ABSTRACT Agroecological management is considered a model of sustainable agriculture that offers social, environmental and economic benefits. The hypotheses of this study were that agroecological production systems can promote changes in the physical fractions of soil organic matter (SOM) associated with aggregates of different origins, and that the greater diversity of plant species in the production system may favour an increase in the carbon concentration of these aggregates. The aim of this study was to a) determine the mass of the free light fraction (FLF), intra-aggregate light fraction (ILF) and light organic matter fraction (LOM) of biogenic and physiogenic soil aggregates; and b) quantify the organic carbon content of the three light SOM fractions and the residual particulate SOM fraction. Five production systems were evaluated: AgF - Agroforestry system; CSun - Coffee grown in full sun; CSha - Coffee grown in shade; FLE - Flemingia grown in alleys; and NT - No-tillage. The aggregates were separated, identified and classified according to their origin or formation pathway into biogenic (formed by biological processes) or physiogenic aggregates (resulting from chemical and physical actions). From these, the mass and carbon content of the FLF, ILF, LOM and residual particulate fractions were quantified. The greater diversity of plant species found in the AgF system has not yet favoured an increase in the carbon content of the aggregates. The longer set-up time and the management practices of the CSun system has led to an increase in the carbon content of the organic fractions of the aggregates (3.44-1.63 g kg-1 for C-LOM; 1.93-1.13 g kg-1 for C-FLF). The lowest overall mean values for LOM and ILF were found mainly in the aggregates of the NT system (1.22-1.67 and 1.55-2.20 g kg-1, respectively), being associated with the shorter time and greater mobilisation of the arable layer. Biogenic aggregation afforded the highest overall mean values for LOM, and increased the mass of the light fractions (15.5%-27.8% for FLF; 23.4%-8.0% for ILF) and the carbon in the C-LOM, C-FLF and residual particulate fractions (42.3%, 12.9%, and 35.0%, respectively) in the surface layer, suggesting an improvement in soil quality.

RESUMO Várias espécies lenhosas tropicais são altamente responsivas a fungos micorrízicos arbusculares (FMA) e dependem da simbiose para nutrição e sucesso no estabelecimento em campo. O objetivo deste estudo foi avaliar a resposta de Schinus terebinthifolius, uma espécie nativa da Mata Atlântica e Caatinga, à inoculação com três espécies de FMA (Dentiscutata heterogama, Gigaspora margarita e Rhizophagus clarus), individualmente ou misturadas, em diferentes níveis de adubação fosfatada (0, 71, 213 e 650 mg kg−1 de P). O experimento foi conduzido em vasos de 1 kg, seguindo um delineamento inteiramente casualizado com seis repetições por tratamento, para avaliar as características morfológicas e nutricionais, após 116 dias, incluindo diâmetro do colo, altura, biomassa e teor de P na parte aérea da planta. Nossos resultados evidenciaram que S. terebinthifolius foi altamente dependente de micorrizas e apresentou respostas diferentes dependendo da espécie de FMA. O maior acúmulo de biomassa total ocorreu quando foi utilizada uma mistura das três espécies de FMA, o que indicou sinergismo entre os fungos. De uma forma geral, a maior resposta positiva à inoculação foi observada em nível intermediário de P (213 mg kg−1), e embora a biomassa da parte aérea tenha sido reduzida nas doses intermediárias de P, foi observada uma compensação com um aumento na biomassa radicular. Esses resultados indicam complementaridade em oposição à redundância funcional das espécies de FMA e destacam a importância do uso de inóculo misto na produção de mudas de S. terebinthifolius para programas de revegetação.

ABSTRACT Several tropical woody species are highly responsive to arbuscular mycorrhizal fungi (AMF) and depend on their symbiosis for nutrition and successful establishment in the field. The objective of this study was to evaluate the response of Schinus terebinthifolius, a native species of the Brazilian Atlantic Forest and Caatinga, to inoculation with three AMF species (Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus), either individually or mixed, at different levels of phosphorus fertilization (0, 71, 213, and 650 mg kg−1 of P). We conducted the experiment in 1 kg pots, following a completely randomized design with six replicates per treatment, to evaluate morphological and nutritional traits after 116 days, including stem diameter, plant height, plant biomass, and shoot P content. Our results showed that S. terebinthifolius was highly dependent on mycorrhizae and presented different responses depending on the AMF species. The greatest total biomass accumulation occurred when a mixture of the three AMF species was used, which indicated synergism between the fungi. The highest overall positive response to inoculation were observed at an intermediate P level (213 mg kg−1), and although shoot biomass was reduced at the intermediate P doses, an increase in root biomass compensated for this. These results indicate complementarity as opposed to functional redundancy of the AMF species and highlight the importance of using a mixed inoculum in seedling production of S. terebinthifolius for revegetation programs.

Abstract The aim of the study was to investigate Pseudobombax aff. petropolitanum (PP) contribution on annual fine litterfall, carbon content, and nutrient concentration, compared to other woody species (OS) on a neotropical inselberg in Espírito Santo state, Brazil. Annual fine litterfall was systematic monthly collected (November 2011-October 2012) by means of 15 littertraps (0.25 m2) placed in five transects, oven-dried (65 °C, 72 h), weighed, and C content and nutrients concentration (N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Zn) were estimated. PP performed lower litterfall, C content, and nutrient concentration excepting higher K concentration, compared to OS. The results suggested that PP performed higher nutrient conservation, which indicated its potential in restoring degraded areas observed in the inselberg.

