Alexandre Francisco da Silva

Composição florística de dois trechos em diferentes etapas serais de uma floresta estacional semidecidual em Viçosa, Minas Gerais

This study was carried out in two sites of a semideciduous forest, under different stages of secondary succession in Vicosa, MG to verify qualitative variations in floristic composition. In each site, ten plots of 10 m x 20 m were delimited, with all woody individuals with circumference at 130 cm height from the soil larger than or equal to 5 cm being listed. Floristic similarity among parcels was evaluated through clustering analysis, using the Sorensen index. Sixty-seven species were sampled in the 15-year-old area, and 69 species in the 30-year-old area. Among the exclusive species, 38 were placed in the younger site and 40 in the older. The families Annonaceae, Leguminosae Caesalpinioideae and Sapindaceae, with five, four and four species, respectively, and the genus Nectandra, with two species, were better represented in the 15-year-old site. On the other hand, the families Flacourtiaceae, Meliaceae and Myrtaceae, with four, three and four species, respectively, and the genus Ocotea, with three species, were better represented in the 30-year-old site. Floristic similarity among plots from the same area was considered high, being related to spatial proximity, which reflects similar bakgrounds of disturbance and regeneration, consequently resulting in similar floristic compositions and secondary succession stage.

Composição florística da vegetação arbórea de um trecho de floresta de galeria do Parque Estadual do Rola-Moça na Região Metropolitana de Belo Horizonte, MG, Brasil

The study was developed in a gallery forest in the Area de Protecao Especial do Barreiro area in Rola-Moca state Park, Metropolitan Region of Belo Horizonte (MG). The objective was to determine the floristic composition of that forest, important for subsidy in recovery projects. The floristic composition was determinated from phytosociological sample through the method of quadrats, being demarcated 36 quadrats of 10×10m. All the arboreal individuals were included with girth at breast height equal to or greater than 15cm. Were encountered, 97 species, distributed from 79 genera of 43 families. The floristic composition when compared with other gallery forest in the Southeast and Center-west presented low similarity, being the largest similarity verified to the forest of south of Minas state. The floristic richness showed significant differences when related with distance of the stream, being the zone located at 28, 64 and 82m responsible for the largest richness values.

A woody community structure in a cerrado sensu stricto area of the municipality of Senador Modestino Gonçalves, north of Minas Gerais State, Brazil

The aim of this work was to study the phytossociological structure of a tree community in a cerrado fragment located in Senador Modestino Goncalves, 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.

Seed rain in a seasonal semideciduous forest at Viçosa, Minas Gerais State, Brazil

This study aims to evaluate the floristic composition, density and frequency of seeds in 25 traps in a section of seasonal semideciduous forest, as well as classify taxons as to life form, dispersal syndromes, and succession phase of the tree species, and verify floristic similarities between seed rain species and tree species located in the same plots. The work was carried out from December/2004 to November/2006. Forty three taxons were recognized and Leguminosae was represented by 11 species. The dominant life form was arboreal (63.1%), climbers were represented by 28.9% of the sampled species, herbs by 5.3% and shrubs by 2.6%. Mean seed density in the first year was 113.92 seeds.m-2 and 2603.84 seeds.m-2 in the second year. These differences showed spatial and seasonal heterogeneity of the seed rain. Floristic similarity using Sorensens index between seed-rain species and tree species from the studied fragment was 32%, a value considered to be low (< 50%). This result showed that the adjacent arboreal vegetation composition had little influence on the seed rain.

Florística e estrutura horizontal da vegetação arbórea de uma ravina em um fragmento florestal no município de Viçosa, MG

This study was developed in a section of a Montane Seasonal Semideciduous Forest fragment, in the Bom Sucesso Farm, Vicosa - MG - Brazil. This study aimed at finding out about the floristic composition and the phytosociologic structure of the tree component. Ten transects of 50x10m, subdivided into 5 plots of 10x10m each, totalling 50 plots within 5000m 2 were established. In the sampling, all the tree individuals with a minimum of 15cm of stem circunference at 130cm above ground were evaluated. A total of 151 species pertaining to 108 genera of 45 botanic families were identified. Within 0.5 ha, 820 alive trees and 32 dead standing up trees were sampled, which means a total density of 1704 individuals/ha. The basal area/ hectare was 38.450m 2 and the average height was 8.43m. The species Euterpe edulis was prominent in the structure of the studied vegetation, with 314 individuals sampled, resulting in a relative density of 37.38%, absolute frequency of 90%, relative frequency (FR) of 8.91%, relative dominance of 18.79%. The Shannon diversity index was 3.52 and the equability was 0.696. The result of floristic composition and phytosociologic structure showed high richness and medium diversity, although most of the species were represented by few individuals.

