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Wildcliff Nature Reserve
Dedicated to
plant and wildlife conservation in South Africa's Cape Floral Kingdom
Ants
in the Fynbos: Invasive and Native
 The Argentine Ant, Linepithema
humile (Hymenoptera:
Formicidae), is well known to be a globally successful invasive
species.
- In South Africa it has been shown to
have significant
negative impacts on native ant diversity, and to negatively impact seed
dispersal and germination and establishment rates of fynbos plant
species.
- Invasive ants have a great
potential to alter ecosystem processes, including ant-mediated seed
dispersal or plant pollination. In California the removal of seeds
produced by the myrmecochorous (ant-dispersed) tree poppy Dendromecon
rigida is less in areas inhabited by the Argentine ant
than in areas inhabited by the common harvester ant (Pogonomyrmex
subnitidus). A similar outcome has
occured in the South African fynbos, where the displacement of
large native ants by L. humile has lead to a reduction in the
dispersal of large ant-dispersed seeds and a reduction in the
reproduction of those plants.
- Native ants and other insects play an
important role in burying and dispersing seeds, and in pollination of
the fynbos vegetation. Native arthropods are
greatly threatened by Argentine ants. In South Africa, the Argentine
ant can collect up to 42% of available nectar before bees can forage
(Buys 1987, in Holway et al. 2002a). In Hawaii the Argentine
ant reduces numbers of many native arthropods, including essential
pollinators (Cole et al. 1992, in Krushelnycky et al.
2004), the loss of which could threaten insect-pollinated plants such
as the endangered “silversword.”
- However, the impact of the Argentine
ant on the
functioning of fynbos ecosystems remains poorly understood. Prof
Melodie McGeoch of Stellenbosch University is seeking to
quantify the impact of the Argentine ant on
ecosystem services in the Cape Floristic Region.
- The Wildcliff study will investigate
the
impact of the
Argentine ant on the ecosystem of the Wildcliff Nature Reserve in the
Cape Floristic Region and assess the long-term biodiversity
consequences thereof.
- The project will use a combination of
literature,
existing data and additional field work to address its objectives.
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Researcher: Marijke Wouters,
Belgian entomologist
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Links & References
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