4)Impacts. Some observations: Measuring impact is complex What should be measured and how?
-
date post
21-Dec-2015 -
Category
Documents
-
view
215 -
download
1
Transcript of 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?
![Page 1: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/1.jpg)
4) Impacts
![Page 2: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/2.jpg)
4) Impacts
Some observations:• Measuring impact is complex
What should be measured and how?
![Page 3: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/3.jpg)
4) Impacts
Some observations:• Measuring impact is complex
What should be measured and how?For individual plant, individual species, or multiple species?
![Page 4: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/4.jpg)
4) Impacts
Some observations:• Measuring impact is complex
What should be measured and how?For individual plant, individual species, or multiple species?Over what time frame?
![Page 5: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/5.jpg)
4) Impacts
Some observations:• Measuring impact is complex• Lack of comprehensive data
![Page 6: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/6.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect different community & ecosystem
processes
![Page 7: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/7.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availability
![Page 8: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/8.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availabilityPrimary productivity
![Page 9: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/9.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availabilityPrimary productivityDisturbance regimes
![Page 10: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/10.jpg)
4) Impactsa) Ecological
Conceptual model: From Walker & Smith in Lukens & Thieret (1997)• Invasive species affect:
Nutrient & water availabilityPrimary productivityDisturbance regimesCommunity dynamics
![Page 11: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/11.jpg)
i) Species replacement• Direct competition From Sherer-Lorenzen in Mooney & Hobbs
(2000)Moist, nutrient rich, disturbed sites in central Europe
4) Impactsa) Ecological
![Page 12: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/12.jpg)
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)4) Impactsa) Ecological
![Page 13: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/13.jpg)
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)4) Impactsa) Ecological
![Page 14: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/14.jpg)
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
4) Impactsa) Ecological
![Page 15: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/15.jpg)
i) Species replacement• Direct competition• Large scale species displacements
From Alvarez & Cushman (2002)Cape ivy invading coastal habitatsDecreases species richness for
natives (36%)
4) Impactsa) Ecological
![Page 16: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/16.jpg)
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%)
4) Impactsa) Ecological
![Page 17: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/17.jpg)
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%)
4) Impactsa) Ecological
![Page 18: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/18.jpg)
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
4) Impactsa) Ecological
![Page 19: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/19.jpg)
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
4) Impactsa) Ecological
![Page 20: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/20.jpg)
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
4) Impactsa) Ecological
![Page 21: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/21.jpg)
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%)
4) Impactsa) Ecological
![Page 22: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/22.jpg)
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%)
4) Impactsa) Ecological
![Page 23: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/23.jpg)
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%)
4) Impactsa) Ecological
![Page 24: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/24.jpg)
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)
4) Impactsa) Ecological
![Page 25: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/25.jpg)
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
4) Impactsa) Ecological
![Page 26: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/26.jpg)
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
4) Impactsa) Ecological
![Page 27: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/27.jpg)
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?
