Underutilised crops and invasive species understanding the links

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Underutilised crops and invasive species
understanding the links

• Hannah Jaenicke
• International Centre for Underutilised Crops,
  Colombo, Sri Lanka (h.jaenicke_at_cgiar.org)
• and
• Nick Pasiecznik
• Agroforestry Enterprises, Cussy-en-Morvan, France
  (npasiecznik_at_wanadoo.fr)

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An important but overlooked issue

• Significant number underutilised crops (UC) are
  also on lists of invasive species (IS)
• IS can have massive negative impacts on rural
  livelihoods, the environment and biodiversity
• Professionals involved with UC must be aware of
  the potential risks, and take the necessary steps
  to minimise them

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What is an invasive species ?

• Organisms that cause, or have the potential to
  cause, harm to the environment, economies, or
  human health
• Widely described as the second greatest threat
  to biodiversity, after habitat loss
• They are often, but not always, also alien
  species to the area concerned

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Reasons for plant introduction

• Some have been introduced accidentally, (e.g. as
  seeds contaminating other traded products such as
  grain, wool, animals, etc.)
• But most were introduced intentionally, for
• Production as crops for food, fodder, fibre,
  fuel, etc.
• Protection windbreaks, soil conservation,
  erosion control, etc.
• Social value mostly as ornamental plants

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What plants are both crops and invasive species?

• Common crops (only) invasive in sensitive areas
  e.g. tomato and others in the Galapagos, and okra
  and many others in national parks
• UC now considered almost exclusively as invasive
  species e.g. prickly pear cactus (Opuntia
  ficus-indica), black wattle (Acacia mearnsii) and
  mesquite (Prosopis juliflora and other P. spp.)
  as such, these are candidates for control by
  utilisation
• UC considered as having economic potential, but
  which are noted as invasive, somewhere in the
  world

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Underutilised crops that could potentially become
invasive species

• Food crops an increasing number are also
  invasive in some areas
• Tree crops many have proven invasive,
  especially in sensitive island ecosystems
• Fodder plants including many grasses but also a
  number of shrubs and trees
• Fuel crops many now being promoted for biofuel
  are high risk invasive species

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Who takes the blame if an introduction goes
wrong?

• Not I said the agronomist, not I said the
  forester, not I said the plant breeder.....
• So, poor farmers whose lives we are trying to
  help may be left with a new nuisance weed, and
  some concerned professionals walk away.?
• Polluter pays principle now becoming more
  common, (this should force us to be more aware of
  the risks - if a desire for a clear conscience is
  not enough !)

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Examples of good practice

• Balanced information provision
• Weed risk assessments
• Monitoring and surveillance
• Predefined control and management strategies

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Recommendations (1)

• Documentation promoting UC must include
  information on whether and where the plant is
  recorded as being invasive, derived from searches
  of the many databases and associated literature.
  Clear warnings should be attached to those that
  have already proved invasive anywhere in the
  world.
• 2. Weed risk analyses/assessments, based on
  existing models, should be conducted on
  potentially invasive species prior to
  introduction to a new area. Species that fail
  should not be introduced at any cost, and results
  should be widely publicised ensuring others do
  not make the same mistake.

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Recommendations (2)

• Underutilised crops that have proven invasive
  elsewhere, should be monitored for possible
  escape from cultivation, naturalisation and
  spread to new areas or habitats within that area.
  Control and management strategies should also be
  agreed with the necessary authorities in the
  event of future invasion.
• Those involved in developing and promoting
  underutilised crops need to provide information
  on their uses and management to others involved
  in their control and management as invasive
  species.
• 5. A system and protocol needs to be developed
  for the open exchange of information between
  people working on species that are both
  underutilised crops and invasive species. This
  must aim to improve the management of existing
  plant invasions and prevent further ill-conceived
  introductions.

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A two-way process

• Underutilised crops may be invasive species in
  the future but conversely, invasive species may
  also prove to be underutilised crops. Control by
  utilisation is being seen as an increasingly
  viable option in invasive species management
• Those involved in developing and promoting
  underutilised crops need to provide information
  on their uses and management to those involved in
  their control and management as invasive species
• A system and protocol needs to be developed for
  the open exchange of information between people
  working on species that are both underutilised
  crops and invasive species
• This must aim to improve the management of
  existing plant invasions and prevent further
  ill-conceived introductions

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Stay the course !

• Those of us involved in promoting further plant
  introductions and managing existing invasions
  have a responsibility to make more long-term
  commitments to those people whom we are supposed
  to be helping
• Ensure that what we promote will not become a
  disaster in the future, and offer help to deal
  with any unpredicted invasions at a later date

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Conclusion

• New plant introductions will continue to happen
  in the future, with good reasons and intentions
• The challenge we face is to ensure that the risks
  of negative ecological and economical impacts
  following such introductions are minimized