POLICY RELEVANT ECOSYSTEM SERVICES VALUATION; RAINFOREST NON·TIMBER PRODUCTS

One recent study has estimated the current economic value of seventeen ecosystem serviceson a biosphere-wide basis at between US$ I (i - 54 trillion (1012) per year. representing anaverage annual value some I.X times the current global gross national products (Costanza('I (/1. 1997). Such global aggregate values. while they serve to raise awareness andstimulate dialogue between scientists. social scientists. policymakcrs and citizens. shouldnot be taken too literally. The challenge will he to quantify in monetary terms and provehow valuable ecosystem services arc: as well as to formulate mechanisms by which suchfunction-based values can he realistically appropriated by society. In a much quoted paper(Peters et al.. 19X9) the economic value (net present value) of the fruits and latex harvestfrom an Amazonian forest was estimated to he US$ 6.:nO ha·l. Even more significantly. itwas also claimed that such an economic return was sawntimber extraction/production(NPV = US$ I.(JOO ha'). timber and pulpwood extraction/production (NPV = US$ 3.lX4ha·l) or fully-stocked cattle pasture (NPV = US$ 2.2960 ha-I). This is a strong conclusionwith obvious implications for tropical forest conservation verses development policy. Thetemptation then is that such findings are gcncraliscd.This paper focuses on tropical rainforest ecosystems and the use value of their non-timberforest products (NTFPs) provisions to test whethcr this conclusion is universally valid?The study has rigorously applied its data collection and analysis to validity and reliabilityprotocols in order to estimate the policy relevant NTFPs value derived from the Sinharajarainforest in Sri Lanka. This forest land use has then been compared with alternative lane!us options in a cost-benefit analysis. The results indicate that the NPV of the actual NTFPsnow from the Sinharaja is US$ 147 ha-I which is significantly lower than the landclearance value USS 42XI ha-I (tea cultivation). This means that previous studies havesignificantly overestimated NTFPs value. and consequently that biodiversity conservationpolicy cannot be economically justified (economic efficiency criterion) on the basis ofsustainable NTFPs collection alone. Such a strategy docs. however. also have other widersocial benefits for local forest village communities such as income distribution effects.Conservation of the forest ecosystem would also generate other uses and non-use valueslinked to other 'NTFPs-col11patiblc' forest function services. An economic case for such aconservation strategy will have to he based on the multiple services value that a given'healthy' forest ecosystem can provide sustainably over lime,