Download English - Invasive Species Specialist Group

Developing legal and
institutional frameworks
for invasive alien species
Module 1:
what decision-makers
need to know about
invasive species
what this module covers
1.
what ‘invasive alien species’
and ‘invasion’ means
Module 1
what decision-makers need
to know about invasive
species
2.
pathways for species
introductions
Module 2
laying the foundations for
effective national frameworks
3.
impacts of IAS
Module 3
preventing
biological invasions
4.
problems of prediction and
links to other environmental
pressures
Module 4
responding
to biological invasions
Module 5
getting results: compliance,
enforcement and liability
Module 6
legal frameworks for
cooperation beyond borders
5.
2
the importance of information
and available international
resources
what decision-makers need to know about invasive alien species
what are invasive alien species?
many different terms – a complex area
an alien species is a species that has been
introduced to a location (ecosystem or area) where it
does not occur naturally
an invasive alien species (IAS) is an alien species
that causes (or has the potential to cause) harm to
the environment, economies and/or human health
introductions are nothing new...
...but globalisation
has led to massive
expansion of
opportunities for
introductions
what type of species invade?
from all taxonomic groups
• vertebrates (e.g. mammals, fish, birds,
reptiles)
• invertebrates (e.g. insects, snails, worms)
• aquatic, marine and terrestrial plants (e.g.
weeds, trees)
• micro-organisms (e.g. viruses, bacteria)
Process of Invasion
1. Introduction
2. Establishment
– intentional or unintentional
– survives but doesn’t spread
(a) naturalisation – becomes part
of new habitat’s flora/fauna
3. Spread
(b) invasion – expands and
impacts on species, ecosystems
people and development
1. Introduction
2. Establishment
3a.Spread - Naturalisation
3b. SPREAD - INVASION
the House Sparrow
spreading and invading
Tanzania over 90 years
Many IAS undergo a lag phase after initial establishment,
and may remain unobtrusive before becoming invasive and
spreading rapidly
Population
size
In some species (e.g. trees) this may be more than 100
years, in others (e.g. water hyacinth) it may be a few
weeks
Carrying capacity
Lag
phase
Time
habitat occupation changes
during invasion
Introduction
Invasion
Consolidation
Process of Invasion from
Introduction to Consolidation
(after Williams, 2003)
Invasions can thus be stopped
at several stages:
• best is prevention = stopping introductions
• next best is eradication = destroying or removing a new
invasion
• third is containment = stopping a new invasion from further
spreading
• last (and most expensive and time-consuming) is
management of established invasions + restoration of
affected systems
• Sequence endorsed under Convention on Biological
Diversity
how do species get moved
around?
Vectors – The specific mechanism by
which a species is moved along a pathway
(clothing, vehicle, boat hulls, ballast water,
packaging, soil around plant roots...)
e.g. a tourist carrying seeds is a
vector in the pathway of international airline
flights
Pathways – The routes along which a
species is moved or moves itself (roads,
railways, air corridors, shipping lanes,
rivers) ... including trade itself
Shipping routes now reach every continent (even
Antarctica) and air travel reaches most cities in the world
ballast water
• a major vector for unintentional introductions in the
shipping pathway
• up to 14 billion tonnes of ballast water transported around
the world each year
• an estimated 7 000 – 10 000 species may be present in
ballast water at any given time
Zebra mussels were
introduced to the Great
Lakes of North
America in ballast
water in the 1980s,
and now cause severe
economic impacts
direct & indirect causes of
introductions
introduction
direct causes
indirect economic causes
introduction of species for
commercial purposes
forces and conditions which
determine trade, production and
consumption practices and
e.g. aquaculture, seeds, crops,
livestock, food, biofuels
establishment
introduction of species for
control purposes
e.g. biocontrol, landscape restoration
spread
naturalisation
introduction of species for
lifestyle and aesthetic
purposes
e.g. pets, ornamental plants, aquariums
unintentional or accidental
introductions
invasion
e.g. contaminated imports, hitch-hikers
in freight or luggage, ballast water,
dumping
preferences
e.g. expanding travel & trade, globalisation,
subsidies to production, trade and
investment incentives, market demand and
consumer preferences, low fines, high
reliance of economy on imports
forces and conditions which
determine land and resource
use practices and preferences
e.g. high reliance of economy on particular
productions sectors, incentives to clear land
and replace native species, price support to
exotic monocrops, unclear institutions and
property rights, lack of budgets and funding
to conservation
introduction of species
Movement by human action of a species outside its native
range can result in introduction (into/within a country)
Some establish,
naturalise and
spread
Some establish,
naturalise and
spread
intentional introduction
for food,
agriculture, forestry,
horticulture,
fisheries, hunting,
ornamental and for
pleasure ...
