1.
What happens when a species is introduced
into an ecosystem where it doesn’t occur
naturally?
Are eco-systems flexible and able to cope with
change, or can a new arrival have far-reaching
repercussions and do permanent damage?
Will something special be lost forever?
Does it matter?

2.
In the distant past, the earth’s mountains and
oceans represented formidable natural barriers to
all but the hardiest of species
Ecosystems evolved in relative isolation
Early human migration saw the first intentional
introductions of alien species as our ancestors
attempted to satisfy physical and social needs
The magnitude and frequency of those early
introductions were minor compared to those
associated with today’s extensive global trade and
passenger movements

3.
On April 27, 2009, news about the outbreak of swine flu in Mexico
caught the attention of people all over the world
In spite of unprecedented measures to check its spread, the swine
flu virus managed to sneak into more than 30 countries, including
India, and within weeks it had infected nearly 5,000 people all over
the world
(Venkatraman, 2009)

4.
 Recently, a new strain of the stem rust virus Ug99 invading
wheat leading to the loss of almost the entire crop in many
 African countries including Kenya, Ethiopia and Tanzania
 It has been spotted in Iran and is believed to be heading
towards countries in South Asia
 It may spell doom for the food security of the region
because all wheat varieties cultivated in Asia are
susceptible to Ug99
 As one of the megadiversity countries in the world, India is
particularly vulnerable to invasions by alien species.
(Venkatraman, 2009)

5.
Amrita Daripa

6.
Species introduction is usually vectored by human
transportation and trade
If a species’ new habitat is similar enough to its native
range, it may survive and reproduce
For a species to become invasive, it must successfully
out-compete native organisms, spread through its new
environment, increase in population and harm
ecosystems in its introduced range
To summarise, for an alien species to become invasive,
it must arrive, survive and thrive
(Venkatraman,2009)

7.
Compared to other threats to biodiversity invasive introduced
species rank second only to habitat destruction
Of all 1,880 imperiled species in the U.S. 49% are endangered
because of introduced species
Introduced species are a greater threat to native biodiversity
than pollution, harvest, and disease combined
Through damage to agriculture, forestry, fisheries, and other
human enterprises introduced species inflict economic cost
estimated at $137 billion/year to the U.S. economy
Of course some introduced species (such as most of our food
crops and pets) are beneficial. However, others are very
damaging
(Simberloff, 2000)
Contd…

8.
Native plants Occurring within their natural range (past or present)
Dispersal potential (i.e. within the range they occupy
naturally or could occupy without direct or indirect
introduction by humans)
Alien plants Plant taxa whose presence in a given area due to
intentional or accidental introduction as a result of
human activity (Syn.: exotic plants, non-native, non-
indigenous plants)

9.
Invasive plants Plants that produce reproductive offspring, often in
very large numbers, at considerable distances from
parent plants and have the potential to spread over
a considerable area
Invasive alien plants Plants become established in natural or seminatural
ecosystems or habitats and are agents of change,
threatening native biological diversity
(M. Kunwar, 2003)
Contd…

10.
 Increased consumption by
predators
 Competition for habitats or
resources
 Change of ecological conditions
 ”Genetic pollution”
(Klingenstein and(Klingenstein and Thuweba, 2003), 2003)

11.
 Can damage native species through an increased
predation pressure that can be species-specific or
indifferent
 Increasing parasitism (e.g. by parasites which are
used for pest control)
 From the spread of illnesses within native species
(e.g. death of elm trees, Ulmus spp., through the
spread of a disease vector, the elm split pin
beetle)
 Can also upset whole biological communities such
as displacement of native species by stands of
the Japanese knotweed (Fallopia japonica)(Klingenstein and(Klingenstein and Thuweba, 2003), 2003)

12.
 Damage relevant to conservation arises by competition between
alien species and native species for habitats and resources
 Invasive alien species can displace single native species by taking
over their ecological niches
 Alien rugosa rose (Rosa rugosa) replacing the native Scotch rose
(R. spinossissima) in the dunes of north Germany
Rosa rugosaRosa spinossissima
(Klingenstein and(Klingenstein and Thuweba, 2003), 2003)

