Dinâmica e ecologia funcional das espécies lenhosas de Cerrado na FLONA de Paraopeba, MG

Abstract

The succession and vegetation dynamics is the form how the species composition and physiognomy of vegetation, change a particular location over time. Regardless of the taxonomic or phylogenetic relationships, the functional classification of plants allows the gathering of groups of species that respond similarly to biotic and abiotic factors, allowing better understanding the ecosystem. The aim of this study was to evaluate the temporal variation in vegetation structure during the period of four years (2005-2009), in a gradient of Cerrado Paraopeba located in the city of Minas Gerais. The specific objective was to test the hypothesis that different groups of species have different adaptability to soil types of the five Cerrado Paraopeba, each functional group with the highest rates of recruitment and growth on the soil type that are best adapted. For vegetation sampling, five transects were installed 20 x 100 m, divided into plots of 10 x 10 m, with a total ha. The transects were installed at five sites with different soil conditions in order to sample different soil conditions, and consequently a greater number of vegetation. All individuals of woody layer in the plots with a circumference at ground level (CAS) ≥ 10 cm were marked and measured. Were considered as recruits, all individuals have emerged and had not been previously measured and marked for not having met the inclusion criteria, and considered dead, all plants sampled in the first survey that were not found in the plots. The collection of soil was performed in five transects marked in the first survey. These transects were divided into five plots of 20 x 20 m. In a radius of five meters measured from the center of each plot was randomly collected 10 soil samples 0-20 cm depth, which were three repetitions. The samples were homogenized to form a composite sample of soil, adding five samples per transect, representing 25 samples. Functional types were assigned based on the theory of adaptive strategies of plants - competitors, ruderal and stress tolerant. We observed two primary strategies in the Paraopeba National Reserve Cerrado: the competitors (CC) and stress-tolerant (AT), and two secondary strategies: the ASC (aluminum semitolerant) and ATC (aluminum-tolerant competitors). The functional groups related to faces and soils corroborate literature showing that species with low tolerance, are actually tailored to settle in soils where aluminum levels are low, while those with high or moderate resistance are able to survive high concentrations of element. Regarding the growth of basal area of species within the groups confirmed the hypothesis that the ASC had the highest growth in basal area (0.95 m 2 ) in Red Latosol Mesotrophic, followed by CC (0.65 m 2 ) on the same soil type. And with respect to density, again the ASC (23.6 ind.) followed by CC (13.83 ind.) on Red Latosol Mesotrophic, and yet, the ATC and AT with the highest number of individuals in the Yellow Cambisol and Yellow Latosol, respectively. However, while aluminum is a widespread mineral in soils of the Cerrado, such studies only indicate the species that are established in soils with greater or lesser availability of this element.