Available at http://planet.uwc.ac.za/nisl/Eco_people/Presentations/

The Biology and Dynamics of The Biology and Dynamics of Biological invasionsBiological invasions

Megan Van Der Bank2401402

Department of Biodiversity and Conservation Biology, University

of the Western Cape

htt

p:/

/ww

w.b

enett

onta

lk.c

om

/bio

div

ers

ity.jpg

IndexIndex

Introduction Invasive Argentinean ants in the Fynbos Biome Weeds in Australian rangelands The Black striped mussel in Australia Acacia mearnsii in South Africa The Cane Toad (Bufo marinus) in Australia The invasive Red deer (Cervus elaphus)

The Chinese Mitten Crab (Eriocheir sinensis) Invasive Red mangroves and pickleweed in Hawaiian wetlands The local and global effects of invasive species on biodiversity References

Presently, alien species are one of the biggest threats to biodiversity, only second to habitat destruction

Globalization has increase mobility of biota

Intentional introductions (McNeely. 2001)

Accidental introduction (Chapin et al. 2000)

Alien species become naturalized

Outcompete native species for natural resources (Chapin et al. 2000) and prey on indigenous species

These invasive species lack natural enemies, which gives them a competitive edge

Many become pests

IntroductionIntroduction

Invasive Argentinean ants in the Fynbos BiomeInvasive Argentinean ants in the Fynbos Biome

Invasive Iridomyrmex humilis displace native ants Slower to discover seeds of myrmecochorous Mimetes

cucullatus; seeds are moved shorter distances; fail to store seeds below soil

Exposure to competitors, predators and fire Affects seedling growth which competes with parent plant

(Bond and Slingsby. 1984)

htt

p:/

/ww

w.v

iaru

ral.co

m.a

r/via

rura

l.co

m.a

r/agri

cult

ura

/aa-h

orm

igas/

irid

om

yrm

ex-

hum

ilis.

htm

Weeds in Australian rangelandsWeeds in Australian rangelands

Australian rangelands constitute 70 % of the Australian continent Rate of naturalization is 10 species per year Weeds are able to reach high densities and biomass-dominating

the stratum Weeds sequester resources otherwise available to native plant

species Landscape dysfunction- ramifications for food web Effect on specialist herbivores; decomposers Alter fire regimes Native plant species richness decease; native animal species may

respond positively or negatively (Grice. 2004)

Native to tropical and sub-tropical waters of the Western Atlantic (Columbia to the Gulf of Mexico) [1]

Detected in Darwin Harbour (1999) in Australia’s Northern Territory

Introduction via vessel hull fouling; fouling of aquaculture; ballast

Bivalves able to form dense monospecific mats

Reduction in biodiversity, fouling of wharves, seawater systems and marine farms [1]

Treatment with copper sulphate and sodium hypochlorite [4]

Total cost of $ 2.2 million per annum (excluding personnel costs) [1]

The Black striped mussel in AustraliaThe Black striped mussel in Australia

htt

p:/

/im

ag

es.

goog

le.c

o.z

a/

img

res?

img

url

=h

ttp

://w

ww

.mari

ne.c

siro

.au

/Le

aflets

Fold

er/

imag

es/

bls

trip

ed

.jp

g&

img

refu

rl=

htt

p:/

/ww

w.m

ari

ne.c

siro

.au

/Le

aflets

Fold

er/

bls

trip

ed

.htm

l&h

=1

59

&w

=2

50

&sz

=1

5&

hl=

en

&st

art

=8

&tb

nid

=0

3k-

Goxsb

IAO

jM:&

tbn

h=

71

&tb

nw

=1

11

&p

rev

=/im

ag

es%

3Fq

%3

DB

lack

%2

Bst

rip

ed

%2

Bm

uss

el%

26

gb

v%

3D

2%

26

svn

um

%3

D1

0%

26

hl%

3D

en

%2

6sa

%3

DG

Native to Australia and was introduced into South Africa about 150 years ago as a source of bark products [2]