Abstract The study evaluated the ecology of soil invertebrate faunal communities in periodically flooded forest (CF) fragments and anthropic fields (AF) in the Atlantic Forest. The sampling occurred in the rainy and dry seasons using pitfall traps. We estimated the total activity, richness, diversity, and evenness as well as the activity of the taxonomic and functional groups. Total activity and richness varied as a function of seasonality. Entomobryomorpha, Poduromorpha, and Symphypleona were the most representative taxonomic groups. Enchytraeidae and Blattaria were exclusive to CF. Auchenorrhyncha, Chilopoda, Heteroptera, and Thysanoptera were exclusive to AF. The functional group of microphagous/saprophagous (M/S) showed the highest activity, independent of the environment and season. Greater dissimilarity was observed among the invertebrate fauna in AF when compared to CF. Periodically flooded areas favored groups from the saprophagous trophic guild, while AF areas favored predator and herbivore groups. Soil fauna present in forest environments presented less seasonal variability.

ABSTRACT The present study aimed to evaluate fine aboveground litterfall, deposition of nitrogen and phosphorus from total litterfall and leaf litter decomposition in areas of tall forest (Mata Alta) and low forest on sandy soils (Mussununga) in southeastern Brazil. Fine litterfall was collected monthly for two years (from June/2007 to May/2009) in 10 conical collectors (0.25 m2) in each phytophysiognomy (1 ha plots). The material was subsequently separated into leaves, branches, flowers and fruits, and unidentified material. Leaf decomposition rates were evaluated using 15 litterbags, three of which were collected every 30 days. Higher litterfall occurred in both phytophysiognomies during the rainy season, with leaves predominating. The lowest litterfall, nutrient input, and leaf litter decomposition values appeared to be nutrient conservation strategies, contributing to the ecological functioning of the Mussununga where soil fertility was lower than in the Mata Alta.

ABSTRACT This study aimed to evaluate the use of litterfall as an indicator of fragmentation in a Semi-deciduous Seasonal Forest in Além Paraíba, MG, Brazil. Litterfall was collected monthly for one year in conical collectors (0.25 m2 of surface), located at seven distances from the forest edge: 10, 30, 60, 100, 160, 250 and 350 m. The litterfall was dried in an oven and separated (leaves, branches, reproductive structures, miscellaneous). Litterfall was greater near the forest edge, probably due to a predominance of species with high leaf deposition (pioneers and deciduous). Litterfall had peaks at the beginning of the rainy season for the average obtained from the seven distances from the forest edge. The edge effect did not clearly influence the contribution of the fractions or the seasonality of total litterfall.

RESUMO Este trabalho quantificou a biomassa aérea e o conteúdo de nutrientes de bromélias terrestres na floresta de duna na Restinga da Marambaia, RJ. Dados de indivíduos em “quadrats” (4 m2) demarcados numa linha perpendicular ao mar foram coletados em agosto de 2001. Diâmetro (d) e altura (h) foram as variáveis que melhor se correlacionaram com a biomassa aérea de Quesnelia quesneliana, que apresentou a maior biomassa e concentrações de K. Número total de folhas foi a variável que melhor se correlacionou com a biomassa em Billbergia amoena e Neoregelia cruenta. N. cruenta apresentou as maiores concentrações de N e P. O conteúdo de nutrientes foi maior em Q. quesneliana.

ABSTRACT This study quantified the aboveground biomass and nutrient contents in terrestrial bromeliads in a dune forest at Restinga da Marambaia, RJ. Data of individuals in “quadrats” (4 m2) marked on a line perpendicular to the sea were collected in August 2001. Diameter (d) and height (h) were the variables that best correlated with the biomass of Quesnelia quesneliana, which presented highest biomass and concentrations of K. The total number of leaves was the variable that best correlated with the biomass of Billbergia amoena and Neoregelia cruenta. N. cruenta presented the highest concentrations of N and P. Nutrient contents were higher in Q. quesneliana.

Abstract The present study aimed to evaluate the occurrence of conflicts between the street arborization and the urban equipments in Taquara, RJ. The quali-quantitative inventory carried in 10% of the sheets in the area showed that there wasn’t any tree in 11,1% of the streets. It was observed the presence of 242 trees elements, wich were distributed in 41 species. The fact that 70,2% of this total presented at least one type of conflict with urban equipments, showed the necessity of developing an appropriate planning of public arborization in the area.

Resumo Este trabalho teve como objetivo avaliar a ocorrência de conflitos entre a arborização viária e os equipamentos urbanos no bairro da Taquara, RJ. Foi realizado o inventário quali-quantitativo em uma amostra de 10% das vias públicas do bairro, das quais 11,1% não apresentaram nenhum indivíduo arbóreo. Foram contabilizados 242 indivíduos arbóreos, que se distribuíram em 41 espécies. Deste universo, 70,2% apresentaram pelo menos um tipo de conflito com equipamentos urbanos, o que evidencia a necessidade de se desenvolver um planejamento adequado para a arborização de vias públicas da região.