4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive...
-
date post
22-Dec-2015 -
Category
Documents
-
view
213 -
download
0
Transcript of 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive...
![Page 1: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/1.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availability
![Page 2: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/2.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availabilityPrimary productivity
![Page 3: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/3.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availabilityPrimary productivityDisturbance regimes
![Page 4: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/4.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availabilityPrimary productivityDisturbance regimesCommunity dynamics
![Page 5: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/5.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition From Sherer-Lorenzen in Mooney & Hobbs
(2000)Moist, nutrient rich, disturbed sites in central Europe
![Page 6: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/6.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition From Sherer-
Lorenzen in Mooney & Hobbs (2000)Moist, nutrient rich, disturbed
sites in central EuropeTypically dominated by native
herb Urtica dioica (stinging nettle)
Helianthus tuberosus (Jerusalem artichoke) invading
Urtica (native)Helianthus (invasive)
![Page 7: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/7.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition From Sherer-
Lorenzen in Mooney & Hobbs (2000)Moist, nutrient rich, disturbed
sites in central EuropeTypically dominated by native herb
Urtica dioica (stinging nettle)Helianthus tuberosus (Jerusalem
artichoke) invadingHelianthus undermines and
outshades Urtica, displacing it
Urtica (native)Helianthus (invasive)
![Page 8: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/8.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002) Ecological Applications 12:1434-14443 coastal habitats in SF Bay AreaInvasive = Delairea odorata (Cape
ivy) evergreen vine native to South Africa
![Page 9: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/9.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsDecreases species richness for
natives (36%)
![Page 10: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/10.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsDecreases species richness for
natives & non-natives (37%)
![Page 11: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/11.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsDecreases species richness for
natives & non-natives and species diversity (31%)
![Page 12: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/12.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002) Cape ivy invading coastal habitatsFewer native & non-native speciesDecreases occur across all habitat
types
![Page 13: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/13.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsFewer native & non-native species
across all habitats and for all plant life forms
![Page 14: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/14.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsFewer native & non-native speciesExperimentally removed Cape ivy:
Control = no removalDisturbance = insert pitchfork
into soil to simulate soil disturbance that accompanies plant removal
Reduction = hand weeded Cape ivy
![Page 15: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/15.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsFewer native & non-native speciesExperimentally removed Cape ivy:
Natives richness ↑ (10%)
![Page 16: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/16.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002) Cape ivy invading coastal habitatsFewer native & non-native speciesExperimentally removed Cape ivy:
Natives richness ↑ (10%)Non-natives richness ↑ (43%)
![Page 17: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/17.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsFewer native & non-native speciesExperimentally removed Cape ivy:
Natives richness ↑ (10%)Non-natives richness ↑ (43%)Diversity ↑ (32%)
![Page 18: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/18.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsFewer native & non-native speciesExperimentally removed Cape ivy:
Other species recover,especially forbs (other life
forms NS)
![Page 19: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/19.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors
From D’Antonio et al. (2000) Austral Ecology 25: 507-522Series of 14 study sites (#’s) from eastern coastal lowlands to
seasonal submontane zone on Big Island, Hawaii
![Page 20: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/20.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors
From D’Antonio et al. (2000)Series of 14 study sites (#’s) from eastern coastal lowlands to
seasonal submontane zone on Big Island, HawaiiLowlands: warm tropical zone with 1500-2000 mm yr-1, but dry
summers; elevation from sea level to 400 mSubmontane: several °C cooler, but similar amount and
seasonality of precipitation; 400 – 1200 m elevation
![Page 21: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/21.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors
From D’Antonio et al. (2000)Series of 14 study sites (#’s) from eastern coastal lowlands to
seasonal submontane zone on Big Island, HawaiiLowlands: warm tropical zone with 1500-2000 mm yr-1, but dry
summers; elevation from sea level to 400 mSubmontane: several °C cooler, but similar amount and seasonality
of precipitation; 400 – 1200 m elevationIn both zones, fires occur; most ignited by lava or by humansDo fires consistently favor invasives across this elevational
gradient?