Invasive in South Africa and other countries such as China, Japan, New Zealand, France, United States [3]

S. mearnsii able to produce copious amounts of long lived seeds [2][3]

Forms monospecific crowns which shades other vegetation [2]

Competes with grazing grasses resulting in decreased grass cover

Taps into South Africa’s already dwindling water supply (577 million cubic meters annually) [2]

Increased fuel loads affects fire intensity (Ehrenfeld. 2006)

Nitrogen enrichment (due to nitrogen fixation) makes habitat unsuitable for growth of indigenous species, and more susceptible to invasion by other exotics (Ehrenfeld. 2006)

Infested areas shows decreased species richness of birds and ground plant cover [2]

Acacia mearnsiiAcacia mearnsii in South Africa in South Africa

htt

p:/

/ww

w.h

ear.

org

/Pie

r/sp

eci

es/

aca

cia_m

earn

sii.ht

m

Indigenous to South America, Central America, Mexico, Southern United States

Deliberately introduced into Australia as a biological control agent to prevent French’s Cane Beetle from destroying sugar cane in Northern Queensland [4]

Very fecund (females produce 8000-35 000 eggs, usually twice a year [4]

Adaptable: able to loose 50 % of its body water, tolerate salinities up to 15 % [4]

Competes with native amphibians for breeding ground and food

Toxic at all life stages and causes death of indigenous animals

Current research for control: biological control from a native amphibian virus (gene manipulation) [4]

The Cane Toad (The Cane Toad (Bufo marinusBufo marinus) in Australia) in Australia

htt

p:/

/ww

w.jcu

.edu.a

u/s

chool/tb

iol/zo

olo

gy/

herp

/tfr

g/b

ufo

.jpg

The invasive Red deer (The invasive Red deer (Cervus elaphusCervus elaphus))

Native to parts of Europe and was introduced into Australia, New Zealand, North America and South America [5]

Invades natural and planted forests, rangelands, grasslands, shrublands, tundra

Prevents regeneration of preferred plant species (may cause canopy collapse in woodland and forest settings) [5]

Change structure and composition of native ecosystems Competes with native deer species such as (Hippocamelus

bisulcus) in Chile [5]

Loss of heather cover in the highlands of Scotland

(Clutton-Brock et al. 2004)

ww

w.h

lase

k.co

m/f

oto

/cerv

us_

ela

phus_

db0

70

4.jpg

The Chinese Mitten Crab (The Chinese Mitten Crab (Eriocheir sinensisEriocheir sinensis)) Recognized as one of the world’s top 100 invaders by the ISSG

(Invasive species specialist group) [7]

Native to the coastal rivers and estuaries of the Yellow Sea (West China, Korea) [7][8]

Has spread widely in the US (Great Lakes, California, Pacific Northwest, Louisiana, mouth of the Mississippi River) and become established in Northern Europe

Introduction via live seafood trade, ballast, ship hull fouling Success of E. sinensis is due to tolerance to a varying hydrological

conditions and high female fecundity [7]

Pest: consume young rice shoots, commercial fishing, human health concern [6]

Affects landscape and biodiversity in infested areas : degrade estuarine and freshwater food webs; compete directly with indigenous invertebrates; successive burrowing causes landscape instability [6]

htt

p:/

/cars

.er.

usg

s.gov/p

ost

ers

/Nonin

dig

enous/

Nonin

dig

enous_

Cru

stace

an

s/cr

abm

ap2

a.g

if

htt

p:/

/cars

.er.

usg

s.gov/p

ost

ers

/Nonin

dig

enous/

Nonin

di

genous_

Cru

stace

ans/

crab2

a.jpg

Invasive Red mangroves and pickleweed in Hawaiian Invasive Red mangroves and pickleweed in Hawaiian wetlandswetlands

