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Da Silva C.F.,Federal Rural University of Rio de Janeiro | Do Carmo E.R.,State University of Norte Fluminense | Martins M.A.,Titular da UENF | De Freitas M.S.M.,Associada da UENF | And 2 more authors.
Bioscience Journal | Year: 2015

The aim of this study was to evaluate the contribution of pure stands of Eucalyptus camaldulensis and Acacia mangium for litter deposition and nutrient return in a pit of clay extraction in northern Rio de Janeiro (RJ). We conducted a randomized block design experiment with two treatments and three replications. For the evaluation of the annual deposition of litter and nutrients (N, P, K, Ca and Mg), we used circular collectors during a year (from July 2006 to June 2007). The planting of Acacia mangium in clay extraction pits contributed with the largest annual deposition of litter and with a litter of better quality compared to Eucalyptus camaldulensis, with higher levels of P and N and lower C:N and polyphenol:N ratios. This fact possibly allows higher rates of decomposition by edaphic microorganisms and, hence, a faster release of these nutrients to the soil. In addition, the planting of legumes showed higher annual deposition of P and N. © 2015, Universidade Federal de Uberlandia. Source

Menezes C.E.G.,Federal University of Rio de Janeiro | Pereira M.G.,Federal Rural University of Rio de Janeiro | Correia M.E.F.,Pesquisadora da Embrapa Agrobiologia | dos Anjos L.H.C.,Federal Rural University of Rio de Janeiro | And 2 more authors.
Ciencia Florestal | Year: 2010

The aim of this study was to evaluate litter input and decomposition and root biomass of three forest fragments at different successional stages (advanced, medium and initial) in Pinheiral Municipality, in the state of RJ, Brazil. To evaluate litter input, 10 conic collectors were installed in each fragment. The root biomass was quantified by monolith method in two periods (wet and dry) at depths of 0-10, 10-20 and 20-30 cm, and 10 samples were collected in each area. To evaluate the decomposition rate in each area, 12 litter bags were distributed. No significant differences were observed for litter input between the areas, but there was a tendency to increase litter input with successional evolution. No significant differences were observed for seasonal litter input between areas during the year, but there was a small increase in the months of July and August. At the advanced stage, litter input could be grouped into two periods: February to July, with lower values; and August to January, with higher values. The leaf fractions and reproductive material input were reduced, while branch and other fractions increased with succession. For litter decomposition, the intermediate stage showed the lowest decomposition constant (k) (0.0038 g g -1day-1) and the highest half life time (182 days), followed by the initial (0044 g g -1day-1 and 154 days) and advanced (0.0064 g g -1day-1 and 108 days) stages. The root biomass in different areas and depths for both two periods studied showed higher values in the advanced stage, followed by the intermediate stage and the lowest values were found in the initial stage. The seasonal root biomass difference occurred mainly in the intermediate stage, with higher values in June. Source

Machado D.L.,Sao Paulo State University | Pereira M.G.,Federal Rural University of Rio de Janeiro | Correia M.E.F.,Pesquisadora da Embrapa Agrobiologia | Diniz A.R.,Federal Rural University of Rio de Janeiro | Menezes C.E.G.,Federal University of Rio de Janeiro
Ciencia Florestal | Year: 2015

