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 Cuiabá city in Mato Grosso state from march 1998 to february 1999, with aid of ethanol traps model “escolitídeo-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.O acúmulo de N, P, K, Ca e Mg nos tecidos da parte aérea e na serapilheira acumulada sobre o solo, bem como a velocidade de decomposição de filódios e a eficiência de uso de nutrientes (CUB) da Acacia mangium Willd (mangium) foram avaliados num povoamento localizado em Seropédica, RJ. A espécie apresentou elevada eficiência de uso dos nutrientes, acumulando, aos cinco anos, grande quantidade de biomassa em sua parte aérea (135 t.ha-1) e contendo: 544,9 kg.ha-1 de N; 281,7 kg.ha-1 de Ca; 242,9 kg.ha-1 de K; 47 kg.ha-1 de Mg e 35,2 kg.ha-1 de P. Na serapilheira acumulada sobre o solo (12,7 t.ha-1), foram encontradas reservas significativas dos nutrientes (251,0; 5,7; 14,6; 102,7 e 22,7 kg.ha-1 de N, P, K, Ca e Mg respectivamente). A constante de decomposição (k) foi estimada em 0,00165 g.g-1.dia-1 e o tempo de meia vida dos filódios em 421 dias. A acumulação de serapilheira pode ser positiva no sentido de constituir reserva de nutrientes para cultivos em sucessão, mas também pode representar uma desvantagem, por servir como combustível em áreas sujeitas a queimadas

SURVEY OF SCOLYTIDAE (COLEOPTERA) IN PLANTATIONS OF Eucalyptus spp. IN CUIABÁ, STATE OF MATO GROSSO, BRAZIL

<p>A survey of Scolytidae population of species of Scolytidae family was made in plantations of <em>Eucalyptus camaldulensis Dehnh, Eucalyptus citriodora </em>Hook. f.<em>, Eucalyptus pellita</em> F. Muell. <em>and Eucalyptus urophylla</em> S.T. Blake, located at Cuiabá city in Mato Grosso state from march 1998 to february 1999, with aid of ethanol traps model “escolitídeo-Curitiba”. The were used 24 traps, six per <em>Eucalyptus</em> 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 <em>Eucalyptus pellita</em> and <em>Eucalyptus urophylla</em> were collected the largest amount of individuals, in both analyzed periods. <em>Cryptocarenus diademantus </em>Eggers, 1937;<em> Cryptocarenus seriatus </em>Eggers, 1933;<em> Cryptocarenus heveae </em>(Hagedorni, 1912<em>); Hypothenemus obscurus </em>(Fabricius, 1801) <em>and Xyleborus spinosulus </em>(Schedl, 1934) were in number, the most important in plantations of the four species of <em>Eucalyptus</em>.</p

The Role of the Humic Substances in the Fractioning of Heavy Metals in Rodrigo de Freitas Lagoon, Rio de Janeiro - Brazil

One of the main results of the processes related to urbanization is the contamination of the adjacent water bodies. Inserted in this context, the Rodrigo de Freitas lagoon is situated in the south zone of the city of Rio de Janeiro. This ecosystem receives several inputs containing all sorts of pollutants, including heavy metals. The present work aimed to study the partitioning of heavy metals in the sediments of Rodrigo de Freitas and the influence of organic matter in this fractionation dynamic. The results of these analyses presented the contents of organic matter as an important metal-capturing agent. Fractionation of organic matter resulted in a predominance of humine. Heavy metal partitioning showed that the metals bound by the water-soluble phase have no significant concentrations. Special features such as, reducing sediment, high levels of organic matter and fine grain size have transformed this ecosystem in an effective deposit of pollutants, where heavy metals are not available in easily reactive fractions