RESUMOO objetivo deste estudo foi caracterizar a florística e calcular os parâmetros fitossociológicos das espécies presentes nas áreas de campo sujo e cerrado sensu stricto na Estação Ecológica de Pirapitinga -MG (ESEC). O estudo foi realizado na ESEC de Pirapitinga no município de Morada Nova de Minas, Estado de Minas Gerais. Para o levantamento da florística e da fitossociologia, foi alocado um total de 190 subparcelas com 100 m 2 cada, amostrando-se todos os indivíduos com circunferência à altura do solo (CAS) ≥ 16 cm, em áreas de campo sujo e cerrado sensu stricto. Foram calculados os parâmetros de frequência, densidade, dominância, os valores de importância e os índices de diversidade de Shannon e equabilidade de Pielou. A similaridade florística entre as áreas foi determinada por meio do índice de Sorensen. Nas duas áreas de estudo, foram amostrados um total de 3.224 indivíduos distribuídos em 81 espécies, 70 gêneros e 40 famílias. As famílias mais ricas foram Fabaceae e Vochysiaceae. O cerrado sensu stricto foi a formação vegetal com maior riqueza de espécies (81) e maior densidade (2.257 ind ha -1 ). Ambas as áreas estudadas apresentam-se com alta diversidade e baixa dominância ecológica e possuem distribuição diamétrica em forma de J-invertido, indicando o predomínio de indivíduos jovens. Palavras-chave: bioma cerrado; floresta natural; unidade de conservação. ABSTRACTThe objectives of this study were to characterize the floristic and to calculate the phytosociological parameters of species present in the areas of 'campo sujo' and 'cerrado' sensu stricto in the Ecological Station of Pirapitinga, Minas Gerais state (ESEC). For the floristic and phytosociologic survey, a total of 190 plots of 100 m 2 each were allocated, where all the individuals with circumference at soil level (CSL) ≥ 16 cm in areas of 'campo sujo' and 'cerrado' sensu stricto were sampled. The parameters of frequency, density, dominance, and importance values and Shannon and Pielou indexes were calculated. The floristic similarity between areas was determinated by Sorensen index. In the study areas, a total of 3,224 individuals distributed in 81 species, 70 genera and 40 families were sampled. The richest families were Vochysiaceae and Fabaceae. The cerrado sensu stricto was the vegetal formation with the highest richness of species (81) and highest density (2.257 ind ha -1 ). Both areas have studied with high diversity and ecological dominance and have low diameter distribution in the form of inverted-J, indicating the predominance of young individuals.

The State of Rio de Janeiro still holds unknown portions of the Atlantic Forest, which represent gaps in the knowledge of this ecosystem. Paracambi and neighbor municipal districts comprise a vast stretch of virtually unknown forest that makes up part of the Serra do Mar biodiversity corridor. The following study describes the tree community structure in a stretch of the ombrophilous Atlantic Forest, in the Parque Natural Municipal do Curió (Curio MNP), Paracambi, Rio de Janeiro, which serves as the basis to evaluate species diversity and conservation status. The altitudes in the area ranges from 100 to 690 m and the climate varies from mild subtropical to tropical hot and humid. Forty plots (10x10m) were randomly placed along the area, where all the stems equal to or greater than five centimeters (5 cm) diameter at breast high from ground level were measured. A total of 749 individuals, pertaining to 128 genera and 210 species were recorded, eight of which are listed as threatened of extinction in the Brazilian flora. The Shannon-Weaver diversity index (H′) was 4.7 nat.ind.-1 and the species with greater importance value was Pseudopiptadenia contorta (1.6460 m2; 18 individuals) while the most common species wereSenefeldera vertcilata (48) and Actinostemon verticilatus (47 individuals). Despite the sample area being a little smaller than that commonly adopted in tropical studies, data pointed to a richness hitherto not registered in any other study for the State of Rio de Janeiro, no matter the inclusion criteria used, and also confirmed by the two estimator indices used, which have revealed very similar results. The vertical forest structure, the values associated to the successional stage of the species and other aspects of community structure indicate that the Curio MNP encompasses forest stretches in advanced stages of ecological succession. Besides its key location for the connectivity of forest fragments in the region, the results emphasize the ecological importance of this forest remnant and the need for its conservation.

