReprReprAdult 3Adult 3(>3 roz.)(>3 roz.)

ReprReprAdult 2Adult 2(2-3 roz.)(2-3 roz.)

ReprReprAdult 1Adult 1(1 roz.)(1 roz.)

NFNFAdult Adult

juvenilejuvenileseedlingseedling

YEAR tYEAR t

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analysis of temporal changesanalysis of temporal changesn(t + 1) = n(t + 1) = AA n(t)n(t)


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SymboSymboll

DefinitionDefinition Demographic Demographic interpretationinterpretation

AA a square matrix containing the coefficients that a square matrix containing the coefficients that represent proportions of – mostly year-to-year – represent proportions of – mostly year-to-year – transitions between life stages.transitions between life stages.

Projection Projection matrixmatrix

aaijijthe element in row i, collum j of the projection matrix A the element in row i, collum j of the projection matrix A matrix matrix

elementelement

the dominant eigenvalue of Athe dominant eigenvalue of A population population growth rate growth rate

A A = = (the right eigenvector of A associated with (the right eigenvector of A associated with ))

stable stagestable stagedistributiondistribution

A = A = ((the left eigenvector of A associated with the left eigenvector of A associated with ))

reproductive reproductive valuesvalues

ssijij / / aaij ij

(the sensitivity of (the sensitivity of to changes in matrix element a to changes in matrix element aijij))sensitivitysensitivity

eeijijaaijij / / aaijij

(the proportional sensitivity of (the proportional sensitivity of to proportional changes to proportional changes in matrix element ain matrix element aijij))

elasticityelasticity

11 / / 22 (ratio between the dominant & subdominant (ratio between the dominant & subdominant eigenvalue)eigenvalue)

damping damping ratioratio

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sensitivity analysissensitivity analysis

(Silvertown (Silvertown et alet al. 1992, . 1992, 1996)1996)

Triangular plot of composite elasticity values Triangular plot of composite elasticity values for for growthgrowth (G), (G), statisstatis (L) and (L) and fecundityfecundity (F) (F)

species populations

C ≈≈ S

R ≈

C ≈≈ S

R ≈

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sites [sites [P. vulgarisP. vulgaris]]

forest edgesforest edgesgrazed parcel marginsgrazed parcel margins

ditch clearing (+mowing)ditch clearing (+mowing)

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population growth rates [population growth rates [P. vulgarisP. vulgaris]]

repeated measures ANOVA:

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1999-2000 2000-2001 2001-2002

po

pu

lati

on

gro

wth

rat

e +

/- S

D

forest edge

grazed

cleared/mown

tests of within-subjects contrastsF P

YEAR 11.019 < 0.05YEAR * MANAGEMENT 6.533 < 0.05

tests of between-subjects effectsF P

MANAGEMENT 6.5650 < 0.05

L

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

G

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

F

0.00.10.20.30.40.50.60.70.80.91.0

L

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

G

0.0

0.1

0.2

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0.5

0.6

0.7

0.8

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1.0

F

0.00.10.20.30.40.50.60.70.80.91.0

L

0.0

0.1

0.2

0.3

0.4

0.5

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0.7

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1.0

G

0.0

0.1

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1.0

F

0.00.10.20.30.40.50.60.70.80.91.0

sensitivity analysis [sensitivity analysis [P. P. vulgarisvulgaris]]

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mown/clearedforest edgegrazed

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0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1999-2000 2000-2001 2001-2002 2002-2003

not mownmown 1mown 2

different mowing different mowing regimesregimes

?

