Mpala Research Centre Discovery Day 2014

1. www.cabi.org
KNOWLEDGE FOR LIFE
Identification and management toolkit for
invasive plant species in Laikipia, Kenya
Frances Williams

2. What are invasive alien
species?
An alien species is a species that has been introduced, as
a result of human activities, 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, economy and/or human health.

3. • Interfere with crop and pasture production through
competition for light, water and nutrients
• Displace crops and pasture species through the
production of toxins that inhibit the growth of other
plants
• Reduce the quality of livestock through toxicity
leading to death or retarded development, lowered
quality of animal products such as meat, milk, fleece,
or hides, or reproductive failure
• Invade water bodies affecting water quality and
quantity.
Perrings, 2005
Some impacts of invasive
plants:

4. Pastoralism contributes 50% to agricultural
Gross Domestic Product (GDP) in Kenya
A recent study indicated that without any management
of invasive plants there would be a 71% reduction in
grazing capacity in South Africa (van Wilgen et al.,
2008). The situation will be no different in East Africa.

5. Parthenium hysterophorus: Impacts on crop and
pasture production, human and animal health
(toxic), and biodiversity
82 – 95% reduction in sorghum
yields in Ethiopia
90% reduction in pasture
carrying capacities
Dermatitis and respiratory
problems in people
Toxic to livestock

6. Lantana camara: Impacts on crop and pasture
production, animal health (toxic) and biodiversity
Damage in India – US$924 million p.a.
Toxic to livestock

7. Prosopis juliflora: Impacts on crop and
pasture production, water resources,
biodiversity, and human health
Reduces water runoff by 481
million m3 p.a. in South Africa “Prosopis is a colonization
without weapons”
“For me dry trees are better than
a green killer”
Forms impenetrable thicketsDisplaces valuable pasture
species

8. Opuntia stricta: Impacts on pasture production,
animal health, and biodiversity

9. To develop toolkits for the identification and
management of IAPs to improve the ability of
those involved in conservation in Laikipia to
identify and control invasive species
Project objective

10. • To identify and fill gaps in existing knowledge on Invasive
Alien Plants (IAPs) presence and threats to biodiversity in
Laikipia
• To make comprehensive data on identification and
management of IAPs in Laikipia freely and widely
available, including an Identification Guide
• To increase the use of information resources by
landowners, communities, conservation organisations,
and other biodiversity stakeholders
• To contribute to the global knowledge pool on the
presence and distribution of IAS
Specific objectives

11. Those responsible for conservation in Laikipia will have
the information they need to manage IAPs better. This
will help to preserve ecosystems and native plants as
well as the animals which depend on them.
Key conservation outcome

12. Thank You