![Page 22: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/22.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Measured cover of native species
![Page 23: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/23.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Measured cover of native and exotic species
![Page 24: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/24.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Measured cover of native and exotic species in adjacent
unburned
![Page 25: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/25.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Measured cover of native and exotic species in adjacent
unburned and burned sites along gradient
![Page 26: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/26.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Measured cover of native and exotic species in adjacent
unburned and burned sites along gradient
Indi
vidu
al s
ites
![Page 27: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/27.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?For seasonal submontane:
For 26 of 35 (74%) occurrences, native had ↓ cover in burned areas
Indi
vidu
al s
ites
![Page 28: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/28.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?For seasonal submontane:
For 26 of 35 (74%) occurrences, native had ↓ cover in burned areas
For 28 of 41 (68%) occurrences, exotics had ↑ cover
Indi
vidu
al s
ites
![Page 29: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/29.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Submontane: Many natives ↓ & many exotics ↑ with fire
Indi
vidu
al s
ites
![Page 30: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/30.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Submontane: Many natives ↓ & many exotics ↑ with fireFor coastal lowlands:
14 of 26 (54%) natives ↓6 of 29 (29%) of exotics ↑
Indi
vidu
al s
ites
![Page 31: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/31.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Submontane: Many natives ↓ & many exotics ↑ with fireLowlands: Fewer natives ↓ & fewer exotics ↑ with fire
Indi
vidu
al s
ites
![Page 32: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/32.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Yes, but not uniformly
Indi
vidu
al s
ites
![Page 33: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/33.jpg)
3) Impactsa) Ecological
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Yes, but not uniformlyNot due to differences in rainfall amount or seasonality
Indi
vidu
al s
ites
![Page 34: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/34.jpg)
3) Impactsa) Ecological
Indi
vidu
al s
ites
i) Species replacement• Direct competition• Large scale species displacements• Interacting factors From D’Antonio et al. (2000)
Do fires favor invasives across elevational gradient?Yes, but not uniformlyNot due to differences in rainfall amount or seasonalityAppears to be due to differences in native species
composition: some of the species in coastal lowlands appear to be fire tolerant
![Page 35: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/35.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview
From Walker & Smith in Lukens & Thieret (1997)
Summarized: Typical effects of invasive on specific processes
![Page 36: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/36.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview
From Walker & Smith in Lukens & Thieret (1997)
Summarized: Typical effects of invasive on specific processesAnd how this change on a specific process then feeds back and affects community function or structure
![Page 37: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/37.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview
From Walker & Smith in Lukens & Thieret (1997)
Summarized: Typical effects of invasive on specific processesAnd how this change on a specific process then feeds back and affects community function or structure
![Page 38: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/38.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview
From Walker & Smith in Lukens & Thieret (1997)
Summarized: Typical effects of invasive on specific processesAnd how this change on a specific process then feeds back and affects community function or structure
![Page 39: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/39.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview
From Walker & Smith in Lukens & Thieret (1997)
Summarized: Typical effects of invasive on specific processesAnd how this change on a specific process then feeds back and affects community function or structure
![Page 40: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/40.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002) Nature 418:623-626Woody plant invasion into grasslands thought to increase
amount of C storedIf so, then woody plant invasions are good for C sequestration
![Page 41: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/41.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002)Does woody plant invasion increase C sequestration?Examined 6 sites along precipitation gradient (200 – 1100 mm)
![Page 42: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/42.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002)Does woody plant invasion increase C sequestration?Examined 6 sites along precipitation gradient (200 – 1100 mm)
that had similar age of woody plant invasion
![Page 43: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/43.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002)Does woody plant invasion increase C sequestration?Sites along precipitation gradientMeasured total soil organic carbon
in soil profileCalculated total soil organic C for
0-3 m depth for both grass &invaded sites
![Page 44: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/44.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002)Does woody plant invasion increase C sequestration?Sites along precipitation gradientPlot proportion of total soil organic C
in woody invaded / grass(>1 means more SOC in woody)
![Page 45: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/45.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002)Does woody plant invasion increase C sequestration?Sites along precipitation gradientPlot proportion of total soil organic C
in woody invaded / grassvs. precipitation
![Page 46: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/46.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Ecosystem C storage
From Jackson et al. (2002)Does woody plant invasion increase C sequestration?
