Sérgio de Faria Lopes

An Ecological Comparison of Floristic Composition in Seasonal Semideciduous Forest in Southeast Brazil: Implications for Conservation

We examined floristic patterns of ten seasonal semideciduous forest sites in southeastern Brazil and conducted a central sampling of one hectare for each site, where we took samples and identified all individual living trees with DBH (diameter at breast height, 1.30 m) ≥4.8 cm. Arboreal flora totaled 242 species, 163 genera, and 58 families. Fabaceae (38 species) and Myrtaceae (20 species) were families with the largest number of species. Only Copaifera langsdorffii and Hymenaea courbaril occurred at all sites. Multivariate analysis (detrended correspondence analysis and cluster analysis) using two-way indicator species analysis (TWINSPAN) indicated the formation of a group containing seven fragments in which Siparuna guianensis was the indicator species. This analysis revealed that similarities between studied fragments were due mainly to the successional stage of the community.

Dinâmica da comunidade arbórea de mata de galeria da Estação Ecológica do Panga, Minas Gerais, Brasil

ABSTRACT – (Dynamics of a gallery forest tree community at Panga Ecological Station, Minas Gerais, Brazil). A study of treecommunity dynamics was carried out in two areas of gallery forest at the Panga Ecological Station, Uberlândia, MG. We analyzedchanges in the tree stratum over a 13-year period (1989-2002). Thirty plots (10×10 m) were set out in each area and all live in dividualswith dbh ≥ 4.8 cm were sampled. In area 1, a 1989 survey (T1) recorded 47 species and 501 individuals. The second survey (2002 = T2)recorded 50 species and 444 individuals. Loss of basal area (2.6 m 2 ) did not surpass growth of the survivors (2.38 m) plus incrementprovided by recruitment (0.57 m 2 ). In area 2, 54 species and 324 individuals were recorded at T1 and 52 species and 260 individuals atT2. Loss of basal area (1.44 m 2 ) surpassed survivors’s growth (1.04 m) plus the increment provided by recruitment (0.06 m 2 ). Area 1showed greater instability due to environmental changes, mainly in soil moisture, which led to the replacement of some species. Area 2,characterized at T1 as more stable, showed no important changes during the study period.

Mortality, recruitment and growth of the tree communities in three forest formations at the Panga Ecological Station over ten years (1997-2007)

ABSTRACT The area evaluated in this study was a continuous stretch comprising three vegetation formations: gallery forest, semi-deciduous seasonal forest and cerradao (woodland savanna). The aim of this study was to examine the tree community dynamics in a forest gradient—from gallery forest to cerradao —at Panga Ecological Station, in the city of Uberlandia, located in the state of Minas Gerais, Brazil. The study was based on data from a previous inventory of the continuous forest conducted in 211 permanent 10 × 10 m sample plots in eight parallel transect running perpendicular to Panga Creek. Trees with a diameter at breast height ≥ 4.77 cm were sampled in 1997, 2002 and 2007. With the exception of the cerradao , there was a net reduction in tree density over the studied period of ten years, because mortality rates were higher than the recruitment rates. The basal area in creased during the period of the study, especially at cerradao . The mean mortality rate in the studied area was 2.64%.yr

Estrutura fitossociológica e grupos ecológicos em fragmento de floresta estacional semidecidual, Uberaba, Minas Gerais, Brasil

RESUMO (Estrutura fitossociologica e grupos ecologicos em fragmento de floresta estacional semidecidual, Uberaba, Minas Gerais, Brasil) Estudos em florestas estacionais semideciduais (FES) sao necessarios para caracterizar a estrutura e verificar a formacao de padroes, possibilitando tambem comparacoes de composicao floristica entre fragmentos. Este estudo foi realizado em um fragmento de FES, em Uberaba, MG, na qual foram demarcadas 25 parcelas de 20 × 20 m, amostrando-se todos os individuos arboreos vivos com circunferencia do tronco a 1,30 m do solo > 15 cm. Foram analisados os parâmetros fitossociologicos usuais e, tambem, a similaridade floristica entre a area de estudo e outras areas de FES. Foram amostrados 805 individuos, representados por 90 especies, sendo Micrandra elata (Euphorbiaceae) a especie mais importante na comunidade, seguida de Galipea jasminiflora (Rutaceae). Especies pioneiras tiveram baixa representatividade na amostra. Alem disso, a presenca de individuos de grande porte, de especies pouco comuns, associada a area basal de 45,8 m 2 ha 1 , sao evidencias de se tratar de floresta madura, em bom estado de conservacao, representativa da condicao original. A analise de similaridade entre esta e outras areas florestais remanescentes demonstrou a formacao de quatro grupos distintos, associados a regioes geograficas, com indicios de que florestas em bom estado de conservacao sao mais semelhantes entre si. Palavras-chave: distribuicao espacial, floresta mesofila, similaridade floristica.