The soil fauna, for its diversity and magnitude of the tasks that it carries out in the soil environment, may reflect the state of the ecosystem functioning. Therefore, this study aimed to evaluate the activity, the structural composition and the diversity of soil fauna community in different successional stages of Atlantic forest, in Pinheiral, RJ state. Thus, three areas of lower montane semi-deciduous forest in different succession stages were studied: Forest in initial stage (FIS), Forest in intermediate stage (FINS) and Forest in advanced stage (FAS). In each area, it was demarcated a plot of 30 m x 30 m. To capture the epigean organisms, mesofauna and macrofauna, ‘pitfall-traps’ were used, being distributed, randomly, 10 traps in each area. The samples were taken in April and August 2009. The activity of organisms (arm ind-1 day-1) and ecological index of the richness and evenness were calculated from the quantification and identification of individuals sampled. From the analysis of the results, it was noticed that August featured higher precipitation and directly influenced the activity, structural composition and diversity of soil fauna. The population structure was influenced by successional stages, and group activity Acari, Araneae, Diptera, Formicidae, Hymenoptera and Isopoda increased with advancing succession. Total activity and average wealth index also responded to the advancement of vegetation. The group Entomobryomorpha was the most abundant in all areas, being responsible for the variations of the index of evenness. In general, there were higher values of group activity, total activity and average wealth in FAS, and lower the FIS, thus confirming the potential use of these organisms as indicators of successional dynamics of secondary forests. © 2015, Universidade Federal de Santa Maria. All rights reserved. Source

da Silva C.F.,Federal Rural University of Rio de Janeiro | Miguel D.L.,CPGA CS da UFRRJ | Feitora J.C.F.,Federal Rural University of Rio de Janeiro | Loss A.,Federal University of Santa Catarina | And 2 more authors.
Revista Brasileira de Ciencia do Solo | Year: 2012

Soil characteristics such as total organic carbon (TOC), microbial biomass and enzymatic activity are influenced by many factors and have been suggested as suitable indicators of changes caused by different land use systems and soil management. The objective of this study was to evaluate the COT, microbial biomass and enzymatic activity of a typical Inceptisol in agricultural, forest and grassland areas in the Middle Valley of the Paraíba do Sul river (RJ). The systems evaluated were: annual agriculture (Agan); perennial agriculture (PAg), pasture, early secondary forest (SFEA) intermediate secondary forest (SFSM) in advanced succession stage (SFEA). Soil samples were collected from the 0-5 cm layer in two different seasons (dry and rainy) to determine the total organic carbon (TOC) and biological properties (microbial biomass - CBM; microbial biomass N- NBM; basal respiration - RB; metabolic quotient - qCO2; microbial quotient - qMIC, and activity of the enzymes arylsulfatase, β-glucosidase and acid phosphatase). The soil of the agricultural areas showed a reduction in the TOC and biological properties (enzyme activity and carbon and microbial biomass nitrogen) compared to pasture and forest. The principal component analysis distinguished the agricultural systems from the forest and pasture systems. It was observed that in both periods, the SFSM and pasture were associated with the COT and most biological factors, as opposed to the agricultural systems. Source

Dos Santos Benazzi E.,Federal Rural University of Rio de Janeiro | De Oliveira Bianchi M.,Federal Rural University of Rio de Janeiro | Correia M.E.F.,Pesquisadora da Embrapa Agrobiologia | Lima E.,Federal Rural University of Rio de Janeiro | Zonta E.,Federal Rural University of Rio de Janeiro
Semina:Ciencias Agrarias | Year: 2013

The objective of this study was to evaluate the effects of harvesting methods on the macrofauna, a known indicator of soil quality that detects changes in the system and indicates management alternatives. The experimental design was randomized blocks with six replications, with each block consisting of four parcels that corresponded to treatments green cane (CC), burnt cane (CQ), green cane - burnt cane (CC-Q) and burnt cane - green cane (CQ-C). Samples were collected in February and July 2010. The animals were divided into major taxonomic groups and accounted. Were evaluated ecological indexes (Shannon, Pielou and richness) and average total density of individuals and groups. Data were analyzed by the nonparametric statistical tools by Friedman or Signal test at 5%. To check relationships between soil fauna and environmental variables, was used a multivariate conditional ordination method, the redundancy analysis (RDA). The index richness was more efficient than the total average density to evaluate the influence of cane harvesting systems, with the highest values related to areas harvested without burning. Further, the occurrence of key groups in the areas harvested without burning configures the establishment of a trophic web. There was dominance of the social group Formicidae in all treatments. Source

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