Species Invasions

1
Species Invasions
Photo of the Panama Canal from www.pancanal.com
2
Native and non-native species
Native (indigenous) a group of organisms that
came to be found in a given place by natural
causes
Non-native (exotic, introduced, non-indigenous)
a group of organisms that came to be found in a
given place by anthropogenic causes
Wild Turkey Native to N. Am. (e.g., LA)
Common Pheasant Native to Asia Introduced to N.
Am. (e.g., LA)
Domestic Chicken Wild progenitor Red
Junglefowl, native to Asia Domesticated
introduced to N. Am. (e.g., LA)
Photos from Wikipedia
3
Native and non-native species
Range expansion natural process whereby a
species immigrates into a given place that was
previouslyunoccupied by that species
Cattle Egret Original range western Europe,
plains of Africa, tropical subtropical
Asia Flew across Atlantic to north- eastern
South America 1877 Arrived in FL 1941
First bred in FL 1953 First bred in Canada
1962
Considered native to N. Am. (e.g., LA)
Photo from Wikipedia
4
Native and non-native species
Re-introduction anthropogenic placement of a
species into a given place that was
previouslyoccupied by that species
American bison subsp. Plains bison Original range
plains, prairies savannas of N. Am. (incl.
LA)
There may not be sufficient appropriate habitat
available in LA to re-introduce American bison
Photo from Wikipedia
5
Invasive species
Your textbooks definition Introduced
species More commonly used definition An
introduced species that establishes, expands its
range, and has an appreciable impact on native
organisms ecosystems
We dont normally consider these two
introduced species to be invasive
Domestic Chicken Wild progenitor Red
Junglefowl, native to Asia Domesticated
introduced to N. Am. (e.g., LA)
Common Pheasant Native to Asia Introduced to N.
Am. (e.g., LA)
6
Invasive species
Your textbooks definition Introduced
species More commonly used definition An
introduced species that establishes, expands its
range, and has an appreciable impact on native
organisms ecosystems
Buts cats often become devastatingly invasive
when feral
7
Pairwise species interactions
Influence of species A
- (negative)
(positive)
0 (neutral/null)
-
Influence of Species B
0

From Abrahamson (1989) Morin (1999), pg. 21
8
Invasive species, examples
Parasites (disease organisms other microbes)
e.g., HIV
25 million human deaths since it was first
recognized in 1981 0.6 of humans infected
(40.5 million)
Native to western Africa Introduced globally
Scanning electron micrograph of virus particles
(green) and lymphocyte from Wikipedia
9
Invasive species, examples
Competitors e.g., Eurasian zebra mussel
U.S. Coast Guard estimates economic losses and
control efforts cost 5 billion annually in
the U.S. Outcompetes native mollusks
Native to Russia Introduced to N. Am., etc.
Photographs of color morphs from Wikipedia
10
Invasive species, examples
Predators e.g., brown tree snake on Guam
9 of the islands 11 native forest-dwelling bird
species are now extirpated (extinct on Guam)
Native to southeast Asia Introduced to Guam
Image from http//www.fort.usgs.gov/Resources/Educ
ation/BTS (see this Web page for more info.)
11
Organisms with large impact
Foundation species a species that defines much
of the structure of a community (Dayton 1971)
Photo of bamboo forest from Wikipedia
12
Organisms with large impact
Keystone predator helps maintain diversity by
reducing opportunities for competitive exclusion
(Paine 1966)
Keystone resource helps maintain diversity by
providing food to many species, especially during
lean times (Terborgh 1986)
Photo of Pisaster starfish from
www.royalbcmuseum.bc.ca
Photo of barbet feeding on figs from Wikipedia
13
Organisms with large impact
Ecosystem engineer creates or significantly
modifies habitats (Jones et al. 1994, 1997)
Allogenic (physical modifications through their
activities) Autogenic (modifications through the
presence of their biomass)
Photo of beaver from Wikipedia Map of North
American native range from www.icwdm.org Map of
Tierra del Fuego (introduced range) from
www.student.britannica.com
14
Impacts of Non-native Species
Impact Range x Abundance x per-capita Effect I
R x A x E (Parker et al. 1999)
Photo of beaver from Wikipedia Map of North
American native range from www.icwdm.org Map of
Tierra del Fuego (introduced range) from
www.student.britannica.com
15
Impacts of Non-native Species
Direct and indirect effects


