Restinga forests of the Brazilian coast: richness and abundance of tree species on different soils

The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes.O objetivo deste estudo foi o de determinar as mudanças na composição, abundância e riqueza de espécies ao longo de um gradiente de floresta com variações de solo e inundações. As florestas localizam-se na margem esquerda do Rio Jucu, no Parque Natural Municipal de Jacarenema, Espírito Santo. O levantamento das espécies arbustivo/arbóreas foi realizado em 80 parcelas de 5x25m, distribuídas equitativamente entre as florestas estudadas. Foram incluídos na amostragem todos os indivíduos com >3,2 cm diâmetro à altura do solo (1,30 m). Foram coletadas amostras de solo superficial (0-10 cm) em cada parcela para análise química e física. Os resultados mostraram a existência de gradiente pedológico significativo, que é influenciado pelas variações sazonais do lençol freático. As formações florestais da Restinga apresentaram diferenças significativas na riqueza de espécies, com exceção da Floresta Não Inundável em relação a Floresta Não Inundável de Transição. A Análise de Correlação Canônica (CCA) mostrou que algumas espécies apresentam sua distribuição ao longo do gradiente sob influência da drenagem, das concentrações de nutrientes e das características físicas dos solos. Entre as variáveis testadas, a inundação parece ser o fator mais limitante para o estabelecimento de espécies vegetais nas florestas de Restinga do que os atributos básicos de fertilidade do solo

Restinga forests of the Brazilian coast: richness and abundance of tree species on different soils

The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes

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

Soil-vegetation relationships on a banded ironstone 'island', Carajás Plateau, Brazilian Eastern Amazonia

Vegetation and soil properties of an iron-rich canga (laterite) island on the largest outcrop of banded-iron formation in Serra de Carajás (eastern Amazonia, Brazil) were studied along a topographic gradient (738-762 m asl), and analyzed to test the hypothesis that soil chemical and physical attributes play a key role in the structure and floristic composition of these plant communities. Soil and vegetation were sampled in eight replicate plots within each of the four vegetation types. Surface (0-10 cm) soil samples from each plot were analyzed for basic cations, N, P and plant species density for all species was recorded. CCA ordination analysis showed a strong separation between forest and non-forest sites on the first axis, and between herbaceous and shrubby campo rupestre on the second axis. The four vegetation types shared few plant species, which was attributed to their distinctive soil environments and filtering of their constituent species by chemical, physical and hydrological constraints. Thus, we can infer that Edaphic (pedological) factors are crucial in explaining the types and distributions of campo rupestre vegetation associated with ferruginous ironstone uplands (Canga) in Carajás, eastern Amazonia, therefore the soil properties are the main drivers of vegetation composition and structure on these ironstone islands

Análise da estrutura de uma comunidade lenhosa em área de cerrado sensu stricto no município de Senador Modestino Gonçalves, norte de Minas Gerais, Brasil A woody community structure in a cerrado sensu stricto area of the municipality of Senador Modestino Gonçalves, north of Minas Gerais State, Brazil

Com a finalidade de conhecer a estrutura de uma comunidade arbórea de uma área de Cerrado, fez-se um estudo fitossociológico no Município de Senador Modestino Gonçalves. Para tal foram delimitadas 30 parcelas de 10 x 20m para levantamento dos dados, utilizando-se como critério de inclusão os indivíduos com circunferência do tronco à altura do solo (CAS) = 10 cm. Foram encontradas 91 espécies de 38 famílias. As espécies que se destacaram como as mais importantes foram Qualea grandiflora, Eriotheca pubescens, Caryocar brasiliense, Byrsonima coccolobaefolia, Myrsine guianensis, Qualea parviflora, Dalbergia miscolobium, Stryphnodendron adstringens, Plathymenia reticulata e Lafoensia pacari. Essas 10 espécies representaram 49,32% do VI e 51,26% dos indivíduos amostrados. A área não apresentou espécie com dominância marcante, como mostrou o valor de equabilidade (J'= 0,80). Além de se destacar pela riqueza, o cerrado estudado destacou-se também pelos altos valores de densidade (6.476,67 ind/ha), de área basal (28,93 m²/ha) e pelo alto índice de diversidade (H'=3,61).<br>The aim of this work was to study the phytossociological structure of a tree community in a cerrado fragment located in Senador Modestino Gonçalves, MG. A total of 30 10x20m stands of tree individuals with stem circumferences at the soil level = 10cm were sampled, being found 91 species belonging to 38 families. The most important species were Qualea grandiflora, Eriotheca pubescens, Caryocar brasiliense, Byrsonima coccolobaefolia, Myrsine guianensis, Qualea parviflora, Dalbergia miscolobium, Stryphnodendron adstringens, Plathymenia reticulata and Lafoensia pacari. These species represented 49.32% of the importance value and 51.26% of the individuals. Besides standing out for its richness, the studied cerrado fragment also outstood out for its high tree density, biomass and diversity

Desenvolvimento e validacáo de metodologia analitica por espectrofotometria no visÍvel para quantificacäo de taninos totais na casca do caule de Simarouba amara Aubl

The stem bark of Simarouba amara Aubl., Simaroubaceae, is widely used in Brazilian folk medicine and in many countries of Central and South America for the treatment of malaria, intestinal parasites, diarrhea, anemia and fever. Although quassinoids are considered chemotaxonomic markers of the species, the unavailability of commercialization standards stay as a challenge for its quality control. Therefore, the purpose of this study was the development and validation of an analytical methodology by spectrophotometry to quantify the total tannin content from stem bark of S. amara, since this class of metabolites is one of the most abundant and representative in the species. The proposed method was based on quantification at 760 nm after addition of Folin-Ciocalteu reagent and its validation included all parameters recommended by the RE 899. The results showed that the proposed method was adequately developed and validated, and it is an useful analytical tool for the quality control of S. amara. © 2015, Sociedade de Investigacoes Florestais. All rights reserved