Paulo Sérgio dos Santos Leles

Arborização de vias púbicas em Nova Iguaçu, RJ: o caso dos bairros Rancho Novo e Centro

The objectives of this work were to quantify and qualify the urban trees of Rancho Novo District and Downtown Area of Nova Iguacu City, State of Rio de Janeiro, Brazil. Through the total inventory, 560 individuals distributed in 46 species were found in Rancho Novo District, in contrast to 1,374 individuals and 59 species in Downtown Area. In both areas, about 91% of the plants are among the 20 most frequent species, with Ficus benjamina and Cassia siamea predominating in Rancho Novo (21,6%) and Downtown (19,1 %), respectively. Rancho Novo District presented 18% of arboured public areas against 13,5% of Downtown Area. About 95% of the species were considered as small and medium sizes. The largest height averages were reached by Cassia siamea, in Rancho Novo, and almond trees in Downtown. The species located under electric lines represented 40% of the tree population, being 45% of those trees with evident conflicts. In the Downtown Area, 62% of the population needs pruning, with cleaning being the most important requirement, while in Rancho Novo District pruning is recommended for 50% of the population, mainly Ficus benjamina (14,5%). Cassia siamea is the most pruning demanding species in Downtown, with 25,8% of the recommendations. Large discrepancies were found for tree spacing, with average values of 56m in Rancho Novo District and 74 m in Downtown Area. The substitution of Cassia siamea, amendoeira, flamboyant and sombreiro by more appropriate species of urban trees is recommended.

Soil fauna as an indicator of soil quality in forest stands, pasture and secondary forest

The interactions between soil invertebrates and environmental variations are relatively unknown in the assessment of soil quality. The objective of this study was to evaluate soil quality in areas with different soil management systems, based on soil fauna as indicator, in Alem Paraiba, Minas Gerais, Brazil. The soil invertebrate community was sampled using pitfall traps, in the dry and rainy seasons, from areas with five vegetation types (acacia, mimosa, eucalyptus, pasture, and secondary forest). The abundance of organisms and the total and average richness, Shannons diversity index, the Pielou uniformity index, and change index V were determined. The fauna was most abundant in the areas of secondary forest and mimosa plantations in the dry season (111.3 and 31.7 individuals per trap per day, respectively). In the rainy season, the abundance of organisms in the three vegetation types did not differ. The highest values of average and total richness were recorded in the secondary forest in the dry season and in the mimosa stand in the rainy season. Shannons index ranged from 1.57 in areas with acacia and eucalyptus in the rainy season to 3.19 in the eucalyptus area in the dry season. The uniformity index was highest in forest stands (eucalyptus, acacia and mimosa) in the dry season, but higher in the rainy season in the pasture and secondary forest than in the forest stands. The change index V indicated that the percentage of extremely inhibited groups was lowest in the area with mimosa, both in the dry and rainy season (36 and 23 %, respectively). Of all forest stands, the mimosa area had the most abundant soil fauna.

Root regeneration of eucalyptus seedlings grown in containers and substrata

The objective of this research was to determine the root potential regeneration (P.R.R.) and its effect on the field performance of Eucalyptus camaldulensis and E. urophylla seedlings grown in tubes and pressed blocks, with the following substrates: 1) sugarcane bagasse + filter cake (3:2; v:v) + 0.6% N (urea), and 2) decomposed eucalyptus bark + vermiculite (7:3; v:v). After cutting the lateral roots 2 cm away from the tap-root, the P.R.R. was evaluated measuring some characteristics of the regenerated roots such as: number, length, dry weight, area, volume, and growth rhythm. In the field, the survival was evaluated in the first two months, height growth and diameter at the soil level every other month, and number of primary lateral roots and deformations in 10 month-old plants. Compared to the seedlings grown in tubes, seedlings grown in pressed blocks showed higher values of the P.R.R., and a better growth in the field. In the nursery, decomposed eucalyptus bark + vermiculite was the best growing substrate. However, except for E. urophylla height, all other characteristics measured in the field, as well as for E. camaldulensis, did not differ among the studied substrata. The P.R.R. did not show linear correlation with seedling survival in the field, but it was positively correlated with height and diameter at the ground level, in the first months after planting.

