9 research outputs found
Life-form spectra of quartzite and itabirite rocky outcrop sites, Minas Gerais, Brazil
Environmental severity promotes phylogenetic clustering in campo rupestre vegetation
The stress-dominance hypothesis postulates that the importance of competition in plant communities declines with increasing environmental stress while the importance of environmental filters increases. To test this hypothesis for campo rupestre vegetation, we analyzed phylogenetic diversity and community structure of angiosperm communities at two study sites within the Itacolomi State Park, Minas Gerais, Brazil. Plots representing more favorable habitats, such as those with a higher percentage of rocky outcrops that might permit the tapping of deeper water and nutrient resources as well as higher contents of clay and loam thereby increasing water and nutrient availability, show higher phylogenetic diversity and therefore lower phylogenetic clustering than plots with more sever habitats. This observation is consistent with the stress-dominance hypothesis if we assume ecological niches to be conserved within evolutionary niches. However, more comprehensive studies including tests for phylogenetic signal of ecological niches are necessary before generalizations for larger regions may be carried out
Supplementary material 1: Elevation data of FSN Dynamics Plot from: Tree Diversity and Dynamics of the Forest of Seu Nico, Viçosa, Minas Gerais, Brazil - Biodiversity Data Journal 3: e5425 (31 July 2015) https://doi.org/10.3897/BDJ.3.e5425
X, Y and elevation values of all vertices from 100 subplots from the one hectar FSN Dynamics Plot relative to starting point forming the northwestern verte
Pedology and plant physiognomies in the cerrado, Brazil
This study was carried out in Paraopeba National Reserve. It aims to classify and evaluate the soil of the studied area and to verify the influence of soil attributes on vegetation by testing the following hypotheses: 1) under woodland physiognomies (Cerradão) the soil fertility is higher and the Al content lower; 2) open savanna occurs only in areas with high Al contents. For this purpose, representative soils in the Paraopeba National Reserve were mapped, identified, and samples from five profiles were analyzed. The environmental gradient was easily observed by principal components analyses, where the differences between the sites were highlighted. The Spearman correlation was used to verify the hypothesis. The correlation between vegetation (basal area, density, and richness) and soil (K, Ca2+, and Al3+) was statistically significant. The hypotheses were accepted, but hypothesis 1 only partially. Soil features seem to have an influence on the Cerrado phytophysiognomies and structure. Available phosphorous was an important factor for the maintenance of woodland Cerrado. Also, exchangeable Al3+ plays a major role in the establishment of different Cerrado physiognomies in Paraopeba National Reserve
Florística da vegetação arbustivo - arbórea colonizadora de uma área degradada por mineração de caulim, em Brás Pires, MG
Este estudo teve como objetivos analisar a composição florística da vegetação arbustivo-arbórea colonizadora de uma área degradada por mineração de caulim, em Brás Pires, MG, compará-la com outros fragmentos florestais e caracterizar aspectos de auto-ecologia das espécies e o solo da área. O levantamento florístico abrangeu uma área de 0,5 ha, subdividida em 50 parcelas contíguas de 10 m x 10 m. Foram incluídos todos os indivíduos com CAP igual ou superior a 10 cm. A composição florística é o resultado desse levantamento acrescida de coletas fora da área de amostragem, totalizando 64 espécies, distribuídas em 50 gêneros e 30 famílias. As famílias com maior número de espécies foram Leguminosae (11), Annonaceae (5), Lauraceae e Melastomataceae (4), enquanto o gênero mais rico foi Machaerium (3). A análise do substrato, nas condições em que se encontrava, revelou que este não impedia o estabelecimento da vegetação. A síndrome de dispersão preponderante era a zoocórica, destacando-se a importância de indivíduos remanescentes, fragmentos próximos e sua fauna associada. A maior similaridade florística ocorreu com o fragmento em Cruzeiro, SP, estando ambas as áreas em início de sucessão.This study aimed to analyze the floristic composition of shrub-tree vegetation colonizing an area degraded by kaolin mining in Brás Pires, MG, compare it with other forest fragments and characterize ecological aspects of species and soil of the area. The sampled area was 0.5 ha subdivided in 50 grid plots of 10x10 meters each. All individuals included had CAP equal or larger than 10cm. The floristic composition is the result of the sampled area plus species collected outside of it. A total of 64 species was obtained, distributed in 50 genera and 30 families. The families with the greater number of species were Leguminosae (11), Annonaceae (5), Lauraceae e Melastomataceae (4), while the richest genus was Machaerium (3). The soil analysis revealed that it had not impaired the vegetation colonization. The main dispersal syndrome was zoochorous, showing the importance of remnant individuals, surroundings forest fragments and its fauna. The greatest floristic similarity occurred in Cruzeiro, SP, being both areas at the same successional stage