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Evolutionary changes in invasive plants: Evolutionary changes in invasive plants: A competition test between invasive and native A competition test between invasive and native Jacobaea Jacobaea
vulgaris vulgaris under a specialist or a generalist herbivore pressureunder a specialist or a generalist herbivore pressure
LOGOTiantian Lin
Plant Ecology and PhytochemistryInstitute of Biology Leiden university
SIP 15, Neuchâtel
Invasive plant speciesInvasive plant species
Non-native plant species that successfully establish and
spread in the introduced range.
Only 2% of the introduced plants are becoming invasive weeds.
Biodiversity losses
Habitat degradation
and disruption
Economical losses
Human health
Invasive plant speciesInvasive plant species
Non-native plant species that successfully establish and
spread in the introduced range.
Only 2% of the introduced plants are becoming invasive weeds.
Biodiversity losses
Habitat degradati
on and disruption
Economical losses
Human health
WWhat makes them become hat makes them become invasiveinvasive??
Plant defense types
Quantitative Quantitative QualitativeQualitative
•Cheap (low concentration)
•Toxins
•Against generalists
•Specialist adapted(act as oviposition and feeding stimulant)
e.g.•Glucosinolates•Pyrrolizidine alkaloids
•Expensive (high concentration)
•Digestibility reducers
•Against generalists
•Against specialists
e.g.•Tannins•Tricoms•Hairs
Feeny 1976; Rhoades&Cates 1976
Evolutionary changes in invasive plants
cheap costlyQualitativedefense
Quantitativedefense
against SavedSaved resource resource
(nitrogen and(nitrogen and energy)energy)
against
Evolution of Increased Competitive Ability hypothesis(Blossey&Notzold, 1995; Joshi&Vrieling, 2005)Shifting Defense Hypothesis(Müller-Schärer et al. 2004; Doorduin and Vrieling 2011)
Expectations
Introduced ranges
Native ranges
Invasive Native
Study species
In the invasive areas, In the invasive areas, itit is considered as a weedy species.is considered as a weedy species.
Contains pyrrolizidine alkaloids (PAs) which are toxic to livestock and Contains pyrrolizidine alkaloids (PAs) which are toxic to livestock and human.human.
Jacobaea vulgarisJacobaea vulgaris
• Ragwort, Asteraceae family
• Monocarpic and perennial
• Native to Europe and Western Asia
• Invasive to New Zealand, Australia
and North America since 1850s
Previous studiesPrevious studies
46
136
12
Lin et al. unpublished
Growth-related traits• Photosynthesis• Dry weight • Leaf area
Regrowth-related traits• Root-shoot ratio• Inulin concentration
C/N concentration PA concentration (LC-MS)
Previous studiesPrevious studies
Lin et al. unpublished
Evolutionary changePLS-DA based on plant origins
Invasive
Native
Com
pone
nt2
23%
Component1 24%Lin et al. unpublished
Evolutionary change
Regrowth related
Growth related
Loading plot
Native
Invasive
Lin et al. unpublished
Lowerregrowth
ability
Better growthHigher PAs
Evolutionary change
Invasive plant
Does this evolutionary change Does this evolutionary change affect the competitive ability?affect the competitive ability?
Herbivores
• Specialist • Tyria jacobaeae (Cinnabar moth)
• Native to Europe and western and central Asia • Larvae feed on ragwort plants• One generation per year, appears from May to June.• Introduced into invasive ranges as a biological control
agent.
Herbivores
• Generalist • Mamestra brassicae (Cabbage moth)
• Native to Europe and Asia • larvae feed on a wide range of plant species. • 2-3 generations per year, appears from May to October
Research questions
Do the specialist herbivore decrease the competitive ability of invasive J.vulgaris?
Do invasive J.vulgaris plants have a better competitive ability in the absence of herbivores?
Do the generalist herbivore increase the competitive ability of invasive
J.vulgaris?
Experimental design
N=Native : 3 mother plants* 20 populationsI =Invasive: 3 mother plants* 20 populations
60 random pairs
Mono-culture controls
12 days of herbivory
Competition treatments
For each pair:
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
1 2 3
Total yield
Native yield
Invasive yield
Competition without herbivory
Sh
oot d
ry m
ass
(g)
Invasive 2 1 0
Native 0 1 2
*
Replacement series
43%
Herbivore consumptionS
hoot
fre
sh m
ass
cons
umpt
ion
(g)
***
*
Native
Invasive
Plant performance
0,0
0,5
1,0
1,5
2,0
2,5
3,0
1 2 3
Sh
oot d
ry m
ass
(g)
*** ***
NS43%
77%
Native
Invasive
Conclusion Q1: Do invasive J.vulgaris plants have a better competitive ability in the
absence of herbivores?
A1: Yes, invasive plants are better competitors than native genotypes without herbivores.
Conclusion Q1: Do invasive J.vulgaris plants have a better competitive ability in the
absence of herbivores?
A1: Yes, invasive plants are better competitors than native genotypes without herbivores.
Q2: Do the specialist herbivore decrease the competitive ability of invasive J.vulgaris?
A2: Yes, specialist herbivores fed more on invasive plants, which significantly decreased their competitive ability.
Conclusion Q1: Do invasive J.vulgaris plants have a better competitive ability in the
absence of herbivores?
A1: Yes, invasive plants are better competitors than native genotypes without herbivores.
Q2: Do the specialist herbivore decrease the competitive ability of invasive J.vulgaris?
A2: Yes, specialist herbivores fed more on invasive plants, which significantly decreased their competitive ability.
Q3: Do the generalist herbivore increase the competitive ability of invasive J.vulgaris?
A3: Yes, generalist herbivores fed more on native plants, which significantly increase the competitive ability of invasive plants.
Plant Ecology and Phytochemistry
Thank You
Prof. Dr. Peter G.L. Klinkhamer Prof. Dr. Peter G.L. Klinkhamer
Dr. Klaas Vrieling Dr. Klaas Vrieling
Dr. Patrick P.J. Mulder (RIKILT)Dr. Patrick P.J. Mulder (RIKILT)
Dr. Thijs L. Pons (Utrecht University)Dr. Thijs L. Pons (Utrecht University)
Rosemarie LindenberghRosemarie Lindenbergh
Georgann Rog Georgann Rog
Acknowledgment