Resíduos agroindustriais prensados como substrato para a produção de mudas de cana-de-açúcar

An experiment with Saccharum spp. was carried out to develop a new methodology for plantlet production using pressed industrial residues as substrate. The proportions of sugar cane bagasse, sugar plant filter cake and coconut husk in the substrate composition were analyzed along with the advantages of the Finland pressed block and the conventional systems used for plantlet production. The seedlings quality at the and of the plant propagation stage was evaluated through plantlet diameter and height, shoot and root, total dry weights, and performance at the twelfth month. Selection for planting was based on stem length, diameter, quantity and weight . The three residues tested were suitable to be used in a mixture to prepare pressed blocks. Imported blocks and the ones prepared with both, sugar cane bagasse and the sugar plant filter cake mixed, 70 and 30%, v v-1 respectively, were the most suitable. The average morphological parameters of the plantlets produced by the conventional system were classified among the lowest.

ACÚMULO E DECOMPOSIÇÃO DA SERAPILHEIRA EM QUATRO FORMAÇÕES FLORESTAIS

O objetivo deste trabalho foi quantificar a serapilheira acumulada sobre o solo e sua taxa de decomposicao, em quatro diferentes tipologias florestais: povoamentos de Acacia mangium wild, Mimosa artemisiana Heringer & Paula e Eucalyptus grandis x Eucalyptus urophylla; e uma floresta secundaria na fazenda Cachoeirao, no municipio de Alem Paraiba, MG. Em cada formacao florestal foram feitas duas avaliacoes, a primeira em junho de 2008 e a segunda em junho de 2009, o material foi levado para laboratorio, sendo separado, seco em estufa e pesado. Para avaliacao da decomposicao da serapilheira, foram utilizados litter bags, sendo as coletas realizadas aos 30, 60, 90, 150 e 210 dias apos a instalacao. O povoamento de eucalipto apresentou os maiores estoques nas duas coletas, enquanto mimosa (Mimosa artemisiana Heringer & Paula) apresentou menores valores. A serapilheira de mimosa (Mimosa artemisiana Heringer & Paula) apresentou a maior taxa de decomposicao, com valores de K = 0,0034 e T1/2= 203 dias, enquanto para acacia (Acacia mangium wild) foram verificados menores valores (K= 0,0013 e T1/2= 533 dias). Dentre os povoamentos florestais, mimosa (Mimosa artemisiana Heringer & Paula) e eucalipto (Eucalyptus grandis x Eucalyptus urophylla) produziram a serapilheira mais rapidamente decomposta, o que evidencia a melhor eficiencia dessas especies no processo de ciclagem de nutrientes e incorporacao de materia orgânica ao solo.

Crescimento inicial de seis espécies florestais em diferentes espaçamentos

O objetivo deste trabalho foi verificar a influencia do espacamento de plantio no crescimento de seis especies florestais, aos 22 meses de idade, em plantios de recomposicao florestal, na Bacia do Rio Guandu. O experimento foi instalado na SFE - Usina Termeletrica Barbosa Lima Sobrinho, Municipio de Seropedica-RJ. Foram utilizadas 48 especies arboreas, estabelecidas nos espacamentos 1,0 x 1,0; 1,5 x 1,5; 2,0 x 2,0 e 3,0 x 2,0 m, os quais constituem os tratamentos. Aos 22 meses apos plantio, avaliou-se o crescimento em altura, diâmetro ao nivel do solo (DNS) e largura da copa para as especies Anadenanthera macrocarpa Benth. Brenan (angico vermelho), Schinus terebinthifolius Raddi (aroeira pimenteira), Schizolobium parahyba Blake (guapuruvu), Chorisia speciosa St. Hill (paineira), Cordia sp. (babosa branca) e Inga marginata (inga). Foi constatado que o crescimento das especies comportou de maneira diferenciada nos espacamentos de plantio, sendo que os mesmos influenciaram significativamente no crescimento inicial de todas as especies. Concluiu-se que, de modo geral, nos espacamentos mais amplos, as plantas apresentaram maior crescimento.