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S J

NF

A

RA

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RA

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3 S

J

NF

A RA

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RA

2R

A3

0

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1.2

1.4

1.6

1999 2000

S J

NF

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3 S

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NF

A RA

1 RA

2 RA

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0

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1.6

2000 2001

S J

NF

A

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3 S

J NF

A RA

1

RA

2R

A3

0

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0.6

0.8

1

1.2

1.4

1.6

2000 2001

mown 2

not mown

mown 1

S J

NF

A

RA

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RA

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RA

3 S

J

NF

A RA

1

RA

2R

A3

0

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1.6

1999 2000

S J

NF

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NF

A RA

1 RA

2 RA

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0

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1.6

2000 2001

S J

NF

A

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J NF

A RA

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RA

2R

A3

0

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2000 2001

S J

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NF

A RA

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RA

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A3

0

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1.6

1999 2000

S J

NF

A

RA

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RA

2

RA

3 S

J

NF

A RA

1 RA

2 RA

3

0

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1

1.2

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2000 2001

S J

NF

A

RA

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RA

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J NF

A RA

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RA

2R

A3

0

0.2

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1

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1.4

1.6

2000 2001

mown 2

not mown

mown 1

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not mown mown 1 mown 2


L

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

G

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

F

0.00.10.20.30.40.50.60.70.80.91.0

L

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

G

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

F

0.00.10.20.30.40.50.60.70.80.91.0

L

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

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1.0

G

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

F

0.00.10.20.30.40.50.60.70.80.91.0

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0.7

0.8

0.9

1.0

1.1

1.2

1.3

1.4

1.5

1999-2000 2000-2001 2001-2002

scraping of wholeditch bank

scraping of lowerside of ditch bank

clearing (+mowing) of clearing (+mowing) of ditchesditches

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S J

NF

A

RA

1

RA

2

RA

3 S

J NF

A

RA

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RA

2

RA

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0

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1.6

1999 2000

S J

NF

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J NF

A

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RA

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RA

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2000 2001S J

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A

RA

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RA

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RA

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0

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1.6

2001 2002

Scrapingof whole

ditch bank

S J

NF

A

RA

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RA

2

RA

3 S

J NF

A

RA

1

RA

2

RA

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0

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1

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1999 2000

S J

NF

A

RA

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3 S

J NF

A

RA

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RA

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RA

3

0

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2000 2001S J

NF

A

RA

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RA

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J NF

A

RA

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RA

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RA

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0

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1.6

2001 2002

Scrapingof whole

ditch bank

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Scraping of whole ditchbank

Scraping of lower side of ditch bank

sensitivity analysis [sensitivity analysis [P. vulgarisP. vulgaris]]

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0.7

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1999-2000 2000-2001 2001-2002

arable field

grassland

changes in adjacent land usechanges in adjacent land use

!

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S J

NF

A

RA

1

RA

2

RA

3 S

J

NF

A

RA

1

RA

2R

A3

0

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0.6

0.8

1

1.2

1.4

1.6

1999 2000

S J

NF

A

RA

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RA

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RA

3 S

J

NF

A

RA

1

RA

2R

A3

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1

1.2

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1.6

2000 2001

S J

NF

A

RA

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RA

2

RA

3 S

J NF

A RA

1

RA

2

RA

3

0

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1

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1999 2000

S J

NF

A

RA

1

RA

2

RA

3 S

J NF

A RA

1

RA

2

RA

3

0

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1

1.2

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1.6

2000 2001

arable field

grassland

S J

NF

A

RA

1

RA

2

RA

3 S

J

NF

A

RA

1

RA

2R

A3

0

0.2

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1

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1999 2000

S J

NF

A

RA

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RA

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3 S

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NF

A

RA

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RA

2R

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2000 2001

S J

NF

A

RA

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RA

2

RA

3 S

J

NF

A

RA

1

RA

2R

A3

0

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1

1.2

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1999 2000

S J

NF

A

RA

1

RA

2

RA

3 S

J

NF

A

RA

1

RA

2R

A3

0

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2000 2001

S J

NF

A

RA

1

RA

2

RA

3 S

J NF

A RA

1

RA

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RA

3

0

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1999 2000

S J

NF

A

RA

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RA

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RA

3 S

J NF

A RA

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RA

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0

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1

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2000 2001

S J

NF

A

RA

1

RA

2

RA

3 S

J NF

A RA

1

RA

2

RA

3

0

0.2

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0.8

1

1.2

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1999 2000

S J

NF

A

RA

1

RA

2

RA

3 S

J NF

A RA

1

RA

2

RA

3

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

2000 2001

arable field

grassland

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arable field

grassland

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clearing / mowingclearing / mowing

grassland marginsgrassland margins

sites [sites [P. verisP. veris]]

graft (Voeren)graft (Voeren)

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tests of within-subjects contrastsF Sig.

YEAR 1.936 n.s.YEAR * MANAGEMENT 0.652 n.s.

between subjects effectsF Sig.

