Climate Change and Plant Invasions

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Climate Change and Plant Invasions

• Bruce Osborne M. Angeles Rodriguez-Tunon
• UCD School of Biology and Environmental Science,
  University College Dublin, Belfield, Dublin 4

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Climate Change A Complexity of Responses and
Consequences

From Hellman et al., 2008 Conservation Biology
23, 534-543
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Plant Invasions

• Largely speculative no real comprehensive
  assessment
• Based on pre-conceived expectations-species
  coming from warmer areas MUST establish/increase/h
  ave greater impact!
• Predictions hardly ever community/ecosystem
  based
• Limited by absence of EXPERIMENTAL DATA on
  establishment/impacts/spread

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Species
Fallopia japonica
Pteridium aquilinum
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Field Microclimate SimulationsPassive Enclosures
Uninvaded (UI) And Associated Invaded (I) Areas
(n3) Installed for Duration of Growing season
continuous monitoring of microclimate
inside/outside
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Microclimate Simulations
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Microclimatic DataAverage Maximum Values 2008
Fallopia japonica
Pteridium aquilinum
All significant at plt0.001
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Biomass Production
Fallopia japonica
Invasion plt0.001 Litter production/microclimate
(invaded areas) close to significance
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Biomass Production
Pteridium aquilinum
Invasion plt0.03 Microclimate (Invaded)
plt0.03 Microclimate (Uninvaded) plt0.002
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DecompositionLitter Bags 2008
F. japonica
P. aquilinum
Invasion plt0.01 Microclimate (Invaded) plt0.01
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Mycorrhizal Inoculum PotentialBioassay with
White Clover
F. japonica
Invasion plt0.0001 Microclimate (2007)
plt0.001 Year plt0.0001
P. aquilinum
Microclimate (2008) plt 0.0001 Year plt0.002
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Microarthropods2007
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Summary

• Impacts of microclimate simulations
  species/site/ecosystem/year-dependent
• Simulations can decrease/cause no change in
  productivity, but RELATIVE performance of invader
  can increase at ECOSYSTEM scale
• Emphasizes the importance of ecosystem-level
  analyses at a range of locations
• Effects can be rapid-decomposition, mycorrhizal
  inoculum potential

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Acknowledgements

• We thank the support of the EPA through the
  BIOCHANGE project, the UCD Plant Ecophysiology
  group and Eugene Sherry, Ingrid Arts, Maria Long
  and Ralph Twomey for support. We also thank the
  landowners for access to sites, and the NPWS and
  Co. Clare Heritage Officers for assistance.