13.
 Changes of local site conditions such as food chains are more
complex
 Can also endanger native species indirectly
 Dry pastures favour the spreading of the false acacia (Robinia
pseudoacacia); its nitrogen-enrichment properties, in turn, favour
nitrogen-dependent species (eutrophication), which then displace
the original species
 Alien douglas fir (Pseudotsuga menziesii) in contrast to most native
trees is able to grow on rocks and shadow the original vegetation
(Klingenstein and(Klingenstein and Thuweba, 2003), 2003)

14.
+ =
 Through crossing and gene exchange of native with exotic
 species
Hybridization leads to the substitution of local genes with alien genes
 Decrease of native genes and genetic diversity
 Loss of specialized adaptation mechanisms and characteristics of
local populations
 Same mechanism
Causes potential
danger of
GMO
(Klingenstein and(Klingenstein and Thuweba, 2003), 2003)

15.
About 40% of the species in the Indian flora are alien,
of which 25% are invasive (Gupta, 2005).
Lantana camara, Parthenium hysterophorus, Eupatorium
odoratum, Eupatorium adenophorum, Mikania micrantha,
Ageratum conyzoides, Galinsoga parviflora, Mimosa pudica,
Chromolaena odorata, Prosopis juliflora, Leucaena leucocephala,
some species of Quercus, Eucalyptus spp., Erythrina sp., Acacia
spp., Salix sp., Populus sp., Tamarix sp., Hedychium
gardnerianum, Imperata cylindrica etc.
Parthenium
hysterophorus
Lantana camara
Leucaena
leucocephala
http://upload.wikimedia.org/wikipedia/common
s/c/c3/Lantana_camara_flowers_2.JPG
http://consejo.bz/belize/images/
bushmed/pound-cake-bush.jpg
http://www.maltawildplants.com/
MIMO/Pics/LCNLC/LCNLC-
Leucaena_leucocephala_t2.jpg

16.
Ageratum
conyzoides
Mikania
micrantha
Galinsoga
parviflora
Prosopis juliflora
Eucalyptus
http://www.hear.org/starr/images/full/st
arr-040209-0126.jpg
http://www.hear.org/Pier/images/mimicp11.jpg
http://www.botanik.uni-
karlsruhe.de/garten/fotos-
knoch/Galinsoga
%20parviflora
%20Franzosenkraut
%202.jpg
http://www.landscape-
resources.com/portfolio/treesx/imag
es/Prosopis%20juliflora-1.jpg
http://upload.wikimedia.org/wikipedia/
commons/0/01/Eucalyptus_tree.jpg

17.
Invasive alien Weed Species
Weed Species Introduced from
Parthenium hysterophorus Central America
Eupatorium odoratum Jamaica
Eichornia crassipes Many countries
Lantana camera Many countries
Opuntia sp. Australia
Phaseolus labatus USA
Sorghum halepense USA
Mikania micrantha Malaysia
(Yaduraju et al, 2000)

18.
Pests Crop Introduced from
Sugarcane wooly
aphid (Ceratovacuna
lanigera)
Sugarcane
(Saccharum
officinarum)
Indonesia (Java)
Coconut mite
(Aceria guerreronis)
Coconut (cocos
nucifera)
Guerrero state
(Mexico)
Coffee berry borer
(Hypothenemus
hampei)
Coffee seeds Central America
Spiralling white fly
(Aleurodicus
dispersus)
Guava Sri Lanka
Serpentine leaf
miner (Liriomyza
trifolii)
Fibre crops, pulses,
vegetables,
ornamnetals
Southern USA and
Central America
(Subrahmanyam et al., 2004)

19.
Diseases (Fungal) Introduced from
Leaf rust of coffee
(Haemetia vastritrix)
Sri Lanka
Late blight of potato
(Phytophthora infestans)
Europe
Flag smut of wheat
(Urocystis tritici)
Australia
Downy mildew of grapes
(Plasmopara viticola)
Europe
Blast of rice (Pyricularia
oryzae)
S.E. Asia
Wart of potato
(Synchytrium endobioticum)
Netherland

20.
Diseases (Bacterial) Introduced from
Bacterial leaf blight of paddy
(Xanthomonas campestris p.v. oryzae)
Japan
Diseases (Viral) Introduced from
Bunchy top of banana Sri Lanka
Peanut stripe virus China 1984
Cotton leaf curl Pakistan 1996
Diseases (Nematode) Introduced from
Golden nematode of potato
(Heterodera rostochinensis)
Europe
(Pimentel, 2002)