Alien red mangroves (Rhizophora mangle) and pickleweed (Batis maritima) are major invasive plants in Hawaiian wetlands

Nu’upia fish pond complex home to 10 % of Hawaii’s endangered black-necked stilts (Himantopus mexicanus knudseni)

Pickleweed introduced from South America in 1859 Excludes shorebirds and waterbirds from foraging and nesting on

mudflats (Rauzon and Drigot. 2001) Mangroves introduced from Florida in 1902 to mitigate erosion Decrease water circulation, increases algal production, anoxia,

increases temperature, salinity and acidity of water Stilts more vulnerable to predation by egrets and herons Control measures include: Amphibious Assault Vehicles (pickleweed

control); manual cutting down of trees; possible biological control (Rauzon and Drigot. 2001)

htt

p:/

/ww

w.b

ota

ny.h

aw

aii.

ed

u/f

acu

lty/w

eb

b/B

OT4

10

/Roots

/Man

gro

ves/

Red

Man

gro

vePh

oto

.jp

g

htt

p:/

/ww

w.life.u

iuc.

ed

u/ib

/33

5/B

reed

ing

Syst

em

s/m

an

gro

ve.jp

g

The local and global effects of invasive species on The local and global effects of invasive species on biodiversitybiodiversity

As a biodiversity issue, it is not always possible to say that invasive species are inherently bad (McNeely. 2001)

Globalization causes homogenization Homogenization not synonymous to low diversity at a local scale Dramatic increase in species numbers at a local level, is at expense of

native species Loss of rate native species, leads to global species and genetic

diversity loss (McNeely. 2001) Consensus dependant partly on scale (McNeely. 2001)

References Davis M (2003) Biotic Globalization: Does Competition from introduced

species Threaten Biodiversity? BioScience 53: 481-488 Bond W, Slingsby P (1984) Collapse of an ant-plant mutualism: The Argentine

ant (Iridomyrmex humilis) and myrmecochorous Proteaceae. Ecology 65:1031-1037

Chapin F, Zavaleta E, Eviner V, Naylor R, Vitousek P, Reynolds H, Hooper D, Lavorel S, Sala O, Hobbie S, Mack M, Diaz S (2000) Consequences of changing biodiversity. Nature 405: 234-242

Clutton- Brock T, Coulson T,Milner J (2004) Red deer stocks in the Highlands of Scotland. Nature 429:261

Ehrenfeld J (2006) A potential novel source of information of screening and monitoring the impact of exotic plants on ecosystems. Biological Invasions 8: 1511-1521

Grice A (2004) Weeds and the monitoring of biodiversity in Australian rangelands. Austral Ecology 29: 51-58

McNeely J (2001) Invasive species: a costly catastrophe for native biodiversity. Land Use and Water Resources Research 1: 1-19

Rauzon M, Drigot D (2001) Turning the tide: the eradication of invasive species. IUCN SSC Invasive Species Specialist Group, Cambridge p240-248

12. http://www.biodiv.org/doc/case-studies/ais/cs-ais-au-black-mussel-en.pdf 13. http://www.issg.org/database/species/impact_info.asp?si=51&fr=1&sts= 14. http://www.hear.org/species/acacia_mearnsii/ 15. http://www.aph.gov.au/senate/committee/ecita_ctte/invasive_species/report/c04.

pdf 16. http://www.fao.org/docrep/008/j6854e/J6854E12.htm 17. http://www.wsg.washington.edu/outreach/mas/nis/leastwanted.pdf

18. http://cswgcin.nbii.gov/portal/server.pt?open=512&objID=798&&PageID=2259&mode=2&in_hi_userid=2&cached=true

19. http://cars.er.usgs.gov/posters/Nonindigenous/Nonindigenous_Crustaceans/nonindigenous_crustaceans.html

20. http://en.wikipedia.org/wiki/Invasion_biology_terminology