Dispersão de sementes de uruvalheira (Platypodium elegans vog.) (Fabaceae) em um cerradão, Uberlândia-MG

RESUMO – Estudou-se a dispersao de sementes de cinco arvores-matriz de Platypodium elegans Vog. (Fabaceae) em area de cerradao, na Estacao Ecologica do Panga (EEP). As amostragens foram feitas em parcelas de 0,25 m2, posicionadas em linhas partindo da base da matriz em direcao aos quatro pontos cardeais (Norte, Sul, Leste e Oeste), marcadas a cada metro. No laboratorio, os frutos foram abertos para analise da qualidade das sementes. Foram amostradas 1.131 sementes, das quais 18,4% estavam intactas e 81,6%, danificadas e provavelmente inviaveis para germinacao. A dispersao das sementes sofreu influencia da topografia do local das matrizes, das respostas fisiologicas e geneticas a pre-dispersao, bem como do possivel direcionamento favoravel do vento. Dessa forma, a atuacao conjunta desses fatores funcionaria como facilitadores relevantes na formacao do banco de sementes e moldaria a probabilidade de estabelecimento de novos individuos, tanto na area estudada quanto nas fisionomias adjacentes.. Palavras-chave: Cerradao, Platypodium elegans e Dispersao. SEEDS DISPERSAL OF URUVALHEIRA (Platypodium elegans VOG.) (Fabaceae) IN CERRADAO, UBERLANDIA, MG

Functional leaf traits of understory species: strategies to different disturbance severities

The specific leaf area (SLA) has been related to environmental disturbances, showing a positive correlation between the disturbances intensities and SLA in a plant community. These studies, however, assessed the responses of plant community as a whole, neglecting species attributes, such as the position in the vertical stratum of forests. Considering the importance of SLA to understand forest ecological processes, this study aimed to determine the influence of the disturbance regime on the SLA of understory species, considering that, unlike for communities as a whole, an increase in the disturbance intensity implies a decrease in SLA of understory species. This study was conducted in nine understories of seasonal forests in Brazil. The most abundant species were selected and their SLA were evaluated. The variability of SLA among populations in different forests was analyzed by Students t-tests. The SLA of the understories (SLAU) was also compared by an adaptation of the Community-weighted mean index. The comparison of species SLA showed significant differences among the populations of understories under different disturbance regime, showing a decrease in SLA with an increase in the disturbance intensity. Similar results were found for the SLA of understories communities (SLAU), corroborating our hypothesis. The correlation between a reduction in species SLA and in SLA of understory with an increase in disturbance intensity, contradicted the trend observed in the literature for the community as a whole. This study highlights the importance of the evaluation of SLA in understories, as an indicator of the successional stage of communities.

CAPACIDADE ADAPTATIVA DE ESPÉCIES DO CERRADO UTILIZADAS EM ÁREAS DE RECUPERAÇÃO AMBIENTAL1

The purpose of this study was to measure the adaptive capacity, based on data from specific leaf area (SLA) and petiole length (PL) of Cerrado’s native species of two areas in recovery compared with control subjects. 5 species were selected in Area 1 (intense luminosity) and 10 species were selected in Area 2 (intense luminosity). There were significant differences between species of the two areas and the control subjects, for the most species evaluated. The SLA and PL, unlike what was expected, were significantly higher in Area 2 than control (shading). However, the most species in Area 1 had SLA and PL equal to or less than control and species of Area 2. Therefore, the studied species have ability to adjust its morphology and probably also physiology for acclimatization to the environments with intense luminosity. Thus, these are potential species for use in environmental recovery programs.

Impacts of artificial reservoirs on floristic diversity and plant functional traits in dry forests after 15 years

Dams are of paramount importance to a wide variety of human services and many of their environmental problems are known; however, there are few studies in the world addressing the impacts on the native vegetation previously distant from water bodies which became close to the lakeshore created by a dam. Thus, this paper aims to analyze the responses of a dry forest to a dam after 15 years. For this, 20 random samples of 40 trees were made, 10 close to the lakeshore and 10 distant from it, by applying the central square point method. Close to the dam, we found higher values regarding basal area, number of trees, number of evergreen trees, and zoochoric syndrome, but there were lower values of Shannons diversity index. Therefore, the impacts of the dam after 15 years caused several changes to the tree community. The greater basal area close to the dam suggests that water deficit during the dry season was decreased and plants have thicker trunks. On the other hand, this sector had much more zoochoric syndrome and a larger number of evergreen trees than plots which are distant from water, suggesting changes with regard to the communitys ecological functions. Furthermore, structural floristic data shows that the sector close to the dam is less similar to other deciduous forests within the same geographical region than the sector distant from water, thus providing evidence of the impacts of dams on the tree community.