Avaliação da recuperação de áreas hidromórficas: vegetação e solo à montante do abastecimento público Uberlândia, Minas Gerais, Brasil

Abstract

The Buriti Program, destined to the recovery and preservation of hydric resources in the city of Uberlândia, integrates actions which involve environmental education, the recovery of springs, footpaths, and riparian forests. These actions were accomplished in the years of 2009, 2012 and 2015, upstream the public supply catchment for the city of Uberlândia, with the introduction of native Cerrado species. The importance of this paper lies on the evaluation and comparison of the floristic diversity and soil properties in permanent preservation areas (PPA) recovered by the Buriti Program, contributing to the preservation of hydric resources and biodiversity. While investigating the relation between soil and vegetation, the studies helps implementing more efficient actions regarding ecological restoration, promoting the sustainability of water bodies and delivering crucial data to monitor the effects of environmental preservation along the years. The objectives of this paper were to evaluate and compare the floristic and structural heterogeneity of different Permanent Preservation Areas (PPA) of the Buriti Program with adjacent remnant areas, as well as to investigate whether the physical and chemical properties of the soil influence the distribution of plant species. Three isolated areas with plantations in the years of 2009, 2012 and 2015 were selected for comparison with three adjacent native areas. In each native vegetation planting area, ten portions of 10 x 10 meters were assigned, totaling 60 portions. Soil samples (0 - 20 cm depth) were subjected to chemical and physical analysis. The floristic similarity among the different areas was calculated through Jaccard index. To analyze the variability of the species composition, the non-metric multidimensional scaling method was applied. Phytosociological parameters of density, dominance and absolute and relative frequency, as well as the importance value were evaluated. The diversity indexes by Shannon-Wiener, Simpson and equity by Pielou were calculated. The physical and chemical properties of the soil were resumed through Principal Component Analysis. To evaluate a possible relation between edaphic variables and the abundance of species, the canonical correlation analysis was used. The evaluation of vegetation and/or soil communities in degraded areas in the recovery process, especially in footpaths and gallery forests, is an essential work, once it allows us to implement actions which may benefit the maintenance of water bodies and the creation of floristic database that allow us to monitor the restoration benefits. The results revealed low floristic similarity between recovery and remaining areas, indicating that planted species were not properly chosen according to the local ecological conditions. The diversity was low in all the areas, suggesting degradation due to agricultural activities. Furthermore, the soil density and the organic matter were influenced especially by the nature of the soil, not by its management. These results show the need to a better planning and choice of species, as well as a long-term monitoring to improve regeneration strategies of the Cerrado, aiming a more efficient preservation.