[Show abstract][Hide abstract] ABSTRACT: Este trabalho procurou identificar e quantificar espécies colonizadoras e estrutura em área de empréstimo, assim como listar espécies para recuperação de áreas degradadas. Foram selecionados três ambientes, sendo o ambiente 1 (A1) com histórico de uso menos intenso; ambiente 2 (A2) nível de degradação intermediário e ambiente 3 (A3) com maior degradação. Nos três ambientes foram sorteadas 20 parcelas de 25 m2. Nestas, foram amostrados todos os indivíduos com altura ≥ 0,10 m e DAS ≤ 5,0 cm. Foram calculados os índices de diversidade de Shannon (H’), equabilidade de Pielou (J’), similaridade de Jaccard e Czekanowski, assim como os parâmetros fitossiológicos e a análise de espécies indicadoras. Foram registradas 32 espécies pertencentes a 15 famílias. O ambiente A1 foi o mais rico em espécies e com maior densidade e A2 apresentou a menor riqueza e densidade. Os ambientes apresentaram baixa similaridade florística e estrutural, sendo observadas diferenças estatísticas para a densidade (sendo encontrados 844, 270 e 497 indivíduos em A1, A2 e A3, respectivamente) e diversidade que variou entre 1,680 a 2,074 nats.indivíduo-1. Provavelmente, estas divergências se devem às variações do ambiente impostas pelas diferentes intensidades de degradação.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to evaluate the tree flora in a fragment of semi deciduous forest in the region of the Espinhaco, with aim to propose species for restoration of areas degraded by mining exploitation of iron in similar ecosystems. The inventory floristic and structural of vegetation of shrubs and trees was conducted in September 2007, by the quadrants-point method according to the method of minimum distances, whose inclusion criterion of the stem above the height 1.3 m. The individual were stratified into adults (DBH >= 5.0 cm) and juvenile (DBH < 5.0 cm). We sampled 90 points, which were identified 94 species, 70 genera and 32 families. For the diversity index of Shannon, values presented for each layer were 3.96 nats.ind(-1) and 3.94 nats.ind(-1), and equability of Pielou were 0.896 and 0.938, respectively for layer juvenile and adult. Families that stood out by the number of species were Myrtaceae (17), Fabaceae (12), Rubiaceae (8), Euphrobiaceae (6), Sapindaceae (5) and Lauraceae (5). For the recovery area were selected seven groups of species that will be used for recuperation of degraded areas. The characteristics of the species were sufficient for the definition of functional groups that can be used in recuperation of degraded areas.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to verify the presence of environmental indicator species and the influence of rocky outcrops on the ecological patterns of woody plant species in a Cerrado stricto sensu. Ten plots were sampled where information regarding rocky outcrops and all live individuals with DAG ≥ 5 cm were registered. Detrended Correspondence Analysis (DCA) was performed to assess floristic relations, while Indicator Species Analysis (ISA) was used to determine the environmental preferences of species. Phytosociological parameters were calculated, and the Student's t test was conducted for independent samples with some structural variables. The DAG of live individuals confirmed the existence of two environments and showed that the presence of rocky outcrops changes the floristic composition between them. The ISA verified the presence of environmental indicator species. The presence of rocky outcrops changed the group of species presenting higher Importance Value (VI) in each environment; however, no significant differences were found between the structural parameters assessed in each environment.
Floresta e Ambiente 03/2014; 21(1):8-18. DOI:10.4322/floram.2014.009
[Show abstract][Hide abstract] ABSTRACT: O objetivo do trabalho foi avaliar o uso da Amostragem Adaptativa Cluster (AAC) na
quantificação de indivíduos adultos de Caryocar brasiliense Camb. (Pequi), em
comparação aos métodos de amostragem tradicionais. Foi feito um censo com mapeamento
dos indivíduos adultos de pequi em uma área de cerrado de 36,5ha no Parque Estadual
do Rio Preto/MG. O mapa gerado foi divido em unidades de 20×20m no qual foram
testadas cinco alternativas de amostragem utilizando a Amostragem Casual Simples,
Amostragem Sistemática e Amostragem Adaptativa Cluster. A comparação entre elas foi
feita através do teste F de Graybill a 1% de significância, considerando os
parâmetros precisão e exatidão. Todas as alternativas apresentaram boa exatidão,
sendo a Amostragem Adaptativa Cluster, com condição de inclusão igual a 2, a mais
[Show abstract][Hide abstract] ABSTRACT: This work aimed to verify the existence of variations in composition and distribution of tree species due to soil characteristics in a fragment of dystrophic savanna in Curvelo-MG. On description in the compartment of the phanerophytes of this plant community, were installed ten permanent plots with 1.000 m2 (20 x 50 m) with fixed distances of 100 m between each plot. All alive individuals that had diameter at soil height (DSH - diameter to 0.3 m from ground level) > 5.0 cm were sampled. The Individuals with multiple boles were sampled when the value of square root of the sum-square of DSH had been greater than criterion of the inventory. Were collected Soil samples at two depths (0-20 e 20-40 cm) and was measured the distances of plots of a watercourse. To study the community were generated ordination diagrams of plots, species and environmental variables by means of a canonical correspondence analysis (CCA). The richness sampled was 92 species, 36 families and 74 genera, Erythroxylum, Byrsonima, Myrcia and Qualea. Jackknife estimators (first and second order) designed a wealth of 106.4 and 107.8 species. The species Magonia pubescens, Terminalia argentea, Annona crassiflora, Eugenia dysenterica e Xylopia aromatica were distribuited underneath the environmental gradient.
