Factors |
Research questions: |
Proposed
methods: |
Model accuracy
|
What is the accuracy of the model developed in this review when applied
to additional invasive species?
Specific challenges:
How can we identify a larger array of pathogens on invaders including
low impact pathogens to improve the model?
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Enhance reporting of pathogens on invasive species by including these
data in invasive species monitoring databases. Experimentally test the
impacts of different known pathogens on invaders with a range of traits,
specifically controlling for pathogen traits as well as inoculation
rates to better control for pathogen virulence.
Isolate microbial taxa from these plant species. Identify potential
pathogens and use these to re-infect plants to determine the impacts of
native pathogens.
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Plant traits
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What are the mechanisms driving differences in pathogen susceptibility
with plant traits?
Specific challenges:
Do native and invasive plants differ in SAR or defense priming?
How do EM, AM, and non-mycorrhizal invaders differ in their response to
pathogens both above- and belowground?
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Decouple differences in correlated traits, for example, by testing
disease susceptibility in genetically distinct populations of an
invader.
Compare across congeneric sets of native, non-native, and invasive
plants.
Expose invaders with different mycorrhiza status to a range of potential
pathogens.
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Pathogen traits |
What kinds of pathogens are most likely to cause
invader decline? |
Collect data on pathogen traits and apply a similar
model as developed for plant traits here to determine the most
influential pathogen traits. |
Context dependence
|
How does incorporating context dependence improve the model?
Specific challenges:
How do plant/pathogen traits interact with environmental/abiotic
conditions to influence disease susceptibility?
How do inherent differences in plant tissue nutrient concentrations
interact with environmental and habitat differences in nutrient
availability?
|
Collect data on aspects of context dependence discussed previously and
re-evaluate the model.
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Pathogen/plant trait interactions
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How do pathogen traits interact with plant traits to determine species
combinations that will result in invader decline?
Specific challenges:
To what extent do allelopathic defense compounds affect pathogens with
different traits?
Does the type of pathogen influence whether annual species are less/more
susceptible to pathogens than perennials?
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Combine models with pathogen traits and plant traits to determine
interactions.
Conduct bioassays using extracts from invasive plants comparing
different pathogens such as generalists and specialists.
Expose annual and perennial plants with a range of other traits to
different types of pathogens (e.g. generalists vs. specialists).
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Residence time
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How do invader pathogen interactions change over time?
Specific challenges:
How long is a “weapon” of an invasive species “novel”? I.e. How long
does it take for pathogens to evolve resistance to allelopathic
chemicals of invaders in the novel range?
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Survey pathogen impacts on populations of invaders across different
residence times.
Conduct bioassays using extracts from invasive plants collected along
temporal gradients in invader residence time.
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