Valoração econômica de serviços ambientais em propriedades rurais

• Autor(a) principal: Vilar, Mariana Barbosa
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3016
• topic: Bolsa verde; Área de preservação permanente; Créditos de carbono; Produção de água; Green exchange; Permanent Preservation Areas; Carbon credits; Water production; CNPQ::CIENCIAS AGRARIAS::RECURSOS FLORESTAIS E ENGENHARIA FLORESTAL::MANEJO FLORESTAL

Environmental services related to water production, biodiversity maintenance and climate regulation, are being produced by anonymous farmers, who have not been recognized by the society yet. Nowadays, the environmental law doesn't encourage farmers to maintain important areas to ensure the provision of the environmental services. On the contrary, the current law punishes the farmers through the command control policy that has been proven ineffective. It is necessary to carry out researches to recognize and value the environmental services. The results of these researches can guide the decision makers and the farmers to determine the economic value of their farms. Thus, this study has aimed at determining the economic value of the environmental services provided on ten farms which belong to the Turvo Limpo River Watershed-MG. The economic valuation of environmental services is an important stage for the establishment of incentive systems for environmental protection. Ten farms were visited in a bordering area of three towns: Viçosa, Porto Firme and Guaraciaba-MG. An adaptation of the valuation matrix of environmental damages was used to generate the valuation matrix of environmental benefits. To use this method two categories of variables were identified: quantifiable and intangible variables. Multiplying the intangible variables sum times the quantifiable variables sum yields the Reference Value for the Environmental Benefits (RVEB). The category of quantifiable variables was shown by the carbon stock of the arboreal vegetation and of the grassyherbaceous vegetation in Permanent Preservation Areas (PPAs) around springs located on each studied farm. The biomass of the arboreal vegetation was determined through allometric models. The destructive method would not be technically and legally viable. The biomass of the grassy-herbaceous vegetation was defined through the proportionality method. Conversion of biomass into carbon stock was obtained by using a 0.5 factor, and the estimation of the generated carbon credits by a 3.67 factor. The water production of each spring located on the studied farms was another quantifiable variable that made up the valuation matrix of environmental benefits. Those springs feed the Turvo Limpo River and Turvo Sujo River. These rivers are tributaries of the Doce River, one of the main rivers of Minas Gerais state. The springs flows measurements were carried out from September 2008 until June 2009. The direct method of flow measurement was used through bucket and chronometer. The indirect method was also used through a flow probe. Values of the carbon credits from the Chicago Climate Exchange were attributed to the existent carbon stock on the farms. For the water production on the farms two values were attributed: charging of water used in the South Paraíba River Watershed (scenario 1); and the value used in the system of payment for environmental services employed in Apucarana-PR (scenario 2). The environmental services related to the air quality, water quality, soil conservation and biodiversity characterized the intangible variables. Economic values were not attributed to the intangible variables. Then, quantified indicators were attributed to the intangible variables. The arboreal vegetation presents an average carbon stock of 59.72 t.ha-1 in protected PPAs. The average carbon stock found in the grassy-herbaceous vegetation, which characterized PPAs in a recovering process, was 3.87 t.ha-1. Converting the present carbon stocks of these PPAs to carbon credits, it means for the arboreal vegetation an average value of R$568.06.farm-1 and for the grassy-herbaceous vegetation the amount of R$12.74.farm-1. The maximum annual flow was 333,807.00 m³.year-1, and a minimum annual flow of 1,591.92 m³.year-1. An average water consumption for each farm is 1,603.55m³.year-1, which means that the studied farms are self-sufficient in water production. Considering the net production of water as being the difference between the annual spring flow and the annual water consumption on the farms, an average value of the net production of water is 65,375.16 m³.year-1. This would generate a value for the net production of water equals to R$653.75.year-1 considering scenario 1. At scenario 2, the net production of water had an average value of R$798.00.year-1. The multiplication of the intangible variables times the quantifiable variables yields R$16,942.21.year-1 (scenario 1) and R$21,127.44.year-1 (scenario 2), as an average RVEB value. Adopting the RVEB values as a reference, it s interesting to consider RVEB as a farm s appraisal and valuation due to the existence of natural resources and also to the management adopted by the farmers for the environmental services provision. Improving the valuation method, the intangible variables were weighed through the Delphi technique. For this, 15 specialists were consulted and asked to express their opinion about the level of importance of each indicator used. The new valuation matrix included the intangible variables after weighing and a correction factor. This factor depends on the socioeconomic and environmental features of each farm involved in the research. The new valuation matrix, after improvement through the Delphi technique, indicated weighed values for RVEB per area of R$402.18.(ha.year)-1, in scenario 1; and R$517.78 (ha.year) -1, in scenario 2. The new values attributed to the environmental benefits provided on the studied farms serve as a reference for implementation of public policies, which would encourage farmers to maintain the environmental services. The carbon stock and the water production are important parameters to be considered for economic valuation of the environmental services provided on farms. However, the valuation alone does not mean success of the establishment of the incentive systems for environmental protection. For these systems to succeed, it is necessary to have a political engagement of all involved in this process. Certainly, the benefits will be noticed by both farmers and consumers of environmental services. When an incentive system for environmental protection becomes effective, the natural resources are incorporated into the economic system. In addition, it is possible to minimize the effects of the indiscriminate use of environmental goods and services.