[Show abstract][Hide abstract] ABSTRACT: Studies dealing with the interference of weeds in agro-ecosystems have obtained abundant results for grain production fields and pastures. However, few studies have reported the effect of the presence of such a group of isolated plants on degraded areas under recovery. Thus, this study aims to evaluate the influence of the soil seed bank on the process of environmental restoration of a representative area of campestre cerrado due to the presence of weed grasses. To assess the seed bank, three environments were selected: two degraded environments and one reference-environment (preserved) of campestre cerrado. Soil samples were collected in two seasons (dry and wet), and evaluated in three hundred days. During the evaluation, only six native species and only two species with a habit of arboreal life were found. Most of the seeds which were germinated for the degraded environments in both collections were identified as invasive in the study area. In this sense, the local soil seed bank is not considered sufficient for recovery through ecological succession in these areas, and the use of techniques to accelerate the restoration of these environments is strongly recommended.
[Show abstract][Hide abstract] ABSTRACT: A espécie Lychnophora pohlii Sch. Bip.(Asteraceae), conhecida como "Arnica mineira", é uma planta largamente utilizada na medicina popular e muito abundante na vegetação de campo rupestre de altitude. Nesse contexto, este trabalho teve como objetivo estudar a densidade dessa espécie e sua relação entre os parâmetros do solo em uma área de campo rupestre em Diamantina, região do Alto Jequitinhonha, Minas Gerais. Foram alocadas 10 plotas contíguas de 20 x 50 m, totalizando uma amostragem de 10.000 m2, localizadas dentro do Campus Juscelino Kubitschek da Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM). Nessas plotas, os indivíduos foram avaliados quanto à frequência, dominância e densidade. Estudou-se a relação da densidade dessa espécie com nove atributos químicos e físicos do solo por meio da análise de correspondência canônica (ACC). A maior abundância de indivíduos (I) da espécie Lychnophora pohlii Sch. Bip. foi verificada nas plotas de amostragem da vegetação de número 6, com 255 indivíduos; 7, com 173; 8, com 189; 9, com 159; e 1, com 151. Verificaram-se nessas plotas características florísticas e do solo semelhantes, resultando em uma proximidade espacial quando representadas nos diagramas da ACC. Maiores densidades da espécie Lychnophora pohlii Sch. Bip. foram encontradas em plotas com os maiores valores de pH, P-rem e saturação por bases, variáveis essas mais fortemente correlacionadas pelo primeiro eixo da análise de correspondência canônica.
Revista Brasileira de Ciência do Solo 06/2013; 37(3):565-571. DOI:10.1590/S0100-06832013000300002 · 0.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Historically, forest landscapes have been modified by human activities, causing its destruction and fragmentation to exploit its resources. However, forests play a vital role in protecting the environment, especially on slops, hilltops, lakes, springs and river banks. This study aimed to understand the diversity and structure of vegetation on a slope of riparian forest in Bocaina de Minas, MG and identify key environmental variables that influence the spatial distribution of individual trees. An inventory of the tree community was conducted, in which ten of 10m×40m plots were allocated and systematically distributed throughout the study area. All individuals existing shrubs and trees within the plots with 1.30m diameter ≥ 5.0cm of soil were sampled in order to generate information on the horizontal structure, richness and diversity of the community. Variables related to the substrata were obtained for each plot from the topography and laboratory analysis of soil samples (pH, levels of P, K, Ca, Mg and Al, base saturation (V), organic matter and levels of sand, silt and clay). Other variables such as distance from the river and successional stage of the plots, were also evaluated. In order to correlate environmental variables with the abundance distribution of the species, a canonical correspondence analysis (CCA) and Spearman correlation were used. The Shannon diversity index (H') and evenness index (J') obtained were 3.53 and 0.76, respectively. The emerging patterns of environmental variables and the abundance of species indicate that these were distributed throughout the fragment, mainly due to the P content in soil and successional stage of the plots. In addition, several species have produced significant correlations between their abundance in the plots and the variables related to successional stage, variations in soil, and distance from the banks of water courses.
