摘要
The rich biodiversity of the Cape Floristic Region makes a substantial contribution to the regional (particularly the Western Cape) and national economy. Harvesting of marine resources, such as linefish, rock lobster, abalone and bait species, is worth over R1300 million year−1, or R1.12 million km−1year−1. Harvests of fynbos products such as wildflowers and thatching reed, and forest products, timber and ferns, are worth R27 and R26 ha−1 year−1 on average, respectively, and a total of R78 million year−1. Natural resource-based tourism is one of the greatest income generators in the region, which is renowned for its beauty and floral diversity as well as other nature pursuits such as whale watching and angling. The natural resources of the CFR also contribute indirectly to the region's economic output: fynbos bees contribute to commercial fruit production, and fynbos mountain catchments provide the region's main water supply. Less tangible values include the option, or future use, value of the region's rich biodiversity, and existence value, for which estimates have been made on the basis of contingent valuation studies. The total economic value of the CFR is estimated to be at least R10 000 million per year (US$1=R7 in 2000), equivalent to over 10 % of the regional Gross Geographic Product. However, invasion of aliens, transformation of natural vegetation and overexploitation of resources threaten the sustainability of this value. Invasive alien plants, which are the greatest proximate threat to floral diversity, already intercept significant water supplies. However, clearing is costly, and while government has an incentive to clear publicly owned mountain catchment areas, private land-owners do not. Similarly, private benefits of conserving fynbos areas do not provide sufficient incentive to protect against transformation to more lucrative farming activities, including monoculture of indigenous species. Current values of marine resources are unlikely to be upheld due to the overexploited status of most stocks, a problem which is compounded by poorly defined property rights, open access and inadequate law enforcement. It will be necessary to provide incentives to private landowners and resource users if optimal levels of protection are to be achieved to maximise benefits to society.