Contrary to expectations, ↑ onlyfor dry sites
As precipitation ↑, get less SOCin woody invaded areas
![Page 47: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/47.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Soil N change
From Vitousek & Walker (1989) Ecological Monographs 59:247-265Myrica faya small evergreen tree native to Canary Islands &
other islands in North Atlantic OceanActinorhizal N-fixerBrought to Hawaii, where is invading young lava flows that
had been dominated by natives
![Page 48: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/48.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Soil N change
From Vitousek & Walker (1989)Exotic Myrica faya, actinorhizal N-fixer, greatly ↑ annual N
input into young lava flows
>
>
![Page 49: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/49.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific example: Soil N change
From Vitousek & Walker (1989)Exotic Myrica faya, actinorhizal N-fixer, greatly ↑ annual N
input into young lava flowsHigh N facilitates the invasion of other exotic plants
>
>
![Page 50: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/50.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific examples: Fire effects
From D’Antonio in Mooney & Hobbs (2002)Compiled 20 examples from around the world where invaders
have altered fire regimes
![Page 51: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/51.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific examples: Fire effects
From D’Antonio in Mooney & Hobbs (2002)20 examples where invaders have altered fire regimesMajority involve perennial grasses (13 of 20 = 65%)
4 (20%) involve annual grasses – All are in arid WestOther 3 are trees / shrubs (Florida, South Africa)
![Page 52: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/52.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific examples: Fire effects
From D’Antonio in Mooney & Hobbs (2002)20 examples where invaders have altered fire regimesMajority involve perennial grasses (13 of 20 = 65%)
4 (20%) involve annual grasses – All are in arid WestOther 3 are trees / shrubs (Florida, South Africa)
Majority of invaders represent new life form (14 of 20 = 70%)
![Page 53: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/53.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific examples: Fire effects
From D’Antonio in Mooney & Hobbs (2002)20 examples where invaders have altered fire regimesMajority involve perennial grasses (13 of 20 = 65%)
4 (20%) involve annual grasses – All are in arid WestOther 3 are trees / shrubs (Florida, South Africa)
Majority of invaders represent new life form (14 of 20 = 70%)Majority ↑ fire frequency (14; 70%)
Only 2 (10%) ↓ frequency
![Page 54: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/54.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific examples: Fire effects
From D’Antonio in Mooney & Hobbs (2002)20 examples where invaders have altered fire regimesMajority involve perennial grasses (13 of 20 = 65%)
4 (20%) involve annual grasses – All are in arid WestOther 3 are trees / shrubs (Florida, South Africa)
Majority of invaders represent new life form (14 of 20 = 70%)Majority ↑ fire frequency (14; 70%)
Only 2 (10%) ↓ frequencyMajority ↑ fire size or intensity (11; 55%)
![Page 55: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/55.jpg)
3) Impactsa) Ecological
ii) Ecosystem functions• Overview• Specific examples: General compilation
From Crooks (2002)
![Page 56: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/56.jpg)
3) Impactsa) Ecological
iii) Threatened & endangered species• Overview
~400 of 958 federally listed species (~42%) are because of invasives (includes plants plus other organisms)
![Page 57: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/57.jpg)
3) Impactsa) Ecological
iii) Threatened & endangered species• Overview
~42% are because of invasivesEffects can be by:
Direct species replacementIndirect through effects on community structure or function
![Page 58: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/58.jpg)