[Show abstract][Hide abstract] ABSTRACT: Resumo O presente trabalho teve como objetivo conhecer a densidade e composição do banco de sementes do solo em dois ambientes de mata ciliar alterada, no entorno de uma nascente. A nascente estudada pertence à bacia hidrográfica do rio Capivari, no município de Itumirim, MG (21º16' S e 44º52' W). Nos dois ambientes estudados, foram coletadas 18 amostras de solo a 5,0 cm profundidade, no final da estação chuvosa (maio de 2003). Calculou-se a densidade de sementes e a curva de germinação do banco pelo método de emergência de plântulas. Também foi feita a determinação da composição florística, com base principalmente na morfologia das plântulas. Após um período de 210 dias de avaliação, obteve-se uma densidade de 2.332 sementes/m 2 no Ambiente I e 1.896 sementes/m 2 no Ambiente II. No entanto constatou-se que o banco de sementes dos dois ambientes avaliados era composto apenas por espécies ruderais. Tais resultados evidenciam a necessidade de intervenção humana no processo de recomposição da vegetação ciliar no entorno dessa nascente, por meio da regeneração artificial de espécies arbóreas. Palavras-chave: Banco de sementes do solo; nascente e recomposição da vegetação. Abstract Soil seed bank as to grant recovery of the riparian forest. The present work objective knows the density and composition of soil seed bank in ciliary areas altered in spill of two springs. The studied springs belong to Capivari river catchment, Itumirim, MG (21º16'S and 44º52 ' W). The samples of soils were collected in the end of the rainy station (May of 2003). Were 18 soil samples were collected for the two environments to the depth of 5 cm. was calculated the density of seeds and the curve of germination of the soil seed bank, for method of seedling emergency. It was also made the determination of the floristic composition based mainly on the morphology of the seedling. After a period of 210 days of evaluation obtained a density of 2332 seed/m 2 was observed in the environment I and 1896 seed/m 2 , for the environment. However, it was verified that the bank of seeds of the two appraised East was just composed of ruderal species. Such results evidence the need of human intervention in the process of restoration of the ciliary vegetation in spill of this spring, through the artificial regeneration of the arboreal species. Keyword: Seed bank; spring and restoration of the vegetation.
[Show abstract][Hide abstract] ABSTRACT: This paper mapped and characterized the forest remnants in the domain of UFLA and identified potentials corridors toimprove the connectivity among them. The thematic map for the analyses was built using the SPRING 3.4 program considering aerialimages (2001) and satellite images (Landsat 7, March of 2001). The fragments impacts were analyzed by the application of investigativequestionnaires in order to record the past anthropogenic disturbances. The shrub-tree vegetation of the six main fragments wasinventoried by the quadrants method, with the inclusion level considering trees with DBH higher or equal to 5.0 cm. The fragments Iand IV were respectively the most disturbed fragments. According to the thematic map, the fragment I showed the smallest area, formindex and core area, consequently, the largest edge effect. The fragment III showed the largest area, form index and core area and thesmallest edge effect. Among the main impacts registered, the most important were garbage, external highways, trails and buildconstructions. In the six main fragments 544 individuals were registered, belonging to 48 families, 110 genera and 161 species. Thelargest diversity value was registered in the fragment III (3.917) and the smallest (2.135) in the fragment I. A low similarity wasdetected among the fragments. After the analysis of the results, the connectivity among the fragments was verified with the recoveringof the areas of permanent preservation along the water streams and dams.
[Show abstract][Hide abstract] ABSTRACT: This work aimed at evaluating the natural regeneration dynamics in two springs in process of recovery in Lavras-MG, surrounded in December/2003. To do that, two springs were carried out from August/2005 (18 months) to April/2006 (24 months). 122 plots in the total of 5 x 5m (25m2) were plotted, being 76 plots in spring 1 and 46 plots in spring 2. The plots were distributed systematically throughout all the area of the springs. All individuals with height larger than 0.10 m and DBH lower than 5 cm were identified, having their diameters and height measured. Floristic composition, structural analyses and natural regeneration dynamics were studied. In the total, 524 individuals from 24 family and 55 species were sampled. The Asteraceae family was distinguished in species number in spring 1 and the families Fabaceae Faboideae, Myrtaceae and Solanaceae in spring 2. The species Baccharis dracunculifolia and Vernonia ferruginea presented the highest natural regeneration indexes in spring 1, while the species Vernonia polyanthes and Nectandra nitidula in spring 2. The higher diversity index was registered for the spring 2 in the second evaluation, having an increase from 3,324 (first evaluation) to 3,384 (second evaluation). The floristic similarity index registered between the springs was of 20.0% and 18.5% for the evaluations 1 and 2, respectively. During the time of monitoring, it was verified a significant increase of 33.33% and 15.8% in individuals number sampled in springs 1 and 2, respectively. The natural regeneration method presents potential for the recovering of the vegetation of the two springs; however, it is necessary the adoption of control techniques of Brachiaria sp. grass.