RESUMOO objetivo deste trabalho foi avaliar a florística e a fitossociologia das espécies presentes em áreas de cerradão e mata mesofítica na Estação Ecológica de Pirapitinga, MG. Para o levantamento da florística e da fitossociologia, foram marcadas 108 parcelas de 100 m 2 cada, amostrando-se todos os indivíduos com circunferência à altura do solo (CAS) ≥ 16 cm. Foram calculadas a frequência, densidade, dominância, os valores de importância e de cobertura, índices de Shannon e Pielou e similaridade florística através do índice de Sorensen. Nas duas áreas de estudo, foi amostrado um total de 1.716 indivíduos distribuídos em 67 espécies, 60 gêneros e 35 famílias. As famílias mais ricas foram Fabaceae e Vochysiaceae. O cerradão foi a formação vegetal com maior riqueza de espécies (67) e maior densidade, enquanto a área de mata mesofítica foi a que apresentou uma vegetação com maior desenvolvimento das espécies.Palavras-chave: cerrado lato sensu, floresta natural, unidade de conservação. Floristics and Phytosociology in Areas of Dense Woodland and MesophyticForest in the Pirapitinga Ecological Station, Minas Gerais State, Brazil ABSTRACTThe objective of this study was to evaluate the floristic and phytosociological parameters of the species present in areas of mesophytic forest and dense woodland in the Pirapitinga Ecological Station, Minas Gerais state, Brazil. For the survey of floristic and phytosociological parameters, a total of 108 plots of 100 m 2 were implanted, where all individuals with circumference at ground height (CGH) ≥ 16 cm were sampled in areas of dense woodland and mesophytic forest.The following parameters were calculated: frequency, density, dominance, values of importance and cover, Shannon and evenness indices, and floristic similarity by the Sorensen index. In both study areas, a total of 1,716 individuals of 67 species, 60 genera, and 35 families were sampled. The richest families were Vochysiaceae and Fabaceae. The dense woodland area presented the highest species richness (67) and the highest density, while the mesophytic forest area presented the greatest species development.

Resumo -Abstract -The goal of this study was to evaluate the performance and select probability density functions to describe the diametric distributions of the forest community and the main three species in a tropical rain forest in southern of Rio de Janeiro State. We tested the functions: Normal, Normal Log, Beta, Gamma, Sb Johnson and Weibull. Adjustments were carried out using Solver tool (MSExcel®) which uses the reduced linear gradient algorithm, optimizing the functions parameters. Value D Kolmogorov-Smirnov and estimation of standard error (Syx%) were evaluate to select the best model. In general, Sb Johnson and Weibull functions presented better statistics adjustment and greater precision in the estimates. Even representing the reality of the distribution, the smaller class intervals did not provide better adjustments, more precise estimates being provided by the larger ranges and smaller classes. ISSN: 1983ISSN: -2605 IntroduçãoAs florestas tropicais são caracterizadas pela alta densidade de plantas e pela grande diversidade de espécies, cujos ritmos de crescimento são, em geral, diferentes (Rangel et al., 2006;Puig, 2008). Em resposta aos ritmos distintos de crescimento e à grande variação de idade das árvores, a estrutura diamétrica apresenta configuração diferenciada entre tipologias florestais, estágios sucessionais e para espécies ou grupos de espécies quando analisadas individualmente.O estudo das distribuições de diâmetros teve início em 1898, quando François De Liocourt estabeleceu seu conceito para florestas naturais multiâneas (Barros et

No abstract

National Forest Inventories are important primary data sources for large-scale forest resource surveys, in which volume estimates of sampled trees are essential for quantitative analysis. Volume prediction models in natural forests are scarce in Brazil due to legal restrictions for cutting trees, especially in the Atlantic Forest. This study aimed to fit volume models for the main forest types and timber species of the Atlantic Forest in Rio de Janeiro state, considering two hypotheses: (I) generic volume models provide greater generalizability of estimates; however, (II) they may reduce the accuracy of forest typeand species-specific predictions. Four linear models with logarithmic transformation of variables were evaluated to fit volume models for generic and specific datasets, which correspond to the main forest types and timber species. Goodness-of-fit statistics were calculated to compare the accuracy and efficiency of the models, and selected models were validated through leave-oneout cross-validation procedures. The estimates obtained by generic and specific models were compared by non-parametric hypothesis tests. Generic models showed similar predictions to the specific models for forest types and timber species, with similar potential for stem and total volume predictions. Therefore, generic models can be used for Atlantic Forests in Rio de Janeiro state, while specific models are recommended to obtain more detailed local estimates.

No abstract

Tree height is one of the most important variables for quantitative assessment of forest stocks but is difficult to directly measure. However, such allometric relationships of trees can vary between geographical regions, mainly due to climatic, edaphic, and floristic gradients. Based on the hypothesis that different forest types influence the generic modeling of tree height–diameter relationships on geographical scales, this study aimed to 1) fit equations to estimate tree height in Atlantic Forest types in the state of Rio de Janeiro, Brazil; 2) compare efficiency and precision between generic and specific equations for forest types; and 3) test the effect of different forest types and species on the height–diameter relationship. Four allometric models were tested for all forests (generic) and three main forest types (specific). Effects of tree size, forest types and species on tree height estimation were analyzed using multiple linear models and mixed effect linear models. A significant effect of forest type and species on tree height was seen, showing the need to apply local specific equations to minimize the effects that are not captured by generic equations. Differences in tree allometry between forest types were associated with temperature, rainfall, soil and forest structure. These results confirm the effect of the local environment on the height–diameter relationship of trees as found for large scales in tropical forests.