Transcript Natives vs. Invasives game - Springer Static Content Server

Electronic Supplementary Material for Chapter 12
Fire, Pollution and Grazing, Oh My! A Game in which Native
and Invasive Plants Compete under Multiple Disturbance
Regimes
This chapter is published as:
Schneider HE, Sweet LC. 2016. Fire, Pollution and Grazing, Oh My! A Game in which Native and Invasive Plants
Compete under Multiple Disturbance Regimes. In: Byrne L (ed) Learner-Centered Teaching Activities for
Environmental and Sustainability Studies. Springer, New York. DOI 10.1007/978-3-319-28543-6_12
Heather E. Schneider1 and Lynn C. Sweet2
1Department of Ecology, Evolution, & Marine Biology, University of California-Santa Barbara, CA USA
[email protected]
2Center for Conservation Biology, University of California, Riverside, CA USA
This file contains the following supplementary material:
 D: Presentation slides
This chapter also has the following supplementary material, available on the chapter’s website:
• A: Additional references
• B: Instructions for the game activity
• C: Case study background and vocabulary worksheet
• E: Activity cards
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Fire, pollution and grazing, oh my! A game
where natives and invasives compete for
domination under multiple disturbance
regimes
A brief introduction to native, exotic
and invasive species
From Learner-Centered Activities For Environmental and Sustainability Studies:
Lynn Sweet, PhD & Heather Schneider, PhD
2
Photo: Heather Schneider
Outline
• Ecological definitions
– Using the vocabulary handout that was filled out
for homework, share the definitions of the
ecological terms as we move through the
presentation
• Native, exotic and invasive species
– Slides and video
• Ecosystem disturbances and anthropogenic
impacts
• Game – natives vs. invasives
3
Illustration: Alejandra Martinez-Berdeja
Ecological Definitions: Levels of
Organization
• Population
– A group of organisms belonging to the same
species in the same location that can exchange
genetic material with one another for the
purposes of reproduction
• Community
– A group of organisms belonging to multiple
species (plants, animals, fungi, etc.) that occupy
the same location
4
Ecological Definitions: Levels of
Organization
• Ecosystem
– A community of organisms interacting with each
other and their abiotic environment as a system
• Ecosystem services
– The processes that promote healthy environments
and benefit humans and other organisms
– For example: nutrient cycling (supporting service),
fresh water (provisioning service), pollination
(regulating service), and recreation (cultural
service) (Millennium Ecosystem Assessment)
5
Ecological Definitions: Interactions
• Competition
– An interaction between individuals in close proximity
and are vying for the same resources resulting in a
negative outcome for at least one of the individuals
• This can also be used at a larger scale (i.e. invasive species
tend to out-compete natives)
• Facilitation
– An interaction between individuals that results in a
positive outcome for one or both of them
• Neutralism
– Plants can also have neutral interactions
6
Native Species…
• have been historically present in a specific
area and are adapted to the local
environment
• are connected to the community through
biotic and abiotic interactions (food, shelter,
nutrient cycling)
• provide valuable ecosystem services
7
Exotic species…
• are species that are not native to their current
location, but are native elsewhere and arrived as a
result of human activity.
• are not necessarily well-suited to the native
ecosystem, may not provide food or habitat for other
species and may not interact in the same way as
native plants in the ecosystem.
• are sometimes used by native species for food and
habitat, but these may be of lower quality than
native resources.
• may be relatively benign to the new environment.
8
Invasive species:
• Invasives can be either native or exotic species that establish a
reproductive population and spread to the detriment of the native
community.
• Although some native species can be invasive, many of the worst
invasives are exotic.
• These plants are often problematic because they may not provide
habitat for other species and interact differently with the local
ecosystem than local species.
• They may out-compete native species and produce mono-cultures
that reduce local biodiversity.
• Ecosystem services may be disrupted by the invasion of exotic
plant species.
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The Steps of Exotic Species Invasion
Native elsewhere
Survival in
transport
Arrive and
establish in
new location
Spread
Lag period
Establish in
new areas
Ecological &
human impact
Sakai AK et al. 2001. The population biology of invasive species. Annual Review of Ecological Systematics 32:305-332
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What are invasive plants and why should
we care?
“Weeds of Mass Destruction” Video:
https://www.youtube.com/watch?v=Q0Nk9EJpQWU&list
=PL5BRja99NkXlF5CU0TILV1IKzidCTs2Uh&index=24
Photo: Katie Ashdown; Fickr
Photo: Natalie Maynor; Fickr
Photo licenses: https://creativecommons.org/licenses/by/2.0/legalcode
Kudzu (Japanese arrowroot)
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Ecosystems: Natural Disturbances
• Naturally occurring events that can disrupt the
structure and function of an ecosystem:
– Flooding
– Fire
– Browsing
– Trampling
• Natural disturbances may be common or
infrequent, but in general, the ecosystem is
adapted to these events and some species may
require these events to survive and reproduce.
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Ecosystems: Anthropogenic
Impacts
• Impacts that are caused by humans or become
more frequent due to human activity, such as:
– Air pollution
– Increase in wildfire frequency
– Urban development
– Grazing animals (e.g. cows, sheep)
– Deforestation/habitat clearing
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Life in Balance: The Intermediate
Disturbance Hypothesis
Local species diversity is maximized when
ecological disturbance is neither too rare nor too
frequent. (Connell, 1978)
• Can you fill in the graph on the next slide, based
on the intermediate disturbance hypothesis?
• How do you think anthropogenic impacts affect
the frequency and intensity of
disturbance?
Connell, JH. 1978. Diversity in tropical rain forests and coral reefs.