MANAGEMENT 4.369 < 0.05

population growth rates [population growth rates [P. verisP. veris]]

repeated measures ANOVA:

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

2000-2001 2001-2002

po

pu

lati

on

gro

wth

ra

te +

/- S

D

cleared/mown

grazed

graft

sensitivity analysis [sensitivity analysis [P. verisP. veris]]

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F

L

F

G L

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conclusions temporal analysis [conclusions temporal analysis [P. vulgaris & P. verisP. vulgaris & P. veris] - 1] - 1

P. vulgarisP. vulgaris P. verisP. veris

mown / mown / clearedcleared

grazedgrazed forest forest edgeedge

mown / mown / clearedcleared

grazedgrazed graftgraft

λλ:: management management effect?effect?

aa bb abab aa bb abab

λλ:: year effect? year effect? yesyes nono

Sensitivity Sensitivity analysisanalysis

λλ

rel. dep. rel. dep. on on

fecundityfecundity

λλ

higly higly dep. on dep. on survival survival adultsadults

intermedintermed..

λλ

rel. dep. rel. dep. on on

fecundityfecundity

λλ

higly higly dep. on dep. on survival survival adultsadults

intermed.intermed.

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conclusions temporal analysis [conclusions temporal analysis [P. vulgarisP. vulgaris] - 2] - 2

(a) mowing regime

- first year : effect of mowing once or twice a year ≅

- In the “long run”: only mowing twice a year (July & October) efficient to counter population senescence to lift λ above 1

(b) ditch clearing regime (& mowing of ditch bank)

- large impact on population growth rate (depending on intensity)

- temporarily higher mortality levels

- compensated by higher seedling recruitment and survival

c) changes in adjacent land use

- grassland -> arable field: (1) effect on population growth rate and (2) populations more responsive to survival of veg. adults

- population quickly recovers when the original land use is restored

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conclusions temporal analysis [conclusions temporal analysis [P. vulgaris & P. verisP. vulgaris & P. veris] - 3] - 3

in general:

- disturbances of any kind force populations into earlier stages

of

the successional G-L-F trajectory (Silvertown et al. 1996)

- however, these more dynamic populations (i.e. more

dependent on / responsive to fecundity and growth) are not

necessarily associated with higher population growth

rates (’s)

analysis of spatial patternsanalysis of spatial patterns11

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calculation of dispersal distances

dispersal curves for the two species for different management regimes-> tail (max. dispersal distance)?!

dispersal distance and survival -> Janzen (1970)-Connell (1971) vs. Hubbell (1979)

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1 0 1 Meters

calculation of dispersal distances

# reproductive adults year x# seedlings year x+1

calculation of dispersal distancescalculation of dispersal distances

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dispersal distance & management regime [dispersal distance & management regime [P. vulgarisP. vulgaris]]