3) Impactsa) Ecological
iii) Threatened & endangered species• Overview• Specific examples: King Ranch bluestem
Bothriochloa ischaemum (Caucasian bluestem) brought in to southern Great Plains (NM, OK, TX) from Russia in 1929
C4 perennial bunchgrass:establishes readily from seedlong growing seasontolerates heavy grazingfair forage qualityforms dense sod in mature pastures
![Page 59: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/59.jpg)
3) Impactsa) Ecological
iii) Threatened & endangered species• Overview• Specific examples: King Ranch bluestem
Bothriochloa ischaemum (Caucasian bluestem) brought in to southern Great Plains (NM, OK, TX) from Russia in 1929
C4 perennial bunchgrass: desirable forage speciesSeeded extensively (for example, ~2 million acres in western
OK)
![Page 60: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/60.jpg)
3) Impactsa) Ecological
iii) Threatened & endangered species• Overview• Specific examples: King Ranch bluestem
Bothriochloa ischaemum (Caucasian bluestem) brought in to southern Great Plains (NM, OK, TX) from Russia in 1929
C4 perennial bunchgrass: desirable forage speciesSeeded extensivelyBut extremely invasive:
Spread along highways into native areas (cemetaries, native grasslands)
Difficult to controlThreatens federally listed endangered plant Ambrosia
cheiranthefolia (south Texas ambrosia)
![Page 61: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/61.jpg)
3) Impactsa) Ecological
iii) Threatened & endangered species• Overview• Specific examples: Hawaii
80-90 native plant species extinct270 plant species listed as threatened or endangered
![Page 62: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/62.jpg)
3) Impactsa) Ecological
Summary• Only a small percentage (0.1%) of introduced plants become a
problem
![Page 63: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/63.jpg)
3) Impactsa) Ecological
Summary• Only a small percentage (0.1%) of introduced plants become a
problem• Ecological impacts typically involve: (1) nutrients/water flow; (2)
primary production impacts; (3) alterations of disturbance regimes; and (4) changes in community dynamics
![Page 64: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/64.jpg)
3) Impactsa) Ecological
Summary• Only a small percentage (0.1%) of introduced plants become a
problem• Ecological impacts typically involve: (1) nutrients/water flow; (2)
primary production impacts; (3) alterations of disturbance regimes; and (4) changes in community dynamics
• Effects observed as:Species replacements (direct/individual or large scale, w/ or
w/o interactions with other factors such as fire)
![Page 65: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/65.jpg)
3) Impactsa) Ecological
Summary• Only a small percentage (0.1%) of introduced plants become a
problem• Ecological impacts typically involve: (1) nutrients/water flow; (2)
primary production impacts; (3) alterations of disturbance regimes; and (4) changes in community dynamics
• Effects observed as:Species replacements (direct/individual or large scale, w/ or w/o
interactions with other factors such as fire)Ecosystem functions (C sequestration, N fixation, fire
frequency/intensity)
![Page 66: 4)Impacts a)Ecological Conceptual model: From Walker & Smith in Lukens & Thieret (1997) Invasive species affect: Nutrient & water availability.](https://reader038.fdocuments.in/reader038/viewer/2022110323/56649d7f5503460f94a63215/html5/thumbnails/66.jpg)
3) Impactsa) Ecological
Summary• Only a small percentage (0.1%) of introduced plants become a
problem• Ecological impacts typically involve: (1) nutrients/water flow; (2)
primary production impacts; (3) alterations of disturbance regimes; and (4) changes in community dynamics
• Effects observed as:Species replacements (direct/individual or large scale, w/ or w/o
interactions with other factors such as fire)Ecosystem functions (C sequestration, N fixation, fire
frequency/intensity)Complete or nearly complete loss of native species
(threatened or endangered species)