unintentional introduction
species that move
with other imports
as ‘hitchhikers’ or
‘stowaways’
impacts of IAS
negative impacts on:
• ecosystems
• economies
• human health
ecological impacts
• direct predation/herbivory
• competition for resources/exclusion
(e.g. light, food)
• transmission of pathogens and parasites
• alteration of micro-climate, nutrient availability, ecoystem
cycles (energy, water, minerals, organics)
• disturbance to ecological processes (e.g. pollination)
• disruption of ecosystem services (e.g. flood attenuation)
• environmental degradation, facilitating further invasions
economic impacts
estimated at 5% global GDP
Direct costs
• Direct loss of crops, reduced yields
• Lost export earnings
• Loss of tourism revenues
• Management costs
Indirect costs
• Impaired ecosystem services
• Damaged infrastructure
• Costs to natural environment and
societal or cultural values
health impacts
Direct impacts
• Disease
• Allergic reactions
• Injuries through stinging or biting
Indirect impacts
• Providing a vector for disease
invasions
impact on the
provision of
ECOSYSTEM SERVICES
which results in
changes in
CONSTITUENTS OF WELL-BEING
Security
• Personal safety
• Secure resource access
• Security from disasters
Provisioning
• Food
• Fresh water
• Wood and fiber
• Fuel
•…
Supporting
• Nutrient cycling
• Soil formation
• Primary production
•…
Basic material for good life
• Adequate livelihoods
• Sufficient nutritious food
• Shelter
• Access to goods
Regulating
• Climate regulation
• Flood regulation
• Disease prevention
• Water purification
•…
Health
• Strength
• Feeling well
• Access to clean air & water
Cultural
• Aesthetic
• Spiritual
• Educational
• Recreational
•…
Freedom of choice
and action
Opportunity to be
able to achieve what
an individual values
being and doing
Good social relations
• Social cohesion
• Mutual respect
• Ability to help others
Adapted from Millennium Ecosystem Assessment 2005
understanding, assessing and acting on invasives in the light of the
changes in ecosystem services and human wellbeing they give rise to
economic analysis
Millennium Ecosystem Assessment /Emerson & Howard
Lantana camara is a classic IAS which (after
160 years) is still spreading across Africa and
invading new lands - as well as in Australia,
Asia and North America
Lantana replaces
native vegetation
and pasture, is
poisonous to
livestock and
harbours tsestse
flies and rats
an example of spread and invasion impacts
Kafue Floodplain, Zambia, dry
1974
Kafue Floodplain flooded
1974
The Kafue
Floodplain
was home to
many wild
animals and
plants + cattle
grazing,
fishing,
conservation
& tourism
In 1974 there was an
occasional plant of
Mimosa pigra on the
edges of the Kafue River
Mimosa pigra (continued)
A heavy flood in 1981/2 brought a few plants of
Mimosa pigra on to the floodplain
(which was a
new ecosystem
changed by a
dam upstream)
1982
Mimosa pigra (continued)
After a slow start
in the late 1980s,
M. pigra began to
spread
By 2000 it was
covering a few
hundred hectares
2001
Mimosa pigra (continued)
By 2007 it was
growing up to 4m high
and covering 3,000
hectares
2007
…. and excluding almost
every other plant and
most animals ….
2007
Mimosa pigra continued
3,000 ha of an available 12,000 ha are now covered
Today:
no livestock
no fisheries
no tourism
on this part
of the
Kafue
Floodplain
costs to
livelihoods
&
invasion impacts – human development
Water hyacinth affecting Kafue Gorge Dam and hydropower station, Zambia
(photo
M. Mumba)
impacts on production (eco)systems
ecosystems, native or cultured,
that are used for food and
commodity production can also
be invaded by alien species
forestry, fisheries, agriculture,
aquaculture
Tall trees of Senna
spectabilis from S.
America replacing
native forest in
Uganda
parasitism, pathogenesis,
predation, competition,
exclusion and destruction of
productive systems are all
recorded – most known from
farming, horticulture and
livestock production
“Invasiveness” of an
alien species
what makes a good invader?
•rapid growth rate
•great dispersal characteristics
•large reproductive capacity
•broad environmental tolerance
•effective competitor with local species
Lianes in Seychelles
all invasive plants can be called “weeds”
BUT not all weeds are invasive species
current and future trends
human activities are changing natural ecosystems and
making them more susceptible to IAS
• globalisation
• land-use change
• climate change
invasives and climate change
climate change is upon us - although not exactly
predictable in area or extent
climate change will make ecosystems more vulnerable
to invasions
invasive species are already “taking advantage” of
changed climatic conditions and expanding to the
detriment of local species, habitats and ecosystems
thus we must be prepared for ecosystems affected by
climate change to be further invaded and we must
develop tools to predict and prevent these extra
invasions
causes and effects of IAS are international
or regional
IAS management and control supported by
bilateral, regional and global instruments
and guidance (see Modules 2 & 6)
Convention on Biological Diversity
1992 (CBD)
Parties to “prevent the introduction of, control or eradicate
those alien species which threaten ecosystems, habitats or
species” (Art.8(h))
emerging principles of IAS management
• the precautionary principle
• the principle of preventive action
• the ecosystem approach
• sharing of information
• user-pays principle
• cross-sectoral approach to management
Sharing of expertise and
information is crucial
Types of information to be shared?
•
Inventories and databases
•
Incident lists and case studies
•
Potential threats to neighbouring countries
•
Information on taxonomy, ecology and genetics of IAS
•
Prevention and control methods where available
•
National and regional guidelines and measures
Many IAS databases accessible electronically
EAFRINET
The eastern Africa LOOP of BioNET-International
Some GISP products that can help