Efeitos da inoculação com rizóbio e da adubação nitrogenada na produção de mudas de Sesbânia em substrato constituído de resíduos agroindustriais

Com o objetivo de avaliar o efeito de diferentes fontes e doses de N e da inoculacao com rizobio na producao de mudas de Sesbania virgata (sesbânia), conduziu-se um experimento no qual se utilizou como substrato composto de bagaco de cana-de-acucar + torta de filtro de usina peneirados (3:2, v:v) e decompostos. Foram testados os seguintes tratamentos em esquema fatorial: 3 doses de N (100, 200 e 300 mg/dm3) x 3 doses de N (ureia, sulfato de amonio e nitrato de amonio) + 2 tratamentos adicionais (inoculado e nao-inoculado com rizobio). As tres adubacoes foram realizadas a cada 15 dias, sendo a primeira 30 dias apos a semeadura. O experimento foi conduzido sob delineamento inteiramente casualizado, com tres repeticoes compostas por 80 mudas. As mudas foram avaliadas em altura, diâmetro, massas de materia seca da parte aerea e do sistema radicular, area foliar e potencial de regeneracao de raizes. Conclui-se que para este substrato a inoculacao das sementes foi suficiente para atender a demanda de N das mudas de sesbânia.

Sistema de blocos prensados para produção de mudas de três espécies arbéreas nativas

The objective of this work was to evaluate the feasibility of using pressed blocks as containers for the production of Inga marginata, Jacaranda puberula and Zeyheria tuberculosa seedlings. The pressed block system (440 cm3) was compared to plastic bags (330 cm3) and circular section tubes (280 cm3). The substrate used was a mixture of organic matter, ground charcoal and clayish soil (6:2:2). After pressing, the size of the blocks was 60 x 40 x 12 cm (length, width and height). Height and diameter of the seedlings were measured monthly, starting at 60 to 150 days after transplantation. The next step was to determine the dry matter weight of the aerial part and root system. To evaluate the behavior of the seedlings produced in the various treatments under field conditions, the survival rate at two months from planting was measured. The seedlings produced by the pressed block system showed a growth higher than or similar to those produced in plastic bags or tubes. Under field conditions, no statistical differences were observed for survival rate and growth of the seedlings from the pressed blocks, plastic bags and tubes. The pressed block system was found to be technically feasible for the production of seedlings of the forest trees species studied.

Aporte de Serapilheira e Nutrientes em Área de Restauração Florestal com Diferentes Espaçamentos de Plantio

Os objetivos deste estudo foram avaliar a deposicao de serapilheira ao longo de dois anos e a qualidade nutricional da serapilheira, em funcao do espacamento de plantio visando a restauracao florestal. Os espacamentos de plantio 1 × 1; 1,5 × 1,5; 2 × 2 e 3 × 2 m, constituem as unidades amostrais dos tratamentos. No espacamento 1 × 1 m foi observada a maior deposicao de serapilheira, nao havendo diferencas entre as unidades dos demais espacamentos. A fracao folha mostrou, em todos os espacamentos, maior aporte de serapilheira (77%). O maior conteudo de nutrientes foi observado no espacamento 1 × 1 m. Em geral, constatou-se a seguinte ordem quanto o conteudo de nutrientes da serapilheira N > Ca > K > Mg > P.

Litterfall: A Bio-indicator for Edge Effect in a Semi-deciduous Seasonal Forest

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.