Wanying Zhao, Charles Goebel, Andy Michel, and John Cardina

The Ohio State University

GENETIC AND AGE DISTRIBUTION PATTERN TO RECONSTRUCT THE INVASION HISTORY.

How to control invasive plant?

Sensitive habitat

1km

Sensitive habitat

What do we need for invasive plant control? • How long is the invasion history in a natural area?

• How fast is the invasion?

1950?

1960?

1970? 1970 1980 1990 2000

What do we need for invasive plant control? • How long is the invasion history in a natural area?

• How fast is the invasion?

• What is the spatial distribution pattern?

• How invasive plant spread over time?

Common privet (Ligustrum vulgare)

• Semi-evergreen shrub

• Oleaceae (olive family)

• 3-5m tall

• Produces many berries

• Spread by birds,

other animals

• Regenerates from root

and stump sprouts.

• Forms dense thickets

• Can displace native species

http://www.dreviny-okrasne.cz

Objectives

• To study the invasion history and spatial distribution pattern of Ligustrum vulgare over time and space in Wooster Memorial Park (WMP).

• Using chloroplast DNA markers to characterize spatial genetic structure in large scale and to describe how haplotypes spread in WMP.

Sample collection in Wooster Memorial Park

Sample collection in WMP • 345 samples

• ArcGIS version 10

Age determination

• Stem was sanded and scanned to image.

• Ages of 331 samples in Wooster Memorial Park were determined by tree ring counting in WinDendro.

• Age of each sample was put in ArcGIS-10.

Invasion history of L. vulgare in WMP

0

50

100

150

200

250

300

350

1970 1975 1980 1985 1990 1995 2000 2005 2010

Nu

mb

er

of

tota

l pat

che

s

Year

19 years

310 patches

19/year

12 patches

1972

Habitat preferences of initial patches

Age (No. of samples) Locations

39 (1), 28 (1), 21(1) Farm-upland forest

29 (1) Trail-stream-slope forest

28 (1), 22(1) Upland-slope forest

27 (1) Grassland-evergreen forest

25 (1), 23(1) Upland forest

22 (1) Bottomland forest (open area)

21 (1) Stream-bottomland forest

21 (1) Edge of the park (upland forest)

Spatial distribution pattern over time • Average Nearest Neighbor

• Spatial autocorrelation (Global Moran’s I)

• Hot spot analysis (Getis-Ord Gi*)

To describe how the samples distributed with respect to whether they were Geographically clustered, random or dispersed. To evaluation spatial distribution pattern of age with respect to if older or younger patches tend to be more closed to each other. To identify statistically significant spatial clusters of high values (old) and low values (young).

Average Nearest Neighbor

-3

-2

-1

0

1

2

3

4

5

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010

Z s

core

Year

clustered

dispersed

random

Spatial Autocorrelation (Moran’s I)

-2

-1

0

1

2

3

4

5

6

1994 1996 1998 2000 2002 2004 2006 2008 2010

Z s

core

Year

dispersed

clustered

random

Hot spot analysis

Spatial genetic structure - Sampling

14

24

23 24

24

24 24 24

Wooster Memorial Park

Chloroplast DNA markers • cpDNA has been used as molecular marker in landscape genetics,

phylogeography and population genetics.

• Two cpDNA markers were characterized from Demesure et al. 1995.

• trnH and trnS

• Identified haplotypes of all the samples and calculated haplotype frequencies in each site.

Haplotype distribution map - trnH

Haplotype distribution map - trnS

Haplotype at trnH distribution in WMP

Haplotype at trnS distribution in WMP

Conclusions: Implications for management

• Early detection – Where?

• Target edge habitats.

• Spatially dispersed pattern.

• Control effort – When?

• About 20 years lag phase.

• Average 19 new patches per year after lag phase.

• Spatially spread – Random.

• There is no pattern related to landscape features.

• Hot spots and cold spots formation.

Acknowledgement • Committee members:

Dr. John Cardina, Dr. Andy Michel, Dr. Charles Goebel

• Lab members:

Cathy, Jenny, Sarahi, Lourdes

• Field group:

Peter, Nick, Heather

• Park managers

• Funding is supported by OARDC SEEDS interdisciplinary grant.