Proposition and Evaluation of Native Vegetation Recovering Index (Nvri) of Rural Property

Abstract

-The new Brazilian Forest Code (Laws no. 12,651/2012 and no. 12,727/2012) establishes a set of rules in relation to native vegetation areas, such as Permanent Preservation Areas and 'Legal Reserve', that must be preserved by the landowner. Thus, it becomes relevant to survey these areas, as well as to assess the need for recovering them. In this context, this research aimed to propose a method for calculating the Native Vegetation Recovering Index (NVRI) for rural properties and to validate it on a case study of Porto Alegre/RS drawing on geotechnology and on a technical cadaster. The method enabled to assess the range of native vegetation and to characterize the Permanent Preservation Areas and the Legal Reserve of rural property, as well as to estimate the fraction of the area to be recovered with native vegetation in each property. In the case study, the calculated NVRI was null for 61 properties, and ranged from 0.1% to 94.0% for other 15 properties examined. For properties sized up to 01FM (one fiscal module), the NVRI was 1.3%; for those sized between 01 and 02FM, it was zero; for properties sized between 02 and 04FM, NVRI was 1.5%; and for properties above 04FM, it was 10.8%. For the total surveyed properties, the calculated NVRI showed that 9.2% of the area that should be covered with native vegetation is in need to be recovered, since it is disfigured in terms of its native flora. By enabling to assess the situation of each rural property regarding its compliance with guidelines established in the new Forest Code, the applied method becomes a supporting tool for policies on territorial and environmental management.