Aspectos ecológicos da vegetação lenhosa das áreas de preservação permanente, no município de Mineiros, Goiás, à luz da nova política de proteção da vegetação nativa - a lei 12.651/2012

Abstract

Permanent preservation areas (PPAs) adjacent to drainage channels may include forests, savannahs, or grassland Under a former environmental legislation ("Forest Code"), it was required to maintain a stripof native vegetation (at least 30 m wide) at the margin of any drainage channel, to support environmental functions. Under the current native vegetation protection policy, if a riparian margin was degraded priorto 2008, the landholder is required to regenerate a strip of only 5-20 m, in some cases. The present study evaluated and compared the ligneous vegetation structure in 10 preserved PPAs (following the requirements of the old law) and 10 degraded PPAs (conforming to the current environmental legislation), in Mineirosmunicipality, southwest Goiás. Sixty plots measuring 15 m × 30 m were delineated, and data for all ligneousindividuals with a diameter at breast height (DBH) > 5 cm were recorded. A total of 2,662 individuals were documented, distributed among 208 species. Of the total, 1,573 individuals belonging to 167 species werefrom the preserved PPAs, and 1,089 individuals across 142 species were from the degraded PPAs. Accordingto these results, the preserved PPAs were richer in species composition than in the degraded PPAs (245.5± 34.36 and 213.3 ± 34.1, respectively), in addition to being more abundant in terms of individuals. The importance value index (IVI) was well distributed among the species. All the degraded PPAs presented signs of erosion. It was concluded that the reduced width of the PPAs (5-20 m) under the current native vegetation protection policy would result in a loss of the environmental functions sought by the legislation.