Science 199: 1302-1310.
Illustration: Alejandra Martinez-Berdeja
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Intermediate Disturbance Hypothesis
Describe what
this point on
the graph
shows.
Species diversity
High
What’s
happening
here?
Why would
this happen?
Low
Frequent/high
intensity
Disturbance
Infrequent/ low
intensity
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Ecosystems: Invasion & Ecosystem
Changes
• Many invasive species are adapted to living with
frequent disturbances.
• Invasive plants may benefit from some natural
disturbances and anthropogenic impacts more
than natives:
– Nitrogen deposition (pollution, increases soil fertility)
– Wildfire
– Grazing & browsing (herbivores)
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Ecosystems: Effects of Invasion
• Invasive plants may cause changes to ecosystems
and communities by:
– Increasing wildfire frequency
– Affecting erosion and soil movement
• Increasing erosion if root structure is not as strong as natives
• Stabilizing sand dunes that would otherwise be mobile if
roots are strong and vegetation is persistent
– Potentially increase browsing pressure on natives by
attracting different herbivores
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Winners and Losers
• Post-disturbance, species survive and reproduce
differently depending on their particular
adaptations.
• Population size may increase or decrease
following ecosystem change.
– For example, a native species may require spring
flooding for seed dispersal.
– An invasive species may also use the flooding event to
spread.
– A different native species may not tolerate flooding,
due to overly saturated soil, and may become less
common in an area that sees an increase in flooding
frequency or intensity.
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Activity: Natives Battle Invasives!
• We will investigate the dynamic responses of native
and invasive populations to disturbances and
anthropogenic impacts within a plant community.
• For the activity, we will define plant species responses
in two simple ways:
– Responding positively to a disturbance:
– Responding negatively to a disturbance:
+
• We will also use the concept of fertility (number of
offspring produced). + signs indicate how many more
plants are produced during each cycle of the game.
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Natives Battle Invasives
• Each student will receive a their species
identity card and line up to be part of the
ecosystem, invasives in one line, natives in
another.
• The instructor will call out a disturbance or
event.
• Check out your plant’s response to the
disturbance or event:
– If you have a - , sit down. If you have a +, remain
standing.
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Natives Battle Invasives!
Native Plants:
Purple needlegrass
California poppy
Elegant clarkia
Valley oak
Invasive Plants:
Black mustard
Ripgut brome
Fennel
Redstem filaree
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Illustration: Alejandra Martinez-Berdeja
Natives Battle Invasives!
Events:
– Nitrogen deposition
– Fire
– Habitat clearing
– Two-year drought
– Managed grazing
– Reproduce!
– Competition Questions!
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EXAMPLE SPECIES CARD
Native Plant: CALIFORNIA POPPY
(Eschscholzia californica)
Nitrogen deposition +
Fire +
Managed grazing +
Two-year drought +
Habitat clearing Reproduce! ++
Heather Schneider
Heather Schneider
Heather Schneider
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Data Collection: Species Composition
Optional Scorecard
Record the number of native individuals and invasive individuals still standing at the end of each round
OR use the editable charts on slides 26-27.
REGIME 1: Natural Ecosystem/Intermediate Disturbance
T0
1
2 3 4
5
6
7
8
9
10
11
REGIME 2: Anthropogenic Effects and Increased Disturbance
T0
1
2 3 4
5
6
7
8
9 10
11
Natives
Invasives
T0 = initial numbers
Natives
Invasives
24
Data Collection: Species Composition
Optional Scorecard
Record the number of native individuals and invasive individuals still standing at the end of each round
OR use the editable charts on slides 26-27.
Optional Additional Round 3
T0
1
2 3
4
5
6
7
8
9
10
11
4
5
6
7
8
9
10
11
Natives
Invasives
T0 = initial numbers
Optional Additional Round 4
T0
1
2 3
Natives
Invasives
25
Data Collection: Species Composition
Optional CHART
Record the number of native individuals and invasive individuals still standing at the end of each round.
TO FILL IN THE CHART: Right-click (Mac ctrl-click) on the plot area and choose “edit data”
REGIME 1: Natural Ecosystem/Intermediate Disturbance
# Individuals
1.5
1
NATIVES
0.5
INVASIVES
0
T0 1 2 3 4 5 6 7 8 9 10 11
T0 = initial number
Time Step
REGIME 2: Anthropogenic Effects and Increased Disturbance
# Individuals
1.5
1
NATIVES
0.5
INVASIVES
0
T0 1 2 3 4 5 6 7 8 9 10 11
Time Step
26
Data Collection: Species Composition
Optional CHART
Record the number of native individuals and invasive individuals still standing at the end of each round.
TO FILL IN THE CHART: Right-click (Mac ctrl-click) on the plot area and choose “edit data”
Optional Additional Round 3
# Individuals
1.5
1
NATIVES
0.5
INVASIVES
0
T0 1 2 3 4 5 6 7 8 9 10 11
Time Step
T0 = initial number
Optional Additional Round 4
# Individuals
1.5
1
NATIVES
0.5
INVASIVES
0
T0 1 2 3 4 5 6 7 8 9 10 11
Time Step
27
Questions for Discussion
• Describe the changes in the populations of native
and invasive plants over the course of the game.
• Which disturbance seemed to benefit the
invasive species the most? Did any disturbance
benefit native plants more than invasive plants?
• What are the main differences between the
biology and ecology of the invasives versus the
natives?
• Can we make any generalizations about whether
disturbances are “good” or “bad” for native
communities? … Is this always the case?
• Do you think that ecosystem services might be
changed with disturbance?
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