21.
Case studies

22.
 Entered the country in the 1950s along with the supply of
P.L. 480 (Public Law 480 food aid programme) wheat from
the United States
 Other than occupying wasteland, roadsides, and railway
tracks, it has colonised public parks, residential colonies
and orchards.
 The weed is highly allergenic and causes respiratory
problems, dermatitis and asthma.
(Venkatraman, 2009)
Parthenium

23.
 One of the world’s seven most devastating and
hazardous weeds
 Invaded 14.25 million hectares of farm land during 2001-
2007
 Proper management of the weed could increase crop
yield by 30%
 The weed plant, also known as ‘congress grass’ and
‘gajar ghas’, is found abundantly in Andhra Pradesh,
Karnataka, Madhya Pradesh, Maharashtra and Uttar
Pradesh
(Varshney, 2009)
Contd…

24.
 Considered one of the 10 notorious weeds in the
world
 A native of Central and South America lantana came
to India as an ornamental plant in 1807, when the
British introduced it into the Calcutta Botanical
Garden
 Since then it has occupied over one lakh hectares of
land in the country and proved to be a bane of cash
crops such as coffee, cotton, oil palm and coconut
(Venkatraman, 2009)
Lantana camara

25.
Originated in the Amazon basin
Become a big nuisance in
ponds, lakes and lagoons in the
country
(Venkatraman, 2009)
Hebbal lake in Bangalore
Eichhornia crassipes

26.
By 1998 it covered about 20,000 ha
Paralysed activities in ports, villages and
bays
Economic impacts of the water hyacinth, in
seven African countries, have been
estimated at between US$20-50 million
every year
Across Africa costs may be as much
as US$100 million annually
(UNEP/GRID and USGS EROS Data(UNEP 2003, McNeely and others 2001, GISP 2004)

27.
 Perennial creeping climber
 Nominated as among 100 of the "World's Worst" invaders
 Introduced into India after the Second World War to
camouflage airfields
 Occurs in: agricultural areas, coastland, natural forests,
planted forests, riparian zones, ruderal/disturbed,
scrub/shrublands, urban areas, wetlands
 Once established spreads at an alarming rate 27 mm a
day
Mikania

28.
 Damages or kills other plants by cutting out the light
and smothering them
 One of the worst weeds of tea, coconut plantations, oil
palm, banana, cocoa and forestry crops, and in
pastures in India
 It does not grow well in rice paddies, it can encroach
from the edges to smother the crop
(IUCN/SSC Invasive Species Specialist
Group (ISSG), 2005)
Contd…

29.
 Introduced as an ornamental plant in the
Calcutta Botanical Garden in the 1840s
 Since then it has spread throughout South-East
Asia
 Its capacity for regeneration and prolific seed
production enables it to form dense tangled
bushes
 which depress the growth and yield of crops
such as rubber, cardamom, coffee, tea and
mango
(Venkatraman, 2009)

30.
 Maximum biomass contributor among all the herbaceous
species recorded
 Total net primary productivity (TNP) ranged from 1528.5
to 2163.4 g m−2
yr−1
 The values of aboveground biomass of Eupatorium
glandulosum were more than 32% of the total biomass of
all species
Bughani and Rajwar, 2005

31.
 The individual highest contribution of biomass and TNP
by this weed has caused reduction in the biomass and
production of other species
 Due to the dominance and invasive effect of this exotic
species, fodder grasses and other economic herbs are
being replaced
 The invasive nature of this species has also become
stronger due to its more tolerant and expanding nature
Contd…

32.
 Introduced in India in the last century and was
thought to be a very promising species for the
afforestation of dry and degraded land
 Emerged as a noxious invader that can grow in
diverse ecosystems, right from coastal areas to
desert regions
 Its rapid growth and dense formation enable it to
wipe out other plant species in its surroundings
Prosopis juliflora
(Venkatraman, 2009)

33.
Impacts

34.
e.g. alien weeds
Water hyacinth and other alien water
weeds currently cost developing countries
over US$100 million annually
(NBA, 2009)

35.
Crops Rupees (Crore)/
year
Rice 9468
Wheat 1213
Cotton 3105
Sugarcane 1500
Groundnut 813
Maize 650
(Pimentel, 2002)
Estimated cost of alien plant pathogen to Indian
crops amounts to $35.5 billion/year

