Rafael Nogueira Scoriza

Fauna do Solo como Indicadora em Fragmentos Florestais na Encosta de Morrotes

A diferenca sucessional entre os fragmentos florestais reflete-se na comunidade da fauna do solo, mostrando-se um bioindicador eficiente. A nao diferenciacao entre tercos indica que a degradacao antropica ocorre de forma homogenea em toda a extensao da encosta florestal.

Arbuscular mycorrhizal fungi in soils of arboreal Caatinga submitted to forest management

The arbuscular mycorrhizal fungi (AMF) community presents a variable tolerance to changes in the medium, to which it responds modifying the number of propagules. For this reason, the study of the effect of different management practices on this community can help to understand the magnitude of the changes caused to the ecosystem. The objective of this study was to evaluate changes in the community of arbuscular mycorrhizal fungi in the soil in an area of arboreal Caatinga bmitted to forest management. The study was conducted in Contendas do Sincora (BA). Three types of forest management (clear-cutting, selective logging based on diameter, and selective logging based on species) and one control area were evaluated. Soil samples were collected at 0-10 cm depth in two periods (five and 10 months after management). AMF spores were present in low density (< 1 spore g-1 soil), dry and non-viable, and were generally more abundant in managed areas. Fewer species were observed in the control area. The AMF community showed to be related to the attributes of the soil and sensitive to management practices, demonstrating greater impact under clear cut management.

FUNGOS MICORRÍZICOS ARBUSCULARES E SERAPILHEIRA COMO INDICADORES DO EFEITO DE BORDA EM FRAGMENTO DE FLORESTA ESTACIONAL

Deforestation causes the formation of forest fragments and edges, changing the biotic and abiotic conditions of a forest ecosystem. The edge effects in a forest can be assessed by soil indicators. The objective of this study was to evaluate the litter stock and arbuscular mycorrhizal fungal community as edge effect indicators in a fragment of a seasonal forest in Vitoria da Conquista, Bahia state. Sampling was carried out at the end of each season. Four sampling ranges were established in the edge-interior direction (edge: 0–10 m, range 1: 40–50 m, range 2: 80–90 m, and interior: 400 m). The accumulated litter was collected four times using a wooden template (area 0.25 m 2 ). The soil samples (layer 0–5 cm) for extracting the spores of mycorrhizal fungi were collected from the same litter collection areas. The edge effect in areas of a seasonal forest can change the litter stock, showing a mass reduction closer to the edge. The community of mycorrhizal fungi shows the occurrence of unique species in the gradient of edge-interior fragment.

Macrofauna edáfica como indicadora em revegetação com leguminosas arbóreas

O trabalho foi desenvolvido em uma area de pasto abandonada revegetada com leguminosas arboreas. Localizada no municipio de Valenca, RJ, nela foram utilizadas diferentes proporcoes de leguminosas arboreas fixadoras de nitrogenio: 0% (0L), 25% (25L), 50% (50L) e 75% (75L). Para avaliacao da macrofauna do solo, as amostragens foram feitas nas epocas seca e umida, utilizando-se o metodo TSBF. Outras amostragens foram realizadas, ainda, em uma floresta secundaria (FS) e em duas areas de pasto (PA e PB). O processo de revegetacao aumentou a diversidade da fauna do solo de uma forma geral. Formicidae foi o grupo da macrofauna de maior abundância em todas as areas, para as duas epocas de avaliacao. Na epoca chuvosa, houve aumento consideravel na quantidade de invertebrados na camada serapilheira nos tratamentos 0L, 25L, 50L, 75L e Floresta Secundaria, o que no periodo seco aconteceu na camada 0-10 cm.

Ecotoxicological potential of copper-based organic fungicide in non-target soil organisms.

The Viçosa (Blooming) mixture is an important product for pest and disease control in agriculture. It is considered as an alternative fungicide, and no effects are expected when exposed to humans and non-target organisms, which may not be true because it contains copper in its composition and may be applied multiple times in certain crops. Thus, the objective of this study was to verify its ecotoxicological potential through survival and reproduction trials of the invertebrates of the soil Enchytraeus crypticus and Folsomia candida. Both trials lasted 28 days in a completely randomized design, in tropical artificial (TAS) and natural soils. From the recommended 0.5% concentration of Viçosa mixture, increasing doses equivalent to 0% (control), 0.1, 0.3, 0.5, 1 and 3% were tested. There were effects on survival and reproduction of soil invertebrates on TAS and natural soils from the lowest dose of 0.1%. Therefore, it is concluded that the use of this copper-based mixture presents toxic potential over the life cycle of invertebrates living in the soil, and there is need of new studies that evaluate the effects in natural environment.

ISOLAMENTO E CARACTERIZAÇÃO DE ESTIRPES DE RIZÓBIO NA ESPÉCIE Pterogyne nitens Tull

The legume Pterogyne nitens Tull. belonging to the subfamily Caesalpinoideae is a widely distributed species, hardiness and rapid growth, and these interesting characteristics for use in recovery of degraded areas. When in symbiosis with nitrogen fixing bacteria, these legumes are more tolerant to adverse conditions. Therefore, the objective of this work was isolate and to characterize strains of rhizobia in the specie Pterogyne nitens Tull. For this, Samples of soil from planting madeira nova were placed in 25 plastic pots of 500 mL. Then two mechanically scarified seeds were planted in each pot. After 120 days of the planting, the roots were analyzed for the presence of nodules and growth of rhizobia in culture medium 79. Moreover, were grown in culture medium, bacteria BR 3630, BR 6205, BR 6212 and BR 4406, acquired from Embrapa Agrobiologia, Seropedica - RJ, for comparison purposes. There were no nodules on the roots, but from extract of the roots was possible to obtain an isolate with characteristics similar strain Mesorhizobium elkanii (BR 3630) from Embrapa Agrobiology.