[Show abstract][Hide abstract] ABSTRACT: 2 , sendo 10 em um remanescente de caatinga bem conservada (Ambiente I) e 10 em uma área de caatinga invadida por P. juliflora (Ambiente II). A área invadida apresentou-se muito mais pobre em relação à primeira, em todos os parâmetros avaliados. Os impactos causados pela invasora foram sentidos tanto na estrutura, quanto na diversidade biológica da comunidade. A Densidade Relativa de P. juliflora no estrato adulto da área invadida atingiu cerca de 90%, o que reflete a sua capacidade de competição e eliminação das demais espécies. O índice de diversidade de Shannon-Weaver (H') apresentou os valores de 2,81 e 0,61 para o componente adulto dos Ambientes I e II, respectivamente. Para a regeneração natural os valores desse índice foram de 2,31 e 1,14 para os mesmos Ambientes. Conclui-se que P. juliflora forma densos maciços populacionais e compete com as espécies nativas, afetando severamente a composição florística, a diversidade e a estrutura das comunidades autóctones invadidas. Palavras-chave: contaminação biológica, Prosopis juliflora, perda de biodiversidade, caatinga ABSTRACT - (Effects of the biological invasion of algaroba - Prosopis juliflora (Sw.) DC. on composition and structure of the shrub- tree stratum of the caatinga in Monteiro Municipality, Paraíba State, Brazil). Biological contamination is currently one of the main causes of biodiversity loss on the planet. The aim of this study was to evaluate the impacts caused by P. juliflora invasion on caatinga phytodiversity in Monteiro Municipality, in both the adult stratum and natural regeneration. Twenty plots of 400 m 2 were set up, 10 in a conserved caatinga fragment (Environment I) and 10 in a caatinga area invaded by P. juliflora (Environment II). The invaded area was much poorer in relation to the conserved area for all parameters investigated. The impacts caused by the alien species were felt in structure as well in community biological diversity. The relative density of P. juliflora in the adult stratum of the invaded area was ca. 90%, which reflects its capacity to compete and eliminate other species. The Shannon-Weaver diversity index (H') had values of 2.81 and 0.61 for the adult component of Environments I and II, respectively. For natural regeneration, this index was 2.31 and 1.14 for the same sites. It was concluded that P. juliflora forms dense populations that grow along with native species, severely affecting the floristic composition, diversity and structure of autochthonous communities
[Show abstract][Hide abstract] ABSTRACT: Biological contamination is currently one of the main causes of biodiversity loss on the planet. The aim of this study was to evaluate the impacts caused by P. juliflora invasion on caatinga phytodiversity in Monteiro Municipality, in both the adult stratum and natural regeneration. Twenty plots of 400 m2 were set up, 10 in a conserved caatinga fragment (Environment I) and 10 in a caatinga area invaded by P. juliflora (Environment II). The invaded area was much poorer in relation to the conserved area for all parameters investigated. The impacts caused by the alien species were felt in structure as well in community biological diversity. The relative density of P. juliflora in the adult stratum of the invaded area was ca. 90%, which reflects its capacity to compete and eliminate other species. The Shannon-Weaver diversity index (H') had values of 2.81 and 0.61 for the adult component of Environments I and II, respectively. For natural regeneration, this index was 2.31 and 1.14 for the same sites. It was concluded that P. juliflora forms dense populations that grow along with native species, severely affecting the floristic composition, diversity and structure of autochthonous communities.
[Show abstract][Hide abstract] ABSTRACT: Floristic composition and vegetation structure of plants 3 cm stem diameter or greater were compared at four sites in the Agreste of Paraíba, Brazil: (1) little disturbed for five decades (LD); (2) grazed fragment, selectively logged 16 years before sampling (GF); (3) naturally regrowing for 30 years after 39 years of agriculture (OR); and (4) naturally regrowing for 20 years after 35 years of agriculture plus 15 years of pasture (NR). Cattle graze frequently in the last three sites but very seldom in LD. The little disturbed site had more species (53) than the other three sites (36, 25, and 11 species in GF, OG, and NG, respectively) and also more (3253, 2780, 2780, and 2115 plants/ha) and larger plants (34.8, 26.8, 18.6, and 7.8 m2/ha), including taller tree species (up to 15 m) absent in the other sites (maximum height: 14, 6, and 5 m). Differences were striking in relation to NR, the site with longer use and shorter regrowth period, which was strongly dominated by only two species: Mimosa tenuiflora (73% relative density and 81% basal area) and Piptadenia stipulacea (21% relative density and 16% basal area). These results indicate that abandoned agricultural sites may take several decades to reestablish vegetation similar to the original.