Climate Change and Plant Invasions Bruce Osborne & M. Angeles Rodriguez-Tunon UCD School of Biology...
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Transcript of Climate Change and Plant Invasions Bruce Osborne & M. Angeles Rodriguez-Tunon UCD School of Biology...
Climate Change and Plant Invasions
Bruce Osborne & M. Angeles Rodriguez-Tunon
UCD School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4
Climate Change: A Complexity of Responses and Consequences
From Hellman et al., 2008; Conservation Biology 23, 534-543
Plant Invasions
• Largely speculative; no real comprehensive assessment
• Based on pre-conceived ‘expectations’-species coming from warmer areas MUST establish/increase/have greater impact!
• Predictions hardly ever community/ecosystem based
• Limited by absence of EXPERIMENTAL DATA on establishment/impacts/spread
SpeciesFallopia japonica Pteridium aquilinum
Field Microclimate SimulationsPassive Enclosures
Uninvaded (UI) And Associated Invaded (I) Areas (n=3); Installed for Duration of Growing season; continuous monitoring of microclimate inside/outside
Microclimate Simulations
Microclimatic DataAverage Maximum Values 2008
Change (+/-)
Air Temperature +3.4 °C
Soil Temperature -0.4°C (UI)
+1°C (I)
Soil Moisture Content -33%
Relative Humidity +27%
Change (+/-)
Air Temperature +3.5°C
Soil Temperature +0.34°C (UI)
+0.57°C (I)
Soil Moisture Content -41% (UI)
-21% (I)
Relative Humidity -17%
Fallopia japonica Pteridium aquilinum
All significant at p<0.001
Biomass Production
0
500
1000
1500
2000
InvadedInside
InvadedOutside
UninvadedInside
UninvadedOutside
Biom
ass
(g d
ry w
eigh
t . m
-2)
Litter
Grassland
Fallopia japonica
Fallopia japonica
Invasion: p<0.001Litter production/microclimate (invaded areas) close to significance
Biomass Production
Biomass 2007
0100200300400500600700800
InvadedInside
InvadedOutside
UninvadedInside
UninvadedOutside
Bio
mas
s (g
dry
wei
gh
t .
m-2
)Grassland
Pteridium aquilinum
Pteridium aquilinum
Biomass 2008
0100200300400500600700800
InvadedInside
InvadedOutside
UninvadedInside
UninvadedOutside
Bio
mas
s (g
dry
wei
gh
t .
m-2
)
Grassland
Pteridium aquilinum
Invasion: p<0.03Microclimate (Invaded) p<0.03Microclimate (Uninvaded) p<0.002
DecompositionLitter Bags 2008
0
10
20
30
40
50
60
Invaded Inside Invaded Outside UninvadedInside
UninvadedOutside
DO
M (
%)
0
10
20
30
40
50
60
Invaded Inside Invaded Outside UninvadedInside
UninvadedOutside
DO
M(%
)
F. japonica
P. aquilinum
Invasion: p<0.01Microclimate (Invaded): p<0.01
Mycorrhizal Inoculum PotentialBioassay with White Clover
0
10
20
30
40
50
60
70
80
2007 2008
Ro
ot
colo
niz
atio
n (
%)
Invaded Inside
Invaded Outside
Uninvaded Inside
Uninvaded Outside
0
10
20
30
40
50
60
70
80
2007 2008
Ro
ot
colo
niz
atio
n (
%)
Invaded Inside
Invaded Outside
Uninvaded Inside
Uninvaded Outside
F. japonica
P. aquilinum
Invasion: p<0.0001Microclimate (2007): p<0.001Year p<0.0001
Microclimate (2008): p< 0.0001Year p<0.002
Microarthropods2007
Fallopia japonica Pteridium aquilinum Collembola
(sp/10g soil) Oribatida (fam/10g soil)
Collembola (sp/10g soil)
Oribatida (fam/10g soil)
Totals 14 13 28 19 Invaded Inside 0.19 0.13 0.21 0.12 11.93 14.49 25.84 5.18 Invaded Outside 0.17 0.11 0.17 0.11 13.31 34.26 30.15 8.17 Uninvaded Inside 0.24 0.02 0.21 0.19 8.52 5.53 22.50 9.3 Uninvaded Outside 0.29 0.03 0.24 0.01 26.57 34.39 39.55 29.1
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
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.