Estrutura e diversidade do cerrado stricto sensu em beira de rodovias

Abstract

Roads have one of the greatest direct and negative impacts on the environment, and there must be a roadway between the road and nearby properties, which is defined as a Permanent Preservation Area. The objective of this work was: 1) To evaluate the current condition of the cerrado tree communities present in the non aedificandi ranges, which suffer impacts caused by the highways and their surroundings; 2) To compare the diversity of the Cerrado along the highways, the possible floristic and structural differences caused by anthropic impacts in relation to native cerrado and to provide data capable of defining the real value of the non aedificandi conservation for the conservation of the Cerrado biome. With the hypothesis that the bands non aedificandi offer subsidy for the conservation of the native vegetation of Cerrado representing conserved areas. The study was performed in the non-aedificandi bands in four locations: in the northwest of the state of Goiás (NO-GO) in GO-164; GO-070 and GO-060, in the south of the state of Goiás (S-GO) in BR-153, in the southeast region of the state of Goiás (SE-GO), during GO-330; GO-213 and BR-490 and in the Triângulo Mineiro and Alto do Paranaíba in Minas Gerais (TRI) in MG-190; MG-223; BR-365 and BR-352. Only the margins of the highways where the tree savanna phytophysiognomy. We sampled 100 plots of 50 x 10 m randomly arranged, totaling a sample area of 5 ha. All living woody individuals with a circumference at 30 cm of soil equal to or greater than 15 cm were listed, the species classification was done according to the APG III system and the specific names updated from theplantlist.org. The floristic survey carried out in the four regions showed a total of 1663 individuals distributed in 163 species and 44 families. The Fabaceae family obtained a larger number of species (30), followed by Bignoniaceae (17), Myrtaceae (13) and Malvaceae / Vochysiaceae (9). The mean number of individuals for the NO-GO, TRI, SE-GO and S-GO regions was 504.44, 395, 307.69 and 151.03 ha-1 , respectively. Of the species found in conserved areas, 76.3% were found along the roadsides. The highest species richness was in the NO-GO area with 103.33 ha-1 and the lowest was S-GO with 22.07 ha-1 . The cumulative wealth curve did not stabilize for any area except for S-GO. Only three species had occurrences in the four regions: Aspidosperma macrocarpon Mart., Machaerium opacum Vogel and Platypodium elegans Vogel. The vegetated strips along the highways form small habitats capable of sustaining a diversity similar to that found in natural areas; however, the species that support the impacts may be very different from those in native areas, as a result of the increased incidence of fires, the species that have the most frequent resistance mechanism in this environment.