Estrutura do componente arbóreo de um trecho de Floresta Atlântica na Área de Proteção Ambiental da Serra da Capoeira Grande, Rio de Janeiro, RJ, Brasil

The Area de Protecao Ambiental Serra da Capoeira Grande is a 80 ha site and one of the last forest remnants in Rio de Janeiro municipality where Caesalpinia echinata Lam. (brazilwood) occurs naturally. Trees were sampled according to the point-centered-quarter method. The inclusion criteria was PBH ³ 15 cm and a total of 200 points were surveyed. 44 species were identified, belonging to 36 genera and 22 botanical families The families with the higher importance value indices (VI) were Solanaceae (34.1%), Leguminosae (Mimosoideae with 16.4%, Papilionoideae with 7.9% and Caesalpinioideae with 2.1%), Nyctaginaceae (13.0%), Anacardiaceae (6.5%) and Flacourtiaceae (6.1%). The species with greater number of individuals were the same with higher VI. They are: Metternichia princeps Mik. with 40.4% of the individuals and 33.7% of the total VI, Pseudopiptadenia contorta G.P. Lewis & M.P. Lima (9.3 and 12.6%), Guapira hirsuta (Choisy) Lundell (7.5 and 7.8%), Astronium fraxinifolium Schott ex Spreng. (5.6 and 5.7%). Caesalpinia echinata Lam. followed with 2.4% of the individuals and 2.1% of the total VI. Trunk diameters of the individuals are concentred in the smallest classes diameter distribution of the most important species sampled indicate abundant regeneration.

Composição florísitca de uma área de cerrado sensu stricto no município de Senador Modestino Gonçalves, Vale do Jequitinhonha (MG) e análise de similaridade florística de algumas áreas de cerrado em minas gerais

Studies on factors influencing species distribution are necessary because of the accelerated agricultural advancement over these species. Thus, this study aimed to assess Senador Modestino Goncalves floristic composition and possible cerrado floristic connections in Minas Gerais. Twenty-eight areas were assessed for floristic similarity, including Senador Modestino Goncalves. Sfrensen index was used in comparative analyses. Floristic analysis identified 91 species, 65 genera and 38 families. Greater richness was represented by Leguminosae (13), Malpighiaceae (11), Myrtaceae (7), Vochysiaceae (4), Sapindaceae (4), and Rubiaceae (4). A strong floristic similarity was found in cerrado vegetation, with six groups being formed with superior similarities for 0.5. However, the factors influencing this distribution could not be verified, but geographical proximity and altitude seem to have a strong influence on some of these groups.

BIOLOGIA DE Thaumastocoris peregrinus CARPINTERO E DELLAPÉ (HEMIPTERA: THAUMASTOCORIDAE) EM DEZ ESPÉCIES DE EUCALIPTO

The bronze bug Thaumastocoris peregrinus is native from Australia and has been detected in Brazil since 2008, causing damages in eucalyptus plantations. This insect feeds on phloem-sap, preferentially on the oldest leaves that evolves into chlorotic spots and later in bronze spots. In high infestations, plant defoliation may occur. Although the presence of bronze bug on eucalyptus trees has been often recorded, still there is lack of behavioral studies. Therefore, the biology of the Thaumastocoris peregrinus was evaluated in different species of eucalyptus, commercially available in Rio Grande do Sul state. From all tested species, Eucalyptus dunnii conferred the greatest longevity, number of adults, egg and insect viability.

Microbiological Attributes of Soil Under Spontaneous Restoration

The aim of this study was to evaluate the effect of vegetation on soil microbial activity during spontaneous restoration and the effect of remaining eucalypts on the restoration stage of reserve ranges installed in eucalypt plantations. The studied areas were in the following stages: initial restoration stage with and without remaining eucalypts; advanced restoration stage with and without remaining eucalypts. Areas of Cerrado, native forest and commercial eucalypt plantation (Eucalypts) were evaluated for reference. Principal component analysis detected the following groups: 1Cerrado and areas in initial restoration stage with or without eucalypts and areas in advanced restoration stage without eucalypts; 2areas in advanced restoration stage with eucalypts; 3native forest; 4Eucalypts. The restoration areas are at intermediate stage of recovery, slightly superior to the advanced stage. Basal respiration, organic and microbial soil carbon and microbial and metabolic quotients were more similar to those observed in Cerrado than in eucalypt cultivation areas and little influence of the remaining eucalypts plants was observed.

FITOSSOCIOLOGIA DO ESTRATO ARBÓREO DE UM FRAGMENTO DE FLORESTA ESTACIONAL SEMIDECIDUAL MONTANA – “MATA DA AGRONOMIA”, VIÇOSA-MG

A area de estudo se localiza no municipio de Vicosa-MG, nas coordenadas 20°46’30.2’’S e 42°52’18.4’’W. O objetivo deste trabalho foi determinar a estrutura fitossociologica e grupos ecologicos da vegetacao arborea de um fragmento de Floresta Estacional Semidecidual Montana denominado Mata da Agronomia. Para o estudo fitossociologico, foi utilizado o metodo de quadrantes. As especies amostradas foram classificadas de acordo com seu grupo ecologico (pioneiras, secundarias iniciais, secundarias tardias e indiferentes). O indice de diversidade encontrado foi de 3,728. O maior valor de importância foi representado por Piptadenia gonoacantha com 20,76 % seguidas de Vernonia diffusa 8,12% e Anadenanthera colubrina 5,43%. A familia Fabaceae apresentou o maior Valor de Importância com 39,43% seguidas de Asteraceae 10,08% e Euphorbiaceae 3,81%. Entre os grupos ecologicos, levando em consideracao o Valor de Importância, as pioneiras totalizaram 51,97%, seguidas das secundarias iniciais com 39,93%, secundarias tardias com 5,58%, indiferentes com 0,79%, e as nao identificadas com 0,79%. A presenca de pioneiras com alto Valor de Importância, e baixo valores para as secundarias tardias permite concluir que a area se encontra em estadio secundario medio de sucessao.