dispersal distance

2.852.65

2.452.25

2.051.85

1.651.45

1.251.05

.85.65

.45.25

.05

forest 200012

10

8

6

4

2

0

Std. Dev = .22

Mean = .29

N = 33.00

dispersal distance

2.85

2.65

2.45

2.25

2.05

1.85

1.65

1.45

1.25

1.05

.85

.65

.45

.25

.05

grazed 200050

40

30

20

10

0

Std. Dev = .26

Mean = .26

N = 164.00

dispersal distance

mown/cleared 2000300

200

100

0

Std. Dev = .44

Mean = .42

N = 724.00

dispersal distance

3.152.95

2.752.55

2.352.15

1.951.75

1.551.35

1.15.95

.75.55

.35.15

forest 200130

20

10

0

Std. Dev = .14

Mean = .25

N = 61.00

dispersal distance

2.852.65

2.452.25

2.051.85

1.651.45

1.251.05

.85.65

.45.25

.05

grazed 200150

40

30

20

10

0

Std. Dev = .22

Mean = .17

N = 99.00

dispersal distance


200

100

0

Std. Dev = .51

Mean = .38

N = 621.00

dispersal distance

2.852.65

2.452.25

2.051.85

1.651.45

1.251.05

.85.65

.45.25

.05

forest 2002140

120

100

80

60

40

20

0

Std. Dev = .11

Mean = .19

N = 254.00

dispersal distance

2.8502.650

2.4502.250

2.0501.850

1.6501.450

1.2501.050

.850.650

.450.250

.050

grazed 200260

50

40

30

20

10

0

Std. Dev = .10

Mean = .158

N = 137.00

dispersal distance

mown/cleared 200250

40

30

20

10

0

Std. Dev = .31

Mean = .36

N = 176.00

max. = 1.04 m

max. = 1.26 m

max. = 0.61 m

mean = 0.29 m

mean = 0.25 m

mean = 0.19 m

max. = 2.12 m

mean = 0.17 m

max. = 0.54 m

mean = 0.16 m

max. = 2.45 m

mean = 0.26 m

max. = 2.62 m

mean = 0.42 m

max. = 3.89 m

mean = 0.38 m

max. = 1.89 m

mean = 0.36 m

a

a

a

ab

b

b

b

c

b

dispersal distance

grazed 2001100

80

60

40

20

0

Std. Dev = .08

Mean = .108

N = 376.00

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grazed 200240

30

20

10

0

Std. Dev = .08

Mean = .15

N = 187.00

dispersal distance & management regime [dispersal distance & management regime [P. verisP. veris]]

dispersal distance


200

100

0

Std. Dev = .19

Mean = .23

N = 2466.00

dispersal distance


200

100

0

Std. Dev = .16

Mean = .25

N = 2621.00

max. = 0.57 m

max. = 2.60 m max. = 0.47 m

max. = 5.49 m

mean = 0.10 m

mean = 0.15 m

mean = 0.23 m

mean = 0.25 m

<P < 0.001

≈ ?n.s

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P. vulgarisP. vulgaris

dispersal distance & survivaldispersal distance & survival

Wald χ² = 44.285n = 1720P < 0.001

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P. vulgarisP. vulgaris


dispersal distance

Wald χ² = 4.425n = 91; P = 0.035

Wald χ² = 0.065n = 271; P = 0.798

Wald χ² = 53.200n = 1344; P < 0.001

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P. verisP. veris

dispersal distance

2.01.81.61.41.21.0.8.6.4.20.0

1.2

1.0

.8

.6

.4

.2

0.0

-.2

survival prob

fate(1=surv, 0=mort)

Wald χ² = 15.223n = 2815P < 0.001

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P. verisP. veris

dispersal distance

Wald χ² = 7.141n = 344; P = 0.008

Wald χ² = 16.137n = 2438; P < 0.001

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spatial patterns: conclusionsspatial patterns: conclusions

P. vulgarisP. vulgaris P. verisP. veris

managemenmanagementt

forest forest edgeedge

grazedgrazed mown / mown / clearedcleared

grazedgrazed mown / mown / clearedcleared

dispersal dispersal distancedistance **** **** ****** ** ******

seedling / seedling / juvenile juvenile survivalsurvival

********(63 %) (63 %)

********(62 %)(62 %)

******(47 %)(47 %)

****(19 %)(19 %)

**(8 %)(8 %)

dispersal dispersal (D) ~ (D) ~ survival survival (S)(S)

S ▲ if D ▲S ▲ if D ▲

herbivory / herbivory / pathogens / pathogens / intraspecific intraspecific comp. ?comp. ?

n.s.n.s. S ▲ if D ▲S ▲ if D ▲

herbivory / herbivory / pathogens / pathogens / intraspecific intraspecific comp. comp.

S ▲ if D ▲S ▲ if D ▲

herbivory ?herbivory ?

S ▼ if D ▲S ▼ if D ▲

high high disturbance disturbance regime ?regime ?

J.-C. J.-C. J.-C. H.

further analyses (1)further analyses (1)11

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temporal changes

- relationship with reproductive output

- comparison of population growth rate by randomization tests

- LTRE (mowing regime P. vulgaris, management regime P. veris)

- stochastic population modelling (Caswell 2001, Tuljapulkar & Caswell 1997)

spatial patterns - relationship between aggregation & dispersal distance (calculation of Ripley’s K & comparison between

management regimes)

- aggregation and flower morph types ?

- ? ? ?

incorporating plant performance

- link with recruitment / population dynamics ?

further analyses (2)further analyses (2)11

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0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

0.0 0.5 1.0 1.5 2.0 2.5

distance

rip

ley

's K

L_T_

L_T_2_5

L_T_97_5

Spatio-temporal patterns in plant populations in small landscape elements Patrick Endels Laboratory...

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Transcript of Spatio-temporal patterns in plant populations in small landscape elements Patrick Endels Laboratory...