Ecological and evolutionary effects


Consider the potential evolutionary consequences
of reduced daytime predation on mosquito
behavior, e.g., increased daytime activity


Mosquitoes
Photos from Wikipedia
16
Scale of Biological Invasions
North American plains and prairies 11 of plant
spp.
Hawaii 35 of plant spp.
Successful invaders in San Francisco Bay 1
marine sp. every 14 wk (1961 to 1995)
Rate of introduction of crustracean zooplankton
into Great Lakes region 50,000 times background
natural immigration rate
San Francisco Bay Great Lakes illustrate that
the rates are (much) higher than natural rates
Refs. White et al. (2000) Pimentel et al.
(2000) Cohen Carlton (1998) Hebert
Cristescu (2002)
17
How are species introduced?
Intentional agriculture, hunting, fishing,
ornamental, etc.
Unintentional transport (airplanes, ships,
cars, shoes, etc.), escaped pets, etc.
Photo of cornfield from www.ugogrill.com
Photo of the Panama Canal from www.pancanal.com
18
Successful invasions
Under the right conditions any community can
be invaded and any organism can be a successful
invader somewhere
Potential invaders begin as rare populations,
faced with the same disadvantages of any small
population(e.g., demographic stochasticity,
Allee effects, inbreeding, etc.)
19
Successful invasions Passing through filters
Past
Present
A B C D E F G H I
A B C D E F G H I
Regional species pool
Anthropogenic introductions
Biogeographic filter
F G H I
Physiological filter
Biotic filter
Local assemblage
A B C
A B C H I
See Fig. 9.9, pg. 307 of your textbook (Groom et
al., Principles of Conservation Biology, 3rd ed.)
20
Successful invasions Enemy escape / release
Parasite species richness (S, shown below) and
parasite prevalence ( infected hosts) showed
similar patterns
1.0
1-to-1 line
molluscs
crustaceans
Standardized S of parasites in introduced range
0.5
amphibians reptiles
fish
birds
mammals
0
0
1.0
0.5
Standardized S of parasites in native range
Redrawn from Torchin et al. (2003) Nature
21
Successful invasions Making predictions (its a
two-way street)
Traits of organisms (Not surprisingly one of the
best traits for predicting invasiveness is
whether the speciesis invasive elsewhere)
Characteristics (biological and physical) of
focal site E.g., Eltons (1958) biotic
resistance hypothesis (species-rich communities
are more resistant to invasion)
22
Synergistic Effects Invasional Meltdown
a process by which a group of nonindigenous
species facilitate one anothers invasion in
various ways, increasing the likelihood of
survival and/or of ecological impact, and
possibly the magnitude of impact
Daniel Simberloff
(recd. Ph.D. 1969 E. O. Wilsons student who
experimentally investigated the Theory of Island
Biogeography on mangrove islands in Florida)
Definition from Simberloff Von Holle (1999)
Photo from www.conservationbytes.com
23
Control of introduced and invasive species
Physical control
Chemical control E.g., chlorine bags over
Caulerpa in CA
Biological control Presents the paradox of
adding species (diluting natural biodiversity)
to control or remove other species
Invasion prevention use the Precautionary
Principle
Photo of Caulerpa from www.outernode.pir.sa.gov.au
24
Legislation
National Invasive Species Councils National
Invasive Species Management Plan Established by
a Clinton Executive Order, 1999 Coordinates all
U.S. federal activity and legislation on
introduced species Updated every 2 yr
National Invasive Species Information Center