www.cabi.org

KNOWLEDGE FOR LIFE

Identification and management toolkit for invasive plant species in Laikipia, Kenya

Frances Williams

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.

• 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:

Pastoralism contributes 50% to agricultural Gross Domestic Product (GDP) in Kenya

A recent study indicated that without any managementof 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.

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

Lantana camara: Impacts on crop and pastureproduction, animal health (toxic) and biodiversity

Damage in India – US$924 million p.a.

Toxic to livestock

Prosopis juliflora: Impacts on crop andpasture 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

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

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

• 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

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

Thank You