Eduardo F. C. Campello

Communities of P-Solubilizing Bacteria, Fungi and Arbuscular Mycorrhizal Fungi in grass pasture and secondary forest of Paraty, RJ - Brazil*

Communities of P-solubilizing bacteria, fungi and arbuscular mycorrhizal fungi, were evaluated in two different ecosystems. Samplings taken from two areas of Atlantic forest, in Paraty-RJ, Brazil, one with a secondary forest and the other with a grass pasture were studied. Four growth media: GL (glucose and yeast extract), GES (glucose, soil extract, KNO3, CaCl2, MgSO4, NaCl, FeEDTA and micronutrients solution), GAGES (glucose, soil extract, arabinose, glycerol, CaCl2, MgSO4 and NaCl) and GELP (glucose, soil extract, yeast extract, peptone, CaCl2, MgSO4 and NaCl) were evaluated for the isolation of P-solubilizing microorganisms. The identification of P-solubilizing bacteria was based on 16 S rDNA sequence analysis, while the identification of P-solubilizing fungi and arbuscular mycorrhizal fungi was based on morphology. The greatest number of P-solubilizing bacteria was isolated using GL and GELP growth media. The greatest number of P-solubilizing fungi was isolated using GAGES and GES. The bacteria were identified as Enterobacteriaceae and Bacillus sp., while the P-solubilizing fungi were identified as Aspergillus sp. Glomus macrocarpum and Glomus etunicatum were the dominant mycorrhizal fungi in the secondary forest and grass pasture area, respectively.

Dinâmica da serapilheira e transferência de nitrogênio ao solo, em plantios de Pseudosamanea guachapele e Eucalyptus grandis

Este trabalho teve como objetivo avaliar a deposicao de serapilheira e a transferencia de N associada as folhas e foliolos desse residuo em plantios puros e consorciado de guachapele (Pseudosamanea guachapele) e eucalipto (Eucalyptus grandis), aos sete anos de idade, em Seropedica, RJ. No ano de avaliacao (2000/2001) a deposicao anual de serapilheira nos diferentes plantios nao diferiu significativamente 12,75 Mg ha-1 (guachapele); 11,84 Mg ha-1 (eucalipto) e 12,44 Mg ha-1 (consorciado). Mesmo com pequena participacao na composicao da serapilheira em plantio consorciado (11% do total depositado), a leguminosa proporciona reducao no tempo medio de residencia dos residuos no solo de 0,3 ano, comparativamente ao plantio puro de eucalipto.

Acúmulo de nutrientes na parte aérea, na serapilheira acumulada sobre o solo e decomposição de filódios de Acacia mangium Willd.

A survey of Scolytidae population of species of Scolytidae family was made in plantations of Eucalyptus camaldulensis Dehnh, Eucalyptus citriodora Hook. f. , Eucalyptus pellita F. Muell. and Eucalyptus urophylla S.T. Blake, located at Cuiaba city in Mato Grosso state from march 1998 to february 1999, with aid of ethanol traps model “escolitideo-Curitiba”. The were used 24 traps, six per Eucalyptus plot/specie. Collection was made every 15 days and divided in two periods: drought (may – October) and rRainy Season (november – april). There were collected a total of 19.153 individuals, distributed in 11 genera and 42 species. In the dry and rain periods there were collected 9.865 and 9.288 individuals, respectively. In plantations of Eucalyptus pellita and Eucalyptus urophylla were collected the largest amount of individuals, in both analyzed periods. Cryptocarenus diademantus Eggers, 1937; Cryptocarenus seriatus Eggers, 1933; Cryptocarenus heveae (Hagedorni, 1912 ); Hypothenemus obscurus (Fabricius, 1801) and Xyleborus spinosulus (Schedl, 1934) were in number, the most important in plantations of the four species of Eucalyptus .

ACCUMULATION AND DISTRIBUTION OF ABOVEGROUND BIOMASS AND NUTRIENTS IN PURE AND MIXED STANDS OF GUACHAPELE AND EUCALYPTUS

ABSTRACT The biomass accumulation and the distribution of nutrients in the different components of the aerial parts (leaves, branch, bark, and wood) of pure and mixed stands of guachapele [Pseudosamanea guachapele (Kunth) Harms] and eucalyptus (Eucalyptus grandis W. Hill ex Maiden) were quantified in Seropédica, Rio de Janeiro State, Brazil. Mixed stands had the highest production of stem tissue (204 m3/ha), in contrast with the pure plantations of each species (78.1 m3/ha for guachapele and 199 m3/ha for the eucalyptus). Total dry biomass of eucalyptus was 1.6 times more than that of guachapele in monoculture and 6.8 times larger than that in the mixed stands. The eucalyptus had 10% less biomass in mixed stands than in pure stands. Despite production of less biomass, the guachapele had more nutrient uptake, accumulating, as a pure stand, 484.68 kg/ha of nitrogen (N), 35.0 kg/ha of phosphorus (P), 274.5 kg/ha of potassium (K), 223.8 kg/ha of calcium (Ca), and 40.7 kg/ha of magnesium (Mg). The eucalyptus plants were more efficient in the utilization of N, P, K, Ca, and Mg than the guachapele and this efficiency was increased in the mixed stands. Among the treatments the litter layer, in the pure stand of guachapele contained the highest quantities of N (273.1 kg/ha) and P (8.2 kg/ha), while the pure stands of eucalyptus of K (22.6 kg/ha), Ca (163.8 kg/ha), and Mg (28 kg/ha).

Vegetation of Unconsolidated Bauxite Mining Residues in the Amazon by Direct Sowing of Inoculated Legumes Seeds

Bauxite mining residues in Porto Trombetas-Pa, in the Brazilian Amazon are deposited in large ponds over 10 m depth and left to consolidate. The residues do not contain any detectable C, N, and P and very low concentrations of K, Ca and Mg. Vegetation of these residues are required as the first step in reclamation of the area. The liquid nature of this colloidal suspension does not allow access for planting seedlings and for this reason seeds must be distributed in a water jet (hydro-sowing). Aeschynomene sensitiva, A. fluminensis, Sesbania virgata, S. exasperata, Neptunia plena and Acacia holosericea were inoculated with specific rhizobia and direct sown over the unconsolidated residue together with rock phosphate, K2SO4, lime and minor elements.