Interação microrganismo, solo e flora como condutores da diversidade na Mata Atlântica

Abstract

Recebido em 16/05/2011. Aceito em 9/07/2012 RESUMO (Interação microrganismo, solo e flora como condutores da diversidade na Mata Atlântica). O presente trabalho teve como objetivo fornecer dados para uma melhor compreensão entre a interação de microrganismos, flora e solo. O estudo foi realizado no Parque Natural Municipal do Curió, Paracambi, RJ. Foram selecionadas duas áreas, com diferentes graus de alteração antrópica, sendo em cada uma destas delimitado um talhão de aproximadamente 1.000 m 2 , e nestes foram realizados levantamentos floristicos e coletas de amostras de terra e serrapilheira para a avaliação da fertilidade e dos microrganismos. Nas duas áreas quantificou-se um total de 89 espécies, reunidas em 59 gêneros e 33 famílias, entre espécies arbóreas, arbustivas, herbáceas e trepadeiras. Na área com maior grau de antropização ocorreram os maiores valores de pH, Ca e K, indicando um ambiente de maior eutrofismo. Já na área com menor grau de alteração, observaram-se maiores valores de H + Al, decorrentes da maior quantidade de material orgânico. Para a serrapilheira, foi verificado um padrão com tendência similar a observada para o solo. Os maiores valores de serrapilheira aportada, também contribuem para os maiores valores de K, elemento facilmente lixiviável no material em decomposição. Quanto à abundância dos microrganismos tanto na serrapilheira como no solo foi observada uma distribuição diferenciada dos microrganismos devido a variação da umidade relativa e temperatura, sendo as bactérias as predominantes, padrão este também observado para as diferentes áreas. Palavras-chave:Ecossistema funcional, Decomposição, Utilização do substrato, Sucessão ecológica, Atividade microbiana ABSTRACT (Interaction of microorganisms, soil and flora as drivers of diversity in the Atlantic Forest). This study aimed to better understand the interaction between microorganisms, plants and soil. The study was conducted in Parque Natural Municipal do Curió (Paracambi, RJ). We selected two areas with different degrees of human disturbance, and in each of these enclosed a plot of 1,000 m 2 . Floristic surveys were carried out and litter and soil samples were collected to evaluate fertility and the microorganisms. In both areas, 89 species were found, within 59 genera and 33 families, of trees, shrubs, herbs and vines. The highest values of pH, Ca and K were found in the area with the highest degree of human disturbance, indicating an environment of increased tropism. In the area with a lower degree of alteration, we observed higher values of H + Al, resulting from a higher amount of organic material. For the litter, the pattern was similar to that found for the soil. The highest values for the leaf litter also contributed to higher values of K, which is an element that easily leaches from mulch. Considering the abundance of microorganisms in both the litter and in soil, an uneven distribution of microorganisms was found due to the variation of relative humidity and temperature; bacteria were predominant, a pattern observed...

Justicia paracambi, a new Brazilian species of Acanthaceae

“…The Parque Natural Municipal do Curió (Curio Municipal Natural Park) (Curio PNM) is located in the municipal district of Paracambi, Rio de Janeiro, around the geographical coordinates 22°34' and 22°36' longitude and 43°42' and 43°41' latitude, covering an area of approximately 900 ha (Fraga et al 2012). The fragment is mostly woody and covered in Atlantic rain forest (Cysneiros et al 2015).…”

“…The main aim of this park is to protect local rich water resources, as it is permeated by small rivers, streams and contains some seasonal wetlands. The topography is distinctly hilly, with elevations extending from 100 to 690 m, and the climate ranges from mild subtropical to hot and humid tropical, with an average 23.4° C of annual temperature (Fraga et al 2012). During the studies carried out by Fraga and colleagues (2012) from the Universidade Federal Rural do Rio de Janeiro (UFRRJ) this new species of Justicia was collected near watercourses at low altitude.…”

“…This area is protected, being part of the Parque Natural Municipal do Curió (Municipal Natural Park of Curió), which is mainly occupied by a rich forest with most of it in an excellent state of conservation (Fraga et al 2012, Cysneiros et al 2015. It forms part of a forest continuum between the Reserva Biológica do Tinguá (Tinguá Biological Reserve), in the northeast, and the Parque Estadual Cunhambebe (Cunhambebe State Park) in the southeast of the State.…”

“…These forests make up the Serra do Mar Atlantic Forest biodiversity corridor, joining the montane forests of Rio de Janeiro and São Paulo States (Tabarelli et al 2005). Fraga et al (2012) pointed out the importance of Acanthaceae in the understory of the forest in the Curió Park.…”

Occurrence of entomopathogenic fungi in atlantic forest soils

“…An aliquot of 1 ml of this homogeneous suspension was removed and placed in a tube with 9 ml of peptone water, and so forth, were prepared decimal dilutions to 10 -4 .100 µL were inoculated from dilutions 10 -1 , 10 -2 and 10 -3 on MS plates and incubated at 25±1°C. Each dilution had three repetitions and each sample had three dilutions plated [12]. The colony forming units (CFUs) per gram of soil were counted on the 7th day after the inoculation.…”