4) Impactsa) Ecological
![Page 28: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/28.jpg)
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
4) Impactsa) Ecological
![Page 29: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/29.jpg)
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
4) Impactsa) Ecological
![Page 30: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/30.jpg)
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
4) Impactsa) Ecological
![Page 31: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/31.jpg)
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
4) Impactsa) Ecological
![Page 32: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/32.jpg)
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
4) Impactsa) Ecological
![Page 33: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/33.jpg)
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
4) Impactsa) Ecological
![Page 34: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/34.jpg)
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
4) Impactsa) Ecological
![Page 35: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/35.jpg)
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
4) Impactsa) Ecological
![Page 36: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/36.jpg)
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
4) Impactsa) Ecological
![Page 37: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/37.jpg)
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
4) Impactsa) Ecological
![Page 38: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/38.jpg)
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
4) Impactsa) Ecological
![Page 39: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/39.jpg)
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
4) Impactsa) Ecological
![Page 40: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/40.jpg)
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
4) Impactsa) Ecological
![Page 41: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/41.jpg)
ii) Ecosystem functions• Overview
From Walker & Smith in Lukens & Thieret (1997)
Summarized: Typical effects of invasive on specific processes
4) Impactsa) Ecological
![Page 42: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/42.jpg)
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
4) Impactsa) Ecological
![Page 43: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/43.jpg)
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
4) Impactsa) Ecological
![Page 44: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/44.jpg)
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
4) Impactsa) Ecological
![Page 45: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/45.jpg)
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
4) Impactsa) Ecological
![Page 46: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/46.jpg)
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
4) Impactsa) Ecological
![Page 47: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/47.jpg)
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
4) Impactsa) Ecological
![Page 48: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/48.jpg)
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
4) Impactsa) Ecological
![Page 49: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/49.jpg)
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)
4) Impactsa) Ecological
![Page 50: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/50.jpg)
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
4) Impactsa) Ecological
![Page 51: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/51.jpg)
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
4) Impactsa) Ecological
![Page 52: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/52.jpg)
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)
4) Impactsa) Ecological
![Page 53: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/53.jpg)
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
4) Impactsa) Ecological
![Page 54: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/54.jpg)
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
4) Impactsa) Ecological
![Page 55: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/55.jpg)
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
4) Impactsa) Ecological
![Page 56: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/56.jpg)
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 flowsLB = Lower Byron; high density of Myrica for >10 yearsUB = Upper Byron; kept free of Myrica
>
>
4) Impactsa) Ecological
![Page 57: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/57.jpg)
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
>
>
4) Impactsa) Ecological
![Page 58: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/58.jpg)
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
4) Impactsa) Ecological
![Page 59: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/59.jpg)
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)
4) Impactsa) Ecological
![Page 60: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/60.jpg)
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%)
4) Impactsa) Ecological
![Page 61: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/61.jpg)
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
4) Impactsa) Ecological
![Page 62: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/62.jpg)
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%)
4) Impactsa) Ecological
![Page 63: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/63.jpg)
ii) Ecosystem functions• Overview• Specific examples: General compilation
From Crooks (2002)
4) Impactsa) Ecological
![Page 64: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/64.jpg)
ii) Ecosystem functions• Overview• Specific examples
From Crooks (2002)
Ecosystem engineers:• Alter ecosystem physical processes (water use, N cycling) • Change habitat structure (more complexity, less complexity)• Effects cascade through community
4) Impactsa) Ecological
![Page 65: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/65.jpg)
iii) Threatened & endangered species• Overview
~400 of 958 federally listed species (~42%) are because of invasives (includes plants plus other organisms)
4) Impactsa) Ecological
![Page 66: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/66.jpg)
iii) Threatened & endangered species• Overview
~42% are because of invasivesEffects can be by:
Direct species replacementIndirect through effects on community structure or function
4) Impactsa) Ecological
![Page 67: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/67.jpg)
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
4) Impactsa) Ecological
![Page 68: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/68.jpg)
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)
4) Impactsa) Ecological
![Page 69: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/69.jpg)
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)
4) Impactsa) Ecological
![Page 70: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/70.jpg)
iii) Threatened & endangered species• Overview• Specific examples: Hawaii
80-90 native plant species extinct270 plant species listed as threatened or endangered
4) Impactsa) Ecological
![Page 71: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/71.jpg)
Summary• Ecological impacts typically involve: (1) nutrients/water flow; (2)
primary production impacts; (3) alterations of disturbance regimes; and (4) changes in community dynamics
4) Impactsa) Ecological
![Page 72: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/72.jpg)
Summary• 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)
4) Impactsa) Ecological
![Page 73: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/73.jpg)
Summary• 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)
4) Impactsa) Ecological
![Page 74: 4)Impacts. Some observations: Measuring impact is complex What should be measured and how?](https://reader037.fdocuments.us/reader037/viewer/2022103123/56649d595503460f94a38dce/html5/thumbnails/74.jpg)
Summary• 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)
4) Impactsa) Ecological