Identificação de serviços ecossistêmicos de campos naturais no Bioma Pampa e valoração do estoque de carbono do solo utilizando a metodologia TESSA

Abstract

The ecosystem services are considered the benefits which the people got from nature. The evaluation of this services can aid in the mitigation of the factors of degradation from one of grasslands ecosystems more important of the world, the natural fields of Pampa. This work aims to adapt this biome into the reality to the methodology TESSA (Toolkit for Ecossistem Service – Site-based Assessment) a set of tools that acess and monitor ES, with low investment. For this purpose were chosen two certificated farms by Alianza del Pastizal in Lavras do Sul city, RS, Brazil. The amount was done through of samples of biodiverty, forage mass and soil, unshaped and shaped,in the depth of 0 - 5cm, 5 - 10cm e 10 -20 cm in two farms, called of Preserved (P) and in Recovering (R). They were chosen three transects on toposequence (top, encost and low), open trenches and collected. The qualitative research was done with researches from Embrapa Pecuária Sul and livestocks farmers from the Rural Sindicate of Lavras do Sul I the way of workshops were day pointed the main ES and graduated the importance. All data were subimited to Analysis of the Main Components (AMC) and the data of carbon stock and Economic Evaluation were determinated by an analysis of two ways followed by posttest of Bonferroni (p<0,05). The test of AMC with average from each toposequence with the results of absolute covering of each species found, uncovered soil, hight, forage mass, organic carbon, soil density, Ph, H + Al, aluminum, calcium, magnesium, phosphorus, potassium and Shannon and Pielou index had as result the main component 1 that explained 99,6% of the results, with the forage mass index and hight of grassland, showing the direct correlation of conservation of environmental services with the good practices of management in this ecosystem. The qualitative results showed that among the main ES noticed by farmers and researches are native environment, water quality, meet quality, way of life and the beauty of landscape, except the carbon, that wasn’t mentioned by farmers. As main threats to the conservation of biodiversity are the familiar succession, infrastructure, land reform, governmental actions and presence of invader species. The carbon organic amount in the layer of 20cm of soil was found significate difference either between the two farms or between the topo sequences. The results turned in to dollars in the volunteer market made possible to get to the average values of U$ 359,00 to the preserved grasslands and U$ 250,00. The carbon market is volunteer, therefore its value might be “any dealt value” but its utility is in demonstrate the differences between two farms studied. The difference of values between two farms is of U$ 108,00. The public policies must be led since from the threats noticed. The amount of organic carbon of natural grasslands in the farms analyzed is engaged to the historical and management livestock adopted. The data indicate that these ecosystems with good livestock management have good important stocks, therefore its conservation is relevant to the mitigation of climate changes. It is suggested in this paper that the values for the ecosystem service payment projects provided by these livestock farmers are or the Carbon Stock (U$ 108,00) of the difference or the difference between the opportunity cost of the land lease, from U$ 140, compared with production of more profitable alternatives.