36.
 Invasive alien species can directly affect human
health
 Use of pesticides and herbicides, which pollute
water and soil have indirect health effects on
humans
 They mainly causing flu, allergies, respiratory
disorders and even infertility among humans and
animals

37.
Pollens are a major cause of asthma
Major cause of Allergic, Trinities
Sinusitis, affecting about ten percent of
the people who live near it
Major cause of dermatitis, a skin
disease, among animals and human
being
Reduces yield of milk and weight of
animals
Causes irritation to eyes
Health hazards of Parthenium
(Priyadarshi, 2008)

38.
Biological control
Chemical control
Mechanical control
Ecosystem management
(Simberloff, 2000)

39.
 Introducing a natural enemy usually from
the native range of the introduced pest.
 Prickly pear cactus from the Americas is
well controlled on hundreds of thousands
of square miles of Australian rangeland by
caterpillars of a moth introduced from
South America
 Disadvantage –
› Some agents attack nontarget species
(Simberloff, 2000)

40.
 Involves using a pesticide, such as an herbicide or
insecticide
 Chemicals can effectively control some species
water hyacinth in Florida
 Disadvantage –
› They may have nontarget impacts
› They are often expensive
› Pests can evolve resistance to them.
(Simberloff, 2000)

41.
 Hand pulling or various kinds of machinery are
employed
 For example, volunteer convict labor is used in
Florida to cut paperbark trees and in Kentucky to
rip out Eurasian musk thistle
 Disadvantage –
› Some invaders cannot be easily found for mechanical
removal or occupy a habitat (for example, the marine
benthos) that is not readily accessible.
(Simberloff, 2000)

42.
 Entire ecosystem is subject to a regular treatment
(such as a simulated natural fire regime) that tends to
favour adapted native species over most exotic
invaders
The specific ways in which it can be employed must
be determined in each type of habitat
(Simberloff, 2000)

43.
Requires international cooperation and
action
Preventing the international movement of
IAS and their rapid detection on the
borders are less costly than their control
and eradication
Preventing the entry of IAS is carried out
through inspections of international
shipments, customs checks and
quarantine regulations
Invasive alien species are a
global issue

44.
Convention on International Trade in Endangered Species
(CITES; 1973)
Export and trade of species may be limited, if they endanger
biodiversity in the importing country

45.
Convention on Biological Diversity
(CBD; Rio 1992)
Article 8 h: Contracting parties shall ...
prevent the introduction of, control or eradicate those alien
species which threaten ecosystems, habitats or species
Guiding Principles for invasive alien species (2002)
precautionary, three-stage approach
(prevention, control, management)

46.
Guiding principle 10: Intentional introduction
1. No intentional introduction of an alien species already invasive or
potentially invasive should take place without authorization from an
authority. A risk analysis should be carried out to authorize an
introduction. The burden of proof should be with the proposer of the
introduction. Authorization may be accompanied by conditions (e.g.,
monitoring procedures, payment for assessment and management).
2. Lack of scientific certainty should not prevent an authority to prevent
the [introduction]
"intentional introduction" refers to the movement and/or release by humans
outside of its natural range
Guiding Principles on IAS
Decision VI/23

47.
International Plant Protection Convention
(IPPC)
International standard for phytosanitary measures 11 (2003):
Risk assessment for quarantine pests including analysis of
environmental risks

48.
Operations are carried out by the Directorate of Plant
Protection, Quarantine and Storage, which functions under
Ministry of Agriculture
Plant Quarantine (Regulation of Import into India) Order,
2003 :
› to prevent the introduction and spread of exotic pests
that are destructive by regulating the import of plants
and plant products through adequate policy and
statutory measures
› to support India’s agricultural exports through credible
export certification
› to facilitate safe global trade in agriculture by assisting
and by providing phytosanitary certification
(Shah, 2003)

49.
(Shah, 2003)

50.
(Shah, 2003)

51.
Plant Quarantine network in India
(Khetarpal, 2006)

52.
IAS is a global problem
It is a major threat to biodiversity and food security
All the nations have to work together to prevent its
spread
All the nations must follow International norms for
trade and transport
At national level plant quarantine should be followed
strictly
Awareness should be created to the farmers on IAS
Inter departmental co-operation is highly needed to
eliminate the problem of alien species

53.
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