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?

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

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)

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)

Amrita Daripa

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)

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…

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)

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…

Increased consumption by predators

Competition for habitats or resources

Change of ecological conditions ”Genetic pollution”

(Klingenstein and (Klingenstein and Thuweba, 2003), 2003)

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)

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)

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)

+ =

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 mechanismCauses potential danger of GMO

(Klingenstein and (Klingenstein and Thuweba, 2003), 2003)

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/commons/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

Ageratum conyzoides

Mikania micrantha

Galinsoga parviflora

Prosopis juliflora

Eucalyptus

http://www.hear.org/starr/images/full/starr-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/images/Prosopis%20juliflora-1.jpg

http://upload.wikimedia.org/wikipedia/commons/0/01/Eucalyptus_tree.jpg

Invasive alien Weed Species

Weed Species Introduced fromParthenium hysterophorus

Central America

Eupatorium odoratum Jamaica

Eichornia crassipes Many countriesLantana camera Many countries

Opuntia sp. Australia

Phaseolus labatus USASorghum halepense USA

Mikania micrantha Malaysia

(Yaduraju et al, 2000)

Pests Crop Introduced fromSugarcane 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)

Diseases (Fungal) Introduced fromLeaf 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

Diseases (Bacterial) Introduced from

Bacterial leaf blight of paddy (Xanthomonas campestris p.v. oryzae)

Japan

Diseases (Viral) Introduced from

Bunchy top of banana Sri LankaPeanut stripe virus China 1984Cotton leaf curl Pakistan 1996Diseases (Nematode) Introduced from

Golden nematode of potato (Heterodera rostochinensis)

Europe

(Pimentel, 2002)

Case Studies

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

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…

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

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

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 muchas US$100 million annually

(UNEP/GRID and USGS EROS Data Centre,2004)(UNEP 2003, McNeely and others 2001, GISP

2004)

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

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…

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)

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

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…

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 todesert regions

Its rapid growth and dense formation enable it to wipe out other plant species in its surroundings

Prosopis juliflora

(Venkatraman, 2009)

Impacts

e.g. alien weeds

Water hyacinth and other alien water weeds currently cost developing countries over US$100 million annually

(NBA, 2009)

Crops Rupees (Crore)/ year

Rice 9468Wheat 1213Cotton 3105Sugarcane 1500Groundnut 813Maize 650

(Pimentel, 2002)

Estimated cost of alien plant pathogen to Indian crops amounts to $35.5 billion/year

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

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)

Biological controlChemical controlMechanical controlEcosystem

management

(Simberloff, 2000)

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)

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)

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)

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)

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

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

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)

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 IASDecision VI/23

International Plant Protection Convention (IPPC)

International standard for phytosanitary measures 11 (2003):Risk assessment for quarantine pests including analysis of environmental risks

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)

(Shah, 2003)

(Shah, 2003)

Plant Quarantine network in India

(Khetarpal, 2006)

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

THANKYOU