An ecological economic simulation model of mountain fynbos ecosystems - Dynamics, valuation and management

Mountain fynbos ecosystems in South Africa are threatened by alien plant invasions and by a lack of funding for effective management of these invasions. This paper develops an ecological-economic argument for the effective management of plant invasions in mountain fynbos ecosystems. We do this by building a dynamic ecological economic model which values the ecosystem services that fynbos ecosystems provide under different management regimes. We propose that the services that mountain fynbos ecosystems provide fall into six components: water production, wildflower harvest, hiker visitation, ecotourist visitation, endemic species and genetic storage. A scenario analysis based on a hypothetical 4 km(2) mountain fynbos ecosystem in the western part of the fynbos biome estimated that the ecosystem's value varies from R19 million (under low valuation and poor management scenario) to R300 million (under high valuation and good management scenario) [R4.50=US$1]. Water production and genetic storage were the most valuable ecosystem services. The model showed that the cost of clearing alien plants (under the proactive management scenario) was a tiny (0.6-5%) proportion of the value of mountain fynbos ecosystems. This result motivates an injection of funds for clearing alien plants from mountain fynbos ecosystems. (C) 1997 Elsevier Science B.V.